US2523527A - Shaping die - Google Patents

Description

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M. STEDER SHAPING DIE Filed Feb. 27, 1947 Sept. 26, 1950 Ella is fixed to a base 52.

Patented Sept. 26, 1950 SHAPING DIE Marshall Steder, Chicago, Ill., assignor to L. J. Miley Company, acorporation of Illinois Application February 27, 1947, Serial No. 731,364

i This invention relates to a shaping die, and particularly to a die for bending a piece of material having a web and a base portion attached thereto so that the base portion is of arcuate shape with the web on the inside of the arc.

The present invention is particularly designed for forming brake shoes from straight pieces of a steel T-bar. The brake shoes are formed by bending the base of the T in an arcuate shape correspondin in curvature to the inside of the brake drum while'maintaining the web of the T in a single plane with the web on the inside of the arc. This was formerly done by using a fixed die with the web of the T fitting into a slot in the die and the base of the T being tangent to a curved shaping surface of the die. Pressure was then applied to the base to bend it against the shaping surface. It was found, however, that there were a large number of the brake shoes that had to be rejected because of wrinkling of the web. This was caused because of the fact that steel .T-bars were not uniform in thickness and some of the webs were too narrow to completely fill the slot. Ordinary mill steel has tolerances of 11005111011. Wrinkles are also caused by the die surface wearing during use and thus causing the wrinkles to get progressively worse.

One feature of this invention is the provision of the improved shaping die for making brake shoes or the like wherein wrinkling of the web is prevented; another feature of the invention is the provision of a shaping die having one die 'member made in two parts and movable toward and way from each other With means for holding the web therebetween. Other features and advantages of the invention will be apparent from the following description and the accompanying drawings.

Of the drawings, Fig. 1 is a front elevation of one embodiment of the inventionwith portions broken away for clarity of illustration; Fig. 2 is a vertical section taken along line 2-2 of Fig. 1; Fig. 3 is a front elevation of another embodiment of the invention; and Fig. 4 is a side elevation of the embodiment shown in Fig. 3.

In the embodiment shown in Figs. 1 and 2 the shaping die comprises a male or first die member ill and a female or second die member II. The first die member ltl ismade in two parts lfla and Nib by a central dividing plane. One part "ltlb have an ar-cuate curved. surfa e W tha 1 -5 The other part lllb is '7 Claims. (Cl. 153-48) the same curvature as that of the finished brake shoe. Extending between the two die parts Ella and lb are three compression springs 13 serving as means'normally urging the two parts away from each other. Each spring 13 is seated in two aligned cavities Hid with both cavities being located. in a, die part Ella and lflb. Three of these springs is are provided with each spring forming the angle of an isosceles triangle. Means are also provided for limiting the extent of movement caused by the springs. As shown, this means comprises a pair of shoulder screws It with each screw extending through the movable die part Illb and engaging threads in the fixed die part Illa. Each screw has an enlarged head portion Ma held within a countersunk hole on the outer surface of the movable die part 10b. This serves to limit the outward movement of the movable die part [0b and the distance of movement may be regulated by regulating the effective length of the shoulder screws I4.

Attached to the base l2 extending upwardly there is located a stop member l5. This stop member is located at the exact distance from the center of the first die member ill so that a T-bar l6 placed on the first die member will abut against the stop member l5 and be automatically locked in the correct position for bending. As shown in Figs. 1 and 2, the T-bar i6 is positioned with its web lfia extending downwardly between the die parts "la and [0b while the base l6b of the T-bar rests on top of the curved shaping surface lilo. The effective length of the shoulder screws .l l'is such that the web lea may be easily placed between the die parts, but will have a snug fit therein.

