US2105289A - Press - Google Patents

Description

PRESS Filed NOV. 19, 1934 ZZ r Z3 mr'lwelwls- A S v Patented Jan. 1i, 1938' UNI-rsu srarrs gitane rases Appiication November i9, 1934, Serial No. 753,710

6 Claims.

This invention relates to presses and particularly to presses for shaping short cylindrical hoop-like members of ductile metal into annular elements suitable for'use as rims for bicycle wheels or for analogous purposes.

` Heretofore metallic bicycle rims have generally been formed by subjecting a flat band of ductile metal to a rolling operation, the band being passed endwise into and through a rolling 10 mill in which it is given the desired cross-sectional shape and approximately a circular form, the ends of the band being thereafter welded together. I have discovered that a superior bicycle rim may be formed by first securing the ends of a at metallic band together, as by a welding operation, to form a short cylindrical blank and thereafter subjecting this short cylindrical blank to shaping operations'whereby its marginsare outwardly stretched and the rim is given the desired cross-section. A rim formed in this manner is stronger and has less tendency to warp or get out of shape than rims formed upon previously known means land is also superior in appearance.

For the purpose of stretching the marginal portions of the blank and giving these marginsthe desired cross-sectional shape, a novel form of press has been devised, which press comprises the subject matter oi the present application and will be hereinafter described in'detail. The principles of the invention may be employed in presses designed for the manufacture of articles other than bicycle rims, and hence, as will be appreciated by one skilled in the art, the design and arrangement of the component elements of the invention may be considerably varied without departing from the import thereof.' The embodiment of the inventionrwhich will Ybe hereinaiterdescribed in detail and illustrated in the accompanying drawing is therefore set forth by way of example only.

40 In the drawing:` Y

Figure l illustrates the press in plan view, portions being broken away; i,

Figure 2 is an axial section through the press, the parts being shown in the positions which they occupy just prior to the pressing operation;

Figure 3 is a similar view but showing theparts in the positions which they occupy at the completion of a pressing operation;

Figures l and 5 are partial axial sections through the press, the shapes of several of the press elements, however, having been modified in order to perform further shaping operations upon the blank; and Y Figure 6 illustrates in section the original blank,

the blank after one pressing operation has been performed, and the blank after the final pressing operation has been performed.

The press comprises essentiallya base indicated at it, which may conveniently be in the form of a disc, an vannular lower die member il resting 5 upon the base, a disc-like upper die member i2 which may if desired be attachedto the upper plate ci a power press of known character, an intermediate disc i3 carrying an expanding blankgripping means generally indicated at it, and an 10 outer conining ring indicated at i5. The lower and upper die members ii and i2 are provided with blank engaging and shaping surfaces ll and i 2 respectively, and the confining ring, which Y, is formed in two annular portions normally l5 spaced apart by yielding elements or springs i6, is provided with complementary blank engaging and'shaping surfaces iii and H52. The short cylindrical ductile blank, which is indicated at ifi, is adapted to have its upper margin engaged 20 by and shaped between the complementary surfaces i2 and it of the press, the complementary surfaces li and 52 oi the press cooperating in the shaping and expanding ofk the lower margin of the blank when the press is actuated. As 25 shown, the blank engaging surface ii' of the lower die il is generally conical in shape, and the blank engaging surface i2 of the upper die i2 is of the same shape so that, as the dies are caused to approach each other in the operation 30 of the press, the margins oi the blank il are wedged or stretched outwardly.

The interior blank engaging means lli comprises a series of generally segmental plates 2i] Y having radial edges and curved outer ends so as 35 to iit closely against the inner wall surface of the blank. These segments are slidably mounted upon the upper surface of disc i3, bolts 2i having their lower ends secured in disc I3 which passes through radial slots formed in the seg- 40 mental plates, and the heads of these bolts serving as means iorpreventing upward displacement of the plates respectively. To the inner end of each plate is connected the outerend of a togglelink 522, and the inner ends of these toggle 45 links are in turn pivotally connected to a central disc 23 xed upon the upper end of a shaft 2i which projects downwardly through central apertures formed in the intermediate disc I3 and the base it respectively. By rotating the shaft 24 in 50 one direction, the disc 23 is also caused to rotate and hence to swing the inner ends of the toggle levers 2i circumferentiaily of the press.

in Figure 1 two positions of one of the toggle levers are indicated by full and dotted lines. 55

When this toggle lever is in its full-line position, the segment I4 to which it is connected is inwardly spaced from the surface of the blank I'I, as clearly indicated in Figure 2, and when the toggle lever is moved to its dotted-line position, the segment is thrust outwardly to the position shown in dotted lines in Figure l and the curved outer edge of the segment is in tight engagement with the inner cylindrical surface of the blank at a point midway between its edges. Naturally all of the toggles operate simultaneously as shaft 24 is rotated, and hence the blank is simultaneously engaged by and disengaged from the various segments 20. Disc I3 is normally maintained in the position in which it is shown in Figure 2, yieldable elements 25 being provided for normally maintaining the disc in this position while at the same time permitting movement of the disc toward the base I when pressure is applied in the operation of the press.

