Automatic strapping machine
US 3126686 A
Description (OCR text may contain errors)
March 31, 1964 A. J. KOBYLANSKI ETAL 3,126,686.
AUTOMATIC STRAPPING MACHINE Filed Dec. 6. 1961 10 Sheets-Sheet 1 March 31, 1964 A. J. KOBYLANSKI ETAL 3,126,686
AUTOMATIC STRAPPING MACHINE Filed Dec. 6. 1961 10 Sheets-Sheet 2 A. J. KOBYLANSKI ETAL 3,126,686
AUTOMATIC STRAPPING MACHINE March 31, 1964 Filed Dec. 6. 1961 1Q Sheets-Sheet 3 I 3w 3N March 31, 1964 A. J. KOBYLANSKI ETAL 3,126,686
AUTOMATIC STRAPPING MACHINE Filed Dec. 6, 1961 T 10 Sheets-Sheet 5 T I I90 2 lBB March 31, 964 A4 J. KOBYLANSKI ETAL 3, 5
AUTOMATIC STRAPPING MACHINE Filed Dec. 6, 1961 10 Sheets-Sheet 6 March 31, 1964 A. J. KOBYLANSKI ETAL 3,126,636
AUTOMATIC STRAPPING MACHINE Filed Dec. 6. 1961 10 Sheets-Sheet 7 l l l i I A. J. KOBYLANSKI ETAL AUTOMATIC STRAPPING MACHINE March 31, 1964 10 Sheets-Sheet 8 Filed Dec. 6. 1961 March 1964 A. J- KOBYLANSKI ETAL 2 AUTOMATIC STRAPPING MACHINE Filed Dec. 6. 1961 10 Sheets-Sheet 9 PIA/657$ JEALER PLATA' March 31, 1964 A. JIKQBYLANSKI ET-AL AUTOMATIC STRAPPING MACHINE Filed Dec. 6. 1951' 10 Sheets-Sheet 1O hw mmm I IIII ll llll ,l i! -liiu 4 IIIIIIIIII L I 4| locking engagement.
United States Patent 3,126,686 AUTOMATIC STRAPPING MACHINE Anthony J. Kobylan'ski, Montreal, Quebec, and Paul Emile Fontaine, Verdun, Quebec, Canada, assignors,
by mesne assignments, to FMC Corporation, San Jose,
Calif., a corporation of Delaware Filed Dec. 6, 1961, Ser. No. 157,405 19 Claims. (Cl. 53-198) This invention relates to a machine or apparatus for securing flexible bands about an article such as a package and more particularly to a machine for automatically applying and securing a flexible, non-metallic strap about articles or groups of articles of varying sizes and shapes.
It has long been customary to secure bands such as wire, twine or steel straps about packages and cartons which may be subjected to rough treatment during shipment, in order to reinforce them and minimize or eliminate damage to the package and contents. When the binding material is wire, it is quite generally held in place by twisting the ends thereof together and when twine is employed, the ends are usually secured by tying. In the case of steel strap, the ends of the strap are positioned in mutually lapping relationship and held together either by welding or by encircling the lapping portions with a sleeve and deforming the edges of the strap into inter- Various types and styles of machines are described in the patent art for automatically securing wire, twine and steel strapping about shipping cartons or the like, such machines being normally adapted to handle only one particular type of binding material.
There has recently been introduced a new type of binding or strapping material which is used in a manner similar to steel strapping and offers for many applications advantages over steel strapping. This new strapping material consists of a plurality of high tenacity tire cords adhered together side by side in the form of a flat weftless tape or strap. For convenience of reference such strapping material will be referred to as cord strapping. Cord strapping is much more flexible than steel strap and because of this, and for other reasons, it cannot be used with most machinery designed to apply steel strap. While cord strapping may be secured by tying the ends together, it is preferable to mutually overlap the ends and hold them together by means of a metal seal or sleeve which is crimped thereabout so that the strap lies fiat against the package, in the manner of the familiar steel strap.
While the hereinafter disclosed embodiment of the present invention is specifically directed to a machine intended to apply cord strapping, it will be apparent that such machine is equally suitable for applying other types of flexible, non-metallic strapping and that with minor modifications well within the skill of the art, it can be adapted for use with such binding materials as wire, twine or steel strapping.
It is the general object of this invention to provide an improved apparatus for automatically applying and securing a flexible binding material about an article or group of articles.
A more specific object of the invention is to provide such an apparatus which will accommodate articles of different sizes and/ or shapes without the need of any adjustment whatsoever.
Another object of the present invention is to provide a machine particularly adapted to secure cord strapping about a package in such manner that the overlapping ends of the strap will lie fiat against the package.
A further object of the invention is to provide an automatic strapping machine having means whereby the tension on the strap may be readily regulated.
Another object of the invention is to provide an auto- 3 ,126,686 Patented 'Mar. 31, 1964 w ICC matic strapping machine having improved means for securing the ends of the strap together.
A still further object of the invention is to provide an automatic strapping machine having improved means for severing the secured portion of the strap from the strap supply.
Yet another object is to provide, in an automatic strapping machine, an improved means for grasping the strap in order to move the same about a package.
Other objects, advantages and novel features of the invention will become apparent as the description of a preferred embodiment thereof proceeds.
Referring now to the drawings:
FIGS. 1 through 6 represent diagrammatically the overall sequence of operations of the machine during the strapping of a package;
FIG. 7 is a diagrammatic view showing the power system of the machine;
FIG. 8 is a side eelvational view of a portion of the machine;
FIG. 9 is an elevational view of a portion of the apparatus showing the strap carrier in strap gripping condition;
FIG. 10 is a fragmentary View on an enlarged scale showing the engagement between the strap carrier and the strap;
FIG. 11 is a side elevational View of the strap carrier showing the parts in strap gripping condition;
FIG. 12 is a sectional view taken along the line XII- XII of FIG. 11;
FIG. 13 is an end elevational view of the strap carrier showing the same in strap released condition;
FIG. 14 is a view partly in section and partly in diagrammatic side elevation of a portion of the machine;
FIG. 15 is a sectional view taken along the line XV XV of FIG. 14;
FIG. 16 is a side elevational view showing the operation of a strap gripping device effective during tensioning of the strap;
FIG. 17 is a view taken along the line XVIIXVII of FIG. 16;
FIG. 18 is a view partially in section and partially in side elevation showing particularly the manner of feeding seals to the sealer;
FIG. 19 is a plan view of the mechanism for feeding seals to the sealer;
FIG. 20 is a perspective view of the seal used with the machine;
FIG. 21 is a perspective view showing the seal applied to the strap;
FIG. 22 is an elevational View showing particularly the devices associated with sealing or securing the ends of the strap;
FIG. 23 is a plan view of the sealer, one cover plate being removed;
FIG. 24 is a view partially in section and partially in plan of a portion of the mechanism;
FIG. 25 is a plan view of the cutter which severs the secured portion of the strap from the supply;
FIG. 26 is a side elevational view of the cutter;
FIG. 27 is an end elevational view of the cutter;
FIG. 28 is a side elevational view showingthe drive and cycle control mechanism;
FIG. 29 is a fragmentary view showing a portion of the cam mechanism controlling forward and reverse movements of the machine;
FIG. 30 is an exploded view of the cycle control cams showing the relative positions thereof when not in operation;
FIG. 31 is a graph showing the operating sequence of certain of the cams;
FIG. 32 is a plan view of the drive and cycle control mechanism;
FIG. 33 is a sectional view shcwing details of the operating mechanism of a clutch which controls the stopping positions of the chain which carries the strap carrier, the parts being shown with the machine in idle condition;
FIG. 34 is a view similar to FIG. 33 showing the parts positioned at the beginning of the forward drive; and
FIG. 35 is a plan view of a portion of the transmission and clutch control mechanism.
