Patent Publication Number: US-9895563-B2

Title: Fire sprinkler with improved protective shell

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to a fire sprinkler and, more particularly, to a fire sprinkler containing an improved protective shell. 
     DESCRIPTION OF THE PRIOR ART 
     As commonly known, fire sprinklers are usually installed in a building for fire protection. To detect a fire, the existing fire sprinklers employ a valve body provided with a heat-activated glass bulb that can urge against the orifice cap of the valve body. With this type of fire sprinkler, when a fire occurs, due to a high temperature, the heat-activated glass bulb can break and thus water can flow out of the orifice of the valve body to produce a water spray to extinguish the flames. 
     Generally, the valve body employed in the conventional fire sprinklers is provided with two opposing bars that can form a frame to support the heat-activated glass bulb. Also, the valve body is mounted with a protective shell around the opposing bars of the frame of the valve body to protect the glass bulb from being damaged while in normal condition. For this purpose, the protective shell is provided with internal threads while the opposing bars of the frame are provided with external threads. Through the engagement between the internal threads of the protective shell and the external threads of the opposing bars, the protective shell can be mounted to the valve body. However, the threaded structure of the conventional fire sprinklers has the following disadvantages:
         1. The contact area between the protective shell and the opposing bars of the frame is limited, and thus the protective shell is easy to be shaken when it is subject to an external vibration, which may result from a construction activity or an earthquake, or the protective shell is easy to be tilted when it is touched by other pipes. Thus, the mounting stability and robustness of the protective shell with the opposing bars of the frame is inadequate.   2. Although the protective shell can provide a protection for the heat-activated glass bulb, it can cause poor ventilation within the protective shell and thus the capability of the glass bulb to detect a high temperature in a mom can be reduced.       