In order to apply pressure to the T-bar l6 and bend it around the curved surface ltlc, the second die member H is provided with a hollowed interior ll. This hollowed interior is arranged to press the base It of the T-bar against the surface lllc and to press the side portions of the web Ilia between the first die parts Illa and [0b. The second die member II also has a dual function of pressing the die parts Illa and lb together to apply pressure on the web- Mia and prevent its wrinkling. This is done by having the outer surface of the parts Illa and lilb sloping gradually outwardly from the top to the bottom. The sides of the hollowed interior are similarly sloped from the innermost point to the outer edge. The outer edges Ha are also slightly rounded. By having these side surfaces carefully machined so that the slopes are the same and gradual, a cam action is provided forcing the two die parts Illa and IIlb together to hold the Web [6a. Although as pointed out above successive T-bars I6 will vary somewhat in thickness, the amount of pressure applied is so great that a T-bar having a web of excessive thickness will be compressed due to the elasticity of the metal and will be bent without wrinkling the web I6a. This is also true of those T-bars whose thicknesses are slightly smaller than the average.

In using the shaping die, the T-bars I 5 are first cut to the required length. A cut bar is then placed on the first die member ID in the position shown in Figs. 1 and 2 with one end of the bar in contact with the stop member I5. The second die member I I is then brought down over the first die member III. This forces the first die parts I01; and III!) together to hold the web I611. of the bar against wrinkling, bends the base Ifib f the T on to the surface I Be and forces the side parts of the web Ilia between the die parts Illa and IIlb.

In the embodiment shown in Figs. 3 and 4, the first die member III) is formed of two parts I Illa and IIBb being movable toward and away from the part II 0a. The fixed part IiiIa is fastened to a base I I2 and is also provided with a backing member I20. Spring II3 similar to the springs I3 previously described are provided between the two die parts Him and I III?) except in this instance only two springs are shown. The movable die member Hill) is moved toward the fixed die member IIIIa by means of a crank I 2| having threads I2 I a on one end engaging similar threads in a base member such as a block I22 and bearing against the movable die member Hub. The movable die member is moved by turning the crank I2I by means of the crank handle IZIb. A stop member H5 is also provided for locking the T-bar H6 in its proper position. In order to bend the T-bar H6 a second die member III is provided shaped similarly to the previously described die member I I except for having cut out portions IIIa and III!) at the bottom passing around the backing member IZII and the block I22 respectively when the second die member I I I is forced down on the first die member III).

In operating the embodiment shown in Figs. 3 and 4, the section of the T-bar H6 is placed on top of the first die member I III in the manner previously described, the crank I2I is turned to force the movable die part I IIIb toward the fixed die part HM and hold the web of the T-bar therebetween. The second die member III is then forced down over the first die member III) to bend the T-bar I I6.

The two die members may be forced together in any manner desired, but because of the large pressure employed, ordinarily 100 pounds per square inch or more, this is usuall accomplished by a conventional hydraulic ram.

In the embodiment shown in Figs. 3 and 4, the movable die part H8?) is caused to move toward the fixed die part I Illa by the crank I2I. Other means may, of course, be used so long as pressure may be quickly and easily applied to the movable die part I I Ilb.

Having described my invention a related to the embodiments shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description unless otherwise specified, but rather be construed broadly within its spirit and scope as set out n the accompanying claims.

I claim: 1. A shaping die for bendin ,a piece of material having a web and a base portion attached thereto, said die comprising: a first member having an edge surface shaped to conform to the intended shape of the base portion and a pair of opposite side surfaces, saidfirst member being made of two parts formed by a central dividing plane and relatively movable toward and away from each other to hold the web therebetween; and a second member having a surface for pressing the base portion of the material against said surface of the first member and a pair of inner side surfaces for simultaneously pressing said two parts toward each other to grasp the web.

2. A shaping die for bending a piece of material having a web and a base portion attached thereto, said die comprising: a first member having an edge surface shaped to conform to the intended shape of the base portion and a pair of opposite side surfaces, said first member being made of two parts formed by a central dividing plane and relatively movable toward and away from each other to hold the web therebetween; and a second member having one surface for pressing the base portion against said surface of the first member and two oppositely disposed inner side surfaces for engaging said side surfaces on the first member and press said two parts toward each other to grasp the web.

