US2240294A

US2240294A - Apparatus for forming metal parts

Info

Publication number: US2240294A
Application number: US243169A
Authority: US
Inventors: Edward J Greif
Original assignee: Borg Warner Corp
Current assignee: Borg Warner Corp
Priority date: 1937-04-09
Filing date: 1938-11-30
Publication date: 1941-04-29
Anticipated expiration: 1958-04-29

Description

April 29, 1941. GRElF 2,240,294

APPARATUS FOR FORMING METAL PARTS Original Filed April 9. 1937 A 47 2mg i ii M INVENT OR.

BY a waroq Grey TTC Y.

Patented Apr. 29, 1941 UNETED ST? T OFFICE ARPARATUS FOR FORMING-METAL PARTS Edward .1. Greif, Chicago, 111., assignor to Borg- Warner Corporation, Chicago, 111., a corporation of Illinois 12 Claims.

This invention relates to the making of large volume receptacles such as washing machine tubs, and has as its primary object to provide apparatus for forming in a washing machine tub of the v type wherein the side wall of the tub is connected to a mouth of reduced diameter by an upwardly and inwardly curving integral shoulder region, a sunken, concealed cover seat in which the cover may be supported with its edges concealed and its upper surface forming a smooth symmetric-a1 continuation of said curved shoulder region. The present application is a division of my pending application Serial N0. 135,990, filed April 9,-1937, for Forming metal parts.

The apparatus of the present invention forms one of a series of mechanisms for performing a series of operations upon the receptacle. In one of the intermediate operations, Ithe neck region is folded axially into the receptacle from the rim of the in-curved shoulder region. The apparatus of the present invention operates upon the substantially cylindrical neck region thus formed, so as to form the cover seat therein by the action of opposed axially movable die elements. The invention deals with the problem of applying a forming die to the peripheral surface of the infolded neck region, which forming die must be necessarily of greater diameter than the diameter of the mouth of the receptacle and yet must be inserted through said mouth in order to gain access to said peripheral surface. This problem is met by providing a die element in the form of a sectional annulus, the sections of which may be separately inserted and removed.

The object of the invention, therefore, is .to provide an apparatus including such a sectional die, adapted to cooperate with a complementary male die element for forming the cover seat in the in-iolded neck region when the die elements are urged axially toward each other under pressure, together with means insertable through the receptacle mouth and adapted to be extended radially into engagement with the annular die element and to transmit axial pressure thereto.

Other objects of the invention are to provide means for supporting the curved shoulder region of the receptacle against deformation during the forming of the neck region, for stripping the receptacle from the die at the completion of the forming operation, and for retracting the pressure applying means to a position allowing the removal of the receptacle.

The above and other objects, advantages and uses of my invention will become apparent from a reading of thefollowing specification and claims taken in connection with the appended drawing which forms a part of the specification and wherein:

Fig. l is an axial sectional view through a portion of an apparatus embodying the invention, the parts being shown in the position of completion of the forming operation;

Fig. 2 is a plan view of a portion of such apparatus; and

Fig. 3 is an axial sectional view "of a portion of such apparatus, the parts being shown in an initial stage of operation.

In the process of fabricating a Washing machine tub, one step of which isperformed bythe (apparatus of the present invention, a sheet metal blank is first drawn into the general; shape of the tub, having a bottom wall It provided with a central aperture ll iorreception of the agitator drive shaft, and having a side wall l2. The edge region of the side wall [2 is, in a subsequent operation, curved inwardly to form the shoulder portion 13 and a neck region which projects nadially inwardly of the shoulder l3. This neck region is, in a subsequent operation, folded axially into the receptacle to form a substantially cylindrical neck region l4 shown in Fig. 3, spaced from the side wall [2 by an annular space IS. The rim l 6 of the tub is formed by the junction between the neck region I' l and the shoulder It.

