Improvements in or applicable; to mechanical Stokers.
Year: 1894

page_text: Improvements in or applicable; to mechanical Stokers.
I WILLIAM DENHAM GRIMSHAW of Plantation Mills Accrington in the County
of Lancaster, Calico Printer, do hereby declare the nature of this invention to be
as follows:-
This invention relates to improvements upon that class of mechanical stokers
for which Letters Patent were granted to me bearing date the 28th day of
December 1891, No. 22569.
According to my present invention, instead of using three fans and three fan
boxes as mentioned in the Specification of the Letters Patent above referred to,
I propose to use two fans both of the same diameter and working in one and the
same fan box, and fixed side by side upon the same shaft, the two fans being placed
at right angles to each other.
Opposite to the mouth of the fan box I have two directing plates which are so
hinged as to be adjustable on a central pivot by means of screwed rods. the fixed
casting for the said hinge being made with a tapered plate or midfeather which
protects the hinge from the coal and divides the stream of the latter against the
two directing plates.
In a casing placed between the hopper and the fan box are two rakes which are
connected together by tie bars and have a very slight to-and-fro motion given to
them (say about five-eighths of an inch) and as they both impel the coal or fuel.
towards a single central opening in the top of the fan box there are two impulses
given to the coal at each revolution of the crank wheel which is connected to the
rakes and driven in the manner described in the Specification of Letters Patent
No. 22569 of 1891 above referred to.
It will therefore be evident that one or other of the rakes is always feeding the
central orifice (one advancing as the other recedes) and hence there is a continuous
supply of fuel given to the fan box and as the fans are (as before stated) set at
right angles to each other they further assist in making the supply of fuel to the
fire continuous and even.
In order to prevent the coal from becoming choked in the hopper bottom I make
in the latter two openings (one in front of each rake) which not only being divided
but also being larger in area than the single opening hitherto employed, will be
much less liable to become choked, and even if this should happen to one it is
very improbable that they would ever both become choked at one and the same
time and therefore the supply of fuel would never be likely to ceuse altogether as
might be the case were only one opening to be employed.
Dated this 7th day of July 1894.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant..

page_text: I WILLIAM DENHAM GRIMSHAW of Plantation Mills, Accrington, in the
County of Lancaster, Calico Printer 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 upon that class of mechanical stokers
for which Letters Patent were granted to me bearing date the 28th day of
December 1891 No. 22569.
The invention will be readily understood from the following description on
reference to the accompanying drawings of which
Fig. 1 is a front elevation partly in section of my improvements shewn applied
to so much of a furnace front as is necessary to illustrate the application of my
invention;
Fig. 2 is a horizontal section through the fan box ; and
Fig. 3 shews, in transverse section and partial plan, one of the rakes and the tie
bars hereafter described.
Fig. 4 shews the midfeather and one directing plate detached.
According to my present invention, instead of using three fans and three fan
boxes as mentioned in the Specification of the Letters Patent above referred to,
I propose to use two fans a a', both of the same diameter and working in one and the
same fan box b, and fixed side by side upon the same shaft c, the two fans a a¹
being placed at right angles to each other, as shewn by Figs. 1 and 2.
Opposite to the mouth of the fan box b I have two directing plates d d' (sec
Fig. 2) which are so hinged as to be adjustable on a central pivot e by means of
screwed rods ff' and levers f+, the fixed casting g for the said hinge being made
with a tapered plate or midfeather 9+ (see Fig. 4), which protects the hinge from
the coal and divides the stream of the latter against the two directing plates d
and d¹.
In a casing i, placed between the hopper h and the fan box b, are two rakes k k¹
which are connected together by tie bars k+, and have a very slight to-and-fro
motion given to them (say about five-eighths of an inch), and as they both impel
the coal or fuel towards a single central opening 6+ at the top of the fan box b
there are two impulses given to the coal at each revolution of the worm wheel or
crank wheel m, which is connected to the rakes k k', and driven, in the manner
described in the Specification of Letters Patent No. 22:69 of 1891 above
referred to.
It will therefore be evident that one or other of the rakes k, k¹ is always feeding
the central orifice 6+ (one advancing as the other recedes), and hence there is a
continuous supply of fuel given to the fan box b, and as the fans a a' are (as before
stated) set at right angles to each other they further assist in making the supply of
fuel to the fire continuous and even.
In order to prevent the coal from becoming choked in the hopper bottom + I make
in the latter two openings, see Fig. 1 (one in front of each rake), which not only
being divided but also being larger in area than the single opening hithert
employed, will be much less liable to become choked, and even if this should
happen to one it is very improbable that they would ever both become choked at
one and the same time, and therefore the supply of fuel would never be likely t
cease altogether as might be the case were only one opening to be employed.

page_text: 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 :-
The improvements in mechanical stokers substantially as hereinbefore described
and illustrated by the annexed drawings.
Dated this 5th day of April 1895.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.