US2941290A - Method of producing a sphere with a hole therethrough - Google Patents

Description

2,941,290 METHOD OF PRODUCING A SPHERE WITH A HOLE THERETHROUGH Filed Jan. 11, 1955 L. R- HEIM June 21,- 1960 2 Sheets-Sheet 1 3x3, INVENTOR in; m

ATTO RN EYS.

L. R. HEIM 2,941,290 METHOD OF PRODUCING A SPHERE WITH A HOLE THERETHROUGH June 21, 1960 Filed Jan. l1, 1955 2 Sheets-Sheet 2 INVE TOR BY United States Patent METHOD OF PRODUCING A SPHERE WITH A HOLE THERETHROUGH Lewis R. Heim, Fairfield, Conn., assignor to The Heim Company, Fairfield, Conn, a corporation of Connecticut Filed Jan. 11, 1355, Ser. No. 481,069

3 Claims. ((31. 29-545) This invention relates to a method of producing a spherical member or ball with a hole therethrough, and has for an object to provide an improved method for sizing and forming a spherical member to the proper diameter and shape from forms or .blanks made from metal or other suitable ductile material.

A'further object is to provide such a method in which an undersize blank or form is made from metal or other suitable material and an undersized hole produced therethrough, and then this blank or form is expanded and sized to a predetermined diameter and form.

With the foregoing and other objects in view, I have devised the construction illustrated in the accompanying drawings forming a part of this specification. It is, however, to be understood the invention is not limited to the specific details of construction and arrangement shown, but may embody various changes and modifications within the scope of the invention.

In these drawings:

Fig. 1 is a longitudinal section showing an expanding and forming die set in a power press for carrying out this method and showing the dies in separated or retracted position prior to the expanding and sizing operation;

Fig. 2 is a similar section showing them together at the completion of or after performing the expanding and sizing operation;

Fig. 3 is a side view of a portion of a metal bar or rod indicating how the blanks or forms for producing the spherical member may be machined from this bar;

Fig. 4 is a side view of one form of blank which may be used and machined from the bar;

Fig. 5 is an end view thereof looking toward the bottom of Fig. 4;

Fig. 6 is a side view showing another form of blankwhich may be used;

Fig. 7 is an end view thereof looking toward the bottom of Fig. 6;

Fig. 8 is a side view of the completed spherical member or ball after expanding and sizing the machined form or blank;

Fig. 9 is an end view thereof looking toward the bottom of Fig. 8;

Fig. 10 is a section showing another arrangement of dies which may be used in this method and showing them in the separated position, and

Fig. 11 is a section of the dies of Fig. 10 showing them in the closed position after performing the expanding and sizing operation.

In forming a substantially spherical member or ball by this method, a blank or form may be provided by a number of different ways. One is to machine it from flats 16 at its opposite ends. The blankof Figs. 6 and 7 a bar or rod 10' of metal, as indicated in Fig. 3, the 7 blank or form being indicated at 11 circular in cross section and having an outer surface 12 convexly curved longitudinally of the blank and with a longitudinal opening 13 of a given size therethrough, the blank being then cut ofi from the rod at the point .14 and used in this improved expanding and sizing method to form the is the ellipsoidal blank 11 of Fig. 3,with the outer ellipsoidal surface 12 and having the opening 13 therethrough. This blank preferably also has flats 17 at its opposite ends.

Afterthese undersized blanks or forms are made they are expanded and sized to a predetermined diameter and form by the dies and operating means therefor shown in Figs. 1, 2, l0 and 11. Referring first to Figs. 1 and 2, the die set is shown adapted for mounting in a power press (not shown) for operation thereby, and comprises a die shoe 18 provided with a recess 19 in which is seated the lower die block 20 and which may be held in place by a set screw 21. This die block is provided with a recess or socket 22 in which is seated a lower die 23 which may be locked in place by a set screw 24. The shoe and block 18 and 20 are provided with a vertical opening 25 in which is a coil spring 26 pressing at its upper end against the under side of the head 27 of a slidable pilot 28, the head 27 being in the opening in the block and its body portion in an opening 29 in the die 23. The outward end of this pilot is reduced in diameter as indicated at 30, and in the top of the die is formed a substantially semispherical recess 31, the opening 29 leading to the bottom of this recess.

The upper die and. its mounting comprises the die 32 similiar to and over the die 23, andhaving in its lower end a substantially semispherical recess 33 similar to the recess 31 and in alignment therewith. This die has a passage or opening 34 therethrough in which is slidably mounted a punch 35 having a reduced and tapered lower end 36 extending into the socket 33. This die is mounted in a recess or socket 37 in the lower end of a hollow sleeve 38, and may be secured by a set screw 32a. Mounted for limited longitudinal sliding movement in this sleeve 38 is a cylindrical block 39 forming a carrier for the punch 35, this punch having an enlarged threaded upper end 40 screw threaded into the lower end of block 39, and may be secured in adjusted positions by a set screw 41. This block 39 is provided with a transverse elongated slot 42 extending therethrough in which is slidable a flat bar 43 pnojecting at its opposite ends through openings 44 in the sides of the sleeve 38, and springs 45 connected to this bar tend to lift it and the sleeve 38. Transverse pins 46 may be mounted in the bar 43' to keep it centered in the sleeve 38. The block 39 is provided with a longitudinal passage 47 in which is a plunger rod 48 normally engaging at its lower end on the top of the bar 43.

