US 3165787 A
Description (OCR text may contain errors)
Jan. 19, 1965 c. F. CARMACK MEANS FORMING RADIAL HOLES BY A VERTICALLY TRAVELING PUNCH Filed April 20, 1962 a NkEi g JINvENTUR N ELEEI FRANCIS FARMAEK Y M Q bwtz/ United States Patent O 3,165,737 MEANS FORMHXEG RADEAL HQQLES BY A VERTI- ALLY TRA'VELWG PUNCH Cleo Francis Carin-sch, 924 Thornhurg St,
New Castie, Ind. Filed Apr. 20, 1962, Ser. No. 189,027 3 Ciahns. (Ci. 18-42) This invention relates to a structure for forming arcuate lengths of brake shoe lining with holes formed therethrough radially of the curvature of the lining, these holes being for the purpose of receiving rivets for attaching the lining to the brake shoe. The invention contemplates the use of brake lining material in a dough-like or plastic state so that it may be readily formed and perforated in one operation.
One of the primary problems in forming the lining is to form the rivet holes to be axially aligned with the radius of the curvature of the finished lining, doing so by a vertically reciprocable die member.
These and other objects and advantages of the invention will become apparent to those versed in the art in the following description of one particular form of the invention as illustrated in the accompanying drawing, in which FIG. 1 is a view in fragmentary vertical section of a die structure utilized in carrying out the purpose of the invention;
FIG. 2 is a view in vertical transverse section on the line 22 in FIG. 1; and
FIG.- 3 is a view in detail on an enlarged scale and in ventical section through one of the hole punching structures.
In FIG. 2, the structure is shown with the die members closed and the same thing is true of the showing in FIG. 3. The view shown in FIG. 1 shows the die members open after the brake lining member has been fully formed.
'A lower die member designated by the numeral has an arcuate upper face 11, the curvature of which corresponds to the curvature desired in the .finished lining product; This curvature will vary in its radius of 'curva-. tures and'also in the arcuate lengths depending uponthe use to which the finished lining 12 is to be put. That is, who er or not it is used on the ordinary passenger car where the-thickness and lengthof the lining willbe less, or whether it is who used on one of the heavy duty trucks where the lining will be thicker and longer with a longer radius of curvature.
The arcuate surface 11 is the in the mold member 10, the depth of which be equal to the thickness desired of the finished lining 12. This thic ess is indicated by the end Wall 13 asto its height.
An upper die member 14 is formed to have an under surface 15 of a curvature, the radiusof which is equal to that of the lower cavity floor 11 plus the thickness of the lining 12 tooe formed. The die member 14 will normally be guided for vertical reciprocation between walls 16 and 17. Also the upper die member 14 will have its lower limit of travel determined by an abutment 18 on-one end floor of an arcuate cavity 3,155,787 Patented Jan; 19, 1965 ice 21 are secured by their upper ends to some means for pressing and lowering them, herein shown as a plate 22. In each instance,-the bore is provided with a lower end counterbore 23. A punch 24 is received in the counterbore 23 and is slidingly guided therein by an enlarged diameter head 25. The lower end of the counterbore 23 has a guide and stripping plate 26 through which the punch 24 may slide. This plate 26, overhangs the counter-bore 23 sufiiciently to form an abutment 27 against which the lower end of a compression spring 28 bears. The upper end of this compression spring 28 bears against the underside of the head 25, thereby normally urging the punch 24 to its uppermost position which will be that where the head abuts the shoulder 29 at the junction of the bore 20 and the counterbore 23. Where the bores 29 are in their centrally aligned position as above indicated, the counterbore 23 will likewise in each instance be aligned axially with the bore 20. 7
Where holes are to be punched through the lining 12, toward its outer respective ends, the punches 24 will not be ventically reciprocated, but must be radially reciprocated. That is the punch 24 itself must reciprocate on a radial line which will form the axis of the hole. The axis therefore of the punches 24 will increase in angulari- -ty from positions nearer the center bore 20 toward the outermost positions of those bores. Likewise the lengths of plungers will have to be increased from the shortest one designated by the numeral 21 to the increasing length ranging from the plunger 21a to the plunger 21b.
The punch 24 in each instance carries a depression 30 entering its upper-side. Into this depression is dropped a ball, such as a ball bearing 31. Referring first to the central bore 29, FIG. 1, and on top of that ball 31, there is dropped a spacer member 32. That is, the ball 31 and of the ball 31, and has a concave seat 33 entering it from the underside to fit the curvature of the ball 31. Then a second ball bearing 3d is dropped downwardly through the bore 2%) to rest in a concave upper seat 35 in which the underside of the ball 34 rests. The plunger 21b is provided with a concave seat 36 in its lower end fitting over. the topside of the ball 34. While these two balls 31 and 34 and the intervening spacer 32 may be omitted for the central bores 29, and the plunger21 extended down- 3G? in the topend of the punch 24. Then the spacer 32 p I wardly to come into contact with the head '25 of the ipunch 24 ,thatcan'not be the situation in the outermost bores 20. 4 1
t For example, in the outermost bore 26 receiving the plunger Zlb, the counterbore 23 is at a decided angle in respect to its axis to the axis of the bore 23. In fact the bore 23 is'continued to meet and open into the counterbore 23. In this situation, the lower ball 31 will drop down (punch 24-being inits normal upper position) into (this angular portion 231: of the bore to seat in the cavity is dropped down onto the ball 31 followed by the ball 34, and the plunger 21b with its concave seat 36 fitting over the ball 34 as above described. The same construction is utilized in the bore 2tl receiving the plunger 21:; where the angularity'exists, but is not as great as in the outermost location just described.-, 1
29 for each hole to be punched through the lining. 'The central bore Ztl will, by its vertical axis, be halfway from the ends of the member 14.
