US 3135192 A
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Description (OCR text may contain errors)
June 2, 1964 DERRICKSON 3,135,192
STRAPPING APPARATUS Filed July 10, 1962 5 Sheets-Sheet 1 June 1964 M. o. DERRICKSON 3,
STRAPPING APPARATUS Filed July 10, 1962 3 Sheets-Sheet 2 United States Patent Office 3,135,192 Patented June 2, 1964 corporation of Delaware Filed July 10, 1962, Ser. No. 208,851 4 Qlaims. (Cl. Hill-8) This invention relates to an apparatus for facilitating the strapping or banding of relatively large objects such as a carton or stacked group of cartons and more particularly to apparatus for positioning a flexible strap about such an. object'so that an operator may subsequently employ manual means for tensioning the strap and securing the same about the object. 7
it is common practice to provide tensioned bands or straps about boxes, cartons and the like to reinforce them and minimize damage during shipment. Tensioned straps are also employed for unitizing or bundling groups of articles, that is, to form a single package of a group of separate articles, and to further facilitate the handling of groups of articles they are frequently strapped to a pallet so that they may be moved by a fork lift truck. Throughout the remainder of this specification the term package will be employed to designate both a single article or object such as a carton, boX or the like and a group of associated articles whetheror not positioned on a pallet.
While various specific techniques are employed for strapping packages, the basic operations involve positioning the strapping material about the package, tensioning the same and securing the ends together so as to hold it under tension. The tensioning and securing operations may be carried out with the aid of specially designed tools or maybe performed entirely by hand, depending uponthe nature of the strappingmaterial, the type of securement and the degree of tension required. When working with relatively small packages one man can easily position the strapping about the packageas Well as perform the tensioning and securing-operations but when the package is large it is inconvenient and time consuming forone man to properly position the strapping material, although once positioned he can tension and secure it since these latter operations are substantially the same irrespective of the size of the package.
There are strapping machines available which will automatically perform all the operations necessary for strapping a package and some of these will handle large packages but the use of such machines is economically feasible only where the volume of work is large, such as at the end of a production line. There are also machines which Will position the strapping material about a large package; the subsequent tensioning and securing operations being performed manually. It is toward the improvement of this latter type of machine that the present invention is directed.
It is the primary object of this invention to provide an improved apparatus for positioninga strap, particularly a relatively flexible non-metallic strap, about a large package to thus facilitate the strapping of such large packages by a single operator.
Toward the attainment of the above objective the invention provides novel features and arrangements of parts as will be described with reference to the accompanying drawings showing a preferred embodiment and wherein:
FIG. 1 is a side elevational view of the apparatus;
FIG. 2 is a side elevational view on an enlarged scale showing the side opposite to that of FIG. 1, certain parts being broken to permit the enlarged showing;
FIG. 3 is a section taken along the line 111 -111 of FIG. 2, certain parts being omitted for clarity of illustration;
FIG. 4 is a side elevational view, partly broken away, of a strap carrying element forming a part of the apparatus;
FIG. 5 is a plan view, partially in section and partially diagrammatic showing a portion of a cycle control mechanism; and
FIG. 6 is a perspective view showing a seal feeding means of the apparatus.
Referring first to FIG. 1, the apparatus comprises a generally G-shaped framework consisting of an upright portion 1%, an upper horizontally extending arm 11 and a lower horizontal arm 12 supported by adjustable feet 14; The various members of the framework are in the form of channels and supported for movement primarily within the channels is an endless chain 15 trained about sprockets 1.6, 17, 18, 19, 2t and 21. As shown in FIG. 1, the sprockets support the chain in such manner that parallel runs thereof form over-all an erect generally 8- shaped configuration. The lower run of that portion of the chain traveling along arm 11 is free of confinement by the channel but the other runs of the chain are guarded by the channel members forming the framework so as to eliminate the danger of the operator coming in contact with the moving chain while the apparatus is in op eration. Arm 12 is shown in section in FIG. 3 where the channel-like structure thereof is apparent. The other other two members 10 and 11 of the framework are of similar construction.
Extending outwardly from opposite top edges of lower arm 12 are a pair of platforms 22 and 23 each of which is provided with anti-friction rollers 24. Platform 22 is supported on the floor by an adjustable post 25 and platform 23 is supported by an adjustable post 26. The ad justable feet 14 and posts 25 and 26 provide a height adjustment whereby the platforms may be placed at the proper elevation to receive a package from a roller conveyor or the like, not shown. In FIG. 1 a large package is indicated at 2'7 and it will be apparent that since the package is supported on the rollers 24 it may easily be manipulated to position it in the precise relation desired with respect to upright 10 and arm 12 so that the strapping material will be properly positioned about the pack age, as will presently be explained.
