Improvements in Smoke Box Doors and their Bearings for Traction and like Engines.
Year: 1891

page_text: Date of Application, 12th Aug., 1891
Complete Specification Left, 12th May, 1892-Accepted, 18th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Smoke Box Doors and their Bearings for Traction
and like Engines.
I WILLIAM ALLCHIN of The Globe Works Northampton in the County of
Northampton Engineer do hereby declare the nature of this invention to be as
follows
--
And it is intended to provide more effectual means for closing the doors of smoke
boxes particularly those of traction, portable and semi-portable engines thereby
rendering such smoke boxes practically air tight and so increasing the draught and
ensuring more perfect combustion whilst at the same time lessening the risk of
danger arising from escaping sparks.
In carrying out my invention instead of cutting, or forming the edge or fitting
part of the outer plate of the door at right angles to its plane or say, horizontally
(at top and bottom) in section and also cutting, recessing or rabbeting that portion
of the front plate of the smoke box forming the aperture in corresponding manner
so that the door plate must necessarily be of somewhat less diameter than the said
aperture and the meeting parts abut against each other more or less loosely-I cut
or form the edge of my door plate on the splay or at a convenient angle greater
than a right angle and I also cut or form the edge or circumference of the aperture
which the smoke box door closes with a splayed edge or face at an acute angle so
that the one fits closely to and overlaps the other and the door may be screwed up
in the usual manner until the meeting angular or splayed surfaces fit so tightly
against each other as to form a perfect joint.
Dated this 19th day of August 1891
WM. ALLCHIN,
Per Popplewell & Co.,
A cents
COMPLETE SPECIFICATION.
Improvements in Smoke Box Doors and their Bearings for Traction
and like Engines.
1, WILLIAM ALLCHIN of The Globe Works Northampton in the County of
Northampton 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:
The object of my invention is to provide more effectual means for closing the
apertures of smoke boxes and particularly those of traction, portable or semi-portable
engines and in such a manner as to render such smoke boxes practically air tight,
so increasing the draught and ensuring more perfect combustion of fuel and at the
same time preventing the escape of sparks and so reducing the risk of damage to
property sometimes caused thereby.
The ordinary method of constructing smoke box doors and of forming the apertures
in such smoke boxes is to cut the plates at right angles to their planes the plate
forming the door being thus slightly less in diameter than the aperture which it is-
supposed to fit and close by bearing against an inner plate say an ☐ iron projecting
below or beyond the cut plate and forming a rebate or recess.
Now by my invention I cut the plates forming the aperture and door in a different
manner that is to say not at right angles to their planes and in order to explain my
method more clearly I shall refer to the accompanying drawing which shews a
section of the front part of a smoke box and its door.

page_text: A is the main plate of the door and it will be seen that I cut the circumferential
edge at a convenient angle greater than a right angle to its inner face as shewn
at b. b. and I cut the edge of the aperture plates at a convenient angle less than a
right angle to the inner face as shewn at c. c. of such plates C. C. The door plate A
thus bears with its splayed edge b. b. against the oppositely splayed edge c. c. of the
aperture in smoke box and also against the angle iron B. B.
The usual means for screwing up and securing are employed and it will be seen
that the door may be screwed up until a practically perfect joint is effected and the
door made air tight.
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
In traction, portable or semi-portable engines cutting or forming the edges of the
apertures and doors respectively of their smoke boxes at such angles as will enable
the edge or edges of the plate or plates forming the door to bear against and be
screwed close up to the edge or edges of the plate or plates forming the boundary
or limiting the area of the aperture substantially as hereinbefore described and as
illustrated by accompanying drawing.
Dated this 12th day of May 1892.
POPPLEWELL & Co.,
17 & 18, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.