Improvements in Brake-shoes.
Year: 1899

page_text: Date of Application, 2nd May, 1899-Accepted, 15th July, 1899
COMPLETE SPECIFICATION.
Improvements in Brake-shoes.
I, ALFRED LINCOLN STREETER, of 507, Jackson Boulevard, Chicago, in the
County of Cook, and State of Illinois, United States of America, Gentleman, 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:
This invention relates to improvements in brake-shoes and relates particularly to
improvements in brake-shoes of the type consisting of a cast metal body portion,
the face or friction surface of which comprises a piece or pieces of relatively. hard
metal embedded therein.
...
I am aware that brake-shoes of this general type consisting either of body portions
of cast iron and pieces of steel, wrought iron or cast iron embedded in the faces or
friction surfaces thereof, are old in the art. Prior to my invention, however, all
brake-shoes of this type have been objectionable for the reason, among others,
that they cut and gouge the treads of ordinary steel tired truck wheels to such an
extent that they are entirely unadapted for use on and are practically unused on
such wheels.
A primary object of my invention is to provide a brake-shoe of this type
adapted for use on steel tired wheels and which will be relatively very cheap
and durable.
A brake-shoe, embodying my invention, comprises a body portion of cast iron in
the face or friction surface of which is or are embedded a piece or pieces of white
cast iron, the body portion of said brake-shoe in contact with said piece or pieces
so embedded therein, being chilled and the chill decreasing at points remote
therefrom.
In the manufacture of my improved brake-shoe, I first cast a piece or pieces of
white cast iron of desired size and shape, either in a chilling mold or in an
ordinary sand mold. Said piece or pieces are then removed from the molds in
which they are cast and are seated in an ordinary sand mold for the body portion
of said brake-shoc, which is then cast therein.
The body portion of the shoe in contact with the piece or pieces, so embedded
therein, will thus be chilled and hardened and will decrease in hardness at points
remote therefrom. I have discovered also that a body of white cast iron will not
become annealed or softened when molten metal is cast around it, but will retain
its. original hardness. White cast iron being substantially the same in chemical
composition and in physical properties as chilled cast iron, it therefore results
from the structure of my brake-shoes and the method of manufacture, that they
will have relatively hard pieces embedded in their faces or friction surfaces, that
the body portions thereof in contact with said pieces, so embedded therein, will be.
chilled and will be of practically the same hardness as said pieces and will
decrease in hardness at points remote therefrom..
A brake-shoe, embodying my invention, also comprises the various other features
and details of construction hereinafter described and claimed.

