US3683955A - Gas control valve - Google Patents

Abstract

A flow control valve for gas fired hand tools having adjustable pilot flow and main flow conditions controlled by one valve element. The valve has two controls: one to set the pilot and main flow rates and the other to change the valve from pilot condition to main flow condition.

Description

United States Patent Beynon [54] GAS CONTROL VALVE [72] inventor: lan L. Beynon, Templestowe, Victoria, Australia [73] Assignee: Companion Heaters Proprietary Limited, Victoria, Australia [22] Filed: March 31, 1970 [21] Appl. No.: 24,323

[30] Foreign Application Priority Data [15] 3,683,955 145] Aug. 15, 1972 [56] References Cited UNITED STATES PATENTS 3,451,421 6/1969 Vicenzi et a1 137/495 3,493,010 2/1970 Dreibelbis ..137/495 X 1,530,094 3/1925 Ryan ..137/225 1,969,225 8/ l 934 Lear 137/223 2,156,823 5/1939 Stettner ..137/505.42 2,868,224 1/1959 Karlsson et al. 1 371505.42 X 3,294,114 12/1966 Birkemeier............137/495 X 3,433,255 3/ i969 Cubberley et a1 137/495 X April 1, 1969 Australia ..52,893/69 Primary Examiner-Alan Cohan Assistant Exanuner-Robert J. Miller [52] US. Cl ..l37/495 Attorney-Robert E. Burns and Emmanuel J. bobato [51] Int. Cl ..F16k 25/00 [58] Field of Search ..l37/495, 223, 225 A, 233, [57] ABSTRACT 234.5

A flow control valve for gas fired hand tools having 137/503 adjustable pilot flow and main flow conditions controlled by one valve element. The valve has two controls: one to set the pilot and main flow rates and the other to change the valve from pilot condition to main flow condition.

8 Claims, 3 Drawing Figures Pmmd Aug. 15, 1972 Q 3,683,

3 Sheets-Sheet l Patented Aug. 15, 1972 3,683,955

3 Sheets-Sheet 2 Patented Aug. 15, 1972 3,683,955

3 Sheets-Sheet 5 GAS CONTROL VALVE BACKGROUND OF THE INVENTION This invention relates to control valves for use particularly with gas-fired hand tools.

In the use of gas-fired hand tools, such as soldering irons, hand burners and the like, it is desirable that the appliance may readily be brought to full flame when it is actually in use but left on pilot flame during periods of a particular job when the operator is not actually using that particular tool. During those latter time intervals it is desirable that the flame may be turned down to a pilot flame from which it can readily be returned to full flame without the necessity for relighting the burner.

There are known constructions for providing both pilot flame and full flame operation but these have a number of disadvantages. They haveheretofore been relatively complex in construction and have also been restricted in their applicability to burners burning at different rates. In one known construction, the main control valve has incorporated into it an auxiliary valve provided with a fixed orifice so that when it is in operation, it passes only a small metered quantity of gas sufficient to keep a pilot flame burning. The auxiliary valve is provided with a replaceable insert which must be changed if a different flow rate is required for the pilot operation. In another known construction, a separate auxiliary valve is provided in series with the main control valve and this valve is operated by a trigger on the tool handle so that when the trigger is not operated, the auxiliary valve restricts the flow rate to that required for pilot burning and when the trigger is operated, the auxiliary valve is rendered inoperative so that full flow occurs to the burner through the main valve. Both of these constructions suffer from the disadvantages that they required the provision of an additional valve element and also from the fact that they control the flow by the use of a restricted orifice and are therefore not readily adaptable to varying pressures and flow rate requirements.

SUMMARY The principal object of this invention is to provide an improved valve construction which enables a single valve element to readily control both main flow and pilot flow and also to provide a construction in which, when the main control valve is of the pressure control type, the pilot flow is also pressure controlled.

According to this invention there is provided a gas flow control valve having a movable valve element and a first control member operable to move the valve element to determine the gas flow through the valve and a second or overriding control member operable to cause further movement of the valve element to a position to provide a gas flow rate greater than that determined by the first control member.

Preferably the second control member is carried by the first control member so that the total extent of opening of the valve element can be determined by adjustment of the first control member.

Preferably, the first control member comprises a push rod mounted in a spindle and adapted to be moved axially by the spindle to cause opening of the valve, said push rod being also free to move axially relative to the spindle on operation of the second control member to cause said further movement. Preferably, the second control member includes a surface adapted in operation to be brought into engagement with the push rod to cause said further movement.

In order that the invention may be better understood a preferred embodiment will now be described by way of example with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a longitudinal section of a valve according to the invention, showing the arrangement of parts when the valve is in off" position,

FIG. 2 shows the valve in pilot" position,

FIG. 3 shows the valve in full flow" or operating position.

DESCRIPTION OF PREFERRED EMBODIMENT In this preferred construction, a valve body 1 is provided with a valve chamber 2 having inlet and outlet passages 3 and 4 respectivelyand a valve member 5 positioned in the chamber between the passages. In this preferred embodiment the valve member is of the Schrader type and is located in the valve body with its operating pin 6 projecting upwardly into the valve chamber. Mounted in the chamber above the valve operating pin is a flexible diaphragm 7. A hollow cover nu-t 8 is screwed into the valve body above the diaphragm and this nut carries a rotatable spindle 9 which is screw-threaded to the nut and movable axially with respect to it on rotation of the spindle. The spindle in turn carries an operating knob 10 by means of which it can be rotated in the screw threads provided in the nut.

The spindle is hollow and carries within it a push rod 1 l which is provided with a head 12 adapted to bear on the upper surface of the diaphragm. The lower end of the spindle has an enlarged diameter and in a recess 30 formed in the enlargement there is provided a compression spring 13 which bears at its upper end against the upper end of the recess and, at its lower end, against the head of the push rod, thereby pushing the push rod down onto the diaphragm. The length of the push rod is such that, with the valve in the fully closed condition, its upper end lies just below the lower inside face of a hollow cap, 15, described below.

The upper end of the operating knob 10 is provided with a recess 14 into which the upper part of the spindle (and therefore the push rod) projects. A hollow cap l5 and 15A is screw-threaded to the spindle at this point and carries within it an operating plunger 16 which in turn carries at its upper end a button, 17. A compression spring 18 surrounds the cap and bears at its lower end against the floor of the recess 14 in the knob and at its upper end against the under side of the button 17.

The operating plunger 16 has a mid-section 19 of approximately the same diameter as the opening in the cap through which it projects. It has an upper section 20 which has a lesser diameter than the mid section, and a lower section 21 which is of greater diameter than the mid-section l9 and which, when the plunger is not operated, bears against the underside of the top 15A of the cap 15 thereby preventing the spring from lifting the plunger out of the cap. When the button is pushed down, the upper section of the operating plunger moves into the opening of the cap and movement of the button to one side or another will cause the shoulder 26 formed between the mid section 19 and the upper section 20 of the plunger to catch against the underside of the opening in the top 15A of the cap and lock it in the depressed condition. In this condition the compression spring which bears against the underside of the button will be laterally deflected as shown at C in H0. 3 giving rise to a self-centering action which will immediately cause the button to return to the up" position under the influence of the spring on any movement sufficient to disengage the shoulder from the under side of the cap.

To take up backlash in the spindle assembly and to provide consistant knob friction, a polytetrafluoroethylene washer 22 and a brass washer 23 may be positioned in a recess 31 on the underside of the knob and a compression spring 24 may be provided surrounding the spindle to bear at its upper end against these washers, and at its lower end against the cover nut 8.

A loose washer 25 may be provided between the push rod head 12 and the cover nut 8 to protect the diaphragm when high pressures are applied.

The operation of the valve is as follows:

When the valve is in the closed condition shown in FIG. 1, the push rod 11 may rest lightly against the diaphragm 7 so as not to deflect the diaphragm sufficiently to contact the operating pin 6 on the valve element and thereby to operate the valve. The valve is initially opened by the first positioning means by turning the operating knob to cause the spindle 9 to advance in the threads in the cover nut and thereby compress the spring 13 causing the head of the push rod 11 to push the diaphragm down till it contacts the operating pin 6 of the valve element. The valve is thus opened and gas can flow through the gas chamber and out the outlet passage to the burner. At the same time, movement of the spindle 9 relative to the push rod 11 will cause the upper end of the spindle to project into the cap above the upper end of the spindle. The knob is operated just sufficiently to provide the desired degree of pilot flame burning.

