Improvements in Furnace Doors.
Year: 1895

page_text: Date of Application, 6th Aug., 1895-Accepted, 14th Sept., 1895
Improvements in Furnace Doors.
I, DAVID EPHRAIM ROBINSON, of Arden, in the County of Barbour, and
State of West Virginia, United States of America, Gentleman, 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:-
My invention relates to an improvement in furnace doors or more particularly the
means for opening and closing the doors of a furnace. The object of my invention
is to provide neans within convenient reach of the fireman or furnace attendant
whereby he may be enabled to instantly open and close the doors of the furnace at
will, and thus prevent continuous drafts of cold air from entering and chilling the
boiler tubes.
While my invention is especially useful in and applicable to locomotive fire boxes,
it is equally applicable to stationary or marine boiler furnaces.
It consists in certain features and details of construction, and arrangement of
parts hereinafter specifically described, and pointed out in the claims.
In the accompanying drawings
:-
Figure 1 is a perspective view of a portion of a fire-box showing the furnace
doors, and means, constructed in accordance with my invention, for opening and
closing said doors, the floor or platform being broken away for the purpose.
Figure 2 is a rear view looking from the interior of the furnace, showing the
sliding doors, operating levers, and their connections.
Figure 3 is a detail perspective view of the releasing mechanism, and the
rock-shaft, and connections for operating the same.
Similar numerals of reference indicate corresponding parts in the various figures
of the drawings.
1 represents a portion of the front wall, broken away, of the furnace or fire-box;
2, 2, the doors thereof made in two separate and independent sections, as shown in
the drawings. The door sections 2, 2, slide in suitable horizontally-arranged ways
or tracks attached to the front of the furnace in the manner well understood. As
the doors 2, 2, are ordinarily quite heavy, weighing from 30 to 50 pounds, or even
more, I piefer to mount said doors upon suitable rollers, located beneath the same,
in the lower track or way attached to the front of the furnace. The door sections
are each made double or have an inner and an outer plate with an intervening air
space, and are provided each with a pin or pivot 3 therein adapted to be engaged
by the operating levers 4, 4, the upper ends of which are slotted and adapted to lie
between the inner and outer plates of the doors and to engage said pivots.
The levers 4, 4, extend downwardly to a point beneath the line of the floor or
platform, and are pivoted at 5, 5. At their lower extremities the levers +, 4, are
connected by two pivoted arms or links 6, 6, which are, in turn, pivoted together
at a central point by a horizontal pivot 7, thus forming toggle levers. 8 indicates
a horizontal lever pivoted at its forward end at 9 to the platform framework or
other connecting point. This lever extends from thence rearward and is
connected at its rear end to the central pivot of the toggle levers 6, 6, by
means of a link 10, also pivoted to said horizontal lever. At a point intermediate
the ends of lever 8 the latter has pivoted to it a vertical post 11 extending
upward through a perforation or opening in the platform upon which the attendant

page_text: stands. This vertical post is provided with an enlargement or foot piece upon its
upper end, by means of which it is adapted to be depressed by foot power.
12 indicates a strong flat spring secured beneath the platform and having a
bifurcated end adapted to engage trunnions 13 extending laterally from the
vertical post 11 whereby the latter and the parts connected therewith are held and
the doors kept closed, as will hereinafter appear.
14 indicates a notch or depression in one face of the vertical post 11, and
15 indicates a catch or latch bar adapted to engage the notch 14 when the post 11
is depressed for holding said post 11 in such depressed position. The catch 15 is
preferably pivoted to a lug 16 on the framework and its other end is connected
pivotally with a sliding rod 17 sliding in suitable ways 18 secured to convenient
points beneath the platform. The opposite end of the rod 17 is pivotally connected
with a crank-arm 18, on a horizontal rock-shaft 19 as shown. The rock-shaft 19
is provided with additional crank-arms 20, 21, and 22.
23 indicates a vertical post extending upwardly through the perforation or
opening in the platform above which it is provided with a flange or foot piece
similar to, but preferably smaller than, the foot piece on the post 11. The lower
end of the post 23 rests upon, and is pivoted to the crank-arm 22 of the rock-
shaft 19. 24 indicates a vertical post or standard rigidly secured upon the
platform and extending upwardly therefrom, and 25 a hand lever pivoted to said
vertical post 24. A vertical rod 26 attached to said hand lever 25 extends
downwardly through the platform and is connected to the end of the crank arm 20
on the rock shaft 19. 27 indicates a flat spring secured to the lower face
of the platform, and 28 a rod or chain interposed between and connecting the free
end of the spring, and the crank arm 21 of the rock shaft 19.
The operation of the device is as follows:- -When it is desired to open the doors
of the furnace, the attendant presses his foot upon the upper end of the vertical
post 11, which acts to depress the horizontal lever 8, thereby causing the latter to
act upon the toggle levers 6, 6, which act to draw the lower end of levers 4, 4,
together and thrust the upper ends of said levers apart, thereby opening the
doors 2, 2. When depressed in this manner the pivoted catch 15 engages the
notch 14 in the vertical post 11, said catch 15 being operated by the tension of
the spring 27 through the interposed connections consisting of the crank arms 21,
and 18, the rod 17 and the rod or chain 28. Thus the doors are held open. To
close the doors, the attendant depresses the post 23 which acts upon the crank-
arm 22 of the rock shaft 19 thereby operating through the crank-arm 18 and rod 17
to push the catch 15 out of engagement with the vertical post, and the strong
spring 12 will exert its tension to return the parts to their normal position and close
the doors. The catch may be released in another way by pulling up on the hand
lever 25 thereby operating through the rod 26, crank 20, rock-shaft 19 crank 18°,
and rod 17 to throw said catch out of engagement with the post 11. By means of
the construction above described it will be apparent that the doors may be quickly
thrown open and instantly closed by means within convenient reach of the fireman,
engineer, or other attendant. This operation will occupy but a few seconds and
the fire may be readily kept up without the necessity of having the doors open for
any considerable period of time. This is very important and for the reason that
it is almost impossible to keep a sufficient head of steam in a locomotive for
propelling a heavy train up a long grade where the doors are allowed to remain
open and the boiler tubes exposed to cold drafts of air.
By means of my invention the fireman having filled his shovel with coal, steps
to the doors of the furnace and pressing upon the top of the post 11, quickly
throws open the doors and feeds coal to the furnace, when by letting his shovel fall
upon the top of the post 23, or by pressing thereon with his foot, the doors are
instantly closed.
Various changes in the form, proportion and the minor details of construction
may be resorted to without departing from the principle or sacrificing any of the
advantages of this invention.

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
1. A furnace door comprising twin halves or sections each composed of front
and rear plates and mounted in suitable horizontal tracks or ways adapting said
sections to move laterally in a horizontal plane, in combination with the pivoted
and spring-actuated levers arranged with their ends between said plates and slotted
to engage pins also arranged between said plates for operating the door sections,
and one or more foot levers for operating said door levers, substantially as
specified.
2. A furnace door made of two halves or sections and arranged to move in a
horizontal plane between suitable ways or tracks, in combination with a pair of
pivoted levers connected with said sections for opening and closing the same, a
forwardly extending horizontal lever for operating said door levers, a foot post or
standard counected with said horizontal lever and extending to a point within
convenient reach of the attendant and a spring-actuated catch for holding the door
sections open, substantially as specified.
3. The combination with a furnace door made in two sections, of two vertical
levers for opening and closing the same, a horizontal lever connected with said
vertical levers for operating the same, a spring-actuated catch for holding the door
sections open, and a releasing mechanism consisting of a rock-shaft and a push-rod
connected with said spring-actuated catch for closing the door sections, substantially
as specified.
4. The combination with a furnace door made in two sections and provided with
trunnions or pivots, of two vertical levers slotted at their upper ends to engage
said pivots, a pair of pivoted links or toggle-levers connecting the lower ends of
said vertical levers, a horizontal lever for operating said toggle lever, a foot post
for depressing the horizontal lever and a catch for engaging said foot post, as and
for the purpose substantially specified.
5. A furnace door made in two sections adapted to be moved laterally in a
horizontal plane, means for opening and closing said door sections, and a pivoted
catch for holding the same open, in combination with a rock-shaft provided with a
crank-arm, a rod interposed between said crank-arm and the pivoted catch, and
means for operating said rock-shaft, in the manner substantially as specified.
6. A furnace door made in two sections, means connected therewith for
opening and closing the same, and a spring-actuated catch for holding the
door sections open, in combination with a rod for releasing the catch, a rock-
shaft provided with a crank-arm for operating said rod, a vertically-extending
rod connected with a crank-arm on the rock-shaft and passing up through the
floor or platform, and a pivoted hand lever connected to said vertical rod,
and located within convenient reach of the engineer or fireman, substantially as
specified.
Dated this 6th day of August 1895.
BOULT & WADE,
Agents for the Applicant.