IMPROVEMENTS IN PNEUMATIC SIGNALLING OR COMMUNICATING APPARATUS, AND IN THE MODE OF AND APPARATUS FOR TESTING THE TRANSMITTING TUBES FOR THE SAME, APPLI- PROVISIONAL SPECIFICATION
Year: 1875

page_text: LETTERS PATENT to Sir Samuel Canning, Knight, of Great Winchester
Street Buildings, in the City of London, Civil Engineer, and Henry.
Francis Joel, of Lavender Grove, Dalston, in the County of Middle-
sex, Engineer, for the Invention of "IMPROVEMENTS IN PNEUMATIC
SIGNALLING OR COMMUNICATING APPARATUS, AND IN THE MODE OF AND
APPARATUS FOR TESTING THE TRANSMITTING TUBES FOR THE SAME, APPLI-
PROVISIONAL SPECIFICATION left by the said Sir Samuel Canning
and Henry Francis Joel at the Office of the Commissioners of
Patents, with their Petition, on the 13th July 1875.
We, Sir SAMUEL CANNING, Knight, of Great Winchester Street
Buildings, in the City of London, Civil Engineer, and HENRY FRANCIS
JOEL, of Lavender Grove, Dalston, in the County of Middlesex, Engincer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN PNEUMATIC SIGNALLING OR COMMUNICATING APPARATUS, AND IN THE MODE OF

page_text: H
AND APPARATUS FOR TESTING THE TRANSMITTING TUBES FOR THE SAME, APPLICABLE
ALSO TO THE TESTING OF GAS AND OTHER PIPES OR TUBES," to be as follows:-
This Invention relates,-
:-
First. To the recorder or receiving instrument of pneumatic signalling
or communicating apparatus, and has for its object the simplifying the
construction of the same and rendering it more certain in its action,
whilst the operation of resetting or readjusting is, more easily and
expeditiously accomplished than by the arrangements hitherto proposed;
the cost of manufacture is also much reduced.
Secondly. To an improved construction of air transmitters and receivers
for pneumatic signalling apparatus.
Thirdly. To a peculiar mode of and apparatus for testing the soundness
or otherwise of the transmitting tubes employed in connection with
pneumatic signalling or communicating apparatus, and for localising
any leak that may exist therein, the same being equally applicable to
the testing of gas and other pipes or tubes.
In our improved recorder or receiving instrument we employ one or
more rows of tablets or tell-tales, and we reset or readjust (so as to be
out of sight) any one or more of the said tablets in any one or more of
the rows of tablets by a single motion, it being simply requisite for that
purpose to press against a concealed button in the under side of the
outer casing. This button is attached to or communicates with the
lower end of a vertical rod or bar, which engages with the horizontal
arms of a series of bell cranks, whose vertical arms are severally pin-
jointed to one end of a corresponding number of horizontal resetting bars
(one for each row of tablets), the opposite ends of such bars being pin-
jointed to upright levers of the same length as the vertical arms of the
bell cranks. Thus on pressing up the button the whole of the bars will
be simultaneously caused to move longitudinally on the fulcra of their
supporting levers, and by means of pins projecting from the said bars
and acting against short arms on the bosses of the several suspended
tablets will cause such tablets as may be hanging down and exposed to
view to be turned upwards out of sight, in which latter position each
tablet is individually retained (until released for giving an order) by the
short arm of a self-acting gravitating catch lever, which works freely on
a pin in the main framing. From the boss of this catch lever there