in most instances, the brake lining 12 will have 'sufiicient width as to warrant the use oftwo holes side by side being formed through the lining in each instance of formiug those holes clear through. For example, as indicated in FIG. 2, two bores are shown wherein each of these bores slidingly receive a plunger 21. These two plungers In operation, all of the plungers 2 1, 21a and 21b are tied together by the upper plate 22, and some mechanism (not shown) is employed particularly to lower the plate 22 to reciprocate downwardly the plungers simultaneous-- ly. With the plate 22 in the upper position as indicated in FIG. 1, and the punches 24 likewise in their uppermost positions, the material (a mixture) in its dough-like state i and in the proper quantity is placed in the cavity defined v by the floor 11, ends 13, and 13a, and the sides 37 and holes therethrough,
33, and then the plateZZ is lowered so that initially the under face of the upper die member 14 squeezes the lining material around over the surface 11 normally stopping the die member 14 first in its abutment on the lower die member 10, preferably utilizing springs 39 and to be compressed in that lowering action and to aid in quick lifting of the die member 14 when the two die members are to be separated one from the other.
The continued downward, pressure of the plate 22 on the plungers 21 causes the plungers to exert pressure on the balls 34, spacers 32 and ball 31 against the punches 24 causing them to traveloutwardly or rather downwardly through the plates 27 to have their lower ends enter the lining material and form counterbores 41 therein preferably withv a lower frusto-conical annular seat 42 and have the cylindrical hole punching portion 43 of the punch 24 pass on downwardly through the remaining thickness of the brake lining 12 and enter a passageway 45 provided in each instance through the lower die mem ber 10.
Normally, it is well known, the cylindrical portion 41 is provided for wear on the brake lining 12 so as to pre-v vent heads of rivets (not shown) normally passing through the holes 44 from rubbing on the brake drum. The frusto-conical portion is provided to accommodate the underside of the rivets which are in themselves provided with countersunk heads.
Therefore it is to be seen that with one stroke-of the upper die portion 14, the brake lining 12 is squeezed into uniform thickness throughout the cavity and the holes for rivets are formed. The springs 23 return the punches 24 to their normal positions as indicated in FIG. '1 from the lowered positions as shown in FIGS. 2 and 3. The returning travel of the punches 24 through the plates 26 not only guide those punches as above indicated, but keep them clean and freefrom accumulation of the material forming the brake lining 12.
Therefore while I have herein shown and described my invention in the one particular form, it is obvious that changes may be employed, particularly in the construction of the two die members 14 and 10, and in their mode of operation, and I therefore do not desire to be limited to that precise construction except as may be required by the following claims.
1. In a device for forming brake shoe linings with rivet a first die member having a cavity with an arcuate floor therearound;
a second die member having an arcuate face opposing said cavity;
said second die member having a plurality of apart bores with parallel major lengths;
spaced lengths with said balls being disposed between said punches and said plungers; and
springs normally retaining said punches in retracted positions in said bore minor lengths;
said second die member being shifted by pressure on said plungers to close over said cavity of the first die member by the arcuate face of the second die member and through said balls, overcome said springs and move said punches radially across said cavity.
. The structure of claim 1 in which there is spacer member between said balls with a concave cavity on opposite sides into which said balls may partially enter;
said punches, each has a concave head surface into which a ball may seat; and
at least one of said balls is free to tr verse the junction between said major and minor bore lengths under the pressure of the plunger in one direction and a punch spring in the opposite direction.
3. The structure of claim 2 in which said minor bore lengths each has a diameter exceeding that of the major bore lengths;
there is a head on each punch;
one of said springs surrounds each of said punches; and
there is a guide plate around each of openings of the minor bores through said second die member face, through which said punch slides, and against which the spring bears by one end, the spring hearing by the other end against said punch head.
References Cited by the Examiner UNITED STATES PATENTS 1,677,677 7/28 Irwin.
2,087,470 7/37 Davidson et a1. 18-56 2,163,814 6/39 Swarouski.
2,586,300 *2/52 Campbell 18-34 2,697,264 12/54 Queberg L. 25-34 2,790,206 4/57 Cofek 18-55 XR 2,919,470 1/60 Deters 18-34 MICHAEL V. BRINDISI, Primary Examiner.