US3254521A - Apparatus for forming metallic sheet members - Google Patents

Description

R. E. ROPER 3,254,521

APPARATUS FOR FORMING METALLIC vSHEET MEMBERS June 7, 1966 5 Sheets-Sheet 1 Original Filed Feb. 23, 1962 Fig. 1.

RM EU AH'orn 95 R. E. RoPER 3,254,521

APPARATUS FOR FORMING METALLIC SHEET MEMBERS June 7, 1966 5 Sheets-Sheet 2 Original Filed Feb. 23, 1962 INVENTOR. RALPH E. RoPER BY ;/W/z,.wfaw

AHo vn cys Fig. a.

June 7, 1966 R. E. ROPER 3,254,521

APPARATUS FOR FORMING METALLIC SHEET MEMBERS 5 Sheets-Sheet 5 Original Filed Feb. 25. 1962 Fig. 5.

June 7, 1966 R. E. RoPER 3,254,521

APPARATUS FOR FORMING METALLIC SHEET MEMBERS original Filed Feb. 2:5. 1962 5 sheets-sheet 4 o INVENTOR. Flg. 7 RALPH E. Roman AHorneys June 7, 1966 R. E. RoPER 3,254,521

APPARATUS FOR FORMING METALLIC SHEET MEMBERS Original Filed Feb. 25, 1962 5 Sheets-Sheet 5 9 unv Il! l lll/11111111 INVENTOR RALPH E. RoPER BY Mmwfw AH'orneyS United States Patent O 3,254,521 APPARATUS FOR FORMING METALLIC SHEET MEMBERS Ralph E. Roper, Indianapolis, Ind., assignor to Wallace Expanding Machines, lne., Indianapolis, Ind., a corporation of Indiana Original application Feb. 23, 1962, Ser. No. 175,152, now Patent No. 3,222,910, dated Dec. 14, 1965. Divided and this application Feb. 11, 1965, Ser. No. 438,156

This application is a division of application, Serial No. 175,152, filed February 23, 1962, now Patent No. 3,222,- 910, issued December 14, 1965.

The present invention relates to apparatus for forming metallic sheet into parts such. as :automobile fenders, doors, bonnets and other drawn sheet metal parts.

It is conventional practice in the automobile industry to draw fenders, doors and in fact practically all sheet metal parts of this type by the use of toggle presses. These toggle presses usually operate to grip a at sheet of metal around and adjacent the edge thereof. The sheet is then formed inwardly of the gripped edge thereof by the use of cooperating male and female dies. Many Vproblems are involved in drawing metal in this manner. First, it is frequently necessary to ovedraw a part in order that it have the correct final shape. The amount of overdrawing necessary can only be an educated guess which must be made by one having long experience in the iield. Even then the .final product is unpredictable and may be far outside the desired tolerances.

Second, the toggle press is usually the weak link in the forming process. In practically all production lines, the various other apparatus such as trimming and ilanging devices and the like must wait on the toggle press which paces the production line. Also, the toggle press is usually capable of forming only a single lshape or part at one time and consequently, long expensive down time is experienced during which the toggle press is converted over from one part tov another. For example, the toggle press might be operated to produce left-hand automobile doors for a period of time and then converted over to right-hand automobile doors. It will be evident that thisv situation also results in storage problems of the one type of part which has been most recently formed and alsocauses diculties in production planning.

Consequently, a primary object of the present invention is to provide improved apparatus for forming metallic sheet material into parts.

A further object of the present invention is to provide apparatus for sheet metal forming which, as compared to toggle presses,r drastically reduces scrap, greatly increases structural strength, permits the use of lighter gauge metal and reduces tooling costs.

Another object of the present invention is to provide apparatus for sheet metal forming which, as compared to toggle presses, drastically reduces initial cost.

Still another object of the invention is to provide apparatus for sheet metal forming which, as compared to togglev presses,v increases speed of production, reduces the amount of metal finishing required and makes possible greater exibility in the shapes that can be formed.

