Brake shoe resizer

A brake shoe resizer characterized as a hydraulically operated die which includes a groove presenting a shape corresponding to the area of the ribs surrounding the openings for the brake shoe anchor pin. Guide and/or stop means are provided for positioning and/or checking purposes during the reworking operation. The latter includes introduction of a guide pin into the openings for the anchor pin and the successive reshaping of each such openings after the selective heating of the areas around the anchor pin openings prior to die or reforming action. The overall assembly further includes structure for reshaping the curvature of the brake shoe, if necessary, and, as well, the spacing between the ribs presented on the brake shoe.

As is known, the usage of brake shoes in combination with vehicle axles is 
widespread, typically employing an anchor pin for accomplishing pivotal 
movement during usage. A serious drawback, however, is that after periods 
of service, the holes which receive the anchor pin oftentimes become 
misshapen, with the latter mostly resulting in complete brake shoe 
replacement. In view of the expense involved, a need has arisen for 
reworking an existing and worn brake shoe at a single site which not only 
is capable of resizing the holes for the anchor pin but, as well, assures 
proper brake shoe curvature and spacing between the ribs through which the 
anchor pin openings or holes are disposed. 
The invention satisfies the aforesaid purposes in presenting a brake shoe 
resizer which effectively serves the various reworking needs. Basically, 
the instant resizer arrangement involves a hydraulically operated die 
which receives, within a groove, one of the ribs and then the other of the 
ribs of the brake shoe, in successive operations, i.e. after each rib has 
been heated to a molten state. With the use of a guide pin (having the 
proper dimensions of the anchor pin) placed through the openings, 
engagement by the die groove, in two stages, repositions the heated or 
molten opening areas to an original condition. 
In addition to resizing the holes for the anchor pin, the invention 
affords, at the same operational site, an arrangement for reestablishing 
the proper contour or curvature of the brake shoe and, additionally, means 
for reestablishing the spacing between the ribs of the brake shoe, i.e. in 
a generally parallel relationship. Moreover, and to complete the resizing 
assembly, an arrangement of stops or blocks permit positive checking 
and/or placement of the brake shoe during the operational stages of 
reworking.