GENERAL OPERATION (FIGS. 1-6) Before describing the details of construction and operation, the machine will be described briefly in a general way and attention is directed first to FIGS. 1 through 6. The package It) to be strapped is placed on a slotted table 11 within the confines of an endless chain 12 which is trained about sprockets 13, 14, 15, and 16, sprocket 13 being driven, as will be described, and sprockets 14, 15, and 16 being idlers which merely guide the chain. A roll 17 or other supply of 'fiexible strapping material is positioned in proximity to the slotted table and the strap 18 passes from the supply through a normally open gripping device generally indicated at 19, over a guide roller 29, about a tensioning roller 21 and the leading end thereof is attached to a strap carrier secured to chain 12, said carrier being designated generally at 22. At the beginning of the strapping operation the parts are positioned as shown in FIG. 1 and when the machine is started, chain 12 moves counterclockwise and the strap carrier 22 moves completely about the package and comes to rest in the position shown in FIG. 2 with the trailing end of the strap overlapping the leading end held by said carrier. Next a pair of relatively thin fingers 23 are projected be tween the overlapping portions of the strap and the package and, as indicated in FIG. 3, tensioning roller 21 is moved downward to remove the slack in the strap and tighten the strap about the package. However, as roller 21 starts its downward movement, gripping device 19 grips the strap between said roller and the supply roll 17 so that downward movement of roller 21 does not withdraw strap from the supply but is only effective to tighten the strap about the package.
The purpose of fingers 23 is to hold the strap slightly away from the package so as to permit a sealer, indicated generally at 24 in FIG. 4, to apply a seal 25 about overlapping ends of the strap. FIG. 4 indicates that the sealer 24 has moved about the strap and applied the seal and has returned to normal position and it will be observed that fingers 23 have been withdrawn, tensioning roller 21 has returned to normal position and gripper 19 has released the strap. As will presently be explained, withdrawal of the fingers, return of the tensioning roller and release of the gripper 19, all take place while the sealer is in contact with the strap.
After the overlapping ends of the strap have been secured together and the sealer has returned to its home position, chain 12 is driven in the reverse or clockwise direction to move strap carrier 22 from the position shown in FIGS. 2, 3, and 4 back to the FIG. 1 position. However, before the reverse movement of the chain is instituted, the strap carrier must be released from the strap and to this end there is a lever 26 slidably and pivotably mounted on a stationary part of the machine and articulated to a slidably mounted plate 27, shown in FIGS. and 6. Just before chain 12 begins the reverse movement, plate 27 is moved from the position shown in FIG. 5 to the position shown in FIG. 6 and during the course of this movement lever 26 is moved slightly toward the left and the free end thereof is swung upward to rock a portion of strap carrier 22 and cause it to release the strap. Further leftward movement of plate 27 brings the leading edge thereof into engagement with the strap carrier and moves said strap carrier bodily away from the strap from the position shown in FIG. 5 to the full line position shown in FIG. 6. As the chain then moves clockwise (downward as seen in FIGS. 5 and 6) strap 6". carrier 22 slides along the edge of plate 27 until it reaches the bottom of the plate, whereupon said carrier snaps to the right under the action of a spring and re-engages the strap.
Plate 27 also controls a scissors-like strap severing device generally indicated at 28 in FIG. 6. Severing device 23 is normally located to the right of the position shown in FIG. 6 and when plate 27 moves to the FIG. 6 position, it permits the severing device to move to the position shown, with the two blades of the scissors-like device on opposite sides of the strap. Return movement of plate 27 is first effective to operate the severing device so as to cut the strap between seal and strap carrier 22 and then to move the severing device bodily away from the path of movement of the strap. The strapping operation is now completed and the various parts of the machine are in position for starting the next strapping operation.
While certain of the above referred to elements of the machine are operated by, or the operation is instituted by, others of the elements, a number of them have their own independent power drives, the operation of which is controlled either by the movement of chain 12 or by a common cycle control mechanism. The power system of the machine is shown diagrammatically in FIG. 7 and will now be briefly described.
POWER SYSTEM (FIG. 7)
Chain sprocket 13 is driven by an electric motor 29 which is connected to said sprocket through a forward and reverse transmission 30 and a clutch 31. Motor 29 is connected to a power line 32 through a switch 33 and when the switch is closed the machine is conditioned for operation, although merely closing the switch does not institute any machine operation because transmission 30 is normally in neutral condition. The major functions of the machine are powered pneumatically and operation of the machine is instituted pneumatically. Air under pressure is supplied through a line 34 to a reservoir 35 and a line 36 connects said reservoir to a normally closed valve 37, which in turn is connected through a line 38 to one end of an air cylinder 39. Valve 37 is manually controlled, preferably by a foot lever 40, and when the operator depresses said foot lever, air is admitted to line 38 and cylinder 39. However, valve 37 is so constructed that it closes automatically a short period of time after being opened by the foot lever, even if the foot lever is held depressed. Air cylinder 39 has a piston 41 which is connected by a linkage 42 to a slide 43 which controls transmission 3%), in a manner presently to be explained. A cam follower 44 is associated with linkage 42 and a spring 45 normally holds the cam follower against a set of cams designated generally at 46, the action of cams 46 on follower 44 normally positioning slide 43 so that the transmission is in neutral. When air is admitted to cylinder 39, linkage 41 and slide 43 are moved toward the left as viewed in FIG. 7 and shift the transmission into forward drive. Clutch 31 is normally disengaged but movement of slide 43 causes it to become engaged, so that when transmission 30 is shifted into forward drive, motor 29 begins to drive sprocket 13 and chain 12 in the forward direction, that is, counterclockwise as viewed in FIGS. 1 through 4. As strap carrier 22 approaches its FIG. 2 position, it operates means presently to be explained which disengage clutch 31 and stop the forward movement of the chain, although output shaft 47 of the transmission continues to rotate in the forward direction because at that time the transmission is still in forward drive, being held in this condition by the set of cams 46.
Transmission output shaft 47 is connected through a gear train designated generally in FIG. 7 at 43 to a cycle control shaft 49 on which cam set 46 is mounted and to which is keyed three other cams A, B, and C. As will be explained later in detail, shaft 49' is driven in a forward direction for approximately 400, at which time d cam set 46 is effective to permit spring 45 to move slide 43 toward the right and shift transmission into reverse, in which condition it remains until shaft 49 is driven in reverse through a angle to restore it to its relative starting position, being then actually one complete revolution removed from where it started.
A cam follower 50 normally rides a high portion of cam A but during the continued forward rotation of shaft 4?, after clutch 31 has been disengaged and strap carrier 22 has come to rest in the FIG. 2 position, follower 50 moves into a low portion of the cam. Cam follower 50 is associated with a three ported valve 51 having an inlet connected by a line 52 to air supply reservoir 35 and a pair of outlet ports connected by lines 53 and 54 to opposite ends of a double acting air cylinder 55, a piston 56 of which is connected through a linkage, not shown in FIG. 7, to the hereinbefore mentioned finger 23. When follower St is engaged with the high portion of cam A, valve 51 is conditioned to admit air into line 53 which causes cylinder 55 to hold fingers 23 in retracted position and when said follower drops into the low portion of the cam it causes valve 51 to close line 53 and open line 54, whereupon air is admitted to the opposite end of cylinder 55 to cause fingers 23 to move between the strap 18 and the package, as shown in FIG. 3.
The linkage between piston 56 and fingers 23 includes an element 57 which, when the fingers move forward, is effective to operate a three ported valve 58. Valve 58 is connected by a line 59 to the air reservoir 35 and has discharge ports connected by lines 60 and 61 to opposite ends of a double acting cylinder 62 which has a piston 63 connected to strap tensioning roller 21. Normally valve 58 admits air into line 60 to hold tensioning roller 21 in its upper position shown in FIGS. 1 and 2 but as fingers 23 reach their forward position, element 57 operates said valve so as to close line 60 and admit air into line 61 to thereby cause roller 21 to move downward to tighten the strap. A manually operated pressure regulating valve 64 in line 59 enables adjustment of the force on tensioning roller 21 and thus determines the amount of tension applied to the strap. Piston 63 has a long stroke so that it can remove a fairly large amount of slack which may be in the strap but the air in cylinder 62 will exert only the pressure determined by the setting of valve 64 so that the tension applied to the strap is independent of the amount of slack or size of the article being strapped.
Cam B controls the action of a follower 65 which determines the setting of a three ported valve 66. A line 67 leads from reservoir 35 to valve 66 and lines 6:; and 69 connect the two output ports of said valve to opposite ends of a double acting cylinder 70 which has a piston 71 connected through a linkage not shown in FIG. 7 to sealer 24. When follower 65 is riding a high segment of cam B, valve 66 is conditioned to admit air into line 68 which causes cylinder 70 to hold the sealer away from the strap. When follower 65 moves into a low segment of the cam, valve 66 is operated to close the port to line 68 and open the port to line 69 so that air is admitted to the opposite end of cylinder 79, which causes sealer 24 to be projected into sealing engagement with the strap.
