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Патент USA US3072347

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Jan. 8, 1963
Filed Dec. 24, 1959
United States Patent ()?iice
Patented Jan. 8, 1953
control action and a snap closing ‘action are obtained
using a single needle valve or a single valve similar to a
Richard D. tGrayson, La tCanada, Caliih, assignor to Gen
eral (Jontrols 0a., Glendale, Qali?, a corporation of
needle valve.
Another object of the present invention is to provide an
improved thermostatically operated valve which is par
ticularly useful in a system of this character.
Filed Dec. 24, 195% Ser. No. 361,310
3 Claims. (til. Z36—-—32)
Another object of the present invention is ‘to provide
a gas control of this character in which the ?ow of gas
The present invention relates generally to a thermo
is continuously modulated from a predetermined maxi
statically controlled valve and particularly one which 10 mum rate to a predetermined minimum rate and in which
controls the ?ow of gas to the top‘ burner of a gas stove
the ?ow of gas is abruptly shut ‘off when the demand for
having a heat-sensing element in contact with a cooking
gas tends to fall below such predetermined minimum
utensil on such burner although in its ‘broader aspects the
present invention is applicable to other gas-controlled
Another object of the present invention is to provide
heating systems such as, for example, room heater controls
a control of the character set ‘forth in the preceding para
and the like.
graph in which adjustable means are provided for adjust
One of the main problems encountered in a top burner
ing such predetermined maximum rate.
thermostatic control ‘arises from the fact that a relatively
Another object of the present invention is to provide
small gas ?ow must be controlled to maintain a constant
a gas control of the character set forth in the two preced
temperature of, for example, 200° F. in a small cooking 20 ing paragraphs in which the ?ow velocity of gas passing
vessel on the burner, such gas ?ow being usually less than
through the outlet ori?ce is a substantially constant value
a ?ow of 800 B.t.u. below which ‘the burner ?ame tends
during its modulation in the range between such maximum
to ?utter and become extinguished.
and minimum values.
Previous attempts have been made to solve this problem
Another object ‘of the present invention is to provide
by modulating the burner from ‘an “On” condition to an 25 an improved gas control of this character ‘for a burner
“Off” condition, ie in the range between 800‘ Btu. and
having associated therewith a venturi section for inspirat~
O B.t.u., while maintaining a small stand-by pilot ?ame
ing air, the control being characterized by a single mov
adjacent to the burner ports. As the gas flow is modu
able valve element for continuously modulating the flow
lated up ‘and down in the range between 800 and () 31.11.,
of gas into such venturi section at a substantially constant
the burner operation is erratic ‘and raw gas is usually re
30 speed within the range of continuous modulation.
leased, resulting in an objectionable gas odor due, for
Another object of the present invention is to provide
example, to the aldehydes therein which have a distinct
a control as set forth in the preceding paragraph in which
and powerful ‘odor. This condition may also lead to “?ash
such single movable valve element is operated to a closed
back” with the gas igniting at the burner ori?ce and fur
position with a snap action when the demand for gas falls
ther to additional combustion problems resulting from
below a predetermined minimum rate.
the loss of gas velocity at the ori?ce at very low inputs
Another object of the present invention is to provide a
due to throttling of the ‘gas upstream from the ori?ce.
gas control of this character for maintaining a substan
In accordance with an important feature of the present
tially constant temperature in the vicinity of a gas burner,
invention, a single valve is used to accomplish both a
there being provided for this purpose thermostatic means
modulating and snap-controlling action. lnaccordance
responsive to temperature in the burner for continuously
with prior art practice two valves are provided, i.e. a
modulating the rate of gas flow between a maximum and
a minimum value with such thermostatic means func
tioning also to cause the valve to snap to closed position
when the demand for gas tends to fall below such mini
modulating valve for operating between minimum and
maximum ?ame, and a second snap valve for snapping
off the minimum ?ame.
Such single valve, in accordance with features of the
present invention, is temporarily restrained from further
closing movement when the minimum ?ame position has
been reached; and further increase in temperature caused
by gas escaping in such minimum ?ame position causes
a build-up of forces which eventually overpower the re
straining member. As soon ‘as the restraining member
starts to yield, there is sufficient stored energy in the
various resilient portions of the mechanism to cause the
valve to snap to the closed position. Subsequently, as
the temperature drops, the closing forces relax to the
point where the magnet is capable of abruptly opening
mum value.
Another object of the present invention is to provide
a gas control of this character which incorporates ad
justable means for establishing such substantially constant
The features of the present invention which are believed
to be novel are set forth with particularity in the ap~
pended claims. This invention itself, both as to its or
ganization and manner of operation, together with further
objectsand advantages thereof, may be best understood
by reference to the following description taken in con
nection with the accompanying drawings in which:
the valve to the minimum flame position.
