Improvements in Braking and Starting Gear for Tramway Cars and other Vehicles.
Year: 1886

page_text: Date of Application, 26th June, 1886.
Complete Left, 26th Mar., 1887.
Complete Accepted, 26th Apr., 1887.
Improvements in Braking and Starting Gear for Tramway Cars
and other Vehicles.
I WILLIAM THOMSON of Smith Street Kinning Park Glasgow Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention relates to improvements in apparatus of the class wherein the energy
due to the momentum of tramway car or other vehicle in motion is, in the act of
arresting such motion, stored up by the compression of a spring or an elastic fluid or
by raising a load or similar. means and is utilised for starting the vehicle or lessening
the power required for starting. Under my invention I fix upon one or inore of the
running axles of the vehicle a pinion adapted to engage with either of two racks
carried one over and the other under the pinion upon a rectangular framing which is
movable vertically to bring either the upper or lower rack into gear with the pinion.
To the rack frame is attached a bar encircled by a helical spring or a spear and
plunger passing into a cylinder or a chain connected to a weight or other contrivance
adapted to store up energy such contrivance under whatever form being acted on by
the longitudinal movement of the rack frame which is operated, when brought into
gear by the brakesman or driver, with the pinion upon the axle and which then
serves as a brake to the vehicle by retarding the rotatory movement of the axle in
proportion to the amount of energy stored. At one portion of their length the racks
have their teeth shorn off so that the pinion may freely revolve between them, while
the brake is out of action but upon the rack frame being moved to a slight extent
longitudinally by means of an arm on the brake lever or otherwise the pinion engages
one of the racks and brings the retarding action of the spring or other contrivance
into play. When the vehicle runs in one direction the upper rack is brought into
engagement with the pinion for applying the brake and storing up the energy due
to the momentum of the vehicle and on restarting it the lower rack is thrown into
gear while the upper. one is thrown out in order that the return movement of
the rack-frame on the release of the brake may drive the pinion in the proper
direction to impel forward the vehicle; and when the vehicle runs in the opposite
direction the lower rack is brought into engagement to apply the brake and the

page_text: upper one to effect the restarting in a similar manner. The requisite vertical
movement of the rack frame, on which the racks are at such a distance apart
that as the one engages with the pinion the other becomes disengaged, is imparted
to it by cams, wedges, or the like which are attached to discs or lever arms
centred loosely upon the wheel axle on either side of the pinion and which bear
upon side flanges or plane surfaces formed at each side of the racks, the discs or
lever arms which may also serve to guide the rack frame being operated by links
from a hand lever or brake lever upon the vehicle and placed within reach of the
driver or brakesman. Ratchet pawls or grippers are also hung upon the axle one
engaging with the teeth of the lower rack or on its flanges and another suitably
counter-balanced engaging with the upper rack, these pawls serving to retain the
rack frame in position to prevent the reaction of the stored energy when the
brake has been applied and being released for the restarting movement by the action
of the wedges or lifting pins or the like operated by the brake lever. In lieu of the
racks above referred to pitch chains stretched upon a framing may be employel
and geared with the pinion on the wheel axle.
DCL
T
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow,
Agents.
COMPLETE SPECIFICATION.
Improvements in Braking and Starting Gear for Tramway Cars
and other Vehicles.
1, WILLIAM THOMSON of Smith Street, Kinning Park, Glasgow, Engineer, 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 apparatus of the class wherein the
energy due to the momentum of a tramway car or other vehicle in motion is, in the
act of arresting such motion, stored up by the compression of a spring or an
elastic fluid or by raising a load or similar means and is utilised for starting the
vehicle or lessening the power required for starting.
Under my invention which is illustrated in the accompanying drawings as applied
to the framework F, of a tramway car in sectional elevation at figure 1, in plan
at figure 2 and in detail at figures 3, 4 and 5, I fix upon one or more of the
running axles A, A, of the vehicle a pinion B, adapted to engage with either of
two toothed racks C, C, carried one, C, over and the other C, under the
pinion B, upon or as part of a rectangular or oblong framing which is movable
vertically to bring either the upper or lower rack into gear with the pinion.
To the rack frame is attached a rod or bar D, encircled by a helical spring E,

