IMPROVEMENTS IN APPARATUS FOR BURNING GAS FOR COOKING HEATING ILLUMINATING AND LIKE PURPOSES
Year: 1882

page_text: LETTERS PATENT to The Honorable John William Plunkett of Dunstall
Priory in the County of Kent and of Park Square in the County of Middlesex
for an Invention of "IMPROVEMENTS IN APPARATUS FOR BURNING GAS FOR
COOKING HEATING ILLUMINATING AND LIKE PURPOSES "
PROVISIONAL SPECIFICATION left by the said John William Plunkett at
the Office of the Commissioners of Patents on the 23rd December 1882.
The Honorable JOHN WILLIAM PLUNKETT of Dunstall Priory in the County of
Kent and of Park Square in the County of Middlesex "IMPROVEMENTS IN
APPARATUS FOR BURNING GAS FOR COOKING HEATING ILLUMINATING AND LIKE
PURPOSES
"
My Invention has for its object to provide means in connection with apparatus
for cooking, heating or lighting or the like by gas whereby burners of such
apparatus are caused to be supplied with gas by the act or movement which is
necessarily performed in bringing the apparatus into operation that is to say, for
example in opening the door of a gas oven or in placing utensils or other
articles upon the parts where they are to rest whilst being subjected to the action
of heat
The Invention may be carried into effect by causing the door, utensil or other
part of the apparatus or article placed thereon or therein to act upon a lever or rod
which is connected to and acts upon the tap of the gas-cock-In the case of a
cooking oven the door may be furnished with a pusher or inclined plane or its
equivalent to act, when the door is opened, upon the gas cock to open it and in
order to provide against accidents arising from the gas being turned on and
unignited the arrangement described in the Specification of Letters Patent
No 643 granted to me as of the 10th day of February A.D. 1882 may be combined
with the present improvements, in which case the expanding rod or bar or a
Price A1

page_text: connection therewith would be arranged so that when the gas is properly ignited
the expansion of the said rod or bar will cause it to be brought into such a
position as to retain the gas tap in its turned on position after the door is closed-
Should however the gas not be ignited on the door being closed the said rod or bar
will not have expanded and the attachments of the gas tap will consequently be
allowed to drop and close the gas tap
It will be understood that the foregoing arrangements may be adapted for
controlling the supply of gas generally for cooking heating or lighting purposes
for example in the case of hall lamps or in the case of gas burning in a room it
may be kept low until the door of the room is opened which through connections
analogous to those hereinbefore described may cause the full supply of gas to be
turned on to be. turned low again automatically on leaving the room.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John William Plunkett in the Great Seal Patent Office on the
23rd June 1883.
The Honourable JOHN WILLIAM PLUNKETT of Dunstall Priory in the County of
Kent and of Park Square in the County of Middlesex "IMPROVEMENTS IN
APPARATUS FOR BURNING GAS FOR COOKING, HEATING, ILLUMINATING, AND LIKE
PURPOSES."
33
My said Invention has for its object to provide means in connection with
apparatus for cooking heating or lighting or the like by gas whereby burners of
such apparatus are caused to be supplied with gas by the act or movement which
is necessarily performed in bringing the apparatus into operation that is to say
for example in opening the door of a gas oven or in placing utensils or other
articles upon the parts where they are to rest whilst being subjected to the action
of heat.
The Invention may be carried into effect by causing the door utensil or other
part of the apparatus or article placed thereon or therein to act upon a lever or
rod which is connected to and acts upon the tap of the gas cock. In the case of a
cooking oven the door may be furnished with a pusher or inclined plane or its
equivalent to act when the door is opened upon the gas cock to open it and in
order to provide against accidents arising from the gas being turned on and
unignited or improperly ignited. the arrangement described in the Specification of
Letters Patent Number 643 granted to me as of the tenth day of February in the
year of Our Lord One thousand eight hundred and eighty two may be combined
with the present improvements in which case the expanding rod or bar or a
connection therewith would be arranged so that when the gas is properly ignited
the expansion of the said rod or bar will cause it to be brought into such a position
as to retain the gas tap in its turned on position after the door is closed Should
however the gas not be ignited or be improperly ignited on the door being closed
the said rod or bar will not have expanded and the attachments of the gas tap will
consequently be allowed to drop and close the gas tap.
