US2225988A - Apparatus for forming metal parts - Google Patents

Description

Dec. 24, 1940. E. J.'GRE|F 2,225,988

APPARATUS FOR FORMING METAL PARTS Filed April 9, 1937 3 Sheets-Sheet l E. J. GREIF 2,225,988

APPARATUS FOR FORMING METAL PARTS Dec. 24, 1940.,

3 Sheets-Sheet 2 Filed April 9, 1937 fizz/6,1237

Greg

Dec. 24, 1940. E. J. AGREI'F 2,225,988

APPARATUS FOR FORMING METAL PARTS Filed April 9', 1937 3 Sheets-Sheet C5 Z29 J0 Jm 16 .205 I 95 I III jzz/ezzlrs [2 (2rd J we? Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE Edward J. Greif, Chicago, Ill., assignor to Borg- Warner Corporation, Chicago, Ill... acorporation of Illinois Application April 9, 1937, Seri'al'No. 135,990

10 Claims.

from the following detailed description of the invention when taken together with the accompanying drawings, which form a part thereof and in which:

Figs. 1 to 5 show the Various stages in the formation of a receptacle in accordance with this invention.

20 Fig. 6 is an elevation in section through a portion of the apparatus used to give the receptacle the form shown in Fig. 3.

Fig. 7 is a fragmentary plan view of the apparatus used to give the receptacle the form shown 25 in Fig. 4.

Fig. 8 is an elevation in section through a portion of the apparatus of Fig. '7, showing the apparatus in its initial position.

Fig. 9 is an elevation in section through a portion of the apparatus of Fig. 7, showing the apparatus in its final position and showing the actuating means for the apparatus.

Fig. 10 is an elevation in section through a portion of the apparatus used to give the receptacle the form shown in Fig. 5, the apparatus being shown in its initial position.

Fig. 11 is an elevation similar to Fig. 10, but showing the apparatus in its final position; and

Fig. 12 is a fragmentary side elevation of the apparatus of Fig. 10, showing the means for placing the apparatus of Fig. 10 in its final position.

The same reference characters are used to designate similar parts throughout the various figures of the drawings.

In its preferred form, this invention comprises broadly means for clamping a receptacle at or near the point at which it is being shaped, and means operable from within the receptacle to give it the desired form. The receptacle shown in Fig. 3 is formed by clamping it in a press with a collet ring and forcing the inner end downward. The receptacle shown in Fig. 4 is formed by inverting the receptacle, placing a 55 three-part upper die in the channel formed between the side and inturned edge, and forcing the upper die against a lower supporting die. Novel means are provided for forcing the upper die downward and for stripping the receptacle from the lower die. The form shown inFig. 5 is obtained by supporting the receptacle in an inverted position on a track under a revolving roll and raising the track to cause the roll to curl the exposed end of the receptacle radially outward.

The novel method used in the formation of the receptacle includes the steps used to obtain the forms shown in Figs. 2 to 5 and consists in rolling the open end of the receptacle inward to form the bottle-neck of Fig. 2, then bending the neck downward into the receptacle to form a conical surface, then changing the conical surface to form the seat and cylindrical skirt shown in Fig. 4, and, lastly, curling the skirt outward to remove the sharp edges from the inner surface of the opening.

By the method and apparatus of this invention, a receptacle can be made to have a sunken cover seat and a smooth inner edge without the expense and waste of forming the seat portion from a separate sheet as is usually done by other methods. The result is a one-piece receptacle which is neat in appearance and economical to make.

For purposes of illustration, this invention will be described with reference to the formation of a washing machine tub, but it is understood that the invention can be used to'form other receptacles made of sheet metal.

Referring now to Fig. 1 of the drawings for a detailed description of the invention, I5 is a tub which has been formed in the usual manher from a single sheet of metal. The tub is provided with a central aperture l8 at the bottom, asecond aperture I1, which is used for draining purposes, and a bottle-neck IS. The method and apparatus used to'form bottle-neck l8 are described in my co-pending application Serial No. 91,269, filed July 18, 1936 and entitled Machine for forming bottle-necks upon sheet metal tubs (Patent No. 2,170,946, granted Aug. 29, 1939). The apparatus may be briefly described as comprising a series of rolls which force the end of tub l5 inward in combination with forming blocks, and results in a shape such as that shown in Fig. 1. For the formation of the seat shown in Fig. 5, the material above line A-A of Fig. 1 is superfluous and the tub, therefore, is trimmed along line A-A to give it the iorm shown in Fig. 2.

