US3528575A

US3528575A - Feed and transfer systems

Info

Publication number: US3528575A
Application number: US713830A
Authority: US
Inventors: Stuart H Mccaughey
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-03-18
Filing date: 1968-03-18
Publication date: 1970-09-15
Anticipated expiration: 1987-09-15

Description

's t.'15;1"97o I HMCCAUGHEY 3,528,575

FEED AND TRANSFER SYSTEMS Filed March 18, 1968 8 Sheets-Sheet 1 N Q5 I INVENTOR STUART H. McCAUGHEY BY [l /90:75 Qua abate C2 (0mg ATTORN E Y8 s. H. MCCAUGHEY FEED AND TRANSFER SYSTEMS Sept. 15, 1970 8 Sheets-Sheet 2 Filed March 18, 1968 INVENTOR' STUART H. McCAUGHEY BY I if! M &Q) of We p 5;" 1970 s. H. M CAUGHEY FEED AND TRANSFER SYSTEMS.-

Filed March 18; 1968 INVENTOR.

STUART- H. McCAUGHEY v BY fi/e oayggazlz/h ace & Mm;

ATTORNEYS Sept. 15, 1970 s. H. MCCAUGHEY 3,528,575 FEED AND TRANSFER SYSTEMS Filed Max-ch18, 1968 8 Sheets-Sheet A! FIG. 5

INVENTOR STUART H. McCAUGHEY Jf/f/epayq Quazhfome (2 Cum ATTORNEYS Sept. 15, 1970' H, CCCCC HEY 3,528,575

ED AND TRANSF YSTEMS STUART H. McCAUGH EY BY fiz l/cpa e, (i aim; ATTORNEYS Sept. 15, 9 s. H. M CAUGHEY FEED AND TRANSFER SYSTEMS 8 Sheets-Sheet 6 INVENTOR Filed March 18, 1968 TUART H. MCCAUGHE Y fiz /Wye, Quin/(Mae ECU/n1 ATTORNEYS Sept. .15, 1970 I s MCCAUGHEY 3,528,575

I FEED AND TRANSFER SYSTEMS Filed March 18, 1968 I s Sheets-Sheet 7 l f@| o} i Q: m.

i i v m I I v I I /f I m 7 Q5 k INVENTOR STUART H. MCCAUGHEY BYjii/f oag, flmmbm (5 (U2;

ATTORNEYS Sept. 15, 1970 s, MccAUGHEY 3,528,575

FEED AND' TRANSFER SYSTEMS Filed March 18. 1968 8 Sheets-Sheet 8 INVENTOR' STUART H. McCAUGHEY BYjii /e m gumm imce 60mg ATTORNEYS United States Patent US. Cl. 214-85 8 Claims ABSTRACT OF THE DISCLOSURE High speed transfer feed systems are disclosed herein. Feeds have reciprocating multiple-stepped single blank feeding plates with cooperating blank holders. Recessed transfer bars with spring loaded gripping fingers reciprocate differentially with respect to cammed lifting bars which are slidably connected to the transfer bars. The lifting bars lift the transfer bars into contact with blanks before the transfer bars are moved forwardly and lower the transfer bars out of contacts with the blanks after the transfer bars are moved forward to a maximum position and before the transfer bars are returned to their rearward positions. The feed, the transfer bars and the lifting bars are interrelated with cams and lever to coordinate their movement.

BACKGROUND Material handling systems such as feed and transfer systems have many and varied applications. The need for improved feed and transfer systems is especially acute in high speed presses. Consequently, the invention, while not limited for use therewith, will be explained with particular reference to that application.

Known transfer and feed systems, while satisfactory for low speed and medium speed, have drawbacks which render them unsatisfactory for high speed operation. Modern high speed presses as a rule are capable of far greater production rates than the rates at which they are used. Transfer apparatus are often the limiting factor. Workpieces which are not well engaged and held during the rapid accelerations which they undergo while being transferred between work stations tend to float and misalign, causing high reject rates or jamming of the machinery and necessitating high percentages of inspection or sampling. Forces which cause floating and misalignment increase with the square of cyclic speed.

