US3899087A

US3899087A - Article positioning mechanism incorporating vacuum holding and pressure ejection

Info

Publication number: US3899087A
Application number: US437382A
Authority: US
Inventors: George D Tamble; Frederick C Olsen
Original assignee: Standun Inc
Current assignee: Sequa Corp
Priority date: 1974-01-28
Filing date: 1974-01-28
Publication date: 1975-08-12
Anticipated expiration: 1992-08-12

Abstract

A vacuum pad, venturi and vacuum line are preferably mounted as a unit, the vacuum line extending from intermediate the venturi to the vacuum pad and providing a vacuum flow at the pad when a main fluid flow is directed through the venturi. An exhaust line for the main fluid flow from the venturi is at least partially closed during selected periods sufficient for forcing main fluid flow through the vacuum line and to the vacuum pad during which fluid is ejected from the vacuum pad and an article previously vacuum gripped by the vacuum pad is ejected therefrom. When the vacuum pad unit is incorporated in an article inserter, a gaseous fluid cushion may be integrated therewith to permit gaseous fluid compression from deliberate over-travel for firmly retaining an article at a working station.

Description

United States Patent 1 1 Tamble et al.

1 1 ARTICLE POSITIONING MECHANISM INCORPORATING VACUUM HOLDING AND PRESSURE EJECTION [75] Inventors: George D. Tamble, San Pedro;

Frederick C. Olsen, Huntington Beach. both of Calif,

[73] Assignee: Standun, Inc., Compton, Calif,

{22] Filed: Jan. 28, I974 [21] App]. No.: 437,382

OTHER PUBLICATIONS RCA TN. No. 48 2 sheets Pneumatic Transfer Device Troup et al.

[ Aug. 12, 1975 Primary ExuminerFrank E. Werner Attorney, Agent, or FirmMahoney, Schick & Cislo [57] ABSTRACT A vacuum pad, venturi and vacuum line are preferably mounted as a unit, the vacuum line extending from intermediate the venturi to the vacuum pad and providing a vacuum flow at the pad when a main fluid flow is directed through the venturi. An exhaust line for the main fluid flow from the venturi is at least partially closed during selected periods sufficient for forcing main fluid flow through the vacuum line and to the vacuum pad during which fluid is ejected from the vacuum pad and an article previously vacuum gripped by the vacuum pad is ejected therefrom. When the vacuum pad unit is incorporated in an article inserter, a gaseous fluid cushion may be integrated therewith to permit gaseous fluid compression from deliberate over-travel for firmly retaining an article at a working station.

6 Claims, 16 Drawing Figures PATENTED AUB I 2 I975 Fig. 3.

PATENTED AUG 1 2 i975 SHEET PATENTEU M18 1 21975 O O n \r W mm 2 PATENTEB AUG 1 2 I975 VH wilt om mm ARTICLE POSITIONING MECHANISM INCORPORATING VACUUM HOLDING AND PRESSURE EJECTION BACKGROUND OF THE INVENTION:

This invention relates to an article positioning mechanism incorporating vacuum holding and pressure e jection which may be used in many assemblies where vacuum holding is required, yet positive release at a determined moment or location is essential or desirable. Furthermore, with the mechanism of the present invention, the vacuum holding and positive release features are incorporated in a structure of maximum simplicity and despite such simplicity, is still fully serviceable in repeated operation over a long period of life. Still further, the basic mechanism of the present invention is of a highly versatile nature and may be freely adapted to many uses where the combined positive vacuum holding and positive release or pressure ejection requirements are present.

There are many occasions in modern technology wherein vacuum holding coupled with positive release is required or may be advantageously used. This is particularly true in various mass production manufacturing equipment and production lines, for instance, raw materials being fed automatically into one end of a production line, semi-formed articles produced therefrom transferred automatically from one manufacturing machine to the next along the length of a multiple manufacturing operation line and the finished articles received at the end of the manufacturing line, in many cases, even in a final packaged form. In such manufacturing lines, a multiplicity of forms of manufacturing machines are used and may include rotating part positioning tables, continuous part transporting and various forms of inserters for positioning a part within a manufacturing machine for the various operations thereon and the removal therefrom during continuous part movement along the production line.

A prime example of the use of the unique vacuum holding and pressure ejection principles of the present invention, as fully illustrated herein, is in the high speed, mass production of metallic can bodies useable in final form for containing various beverages. The can bodies are of one piece sidewall and bottom wall construction and are formed of aluminum or tin plate, dependent on the ultimate use thereof. Furthermore, in a modern can body manufacturing line, these can bodies are produced at a rate of between two and three per second with the final metal thickness therein being in the order of five one-thousandths to seven onethousandths inches. Thus, it can be easily understood that the can bodies can be easily damaged in production line automatic handling due to the fragility thereof and although large forces are not required for the movement and transporation due to the lightness thereof, this same lightweight characteristic can present problems in the release of can bodies at a particular location and moment from production line transfer equipment.