page_text: passing into and bearing against the end of a cylinder G fixed on the frame-
work F the bar D having a collar d against which the other end of the spring bears;
or a spear and plunger adapted to compress or to rarify air contained in a
cylinder, a chain connected to a weight, or other contrivance adapted to store up
energy may be employed in lieu of the spring, such contrivance under whatever
form being acted on by the longitudinal movement of the rack frame which is
operated when brought into gear, by the brakesman or driver, with the pinion B,
upon the axle A, and which then serves as a brake to the vehicle by retarding
the rotatory movement of the axle in proportion to the amount of energy stored
by compressing the spring or acting on the equivalent thereof. At one portion
of their length, preferably at one end, the racks have their teeth shorn off so that the
pinion B, may freely revolve between them while the brake is out of action, but
upon the rack frame being moved to a slight extent longitudinally by means of a
link and an arm on the brake lever H, as hereinafter described, the pinion
engages one of the racks and brings the retarding action of the spring or
equivalent contrivance into play. When the vehicle runs in the direction indicated
by the arrow, figures 1 and 3, the lower rack is brought into engagement with
the pinion B for applying the brake and storing up the energy due to the
momentum of the vehicle and on restarting it the upper rack C is thrown into
gear while the lower one is thrown out in order that the return movement of
the rack frame on the release of the brake may drive the pinion in the proper
direction to impel forward the vehicle; and when the vehicle runs in the opposite
direction the upper rack is brought into engagement to apply the brake and the
lower one to effect the restarting in a similar manner. The requisite vertical
movement of the rack frame on which the racks C, C, are at such a distance apart
that as the one engages with the pinion B, the other becomes disengaged, is imparted
to it by eccentrics i, i, or by cams, wedges or the like which are formed on or
attached to discs I, I, or to fever arms, centred loosely upon the wheel axle A, on
either side of the pinion B, and which bear upon side flanges or plane surfaces c, c¹,
formed at each side of the racks C, C, the discs or lever arms, which may also serve
to guide the rack frame, being operated by the links h, h, from the hand lever or
brake lever H, upon the vehicle and which is placed at each end within reach of the
driver or brakesman.
The apparatus is operated as follows:-
When the vehicle is moving in the direction indicated by the arrow in figure 1,
and a stop is to be made, the driver draws the brake lever H, in front, from the
vertical, which is the position at mid gear, until it assumes the position shown and
thereby throws upwards the eccentrics which lift the rack frame to bring the teeth of
the lower rack into the line in which they may gear with the pinion B, the said frame
being at the same time pressed back so that the rack and pinion engage. The rack
frame is then by the rotation of the pinion driven back against the pressure of the
- spring E, a braking action being thereby applied to retard the rotation of the
pinion B, and of the wheels on the axle A, until the rack frame reaches the end of its
travel when the pinion and car wheels are stopped. The driver then throws the
brake handle into mid gear thereby bringing the rack frame into a mid position
vertically in which both racks engage the pinion B, and lock it; and when the vehicle
is again to be started the driver throws forward the lever H, into fore gear thereby
bringing down the upper rack C, to be alone in gear with the pinion which is there-
upon caused to rotate by the action of the spring pressing forward the rack frame,
When the
the pull of the horses or of the engine at starting being thus relieved.
rack frame approaches the termination of its forward movement an arm or fork j
thereon strikes against a projecting finger or snug kon each disc I, and turns the
disc to such an extent as to bring the eccentrics E, and the rack frame and with them
the brake lever H, into mid gear the pinion then being free to rotate within the end
part of the rack frame. A second arm or fork on each of the discs I, serves a like
purpose by striking a snug or finger k when the lower rack engages the pinion B,
for restarting and the vehicle moves in the opposite direction, and the snugs k, k',

page_text: also serve by pressing against the arms j, j¹, to move the rack frame into position
longitudinally for bringing the rack teeth into gear with the pinion when the discs I,
and eccentrics E, are turned by the brake lever H, into fore of back gear.
When the apparatus is applied to more than one axle of a vehicle the rack frames
acted on by the pinions upon the several axles are connected together by links as
indicated at figure 5, and the brake lever rods are in like manner connected to operate
the discs and eccentrics on each axle.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the saine is to be performed, I declare that what I claim is :-
1. The combination of parts constituting the improved braking and starting gear
for tramway cars and other vehicles, substantially as herein described with reference
to the drawings annexed.
2. In braking and starting gear for tramway cars and other vehicles the rack
frame C, C, connected to devices for storing energy in combination with a pinion on
the car axle and eccentrics operated by the brake lever for bringing either rack into
gear with the pinion and locking them, substantially as herein described with reference
to the annexed drawings.
3. In braking and starting gear for tramway cars and other vehicles the
eccentrics i, i, operated by the brake lever and arranged to throw the racks C, C¹,
into and out of gear and to lock them, substantially as herein described with reference
to the drawings annexed: