Improvements in Brakes for Cars Worked by Cable on Mountain and other Inclined Railways, Tramways, and Lifts.
Year: 1889

page_text: COMPLETE SPECIFICATION.
Improvements in Brakes for Cars Worked by Cable on Mountain
and other Inclined Railways, Tramways, and Lifts.
ALEXANDER FINDLAY SMITH of 17 Surinamestraat, The Hague, Holland,
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:-
My Invention relates to an improved brake for cars worked by cable haulage on
inclined railways, tramways and lifts, and it has for its object to provide a grip brake
capable of being brought into operation automatically or otherwise, in the event of
the cable breaking, the power necessary to produce the gripping action of the brake
being derived from the descending motion of the car itself.
The improved brake comprises a pair of gripping jaws adapted to clip a central
rail, the said jaws being worked by a right and left handed screw shaft operated
from the wheel axles with which the screw shaft is thrown into gear at the required
moment by means of the mechanism hereafter described, with reference to the
accompanying drawings forming part of this specification, wherein Figure 1 is a
longitudinal section, and figure 2 a transverse section, of the brake applied to a
bogie truck, of which there is one at each end of the carriage. Figures 3 and 4 are
details.
The same letters of reference indicate the same parts in all the figures.
The
A is the central rail and B B a pair of jaws adapted to grip the said rail by
their lower ends and hinged together at their upper ends as at b, the jaws being
hung on a transverse right and left handed screw-shaft C which works in nuts Ď
pivoted on lateral gudgeons in apertures in the radial members of the jaws, the
shaft being hung in brackets E fixed to the frame of the bogie and the jaws being
stayed by rods F anchored to the frame of the bogie. The screw-shaft is geared,
by any suitable means, with a short intermediate shaft G carried by a lever H
pivoted on a centre carried by the framing. Upon the shaft G is mounted
loosely a gear wheel I and a similar wheel J is keyed on the wheel axle K.
wheel is connected to the shaft G through pawls pivoted to the rim of the wheel
and a ratchet wheel g fast on the shaft and contained in a cavity of the wheel, this
pawl and ratchet gear admitting of the wheel running idle, if geared with the
axle K, during the ascent of the car in order that the brake shall not then be
applied. The wheel I is put in gear at required times with the wheel J (for the
purpose of operating the gripping jaws B) by the notion of the lever H by which
the wheel I is carried. The intermediate shaft G is geared with the screw-shaft C
by any suitable mechanism, for instance by an endless chain L running on chain
wheels respectively fast on the middle of the screw-shaft C and on the shaft G,
so that on motion being communicated to the wheel I in the proper direction the
screw shaft will be operated and the gripping jaws B closed on the rail A.
In the example illustrated, the lever H is supposed to be held raised and the brake
kept out of action by the conductor of the car; and for this purpose a chain M
leading from a convenient point within reach of the conductor is passed under a
sheave m' and over a second sheave m² carried by the lever H and is attached to a
pendent hook N pivoted loosely on the intermediate shaft G the hook being adapted
to engage under the wheel axle K for the purpose of holding the wheels 1 J in gear
when once engaged.
It will be obvious that the chain M, instead of being held by the conductor, might
be attached to the cable itself so that on the cable breaking the brake will be applied
automatically. It will also be obvious that other equivalent means of transmitting
motion may be substituted for the endless chain L.

page_text: The action of the apparatus is as follows; During the normal running of the car,
the chain M is drawn up by the conductor, the hook N is disengaged from the wheel
axle, and the lever H is raised, thus disengaging the wheel I from the wheel J. Should
the cable break, the chain M on being released allows the lever H to fall by its own
weight, thus bringing wheels I, J, into gear in which position they are retained by
the hook N engaging with the wheel axle. By the running back of the car down the
incline, the rotation of the axle communicates rotary motion to the screw shaft C
through the pinions I, J, and chain I, whereby the jaws B are closed together and
grip the rail A between them with a progressively increasing force so as to gradually
arrest the motion of the car.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is;
1. The herein described grip brake for railway cars worked by cable haulage on
steep inclines or inclined lifts, consisting of a pair of pendent jaws adapted to grip a
central rail in combination with a right and left handed screw shaft screwing in and
operating the jaws and with mechanism, substantially as described, whereby the screw
shaft is at required times actuated from the wheel axle for the purpose of closing the
jaws, substantially as specified.
2. In the herein described brake, the combination, with the pair of pendent gripping
jaws and with a right and left handed screw working the same, as described, of an
intermediate shaft carried by a lever and geared by an endless chain or other
mechanism with the jaw operating screw and of gear wheels on the intermediate
shaft and wheel axle respectively, adapted to be brought into engagement by the motion
of said lever, for the purpose of applying the brake, as specified.
3. In the herein described brake, the combination, with the pendent gripping jaws
hinged together and worked by a right and left handed screw, an intermediate shaft
carried by a lever geared with the jaw-operating screw and adapted to be geared at
required times with a wheel axle, as described of a pendent hook pivoted to the lever
and adapted to engage with the wheel axle, so as to hold the intermediate shaft in gear
therewith, substantially as specified.
4. In the herein described brake, the combination, with the pendent gripping
jaws hinged together and worked by a right and left handed screw, an intermediate
shaft carried by a lever geared with the jaw operating screw and adapted to be
geared at required times with a wheel axle, as described, of a pendent hook pivoted
to the lever and adapted to engage with the wheel axle and of a flexible connection
attached to said hook and led over sheaves on the lever in such manner that the hook
will be withdrawn from the axle and the intermediate shaft held out of gear therewith
by the tension of such connection, substantially as specified.
Dated this 14th day of October 1889
A FINDLAY SMITH.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.