US3411471A

US3411471A - Apparatus for production of sealing closures from metal strips

Info

Publication number: US3411471A
Application number: US580721A
Authority: US
Inventors: Bereziat Andre; Podesta Armando
Original assignee: ALUMINIUM FRANCAIS
Current assignee: ALUMINIUM FRANCAIS; L'ALUMINIUM FRANCAIS
Priority date: 1965-09-22
Filing date: 1966-09-20
Publication date: 1968-11-19
Anticipated expiration: 1985-11-19
Also published as: GB1162226A; DE1527912A1; FR1466332A; SE332960B; CH447087A

Description

Nov. 19, 1968 A. BEREZIAT ETAL 1 APPARATUS FOR PRODUCTION OF SEALING CLOSURES FROM METAL STRIPS Filed Sept. 20. 1966 2 Sheets-Sheet 1 INVENTORS FIG. I

FIG. 2

144 5 m a 8 1 5 W 0 n J mam a," Y I A. BEREZIAT ETAL APPARATUS FOR PRODUCTION OF SEALING CLOSURES FROM METAL STRIPS Nov. 19, 1968 2 Sheets-Sheet 2 Filed Sept. 20, 1966 FIG. 3

FIG. 4

FIG. 5

United States Patent 20 Claims. (c1. 113-80) This invention relates to the production of caps or closures for sealing containers. To the present such caps are stamped from blanks in the form of discs or squares cut from metal sheets or strips. The centering of these blanks and the stamping equipment represents a fairly delicate problem which often results in an appreciable amount of defective caps. This makes it necessary to sort the caps for elimination of those which are defective.

It is an object of this invention to provide a method and means for the production of sealing caps of the type described in which the blanks can be accurately centered, in which the production of defective caps, by reason of misalignment in centering, is substantially completely eliminated, in which the proportion of defective caps is greatly reduced and therefore produces caps in higher yield and at lower cost.

These and other objects and advantages of this invention will hereinafter appear and for purposes of illustration, but not of limitation, an embodiment of the invention is shown in the accompanying drawings, in which:

FIG. 1 is a schematic view of a portion of the production line embodying the features of this invention, including the strip feed section, the feed and immobilizing section and the cutting and stamping section;

FIG. 2 is a sectional elevational view of a blank stamped With the equipment in FIG. 1;

FIG. 3 is a schematic View of another portion of the production line which includes the presentation and storage section, the punching and rolling section, and the joint forming section which includes the heating furnace and polymerization of the sealing compound;

FIG. 4 is a plan view of an element employed in the production line in FIG. 3; and

FIG. 5 is a sectional elevational view of the finished cap.

The production line, embodying the features of this invention, starts with a thin metallic strip and comprises:

(1) a feeding device for the thin metallic strip;

(2) a feeding and immobilizing unit;

(3) a cutting and stamping unit;

(4) a presenting and storage unit for the stamped blanks; (5) a punching and rolling unit;

(6) a joint-forming unit; and

(7) a polymerization furnace.

In accordance with the preferred practice of this invention, the feeding and immobilizing unit comprises a fixed electromagnet and a metal magnetic member positioned in face to face relation with the fixed electromagnet to establish clamping engagement therebetween; a movable gripper formed of a movable electromagnet and a member positioned in face to face relationship with the latter to establish a clamping engagement therebetween; a means for imparting reciprocating movement to the movable gripper in the direction of movement of the strip and for closing the gripper during movement of the strip and for opening the gripper during the return phase with the fixed gripper being open during the advancing phase and closed during the return phase.

With reference now to the drawings, the thin metallic strip 90 is normally supplied in the form of a roll 9 Which 3,411,471 Patented Nov. 19, 1968 can be mounted for free turning movement on a spindle extending laterally from a fixed frame. The metal strip '90 is often covered on one surface with a plastic material, such as polyethylene. The strip is unreeled from the roll 9 with the plastic film, when present, on the bottom side of the strip.