Chain 15' is a double Width roller chain and the sprockets about which it is trained are double sprockets two of which are shown at 18 and 19 in FIG. 3. Each double sprocket is mounted upon a stub shaft rotatably mounted in one side wall of either upright member Ill or one of the arms 11 and 12 of the framework so as to locate the sprockets within the channels formed by these members. The stub shaft carrying sprocket 19 is indicated at 28 and as shown in FIG. 3 it extends almost all the way across the channel interior of arm 12. The stub shafts carrying the other sprockets are all shorter than shaft 23 and terminate close to the respective sprocket carrier thereby. The shaft carrying sprocket 20 is indicated at 29 and this shaft extends through the side wall of arm 12 and has connected thereto outside the channel formed by said arm a pulley 39 by means of which said sprocket is driven. In FIG. 3, sprocket Zll'is located behind sprocket l9 and cannot be seen.
Pulley 30 is connected by a belt 31' to a pulley 32 secured to the drive shaft of an electric motor 33 carried by a platform 34 which is hinged at 35 on a bracket 36 and supported against downward pivotal movement by ad justable length post 37. When platform 34 is resting on the post 37, belt 31 is loose so that pulley 30 isnot driven even though the motor is in operation. To insure against accidental rotation of pulley 3t and for another reason presently to be described, a brake shoe 38 is mounted beneath platform 34 and when the platform is resting on post 37 said shoe frictionally engages pulley 30.
To cause motor 33 to drive pulley and sprocket 2t) and consequently chain 15 which is trained about said sprocket and the other sprockets previously referred to, platform 34 is swung upwardly to position the motor as shown in dotted lines in FIG. 2 and thus tighten belt 31 as well as withdraw brake shoe 38 from engagement with pulley 30. To this end an arm 39 is secured to platform 34 and pivotally connected at 46 to one end of a link 41, the opposite end of which is pivotally connected at 42 to an arm of a bell crank 43 pivotally mounted at 44 on arm 12 of the machine framework. A foot pedal 45 is provided upon the other arm of bell crank 38 and when the operator steps on the foot pedal, platform 34 is pivoted upward to thus cause the motor to drive chain 15 as aforesaid.
So that it will not be necessary for the operator to hold down the foot pedal all the time the machine is in operation, the following mechanism is provided for holding platform 34 in its upper position. A link 46 is pivotally connected at 47 to a tab 48 extending upwardly from the free forward edge of the platform. At the opposite end, link 46 is pivotally connected at 49 to an arm of a bell crank 50 which is pivotally mounted at 51 on upright 10 and the other arm of which is pivotally connected to one end of a slide 52. Slide 52 is slidably held against the outside of one of the sidewalls of arm 11 of the framework by a strap 53 and said slide is provided with a slot 54. As shown in FIG. 5, a lever 55 is pivotally mounted at 56 on a tab 57 on the inside of the side wall of arm 11 and a spring 58 working between said side wall and one end of the lever urges a shouldered end 59 of the lever through an aligned slot 60 in the side wall so that said shouldered end bears against slide 52. When slide 52 is moved toward the left as viewed in FIGS. 2 and 5, which it is when platform 34 is swung upward as aforesaid, slot 54 moves into alignment with the shouldered end 59 of lever 55 and spring 58 thereupon snaps said shouldered end of the lever into slot 54 to thereby hold the slide in its leftward position and through the linkage described hold platform 34 in its upper position.
With drive belt 31 tight, motor 33 drives chain 15 in the direction indicated by the arrows in the several figures of the drawing until such time as the shouldered end 59 of lever 55 is removed from slot 54 of slide 52 as will presently be described.
Secured to chain 15 is a strap carrier indicated generally at 61 and shown in detail in FIG. 4 to which attention is now directed. Carrier 61 comprises a body portion 62 secured to one side of the chain by a pair of adjacent pins 63 which secure the links of the chain together. In this manner the carrier protrudes outwardly from one side of the chain and does not interfere with the free passage of the chain about the sprockets. Extending perpendicular to body portion 62 and preferably formed integrally therewith is a foot portion 64 with which cooperates a serrated side of a slidably mounted wedge 65. Wedge 65 has secured thereto a pin 66 which slides within a mating bore provided in body portion 62 and a spring 67 mounted around the pin urges wedge 65 in the direction to engage the serrated side thereof with foot portion 64. A lever 68 is pivotally mounted on body portion 62 and said lever has an end 69 which lies in proximity with an ear 76 extending from wedge 65. At its outer end lever 68 carries an operating roller 71. When said lever is swung counterclockwise as viewed in FIG. 4, end 69 thereof engages car 70 and moves the wedge against the action of spring 67 to thereby move the serrated side of the wedge away from the foot portion 64. The details of construction of this carrier are more fully described in the copending application of Alexander Sharko, Serial No. 162,801 filed December 28, 1961.