Related advantages o'f the invention are that it makes possible.. precise forming of parts Without guesswork and makes possible the forming of a plurality of parts simultaneously, thus reducing storage space necessary and alsoA reducing loss of production time in tooling change-over.

Related objects and advantages will become apparent as the description proceeds.

One embodiment of the method of the present invention comprises the steps of bending a sheet of metal into a closed shape with the opposite edges thereof in engage- 3,254,521 Patented June '7, 1966 ice ment, securing the opposite edges together, expanding and stretching the closed shape over a die structure baving a discontinuous forming face wherein each continuous portion of the forming face defines one complete surface of a respective one of said parts and cutting the metal between the thus formed parts to separate them.

One embodiment of the apparatus of the present invention comprises a plurality of dies each having an outwardly facing surface which has the shape desired for one complete surface of a respective one of the parts, means for simultaneously moving the dies radially outwardly to stretch an annular sheet metal member thereover and to form the parts, and means flor separating the thus formed parts.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

FIG. 1 .is a top plan view of an expander forming a part of the present invention.

FIG. 2 is a perspective view of a closed sheet metal rlplember preformed for reception within the expander of FIG. 3 is a vertical section taken along the line 3-3 of FIG. l in the direction of the arrows.

FIG. 4 is a top plan view similar to FIG. 1 but showing the parts in different operating position.

FIG. 5 is a vertical section taken along the line 5-5 of FIG. 4 in the direction of the arrows.

FIG. 6 is a top plan view of apparatus for performing the method of the present invention.

FIG. 7 is an enlarged vertical elevational view taken generally along the line 7-7 of FIG. 6l and showing barrel forming and preforming apparatus forming a part of the present invention.

FIG. 8 is a fragmentary vertical section through cutting apparatus forming a part of the present invention and taken generally along the lline 8-8 of FIG. 6.

FIG. 9 is a fragmentary horizontal section taken along the line 9 9 of FIG. 8 in the direction of the arrows but showing the device in a different operating position. Referring now more particularly to the drawings, there is illustrated in detail in FIGS. 1, 3, 4 and 5 an expander apparatus 9 which operates upon the rectangular shaped closed sheet metal structure shown in FIG. 2 to expand it intoa cluster of connected sheet metal parts. The expander includes a base 10 Which is supported upon vertically extending members 11 and has ixed thereto a cylindrical or ring-shaped vmember 12. In order to r-rnly fix the ring-shaped member to the base, the member 12 is provided with a downwardly projecting annular lip 15 which is received within a suitable annular recess 16 in the base. An annular top plate 17 is fixed to the upper edge of the ring-shaped member 12 in similar fashion with lip 18 in recess 19 whereby a rigid cylindrical housing 20 is provided. To provide an even further amount of strength and rigidity, four shouldered vertical pins 21 are received within suitable apertures in the base and top plate and x these members in spaced relation.

lA plurality of radially extending keys 22 are fixed to and received within suitable radially extending apertures in the base 10. The keys 22 provide trackways for four tool or die carrier members 25 and 26. Fixed t-o the outer faces of the carriers 25 and 26 are scab dies 27 and 28 which can be removed and replaced by different shaped dies if desired depending upon the .type of part being formed. The dies and die carriersv 25-28 are movable between `the base 10 and a center cluster top plate 30 which is fixed in spaced relation to the base 10 by means of shouldered bolts 31, the top plate 30 acting to retain the die carriers upon the trackway forming keys 22.

Each of the die carriers and 26 has a tapered inner surface 32 and 33 against which the tapered outer surfaces 35 and 36 of an inner drive member 37 act. The driver member 37 is fixed to a vertically extending piston rod 40 of a iiuid motor 41 which is fixed to the base 10. When the motor 41 is operated to move the driver 37 downwardly, the surfaces 35 and 36 of the member camagainst the inner surfaces 32 and 33 of the die carriers to move them outwardly. When the fluid motor 41 is operated to move the piston rod 40 and driver member 37 upwardly, the die carriers 25 and 26 are drawn inwardly by means of T-shaped keys 42 and 43 (FIG. 3) fixed to the surfaces 35 and 36 and received within T- shaped slots 45 and 46 (FIG. 4) formed within the die carriers. Thus, it can be appreciated that vertical move- -ment of the driver member 37 in opposite directions produces inward and outward movement of the die carriers 25 and 26 and the dies 27 and 28 mounted thereon.

