US 2751701 A
Description (OCR text may contain errors)
June 26, 1956 w. F. GRUPE 2,751,701
METHOD AND APPARATUS FOR PRINTING BLOWN BOTTLES Filed May 4, 1955 5 Sheets-Sheet l INVE 'NTOR. l V/fl/d/W 5 Grape June 26, 1956 w. F. GRUPE 2,751,701
METHOD AND APPARATUS FOR PRINTING BLOWN BOTTLES Filed May 4, 1953 5 Sheets-Sheet 2 IN VEN TOR. [MW/am E m,
BY 45W TTORNEY.
June 26, 1956 w. F. GRUPE 2,751,701
METHOD AND APPARATUS FOR PRINTING BLOWN BOTTLES Filed May 4, 1953 5 Sheets-Sheet 5 TORNEK June 26, 1956 GRUPE 2,751,701
METHOD AND APPARATUS FOR PRINTiNG BLOWN BOTTLES Filed May 4, 1953 5 Sheets-Sheet 4 INVENTOR.
6 TORNEX June 26, 1956 Filed May 4, 1953 w. F. GRUPE 2,751,701
METHOD AND APPARATUS FOR PRINTING BLOWN BOTTLES 5 Sheets-Sheet 5 afed INVENTOR.
WWW/am F. rgae BY qzww 77URNEK United States Patent METHOD AND APPARATUS FOR PRINTING BLOWN BOTTLES William F. Grape, Union City, N. 3., assignor to Peerless Roli Leaf Company Incorporated, a corporation or New York Application May 4, 1953, Serial No. 352,865
9 (Ilaims. (Cl. 41-1) This invention relates to improvements in printing blown bottles and refers more particularly to a method and machine for applying advertising indicia upon the exterior surface of plastic bottles having flexible walls.
The art of hot stamping or dry imprinting from a pigment-coated film is well known. To apply printing matter, a heated die is moved into pressure contact with the work which is normally supported on a firm bed to resist the pressure of the die. The pigment-coated leaf lays between the die and the work, and the heat of the die softens the resin binders which are blended with the pigment causing the same to be transferred to the work.
When applying printing matter to plastics such as polyethylene, the heat of the die softens or temporarily brings the plastic beneath the die to a semifluid condition permitting fusion of the pigments and resins into the surface of the plastic, thus serving to provide a permanent bond between the pigment and the plastic. Attempts have been made to imprint polyethylene containers by inflating with compressed air and bringing the die, shaped to the surface of the container, into pressure contact for stamping. stamp the container, the air pressure and die will distort the walls, particularly when the wall sections are not of uniform thickness, and in blown containers or bottles, it is practically impossible to insure uniform wall thickness in production runs.
When employing pre-inflation technique, the normal stamping pressures required are of the order of from 60 to 90 pounds per square inch, and if this pressure is applied to the bottle before the die is brought into contact during the imprinting operation, the container is somewhat enlarged and usually distorted. This variation in size and shape is not uniform, making it practically impossible to provide a die which will accurately fit the contour of the container. Obviously if the die is made to fit the container under normal conditions or before inflation, it will not accurately conform to the container surface after inflation.
Another method in the art of imprinting flexible containers is that in which the die is brought down to the position of stamping contact, at which time air is blown into the bottle. By this method the center line of type up and down the container may stamp satisfactorily, but the balance of the impression is blurred or fuzzy as the surface slides or skids under the die.
A further method of stamping is by crushing the bottle or container on a bed and forcing the top and bottom of the bottle down beyond the level of the bed whereby the two walls of the container .lie flat upon one another on the bed. The die and pigment leaf are then applied to the upper surface of the bottle and a satisfactory transfer .of the printing from the die to the container wall is obtained. This method has been used extensively and is practical, usually .giving good results. Also the bottle may be crushed without bending down the top and bottom beyond the level of ,the bed. In either case the quality, however, may be affected by non-uniformity in wall thick- If enough pressure is used to satisfactorily a Ce ness, a factor which is aggravated because of the twowall thickness which are crushed together upon the bed. An. eifort has been made to compensate for irregularities or non-uniformity in the wall thicknesses by using rubber bed; the method, however, has the basic difficulty that the stamping is restricted to one face of the container at any single imprint and the imprint cannot be carried close to the top or bottom of the container due to the impracticability of flattening the top and bottom sections during the crushing operation.