The strip 90 first enters the feeding section comprising a lubricating pad 10 positioned to engage the upper, plastic-free face of the metal strip 90. From the pad, the lubricated strip 90 passes between a pair of wind-0E rolls 11 and 21 which are urged to grip the strip therebetween, with at least one of said rolls being a driven roll operatively connected to the electric motor 14. The strip is caused to pass through a free loop 91 and then over a roller 13. Two switches 15 and 16 are positioned on opposite sides of the loop including an upper switch 15 having its sensing member 151 in position to be engaged by the strip when the loop is shortened to operate a microswitch 152 which, when made, starts the motor 14, and a lower switch 16 having a sensing member 161 adapted to be engaged in response to expansion of the loop 91 to open a microcontact 162 operatively connected to stop operation of the motor 14.

The control of the motor 14 can be effected by various known means. For example, as illustrated in the drawings, such control means comprises a memory relay 17 which, upon being actuated, operates to close two

contacts

171 and 172. The current source 9.00 is connected first to the movable armature 173 of the relay 17 and to one of the terminals of the microcontacts 152, and secondly to one of the terminals of the coil 174 of the relay and to the motor 14. The second terminal of the coil 174 is connected to the microcontact 162 with the other terminal connected to the contact 171 of the relay and to the second terminal in microcontact 152 while the contact 172 of the relay is connected to the motor.

The function of the memory relay is as follows: When the loop 91 rises to engage the sensing member 151, contact 152 closes and supplies voltage to the coil 174 of the relay 17, because the microcontact 162 is also closed; the blade 173 is attracted and closes the contacts of the relay. The motor 14, via the contact 172, is set into operation to effect rotational movement of the rollers 11 and 12 with corresponding advance of the strip 90 whereby the loop 91 becomes lengthened and disengages from contact with the sensing member 151 thereby to close the microcontact 152. The coil 174, via the contact 171, remains connected with the voltage and the relay does not change position so that the motor continues to run and the loop 91 continues to descend since the unwinding speed effected by the rollers 11 and 12 is adapted to be greater than the linear speed of the strip 92 taken up by the devices hereinafter to be described. This operation continues until the loop is increased to the point where it engages the sensing member 161 to lower switch 16, thereby breaking the contact 162 and Stopping the supply to the relay. When contact 172 is broken, operation of the motor ceases. Thereafter the loop 91 rises again, as a result of the take-up of the material by the devices hereinafter described, until it touches the sensing member 151 to reactivate the feed.

From the feed section, the strip 92 enters the feeding and immobilizing section 2.

To the present, this section has generally made use of an apparatus based upon the intermittent drive between a pair of rollers guided by proximity detectors. In addition to the desired longitudinal displacement, such apparatus has a serious disadvantage of causing transverse displacement due to the irregularity in the thickness of the strip 92, and this is particularly prevalent when the metallic strip is covered with a plastic film.

Applicants have succeeded in overcoming these disadvantages by the use of gripper type feeding and immobilizing means hereinafter described. The apparatus comprises a fixed gripper member formed of a fixed electromagnet 21 and a mass of magnetic metal 22 positioned in face to face relationship with the fixed electromagnet and mounted for movement in the direction toward and away from the fixed magnet between clamping and unclamping positions; a movable gripper which is formed of a movable electromagnet 23 and a mass of magnetic metal 24 in the form of a clamping member positioned in face to face relationship therewith and movable in the direction toward and away from each other between clamping and unclamping positions respectively. Longitudinal reciprocatory movement is imparted to the movable gripper assembly by various known means, such for example, as illustrated in the drawings, as a rod 25 of magnetic material which reacts to an electromagnet 26 to effect movement in one direction and means, such as a coil spring 27, which engages the end of the rod constantly to urge the rod to move in the opposite direction. The operation of the assembly can be controlled by a relay 28 having a blade which is mounted for movement between a pair of

spaced contacts

282 and 283. The normal contact 282 communicates with the fixed electromagnet 21 while the contact 283 communicates with the movable magnet 23, preferably through a delay device 261. The winding 284 of the relay 28 is activated in response to a signal from the cutting and stamping unit 3 upon completion of a cycle of operation.

