Abstract:
The sprinkler arrangements described in the specification include a sprinkler body with an axial passage and an axially movable assembly movable between a sealing position and an open position and including a Belleville washer engageable with a shoulder in the sprinkler body to seal the axial passage in the sealing position and a deflector to distribute water emerging from the passage when the movable assembly is in the open position. A locking assembly which is separable from the sprinkler body normally retains the axially movable assembly in the sealing position and is releasable by a temperature sensitive apparatus at an elevated temperature to permit the movable assembly to move to the open position. In one embodiment the axially movable member has a central post which is slidably guided by a tripod at the outer end of the axial passage. The temperature sensitive apparatus includes a locking disc supported by a temperature responsive element which may be a glass bulb supported in a bulb cage, a plug of fusible material supporting a locking pin, or a solder link retaining the ends of lever members to hold the locking disc in place.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to fire extinguishing sprinklers and, more particularly, to new and improved sprinkler arrangements having a compact structure and adapted to respond quickly to elevated temperature conditions indicative of a fire. 
     Sprinkler systems are widely used for automatic fire protection in residential, commercial and public buildings. Heretofore, many sprinklers have been made with a frame structure incorporating a temperature responsive element located within the frame structure. In order to expose the temperature responsive element to ambient conditions such sprinklers must be mounted so that the entire frame structure including a deflector affixed at its outer end projects downwardly from the ceiling, providing an unattractive appearance. Some conventional sprinklers have a slidable valve and deflector arrangement which is normally retained in a retracted condition by a complex captive locking mechanism that, upon activation, moves with the valve from the retracted close position to an open position. Typical sprinklers of this type are disclosed in U.S. Pat. Nos. 4,491,182, 5,036,923, and 5,094,298. 
     In other types of quick response sprinklers, such as shown in U.S. Pat. Nos. 4,766,961, 4,785,888 and 6,152,236, the locking mechanism is ejected from the sprinkler when the deflector is moved from the closed position to the open position. Most of the prior art sprinklers of that type include a deflector supported from pins which are slidably supported in lateral extensions of the sprinkler body so that they are normally disposed in the region surrounding the portion of the body containing the passage for water. Such arrangements not only enlarge the size of the sprinkler but also require complex slidable supporting structures for the deflector. U.S. Pat. No. 6,152,236 discloses a sprinkler having a temperature responsive element having the same diameter as the deflector so as to conceal the deflector. 
     In many sprinklers, a glass bulb is provided as a thermally responsive device to activate the sprinkler at elevated temperatures. Such glass bulbs must be adequately exposed to the surrounding atmosphere to assure a fast response to hot gases but, at the same time, must be adequately protected against accidental or malicious breakage. U.S. Pat. Nos. 5,944,113 and 5,967,237 disclose sprinklers having a glass bulb temperature responsive element which is enclosed in a cage projecting from the outer end of the sprinkler. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a quick response adjustable automatic sprinkler which overcomes disadvantages to the prior art. 
     Another object of the invention is to provide a quick response sprinkler having a simple and compact configuration. 
     A further object of the invention is to provide an enclosure for a glass bulb-type temperature sensitive element for a sprinkler which protects the bulb while assuring access to the bulb by high temperature gases. 
     In accordance with one aspect of the invention a quick response sprinkler arrangement includes a sprinkler body having an axial passage and a deflector supported on a central post which is slidably guided parallel to the axis of the sprinkler passage by a tripod member supported at the outlet end of the passage and having a central opening in which the post is slidable. A tapered neck at the inner end of the post supports a spring washer which engages a shoulder in the passage of the sprinkler body to seal the passage as long as the post and the deflector are retained in an inward position by a locking arrangement. In one form of locking arrangement a plurality of balls are retained by a locking disc so that they engage a peripheral groove in an inner surface of a portion of the sprinkler body, the locking disc being held in position by a thermally responsive element, such as a fusible plug or a glass bulb. 
