Improvements in Brake Shoes.
Year: 1897

page_text: Date of Application, 3rd Aug., 1897-Accepted, 4th Sept., 1897
COMPLETE SPECIFICATION.
Improvements in Brake Shoes.
I, WILLIAM DURHAM SARGENT of 82 to 86 Vauburen Street, Chicago, Illinois,
U.S.A., Manufacturer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
My invention relates to improvements in brake shoes of all kinds and as well
to those which dress the wheel as to others which do not, the same being
applicable to all conditions where a superior braking effect is important or
desirable.
The primary object of this invention is to provide a brake shoe combining
superior braking qualities with great longevity and having a composite, wearing
face, whose component parts constantly change in area and position during wear
of the shoe.
Another object of the invention is to promote the longevity of a cast metal
brake shoe by combining therewith a metal which does not wear or dis-integrate
too rapidly in such a manner that the latter metal is distributed in small parts
throughout the area of the face of the shoe, whereby the wearing or operative
face of the shoe is always of a composite and changing character.
And a further object is to provide a cast metal brake shoe with an insertion
composed of a ductile metal having numerous interstices whereby it is permeated
by the cast metal so as to provide a solid homogeneous body.
And a further object is to provide a brake shoe with an insertion of such a
character and arranged in such a position therein that the parts of the insert
exposed on the wearing face of the shoe will constantly change in area and
position.
With these and other objects in view, my invention consists in providing a
brake shoe with a foraminous ductile metal insertion and by "ductile" metal
it will be understood that I mean any metal the form of which can be changed
or altered without injury, such as malleable or wrought metal of any kind,
whether such metal is soft or hard.
The objects of my invention may be accomplished in a variety of different ways
and by a great many different kinds and forms of insert and in the accompanying
drawings I have shown some of the different embodiments of my invention,
referring to which:-
Figure 1 is a plan view of the wearing face of a brake shoe embodying my
invention, the outline of the insertion being shown on one part thereof in broken
lines.
Figure 2 is a longitudinal sectional view of the brake shoe shown in Figure 1.
Figure 3 is a transverse sectional view of the brake shoe shown in Figure 1.
Figure 4 is a plan view of a section of expanded metal which makes a very
desirable insertion.
Figure 4 is a sectional view on the line 4-4* of Figure 4.
Figures 5 and 6 illustrate different kinds of wire insorte

page_text: Figure 7 shows a wire insertion bent into a sinuous form.
Figure 8 shows a sinuous metal plate provided with a number of perforations.
Figure 9 shows a perforated plate.
Figure 10 illustrates a laminated pile of expanded metal sections.
Figures 11 and 12 are diagrammatic side views of a brake shoe showing two
different ways of arranging the insertion therein.
Figure 13 is a cross sectional view on the line 13-13 of Figure 15.
Figure 14 is a cross sectional view of a brake shoe in which the insertion is
arranged with the meshes at right angles to the meshes of the insertion in Figure 1.
Figure 15 is a plan view of the wearing face of a brake shoe in which the
sections forming the insertion are arranged on edge.
.
Figure 16 is a plan view of the wearing face of a brake shoe having a sinuous
perforated reinforcement therein.
Figure 17 is a similar view of a dressing brake shoe having a sinuous reinforce-
ment therein.
Figure 18 is also a plan view of the wearing face of a wearing brake shoe having
a perforated reinforcement therein, and
Figure 19 is a diagrammatic view showing the manner in which the area and
position of my improved insertion varies in comparison with the solid metal plugs
heretofore employed.
Heretofore some cast metal brake shoes have been made which embody large
wrought metal insertions, but in actual practice it has been found that such
insertions, whose area and position are substantially constant, are very liable
to change in character by the operation of the wheel thereon and to such an
extent that they have a dangerous and destructive action on the tread of the
wheel, by wearing the same evenly. A steel brake shoe has the longest life, but
it is well known that its braking qualities diminish with age and use by reason
of the fact that its wearing face crystallizes and changes its character in parts,
thereby wearing the wheel evenly and causing much trouble. A cast iron shoe
has the best braking qualities by reason of its granular structure, but such a shoe
wears out very rapidly for the same reason.
I have endeavoured by this invention to produce a brake shoe which embodies
the superior braking qualities of a cast iron shoe and the longevity of a steel
shoe without any danger or liability of the shoe injuring the tread of the wheel.
Many other forms of insertions than those shown in the drawings may be
employed to accomplish the objects of my invention, but I have shown some and
different ways in which they may be arranged which will indicate the wide scope
of my invention.
Among the many different kinds of insertions which may be used, I have
found that one composed of sections of expanded metal A to be very desirable.
These sections may be laminated in a pile as shown in Figure 10 and arranged
in the shoe so that the flat surface thereof will form a part of the wearing face
of the shoe as shown in Figure 1; or these sections may be arranged on edge
and side by side so that the edges of the sections will form a part of the wearing
face of the shoe as indicated in Figures 12 and 15. In Figure 11 it will be
observed that the mesh of the expanded metal runs with the length of the shoe,
while in Figure 12 it runs across the shoe, and it will be understood that the
insertions can be arranged within the shoe in many other ways without departing
from the spirit of my invention.
Instead of an insertion composed of expanded metal I may use one composed
of wire B, as shown in Figures 5 and 6, or of metal plates C provided with a
number of perforations as shown in Figure 9 and these inserts may be laminated
in the different ways heretofore described, with relation to the expanded metal
insert, or they may be bent into a sinuous form as shown in Figures 7 and 8,
16 and 17. There are also many different kinds of wire and perforated plate
insertions that may be used, the mesh of the wire inserts may be of different size
and differently arranged as described with reference to the expanded metal insert