page_text: .
:
projects a longer arm, which is lifted, when the corresponding tablet is
to be released, by the end of a releasing lever which works freely on a
separate and independent fulcrum of its own. From the boss of this
lever projects an arm, the extremity of which rests against the end of
a collapsed air bag or bellows in connection with a transmitting tube,
as is well understood. This air bag or bellows may consist of moulded
india-rubber, having each end closed by a metal disc. These discs are
secured against the one side of the india-rubber by having their edges
notched and turned over, and then pressed on to a metal washer placed
on the other side of the india-rubber, thus securing the ends of the
rubber between the disc and the said washer in a perfectly air-tight
manner.
j
:
Every tablet throughout the series is combined with a similar arrange-
ment of mechanism, so that on any one or more of the bellows being
inflated the corresponding releasing lever will lift the longer arm of the
catch lever, thereby withdrawing the catch and allowing that particular
tablet to fall by its own gravity. A bell is rung simultaneously with
the release of any one or more of the order tablets, such bell being by
preference constructed and operated in the manner described and
illustrated at Figures 4 and 5 (Sheet 1) of the Drawings of the Speci-
fication of Letters Patent, No. 3147, A.D. 1874, an extra wheel and
pinion to increase the speed of revolution of the hammer being added if
desired.
The continuous ringing of the said bell by successive inflations of any
one or more of the bellows in any one or more of the rows of bellows is
accomplished by a series of horizontal rocking spindles, one for each row
of bellows. Each of the rocking spindles carries a lever arm, upon
which rests, by a pin or otherwise, a single connecting rod, common
to the series, and jointed at its upper end to the aforesaid toothed
quadrant, which drives the revolving hammer of the bell. Each of
the rocking spindles also carries a series of lever arms, the extremities
of which bear against the ends of the corresponding bellows, so that the
inflation of any one or more of the bellows in any row will cause the
bell (which is common to all the tablets) to be rung simultaneously
with the descent of the tablet or tablets. After reading the order or
orders thus transmitted the attendant resets the exposed tablet or tablets
in any one or more of the rows by simply elevating the before-mentioned
button, the weight of the adjusting rod being sufficient without the aid
'

page_text: of springs to withdraw the elevating pins clear of the short arms on the
tablets after they have been reset, and leave them perfectly free to fall
when again released.
In some cases we propose to combine with the releasing mechanism
of the aforesaid tablets a peculiar arrangement of pendulum in sub-
stitution for the said tablets, the swinging of which pendulum is
produced by the inflation of the bellows bag acting on the releasing
mechanism. By the use of these pendulums no readjustment or
resetting is required. To the upper part of the stem of the pendulum
there is attached, so as to hang loosely, a triangular-shaped trip piece,
the point of suspension being situate near the apex of the angle, which
is rounded off. One side of the base of the said triangular-shaped trip
picco projects over the end of the before-mentioned releasing lever,
the pendulum being suspended by a blade or other spring from a fixed
point above.
As the end of the lever rises it presses under and against one of the
lower angles of the trip piece causing the pendulum to rise and deflect
until the trip piece by turning on the point of suspension is released
from the lever, leaving the pendulum free to oscillate. The return or
descent of the lever does not stop the oscillation of the pendulum as the
upper angle of the trip piece being rounded off, and the said trip piece
working freely on its point of suspension allows the lever to descend to
its original position without interfering with the oscillation of the
pendulum.
According to the second head of our Invention we make the air
transmitters and receivers for the above and other pneumatic signalling
apparatus in the form of a moulded bag or bellows of vulcanized india-
rubber having a short neck which is inserted inside an externally
screwed metal nozzle brazed or otherwise attached to the centre of one
side of a plate or disc, having radially disposed recesses, ribs, or pro-
jections formed on cither side or face. In the same side or end of the
moulded india-rubber bag as the short neck there are moulded a series
of radially disposed projections, recesses, or depressions, over or into
which the recesses, ribs, or projections on the face of the plate or diso
engage, thereby firmly interlocking the two together. Cement or other
adhesive substance may or may not be employed for further securing
the plate to tho rubber, and for fastening the neck of the air bag