Referring now to Fig. 2, it will be observed that tub I5 is provided with a rounded shoulder I9, a flat portion 20, and an upturned edge or neck 2I. Due to the fact that edge 2I is formed by decreasing the diameter of the tub, the thickness of the material at that part is accordingly increased. Even though this portion is subsequently to be forced downward and outward and will therefore undergo an increase in its diameter, it will not be forced outward sufficiently to reduce its thickness to the normal thickness of the tub. The thickness of the metal at edge 2I is therefore reduced, preferably by the rolls which form the neck, to approximately that of the remainder of the tub.

After edge 2| of the tub of Fig. 2 has been reduced in thickness, it is then bent downward in the form shown in Fig. 3. The apparatus for producing this form is shown in Fig. 6, and reference thereto is now made.

The forming apparatus is comprised of a base casting 22 which is cylindrical in form and'provided with a flange 23 by which it may be secured to a suitable press (not shown). Base casting 22 is provided at its upper end with two or more ears 24, only one of which is shown for simplicity, and has a counterbore 25 connected by inclined surfaces 26 and 2! to the inner and upper surfaces 28 and 29, respectively. Inner surface 28 is slightly larger in diameter than the diameter of tub I5. Located in counterbore 25 is a collet ring 38, which is split and notched from opposite sides as at 3| and 32 to render it contractile. It is provided with inclined surfaces 33 and 34 which correspond to inclined surfaces 26 and 21 respectively in base casting 22. It is apparent that pressure upon upper surface 35 of collet ring 30 will cause surfaces 33 and 34 thereof to slide inward and downward upon surfaces 26 and 21, thereby reducing the diameter of collet ring 30. The ring normally is of a diameter comparable to the diameter of surface 28 of base casting 22.

The press is preferably provided with two rams (not shown) to the outer one of which a holder 36 is secured. Holder 36 is likewise provided with two or more cars 31 and 38 corresponding to ears 24 of base casting 22. All of the ears are accurately drilled and reamed to receive locating pins (not shown) which are removed after the base casting and holder are secured to their respective portions of the press.

The inner ram of the press is secured to a die member 39 which is guided in holder 36 by surfaces 46 and 4| in the holder. The downward motion of die member 39 is limited by shoulder 42 on holder 36, which abuts a flange 43 on die member 39 when said die member is at the bottom of its stroke. The bottom portion of holder 36 is shaped as shown at 44 to receive the upper end of tub I5. A portion of the surface of die member 39 is recessed in such a manner as to provide a shoulder 45 which permits inner ends 2! of tub I5 to remain at a slightly smaller diameter than the portion at shoulder 45. A pressure pad 46, which is urged upward by a plurality of compression springs 41 and guided in its upward motion by pins 48, is used to force tub I5 against holder 36.

The operation of the apparatus of Fig. 6 is as follows:

With the press in its starting position, holder 36 and die member 39 are raised above ring 30 and base casting 22. There is no pressure on ring 38 and hence it is in its expanded position. A tub of the form shown in Fig. 2 is inserted into base casting 22 until it rests upon pressure pad 46. The press is then operated, whereupon holder member 36 descends until it contacts shoulder I9 of the tub and thereafter forces tub I5 downward against pressure pad 46 until its lower surface bears against the upper surface 35 of collet ring 30. For the remainder of its stroke, holder 36 will force ring 30 downward and inward, thereby securely clamping tub I5 in base casting 22. With tub I5 securely clamped, the inner ram forces die member 39 downward to give tub I5 the form shown in Fig. 3. Pressure from die member 39 is not transmitted to pressure pad 46 due to the clamping action of collet ring 30, The inner ram then raises die member 39, stripping it from the tub, which is still held by holder 36, and then said holder 36 is raised, thereby relieving collet ring 30 of downward pressure. Collet ring 30 therefore springs outward to release tub I5, and the tub may then be removed for further forming operations.

Referring next to Fig. 3, it will be observed that tub I5 now has a cylindrical portion 49 and a conical skirt 50. The seat is formed from skirt 50 which is purposely made conical for reasons hereinafter tobe described.

The seat-forming apparatus is shown in Figs. '7, 8 and 9. In these figures, 66 is a base casting which is provided with a flange 6|. Base casting 60 is apertured at 62 to receive a bushing 63 in which is mounted a post 64. Threaded over bushing 63 is a lower die member 65 which is made of two parts 66 and 61, respectively. Part 6! is a split ring having a normal inner diameter which is greater than the outside diameter of portion 66. The outer surface 68 of ring 61 and the inner surface 69 of flange 6| are made conical, so that downward pressure on ring 6! causes it to slide along surface 69 and compresses it against portion 66. Ring 61 preserves the form of the shoulder II! of the tub, and part 66 forms a nose ID. a seat II, and a cylindrical portion I2 connecting seat II and nose I0, leaving a cylindrical end I3. Cooperating with lower die 65 is an upper die I4 which is in the form of a ring. Upper die I4 is split as at III! into three or more parts so that it may readily be removed from and inserted into, the nose of the tub.