It is therefore an object of the present invention to
provide an improved control system of this character
corporating features of the present invention'
which overcomes the above-indicated difficulties encoun
cally operated valve shown in FIGURE 1.
tered in the prior art arrangements.
A speci?c object of the present invention is to provide
an improved system of this character in which a thermos
statically controlled valve is incorporated featured by
the fact that substantially full velocity of the ori?ce
stream is maintained at all inputs.
Another object of the present invention is to provide a
control system of the type indicated‘ in the preceding par
agraph in which the valve is a needle valve or a valve
similar to a needle valve.
FIGURE 1 illustrates a top burner control system in
FIGURE 2 illustrates more details of the thermostati
in FIGURE 1 there is illustrated a top burner 19 for
a conventional household cooking stove which incorpo
rates, in conventional manner, a centrally positioned
spring-biased temperature-sensing element ill for contact
ing and sensing the temperature of the bottom of a cook
ing vessel (not shown) resting on such burner.
Also associated with such burner litl is a small pilot
burner (not shown) which is continuously ignited to as
sure burning of all of the gas controlled by the valve struc
ture l2 constructed and functioning novelly in accord
Another object of the present invention is to provide a 70 ance with important features of the present invention.
valve arrangement of this character in which a modulating
This valve structure indicated generally at 12 in FIG
to limit upward movement of lever 32 to a position
wherein it may be again attracted upon subsequent “de
?ation” of bellows 28, in which case the valve 13, 14
is opened with a snap action.
URE 1 involves a movable needle valve element 13 co
operating with its ?xed valve seat 14 for controlling the
flow of gas into the air-gas mixing chamber 15 leading to
the venturi section 16 and the burning ports of burner
lit. The ?ow of air may be controlled by an adjustable
shutter 13 surrounding the chamber 15.
As the gas flow is reduced by forward movement of
the needle valve element 13 in its ori?ce 14, substantially
full velocity of the gas stream through such ori?ce is
The lever 32 thus acts as a temporary stop or abut~
ment at a predetermined gas flow rate corresponding to,
for example, 880 Btu. and should the sensing element
still continue to call for a smaller rate of gas flow, the
valve 13, 14 is closed with a snap action to allow the
maintained, assuring proper air inspiration and optimum 10 heated vessel and sensing element to cool to a tempera
ture at which the valve 13, 14 is reopened with a snap
?ame characteristics at reduced B.t.u. inputs. This needle
action resulting from the quick movement of the lever
valve element 13 is controlled thermostatically in re
32 back to its attracted position. In other words, ?ow
sponse to the temperature sensed by the sensing ele
of gas at rates less than 860 Btu is prevented but when
ment 11.
The ori?ce 14 is mounted in the valve body 2%)1 in such 15 the required input exceeds 890 B.t.u., the valve element
113 modulates between a full open position, established
a way that it injects a gas stream directly into the burner
by stem 151, and the 800 B.t.u. position established by the
venturi tube ltd, the gas being introduced into the cham
temporary stop lever 32.
ber 2%? through its threaded opening 21 which is in com
It will be noted further that the temperature at which
munication with the gas manifold 22 (FIGURE 1).
The stem of needle valve element 13 is guided in guide 20 such snap action of the valve 13, 14 occurs may be
adjusted by adjustment knob 26A, movement of the
?ns 24 which, of course, allow gas ?ow to the ori?ce ‘1d
stem 26 outwardly in the housing 29 serving to establish
and such element 13 is actuated by lever 25.
a lower operating temperature which is maintained sub
Lever 25 has one of its ends bearing on an adjustable
stantially constant in the manner described above with
stem or abutment 26 threaded in housing 2t} and the pre
stressed coil compression spring 29 acting between the 25 the valve 13, 14 being periodically snapped to closed
and open position. Conversely, movement of the stem
inwardly results in maintenance of a higher operating
temperature which may be suf?ciently high to permit
housing 24} and an intermediate portion of lever 25 presses
the same into engagement with both the stem 26 and the
movable lever seat 27 Which is positioned between lever
25 and the movable end of expansible bellows 28.
Bellows 28 is expanded in increased amounts with in 30
maintenance of a substantially constant temperature
without any snap action, i.e. by modulation alone be
creasing temperatures sensed by element 11 and details
of the same may follow conventional practices in which
tracted position of lever 32.
tween positions corresponding to stem 4-1 and the at—
While the drawings show my preferred form of a
a capillary tube 3t) ?lled with a suitable ?uid extends be
pointed needle valve cooperating with a mating tapered
tween the sensing element 11 and bellows 28.
