US 3557598 A
Description (OCR text may contain errors)
Jan. 26, 1971 c. LANGEWIS ETAL 9 I ELECTROMAGNETIC'FEEDING DEVICE I 4. Sheets-Sheet 1 Filed March 4, 1969 m m mm MMM M m MM LE W0 MA a A JQM c. LANGEWIS ETA!- ELECTROMAGNETIC FEEDING DEVICE Jan. 26,1971
4 Sheets-Sheet 7.
Filed Mafch 4, 1969 w M M N A L 6 a N, M C
A. DEAN 5M/TH INVENTOR-SI 4 6K244 ATTORNEY v f I FIE-.5
United States Patent O 3,557,598 ELECTROMAGNETIC FEEDING DEVICE Cornelis Langewis, Walnut Creek, and Arthur Dean Smith, also known as A. Dean Smith, San Lorenzo, Calif., assignors to Kaiser Aluminum & Chemical Corporation, Oakland, Calif., a corporation of Delaware Filed Mar. 4, 1969, Ser. No. 804,248 Int. Cl. B21d 22/00 U.S. Cl. 72-361 13 Claims ABSTRACT OF THE DISCLOSURE An improved electromagnetic device for use in feeding cup-shaped workpieces and the like to an article forming apparatus or press of the type shown, for example, in U.S. Patent 3,314,274 to C. Langewis, granted on Apr. 18, 1967. The electromagnetic device includes a chutelike element and an electrically energizable stator means associated therewith which operates to generate and maintain an electromagnetic field relative to a metal workpiece disposed within the chute-like element in order to efiect advancement of the workpiece along the chutelike element to a position where it can be readily engaged by the ram of the press and thereafter advanced by the ram through one or more forming dies of the press.
BACKGROUND OF THE INVENTION This invention relates to an electromagnetic feeding device which, among other things, can be used in the feeding of cup-shaped blanks to a container fabricating machine. More particularly, it relates to an improved electromagnetic device or linear induction type motor for use in feeding cup-shaped metal blanks to a draw and iron container forming apparatus wherein a chute-like element operates in conjunction with an electrically energizable stator means in a unique fashion to advance a cup-shaped blank through the chute-like element and onto a ledge element where the workpiece becomes aligned with the forming ram as well as the dies of the draw and iron apparatus so that it can be engaged in the proper fashion by the ram during its forward stroke.
Various feeding devices have been designed in the past for feeding successive cup-shaped metal workpieces to a draw and iron container fabricating apparatus. Such feeding devices are exemplified in the pneumatic feeder of co-pending patent application, Ser. No. 652,211 entitled Pneumatic Feeding Device, filed on July 10, 1967, Langewis et a1. applicants, now U.S. Patent No. 3,469,- 432, and the brush feeder of co-pending patent application Ser. No. 691,390 entitled A Feeding Device filed on Dec. 18, 1967, Kapke applicant. The prior art feeding devices as exemplified by the aforesaid applications involved movable mechanical elements such as air pumps or brushes. These mechanical elements require servicing and replacement after certain periods of use, all of which adds to the overall costs of the draw and iron container fabricating operations in which said elements are employed. The instant device because of its simplicity and substantial lack of moving parts is relatively maintenance free and not as subject to wear as the aforesaid pneumatic and brush feeders referred to above.
3,557,598 Patented Jan. 26, 1971 "ice It is the primary purpose of the instant invention to provide an improved feeder device for a container forming press and the like which is generally comprised of a chute-like element and an electrically energized stator means associated therewith. The stator means operates to generate and maintain a magnetic field within the chutelike element whereby metallic articles such as cup-shaped workpieces in the chute-like element are advanced or propelled through the chute-like element to a preselected position where the workpieces can be properly engaged by the forming ram of the press and then advanced through the dies of the press.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view of the feeding device of the instant invention;
FIG. 2 is another fragmentary perspective view on a reduced scale of the feeder device of the instant invention and illustrates further details thereof;
FIG. 3 is an end elevational view of the device of the instant invention;
FIG. 4 is a side elevational view generally taken along line 4-4 of FIG. 3 and with certain parts added and other parts broken away; and
FIG. 5 is a schematic .view of a suitable electrical control circuit for the device of the instant invention.
