Patent Abstract:
A fire extinguisher apparatus and related system is described for automatically suppressing stovetop fires. The fire extinguisher apparatus includes a canister restrained in a first location where the canister is operable to suppress fires on a rear burner of a stovetop. The canister is biased and movable to a second location where the canister is operable to suppress fires on a front burner of the stovetop. A trigger mechanism is provided for automatically moving the canister to the second location in response to a fire on the front burner. The fire extinguisher system includes an arrangement of fire extinguisher apparatuses wherein canisters are movable between the apparatuses to prevent collisions with external obstacles.

Full Description:
BACKGROUND 
     1 . Related Application 
     This application is a non-provisional of and claims the benefit of and priority to U.S. Provisional Patent Application No. 61/703,422 titled “Flame Dispersant Canister Mounting System for Under-Microwave Location” filed Sep. 20, 2012, which is incorporated herein by reference in its entirety. 
     2 . Field of Invention 
     This invention relates in general to a canister containing a fire suppressant powder for mounting above cook stoves, and in particular to a method and apparatus for deploying the canister to dispense the fire suppressant powder to multiple cooking elements. 
     3 . Description of Related Art 
     Stovetop fires can be inadvertently ignited when, e.g., a pan of grease is left unattended on a heating element of a stove. If not promptly extinguished, a stovetop fire can spread to surrounding structures and cause significant damage and injury. To mitigate the risk of stovetop fires, automatically-activated fire extinguishing devices have been developed for mounting above a stovetop, e.g., within a range hood or under a microwave oven mounted over the stovetop. In the event of a stovetop fire, these devices typically release a fire suppressant material from a canister onto the stovetop, thereby extinguishing the fire. One example of an automatically-activated fire extinguishing device is described in commonly-owned, U.S. patent application Ser. No. 13/712,578, filed Dec. 12, 2012, now published as U.S. Patent Application Publication No. 2013/0175058, which is incorporated herein by reference in its entirety. 
     Often, portions of a stovetop are not directly covered by a range hood, microwave or other convenient mounting location for canisters of fire suppressant material, Automatically extinguishing fires that ignite on these portions of a stovetop presents some difficulty. 
     SUMMARY OF EMBODIMENTS OF THE INVENTION 
     In view of the foregoing, embodiments of the present invention provide systems for mounting a flame dispersant canister in a standby configuration over a first location of a stovetop. The canister is selectively movable to a deployed configuration over a second location of the stovetop in response to a fire in the second location. 
     According to one aspect of the disclosure, a fire extinguisher apparatus for automatically suppressing stovetop fires includes a housing with mounting fixtures for coupling the fire extinguisher apparatus—generally above a stovetop. A canister operable for automatically releasing a fire suppressant material in response to a fire adjacent the canister is movably supported by the housing between a first position with respect to the housing for extinguishing fire in a first location on the stovetop and a second position with respect to the housing for extinguishing fire in a second location on the stovetop. A restraining member operably couples the canister to housing such that the canister is restrained in the first position with respect to the housing, and the restraining member is responsive to fire in the second location on the stovetop to permit movement of the canister from the first location with respect to the housing to the second location with respect to the housing. 
     According to another aspect of the disclosure, a fire extinguisher apparatus includes a housing with mounting fixtures thereon for mounting the fire extinguisher apparatus in a mounting location. A hinge member is rotatably coupled to the housing, and a fuse extends through a first aperture in the housing and a second aperture in the hinge member for restraining the hinge member in a first position with respect to the housing. A biasing member operatively biases the hinge member toward a second position with respect to the housing, and a canister is coupled to the hinge member such that the canister is rotatable along with the hinge member with respect to the housing. The canister is operable to automatically release a fire suppressant material therefrom in response to fire adjacent the canister. 
     According to another aspect of the disclosure, a fire extinguishing system includes a left-hand fire extinguisher apparatus and a right-hand fire extinguisher apparatus operable to be mounted in respective left-hand and right-hand positions over the stovetop from the perspective of the operator facing the stovetop. Each of the left-hand fire extinguisher apparatus and the right-hand fire extinguisher apparatus includes a canister operable to automatically release a fire suppressant material therefrom in response to fire adjacent the canister, and the respective canisters are each rotatable from a respective first location to a respective second location about an arc extending between the a left-hand fire extinguisher apparatus and the right-hand fire extinguisher apparatus in response to fire at the respective second locations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the features, advantages and objects of the invention, as well as others which will become apparent, are attained, and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof which are illustrated in the appended drawings that form a part of this specification. It is to be noted, however, that the drawings illustrate only a preferred embodiment of the invention and are therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments. 