The previously referred to plate 27 which causes the strap carrier 22 to release the strap before the chain 12 starts its reverse movement and which controls also the action of severing device 28 is operated by a double acting cylinder 72 the opposite ends of which are connected by lines 73 and 74 to a three ported valve 75. The entry port of valve 75 is connected by a line 76 to reservoir 35 and said valve is controlled by a cam follower 77 which cooperates with cam C. When follower 77 is engaged with a high segment of the cam, valve 75 admits air to line 73 which causes cylinder 72 to hold plate 27 in the position shown in FIG. 5 and when said follower moves into a low segment of the cam the valve closes the port to line 73 and admits air to line 74 which causes cylinder 72 to move the plate to the position shown in FIG. 6.
With the above described overall operation of the machine in mind, the structural features of the various elements will now be explained. As shown in FIG. 8, the framework of the machine includes a yoke which extends above table 11, said yoke comprising a pair of uprights 80 and 82 and a cross member 84. Chain sprockets 14 and 15 are mounted at the intersections of the uprights and the cross member. Chain sprocket 13 is secured to a shaft 86 which, as shown in FIG. 27 is rotatably mounted below table 11 in a frame member 88. Sprocket 13 is vertically aligned with sprocket 14. Chain sprocket 16 is carried by a shaft 90 mounted in a vertically extending slot 92 located in vertical alignment with sprocket 15 but beneath table 11. Slot 92 permits the position of sprocket 16 to be adjusted to facilitate the initial training of chain 12 about the four sprockets. As is common in machines of this type, a slot 14 extends across table 11 between uprights 8t and 82 so as to permit the strap to be drawn entirely about the package and the vertical runs of the chain extend through said slot.
STRAP CARRiER 22 Strap carrier 22 is connected to chain 12 and said carrier is best shown in FIGS. 9-13, to which attention is now directed. Said carrier comprises a body member 96 having a pair of flanges, one of which is indicated at 98 in FIG. 12, which lie against the opposite sides of roller chain 12. A pair of long pins 165) forming pivot points of the chain extend through flanges 98 to thus secure body member fi6 to the chain without interfering with the movement of the chain about the sprockets. Secured to body member 96 by screws 102 is a member 104 having a portion 106 extending outwardly away from chain 12. The outwardly extending portion of member 164 terminates at a shoulder 103 and has a sloping lower surface 110. A member 112 is slidably mounted in body member 26 and a spring 114 urges member 112 toward the right as viewed in FIG. 11. Spring 114 fits about a pin 116 in a cavity in body member 96 and extends into a cylindrical opening 118 in member 112. A screw 126 has an end positioned within a slot in member 112 to limit the movement of said member.
Slide member 112 extends considerably beyond the shoulder 168 of member 104 and includes a strap spanning end portion 122 and a portion 124 having a curved surface 126. Swingably mounted on slide member 112 is a strap gripping member 128 having a half-cylindrical portion 130 located within the strap spanning end portion 122 and a curved operating arm 132. When the machine is not loaded with strap, curved operating arm 132 is held against the curved surface 126 by a spring 134 which extends between a pin 136 in arm 132 and a pin 138 fixed in the portion 124 of member 112.
Gripping member 128 is shown in normal strap-gripping position in FIGS. 9, 10 and 11 and in strap-released position in FIG. 13. It will be noted in FIG. 10 that the half-cylindrical portion 130 is pinching strap 18 between it and a shoulder 139 of the strap-spanning end 122 of member 112 in such manner that a downward pull on the strap will tend to rock portion 136 counterclockwise to increase the grip on the strap and in FIG. 9 it will be observed that the free end of operating arm 132 is aligned with the shoulder 168 of member 104. To release the strap carrier from the strap, gripper 128 is rocked from the FIG. 9 position to the FIG. 13 position so that the end of operating arm 132 is no longer aligned with shoulder 1118. Slide member 112, which carries gripper 128, is then moved to the left as viewed in FIG. 11 until the end of operating arm 132 overrides the extending portion 106 of member 1424 which thus prevents the gripper from being swung back by spring 134.
The strap gripping function of carrier 22 is under control of the previously referred to lever 26 and plate 27. As shown in FIG. 14, lever 26 is provided with an elongated slot 146 through which extends a pin 142 secured to the stationary framework of the machine. A compression spring 144 acting between lever 26 and pin 142 urges said lever toward the left as viewed in FIG. 14. A cam following roller 146 on lever 26 rides in a cam slot 148 provided in plate 27. In FIG. 14, plate 27 is shown in its fully extended position, corresponding to the position shown in FIG. 6, and it will be observed that the free end of lever 26 has been rocked upward by the action of cam slot 148 on roller 146 and that the free end of said lever is extended beyond the path of strap 18. Strap carrier 22 is shown in ghost outline in three positions in FIG. 14, the upper position being at the moment the chain starts its reverse movement, the middle position being during the reverse movement and the lower position being at the end of the reverse movement of the chain. When plate 27 is in its retracted position indicated in FIG. 5, roller 146 of lever 26 is positioned firmly in engagement with the end 151 of cam slot 143 and the end of the cam slot has moved said lever bodily to the right, compressing spring 144. Thus when plate 27 is fully retracted, the end of lever 26 is out of the path of movement of strap carrier 22. As the plate 27 starts to move toward the position shown in FIG. 14, spring 144 holds roller 146 in engagement with the end 150 of cam slot 148 until the back of slot 140 strikes the pin 142 and at that time the free end of lever 26 is directly beneath the end of gripping element rocker arm 152. Continued leftward movement of plate 27 then causes cam slot 148 and roller 146 to lift the free end of lever 26 which thereby swings rocker arm 132 upward from the position shown in FIG. 9 to the position shown in FIG. 13 so as to release the strap as above described. Then further leftward movement of plate 27 brings the leading edge 152 thereof into contact with portion 124 of the strap carrier and forces the slide member 112 to the left to move the strap spanning end 122 of the carrier away from the strap. During the reverse movement of chain 12, strap carrier 22 rides the edge 152 of plate 27 and is thereby held out of contact with the strap. As carrier 22 reaches its lowermost position, shown in FIGS. 1 and 9, it drops off the edge of plate 26 and the spring 114 thereupon snaps slide member 112 forward so that the end 122 of the carrier again surrounds the strap and spring 134 rocks the gripper 128 so as to re-engage the strap.
To assure the strap being in proper alignment to be re-engaged by the carrier 22 when said carrier reaches its starting position, a strap guide 154, best shown in FIG. 9, is provided. Guide 154 is pivotably mounted at 146 and has a slot 158 through which the strap passes. A shoulder 160 of the guide is held by a spring 162 against an adjustable stop 164. When carrier 22 reaches the starting position at the end of the reverse movement of chain 12, it is closely above the guide slot of guide 154 so that when strap spanning end 122 of the carrier moves forward it will properly span the strap. During forward movement of the chain, the end of the strap carrier contacts strap guide 154 and rocks it counterclockwise as viewed in FIG. 9. As soon as the carrier passes by the guide, spring 162 restores said guide to proper guiding position.
FINGERS 23 After the strap carrier has made its complete forward movement from the starting position shown in FIG. 1 and has come to rest in the FIG. 2 position, the hereinbefore mentioned fingers 23 are projected between the strap and the package. As shown in FIG. 22, fingers 23 are slidably mounted in a fixed frame or carriage memher 166 so as to move between an extended position between strap 12 and the package and a retracted position, the extended position being shown in FIG. 22. Lower finger 23 has an arm 168 which extends into a slot in the upper finger whereby the two fingers move as a unit. A link 170 is pivotably connected at one end to lower finger 23 and at the opposite end to one arm of a bell crank 172 pivotably mounted on a shaft 174. Piston 56 of double acting cylinder 55 is connected to the other arm of hell crank 172 and said other arm carries the element 57 which operates the three ported valve 58 controlling the operation of the strap tensioning mechanism.
STRAP TENSIONER 21 AND GRIPPER 19 The strap tensioning mechanism is shown in FIGS. 8, 16, 17 and 28 to which attention is now directed. Roller 21 is mounted on a shaft 176 extending between the arms of a yoke 173 secured to the end of piston 63 of double acting air cylinder 62 (see FIG. 7). As previously mentioned, there is a strap gripping device 19 which operates at the same time as roller 21 so that downward movement of the roller does not withdraw strap from the supply 17 but is only effective to remove the slack from that portion of the strap looped about the package and to tighten the strap about the package. Thus gripping device 19 is an essential part of the strap tensioning mechanism.
