Improvements in or Connected with Compensating Apparatus for Railway and other Signals.
Year: 1885

page_text: Improvements in or Connected with Compensating Apparatus
for Railway and other Signals.
We HENRY JOHNSON, a Director of the Johnson's Compensator Company,
Limited of Queens Chambers, Jolin Dalton Street, Manchester, in the County
of Lancaster, Manufacturers of Railway Signalling Apparatus, and the said
JOHNSON'S COMPENSATOR COMPANY Limited do hereby declare the nature of said
Invention for IMPROVEMENTS IN OR CONNECTED WITH COMPENSATING APPARATUS
FOR RAILWAY AND OTHER SIGNALS, to be as follows:-
This invention relates to what are known as "liquid compensators" for the wires
or chains which connect the actuating lever to the arm or other part of the railway
or other signal.
The chief objects of the Invention are to simplify and improve the construction
and increase the utility of such compensators.
In carrying this Invention into effect we employ a fixed tube or liquid com-
pensator, the plunger of which is connected to a bar or frame free to slide in
guides; on this frame is mounted a tension pulley and the connecting wire or chain
to be compensated passes from the actuating lever over this pulley and returning a
short distance passes over a guide pulley supported in fixed bearings and thence to
the arm of the signal or other part.
Any variation in the length of the connecting wire or chain due to atmospheric
changes is compensated for by the expansion or contraction of the liquid in the
tube which causes the tension pulley on the movable frame to slide to or from the
stationary guide pulley thereby regulating the tension of the said wire or chain.
The apparatus may be adapted to compensate for two or more signals of equal
distance by employing two or more tension and two or more guide pulleys.
By making the pulley in stationary bearings a compound or double pulley with
two rims of different diameters and connecting the wire from the compensator to
the smaller rim and the wire from the signal to the larger rim of the pulley or vice
versa, the two and fro movement of the tension pulley is caused to give diminished
or increased movement to the wire connected to the signal, or the same result
may be obtained by interposing increasing or diminishing stroke levers in the
connections between the compensator and the signal.

page_text: This improved compensator may be adapted to compensate for two or more
signals at varying distances by employing as many additional tension pulleys and
double pulleys as necessary.
When applying the apparatus to the arrangement of pulleys known as "gain
stroke" pulleys used particularly for distance signals, instead of securing the end of
the wire or chain to a point below the lever, the wire is carried under another
pulley and thence out of the cabin to the plunger or movable bar of the com-
pensator to which it is secured, or if preferred the wire is first passed over a tension
pulley on the bar and the end then secured to any stationary part.
When a double wire or chain and two "gain stroke" pulleys are employed for
actuating the signal, the wires pass over two extra pulleys in the cabin and thence
to the plunger or movable bar of the compensator or to two tension pulleys on the
plunger or bar the ends being secured in the manner already described.

page_text: Improvements in or Connected with Compensating Apparatus
for Railway and other Signals.
We HENRY JOHNSON, a Director of The Johnson Compensator Company
Limited, of Queen's Chambers, John Dalton Street, Manchester, in the County
of Lancaster, Manufacturers of Railway Signalling Apparatus, and the said
JOHNSON'S COMPENSATOR COMPANY Limited, do hereby declare the nature of said
Invention for IMPROVEMENTS IN OR CONNECTED WITH COMPENSATING APPARATUS
FOR RAILWAY AND OTHER SIGNALS, 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 what are known as "liquid compensators" for the
wires or chains which connect the actuating lever to the arm or other part of
the railway or other signal.
The chief objects of the Invention are to simplify and improve the construction
and increase the utility of such compensators.
And in order that this Invention may be fully understood and readily carried
into effect we will describe the accompanying Sheet of Drawings, reference being
had to the figures and letters marked thereon.
In the arrangement illustrated by Figure 1 we employ a fixed tube or liquid
compensator preferably made up of two pieces a a' respectively connected together
by the coupling b, shown on an enlarged scale in Fig. 2. One end of the tube a a¹
is secured in the solid carrier or bracket c and the other end is provided with a
stuffing box d through which the plunger e passes. The plunger e is connected to
the bar or frame which is free to slide in guides in the bedplate g; on this.
frame fis mounted a tension pulley h and the connecting wire or chain i passes
from the actuating lever in the cabin round this pulley h and returning a short
distance toward the cabin passes round a guide pulley j supported in fixed bearings
in the plate g and thence to the arm of the signal or other part.
Any variation in the length of the connecting wire or chain i due to atmospheric
changes is compensated for by the expansion or contraction of the liquid in the
tube a a' which causes the tension pulley.h on the movable frame f to slide to or
from the stationary guide pulley ; thereby regulating the tension of the said wire
or chain.
The apparatus may be adapted to compensate for two or more signals of equal
distance by employing two or more tension pulleys h and two or more guide
pulleys j.
The advantage of making the tube of the compensator in two pieces is that in
the event of changing the position of the signal it is not necessary to change or
disturb the compensator beyond simply substituting for the tube a¹ a tabe of such
length as the alteration in distance may render necessary.
:

