US2925480A

US2925480A - Gate valve signal system

Info

Publication number: US2925480A
Application number: US789150A
Authority: US
Inventors: Boehm Albert
Original assignee: American District Telegraph Co
Current assignee: American District Telegraph Co
Priority date: 1959-01-26
Filing date: 1959-01-26
Publication date: 1960-02-16
Anticipated expiration: 1977-02-16

Description

Feb. 16, A BQEHM GATE VALVE SIGNAL SYSTEM 2 Sheets-Sheet 1 Filed Jan. 26, 1959 Feb. 16, 1960 A. BOEHM 2,925,480

GATE VALVE SIGNAL SYSTEM Filed Jan. 26, 1959 2 Sheets-Sheet 2 2| "lea 37 United States Patent O GATE VALVE SIGNAL SYSTEM Albert Boehm, Madison, N.J., assignor to American District Telegraph Company, Jersey City, N.J., a corporation of New Jersey Application January 26, 1959, Serial No. 789,150

4 Claims. (Cl. 200--61.86)

This invention relates to gate valve signaling installations and more particularly to a gate valve and signal means installation especially well suited for use in conjunction with a fire sprinkler system.

The action effected immediately upon the outbreak of a fire usually determines whether the resulting risk to personnel and damage to property will be minimal or substantial. It is customary to utilize a fire sprinkler system constructed to discharge water upon the occurrence of an abnormal rise in temperature and to provide constant supervision of the system by means of signaling devices for providing, at a remote supervisory central station, an indication of the condition of various portions of the system as well as the system as a whole. As evidenced by U.S. Patent No. 1,127,232, it has long been desired to provide a gate valve and signal means installation capable of operating satisfactorily under the rigorous conditions and requirements characteristic of such fire fighting equipment as a fire sprinkler system. Such gate valves are customarily installed between the sprinkler system and its water supply, usually a city water main, and is normally maintained open. A signaling device is utilized to provide a trouble signal at the central station, to which it is connected, when the valve is operated to close the same. When functioning properly such arrangements insure that the central station supervisory personnel are appraised of the fact that the gate valve has been disturbed. The importance of such signaling will be better appreciated when it is understood that in addition to unauthorized tampering as may occur from time to time, it is necessary to insure that a warning signal be given if, upon the occurrence of a fire and during the resulting confusion, some individual should in fact close the valve under the belief that he was opening it, thereby cutting oft" the water supply for the sprinkler system. a

The arrangements which have been available hitherto have left much to be desired. One important drawback of such installations with which I am familiar resides in the fact that they are relatively slow acting. A further drawback resides in the short trouble free life of such arrangements and their inability to function properly when exposed, as they usually are, to dampness or mois-v ture for prolonged intervals.

It is, therefore, a principal object of this invention to provide a gate valve and signaling means for use in conjunction with a supervised fire sprinkler system which is not only fast acting but which is also characterized by a long, trouble free life even though exposed to extremely moist conditions or even when submerged in water for a long time.

Another object is to provide such an apparatus which is simple in construction and which may be readily assembled and installed in the field.

, Inaccordance with'the present invention, a switch, controlling a circuit communicating with a remote central'station, and its leads are sealed in a watertight enclosure. auxiliary operating plate and the switch are mounted in a housing into which a spring loaded plunger extends. The housing is mounted on the gate valve in such manner that the plunger normally maintains the contacts of the switch closed and in response to rotation of the gate valve wheel frees the operating plate to permit the contacts of the switch to open. Enhanced sensitivity is achieved by the manner in which the plunger, operating plate and switch contacts coact, the operating plate bearing against the switch by reason of its being pressed, by the engagement of the plunger with a projection on the operating plate, against a soft, resilient portion of the waterproof switch enclosure.

Further objects as well as advantages of the present invention will be apparent from the following detailed description and the accompanying drawings in which Figure l is an elevational view partially diagrammatic of a fire sprinkler gate valve and signaling means constructed in accordance with the present invention;

Figure 2 is an enlarged view thereof with the cover of the housing partially broken away for convenience; and

Figure 3 is a sectional view taken along the line 33 of Figure 2.

Referring now to the drawings in detail, gate valve 10 is installed in piping 11 extending between a city water main and a fire sprinkler system. Gate valve 10 is of conventional construction and comprises a valve'housin'g 12 to which is affixed a yoke 13 comprising two support arms 14, which in turn serve to support a threaded hub and operating wheel 15 through which valve stem 16 extends in threaded engagement therewith. Gate valve 10 controls communication between the fire sprinkler system and its water supply, i.e., the city water main, and, except for unusual circumstances and under carefully controlled conditions, is normally maintained in its fully opened condition. As shown most clearly in Figure 1 the installation of the gate valve 10 between the fire sprinkler system and the water supply is often effected in a depression or low point represented by pit 18.