That portion of the neck region M which lies adjacent the rim I6 is cylindrical, as at l8, and

the remainder thereof is frusto-conical, converging toward the bottom of the tub. The method and apparatus for bringing the tub to this stage of formation is illustrated and described in the aforesaid co-pending application Serial No. 135,990.

The present invention provides apparatus for die forming the neck region l4'so as to produce therein a seat l1, connected to the rim 1 6 by the throat l3, and terminating in an inwardly oii-set flange it, which is, in a subsequent and final op eration, curled radially outwardly so as to remove the edge region thereof from the region of probable contact With clothes being inserted into and withdrawn from the tub.

The apparatus of the present invention includes a supporting ring 20 for supporting the tub in an inverted position during the seat forming operation, a male die element 2i adapted to engage the inner surface of the neck region l4, an annular die element 22 receivable in the annular space It and adapted to cooperate with the male die element Zl'in forming the seat I 7', and means,

indicated generally at 23, for applying downward pressure to the annular die element 22.

The supporting ring 29 includes an upstanding annular flange 24 for receiving the side wall 12 of the tub, and a downwardly and inwardly curving seat 25 adapted to conform to the surface of the shoulder 13 so as to preserve the shape thereof during the seat forming operation.

In order that the tub may be freely inserted into the supporting ring 20 in preparation for the forming operation, the ring 20 is constructed so that it may expand to a normal, unstressed position wherein the internal diameter of the flange 24 is substantially greater than that of the side wall I2 of the tub, as indicated in Fig. 3. From this normal position, it is adapted to contract into snug constricting engagement with the tub as shown in Fig. 1. This contraction is effected automatically during the forming operation as a result of downward movement of the ring 20 from the initial position shown in Fig. 3 to a position contacting the upper surface 26 of a base 2'! on which the several parts are supported. In thus moving downwardly, a frustoconical outer surface 28 of the ring 2i) cooperates with the conforming inner surface 29 of an upstanding flange 30 formed integrally with the base 21 at the periphery thereof, resulting in the forced contraction of the supporting ring 20 against the resistance of its inherent expanding force. The ring 20 is split so as to allow the required amount of expansion and contraction.

The annular die element 22 is in the form of circumferentially severed sections adapted to be inserted one by one into the annular space I prior to the positioning of the tub between the ring 20 and male die element 2!. The die elements 2i and 22 are provided with cooperating forming surfaces having the shape of the finished seat I l and the adjacent regions l8 and IQ of the neck region. a

The male die element 2| is fixedly positioned upon the base 21, and the annular die element 22 is adapted to move downwardly in order to effect the forming operation.

The die element 22 has a rounded corner 3|, which, together with the conical form of the neck region I4; allows the die elements to slide smoothly over and into the neck region M with a purely axial movement so as to form the two regions of different diameter separated by an offset, without buckling the neck region.

The means for forcing the annular die element 22 downwardly comprises a plurality of radial jaws 32 pivoted at 33 upon brackets 34 which are secured tothe male die element 2| by means of bolts 35. The jaws 32 are adapted to swing radially outwardly and downwardly, and are thus adapted to assume an initial position, shown in dotted'lines in Fig. 1, lying wholly within the innermost circumference of the mouth of the tub so that they may freely enter the mouth. as the tub is placed in position in the die mechanism. From this initial position, the outward and downward swinging serves first to extend the jaw members radially until they project above the annular die element, and, in the latter stage of such movement. to apply downward pressure to the annular die element.

The jaws 32 are spaced apart circumferentially ,iust sufficiently to accommodate the lifting rods 33 which project vertically between them. Upon he lower ends of the rods 33 are threaded nuts 36 which engage the lower edges of the jaws 32 for applying lifting pressure thereto. The upper regions of the lifting rods 33 are slidably mounted in a pressure plate 35 and provided with heads 31 adapted to be engaged by said plate 36 for lifting the jaws 32 to their starting positions during the return stroke of the press in which the mechanism is mounted.

