IMPROVEMENTS IN AND RELATING TO SELF-CLEANING FURNACES
Year: 1876

page_text: LETTERS PATENT to Thomas Henderson, of 13, Harland Road, Birkenhead, in
the County of Chester, Engineer, for the Invention of "IMPROVEMENTS IN AND
RELATING TO SELF-CLEANING FURNACES."
Sealed the 28th March 1877, and dated the 2nd October 1876.
PROVISIONAL SPECIFICATION left by the said Thomas Henderson at the
Office of the Commissioners of Patents on the 2nd October 1876.
THOMAS HENDERSON, of 13, Harland Road, Birkenhead, in the County of Chester,
Engineer. "IMPROVEMENTS IN AND RELATING TO SELF-CLEANING FURNACES."
This Invention consists of improvements and in additions to my self-cleaning
furnace described in Specification No. 1529, of 1875. It is more especially designed
to work by itself without the aid of a mechanical stoker. A horizontal shaft, driven
in any suitable manner, runs along the front of the furnaces. Upon this, opposite
each furnace, is a crank or excentric and strap working the actuating bar to be
bereafter described. The strap of the connecting link or excentric is made with
copious room so that the top brass or nut can freely slide therein, and a screw or
other regulator regulates the position of the said nut in such manner that the crank
pin can freely turn without moving the strap and rod, or moving it to any required
extent, depending upon the play given.
The actuating bar linked to the connecting link, as well as the horizontal
reciprocating bars hereafter described, rest at each end on fixed supports or rollers.
Both have also a notch cut in them in which the vertical flange of the bell-crank
shaft works, with this difference, however, that while the notch of the actuating
bar is made with a proper bearing and strap fitting the flange without appreciable
play, the notches of the other bars have very considerable play, so that they can
remain stationary while the bell crank moves through a small arc (raising the
vertical moving bars a short distance) and then be themselves moved also. I usually
omit the bell crank at the rear end, using two fixed supports (water tubes or other-
wise) instead.
The vertically moving bars are pretty much the same in front as in my old
Patent, resting on the horizontal flange of the bell crank. At the rear ends, however,
the horizontally moving bars end abruptly above their support.
The vertically moving bars also are stepped down vertically an inch or more,

page_text: sometimes perhaps six or seven inches, at the point parallel to that at which the
horizontal bars end when as far forward as they can go. Below this the vertically
moving bar (vertically moving only at the front end) is widened out with horizontal
flanges, so as to almost or quite touch the next similar bar, forming thus a flat dead
surface with very small or no air spaces between. The ends of the horizontally
moving bars project over this dead plate, and as the klinker is brought forward
into it at every stroke, propell the said klinker forward. The support of these,
longer bars is usually a water tube, a solid bearer can however be substituted.
To this bearer is usually hinged a hanging door protected like the bearer with fire-
brick blocks on the back side, a chain from this door passing through an eye in
the back bearer of the horizontally moving bars is brought to the front of the
furnace so as to be actuated by hand when desirable. A water bridge, a foot or
more beyond the end of the bars, completes the apparatus,
The manner of working is as follows:-The crank rocks the connecting crank
and the actuating bar, which in turn rocks the (front) flanged bell crank; this lifts
up the vertically moving bars above the others. When the horizontal moving bars
are brought back to the front on the action of the bell crank being reversed, the
vertically moving bars sink to or below the horizontally moving bars when these
latter come into play, moving on the fuel and at the same time pushing forward the
klinker in front of their ends on the "dead surface;" this shoves the klinker forward
till a part falls down between the water bridge and hanging door. Occasionally
when this space gets partially-filled, especially in the early morning, the door is
raised and the contents cleaned out.
I sometimes arrange the apparatus with two independent bearers in front instead
of two flanges, and so arrange them that one bearer shall bring all the bars to the
rear together and then half of them to the front, the other bearer after a short
interval bringing back the remainder.
The object of putting a roller at the front end, and stationary supports at the rear,
are as follows: To prevent friction in front I use the rollers; to prevent the
horizontally moving bars moving with the actuating bar at a wrong time I prefer
to use a stationary support for them at the rear. The rear support of the longer
bars is simply a fulcrum for the bars to rest on, not slide over; and in some boilers,
as in egg-ended and other externally fired boilers, I make it of a water tube, one
end of which is brought from near the bottom of the boiler, the other from about or
above the water line. This difference in height induces a vigorous circulation.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Thomas Henderson in the Great Seal Patent Office on the 31st March
1877.
THOMAS HENDERSON, of 13, Harland Road, Birkenhead, in the County of Chester,
Engineer. "IMPROVEMENTS IN AND RELATING TO SELF-CLEANING FURNACES."
Fig. 1 is a front view of boiler with bars attached; Fig. 2, transverse section of
same; Fig. 3, longitudinal section; and Fig. 4, sectional plan through flues.
This Invention consists of improvements in and additions to my self-cleaning
furnace described in Specification No. 1529, of 1875. It is more especially designed
to work by itself without the aid of a mechanical stoker. A horizontal shaft A,
driven in any suitable manner, runs along the front of the furnaces. Upon this,
opposite each furnace, is a crank B (or excentric and strap) working the actuating
bar C to be hereafter described. The strap D of the connecting link E or excentric
is made with copious room, so that the top brass or nut F can freely slide therein,
and a screw or other regulator regulates the position of the said nut in such manner
that the crank pin can freely turn without moving the strap and rod, or moving it
to any required extent, depending upon the play given.