         FIG. 1  is a side elevation view of a fire extinguisher apparatus constructed in accordance with an embodiment of the present disclosure, installed in one example position and arranged in a standby configuration in accordance with an embodiment of the present disclosure. 
         FIG. 2  is a cross-sectional view of the fire extinguisher apparatus of  FIG. 1 . 
         FIG. 3  is an exploded assembly view of the fire extinguisher apparatus of  FIG. 1 . 
         FIG. 4  a perspective view of a system of fire extinguisher apparatuses constructed in accordance with an alternate embodiment of the present disclosure, the system of fire extinguisher apparatuses including a right-hand fire extinguisher apparatus and a left-hand fire extinguisher apparatus arranged for side-by-side installation and operation. 
         FIG. 5  is a perspective view of an underside of the left-hand fire extinguisher apparatus of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , an example of a fire extinguisher apparatus  11  is shown mounted in one example location under a microwave oven  12 . The fire extinguisher apparatus  11  is depicted in a standby or loaded configuration, which locates an automatic fire extinguisher canister  55  over a first heating element  67 , for example a rear burner on a cooking stove  16 . An end of a fuse  21  is located above a second heating element  69 , for example a front burner on cooking stove  16 . As described in greater detail below, in response to a fire on the first heating element  67 , an initiator  61  causes the fire extinguisher canister  55  to automatically operate and extinguish the fire. If, however, a fire begins on the second heating element  69 , the fire will light the protruding end of fuse  21 , inducing the fire extinguisher apparatus to move to a deployed configuration wherein fire extinguisher canister  55  is located substantially above second heating element  69 . The fire on the second heating element  69  can then be extinguished. 
     Fire extinguisher apparatus  11  includes a top housing  13  for securing fire extinguisher apparatus  11  to a location above a possible source of a fire such as the under-microwave location depicted. For example, top housing  13  may be mounted above a cook stove  16  using a bracket member  18  attached directly to the wall behind the stove  16  as shown in  FIG. 3 . Alternatively, the top housing  13  may be attached to microwave oven  12  by wires descending from a bar (not shown) that sits above vents of microwave oven. 
     Referring to  FIGS. 2 and 3 , an upper surface of top housing  13  can include multiple mounting attachment fixtures, generally fixtures  14 , to adapt to different types of vent hoods or other mounting arrangements. Top housing  13  is illustrated as having a generally planar, rectangular shaped portion with a front wall  13   a  projecting substantially perpendicularly away from an end of a shortened rear wall  13   b . Obliquely angled side walls  23  extend along the elongate edges from lateral ends of rear wall  13   b  and taper upward from the rear wall  13   b  to a lower surface of the rectangular shaped portion. An end of top housing  13  has an extension or fuse housing  15  which is narrower both horizontally and vertically than the rest of top housing  13 , and extends parallel to the elongate direction of top housing  13  from the front wall  13   a . It is illustrated centered horizontally, and flush vertically with the lower edge of the front wall  13   a  of top housing  13 . Fuse housing  15  includes an aperture  17  in its elongate direction through which a fuse assembly  19  can pass. The fuse housing  15  allows a protruding end of a fuse  21  to remain exposed past the front of fuse housing  15 . As illustrated in  FIG. 3 , the shape of the side walls  23  allows other members of the fire extinguisher apparatus  11  free motion. 
     Continuing with  FIGS. 2 and 3 , a mandrel  25  descends vertically from top housing  13 . Mandrel  25  is attached to the lower surface of the interior of top housing  13  and is substantially centrally aligned therein. The mandrel  25  is a substantially cylindrical member. Located a short distance from the inner surface of top housing  13  is an aperture  26  in the mandrel  25  through which fuse  21  passes. A bottom hinge  27  is fixedly attached to the lower end of mandrel  25  by an annular coupling  29 , shown mounted on an interior lower surface hinge  27  and in which a lower end of mandrel  25  is press fit within. Bottom hinge  27  may also engage a rotational locking feature  31  on mandrel  25  to prevent any rotational movement, here illustrated as a slot in mandrel  25  ( FIG. 3 ) into which a rib (not shown) within annular coupling  29  can fit. Bottom hinge  27  has a substantially cylindrical outer wall  33  attached by a base plate to annular coupling  29 . Outer wall  33  has a top surface  35 , a portion of which slopes downward toward a lower portion of bottom hinge  27 . In an example, the downward slope approximates a helix. In another example, the helical profile extends along about 180° of the periphery of the outer wall  33 . The helical top surface  35  is illustrated aligned so that its middle point is aligned with the sagittal mid-plane of fire extinguisher apparatus  11 . 
