IN AERIAL OR WIRE ROPE TRAMWAYS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by George Brown at the Office of the
Commissioners of Patents on the 15th December 1880. A communication
from abroad by George Kilgour, of Dutoitspan, of Griqualand West, South
Africa.
GEORGE BROWN, of Finsbury Circus, in the City of London, Secretary to the
"AN IMPROVEMENT
London and South African Exploration Company, Limited.
IN AERIAL OR WIRE ROPE TRAMWAYS." [A communication from abroad by
George Kilgour, of Dutoitspan, of Griqualand West, South Africa.]
This Invention relates to an improved "jumper" or support for aerial or wire
rope tramways, particularly when erected in situations involving a sudden deviation
in the direction of the wire ropes from the horizontal to the inclined direction, or
vice versa, as, for example, in passing over the edge of the cliff or bank of a quarry,
mine, or other open excavation.
In aerial or wire rope tramways of this kind, the wire ropes for the carriages (in
which the tubs are hung) to run upon are fixed or anchored at one end and tightly
strained at the other, and in passing over the edge of the cliff or bank of the quarry,
mine, or other excavation, each rope is usually carried over and supported by a
curved rail, termed a jumper, having a groove in its upper surface for the rope to
lie in.
Heretofore these jumpers have been stationary, save that they have been provided
with a screw adjustment to adapt them to suit the relative directions of the
horizontal and inclined parts of the rope. Owing to the sagging of the ropes under
the weight of the loaded tubs, they have a slight longitudinal movement which gives
rise to much friction of the ropes in the grooves, and a strain tending to overturn
the jumpers, the friction and consequent wear of the ropes being increased by the
great strain upon them.
Now the object of this Invention is to avoid this excessive friction and wear of
the ropes at this point, and the Invention consists in mounting the jumper to move
or oscillate on or about a centre, so that the curved rail or part in which the wire
rope lays shall be free to accompany the said rope in its longitudinal movements.
A jumper for a double rope tramway may be constructed according to this
Invention as follows:-

page_text: Two quadrant shaped frames are by suitable ties and struts braced together at
the proper distance apart to carry the wire ropes. The curved part or periphery
of each of these quadrants is a rail, preferably of cast steel, grooved for the wire
rope to lie in, and with bevelled flanges for the wheels of the carriages to run upon
in passing over the jumper. These two quadrant shaped frames are mounted on a
horizontal shaft supported in bearings on a suitable foundation or base plate, upon
which shaft the jumper is free to oscillate as a centre, the centre of oscillation
preferably coinciding with the centre of curvature of the quadrant. Instead of
being mounted to oscillate on a shaft or pivot, the jumper might be made to rock
on any other fulcrum or centre, or be otherwise supported so as to have a motion
about a centre or axis. For example, the curved rail may be supported upon rollers,
themselves rolling on a curved path or frame concentric with the curvature of the
movable rail. Suitable sheaves are mounted in the jumper for supporting and
guiding the hauling rope.