     In one embodiment, a plug of fusible material in a tubular housing supports the locking disc in position and heat is transmitted to the fusible material by a heat collecting structure attached to the tubular housing including a thin metal cup member which opens in the direction facing away from the sprinkler passage and a thin metal dish member open inwardly toward the sprinkler passage and having inclined sides with radially projecting cut outs. In another embodiment the thermally responsive element is a glass bulb which is mounted in a cage having a plurality of longitudinal openings which extend parallel to the sprinkler axis and have concave sides shaped to direct gases inwardly from the periphery of the cage toward the bulb mounted in the cage. In a further embodiment the sprinkler arrangement includes a locking disc covering the sprinkler deflector and having a diametrical channel in its outer surface along with lever members received in the channel each having an inner end engaging a peripheral groove in an inner surface of the sprinkler body and an outer end received in a flat horizontally disposed temperature sensitive solder link element so as to retain the locking disc in locking position until they are released by fusing of the solder in the temperature sensitive element. The locking disc also has a peripheral bevel to direct hot gases toward the upper surface of the temperature sensitive level. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further objects and advantages of the invention will be apparent from the reading of the following description in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a longitudinal sectional view illustrating one representative embodiment of a quick response automatic sprinkler arrangement in accordance with the invention; 
     FIG. 2 is an end view of a tripod member arranged to receive a post supporting a deflector in the sprinkler arrangement of FIG. 1; 
     FIGS. 3 and 4 are plan and cross-sectional views, respectively, of a heat collecting cup member for the embodiment of FIG. 1; 
     FIGS. 5 and 6 are plan and sectional views, respectively, of a heat collecting dish member for the embodiment of FIG. 1; 
     FIG. 7 is a view similar to FIG. 1 illustrating the position of the sprinkler components after activation of the sprinkler; 
     FIG. 8 is a longitudinal sectional view illustrating a second representative embodiment of a sprinkler arrangement in accordance with the invention; 
     FIG. 9 is an enlarged sectional view, taken on the line IX—IX of FIG. 10, illustrating a bulb cage for the glass bulb in the embodiment of FIG. 8; 
     FIG. 10 is an end view of the bulb cage shown in FIG. 9; 
     FIGS. 11A,  11 B and  11 C are schematic diagrams illustrating the flow pattern of hot air impinging on the bulb cage of FIGS. 9 and 10 at various angular orientations; 
     FIG. 12 is a longitudinal sectional view illustrating a third representative embodiment of a sprinkler arrangement according to the invention; 
     FIG. 13 is a longitudinal sectional view illustrating a fourth embodiment of a sprinkler arrangement according to the invention; and 
     FIG. 14 is a plan view of a locking disc used in the embodiment of FIG.  13 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the typical embodiment of the invention illustrated in FIGS. 1-7, a sprinkler  10  includes a hollow body  12  which has an internal axial passageway  14  for water and is externally threaded at one end  16  for attachment to a water supply pipe. The axial passage  14  is normally sealed by a spring washer such as a Belleville washer  18  which is supported on the inner end  20  of a central post  22  and has a peripheral surface engaging a shoulder  24  in the passage wall facing toward the outlet end  26  of the passage. The washer  18  is preferably coated with a resin layer such as a polytetrafluoroethylene layer to resist corrosion and provide good sealing engagement with the shoulder  24 . 
     In order to support the post  22  for axial motion with respect to the sprinkler passage  14 , a tripod member  28  has three angularly spaced legs  30  which are held captive near the outer end of the sprinkler body  12  by a ring  32  which is threaded into internal threads  34  in a cylindrical projection  36  of the housing so that the legs  30  are fixed in position between the inner edge of the ring  32  and a shoulder  38  surrounding the outlet end  26  of the passage. 
     At its outer end the central post  22  carries a planar deflector  40  which is held by a retaining ring  42  in a plane perpendicular to the axis of the sprinkler passage. The post  22  has an outer surface  44  which is slidably received in a central tripod opening  46  which has a conical surface. 
     In order to releasedly retain the central post  22  in its passage-sealing position, a separable valve-retaining assembly  50  is provided. This retaining assembly includes a retaining housing  52  having a cover  54  at its inner end abutting the deflector  40  and a support bushing  56  for a temperature-sensitive device  60  which projects from the outer end of the retaining assembly  50 . Within the retainer housing  52  a locking disc  62  has a beveled outer edge surface  64  and is supported on a shoulder  66  of a central locking pin  68  which extends through the locking disc  62  into an axial recess  70  in the central post  22 . At its opposite end the locking pin  68  engages a piston  72  which is, in turn, supported by a plug  74  of fusible material at the inner end of an axial passage  76  in a tubular housing  78 . 
