Improvements in and relating to Furnace Fire Grates.
Year: 1892

page_text: Date of Application, 31st Aug., 1892
Complete Specification Left, 31st May, 1893—Accepted, 22nd July, 1893
PROVISIONAL SPECIFICATION.
Improvements in and relating to Furnace Fire Grates.
I, PETER JACK, of Kilmalcolm Hydropathic, Renfrewshire, Engineer, do
hereby declare the nature of my invention to be as follows:-
This invention has reference to improvements in the construction and arrangement
and combination of the parts and mechanical motions of the fire grates of furnaces
and especially those of steam boilers, whereby there will be much saving in
labour, and more efficiency, and economy, than with the fire grates heretofore
in use.
The improvements essentially consist in constructing and grouping the fire bars
into a set or sets to be turned or swivelled on longitudinal spindles or axes below
their upper surfaces for the purpose of cleaning out the ashes and clinkers.
Under one arrangement as applied to the furnace of an horizontal internal flue
marine boiler, the improvements consist in placing the grate bars in an horizontal
longitudinal set of nearly half the width of the furnace so as to have two parallel
sets in the width, each set being mounted on end trunnions with polygonal centres
entering recesses formed in them under the bars, these trunnion centres, carrying
each set of furnace bars, being mounted to swivel in stationary bearings fitted
under the front dead plate and back cross beam supported on the sides of the
internal flue in the ashpit, all so that the sets of bars and the bosses of their
polygonal end carrying trunnions may swivel freely in the space between the front
dead plate and the back cross beam. Each of the front trunnions has an overhung
square or polygonal head in front of the furnace plate or door for so turning cach
set of furnace bars for emptying the ashes or clinkers down into the ashpit. These
furnace bars may be made the whole length of the furnace between the front dead
plate and the back flame bridge wall, or only a part of the length, and have an
ordinary stationary furnace bar grate behind the frames of swivelling furnace grate
bars, so that in cleaning one set of swivelling bars all the burning fuel may be
transferred on to the other set, and have only the ashes and clinkers on the one to
be swivelled; or otherwise the burning fuel may be pushed on to the stationary
grate near the flame wall, when this is used, and draw or leave all the ashes or
clinkers on the swivelled bars to be swivelled and cleaned, by giving these a half turn
round to the vertical position, and the bars would be again swivelled horizontally
and the fire drawn on to them and a new charge of fresh fuel placed on top. An
air space would preferably be left between the front dead plate and the ends of the
bar frames and boss of turning trunnion, and which would also allow for the free
expansion and contraction of the sets of grate bars, which may be formed in any
number of convenient sections carried on their turning frames. And by these
improvements the frames of furnace bars may be made of such a depth as to be
reversible, that is, by making the bars and recesses parallel they can be swivelled
on their centre axes right round to make the previous under side to be the top side.
And the top and bottom edges of these bars would preferably be made of rounded
section on each side towards their intermediate recesses. A locking device being
used on the trunnions, such as a notched disc or segment with sliding bolt, for
fixing the bars in their normal horizontal or their tilted position.
Don
1
C
1000
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Furnace Fire Grates.
I, PETER JACK, of Kilmalcolm Hydropathic, Renfrewshire, Engineer, do
hereby declare the nature of my invention, and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement in writing that. is to say :-
This invention has reference to improvements in the construction and arrangement
and combination of the parts and mechanical motions of the fire grates of furnaces
and especially those of steam boilers, whereby there will be much saving in
labour and more efficiency, and economy, than with the fire grates heretofore
in use.
The improvements essentially consist in constructing and grouping the fire bars
into a set or sets to be turned or swivelled on longitudinal spindles or axes below
the upper surfaces for the purpose of cleaning out the ashes and clinkers.
And in order that my said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, I have hereinto
appended an explanatory sheet of drawings in which the same reference letters are
used to indicate corresponding parts in all the figures where shown.