DETAILED DESCRIPTION With further reference to the drawings, and particularly FIGS. 1-4, the electromagnetic feeding device 10 in a preferred embodiment of the instant invention generally comprises a chute or chute-like element 12, a ledge or stop and centering element 14 disposed across the exit end of the chute-like element 12 and an electromagnetic stator 16 disposed adjacent the chute 12 between the ends thereof. As will become more apparent hereafter, the inlet or upper end of chute 12 is supplied with successive metal workpieces W from a hopper or a conveyor, or the like not shown. Chute opening 17 has an overall dimension whereby the workpieces W can pass freely in stacked relation from the inlet to the discharge end of the chute in the manner illustrated in FIGS. 1 and 3-4. The electrical control circuit 18 of FIG. 5 and to be more fully described is electrically connected to the stator 16 for selectively energizing stator 16 in order to generate and maintain a constant traveling electromagnetic field. The magnetic lines of flux of this field are generally disposed at transverse angles to the normal path of movement of the workpieces W in the chute 12 adjacent stator 16 as generally indicated by the dotted lines 15 in FIG. 1.
These magnetic lines of flux of field 15 also travel in repetitive fashion in a downward direction toward the exit end of chute 12 and as indicated by the arrow of FIG. 1. As workpieces W enter opening 17 at the inlet end of the chute 12, and enter field 15, they, in effect, take on the characteristics of a rotor in a conventional poly-phase motor and are rapidly propelled toward the discharge end of chute 12.
This propulsion of the magnetized workpieces W toward the discharge end of chute 12 results in the advance of the stack of workpieces continuously and successively through chute 12 and the endmost or lowermost workpiece is forced into a light pressure contact with the stop element 14. The workpiece in contact with stop 14 remains on stop 14 until it is removed from the stop 14 by the ram 20 of a forming or press apparatus 22, only part of which is shown.
As indicated in FIGS. 1 and 4, container forming apparatus 22 with which feeding device of the instant invention can be used need be only briefly described. It generally comprises a reciprocating forming ram 20 and a series of draw and iron dies with only drawing die 28 being illustrated and the dies are arranged in the usual tool pack 30. This draw and iron apparatus 22 can, for example, be of a type shown in the aforementioned Pat. 3,314,274 of Langewis, issued Apr. 18, 1967, except that drawing die 28 illustrated herein is a straight drawing die instead of the reverse redraw die of the said patent. Ram 20 is disposed for slidable movement within the bore 32 defined by the cylindrical sleeve 34, which is disposed in the barrel 36 of apparatus 22. The forming end of ram 20 can be slidably disposed within a bearing and guide sleeve 38 fixed in a conventional manner to the forward end of sleeve 34. The forward end of sleeve 34 extends beyond the forward flanged end of barrel 36 of apparatus 22 in the manner illustrated in FIG. 4 and is closed ofi by an apertured closure member 40 attached to the outer face of the forward flanged end of barrel 36 by the usual cap screw assemblies generally indicated at 42 in FIG. 3. J49 Glenn JOOP 48 915 Day Job Sec. Jan. 7
Although not shown in the drawings, ram 20 is reciprocated by a suitable fluid actuator back and forth through tool pack 30 and the forward flanged end of barrel 36 in effecting the drawing and ironing of workpieces W as they are successively deposited on stop 14. Reference may be made to the aforesaid Pat. 3,314,274 for a further description of tool pack 30 that can be used and of the fluid actuator for the ram.