3. A shaping die for bending a piece of material having a web and a base portion attached thereto, said die comprising: a first member having an edge surface shaped to conform to the intended shape of the base portion and a pair of side surfaces, said first member being made of two parts formed by a central dividing plane and relatively movable toward and away from each other to hold the web therebetween; and a second member having a surface for pressing the base portion of the material against the shaping surface of the first member and a pair of oppositely disposed inner side surfaces for engaging the side surfaces of the first member and simultaneously press said two parts toward each other to grasp the web.

4. A shaping die for bending a piece of material having a web and a base portion attached thereto, said die comprising: a first member having an edge surface shaped to conform to the intended shape of the base portion and a pair of side surfaces, said first member being made of two parts formed by a central dividing plane and relatively movable toward and away from each other to hold the web therebetween; a sec-- ond member having a surface for pressing the base portion of the material against the shaping surfaces of the first member and a pair of oppositely disposed inner side surfaces for engaging the side surfaces of the first member and simultaneously press said two parts toward each other to grasp the web; means normally urging the two parts away from each other; and means limiting the extent of said movement.

5. A shaping die for bending a piece of material having a web and a base portion attached thereto, said die comprising: a first member having an edge surface shaped to conform to the intended shape of the base portion and a pair of side surfaces, said first member being made of two parts formed by a central dividing plane and relatively movable toward and away from each other to hold the web therebetween; a hollow second member having an inner surface for pressing the base portion of the material against the shaping surface of the first member and a pair of oppositely disposed inner side surfaces for engagingthe side surfaces of the first member and simultaneously press said two parts toward each other to grasp the web; means normally urging the two parts away from each other;

and means limiting the extent of said movement to avdistance wherein said pair of surfaces of the first member is not further apart than the corresponding surfaces on the second member. 6. A shaping die for bending a piece of material having a web and a base portion attached thereto, said die comprising: a first member having one surface shaped to conform to the intended shape of the base portion and a pair of side surfaces, said first member being made of two parts formed by a central dividing plane and relatively movable toward and away from each other to hold the web therebetween; a second member having a surface adapted to press the base portion of the material against the shaping surface of the first member and a pair of oppositely disposed surfaces adapted to engage the side surfaces of the first member and simultaneously press said two parts toward each other to grasp the web; means normally urging the two parts away from each other; and means limiting the extent of said movement to a distance wherein said pair of surfaces of the first member is not further apart than the corresponding surfaces on the second member, said pair of surfaces on the first member being slightly sloped toward each other from the base to the top of the first member and said pair of surfaces on the second member being similarly slightly sloped away from each other from their innermost edge to their outermost edge.

7. A shaping die for bending a piece of material having a web and a base portion attached thereto so that the base portion'is convex on the side opposite the web, said die comprising a male member having a curved outer surface shaped to conform to the intended shape of the base portion and a pair of side surfaces slightly sloping away from each other from said curved surface to the base of the male member, said male member being made of two similar parts formed by a central dividing plane and relatively movable toward and away from each other to hold the web therebetween; a female member having a cavity adapted to fit over the other die member and having an inner surface shaped similarly to said curved surface and adapted to press the base portion of the piece of material against said curved surface, and side surfaces having the same slight slope away from each other from the inner surface outwardly and adapted simultaneously to force said two parts together to grasp the web; means normally urging vthe two parts away from each other; and means limiting the extent of said movement to a distance wherein said pair of surfaces of the male member is not further apart than the corresponding surfaces on the female member.

MARSHALL STEDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 64,585 Schubeus May '7, 1867 1,721,964 Alleenan July 23, 1929 1,785,116 Fassinger Dec. 16, 1930 1,890,949 Proctor Dec. 13, 1932 2,141,736 Castle et al Dec. 27, 1938 2,216,694 Morgan Oct. 1, 1940

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