Figure is a longitudinal sectional elevation. Figure 2 a corresponding
sectional plan view; and Figure 3 a front end view partly in section of a steam
I boiler Z, with an internal furnace flue Z, as fitted with my improved fire grate.
And Figures 4 to 6 are detached detail views hereinafter referred to.
Referring to these drawings-Under the arrangement shown as applied to the
furnace of an horizontal internal flue marine boiler, the improvements consist in
placing the grate bars in an horizontal longitudinal set of nearly half the width of
the furnace so as to have two parallel sets A, A', in the width, cach set being
mounted on central spindles B, which swivel in stationary bearings 13, fitted under
the front dead plate A", and in the back cross beam B2, supported by brackets B³,
on the sides of the interual flue Z in the ashpit all so that the sets of bars A, A',
and their carrying spindles B, may swivel freely in the space between the front
dead plate A and the back cross beam B. Each of the central spindles B, as
shown detached to a large scale in Figure 4, with a part broken away at z, has an
. overhung square or polygonal head B in front of the furnace plate or door, for so
turning each set of furnace bars A, A', for emptying the ashes or clinkers down
into the ashpit. These sets of furnace bars A, A, are shown as formed only a part
of the length of the flue Z' and an ordinary short stationary furnace bar grate A², is
shown as fitted behind the frames of swivelling furnace grate bars A A'; but these
sets of bars A, A, may be made the whole length of the furnace between the front
dead plate A and the back flame bridge wall Z; all so that in cleaning one set of
swivelling bars A, all the burning fuel may be transferred on to the other set, and
have only the ashes and clinkers on the one to be swivelled; or otherwise the
burning fuel may be. pushed on to the stationary grate A³, near the flame wall,
when this is used, and draw or leave all the ashes or clinkers on the swivelled bars A
to be swivelled and cleaned, by giving these a half turn round to the vertical
position, and the bars would be again swivelled horizontally and the fire drawn on
to them and a new charge of fresh fuel placed on top. An air spaces would
preferably be left between the front dead plate A", and the bar carrying frame A',
and boss of turning spindle B, and which would also allow for the free expansion
and contraction of the sets of grate bars A, A', which may be formed in any number
of convenient sections a carried on their front turning frames A', keyed at A³ on
the spindle B, three bars being shown as formed in each section a of the sets A ;
and the whole set formed as six sections a each mounted at their ends by a slot
formed on the central feather of the front and back end frames A', as shown in plan
and edge section detached to an enlarged scale in Figures 5 and 6. And by these

page_text: improvements the frames A A' of furnace bars a may be made of such a depth as to
be reversible, that is, by making the bars a and recesses parallel they can be
swivelled on their centre axes B, B, right round to make the previous under side to
be the top side. And the top and bottom edges of these bars would preferably be
made of rounded section on each side towards their intermediate recesses. Each
set A, A', of furnace bars is locked by a sliding pin or cotter a' in the outer end
sets of bars cach cotter a¹ being secured by a steel screw pin a². Each frame A, A',
of bars is locked in its horizontal position by a sliding spindle reciprocated through
anugs in the drum plate A", its point passing into a hole at 6' in each frame A', and
having its outer end jointed by a pin to the short arm 62 of a hand operated
lever 6, 6, fulcrumed on a bracket at 611 bolted to the front plate of the furnace,
and secured in its locked and unlocked positions by a pin and quadrant at 6ª.
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 :-
First. The construction or arrangement and combination of the parts and
mechanical motions of furnace fire grates, substantially as herein described in
reference to and shown in the accompanying drawings.
Second. The construction of furnace fire grates so that they can be swivelled on
central spindles or end axes to deposit the ashes, or be reversible, substantially as
herein described in reference to and shown in the accompanying drawings.
Third. The construction of swivelling or reversible furnace fire grates from
longitudinal bars built and bound together in portable sections, substantially as
herein described in reference to and shown in the accompanying drawings.
Dated the 29th May 1893.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.