page_text: inside the nozzle so as to ensure a perfectly air-tight closure. The said
nozzle is screwed into a hollow boss in the bottom of a metal box, the
said boss serving also as the connection for the transmitting tube, we
thus obtain not only a perfectly sound joint, but facility is afforded for
removing a damaged air transmitter or receiver.
The projections on the before-mentioned plate by engaging into the
recesses in the bag prevent any strain being exerted on the cement
when screwing the bag and plate into the boss, and also further serve to
prevent the creation of a vacuum in the bag, and the consequent
adhesion of the top to the bottom, thus dispensing with the use of
internal and external springs.
According to the third head of our Invention we propose to test the
transmitting tubes of pneumatic signalling or communicating apparatus
by means of a peculiar testing apparatus specially constructed for the
purpose, the said apparatus and method of using or applying the same
being also applicable to the testing of gas and other pipes or tubes. By
our method of and apparatus for testing we are not only enabled to
ascertain with certainty whether there is a leak in the said pipes, but
also to localize the position of the same when it exists, thereby greatly
facilitating and expediting the repair of the same.
Our said testing apparatus consists of an air container or compresser in
the form of an air bag or bellows, air cylinder, and piston, or otherwise
constructed so as to admit of the air therein being compressed to any
given extent by the action of a weight or other suitable contrivance.
The interior of the said air container or compresser is connected by
means of a pipe with a flexible air-tight indicating bag or bellows,
which in its normal condition is collapsed and is acted upon externally
by a weight or spring. To a plate which rests on the top or bears
against or is connected with the end of the said bellows there is
connected a bar or rack in gear with a spur pinion or working by
friction of surface either grooved or otherwise, the axis of which pinion
or friction pulley carries a pointer or indicator situate in front of a
suitably divided dial. A lateral branch or nozzle opens out of the said
pipe between the air compresser or container, and the indicating bag or
bellows, and to this branch or nozzle there is attached in an air-tight
manner one end of the pipe to be tested, the opposite end of the said
pipe being closed perfectly air-tight.

page_text: The pipes and air container or compresser being full of air at the
normal pressure, and the indicating bag or bellows collapsed or closed
the pointer will rest at zero on the dial. In order to test the soundness
of the pipe a pressure is to be applied to the air container, whereupon
the air in the pipe to be tested will be compressed, whilst at the same
time the indicating bag or bellows will be inflated more or less, and by
actuating the rack and pinion or friction gearing will cause the pointer
to deflect to a position on the dial, according to the pressure, and if the
pipe is sound the pointer will remain there so long as the pressure is
maintained. If a leak exists the said pointer will indicate the same by
gradually returning towards zero as the air escapes from the pipe, and
the indicating bag or bellows collapses under the action of its weight or
spring.
Having discovered the presence of a leak, the position of the said leak
is localized in the following manner :—One end of the pipe to be tested
being connected in an air-tight manner with the lateral nozzle of the
testing instrument, and the other end of the pipe being hermetically
closed, pressure is applied to the air container as before, and the
deflection of the pointer on the dial is carefully noted; this being done
the testing instrument is then removed to the other end of the pipe and
the same operation repeated, the deflection of the pointer on the dial
being also carefully noted. The two deflections or the time taken in
their return to zero having been noted the position of the said leak can
be localized by mathematical formula.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said Sir Samuel Canning and Henry Francis Joel in
the Great Seal Patent Office on the 13th January 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, Sir SAMUEL
CANNING, Knight, of Great Winchester Street Buildings, in the City
of London, Civil Engineer, and HENRY FRANCIS JOEL, of Lavender 3
Grove, Dalston, in the County of Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of July, in the year
of our Lord One thousand eight hundred and seventy-five, in the

page_text: thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Sir Samuel Canning and
Henry Francis Joel, Her special license that we, the said Sir Samuel
Canning and Henry Francis Joel, our executors, administrators, and
assigns, or such others as we, the said Sir Samuel Canning and Henry
Francis Joel, our executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
'make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an In-
vention for "IMPROVEMENTS IN PNEUMATIC SIGNALLING OR COMMUNICATING
APPARATUS, AND IN THE MODE OF AND APPARATUS FOR TESTING THE TRANSMITTING
TUBES FOR THE SAME, APPLICABLE ALSO TO THE TESTING OF GAS AND OTHER PIPES
OR TUBES," upon the condition (amongst others) that we, the said Sir
Samuel Canning and Henry Francis Joel, our executors, or administra-
tors, by an instrument in writing under our, or their, or one of their
hands and seals, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of
'the said Letters Patent.
.
NOW KNOW YE, that we, the said Sir Samuel Canning and Henry
Francis Joel, do hereby declare the nature of the said Invention, and
in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, reference
being had to the accompanying Sheet of Drawings, and to the letters
and figures marked thereon, that is to say :-
Our said Invention relates,
First. To the recorder or receiving instrument of pneumatic signalling