The apparatus functions as follows: When there is no current flowing in the winding 284, the contact 282 is made and the contact 283 is broken; the electromagnet 21 is energized so that the element 22 is attracted to clamping position for engagement of the strip 92 therebetween while the clamping members of the movable gripper are open; the strip is held stationary between the fixed gripper elements 21 and 22 while the cutting and stamping unit 3 is operated through a cycle to produce a stamping, as will hereinafter be described. When this operation is completed, the winding 284 is energized. The contact 282 is broken and the contact 283 is made; the electromagnet 21 is no longer energized so that the fixed gripper elements return to their unclamping position to release the strip while the electromagnet 23 is energized to effect movement of the clamping elements 23 and 24 to clamping position to grip the strip therebetween. After a very short delay by the delay device 21, the winding 26 is energized and the rod 25 is actuated for displacement in the forward direction in opposition to the spring 27 to effect corresponding movements of the movable gripper and the strip 92 clamped therebetween. When the signal stops, the electromagnet 23 is de-energized and the electromagnet 21 is energized to close the contact 282 of the relay whereby the movable gripper elements are returned to unclamping position to release the strip while the fixed gripper elements are actuated to clamping position to engage the strip therebetween.

After a time delay by the circuit 261, the winding 26 is de-energized and the rod 25 is returned to its starting position in response to the forces applied by the spring 27 to effect corresponding return movement of the movable gripper.

The cutting and stamping section 3 is of various known constructions. In the drawings, illustration is made of a die 31 cooperating with a punch 32. The die 31 has an internal cavity 310 shaped to correspond to the external surface to be given to the, stamped element while the punch 32 is formed with a male member 320 shaped to conform to the internal surface to be given to the stamped element with the dimensional differences between the surfaces 310 and 320 corresponding to the maximum thickness of the strip 92. The base 310 of the die 31 is formed with an annular cutting edge 311 about the cavity which is adapted to cooperate with the corresponding recess 321 in the punch to sever the stamped element 93 during completion of the stamping operation.

After completion of the stamping operation, a signal is sent to the winding 284 to cause the advance of the strip 92. For this purpose, a contact 33 is positioned to be engaged by the die in response to its return to open position to close the switch for effecting the operations as previously described. The signal can be obtained by other means, such as a photoelectric cell or by photoresistance which detects the completion of the cutting and stamping cycle.

The remaining strip 92 is wound on a reel (not shown) for recovery as scrap.

The stamped members 93 are advanced from the stamping unit to a presenting and storage unit 4. The purpose of this unit is to supply stamped elements to the subsequent apparatus employed in the production line, namely, a punching and rolling unit 5. The stampings are presented at the desired rate with the edge facing upwardly in a position opposite to that shown in FIG. 2.

The presenting and storage unit illustrated in FIG. 3 comprises a hopper 42 having a plate 421 forming a bottom wall and which is mounted for vibratory movement to effect a desired circulation and tumbling actio of the stamped elements. The stampings 93 leave the hopper by way of a discharge chute 423 having one or more small straightening cones or fingers 422 extending downwardly in a bend 424 to limit passage to stamped elements 94 having their rims properly positioned to face upwardly, while holding back those elements which are not so arranged. The latter are subjected to further action of the vibratory plate 421 to elfect tumbling movements which will turn over the stampings.

Stampings which find their way beyond the gate, without being properly aligned, are adapted to be rejected by a rejector device 43 incorporated in the chute 423 and which comprises a trap in the form of a semi-circular slot 431 in the bottom wall and which is illustrated in greater detail in FIG. 4. The stamped elements 94 which are properly oriented are able to slide over the opening for continued travel down the chute while the stamped elements 95 which are upside down or improperly oriented will tilt into the opening 431 to fall therethrough or are otherwise eliminated.

For proper operation of the vibratory plate 421, the height of the hopper 42 should not be too great. In order to insure a sufficient storage, it is desirable to provide a unit having large lateral dimensions. It is possible to avoid the necessity to make use of a unit of large capacity by providing a storage or stacking box 41 in advance of and in communication with the hopper. The box 41 is preferably also provided with a vibratory bottom plate 411 and it is connected to the hopper by a conveyor tube 413. The transport is effected by known means, such as a pneumatic conveyor arrangement with the compressed air entering the assembly through passage 412 for travel in the direction of the arrow to entrain the stamped elements therewith for passage through the tubing 413 to the hopper 42. The stamped elements from the stamping unit 3 fall into the box 41 as indicated by the arrow 414.

Upon leaving the chute 423, the stamped elements 94 pass on to the inlet of a punching and rolling unit 5.

As the punching and rolling unit 5, use can be made of conventional units but his particularly advantageous to make use of the apparatus which is described in US patent application Ser. No. 509,296, filed Nov. 23, 1965, and entitled Apparatus for the Manufacture of Caps from Sheet Material.