The instant method is distinguished from those that have gone before in that the die is stationary at the time of stamping and the work is brought into pressure contact with the dye by means of compressed air. Skidding, distortion or uneven inflation of the container is eliminated by holding the bottle in a cavity which closely fits the container under normal pressure conditions, thus a container with a wide variation in its wall thickness will stamp evenly because the pressure against the die is uniform regardless of the thickness of the walls. Furthermore, the pressure at all times being directly vertical to the face of the die prevents the tendency to sideslip or skid. Also, the die surface is shaped to the contour of the container section that is being imprinted. By this method, there is practically no restriction as to the area to be stamped which is a great advantage over crush-stamping. Since dies are fitted into holes formed in both halves of the cavity in which the container is held, there is no movement of the container during the printing operation and indicia from the die is readily transferred to one or both sides of the container without appreciable distortion of the walls of the container during printing. Since the die is separate from the cavity, it may be readily heated to a stamping temperature while the walls of the cavity are cooled by circulation of a cooling medium which prevents searing or marring of the finish of the container during the printing operation.
Basically, therefore, the novelty resides in holding the container in a cavity supplied with a die or dies which cavity sets close enough about the container to prevent stretch, distortion, enlargement and avoids creep under the die while being pressure-imprinted with provision for heating the dies and cooling sections of the cavity surrounding the die or dies considerably below stamping temperatures.
It is therefore the primary object of the present invention to eliminate the difiiculties heretofore encountered and to this end there is provided a novel method and apparatus for effecting the results desired which will be explained in the description which follows.
In the accompanying drawings which form a part of the instant specification and are to be read in conjunction therewith, there is shown an apparatus with which the printing method may be practiced, and in the drawings like reference numerals are used to indicate like parts in the various views.
Fig. l is an elevational end view of the machine;
Fig. 2 is a front elevation of the upper portion of the machine showing the mounting of the printing dies and guides;
Fig. 3 is a view taken along the line 3-3 in Fig. 2 in the direction of the arrows;
Fig. 4 is a view taken along the line 4-4 in Fig. 3
- in the direction of the arrows;
Fig. 5 is a horizontal section taken along the line 5-5 in Fig. 2;
Fig. ,6 is a vertical section taken along the line 66 in Fig. 3;
Fig. 7 is an elevational view of a portion of the rear of the machine showing the ,feed mechanism for the roll leaf;
Fig. 8 is a vertical section taken along the line 8-8 in Fig. 3 in the direction of the arrows;
Fig. 9 is a horizontal section through the printing dies in open position;
Fig. 10 is a horizontal section through the printing dies in closed position;
Fig. 11 is a modified form of toggle mechanism for operating the printing dies.
To facilitate an understanding of the method and apparatus, the description and explanation will be separated into three subdivisions, namely the bottle positioning mechanism, the roll-leaf feed, and the printing mechanism.
Bottle positioning mechanism Referring to the drawings, and particularly to Fig. l, at 15 are shown the legs of a frame upon which the machine is mounted. A horizontal platform or top 15a carries the bulk of the mechanism and below this platform and extending between the legs 15 is a shelf or platform 15b which carries motor 16 and reduction gear 17. The motor 16 drives the reduction gear through pulleys 18, 19 and belt 20. Power is transmitted from the reduc tion gear through sprocket 21, chain 22 and sprocket 23, the latter rotatably mounted on shaft 24 shown in Figs. 1 and 3. A clutch mechanism diagrammatically shown at 25 in Fig. 3 is operated by a foot lever 26 best indicated in Fig. 1. The foot lever 26 is fixedly attached to shaft 27, the shaft being supported on brackets depending from a motor platform 15]). Also fixed to the shaft 27 is a crank 29 having connection through rod 30 with the clutch arm 31 best shown in Fig. 8. Clutch arm 31 is pivoted at 32 to a vertical bracket 33 so that operation of foot lever 26 through the connections mentioned functions clutch arm 31 which in turn completes the driving engagement between sprocket 23 and shaft 24.