The pressure plate 36 is mounted upon a plunger 33 and abuts a shoulder 39 thereof from which it receives downward pressure on the downward stroke thereof. The reduced lower end 40 of the plunger 38 is slidably mounted in a bearing 4!, mounted in an aperture 42 in the base 27.

Guide posts 43 are slidably extended at 44 through the pressure plate 36 and threaded into the male die element 2! as shown. Encircling the posts 43 are compression springs 45 which are compressed during the downward stroke of the pressure plate, and which, upon the return stroke of the plunger 38, force the pressure plate 36 back upwardly to its starting position shown in dotted lines. The upward movement of the pressure plate is limited at this position by heads 46 on the posts 43.

In the operation of the apparatus, the tub is inverted and placed over the pressure transmitting apparatus 23 while the latter is in its retracted position shown in dotted lines, the post 38 at the time being elevated to a height sufficient to allow the tub to be inserted beneath its lower end. The rim region of the tub is fitted into the space between the supporting ring 20 and the male die element 2!. Prior to placing the tub in position in the die apparatus, the sectional annular die 22 has been inserted in the annular space l5 Within the tub, as previously described.

The tub being properly positioned in the die apparatus, the plunger 38 is lowered through the opening I I in the tub until the shoulder 39 contacts the pressure plate 36. The parts are then in the position shown in Fig. 3, the supporting ring 20 being in its raised and expanded position, the shoulder 13 of the tub resting against the curved seat 25 thereof, and the annular die element 22 resting against the upper edge of the neck region I4.

Continued downward movement of the plunger 38 under pressure given to it by suitable cross mechanism, causes the jaws 32 to swing outwardly and then downwardly into engagement with the annular die element 22. From this point the jaws 32 commence to apply downward pressure to the annular die element.

This downward pressure causes the annular die element 22 to be forced downwardly into the annular space l5 until its curved lower surface 47 contacts the inner surface of the shoulder region l3, pinching the shoulder against the curved die surface 25 of the supporting ring 20. From this point, the ring 23 will be forced downwardly and inwardly and the die elements 2| and 22 will commence the forming operation. At the completion of the stroke, the ring 20 will be fully contracted and the seat I! will be fully formed. Since the shoulder I3 is tightly engaged between the annular die element 22 and the supporting ring 2!] during the forming operation, its smoothly curved shape will be fully preserved without any buckling or wrinkling therein.

Upward movement of the post 33 allows the pressure plate 36 to be returned to its starting pos tion by the retractor springs 45, and near the top of thestroke, the ring 20 is raised by means of chains 48, thereby releasing it constricting engagement of the tub, and stripping the tub upwardly from the die element 2|. The plunger 38 is then removed through the opening H, and

the tub is removed from the die apparatus.

Lastly, the sections of the annular die element 22' are removed from the tubby inserting a suitable tool, provided for that purpose, into a groove 49 in the annular die element.

I claim:

1. Apparatus for forming a cover seat in a mouth-defining neck region of a receptacle wherein said neck region projects axially into the receptacle in spaced relation to the side wall thereof from an in-turned rim; comprising a male die element adapted to engage the inner surface of said neck region, an annular die element insertible into the receptacle through the mouth thereof and receivable in the annular space between said neck region and the side wall, and means insertible into the receptacle through the mouth thereof and adapted to apply pressure to said annular die element for moving the same toward said male die element whereby to form said neck region between said die elements.

2. Apparatus for forming a cover seat in a mouth-defining neck region of a receptacle wherein said neck region projects axially into the receptacle in spaced relation to the side wall thereof from an in-turned rim; comprising a male die element adapted to engage the inner surface of said neck region, a sectional annular die element adapted to be inserted through the receptacle mouth and into the annular space between the neck region and the side wall, and means insertible through the receptacle mouth and engageable with said annular die element for applying pressure thereto whereby to form said neck region between said die elements.