For the purposes of promoting an understanding of the principles of the 
invention, reference will now be made to the embodiment illustrated in the 
drawing and specific language will be used to describe the same. It will 
nevertheless be understood that no limitation of the scope of the 
invention is thereby intended, such alterations and further modifications 
in the illustrated device, and such further applications of the principles 
of the invention as illustrated therein being contemplated as would 
normally occur to one skilled in the art to which the invention relates. 
Referring now to the figures, a typical brake shoe 10 generally comprises 
an arcuate base plate 10a and upstanding ribs 10b'--10b" secured thereto. 
Each of the ribs 10b'--10b" includes an opening or hole 10c through which 
a standard anchor pin extends during customary usage. The holes or 
openings 10c also serve to receive a gauge pin (not shown, but which 
determines any enlarging or misshaping of the holes 10c) and/or a guide 
pin 15 (used in the resizing operation described herebelow). In any event, 
FIGS. 4 and 5 readily demonstrate a rib hole or opening 10c before (FIG. 
4) and after (FIG. 5) resizing. 
The mechanism presented by the invention is typically defined by a 
framework 20 having a leg mounted support or work surface member 22 and, 
as well, a hydraulically operated die 25. The latter includes a hydraulic 
cylinder 26, with associated gauge 26a, and a power shaft 27 which moves 
the die 25 from the broken line position (of FIG. 1) to the full line 
positions of FIGS. 1, 2 and 3. 
The overall arrangement, which need not be detailed herein, also includes, 
aside from the preceding, a control handle 30 selectively connecting 
hydraulic lines 32; a starter mechanism 34; a motor 35; a cover encased 
drive shaft 35a; and, a hydraulic fluid tank 37, with associated port 37a, 
communicating with the aforesaid hydraulic lines 32. The preceding, 
representatively shown in phantom, serve environmental purposes. 
In any event, the die 25 has a centrally disposed groove 25a in its arcuate 
face (again see FIGS. 1, 2 and 3), where the shape of the groove 25a (and 
face) corresponds to the shape of the ends of ribs 10b'--10b" of the brake 
shoe 10 being reworked. As a matter of readily determining whether the 
ribs 10b'--10b" of the brake shoe 10 are in a proper upright or normal 
condition (with respect to the arcuate base plate 10a), framework 20, 
which supports hydraulic cylinder 26, includes guides 20a. 
Restated otherwise, and during operation, when the brake shoe 10 is at one 
operational position (FIG. 1), the operator can visually determine whether 
or not the corresponding rib 10b' is properly oriented (with a guide 20a 
serving as reference), where the same visual inspection is attained at the 
other brake shoe rib 10b" location of FIG. 3. 
In this connection, and if the spacing between the ribs 10b'--10b" is 
improper, as due to bending, such are placed in a straightening area 
defined by a block 28 and the support or work surface member 22. In other 
words, through hammering action, the spacing between the ribs 10b'--10b" 
of the brake shoe 10 can be readily corrected. The preceding is apparent 
from the showing in the left hand portion of FIG. 1. 
While also appropriate to reworking, attention is directed to the inverted 
upstanding arcuate member 29 shown in FIGS. 1 and 2. The latter provides a 
surface which presents a curvature corresponding to that of the brake shoe 
base plate 10a. If any correction is required, hammering or like forming 
can be achieved. 
As to usage, and assuming the curvature of the base plate 10a and the ribs 
10b'--10b" of the brake shoe 10 being reworked are satisfactory, sizing of 
the openings 10c in the ribs 10b'--10b" is accomplished by placing the 
brake shoe 10 on an arcuate receiving member 21 (see FIG. 2) on the 
framework 20. Actually, a rapid succession of operational steps is 
involved, to-wit, guide pin 15 is placed within the openings 10c in the 
ribs 10b'--10b" of the brake shoe 10 (see FIGS. 1 and 3), either before or 
after one or both of the ribs 10b'--10b" is selectively heated to a molten 
state (depending upon condition). 
As a matter of example, rib 10b" is properly positioned with respect to the 
groove 25a in the die 25, such being assured by a stop 20b' (see FIG. 1). 
Die 25 is then caused to be moved, hydraulically, into engagement with the 
molten rib area surrounding the hole or opening 10c. In other words, the 
die groove 25a reforms the opening 10c in the rib 10b" area around the 
guide pin 15. 
A similar sequence of operational steps is involved with the opening 10c in 
the other rib 10b', i.e. the area around the opening 10c is heated to a 
molten state, the brake shoe 10 moved to the position of FIG. 3, i.e. 
adjacent another stop 20b", and die 25 caused to be selectively and 
hydraulically moved downwardly to contact the area surrounding the die 
shoe opening 10c. As stated, the opening 10c assumes the proper shape 
demonstrated in FIG. 5 rather than that illustrated in FIG. 4. 
In other words, the invention affords a practical and yet convenient manner 
of resizing an existing brake shoe without complete replacement. Not only 
are the anchor pin 12 openings 10c dimensionally corrected, but, at the 
same site, the spacing between the ribs 10b'--10b" of the brake shoe 10 
and the curvature of the brake shoe base plate 10a corrected and/or 
reworked. The operational sequence is relatively simple, where positive 
positioning of the brake shoe 10 being reworked is easily achieved through 
the usage of stops 20b'--20b" at each of the operational positions. 
Obviously, when resizing has been completed, the guide pin 15 used for 
resizing is removed and the brake shoe 10 can be put back into normal 
operation on a vehicle. Thus, the invention affords a practical approach 
to the reworking of a brake shoe, minimizing operational requirements, and 
representing savings both in time and/or labor. 
The brake shoe resizer described hereabove is susceptible to various 
changes within the spirit of the invention including, for example, in 
proportioning; the position of stops 20b'--20b"; and, the like. The 
preceding description, therefore, should be considered illustrative and 
not as limiting the scope of the following claims: