AN IMPROVED TWIN DOOR' WITH AUTO- MATIC MECHANISM TO BE EMPLOYED FOR SANITARY PURPOSES
Year: 1876

page_text: LETTERS PATENT to David Gill, of Weston-super-Mare, in the County of
Somerset, for the Invention of "AN IMPROVED TWIN DOOR' WITH AUTO-
MATIC MECHANISM TO BE EMPLOYED FOR SANITARY PURPOSES."
COMPLETE SPECIFICATION filed by the said David Gill at the Office of the
Commissioners of Patents on the 6th October 1876.
DAVID GILL, of Weston-super-Mare, in the County of Somerset. "AN IMPROVED
TWIN DOOR WITH AUTOMATIC MECHANISM TO BE EMPLOYED FOR SANITARY
PURPOSES."
The object of my said Invention is to isolate waterclosets and apartments in
hospitals, dwelling-houses, and other buildings from other parts thereof as regards air,
effluvia, and sound by means of twin doors in conjunction with suitable mechanism
in such a manner that they will close or open simultaneously. When such doors
are closed an automatic arrangement of mechanism immediately opens a valve and
allows a free circulation of air to pass by means of a suitable channel provided for
that purpose from the outside of the building between the doors; or, in the case of
infectious effluvia or germs of disease being supposed to be present, the valve is em-
ployed for the admission of fumes, vapours, or gases of a disinfecting nature, which are
produced in a chamber in which a substance or substances capable of cooling such
fumes, vapours, or gases is or are placed. The doors thus employed are kept at a
suitable distance from each other, and the inlet valves are inserted in the upright
linings or jambs, an outlet ventilator being placed in the upper part under the lintel
in order to create the requisite current of air.
At the entrance to the apartment or watercloset to be isolated an outer door and
an inner door are hung more or less parallel to each other, and with a certain depth
of space between them when the same are shut. The inner door is hung with a
deeper rebate in the jamb than the outer door, the same being sufficient in thickness
to allow the outer door to open completely; the inner door will consequently be
made wider than the outer door. The doors when hung are connected on the lock
side by a double jointed hinge, which gives a simultaneous motion to the twin door.
On the lock side of theouter door a pin or knob is fixed, and which works in a slot
formed on the jamb for that purpose.

page_text: A valve on the principle of the "hit-and-miss" ventilator is let into the jamb, the
lower part of the slide of the valve being made with such an angle of inclination (or
the pin or knob and slide may each have a partial inclination) that when the door
is shut the pin or knob runs into the slot, and thus causes the slide to rise, and by
so doing the perforations in the slide and in the fixed part of the valve are brought
opposite to each other, but when the twin door is open the slide drops again and
covers the perforations at the back. The valve communicates by means of a suitable
channel with the external air or with a small chamber or apparatus capable of con-
taining a substance or substances from which disinfecting fumes, vapours, or gases
can be evolved. A current of air or of disinfecting fumes, vapours, or gases is thus
set up and maintained between the doors which completely isolates the atmosphere
on the outside from that on the inside, and prevents any prejudicial effects which
would arise in the case of the atmosphere in the two places being of different
density.
It will readily be seen that this is of great importance in the case of apartments
and waterclosets in which the air is charged with noxious vapours or effluvia, or
with infectious germs, which are liable in the absence of proper means being adopted
to prevent such a result of being drawn into other parts of a building.
In order to ensure a continuous current an exit ventilator of sufficient size to draw
the current upwards is inserted in the head of the door frame under the lintel.
I will now proceed to refer to the annexed Drawings, from which the nature of
my said Invention will be more clearly understood.
Figure 1 is a plan of a doorway with the twin doors open.
Figure 2 is a plan of the same with the doors closed.
Figure 3 is an end view of the pin or knob.
Figure 4 is a front view of the valve and slot.
Figure 5 is a plan of the same.
Figures 6 and 7 are vertical sections of the same closed and open.
The same letters of reference indicate similar parts in the several Figures.
A is the entrance to the apartment or watercloset to be isolated; B is the outer
door, and C the inner door; a is the before-mentioned rebate in the jamb; c is the
pin or knob; d is the slot on the jamb; c is the valve, the angle of inclination on
the lower part of the slide being shewn at f; the channel communicating with the
external air is shewn at g.
Having thus declared and ascertained the nature of my said Invention, and in
what manner the same is to be performed, I would observe in conclusion that what
I consider novel and original and therefore claim as constituting the same is, the
combination and arrangement of parts and mechanism, substantially as and for the
purposes herein-before set forth and described, or any mere modifications thereof.
In witness whereof, I, the said David Gill, have hereunto set my hand and
seal, this Third day of October, in the year of our Lord One thousand eight
hundred and seventy-six.