AN IMPROVED EXPANSION AND CONTRACTION COUPLING FOR SIGNAL AND TELEGRAPH WIRES
Year: 1877

page_text: LETTERS PATENT to George Pickersgill, of Todmorden, in the County of
Lancaster, for the Invention of "AN IMPROVED EXPANSION AND CONTRACTION
COUPLING FOR SIGNAL AND TELEGRAPH WIRES."
led the 21st December 1877, and dated the 18th October 1877.
PROVISIONAL SPECIFICATION left by the said George Pickersgill at the
Office of the Commissioners of Patents on the 18th October 1877.
"AN IM-
GEORGE PICKERSGILL, of Todmorden, in the County of Lancaster.
PROVED EXPANSION AND CONTRACTION COUPLING FOR SIGNAL AND TELEGRAPH
WIRES."
Hitherto a simple regulating screw has been used in connection with the wire,
and placed near the pointsman's cabin, to be adjusted when required in accordance
with the varying temperature.
If the adjustment is not attended to when required, accidents are very liable to
occur in consequence of the semaphores not being thrown off or on correctly, which
results from the wire being either too short or too long. The wires vary much in
length, altering by every change of temperature.
Now to obviate the above 1 provide what I term an expansion and contraction
coupling, which is placed in any convenient position, and connect the wires thereby
between the signal box and semaphore, all as hereafter described. It consists of a
metal cylinder or tube in which is provided one or more piston rods, on each of
which and within the cylinder are mounted any required number of rings or discs,
made by preference of vulcanized india-rubber. The rings are retained on the piston
rods by ordinary means. These rods after passing through the covers (provided on
each end of the cylinder) are attached to the wires, and the apparatus at once forms
n compensating medium, allowing the wire to expand or contract, at the same time
always retaining the required amount of tightness.

page_text: The above arrangement effectually prevents the breakage of the wires and ensures
correct signalling.
The apparatus is also applicable for connecting telegraph wires, preventing breakage
of the same, and when used for this purpose the whole apparatus is made by pre-
ference of either copper or brass, having an outer casing of earthenware for "insu-
lating" purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Pickersgill in the Great Seal Patent Office on the 18th
April 1878.
GEORGE PICKERSGILL, of Todmorden, in the County of Lancaster. "AN IM-
PROVED EXPANSION AND CONTRACTION COUPLING FOR SIGNAL AND TELEGRAPH
WIRES."
Hitherto a simple regulating screw has been used in connection with the wire, and
placed near the pointsman's cabin, to be adjusted when required in accordance with
the varying temperature.
If the adjustment is not attended to when required, accidents are very liable to
occur in consequence of the semaphores not being thrown off or on correctly, which
results from the wire being either too short or too long. The wires vary much in
length, altering by every change of temperature.
Now to obviate the above I provide what I term an expansion and contraction
coupling, which is placed in any convenient position, and connect the wires thereby
between the signal box and semaphore, all as hereafter described. It consists of a
metal cylinder or tube in which is provided one or more piston rods, on each of
which and within the cylinder are mounted any required number of rings or discs,
made by preference of vulcanized india-rubber. The rings are retained on the piston
rods by ordinary means. These rods after passing through the covers (provided on
each end of the cylinder) are attached to the wires, and the apparatus at once forms
a compensating medium, allowing the wires to expand or contract at the same
time always retaining the required amount of tightness.
The above arrangement effectually prevents the breakage of the wires, and ensures
correct signalling.
The apparatus is also applicable for connecting telegraph wires, preventing
breakage of the same, and when used for this purpose the whole apparatus is made
by preference of either copper or brass, having an outer casing of earthenware for
"insulating" purposes.
And in order that my Invention may be more completely understood, reference
is given to the accompanying Sheet of Drawings, and to the letters and marks
thereon.
DESCRIPTION OF DRAWINGS.
Figure 1 represents a part longitudinal section: Figure 2 an end elevation of a

page_text: Figure 4 represents a longitudinal section, and Figure 5, a plan of a single-acting
apparatus, also for coupling signal wires.
Figure 6, a longitudinal elevation of external casing and piston rod for the same.
Figure 7 shews a longitudinal section, and Figure 8 a part section of apparatus,
as employed for telegraphing purposes.
Firstly. The apparatus for signalling purposes consists of a metal tube a, in which
I provide one or more piston rods b, as shewn at Figures 1, 2, 3, 4, 5, and 6. The con-
struction of piston rod for compound or double-acting apparatus being shewn at
Figure 3; on each rod I provide a tube c, on which are mounted any number of
rings or discs d, made by preference of vulcanized india-rubber. The piston rod
may be retained in position at e by screws as shewn. At the ends of the rods bor
tubes c are provided the nobs for their equivalents, which, on the signal wires being
attached, a compensating medium is formed, allowing the wire to expand or contract,
at the same time always retaining the required amount of tightness.
The above arrangement prevents the breakage of the wires, and insures correct
signalling.
Secondly. The arrangement of apparatus I employ for telegraphing purposes is
very similar to the herein-before described, with the exception that air external
covering of earthenware is required for insulating purposes, and is shewn at g,
Figures 7 and 8.
Other parts corresponding with the herein-before described apparatus have cor-
responding letters applied thereto.
The intermediate washers are by preference made of copper to assist in preserving
a continuous current of electricity.
The apparatus shown at Figure 7 is a single apparatus and is used for coupling
direct lines of telegraph wires.
Figure 8 represents a combination of apparatus whereby two wires may be
attached to one main, and thereby messages can be sent in different directions at
the same time.
A greater number than shown of these apparatuses may be combined in a similar
manner when necessary.
Having now described the nature of my said Invention, and the manner in which
the same may be performed, I would remark in conclusion that I do not limit myself
to the exact limits, details, and configuration of parts I have explained and shewn,
as the same may be varied or modified without in any way departing from the
nature of my Invention; but what I claim and desire to be secured to me by Letters
Patent is,-
Firstly. The arrangement, construction, and combination of the various parts
shewn at Figures 1, 2, 3, 4, and 5, forming expansion couplings for signal wires,
substantially as herein set forth.
Secondly. The arrangement, construction, and combination of the various parts
shewn at Figures 6, 7, and 8, forming expansion couplings for telegraphing wires,
substantially as herein set forth.
In witness whereof, I, the said George Pickersgill, have hereunto set my
hand and seal, this Fifteenth day of April, in the year of our Lord One
thousand eight hundred and seventy-eight.
GEO. PICKERSGILL. (L.S.)