     Threaded onto the mandrel  25  below top housing  13  and above bottom hinge  27  is a rotator or top hinge  37 . Top hinge  37  is illustrated as having a generally planar rectangular shaped portion with a front wall  37   a  and a rear wall  37   b  projecting substantially perpendicularly away from an end of a shortened edge. Side walls are substantially rectangular and extend along the elongate edges from lateral ends of the rear wall. A front wall  37   a  of top hinge  37  is curved to join with the forward ends of the side walls and projects substantially perpendicularly away from a curved portion of the top portion of top hinge  37 . An axial bore  38  extends through a planar portion of top hinge  37  and is shown girded by inner and outer bore walls  39  and  40  ( FIG. 2 ). Bore walls  39  and  40  are illustrated as forming an annular spring channel which accepts a spring  41 . Spring  41  is illustrated as a compression spring, and may be a helical torsion spring or another type of spring in other embodiments. Mandrel  25  depends downward through the axial bore  38 , and top hinge  37  is rotatable with respect to the top housing  13  and hinge  27  about the axial bore  38 . When top hinge  37  is in a loaded configuration, as shown in  FIG. 2 , spring  41  is compressed between top housing  13  and top hinge  37 , exerting a downward reaction force on top hinge  37 . Top hinge  37  also includes a sliding member  42  configured to engage or mesh with the helical top surface  35  of bottom hinge  27 . Sliding member  42  permits at least a portion of the weight of top hinge  37  to be supported on the helical top surface  35 , which is in turn, supported by top housing  13  by mandrel  25 . Sliding member  42  is illustrated in  FIG. 2  as a vertical rib having a lower end positioned in sliding contact with the upper end of the helical top surface  35  of the bottom hinge  27 . One having ordinary skill in the art could substitute this rib for a mating helical surface, or any other geometry which would allow the top hinge  37  to slidingly contact the helical top surface  35 . One having ordinary skill in the art would also understand that a helical surface could be positioned on the underside of top hinge  37 , and a sliding member could be rigidly attached to mandrel  25  in other embodiments (not shown). 
     Formed through the curved end of top hinge  37  is a fuse aperture  43 . When in a loaded configuration, as shown in  FIG. 2 , fuse  21  extends through apertures  17 ,  26 , and  43 . Fuse  21  therefore prevents top hinge  37  rotating about mandrel  25 . 
     From the rectangular end of top hinge  37 , a rotator arm  45  extends distally from top hinge  37 . Rotator arm  45  is illustrated as a flat, planar member with a proximal end that fits into a slot  47  formed in the top surface of top hinge  37 . Also illustrated, a locking tab  49  that projects upward from the upper surface of rotator arm  45  fits into a cut-out  51  in the top surface of the top hinge  37  to lock rotator arm  45  in place. The distal end of rotator arm  45  is semicircular in shape, and has an axial attachment hole  53  which passes vertically through the center point of the semicircle. 
     Below the distal end of rotator arm  45 , an embodiment of automatic fire extinguisher canister  55  is shown attached. One having ordinary skill in the art will understand that any configuration for an automatically deploying fire extinguisher can be attached to rotator arm  45 . In this embodiment canister  55  is illustrated as being a cylindrical cup-shaped member with a closed top and a bottom lid  57  attached to a lower edge of the cylindrical side wall. Other shapes are feasible. Canister  55  holds a conventional fire extinguishing powder  59  that will flow out bottom lid  57  when bottom lid  57  is opened. An initiator  61  is mounted within container  55  for opening bottom lid  57  in response to sensing flames. Canister  55  also includes a mounting pin  63  adapted to fit through hole  53  defined in rotator arm  45  and be held in place with a cotter pin  65 . 
