Improvements in Buffers and Draw Bars.
Year: 1895

page_text: Date of Application, 6th Aug., 1895-Accepted, 2nd Nov., 1845
Communicated from abroad by GEORGE WESTINGHOUSE, Junior, of Pittsburg,
Pennsylvania, United States of America, Engineer.]
Improvements in Buffers and Draw Bars.
We, THE WESTINGHOUSE BRAKE COMPANY LIMITED, of York Road,
King's Cross, in the County of London, Manufacturers, 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 the construction of buffer and draw bar apparatus in
combination with frictional appliances so arranged as to check and deaden the
movements and relieve the strain upon the springs.
Fig. 1 of the accompanying drawings is a longitudinal section and Fig. 2 is a
transverse section of buffer apparatus according to this invention.
Fig. 3 is a longitudinal section showing the apparatus applied to a draw bar.
Fig. 4 is a plan showing it applied to draw bars extending in both directions.
Fig. 5 is a longitudinal section of combined draw bar and buffer apparatus.
Referring first to Figs. 1 and 2, the buffer block A has a boss a which bears
against a front spring B and slides in a casing C. This casing abuts at its rear
against a back spring D which may be of volute form as shewn or of other suitable
form. The casing C can slide freely within an outer casing E which is fixed to
the carriage frame. The interior of the casing E presents a number of ridges e of
triangular section with intervening hollows occupied by triangular bars F each of
which has a projection f entering a corresponding recess in the cylindrical shell C
which is made in three parts, and encloses in its front portion a conical boss H
against which abuts the front spring B. When the buffer A is forced inwards, the
spring B is partly compressed and urges back the conical boss H which expands
the shell C forcing the triangular bars F as wedges into the hollows between the
ridges e, thus causing great friction so that the casing C is made to move
backwards against the back spring D. Thus by the sliding of shell and its
bars F under the frictional resistance and the resulting movement of the casing C
shocks on the buffer are transmitted to the carriage frame not as blows, but simply
as pressures.
Obviously buffers of similar construction may be employed as stops at terminal
stations, sidings and dead ends. For such purposes they should have considerable
length of stroke and very strong springs or equivalent checks, which aided by the
friction resistance of the triangular bars would serve to stop rolling stock withou
serious shocks.
As shewn in Fig. 3 the washer K on the draw bar L bears against the spring B
which abuts against the conical boss H; the shell C has a shoulder bearing against
one end of the spring D, the other end of which abuts against the end of the
casing E. This casing is provided with the triangular internal ridges and with the
intermediate hollows to receive the triangular bars F. When the draw bar is
subjected to a sudden strain the spring B is partly compressed and pushes forward
the conical boss H which expands the shell C forcing the bars F into the hollows
between the ridges of the casing E. As the boss H shell C and bars F are thus
made to advance compressing the spring D the movement is retarded and deadened
by the friction of the bars F travelling in the furrows of E into which they are
wedged by the action of the conical boss H.

page_text: When the draw bar has to extend in both directions the arrangement shewn in
Fig. 4 is adopted. Here the casing E containing the springs B. D the conical
boss H and the triangular bars F as in Fig. 3 is situated between a key K on the
draw bar L and a cross head M which can slide on the draw bar.
This cross-head is connected by a pair of bolts N to another cross-head M
fitted beyond a key K' on the other draw bar L'. It will be seen that whether
the one draw bar L or the other L¹ be subjected to a sudden strain, the apparatus
in the casing E serves to deaden the shock.
In the arrangement shewn in Fig. 5 which is applicable particularly where a
central buffer is used, the rod P serves both as buffer rod and as draw bar. Its
stroke is limited by a cross pin p passing through a slot of P. A shoulder of a
casing which encloses part of P bears against the spring B, and a key k passes
through the rear part of P behind a casing K enclosing the spring D. The
parts corresponding to those already described are, H the conical boss, C the shell
which is expanded either by the back movement of H when P acts as a buffer rod
or by the forward movement of C when P acts as a draw bar; F are the triangular
bars wedged into and sliding between the internal ridges of the casing E enclosed
by the casing R, made in halves bolted together and fixed to the framing of the
carriage. Thus the shock whether from the sudden push or pull of P is deadened
by being transmitted to the framing through the springs and the triangular bars
sliding with frictional resistance within the casing which is attached to the
framing.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In combination with a buffer or draw bar and the fixed casing through which
it slides, a conical boss free to slide on the bar between two springs, one of which
abuts against a collar on the bar and the other against a shoulder in the casing,
around the conical boss a divided shell carrying a number of bars of triangular
section arranged around the shell like a star, and fitted to slide in triangular
recesses of the casing, so that, when by the movement of the bar the conical boss
is also moved, the shell is expanded and its triangular bars are wedged in the
recesses of the casing producing as they move longitudinally such friction as to
check and deaden the movements of the bar substantially as described.
2. The buffer apparatus substantially as described with reference to Figs. 1
and 2.
3. Draw bar apparatus substantially as described with reference to Fig. 3.
4. Double draw bar apparatus substantially as described with reference to
Fig. 4.
5. Combined buffer and draw bar apparatus substantially as described with
reference to Fig. 5.
Dated this 6th day of August 1905
ABEL & IMRAY,
Agents for the Applicants.