Improvements in Pulls and Pushes for Electric Bells.
Year: 1893

page_text: Date of Application, 1st Aug., 1893
Complete Specification Left, 1st May, 1894-Accepted, 2nd June, 1894
PROVISIONAL SPECIFICATION.
Improvements in Pulls and Pushes for Electric Bells.
I, EDGAR GODWIN HARCOURT, of 35 Westminster Road, Birchfields, in the
County of Stafford, Engineer, do hereby declare the nature of this invention to be
as follows:-
My invention relates to devices for ringing electric bells and its object is to
produce a convenient and effective arrangement by which the electric bell may be
rung by pulling out a knob instead of by pressing a button as is usually done at
present.
The invention consists of a pneumatic cylinder device containing a piston which
piston is pulled out by a suitable knob or handle in such manner that the electric
bell begins to ring when the handle is pulled out and remains ringing while the said
piston impelled by a spring returns in the pneumatic cylinder.
In one method of carrying the invention into effect, I construct a cylinder in
which I fit a piston of any usual kind. The piston may or may not be furnished
with a cup leather. To the piston attach a piston rod and a bell pull handle of
ordinary appearance. The piston rod passes through a plate which may be an
ordinary wall plate secured in any convenient way to the external end of the
cylinder. The plate thus forms a cylinder cover and on the piston rod between
the cover and piston I place a spiral spring which thrusts the piston into the
cylinder till the piston comes into contact with a bottom or bottom plate of the said
cylinder.
To the bottom I attach a valve opening outwards and carrying a projection or
projecting pin passing through the bottom of the cylinder and projecting within it
for some distance. When the piston is thrust to the bottom of its cylinder the
valve is opened by the projecting pin and thrust downwards against the action of a
spring tending to close the said valve.
The stem of the valve when so thrust down or out comes into contact with a
projection from a contact piece moving in a hollow in a plug or piece made of
insulating material. The contact piece is then forced away from contact with two
insulated screws connecting to the wires conveying the electric current. So long as
the piston remains fully thrust home by its spring the contact piece is thus forced
clear and held clear of the two screws within the hollow of the insulating plug and
so the circuit remains interrupted and no current passes. When the electric bell
pull handle is pulled out, the piston moves out and allows the valve to close against
the bottom of the cylinder, at the same time permitting the spring contact piece to
make contact between the two insulated screws. The electric current then passes
and the electric bell rings. When the pull knob or handle is let go the spring
between the piston and cylinder cover forces the piston to return down the cylinder
again but the piston compresses the air contained in the cylinder and the air retains
the piston for some time and prevents it from reaching the end of the cylinder till
the air is allowed to escape. The rate of the escape of air is regulated by the
pressure of a spring on the valve and the pressure on this spring is in turn adjusted
by a screw.
The spring valve may be dispensed with and the rate of return of the piston may
be determined by a screw pin adjusting a discharge aperture. In using the screw
adjusted "leak off" I dispense with the valve and cause a projection from the spring
contact piece to pass through the bottom of the cylinder to come into contact with
the piston when thrust down to the bottom of its stroke to allow the piston to break
contact when at rest.

page_text: The insulating plug may also be placed in the cylinder itself and the circuit
between the wires or screws completed or interrupted by the piston itself.
The invention may be carried out in various ways but an essential feature of the
invention consists in a pneumatic piston freely pulled out but retarded on its return
under the influence of a spring by air compressed under it and allowed to "leak off"
at a regulated rate substantially determined by a pin or valve adjustment.
The cup leather of the piston may be arranged to allow the piston to be readily
pulled out by permitting air to pass in one direction or a valve in the piston may
allow air to escape in one direction while holding it in another. The arrangement
may be adapted either for "pull" or "push" electric contact makers as in either
case the bell may be caused to ring for a predetermined period.
Dated this 29th day of July 1893.
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Pulls and Pushes for Electric Bells.
I, EDGAR GODWIN HARCOURT, of 35 Westminster Road, Birchfields, in the
County of Stafford, 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 :-
My invention relates to devices for ringing electric bells, and its object is to
produce a convenient and effective arrangement by which the electric bell may be
rung by pulling out a kuob instead of by pressing a button as is usually done at
present.
The invention consists of a pneumatic cylinder device, containing a piston which
piston is pulled out by a suitable knob or handle in such manner that the electric
bell begins to ring when the handle is pulled out and remains ringing while the said
piston impelled by a spring returns in the pneumatic cylinder.
Referring to the accompanying sheet of drawings:
-
Figure 1 is a section of an electric pull, arranged in accordance with my
invention.
Figure 2 is a similar section of a modified arrangement.
Figure 3 is a section on an enlarged scale of the non-conducting plug shown in
Figure 2 with contact making arrangement.
Figure 4 shows a modified arrangement of air discharge valve.
In one method of carrying the invention into effect, I construct a cylinder A
Figure 1 in which I fit a piston B of any usual kind. The piston B may or may
not be furnished with a cup leather. To the piston I attach a piston rod B' and a
bell pull handle B2 of ordinary appearance. The piston rod B' passes through a
plate D, which may be an ordinary wall plate secured in any convenient way to the
external end of the cylinder A. The plate thus forms a cylinder cover and on the
piston rod between the cover D and piston B1 place a spiral spring C which
thrusts the piston into the cylinder till the piston comes into contact with a bottom
or bottom plate of the said cylinder. To the bottom of the cylinder A, I attach a
valve H, opening outwards and carrying a projection or projecting pin H2 passing
through the said bottom of the cylinder and projecting within it for some distance.
When the piston B is thrust to the bottom of its cylinder the valve H is opened by
the projection pin H2 and thrust downwards against the action of a spring H¹
tending to close the said valve.
The stem of the valve when so thrust down or out, comes into contact with a
projection C from a contact piece C¹ moving in a hollow in a plug or piece E,
made of insulating material. The contact piece is then forced away from contact

