Year: 1887

page_text: [Communicated from abroad by EDWARD DYER DOUGHERTY, of Philadelphia,
Pennsylvania, United States of America, Manufacturing Engineer.]
1, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex, M.L.M.E.
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 :-
:-
The object of this invention is to provide simple cheap and compact mechanism
whereby the tension of a traction cable may be regulated and the "slack" or looseness
of the cable occasioned by stretching or other causes may be taken up automatically
after the working parts of the device have once been properly adjusted relatively to
the cable.
In the accompanying drawings:-
Fig. 1 represents a side elevation of the apparatus and Fig. 2 is a plan thereof.
A, A are two similar vertical standards or frames made of metal or other suitable
material and braced together to resist lateral strain. On the top of each standard
is formed the half of a journal box within which rest the trunnions B of the
twin oscillating beams C which are secured parallel to each other by transverse bolts c
and also by the shouldered journal shafts c which form axes for grooved pulleys D the
latter being mounted loosely thereon. Caps a are screwed to the flanges of the
standards A to retain the trunnions B in their bearings.
A frame or bed plate E is placed at the rear of the frames A which bedplato
supports a horizontally sliding carriage F on which is mounted a loose pulley G. A
windlass H is attached to work on the side of the frame E and by means of
this and rope or chain passing round sheave blocks JJ attached respectively to
the frames and E the former with the pulley G may be drawn away from the
frames A.
Two chains or ropes K are attached one on each side to the shaft (which carries
the lowest of the pulleys D and these ropes or chains pass under a pair of parallel
pulleys L and over a similar pair of parallel pulleys L' thence downwards and are both

page_text: attached to a weight M. The pulleys L and L' may be mounted on axes fixed to any
convenient support. The weight M may be a solid block of any suitable material or it
may be a box loaded with blocks of heavy material the box being of sufficient capacity
to hold weights exceeding the maximum demands of the service.
In operation the endless cable N is wound round the driving drum O then around
the pulleys D and G as shown in the drawing. It is then stretched to remove
"slack" or looseness by drawing the carriage F and pulley G away from the
frames A by means of the windlass H and blocks J. The chains or ropes K should
be of such length that the weight M. will be raised and suspended when any increase
of draught on the running cable by the attachment of additional cars thereto
causes a change in tension of the cable and such change will be properly compensated
for by the vibration of the beam and pulleys D and the consequent elevation of
the lower pulley which will have the effect of raising the weight M. A decrease of
draught strain will be compensated for and equilibrium maintained by the descent
of the weight M.
23
It will be apparent from the foregoing description that this compensating device
will adjust the tension of the cable automatically to suit variation caused by the
'hooking-on or disconnection of cars on the line when a proper adjustment of
relative parts has been provided by a graduation of the suspended weight to the
maximum strain it is designed to counteract.
The several elements embodied in this compensating device are of simple con-
struction and consequently may be economically made and worked and as ready
access is afforded to adjust and lubricate the bearings excessive wear of frictional
surfaces is avoided and consequently the cost of repairs is reduced to a minimum.
Minor changes may be made in the construction of this apparatus without departing
from the spirit of the invention. As for instance the connection between the beam Č
and weight M need not necessarily consist of rope or chain as rods and crank levers
might be used with the same result. I therefore do not wish to restrict myself to the
exact form and arrangement of the parts shown.
Having now particularly described and ascertained the nature of the said invention
as communicated to me by my foreign correspondent and in what manner the same is
to be performed I declare that what I claim is
1. In a tension device for cable railways the combination with a traction cable
of an oscillating beam such as C upon which the cable has running support and
means of automatic adjustment of the amount of vibration of the beam to regulato
the tension of the cable substantially as described and illustrated in the drawings
annexed.
2. The combination with an endless cable and oscillating beam such as C of a
counteracting weight M and a flexible connection between the weight and oscillating
beam substantially as described.
3. The combination with a cable having automatic adjustment by means of an
oscillating beam such as Cand weight M of a sliding carriage and pulley such as F, G
for stretching the cable or taking up "slack" substantially as described and illustrated
in the annexed drawings.
Dated this 7th day of June 1887.