The surfaces 32 are tapered at a different and greater 'angle to the vertical than the surfaces 33. Thus, when the driver member 37 is moved to its uppermost position as shown in FIGS. 1 and 3, the dies 27 are moved a greater amount radially inwardly than are the dies 28. Each of the dies 28 is formed with a recess 47 in its rearward face which receives the end portion of each of the dies 27. When the dies 27 and 28 are moved to their outward position by the driver member 37, the dies 27 travel a greater radial distance than do the dies 28. By the above described arrangement, the circumference of the inner dies, when in their innermost position, can be made smaller without reducing the distance (taken horizontally) across the forming faces 51 and 52 of those dies.

Four outer die carriers 55 are radially slidable along the trackway-providing keys 22. Preferably, bearings 23 formed of bronze material or the like, are provided in the base 10 at its upper surface across which the die carriers 55 and 26 and 27 travel. Each of the die carriers 55 has an outer die 56 mounted thereon. The outer dies 56 are provided with inwardly projecting portions 57 which function to form the indentations and recesses in the external surfaces of the cluster of parts being formed in the work piece 60.

The annular top plate 17 has fixed in the lower face thereof radially-extending keys 61 which project into upwardly-opening grooves 62 in the upper surface of the outer die carriers 55 and act as additional trackways for the die carriers 55. The outer die carriers are moved inwardly and outwardly by means of cam means 65 which may be in the form of a ring. The cam ring 65 is provided with tapered inwardly facing cam surfaces 66 which act against cooperating surfaces 67 o'n the external faces of the outer die carriers 55. A plurality of fluid cylinders 68 are xed to the base 10 and have their piston rods 69 fixed to the cam ring 65 whereby upward projection of the piston rods causes ythe cam surfaces 66 to move across the surfaces 67 of the outer die carriers and to move the outer die carriers radially inwardly. The inner- `most position of the die carriers 55 is shown in FIG. 5.

In this position, the vertical surfaces 70 of the cam ring 65 are in engagement with the vertical surfaces 71 of the outer die carriers. Consequently, further vertical movement and seating of the cam ring 65 against the top plate 17 produces no corresponding radial movement of the die carriers and the die carriers are locked in the illustrated inward position by the surfaces 70 and 71.

Each of the forming faces 51 and 52 of the dies 27 and 28 defines the desired shape of the complete inner surface of a respective one of the parts to be formed from the work piece 60. In the illustrated embodiment, four automobile door panels are to be formed from the closed sheet metal work piece 60. Referring to FIG. 4, these four desired shapes are shown at 75, 76, 77 and 78 and are connected by scrap metal portions 79.

In order to form the cluster of parts shown in FIG. 4, the rectangular work piece 60 is placed about the dies 27 and 28 in the position show-n in FIG. 1 with the dies all drawn to their innermost position by projection of the piston 40 and driver member 37 to their uppermost position as shown in FIG. 3. The outer cam ring 65 is then moved from the position of FIG. 3 to the position of FIG. 5 by projection of the piston rods 69 of the cylinders 68. The driver member 37 is then moved downwardly to the position of FIG. 5 causing the dies 27 and 28 to move outwardly and to stretch the metal'of the workpiece 60 thereover. Because of the fact that there are no binders or devices gripping any of the metal of the workpiece, it is free to ow uniformly and to stretch out not only over the forming faces of the dies 27 and 28 but also at the scrap portions 79 whereby the nal transverse dimension taken horizontally across the parts -78 is greater than the complete initial circumference of the workpiece 60 as shown in FIG. 2. It should be mentioned that the horizontal cross section of the final parts 75-78 is not necessarily constant and in most cases (for example, in forming fenders) varies greatly from Ithe top of the parts to the bottom thereof. Thus, the metal ows andstretches not only horizontally but also vertically.