Well known transfer systems require inward movement of transfer fingers toward die stations, movement between stations and movement outward from stations. The inward and outward movements increase transfer time between press cycles. When the dies and workpieces are of shapes which do not permit unidirectional transfer, additional relative movements must be provided for. Modern high speed presses have speed capabilities far beyond the capablities of available transfers and feeds. Research continues toward the development of transfer and feed apparatus which will keep pace with high speed presses. Many recent developments have employed conventional laterally opposed forks which move in a single plane inward to grip the workpiece, forward to advance the workpiece and outward to release the workpiece.

THE INVENTION The invention provides feed and transfer systems for advancing articles and for moving articles from station to station such as in presses. Feed and transfer systems described herein are designed for operational speeds in excess of 300 cycles per minute. In each movement the articles are positively held to prevent floating and to provide means by which articles can be transferred with accelerations greater than gravitational accelerations. Motions and masses of feed and transfer equipment are held to minimums in order to minimize forces due to acceleration, since excessive movements, accelerations and masses create excessive forces which have adverse effects upon operation of equipment.

The feed and transfer apparatus of this invention may be driven by any convenient reciprocating drive. Since it is usually desirable to drive the feed and transfer synchronously with an article-working machine, the power for the drive unit may be taken directly from a shaft in the machine drive. In the present case, chain belts interconnect notched pulleys, the machine drive shaft and the feed and transfer drive shaft. Barrel cams keyed to the latter shaft and cam followers provide reciprocating drives for the feed and transfer apparatus.

Workpieces are unstacked from the bottom of a stack with a conventional stack stripper in the first step of the process. Individual workpieces are placed on the first position of a notched feeder which also may be referred to as a stepped feeder, that is a feed device having successive positions for holding and feeding articles. Forward motions of the feed means and workpieces move retainers which are associated with each notch. At the end of the forward travel, the retainers move toward the feed means holding the workpieces against recession and urging them to the next notch. Thus workpieces are advanced stepby-step with each reciprocation of the feed means. The end of the feeder pushes a workpiece into an initial portion of a transfer apparatus.

The unique transfer apparatus of this invention is largely responsible for the high speed operation which heretofore has been unattainable. Workpieces are lifted from station to station while being positively gripped. Two basic elements are driven by the reciprocating cam followers of the transfer drive assembly.

A pair of lifting bars are reciprocated on opposite sides of the work stations, and sloped surfaces on the bars cooperate with fixed rollers to create raising and lowering actions.

Carrier bars are connected to the lifter bars for relative longitudinal sliding therewith. The carrier bars are driven by a separate cam and follower in the drive assembly so that the carrier bars successively are urged upward by the lifting bars, are driven forward by the carrier bar cam, are pulled downward by the lifting bar and are moved rearward by the carrier bar driving cam. Inward upper edges of the carrier bars are recessed at intervals corresponding to spacings between stations. The recesses are aligned with work stations during vertical movements so that the recesses receive edges of workpieces as the carrier bars are raised and release the edges of the workpieces as the carrier bars are lowered into alignment with successive Work stations.

Spring loaded arms are pivoted on longitudinally oriented pins which are mounted in lateral extensions of the carrier bars. Inner ends of the arms are urged downwardly over the recesses in the bars to hold workpieces firmly in the recesses. The function of the arms, while important throughout the whole transfer operation, is especially important during the downward movement of the carrier bars. During that interval accelerations greater than gravitational accelerations may be experienced, and the arms are necessary to overcome the inertia of the workpieces.

Another feed is used in an assembly operation to join additional parts with workpieces. The second feed which is described hereinafter in greater detail has a supply stack and a pusher block which is reciprocated within a stationary block. Movement of parts is accomplished by employing unidirectional spring-loaded detents or fingers which prohibit backward movement of the parts. As the pusher block is moved forward, fingers therein carry the parts forward. Fingers in the stationary block hold the parts while the pusher is withdrawn so that they may be advanced in increments each time the pusher block moves forward.

One objective of this invention is the provision of an active gripping feed and transfer system for advancing articles at high speeds.

This invention has as another objective the provision of a combined feed and transfer method and apparatus in which articles are lifted, translated and lowered from one position to another.

A further objective of this invention is the provision of an improved transfer method and apparatus which employs lifting and lowering means, advancing means and gripping means for transferring articles between sucessive work stations at high repetitive rates.

Another objective of this invention is the providing of feed methods and apparatus which employ downward and forward stepped reciprocating pushers with cooperating transverse reciprocable retainers which are lifted by the pushers and articles thereon in forward feeding movement and which retain articles in forward positions and urge articles to successive steps of the pushers as the latter are withdrawn.