page_text: In Fig. 3 instead of the stationary guide pulley j, a compound or double pulley 11
is shown with two rims of different diameters, the wire or chain from the com-
pensator being connected to the larger rim at and the wire or chain from the
signal to the smaller rim at so that the to and fro movement of the tension
pulley his caused to give a diminished movement to the wire connected to the
signal. In this way a larger size compensator can be made to answer for a shorter
length of connections. Instead of connecting the wires or chains to the pulleyj¹
as here shown the wire from the compensator may if required be connected to the
smaller rim and the wire from the signal to the larger rim so as to cause the
movement of the pulley h to give an increased movement to the wire connected to
the signal; or instead of the pulley 11 the same result may be obtained by inter-
posing increasing or diminishing stroke levers in the connections between the
compensator and the signal.
This improved compensator may be adapted to compensate for two or more
Bignals at varying distances by employing as many additional tension pulleys h
and double pulleys as necessary.
Figs. 4 and 5 represent the apparatus as applied to the arrangement of pulleys
known as "gain stroke pulleys" used particularly for distance signals. The wire
or chain i from the signal passes under the pulley k and over the gain stroke
pulley which is actuated in the ordinary manner by a lever connected to the
rod m, but instead of securing the end of the wire or chain i to a point below the
lever, the wire or chain is carried under another pulley n and thence out of
the cabin to the plunger e of the compensator where it is passed round the tension
pulley and then secured to the stop piece o, or if preferred the wire may be
secured directly to the plunger e.
Figs. 6, 7 and 8 illustrate the apparatus as applied to an arrangement for
working the signal with a double wire or chain and two gain stroke pulleys l. In
this case two extra pulleys n n are employed from which the wires or chains pass
to the compensator where the ends are either secured directly to a cross bar f¹ on
the bar fas shown in Fig. 6; or are passed round two tension pulleys h on the bar
or frame fas shown in Figs. 7 and 8, the ends of the wires or chains being secured
to the stop pieces o as already described.
When compensating for five hundred yards length of signal connections with
say, a compensator tube or reservoir of one inch internal diameter and a five-
eighths of an inch plunger, we find that twenty seven and a quarter ounces of
Russian mineral oil will give a good and satisfactory result.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what
we claim is-
1. In a compensator for railway or other signals, the use and application of a
fixed tube or reservoir containing liquid, which liquid acts by expansion and
contraction upon a plunger so as to compensate automatically for variations in the
length of the connections caused by variations of temperature.
2. In a liquid compensator for signal connections, the combination with a fixed
tube or reservoir containing liquid acting by expansion and contraction on a
plunger connected to a movable bar or frame, of a movable tension pulley or
pulleys carried by said movable bar or frame and a stationary guide pulley or
pulleys for the signal wires, chains, or other connections, substantially as and for
the purposes herein described and as illustrated by Fig. 1.
3. The combination with a fixed liquid compensator provided with a plunger
connected to a movable frame carrying a tension pulley or pulleys, of the compound
pulley, having one end of the signal wire chain, or other connection secured to
the larger rim and one end secured to the smaller rim, substantially in the manner
And for the purposes herein described and as illustrated by Fig. 3,

page_text: 4. The method of making a fixed tube or reservoir of a liquid compensator in
two parts connected together by a suitable coupling, such as the coupling marked b,
Fig. 2, substantially as and for the purpose specified.
5.-The use of the improved fixed liquid compensator substantially as berein set
forth when applied to arrangements of gain stroke pulleys, such as those illustrated
by Figs. 4 to 8.
6. The combination with an arrangement of gain stroke pulleys, of the extra
pulley or pulleys n, and the several arrangements of the improved fixed liquid
compensator for the signal wires, chains, or other connections, substantially as
described and as illustrated by Figs. 4 to 8.