page_text: and the perforations in the plate C may be of different sizes and distributed in
different manner throughout the plates.
The dressing brake shoe may be provided with an insert as shown in Figure 17
and 18; in Figure 17 a perforated insertion is shown, for example, arranged in
a sinuous form on its edge and in Figure 18 an expanded metal insertion is
arranged in a manner similar to that shown in Figure 1. The insertions may
be arranged in this style of shoe in as many different ways as. in the ordinary
shoe heretofore referred to, but when an insertion is arranged as shown in
Figure 18, with its flat side forming a part of the wearing face of the shoe, it
will be unnecessary to provide a connection between the two sides of the shoe
as indicated by D in Figure 17, although this connection may be employed if
desired.
I have shown and described my invention more particularly as embodying
an insertion composed of expanded metal, for the reason that this constitutes a
simple, inexpensive and desirable form of insert which can be readily worked
into any form desired and which is also particularly adaptable to the objects of
my invention. In laminating sections of this expanded metal they are arranged
upon each other so as to break joints, as shown in Figure 10 and in this way
a continuous hole extending throughout the insert of any regular size is avoided.
Instead of having the sections arranged in contact with each other, as indicated
in Figure 10, they may be located at a greater or less distance from each other
and such a construction may be found desirable more particularly when the
sections are arranged on edge in the manner indicated in side views in Figures 11
and 12; or this expanded metal may be bent into a sinuous form, as shown in
Figures 7 and 8 and arranged in the shoe as shown in Figure 16 or in other ways
The same arrangement may be
which will occur to those skilled in the art.
with the other kinds of inserts.
In making a brake shoe in accordance with my invention, the insertion having
been properly shaped and prepared, is supported in a mould and then the metal,
of which the shoe proper is made, such as cast metal, is poured into the mould.
The cast metal will permeate the insert in different directions and fill the inter-
stices thereof so as to form a solid homogeneous body, the insertion and shoe
I prefer
proper being permanently bound together in an inseparable manner.
to make the body proper of the shoe indicated by E of cast metal because of its
superior braking qualities, while the insertion as before stated, is composed of
a ductile metal which co-acts with the cast metal to provide a shoe having all
the braking qualities of a cast metal shoe and the longevity of a steel shoe.
By reason of the peculiar character of expanded metal and the inclination of
and 4 it has been found that an
its component parts, as indicated in Figures
insert composed thereof will be distributed throughout the body of the shoe in
such a manner that the wearing face of the shoe will always be of a finely divided
and composite character, the parts of which are constantly changing in area and
position as the wearing face is worn in use. In Figure 1, I have shown
how the wearing face of the shoe may look before it has been used, in which
parts F of the insertion project through the wearing face of the shoe at intervals.
These projections of course are those parts of the expanded metal which project
most above the central plane thereof, as edges G in Figures 4*, and as these
edges wear down with the face of the shoe, the proportion of the insertion which
becomes exposed gradually increases and spreads out and of course the cast metal
of the shoe proper exposed correspondingly decreases in area and position.
This changing of area and position of the component parts of the wearing
face of the shoe is illustrated in Figure 19, which shows the brake shoe, before
it has been used, in full lines. The dotted line indicates the wearing face of the
shoe after it has been in use and shows that the area and position of the exposed
parts of the insertion will have changed and that the position and area of the
cast metal shoe proper will have correspondingly changed. This is of great
importance in its effect upon the tread of the wheel for as the position and area