The gripping device comprises a block 130 having an end portion 182, a bottom portion 184 and a side portion 186. An angle bracket 188 secured to a frame plate 19%) supports block 180. A cover member 192 is secured to side portion 186 of the block and extends over the end portion 182 leaving a narrow opening therebetween to accommodate the strap. A wedge 194 having a serrated edge 196 rests upon the bottom portion 184 of block 181) and lies against the side portion 186 thereof. A spring 198 fits in aligned bores in wedge 194 and end portion 182 of the block and urges said block in the direction to engage the serrated edge thereof with strap 18 so as to pinch the strap between said serrated edge and the cover member 192. Spring 198, by its engagement with the aligned bores in block and wedge 194 also serves to hold the wedge against the side 186 of the block. By leaving one side of block 130 open, the initial threading of the strap through the gripper is considerably facilitated.
Block 188 is slotted at one end between bottom portion 184 and side portion 186 and a shaft 260 is rotatably mounted in said block so as to extend through this slot and protrude beyond the side 186. A lever 2112 is secured to shaft 2% and works within the slot between bottom portion 154 and side portion 186 and an operating arm 294- is secured to the shaft adjacent the outer side of side portion 186. Arm 2614 is curved and the free end thereof rests upon shaft 176 carrying the tensioning roller 21. When tensioning roller 21 is in its normal position, shaft 176 holds arm 294 in the position shown in the drawings and said arm in turn holds lever 222 in tight engagement with wedge 194 so as to compress spring 198 and prevent the serrated edge of the wedge from engaging the strap. As tensioning roller 21 starts its downward movement, shaft 176 releases the operating lever 284 to thus permit spring 198 to move wedge 194 into engagement with the strap so as to pinch the strap between said wedge and the cover 192 and thereby prevent the further downward movement of roller 21 from drawing the strap from the supply through gripping device 19. As tensioning roller 21 returns to home position, shaft 176 picks up operating arm 2114 to disengage wedge 194 from the strap.
As previously mentioned, air line 59 leading to the cylinder 62 which operates tensioning roller 21 contains a pressure regulating valve 64 whereby the force exerted by roller 21 may be adjusted so as to cause the strap to be tightened to the desired degree. This is an important feature of the machine inasmuch as it permits the machine to be used with a wide variety of packages. For example, if the package being strapped is a wooden box or even a heavy corrugated paper box it will generally be desirable to have the strap tighter than when strapping loose papers or paper backed books such as telephone directories or the like. While the space between table 11 and the chain carrying yoke determines the maximum size package that can be handled by the machine, the minimum size is determined by the stroke of piston rod 63 which carries the tensioning roller. When the package being strapped takes up most of the space between yoke uprights 80 and 82 and the cross member 84, there is very little slack in the strap, so roller 21 need move only a short distance to tighten it but when the package is small there will be more slack so that roller 21 must be moved farther to both remove the slack and tighten the strap. As mentioned, the total amount of slack that tensioning roller 21 can remove depends upon the distance it can move, which is solely dependent upon the stroke of rod 63.. Within these maximum and minimum sizes, the machine can accommodate a variety of shapes and numbers of packages.
When the strap has been drawn tight about the package with the fingers 23 between the package and the overlapping portions of the strap, it is time for sealer 24 to move in and apply the seal. The sealer itself is best shown in FIGS. 18, 22 and 23, to which attention is now directed.
SEALER 24 The sealer comprises upper and lower cover plates 206 and S spaced apart by posts 210, 212, and 214 to which said plates are secured by means of screws, bolts or the like. Pivot pins 216 and 218 extend between cover plates 206 and 208. A plurality of seal crimping jaws 220 are pivotably mounted on pin 216 and a mating plurality of jaws 222 are pivoted on pin 218. There are four jaws 220 and a similar number of jaws 222 and the jaws of each set are spaced apart by stationary spaced plates 224 shaped to engage the sides of seal 25 as shown in FIG. 23, in which figure top cover plate 206 has been removed. Post 214 is slotted to accommodate space plates 224 which are held in position by pivot pins 216 and 218, being placed on said pins alternately with the movable jaws during assembly. Spacer plates 224 have rounded teeth 226 against which the main body of seal 25 rests and which serve as anvils about which the seal is crimped when the movable jaws are operated. A pivot pin 228 connects the four movable jaws 220 to a pair of links 230, there being one link 230 sandwiched between the two outermost jaws and the two inner jaws. A pivot pin 232 interconnects the four jaws 222 and a single link 234, link 234 being located between the two innermost jaws. The two links 230 and the single link 234 are pivotably connected by a pin 236 to a pair of links 238. Link engages the middle of pin 236 and the two links 238 lie adjacent link 234 and between the two links 230. The other ends of links 238 are pivotably connected to a pin 240 carried by a push rod 242 the end of which is bifurcated and fits outside the links 238, as best shown in FIG. 18. With this symmetrical arrangement of the various links, push rod 242 exerts equal force on all four jaws 220 and all four jaws 222.
Push rod 242 and links 238 are slidably guided between a pair of guide members 244 secured to frame plates 206 and 20S and said push rod is further articulated to the frame plates themselves. A pair of rods 246 and 248 are screwed into posts 210 and 212 respectively and extend between and beyond the frame plates 206 and 208. Rods 246 and 248 fit loosely through holes in a cross member 250 secured to push rod 242 and springs 252 and 254 fit around said rods between cross member 250 and the posts 210 and 212.
Frame plates 206 and 208 of sealer 24 are slidably it) mounted in track providing members 256 and 258 of the main framework of the machine in alignment with the path of movement of the strap and between the fingers 23, as shown in FIGS. 18 and 22. Normally the sealer is held in retracted position with the movable jaws open and spaced from the strap.
Push rod 242 of the sealer is connected to a link 260, see FIG. 8, having a slot 262 within which is positioned a pin 264 carried at the end of one arm of a bell crank 266. Bell crank 266 is pivotably mounted at 268 and the other arm thereof is pivotably connected to the aforementioned piston 71 of double acting air cylinder 70. Normally cylinder holds push rod 242 and sealer 24 in retracted position but when air is admitted to the actuating end of the cylinder, bell crank 266 is rocked clockwise as viewed in FIG. 8 to cause the push rod to move the sealer into sealing position.
During the first part of the movement of hell crank 266 the push rod is not affected but pin 264 merely moves to the front of slot 262 of link 260. However, continued rocking of the bell crank causes push rod 242 to move forward and through springs 252 and 254 to move the entire sealer forward in the track providing members 256 and 258. As shown in FIG. 18, a stop member 270 extends below the lower plate 208 of the sealer and when the entire sealer moves forward to the point where the leading ends of the spacer plates 224 are closely adjacent the side of the package, stop member 270 comes into engagement with a fixed stop 272 extending between guide members 256 and 258. Further rocking of the bell crank causes the push rod to continue its forward movement, compressing springs 252 and 254, cross member 250 moving between sealer plates 206 and 208.
Seal 25 has one long leg and one short and as shown in FIG. 23 the short leg is engaged by sealer jaws 220 and the long leg by jaws 222. It is desirably in order to obtain the most efiicient sealing of the ends of the strap to bend the long leg first and then overlap the free end of the long leg with the folded over short leg as shown in FIG. 21. In order to cause jaws 222 to operate before jaws 220, cam members 274 and 276 are secured to frame plates 206 and 208 respectively and extend into the path of movement of the ends of pivot pin 236, see FIGS. 18 and 23. As push rod 242 continues its forward movement after the sealer as a whole has come to rest, pivot pin 236 engages cams 274 and 276 to cause link 234 to swing the jaws 222 closed without etfecting substantial movement of jaws 220 and when jaws 222 are fully closed and pin 236 has passed beyond cams 274 and 276 the links 230 become effective to close jaws 220. It is an important feature of the present invention that the jaws of the sealer be operated seriatim rather than simultaneously. Fingers 23 of course hold the overlapping ends of the strap away from the package in order to permit the bending of the seal about the strap.
Loading the Sealer Referring now to FIGS. 18, 19 and 24, a supply of seals is carried in a magazine 278 mounted directly above sealer 24. Magazine 278 is in the form of a generally U-shaped member open at the top and at both ends and the seals 25 are nested in said magazine with the legs of the seals facing one end thereof. The magazine is supported cantilever style at the end faced by the seals and the support is provided by a pair of members 280 and 282 secured to the top of sealer guiding members 256 and 258 respectively. Magazine 278 fits snugly between members 280 and 282 and rests upon lower flanges 284 and 286 extending inwardly from said members. A cover 238 secured to the tops of members 280 and 282 completes a housing into which the end of magazine 27 8 is fitted. The front ends of members 280 and 282 butt against frame members 290 and 292 which extend slightly into the path of the sides of magazine 278 and serve to limit the movement of the magazine when it is inserted into its support 1 l and assure the proper positioning thereof, as best shown in FIG. 19.