Although the forward and return movements of ram 20 through tool pack 30, the flanged end of barrel 36 and space therebetween is relatively rapid, energization of stator 16 assures that the endmost workpiece W of a given stack of workpieces W will be properly seated against stop 14 prior to each forward stroke of ram 20 so that this endmost workpiece can be picked off of ledge 14 and properly advanced by ram 20 through tool pack 30. When chute 12 is disposed in a vertical or the usual position in the manner shown in FIGS. l-4, gravity also assists stator 16, when energized, to seat the endmost workpiece W against stop 14. It is to be understood, however, that chute 12 can be disposed in any desired position and if, during use, the inlet end of chute 12 faces downwardly the workpieces W within chute opening 17 will tend to drop out from the inlet end of chute 12 due to the influence of gravity. In such instance, the intensity of the electromagnetic field of stator 16 can be regulated by circuit 18, as will be subsequently described, to compensate for the adverse effect due to the influence of gravity.
Chute 12 can be constructed so as to be partially open and provide optimum visual inspection of the workpieces W passing therethrough. The various front and back wall portions at the exit end of chute-like element 12 are partially cut away to define an overall transverse opening 26 adjacent stop block 14 and opening 26 in effect is a continuation of opening 17. A front sidewall portion of chute 12 can be advantageously hingedly connected to another portion of chute 12 to provide quick access for servicing the interior thereof. An auxiliary arresting device 24 is disposed adjacent the exit end of chute 12 and functions to selectively arrest advancement of the workpieces W when the chute device is not in use.
The workpieces W are preferably of cup shape and of at least an electrically conductive metal material such as aluminum or an alloy thereof whereby the traveling magnetic lines of flux in field generated by stator 16 can induce eddy currents in the workpieces W in chute 12. The
induced eddy currents in a given workpiece react to the repetitive and downwardly moving overall electromagnetic field 15 produced by stator 16 to produce a propulsion of a given workpiece toward the discharge end of chute 12 in the same general fashion as the rotor currents in a polyphase induction motor react to the revolving flux produced by the motor stator to produce rotation of the rotor.
Chute 12, however, is preferably made up of a suitable plastic material such as a suitable grade of polyurethane that can withstand the temperature and abuse the chute would be subjected to in feeding workpieces therethrough. By virtue of the chute being constructed of a plastic material, it is electrically non-conductive as well as impermeable to the magnetic lines of flux generated by stator 16. One of the advantages of the chute being constructed of a plastic material is that it minimizes the power requirements for stator 16 to establish and maintain a repetitive magnetic field 15 of sufficient strength for propelling workpieces through the chute, thereby increasing the overall efficiency thereof.
In order to mount the chute 12 on the top of the forming apparatus 22 at the forward flanged end of the barrel 36 thereof, generally channel-shaped brackets 54 and 64 are provided. Bracket 54 is adjustably affixed to the top of the forward flanged end of barrel 36 by passing a series of cap screw assemblies 56 through slotted openings 59 in the web portion 60 of bracket 54 in a known manner. The upstanding legs 58 of bracket 54 at their forward edges are beveled in an upward and rearward direction relative to the forward edge of web 60. A back plate 62 is connected to and rests on web 60 as well as bridging the space between and being connected to legs 58.
The web 65 of bracket 64 is adjustably connected at one end to the outwardly facing side of backplate 62 by way of a series of slotted openings 66 in plate 62 which receive a series of cap screw assemblies 68. The back edge of web 60 of bracket 54 can be extended to underlie the lower flange 70 of bracket 64 to provide additional support for the same and flange 70 of bracket 64 can be adjustably connected to the underlying rearward extension of web 60 by cap screw and slotted opening assemblies 71.
Chute 12 includes top 48 and lower plates 50 and 52 as well as pairs of rods 44 and 46. A strap element 74 of U-shaped configuration is used to aflix the two pairs of rods 44 and 46 to certain portions of brackets 54 and 64 and it is made up of a pair of leg elements 76 and 78 interconnected by a web 80 of channel shape. The outer free end of leg 76 is flanged laterally outward to facilitate connection to one of the upstanding legs 58 of bracket 54 by a cap screw assembly 80'. Leg 78 of strap 74 is provided with a series of openings 82 for receiving Allenhead cap screw assemblies 84 used to anchor leg 78 to the backside of web 65 of bracket 64.