In a continuous metallic can body production line, after various blank and draw, and wall ironing operations, the can bodies are in their final thinwall, cup shaped form with the exception that the sidewalls of the can bodies must be trimmed to final exact length. With the continuously moving production line requirements in mind, it can be envisioned that high speed, precise can body transfer problems are presented, the solution to which may include the optimum features of the vacuum holding and positive release of the present invention. The lightweight, thinwalled, metallic can bodies must be continuously fed to a trimmer location, removed, one at a time, from the transporting means and conveyed to a trimming mandrel, firmly retained on the trimming mandrel during the trimming operation, and finally removed after trimming completion back to the transporting means for conveyance away from the trimmer.

Prior to the present invention, these can body transfer operations have been accomplished by vacuum actuated inserters. The can bodies are conveyed to the trimmer location aligned with the open ends of these cylindrical, cup shaped can bodies facing a trimming mandrel and the closed bottom ends thereof engaged by a vacuum pad or cup of a linearly reciprocal inserter, the inserter moving to vacuum engage the can body closed end, carry the can body to the trimming mandrel telescoping the same thereon, retain the can body on the trimming mandrel during the trimming operation and, still with the vacuum retention, withdraw the can body from the trimming mandrel returning the same to the original pick up station for conveyance away from the trimmer to a subsequent station.

One of the major difficulties encountered has been the release of the finally trimmed can bodies from the vacuum actuated inserter at the pick up station after the trimming operation has been completed and the can body returned to such pick up station. It has been found that due to the extreme light weight of the can bodies coupled with relatively strong vacuum holding being required during the can body transportation and trimming makes it relatively difficult to cleanly break the vacuum holding forces when the can body release is required. Furthermore, with the extremely high speeds involved, it must be appreciated that not only theh transportation of the can bodies to and from the trimmer be completely positive, the release thereof from the vacuum actuated inserter must be instantaneous and accurate in order that the can bodies, once released, will be properly aligned in the conveying or transporting mechanisms for movement away from the trimmer to the next manufacturing operation.

OBJECTS AND SUMMARY OF THE INVENTION It is, therefore, an object of this invention to provide an article positioning mechanism incorporating vacuum holding and pressure ejection wherein virtually the same elements of the mechanism are used to first produce an efficient vacuum holding and are then used to produce an efficient pressure ejection, thereby producing the unique dual action with an overall mechanism of maximum simplification. According to certain of the principles of the present invention, the vacuum force for a vacuum pad is supplied by use of a positive pressure fluid from through a venturi, the reverse pressure or vacuum flow being produced in a vacuum line connected communicating intermediate the venturi in the usual manner. However, the vacuum flow in such vacuum line is reversed and turned into a positive pressure fluid flow for pressure ejection by a partial or full closing of the normal fluid exhaust from the venturi without otherwise altering the overall mechanism.

It is a further object of this invention to provide an article positioning mechanism incorporating vacuum holding and pressure ejection which is readily adaptable to many vacuum holding positive pressure release uses, all of which may incorporate the same basic unique and simplified mechanism. For instance, the basic mechanism of thc present invention may be used at stationary, single work positioning stations, or on continuously rotating, multistation work positioning tables. At the same time, these same mechanisms may be used in workpiece inserters such as the inserters for can body trimmers as hereinbefore discussed.

It is still a further object of this invention to provide an article positioning mechanism incorporating vacuum holding and pressure ejection which includes all of the foregoing basic advantageous qualities of highly simplified construction and ready adaptability to various important uses, yet is capable of precise timed control for both the vacuum holding and pressure ejection features. As hereinbefore pointed out, the change from vacuum holding to pressure ejection may be accomplished simply by covering the main fluid flow exhaust from the venturi, this simple operation producing the reverse fluid flow in the vacuum tube and producing the fluid positive flow therein. Thus, the timing of such change is of an extremely simple nature and will always function at the exact instant desired.

It is an additional object of this invention to provide an article positioning mechanism incorporating vacuum holding and pressure ejection which is particularly adaptable to modern mass production manufacturing lines wherein product part transfers and positioning are of the required precise nature operable at high speed over an extended period of continuous use. For instance, in modern can body production lines as hereinbefore discussed, and particularly can body inserters for trimmers, the can bodies may be efficiently vacuum gripped during transportation thereof between the transporting or conveying mechanisms and the trimming mandrel and with the simple control of the pressure ejection conversion, the can bodies may be redeposited in the transporting mechanism after trimming with the maximum of precise positioning. At the same time, in this can body trimming operation use of the principles of the present invention, since pressurized fluid, preferably gaseous fluid such as air, is used for the provision of both vacuum and pressure ejection, this same pressurized gaseous fluid may be used to additionally provide a cushioning force for the inserter during retention of a particular can body on the trimming mandrel, all in a manner to be hereinafter particularly described.