In the aforementioned copending application, description is made of a punching and rolling unit comprising a pair of punches 51 and 52 shiftable in the direction toward each other firmly to hold the stamped element by gripping the flat base portion therebetween, and a guide member 53 for engaging the lateral portion of the blank comprising a cylindrical portion 531 and a portion 532 having the form of a quarter torus, and which includes an annular punch 54 surrounding the lower punch 52.

The stamped element or blank 96, upon leaving the chute 423, is positioned on the lower punch 52 with its flat base portion 961 resting on the anvil of the punch and with its edge 962 facing upwardly. The upper portion 51 is then displaced in the direction towards the lower punch firmly to engage the flat base portion 961 therebetween. An upward movement of the annular punch 54 and down Ward movement of the guiding member 53 forms the skirt portion of the stamping to S-shape 972 in the lateral portion nearest the base 971 and it also operates to roll over the edge 973 to form the completed cap 97, as shown in FIG. 5.

The completed cap 97 is transferred by an appropriate transport means, such as a conveyor belt or, as illustrated in the drawings, a pneumatic tube 60 of rectangular crosssection through which the cap is conveyed to the jointforming unit 6 which deposits a plastic sealing material onto the inner face 974 of the rim after which the treated cap is baked at elevated temperature to polymerize the sealing compound and provide a fluid-tight sealing joint for the closure.

The joint-forming unit 6 embodies an applicator for the sealing compound of the type well known to the industry. A suitable apparatus comprises a rotating plate 61 on which the cap 96 is held, as by means of a vacuum in a small pipe or socket 611. The jointing and sealing material is distributed into the interior of the cap by a fixed hollow needle 62 provided with an inner needle 622 which functions as a closure valve. In the event that the material being distributed is of the type which might set during the time that the valve is closed, thereby partially or completely to obstruct the nozzle 621 of the needle, it is possible to overcome this difficulty by providing a small brush mounted to engage the end of the hollow needle after each operation, in which the brush may be secured to form a part of the rotating plate 61.

It is generally desirable to provide a plurality of such joint-forming units for each punching and rolling unit. For this purpose, the joint-forming units can be arranged in a single apparatus with means for re-aligning the formed caps into rows, the number of which will correspond with the aligned joint-forming units for the simultaneous operation of the joint-forming units to apply sealing-jointing compound to each of the caps in the aligned units.

After the sealing compound has been applied, the caps are advanced to a furnace 7 in which the plastic material is melted to insure the adherence while being advanced to the polymerized state.

The complete operation of the appartus is as follows:

The thin metal strip is paid off the roll 9 by the feeding unit 1 at a rate to form the loop 91. The strip 90 is lubricated on its upper side by the lubricating pad 10. When the loop 91 becomes too shallow, the strip touches the upper sensing member 151 with the result that the microcontact 152 is closed and the motor 14 is started for operation of the roller 12 for advancement of the strip. Since the strip is reeled off at a rate greater than the rate of movement of the strip 92 through the stamping cycle, the loop 91 increases until it engages the lower sensing member .161 with the result that the microcontact 162 is broken to shutolf the motor. The feed roller 12 stops and the loop 91 again becomes progressively shorter until it once again touches the sensing member 151.

The accurate advance of the strip 92 is effected by the feeding and immobolizing unit 2. When the cutting and stamping unit has completed its cycle of operation and the die 31 and the punch 32 are separated, contact 33 is made with the result that a signal is sent to the winding 284 of the relay 28. The contact 283 is closed and the movable gripper members 23-24 are displaced to clamping position while the fixed gripper elements 21 and 22 are displaced to unclamping position to release the strip in response to the breaking of the contact 282. After a delay via the device 261, the movable gripper members are advanced to effect corresponding advancement of the strip 92 clamped therebetween. When the cutting and stamping unit commences its cycle, as when the punch 32 and die 31 are displaced in the direction one toward the other, the contact 33 is broken with the result that the relay 28 re-assumes its normal position with the result that the fixed gripper elements are displaced to clamping position to engage the strip therebetween while the movable gripper elements are displaced to unclamping position and return to starting position by reaction of the spring 27. When the punch and die of the cutting and stamping unit are once again operated, upon completion of the stamping operation, the contact 33 is again closed for initiation of another cycle of operation.