page_text: •
1. To a peculiar mode of and apparatus for testing the sound-
ness or otherwise of the transmitting tubes employed in connection with
pneumatic signalling or communicating apparatus, and for localizing
any leak that may exist therein, the same being equally applicable to
the testing of gas and other similar pipes or tubes.
And in order that our said Invention may be fully understood we
shall now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the explanatory Sheet of
Drawings hereunto annexed, the same letters of reference indicating
corresponding parts in all the corresponding Figures.
Figure 1 of our Drawings represents a front elevation, and Figure 2 a
corresponding side elevation of our improved recorder or receiving
instrument, the outer casing being removed. A and A' represent two
rows of tablets or tell-tales, but any other number of rows may be used
with any number of tablets in each row. In our Drawings we have
only shown two rows and two tablets in each as an example. These
tablets are suspended freely from pins a, a¹. We reset or readjust (so as
to be out of sight) any one or more of the said tablets in any one or
more of the rows of tablets by a single motion, it being simply requisite
for that purpose to press against a button B in the under side of the
outer casing. This button is attached to or communicates with the
lower end of a vertical rod or bar C, which may be weighted or not,
and which engages with the horizontal arms b, b', of a series of bell-
cranks whose vertical arms c, c', are severally pin jointed to one end of
a corresponding number of horizontal resetting bars D, D' (one for each
row of tablets), the opposite ends of such bars being pin jointed to
upright levers d, d, of the same length as the vertical arms c of the
bell-cranks. Thus on pressing up the button B the whole of the bars
D, D¹, will be simultaneously caused to move longitudinally in the
direction of the arrows on the fulcra e, e¹, of their supporting levers c
and d, and by means of pins f, f', projecting from the said bars and
acting against short arms g, g', on the bosses of the several suspended
tablets A. will cause such tablets as may be hanging down and exposed
to view to be turned upwards out of sight (as shown in the upper row
in Figure 1), in which latter position each tablet is individually retained
(until released for giving an order) by the short arm h, h, of a self-

page_text: acting gravitating catch lever which works freely on a pin i, i, in the
main framing, such short arms h, h', forming the abutments of corre
sponding short catch arms x, x³, on the boss of each tablet, thus
maintaining it in its elevated position. From the boss of this catch
lever there projects a longer arm k, k', which is lifted when the corre-
sponding tablet is to be released by the aid of a releasing lever 1, 1,
(shown more clearly in Figure 2) which works freely on a separate and
independent fulcrum m, m³, of its own. From the boss of this lever
projects an arm n, n¹, the extremity of which rests against the end of a
collapsed air bag or bellows E, E¹, in connection with a transmitting
tube F, F¹ (Figure 2) as is well understood. This air bag or bellows
consists, according to one arrangement, of moulded india-rubber o,
having each end closed by a metal disc p, as shown in detail plan and
elevation at Figure 3, these discs being secured against the one side of
the india-rubber by having their edges notched and turned over as at p',
and then pressed on to a metal washer a placed on the other side of the
india-rubber, as shown clearly in the enlarged sectional detail, Figure 4,
thus securing the ends of the rubber between the disc and the said
washer in a perfectly air-tight manner without the use of screws.
Every tablet throughout the series is combined with a similar
arrangement of mechanism, so that on any one or more of the bellows
E being inflated the corresponding releasing lever will lift the longer
arm of the catch lever, thereby withdrawing the catch h and allowing
that particular tablet to fall by its own gravity. A bell F" is rung
simultaneously with the release of any one or more of the order tablets,
such bell being by preference constructed and operated in the manner
described and illustrated at Figures 4 and 5 (Sheet 1) of the Drawings
of the Specification of Letters Patent, No. 3147, A.D. 1874, an extra
wheel and pinion 8 to increase the speed of revolution of the hammer
being added if desired, as shown in dotted lines in Figure 2.
The continuous ringing of the said bell by successive inflations of
any one or more of the bellows E, in any one or more of the rows of
bellows is accomplished by a series of horizontal rocking spindles G, G',
one for each row of bellows. Each of the rocking spindles carries a
lever arm H, H¹, upon which rests by a pin, or otherwise, a single con-
necting rod 1 (which may or may not be weighted), common to the
3.1.

