Improvements in Furnace Damper Regulators.
Year: 1891

page_text: Improvements in Furnace Damper Regulators.
1, JOSEPH EDWIN WATTS, of 137 Oxford Street, Lawrence, in the County of
Essex, and State of Massachusetts, in the United States of America, Mechanic,
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:-
a
This invention relates to improvements in damper-regulators, in which
thermostat is employed to automatically control said damper and acts dependently
upon the amount of heat desired.
My invention is embodied in the peculiar arrangement of the several parts by
which the regulator can be adjusted to varying degrees of temperature within
certain limits, as may be desired or as circumstances dictate.
The drawings represent in Figure 1 a side elevation, and in Fig. 2 a front
elevation, of a boiler supplied with a regulator containing my invention. Fig. 3 is
a plan. In Fig. 1 the fulcrum bar or rod is shown in section.
In the accompanying drawings is shown a boiler at 2 adapted, preferably, for
hot-water circulation and system, and is composed of the usual principal parts-an
exterior shell 3, a flue 4, a feed-door 5, and an ash-door or damper 6. The latter
is controlled by a damper-regulator, which is composed of a metallic tube 7,
preferably one having a large coefficient of expansion. This tube is connected at
top and bottom with the boiler to permit free circulation of water or steam there-
through, and by the change in the temperature of such water or steam the position
of the damper or ash-door is regulated and the quantity of air admitted to the fire
is controlled. The lower part of this circulating tube or pipe 7 is closely fastened
to the boiler-shell, thereby rendering this point a fixed one, comparatively speaking.
On the other hand, the upper portion is connected by a separate section or elbow-
piece 8 in order to allow for the expansion which is to occur at this end, which is
intended to be a free end. Secured to each end of this tube 7 are plates or
brackets 9, in which is supported the "contact-post " 10, so termed. This latter is
to be made, preferably of wood, with the grain lengthwise, and in which the coefficient
of expansion is a minimum. The ends of this post are capped with metal, the lower
cap 12 being exteriorly screw-threaded and adapted to engage in the lower plate 9,
while the upper one 13 is furnished with a pin 14, moving freely through a hole in
the upper plate 9, said pin terminating in a knife-edge. Exteriorly about this post
is slipped a loose sleeve 20, which is simply to strengthen the post 10 and prevents
it from buckling, but otherwise has no effect upon the action of the said post.
Surmounting the tube 7 and affixed thereto is a support or standard 15, in which
a lever 16 is pivoted, said lever carrying a counter-balance-weight 17 at one end
and being at the other end connected by a chain or other continuous band 18 with
the damper 6. This weight is adjustable upon the lever and is to be changed in
position according to the weight of the damper and renders the latter perfectly
balanced. In this way no work is placed upon the thermostat, but the latter is
free to operate according as the temperature varies in the circulating-tube 7.
Before describing the operation of the above mechanism it is to be understood
that when the boiler is not in use the damper is open, while the lever is in such
position that it rests upon the knife-edge at the extremity of the fulcrum-post 10.
This adjustment may be effected by regulating the length of the connecting-
chain 18, or, preferably, by axial rotation of the contact-post, which can be raised
or lowered in position by turning the lower cap 12, which is split or grooved to
admit a screw-driver or other suitable tool for adjustment.
The operation of the several parts is as follows, it being understood that the

page_text: damper is open, while the lower ends of both the circulating-tube 7 and the
fulcrum-post are fixed points. Assuming that the boiler has been fired, as the
heat of the water or steam passing through the tube 7 begins to expand it
longitudinally the upper free end rises and the lever 16 is lifted on the side
carrying the weight. As a consequence the damper is caused to swing and
partially close. As wood with the fibers lengthwise has little or no coefficient of
expansion, the length of the contact-post remains of a fixed length, while the
expansion and contraction of the tube 7 serve to rock the lever 16, which operates
to close the damper as expansion ensues and opens when contraction takes place.
The ends of this post 10 are capped in order to have the least amount of metal
possible in the construction of said post. In lieu of wood a metallic post may be
employed, the only condition, however, being that its coefficient of expansion shall
be less than that of the tube 7.
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. The combination, with the boiler, of a circulating-tube free to expand at one
end, a lever supported by said tube, a contact-post having a lesser coefficient of
expansion than the said tube and arranged to engage said lever near the fulcrum
of the latter, a damper, and a connection between said lever and said damper.
2. The combination, with the boiler, of the circulating-tube 7, connected with
said boiler and free to expand at one end, the plates 9, attached to said tube, a
contact-post having a lesser coefficient of expansion than the said tube and attached
at one end to one of said plates and passing freely through the other of said plates
to engage the said lever, a damper, and a connection between said damper and
said lever.
3. The combination, with the boiler, of the circulating-tube 7, the plates 9,
attached to said tube, a contact-post 10, having a lesser coefficient of expansion
than said tube and arranged to engage the said lever near its fulcrum, said post
being adjustably secured at its lower end to one of said plates and passing fr
its upper end through the other of said plates, a damper and a connection ....
said damper and said lever.
4. The combination, with the boiler, of the circulating-tube 7, attached to said
boiler at one end and free to expand at the other, a lever supported by said tube,
a contact-post having a lesser coefficient of expansion than the said tube and
arranged to engage said lever near its fulcrum, a damper, a connection between
said damper and said lever, and an adjustable weight on said lever to counter-
balance said damper.
5. In a damper-regulating mechanism, a wooden contact-post arranged to engage
the damper-operating lever and provided with a metallic sleeve loosely but rather
closely surrounding said post and serving to stiffen the latter and prevent it from
bending or buckling when subjected to strain.
December 8th 1891
JOSEPH EDWIN WATTS,
Lawrence, Mass.