Rods 44 which form a sidewall of the chute 12 extend substantially the full length thereof and these rods are weldably afiixed at intermediate portions thereof to the inwardly facing surface portions of leg 78. Rods 46, which are of a somewhat shorter length than rods 44, are weldably affixed at their lower ends to the inwardly facing portions of leg 76 in opposition to rods 44 and these rods 46 form a section of the front sidewall of chute 12. The upper end of plate 50 is interposed between legs 76 and 7 8 of strip element 74 and is weldably connected thereto to form the lower section of the front Wall of chute 12. The upper flanged end of plate 52 is adjustably connected by appropriate cap screw assemblies 86 to the undersurface of the web of bracket 54 adjacent upstanding leg 58 thereof to which leg 76 of strap element 74 is attached. The main body portion of plate 52 is generally aligned with the inner leg 58 of bracket 54 so as to, in effect, form a continuation thereof whereby this leg and plate 52 form the lower section of the rear wall of chute 12 while plate 48 forms the upper part of the rear wall. As indicated in FIG. 1, the lower flanged end of a support plate 88 rests upon and is affixed to flange 72 ot' bracket 64 by means of cap screws 92 that pass through slotted openings 93 in flanged end 90. In aflixiug support plate 88 to bracket '64, a slight clearance is allowed between plate 88 and the pair of rods 44 forming the rear sidewall of chute 12.
Plate 88 supports and is connected to stator 16 by way of cap screws 96. Plate 48 connected to plate 88 in opposition to stator 16 by suitable means (not shown) forms the upper part of the rear wall of chute 12.
Stator 16 is of such a length that its lower edge is normally disposed and spaced above the top of U-shaped strap element 74. In order to prevent inadvertent jamming of a workpiece W against the top of strap element 74 due to the space between strap 74 and stator 16, a pair of relatively short and parallel spaced rods 98 are affixed to the top of channel-shaped element 80 of strap 74 so as to bridge this space whereby these rods 98 in effect form a chute wall connection between plate 50 and stator 16.
By virtue of the alignment of the interior surfaces of stator 16, plate 50 and rods 98 on one side of the chute and a similar alignment between the interior surfaces of plates 48 and 52 and leg 58 of bracket 54 on the other side of the chute as well as the rounded surfaces of rods' 44 and 46 making up the other chute walls, a relatively smooth walled chute without any interior obstructions is provided.
In order to facilitate feeding of successive workpieces into the inlet and of chute 12, the upper ends of rods 44 and 46 can extend above the tops of stator 16and plates 48 and '88 and be flared in an upward and outward curvilinear direction all as shown in FIGS. 3-4. A sharp element 98 can be clampingly affixed to the protruding portions of rods 44 and 46 so as to reinforce the same. If desired, upwardly and outwardly flared plate sections 100 can be affixed to strap element 98 so as to form extensions of the upper edges of stator 16 and plate 48.
The discharge or lower end of chute 12 is closed off by the roughly V-shaped centering and stop or ledge element 14 provided with a bottom 104 and upwardly diverging sides 106. Ledge element is primarily attached by cap screws 102 to closure member 40 at the forward flanged end of barrel 36 of forming apparatus 22. The lower ends of rods 44 can be advantageously seated in suitable openings on one side of stop 14 in the manner illustrated in FIG. 3.
The shallow V-shaped groove of ledge 14 extends across the discharge end of the chute and is aligned with the opening of drawing die 28 in tool pack 38 and forming ram of press 22. The lower edges 10 8 of plates 50 and 52 are cut away to define the top part of opening 26 of the chute while ledge elements 14 forms the bottom of the opening.
