IMPROVEMENTS IN MECHANICAL STOKERS
Year: 1881

page_text: LETTERS PATENT to Thomas Bispham Kay, of Bolton-le-Moors, in the County
of Lancaster, Engineer, and Robert Heywood, of Salford, in the same
County, Bleacher, for an Invention of "IMPROVEMENTS IN MECHANICAL
STOKERS."
PROVISIONAL SPECIFICATION left by the said Thomas Bispham Kay and
Robert Heywood at the Office of the Commissioners of Patents on the
4th July 1881.
THOMAS BISPHAM KAY, of Bolton-le-Moors, in the County of Lancaster, Engineer,
and ROBERT HEYWOOD, of Salford, in the same County, Bleacher. "IMPROVEMENTS
IN MECHANICAL STOKERS."
Our Invention relates to that class of mechanical stokers in which the fire-bars
are caused to move automatically, and consists in the application of an intermittent
lock motion between the driving pulley or motive power and the main cam or
eccentric shaft, consisting of a spur wheel provided with a snug, an extra segment
of teeth, and a lock-rim actuating a toothed pinion provided with a tappet-finger
and a lock plate, whereby the fire-bars inay be alternately moved and held stationary
with their upper surfaces in the same plane, instead of being moved continuously as
heretofore, the burning away thereof diminished, a more efficient feed secured, and
a corresponding saving and economy of working effected. A cam surface or bowl
on the said spur wheel actuating a lever on the reciprocating shaft or a supple-
mentary toothed pinion connected with the feed plate, and actuated by the segment
on the aforesaid spur wheel, may be employed to effect the feed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Bispham Kay and Robert Heywood in the Great Seal Patent
Office on the 3rd January 1882.
THOMAS BISPHAM KAY, of Bolton-le-Moors, in the County of Lancaster, Engineer,
and ROBERT HEYWOOD, of Salford, in the same County, Bleacher. "IMPROVEMENTS
IN MECHANICAL STOKERS."
This Invention relates to that class of mechanical stokers in which the fire-bars
are caused to move automatically, and consists in the application of an intermittent
lock motion between the driving pulley or motive power and the main cam or
eccentric shaft, consisting of a spur wheel provided with a snug, an extra segment
of teeth, and a lock rim actuating a toothed pinion provided with a tappet finger
and a lock plate, whereby the fire bars may be alternately moved and held stationary
with their upper surfaces in the same plane, instead of being moved continuously
as heretofore, the burning away thereof diminished, a more efficient feed secured,
and a corresponding saving and economy of working effected. A cam surface or
bowl on the said spur wheel actuating a lever on the reciprocating shaft or a
supplementary toothed pinion connected with the feed plate and actuated by the
segment on the aforesaid spur wheel may be employed to effect the feed.
And in order that our said Invention may be fully understood, we shall now
proceed more particularly to describe the same, and for that purpose we shall refer
to the several Figures on the Sheet of Drawings hereunto annexed.
Fig. 1. is a side view, and Fig. II. a front view of our improvements in
mechanical stokers, one half of full size.
Here A is a segmental spur wheel, that is, a spur wheel with an extra segment
of teeth affixed thereto, and provided with a set rim a and a cam-snug b (which
wheel we shall herein after call the segment spur), and rotating loose upon the
driving shaft c, upon which is keyed a pinion d gearing into a spur wheel e, having
a pinion attached thereto, and rotating loose upon the main cam or eccentric
shaft G. The pinion f gears into the spur portion of the segment spur A. Upon
the eccentric shaft G is keyed a toothed pinion B, provided with a tappet finger h
and lock plate i passing into the segment of teeth affixed to the segment spur A,
and which we shall herein after call the segment pinion. The mechanism may be
actuated by a pulley fixed upon the end of driving shaft c, and driven by strap
from shafting overhead or otherwise.