This invention has as another objective the provision of feed methods and apparatus employing stationary blocks and pusher blocks reciprocable therein, which blocks have cooperating unidirectional spring-mounted fingers for advancing parts in step-by-step motions.

Other and further objectives of this invention will be apparent from this specification, from the claims which are a part of the specification and the disclosure herein and from the further detailed description of preferred embodiments of this invention as shown in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional elevation of a drive assembly for the feed and transfer system;

FIG. 2 is a plan view of the drive assembly of FIG. 1, showing cam followers and linkage for connection to the feed and transfer system;

FIG. 3 is a side elevation partially in sectional view, showing feed apparatus and driving apparatus for the feed;

FIG. 4 is a top plan of the feed apparatus showing in detail the unstacker;

FIG. 5 is a plan view of the transfer apparatus which also reveals the positioning of a tab feed;

FIG. 5A is a perspective schematic detail of the transfer apparatus;

FIG. 6 is an elevation of a lifting and lowering bar and carrier;

FIG. 7 is a plan View detail of a carrier support and carrier;

FIG. 8 is a section of a lift bar, carrier and support;

FIG. 9 is a plan view of a tab feed; and

FIG. 10 is a side elevation of the tab feed showing the driving apparatus and revealing details of the pusher block.

DETAILED DESCRIPTION To make the drawings more clearly understandable, reference letters have been used to designate interconnecting links between related elements in the several sheets of drawings and to identify the operative equipment which takes motion from those links. The letter A generally identifies the carrier bars of the transfer and their driving linkage. The letter B generally represents the lifting bars of the transfer and their driving linkage. Letter C indicates a connection from a cam follower to a travel multiplying lever. Letter D indicates a connection from that lever to the feed.

The invention herein disclosed is illustrated by a specific embodiment of an app ication to a high speed press. The

particular operation shown in the drawings and described herein is the feeding and transferring of can ends and the feeding of tabs. The press is fitted with dies to form and assemble tear-tab can ends which are used in the packaging of beverages. The press and the dies are not a part of the claimed invention, but they are illustrated for a complete illustration on one preferred embodiment of an application of the invention.

Referring to FIG. 1, the feed and transfer drive housing is generally referred to by the numeral 10. Shaft 12 is mounted in bearings 14, which are supplied with oil by channels 16. Notched pulley 18 is keyed to shaft 12 and is driven by a notched belt 20. Two barrel earns 22 and 24 are also keyed to shaft 12. As discussed later, short travel cam 22 drives lifting and lowering bars in the transfer, while the long travel cam 24 drives the carriers bar and the feed.

As shown in both FIGS. 1 and 2,

cam followers

26 and 28 are set in grooves of

cams

22 and 24 respectively. Both of the followers have laterally extended bodies 30 and 32 which include slide bearings 34 for moving along stabilizing slides 36. Slides 36 are supported above housing 10 by supports 38. Body 30, which is attached to cam follower 26, has a clevis 40 which mounts linkage 42. Linkage 42 is attached to the raising and lowering bars of the transfer as later described. Body 32 of cam follower 28 has pins 44 at its outward extremity. On pins 44 are mounted links 46 which are attached to the advancing means or carrier arms of the transfer.

As shown in FIG. 3, clevis 48 at the rear of body 32 mounts a link 50 which is connected medially to pivoted arm 52. Arm 52 is a travel multiplier which is employed to increase the travel of the feed with respect to the transfer. The lower end of arm 52 may be pivoted at a fixed position, as for example on the drive housing. The upper end of arm 52 is connected to link 54, which is in turn connected to a clevis 56 on feed bars 60.

The feed bars 60 are stepped forward and downward at intervals to form ledges 62. Spring mounted retainers 64 are pressed downward toward the feed bars. Retainers 64 ride over the ledges 62 and articles or can ends 66 when the feed is moving forward, i.e., to the right. Rearward facing slopes 72 and 74 on retainers 64 effect the raising of the retainers. After can ends 66 pass under retainers 64, the forward edges 76 and intermediate ridges 78 of retainers 64 prevent the ends from returning. The retainers are then held upward by limit means While the ends are dropped to subsequent ledges. The last ledge deposits the articles in the first position of transfer apparatus.