. On shaft 24 is fixedly mounted a semi-circular segment 34 and eccentric arm 35 which are the actuating members of a Geneva drive which includes the slotted web 36 fixedly mounted on shaft 37. The latter shaft is carried in bearing brackets 38 shown in Figs. 1 and 3. At the end of eccentric arm 35 is a pin and bearing assembly 35a best shown in Fig. 4 which engages successively the radial slots of web 36 on rotation of shaft 24. During the greater portion of the rotative movement when the bearing 35a is out of engagement with one of the radial slots of the web, and when a bottle is in position to be printed, segment 34 is in bearing engagement with one of the curved surfaces 36a of the web holding the web and shaft 37 rigidly against rotation. Also mounted on shaft 37 is a multi-sided plate in the machine shown as a five-sided plate 39 from which extend tubes or anvils 40. The pentagonal plate 39 has radially drilled ducts 41, each communicating with one of the anvils and short ducts 41a parallel with the axis of the plate providing communication between ducts 41 and duct 42 drilled axially through spacer bushing 43. A gasketed connection between the ducts at the contacting surfaces of plate 39 and spacer 43 furnishes an airtight seal at this point. A radial duct 42a through spacer 43 connects with passageway 42. and has a hose connection 44 for the introduction of compressedair supplied through tube 45. At the extremities of anvils are provided nipples 40a of somewhat smaller diameter adapted to receive the spout ends of bottles or containers 46. The bottles are applied manually to the ends of the anvils in position to be properly engaged by the dies, as will hereinafter be explained.
In order to accurately time the introduction of air into the bottles when they arrive at the printing station, a cam 47 is mounted on the end of shaft 24 shown in Figs. 1 and 3. Rotation of the shaft 24 causes cam 47 to move the pivoted latch 48 against plunger 49 operating an air valve Within the valve body 50. This permits cornpressed air to flow from air supply tube 51 into tube 45 which as previously described is connected to duct 42a in spacer 43. The duct of the anvil at the printing station is the only one aligned with the air duct 42 when the air injection valve is actuated by cam 47. After injection of air into the bottle and completion of the print ing operation, a coil spring returns the plunger and closes the air injection valve and simultaneously permits the pressure built up in the bottle to be exhausted through a relief valve in valve body 50. Release of the air in this fashion takes place between each actuation of the air injection valve by cam 47.
The periodic or interrupted rotation of plate 39 by the- Geneva drive just explained moves the anvils 40 sequent-- tially through a series of stations, at one of these stationsbottles are applied to the anvil adjacent the operator,- at a subsequent station directly opposite the operator as shown in Figs. 3 and 4, the printing operation is performed.
The printing mechanism To operate the dies which have imposed thereon printing inclicia identifying the manufacturer, the class of goods or advertising media, two cams 52 and 53 mounted adjacent cam 47 on shaft 24 operate micro-switches diagrammatically shown at 54- and 55 to function bellows 56 and 57 through solenoids 55 and 59, respectively. As cam 52 is rotated to a position where it rides against the roller 54a of 1nicro-switch 54, the switch energizes: solenoids 53 and 59 which open air valves for the introduction of air behind the pistons in bellows 56 and 57. The movement of the pistons is transmitted through rods 60 and 61 through a toggle mechanism comprising members 62, 63 and 64. Members 62 constitute a exten sion of piston rods 69 and 61 while members 63 and 64 both pivoted at 65 to member 62 transmit the motion of the pistons in opposed directions at right angles to the piston action.
Since the toggle members and die holding plates are identical in their structure and operation, an explanation of one will suffice. Toggle arms 64 besides being pivoted at 65 to member 62 is likewise pivoted at its outer end to pin 66 in boss 67. The boss is carried upon adjusting screw 68 which extends through and is rigidly afiixed to the box-shaped frame 69 and vertical support 70. Adjusting nuts 71 on both the inside and outside of these frame members serve to move the screw and boss inwardly or outwardly with respect to the frame members providing an adjustment for the advancement and retraction of the dies. An oil fitting 72 provides lubrication to the pin 66. Toggle arms 63, besides being pivoted to member 62 at 65, are pivoted to pin 73 carried by an car 74 extending from the outside of plate 75. Plate 75 is insulated from heater block 76 by an insulating plate 77 so the heat from block 76 will not be transmitted to the toggle mechanism and frame of the machine. Also rigidly attached to the outside of plates 75 are two cylindrical guide rods 78 which bear in frames 69 and provide a sliding support for the plates when they are advanced or retracted during the printing operation. The inner face of heater 76 is horizontally grooved to receive the wedge-shaped slide 79a of the die plate 79. Extending from the inner face of the plate is a boss 79b which transmits heat from the heating block 76 to the die 30 affixed to the inner face of the boss. Surrounding the .boss is a jacket 81 through which a cooling medium is circulated being introduced through fitting 82 at the bottom of the jacket and discharged. through a similar fitting atthe top. Hose connection 83 supplies a cooling medium to the bottom of the jacket and similar connection at the top discharges it after it has cooled the cavity and portions of the bottle which surround the printed area.
