US2813682A

US2813682A - Gas valves

Info

Publication number: US2813682A
Authority: US
Inventors: John E Sherlock
Original assignee: British Thermostat Co Ltd
Current assignee: British Thermostat Co Ltd
Priority date: 1955-02-23
Filing date: 1955-02-23
Publication date: 1957-11-19
Anticipated expiration: 1974-11-19

Description

Nov. 19, 1957 J. E. SHERLOCK 2,313,632

GAS VALVES Filed Feb. 25, 1955 3 Sheets-Sheet 1 Inventor A ttorn e yr Nov. 19, 1957 'J. E. SHERLOCK 2,813,632

" GAS VALVES 7 Filed Feb. 25, 1955 s Sheets-Sheet 2 Attorneys J E. SHERLOCK v Nov. 19, 1957 GAS VALVES 3 Sheets-Sheet 3 Filed Feb. 23, 1955 United States Patent GAS VALVES John E. Sherlock, Towpath, Shepperton, England, assignor to The British Thermostat Company Limited, Sunburyoil-Thames, England, a British company Application February 23, 1955, Serial No. 490,097

4 Claims. (Cl. 23699) This invention relates to gas valves with thermostatic control devices for use in regulating the gas supply to cooking ovens and the like and the invention has for its object to provide an improved temperature range adjusting device operable independently of the gas admission valve member or plug cock for the purpose of ensuring smoothness of operation unaffected by any friction in the rotary plug member.

According to the invention a gas supply valve for application to a cooking oven or the like is provided with latching means to lock the rotary plug valve member in its closed and fully open positions and a common hand-operated member for turning the plug member between said positions but capable of disengagement in the fully open position from the latching means for independent operation to vary the temperature at which a thermostatically controlled valve will reduce or cut off the gas supply to the burners.

An embodiment of the invention will now be described with reference to the accompanying drawings of which:

Fig. 1 is a sectional elevation of the combined cock and valve assembly,

Fig. 2 is a plan view of the apparatus shown in Fig. 1,

Fig. 3 is an enlarged view of a small portion of the apparatus shown in Fig. 1,

Fig. 4 is a sectional plan view along the line IV-IV of Fig. 1 showing the mechanism in a difierent working position from that shown in Fig. 2,

Fig. 5 is a fragmentary sectional elevation along the line V-V of Fig. 4, and

Fig. 6 is a section on the line VI-VI of Fig. 1 but with the plug valve locked in the closed position.

Referring to Fig. 1 of the drawings, a gas supply cock 1 of the rotary plug type is mounted in a casing 2 having an inlet passage 3 adapted to be connected to a main gas supply and an outlet passage 4 adapted to be connected to the gas burners in an oven. Communication between the said inlet and outlet passages is controlled by the plug cock 1 and by a valve member 5 movable towards and away from a normally fixed but adjustable seating 6 by the operation of a flexible metallic bellows device 7 connected in known manner by a capillary tube 8 to a thermally sensitive phial 9 disposed adjacent the burners. The bellows, tube and phial form a closed system solidcharged with a substance whose expansion under heat causes the bellows 7 to expand and move the valve member 5 towards its seating 6. Adjustment in the position of this seating varies the temperature range of the apparatus, that is to say, it will raise or lower the temperature at which the gas supply to the burners will be reduced or out 011. The mechanism provided by the present invention for adjusting the position of the valve seating 6 will now be described.

The adjustable seating 6 is formed at the lower end of a cylindrical element 10 slidably mounted in a vertical cylindrical passage 11 forming a communication between the inlet and outlet passages in the casing, a bypass passage 12 being provided between the cylindrical passage 2,813,682 Patented Nov. 19, 1957 11 and the outlet passage 4 to prevent the burner flames from being extinguished when the valve member 5 is seated. The cylindrical element 10 is connected to the lower end of a trimming rod 13 extending vertically in a position off-set from the axis of the plug cock 1. The upper end 14 of the trimming rod is bent at right angles and passes through slots in a main range screw 15 which immediately surrounds the rod and in a sleeve 16 disposed rotatably around a cylindrical casing extension 17 through which the trimming rod 13 passes axially and in which the main range screw 15 has screw-threaded engagement. The exterior of the cylindrical casing extension 17 has two horizontal interconnected latching grooves 18 and 19 (Figs. 4 and 5) disposed at slightly different levels and an upturned groove portion 36 (Fig. 5) which in the fully closed position of the plug valve 1 is in a position to receive a pin 20 extending inwardly from the rotatable sleeve 16. Near its base the cylindrical casing extension 17 (Fig. 1) has a recess 21 (whose purpose will be explained later) and is surrounded by an annular non-rotatable spring-loaded lock plate 22 (Fig. 2) which surrounds the base of the said casing extension. The lock plate 22 is prevented from rotating by two downwardly extending lugs which embrace the body 2.