lt will be observed that in this condition the underside of the diaphragm is subjected to gas pressure and accordingly, the degree of opening of the valve will be determined by the equilibrium reached between the gas pressure operating on the underside of the diaphragm and the force exerted by the operating spring against the head of the push rod. lf now the knob 10 is further rotated to carry the spindle down to its fullest extent, the valve can be moved to its fully open position in the normal way. However, since it will normally be desired to provide full flame and pilot flame operation, this further opening of the valve will not be carried on. Instead, the valve will be set by the knob to provide the desired level of pilot flame and will be left set in that condition throughout the job. The control of the valve to provide full flame operation will now be taken over by the overriding button.

When the value is set by the main control valve to the pilot condition referred to above, it can be brought into the full flame condition as shown in Figure by the second positioning means. The override button is depressed causing the lower end of the override button 17 to engage the upper end of the push rod and this will push the push rod 11 down independently of the spindle 9 to cause further deflection and flexing of the diaphragm and consequent further downward movement of the operating pin 6 of the valve to further open the valve to provide full flame burning while the button remains depressed. As above-described, the button can be locked in the down position by engaging the shoulder 26 of its mid section with the underside of the cap. When it is desired to revert to pilot flame burning, a simple flick of the thumb on the override button will release the button and will cause the push rod to be moved upwardly under the influence of gas pressure on the diaphragm until again an equilibrium condition is reached between the gas pressure and the pressure in the valve compression spring to provide pilot flame burning.

The construction described above provides a means whereby the change can be made effectively and quickly from full flame to pilot flame burning and viceversa using only one valve element and also provides a construction in which the valve element can be pres sure controlled under pilot flame operation. This constitutes a very substantial advantage over the prior constructions. It is to be understood, however, that the invention is not necessarily limited in its application to valves which are pressure responsive, or to valves which are of the Schrader type. It may readily be ap plied to other types of valve, and these and other modifications are to be understood as coming within the spirit and scope of this invention which includes every novel feature and combination of features herein disclosed.

lclaim:

l. A flow control valve for controlling the flow rate of a pressurized fluid comprising: a valve body having therein means defining a fluid inlet receptive of a pressurized fluid during use of the flow control valve, a fluid outlet, and a valve chamber communicating said fluid inlet with said fluid outlet; a valve member movably disposed within said valve chamber and cooperative therewith to define a closed position and a plurality of different valve-open positions in response to movement of said valve member; a flexible diaphragm disposed within said valve chamber flexible into contact with said valve member to effect movement thereof from said closed position to said valve-open positions; a plunger slidable within said valve body to contact and effect flexing of said diaphragm and movement of said valve member; first positioning means including means for efl'ecting sliding movement of said plunger into contact with said diaphragm to flex same and accordingly position said valve member in a first variably set valveopen position thereby permitting a pilot flow rate of fluid through the flow control valve; second positioning means mounted upon and operable independently of said first positioning means and including means for effecting further sliding movement of said plunger in response to a force of a predetermined magnitude applied thereto to further flex said diaphragm and accordingly position said valve member in a second valveopen position wider open than said first valveopen position thereby permitting a main flow rate of fluid through the flow control valve; and return means for automatically returning said valve member to said first valve-open position whenever said force applied to said plunger is removed.

2. A flow control valve according to claim 1', wherein said second positioning means comprises a slidable button, and means mounting said button on said valve body for sliding movement into and out of contact with said plunger to effect sliding movement of said plunger in response to manual depression of said button.

3. A flow control valve according to claim 2; wherein said return means includes spring means continuously biasing said button in a direction away from said plunger.

4. A gas flow control valve comprising: a valve body having means therein defining a valve chamber; a movable valve element disposed within said valve chamber for movement to a closed position and a plurality of open positions; a first control member operable to move said valve element to an open position to determine the gas flow rate through the valve; a second control member operable to effect further opening movement of said valve element to provide a gas flow rate greater than that determined by said first control member; means mounting said second control member on said first control member so that the total extent of opening of said valve element can be determined by ad justment of said first control member, said first control member comprising a spindle, a push rod mounted in said spindle for axial movement by said spindle to cause opening of the valve, and means mounting said push rod for axial movement relative to said spindle on operation of said second control member to cause said further movement of said valve element; said second control member comprising depressible operating means biased to its undepressed position by a spring and manually depressible to contact said push rod and move it axially, said operating means having a shoulder engageable with an abutment to hold said operating means in its depressed position in response to compression and lateral deflection of said spring.

