IMPROVED STARTING AND STOPPING APPARATUS FOR VEHICLES PROPELLED BY ROPE TRACTION
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Henry Marryatt Martin at the Office
of the Commissioners of Patents on the 29th December 1883.
HENRY MARRYATT MARTIN of N° 5 Bedford Place in the County of Middlesex
"IMPROVED STARTING AND STOPPING APPARATUS FOR VEHICLES PROPELLED BY
ROPE TRACTION
"
My invention relates to apparatus for taking hold of and releasing the traction
rope, and working the brakes, so as to effect the starting and stopping of vehicles
propelled by rope traction with ease and certainty, and to avoid, as much as
possible, the damage and wear of the traction rope, and prejudicial strains upon it
or the gripping mechanism. In the system of propulsion to which my invention
relates, there is, as is well known, a traction rope running at considerable speed
over guide pullies arranged at intervals within a channel which has in its upper
part, along its whole length, a narrow opening or slit. Through this slit passes a
connecting stem, usually in the form of a plate thin enough to pass freely along the
slit and wide enough to give the necessary strength for propelling. The upper end
of this stem is attached to the vehicle, and the lower end is furnished with a
gripper or apparatus which engages the rope and grasps it with more or less
firmness, so that the movement of the rope is communicated through the stem to
the vehicle. The gripper stem has necessarily accommodated within its thickness
moving parts, such as slides, rotating spindles or screws, which serve to connect the
gripper with mechanism in the vehicle so that it can be made to engage and grasp
the rope or to release it, as the case may be. As usually arranged, these
connections are worked by separate levers or handles on the vehicle, so that it is
necessary for the conductor to pass from one to the other in order to perform the
various operations required, and also to work other levers controlling the brakes of
the vehicle. Now, according to my invention, I place all these connections,
including those for working the brakes, under the control of one wheel somewhat
like a steering wheel which is held by the hands of the conductor. The connecting
gear is so arranged and provided where necessary with counterweights or springs,
that the wheel, when it is let go, turns to such a position that the rope is released
and the brakes are put on, this being the condition for the vehicle remaining at

page_text: rest. When it is desired to start the vehicle, the conductor has to turn the wheel,
One part of its revolution serves to release the brakes and to bring the gripper
into position for engaging the rope. A farther movement of the wheel serves to
apply the gripper with a yielding grasp to the rope, so that the vehicle is started
gradually into motion. And a final farther movement of the wheel serves, when the
vehicle has attained the speed of the rope, to render the grasp of the gripper firm
and unyielding, so that there is no slip of the rope through it. In this position, the
conductor has to hold the wheel while the vehicle is running, as a driver holds the
reins of horses driven by him. Should an emergency occur requiring the rapid
stopping of the vehicle, the conductor has only to let go the wheel, whereupon
automatically the rope is released and the brakes are applied.
For the purpose of giving a gradual hold of the rope so as to avoid as much as
possible, damage and undue strains to it and to the gripper when the vehicle is
starting into motion, I provide that at first, when the gripper begins to act, it shall
do so with a slipping surface moving along with the rope, but resisted with a
graduated friction, and that after the vehicle and gripper have attained the speed
of the rope, the gripper shall firmly hold the rope by pressing it between surfaces
of caoutchouc, leather, wood or other somewhat yielding material so as to exert no
hard pressure on any part of the rope. The starting part of the gripper may
consist of rollers which can turn in their bearings so as to have at the circumference
the speed of the rope, while their rotation is resisted by more or less friction
applied to their bearings, and the grasping part may be cheeks of caoutchouc, wood,
leather or the like which are advanced so as to grip the rope after the vehicle has
attained its velocity, the starting rollers being then retracted if desired. The
starting and grasping may however be effected by one set of apparatus consisting
of endless bands, one on each side of the rope, which pass round rollers free to
revolve, these bands being pressed with gradually increasing force against the rope
and having their motion resisted by the friction of the surfaces behind them which
press them-forwards. Instead of bands, may be employed chains faced on the sides
presented towards the rope with somewhat yielding material such as caoutchouc,
leather or wood. At first, while the vehicle is stationary or moving slowly, these
bands or chains are free to travel with the rope and are resisted more or less by
friction, but when the vehicle has attained the speed of the rope, the bands or
chains remain stationary relatively to the rope, grasping it firmly but with
comparative softness.
.
In order to prevent the spring oscillations of the vehicle from being communicated
to the rope, I prefer to mount the whole of the gripping apparatus on a two
wheeled truck without springs, this truck being attached to the front of the vehicle
on which the conductor can stand or sit, holding the operating wheel on the truck
immediately in front of him.