     Surrounding the beveled edge surface  64  of the locking disc  62  are a plurality of balls  84  supported in corresponding openings  86  in an annular wall  88  of the retainer housing  52 . The outer surfaces of the balls  84  are received in an annular inner groove  90  in the inner surface of the ring  32  and the inner surfaces of the balls engage the surface  64  of the locking disc  62 . As a result, the locking disc  62  and the balls  84  lock the retaining housing  52  in position in the ring  32  as long as the plug  74  of fusible material remains solid, but when the fusible material is melted at a selected high ambient temperature, the locking pin  66  and the locking disc  62  move downwardly in the axial passage  76 , permitting the balls  84  to move inwardly which, in turn, permits the retaining assembly  50  to be released from the ring  34 . The Belleville washer  18  then forces the central post  22  outwardly, ejecting the locking assembly and the water under pressure in the sprinkler passage forces the deflector  40  outwardly in the sprinkler passage until an outwardly inclined conical surface  94  at the inner end of the central post engages the corresponding conical central opening  46  in the tripod  28  so that the central post is firmly held in the axial orientation by the tripod. 
     In order to convey heat from the surrounding region to the temperature sensitive device  60  in a rapid and efficient manner, an inwardly open heat collecting dish member  96  and an outwardly open heat collecting cup member  98  are mounted at the outer end of the thermally responsive assembly by a nut  100 . As best seen in FIGS. 3 and 4, the heat collecting dish member  96  has four triangular openings  102  from which the metal has been bent downwardly to produce corresponding projecting surfaces  104 . The cup member  98 , as shown in FIGS. 5 and 6, has a peripheral surface  106  which is inclined outwardly away from the horizontal at an angle of about 60° from the horizontal. Both the cup member and the dish member are made of thin heat conductive materials such as 0.012 inch (0.3 mm) thick brass CDA alloy. 
     FIG. 7 illustrates the positions of the various parts of the sprinkler  10  after it has been activating by melting of the fusible plug  74  at a selected elevated temperature. As shown in FIG. 7, the retaining assembly  50  is ejected from the sprinkler body  12  when the locking pin  66  together with the locking disc  62  have moved outwardly from the body  12 , permitting the balls  84  to move inwardly into the openings  86  in the annular wall  88  so that they are released from the annular internal groove  90  in the ring  32 . As a result the movable assembly including the central post  22  with the deflector  40  moves outwardly from the sprinkler passage so that the deflector is positioned beyond the outer end of the ring  32  and the conical surface  94  of the post  22  is firmly engaged in the conical opening  46  of the tripod  28 , permitting water to pass directly to the deflector  40  and be distributed about the region to be protected by the sprinkler. 
     With a sprinkler arrangement of the type described above and shown in FIGS. 1-7, the size, weight and cost of making a sprinkler is substantially reduced in comparison, for example, to a sprinkler of the type shown in U.S. Pat. No. 4,766,961. In particular, the sprinkler of the present invention has an axial length which is 28% less and a weight which is 44% less than a sprinkler of the type described in that patent and has a manufacturing cost estimated at 30 to 40% less than that of the prior art sprinkler. Moreover the thin metal cup and dish members which transfer heat to the temperature sensitive device  60  are less subject to accidental or deliberate breakage and deformation than the disc shaped fins of the prior art arrangement. 
     A second embodiment of the invention, illustrated in FIGS. 8-10, also provides the advantages of reduced size and weight and eliminates susceptibility to possible damage of heat transfer components in the temperature sensitive device  60  of the first embodiment. In this embodiment, a sprinkler  110  has a sprinkler body  112  containing a central passage  114  and an externally threaded end  116  for attachment to a water supply pipe. The passage  114  is normally sealed at its outer end  118  by a spring washer such as a Belleville washer  120  mounted on a centrally positioned diffuser member  122  extending into the end  118  of the passage  114  in the closed position. The Belleville washer  120  preferably has a coating of a resin material such as polytetrofluoroethylene to assure corrosion resistance and form a good seal between a shoulder  124  of the diffuser on which it is supported and a shoulder  126  in the sprinkler body  112  surrounding the outer end  118  of the passage  114 . A deflector  130  mounted on the outer end of the diffuser  122  is supported for axial sliding motion toward and away from the outer end  118  of the passage by two pins  132  received in corresponding openings  134  in the sprinkler body  112 . 