FIG. 4 is a top plan of the feed which reveals the unstacking apparatus 80 with reciprocal bars 82 which pass can end one at a time to the upper ledge of feed bars 60.

FIGS. 5, 6, 7 and 8 are respectively a plan view of a transfer assembled in the press, an elevation of one lifting and lowering apparatus and carrier, and a detail of a carrier and a support. Carrier supports 84 are constrained for reciprocation beside the dies 86 on the press bed 87. Carriers 88 reciprocate with the carrier supports 84 and are moved up and down by lifting and lowering bars 90. Cammed surfaces 92 in the bars 90 raise and lower the bars on stationary rollers 94.

Bars

90 and 88 are interlocked at 96 for positive up and down action. Carrier 88 is held for reciprocation with carrier support 84 by rollers 98 moving in slots 100 in the supports.

Arms 102 are centrally pivoted in carrier support 84 by pins placed in pin slots 104. Compression springs 106 in holes 108 urge the outer ends of the arms upward and the inner ends downward over recesses 112 in inward upper edges of carriers 88.

In operation recesses 112 of carriers 88 are positioned beneath the exposed edged of articles or can ends 66 in the die stations. Cam 22, follower 26, and linkage 42 move the bar 90 forward. Cam surface 92 and roller 94- force bar 90 upward. Carrier 88 moves upward with bar 90, bringing recesses .112 into contact with the exposed edges of the workpieces. Carrier 88 continues to move the workpieces upward into contact with arms 102, raising the inner edges 110 of the arms against spring pressure.

Cam 24, "follower 28 and linkage 46 then move carrier support 84 and carrier 88 forward with the workpieces locked tight in recesses 112 by arms 102. When the workpieces are over the next adjacent stations, cam 22 withdraws bars 90. The cam surface 92 and roller 94 pull bars 90 and the attached carriers down. In the initial part of the downward travel, arms 102 retain workpieces in recesses 112. Arms "102 are stopped when they reach the full extent of their downward travel and the carriers 88 continue downward leaving the workpieces in the stations. Then cam 24 withdraws carrier supports 84 and carriers 88 to their initial positions.

As shown in FIG. 5, tab feed 120 overlies the transfer apparatus. As shown in FIGS. 9 and 10 the tab feed has a stationary block 122 in which pusher block 124 reciprocates. Movement is imparted to pusher block 124 by rigidly interconnected pivoted angle arms 126 and 128.

Arm 126 is connected by a slide to bar 130, which is rigidly mounted to press head 132. Arm 128 is connected to a slide moving with a vertical groove in a downward extension 134 of pusher block 124.

Pusher block 124 receives tabs 125 from a stack means 137, and spring mounted fingers 136 move tabs forward with pusher block 124. The fingers are mounted with springs 138, and they are unidirectional so tabs may freely slide over fingerS 136 as block 124 is withdrawn. Spring mounted fingers 140* in stationary blocks 122 aid in the step-by-step advancing of the tabs. In this manner tabs move forward to hole 142 where they are forced downward by cooperatively configured die heads 146 for assembling the tabs 125 with can ends 66.

As shown in FIGS. and 10, auxiliary feed 120 is positioned immediately over the dies and transfer on press base 87. Thus die head 146 receives tab 125 in hole 142 as the head is moving downward. The die head continues to move downward, driving the tab to the exact desired position on the can end, and continued movement of the die rivets the tab to the can end.

All other known tab feeds for similar assembly operations have used vacuum to pick up and hold the tabs, and those devices have been unable to pick up and deposit the tab exactly in the desired position. Moreover, additional riveting steps have been required. The former operations have resulted in misplaced tabs and in high reject rates.

Although this invention has been described in part by a specific embodiment, it will be obvious to those skilled in the art that modifications and variations may be made to this invention without departing from the invention.

I claim:

1. Article feed apparatus comprising:

frame means,

reciprocating drive means connected to the frame means and to a source of power,

notched feed means slidably mounted on the frame means and connected to the drive means for reciprocation therewith,

retainer means movably mounted on the frame means for movement into and out of engagement with articles on the feed means, the retainer means being normally positioned in engagement with the upper side of articles on the feed means and being adapted to be moved out of engagement with the upper side of articles on the feed means by forward movement of the feed whereby the retainer means releases articles for forward movement with the feed means, engages articles and prevents articles from moving backward with the feed means, and promotes passage of articles to next adjacent notches upon reciprocation of the feed means.