For convenience in assembly, the confining ring I5 is formed in two sections, the ends of which are releasably connected together by latching devices of any desired type, such as indicated at 26 in Figure l. For the further convenience of the operator in manipulating the confining ring, each of the two sections thereof is jointed at a mid-point, hinges 2'I being provided at these points to permit relative movement of the two parts thus joined, as indicated in dotted lines in Figure 1.

In operating the press shown in Figures l, 2, and 3, a shortcylindrical blank of ductile metal is first positioned as shown in Figure 2 with its edges equidistantly spaced from the segmental gripping and securing device I 4. The shaft 23 is then rotated to simultaneously rock all of the toggle members 22 and to thrust outwardly the sections of the internal gripping device, the curved outer edges of these sections frictionally gripping the inner surface of the blank. The swinging movement of each of the toggles 22 is carried, in thus expanding the securing plate I4, slightly beyond a truly radial position, and a positive stop for the operating shaft 24 is provided to prevent further rotation. The toggles are thus locked in position with the plate I4 expanded. Thereafter pressure is applied to the upper die I2 and the base I0 to cause these members to approach each other, whereupon the cooperating blank engaging and shaping surfaces of the upper and lower die members and the conflning ring I5 cooperate in expanding and shaping the upper and lower margins of the blank.

At the conclusion of the operating stroke of the press, the parts occupy the positions in which they are shown in Figure 3, the upper and lower surfaces of the die members being in close contact with the outer edges of segments 20, the upper and lower sections of the confining ring I5 pressed into close contact, the supporting ring 3G for the confining ring lowered into contact with the upper surface of base IIJ, and the confining ring supporting springs 3| being compressed. As the dies are closed, the upper and lower margins of the blank are outwardly stretched, the metal being stretched beyond its elastic limit so as to retain a permanent set. As a result of this operation the blank has been caused to assume in section the shape shown in the intermediate illustration in Figure 6.

For the purpose of further shaping the blank so that it is caused to assume in cross-section the shape shown in the right-hand portion of Figure 6, the blank engaging and shaping elements of the press are changed, the shoulder blank engaging elements indicated in Figures 4 and 5 being substituted for those corresponding elements having the more gently curved blank engaging surfaces shown in Figures 2 and 3. As will be seen from an inspection of Figures 4 and 5, the substituted parts retain the same relative positions as before, but the confining ring 33 is formed in one piece and its blank engaging surfaces 33 and 332 are rather sharply curved as shown. The blank engaging surface 34 of the upper die member and the blank engaging surface 35' of the lower die member 35 are correspondingly shaped. The substituted conning ring 33 may be formed in one instead of two pieces, as shown. After closing of the press including the modified blank engaging members, the blank is removed and passed on to other fabricating machines for subsequent operations,

as for instance spinning and curving of its outer edges, perforations for spoke receiving sleeves, etc.

AsV has been previously pointed out, in shaping short cylindrical ductile metallic members or blanks for other purposes, the design of the cooperating shaping members may be further modified without departure from the invention, and also the exact arrangement of the parts may be considerably varied in adapting the invention for the shaping of blanks of various types. v

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. A press for uniformly expanding the margins of short continuous cylindrical blanks of ductile metal comprising means for frictionally gripping the inner surface of the blank intermediate the edges thereof to secure the same in position to be acted upon, upper and lower dies relatively movable toward each other along the axis of the blank and having generally conical blank engaging and shaping surfaces adapted to engage the inner wall surfaces of the margins of vthe blank when so moved to outwardly deflect such margins by stretching the metal thereof, and an annular confining die adapted to encircle the blank and having spaced blank engaging surfaces adapted to cooperate respectively with the blank engaging surfaces of the upper and lower dies.

2. A press for uniformly expanding the margins of short continuous cylindrical blanks of ductile metal comprising means for frictionally gripping the inner surface of the blank midway between the edges thereof to secure the same in position to be acted upon, and means movable axially of the blank for outwardly deflecting and shaping the marginal portions of the blank by stretching the metal thereof.

3. A press for uniformly expanding the margins of short continuous cylindrical blanks of ductile metal comprising means for frictionally gripping the inner surface of the blank midway between the edges of the same to frictionally hold the blank in position to b-e acted upon, confining means encircling the blank and engaging the outer wall thereof midway between the edges, and means movable axially of the blank for outwardly deflecting and shaping the marginal portions of the blank by stretching the metal thereof.

4. The combination set forth in claim 3 in which the confining means comprises two similar annular members and yieldable elements normally maintaining the same in spaced relation- Cil ship, said elements being compressible by said delecting and shaping means.

5. The combination set forth in claim 3 in which the gripping means comprises a plurality of segmental plates and mechanism for simultaneously moving said plates outwardly or inwardly as desired.

6. The combination set forth in claim 3 in which the gripping means comprises a plurality lof segmental plates and mechanism for simultaneously moving said plates outwardl;7 to blank engaging position, locking them in such position, or retracting the same as desired.

EDWARD J. LOBDELL, JR.

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