page_text: The actuating bar C linked to the connecting link E, as well as the horizontal
reciprocating bars K, K, hereafter described, rest at each end on fixed supporters or
rollers L, M. Both have also a notch cut in them in which the vertical flange N of
the bell-crank shaft P works, with this difference, however, that while the notch of
the actuating bar C is made with a proper bearing and strap fitting the flange
without appreciable play, the notches of the other bars have very considerable play,
so that they can remain stationary while the bell crank moves through a small arc
(raising the vertical moving bars J, J, a short distance), and then be themselves
moved also. I usually omit the bell crank at the rear end, using two fixed
supports Q, R, (water tubes or otherwise instead).
The vertically moving bars J, J, are pretty much the same in front as in my old
Patent, resting on the horizontal flange N¹, of the bell crank; at the rear end,
however, the bars K, K, end abruptly above their support."
The alternate bars J, J, also are stepped down vertically an inch or more, some-
times perhaps six or seven inches, at the point parallel to that at which the
horizontal bars end when as far forward as they can go; below this the bars J, J,
(vertically moving only at the front end) are widened out with horizontal flanges,
so as to almost or quite touch the next similar bar, forming thus a flat dead surface
with very small or no air spaces between. The ends of the alternating bars K, K,
project over this dead plate, and as the clinker is brought forward on to it at every
stroke, propell the said clinker forward. The support of these longer bars is usually
a water tube, a solid bearer as shown in the Drawings at R can however be
substituted. To this bearer R is usually hinged a hanging door S protected like
the bearer with fire-brick blocks on the back side; a chain T from this door passing
through an eye in the back bearer Q of the horizontally moving bars K, K, is
brought to the front of the furnace so as to be actuated by hand when desirable. A
water or other bridge U, a foot or more beyond the end of the bars, completes the
apparatus.
The manner of working is as follows:-The crank B rocks the connecting link E
and the actuating bar C which in turn rocks the (front) flanged bell crank P. This
lifts up the vertically moving bars J, J, above the others when the horizontally
moving bars K, K, are brought back to the front. On the action of the bell crank
being reversed, the bars J, J, sink to or below the bars K, K, when these latter
come into play, moving on the fuel and at the same time pushing forward the
clinker in front of their ends on the dead surface. . This shoves the clinker forward
till a part falls down between the water bridge and hanging door. Occasionally
when this space gets partially filled, especially in the early morning, the door is
raised and the contents cleaned out.
I sometimes arrange the apparatus with two independent bearers in front instead
of two flanges, and so arrange them that one bearer shall bring all the bars to the
rear together and then half of them to the front, the other bearer after a short
interval bringing back the remainder.
The objects of putting a roller at the front end and stationary supports at the rear
are as follows:-To prevent friction in front I use the rollers; to prevent the
horizontally moving bars moving with the actuating bars at a wrong time I prefer
to use a stationary support for them at the rear. The rear support of the longer
bars is simply a fulcrum for the bars to rest on, not slide over; and in some boilers,
as in egg-ended and other externally fired boilers, I make it of a water tube, one
end of which is brought from near the bottom of the boiler, the other from about or
above the water line. This difference in height induces a rigorous circulation.
Having now described my Invention, and the best mode known to me of carrying
it into effect, I wish it to be understood that what I claim as my Invention under
the herein-before in part recited Letters Patent is,―
1st. The combination of the bars K, K, moving approximately horizontally
with the alternate bars J, J, moving approximately vertically, operating sub-
stantially as described.
2nd. The combination of the rear dead plate formed of the broad flanges of

page_text: alternate fire-bars with the short ends of the horizontally reciprocating bars K, K,
for the purposes described.
3rd. The mechanism consisting of link E with crank B, and adjustable strap for
the purposes described.
4th. The general arrangement of furnace, substantially as described.
In witness whereof, I, the said Thomas Henderson, have hereunto set my
hand and seal, this Twenty-seventh day of March, in the year of our Lord
1877.
Witness,
W. P. THOMPSON,
British and Foreign Patent Agent,
6, Lord Street,
Liverpool.
(L.S.) THOMAS HENDERSON.