Improved Apparatus for Maintaining the Tension of or Compensating for the Expansion and Contraction of Signal or Line Wires.
Year: 1893

page_text: Date of Application, 11th Mar., 1893
Complete Specification Left, 11th Dec., 1893-Accepted, 13th Jan., 1894
PROVISIONAL SPECIFICATION.
Improved Apparatus for Maintaining the Tension of or Compensating
for the Expansion and Contraction of Signal or Line Wires.
I, ALBERT EDWARD BERRY of Victoria Road Sowerby Bridge, Yorkshire,
Engineer do hereby declare the nature of this invention to be as follows:-
This invention has for its object the application to or connection with signal or
line wires of apparatus for automatically regulating and maintaining their tension so
as to compensate for the contraction and expansion in length to which they are
liable by reason of variations of temperature, or elongation or expansion caused by
strain; the effects of which, if not remedied, are to imperfectly operate the signal
or object with which they are connected.
In carrying out my invention I employ a suitably studded or chain wheel for
each wire, said wheel being mounted on a short shaft journalled in bearings adapted
to slide in ways or grooves in opposing plates, blocks, or brackets which form the
supports. The shaft, by preference, is connected by a lever or levers or connecting
rod to the signal or operating lever so that the movement of the latter to raise or
lower the signal causes the shaft, with its wheel, to slide laterally in the grooves or
ways in the aforesaid supports a distance equal or equivalent to the extent of
movement of the signal or object the lever operates. The parts described may be
conveniently placed under the floor of the signal cabin when applied to signal wires.
To the free end of the wire a chain is secured which passes over the chain wheel
and lays hold of the pegs or studs thereon, or the chain may carry teeth or
projections which enter notches in the periphery of the chain wheel; the opposite
end of the wire being connected in the ordinary way to the signal or object it is
intended to operate.
The end of the chain which is passed over the chain wheel has suspended
therefrom a suitable weight, which, as the wire expands or contracts causes the
chain wheel to be rotated or partially rotated to a corresponding extent and tightens
or pays out the wire to compensate for such expansion or contraction.
When the signal or operating lever is actuated, a suitable arrangement of
inclined planes, wedges, cams or clamps are brought into action to grip the shaft or
wheel so as to hold the same rigid and prevent rotation of said wheel during the
time the lever is being moved and sliding the wheel and shaft laterally in the
grooves or ways in the supports, whereby the chain and consequently the wire are
moved a corresponding distance and the signal or object thus operated.
Instead of wedges, inclined surfaces, cams or clamps for preventing rotation of
the wheel and shaft whilst the signal is being operated I may employ a sliding rack
and mount on the chain wheel shaft a pinion or toothed wheel adapted to be
engaged by the rack when the latter is moved endwise by the pull of the operating
lever and thus lock the parts; or a right and left hand screw may be employed for
the same purpose.
Dated this 9th day of March 1893.
TASKER & CROSSLEY,
Halifax, Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improved Apparatus for Maintaining the Tension of or Compensating
for the Expansion and Contraction of Signal or Line Wires.
I, ALBERT EDWARD BERRY, of Victoria Road, Sowerby Bridge, Yorkshire,
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 has for its object the application to or connection with signal or
line wires of apparatus for automatically regulating and maintaining their tension
so as to compensate for the contraction and expansion in length to which they are
liable by reason of variations of temperature, or elongation or expansion caused by
strain, the effects of which, if not remedied, are to imperfectly operate the signal or
object with which they are connected.
In carrying out my invention I employ a suitably studded or chain wheel for
each wire, said wheel being mounted on a short shaft journalled in bearings in a
suitable bracket on which said shaft is also secured a toothed wheel adapted to be
engaged and rotated by a rack when the latter is operated by the pull of the
signal lever, but when the lever is pushed home and said rack is in its normal
position, the toothed wheel and shaft are free to rotate independently of the rack.
A chain connected at one end to the signal wire whose tension is to be regulated is
passed over the chain wheel and lays hold of the pegs or teeth thereon and from the
free end of said chain a weight or weights is or are suspended which as the signal
wire expands or contracts causes the chain wheel to be rotated or partially rotated
in one direction or the other to a corresponding extent and thus tighten or pay out
the wire to compensate for the expansion or contraction which has taken place.