Switch housing 20, mounted on supporting arms 14 of yoke 13 as willbe more fully described hereinafter, has a generally cylindrical main body portion, preferably formed as a one piece bronze casting, adapted to be closed on one side by a cover 21 and forming on its opposite side an elongated exteriorly threaded boss 22 Boss 22 is open ended so that a plunger 23 mounted therein may extend therethrough. As shown most clearly in Figure 3 the base of housing 20 is formed to provide an annular recess 24 to receive the shoulder of a bushing 25. Bushing 25 is secured in recess 24 by means ofa flange 26 forming part of a mounting bracket 27 having a second flange 28 which is in turn secured to a stepped or re-entrant portion 29 of housing 20.

As has been indicated, plunger 23 extends through boss 22 and has a head 30 afiixed to its outwardly extending end, which terminates in a spheroidal surface for a purpose which will be more fully pointed out hereinafter. Spaced from head 30 and within boss 22, a'collar 31 is fixed to plunger 23 and serves to limit outward motion of plunger 23 when it engages the end wall of boss 22. A coil spring 32 is mounted about plunger 23 withinboss 22 and is retained under compression between collar 31 and bushing 25. Thus, plunger 23 is normally urged in the direction to extend outwardly of boss 22 under the influence of spring 32 acting against collar 31. 3

The inner end portion of plunger 23 is formed witha reduced diameter indicated at 33 which terminates in a shoulder 34 having a relatively short radius of curvature along the longitudinal axis of plunger 23. f Secured between mounting bracket 27 and the base and r'e-entrant portion of housing 20 is a microswitch 36 2,925,4so m I v sealed within a watertight enclosure 37 formed of neoprene or other suitable material.

Leads

35, 35 are connected to the contacts of microswitch 36 and are enclosed within a watertight, tubular enclosure 50, also of neoprene or the like, which is sealed into enclosure 37 so as .to form one continuous watertight enclosure extending to a height well above gate valve-10, as'for example, up to the junction box 51 inside of an outer protective conduit 52. Microswitch 36 is a snap action type of switch having its actuating arm juxtaposed to the inner surface of a highly pliable portion of enclosure 37 indicated at 33. As most clearly shown in Figure 2, enclosure portion 38 is clear of the bracket 27. A resilient operating plate 39 issecured, adjacent to one end thereof, to mounting bracket 27 and extends within housing 20 exteriorly of switch enclosure 37. The free end portion 40 of plate 391's embossed or otherwise formed with a relatively sharp projection 41. Preferably projection 41 is formed as an embossing in the surface of the free end portion .40 of plate 39 and has a short radius of curvature as compared to that of the shoulder '34 formed on plunger 23. While projection 41 is formed relatively shallow in depth it will be recognized that it need only be deep enough to provide for operation of switch 36. The free end portion 40 of plate 39 and its projection 41 are juxta posed to the path traveled by plunger 23 so that when spring 32 is sufliciently compressed, shoulder 34 engages projection 41 thereby maintaining operating plate portion 40 displaced to the left as viewed in Figures 2 and 3. A stud 42'is threaded through the operating plate portion 40 in alignment with the pliable portion 38 of enclosure 37 and the operating arm of switch 36. Stud 42 is adjusted and then fixed in place so that with shoulder 34 engaging the projection 41, switch 36 is maintained closed. 7 As indicated most clearly in Figures 2 and 3, housing 20 is mounted on the arms 14 of valve yoke 13 so that plunger head 30 bears against an unthreaded portion of valve stem 16 and normally seats in a recess 45 formed in the smooth surface portion of valve stem 16. 'Across the support arms 14 of valve yoke 13 and secured by means of a pair of hooks 47, there extends a mounting yoke 46 having a threaded hub into which the boss 22 of housing-20 is threaded. Housing 20 is mounted on yoke 46 with gate valve fully open. Boss 22 is threaded into the hub of yoke 46 just far enough'so that head 30, while seated in recess 45 and bearing against valve stem 16, causes its plunger 23'to compress spring 32 until plunger shoulder 34 engages projection-41 on operating plate portion 40 and holds the latter in its deflected position, closing the contacts of switch 36. This adjustment is readily effected by connecting a buzzer or other suitable signaling device across the circuit controlled by switch 36.. As has already been pointed out, switch 36 is normally open and is only closed when stud 42 bears against its, operating arm due to the engagement of shoulder 34 with'projection 41. Thus the proper adjustment is effected when the buzzer or other suitable device is actuated to indicate that the contacts of switch 36 are closed. A lock nut 48 is then tightened against the hub of yoke 46 to clamp housing in place.

As is clearly apparent from Figure 3 only a relatively small movement of stem 16 is required to carry recess 45 out of registration with plunger head 30. As this .is

effected, plunger'23vis cammed inwards into boss 22 and housing 20. 'Because of the short radius of curvature of plunger shoulder 34 and the even shorter radius of curvatureof projection 41 only a very small displacement of plunger 23 is required to displace shoulder 34 sufliciently to permit operating plate portion 40 to move to the right (as viewed) thereby permitting switch 36 to open and provide an immediate signal, over the circuit to the central station, indicative of tampering with gate valve 10. Because switch 36 and its leads 35 are encased in one continuous waterproof enclosure to apoint well above the level of any anticipated high water and because all the metal portions of the apparatus are constructed of metals which are not adversely affected by moisture, no further precautions are necessary to safeguard the assembly against moisture. The apparatus as thus constructed affords a long trouble free life even though fully submerged under water from time to time.