Seals 25 are urged toward the forward end of the magazine by a weight 294, see FIG. 8. Weight 294 is connected to a follower 295 by a pair of strands 298 and 30%) which pass over suitable pulleys so that the weight tends to move the follower toward the front of the seal carrying magazine. Follower 2% rides the legs of the U- shaped channel member comprising the magazine and has a portion located within the magazine so as to bear against the seals as will readily be understood. As shown in FIG. 19, the short leg of the leading seal is positioned against a stop ledge 392 of member 2&0 and the long leg bears against a member 304 secured to member 292. This arrangement positions the leading seal directly above the sealer so that it can be pushed down into the sealer.
For pushing a seal into the jaws of the sealer the following mechanism is provided and attention is directed to FIGS. 8, 18, 22 and 24. A finger 306 is pivotably mounted at 3&8 on an arm 319 of a slide 312. Slide 312 operates in a slot 314- cut into one face of frame member 292 and a cover plate 316 secured by knurled bolts 318 to frame member 2% holds said slide in engagement with slot 314. As shown in FIG. 22, slide 312 terminates at the bottom in two legs and a pin 252i) extends between the legs and protrudes from the side of the slide. A roller 322 mounted on pin 32%) between the legs of slide 312 is held against one end of a pivotably mounted lever 324 by means of a spring 326 extending between pin 32-0 and a stationary anchor. Lever 324 is pivotably mounted at 328 in a bracket 33%, see FIG. 8, and at the end opposite its engagement with roller 322 said lever is engaged by a roller 332 mounted on pin 264 of bell crank 266.
As bell crank 266 is swung clockwise to operate sealer 24 as previously explained, roller 332 moves onto a cam surface 334 of lever 324 and when said bell crank is fully operated roller 332 is engaged with the highest point of cam surface 334 with the consequence that lever 324 is rocked counterclockwise as viewed in FIG. 8 to thereby move finger carrying slide 312 upward to position finger 366 as shown in FIG. 18. in the EEG. 18 position, finger 336 is held in engagement with an adjustable stop 336 by a light spring 333. Stop 336 is mounted in a bracket 34% secured to the cover plate 288 of the support for the seal carrying magazine 278. Stop 336 is so adjusted that a shoulder 342 of finger is directly above the top edge of the foremost seal 25 which is located just forward of the forward end of magazine 278, being held in that position by the engagement of its legs with stops 3G2 and 3% as aforesaid.
As sealer 24- reaches its home position after completing a sealing operation, rollers 332 releases lever 324 and spring 326 thereupon moves slide 312 and finger 3% downward. During downward movement of finger 366, the shoulder 342 thereof engages the foremost seal 25 and shoves it downward into the sealer. A plate 344 secured to the bottom housing plate 268 of the sealer prevents the seal from dropping through the bottom of the sealer and locates the seal in proper position with respect to the movable jaws. The sealer is thus loaded and ready for the next sealing operation.
It has been mentioned briefly that after the seal is applied and the strap carrier 22 has been moved back to starting position, the strap is out between the seal and the point where carrier 22 has re-engaged the supply of strap. The operation of the strap severing device 28 will now be explained by referring particularly to FIGS. 22, 25, 26, and 27.
Cutter 28 A plate 346 is secured to a frame member 343 which in turn is fastened to a bracket 35% carried by table 11. Frame member 348 extends through a slot in the table and positions plate 346 parallel to the table as best shown in FIG. 27. Secured to the top surface of plate 346 by bolts 352 is a guide member 354 having a pair of grooves 356 and 358 cut into the sides thereof so that said grooves open toward the longitudinal center line of said guide member. A slide member 360 is provided with outwardly directed flanges, one of which is indicated at 362 in FIGS. 25 and 26, which fit within the grooves 356 and 353. Pusher plate 364 is positioned within a cut-out 366 in table 11 and said pusher plate is provided with outwardly projecting tabs 368 and 370 which ride in grooves 356 and 258. A rod 372 projects from pusher plate 364 and a spring 374 surrounds said rod and extends into a retaining bore cut into table 11. Spring 374 urges pusher plate 364 to the right as viewed in FIGS. 22 and 25 so that said pusher plate in turn urges slide member 360 to the right.
A shoulder portion 376 of slide member 360 normally engages a projection 37% of a lever 380 whereby movement of said slide member by pusher plate 364 is prevented. Lever 339 is pivotably mounted on a pin 382 fitted within guide member 3 4 and works within a slot 3234 cut into and entirely across the bottom of the guide member. An opening 331 extends through the guide member in alignment with slot 334 and the projection 373 extends through said opening and into the path of shoulder portion 376 of slide member 366. A leaf spring 3% holds lever 380 so that the projection 378 is in alignment with shoulder 376.
Swingably mounted on a pin 3% fixed in slide member 360 is a cutter member 3%. A block 392 is secured to and extends above slide member 369 and a spring 394 working between a cut-out 396 in said block and a cutout 3% in cutter member 2% urges said cutter member toward the position shown in FIG. 25 with a side of the cutter member butted against and stopped by a sloping side of block 392. Cutter member 395) has a cutting edge 4% which cooperates with a scissors-like action with a relatively stationary cutting edge 4&2 provided on an extension 494 of a cover plate 496 secured to slide member 236i). A roller 463 is carried by a pin 419 beneath cutter member 3% and works within a cut-out 412 provided in slide member 360. Cutter member 399 is provided with projections 414 and 416, the purpose of which will presently appear.
It has previously been mentioned that the action of cutter 28 is controlled by the plate 27 which is movable from a normally retracted position shown in FIG. 5 to a projected position shown in FIG. 6. Plate 27 has a downwardly projecting wing 418 which, as best shown in FIGS. 26 and 27, lies adjacent one side of guide member 354 of the cutter assembly. When plate 27 is in its retracted position, an edge of wing 418 is engaged with projection 414 of cutter member 390 and through said cutter member is effective to hold slide 360 in retracted position. When plate 27 moves to its forward position, slide 360 moves, as will presently be explained, to the position shown in FIGS. 25 and 26 wherein cutter blades 4th) and 404 are located on opposite sides of the strap 18 and in position for cutting said strap. Slide 360 is held in this forward position by a latch 420 which is pivotably mounted on guide member 354 and urged by a spring 422 into latching engagement with the block 392.
It will be remembered that plate 27 is held in forward position during the reverse movement of strap carrier 22 and is not restored to home position until after the strap carrier has re-engaged the strap at a point below table 11. As plate 27 makes its return movement, downwardly projecting wing 418 thereof engages roller 468 and swings cutter member 390 about the pivot 388 to bring about the scissors action between blade 40!) and the relatively stationary blade 402 to thus cut strap 18 at about the plane of table 11. As cutter member 390 swings counterclockwise as viewed in FIG. 25, the projection 416 thereof engages latch member 426 and causes it to release block 392. Continued homeward movement of plate 27 then brings the wing 413 into engagement with cutter projection 414 so that during the last part of the return movement of 13 plate 27 slide 360 of the cutter assembly is moved to the left as viewed in FIG. against the action of spring 374. When slide 360 is in fully r tracted position the cutting edges 460 and 4M- are out of the path of movement of the strap, this condition being shown in FIGS. 22 and 24-. In this position, the blades of the cutter are held closed by the action of the side of wing 418 against roller 468.
As plate 27 moves toward the FIG. 6 position, the wing 418 thereof releases projection 414 of cutting member 390 but slide 360 does not immediately move forward because it is restrained by the action of lever projection 37% which bears against shoulder 376 as aforesaid. The first effective action of plate 27 with respect to the cutter is when the side of wing 418 moves away from roller 408 to permit spring 394 to open the cutter. Continued movement of the plate 27 then brings a cam surface 424 on the bottom edge of wing 418 into engagement with the free end of lever 38% to rock said lever and release the projection 373 thereof from engagement with slide 369. Spring 374 then snaps slide 360 forward to position the cutting edges 4th) and 462 as shown in FIG. 25.