     A dust cover  136  surrounds the central portion of the sprinkler body  112  enclosing the pins  132  and a collar  140 , threadedly mounted at the outer end of the sprinkler body  112 , has an internal groove  142  in which the outermost balls  144  of a plurality of linear arrays of such balls are received in order to retain a locking assembly  146  containing the balls in position and the outer end of the sprinkler body. In the unactivated condition of the sprinkler the arrays of balls  144  are urged outwardly in radially extending openings  148  in a support bushing  150  by an inclined outer surface  152  of a central piston  154  which is normally held in the ball-retaining position by a temperature-sensitive device  156 . In this embodiment, the temperature sensitive device  156  includes a glass bulb  158  supported in a bulb cage  160  which is threaded into a central opening in the support bushing  150 . The piston  154  is slidably guided in a guide sleeve  162  which is made of or coated with a synthetic resin material such as polytetrofluorethylene to assure smooth axial sliding motion of the piston and to avoid the effects of corrosion. The glass bulb  158  is a quick response bulb designed to fragment at a selected high temperature such as  155 ° F. In order to avoid stress fracture of the bulb, the compressive load applied to the bulb is reduced by the mechanical advantage produced by the inclined surface  152  which engages the balls  144  to urge them outwardly into the groove  142  in the collar  140  as the collar is threaded onto the sprinkler body  112 . The inner surface  164  of the locking assembly engages a shoulder  166  at the outer end of the diffuser  122  so that threading of the collar  140  onto the sprinkler body  112  urges the diffuser member  122  inwardly into the passage  114 . During assembly, the collar  140  is tightened sufficiently to produce a desired deflection of the Belleville washer  120 . 
     The bulb cage  160  has a central opening  170  in which the bulb is received and, as best seen in FIGS. 9 and 10, the cage has five lateral openings  172  formed by cylindrical cuts in the cage wall extending parallel to the axis of the bulb cage to provide communication between the central opening  170  and the exterior of the bulb cage. As shown in FIG. 10, the resulting side walls  174  of the cylindrical openings  172  have a corresponding arcuate shape and this shape facilitates motion of air moving adjacent to the bulb cage into the interior of the bulb cage to transfer heat to the bulb. Because there are an odd number, such as five, of such openings distributed uniformly around the periphery of the bulb cage, a portion of the air passing in any direction adjacent to the bulb cage is diverted into the central opening  170  by two or more of the walls  174 . This is illustrated in FIGS. 11A,  11 B and  11 C which show how the surfaces  174  direct air inwardly toward the bulb regardless of the angle at which the air approaches the bulb cage. Furthermore, the spacing  176  between the outer edges  178  of each opening  172  is larger than the spacing  180  between inner edges  182  of each of the openings  172  and the spacing  184  between the bulb  158  and the inner surface  170  is smaller than the spacing  180 . This arrangement causes the air which flows through one of the openings  172  toward the bulb  158 , then around the bulb and out of another opening  172  at the opposite side of the cage to flow more rapidly in the region surrounding the bulb, thereby not only increasing the rate of heat transfer from the air to the bulb but also producing a venturi effect at the intermediate opening  172  past which the air is flowing from one side of the cage to the other, so as to draw air in toward the bulb from the airstream flowing past that opening. 
     In the schematic illustrations of FIGS. 11A,  11 B, and  11 C, twenty-seven equally spaced arrows represent a stream of air passing in a direction toward the bulb cage  160  at three different angular orientations spaced by 120°. In each of the illustrated orientations fourteen of the twenty-seven arrows either strike the bulb directly or are intercepted by a concave surface  174  from which they are deflected inwardly toward the bulb. Consequently, at each orientation of the bulb cage, at least 50%, i.e., approximately 52%, of the approaching air stream impinges the bulb directly or after deflection by the concave surfaces. In addition, as discussed above, a proportion of the air passing adjacent to an intervening opening which does not receive air directly is drawn into the cage by the venturi effect. Consequently, a rapid response to impingement of hot gases or air at elevated temperature is provided by this temperature-sensitive arrangement. 