page_text: In the accompanying drawings, a brake shoe, embodying my invention, is fully
illustrated.
Figs. 1 and 2 are plan and side views, respectively, of a piece designed to be
embedded in the face or friction surface of my improved, brake-shoe.
Fig. 3 is a sectional view of my improved brake-shoe on the line 3-3 of
Fig. 4.
Fig. 4 is a plan view of the face or friction surface of a shoe embodying my
invention; and
Fig. 5 is a transverse sectional view of my improved shoe on the line 5--5 of
Fig. 4.
Referring now to the drawings, A designates the body portion of a brake-shoe
and A a piece of white cast iron embedded therein so that it will be exposed at
the face or friction surface thereof, which, for purposes of convenient reference, I
will hereinafter designate as an insert.".
As shown, the insert A¹ consists of two transverse end portions a, which are
connected by a curved or sinuous lingitudinal portion a'. I do not desire, however,
to be limited either to a single insert or to an insert of the specific shape shown,
as my invention contemplates the use of any desired number of inserts of any
desired form.
In the manufacture of my improved brake-shop, I first form the insert 'A', which
will preferably be thinner at one edge than at the other, say, for example three-
eights (8) of an inch at the edge designed to be exposed at the face or friction
surface of the shoe, anil seven sixteenths (7) of an inch at its other edge. The
insert A may be cast either in an ordinary sand mold or in a "chill" mold, but
in practice I prefer to use an ordinary sand mold.
*
In the manufacture of my improved brake-shoes, I have made the inserts A¹
from what is commonly known as car-wheel" cast iron, which I find do not
become annealed or softened when the body portions A of the shoes are cast around
them. I do not desire, however to limit myself to this particular grade of cast
iron for making said inserts, as other grades of cast iron may retain their hardness
equally well. My invention therefore, contemplates the use of any grade of cast
iron that will not become annealed or softened when molten metal is cast around it.
The insert A is then placed in an ordinary sand mold, in proper position, after
which the cast iron for the body portion, in a molten state, is poured around it.
Owing to its shape, as described, the insert A' will be dovetailed and rigidly
secured in the body portion A of said. shoe, against possibility of accidental
displacement.
The insert A will operate in a familiar manner; to chill the body portion A of
said shoe, immediately adjacent thereto. Said body portion of said shoe in contact
with the insert A¹, will thus be of practically the same hardness as said insert and
the hardness thereof will decrease at points remote therefrom. Brake-shoes,
embodying my invention, possess a very great advantage over other shoes of this
type, for the reason that they are adapted for use on steel-tired wheels, it being
a well known fact that brake-shoes of this type have not, heretofore, been used on
steel-tired wheels on account of the manner in which they cut and gouge the
treads thereof.
In Figures 3, 4 and 5, of the drawings, the chilled and hardened portions of
said brake-shoe are indicated by the darkened sections.
An objectionable, feature of brake-shoes of this general type, as heretofore con-
structed, has been their liability to break in handling. It is a well known fact
that, when a brake-shoe, having a piece or pieces embedded in the face or friction
surface thereof, is thrown down or is allowed to fall so as to strike on the attaching
lug, said shoe is very liable to break transversely at one end or the other of said
attaching lug. In the drawings, Figure 3, the dotted lines a² indicate, approxi-
mately, the probable lines of fracture in a shoe of the construction shown.
A further object, of my invention is to remedy this defect by strengthening the
shoe at these points.

page_text: As it relates to this feature, my invention consists in forming transverse
grooves a, in the face of the inserts A¹, designed to be exposed at the friction
surface of said shoe and opposite to the shoulders at each end of the attaching
lug A2, that is where the lines of fracture a³ will intersect said insert when
embedded in the shoe. When the body portion A of the shoe is cast around said
insert, it will fill said grooves and will form strengthening ties a³, which will
reinforce the shoe at these points where they are most liable to break.
I do not desire to limit myself to ties at, located in the exact positions shown in
the drawings, as such ties may be provided at any place in the face of a brake-
shoe, where it is desired to strengthen or reinforce it.
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. As a new article of manufacture, a brake-shoe having an insert or inserts of
white cast iron embedded in the face or friction surface thereof, the body portion of
said brake-shoe in contact with said insert or inserts being chilled and the chill
decreasing at points remote therefrom, substantially as described.
.
2. As a new article of manufacture, a brake-shoe having an insert of white cast
iron embedded in the face or friction surface thereof, said insert comprising
transverse end portions connected by a curved or sinuous longitudinal portion, the
body portion of said brake-shoe in contact with said insert being chilled and the
chill decreasing at points remote therefrom, substantially as described.
3. As a new article of manufacture, a brake-shoe having an insert or inserts
embedded in the face or friction surface thereof, said shoe being reinforced or
strengthened at points opposite to the sides or ends of the attaching lug by ties
formed integral with the body portion of said shoe and extending transversely
across the front or exposed side or sides of said insert or inserts, said insert
or inserts being grooved transversely to receive said ties, substantially as described.
4. As a new article of manufacture, a brake-shoe having an insert of white cast
iron embedded in the face or friction surface thereof, said insert comprising a
piece which extends longitudinally of said brake-shoe, the body portion of said
brake-shoe in contact with said insert being chilled and the chill decreasing at
points remote therefrom, said brake-shoe being reinforced or strengthened at
points opposite the sides or ends of the attaching lug of said shoe by transverse
ties formed integral with the body portion of said shoe, said insert being grooved
transversely to receive said strengthening ties, substantially as described.
5. As a new article of manufacture, a brake-shoe having an insert or inserts
embedded in the face or friction surface thereof, said shoe being reinforced or
strengthened by ties formed integral with the body portion of said shoe and
extending transversely across the front or exposed side or sides of said insert or
inserts, said insert or inserts being grooved transversely to receive said ties,
substantially as described.
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