Other objects and advantages of the invention will be apparent from the following specification and the accompanying drawings which are for the purpose of illustration only.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a typical metallic can body trimmer making use of a can body inserter incorporating an embodiment of the article positioning mechanism principles of the present invention;

FIG. 2 is a top plan view of the can body trimmer of FIG. 1 with parts broken away and looking in the direction of the arrows 2-2 in FIG. 1;

FIG. 3 is a vertical sectional view of the can body trimmer of FIG. I looking in the direction of the arrows 3--3 in FIG. 2;

FIG. 4 is an enlarged, fragmentary, top plan view looking in the direction of the arrows 44 in FIG. 1 and showing the can body inserter in fully retracted position;

FIG. 5 is an enlarged, fragmentary, vertical sectional view looking in the direction of the arrows 5-5 in FIG. 4 and showing a rearward portion of the can body inserter;

FIG. 6 is an enlarged, fragmentary, vertical sectional view looking in the direction of the arrows 6--6 in FIG. 4 showing a forward portion of the can body inserter;

FIG. 7 is a vertical sectional view similar to FIG. 6 and showing the can body inserter advanced forwardly in its forward stroke just contacting a metallic can body for movement thereof to the trimming mandrel;

FIG. 8 is an enlarged, fragmentary, vertical sectional view looking in the direction of the arrows 8-8 in FIG. 2 showing the drive and trimming portion of the can body trimmer of FIGS. 1 through 3 and showing the can body inserter at the forward end of its forward stroke retaining a metallic can body of the trimming mandrel during the trimming operation;

FIG. 9 is a vertical sectional view looking in the direction of the arrows 9-9 in FIG. 5 showing a portion of the fluid supply and drive connections to the can body inserter of FIGS. 5 and 6;

FIG. 10 is a fragmentary, vertical sectional view looking in the direction of the arrows 10-40 in FIG. 9 further showing a portion of the fluid supply and drive connections to the can body inserter of FIGS. 5 and 6, the inserter being in fully retracted position.

FIG. 11 is a view similar to FIG. 10 with the can body inserter in fully forward or extended position for retaining the can body on the trimming mandrel as in FIG. 8',

FIG. 12 is a vertical sectional view similar to FIGS. 6 and 7 showing the can body trimmer incorporating a second embodiment of the principles of the present invention, the inserter being in fully retracted position; and

FIGS. 13 through 16 are somewhat diagrammatic, fragmentary, vertical sectional views of the can body inserter of FIG. I through 12 illustrating the inserter reciprocal movement from fully retracted through trimming mandrel positioning back to fully retracted for engaging a can body at transportation means, carrying the can body to and positioning it on the trimming mandrel during the trimming operation and withdrawing the trimmed can body repositioning it on the transportation means.

DESCRIPTION OF THE BEST EMBODIMENTS CONTEMPLATED As has been hereinbefore pointed out, the article positioning mechanism principles of the present invention are particularly adaptable to and advantageously usable in a metallic can body inserter of a metallic can body trimmer and the principles of the present invention are therefore illustrated and described hereinafter in such use. It is not intended, however, to limit the principles of present invention thereby beyond the limitation clearly defined in the appended claims. Furthermore, the various elements of the metallic can body trimmer may be constructed by usual fabrication methods and from usual materials appropriate for the ultimate use and all well known to those skilled in the art.

Referring for the moment to FIGS. 1 through 3 and 8, the metallic can body trimmer forming the environment for the can body inserter incorporating the principles of the present invention is somewhat briefly shown and includes a main frame generally indicated at mounting a feed and positioning assembly generally indicated at 22, a trimming assembly generally indicated at 24 and a scrap disposal assembly generally indicated at 26, all integrated and controlled for carrying out the metallic can body trimming operation through a control panel generally indicated at 28. The articles to be trimmed are one piece, cup-shaped, metallic can bodies 30, each having a cylindrical sidewall terminating at one end in an integral bottom wall and opening at the opposite end, all in usual form. The can bodies in untrimmed form are fed to the trimmer for the trimming operation, the trimming operation consisting of evenly trimming the can body sidewalls at the open ends thereof to precise determined length, with the trimmed can bodies existing from the trimmer.

The trimmer will usually form a part of a continuous can body production line and the can bodies 30 are fed to the trimmer from preceding conveyor means (not shown) into an infeed guide 32 of the feed and positioning assembly 22, the can bodies being positioned with their main axes horizontal, the open ends thereof to the right and the closed ends to the left as shown in FIGS. 1 and 2. With the can bodies 30 thusly resting on the cylindrical sidewalls thereof, they are vertically stacked, one above the other in the infeed guide 32.

From the infeed guide 32, the can bodies 30 are received, one at a time, downwardly in pockets 34 of a rotatably indexing star wheel 36 where they are carried, again one at the time, by intermittent star wheel indexing movements to a feed station generally indicated at 38. Between the movements of the star wheel 36, each can body 30 is positioned at the feed station 38 axially aligned with an inserter generally indicated at 40 of the feed and positioning assembly 22 and a trimming mandrel 42 of the trimming assembly 24, the can body bottomwall facing the inserter and the can body open end facing the trimming mandrel. The inserter 40 is the mechanism of the trimmer which incorporates the article positioning mechanism principles of the present invention and will be described in detail hereinafter subsequent to this brief description of the trimmer construction and general operation.