The means for forcing upper die I4 against lower die 65 comprises a plurality of jaws I5 which are pivoted in bearings I6 secured by bolts 31, or otherwise, to part 66 of lower die 65. As shown in Fig. 7, jaws I5 are relatively closely spaced. The spacing however, is sufficient to permit a bolt I8 to pass therebetween. Bolts I8 are threaded through suitable apertures in a pressure plate I9, which overhangs pivots I6, and thence between adjacent jaws to a nut 86. Said nut is wider than the space between adjacent jaws and cannot be raised without likewise raising jaws I5.

Pressure plate I9 is also threaded over bolt 64 and abuts ashoulder 8| thereon. Downward motion of bolt 64 therefore causes pressure plate I9 to be lowered with it. Guide posts in the form of bolts 82 are provided for pressure plate I9, said bolts being threaded through suitable apertures therein. Apertures 83 are enlarged at their lower extremities to receive compression springs 84 which surround bolts 82 and press against part 66 of lower die 65. Springs 84, therefore, serve to raise pressure plate I9 after it has been lowered by post 64, the height to which it is raised being limited by the height of head 85 of bolt 82 above lower die 65. The head 86 of bolt 18 is likewise removed from pressure plate I9, but a shorter distance, so that upward movement of pressure plate I9 first raises the plate from the jaws I5 and then, through contact with heads 86, raises bolts 18, and with these bolts, through nut 80, the jaws I5. Said jaws will swing about pivots I6 and will assume a position such as that shown in dotted lines in Fig. 9. It will be observed that in the raised position jaws I5 do not extend over edge I3 of tub I5 and hence the tub can be lifted over the jaws.

In the form of apparatus shown in Fig. 9, power for lowering plate I9 is supplied through post 64 from its upper end, which is threaded through aperture it in tub I5. It is understood, however, that for tubs not having an aperture such as Iii, the power could likewise be supplied from the lower end of post 84.

The operation of the seat-forming apparatus can best be described with reference to Fig. 8.

- A tub having the form shown in Fig. 3 is inverted and upper die I4 is inserted in the nose of the tub. It will readily be seen now that if the folded portion of the nose were not made conical as at 5E3, downward pressure of upper die I4 would cause this portion to buckle. The conical form, however, causes edge I3 torest upon rounded corner 81 of upper die I4 and allows the edge to slide therearound without buckling when pressure is applied. The inverted tub with upper die 74 in place is then inserted into ring 61 of lower die 65. At this point ring 61 is in its expanded position and hence does not contact tub I5 except at the lowermost point of shoulder I9. Post M is then lowered, carrying with it pressure plate "I9, which lowers jaws I5 upon upper die 14. Continued downward movement of pressure plate I9 causes upper die M to contact the nose of the tub, thereby pinching the tub between itself and ring El. From this point onward, ring 61 commerces to contract and descend. At the completion of the stroke, ring 61 is fully contracted and upper die 14 has completed the formation of the seat in tub I5. Upward movement of post 64 then raises jaws I5, relieving upper die 14 of pressure,

7 and near the top of the stroke, ring 61 is raised by means of chains (not shown) thereby spreading it and simultaneously stripping tub I5 from portion 66 of lower die 65. Upper die I4 is then removed from tub I5 by inserting a suitable tool into groove 88 provided for that purpose and pulling it from nose 'II] of the tub. The tub now has the form shown in Fig. 4 and is ready for the curling operation.

Referring lastly to Figs. 10, l1 and 12, the curling apparatus is seen to comprise a circular track 88, which fits into the seat of the tub, and a curling roll 9i provided with a cylindrical portion 92 adapted to engage track 5%. Roll 9I is mounted on a bracket 93 which in turn is secured to an arm at threaded over a shaft 95. Track 90 is supported from a camming ring 96 through rollers 8'! which cooperate in camming slots 98 in ring 96. Rollers 9'! are mounted on axles 98 which may take the form of screws threaded into track 95. Ring 96 is mounted in a machined recess I08 in frame NH and is free to rotate relative thereto. Track 96, however, is held against rotation with respect to frame IIlI by pins I02. A control lever I83 is secured to ring 96 and provides the means for rotating said ring.