When, however, the signal lever is operated to draw down the signal, the rack
engages with the toothed wheel and rotates the same and the chain wheel to the
extent required to complete the full movement of the semaphore and during such
time the said parts are locked or prevented from independent movement.
In order that my invention may be more fully explained reference is herein had
to the accompanying drawings, wherein
Fig. 1 is end elevation of my improved compensating device for signal or line
wires; Fig. 2 is front elevation of same, and Fig. 3 is transverse section of Fig. 2.
In the drawings A represents the signal or operating lever commonly employed
and B the signal or line wire whose tension is to be regulated. C is a bracket or
pedestal supported by a bar or girder D in a convenient position under the floor of
the cabin and having journalled therein a short shaft E on which a toothed wheel F
and chain wheel G are fast. Over the chain wheel G is passed a chain H of any
suitable construction which is secured at one end to the wire B and has suspended
from its opposite end a weight or weights I which counterbalance or slightly
overbalance the weight or weights at the signal end of the wire., K is a rack
suitably connected or joined to the signal or operating lever A and adapted to slide
up and down in a dovetailed or other form of groove L in the part C¹ of the
bracket C, said rack being preferably constructed with openings or recesses a of
the same pitch as the teeth on the wheel F which are capable of successively
entering said openings as the rack is moved up and down. The length of the
rack K and the number of openings a formed therein will obviously depend upon
the extent of movement of the semaphore or object to be operated. Near the
upper end of the rack an elongated slot or recess b is formed which, when the rack
is in its normal position as shewn in Figs. 1 and 2 is brought opposite the wheel F
which is thus enabled to clear the rack and to rotate independently thereof. The
said normal position of the rack is assumed when the signal is at danger and
therefore until said signal is drawn down, the shaft E with the wheels F and G are

page_text: free to be rotated in one direction or the other by the expansion or contraction in
length of the wire B, which eases or draws down the chain H and the latter laying
hold of the teeth on the wheel G causes it to be rotated or partially rotated to a
corresponding extent, the weight or weights I assisting to take up the wire in the
case of expansion and tending to resist contraction. To whatever extent the wire
may expand or contract the wheels G and F are moved round a corresponding
distance, and said movement is in no wise altered or effected by the actuation from
time to time of the signal, as, on the lever A being drawn forward to raise the
rack K, the lower end of the slot or recess is brought into engagement with the
nearest tooth on the wheel F in its path as shewn in Fig. 3 whereupon further
independent movement of the wheels G and F is prevented. As the rack continues
its upward movement the teeth on the wheel F successively enter and engage with
the corresponding openings a in the rack, whereby said wheel and the chain
wheel G are rotated a distance corresponding to the extent of movement required
to draw down the signal. On the lever A being released and moved back "home
the descent of the rack rotates the wheels G and F in the opposite direction to
that indicated by the arrow into the same relative positions they occupied before
the signal was operated and allows the signal to move back to the horizontal. By
the means and method thus set forth the signal or line wire is maintained at one-
uniform tension and all contraction and expansion thereof compensated for as it
takes place. The device is simple, not liable to get out of order, and does not
require alteration of signal levers or disturb the present arrangement and
disposition of the wires. The parts described may be varied in structural details
as is found necessary or convenient to readily adapt it to existing systems of
actuating line wires, without departing from the main features of my invention..
A device such as before described is used in conjunction with each wire.
"
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
Firstly. The means and method substantially as herein shewn and described for
maintaining the tension of or compensating for the expansion and contraction of
signal or line wires.
Secondly. The combination of the chain wheel G, chain H weighted at one end
and secured at the opposite end to the wire whose tension is to be regulated, toothed
wheel F, and a rack such as K, operated by or from the signal or operating lever,
all arranged, constructed, and operating in the manner and for the purposes.
substantially as herein shewn and described.
Dated this 9th day of December 1893.
TASKER & CROSSLEI,
Halifax, Agents.