     Referring to  FIG. 2 , fuse assembly  19  includes a fuse  21  and a locking assembly. The locking assembly, not shown, may include an eyelet crimped to the fuse a distance away from the proximally protruding end of fuse  21  to expose a length of fuse  21 . The eyelet and fuse  21  are pressed into a connector having legs which are adapted to be pressed into the fuse housing  15  through aperture  17 . A stopper is pressed onto the legs of the connector to hold fuse assembly  19  in place when installed in fuse housing  15 . Fuse  21  may be, for example, red visco fuse or any other fuse well known in the art. 
     Thus far, fire extinguisher apparatus  11  has been described in the loaded configuration. This is the standby position in which apparatus  11  is normally positioned after installation. As illustrated in  FIGS. 2 and 3 , top hinge  37  is locked in an upper position between the upper helical surface  35  and top housing  13 . Spring pressure from spring  41  presses downward on top hinge  37  and causes a rotational force from the upper helical surface  35  and sliding member  42 . This rotational force is counteracted by fuse  21  extending through apertures  26  and  43 . The rotational force causes shear forces within fuse  21  as it is connected to the mandrel  25  on one end and the fuse housing  15  on the other through apertures  26  and  19  respectively. The shear force is not sufficient to cut fuse  21 , and thus fuse  21  normally maintains the fire extinguisher apparatus  11  in the standby configuration. 
     When a fire on second heating element  69  ( FIG. 1 ) ignites fuse  21 , a flame front travels along fuse  21  through aperture  17  ( FIG. 2 ), through fuse housing  15 , and through aperture  43 . Once the flame front passes aperture  43 , the downward pressure from spring  41  is no longer restrained by fuse  21 . The continued downward force of the compressed spring  41  causes a downward and rotational motion of top hinge  37 . As top hinge  37  travels downward, sliding member  42  remains in sliding contact with upper helical surface  35 , causing a rotation of top hinge  37  about the vertical axis  25   a  defined by mandrel  25 . As rotator arm  45  and fire extinguisher canister  55  are rigidly attached to top hinge  37 , they too move downward and are rotated about the vertical axis  25   a . Top hinge  37  is arrested in its downward and rotational motion by a stop-feature of bottom hinge  27 , such as a vertical wall portion  71  as illustrated in  FIG. 3 . In this embodiment, the upper helical surface  35  allows top hinge  37 , rotator arm  45 , and fire extinguisher canister  55  to traverse a 180° arc into a deployed position, wherein fire extinguisher canister  55  is positioned substantially above second heating element  69 . At this time, in response to the fire, above which fire extinguisher canister  55  is disposed, initiator  61  causes the fire extinguisher canister  55  to automatically operate and extinguish the fire. 
     From the deployed position, the fire extinguisher apparatus  11  can be expediently reloaded. The expended fire extinguisher canister  55  is removed from rotator arm  45  by removing cotter pin  65 , allowing mounting pin  63  to pass through attachment hole  53 . A new fire extinguisher canister  55  is replaced and mounted to the rotator arm  45  through attachment hole  53  and secured with cotter pin  65 . The non-consumed components of fuse assembly  19  are removed from aperture  17  of fuse housing  15 . Rotator arm  45  and top hinge  37  are together manually moved from the deployed position to the loaded position against the spring force of spring  41 . A new fuse assembly  19  is inserted through aperture  17  of fuse housing  15  so that fuse  21  also passes through apertures  43  of top hinge  37  and aperture  26  of the mandrel, thereby locking top hinge in the loaded position. As previously described, legs of fuse assembly  19  are pressed into the fuse housing  15  through aperture  17 . A stopper is pressed onto the legs of the connector to hold the fuse assembly  19  in place. 
