Safety shutoff valve mechanism
US 2427935 A
Descripción (El texto procesado por OCR puede contener errores)
SWL 23 1947 T. F. VAN DENBERG E'r AL 2,427,935
SAFETY SHUT-OFF VALVE MECHANIS 2 Sheets-Sheet 1 4INV-EN TORJ VAN Ds. enna f J'o BY 'mijn f 197' TORNEY,
HN LLLY Wam FT' Filed Nov; 27, 1944 1 l I. r
T. F. VAN DENBERG Er AL 2,427,935
SAFETY SHUT-OFF VALVE MECHANISM Filed Nv. 27,v 1944 y sept. 23, 1947,
I 2 Sheets-Sheet "2 IN VENTORJ.
Momes Fz-'VANDLNBLRG JoHN amv iatented Sept. 23, 1947 UNITED STATES PATENT OFFICE SAFETY SHUTOFF VALVE MECHANISM g, Cleveland Heights, and
Ohio, assignors to The Titan Valve and Manufacturing Company, Cleveland', Ohio, a corporation of Ohio Application November 27, 1944, Serial No. 565,210
Thomas F. Van Denber John Selby, Euclid,
This invention relates to safe control mechanism, such as is used for safeguarding the supply of fuel to a burner against the possibility of accident or injury as the result of extinguishment oi a pilot light for the burner.
The invention has more particular relation to that class of safety devices in which a single control device, such as an electric switch, valve member,7 or lthe like is movable back and forth between idle or safe position and active or operating position, being releasably held in the operating position by maintaining meanssensitive to variations in a condition, such as temperature, the maintaining means and control device being separately actuated to maintaining position and operating position, respectively, by the independent advance and retraction of a reset or cooking device.
One object of the invention is to provide improved control mechanism of the character described which reduces the number of necessary parts, simplifies the construction' and secures more reliable and certain operation.
Another object is to provide improved mechanism of this kind in which all parts are arranged symmetrically about a common axis.
A further object is to provide control mecha- .nism of this kind in which the casing or enclosing housing is in one piece and all working parts may be assembled on the bench in one unit for insertion into and attachment to the casing.
Still another object is to provide control mechanism of this kind embodying maintaining means in the form of cooperating magnet and armature members, one of which is attached to and is carried by a central stem upon which the cocking device is sleeved and slidable.
Finally, another object is to provide improved control mechanism of this kind in which alloperating parts are assembled and supported upon a single stem or rod which forms one of the operating parts for the pilot valve and also serves as a guide for the movable main or shutoff valve.
Further objects of the invention in part are obvious and in part will appear more in detail hereinafter.
In the drawings, which represent one suitable embodiment of the invention,
Fig. l is a longitudinal sectional elevation, showing the parts in normal safe or idle position;
Fig. 2 is a similar view, showing the cooking device advanced, certain parts being omitted;
Fig. 3 is a similar view illustrating all parts in the active or operation position;
Fig. 4 is a cross section on the line 4 4, Fig, 1; and.
Fig. 5 is a cross section on the line 5-5, Fig. 3.
While the invention may be applied for use in the operation of any kind of control devices, such as an electric switch, a valve, or the like, for convenience, and in no sense of limitation, it has been illustrated in a form including `a valve for controlling the flow of fuel to a burner. The drawings illustrate valve mechanism including a lhollow body or casing IIB, which is a single integral member, in which is a safety shutoff valve I I controlling the ow of fuel, such as gas, through an opening in a cross wall I2 dividing the cavity within the hollow body into supply and discharge chambers I3, III, the former communicating with a supply conduit I5 andthe latter with a conduit I6 leading to the main burner I1. `The l I8, being biased to move toward closed position byin a compression spring I9. Tube I8 is sleeved upon.'`
an operating rod or stem 2U biased for outward'` iv movement, or to the left in Fig. 1 by a compres- The outer endvof rod 20 is en--l-zy closed within a cap 22 attached to the tube I8, and the outer end of which cap forms a push button for depression by the operators iinger, to
sion spring 2 I.
enable the cooking or resetting operation to bev performed. Tube I8 is biased for outward movement, or to the left in Fig. 1, by the compression spring 23, which, at its inner end, abuts a washer 24 which confines in place a sealing device, such as the O ring 25 seated against an inwardly extending iiange 28 of a thimble 2l screwed into the casing and to which all of the operating parts are connected.