With one of the can bodies 30 positioned at the feed station 38, that can body is removed from the star wheel pocket 34 by forward advancement of the inserter 40 or movement of the inserter to the right as shown in FIGS. 1 and 2, with the can body ultimately being positioned by the inserter telescoped over the trimming mandrel 42 as shown in FIG. 8 While positioned at the trimming mandrel 42, the can body 30 is trimmed by appropriate metal trimming apparatus of the trimming assembly 24 and the trimmed scrap metal is appropriately severed into scrap pieces 44 by elements of the scrap disposal assembly 26 where they fall downwardly for elimination through the scrap chute 46. After this trimming operation has been completed, the particular can body 30, now trimmed, is withdrawn from the trimming mandrel 42 by rearward movement of the inserter 40 and returned to the feed station 38 into the pocket 34 of the star wheel 36, the star wheel ultimately indexing and ultimately depositing the trimming can bodies into the outfeed guide 48 for exit by gravity into a further conveying means (not shown) of the can body production line.

As hereinbefore alluded to, the can body trimmer just briefly described forms the environmental background for the inserter 40 incorporating an embodiment of the article positioning mechanism principles of the present invention and the particulars of the inserter are clearly shown in FIGS. 4 through 11. Referring thereto, the inserter 40 includes movable frame means in the form of a tubular member 50 mounted reciprocal in a stationary sleeve 52, the latter being flanged at a forward end thereof or to the right as shown and secured to an element of the trimmer main frame 20. A guide bar 54 is secured to a rearward portion of the stationary sleeve 52 and extends rearwardly over the tubular member 50 spaced thereabove with a downwardly opening guide slot 56 of the guide bar exactly forwardly and rearwardly aligned with the path of travel of the reciprocal stationary sleeve.

A venturi assembly generally indicated at 58 is threadably secured partially telescoped by the forward end of the tubular member 50 and as best seen in FIGS. 6 and 7 includes a venturi body 60 having a main fluid flow passage therethrough comprised of a fluid inlet 62 communicating rearwardly into the interior of the tubular member 50, a somewhat conventional venturi 64 and a fluid exhaust outlet 66, the latter exhaust outlet opening generally radially of the venturi body through a body cylindrical surface 68. Furthermore, a fluid jet or nozzle is secured within the fluid inlet 62 projecting forwardly into the venturi 64, the exact construction of the venturi and jet or nozzle and their relative positioning being well known to those skilled in the art. Still further, the venturi body 60 includes a vacuum passage or line communicating rearwardly intermediate the venturi 64 in well known manner and communicating forwardly through a vacuum nozzle 72 and centrally of a vacuum pad, in this case a vacuum cup 74 secured to the forward end of the body 60 spaced forwardly of the tubular member 50.

For important purposes of the present invention as will be hereinafter explained in detail, a fluid diverting collar 76 is secured to the stationary sleeve 52 telescoping the forward and rearward path of travel of the reciprocal inserter 40 fluid sealed against the movable tubular member 50. When the inserter 40 is in fully retracted position as shown in FIG. 6 the vacuum pad or cup 74 is forwardly adjacent the fluid diverting collar and the venturi body cylindrical surface 68 is radially outwardly abutting an inner surface of the diverting collar. A plastic sealing ring 78 is radially outwardly recessed within the fluid diverting collar 76 at the inner surface thereof, and most important, with the inserter 40 in its rearward fully retracted position as shown in FIG. 6, the fluid diverting collar 76, through the sealing ring 78 radially covers and seals off, preferably totally, the fluid exhaust outlet 66 of the venturi assembly 58, but when the inserter 40 is in any forward position of its path of travel, whether moving forwardly or rearwardly, wherein the fluid exhaust outlet 66 of the venturi assembly 58 is removed forwardly from the fluid diverting collar 76, free fluid passage from the fluid exhaust outlet is permitted as illustrated in FIG. 7.

The overall result of this unique arrangement of the venturi assembly 58 of the inserter 40 and the stationary fluid diverting collar 76 is that when the inserter 40 is in any of its forward positions in its reciprocal path of travel wherein the fluid exhaust outlet 66 of the venturi assembly 58 is forwardly free of the fluid diverting collar 76, for example as shown in FIG. 7, free flow of pressurized fluid from the interior of the tubular member 50 forwardly through the fluid inlet 62, venturi 64 and from the fluid exhaust outlet 66 creates a reverse vacuum flow in the vacuum passage 70, in turn, creating a vacuum flow from or a vacuum within the vacuum cup 74. This would be the usual well known use of the venturi assembly 58. However, when the inserter 40 directly approaches and is finally in its fully retracted position wherein the fluid exhaust outlet 66 of the venturi assembly 58 is for the major portion or totally covered and closed off or blocked by the fluid diverting collar 76, for instance as shown in FIG. 6, the main fluid flow through the venturi assembly 58 cannot exhaust from the fluid exhaust outlet 66 so that the reverse fluid pressure created by such blockage destroys the vacuum producing properties of the venturi 64 ceasing the reverse vacuum flow through the vacuum passage 70 and forces a positive pressure fluid flow reverse forwardly through the vacuum passage 70 and from the vacuum cup 74. Thus, a vacuum flow for vacuum gripping of the vacuum cup 74 during any forward positioning of the inserter 40 with the fluid exhaust outlet 66 free of the fluid diverting collar 76, and a positive pressure ejecting fluid stream from the vaccum cup 74 when the inserter 40 is nearly or fully rearwardly retracted with the fluid exhaust outlet 66 covered by the fluid diverting collar 76.

