An Improved Pulley Arrangement for Conducting the Haulage Cable around Curves on Cable Tramways.
Year: 1891

page_text: Date of Application, 28th July, 1891-Accepted, 29th Aug., 1891
COMPLETE SPECIFICATION.
An Improved Pulley Arrangement for Conducting the Haulage
Cable around Curves on Cable Tramways.
1, NOWELL HENRY RICHARDS, of The Melbourne Tramway and Omnibus
Company Limited, Melbourne in the Colony of Victoria, 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 :-
This invention relates to the means employed for conducting haulage cables
around curves on cable tramways.
Heretofore it has been usual to arrange comparatively small pulleys along the
inside of the curve in order to conduct the haulage rope or cable around it. The
effect of this arrangement of pulleys is injurious, partly because the rope is bent
at so many different points, and partly because of the frictional contact between the
outer strands of said rope and said pulleys, and partly because of the chafing of
the inside wires.
'
i
The object of this invention is to prevent this wear and tear of the cable as well
as to reduce the frictional resistance incidental to the use of so many curve.
pulleys.
Now my invention consists in the employment of a single comparatively large
horizontal pulley arranged in such a position outside the track as that a line
continued from the straight part of the cable slot at the commencement of the curve
is tangential to the periphery of said curve pulley so that the cable can run straight
along the cable tunnel, pass out of it at the commencement of the curve, continue
still in the same straight line until it reaches the periphery of the curve pulley,.
then pass easily around the periphery of said pulley and again travel in a straight
line to the opposite end of the curve where it again enters the cable tunnel and
then continues to travel in the same straight line along the straight part of
the track.
With this arrangement of curve pulley it is obvious that the cable has only one
large bend to make instead of a number of small ones, and that there is not so much
wear and tear of its outside strands by reason of its frictional contact with a number
of small pulleys.
Referring to the accompanying drawings,
Figure 1 is a plan of a curve in a cable tramway, showing it fitted with a single
curve pulley arranged according to this invention.
Figure 2 is a vertical transverse section on line 2-2, Figure 1.
Figure 3 is a diagrammatic view illustrating the ordinary arrangement of pulleys
for conducting the haulage rope or cable of a cable tramway around a curve,
and
Figure 4 is a similar view illustrating my improved arrangement of pulley for
conducting the haulage cable round a curve on a cable tramway.
The same letters of reference are used to indicate the same parts in all the
figures.
In the case of a double track, as illustrated in Figures 1 and 2 of my drawings,
I provide two comparatively large horizontal pulleys A-A', one for the inner and
the other for the outer track, and I arrange each of said pulleys so that its periphery
is in a line with the straight parts of the track, that is, if a line were continued
from each of said straight parts it would form a tangent to the periphery of each
of said wheels.
B-B represent the cables which are supported in the straight parts of the cable
tunnels in the ordinary manner, but which are according to my invention led out

page_text: of said tunnels at the commencement of the curve and pass in a straight line around
one or other of the single curve pulleys A or A.'.
These latter are mounted in bearings within a pit or recess C. formed beneath
the roadway outside the track and bridged over with girders and lined with cement
or other suitable material. A man-hole c-c' is provided above each of the curve
pulleys.A A to allow of their being oiled or otherwise attended to when required,
whilst preferably in one corner of the pit a wheel trap D is provided, said trap
being made large enough to allow a half of each of the pulleys A-A' to be passed
through at a time, said pulleys being split or made in halves to enable them to be thus
passed into the pit and be mounted in position therein.
In order that the cable B¹ may pass from the straight part of the outer track in
a straight line to the periphery of the curve pulley A and from thence in a straight
line to the straight part of the track at the opposite end of the curve, I form a
short cable tunnel or passage between each end of the curve and each of the sides
of the pit C and in order to allow the inner cable B to pass out of its tunnel at the
commencement of the inner curve to the periphery of the pulley A and back again
in a straight line to the end of said curve, I form passages or tunnels E² through
the partition or partitions, if any existing between the cable tunnels of the up and
down line so that said inner cable B is free to travel around its pulley in a similar
way to the outer cable B'.
With this arrangement of curve pulley, a cable will only be bent once at each
curve, as clearly illustrated in Figures 1 and 4, thus avoiding the numerous small
bends and the frictional contact incidental to the ordinary arrangement of curve
pulleys, as illustrated in Figure 3.
It will be obvious that my invention is only applicable to carves round which the
cars can travel by their own momenturn.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is:
The herein described pulley arrangement for conducting a haulage cable around
curves on cable tramways consisting in mounting a comparatively large horizontal
pulley in bearings outside the track in such a position as that a line continued from
the straight part of the track will be tangential to the periphery of said pulley,
substantially as and for the purposes herein described and explained and as
illustrated in the accompanying drawings.
Dated this Eighteenth day of June One thousand eight hundred and ninety-one.