Shaft 95 is provided with threads I54 and a nut 295 which prevents vertical movement of arm 94 upon shaft 95 and secures arm 95 for rotation with shaft 95. Only one arm and roll are used in this apparatus and hence tub I5 may readily he slipped between the roll and track.

To form the curled edge by the apparatus just described, the tub, which now has the form shown in Fig. 4, is placed on track 99, again in an inverted position. Shaft 95 is rotated, carrying with it arm 94 and roll 9|, and control lever I03 is gradually pulled forward until cylindrical portionv 82 of roll 9! contacts track 90. The raising action arises from the coaction between roller 91 and camming surfaces 98. As shown in Fig. 12, it is obvious that motion of control arm I03 to the right. will. cause rolls 9'! to climb upward on cam surfaces 98 and raise with them the cooperating axles 98, thereby raising track 90 with respect to frame I When track 90 contacts roll 9!, as shown in Fig. 1]., edge I3 will have been turned outward by the sloping contour of roll SI After the edge has been curled, lever I 93 is moved in the opposite direction, thereby lowering track 88' and permitting tub I5 to be removed from the apparatus. The tub now has the form shown in Fig. 5.

It is apparent from the foregoing description,

that by my method a receptacle can be made to have a sunken cover seat of reduced diameter without requiring the use of a separate sheet of metal for the formation thereof. The seat may likewise be formed in such a manner that the edge, which is usually sharp, is curled outward where will not come in contact with clothing and other materials which may be pulled across the seat. The metal of the seat is not unduly strained and is free from undesirable wrinkles. It is apparent also that by my method, dies of a greater diameter than the diameter of the seat may be used internally of the tub and yet will not require a special opening in the tub for their insertion and withdrawal.

It is understood that the foregoing description is merely illustrative of a preferred embodiment of the invention and that the scope of the invention, therefore, is not to be limited thereto, but is to be determined by the appended claims.

I claim:

1. In an apparatus for forming a concealed cover seat in a relatively thin walled sheet metal receptacle having a neck flange converging upwardly and inwardly in an intermediate stage of formation, a male die element adapted to engage the inner region of said flange and to fold it axially into the interior of the receptacle, a contractile collet adapted to receive the receptacle in a position centered below the die element, means movable independently of. and in timed relation to the movement of said die element, adapted to-engage said collet and to move the same axially, and means cooperating with said collet when thus moved axially so as to cause the collet to contract into frictional engagement with the side wall of the receptacle and exert a restraining force against further axial movement of the receptacle for supporting the same against buckling under the pressure of said die element.

2. In an apparatus for forming a concealed cover seat in a relatively thin walled sheet metal receptacle, a male die element adapted to engage the upper edge region of said receptacle and to fold it axially into the interior thereof, a member adapted to be engaged by the bottom of the receptacle and to oppose the pressure of said die element, a contractile collet adaptedv to receive the receptacle in a position centered below the die element, means movable independently of and in timed relation to the movement of said die element, adapted to engage said collet and to move the same axially, and means cooperating with said collet when thus moved axially so as to cause the collet to contract into frictional en- 5, gagement with the side wall of the receptacle and thereafter to restrain further axial movement of the collet, for absorbing the axial pressure imposed upon the receptacle by said die element in sufiicient quantity to reduce the pressure transmitted through the receptacle to the said member sufficiently to avoid deformation of the receptacle under such pressure.

3. In an apparatus for forming a concealed cover seat in a relatively thin walled sheet metal receptacle, a male die element adapted to engage the upper edge region of said receptacle and to fold it axially into the interior thereof, a yieldingly mounted bottom member adapted to receive the lower region of the receptacle and to yieldingly oppose the axial pressure of said male die element, a contractile collet adapted to receive the intermediate region of the receptacle, means movable independently of and in timed relation to the movement of said die element and adapted to engage said collet in advance of the working portion of the stroke of said die element and to move the same axially, and means cooperating with said collet when thus moved axially so as to cause the collet to contract into frictional engagement with the side Wall of the receptacle and thereafter to restrain further axial movement of the collet during the working stroke of the die member for absorbing the axial pressure of said die element in sufficient amount to avoid deformation of the receptacle between the die element and said bottom member.