Referring for the moment of FIGS. 4, 5, 9, 10, and 11, the tubular member 50 of the reciprocal inserter 40 has a guide collar assembly 80 secured to the periphery thereof near the tubular member rearward end which includes an upstanding guide 82 forwardly and rearwardly movably received in the guide slot 56 of the stationary guide bar 54 so that the inserter 40 is precisely guided in its reciprocal movements. Furthermore, a drive piston 84 is slidable within the rearward end of the inserter tubular member 50 with a transverse or diametrically extending drive bar 86 beieng secured through the piston and projecting transversely or diametrically oppositely through clearance slots 88 in the walls of the inserter tubular member 50. The opposite ends of the drive bar 86 are pivotally connected to a pair of pivotal drive arm assemblies 90 appropriately connected to the main drive assembly (not shown) of the trimmer for transmitting the reciprocal motion to the drive bar 86 and, in turn, to the inserter tubular member 50, the latter power connection to be hereinafter explained more in detail.

As may be most clearly seen in FIGS. and 9, a fluid supply hose, preferably a gaseous fluid supply hose 92 constantly supplying a flow of pressurized gaseous fluid, such as air, is connected communicating through one end of the transverse drive bar 86 into a fluid supply passage 94 of the bar which, in turn, communicates centrally of the drive piston 84 with a forwardly extending fluid supply passage 96 opening forwardly of the piston into the interior of the inserter tubular member 50. Thus, with pressurized fluid, preferably gaseous fluid such as air as stated, constantly flowing from the fluid supply hose 92, through the drive bar 86 and the piston 84 forwardly into the interior of the inserter tubular member 50 and ultimately forwardly and through the venturi assembly 58, the venturi assembly will be provided with a constant supply of such pressuried gaseous fluid, while at the same time, the gaseous fluid being pressurized will exert a rearward force against the piston 84 reacting from the immovable venturi assembly 58 which will force the piston 84 rearwardly the extent of drive bar 86 within the tubular member clearance slots 88 to the position shown in FIG. 10. In other words, the gaseous fluid supply must be under a sufficient determined pressure so that even when there is full fluid flow through the venturi assembly 58 or when this fluid flow is not obstructed by the fluid diverting collar 76, there will always be a full supply of pressurized fluid in the diverter tubular member 50 and the same will always be maintained at a determined positive pressure.

Normally, therefore, the drive piston 84 will be maintained by the pressurized gaseous fluid within the inserter tubular member 50 at its rearward position in the tubular member as determined by the drive bar 86 testing rearwardly against the rearward extremities of the tubular member clearance slots 88. The pressure of the pressurized gaseous fluid is maintained within the inserter tubular member 50 sufficiently high so that reciprocal movements of the drive arm assemblies 90 will be transmitted through the drive bar 86, the drive piston 84 and into the inserter tubular member 50, thereby normally reciprocally driving the inserter 40 in its forward and rearward precise reciprocal movements. When, however, the inserter vacuum cup 74 meets a solid obstruction during forward movement of theinserter 40 sufficient to overcome the contained pressure of the pressurized gaseous fluid within the inserter tubular member 50, the pressurized gaseous fluid within the inserter tubular member can compress by forward slidable movement of the piston 84 within the tubular member until the drive bar 86 reaches the forward extremities of the tubular member clearance slots 84, a commencement of such relative movement being illustrated in FIG. 11. This thereby provides a limited yieldable cushion for the inserter 40 during forward movement thereof.

The more detailed operational steps of the inserter 40 incorporating the unique article positioning mechanism principles of the present invention are illustrated in sequence in FIGS. 13 through 16. Coordinating these operational steps with the general operation of the. metallic can body trimmer, assume that an untrimmed can body 30 has been moved to the feed station 38 positioned axially aligned with the trimming mandrel 42 spaced to the left thereof as shown in FIG. 13. At this stage, the inserter 40 is in fully retracted position as shown and the fluid diverting collar 76 is covering the fluid exhaust outlet 66 of the venturi assembly 58 causing a positive flow of gaseous fluid from the inserter vacuum cup 74 which is regulated by the vacuum nozzle 72 sufficiently small in force so as not to disturb, at this time, the can body 30.

