Patent Publication Number: US-3877527-A

Title: Thermally insulated actuator for fire sprinkler heads

Description:
United States Patent Johnson Apr. 15, 1975 [541 THERMALLY INSULATED ACTUATOR 3,392,787 7/1968 Weise 169/26 FOR FIRE SPRINKLER HEADS 3,587,747 6/1971 Romero 169/26 3,791,450 2/1974 Poitras 169/37 Wilfred V. Johnson, 36 Rocky Hill Rd., Oxford, Mass. 01540 Filed: Sept. 24, 1973 Appl. 190.; 399,852  
 Related U.S. Application Data Continuation-impart of Ser. No. 143,394, May 14, 1971, Pat. No. 3,802,510.  
 Inventor:  
 U.S. C1 169/90; 251/11 Int. Cl. A62c 37/08 Field of Search 169/1 R, 1 B, 2 R, 26,  
 References Cited UNITED STATES PATENTS 4/1966 Romero 169/26 Primary ExaminerM. Henson Wood, Jr. Assistant ExaminerMichael Mar Attorney, Agent, or FirmJ0hn E. Toupal [57] ABSTRACT Disclosed is a mounting system for temperature responsive actuators of automatic fire extinguishing sprinkler heads. Thermal insulation is provided between the temperature responsive actuator and the housing of the sprinkler head.  
 12 Claims, 7 Drawing Figures PATENTEUAFR 1 EMS sum 2 pg 2 TI-IERMALLY INSULATED ACTUATOR FOR FIRE SPRINKLER HEADS BACKGROUND OF THE INVENTION This invention is a continuation-in-part of my copending U.S. application Ser. No. 143.394. filed May 14. 1971 now U.S. Pat. No. 3.802.510 and entitled Automatic Fire Sprinkler Head.  
  This invention relates to fire extinguishing systems and, more particularly. to a mounting system for mounting a temperature responsive actuator to the housing of a fire extinguisher sprinkler head while maintaining thermal isolation therebetween.  
  The many advantages of automatic fire extinguishing systems have long been known. Furthermore. renewed interest in automatically resetable heads for fire sprinkling systems is evident. Examples of that interest are several recently issued U.s. Pats. such as Nos. 3.698.483; 3.702.160 and 3.734.l9l.  
  A problem found in conjunction with resettable heads that did not occur with use of the more conventional one shot&#34; heads is the danger of premature closing. This can occur if the fire is substantially extinguished and the ambient temperature drops. In such an event. the fire intensity is sure to increase after the cessation of water flow. Extinguishing action can also be terminated prematurely if cooling action around the head due to the flow of the extinguishing medium reaches the thermally responsive control device. Clearly. premature termination of water flow can lead to catastrophic results.  
  An object of this invention. therefore. is to provide a resettable sprinkler head this is reliable and resists premature termination of flow.  
 SUMMARY OF THE INVENTION This invention is characterized by a valve assembly for automatic fire extinguishing systems and includes a housing that defines a fluid passage therethrough. A valve member is within the fluid passage and is coupled to a temperature responsive actuator. Temperature insulation is utilized in the mounting to secure the actuator to the valve housing and restrict thermal communication therebetween. Consequently. many of the aforementioned problems associated with fire extinguishing sprinkler heads are prevented. For example. the flow of cool fire extinguishing medium through the housing cannot effectively cool the temperature responsive sensor and thus prematurely close the valve. In addition. the sensor is more responsive to increases in ambient temperature in that heat loss to the valve housing is minimized.  
  One embodiment disclosed herein includes a large heat sink in thermal contact with the temperature responsive sensor. The heat sink is heated while a fire persists and. upon extinguishment of the fire or a reduction in the intensity thereof. maintains the temperature responsive sensor at an elevated temperature and thus retains the valve open for a delay period. Consequently the chance of a sprinkler head prematurely closing due to near extinguishment of a fire is reduced.  
 DESCRIPTION OF THE DRAWINGS These and other features and objects of the present invention will become more apparent upon a perusal of the following description taken in conjunction with the accompanying drawings wherein:  
  FIG. I is a sectional elevation view of a fire sprinkler head apparatus:  
  FIG. 2 is a sectional elevation view of another fire sprinkler head embodying the subject insulated mounting system; i  
  FIG. 3 is a sectional plan view of the head depicted in FIG. 2:  
  FIG. 4 is an exploded sectional view of the insulated mounting system utilized in the head shown in FIGS. 2 and 3:  
  FIG. 5 is a sectional detail view of the mounting system utilized in the head shown in FIGS. 2 and 3:  
  FIG. 6 is a sectional view of an alternate insulated mounting system: and  
  FIG. 7 is a sectional view of another alternate mounting system.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 there is shown a sectional view of an embodiment 21 of the invention including a housing 22 that defines an inlet opening 23 and a plurality of outlet openings 24. Enclosed in a cavity 25 within the housing 22 is a valve member 26 that is connected by a reciprocating actuator 27 to a temperature responsive control mechanism 28. Contained within the control mechanism 28 is a body of expansible material that exhibits a substantial volume change during the liquid to solid transition. The melting point can be selected accurately from a wide temperature range by varying the composition of the material. Suitable mechanisms of this type are disclosed. for example. in U.S. pats. Nos. 2.815.174: 2.938.384: and 3.092.322. Changes in volume of the material within housing 28 produce reciprocating mechanical motion of the operatively coupled actuator 27. Also disposed within the cavity 25, and positioned between the top thereof and the vavle member 26 is a bias spring 29 that presses the valve member toward the bottom of the cavity. thereby covering and closing the outlets 24. Projecting from the annular surface of the valve member 26 are a plurality of guides 31 that keep the valve member transversely centered within the cavity 25. When the valve member 26 is forced upward by the actuator 27. thereby opening the outlets 24. water freely flows from the inlet 23 to the outlets 24 through a plurality of gaps 32 disposed between and defined by the guides 31. Disposed below the outlets 24 and in the path of discharge is a deflector 33 to disperse the flow of water. Between the deflector 33 and the actuator 28 is a large body 34 of thermal insulation material that prevents the flow of water around the deflector 33 from influencing the temperature sensed by the control mechanism 28. An upper portion 35 of the housing 22 is threaded so that the embodiment 21 may be installed in existing fire extinguishing systems by simply changing valves.  
  During operation of embodiment 21 valve member 26 is normally in the closed position as shown in FIG. 1, and held in place by bias spring 29. In the event of a fire. heat raises the ambient temperature and the temperature of the control mechanism 28 quickly reaches the melting point of the expansible material. The melting point is sharply defined. and therefore the entire body of expansible material quickly melts and the resultant increase in volume forces the piston actuator 27 in an upward direction. The force of the spring 29 is overcome and the valve member 26 is moved to the open position. uncovering the outlets 24. Water then flows through the inlet 23. the gaps 32 and the outlets 24 over the deflector 33 thereby spraying the surrounding area. When the fire is extinguished. as evidenced by a decrease in ambient temperature. the temperature of the control mechanism falls to below the melting point of the expansible material. and the body of expansible material then solidifies and contracts. As the contraction takes place the spring 29 pushes the valve member 26 back to the closed position thereby stopping the flow of water automatically. Typically. the actuator mechanism 28 would be selected to have a reponse in a temperature range between l-220F.  
  Referring not to FIGS. 2 and 3 there is shown another embodiment 37 of the invention including a housing 38 defining an inlet opening 39 and an outlet opening 41. Within the housing 38 is a cavity 42 with an eccentric cam 43 resting on a lower surface 44 thereof. The eccentric cam 43 defines a valve opening 45 and is pivotally mounted by a pin 46. A bias spring 47 holds the cam 43 in a closed position. that is. with the valve opening 45 horizontally displaced from the outlet 41. Mounted on the housing 38 is a temperature responsive control mechanism 48 that is operatively coupled to the cam 43 by a reciprocating actuator 49. The control mechanism 48 comprises a sensor similar to that denoted by number 28 is embodiment 21. The cam 43 mechanically couples the spring 47 to the actuator 49 as a lever. thereby amplifying the force exerted by the spring 47 on the actuator 49. Disposed below the control mechanism 48 is a deflector 51 to prevent the cooling of the control mechanism by splashing water discharged against a dispensing deflector located below the outlet 41. An upper portion 52 of housing 38 is threaded so that the unit 37 may be easily substituted for conventional fusible type nozzles in existing fire extinguishing systems.  
  During operation of embodiment 37 the bias spring 47 normally holds the eccentric cam 43 in the closed position. Heat. caused by a fire. raises the ambient temperature and therefore the temperature of the control mechanism 48 until the melting point of the expansible material is reached. The body of the expansible material then melts quickly. and the associated increase of volume forces the actuator 49 to the left as viewed in FIG. 3. The eccentric cam 43 is thereby rotated clockwise to the open positions. that is. with the valve opening 45 disposed between the inlet 39 and the outlet 41. Water then flows through the valve 37. When the fire is extinguished and the ambient temperature drops. the body of expansible material solidifies. with an associated decrease in volume. As the decrease in volume occurs. the bias spring 47. through the lever action of the cam 43. forces the actuator 49 to the right as viewed in FIG. 3. The valve 37 is then closed. and ready to be recycled. The mechanical leverage furnished by the cam 43 amplifies the force provided by the spring 47 to insure full retraction of the actuator 49 and thereby full closure of the valve. This is an important feature in that actuator mechanisms of this type offer a substantial resistance to full retraction because of the elastic nature of internal gaskets (not shown) that are generally employed. Thus. the lever motion of cam 43 permits use of the full stroke of the actuator 49 while minimizing the bias requirements of the spring 47. Another important feature of embodiment 37 is that the reciprocating movement of the actuator 49 is transverse to the direction of fluid discharge from the outlet 41. Because of this relationship and the use of a slide valve. the control mechanism can be mounted out of the path of fluid flow to provide an extremely compact unit.  
  Referring now to FIGS. 4 and 5 there is shown in detail the thermally responsive control mechanism 48. An insulated mounting system couples the housing of a thermally responsive sensor actuator 55 to the housing 38 (FIG. 3). A first insulating washer 56 with a passage therethrough fits against the inner face 57 of the sensor housing. A second insulating washer 58 forms. together with the first insulating washer 56. an insulating sheath. Retained by the sheath is an annular coupling ring 59 on a threaded rigid mounting member 61. A tubular cover 63 with an inwardly turned collar 64 on the outer end fits over the sheath and the mounting member 61. Passing through openings in each of the aforementioned components is the actuator rod 49.  
  FIG. 5 shows the components depicted in FIG. 4 in an assembled juxtaposition. It will be appreciated that during assembly the inner end of the tubular cover 63 is crimped to form an inner collar 65 and thus secure the various components together. The tubular cover 63 is in thermal contact with the housing of the actuator 55. However. it is not in thermal contact with the rigid threaded mounting member 61. Structural coupling therebetween is supplied through the annular washers 56 and 58. Thus. thethreaded mounting member 61 is effectively thermally isolated from the housing of the thermal actuator 55. Mounting of the apparatus 48 includes screwing the member 61 into a threaded opening in the side of the housing 38 and tightening the assembly with a wrench accommodated by the exposed outer body surface of the member 61. Preferably. once assembled. the spacing between the wrench receiving body portion of member 61 and the housing 38 is small. for example 3/16 inches. so as to require a specially sized wrench for disengagement. In this way once assembled the unit is rendered less subject to tampering.  