page_text: Figure 7 is a vertical section showing the construction of our improved
air transmitters and receivers, which constitutes the second head of our
Invention. We make the air transmitters and receivers for the above
and other pneumatic signalling apparatus in the form of a moulded bag
or bellows A, of vulcanized india-rubber, having a short neck a which
is inserted inside, an externally screwed metal nozzle b, brazed or
otherwise attached to the centre of one side of a plate or disc B (shown
in detail at Figure 8), having radially disposed recesses, ribs, or pro-
jections c, c, formed on either side or face. In the same side or end of
the moulded india-rubber bag as the short neck a, there are moulded a
series of radially disposed projections, recesses, or depressions c², c¹, over
or into which the recesses, ribs, or projections c on the face of the plate
or disc B engage, thereby firmly interlocking the two together. Cement
or other adhesive substance may or may not be employed for further
securing the plate to the rubber and for fastening the neck of the air
bag inside the nozzle, so as to insure a perfectly air-tight closure. The
said nozzle is screwed into a hollow boss d in the bottom of a metal
box C, the said boss d serving also as the connection for the transmitting
tube F; we thus obtain not only a perfectly sound joint, but facility is
afforded for removing a damaged air transmitter or receiver. The
projections on the before-mentioned plate B, by engaging into the
recesses in the bag, prevent any strain being exerted on the cement
when screwing the bag and plate into the boss d, and also further serve
to prevent the creation of a vacuum in the bag and the consequent
adhesion of the top to the bottom, thus dispensing with the use of
internal or external springs.
We shall now proceed to describe our peculiar mode of and apparatus
for testing the soundness or otherwise of the transmitting tubes of
pneumatic signalling or. communicating apparatus, and for localizing
any leak that may exist therein, the same being equally applicable to
the testing of gas and other similar pipes or tubes.
Figure 9 is a plan, and Figure 10 a vertical section of our peculiar
testing apparatus, specially constructed for the purpose, and being also
applicable to the testing of gas and other similar pipes or tubes.
By our method of and apparatus for testing we are not only enabled
to ascertain with certainty whether there is a leak in the said pipes;

page_text: but also to localise the position of the leak when it exists, thereby
greatly facilitating and expediting the repair of the pipe or tube.
Our said testing apparatus consists of an air container or compresser
A, in the form of an air bag or bellows, air cylinder and piston (as
shown in our Drawings), or otherwise constructed so as to admit of the
air therein being compressed to any given extent by the action of a
weight or other suitable contrivance.
V
In our Drawings we have shown a hollow piston B, which may be
loaded with shot or otherwise weighted. The interior of the said air
container or compresser A is connected by means of a pipe C with a
flexible air-tight indicating bag or bellows, or (which we prefer) with a
second smaller cylinder a and piston b, as shown in our Drawings,
which in its normal condition is collapsed or has its piston at or near
the bottom, and is acted upon externally by a weight or spring (in our
Drawings we have represented the head of the piston enlarged so as to
give the necessary compressing power). To a plate which rests on the
top or bears against or is connected with the end of the said bellows
(when a bellows is employed) there is connected a bar or rack c, which in
our Drawings is shown connected to the piston 6, such bar or rack being
in either case in gear with a spur pinion d, or working in connection
with a friction pulley either grooved or otherwise, the axis of which
pinion or friction pulley carries a pointer or indicator e situate in front
of a suitably divided dial f. A lateral branch or nozzle D opens out of
the pipe C between the air compresser or container A, and the indicating
bag or bellows or cylinder a, and to this branch or nozzle thero is
attached in an air-tight manner one end of the pipe to be tested, the
opposite end of the said pipe being closed perfectly air-tight.
The pipes and air container or compresser A being full of air at the
normal pressure, and the indicating bag or bellows or cylinder a
collapsed or with its piston 6 down, the pointer e will rest at zero on the
dial. In order to test the soundness of the pipe a pressure is to be
applied to the air container A, whereupon the air in the pipe to be
tested will be compressed, whilst at the same time the indicating bag or
bellows will be inflated or the piston 6 (as the case may be) elevated
more or less, and by actuating the rack and pinion or friction gearing
will cause the pointer e to deflect to a position on the dial f, according to