To change a die 80, it is necessary only to remove holding bar 84 position above slide 79a, lift the slotted strip SSvertically and slide plate 79 and the jacketed cavity e ire-1 ,vioa
"81 horizontally from engagement with heater "bloc-k 76.
simplicity, since such heaters and their controls are of conventional design.
.Roll leaf feed jRoll leaf having applied Lthereon pigment which .is :to be imprinted by the dies is mounted on spools 86 shown in Figs. 2 and 4. The leaf .is fed over through, guide rods 87 and guide slots 81a shown in Fig. 9.immediately above and below the dies. The .leaf strips pass over guide rods 88 positioned below the dies, thence "between the knurled feed rolls S9 and rubber rolls '90. The interrupted feed of the roll leaf across the dies during theprinting operation is governed by the drive of feed rolls 89, and this is synchronized with the Geneva drive which advances the bottles from station to station. The feed roll drive is taken from shaft 24 through an internal cam 91 best shown in Figs. 3 and 6. Rotation of-the cam oscillates yoke 92 which straddles bearing 24a actuatedby a pin bearing 93 extending from the side of the yoke which travels in camway 91a. The oscillation of the yoke is transmitted through arms 94 and 95 to shaft 96 which bears in support 70 and bracket 97. Aflixed to the inner end of shaft 96 is beveled gear '98 which meshes with 'gears 99 and 100. The oscillating movement of yoke :92 is thus transferred from the yoke through .the connections described totcross shaft 161 upon which gear.99 isfixedly mounted and :gear
we rotatively mounted. On one-end of the shaft101is a slotted lever 102 shown .in Figs. and 7 and on .the opposite end a bell crank 103 is fixed to a boss extension of gear 106 best shown in Fig. 2. Lever 102 converts the oscillations of shaft 101 directly to a rack and pinion assembly as shown in Fig. 7 while bell crank 103 transfers the oscillations of the shaft through lever arms 104 and 105 to a similar lever arm 102 mounted on shaft 106 and rack and pinion on the opposite side of the machine. A description of one of these rack and pinion assemblies will therefore sufiice.
Referring to Figs. 5 and 7, oscillation of shaft 101 moves the slotted arm 102 through the segment of a circle and slides rack 107 in the trough or guide plate 108 producing oscillation of pinion 109 and shaft 110 upon which it is fixedly mounted. Also mounted fixedly to the shaft is a plate 111 to which is pivoted a dog 112 shown best in Fig. 5. This dog engages the teeth of gear wheel 113 which is fixedly attached to feed roll 89, both being rotatably mounted on shaft 119. Thus, it will be seen that oscillations of shaft 101 transmitted through the rack and pinion assembly are converted to an interrupted rotative movement of feed rolls 89 through the action of the dogs 112 engaging gears 113. Adjustment of the feed is made at the slotted arms 102.
A modified type of toggle assembly is shown in Fig. 11. In this construction, the piston thrust is transmitted from rods :30, extensions 62 through hell cranks 114, pivoted at 115, thence through levers 116 to toggle members 63 and as which convert the movement of the levers 116 to a horizontal movement of plates 75 to which are attached the heaters and cooling jackets as well as die carrying members previously explained. Coil springs 117 under tension urge the die holding members apart and return the plates to an open position as shown in Fig. 11 after the printing operation has been performed. Guide plates 73a assure proper closing and opening of the die holding members.
In view of the foregoing description and explanation, the operation of the apparatus and method should be obvious. The operator standing in front of the machine applies a plastic bottle to the end of the anvil positioned at the closest and most convenient station, then presses the foot pedal 26. Through the clutch mechanism and Geneva drive the bottles are rotated successively to 'the station between the printing dies where the dies are closed by actuation of the toggle mechanisms. These toggles'are functioned by the bellow pistons which in turn are actuated from cam 47, micro-switches 54 and 55 and solenoid-operated valves connected into the air supply to each bellow. The toggles close and open the die holding members, the latter formed with cavities to fit closely around the bottle when'in a closed position. The dies are mounted on 'heated'bosses 76 and are formed to fit the contour of the'bottle where imprinting 'of the dies is to take place. It will'be noted that a die is held in both members on opposite sides of the'bottle or if desired, but a single side may be printed. In all events, during the printing the die or dies are heated to a predetermined temperature which will indelibly apply the pigment of the roll leaf to the bottle surfaces. These temperatures are accurately regulated by controls previously mentioned. At the same time, the bottle surfaces surrounding the printed areas are kept at relatively normal temperatures by circulation of a cooling medium through the jackets 81.