The valve III is movable back and forth, by sliding movement on or with tube I8, between the normal safe or inactive position shown in Fig. 1 and the operating position shown in Fig* 3. When moved thereto, it may be maintained or held in the operating position by any suitable holding means, preferably operated by the cocking device. These holding means may be of any suitable form, such as a latch, or an electromagnet and armature energized by any suitable source of current, such as a thermocouple, but in the form shown the holding devices include the two members of a permanent magnet couple of the same general form and operating in the same general manner as those described and shown in a prior application forv Safety valve mechanism, Serial No. 558,514, iiled October 13, 1944, by Van Denberg and Selby, to which reference may be had if necessary or desirable, Either or both of the members of the magnet couple may be movable. In the arrangement shown the amature member 28 is of washer form and firmly anchored or fixed in the body or casing. Its coop-4 erating mating member is the permanent magnet 28 mounted upon and movable with the stem 20, which also carries a sealing ring 3|! adapted to seat upon an annular flange on the inner end of the valve member II for preventing gas leakage through the working joints.
Upon the inner end of the stern is threaded an enlarged extension 3|, serving as a pilot valve, for which purpose it is provided with an annular groove 32 cooperating with a channel 33 communicating at one end with a pilot gas supply pipe 34 and at its opposite end with the tube of the pilot burner 35, located adjacent to the main burner II. The stem extension 3| also serves as one of a. pair of stop abutments controlling the production of the holding or maintaining eiIect. This it accomplishes by cooperation with an adjustable stop device sensitive to variations in an operation condition, such as variations in the temperature resulting from presence or absence of pilot flame. In the arrangement shown I provide a thermostatic device of tube and rod form, including a tube 38 and a rod 31, one of which, such as tube 36, may be made of material expansible by heat, such as brass or copper, and the other of which may be made of relatively nonexpansible material, such as invar, or vice versa. To avoid the effects of variations in ambient temperature a push rod 38 is interposed between the inner end of the rod 31 and the stem extension 3|, said push rod being made of material having the same coeillcient of expansion under heat as that of the tube Il.
As will appear hereinafter, during the cooking operation, upon advance of tube IB and stem 20 to the right in Fig. l, the holding or maintaining devices are adjusted near to each other, but short of actual contact, ready for the production of maintaining effect. subject to the appropriate or necessary variation in temperature. This adjustment is produced without effect upon the shutoff valve II which remains in its safe or closed position. Its movement to operating position is initiated or produced by the return or retracting movement of the cooking parts after the holding effect is secured. For that purpose means is provided for making the cooking parts effective upon the valve for opening it during the latter portion oi' the cooking operation. To this end the stem 20 is provided with an annular external groove 39 having inclined end walls, and the inner cylindrical wall of valve II is provided with an annular recess 40, which annular recesses cooperate with one or more balls 4| (two, three or more of which may be used) each of which balls A is confined in an opening 42 in the tube I8, as the result of Iwhich the balls move back and forth with the tube during its endwise movement and are also capable of inward or outward movement radially of the central axis, without escape from the tube opening.
The valve mechanism described operates as follows:
Fig. 1 illustrates all parts in the normal safe or inactive position. The pilot valve is closed, so that no gas flows to the pilotburner. The safety shutoff valve |I is also closed so that no gas flows to the main fburner. The pilot valve is held closed by spring 2 I, which is somewhat weaker than spring I! which holds the shutoff valve closed. Sealing ring 30 prevents gas escape 4 through the operating joints. The balls 4I rest in the annular groove 39 in stem 20 and lie opposite a cylindrical portion of the opening in valve I I. v
To set the parts into operation pressure is applied to the outer end of cap 22. The first effect is to take up any lost motion between the inner end of tube I8 and the shoulder on rod 2|) at the sealing device 30. Then the rod 20 and tube I8 move together tothe right to the position shown in Fig. 2, where the end of stem extension 3| has engaged the end of the push rod 38, with all lost motion taken up. Annular groove 32 is now opposite the pilot channel 33 so that gas flows to the pilot burner. However, as in the prior application before referred to, the two members of the permanent magnet couple are not yet in actual contact with each other, being separated by a space of the order of .020 of an inch. Therefore, if the cooking device is released the parts return to their original positions, shutting oi the pilot gas supply. However, if thepilot burner is ignited the flame jets from its burner ports play upon the thermostatic device and expand the tube thereof, in the form shown, so that the /thermostatic rod 31 and push rod 38 move to the right until the permanent magnet reaches actual contact with the armature, with a holding or maintaining effect. The ,inclined wall at the left-hand end of the annular groove 39 in stem 20 is at the right of the inclined wall at the end of the annular groove 40 in the valve II. Therefore, when the linger is removed from cap 22, tube I8 moves to the left under the compressure of spring 23, causing the balls 4| to move radially outwardly and enter the annular groove 40 and ride along the outer surface of rod 20. Retracting movement of tube I8 also moves valve II to the left to the open or active operating position shown in Fig. 3. This opens communication from the supply to the discharge chamber and gas flows to the main burner where it is ignited by the pilot llame.
