IMPROVEMENTS IN SELF-ACTING BRAKES FOR USE ON RAILWAYS, TRAMWAYS, OR COMMON ROADS
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by William Spence at the Office
of the Commissioners of Patents, with his Petition, on the 22nd
November 1875.-A communication from abroad by Watson Playter
Widdifield, of the Village of Siloam, in the Province of Ontario,
Canada, Timber Merchant.
I, WILLIAM SPENCE, of 8, Quality Court, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN SELF-ACTING BRAKES FOR USE ON
RAILWAYS, TRAMWAYS, OR COMMON ROADS," (communicated to me from abroad
by Watson Playter Widdifield, of the Village of Siloam, in the Province
of Ontario, Canada, Timber Merchant,) to be as follows:—
This Invention has reference more particularly to an automatically
acting power brake applicable to railway, tramway, and road vehicle
wheels, and it consists first of a revolving drum mounted on a swinging
frame, to which drum are attached chains connected to the brake beams
at both ends of the car or truck. The drum is driven from any one of
the axles by friction wheels, which are brought into connection by the
receding action of the draw head or buffer, when the forward motion of

page_text: •
motive power.
This Invention consists further in the contrivances for reversing the
winding of the brake chains to correspond with the direction of move-
ment of the vehicle, and it consists lastly in the means for applying the
brakes when required by hand. In a car fitted with this brake the truck
may be constructed as usual, or may be built to any suitable design.
From the sides of the truck frame a shaft is supported by swinging
links in such a manner that it with its attachments can be drawn
towards the axle when desired, but when at rest it hangs plumb and
clear of the axle.. On one of the truck axles a friction pulley of
suitable diameter and length is securely attached.
On the swinging
"
shaft a similar friction wheel of suitable diameter is fastened, which
wheel when the shaft is drawn forward engages with the friction
pulley on the truck axle, receiving when so engaged a rotary motion
when the wheels are turned. The friction wheel on the swinging shaft
is mounted loosely, but is furnished on one side with clutches which
engage respectively with either one of a pair of stud pins fastened on
the shaft. The said loosely mounted friction wheel is thrown in and
out of gear with either of the said pins by means of a lever operated
from the car platform in any suitable manner. On the swinging shaft
revolved in the manner above described two or more sets of chains are
attached by eye bolts, which chains are connected to tlie brake beams;
of these one set draws the brakes up when the car is travelling in a
forward direction, the other set drawing up the brakes when the motion
is in the opposite direction. The two sets of chains are attached to the
shaft in different positions on its circumference. The draw bar may be
of ordinary construction, and has attached one end of a pivoted lever;
from the other end of this lever a chain runs connecting the swinging
shaft with friction pulley and chains attached.
When the car is travelling in the direction forwardly the draw heads
are drawn apart, and the chain connecting with the swinging shaft is
slack, allowing the links to hang plumb; when a stoppage is required
so soon as the tractive force is withdrawn the draw heads come together,
and are forced backwards, compressing the buffer springs. This retrograde
movement of the draw heads draws the friction wheel on the swinging
shaft into close connection with the friction pulley on the revolving axle,
causing the said shaft, if the clutch and stud pin are in gear, to revolve

page_text: in an opposite direction, winding up the brake chains and applying the
brakes until the forward motion of the wheels is stopped, or the tractive
force is again applied, or until the direction of the motion of the wheels
is changed, as in backing up after a stoppage. In this latter case the
clutch is automatically thrown out of gear with the shaft.
When "backing up" or when the motion is the reverse of the
preceding, the clutch is thrown into gear with the other pin fastened on
the shaft, and the chain is wound up as before. When it is desired to
move forward or backward without an application of the brakes, the
friction wheel is kept in a central position between and out gear with
both the stud pins merely revolving on the shaft, and being kept in
position by the forked end of the lever which extends forward to the
car platform. The clutch end of this lever is made sufficiently flexible
to allow the lever to be thrown from side to side as required, when the
friction pulleys are in gear with each other the revolving motion aided
by the pressure of the spring lever gradually moving the moveable
wheel as desired.
If it should be desired in the case of railway trains the winding up
apparatus could be applied to but one truck, say, one of the tender trucks,
the connection with all the other brakes being made by a chain or wire
rope passing over suitably arranged pulleys. The application of the
whole of the brakes would then be under the control of one man, and
at the same time each individual car could be fitted with the ordinary
hand brake in case of accident to the power brake.