As the dies 27 and 28 move outwardly, they engage the outer dies 56 and cause the projections 57 of the outer dies to force against the workpiece 60 and to produce the desired indentations and recesses in the external surface of the parts 75-78. The final forming position ofthe apparatus is shown in FIG. 4. It can be appreciated that until the inner and outer dies are fully engaged, the metal is free to flow and stretch and there are n0 binders or members gripping the work piece and preventing free ow.

The outer dies are then moved outwardly to their original position by downward movement of the cam ring 65. The cam ring has mounted thereon a plurality of T-shaped keys 80 which lare receivable within T-shaped slots 81 in the external surface of the die carriers 5,5. As the cam ring moves downwardly, the keys 80 move into the slots 81 and cam against the surfaces 82 of the louter dies causing the outer dies to be moved outwardly away from the work piece and to return to the position shown in FIGS. 1 and 3. The driver member 37 is raised upwardly by projection of the piston rod 40 causing the die carriers 25 and 26 and the dies 27 and 28 to be moved inwardly and to return Ito the position illustrated in FIGS. 1 and 3.

It should be noted that the parts 75 and 77 are allochirally related to the parts 76 and 79. In the illustrated embodiment of the invention, the parts 75 and 77 may be identical left-hand automobile doors yand the parts 76 and 78 identical right-hand automobile doors. Because such allochirally related parts have the same vetrical dimension and similar shapes, the present invention is particularly adapted for forming such parts. This is true because the amount of metal needed and the amount of drawing needed for each such part around the workpiece is equal. Thus, an inexpensive and easily constructed workpiece of constant axial length is used in the present embodiment.

Fixed to the base 10 is a plurality of fluid cylinders 85 having .piston rods 86 with pads'87 on the distal ends thereof. The fluid motors are then operated to project theirV piston rods and raise the feet 87 to lift theformed workpiece upwardly out of the apparatus. The workpiece is then picked up by automatic transfer means and carried to further apparatus which cuts the workpiece along the scrap portion area 79 -to separate the parts. lhis further cutting apparatus is described in detail be- Referring to FIG. 6, the complete system for practicing the method of the present invention is illustrated schematically. A conventional barrel forming and welding machine 90 functions to convert strips of sheet metal into sheet metal cylinders of a desired diameter. The machine 90 bends the :sheet metal until the opposite edges thereof engage and then welds the opposite edges together to form the desired cylindrical shape. A suitable machine of this type for use in the present invention is Special Appliance Type barrel Welder manufactured by Federal-Warco Division of McKay Machine Co., Warren, Ohio. Alternatively, this welded cylindrical workpiece could be manufactured manually by manually bending a rectangular sheet of metal until the opposite edges engage, welding the edges together and grinding down the weld in a conventional manner so that the thickness of the welded portion is equal to the thickness of the sheet metal.

After the machine 90 has formed the sheet metal into the desired welded cylindrical workpiece, the cylindrical workpiece is moved by the machine 90 onto "an expander 91 forming a part of preforming apparatus 92. As shown in dotted lines in FIG. 7, the expander 91 may be tilted to a position wherein the axis of the expander 91 extends horizontally so that the cylindrical workpiece can be placed thereover by machine 90.

The preformer 92 includes a base 95 including vertical posts 96 and horizontal members 97 fixed to and connecting the posts 96. A table 100 is pivoted upon the base 95v at 101. Four dies 102 are horizontally slidable upon the upper `surface of the table 100 and are guided for radial movement by guide members 103. Each ofv the dies 102 is provided with 4a pair of the guide members 103, each of which is fixed to the table 100 and has an inwardly projecting portion 105 received within a horizon- I the dies 102. A driver member 106 having a cross-shaped cross section is received within the dies 102 and .is keyed thereto by T-shaped keys 107 in the manner described above with respect to the expander of FIGS. 1, and 3-5. Similarly to the above described expander, the driver 106 and dies have cooperating tapering cam surfaces 108 and 109. Thus, vertical movement of the driver 106 in opposite directions produces inward and outward movement of the dies 102. Axial movement of the driver member 106 is effected by cylinder motor 110 4fixed to the table 100 and having its piston 111 fixed to the driver member.

A tilt cylinder motor 112 is pivoted to the horizontal members 97 and has its piston rod 115 pivoted to the table 100. The tilt cylinder 112 functions to move the table 100 between the solid line position and the dotted line position of FIG. 7. As mentioned, when the expander 91 is in the dotted line position, the cylindrical work piece is received .thereon from the machine 90, the expander 92 is then moved to the solid line position wherein the cylinder seats itself against the table 100. The cylinder 110 is then operated to move the driver member 106 downwardly and to expand the dies 102 preforming the cylindrical work piece into the rectanguiar workpiece shape 60 shown in FIG. 2. The workpiece is then removed lfrom the expander 91 by returning the driver 106 of the expander to the upward illustrated solid line position and by suitable automatic transfer apparatus 115. This automatic transfer apparatus functions to transport the workpiece 60 to and into the expander 9 of FIGS. l and 3-5 where the above described forming operations take place. As an alternative to the above described barrel forming machine 90 and preformer 92, the rectangular Vworkpiece of FIG. 2 might be formed and Welded by a single machine. This alternative is especially desirable where the workpiece is relatively large.

The rectangular workpiece is then expanded to the shape shown in FIG. 4 by means of the expander apparatus 9 and as above described in connection with FIGS. 1 and 3 5. The expanded workpiece is then lifted out of the expander 9 by means of the fiuid cylinders 85 and is transported by automatic transfer apparatus 116 to a splitter apparatus 117 shown schematically in FIG. 6 and in greater detail in FIGS. 8 and 9. The function of the splitter apparatus 117 is to separate the various parts formed in the expanded workpiece from one another. In the present embodiment,`the splitter apparatus separates the parts 75-78 by a single cut through each of the scrap portions 79. The four resulting parts are then conveyed along conventional conveyors 120 to suitable conventional trimmer die apparatus which function to trim the remaining portions of the scrap 79 from the individual parts 75-78; Alternatively, the splitter apparatus 117 may be designed so as to complete this trimming function in a single operation.

Referring more particularly 4to FIGS. 8 and 9, the splitter apparatus comprises vertical supporting structure having a cross shaped base plate 126 fixed to the Vupper ends thereof. Four cutter assembly support plates 127 are slidably mounted for horizontal radial movement with relation to the .axis of the splitter apparatus by means of L-shaped cross section guide members 130 fixed to the base 126. Each of the guides 130 has an inwardly projecting portion 131 which extends over its respective support plate 127 and retains the support plate between the` guides 130.

A threaded adjusting rod 132 is provided for radially adjusting the position of each support plate 127and is rotatably mounted at one end upon the vertical supporting structure 125 and at the other end upon the base 126 by means of suitable bearing elements 135 and 136 fixed to the structure 125 and the base 126, respectively. The bearing elements 135 and 136 include suitable means for retaining the rod 132 against axial movement. At the outward end of each rod 132, there is fixed a crank 137 for rotating the rod. Each of lthe support plates 127 has a depending element 140 fixed thereto and threadedly receiving the rod 132. It can be appreciated that the support plate 127 may be adjusted as to radial position by rotating the rod 132 by means of the crank 137. Normally, the support plate 127 will be adjusted for a particular type of par-t and will remain in the adjusted position until manufacture of that type of part has been completed at which time the tooling of the splitter apparatus aswell as the positions of the 'support plates 127 are converted over to a new par-t.

A cutter assembly 140 is mounted for radial horizontal movement upon each of the support plates 127 by means of L-shaped cross section guides 141 fixed to the support plates 127 and extending over the base plate 143 of each cutter assembly.

A fluid motor 142 is fixed' to each support plate 127 and has its piston rod `145 fixed to the base 143 of `the cutter assembly 140. Anvil structure 146 is fixed to each of the cutter assembly base plates 143 and extends upwardly therefrom. The anvil structure includes a die carrier 147 and an anvil die 150 fixed to the outer surface of the die carrier 147. Each anvil die 150has an outwardly facing die face 151 shaped identically to that portion of the inner surface 152 of the workpiece 155 which is adjacent to the area to be cut. In the center of each anvil die 151, there is an indentation 156 which extends the complete length of the die and has a shape corresponding to the cutter die 157. Because the anvil die face 151 is shaped identically to the workpiece, the anvil Vdie structure 146 is used to .position the workpiece prior to the cutting operation. This positioning function is accomplished by actuating the fluid cylinders 142 to retract their piston rods 145 and move the cutter assemblies 140 radially outwardly causing the anvil faces 151 to engage the workpiece at the areas 152 and position the workpiece for the cutting operation.

Each of the cutter assemblies further includes vertical side plates 160 and a rear or outer vertical plate 161 all of which are fixed to .the base plate 143 of the assembly and define a three-sided enclosure for the cutter die structure 162. The cutter die structure includes a die carrier 165 and the cutter die 157 fixed to the inner yface of the die carrier. The cutter die structure 162 is guided for `radical horizontal movement by means of the base 143, the side members 160 and a top member 166 fixed to the side members 160 and the outer member v1611.

A cam member -167 is received between the outer member 161 and the die carrier 165 and is guided for vertical movement by means of L-shaped guides 170 fixed to .the router 'member 161. 'Ihe cam member 167 has a T-shaped key 171 fixed to its cam face 172 and received within a T-shaped groove 175 in the cam face 176 of the die carrier 165. A iiuid motor 177 is fixed to the base 143 of each cutter assembly y140 and has its piston rod 180 fixed to the cam member 167. `It can be seen that retraction and projection of the piston rod 180 will move the cam member 167 vertically in opposite directions andl will move the die carrier 165 radially inwardly and outwardly.

A latch element 181 is pivoted at 182 to the top member 166 of each cutter assembly 140 and includes a pair of arms 185, each of which has an indentation 186 receivable upon a pair of pins 187 which extend oppositely from each of the anvil structures 146. The latch element 181 may be swung into and out of. engagement with the pins 187 by means of fluid motors 190 each of which are pivoted at one end to the respective top members 166 land have their piston rods 191 pivoted to the latch elements 131.

Each of the cutter assemblies 140 has an inwardly projcting work piece support 192 Xed thereto. Each anvil die carrier 147 has a pair of bores 200 within which are mounted pin guides 201 which slidably receive guide pins 202 fixed to the die carriers 4165. The pins 202 and guides '1 insure that the dies -156 and 157 are maintained centered during the splitting operation.

After the work piece has been dropped into the splitter apparatus and rests upon the work piece supports 192, the latching elements 181fmay be swung into engagement with the pins 187, thusl locking the upper ends of each anvil structure 146 against horizontal movement with respect Ito respective top members 166. Thus, the latchin-g elements 181 function to retain the anvil structures rigidly in position so that the cutter dies 157 have arm back-up member against which to cut. After the latching elements 181 have been properly secured .to the pins 187 and the anvils 147 are moved outwardly to properly position the workpiece, the uid motor -177 may be roperated to move the cam |167 of each cutter assembly downwardly to cut the scrap areas 79 and to separate the eX- panded parts 75-78 making up the Work piece 158. Preferably, the cutter dies 157 and anvil dies 156 are each formed so that a pair of notches is produced in each scrap portion 79, these notches assisting in positioning the separated parts in their respective trim die apparatus.

After the parts have been thus separated, the cams r167 are'ra'ised by actuation of the fluid motors 177 and each of the cutter dies 157 is retracted outwardly away from the workpiece. The separated parts are then free to be conveyed away upon the conveyors 120. The anvil structures 146 are then moved inwardly by fluid motors 142 in readiness for a further workpiece by actuation of the fluid motors 142.