     In a third embodiment of the invention a sprinkler  200 , illustrated in FIG. 12, is similar to the embodiment of FIGS. 1-7 but has a locking assembly  202  in which a temperature sensitive device  204  includes a glass bulb  206  mounted in a bulb cage  208  of the same type described above as with respect to FIGS. 8-11 in place of the temperature sensitive device using a fusible material described in connection with FIGS. 1-7. This arrangement combines the compact configuration of the sprinkler body and release mechanism with the simple structure of the glass bulb temperature sensitive device. 
     An additional embodiment of the invention, shown in FIGS. 13 and 14, also provide the advantage of reduced size and weight and uses a rapid response heat sensitive arrangement of established and proved construction. In this embodiment, a sprinkler arrangement  210  has a sprinkler body  212  containing a central passage  214  and an external thread  216  at its inner end for attachment to a water supply. The passage  214  is normally closed at its outer end  218  by a spring washer  220  such as a Belleville washer mounted on a centrally positioned diffuser member  222  projecting into the outer end  218  of the passage  214  in the closed position. The Belleville washer  220  preferably has a coating of a resin material such as a polytetrofluoroethylene to resist corrosion and assure a good seal between a shoulder  224  of the diffuser  222  on which it is seated and a shoulder  226  in the sprinkler body  212  surrounding the outer end  218  of the passage  214 . A deflector  230  mounted on the outer end of the diffuser  222  is supported for sliding motion toward and away from the outer end  218  of the passage by two pins  232  received in corresponding openings  234  of the sprinkler body  212  and a dust cover  236  surrounds the central portion of the sprinkler body  212  enclosing the pins  232 . 
     A collar  240  projecting forwardly from the sprinkler body has an internal groove  242  near its outer end and a movable assembly  244  consisting of the deflector  230  and the sealing member  220  is retained in the passage sealing position by a locking assembly  246  which includes a locking disc  248  positioned within the collar  240 . The locking disc has an adjustable screw  250  received in a central opening  252  in the outer end of the diffuser  222  and, to retain the locking disc in its illustrated position holding the movable assembly  244  in the sealing position, two levers  256 , received a diametrical channel  258  in the outer surface of the locking disc  248 , have inner ends  260  engaging the groove  242  and outer ends  262  received in corresponding openings  264  in a temperature sensitive solder link device  266 . The solder link device consists of two flat metal plates  268  and  270  held together by a layer  272  of solder which is arranged to melt and release the plates permitting the levers  256  to separate and release the locking disc  248  when the temperature exceeds a selected high level such as 165° F. A central opening  274  in the temperature sensitive device permits access to the adjusting screw  250  after the locking assembly has been installed. A wave spring  276  positioned between the locking disc  248  and the deflector  230  urge the movable assembly in the direction away from the axial passage  214 . 
     Since the locking disc  248  has approximately the same diameter as the deflector  230 , it completely fills the opening in the collar  240 , thereby concealing the movable assembly  244  until the locking assembly has been released and ejected from the collar at an elevated temperature, thereby permitting the deflector to move outwardly to a position beyond the collar to distribute water emerging from the passage  214 . 
     To expedite actuation of the temperature sensitive device, the locking disc  248  has an annular outer surface portion  280  which is inclined outwardly in the direction from the periphery of the disc to a central surface portion  282  located directly behind the center of the temperature sensitive device  266  both surface portions  280  and  282  being bisected by the channel  258  in which the levers  256  are positioned. As best seen in FIG. 13, the annular surface portion  280  can direct hot gases approaching the sides of the locking disc outwardly toward the rear surface of the temperature sensitive device  266 , thereby facilitating rapid actuation of the device. 
     Although the invention has been described herein with reference to specific embodiments, many modifications and variations therein will readily occur to those skilled in the art. Accordingly, all such variations and modifications are included within the intended scope of the invention.