The stamped element 93 falls or is otherwise fed into the storage or stacking box 41. It is vibrated by the plate 411 for entrance into the tube 413 through which it is conveyed, in the direction of the arrow 415, by the stream of air supplied by the passage 412 for displacement of the stampings to the hopper 41. In the hopper, the vibrating plate 421 operates to effect tumbling movement of the stampings until they are presented in the upright position shown by the numeral 94 at the inlet of the chute 423 for passage beneath the feeler fingers of cones 422 into the chute. Those in an upright position are able to slide over the opening 431 to the inlet end of the punching and rolling unit 5. Those stampings 95 entering the chute 423 in an inverted position or otherwise improperly oriented are removed when the leading downwardly facing edge enters the circular slot 431.

In the punching and rolling unit 5, the stamped element 96 is gripped between the pair of punches 51 and 52 after which it is pinched by the annular punch 54 while an edge is rolled by the element 973.

The formed cap 97 is conveyed through the tube 60 to the joint-forming unit 6. It is received and held on a rotating plate 61 by vacuum means set up Within the socket 611. The inner needle 622, which functions as a valve for the hollow needle 621, is retracted to open the valve to enable sealing material to flow for distribution at 974 along the inner face of the cap. After a complete rotation, the needle 622 is displaced to close the Valve in hollow needle 621 to stop the flow of sealing material. The brush, when present on the rotating plate, engages the discharge end of the hollow needle to effect a desired cleaning operation. Air is bled into the socket 611 to re lease the suction holding the cap whereby the latter can then be advanced to the furnace 7 for heating the sealing compound to an elevated temperature to wet out the surface and to advance the material to a set stage.

It will be apparent that we have provided a simple and efficient system embodying an arrangement of elements whereby accurate control can be achieved of the movements and of the positioning of the metal strip and blanks stamped therefrom to effect the formation of caps or closures having a minimum proportion of rejections.

It will be understood that changes may be made in the details of construction, arrangement and operation, without departing from the spirit of the invention, especially as defined in the following claims.

We claim:

1. In an apparatus for the fabrication of closure caps from strips of metal, including means for preforming and cutting blanks from the strip, means for forming the preformed blanks to the final shape of the closure and means for applying a sealing compound onto the interior surfaces of the formed closure, a feed device for feeding the metallic strip to the means for preforming and cutting blanks from the strip comprising a pair of wind-off rolls operatively engaging the strip therebetween for advancing the strip responsive to turning movement of the rolls and means for driving at least one of the wind-off rolls, a pair of vertically spaced apart switch operating members between which the strip is looped after passage from between the wind-off rolls, means responsive to engagement of the upper of the switch operating members by the strip to effect operation of the driving means for advancing the strip and responsive to engagement of the lower of the switch operating members by the strip to discontinue operation of the driving means to stop advancement of the strip, a gripper assembly in fixed position beyond the loop and embodying elements movable between clamping and unclamping positions with the strip passing therebetween, a gripper assembly having elements movable between clamping and unclamping positions on the strip passing therebetween and means mounting the gripper assembly beyond the fixed gripper assembly for movement linearly between advanced and retracted positions, means responsive to the operation of the means for preforming and cutting blanks from the strip for operation of the fixed gripper assembly to unclamping position when the movable gripper assembly is in clamping position and for operation of the fixed gripper assembly to clamping position when the movable gripper assembly is in unclamping position and for displacement of the movable gripper assembly from retracted position to advanced position while the movable gripper assembly is in clamping position to advance the strip stepwise to the preforming and cutting means while the latter is in open position, and means constantly urging the movable gripper assembly toward its retracted position.

2. An apparatus as claimed in claim 1 which includes a lubricating member in advance of the wind-off rolls for lubricating the upper surface of the metal strip.

3. An apparatus as claimed in claim 1 in which the switch operating means comprises rnicrocontacts in position to be engaged by the looped strip.

4. An apparatus as claimed in claim 1 in which the fixed gripper assembly comprises a pair of magnetic metal plates between which the strip passes, and in which at least one of the plates is mounted for movement in the direction toward and away from the other between clamping and unclamping positions respectively to engage and hold the strip therebetween, when in clamping position, and to release the strip for free passage therebetween, when in unclamping position.