Plate 27 itself is slidably mounted between the cutter supporting frame member 348 and the frame 166 which supports fingers 23. As shown in FIG. 22, a link 426 is connected to plate 27 and to one arm of a bell crank 430 which is pivotably mounted on shaft 174. The other arm of hell crank 430 is connected to a piston 432 of double acting air cylinder 72. Thus movement of plate 27 is controlled by cam C as aforesaid.
CYCLE CONTROL The mechanical drive of the machine, and the fluid system which operates finger 23, tension roller 21, sealer 24 and the plate 27, have previously been described in a general way and will now be described in more detail. Referring first to FIG. 28, motor 29 drives forward and reverse transmission 36 through a right angled speed reduction unit 434 said speed reduction unit being driven from the shaft 436 of the motor and having an output connected through a coupling 438 to an input shaft 440 of the transmission. As shown in FIG. 14, the output shaft 47 of the transmission has splined thereon a pair of gears 444 and 446 interconnected by a shifter yoke 448 by means of which the meshing of said gears with a drive gear 450 of input shaft 440 may be controlled. Output shaft 47 carries outside the transmission housing a gear 452 which through the gear train 48 drives a gear 454 secured on cam shaft 49, see FIG. 32. Output shaft 47 also drives chain sprocket 13 through the clutch 31, see FIG. 14, as will later be described. Shifter yoke 448 has a cam following pin 456 connected to the top thereof and said pin engages a cam slot 458 in slide 43 which extends through the transmission housing transversely of yoke 448. Normally slide 43 is positioned to locate pin 456 in an intermediate position in slot 458 as shown in FIG. 32. In this position neither gear 444 nor 446 is meshed with gear 455) and the transmission is in neutral.
The previously referred to linkage 42 which connects starting cylinder as to slide 43 is best shown in FIG. 28. A link 460 is pivotably connected at one end to a downwardly directed arm 462 of slide 43 and at the other end to an arm 464 secured to a lever 466. Lever 466 is pivotably connected at the top to the stationary framework of the machine at 468 and at the bottom is connected by a pin 470 to piston 41 of the cylinder 39. The cam following roller 44 is mounted on arm 464 and normally is held in engagement with the set of cams 46 by the spring which is connected at one end to pin 47d and anchored to the framework at the other end.
The set of cams 46 includes three elements 472, 474, and 476 mounted side-by-side on cam shaft 49, element 474 being keyed to the shaft and elements 472 and 476 being loosely mounted thereon. The three cam elements are shown in FIGS. 28 and 32 but the configuration thereof is best shown in FIG. 30. Cam following roller 14- 44 is wide enough to span all three elements and when the machine is at rest said roller is engaged with an intermediate height segment 478 of cam element 474 to thus position slide 43 in intermediate or neutral position.
A spring 480 is connected at one end to a pin 482 secured to cam element 472 and at the other end is anchored to a pin 483 secured in the machine framework. With the machine at rest, spring 480 holds cam element 472 in the position shown in FIG. 28 with a shoulder 484 thereof bearing against a pin 486 protruding from cam element 474. In this position cam element 472 presents a high surface 488 to an arm 4% connected with cam follower 77, see FIG. 32, for a purpose presently to be explained.
Cam element 476 is provided with a slot 492, within which projects a pin 494 protruding from cam element 474 and earn element 476 also has a friction disk 4% connected tl ereto by means of which cam element 474 exerts a drag thereon.
When the machine is started by operation of foot pedal 40, cylinder 39 causes its piston 41 to swing link 466 counterclockwise as viewed in FIG. 28 far enough to move roller 44 entirely out of the path of the set of cams 46. This moves slide 43 to the right as viewed in FIG. 32 far enough to locate pin 456 of shifter yoke 448 substantially against an end 498 of cam slot 458 to thus shift transmission gear 446 into engagement with drive gear 451) and start the forward motion of cam shaft 49 and chain 12. The forward motion of cam shaft 49 is clockwise as viewed in FIG. 28 and as cam element 474, keyed to shaft 49, begins to turn it drags cam element 476 along with it through friction disk 4% and spring 480 causes cam element 472 to follow pin 486. Shortly, a high surface 500 of cam element 476 is presented in alignment with roller 44 and it is at this time that valve 37, see FIG. 7, automatically releases the pressure on cylinder 39 to permit spring 45 to move roller 44 into engagement with the high surface of cam element 476. This causes the end 498 of slot 458, see FIG. 32, to move slightly away from shifter yoke pin 456 but said pin remains in the same run of the slot and the transmission continues in forward drive. When cam follower 44 moves into engagement with cam element 476 it overcomes the frictional drive provided by friction disk 496 so that element 476 no longer moves in unison with cam element 474 until pin 494 of cam element 474 moves into the forward end of slot 492 at which time cam element 476 is picked up and again begins to rotate in forward direction. In FIG. 29, the two cam elements 474 and 476 are shown at the moment pin 4% reaches the forward end of slot 492 and begins to positively move cam 476. Cam elements 474 and 476 continue to move as a unit in the clockwise direction until a sloping surface 592 of cam element 476 becomes aligned with follower 44, it being apparent from FIG. 29 that at that time a low segment 594 of cam element 474 will be aligned with follower 44. When cam follower 44 leaves the high surface 500 of cam element 476 and moves onto the sloping surface 592, the force of follower 44 is sufiicient to rotate cam element 476 rapidly in a clockwise direction so that the follower moves down into contact with the low segment 504 of cam element 474, sloping surface 502 terminating somewhat lower than low segment 504. Slot 4% of cam element 476 permits this free movement of said cam element. When follower 44 moves onto the low segment 504, slide 43 is moved to the left as viewed in FIG. 32 far enough to condition transmission 30 for reverse operation.
During forward movement of cam element 474, cam element 472 follows pin 486 under the action of spring 486) until pin 482 on cam element 472 becomes aligned between cam shaft 49 and spring anchor pin 483, at which time cam element 472 temporarily ceases to move, the high surface 438 thereof still being aligned with arm 490. Cam element 474 is provided with a pin 5% and as said cam element continues its forward rotation pin engages the back of a slot 50?: cut into cam element 472 and moves cam element 472 around until pin 482 moves over an extended center line between cam shaft 49 and spring anchor pin 483. Spring 280 then snaps cam element 472 in the clockwise direction until the shoulder 484 thereof engages the side of arm :90 which at that time has moved inward, as will later be explained.
As mentioned above, when follower 44 moves into engagement with low segment 504 of cam element 474, transmission becomes conditioned for reverse opera tion and cam shaft 59 therefore begins to turn in the counterclockwise direction. At the end of its forward movement, shaft 49 has turned through approximately 400 and it now moves backward approximately to return to the starting position shown in FIG. 28. At the beginning of the reverse movement, sloping surface 562 of cam element 476 is in engagement with follower 4 5 and the force provided by friction disk 4% is not sulficient to permit rotation of cam element 474 to be imparted to cam element 476 but before cam element 474 reaches home position, pin 4&4 moves into engagement with one end of slot 492 and thereby picks up cam element 476 and restores it to home position. Also, just before cam element 474 reaches home position, arm 4% moves out of the path of shoulder 48 of cam element 472 to permit spring 480 to swing cam element 4-72 back against pin 486 of cam element 474. At the end of the reverse movement of cam shaft 43, a steeply sloped segment 510 of cam element 474 engages follower 44 and raisees it onto intermediate segment 4'78 of said cam element, thus putting transmission 30 in neutral and stopping the movement of cam shaft.
Cams A, B, and C which control fingers 23, sealer 24 and plate 27 are keyed to earn shaft 49 and in FIG. 30 said cams are shown with their respective valve controlling follows located in relation thereto as they are when the machine is at rest. As the cam shaft and cams A, B, and C begin their forward or clockwise rotation, a low segment 512 of cam C is quickly presented to follower 77 which controls the plate 27 as previously explained. However, follower 77 does not drop into the low segment of the cam at this time because, as shown in FlG. 28, the hereinbefore described arm 490 of said follower is aligned with the high surface of cam element 472 and engages cam element 4'72 after a very slight movement. In the chart shown in FIG. 31 the raised portions of the lines indicate the timing of the low portions of cams A, B, and C and the dotted line over the first elevation of the lowest line indicates that the low surface of cam C is presented during the early part of the cycle but is not effective at that time.
