вход по аккаунту


Патент USA US2137581

код для вставки
Nov. 22, 1938.
Filed Nov. l, 1937
Patented Nov. 22, 1938
William M. Myler, Jr., Columbus, Ohio, assignor
to Surface Combustion Corporation, Toledo,
Ohio, a corporation of New York
Application November 1, 1937, Serial No. 172,179
1 Claim. (Cl. 126-110)
'I'his invention relates to improvements in space
heaters of the type embodying a gas-fired radiator,
a fan for blowing air past the radiator where
by to heat the air, a room thermostat for start
5 ing and stopping the motor which drives the
fan and means for shutting off the burner when
tion is applied to a heater of the type shown in
Fig. 1.
The space heater is shown as comprising a
combustion chamber IIl whose top side is in open
communication with a plurality of radiator'tubes 5
II of relatively thin sheet metal, the tubes being
there is no call for heat. In space heaters of arranged in laterally spaced relation to form air
this type and more particularly in so-called “unit ‘ passages therebetween. The upper ends of said
heaters” adapted to be hung near the ceiling of tubes open into an exhaust chamber I2 from which
10 the enclosure to be heated, the radiator is usually leads an exhaust flue I3 for conducting the gases
made of relatively thin sheet metal and is, there
of combustion to a point outside of the enclosure
fore, relatively easily damaged by overheating. where
The most usual cause of overheating is failure of being shown as having anopening I4 open to the
the burner gas valve to close when the fan stops
of the enclosure with a result that the
running. such failure usually being due to the atmosphere
chamber also serves as a draft diverter. In the
valve having become dirty or gummy from the combustion chamber I0 is a gas burner I5 to which
fuel gas. Various schemes have been proposed the flow of gas is controlled by a gas valve I6
to overcome the danger of the main gas valve fail
ing to close when it should, but all such schemes
20 of which I am aware have proceeded on the as
sumption that it was absolutely necessary to shut
off the gas to the burner.
The object of the present invention is to pro
vide a relatively simple and practical way of over
25 coming the danger of damage to the radiator in
case the burner gas valve fails to close the way
it should. According to the present invention,
no special means are provided to insure that the
supply of gas to the burner shall be cut off in case
30 the main gas valve fails to function normally.
Briefly stated, what I do is to provide means, in
dependent of the room thermostat, for causing
the fan to operate in case the burner gas valve
fails to close the way it should. By thus causing
35 the fan to operate, the flow of air produced by the
fan will keep the radiator suñiciently cool to pre
vent its being damaged. Moreover, the means
which I employ is such as to cause the fan to
start and stop periodically, thus calling attention
40 to the fact that the heater is not operating in a
'normal way.
For a more complete understanding of the in
vention reference is made to the detailed descrip
tion taken in connection with the accompanying
45 drawing, wherein the preferred form of the ‘in
vention is shown.
in a gas supply I'I.
The pilot for the burner is
indicated at I5'. I8 indicates a fan for blowing
air past the radiator tubes whereby to heat the 20
air passing therebetween; and I9 indicates ad
justable air deflectors at the air exit side of the
radiator. The fan is driven by a motor 20 sup
ported on a bracket 2I secured to the framework
of the heater.
At the discharge side of the fan is hung a freely
movable vane 23 which, when the fan is running,
is held by the force of the air from the fan in
such position that it will cause a mechanism (not
shown in Fig. 1) to open the gas valve I6 with 30
resultant flow of fuel to the burner.
A unit heater of the type described is well
known in the art and per se forms no part of the
present invention. It remains to be said that a
room thermostat controls the application of power 35
to the fan motor.
One of the essential elements of the present in
vention is a safety thermostat which is so 1o
cated as to be responsive to the temperature of a
heated part of the heater itself. In Fig. 1, the
most convenient and preferred position is indi
cated by the rectangle 25', this position being ad
jacent to the wall III’ of the combustion chamber
I0. As will more fully appear hereinafter, the
function of said thermostat is to cause the fan 45
I8 to run for a period and then stop in case the \
gas burner does not shut oil’ when the room
Fig. 1 is a side elevation of a type of space thermostat moves to no-call-for-heat position.
heater with which the invention has special utility, The said safety thermostat is indicated at 25 in
5o parts of the heater being in section and certain Fig. 3 and, for purposes of illustration rather
other parts being more or less diagrammaticallyy than limitation, has been shown as comprising a 50
Fig. 2 is a fragmentary sectional view of line
2-2 of Flg. 1, and
Fig. 3 is a diagram illustrating how the inven
bimetal disc supported by spacer brackets 39 se
cured to the said wall I0'. Thermostats of this
type operate with a snap action and are well
known in the art.