It will thus be seen that upon increase in temperature 35 ori?ce, the form of the valve may be different, i.e. it
may comprise a small diameter rod projecting in vary
the lever 25 is pivoted counterclockwise (FIGURE 2)
ing degrees in a circular seat with, for example, a ?ange
about the adjustable abutment 26. The needle valve
on the rod cooperating with an adjacent circular seat
element 13 follows such movement of lever 25 since the
lower ?anged portion 13A of valve 13 is pressed into en
for full closure of the valve.
gagement with one end of lever 25 by the coil compres
Although the drawings show a magnet 36 for ac
sion spring 133 acting between element 13 and a thread
complishing the above-described purposes, it is under
ed portion of housing 20.
stood that other biasing means having a “negative spring
The lever 25 also under certain conditions is movable
rate” may be substituted therefor. Further, instead of
into engagement with the free end of the cantilever-sup
a needle valve as shown in the drawings, a small di
ported lever 32 to move it out of its normally attracted 45 ameter poppet valve could be substituted for the same.
position by magnet 36. Lever 32 is of magnetizable ma
While the particular embodiments of the present in
terial, has one of its ends anchored at ‘34 on the housing
have been shown and described, it will be obvi
Ztl, and is normally held in attracted position by perma~
ous to those skilled in the art that changes and modi?
nent magnet 36 on housing 2t} against the lower housing
50 cations may be made without departing from this in
stop member 38.
vention in its broader aspects and, therefore, the aim
In operation of the arrangement shown in FIGURE 2,
in the appended claims is to cover all such changes and
it is initially assumed that the sensing element 11 is in a
modi?cations as ‘fall within the true spirit and scope of
‘cold” but preheated condition, i.e. it “calls” for heat and
this invention.
the parts are in the positions illustrated. It is noted that
I claim:
in the extreme cold condition of element 11 the bellows 55
1. In means forming an ori?ce, a gas control system,
28 is “deflated” and the movement of lever 25 and needle
a burner, a single movable valve element in communica
valve element 13 is arrested by the threaded stem 41 of
tion with said burner and cooperating with said ori?ce
adjustable knob 40 which is preadjusted to establish the
to continuously control the ?ow of gas through said
maximum burner ?ame, i.e. the maximum opening be
tween valve element 13 and its ori?ce 14. As the tem 60 ori?ce to said burner over a range extending’ from a
maximum rate to a minimum rate which is substantially
perature of the sensing element 11 rises, the bellows 28
expands, however, still allowing the ?ow of gas through
greater than a Zero rate, an abutment, valve element
ori?ce 14 at substantially the same velocity but in smaller
quantity, i.e. smaller B.t.u. rate. As the temperature of
element 11 increases further, the lever 25 is moved into
engagement with the free end of the magnetically at
moving means comprising a lever having one of its
ends engageable with said valve element and the other
one of its ends engaging said abutment, thermostatic
'means associated with said burner and responsive to
temperature at said burner and engaging an intermedi
ate portion of said lever, spring means acting On said
70 lever at a point thereon between said abutment and
said intermediate portion to bias said valve element
away from said ori?ce, said thermostatic means moving
tracted lever 32 which then serves as a temporary stop for
further movement of lever 25 and the valve element 13.
Upon substantial further increase in temperature, the
force of attraction between the temporary stop 38 and
magnet 36 is overcome and the lever 32 is then free to
said valve element towards valve closing position upon
rise in said temperature condition, temporary abutment
A second permanent housing stop 24A may be provided 75 means for temporarily preventing movement of said
move to allow the valve element 13 to snap into closing
position in its ori?ce 14 to prevent further flow of gas.
valve element to its fully closed position after said
thermostatic means mOVes said valve element to a posi
tion corresponding to said minimum rate, means as—
sociated with said temporary abutment means and
operated by said thermostatic means for disabling said
temporary abutment means when said temperature con
dition assumes a predetermined maximum temperature
2. A control as set forth in claim 1 in which the ?rst
mentioned abutment is adjustable to pivot said lever
and move said valve element with respect to said ori?ce
to adjust said predetermined maximum temperature
3. A control as set forth in claim 1 in which an adjust
ment abutable abutment is in the path of movement of 15
said lever for engagement therewith to limit movement
of said valve element to adjust said maximum rate.
References Cited in the file of this patent
Colgate ____________ __ Apr. 11,
Shivers ____________ __ Sept. 6,
Mitchell _____________ ._ Aug. 30,
McCarty et al. ________ __ Oct. 4,
Matthews __________ __ Oct. 23, 1956
Hetherington ________ __ Apr. 28, 1959
Great Britain ________ __ Jan. 22, 1958
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