When cam shaft 49 has rotated approximately 272 a low segment 514 of cam A moves into alignment with follower 50 and follower 50 drops into said low segment to thereupon cause valve 51 to operate cylinder 55 and project fingers 23 forward as previously described. Follower 50 remains in engagement with the low segment of cam A until cam shaft 49 has rotated approximately 332, at which time it rides back onto the high segment of the cam to cause fingers 27 to be retracted. During the remainder of the forward movement of cam shaft 49 and during the reverse movement thereof follower 50 continues in engagement with the high surface of cam A.
Since sealer 24 must begin to operate while fingers 27 are in position between the strap and the box, a low segment 516 of cam B moves into alignment with its follower while follower 50 is still engaged with the low segment of cam A. As indicated in FIG. 31, cam B presents its low surface to follower 65 when cam shaft 49 has rotated approximately 290 and follower 65 continues to ride the low segment until shaft 49 has rotated approximately 355. The degree marks on the chart in FIG. 31 are intended to indicate a forward rotation of cam shaft 49 of 400 followed by a reverse rotation of 40 and cam B presents its high surface to follower 65 for the second l. 13 time during the last 45 of forward rotation and the 40 of reverse rotation. It will be noted that fingers 23 are retracted before sealer 2-. completes its full movement.
Low surface 512 of cam C, which was inetfectively presented to follower '77 early in the cycle is not presented again until cam shaft 49 nears the end of its forward movement. As indicated in FIG. 31, the second presentation of low segment 512 takes place at approximately 380 rotation of the cam shaft. This time the high surface of cam element 472 is not aligned with arm 490 of follower 77 and said follower therefore moves onto the low segment of cam C. Follower '77, through valve and cylinder '72 thus causes plate 27 to move forward near the end of the forward rotation of cam shaft 49 to effectuate release of the strap carrier 22 as previously described. Since strap carrier 22 rides the forward edge of plate 27 during reverse movement of chain 12 and since plate 27 operates cutter 2% during its return movement, it is nece sary for plate 27 to remain in forward position until just before the entire cycle is completed and from FIG. 31 it will be seen that the high surface of cam C does not reengage follower 77 until shortly before cam shaft 49 has completed its 40 of reverse movement. Unlike followers 50 and :55, follower '77 moves onto and off low segment 512 over the same sloping cam surface 518. Followers 59 and 65 ride onto the low surfaces of their respective cams at one end and off at the other.
While cam shaft 49 and chain 12 begin their forward and reverse movements at the same time their periods or time of operation are different. Thus cam shaft 49 rotates in the forward direction at all times that transmission 30 is conditioned for forward drive and likewise rotates in reverse direction at all times that the transmission is conditioned for reverse. As previously mentioned, however, there is a clutch 33. between transmission 30 and the sprocket 13 which drives chain 12 and this clutch is effective to interrupt the drive to sprocket 13 as will now be explained. First, it might be mentioned that cam shaft 49 rotates in forward direction for a considerable distance after the drive to chain 12 is interrupted and in fact the forward movement of chain 12 is stopped before any of the followers 56, 65, and 7'7 drop into the low portions of their respective cams A, B, and C. The actual timing of cams A, B, and C shown in FIG. 31 is not particularly important, so long as those relative times are maintained, that is that the low part of cam B becomes effective while follower 50 is still in the low part of cam A and that the low portions of both cams A and B have passed their respective followers before the low portion of cam C becomes effective.
CLUTCH CONTROL Referring now to FIGS. 14, 15, 33, 34, and 35; clutch 31 comprises a driving member 520 secured to output shaft 47 of transmission 30 and a driven member 522 secured to shaft @6 to which sprocket 13 is fixed. The clutch is a positive drive type and includes a dog 52-4 slidably mounted in driving member 520 and urged by a spring 526 toward the face of driven member 522 which has an open topped slot into which the end of the dog fits when the clutch is in engaged condition. Dog 524- has an upstanding ear 523 which extends above the cylindrical periphery of driving member 520 and said ear has a pair of cam surfaces adapted to be engaged by a vertically movable slide 530 to move dog 524 against the action of spring 526 to disengage the clutch.
Slide 530 is mounted in a slot 532 out into one face of a thick plate 534. A cover plate 536 overlies slot 532 and serves to confine slide 530 within said slot. Plate 534 is mounted on a spacer member 533 secured to the machine frame member 88, said spacer member serving to locate slide 530 in the proper position with respect to the ear of clutch dog 524. Slide 530 is held in an elevated position shown in FIGS. l4, l5, and 34 by a member 540 which is slidably mounted in an opening cut through one side of the thick plate 534 and has an end extending into a ll 7 notch 542 cut into one edge of slide 530. The other end of member 540 is articulated to one end of a lever 544 pivotably mounted on a pin 546 between a pair of ears 54S extending from spacer member 538. A light spring 550 urges member 540 toward the left as viewed in FIG. 32 to engage said member with slide 530.
A lever 552, see FIGS. 14 and 28, is pivotably mounted on a pin 554 in a bracket 556 secured to frame member 88. Lever 552 has a nose 558 extending through a slot in yoke member 8t) and a spring 569 connected to the bottom end of lever 552 holds nose 558 in the path of movement of strap carrier 22. The lower end of lever 552 is located in proximity with lever 544 so that when lever 552 is rocked by engagement of the strap carrier with the nose 558 thereof, it rocks lever 544 counterclockwise as viewed in FIG. 32 to withdraw member 540 from engagement with slide 530. Nose 558 is located midway the upper stopping position of strap carrier 22 and the lower stopping position and consequently is struck by the strap carrier during both its forward and reverse movements. In fact, lever 552 is rocked twice during the forward movement of strap carrier 22, the first time being just after the carrier begins its forward movement. However, as will be explained, the first rocking of lever 552 and consequent withdrawal of member 540 from engagement with slide 534) is not effective to permit said slide to move downward into clutch disengaging position.
Extending from cover plate 536, is a bracket 562 which is slotted and within the slot a lever 564 is pivotably mounted by means of a pin 566. A compression spring 568 working between bracket 562 and lever 564 tends to rock the lever in a clockwise direction as viewed in FIGS. 14, 33, and 34. Lever 564 is also slotted and an arm 570 is mounted within the slotted portion and pivotably connected to the lever by a pin 572. A compression spring 574 working between lever 564 and arm 570 urges said arm in a clockwise direction so that a pin 576 carried by said arm engages a camming surface 573 of cover plate 536, the free end of said arm working within an opening provided in said cover plate.
Referring to FIGS. 32 and 35, it has been mentioned that at the beginning of a cycle of operation, slide 43 is moved through the housing of transmission 30 far enough so that the end 498 of slot 458 is engaged with the pin 456 of shifter yoke 448 and that shortly after the cycle begins, slide 43 recedes as follower 44 moves into engagement with the cam set 46 but that the transmission is still held in forward drive because slide 43 does not recede far enough to cause the slot 458 to shift yoke 448. Slide 43 carries a pin 588 which, when said slide is shifted to the starting position, engages a sloping end 532 of a slide 584. Slide 584 is mounted for free sliding movement in a top cover 586 of the transmission housing and has an end protruding through a side wall of the housing. When slide 584 is engaged by pin 53% it is shifted to the right as viewed in FIG. 35.
Slide 584 is located directly above shifter yoke 448 and both are aligned with lever 564 of the clutch control mechanism. FIG. 34 shows the parts at the beginning of a cycle of operation while slide 584 is being held in its rightwardly shifted position by pin 580 and it will be observed that slide 584 is holding lever 564 in such position that the free end of arm 570 is located beneath a shoulder S6 defining the top of a cut-out portion in clutch releasing slide 539. Cam surface 578 of cover plate 536 and spring 574 cooperate in holding arm 570 in the position shown. With arm 57% in the position shown in FIG. 34, slide 530 cannot move down even though released by member 54% and said arm is held in this position by slide 584 until after strap carrier 22 passes by the nose of release lever 552 to efifect actuation of member 540 as described.
As soon as slide 43 is slightly retracted due to release of the air pressure from piston 39, pin 5S0 releases slide 584 and springs 568 and 574 are effective to move their associated parts to the position shown in FIG. 33 with the end of arm 570 located considerably below shoulder 586 of clutch release slide 534 Under this circumstance, slide 53% is free to move downward when released by member 54% and in FIG. 33 said slide is shown in its downward position. When slide 536 is down the lower end thereof is in the path of movement of ear 528 of clutch dog 524 and when said ear moves into engagement with the slide, dog 524 is cammed out of engagement with driven clutch member 522 to release the clutch.