Timed with the movement of the bottles from station to station and the opening and closing of the die-holding members are two bands or strips of roll leaf which pass between the dies and bottle surfaces in an intermittent feed. This feed, as explained, is from shaft 24 through the internal cam and yoke assembly shown in Fig. 6 and the beveled .gear, rack and pinion and dog assemblies shown in Fig. 5.
When the dies have closed upon the bottle as shown in Fig. 10, cam 47 actuates the air injection valve, evenly expanding the walls of the bottle or container against the dies and walls of the surrounding cooling jackets. In this fashion, there is obtained a smooth e'ven imprint of the dies while the surrounding surfaces of the bottle are snugly held to prevent distortion and marring from the heat applied behind the dies.
From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodmients may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
Having thus described my invention, 1 claim:
1. Transfer applying apparatus for printing indicia on open-mouth containers of the type having a base and flexible side walls, comprising a movable carrier having a plurality of container closures, each constructed to receive and support one of the containers, a container printing station beside the carrier, stop motion drive mechanism for operating said carrier to bring said closures successively into register with said station, die holding members internally shaped to conform with the outer contour of the container at said station, intermittently operated mechanism synchronized with said carrier for positioning said die holding members about each container arriving at said station to embrace the walls thereof, at least one of said die holding members having a printing die on the inner face thereof, and means including a duct through each closure for subjecting a container supported by that closure to internal pressure during the interval that the container is embraced by said die holding members, thereby to urge the container Walls outwardly toward said die holding members and die.
2. Apparatus as in claim 1 having means for continuously heating said die and continuously cooling the balance of said die holding members.
3. Apparatus as in claim 1 having a pigmented strip overlaying the face of the die whereby it is interposed between said die and a portion of the wall of a bottle embraced by said die holding members, and intermittently operated strip feed mechanism for advancing said strip relative to the die in timed relation to the operation of said carrier.
4. Transfer applying apparatus for printing openmouth self-sustaining containers of the type having a base and flexible side walls, comprising die holding members for receiving one of said containers and embracing the side walls thereof, the interior shape of said die holding members conforming to the normal exterior shape of said side walls, thereby to snugly engage the side walls at all points without compressing or distorting the container, at least one of said die holding members having a printing die on its inner surface, a cyclically operating rotative carrier mechanism for introducing containers one after another into said die holding members, and other mechanism synchronized with said first mechanism for subjecting each container in turn to internal fluid pressure through the open mouth thereof during the interval that the container is embraced by said die holding members thereby to urge the container walls into pressure engagement with the interior of the die holding members and printing die.
5. Apparatus as in claim 4 wherein said die holding members form a seat for engaging the base of the container to resist axial thrust on the container when it is subjected to internal fluid pressure.
6. Apparatus as in claim 4 having a pigmented strip overlying the face of the die and interposed between said die and a portion of the wall of the container embraced by said die holding members, and an intermit- 8 tently operated strip feeding mechanism for advancing said strip in timed relation with the operation of said rotative mechanism.
7. A method of printing containers having flexible walls comprising the steps of successively positioning a container between die holding members having cavities closely fitting the outside contour of the container, feeding a pigmented roll leaf between a surface of the container and one of the die holding members, closing the die holding members upon the container and applying pressure within the container to expand it against the walls of the die holding members and roll leaf covered die whereby indicia on the die is transferred to the surface of the container, separating the die holding members, removing the container therefrom and repeating the cycle.
8. A method as in claim 7 wherein pigmented roll leaf is fed between opposite outside surfaces of the container and both die holding members whereby indicia is transferred simultaneously to opposite sides of the container.
9. A method as in claim 7 including the steps of heating portions of the die holding member to which the die is attached and cooling the cavity walls surrounding the die.
References Cited in the file of this patent UNITED STATES PATENTS 1,646,021 Grosser Oct. 18, 1927 1,922,852 Humphrey Aug. 15, 1933 2,203,572 Johnson. June 4, 1940 2,491,947 Bardash Dec. 20, 1949 2,684,775 Von Hofe July 27, 1954