It will be understood that the foregoing arrangements may be adapted in
combination with the arrangements described in my said prior Specification for
controlling the supply of gas generally for cooking heating or lighting purposes for
example in the case of Hall lamps or in the case of gas burning in a room it may
be kept low or turned off until the door of the room is opened which through
connections analogous to those herein before described may cause the full supply of
gas to be turned on and also if desired to be turned low again automatically on
leaving the room.
And in Order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the annexed Drawings the same letters of reference indicating corresponding parts
in all the Figures.
Figure 1 is a perspective view of a gas oven fitted with means according to my
Invention for turning on the gas by the act of opening the ovendoor. Figure 2 is
a section of the upper part of a gas stove fitted with an arrangement for turning
on the gas by placing a cooking utensil in position for heating-Figures 3 and 4 are
views at right angles to each other of an ordinary street lamp fitted with an
arrangement for turning on the gas by opening the lamp door and also with means
for shutting off the gas automatically after the door is closed should the lighting
of it be omitted or should the light be accidentally extinguished and Figure 5
illustrates an arrangement for turning on the gas in a closet by the act of opening
a closet door, this being also combined with means for shutting off the gas if it be
unlighted or accidentally extinguished after the door is closed.

page_text: Referring to Figure. 1, A is the door of the oven B the gas supply pipe and C the
gas tap, the plug of which tap is provided with a lever arm D to the outer end of
which is connected the upper end of a bar or rod E weighted by a weight at e so
that it will readily descend if unsupported and close the gas tap; F is a guide for
the said rod.
The gas tap is opened by the act of opening the oven door in the following
manner fitted or formed on the oven door a cam like projection G which when
the oven door is opened depresses one arm of a lever H the opposite arm of which
lever by acting on the underside of a projection on the rod E (which may be the
weight e fastened to the said rod) raises the said rod and thus by reason of its
connection with the arm D the gas tap is opened to supply gas to the burners
ready for lighting.
The gas having been lighted the expansion rods (described in the Specification
to my prior Patent herein before referred to) have expanded sufficiently to cause the
bar I to project beneath the lower end of the rod E which will thus be supported
in its raised position by the said bar I and consequently the gas tap will be
maintained open when the door A is closed. Should however the gas be improperly
lighted or accidentally extinguished by the too sudden closing of the oven door
or otherwise the expansion rods will immediately commence to contract and the
bar I will move from beneath the rod E which will then immediately descend and
close the gas tap C and thus cut off the supply of gas and thereby prevent waste
and the liability to accident from explosion. Should the gas by oversight not
have been ignited it will be evident that as soon as the door A is closed the rod E
• finding no support beneath it (as there will of course have been no expansion to
cause the bar I to project to beneath the said rod E) will fall and close the gas
tap. The following is an arrangement for opening the gas tap by the act of placing
This I will describe with reference to
a cooking utensil in position on the oven.
Figure 2. The hot plate on top of the oven is composed of one part or flap or it
may be divided into a number of parts or flaps (K K¹) each of which is intended to
receive a cooking utensil These flaps are hinged to the top frame of the oven and
are counterweighted so as to cause them to assume an elevated position as shewn
at the left hand side of this Figure. The hinges C of the flaps are hollow and
provided with ports or passages a through which the gas passes from the supply
pipe B to the burners situated beneath the flaps when they are depressed into a
horizontal position as shewn at K' by the weight of a cooking utensil or otherwise.
So soon however as the cooking utensil is removed so as to relieve the flap of
pressure the counterweight b will cause it to turn on its hinge and thereby
cut off the supply of gas and at the same time bring the flap into its elevated
position.