Axial displacement of valve stem 16 in either direction serves to actuate switch 36. Also, disturbance of the switch housing results in actuation of switch 36 because movement of plunger 23 outwardly, as well asinwardly, serves to displace shoulder 34 from projection 41.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. I

What is claimed is:

1. Fire sprinkler system gate valve signaling means, comprising a housing, a plunger extending through a wall of said housing and having a shoulder formed onthe end thereof within said housing, an electric switch mounted within said housing adjacent to said shoulder, a watertight enclosure surrounding said switch and hav ing a flexible portion juxtaposed to the operating arm of said switch, a flexible operating plate mountedin said housing and having a defiectable portion extending be tween said shoulder and said resilient portion of said enclosure, said deflectable portion of said operating plate having a projection formed thereon extending towards said shoulder, resilientmeans urging said plunger in a direction to carry said shoulder away from said projection, and means for mounting said housing with the outer end of said plunger engaging the stem of a gate valve and with said shoulder engaging said projection and deflecting said operating plate to maintain the operating arm of said switch in a predetermined position.

2. Fire sprinkler system gate valve signaling means, comprising a housing, said housing having an elongated boss formed thereon, an elongated plunger extending through said boss and into said housing, means support ing said plunger for limited displacement relative to said boss and housing, said plunger having a shoulder formed on the inwardly presented end thereof, an electrical switch mounted in said housing adjacent to said plunger, a Watertight enclosure surrounding said switch and having'a flexible portion juxtaposed to the operating arm of said switch, an elongated resilient operating plate mounted in said housing and having a deflectable portion thereofextending between said flexible portion of said enclosure and said shoulder, said free end portion of said operating plate having a projection formed thereon extending towards and adapted to be engaged by said shoulder, means engaging said boss for supporting said housing with the outer end of said plunger engaging the stem of a gate valve and with said shoulder engaging said projection,,said operating plate being deflected to maintain the operating arm of said switch in a predetermined p0 sition when said projection is in engagement with said shoulder, resilient means urging said plunger away from said projection and in the direction to engage the 'valve trical switch mounted in said housing adjacent to said plunger, a watertight enclosure surrounding said switch and having a flexible portion juxtaposed to the operating arm of said switch, an elongated resilient operating plate mounted in said housing and having a deflectable portion thereof extending between said flexible portion of said enclosure and said shoulder, said free end portion of said operating plate having a projection formed thereon extending towards and adapted to be engaged by said shoulder, means engaging said boss for supporting said housing with the outer end of said plunger seated in a recess formed in the stem of a gate valve and with said shoulder engaging said projection, said operating plate being deflected to maintain the operating .arm of said switch in a predetermined position when said projection is in engagement with said shoulder, resilient means urging said plunger in the direction to move out of said housing to carry said shoulder away from said projection, elongated conductive means connected to said switch for connecting the same into a circuit and extending to a point remote therefrom, and an elongated watertight enclosure surrounding said conductive means and sealed into the switch enclosure.

4. A fire sprinkler system gate valve and signaling means, comprising a valve casing, a valve stem for operating said valve extending from said casing and having threaded and unthreaded portions, said valve stem having a recess formed in the surface of its unthreaded portion, a housing having an elongated tubular boss formed thereon, means engaging said boss and supporting said housing on said casing in juxtaposition with said valve stem adjacent to said recess, an elongated plunger extending through said boss and having an external end seated in said recess and having its inner end extending in said housing, said plunger having a shoulder formed on the inner end thereof in said housing, an electrical switch mounted in said housing adjacent to said plunger, a watertight enclosure surrounding said switch and having a flexible portion juxtaposed to the operating arm of said switch, an elongated resilient operating plate mounted in said housing and having a defiectable portion thereof extending between said flexible portion of said enclosure and said shoulder, said operating plate having a projection formed on the deflectable portion thereof and extending towards and engaging said shoulder, resilient means urging said plunger along said tubular boss toward said valve stem, said operating plate being deflected to a stressed position to deform the flexible portion of said enclosure and maintain the operating arm of said switch in a predetermined position, and the walls defining the recess in said valve stem being inclined so that motion of said valve stem causes said plunger in engagement with the walls of said recess to be cammed into said boss and housing to carry said shoulder out of engagement with said projection thereby leaving said deflectable portion free to move from its said stressed position.

References Cited in the file of this patent UNITED STATES PATENTS 862,551 Gardner Aug. 6, 1907 896,864 Spamer Aug. 25, 1908 1,127,232 Grimes Feb. 2, 1915