An Improved Draught Appliance for Locomotive Engines.
Year: 1891

page_text: Date of Application, 9th Mar., 1891
Complete Specification Left 9th Dec., 1891-Accepted, 9th Jan., 1892
PROVISIONAL SPECIFICATION.
An Improved Draught Appliance for Locomotive Engines.
I, JOHN PITT BAYLY, of 18 Fulham Place, Paddington, W., in the County of
London, Patent Agent, do hereby declare the nature of this invention (a communi-
cation to me from abroad by Mark Maxwell Lindsley, Draughtsman, of Parell
Works, Bombay, India,) to be as follows:--
My invention relates to an improved draught appliance for locomotive engines
and consists in extending the chimney down to a point about the centre of the top
and bottom rows of tubes and terminating it in the direction of the front door of
the smoke box. The mouth of the chimney is fitted with a damper valve which
is worked from the footplate of the engine by the driver to increase or decrease the
draught as required.
The main object is to get an equal draught through all the tubes and to regulate
that draught without in any way interfering with the exhaust blast.
It will be understood that the foregoing is given by way of illustration, and that
the materials and shapes may be varied in many ways within the scope of my
invention.
Dated this 9th day of March 1891
J. P. BAYLY,
Applicant.
COMPLETE SPECIFICATION.
An Improved Draught Appliance for Locomotive Engines.
I, JOHN PITT BAYLY, of 18 Fulham Place, Paddington, W., in the County of
London, Patent Agent, do hereby declare the nature of this invention (a communi-
cation to me from abroad by Mark Maxwell Lindsley, Chief Draughtsman of
the Locomotive and Carriage Department, Bombay Baroda and Central India
Railway, Parel Works, Bombay, India,) and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The main object is to get an equal draught through all the tubes and to regulate
that draught without in any way interfering with the exhaust blast, this I obtain
by extending the chimney down to a point about the centre of the top and bottom
rows of tubes and terminating it in the direction of the front door of the smoke box.
The mouth of the chimney is fitted with a damper valve which is worked from the
foot plate of the engine by the driver to increase or decrease the draught as
required.
The manner in which this is performed I will now describe with reference to the
drawing filed herewith :-Ordinarily the chimney of a locomotive type boiler is
only carried down to a point marked a and the top of the blast pipe b is ordinarily
about the height in relation to the top row of tubes as shewn; the exhaust steam
passes through the blast pipe b into the chimney leaving a partial vacum after each
exhaust, this partial vacum is filled by drawing the gases from the fire box through
the tubes and owing to the top rows of tubes being nearest to where the partial
vacum is formed, it causes a greater draught through them than through the lower
tubes and consequently a great loss of heat to the lower tubes where as by extending
the chimney down to a position about and terminating with a bend d in the
direction e thereby enclosing the upper portion of the blast pipe 6 and forming the
blast pipe 6 and chimney into a simple ejector with an open mouth to the chimney

page_text: at g as nearly as possible at an equal distance from all the tubes an equal draught
is obtained which is regulated by opening or closing the valve h which has a spindle
passing through it and carried through the side of the smoke-box, to the end of
which is attached a crank j and connected to the crank j is a rod extending to a
position where the driver can reach it from the foot plate of the engine.
It will be understood that the foregoing is given by way of illustration, and that
the materials and shapes may be varied in many ways within the scope of my
invention.
Having thus 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 combination with a locomotive or stationary engine having an exhaust steam
pipe in the smoke box, an improved draught appliance which consists in extending
the chimney down to a point about the centre of the top and bottom rows of tubes
and terminating it in the direction of the front door of the smoke box, the mouth of
the chimney is fitted with a damper valve which is worked from the foot plate of the
engine or any other convenient position by the driver to increase or decrease
the draught as required, the object being to place the mouth of the chimney as
nearly as possible at an equal distance from all the tubes. The blast pipe passes
through the bottom of the chimney thereby forming the chimney and blast
pipe into a simple ejector, all acting and operating substantially as herein
described.
Dated this 9th day of December 1891.
J. P. BAYLY,
Applicant.