2. The apparatus of claim v1 wherein the notched feeding means comprises a series of forward and downward stepped ledges, whereby articles move to successively lower steps.

3. The apparatus of claim 1 wherein the retainer means are constrained for reciprocal movement toward and away from the feed means, and wherein the retainer means define backward-facing slopes, whereby forward moving feed means and articles thereon initially contact the slopes and move the retainer means away from the feed means.

4. Article feed and transfer apparatus comprising:

a frame means,

supply means mounted on the frame means for holding articles, feed means connected to the frame and to the supply means for moving articles from the supply means, the feed means comprising stepped means mounted for sliding adjacent the supply means for receiving articles therefrom, reciprocating means connected to the stepped means for reciprocating the stepped means adjacent the supply means, and retaining means moveably mounted with respect to said supply means,

transfer means connected to the frame means and positioned adjacent the feed means for receiving articles therefrom and for moving articles along a line, the transfer means having lateral displacing means for displacing and returning articles away from and toward the line, advancing means connected to the displacing means for advancing articles in the direction of the line when articles have been displaced from the line, and gripping means mounted on the advancing means for holding articles while they are displaced from the line.

5. Article transfer apparatus comprising:

frame means,

first and second stations fixed with respect to the frame means, first and second reciprocating driving means mounted on the frame means and operatively connected to cams which are connected to a continuously rotating shaft which is connected to a source of power,

displacing means connected to the first driving means mounted on the frame for movement adjacent the stations and adapted to move articles away from and toward the stations in directions angularly related to a line common to the stations,

advancing means connected to the second driving means and mounted on the frame means adjacent the stations for moving articles in the direction of a line common to the stations, and

gripper means mounted in the advancing means for movement therewith, the gripper means resiliently overlying portions of the advancing means configured for holding articles.

6. Article transfer apparatus comprising:

frame means,

advancing means connected to the second driving means and mounted on the frame means adjacent the stations for moving articles in the direction of a line common to the stations,

wherein the displacing means is constrained for move ment back and forth along the stations, wherein the 7 displacing means and the frame means define co; operating camming members which constrain the displacing means to move at an angle to the stations when the drive means operates the displacing means, wherein the advancing means is slideably interconnected with the displacing means for movement therewith, and wherein the advancing means is configured to receive articles at the first station and to release articles at the second station, whereby the reciprocating driving means cooperate with the displacing and advancing means to move the displacing means, thus relatively moving the camming members, causing the displacing and advancing means to move away from and then toward a line connecting the stations, the driving means and the advancing means cooperating to move the article in the direction of a line con necting the stations while the advancing means is displaced therefrom, whereby the advancing means receives an article from the first station, is displaced from a line between the stations, moves in the direction of the line, moves toward the line and releases an article at the second station.

7. Article transfer apparatus comprising:

frame means,

first and second stations fixed with respect to the frame means,

first and second reciprocating driving means mounted on the frame means and operatively connected to cams which are connected to a continuously rotating shaft which is connected to a source of power,

displacing means connected to the first driving means mounted on the flame for movement adjacent the stations and adapted to move articles away from and toward the stations in directions angularly related to a line common to the stations,

wherein the displacing means comprises a first pair of horizontally oriented bars disposed on opposite sides of the stations and defining sloped cam surfaces, wherein the frame means has stationary members co operating with the cam surfaces, wherein the advancing means comprise a second pair of spaced horizontal bars overlying the first pair and interengaging the first pair for relative longitudinal sliding and for prevention of relative vertical movement therebetween, the second pair of bars defining opposite recesses in inward upper edges thereof, the recesses being spaced at lengths along the bars commensurate with lengths between adjacent stations.

8. The article transfer apparatus of claim 7 wherein the advancing means further comprise retainer means have arms intermediately pivoted on pins extending laterally therefrom, the arms having inner ends overlying at least portions of the recesses, and being resiliently urged toward the recesses.

References Cited UNITED STATES PATENTS 2,539,652 1/1951 Amberg.

3,155,241 11/1964 Suofy.

3,430,782 3/1969 Henkel 2141 3,432,042 3/1969 Bautz 214-1 GERALD M. FORLENZA, Primary Examiner G F. ABRAHAM, Assistant Examiner U.S. Cl. X.R.