Rods 44 close olf one side of opening 26 while a hingedly connection sidewall access door 110 comprised of a pair of parallel spaced rods 112 and upper and lower rod connected blocks 114 and 116 closes off the other sidewall of opening 20. A vertically extending groove 118 in ledge 14 is bridged by a pin 120 which fits within L- shaped slot 122 in block 116 for effecting pivotal connection of the block 116 to stop 14, and in turn the overall sidewall 110 to chute 12.
Upper rod block 114 is provided with a latch finger 124 for slidably engaging leg 76 of strap 74. The wall section or door 110 is installed simply by locating pin 120 in ledge element 14 in slot 122 of block 116 and then lifting wall section 110 upwardly until finger 124 can slide over strap 74. Removal of wall section 110 is effected by raising wall section 110 upwardly until finger 124 clears strap 7-4. Wall 110 is then pivoted outwardly and pin 120 disengaged from slot 122.
The elongated stator plate 126 made from an appropriate magnetically permeable material is provided with a series of uniformly and parallel spaced transversely extending slots or grooves 12%, certain ones of which are indicated in FIGS. 1 and 4. Grooves 128 are adapted to 6 receive the electromagnetic field coils 136 that form part of control circuit 18.
As indicated in FIG. 5, the control circuit 18 which represents one form of a suitable circuit that may be used with the device of the instant invention is generally comprised of three interconnected conductor leads 130, 132, 134 connected at their terminal ends to a suitable 3-phase, 60-cycle AC source, not shown. Electromagnetic induction coils 136 are series connected to the other terminal ends of conductor leads 130, 132 and 134 and to each other at a common point 135. A solenoid operated switching device 144 is connected across leads 130, 132 and 134 for effecting energization of coils 136. To this end, a branch line 138 is connected across lines 132 and 134. A normally open, manually operated switch 142 and solenoid 144 are series connected to line 132. Solenoid 144 controls three relatively spaced, normally open con tact switches 146 across lines 130, 132 and 134 in the manner shown in FIG. 5. Closing of switch 142 will energize solenoid 144 and effect closing of switches 146 thereby energizing each pair of the three pairs of coils 136 series connected to their associated leads 130, 132 and -.134. In order for the operator to regulate the intensity of the magnetic field generated by coils 136 in each one of three leads 130, 132 and 134, a 'variable rheostat element 148 can be series connected to these leads as illustrated in FIG. 5 A common control rod 150 connected to each one of three rheostats 148 can be used to simultaneously control all rheostats 148 and provide uniform regulation of the current flow in each of the leads 130, 132 and 134.
Each one of the coils 136 of the three pairs of coils are selectively and individually located in a groove 128 of the stator 16 in a well known manner. Thus, one coil 136 for lead is placed in the topmost groove 128 of stator 16, one coil 136 for lead 132 is placed in the second or next stator groove from the top of stator 16 and one coil 136 for lead 134 is placed in the third groove from the top. The remaining coils 136 for each lead 130, 132 and 134 are respectively placed in the fourth, fifth andl sixth grooves from the top of stator 16, all as indicated in FIGS. 1 and 3. When interconnected leads 130, 132 and 134 are energized by the three phase AC source (not shown) upon closure of switch 142, coils 136 in each of the leads will be successively energized and magnetized to provide a constantly reoccurring and linearly traveling magnetic field that generally moves from the entry end of the chute 12 towards the exit end. The workpieces in the path of this field react in the fashion of the rotor in a poly-phase motor and are continuously urged or propelled toward the ledge element 14.
Each coil 136 is anchored in its respective groove 128 by a suitable epoxy resinous material 150. Although not shown, it is to be understood that the top side of plate 126 can be covered by a thin sheet of relatively electrically resistive material for the purpose of protecting coils 136 disposed in epoxy-filled grooves 128. Since the plate is constructed of relatively electrically resistive material, it does not adversely affect the generation and maintenance of the lines ofr flux in electromagnetic field 15 across opening 17 of chute 12 upon electrical energization of coils 136 of stator :16.