     Referring now to  FIG. 4 , according to an alternate embodiment of the present disclosure, a system  100  comprises a side-by-side installation arrangement for a left-hand fire extinguisher apparatus  102  and a right-hand fire extinguisher apparatus  104 . As depicted, both fire extinguisher apparatuses  102 ,  104  are in a loaded or standby configuration. The system  100  facilitates cooperative use, for example, of the right and left hand fire extinguisher apparatuses  102 ,  104  arranged over a cook stove (not shown) with four heating elements. Each fire extinguisher apparatus  102 ,  104  includes a fire extinguisher canister  55  for positioning over respective a first location such as a respective rear heating element. An exposed portion of fuse  21  is provided for positioning over a second location such as a respective front heating element. The left-hand fire extinguisher apparatus  102  includes a top housing  113   a  coupled to mounting attachment fixtures  114   a  configured for coupling the fire extinguisher apparatus  102  on a left-hand side of a stovetop from the perspective of an operator facing the stovetop. Similarly, the right-hand fire extinguisher apparatus  102  includes top housing  113   b  coupled to mounting attachment fixtures  114   b  configured for coupling the fire extinguisher apparatus  102  on a right-hand side stovetop from the perspective of an operator facing the stovetop. When the fire extinguisher apparatuses  102 ,  104  are mounted in this manner, mounting plates  116   a ,  116   b  protrude inwardly from top housings  113   a ,  113   b , ensuring that a sufficient clearance is maintained between the fire extinguisher apparatuses  102 ,  104 . 
     In operation, the canisters  55  are operable to extinguish a fire on either of the rear burners in the standby or loaded configuration depicted. A fire on either of the front burners will ignite fuse  21 , thereby releasing canisters  55  from the standby configuration over the first position. Fire extinguisher apparatuses  102 ,  104  are configured such that, once released, canisters  55  traverse an arc from over the first position to over the second position as illustrated by arrows  118   a ,  118   b . Each of the canisters  55  travels on an interior of the system  100  between the fire extinguisher apparatuses  102 ,  104 , so not to be impeded by obstacles (not shown) such as cabinets or other appliances that may be placed on lateral side of the system  100 . 
     Referring now to  FIG. 5 , an underside of left-hand fire extinguisher apparatus  102  is depicted. Canister  55  is mounted for rotation with a top hinge  137  about an axis  145   a  defined by a mandrel  145 . Mandrel  145  depends downwardly from top housing  113   a , and supports a e-clip  139  or similar fastener at a lower end thereof. Also depending downwardly from top housing  113   a  is a vertical rib  147 . A lower protrusion  148  extending from the vertical rib  147  supports a roller  149  fastened by a hex nut  151 . 
     The top hinge  137  includes a bearing tube  155  disposed about mandrel  145  and cylindrically-shaped walls  157   a ,  157   b  disposed on opposing sides of vertical rib  147 . Portions of the curved, cylindrically-shaped walls  157   a ,  157   b  slope upward toward a ceiling  159  of top hinge  137 . A first cylindrically-shaped wall  157   a  rests on roller  149  supporting the weight of top hinge  137  and canister  55 . A second cylindrically-shaped wall  157   b  is similarly sloped so as to provide clearance for relative motion between the second cylindrically-shaped wall  157   b  and hex nut  151 . The top hinge  137  is rotationally restrained with respect to top housing  113   a  by fuse  21  extending through a fuse aperture  163  defined in top housing  113  and a fuse aperture  165  defined in top hinge  137 . 
     In operation, as described above, a fire on a front burner in the second location ignites fuse  21  to release canister  55 . Once a sufficient portion of fuse  21  is consumed by fire, the rotational restraint defined between fuse apertures  163  and  165  is severed, and the top hinge  137  is free to rotate with respect to top housing  113   a  about axis  145   a . In some embodiments, gravity alone propels cylindrically-shaped wall  157   a  over roller  149  as canister  55  traverses the arc illustrated arrow  118   a . In other embodiments, a spring or other biasing member (not shown) may be provided to assist gravity in moving canister  55  in the direction of arrow  118   a . For instance, a compression spring housed within bearing tube  155  may provide a biasing force between top housing  113   a  and top hinge  137 , tending to separate top housing  113   a  and top hinge  137  along axis  145   a . The relative rotational. motion between top housing  113   a  and top hinge  137  may be arrested by engagement of the bearing tube  155  and e-clip  139 , or engagement of roller against a stop member (not shown) disposed at an upper end of cylindrically-shaped wall  157   a , or by another mechanism. Once the rotational motion is arrested, canister  55  is appropriately positioned over the second position to extinguish a fire on a front burner. 
     As will be appreciated by those skilled in the art, right-hand fire extinguisher apparatus  104  ( FIG. 4 ) operates in a similar manner. Mirror-image parts may be provided such that canister  55  on either fire extinguisher apparatus  102 ,  104  initially traverses an arc toward the other fire extinguisher apparatus,  102 ,  104  once the rotational restraint provided by fuse  21  is severed. 
     The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.

Technology Classification (CPC): 0