From the above description, it will be evident that the lpresent invention provides an improved process and -appared to toggle press operation wherein each stamping produces only a single part. It has also been found that the present invention permits p-recise forming of parts such as automobile doors and fenders and that this pre' ciseness greatly exceeds anything known in conventional toggle press procedure, eliminates guesswork and per-mits formation of parts to very narrow tolerances.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrict-ive in character, as modifications may readily suggest themselves to persons skilled in .this art and within the broad scope of the invention, reference being had to the appended claims.

As used in the following claims, the terms tubular and closed shape are intended to mean cylindrical and also to describe the rectangular shape of FIG. 2 as well as other such shapes.

The invention claimed is:

1. Apparatus for forming a cluster of parts comprising a plurality of dies each having an outwardly facing forming surface having an other than annular shape desired for one surface of a respective one of said parts, each of said die forming surfaces including a plurality of forming portions adapted to engage the inside surface of an annular member for the forming thereof, and means for moving said dies outwardly away from one another to stretch an annular member thereover, all of the forming portions of each respective forming surface being y lixed with respect to the other forming portions of the respective forming surface whereby each forming surface retains the same shape throughout the forming process.

2. Apparatus for forming sheet metal parts comprising a plurality of dies each having an outwardly facing forming surface having an other than annular shape desired for one complete surface of a respective one of said parts, each of said die forming surfaces including a plurality of forming portions adapted to engage the inside surface of an annular member for the forming thereof, means for simultaneously moving said dies outwardly to stretch an annular member thereover and form the parts, all of the forming portions of each respective forming surface being Xed with respect to the other forming portions of the respective forming surface whereby each forming surface retains the same shape throughout the forming process, and means for separating the thus formed parts.

3. Apparatus for forming a cluster of sheet metal parts comprising a plurality of dies each having an outwardly facing surface having the shape desired for the complete inner surface of a respective one of said parts, a plurality of outer dies each having an inwardly facing surface including inwardly projecting portions having the shape desired for recesses and indentations in the outer surface of a respective one of said parts, and means for simultaneously moving said inner dies outwardly to stretch an `annular member thereover and to force the annular member against said outer dies,

4. Apparatus for forming a cluster of sheet metal parts comprising a plurality of dies each having an outwardly facing surface having the shape desired for the complete inner surface of a respective one of said parts, a plurality of outer dies each having an inwardly facing surface including inwardly projecting portions having the shape desired for recesses and indentations in the outer surface of a respective one of said parts, means for moving said outer dies inwardly and locking them in an inward position ready for forming of said parts, and means for moving said inner dies simultaneously outwardly to stretch an annular member thereover and to force the annular member against said outer dies.

5. Apparatus for forming a cluster ofy sheet metal parts comprising a base, a plurality of inner dies slidably mounted on said base for radial movement, a plurality of outer dies mounted radially outwardly of said inner dies on said base for radial movement coaxial to said inner dies, a ring fixed to said base and surrounding said outer dies, cam means received and axially movable between said ring and said outer dies and keyed to said outer dies whereby axial movement of said cam means produces inward and outward radial movement of said outer dies, means for axially moving said cam means, a wedge-shaped inner driver. received inwardly of said inner dies for coaxial movement with respect thereto, said -inner driver being keyed to said inner dies whereby axial movement of said driver produces inward and outward radial movement of said inner dies7 and means for producing axial movement of said inner driver.

6. Apparatus for forming a cluster of sheet metal parts comprising a base, a plurality of inner dies slidably mounted on said `base for radial horizontal movement, a plurality of outer dies mounted radially outwardly of said .inner dies on said base for radial horizontal movement coaxial to said inner dies, a ring fixed to said base and surrounding said outer dies, cam means received and axially movable between said ring and said outer dies and keyed to said outer dies whereby axial movement of said cam means produces inward and outward radial movement of said outer dies, means for vertically moving said cam means, a wedge-shaped inner driver received inwardly of said inner dies for coaxial movement with respect thereto, said inner driver being keyed to said inner dies whereby axial movement of said driver produces inward and outward radial movement of said inner dies, means for producing axial movement of said inner driver, said wedge-shaped driver having a tapered portion engaging a cooperating tapered portion of each of said inner dies, the taper of alternate ones of said engaging portions being greater than the taper of the other of said engaging portions whereby alternate ones of said dies are drawn inwardly to a greater extent than others of said dies, the other of said dies having recesses on their rearward faces which receive portions of the alternate ones of said dies whereby the minimum circumference of the inner dies can be as small as possible as compared to the distance across the forming faces of said dies.