Although magnetic field 15 is illustrated in FIGS. 1 and 3 as being of a size corresponding to the overall cross-section dimension of one and a half workpieces W, a field having a size comparable to the overall crosssectional dimensions of six to seven workpieces W placed edge to edge can be used to propel workpieces W downwardly and an endmost workpiece into engagement against stop 14. If desired, raised ribs, not shown, can be provided on the inside surfaces of plate 50 and stator 16 in order to minimize frictional contact of the bottom of cup-shaped workpieces W with these elements during travel of the workpieces through chute 12.
The cup-shaped workpieces fed into chute 12 are preferably arranged therein such that the bottoms of the workpieces face the stator 16 so that the desired Workpiece eddy currents can be rapidly generated and maintained in the workpieces. The downward propulsion forces given to each workpiece W advantageously act to urge each workpiece against an adjacent workpiece so that each workpiece will be forced tightly against an adjacent workpiece and thus produce a relatively uninterrupted and rapid flow of workpieces to ledge 14.
As ram 20 of press 22 moves forward into the open end of workpiece W and across ledge 14, it will remove the workpiece from ledge 14 and then pass the workpiece through the dies in tool pack 30 in the manner illustrated in FIGS. 1 and 4. As the ram in its continued advancement forces the workpiece through the tool pack, the trailing end portion of the ram advantageously and momentarily closes off the bottom of opening 26 and thereby arrests further movement of the overall stack of workpieces downwardly. After the full forward stroke of ram 20 has been completed, the ram is withdrawn from the tool pack 30 by its fluid actuator.
As the ram on the back stroke recedes into sleeve 38 of press 22 the momentarily closed opening 26 is again reopened so that the next and now bottommost workpiece W can be advanced or propelled onto ledge 14.
Plate 48 can be constructed of a suitable grade of steel or other material for the purpose of causing the magnetic lines of flux of field repetitively generated by stator 16 to be substantially and uniformly directed across opening 17 of chute 12 while at the same time minimizing the electrical power requirements for stator 16, thus increasing the overall efficiency thereof. Further, although the workpiece W in advancing through chute 12 is subjected to the exciting field 15 for only a relatively short period of time during the stroking of ram 20, a suitable cooling device, not shown, can be disposed adjacent the inlet of device 10 to minimize the heating of the stator 16 and the workpieces W due to the induced eddy currents in the workpieces W.
The auxiliary arresting device 24 referred to above for holding the stacked cup-shaped workpiece in chute 12 when it is not in operation is comprised of a fluid actuator 152 and a pivoted arresting arm 154 that is movable in between rods 44 and against one of the workpieces W. A bracket 156 is used to support actuator 152 and arm '154 and bracket 156 includes upstanding legs 158 and 160 and a depending leg 162 for mounting the bracket on the forward flanged end of barrel 36 of the press. Arm 154 is pivotally connected at 166 to upstanding leg 160 or bracket 156 while the cylinder of actuator 152 is pivotally connected at 168 to the upper end of upstanding leg 158. The forward free end of piston rod sub-assembly 170 of actuator 152 is pivotally connected to arm 154 at 172. The actuator cylinder contains a spring for biasing the piston rod sub-assembly 170 and arm 154 to their respective retracted positions.
The piston side of the piston rod sub-assembly is appropriately connected to the usual source of fluid for actuating piston rod sub-assembly 170 to the right, as viewed in FIG. 3, and for pivotally advancing arm 154 in a counterclockwise direction and into engagement with the next-to-the-bottomrnost workpiece W in chute 12. Arresting device 24 can be used to stop the flow of workpieces W to ledge element 14 at any time such as when it is desired to idly stroke ram to and through tool pack or during the times that press 22 is inoperative.
In those instances where the feeding device 10 is used with a forming apparatus such as shown in the US. Patent 3,314,274 to Langewis, granted on Apr. 18, 1967, wherein the entry die of tool pack 30 contains a reverse redraw die instead of straight drawing die 28, the bottom portions of workpieces W in chute 12 should be reversely disposed in chute 12 in contrast to the workpiece arrangement depicted in FIGS. 1 and 3-4. In such instances, it
is preferable that the positions of stator 16 and plate 48 be reversed relative to plate 88.