The parts remain in the active or operating position until the pilot iiame goes out. When this occurs the thermostatic device cools down, and tube 36 contracts and moves the push rod 38 to the left, thus applying pressure to the stem extension 3| and to the permanent magnet which it supports, to an extent sufiicient to bodily move the permanent magnet out of engaging contact with its mating armature member. Thereupon the stem 20 is retracted by the expanding effect of its spring 2|, causing it to return to its original position shown in Fig. 1. Such motion brings the channel 33 opposite to the balls I4, which enter said channel and therefore are disengaged or freed from the valve member II, releasing the same and permitting it promptly to advance to its safe or closed position under the inuence of its spring I9. 'I'his brings all parts to their original safe positionsl ready for another cycle of 0perations.
It will be observed that in this mechanism the valve housing or body is a single member or casting, without any cap or joint, but cored out to provide the necessary interior chambers, working parts are attached to and supported by thecentral stem 20 and the thimble 21 in which it is mounted, so that the working parts conveniently may be made and assembled on the bench with all parts exposed to View and convenient for assembly and adjustment. Also, all parts are symmetrically disposed around the axis of stem 20. YAdvance of the cooking device brings the maintaining or holding devices into close rela- All.
tion, but the actual production of a holding eiect is sensitive to the necessary variation in temperature produced by ignition of the pilot burner. The production of the holding effect is independent of valve movement or operation. Retraction of the cooking device opens the valve without eifect upon the holding devices which, thereafter, are sensitive only to the appropriate variation in the controlling condition, such as temperature.
The mechanism is of simple form, can be made and assembled at low cost, and is highly satisfactory in operation.
What we claim is:
1. Control mechanism of the character described, comprising a hollow body provided with supply and discharge chambers communicating through an opening in a cross wall, a valve controlling ilow through said opening, and a thimble secured in an opening of the body, a stem movably supported in said thimble, a valve slidable back and forth along said stem, a holding device advanced by and with said stem to holding position when the stem is moved in one direction, a cocking device carried by said thimble and slidable on the stem for so moving said stem, and operating connections between said valve and device for opening the valve when the device is moved in the opposite direction.
2. Control mechanism of the character described, comprising a control device movable back and forth between safe and operating positions,
a stem along which said device is movable, hold-1' ing members relatively movable longitudinally of the stem into and out of holding relation, one of which is secured to -said stem for operative movement thereby, a tubular cooking device slidable on said stem, and means arranged upon movement of said cooking device in one direction to couple it to said stem for movement thereof and upon movement in the opposite direction to coupleit to said control device for movement thereof.
3. Control mechanism of the character described, comprising a control device movable back and forth between safe and operating positions, a stem along which said device is movable, holding .members relatively movable into and out of holding relation, one of which is operated by said i stern, a tubular cooking device slidable on said stem, means arranged upon movement of said cooking device in one direction to couple it to said stem for movement thereof and upon movement in the opposite direction to couple it to said control device for movement thereof, stop means for limiting relative approach of said holding members to a position in which they are close but out of contact, and thermostatic means controlling said stop means for permitting actual contact of said holding members.
4. Control mechanism of the character described, comprising a control device movable back and forth between safe and operating positions, a stem along which said device is movable, holding members relatively movable into and out of holding relation, one of which is operated by said stem, a tubular cooking device slidable on said stem, means arranged upon movement of said` cooking device in one direction to couple it to said stem for movement thereof and upon movement in the opposite direction to couple it to said control device for movement thereof, stop means for limiting relative approach of said holding members to a position in which they are close but out of contact, and thermostatic means controlling said stop means for permitting actual contact of said holding members and for separating them when in contact to release the control device.
THOMAS F. VAN DENBERG.
REFERENCES errno The following references are of record in the file of this patent:
UNrrED sTATEs` PATENTS Shaw Aug. 22, 1939