5. A gas flow control as claimed in claim 4; including means resiliently urging said push rod into contact with one side of a diaphragm interposed between the end of said push rod and said valve element, the other side of said diaphragm being exposed to the pressure of the gas flowing through the valve whereby the control is pres sure sensitive. control 6. A gas flow control valve as claimed in claim 4; wherein said operating means may be returned to its undepressed position under the action of the compressed and laterally deflected spring in response to sufficient movement thereof to disengage said shoulder from said abutment.

7. A gas flow control valve as claimed in claim 5; wherein said operating means may be returned to its undepressed position under the action of the compressed and laterally deflected spring in response to sufiicient movement thereof to disengage said shoulder from said abutment.

8. A gas flow control valve as claimed in claim 4; wherein said movable valve element is of the Schrader type.

Claims (8)

1. A flow control valve for controlling the flow rate of a pressurized fluid comprising: a valve body having therein means defining a fluid inlet receptive of a pressurized fluid during use of the flow control valve, a fluid outlet, and a valve chamber communicating said fluid inlet with said fluid outlet; a valve member movably disposed within said valve chamber and cooperative therewith to define a closed position and a plurality of different valve-open positions in response to movement of said valve member; a flexible diaphragm disposed within said valve chamber flexible into contact with said valve member to effect movement thereof from said closed position to said valve-open positions; a plunger slidable within said valve body to contact and effect flexing of said diaphragm and movement of said valve member; first positioning means including means for effecting sliding movement of said plunger into contact with said diaphragm to flex same and accordingly position said valve member in a first variably set valve-open position thereby permitting a pilot flow rate of fluid through the flow control valve; second positioning means mounted upon and operable independently of said first positioning means and including means for effecting further sliding movement of said plunger in response to a force of a predetermined magnitude applied thereto to further flex said diaphragm and accordingly position said valve member in a second valve-open position wider open than said first valve-open position thereby permitting a main flow rate of fluid through the flow control valve; and return means for automatically returning said valve member to said first valve-open position whenever said force applied to said plunger is removed.

2. A flow control valve according to claim 1; wherein said second positioning means comprises a slidable button, and means mounting said button on said valve body for sliding movement into and out of contact with said plunger to effect sliding movement of said plunger in response to manual depression of said button.

3. A flow control valve according to claim 2; wherein said return means includes spring means continuously biasing said button in a direction away from said plunger.

4. A gas flow control valve comprising: a valve body having means therein defining a valve chamber; a movable valve element disposed within said valve chamber for movement to a closed position and a plurality of open positions; a first control member operable to move said valve element to an open position to determine the gas flow rate through the valve; a second control member operable to effect further opening movement of said valve element to provide a gas flow rate greater than that determined by said first control member; means mounting said second control member on said first control member so that the total extent of opening of said valve element can be determined by adjustment of said first control member, said first control member comprising a spindle, a push rod mounted in said spindle for axial movement by said spindle to cause opening of the valve, and means mounting said push rod for axial movement relative to said spindle on operation of said second control member to cause said further movement of said valve element; said second control member comprising depressible operating means biased to its undepressed position by a spring and manually depressible to contact said push rod and move it axially, said operating means having a shoulder engageable with an abutment to hold said operating means in its depressed position in response to compression and lateral deflection of said spring.

5. A gas flow control as claimed in claim 4; including means resiliently urging said push rod into contact with one side of a diaphragm interposed between the end of said push rod and said valve element, the other side of said diaphragm being exposed to the pressure of the gas flowing through the valve whereby the control is pressure sensitive. control

6. A gas flow control valve as claimed in claim 4; wherein said operating means may be returned to its undepressed position under the action of the compressed and laterally deflected spring in response to sufficient movement thereof to disengage said shoulder from said abutment.

7. A gas flow control valve as claimed in claim 5; wherein said operating means may be returned to its undepressed position under the action of the compressed and laterally deflected spring in response to sufficient movement thereof to disengage said shoulder from said abutment.

8. A gas flow control valve as claimed in claim 4; wherein said movable valve element is of the Schrader type.

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