A roll of strapping material 72 is rotatably mounted on a post 73 upstanding from the upper portion of the framework and the strap 74 is led from the roll through a guide 75 and about a pair of rollers 76 and 77 mounted on the end of arm 11. When the apparatus is to be placed in operation, the operator grasps roller 71 of the carrier 61 and swings lever 68 so as to release wedge 65 from engagement with the foot 64. The end of the strap is then placed between the wedge and the foot and lever 68 is released so that the carrier grips the end of the strap as will readily be understood. Foot pedal 45 is then depressed to cause the chain 15 and carrier 61 to start to move as aforesaid. As indicated in FIG. 1, this movement of the chain causes the carrier 61 to draw the strap down about the rearward vertical side of package 27 and then forward beneath said package. Sprocket 159 defines one end of the G-shaped configuration of the chain and as the carrier passes around sprocket 19 and starts to move leftward along arm 12 as viewed in FIG. 1, a loop of the strap is caught by sprocket shaft 28 which, as previously mentioned, extends almost all the way across the channel of arm 12. The strap does not get caught by the shafts supporting any of the other sprockets because these shafts all terminate at the sprocket and carrier 61, as indicated in FIG. 3, is on the side of the chain opposite said shafts.
As carrier 61 proceeds rearwardly along arm 12, roller 71 contacts a cam 79 mounted in the lower portion of said arm. This contact of roller 71 with cam 79 swings carrier lever 68 in the direction to cause the wedge 65 of the carrier to release the strap. Since the strap is under tension and bent sharply about the shaft 28, the end of the strap snaps forward to approximately the position indicated at 74 where it is accessible to the operator who then picks up the free end of the strap and draws it upward to the point where he can conveniently reach that portion of the strap between the rear upper edge of the package and the roller 77. The operator then withdraws from roll 72 enough strap so that the strap will completely encircle the package and after cutting the strap he proceeds to tension and secure the same about the package in any desired manner. As previously mentioned, the present apparatus is intended primarily for use with non-metallic strapping and the flexibility of such strapping permits the sharp bend about shaft 28 and also causes the strap to snap out to the position indicated at 74' when it is released from the carrier.
Secured to chain 15 in the vicinity of carrier 61 but on the opposite side of the chain is a cam 84) and after the carrier releases the strap the chain continues to move until cam 80 contacts lever 55 adjacent spring 58 to thereby rock said lever and release the shouldered end 59 thereof from slide 52 as illustrated diagrammatically in FIG. 5. Upon release of slide 52, the Weight of motor 33 causes hinged platform 34 to swing downward into contact with adjustable post 37, thus loosening drive belt 31. Due to its inertia, the chain will continue to move for some distance after the power is disconnected and it is the action of the hereinbefore mentioned brake shoe 38 against pulley 30 which determines the actual stopping position of carrier 61. By adjusting the height of post 37, the force of the brake shoe against the pulley may be regulated to thus cause the carrier to stop at the desired position. While this stopping position of the strap carrier is not critical, it must be some place along the underside of arm 11 and may conveniently be as shown in FIG. 1.
It has been mentioned that a common way of securing the strap is by the use of a so-called closed seal. Closed seals are in the form of flattened tubes or sleeves which are threaded on the strap and crimped about overlapping portions of the strap to prevent relative movement between the overlapping portions. The present apparatus provides an arrangement for conveniently associating such seals with the strap, as will now be described.
As best shown in FIG. 6, a magazine 81 is secured to the side of the forward end of upper arm 11 of the machine framework. A plurality of closed seals 82 are stacked on end side-by-side in said magazine and urged by a spring pressed plunger 83 toward the front end of the magazine which is open and leads into a chute 84 which will accommodate a plurality of seals in edge-toedge relation but is not wide enough to permit the seals to lie side-by-side. Thus, only one seal at a time may enter chute 84 from the magazine. A pusher 85 within chute 84 has secured thereto a rod 86 which extends through one end of the chute and is provided with a finger piece 87 Rod 86 works within a cylinder 88 and a spring, not shown, urges said rod to position pusher 85 as shown in FIG. 6. By pressing finger piece 87, pusher 85 is caused to move the seal directly in front of the magazine further into the chute so that when the finger piece is released another seal is moved from the magazine into the chute when pusher 85 returns to home position.