In the layout of the controlling mechanism
shown in Fig. 3 the mechanism for opening the
gas valve I5 is shown as including a solenoid 30
in a power circuit 3l which also includes two
switches 23' and 32, the s'witch 23' being oper
atively connected to the vane 23 for operation
thereby. In the position of the parts shown in
Fig. 8, the gas valve is supposed to be stuck open
and not positively held open by power applied to
10 the solenoid.
The normal power circuit for the
fan motor 20 is indicated at 33. In this circuit
is a switch 34 which is operatively connected to
a temperature controller or room thermostat 35
in such a way that when the controller calls for
15 heat the switch will be moved to closed position
and thereby admit power to the fan motor 20.
35 indicates another power circuit which shunts
out Ythe switch 34. In this circuit 36 is a switch
31 shown as closed. 'I‘his switch 31 is operatively
connected to the safety thermostat 25 as by a
stem 33. When the switch 31 is closed, it means
mined maximum and that after it has been actu
ated, it will remain in actuated position long
enough to permit the temperature of the wall to
reach a predetermined minimum which may be
the maximum temperature that prevails under
normal operating conditions.
Although it is preferred that the switch 32 be
provided for preventing the application of power
to the solenoid 30 when the safety thermostat 25
is actuated to close the switch 31 and thereby to 10
start the fan going, nevertheless it is within the
spirit of the invention to omit the switch 32 and
make the power line 3l continuous except for the
switch 23' which is actuated by the vane 23. In
such event power would, of course, be applied to 15
the solenoid 30 when the fan is running with the
result that the valve I6 would not be free .to close.
However, in such case, if the condition of the
valve i6 is such that it would normally close
when power was not applied to the solenoid, it 20
would have an opportunity of closing when the
that the safety thermostat 25 has been actuated
due to the excessive temperature prevailing at
safety thermostat 25 moved back to inactive
the combustion chamber wall ill'.
It will now be seen that when the switch 31 is
closed, power flows to the fan motor 20 which is
the same thing as saying that the fan I8 is run
I also wish to state that although the inven
tion has been shown in connection with electric 25
>power means for opening the gas valve, never
theless it is equally adapted for use in connec
tion with space heaters having means other than
electrical means, for example gas operated means,
for opening the gas valve. It is, therefore, to be 30
ning. Although when the fan is running the
vane 23 operates to close the switch 23', never
theless power is not applied to the solenoid 30 by
reason of the fact that the switch 32 is open.
'I‘his switch 32 is shown as mounted on the same
stem 33 as the switch 31. After the fan I8 has
been running for a relatively short period, the
air from the fan will cool the wall I0' of the com
bustion chamber to such degree that the thermo
stat 25 will snap back into its normal position
with consequent opening of the switch 31 and
closing of the switch 32. If the gas valve i6 still
remains in stuck open position and the room
40 thermostat 35 does not close the switch 34 in the
meantime, the wall I0' will again become sum
ciently hot to cause the thermostat 25 to operate.
This periodic starting and stopping of the fan
by the safety thermostat 25 will, of course, indi
45 cate that something is wrong with the normal
operation of the heater.
It will be understood from the foregoing that
the safety thermostat 25 will remain in normally
inactive position as long as the combustion
chamber wall Il' does not exceed a predeter
understood that no limitations are intended ex
cept as may be expressed in the appended claim. I
What I claim is:
In apparatus comprising a fuel-fired radiator,
' and a fan for causing air to flow over the radiator
whereby to abstract heat therefrom, and a main
control switch for starting and stopping the fan,
and a fuel supply valve for the radiator, said
valve being normally closed when the fan is not
running, and means dependent on the operation
of the fan for opening the fuel valve, the combi
nation of means for preventing the radiator from
overheating in case the fuel valve sticks open
after the fan has been shut oiI by said control
switch, said means comprising means responsive
to an abnormal heat condition at the radiator
for automatically re-applying power to the fan
whereby to cause the air from the fan to abstract
heat from the radiator as long as said abnormal
heat condition exists.
Без категории
Размер файла
287 Кб
Пожаловаться на содержимое документа