The instant feeding device is efiicient and reliable in advancing a series of cup-shaped metal workpieces W rapidly, continuously and successively toward ledge 14 and to a position on the ledge where the workpiece is accurately aligned both with ram and dies of press 22. The instant device because of its relative lack of moving parts is substantially jam-proof. By minimizing physical contact with the workpieces W during feeding of the same to ledge 14, denting and surface marring of the workpiece, which could deleteriously affect the drawing and ironing 0f the workpiece, is obviated.
The intensity of magnetic field 15 can be precisely controlled whereby workpieces W will always move at the proper rate through chute 12 in accordance with operating strokes of ram 20 of press 22.
Although preferred embodiments of the instant invention have been disclosed and described, it will be apparent that various changes and modifications may be made therein without departing from the scope of the appended claims, wherein:
What is claimed is:
1. In combination with an article forming press of the type described and provided with a die means and a reciprocating forming ram aligned with an advanceable through said die means, a workpiece feeder device for said press, said feeder device comprising a chute-like means for receiving workpieces at one end thereof and for discharging the workpieces at another end thereof, the discharge end of said chute-like means being disposed adjacent the die means of the press, a workpiece receiving means located adjacent the entry end of said die means and the discharge end of said chute-like means for receivr ing a workpiece discharged from said chute-like means and for orienting and centering the workpiece relative to said die means and ram, an electrically energizable stator means for generating and maintaining a traveling electromagnetic field in the path of travel of the workpiece in said chute means and for effecting travel of said field toward the workpiece receiving means so as to continuously propel a workpiece within said chute-like means towards and into light pressing engagement with said workpiece receiving means whence the workpiece can be removed by said rarn upon the forward advancement thereof past said workpiece receiving means.
2. The combination of claim 1 wherein said stator means forms a part of said chute-like means.
3. The combination of claim 1 wherein the workpiece receiving means is provided with groove means for receiving and retaining a workpiece.
4. The combination of claim 1 wherein said chute-like means includes hingedly connected sidewall means providing access to the interior thereof.
5. The combination of claim 1 wherein said chute means is oriented in a substantially vertical plane.
6. The combination of claim 1 including means for arresting the feeding of a workpiece in said chute-like means towards said workpiece receiving means.
7. The combination of claim 6 wherein said arresting means is located intermediate said workpiece receiving means and the entry end of said chute means.
8. In combination with a press provided with a die means and a reciprocating forming ram aligned with and advanceable through said die means, a device for feeding metal cup-shaped workpieces to said press, said feeding device comprising a chute-like means for receiving a cupshaped workpiece at one end and for discharging the workpiece at another end thereof, a combination workpiece stop and centering element located adjacent said die means and the discharge end of said chute-like means for receiving and orienting the workpiece relative to said die means and ram, the improvement comprising an electrically energizable stator means for generating and maintaining a traveling electromagnetic field in the path of travel of the workpiece in said chute means and for effecting movements of said field toward the workpiece receiving means so as to propel a workpiece through said chute-like means into light pressing engagement with said workpiece receiving means whence the workpiece can be removed by the ram upon the forward advancement thereof past said workpiece receiving means.
9. The combination of claim 8 in which said stator means forms part of said chute means.
10. The combination of claim 8 wherein the workpiece receiving means is provided with groove means for receiving and retaining a workpiece.
11. The combination of claim 8 wherein said chute means is oriented in a substantially vertical plane.
10 12. The combination of claim 8 including means for arresting the feeding of a workpiece in said chute-like means towards said workpiece receiving means.
13. The combination of claim 12 wherein said arresting means is located intermediate said workpiece receiving means and the entry end of said chute means.
References Cited UNITED STATES PATENTS RICHARD J. HERB ST, Primary Examiner