In order to explain intelligibly the action of the mechanism herein before
described, we will assume the sets of bars to be stationary with their upper
surfaces level or in the same plane, and the segment pinion B keyed on to the
eccentric shaft G which actuates the said bars, with one side of its lock plate face
to face with the set rim a upon segment spur A, by which it is maintained in
position. The latter, actuated through pinion f, spur wheel c, and pinion d from
pulley, continues its rotation until the cam snug b comes into contact with the
front edge of one end of the tappet finger h upon segment B, causing the latter to
commence to rotate, and the set rim a upon segment spur A having a piece cut out
immediately opposite the segment of teeth thereupon, and the latter coming into
gear with the teeth upon the segment pinion B, the lock plate turns in the space
cut out for it, and the rotation of B is continued until the said segment of teeth
has passed, and the other side of the lock plate i is face to face with the set rim a
upon the segment spur A, and the segment pinion B has made one semi-rotation.
One set of bars will thus have been caused to make one movement forwards,
carrying the fuel towards the end of the furnace flue, and the other set will have
been caused to make one movement back, both becoming again stationary for an
interval of time, with their tops level or in the same plane, until the cam snug b
on segment wheel A continuing its rotation comes into contact with the other end
of the tappet finger h on segment pinion B, which commences another semi-rotation,
causing those bars which were just previously moved forward to be moved back,

page_text: and those which were moved back to be moved forward, all becoming again
stationary for another interval of time with their tops level or in the same plane.
A cam disc fixed upon shaft c, and acting upon tappet finger h, may in some cases
be employed to assist the segment pinion B in completing its semi-rotation, in
which case the spur wheel will have to be a multiple of the pinion to insure a
synchronical movement of the cam disc with the tappet finger. Each movement of
the bars is thus commenced slowly by the snug cam 6 acting on one extremity of
the tappet finger h, is continued at an accelerated speed by the segment gear, and
is finished by the positive action of the cam disc r on the other end of the tappet
finger h.
Without confining ourselves to any particular mechanical stoker having firebars
moved automatically in the application of this our Invention, we may here say
that for the purpose of illustration we have described it as applied to that class of
mechanical stoker now in general use, in which there are two sets of bars actuated
by an eccentricated shaft, the motion of which is continuous, and so that the upper
surface of one set of bars being always more or less raised above the upper surface
of the other set (excepting when passing the centre of oscillation), is thereby more
exposed to the action of the fire than is the case with stationary bars having their
surfaces level or in the same plane, and resulting in an excessive burning away
thereof and loss of fuel. It will be obvious that this defect will be remedied in
proportion to the length of dwell secured for the bars when passing the centre of
oscillation, that is, when their upper surfaces are level or in the same plane. We
have not thought it necessary to explain at length the other parts of this class of
Inechanical stoker, as the construction and working thereof are well known, but
have confined ourselves to a complete explanation of the various parts so far only
as our present Invention is concerned.
Now having described the nature and objects of our said Invention, together
with the manner in which the same is to be or may be performed or carried into
practical effect, we wish it to be distinctly understood that we do not claim the
cam or eccentric shaft, or any particular mode of connecting it with the fire bars
so as to actuate the same, but what we do claim as secured to us under the above
in part recited Letters Patent is,―
1st. The arrangement of parts marked G, A, a, b, B, h, i, r.
2ndly. The general arrangement of mechanism for actuating mechanical stokers,
or any mere modification or imitation of the above mentioned arrangement of parts,
when used substantially in the same manner and for the same purposes as herein
before described, set forth, and illustrated.
In witness whereof, we, the said Thomas Bispham Kay and Robert Heywood,
have hereunto set our hands and seals, this Thirty first day of December,
in the year of our Lord One thousand night hundred and sightse
Signed by the sd. Tho. B. Kay in
the presence of
H. A. KAY,
371, Westgate Road,
Newcastle on Tyne.
Signed by the sd. Robert Heywood in
the presence of
JOHN HEYWOOD,
Egerton House,
Bolton.
THU. B. KAY.
(L.S.)
ROBERT HEYWOOD. (LS.)