IMPROVEMENTS IN SHACKLE AND TERMINAL INSULATORS FOR TELEGRAPH WIRES."
Year: 1880

page_text: LETTERS PATENT to John William Fletcher, of Stockport, in the County of
Cheshire, for an Invention of "IMPROVEMENTS IN SHACKLE AND TERMINAL
INSULATORS FOR TELEGRAPH WIRES."
PROVISIONAL SPECIFICATION left by the said John William Fletcher at the
Office of the Commissioners of Patents on the 28th September 1880.
JOHN WILLIAM FLETCHER, of Stockport, in the County of Cheshire.
"IMPROVEMENTS IN SHACKLE AND TERMINAL INSULATORS FOR TELEGRAPH
WIRES."
This Invention has for its object improvements in shackles and terminal
insulators for telegraph wires.
Shackles as at present constructed often give rise to an excessive amount of
electrical leakage from the telegraph line. To avoid this I adopt the following
construction-The lower part of my insulator is similar to that well known as
a No. S insulator. The No. 8 insulator consists of a double cup of earthenware,
which when in use is inverted. There is a hole in the bottom to receive an
upright metal stem, and on the stem the insulator is carried. Around the head of
this insulator there is a groove in which the telegraph wire lies. The upper part of
my "shackle and terminal insulator" is also similar to a No. 8 insulator, but
inverted, so that the open end of the double cup is both upwards and downwards.
The whole may be formed of one or more pieces, but preferably of one piece of
earthenware, and it is mounted differently to an ordinary shackle, being upon a
vertical bolt passing through it, and the upper and lower arms (or pole attach-
ments). My "shackle and terminal insulator" thus resembles two No. 8 insulators
formed as aforesaid in one or more pieces, and joined head to head, and there are
two or more grooves around the centre to admit of the insulator receiving the
telegraph wires, so that my insulator will serve in place of two shackles of the
ordinary description, whilst it produces less leakage than one such shackle.
The upper cups of my "shackle and terminal insulator" being open at the top,
I provide drainage holes by which they empty themselves of any rain water or dirt
which may enter; these drainage passages pass downwards from the head and
through the insulator.

page_text: In place of forming the upper part of my insulator as described above, I may
give to it the mushroom like head of the ordinary shackle.
The following are some of the advantages which my improved "shackle and
terminal insulators" have over those at present in use :-.
First. That it has the strength of a Bright's shackle and the insulation of an
ordinary No. 8 insulator, and as by its use the bearings are reduced, so the leakage
is reduced by one half irrespective of its superiority as an insulator.
Second. Self cleansing, as each shower of rain will wash both inside and outside.
Third. The liability of the cross over wires (as now, from shackle to shackle)
touching either straps, bolts, or arms is obviated, hence leakage from that cause
prevented.
Fourth. That when used as an ordinary insulator on sharp curves no guards are
required.
Fifth. The canting of the arms is prevented as the insulator bolt braces them
together.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John William Fletcher in the Great Seal Patent Office on the
28th March 1881.
JOHN WILLIAM FLETCHER, of Stockport, in the County of Cheshire.
"IMPROVEMENTS IN SHACKLE AND TERMINAL INSULATORS FOR TELEGRAPH
WIRES,"
This Invention bas for its object improvements in shackles and terminal
insulators for telegraph wires.
Shackles as at present constructed often give rise to an excessive amount of
electrical leakage from tho telegraph line. To avoid this I adopt the following
construction: The lower part of my insulator is similar to that well known as
a No. 8 insulator.
The No. 8 insulator consists of a double cup of earthenware, which when in use
is inverted. There is a hole in the bottom to receive an upright metal stem, and on
the stem the insulator is carried. Around the head of this insulator there is a
groove in which the telegraph wire lies. The upper part of my "shackle and
terminal insulator" is also similar to a No. 8 insulator, but inverted, so that the
open end of the double cup is both upwards and downwards. The whole may be
formed of one or more pieces, but preferably of one piece, of earthenware, and it is
mounted differently to an ordinary shackle, being upon a vertical bolt passing
through it, and the upper and lower arms (or pole attachments). My "shackle and
terminal insulator" thus resembles two No. 8 insulators formed as aforesaid in one
or more pieces, and joined head to head, and there are two or more grooves around
the centre to admit of the insulator receiving the telegraph wires, so that my
insulator will serve in place of two shackles of the ordinary description, whilst it
produces less leakage than one such shackle.
The upper cups of my "shackle and terminal insulator" being open at the top,
I provide drainage holes by which they empty themselves of any rain water or dirt
which may enter; these drainage passages pass downwards from the head and
through the insulator.
In place of forming the upper part of my insulator as described above, I may
give to it the mushroom like head of the ordinary shackle.
The following are some of the advantages which my improved "shackle and
terminal insulators" have over those at present in use:-
First. That it has the strength of a Bright's shackle and the insulation of an
ordinary No. 8 insulator, and as by its use the bearings are reduced, so the leakage
is reduced by one half irrespective of its superiority as an insulator.
Second. Self cleansing, as each shower of rain will wash both inside and outside.
Third. The liability of the cross-over wires (as now, from shackle to shackle)
touching either straps, bolts, or arms is obviated, hence leakage from that cause
prevented.
Fourth. That when used as an ordinary insulator on sharp curves no guards are
required.
Fifth. The canting of the arms is prevented as the insulator bolt braces them
together.
In order that my said Invention may be most fully understood, and readily
carried into effect, I will proceed to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS
Figure 1 shows a number of my shackles or terminal insulators mounted upon a
telegraph post.

page_text: Figure 2 is an elevation of one of the insulators; that here shown is made in one
piece, the bolt on which the insulator is carried is also shown; Figure 3 is a
longitudinal section of the same insulator; Figure 4 is a plan; Figure 5 is a
section on the line a in Figures 2 and 3; Figure 6 is a section on the line b in the
same Figures,
Figure 7 is an elevation of a similar insulator, but made in two parts, as appears
in Figure 8, which is a vertical section; Figure 9 is an elevation of the inner part,
it is somewhat taper being larger at the lower end than it is at the upper. The
downward strain of the wires causes the outer portion of the insulator to keep its
position on the inner portion, and this to rest against the collar upon the bolt, as
appears in Figure 1. In some exceptional cases, where the strain of the wires is in
an upward direction, the insulator and the bolt are inverted; Figure 10 is a section
on the line a in Figures 7 and 8; Figure 11 is a section on the line 6 in Figures 7
and 8, and Figure 12 is a section on the line c in Figure 9; Figure 13 shows the
manner of attaching the wire when this insulator is employed merely for safety, as
in crossing roads.
Figure 14 shows the way in which the wire is terminated at an angle; Figure 15
shows the wires terminated to be led into offices.
Figure 16 shows the method of mounting the insulator upon a saddle.
Figures 17 show bolts employed for supporting my insulators.
Figure 18 is an elevation of an insulator similar to those already described, but
having a mushroom head; Figure 19 is a vertical section of the same insulator,
and Figure 20 is an elevation of the inner part thereof.
I claim my shackle and terminal insulators, substantially as described and
illustrated by the annexed Drawings.
In witness whereof, I, the said John William Fletcher, have hereunto set
my hand and seal, this Twenty-fifth day of March, in the year of our
Lord One thousand eight hundred and eighty-one.
TNO IM
ATTAו הד
TNO
ΑΠΟ ΤΗΝ Τ
(M.S.)