Chute 84 is in the form of a trough and the bottom thereof has an opening underlying the seal most remote from pusher 85, such seal being designated 82'. Rockably mounted on the side of chute 84 adjacent seal 82 is a latch or detent 89 which is urged by a spring 90 to position a portion 91 thereof beneath one of the side faces of seal 82 to prevent said seal from dropping through the opening in the bottom of the chute. Strap 74, as it passes between guide rollers 76 and 77, is fed through closed seal 82' and as the strap is drawn about the package, as previously described, it is pulled through the seal, which remains in place in chute 84 due to the latch 89. Thus, a closed seal is in position about the strap at the time the strap is pulled about the package so that the operator need merely operate latch 89 to cause the seal to slide down so that it may be used in the customary manner for securing the strap in position about the package. Of course if some other method of securing the strap is to be employed, the seals are omitted and the strap is merely passed through the empty chute 84.
Platform rollers 24 hold the package free of contact with platforms 22 and 23 and the top of arm 12 so that the package-may be readily manipulated to cause the strap to be positioned in any desired location about the package or to be turned after a first strap is applied so that a second one may be applied at right angles thereto.
Having thus described a preferred embodiment of the invention, what is claimed is:
1. In an apparatus for facilitating the strapping of relatively large packages, an endless roller chain, a plurality of sprockets supporting said chain in such manner that parallel runs thereof form over-all an erect generally 0- shaped configuration, support means for supporting a package within the C-shaped configuration of said chain whereby parallel runs of the chain underlie the package, a strap carrier secured to said chain and protruding outwardly from one side thereof, said carrier having a home position along the upper portion of the G-shaped configuration of said chain, said carrier comprising gripping means for gripping an end of strapping material leading from a supply of such material, drive means for driving said chain in a path about said sprockets whereby said strap carrier draws the strapping material gripped by the gripping means thereof partially about the package resting on said support means, one of said sprockets defining an end of the C-shaped configuration of said chain being located close to said support means so as to be beneath the package supported thereby, said carrier describing a bend as it passes about said one of said sprockets, a shaft supporting said one of said sprockets, said shaft extending into the bend described by said strap carrier as it passes about said one of said sprockets whereby the strap held by the gripping means of the carrier is bent sharply as the carrier continues to move, means for causing the gripping means of said carrier to completely release the strapping material after the carrier has passed around said one of said sprockets and the strap has been bent about the shaft supporting the said one of said sprockets, and means for disengaging said drive means as said strap carrier approaches its home position.
2. In an apparatus for facilitating the strapping of relatively large packages, a generally C-shaped framework comprising upper and lower horizontally extending arms interconnected at one end by a vertical section, an endless chain, a plurality of sprockets supporting said chain on said framework in such manner that vertically spaced parallel runs of the chain extend along the upper and lower arms of the framework, a strap carrier secured to said chain, said carrier having a home position along the lower run of the chain extending along the upper arm of the framework, said carrier comprising gripping means for gripping an end of strapping material leading from a supply of such material, support means for supporting a package in overlying relation to the lower arm of the framework, drive means for driving said chain about said sprockets whereby said carrier passes beneath the package, manually operable means for engaging said drive means, means for completely releasing the gripping means of the carrier from the strap while the carrier is beneath the package, automatically operable means for disengaging said drive means, and means for stopping said chain when said carrier reaches its home position.
3. In an apparatus for facilitating the strapping of relatively large packages, support means for supporting a package to be strapped, a strap gripping device for gripping an end of strapping material leading from a supply and pulling it about three sides of a package supported on said support means, means for directing said gripping device through a generally C-shaped closed circuit passing beneath a package supported on said support means, said strap gripping device having a home position along the upper portion of the means for directing it through the C-shaped configuration, drive means for driving said gripping device completely through said circuit from said home position and back to said home position in a single trip, manually operable means for engaging said drive means, means located beneath said support for completely releasing said gripping device from the strap when said device is passing through that portion of the circuit which is beneath the package, and means for arresting said gripping device when it returns to its home position.
4. In an apparatus for facilitating the strapping of relatively large packages, support means for supporting a package to be strapped, an endless conveyor, means supporting said conveyor in such manner that parallel runs thereof form over-all an erect generally C-shaped figure having a vertically extending side arm and upper and lower arms extending horizontally, said lower arm passing beneath said support, a strap carrier secured to said conveyor and having a home position along the upper arm of said C-shaped figure, said carrier comprising gripping means for gripping an end of strapping material leading from a supply, drive means for driving said conveyor through a complete circuit which moves said carrier from its home position and back to its home position in a single trip, means for completely releasing the gripping means of the carrier from the strap as the carrier passes along the lower arm of the C-shaped figure formed by said conveyor, and means for interrupting said drive means arnd stopping said conveyor when said strap carrier returns to its home position.
References Cited in the file of this patent UNITED STATES PATENTS