As best shown in FIG. 15, a pair of levers 5% and 592 are pivotably mounted on the lower end of plate 534 which is curved so as to extend about the upper por tion of clutch members 52% and 522. Springs 594 and 5% extending between levers 5% and 592 and the supporting plate 534 urge said levers in the directions to engage protrusions thereon with driven clutch member 522. When slide 530 is in the elevated position, the free ends of levers 5% and 592 engage respectively pins 595 and 597 extending from said slide, which it is to be noted has a curved lower surface 59% substantially matching the curvature of the periphery of clutch member 520. The fact that surface 598 is curved gives the illusion in FIGS. 14 and 34 that plate 530 is in position to cause disengagement of the clutch but actually plate 530 is entirely clear of the path of dog 524 when in the FIGS. 14 and 34 position, as is shown in FIG. 15. When slide 53!) moves down, pins 595 and 597 release levers 590 and 592 to the action of their respective springs. When clutch member 52% then rotates to the point where the ear 528 of dog 524 engages slide 53! the clutch is released as aforesaid but driven member 522 of the clutch rotates a short distance due to the momentum of chain 12 until the slot in member 522 vacated by dog 524 comes into alignment with the protrusion of lever 5% or 592. which drops into the slot in member 522 to bring the chain and strap carrier to rest in the exact desired position. When the machine is in forward drive, it is the lever 59% which arrests the driven member of the clutch and when in reverse the lever 592 serves the same purpose. The timing of the release of slide 53% is such that clutch 31 stays engaged until it has driven strap carrier to near the desired stopping position before said slide is engaged by the ear of dog 524 and very shortly thereafter the driven member of the clutch is positively arrested.
In FIG. 14, the parts are shown conditioned for reverse operation and it will be observed that the end of arm 574i is completely out of the path of movement of slide 539 so that said slide is free to move down when released by member 549 in the manner explained. Arm 570 is held in this position due to the fact that shifter yoke 443 is engaged with lever 564 and has rocked said lever far enough that cam surface 578 in cooperation with pin 576 has swung the arm 570 in a counterclockwise direction. It will be remembered that as viewed in FIGS. 14, 33, 34, and 35, slide 554 moves to the right when the machine is first conditioned for forward operation but that shifter yoke 448 is moved toward the left and that when the machine is conditioned for reverse, shifter yoke 44% is moved to the right.
FIG. 33 shows the lever 564 and arm 57% in the positions which they occupy both when the machine is running in forward direction, that is, except for the very beginning of the forward movement, and when strap carrier 22 is at rest in both the FIG. 1 and FIG. 2 positions. Assuming that the strap carrier 22 is at rest in the FIG. 1 position and that the operator depresses foot pedal 40 to start the machine, slide 584 then moves forward to the position shown in FIG. 34 to cause arm 57% to swing counterclockwise and at the same time to move upward, this motion being effected in part by the action of cam surface 57% on pin 476. This movement causes the end of arm 57%) to engage shoulder 586 of slide 530 and raise said slide until the notch 542 thereof is aligned with the member 540 which thereupon snaps into the notch to hold slide 534 in the elevated position, as shown in FIG. 34.
a After strap carrier 22 passes by the lever 552 the first time, the pressure is released from slide 534 as above described so that lever 56 i and arm 57th are permitted to move to the position shown in FIG. 33. When strap carrier 22 has come to rest in the FIG. 2 position, the shifting of transmission 30 into reverse causes shifter yoke 443 to rock lever 5'4 and arm 5'70 from the positions shown in FIG. 33 to the position shown in FIG. 14 and during this movement the end of arm 570 first restores slide 53% to latching engagement with member and then moves leftward away from slide 530 so that said slide will be free to move down when released by member 543.
Having thus described a preferred embodiment of the invention, what is claimed is:
. In an automatic binding machine, a carrier for gripping an end of a flexible binding material extending from a supply, means for moving said carrier in a first direction from a starting position through a circuit of more than 360 which encompasses an article to be bound whereby the binding material is looped about the article with the end engaged by said carrier lapping that portion of the binding material extending toward the supply, means for securing the lapping portions of the binding material together, means for disengaging said carrier from the binding material, means for moving said carrier in the direction opposite to the first direction to restore said carrier to starting position, and means for re-engaging said carrier with the binding material when said carrier is restored to starting position.
2. In an automatic binding machine, a carrier for gripping an end of a flexible binding material extending from a supply, means for moving said carrier in a first direction from a starting position through a circuit of more than 369 which encompasses an article to be bound whereby the binding material is looped about the article with the end engaged by said carrier lapping that portion of the binding material extending toward the supply, means for securing the lapping portions of the binding material together, means for disengaging said carrier from the binding material, means for moving said carrier in the direction opposite to the first direction to restore said carrier to starting position, means for re-engaging said carrier with the binding material when said carrier is restored to starting position, and means for cutting the binding material between the point where the lapped portions thereof are secured together and the point where the binding material is re-engaged by said carrier.
3. In an automatic binding machine, a carrier for gripping an end of a flexible binding material extending from a supply, means for moving said carrier in a first direction from a starting position through a circuit of more than 360 which encompasses an article to be bound whereby the binding material is looped about the article with the end engaged by said carrier lapping that portion of the binding material extending toward the supply, means for tightening the binding material about the article being bound, means for securing the lapping portions of the binding material together, means for disengaging said carrier from the binding material, means for moving said carrier in the direction oppositte to the first direction to restore said carrier to starting position, means for reengaging said carrier with the binding material when said carrier is restored to starting position, and means for cutting the binding material between the point Where the lapped portions thereof are secured together and the point where the binding material is re-engaged by said carrier.
4. in an automatic binding machine, a carrier for gripping an end of a flexible binding material extending from a supply, means for moving said carrier in a first direction from a starting position through a circuit of more than 360 which encompasses an article to be bound whereby the binding material is looped about the article with the end engaged by said carrier lapping that portion of the binding material extending toward the supply,
cycle control means, means controlled by said cycle control means for tightening the binding material about the article being bound, means controlled by said cycle control means for securing the lapping portions of the binding material together, means for disengaging said carrier from the binding material, means for moving said carrier in the direction opposite to the first direction to restore said carrier to starting position, means for re-engaging said carrier with the binding material when said carrier is restored to starting position, and means controlled by said cycle control means for cutting the binding material between the point where the lapped portions thereof are secured together and the point where the binding material is re-engaged by said carrier.
5. In an automatic binding machine, a carrier for gripping an end of a flexible binding material extending from a supply, means for moving said carrier in a first direction from a starting position through a circuit of more than 360 which encompasses an article to be bound whereby the binding material is looped about the article with the end engaged by said carrier lapping that portion of the binding material extending toward the supply, cycle control means, tightening means controlled by said cycle control means for tightening the binding material about the article being bound, manually controlled means for regulating the tension applied to the binding material by said tightening means, means controlled by said cycle control means for securing the lapping portions of the binding material together, means for disengaging said carrier from the binding material, means for moving said carrier in the direction opposite to the first direction to restore said carrier to starting position, means for reengaging said carrier with the binding material when said carrier is restored to starting position, and means controlled by said cycle control means for cutting the binding material between the point where the lapped portions thereof are secured together and the point where the binding material is re-engaged by said carrier.
6. In an automatic binding machine, a carrier for gripping an end of a fiexible binding material extending from a supply, means for moving said carrier in a first direction from a starting position through a circuit of more than 360 which encompasses an article to be bound whereby the binding material is looped about the article with the end engaged by said carrier lapping that portion of the binding material extending toward the supply, cycle control means, tightening means controlled by said cycle control means for tightening the binding material about the article being bound, said tightening means engaging the binding material between the lapping portions thereof and the supply, means controlled by said cycle control means for securing the lapping portions of the binding material together, means for disengaging said carrier from the binding material, means for moving said carrier in the direction opposite to the first direction to restore said carrier to starting position, means for re-engaging said carrier with the binding material when said carrier is restored to starting position, and means controlled by said cycle control means for cutting the binding material between the point where the lapped portions thereof are secured together and the point where the binding material is re-engaged by said carrier.
7. In an automatic strapping machine, a carrier for gripping an end of a flexible fiat strap extending from a supply, means for moving said carrier in a first direction from a starting position through a circuit of more than 360 which encompasses an article to be bound whereby the strap is looped about the article with the end engaged by said carrier lapping that portion of the strap extending toward the supply and with the end of the strap gripped by said carrier located between the article and that portion of the strap extending toward the supply, means for tigh ening the strap about the article being bound, means for spacing the lapping portions of the strap from the article being bound, means for applying a seal about the lapping