5. An apparatus as claimed in claim 1 in which the movable clamping assembly comprises a pair of magnetic metal plates between which the strip passes and in which at least one of the plates is mounted for movement in the direction towards and away from the other between clamping and unclamping positions respectively to engage and hold the strip therebetween, when in clamping position, and to release the strip for free passage therebetween, when in unclamping position.

6. An apparatus as claimed in claim 1 which includes a time delay device in the circuit that is responsive to the operation of the preforming and cutting means for delaying the advancement of the movable gripper assembly from retracted to advanced positions until after the movable gripper assembly has been operated to clamping position and which operates to delay the return of the movable gripper assembly from advanced to retracted positions until after the movable gripper assembly has been operated to unclamping position.

7. An apparatus as claimed in claim 1 in which the means constantly urging the movable clamping assembly to retracted position comprises a compression spring.

8. An apparatus as claimed in claim 1 which includes means for storage and feeding the preformed blanks in proper position to the means for forming the cap to final shape from the preformed blank comprising a hopper adapted to hold a plurality of preformed blanks, a movable bottom wall on which the preformed blanks rest in the hopper to cause tumbling movement of the preformed blanks to change the positions thereof, a feed chute in communication with the hopper to which the preformed blanks in the hopper are presented, means at the entrance portion of the chute to block passage of preformed blanks other than single blanks in upright position, and means in a further portion of the chute for removal of improperly positioned blanks which find their way from the hopper into the chute.

9. An apparatus as claimed in claim 8 which includes a storage hopper in advance of the feed hopper, means for agitation of the preformed blanks in the storage hopper and pneumatic means communicating the storage hopper with the feed hopper for conveying separated preformed blanks from the storage hopper to the feed hopper.

10. An apparatus as claimed in claim 9 in which the agitation means comprises a bottom wall to the storage hopper and means for vibrating said bottom wall.

11. An apparatus as claimed in claim 8 in which the feed chute is a tubular passage communicated at one end with the feed hopper. t

12. An apparatus as claimed in claim 8 in which the means at the entrance portion of the feed chute for monitoring the passage of preformed blanks comprises a bend in the feed chute and feelers extending downwardly into the bend to limit passage to single preformed blanks in upright position.

13. An apparatus as claimed in claim 8 in which the means within the chute for removal of inverted preformed blanks comprises a circular slot dimensioned to enable the edge of the inverted blanks to pass therethrough while the base portions of upright blanks are able to slide thereover.

14. In an apparatus as claimed in claim 1 in which the means for introducing a sealing compound into the interior surfaces of the formed closure comprises a rotating plate on which the formed closure is held in upright position and a valve controlled nozzle means for introducing the sealing compound onto the interior surfaces of the formed closure, the improvement which comprises a brush on the rotating plate positioned to engage the outlet end of the nozzle during rotational movement of the plate after the valve has closed to discontinue flow of sealing compound from the nozzle into the closure to wipe off the nozzle.

15. In an apparatus for the fabrication of closure caps from strips of metal, which includes means for preforming and cutting blanks from the strip, forming the preformed blanks to the final shape of the closure and applying a sealing compound onto the interior surfaces of the formed closure, the improvement which comprises means for storage and feeding the preformed blanks in proper position to the means for forming the blanks to final shape comprising a hopper adapted to hold a plurality of preformed blanks, a movable bottom wall on which the preformed blanks rest in the hopper to cause tumbling movement of the preformed blanks to change the positions thereof, a feed chute in communication with the hopper to which the preformed blanks in the hopper are presented, means at the entrance portion of the chute to block passage of preformed blanks other than single blanks in upright position, and means in a further portion of the chute for removal of improperly positioned blanks which find their way from the hopper into the chute.

16. An apparatus as claimed in claim 15 which includes a storage hopper in advance of the feed hopper, means for agitation of the preformed blanks in the storage hopper and pneumatic means communicating the storage hopper with the feed hopper for conveying separated preformed blanks from the storage hopper to the feed hopper.

17. An apparatus as claimed in claim 15 in which the agitation means comprises a bottom wall to the storage hopper and means for vibrating said bottom wall.

18. An apparatus as claimed in claim 15 in which the feed chute is a tubular passage communicated at one end with the feed hopper.