page_text: the pressure, and if the pipe being tested is sound, the pointer will
remain there so long as the pressure is maintained. If a leak exists the
said pointer will indicate the same by gradually returning towards zero
as the air escapes through the leak in the pipe, and the indicating bag
or bellows collapses or the piston 6 descends under the action of its
weight or spring.
Having discovered the presence of a leak, the position of the said leak
is localized in the following manner :-One end of the pipe to be tested
being connected in an air-tight manner with the lateral nozzle D of the
testing instrument, and the other end of the pipe being hermetically
closed, pressure is applied to the air container A as before, and the
deflection of the pointer e on the dial is carefully noted, this being done
the testing instrument is then removed to the other end of the pipe and
the same operation repeated, the deflection of the pointer on the dial
being also carefully noted. The two deflections having been noted, the
position of the said leak may be localized by the following or some such
mathematical formula. Let D be the number of degrees shown on the
dial of the testing. instrument when testing from one end of the pipe;
D', the number of degrees indicated when testing from the opposite
end of the same pipe, and L, the length of the whole pipe in feet,
then (D+D') = the length of the pipe to the fault from the end
giving the deflection of the pointer or number of degrees D and
(L+DI) = the length of the pipe to the fault from the end giving the
deflection D'. Similar results can be arrived at by noting the time
occupied by the pointer in returning to zero on the dial.
L x D1
D X D
Having now described and particularly ascertained the nature of our
said Invention, and the manner in which the same is or may be used or
carried into effect, we would observe in conclusion that what we consider
to be novel and original and therefore claim as the Invention secured
to us by the herein-before in part recited Letters Patent is,―
First. The mode of resetting or readjusting the tablets of a pneumatio
recorder or receiving instrument by the use of horizontal bars mounted
on upright levers, and actuated by a vertical rod common to the series
of bars, the gravity of the said rod restoring the bars to their normal
positions again after the tablets have been reset without the necessity for

page_text: the use of springs, substantially as herein-before described and illus-
trated by Figures 1 and 2 of our Drawings.
Secondly. The peculiar trigger action for releasing and for main-
taining in an elevated position the tablets of a pneumatic recorder or
receiving instrument, such trigger action comprising the combination of
the short arm h, the catch arm 2, the gravitating lever arm k, and the
releasing lever when arranged to operate together, substantially as
herein-before described and illustrated by Figures 1 and 2 of our

page_text: tubes, substantially in the manner herein-before described and illus-
trated by Figures 9 and 10 of our Drawings.
In witness whereof, I, the said Sir Samuel Canning, for and on
behalf of myself and the said Henry Francis Joel, have hereunto
set my hand and seal, this Thirteenth day of January, in the
year of our Lord One thousand eight hundred and seventy-six.
SAMUEL CANNING. (L.S.)
Witness,
EDWIN P. ALEXANDER,
Consulting Engineer and Patent Agent,
14, Southampton Buildings,
Chancery Lane,
W.O.