Improvements in Mechanical Stokers for Steam Boilers.
Year: 1889

page_text: Date of Application, 12th Oct., 1889
Complete Specification Left, 12th Aug., 1890-Accepted, 11th Oct., 1890
PROVISIONAL SPECIFICATION.
Improvements in Mechanical Stokers for Steam Boilers.
I, ANDREW BELL, Engineer, 298 Lower Broughton Road Manchester, in the County
of Lancaster, do hereby declare the nature of this invention to be as follows:→
1st. My improvements consist in an arrangement of the hopper whereby a damper
is inserted above the pusher, or plunger, in order that the quantity of coal required
may be conveyed or pushed into the furnace by a hand rake when the stoker is at
rest, the pusher being removed for the time being, a door is placed over the aperture
to prevent the admission of cold air.
2nd. In order to reduce the friction of the furnace bars, I place them on rollers,
or round balls, which are held in position by a casting with ribs cast thereon, or
a curve in the bottom of the bars, for a round metal ball to rotate in.
3rd. My furnace bars are to work in clusters of five, which may be increased or
decreased in number as required, some have slot holes others have round holes in
order to cause an irregular motion whereby the clinker is broken up and prevented.
These bars are so constructed that each drop into position without disarranging
others.
4th. Consists in improvements in the construction of Sinclair's Patent Stoker
No. 3808 year 1882 by carrying the crank shaft closer to the boiler by means of
brackets attached to the front of stoker, and thus placing all the bearings underneath
the hopper, where they are sheltered from the coal and dust, and allowing more room
for firing, also doing away with the sole-plate and standards which now carry the
crank shaft, and avoiding the cutting of cast iron plates, and stone work in floor in
front of boiler.
5th. An arrangement for moving the coal pusher or plunger backward and
forwards any desired distance to supply the quantity of coal required by means of a
lever, actuated by a pin attachment to the connecting rod which works in a slot, or
groove, in the lever, this lever is attached to the bottom plate of hopper, which is at
rest, by a pin joint, on which the lover oscilates; thereby imparting a steady forward
and backward movement to the other end of lever which is connected by a regulating
screw to the pusher.
COMPLETE SPECIFICATION.
Improvements in Mechanical Stokers for Steam Boilers.
I ANDREW BELL of 298 Lower Broughton Road Manchester in the County of
Lancaster 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 improvements in mechanical stokers known as Sinclair's
Stokers and others of similar construction and it will be readily understood from the
following description on reference to the annexed drawing which is a vertical section
taken through one of the flues of a boiler shewing my improvements applied
thereto.
On the drawing a is a hopper, b the pusher or plunger, c one of the fire bars and
d the flue.
My invention consists in the first place of an improved arrangement of the
hopper a whereby a damper a¹ is inserted above the pusher or plunger 6 in order
that the quantity of fuel required may be conveyed or pushed into the furnace by
[Price 6d.]

page_text: a hand rake when the stoker is at rest, the pusher 6 being removed for the time
being and a door being temporarily placed over the aperture to prevent the admission
of cold air. The damper a¹ being closed, the hand rake may be pushed inwards
without fear of the coal falling from the hopper and being pulled out of the furnace
when the rake is pulled back.
In order to reduce the friction of the furnace bars c as they move in and out
I mount them upon rollers preferably flanged to receive the bars or upon round
balls held in position by a casting or plate e with ribs at either side.
The underside of the ends of the bars c are made with a groove for the balls c* to
roll in.
The furnace bars c work in clusters of two or more connected to the pin f of each
connecting rod 9 some by holes fitting the said pin. others by slots indicated by dotted
lines in which the pin moves before moving the bar in order to cause an irregular
motion of the different bars, whereby the clinker is broken up or prevented from
forming.
The bars are so constructed by being slotted vertically as shewn that each drops
into position without disarranging the others.
I also improve the arrangement of Sinclair's Stoker as described by the said
inventor, in the Specification of his Patent No. 3808 of 1882 by mounting the crank
shaft h, closer to the boiler, the said shaft being carried by brackets attached to the
front of the stoker as shown at i and thus placing all the bearings underneath the
hopper a where they are sheltered from the coal and dust.
This arrangement also allows more room for firing and does away with the sole
plate and standards previously employed in these stokers for carrying the said crank
shaft and avoids the necessity for cutting the cast iron plates and stonework in the
floor in front of the boiler when applying the stoker thereto.
l
The coal pusher or plunger b is also so arranged that it can move backwards and
forwards for any desired distance to supply the coal. This is effected by a lever k
actuated by a pin attached to the connecting rod g, the said pin working in a slot
or groove in the lever, the fulcrum k* of which is supported by a hearing fixed or
cast to the bottom plate a², of the hopper.
b
The lever oscillates on the fulcrum * and imparts a steady forward and back-
ward movement to the pusher or plunger 6 to which its upper end is connected by a
screwed rod n provided with an adjusting nut n¹ so that more or less traverse can be
given to the said plunger as the nut n¹ is set to meet it sooner or later.
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 1
claim is :-
1. In mechanical stokers of the class hereinbefore referred to, the combination with
the hopper of a damper or slide inserted above the pusher, or plunger when firing by
hand substantially as and for the purposes described.
2. In mechanical stokers of the said class the combination with the ends of the
furnace bars of antifriction rollers or balls with a plate having ribs or flanges sub-
stantially as and for the purpose described.
3. Mounting the crank shaft of such mechanical stokers upon brackets attached to
the front of the stoker whereby the necessity for a sole plate and standards is obviated,
and the bearings are protected from coal and dust.
4. The arrangement for adjusting the position of the coal pusher or plunger so as
to regulate the supply of coal consisting in the combination of a slotted lever and a
regulating screw and adjustable nut substantially as and for the purposes hereinbefore
described.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.