3. Apparatus for forming a cover seat in a mouth-defining neck region of a receptacle wherein said neck region projects axially into the receptacle in spaced relation to the side wall thereof from an in-turned rim; comprising a male die element adapted to engage the inner surface of said neck region, a sectional annular die element adapted to be inserted through the receptacle mouth and into the annular space between the neck region and the side wall, and means insertible through the receptacle mouth and radially extensible into engagement with said sectional die for moving the latter toward said male die element whereby to form said neck region between said die element.

4. Apparatus for forming a cover seat in a mouth-defining neck region of a receptacle wherein said neck region proiects axially into the receptacle in spaced relation to the side wall thereof, from the rim of an in-curved shoulder region; comprising a die including an annular supporting ring shaped to conform to said shoulder and adapted to support the same against deformation during the forming operation and a male die element adapted to engage the inner surface of said neck region, a sectional annular die element adapted to be inserted in the annular space between the neck region. and the side wall, and means adapted to apply pressure to said annular die element within the receptacle for moving said annular die element toward said male die element whereby to form said neck region between said die elements.

5. Apparatus for forming a cover seat in a mouth-defining neck region of a receptacle wherein said neck region projects axially into the receptacle in spaced relation to the side wall thereof from an in-turned rim; comprising a downwardly 'y-ieldable contractile supporting ring adapted to receive the rim and adjacent wall region of the receptacle and to support the receptacle in an inverted position, means adaptedto coact with said ring when the latter is moved downwardly for contracting the same into snug engagement with the receptacle, a male 'die element adapted to engage the inner surface of said neck region, an annular die element insertible in the annular space between the neck region and the side wall, and means insertible into the receptacle and engageable with said annular die element for applying downward pressure thereto whereby to force said supporting ring downwardly and form said neck region between said die elements.

6. Apparatus as defined in claim 5, including means to raise said supporting ring at the end of the forming operation so as to strip the receptacle from said male die element.

'7. Apparatus for forming a cover seat in a mouth-defining neck region of a receptacle wherein said neck region projects axially into the receptacle in spaced relation to the side wall thereof, from the rim of an incurved shoulder region; comprising a fixed male die element adapted to engage the inner surface of said neck region, an axially yieldable ring interiorly shaped to conform to the surface of said shoulder region and adapted to receive the same in an initial position axially removed from said male die element, an annular die element insertible in the annular space between the neck region and the side wall of the receptacle, means for applying axial pressure to said annular die element so as to move the same toward said male die element, said annular die element being adapted to transmit said pressure through said shoulder region to said ring and to thereby move said ring axially, and means cooperating with said ring when thus moved axially for contracting the same into constricting engagement with said shoulder region for preserving the contour thereof during the forming operation.

8. Apparatus as defined in claim 7, wherein the means for contracting said ring comprises a base supporting said male die element and having an upstanding flange provided with an inner frusto-conical surface adapted to coact with a conforming surface on the periphery of said ring.

9. Apparatus for forming a cover seat in a mouth-defining neck region of a receptacle wherein said neck region projects axially into the receptacle in spaced relation to the side wall thereof from an in--turned rim; comprising a male die element adapted to engage the inner surface of said neck region, an annular die element receivable in the annular space between the neck region and the wall, and a plurality of jaws pivoted at points located on a lesser radius than the minimum radius of the receptacle mouth and adapted to swing radially outwardly from positions wherein they are insertable through the receptacle mouth, to positions wherein they are engageable with said annular die element and adapted to transmit pressure thereto for moving the same toward said male die element whereby to form said neck region between said die elements.

10. Apparatus as defined in claim 9, including a pressure plate associated with said jaws and adapted to apply pressure thereto from a press plunger.

11. Apparatus as defined in claim 9, including means for simultaneously engaging said jaws and transmitting pressure to them, and means operable upon the release of said jaw engaging means for retracting said jaws to positions wherein they may be removed from the receptacle.

12. Apparatus as defined in claim 9, wherein said jaws are pivoted to said male die element, and including a pressure plate adapted to engage said jaws for applying pressure thereto, retractor EDWARD J. GREIF.