7. Apparatus for forming a cluster of allochiral `sheet metal parts comprising a plurality of dies having outwardly facing allochiral forming faces each having an other than annular shape desired for one surface of a Y metal parts comprising a plurality of dies each having an -outwardly facing forming surface having an other than annuiar shape desired for the complete inner surface of a respective one of said parts, one of said dies having a forming face which is allochiral in relation to the forming faces of another of said dies, each of said die forming surfaces including a plurality of forming portions adapted to engage the inside surface of a tubular sheet metal member for the forming thereof, and means for moving said dies simultaneously outwardly to stretch a tubular sheet metal member thereover, all of the forming portions of each respective `forming surface being fixed with respect to the other forming portions of the respective forming surface whereby each forming surface retains the same shape throughout the forming process.

9. Apparatus for, forming a cluster of sheet metal parts comprising a plurality of dies each having an outwardly facing forming surface having an other than annular shape desired for one complete surface of a respective one of vsaid parts, said dies being movable from a retracted position wherein the dies are adjacent one another to an expanded position wherein the dies are spaced from one another, each of said die forming surfaces including a plurality of forming portions adapted to engage the inside surface of an annular member for the forming thereof, and means for moving'said dies from said retracted to said expanded position whereby an annular member can be stretched over said dies with said die faces forming individual parts therein and the portions of said member at the spaces between said dies being stretched to form scrap connecting said individual parts, all of the forming portions of each respective forming surface 'being fixed with respect to the other forming portions of the respective forming surface whereby each forming surface retains the same shape throughout the forming process.

1t?. Apparatus for forming a cluster of sheet metal parts comprising a plurality of inner dies each having an outwardly facing forming surface having the shape desired for one complete surface of a respective one of said parts, said inner dies being movable from a retracted position wherein the dies are adjacent one anotherv to an expanded position wherein the dies are spaced from one another, a plurality of outer dies having inwardly facing forming surfaces including inwardly projecting portions having the shape desired for recesses and indentations in the outer surface of said parts, means for moving said outer dies inwardly land locking them in an inward position ready for forming of said parts, and means for moving said inner dies from said retracted to said expanded position whereby a tubular sheet metal member can be stretched over said dies with said inner die forming `faces forming individual parts therein and the portions of said member at the spaces between said inner dies being stretched to form scrap connecting said individual parts. I

References Cited by the Examiner UNTED STATES PATENTS 7/1934 Ireland 113-118 9/ 1963 Seeloff 72-393

Claims (1)

1. APPARATUS FOR FORMING A CLUSTER OF PARTS COMPRISING A PLURALITY OF DIES EACH HAVING AN OUTWARDLY FACING FORMING SURFACE HAVING AN OTHER THAN ANNULAR SHAPE DESIRED FOR ONE SURFACE OF A RESPECTIVE ONE OF SAID PARTS, EACH OF SAID DIE FORMING SURFACES INCLUDING A PLURALITY OF FORMING PORTIONS ADAPTED TO ENGAGE THE INSIDE SURFACE OF AN ANNULAR MEMBER FOR THE FORMING THERETO, AND MEANS FOR MOVING SAID DIES OUTWARDLY AWAY FROM ONE ANOTHER TO STRETCH AN ANNULAR MEMBER THEREOVER, ALL OF THE FORMING PORTIONS OF EACH RESPECTIVE FORMING SURFACE BEING FIXED WITH RESPECT TO THE OTHER FORMING PORTIONS OF THE REPECTIVE FORMING SURFACE WHEREBY EACH FORMING SURFACE RETAINS THE SAME SHAPED THROUGHOUT THE FORMING PORCESS.

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