page_text: of the component parts of the wearing face of the shoe are constantly changing,
the exposed parts of the insertion and the cast metal will engage different parts
of the tread of the wheel instead of operating against the same parts of the tread,
thereby dressing and wearing the tread of the wheel evenly and uniformly
without wearing it in grooves or more in parts than in others, as would likely
be the case if the same area of the insertion engaged the same part of the tread
continually.
The wrought metal insertion which have heretofore been used to some extent,
are of the character substantially indicated by H in Figure 19, and being of a
slightly wedged shaped form their area changes in a very slight degree, but these
insertions are of such size and their area and position are, to all intents and
purposes, so absolutely constant that they have been found to change in character
after being used to some extent until they have a destructive effect on the tread
of the wheel. When the shoe is held in contact with the wheel these insertions H
became heated to a very high degree and, being instantly chilled when the brake
is loosened and the shoe is released from contact with the wheel, the exposed
face of the insertion is crystallized and these crystals dropping off leave the face
of the insertion irregular and of such a character that it will injure, to a more
or less extent, the tread of the shoe.
The perforated metal insertion herein described, however, overcomes this radical
defect in the insertion H, because the metal forming the insertion is finely dis-
tributed throughout the area of the shoe, whereby the wearing face of the shoe
consists of the face of the cast metal shoe proper, with numerous small parts
of the insertion distributed throughout the same.
A brake shoe made in accordance with my invention as herein described will
possess superior qualities both as to its braking effect and its longevity and it will
have a composite wearing face in which the ductile metal insert is finely divided
and substantially uniformly distributed in very small parts. As the shoe wears
the proportions of the two metals forming the wearing face of the shoe remain
substantially constant, but the disposition and the area of the ductile metal, with
relation to the cast metal, constantly change as herein before described. In this
respect my invention is differentiated from those brake shoes having wrought
metal insertion such as H, and also from that type of brake shoes having rods
extending transversely through the shoe, such shoes not having a finely divided
insertion and a constantly changing wearing face in the sense that those terms
are used with relation to my invention. I obtain the desirable results before
mentioned by having one of the metals of which the shoe is composed distributed
throughout the body of the shoe in different planes.
Figures 1 and 15 show the position of these exposed parts of the insertion on
the face of the shoe, and Figures 3, 13 and 14 also shew in cross sectional views
how the insertion is distributed through the shoe.
When the brake shoe is made it may be found more convenient to arrange the
insertion within the shoe in such a manner that it will not be exposed at all on
the wearing face of the shoe, a thin continuous surface of cast metal forming
temporarily the wearing face of the shoe, but if this method is followed the con-
tinuous face of cast metal will quickly wear off in use and the small parts of
the insertion come into operative position.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is:
1. A brake shoe composed partly of metal having superior braking qualities,
such as cast metal, and partly of ductile metal possessing great longevity, the
ductile metal being distributed throughout the body of the shoe in different planes
to provide a wearing face for the shoe of a finely divided and composite character.
2. A brake shoe composed of two different kinds of metal disposed in different
planes and so combined as to provide a wearing face for the shoe of a finely divided

page_text: and composite character and which is constantly changing, whereby the relative
disposition of the two metals on the wearing face constantly changes as the shoe
wears.
3. A brake shoe composed of two different kinds of metal, one of which is
disposed in differing planes and constantly changes in position on the wearing
face of the shoe, said metals being so combined as to provide a wearing face for
the shoe of a finely divided and composite character.
4. A brake shoe composed of two different kinds of metal, one of which is
disposed in differing planes and constantly changes in area on its wearing face,
said metals being so combined as to provide a wearing face for the shoe of a finely
divided and composite character.
5. A brake shoe composed of two different kinds of metal, one of which is
disposed in differing planes and constantly changes in area and position on its
wearing face, to provide a wearing face of a finely divided and composite character.
6. A cast metal brake shoe, having an insertion consisting of a foraminous
ductile metal body and constituting a part of the wearing face of the shoe.
7. A cast metal brake shoe, having a foraminous ductile metal insertion con-
stituting a part of the wearing face of the shoe, said insertion being permeated
in different directions by the cast metal, so as to form a solid homogeneous mass.
8. A cast metal brake shoe, having an insertion composed of a number of
foraminous sections of ductile metal.
9. A cast metal brake shoe, having an insertion composed of a laminated pile
of foraminous sections of ductile metal.
10. A cast metal brake shoe, having an insertion composed of expanded metal.
11. A cast metal brake shoe, having an insertion composed of a laminated pile
of sections of expanded metal.
12. A. cast metal brake shoe, having an insertion composed of a laminated pile
of foraminous sections, said sections being arranged with relation to each other
so that the hole therein will not register.
13. A cast metal brake shoe having a foraminous sinuous reinforcement
embedded therein, substantially as and for the purpose described.
Dated this 3rd day of August 1897
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.