As shown in FIG. 14, the inserter 40 has begun its forward stroke in its reciprocal movement and the fluid exhaust outlet 66 of the venturi assembly 58 is removed from the fluid diverting collar 76 so that there will be the usual reverse vacuum flow in the venturi assembly vacuum passage creating vacuum at the vacuum cup 74. As the inserter 40 contacts the can body 30, therefor, the can body will be vacuum gripped by the inserter vacuum cup 74 and the continuing movement of the inserter will commence movement of the can body from the star wheel 36 and the feed station 38. Since the can body 30 is relatively freely removable from the star wheel 36 and presents only a slight resistance force, there is not sufficient force rearwardly to the inserter tubular member 50 which could cause any compression of the pressurized gaseous fluid therein and the inserter piston 84 remains at its rearward relative position determined by the drive bar 86 engaging the rearward extremities of the tubular member clearance slots 88.

As shown in FIG. 15, the inserter vacuum cup 74 vacuum gripping and forwardly urging the can body 30 telescopes the can body over the trimming mandrel 42 of the trimming assembly 24 with the can body being urged forwardly by the inserter 40 until the bottomwall of the can body firmly forwardly engages the trimming mandrel. The forward stroke of the inserter 40 is arranged such that there is a slight overtravel of the inserter and the vacuum cup 74 thereof, that is, if the can body 30 and the trimming mandrel 42 were not present, the inserter 40 could move slightly forwardly a greater distance than the bottomwall of the can body when firmly seated against the trimming mandrel. Thus, as shown in FIG. and also in FIG. 11, immediately after the bottomwall of the can body 30 seats forwardly firmly against the trimming mandrel 42, this tendency of overtravel of the inserter 40 causes the inserter drive arm assemblies 90 to move slightly further forwardly causing the drive bar 86 to move the piston 84 slightly further forwardly relative to the inserter tubular member 50 compressing the pressurized gaseous fluid within the tubular member and moving the drive bar slightly forwardly in the tubular member clearance slots 88. A positive holding pressure is, thereby, exerted against the can body 30 firmly forwardly pressure retaining the can body on the trimming mandrel 42 during the trimming operation.

Upon completion of the trimming operation at the trimming mandrel 42, the inserter 40 begins its rearward stroke with the vacuum gripping by the inserter vacuum cup 74 utlimately removing the now trimmed can body 30 from the trimming mandrel 42 and returning the can body to the star wheel 36. At the initiating of this rearward movement in the commencement of the inserter rearward stroke, the overtravel pressure force is removed from the inserter 40 so that the pressurized gaseous fluid within the inserter tubular member 50 returns the piston 84 rearwardly until the drive bar 86 engages the tubular member 50 at the rearward extremities of the tubular member clearance slots 88. The inserter 40 with the continued vacuum gripping of the now trimmed can body 30 by the vacuum cup 74 continues to draw the can body rearwardly within the star wheel 36 until the fluid exhaust outlet 66 of the venturi assembly 58 is sufficiently covered by the fluid diverting collar 76.

As shown in FIG. 16, the gaseous fluid flow in the vacuum passage 70 of the venturi assembly 58 has been reversed by the covering of the fluid exhaust outlet 66 by the fluid diverting collar 76 and a positive pressure flow of gaseous fluid is being directed from the inserter vacuum cup 74. This action positively releases or pressure ejects the now trimmed can body 30 from gripping by the inserter 40 and seats the can body in the star wheel 36 ready for transportation away from the feed station 38. Indexing of the star wheel 36 carries the now trimmed can body 30 away and positions the next untrimmed can body 30 at the feed station 38 as in FIG. 13 and the overall action of the inserter 40 is repeated.

A slightly modified second embodiment of the inserter 40 incorporating the same unique principles of the article positioning mechanism of the present invention is shown in FIG. 12 and the modifications in this 5 second embodiment relate soley to the mounting of the inserter tubular member 50, more particularly, the formation of the fluid diverting means. The inserter tubular member 50 and venturi assembly 58 therein are formed substantially the same as previously described. Furthermore, the general reciprocal mounting of the tubular member 50 including the stationary sleeve 52 mounting the inserter 40 on the main frame is substantially the same.

However, in this second embodiment. the fluid diverting means is a slightly altered fluid diverting collar 98 similarly secured to the stationary sleeve 52 telescoping the tubular member 50 and venturi assembly 58 forward and rearward reciprocal path of travel. As shown in FIG. 12, this fluid diverting collar 98 includes a rearward stationary collar section 100 partially forwardly telescoping a forward threadably adjustable collar section 102, the forward section covering, but remaining spaced slightly radially outwardly from the venturi body cylindrical surface 68 and fluid exhaust outlet 66 when the inserter 40 is in its fully retracted position. Thus, an annular chamber 104 is formed inwardly of the fluid diverting collar 98 surrounding the forward extremity of the inserter tubular member 50 and the venturi assembly 58 rearwardly of a slightly modified vacuum pad or cup 106 when the inserter 40 is in its fully retracted position.

This annular chamber 104 is maintained rearwardly sealed by the same sealable mounting of the tubular member 50 in the fluid diverting collar 98 and main frame 20 as previously, that is, a slidable sealed mounting. With the inserter 40 in its fully retracted position, the annular chamber 104 is forwardly sealed by a resilient O-ring 108 carried in an annular groove 110 surrounding the vacuum pad or cup 106 which bears rearwardly against the forward extremity of the forward adjustable collar section 102 of the fluid diverting collar 98 as shown. The annular chamber 104 is, therefore, effectively sealed off in this inserter fully retracted position for closing off the fluid exhaust outlet 66 of the inserter venturi assembly 58 and converting the vacuum gripping of the vacuum pad or cup 106 to the positive fluid flow or pressure ejection as hereinbefore described.

With this modified form of fluid diverting collar 98 in this second embodiment, however, it is apparent that as the fluid exhaust outlet 66 of the inserter venturi assembly 58 enters this modified fluid diverting collar 98 and the annular chamber 104 formed thereby, the reaction of closing off the fluid exhaust outlet of the venturi assembly will be very slightly delayed as required by the fluid filling of the annular chamber, although the action thereof can be perfectly timed. An added feature is that the forward section 102 of the fluid diverting collar 98 is threadably adjustable relative to the rearward section 100 so that the moment of covering of the venturi fluid exhaust outlet 66 and thereby the conversion of the venturi assembly 58 from vacuum gripping to positive pressure ejection can be adjustably selectively varied. Other than these foregoing slight modifications and changes, the inserter 40 is operable in the identical manner and provides the same unique results as hereinbefore described.

According to the present invention, therefore, an ar ticle positioning mechanism is provided incorporating vacuum gripping or holding and pressure ejection, a unique dual action, in a highly simplified construction. As illustrated herein, vacuum gripping for the inserter vacuum cup 74 is provided by the usual vacuum flow from a usual venturi assembly 58, but by uniquely ar ranging the fluid diverting collar 76 for closing off the fluid exhaust outlet 66 of the venturi assembly at an appropriate moment, the same venturi elements are converted such that a positive pressure fluid flow is emitted from the vacuum cup, converting the vacuum gripping to pressure ejection by the vacuum cup. This simplifled, dual acting structure has been advantageously applied herein to the trimmer of a metallic can body mass production line.

It is evident, however, that these precise timing, dual action, article positioning mechanism principles may be readily applied to many uses where vacuum gripping and pressure ejection are alternately required. The precise timing between the vacuum gripping and pressure ejection is solely dependent on the relative positioning of the fluid diverting means relative to the fluid exhaust outlet of the venturi assembly, whether the venturi assembly is relatively movable or otherwise. in the particular embodiment illustrated, the fluid diverting collar 76 is mounted stationary and the venturi assembly 58 is movable in a defined path, but if other requirements were presented, the reverse of relative movement could be used or a diverting means other than a collar could be used, all incorporating the same basic unique principles.

Still further, with the dual vacuum holding and pressure ejecting principles of the present invention applied to an inserter 40, similar devices being used for many purposes other than that illustrated herein, the inserter cushioning principles can likewise be applied to these other inserter uses. As is evident from the present inserter embodiment thereof, these unique cushioning effect principles are easily added where positive pressure flow of gaseous fluid is used to produce the inserter vacuum gripping and pressure ejection. Such additions for the unique cushioning are of an extremely simple form and may be provided at a minimal additional expense.

We claim:

1. In a vacuum supplied gripping device for selectively vacuum retaining workpieces; the combination of: vacuum pad means for contacting and vacuum gripping a workpiece upon vacuum being supplied thereto; a venturi normally having a full main fluid flow therethrough and exhausting therefrom; vacuum line means communicating intermediate said venturi normally creating a vacuum flow in said vacuum line means during said full main fluid flow through said venturi, said vacuum line means communicating with said vacuum pad means normally supplying said vacuum for said pad means vacuum gripping; said vacuum pad means, said venturi and said vacuum line means being mounted as a unit on movable frame means movable forwardly and rearwardly in a defined reciprocal path, said movable frame means including an outer cylindrical surface at said unit; said venturi including a fluid exhaust line operably connected thereto receiving said exhaust of said main fluid flow, said fluid exhaust line opening through said outer cylindrical surface of said movable frame means spaced from said venturi; diverting means operable for closing off a portion of said exhaust of said full main fluid flow from said venturi sufficient to divert at least a portion of said full main fluid flow through said vacuum line means to said vacuum pad means changing said vacuum flow to a reverse positive pressure fluid flow to said vacuum pad means, said diverting means including collar means telescoping said movable frame means and mounted at a determined location of said unit reciprocal path for registering with said cylindrical surface of said movable frame means and said fluid exhaust line opening to close off at least a portion of said fluid exhaust line opening at said determined location.

2. in a vacuum supplied gripping device as defined in claim 1 in which said vacuum pad means, said venturi and said vacuum line means are mounted as said unit on said movable frame means movable forwardly and rearwardly in said defined reciprocal path reversing said movement at end portions of said reciprocal path; and in which said diverting means collar means is mounted at one of said end portions of said unit reciprocal path for registering with said cylindrical surface of said movable frame means and said fluid exhaust line opening to close off at least said portion of said fluid exhaust line opening during location of said unit at said reciprocal path one end portion.

3. In a vacuum supplied gripping device for selectively vacuum retaining workpieces; the combination of: vacuum pad means for contacting and vacuum gripping a workpiece upon vacuum being supplied thereto; a venturi normally having a full main fluid flow therethrough and exhausting therefrom; vacuum line means communicating intermediate said venturi normally creating a vacuum flow in said vacuum line means during siad full main fluid flow through said venturi, said vacuum line means communicating with said vacuum pad means normally supplying said vacuum for said pad means vacuum gripping; movable frame means mounting said vacuum pad means, said venturi and said vacuum line means movable as a unit in a forward and rearward defined reciprocal path from a rearward end portion of said path through an adjacent can body supply station to a can body working station at a forward end of said path and then reverse rearwardly back through said can body supply station to said rearward end portion of said path; said movable frame means including a rigid tubular member secured to said unit extending rearwardly therefrom transmitting motion to said unit moving said unit in said forward and rearward defined reciprocal path, drive means operably connected to said tubular member for moving said tubular member and said unit in said forward and rearward defined reciprocal path, said tubular member interiorly communicating with said venturi, main fluid flow supply means operably connected to said tubular member for supplying said main fluid flow through said tubular member to said venturi; said venturi including a fluid exhaust line connected exhausting said main fluid flow from said venturi, said fluid exhaust line opening outwardly through said movable frame means; diverting means operable for closing off a portion of said exhaust of said full main fluid flow from said venturi sufficient to divert at least a portion of said full main fluid flow through said vacuum line means to said vacuum pad means changing said vacuum flow to a reverse positive pressure fluid flow to said vacuum pad means, said diverting means being mounted at said rearward end portion of said unit reciprocal path registering with said opening of said venturi fluid exhaust line for closing off at least a portion of said fluid exhaust line opening when said unit is at said rearward end of said path and rearward of said can body supply station.

4. In a vacuum supplied gripping device as defined in claim 3 in which said movable frame means rigid tubular member secured to said unit extending rearwardly therefrom has a hollow interior communicating forwardly with said venturi, a piston in said tubular member spaced rearwardly of said unit having means for permitting limited forward and rearward movement of said piston within said tubular member, fluid supply means operably connected to said tubular member interior for supplying a flow of pressurized gaseous fluid such as air to said tubular member interior between said unit and piston supplying said main fluid flow to said venturi, said pressurized gaseous fluid within said tubular member interior exerting a force rearwardly against said piston normally retaining said piston at a rearward extremity of said limited forward and rearward movement within said tubular member interior, said drive means being operably connected to said piston for normally moving said piston and said tubular member and unit through said piston in said forward and rearward defined reciprocal path with said piston moving forwardly within said tubular member by compressing said pressurized gaseous fluid within said tubular member upon said vacuum pad means transmitting a rearward force rearwardly through said tubular member sufficient to cause compression of said gaseous fluid within said tubular member interior.

5. In a vacuum supplied gripping device for selectively vacuum retaining workpieces; the combination of: vacuum pad means for contacting and vacuum gripping a workpiece upon vacuum being supplied thereto; a venturi normally having a full main fluid flow therethrough and exhausting therefrom; vacuum line means communicating intermediate said venturi normally creating a vacuum flow in said vacuum line means during said full main fluid flow through said venturi, said vacuum line means communicating with said vacuum pad means normally supplying said vacuum for said pad means vacuum gripping; said vacuum pad means, said venturi and said vacuum line means being mounted as a unit on movable frame means movable forwardly and rearwardly in a defined reciprocal path, said movable frame means including a side surface at said unit; said venturi including a fluid exhaust line operably connected thereto receiving said exhaust of said main fluid flow, said fluid exhaust line opening through said side surface of said movable frame means spaced from said venturi; diverting means operable for closing off a portion of said exhaust of said full main fluid flow from said venturi sufficient to divert at least a portion of said full main fluid flow through said vacuum line means to said vacuum pad means changing said vacuum flow to a reverse positive pressure fluid flow to said vacuum pad means, said diverting means being mounted stationary at a determined location of said unit reciprocal path for registering with said side surface of said movable frame means and over said fluid exhaust line opening to close off at least a portion of said fluid exhaust line opening at said determined location.

6. In a vacuum supplied gripping device as defined in claim 5 in which said vacuum pad means, said venturi and said vacuum line means are mounted as said unit on said movable frame means movable forwardly and rearwardly in said defined reciprocal path reversing said movement at end portions of said reciprocal path; and in which said diverting means is mounted stationary beside one of said end portions of said unit reciprocal path for registering with said side surface of said movable frame means and over said fluid exhaust line opening to close off at least a portion of said fluid exhaust line opening during location of said unit at said reciprocal path one end portion.