Improvements in Fire Bars for Mechanical Stokers.
Year: 1899

page_text: Date of Application, 27th Jan., 1899
Complete Specification Left, 16th Oct., 1899-Accepted, 18th Nov., 1899
PROVISIONAL SPECIFICATION.
Improvements in Fire Bars for Mechanical Stokers.
We, JOHN VICARS the elder, THOMAS VICARS, and JOHN VICARS the younger,
all of 56, Seel Street, Liverpool; in the County of Lancaster, Engineers, do hereby
declare the nature of this invention to be as follows:-
In mechanical stokers with fire bars having a mechanical reciprocating motion
the fire bars as at present constructed are liable to become distorted or bent by
reason of the great heat to which they are subjected. It has been attempted by
increasing the thickness of the bars to prevent this distortion or bending, but
such increase of thickness decreases the number of bars and air spaces and thus
reduces the amount of fuel that can be burnt per square foot of grate surface
and the greater thickness of metal absorbs more heat thus establishing a greater
tendency to burning away and distortion.
Our invention has for its object to enable comparatively thin bars to be used
without such liability to distortion or bending and by the use of thin bars the
spaces between them may be narrower thus preventing loss of fuel by riddling.
For this purpose we construct the fire bars with transverse openings through
the webs of the bars at intervals in their length, leaving sufficient metal to form
an adequate connection or support between the lower and upper edges of the bars.
By this means the vertical strength of the bars is retained and at the same time
there is comparatively little metal left to absorb heat, thus the bars can be kept
at a lower temperature and distortion or bending is avoided.
As a further means for preventing bending of the bars and for keeping the
air spaces regular we provide projections or studs on one side of each bar, which
projections or studs bear against the sides of the adjoining bars.
Dated this Twanty airth day of January 1900
We, JOHN VICARS the elder, THOMAS VICARS, and JOHN VICARS the younger,
all of 56, Seel Street, Liverpool, in the County of Lancaster, Engineers, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
In mechanical stokers with fire bars having a mechanical reciprocating motion
the fire bars as at present constructed are liable to become distorted or bent by

page_text: reason of the great heat to which they are subjected. It has been attempted by
increasing the thickness of the bars to prevent this distortion or bending, but
such increase of thickness decreases the number of bars and air spaces and thus
reduces the amount of fuel that can be burnt per square foot or grate surface
and the greater thickness of metal absorbs more heat thus establishing a greater
tendency to burning away and distortion.
Our invention has for its object to enable comparatively thin bars to be used
without such liability to distortion or bending and by the use of thin bars the
spaces between them may be narrower thus preventing loss of fuel by riddling.
For this purpose we construct the fire bars with transverse openings through
the webs of the bars at intervals in their length, leaving sufficient metal to form
an adequate connection or support between the lower and upper edges of the bars.
By this means the vertical strength of the bars is retained and at the same time
there is comparatively little metal left to absorb heat, thus the bars can be kept
at a lower temperature and distortion or bending is avoided.
As a further means for preventing bending of the bars and for keeping the
air spaces regular we provide projections or studs on one side of each bar, which
projections or studs bear against the sides of the adjoining bars.
In the accompanying drawings Fig. 1 is a side elevation and Fig. 2 a plan of a
fire bar constructed according to our invention and Fig. 3 is a transverse section of
a number of bars together. a is the fire bar, 6 are transverse openings through the
webs, enough metat being left at c to form a connection of the necessary strength
between the top a' and the bottom a of the bar but not capable of retaining much
heat. The openings 6 allow of free passage of air through the bars which assists
in keeping them comparatively cool. d, d', are projections or studs at the top
and bottom of each bar which projections bear against or nearly touch the sides
of the adjoining bars, thus any lateral bending of the bars is prevented and the
distance between the bars kept normal whilst at the same time the passage of air
between the bars is not obstructed. e is the fixed bar at the side of the furnace f,
the projections d, on one of the bars a bear against this bar e whilst at the other
side of the furnace a bar similar to e has projections like d, d', which bear against
the nearest of the fire bars a, thus the whole of the fire bars are rigidly supported
laterally. It will be obvious that the openings b might be of other than circular
form as shown, also that the number and position of the projections d, d',
might be varied.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
Fire bars constructed with transverse openings through the webs and with
projections or studs at the sides substantially as and for the purpose set forth.
Dated the Fourteenth day of October 1899.
W. B. JOHNSON,
4, Clayton Square, Liverpool,
Agent.