19. An apparatus as claimed in claim 15 in which the means at the entrance portion of the feed chute for monitoring the passage of preformed blanks comprises a bend in the feed chute and feelers extending downwardly into the bend to limit passage to single preformed blanks in upright position.

20. An apparatus as claimed in claim 15 in which the means within the chute for removal of inverted preformed blanks comprises a circular slot dimensioned to enable the edge of the inverted blanks to pass therethrough while the base portions of upright blanks are able to slide thereover.

1 0 References Cited UNITED STATES PATENTS 1,940,188 12/1933 Schweickardt 113--114 2,203,287 6/1940 Smith 113--114 CHARLES W. LANHAM, Primary Examiner.

R. D. GREFE, Assistant Examiner.

Claims

1. IN AN APPARATUS FOR THE FABRICATION OF CLOSURE CAPS FROM STRIPS OF METAL, INCLUDING MEANS FOR PERFORMING AND CUTTING BLANKS FROM THE STRIP, MEANS FOR FORMING THE PREFORMED BLANKS TO THE FINAL SHAPE OF THE CLOSURE AND MEANS FOR APPLYING A SEALING COMPOUND ONTO THE INTERIOR SURFACES OF THE FORMED CLOSURE, A FEED DEVICE FOR FEEDING THE METALLIC STRIP TO THE MEANS FOR PERFORMING AND CUTTING BLANKS FROM THE STRIP COMPRISING A PAIR OF WIND-OFF ROLLS OPERATIVELY ENGAGING THE STRIP THEREBETWEEN FOR ADVANCING THE STRIP RESPONSIVE TO TURNING MOVEMENT OF THE ROLLS AND MEANS FOR DRIVING AT LEAST ONE OF THE WIND-OFF ROLLS, A PAIR OF VERTICALLY SPACED APART SWITCH OPERATING MEMBERS BETWEEN WHICH THE STRIP IS LOOPED AFTER PASSAGE FROM BETWEEN THE WIND-OFF ROLLS, MEANS RESPONSIVE TO ENGAGEMENT OF THE UPPER OF THE SWITCH OPERATING MEMBERS BY THE STRIP TO EFFECT OPERATION OF THE DRIVING MEANS FOR ADVANCING THE STRIP AND RESPONSIVE TO ENGAGEMENT OF THE LOWER OF THE SWITCH OPERATING MEMBERS BY THE STRIP TO DISCONTINUE OPERATION OF THE DRIVINGMEANS TO STOP ADVANCEMENT OF THE STRIP, A GRIPER ASSEMBLY IN FIXED POSITION BEYOND THE LOOP AND EMBODYING ELEMENTS MOVABLE BETWEEN CLAMPING AND UNCLAMPING POSITIONS WITH THE STRIP PASSING THEREBETWEEN A GRIPPER ASSEMBLY HAVING ELEMENTS MOVABLE BETWEEN CLAMPING AND UNCLAMPING POSITIONS ON THE STRIP PASSING THEREBETWEEN AND MEANS MOUNTING THE GRIPPER ASSEMBLY BEYOND THE FIXED GRIPPER ASSEMBLY FOR MOVEMENT LINEARLY BETWEEN ADVANCED AND RETRACTED POSITIONS, MEANS RESPONSIVE TO THE OPERATION OF THE MEANS FOR PREFORMING AND CUTTING THE BLANKS FROM THE STRIP FOR OPERATION OF THE FIXED GRIPPER ASSEMBLY TO UNCLAMPING POSITION AND FOR ABLE GRIPPER ASSEMBLY IS IN CLAMPING POSITION AND FOR OPERATION OF THE FIXED GRIPPER ASSEMBLY TO CLAMPING POSITION WHEN THE MOVABLE GRIPPER ASSEMBLY IS IN UNCLAMPING POSITION AND FOR DISPLACEMENT OF THE MOVABLE GRIPPER ASSEMBLY FROM RETRACTED POSITION TO ADVANCED POSITION WHILE THE MOVABLE GRIPPER ASSEMBLY IS IN CLAMPING POSITION TO ADVANCE THE STRIP STEPWISE TO THE PREFORMING AND CUTTING MEANS WHILE THE LATTER IS IN OPEN POSITION, AND MEANS CONSTANTLY URGING THE MOVABLE GRIPPER ASSEMBLY TOWARD ITS RETRACTED POSITION.