  Referring now to FIG. 6 there is shown an alternate mounting system 71 including a thermally responsive sensor 55 and two washers 56 and 58 that form a sheath around an annular ring 59 ofa rigid mounting member 61. A tubular cover 72 includes an enlarged heat sink portion 73. The actuator rod 49 is not shown to preserve clarity. Observation of FIG. 6 will show that the mounting system 71 is substantially similar to the mounting system 48 except for the inclusion of the heat sink in thermal contact with the housing of the actuator 55 and that an inner collar 74 is formed around a different portion of the housing 55. Also. the member 61 is provided with an annular recess that accommodates an O-ring 75 that prevents flow of extinguishant fluid out of the valve and into the actuator along the path between the surfaces of the actuator rod and the member 61. The inner collar 74 is formed in the different location to insure thermal communication between the heat sink and the housing of the sensor 55. Mounting is. of course. performed similarly by screwing the threaded mounting member 61 into the housing 38.  
  FIG. 7 illustrates a slightly modified version of the sensor shown in FlG. 6. ln this case the heat sink 73 is replaced by a thin walled tubular cover 81 that renders the unit more sensitive to changes in ambient temperature. Again, an O-ring 83 isolates the actuator from extinguishing fluid. Still further temperature sensitivity is established by a plurality of apertures 82 in the tube 8l that permit air to flow across that portion of the sensor 55 enclosed by the tube 81.  
  Obviously. many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood. therefore. that the invention can be practiced otherwise than as specifically described.  
  What is claimed is: l. A valve assembly for use in automatic fire extinguishing systems and comprising:  
 a housing defining a fluid passage therethrough; a valve member in said passage for controlling the flow of fluids therethrough;  
 temperature responsive actuator means for operating said valve member in response to ambient temperature changes. said actuator means further comprising an actuator housing and a recyclable actuator means for repeatedly operating said valve member in response to repeated ambient temperature changes; and  
 temperature insulation means for securing said actuator housing to said housing and for restricting thermal communication therebetween.  
  2. A valve assembly according to claim 1 comprising fluid dispersion means disposed near one end of said fluid passage for dispersing fluid emerging therefrom.  
  3. A valve assembly according to claim 1 wherein said actuator means comprises a body of material that exhibits a substantial volume increase during the solid to liquid transition and a corresponding volume decrease during the liquid to solid transition and wherein said volume increase is utilized to actuate said valve member.  
  4. A valve assembly according to claim 1 wherein said temperature insulation means is annular and is coupled to said housing at one end and to said actuator housing at the end of said insulation means opposite said one end.  
  5. A valve assembly according to claim 4 wherein said actuator means comprises an actuator rod emerging from said actuator housing and operatively coupled to said valve member and wherein said actuator rod passes through said insulation means.  
  6. A valve assembly according to claim 1 wherein said temperature insulation means comprises insulated mounting means for attaching to said housing and further comprises coupling means for coupling said actuator housing to said insulated mounting means so as to provide thermal insulation in all direct heat transfer paths between said housing and said actuator housing.  
  7. A valve assembly according to claim 6 wherein said insulated mounting means comprises a rigid mounting member for coupling to said housing and further comprises insulating sheath means for covering said rigid member.  
  8. A valve assembly according to claim 7 wherein said rigid mounting member comprises an annular portion spaced apart from said housing and said coupling means comprises a tube with an inward collar at each end thereof. and wherein one of said collars is in operative engagement with said annular member and the other one of said collars is in operative engagement with said actuator housing so as to secure said actuator housing to said annular member but wherein a portion of said sheath is disposed between said annular portion and said actuator housing.  
  9. A valve assembly according to claim 8 wherein another portion of said sheath is disposed between said annular member and said one of said collars.  
  10. A valve assembly according to claim 8 wherein said tube comprises an enlarged heat sink portion.  
  11. A valve assembly according to claim 8 wherein said tube comprises openings providing air flow paths to said actuator housing.  
  12. A valve assembly according to claim 8 including seal means providing a fluid tight seal between said actuator rod and said insulation means.