Improvements in Apparatus for Locking the Draught Doors of Stoves.
Year: 1889

page_text: Date of Application, 19th Dec., 1889
Complete Specification Left, 11th Aug., 1890-Accepted, 4th Oct.. 1890
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Locking the Draught Doors of
Stoves.
I CHARLES PORTWAY, of The Tortoise Stove Works, Halstead, in the County of
Essex, Iron Founder do hereby declare the nature of this invention to be as
follows:-
In stoves such as slow combustion stoves of the kind commonly known in the trade
as Portway's Tortoise Slow Combustion Stoves " doors are provided for the
regulation of dranght and for the removal of ashes and attention to the stove or its
contents.
These doors are slung on a pin so as to swing to and from their seats but they
also are capable of sliding side wise on their pins so as to leave gaps or openings
between the ends of the doors and the openings in their seats through which gaps
the air to accelerate combustion is permitted to flow or when desired these doors are
closed entirely and combustion is choked, these doors forming a convenient means of
regulating combustion.
In practice however it is found that when the door of a stove has been set as
described to a certain extent of aperture so as to regulate the draught to promote a
certain rate of combustion the door is liable especially in public places to be tampered
with by unauthorised or mischievous persons and the rate is altered.
To prevent this I form on the door and its adjacent parts the members of a simple
locking arrangement, which when the door has been set to the desired position, are
caused to engage by the movement of an applied key and the further alteration of
the position of the parts is prevented except the parts or members be unlocked or
disengaged.
A convenient form of lock to prevent lifting of the door as well as sliding of
it on its seat is to form projections on the doors taking into indentations on the seat or
vice versa or indentations and projections or both capable of engagement, the locking
in the engaged position being effected by means of a keyed pin in a handle lng,
having a spindle passing through the lug as its seating, and carrying on its inner
side an inclined piece or locking cam, which inclined cam has part cut away so
that in one position it can drop past a lip or flange of the seat of the door or
fixed part of the stove and when the inclined cam, under the influence of the key,
applied to the keyed end of the spindle is rotated the cam locks itself tightly behind
the lip or flange and locks the door from being lifted, whilst the serrations or
engaged irregularities of the surfaces of the door and seat prevent lateral move-
ment, whilst except the key no part is separable so as to be in danger of being lost.
The construction of the parts may be considerably varied, such as by a screw
worked by a removable key engaging one of a series of holes spaced so as to he
alternatively used according to the extent of opening desired to be maintained for
the door.
Dated the 19th day of December 1889.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Locking the Draught Doors of
Stoves.
I CHARLES PORTWAY of The Tortoise Stove Works Halstead, in the County of
Essex, Iron Founder 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 :-
In stoves such as slow combustion stoves of the kind commonly known in the
trade as "
Portway's Tortoise Slow Combustion Stoves" doors are provided for the
regulation of draught and for the removal of ashes and attention to the stove or
its contents.

page_text: Figs. 6, 7 and 8, where a screw i retained by a plate k rivetted to the front of the
door c and rotated by a removable key 1 (Fig. 8) engages one of a series of tapped
holes m in the lug 6 spaced so as to be alternatively used according to the extent of
opening desired to be maintained for the door c.
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 :-
The apparatus for locking the draught doors of stoves to prevent illicit interference
therewith by means of a keyed part operated by a removable key substantially as
hereinbefore set forth.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.