Year: 1887

page_text: Date of Application, 28th June, 1887
Complete Left, 28th Mar., 1888
Complete Accepted, 11th May, 1888
I, JAMES HAY CORMACK of 36 Abercorn Street in the City of Glasgow, Heating
and Ventilating Engineer do hereby declare the nature of this invention to be as
follows:-
My invention which relates to doors for soot boxes and flues of ovens, ranges, steam
boilers, heating apparatus and the like has for its object to make provision whereby in
the event of explosion or back draught in a flue the door will blow open and will
again close automatically upon the lowering of the internal pressure and whereby the
door may be readily held open for cleaning out soot or for inspection of the fluc. In
the soot box or framing of the doorway of the flue is formed an inwardly projecting
flange extending from the top a short way down each side of the door-way and
terminating in hook like supports for pivots which are formed on each side of the door
near the upper edge.
On each side of the door which is or may be composed of a flat or moulded plate
of rectangular or other form slits or checks are cut in the edges which overlap the
flange in the doorway the object being to permit of the door swinging on its pivots
which do not or need not project beyond the edges of the door and to allow of the
door when swung from the vertical to the horizontal position being raised in the
doorway the slits or checks embracing and being guided by the flanges upon the door-
way. When so raised that the upper edge of the door may bear against the top of
the doorway or box the weight of the lower part of the door which then projects
forward retains the door in an open position and when again lowered to rest on its
pivots the door is free to swing close or to be opened by hand or by back draught
from the flue.
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Doors for Flues, Soot Boxes, and
the like.
I, JAMES HAY CORMACK of Abercorn Street, Glasgow in the County of Lanark,
North Britain, 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 :-
This Invention relates to self-closing doors and their application to Flues, soot
boxes, or other similar parts; the object being to provide a surplus self-closing outlet
or door for the products of combustion when an extra pressure occurs therein by the
sudden combustion or explosion of an extra accumulation of combustible products,
such as may occur when the fires are banked up during the night.
On the accompanying Drawing Figs. 1 and 2 are respectively a front elevation
showing part of door broken off, and a vertical section of the door in its frame;
while Fig. 3 is a back view of door alone.
The cast iron Door a is of rectangular shape and fitted into an iron case or frame e
which has a rim e¹ round front thereof, all so as to be easily built into the flue. The
door a when shut fits close above level of hinge o, against the inside of overlaping
ledge c round upper part of case e, and also below, level of hinge o into check or
recess ground lower part of inner edge of case e. The door a is also made below
said level with an overlaping edge i on front which fits against front of case e. The
door has rectangular recesses m in sides, between which project the rounded or knife-
edged ends of a raised ridge n on back of door, said ends constituting trunnions o
which fit into loops o¹ formed on bottom of ledge c of case thus forming the hinge.
The bottom part of door being thus free to oscillate outwards similarly to a valve,
opens when an extra pressure on inside thereof actuates it thus relieving said pressure
and preventing disruption of the brick or other work of flue and closing again by
virtue of its own weight.
The door is so made and fitted into case that it may be readily disconnected there-
from by twisting it by handle v diagonally, as indicated by dotted lines u Fig. 1, so as
to clear the lower trunnion o from right hand loop o¹ when it can be taken out, thus
making a free opening into flue through which soot or other matter may be
withdrawn.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed I declare that what I
claim is.
1st. A self-closing door and casing constructed and operating, as and for the
purposes described and shown.
2nd. The application and use in Flues, of a self-closing door, constructed and
operating as described and shown.
Dated this 26th day of March 1888