page_text: with two insulated screws F F¹ connecting to the wires conveying the electric
current. So long as the piston B remains fully thrust home by its spring C the
contact piece C' is thus forced clear and held clear of the two screws F, F within
the hollow of the insulating plug E, and so the circuit remains interrupted and no
current passes.
When the electric bell pull handle B2 is pulled out, the piston B
moves out, and allows the valve H to close against the bottom of the cylinder, at
the same time permitting the spring contact piece C¹ to make contact between the
two insulated screws F F. The electric current then passes and the electric bell
rings. When the pull knob or handle B is let go, the spring between the piston
and cylinder cover forces the piston B to return down the cylinder again but the
piston compresses the air contained in the cylinder, and the air retains the piston B
for some time and prevents it from reaching the end of the cylinder till the air is
allowed to escape. The rate of the escape of air is regulated by the pressure of a
spring H' on the valve H and the pressure on this spring is in turn adjusted by a
screw.
The spring valve may be dispensed with and the rate of return of the piston may
be determined by a screw pin adjusting a discharge aperture as illustrated at
Figures 2, 3 and 4.
The action of the modification shown in these figures is similar to that shown in
Figure 1; A is the cylinder, B the piston, B₁ the piston rod, B² the knob or
handle, D the wall plate, C the spiral spring, and E the insulating socket piece
which in this case forms the cylinder bottom. The insulated screws F, F in this
case pass through the plug parallel to the axis of the cylinder, and they are
connected when the current is to pass by the spring piece G. This piece is
operated by the projection B³ from the piston B, so that when the said piston is
forced down by the spring C, then the spring contact piece G is forced out of
contact with the head of the screw F and so the current is interrupted. This
position is shown at Figure 2. When the knob B² and piston B is pulled out, the
spring contact piece assumes the position shown at Figure 3, and the current
passes between the screws F, F1, and the bell rings. The plug E carries a
"leak off" screw E' (Figure 3) having a tapered flat E made on its side. This
allows the adjustment of the rate of return of the piston B, by varying the area of
the air discharge aperture. A screw pin valve as E Figure 4 may be used instead
of that shown at Figures 2 and 3 if desired.
By using the screw adjusted "leak off" I thus dispense with the valve H
and cause the spring contact piece to come into contact with the piston when
thrust down to the bottom of its stroke to allow the piston to break contact when
at rest.
The insulating plug may also be placed in the cylinder itself and the circuit
between the wires or screws completed or interrupted by the piston itself.
The invention may be carried out in various ways, but an essential feature
of the invention consists in a pneumatic piston freely palled out but retarded
on its return under the influence of a spring by air compressed under it and allowed
to "leak off" at a regulated rate, substantially determined by a pin or valve
adjustment.
The cup leather of the piston may be arranged to allow the piston to be
readily pulled out by permitting air to pass in one direction or a valve in the
piston may allow air to escape in one direction while holding it in another.
The arrangement may be adapted either for "pull" or push electric contact
makers as in either case the bell may be caused to ring for a predetermined
period.
66
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. A bell pull or push device for electric bells in which a pneumatic cylinder
contains a piston, which piston is pulled out or pushed in by a knob or handle or
+
'

page_text: button against a spring or other resistance, so that an electric circuit is com-
pleted when the piston is out, and the return of the said piston is effected by
the spring or equivalent pressure resisted by air compressed under the piston
and allowed to leak off at a regulated rate causing the bell to ring till the
piston again reaches the position of rest, substantially as hereinbefore described.
2. A bell pull device for electric bells, comprising a cylinder as A Figure 1,
piston as B, spring as C, leak off valve as H beld open by the piston when
at rest, insulated plug as E, connections as F F', spring contact piece as C making
contact when the piston B is pulled out, all operating substantially as bereinbefore
.described.
3. A bell pull device for electric bells, comprising a cylinder as A Figure 2,
piston as B, spring as C, screw adjustable leak off pin as E¹ (Figures 3 or 4)
insulated plug as E, connections as F F', spring contact piece as G making
contact when the piston is pulled out, all operating substantially as hereinbefore
.described.
4. The specific constructions and arrangements of electric bell pulls as herein before
.described and illustrated in the accompanying drawings.
T
C
100
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents for the Applicant.