The plug cock 1 is partially rotatable by hand through an arc of degrees from a closed position through a half-open position as shown in Fig. 2 to a fully open position as shown in Fig. 4. v

The operation of the plug cock is effected by means of a knob (not shown) disposed on the exterior of the oven and mounted on the end of the rotatable sleeve 16. This sleeve carries a crank pin 23 (Fig. 1) adapted to engage between the ends of a forked arm 24 (Fig. 4) carried by the upper end of the plug cock 1 which can thereby be moved from closed to open position or vice-versa by operation of the knob. The lock plate 22 is provided with a central boss 25 (Fig. l) and with two arms having upwardly directed projections 26 and 27 (Fig. 2) at their ends to engage the forked arm 24 for the purpose of latching the plug cock 1 in its open or its closed position. When the oven is inoperative, the plug cock 1 is locked in the off position shown in Fig. 1 by engagement of the forked arm between the projection 26 and the boss 25 on the lock plate 22 as shown in Fig. 6. To release the plug cock 1, the operating knob and rotatable sleeve 16 are pressed inwardly (i. e. downwardly in Fig. 1) against the action of a spring 28 to remove the boss 25 on the lock plate 22 from the plane of the forked arm 24 and the knob can then be turned to the operative position, the recess 21 providing the necessary clearance to allow the forked arm 24 to rotate. The initial inward movement of the operating knob is permitted by sliding of the pin 20 out of the upturned groove portion 36 previously referred to. By the engagement of the crank pin 23 with the forked arm 24 the plug valve member 1 is turned during the operation above described to the position for full gas flow to the burners, as shown in Fig. 4, the plug valve member 1 being latched in this position by the action of the spring 28 which restores the rotatable sleeve 16 and operating knob to their normal positions as soon as the hand of the operator is removed from the knob and as soon as the pin 20 reaches the end of the first groove 18. The cock plug 1 is maintained latched in its open position as one of the free ends of the forked arm 24 is engaged between the projection 27 and the boss 25 on the lock plate 22 but the crank pin 23 can now leave the open end of the forked lever 24 so that the rotatable sleeve 15 is free for further turning movement in the same direction as that taken to turn on the gas supply, i. e. anticlockwise in Fig. 4. This further turning movement is permitted to the extent imposed by the second portion 19 of the groove in the cylindrical casing extension 17. This movement is communicated through the upper bent end 14 of the trimming rod 13 to the range screw 15 which is also turned carrying the rod and adjusting the valve seating 6 to vary the closing position of the thermostatically controlled valve 5. In the embodiment showmitheiupper end of the cylindrical element is separate from the lowerend of the trimming rod 13 and is urged to follow its movement by a spring 29 (Fig. 1) acting ontheseatingfi. The'bellows 30 acts as a sealing member between the element 10 and the cylinder passage 11.

In order to compensate for errors in position of the valve head 5 caused by varying temperatures at the lower end of the device, a bi-metal disc31 (Fig. 3) is inserted between a bellows plate 32 and a rod 33 to whichiisfixed the valve head 5. An overload spring 37 permits further movement of the bellows plate 32 after the valve 5 has been fully closed. 7 V

At the conclusion of operation, theknob and sleeve 16 are again depressed by turning the knob in the direction to return the pin 20 from the groove portion 19 to the groove portion 18 to unlatch the plug cock member 1 and then return the latter to the 01f position. i.

Initial setting of the trimming rod 13 and the. valve seating 6 is eifected by adjusting a trimmingscrew, 34 which bears upon the upper end 14 of the trimming rod, a resilient bushing 35 being disposed beneath the cranked end 14 of the trimming rod to ensure positive contact thereof with the trimming screw 34. Turning the trimming rod in the direction to lower the ,valve seat 6 will set it for the lower limit of a selected temperature range, and turning of the trimming rod in the direction to raise said valve seat will set it for the upper limit of such temperature range.

The operating knob is rotatable against a fixed pointer on the oven casing and the knob carries indications of the off and the on" positions and also a series of numbered graduations used during the additional turning movement of the knob to indicate the temperature range adjustment required.

The arrangement above described permits approximately 90 degrees angular movement of the plug cock 1 and 180 degrees movement for the temperature range adjustment mechanism entirely free from any interference by the plug cock.

I claim:

l. A gas supply valve for controlling the supply of gas to an oven burner, comprising a rotary plug valve member having a forked operating arm for turning it into closed and fully open positions, a manually rotatable member having a crank pin mounted eccentrically thereon and en gageable with said forked arm to turn said plug valve member between its said positions and disengageable from said forked arm by rotation of said manually rotatable member While said plug valve member is in its fully open position, a thermostatically controlled valve member operable to reduce or cut off the supply of gas to the burner, means operable by said manually rotatable member to adapt said thermostatically controlled valve member for operation through a range of .-temperatures, and latch means comprising a non-rotatable lock plate engaged by said manually rotatable member and having thereon a central boss and a pair of projections on the respective sides of said boss, and a spring acting onsaid lock plate to hold said plate in a position to lock said forked arm in a position between one of said projections and the central boss on the lock plate when said forked arm assumes said position, said forked arm being releasable from said position only by axial movement of said manually rotatable member to displace the lock plate against said spring to permit movement of said forked arm to turn the plug valve member between its closed and fully open positions.

2. A gas supply valve as defined in claim. 1, wherein said boss is mounted co-axiallywith andadjacent to said manually rotatable member, and including a stationary body in which said valve members are located, and a pin fixed to said manually rotatable member and cooperative with, a cam groove in said stationary body to permit axial movement of said manually rotatable member and rotation thereofto open or. close said rotary plug valve member and thereby cause displacement of said lock plate from its locking position. l

3. Agas supply valve as defined in claim 2, including an adjustable valve seat With which said thermostatically controlled valvemember cooperates, and a rotatable rod engageable with said valve seat and having a portion of its length in screw-threaded relationship with said stationary body and an end thereof engaging in a slot in said manually rotatable member for rotation therewith, said rod being movable axially by rotation of said manually rotatable member to alter the position of said valve seat relatively to said thermostatically controlled valve member.

4. ,A gas supply valve asdefined in claim 3, including a second cam groove in said stationary body, which adjoins said first-mentioned cam groove and with which said pin also cooperates, said second cam groove having a length which controls the extent of rotation of said manually rotatable member and thereby determines the range of movement of said valve seat.

Matthews et al. Nov. 16, 1937 Mills Nov. 4, 1952