4. In an apparatus for forming a concealed cover seat in a relatively thin walled sheet metal receptacle having a neck flange converging up- 40 wardly and inwardly in an intermediate stage of formation, a male die element adapted to engage the inner region of said flange and to fold it axially into the interior of the receptacle, a holder movable independently of and in timed rela- 45 tion to the movement of said male die element and adapted to receive the upper region of the receptacle, a contractile collet arranged below and in register with said holder and adapted to be engaged by said holder and thereby moved 50. axially, and means cooperating with said collet when thus moved axially for causing the same to contract into frictional engagement with the intermediate region of the side wall of the receptacle and thereafter to restrain further axial 55 movement of the collet While the die element is folding the flange into the receptacle for supporting the same against buckling under the pressure of said die element.

5. In an apparatus for forming a concealed 60 cover seat in a relatively thin walled sheet metal receptacle, a male die element adapted to engage the upper edge region of said receptacle and to fold it axially into the interior thereof, an annular holder arranged to receive the upper re- 65 gion of the receptacle and movable independently of and in timed relation to the movement of said male die element, a contractile collet arranged to receive the intermediate region of the receptacle, and adapted to be engaged by said holder in advance of the working portion of the stroke of the male die element and thereby moved axially, a bottom member adapted to receive the lower region of the receptacle and to oppose the pressure of said male die element transmitted with said collet when thus moved axially so as to cause the collet to contract into frictional engagement with the receptacle and thereafter to restrain further axial movement of the collet to cause said collet to cooperate with said bottom member in supporting the receptacle against deformation under said pressure.

'6. In an apparatus for forming a concealed cover seat in a relatively thin walled sheet metal receptacle, a male die element adapted to engage 10 the upper edge region of the receptacle and to fold it axially into the interior thereof, a contractile collet adapted to receive the receptacle in a position centered below the die element, means movable independently of said die element and 15 adapted to engage said collet in advance of the working portion of each stroke of said die element and to move the same axially, and means cooperating with said collet when thus moved axially so as to cause the collet to contract into frictional 20 engagement with the side wall of the receptacle and to support the receptacle against deformation under the pressure of said die element transmitted through the receptacle.

'7. In an apparatus for forming a concealed 25 cover seat in a relatively thin walled sheet metal receptacle, a male die element adapted to engage the upper edge region of said receptacle and to fold it axially into the interior thereof, a bottom member adapted to yieldingly engage the 30 bottom of the receptacle in opposition to the axial pressure of said die element transmitted through the receptacle, an annular holder adapted to receive the upper region of the receptacle and to move the receptacle into engagement with said bottom member, a contractile collet adapted to receive the intermediate region of the receptacle and to be engaged by said holder in advance of the working portion of the stroke of said die element and to be thereby moved axially, and means 00- 40 operating with said collet when thus moved axially so as to cause the collet to contract into frictional engagement with the receptacle and thereafter to restrain further axial movement of the collet to cause the collet to cooperate with said bottom member in supporting the receptacle against said axial pressure without deformation thereunder.

8. In an apparatus for forming a straight-sided receptacle, a die member adapted to bear against one end region of the receptacle in a direction parallel to the sides thereof to fold the edge of the receptacle, a holder adapted to bear against an adjacent portion of the said end region of the receptacle in the same direction as the die member, means engaging the receptacle adjacent the opposite end region for urging said receptacle toward the holder, friction means engaging the straight sides of the receptacle for maintaining said receptacle in position while said die member is folding the edge thereof, and means cooperating with the friction means to take the reaction of the urging means, whereby pressure transmitted through the receptacle to the urging means is reduced below the point at which said 5 urging means can deform said receptacle.

9. In an apparatus for forming a straight-sided receptacle, the combination as described in claim 8, said friction means comprising a deformable ring cooperating with the urging means and having a cam surface, and said means cooperating with the friction means having a cam surface contacting the cam surface of the ring, said cam surfaces being so disposed that the diameter of through the receptacle, and means cooprating the ring is reduced as it is acted upon by the 75 urging means, whereby to clamp said receptacle in place.

10. In an apparatus for forming a receptacle, a die member adapted to fold the edge of the receptacle, a reciprocable holder for the receptacle, a pressure pad for yieldingly urging said receptacle toward the holder to position said receptacle therein, a reciprocable split collet ring surrounding said receptacle and having cam surfaces, and a stationary base member surrounding said collet ring and having cam surfaces cooperatively related to said collet ring cam surfaces, the base member cam surfaces and ring cam surfaces being so disposed as to cause the ring to alter its diameter as the ring is moved relative to the base member, said holder bearing against the collet ring to move the ring relative to the base member, whereby to decrease the diameter of the ring and to clamp the receptacle thereto while said receptacle is acted upon by! the die member.

EDWARD J. GREIF.

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