It will be evident that this arrangement or an arrangement of an analogous
kind may be applied to all or any of the gas taps which can conveniently be
operated by this means so that the placing of a utensil on any one part of the oven
will turn on the gas for this particular part and cause it to be automatically
turned off again or nearly so when the utensil is removed.
In applying my Invention to Hall Lamps or Street Lamps as illustrated in
Figures 3, and 4 or to Lamps of a similar construction in which the burner is
enclosed in an outer casing or lantern I effect the turning on of the gas by the act
of opening the door of the Lamp in the following manner:-I fit a lever D on the
plug of the gas tap and connect to one end & thereof a chain K which chain after
passing under a pulley e is connected by its opposite end to the door A of the
Lamp as at c¹. It will thus be seen that when the door is opened for the purpose
of lighting the gas the chain will be pulled and cause the plug of the tap to open
or turn on the gas. The jet is then lighted and the expanding rod or bar f
(arranged like that described in the Specification of my before named prior Patent)
arranged horizontally over the gas jet becomes sufficiently expanded by the heat
to cause the inclined end g of the lever h to engage with the weighted end d¹ of
the lever D and thus maintain the gas tap open. The Lamp door is now closed the

page_text: chain K2 being slack and lying on the bottom of the Lamp. Should the jet be
accidentally extinguished the rod or bar f will contract whereupon the projection g
on the lower end of the bar h will yield to the pressure of the end d' of the lever D
and the said end of the lever will fall and close the tap and cut off the supply of
gas. Should the jet not have been lighted the lever will of course fall and turn
off the gas on the door being closed
A similar arrangement to that last described may be employed for turning on
the gas in rooms such for example as closets by the opening of the room or closet
door as illustrated in Figure 5 in which D is a lever fitted on the plug of the gas
tap one end d¹ being supported by the projection on the lower end of the arm h
when the bar f is expanded as described in the Specification of my aforesaid prior
patent) the other end d is attached by the chain K' to the closet door A the said
chain being supported and guided on pulleys e so that by the act of opening the
said door A the plug of the gas tap will be opened and the gas turned on and will
then be lighted the said tap being maintained in its open position (when the door
is closed) by the expansion of the rod or bar f in the manner hereinbefore
described. Should the gas jet be extinguished the contraction of the rod or bar f
will cause the lever to be released and turn off the gas as hereinbefore described.
Should the jet not have been lighted the lever will of course fall and turn off the
gas on the door being closed.
Having now described and particularly ascertained the nature of my said
Invention and in what manner the same is or may be used or carried into effect
I would observe in conclusion that I do not confine myself to the precise details
herein before described as it is obvious that the same may be varied without
departing from the nature of my Invention but what I consider to be novel and
original and therefore claim as the Invention secured to me by the hereinbefore
in part recited Letters patent is :—
First: In gas cooking ovens or stoves or like apparatus for cooking or heating
purposes the provision of means for turning on the gas by the act of opening the
door of the oven or by the act of placing a utensil in or on a gas oven hot plate or
the like or by other act or movement which is necessarily performed in bringing
the apparatus into operation substantially in the manner hereinbefore described
with reference to Figures 1 and 2 of the accompanying drawings.
Second: In gas ovens the combination with the expansion safety apparatus
described in the aforesaid Specification of my said prior patent of means whereby the
gas is turned on when the door of the oven is opened and whereby the gas tap is
retained open so long as the gas is burning but whereby should the gas be
unlighted or improperly lighted or be extinguished the supply of gas is auto-
matically cut off substantially as hereinbefore described and illustrated in Figure 1
of the accompanying drawings
Third-The combination with the expansion safety apparatus described in the
aforesaid Specification of my said prior patent of means whereby when the door of a
lamp casing or chamber in which the gas burner is situated is opened the gas is
automatically turned on and automatically turned off if unlighted or accidentally
extinguished substantially as hereinbefore described with reference to Figures 3,
4 and 5 of the accompanying drawings.
In witness whereof I the said John William Plunkett have to this my
Specification set my hand and seal this twentieth day of June One thousand
eight hundred and eighty three.
JOHN. W. PLUNKETT. (L.S.)