In the operation of expanding and sizing the blanks 11 or 11a, the blank is placed in the recess 31 in the lower die 23, this recess and the recess 33 being made to the size and shape desired for the finished ball or sphere, and is larger than the blank by the desired amount to provide the clearance space 49 about the blank. In this position the pilot 38 is held in its upper position by the spring 26 with its upper reduced end 30 in and fitting the hole 13 provided in the blank. This properly centers the blank in the die and holds it in the centered and upright position in alignment With the recess 33 in the upper die and the lower end of the punch 3 block 39 bar 43 and plunger 48 move downwardly together under action of the power press, until the lower end of the die 32 rests on top of the lower die 23, as shown in Fig. 2, if the ball is to be expanded :from the inside by action of the plunger 35 only. However, if theba'll .is being compressed axially, then die .32 stops its downward travel when'the face 17 .of the ball is engaged by the top wall 33a of cavity 33 in the die 32. Die 32 resumes its downward travel when shoulder 39a on block 39 hits the upper end 38a of sleeve 38. The die 32 is then carried down under power tolongitudinally compress the ball until the lower end of die 32 rests on top of lower die 23. This arrests downward movement 'of the die 32, the sleeve 38, bar 43 and plunger 48. Then the block 39 and the punch 35 continue to move downwardly forcing the tapered lower end 36 of the punch through the opening 13 in the blank 11, and the .pu'nch is carried far enough to pass the tapered end portion 36 :of punch 35 through the blank and until its cylindrical ibody'portion 35a also passes into and through the blank, as indicated in Fig. 2, the punch in this movernen't forcing the pilot 28 downwardly out of the openingtin the blank. As the body 35a of the punch 35 is of larger diameter than the hole 13 of the blank, it will expand this blank into the recesses 31 and 33, which are now lined up in the two dies, thus-filling these recesses and forming and sizing the outer surface of the blank'to the size and shape of these recesses. This expanding and sizing operation may be performed solely by the expanding action of the punch passing through the blank or previously machined form, or the dies could be so designed that there is longitudinal pressure applied to the blank, thus giving an expanding action on the blank by pressure on the opposite ends 17 of the blank, while the side walls of the opening 13 are held by the punch 35 against contracting.

After the expanding and sizing operationis completed, the entire upper die assembly moves upwardly to predetermined stops 43a, carrying the formed ball with it. The stops 43a are comprised of adjustable set screws in the frame of the press and these screws or stops engage bar 43 while the die set is moving upwardly, thus holding bar 43, sleeve 38 and die 32 against further upward movement. Plunger 48 and punch 35 continue in upward motion, thus stripping formed ball 50 from punch 35, after which plunger 48 and punch '35 continue upward movement until full upward position is attained, as shown in Fig. 1, in preparation for the next sizing and expanding operation. At the termination of the stripping operation the expanded and sized, and therefore the completed, formed ball or sphere 50 with its spherical outer surface 52 falls from the punch 35 and recess '33 and may be removed from the operating area. This ball member may be used as formed, or it may be heat-treated, or it could be'tumbled in a tumbling barrel for a better surface finish. Still further, this ball member could be ground-and lapped to a high degree of precision, especially when it is used in a self aligning hearing.

Although as stated the undersized machined form or blank could be machined with an outer substantially spherical surface 15 as shown on blank 11a of Figs. 4 and 5, it is preferably somewhat elongated as shown in Figs. 6 and 7 and of a substantially ellipsoidal shape, or with its side walls 12 longitudinally convexly curved on a longer and flatter curve than would be a spherical surface. This is because with this form the variations between the thicknesses of the side walls of the blank between the center and the ends is less at different transverse planes, and the metal has less tendency to pile up, so to speak, at the center of the blank than with the spherical surface. In other words, it tends to expand more evenly throughout the length of the blank. The

outer curved surfaces 12 and 15 could be carried to the edges of the hole 13, but it is preferred to provide the starting flats 16 and 17 at the opposite ends to prevent crushing by the longitudinal pressure of the dies, and also to prevent extrusion of the metal into the dies.

In Figs. 10 and 11 is shown a modified arrangement of dies for carrying out this method. Here the dies 53 and 54 corresponding to the dies 23 and 32 are not provided with the recesses 31 and 33. Therefore the undersized machined blank or form 11 or 11a is expanded by either the punch 35, or the longitudinal pressure of the dies on its opposite ends, or both together, with no external holding of its longitudinally convexed outer side walls or surfaces 12 or 15. Otherwise the method and action of expanding and sizing the undersized machined blank is the same as that described in connection with Figs. 1 and 2.

Although in Fig. 3 the blank or form '11 is .shown as being machined from a bar or rod, thisis only one way of forming this blank. It is to be understood it may be made by othermethods, such, for example, as by hiquetting .and sintering powdered metal, cold or hot forging, molding, and similar methods.

Having thus set forth the nature of my invention, I claim: 1

1. The method of making a substantially spherical member with a hole therethrough which comprises making or forming on bar stock of suitable ductile material an undersized form with a cylindrical opening therethrough, a convexly curved outer surface, and side walls in which the variation in thickness between the center and the ends is less than it would be if the surface were spherical, cutting the form from the stock and expanding the form radially by compressing it longitudinally while supporting the side walls of the opening :against inward movement, whereby expansion occurs more evenly throughout the length of the opening than it would if the surface were spherical.

2. The method of claim 1, in which the form is expanded into a preformed'recess in a dieset.

3. The method of making a substantially spherical member with a hole therethrough which comprises making or forming from a suitable ductile material an undersized form with a cylindrical opening therethrough, a convexly curved outer surface, and side walls in which the variation in thickness between the center and the ends is substantially less than it would be-if the surface were spherical, and simultaneously decreasing the length of the form and expanding the form radially by compressing it longitudinally while forcing through-the openinga punch of larger diameter than that of the opening, whereby radial expansion occurs more evenly throughout the length of theopening than it would if the surface were spherical.

References Cited in the file-of this patent UNITED STATES PATENTS Hamilton Mar. M, 1953

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