     SUMMARY OF THE INVENTION 
     In view of the foregoing, one object of the present invention is to provide a fire sprinkler that can solve the problem of the inadequate robustness of a mounting between the protective shell and the valve body. 
     To achieve the above object, two embodiments of the present invention concerning the fire sprinkler are disclosed, each of which comprises a valve body and a protective shell. The valve body defines therein an orifice that is normally fitted with a cap. The valve body is provided with two opposing bars extending downwardly from two sides thereof to form a frame that supports a heat-activated glass bulb located between the two opposing bars and engaged between the cap and a bottom of the frame. The protective shell can be mounted to the opposing bars of the frame so as to surround the heat-activated glass bulb. Each of the opposing bars is provided with a stop portion at an outer side surface thereof. The protective shell is provided with two opposing guide portions at an inner surface thereof and is provided with two opposing engagement portions in cooperation with the guide portions, wherein each guide portion of the protective shell receives one of the opposing bars, so that the opposing bars can be guided to move relative to the protective shell in a linear direction to allow the engagement portions of the protective shell to be engaged with the stop portions of the opposing bars. 
     According to one feature of the embodiments of the present invention, in mounting the fire sprinkler of the present invention, the protective shell can be moved linearly, rather than being moved rotationally as in the conventional devices, to adjust the height of the protective shell. This feature allows the position of the protective shell to be adjusted more quickly and conveniently as compared with the conventional one. Furthermore, through the confining function of the guide portions of the protective shell, the protective shell and the valve body can be mounted more securely, and thus the protective shell can resist vibrations or impacts from construction activity or earthquake. 
     More specifically, each guide portion is formed into a channel-like member that has two side walls and defines a channel therebetween. The two side walls of the channel-like member receives one of the opposing bars to confine the associated bar to moving along the channel. Each engagement portion can be formed on a bottom of the channel of the channel-like member or the two side walls of the channel-like member. Accordingly, the position of the engagement portions of the protective shell relative to the stop portions of the opposing bars can be adjusted, so that the protective shell can be mounted to the valve body at an appropriate height. 
     More specifically, each stop portion is formed into a tooth-like surface whereas each engagement portion is formed into an elastic tongue-shaped member or an elastic hook capable of engaging with the tooth-like surface. Accordingly, the position of the engagement portions of the protective shell relative to the stop portions of the opposing bars can be adjusted, so that the protective shell can be mounted to the valve body at an appropriate height. 
     More specifically, each stop portion defines a plurality of notches or rounded grooves being arranged at regular intervals whereas each engagement portion is formed into an elastic hook or provided with an elastically driven ball to be engaged with one of the notches or one of the rounded grooves. Accordingly, the position of the engagement portions of the protective shell relative to the stop portions of the opposing bars can be adjusted, so that the protective shell can be mounted to the valve body at an appropriate height. 
     Another object of the present invention is to provide a fire sprinkler that can solve the problem of the reduced capability of the heat-activated glass bulb resulting from the provision of the protective shell. 
     To achieve the above object, the protective shell can be defined with at least one ventilation hole to increase the thermal transfer. The ventilation hole can have various forms, such as a circular hole, a rectangular hole, a number of elongated rectangular holes, an array of square holes and the like. The ventilation hole can speed up the heated ambient air flowing into the protective shell to allow the glass bulb therein to get broken more easily, so that the time required to break the glass bulb can be shortened, and thus the fire detection capability of the fire sprinkler can be increased. 
     Other objects, advantages, and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an exploded view of a first embodiment of the present invention. 
         FIG. 2  shows an assembled view of the first embodiment of the present invention. 
         FIG. 3  shows a sectional working view of the first embodiment of the present invention, wherein the fire sprinkler is installed at the ceiling. 
         FIG. 4  shows a sectional view taken along A-A line in  FIG. 3 . 
         FIG. 5  shows an enlarged fragmentary view of an embodiment with regard to the disposition of the engagement portion and the stop portion shown in  FIG. 4 . 
         FIG. 6  shows an enlarged fragmentary view of another embodiment with regard to the disposition of the engagement portion and the stop portion shown in  FIG. 4 . 
         FIG. 7  shows an enlarged fragmentary view of an embodiment with regard to the mounting between the stop portion and the engagement portion shown in  FIG. 3 . 
         FIG. 8  shows an enlarged fragmentary view of another embodiment with regard to the mounting between the stop portion and the engagement portion shown in  FIG. 3 . 
         FIG. 9  shows an enlarged fragmentary view of the protective shell shown in  FIG. 2 , wherein a circular ventilation hole is added to the protective shell. 
         FIG. 10  shows an enlarged fragmentary view of the protective shell shown in  FIG. 2 , wherein a rectangular ventilation hole is added to the protective shell. 
         FIG. 11  shows an enlarged fragmentary view of the protective shell shown in  FIG. 2 , wherein a number of elongated rectangular ventilation holes are added to the protective shell. 
         FIG. 12  shows an enlarged fragmentary view of the protective shell shown in  FIG. 2 , wherein an array of square ventilation holes is added to the protective shell. 
         FIG. 13  shows an exploded view of a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1 through 4  show a first embodiment of the present invention concerning a fire sprinkler, which generally comprises a valve body  10  and a protective shell  20 . 
     As shown in  FIG. 3 , the fire sprinkler is installed at a ceiling  40 . For fire protection, the fire sprinkler should extend through an opening  41  of the ceiling  40 . The valve body  10  is provided with a threaded portion  16  at its top, through which a water supply pipe  30  for fire protection can be connected to the fire sprinkler. Furthermore, the valve body  10  defines therein an orifice that is normally fitted with a cap  11 , which is urged by a heat-activated glass bulb  12  so as to close the orifice and thus prevent water flowing from the orifice while in normal condition. The valve body  10  is provided with two opposing bars  13  extending downwardly from two sides thereof to form a frame that can support the heat-activated glass bulb  10  being located between the two opposing bars  13  and being engaged between the cap  11  and a bottom of the frame. The frame, being constructed of the two opposing bars  13 , is provided with two slidable posts  14  that are connected to a deflector  15  at their bottom ends. Thus, in a fire emergency, water can flow from the orifice of the valve body  10  to impact the deflector  15  so as to produce a specific water spray pattern, which can increase the water distribution area. 
     The protective shell  20  has a generally cylindrical shape and is formed with an inwardly extending flange  25  at its top. The inwardly extending flange  25  defines two opposing indentations  251 . The inside diameter of the inwardly extending flange  25  is less than the dimension of the valve body  10 . The maximum distance between the indentations  251  is greater than the dimension of the valve body  10 . As such, the valve body  10  can be mounted with the protective shell  20  in a limited manner, thereby facilitating the protective shell  20  to be mounted to the valve body  10 . Furthermore, the protective shell  20  is formed with circular flange at its bottom. The circular flange is formed with an attachment tab  23  that can be bonded to a bottom plate  24  through a low melting-point metal, such as tin. As such, in a fire emergency, the low melting-point metal can be melted, and this will cause the bottom plate  24  to fall down to allow high-temperature air to go into the protective shell  20 , thereby causing the heat-activated glass bulb  12  to break, which in turn causes the cap  11  to fall down, and thus permits water flowing out of the orifice of the valve body  10 . 
     The protective shell  20  can be mounted to the opposing bars  13  of the frame of the valve body  10  to surround the valve body  10  and the heat-activated glass bulb  12 . To describe in more detail, each of the opposing bars  13  is provided with a stop portion  131  at an outer side surface thereof; the protective shell  20  is provided with two opposing guide portions  21  at an inner surface thereof and is provided with two opposing engagement portions  22  in cooperation with the two guide portions  21 , wherein each guide portion  21  of the protective shell  20  is capable of receiving one of the opposing bars  13  of the frame, so that the opposing bars  13  can be guided to move relative to the protective shell  20  in a linear direction to allow the engagement portions  22  of the protective shell  20  to be engaged with the stop portions  131  of the opposing bars  13 . To describe in more detail, each guide portion  21  can be produced through a punching process to form a channel-like member that has two side walls  211  and defines a channel  212  therebetween, wherein the two side walls  211  can receive one of the opposing bars  13  to confine the associated bar  13  to moving along the channel  212  To describe in more detail, each engagement portion  22  of the protective shell  20  can be formed into an elastic tongue-shaped member, which can be engaged with the stop portion  131  of one bar of the frame, so that the position of the engagement portions  22  of the protective shell  20  relative to the stop portions  131  of the opposing bars  13  can be adjusted, and thus the protective shell  20  can be mounted to the valve body  10  at an appropriate height. As such, when installing the fire sprinkler of the present invention, the height of the protective shell  20  can be adjusted according to the height of the ceiling  40  of a site, so that the protective shell  20  can be prevented from extending out of the ceiling  40  too much, so that the overall appearance of the ceiling  40  of the site will not be downgraded. 
       FIGS. 5 and 6  show enlarged views of different embodiments with regard to the disposition of the engagement portions  22  of the protective shell  20  and the guide portions  131  of the opposing bars  13 , wherein the engagement portions  22  can be formed on a bottom  213  of the channel  212  of the channel-like member (see  FIG. 5 ), or alternatively, the engagement portions  22  can be formed on the two side walls  211  of the channel-like member (see  FIG. 6 ). Each embodiment allows the engagement portions  22  of the protective shell  20  to be engaged with the stop portions  131  of the opposing bars  13  of the frame, so that the protective shell  20  can be mounted to the valve body  10  at an appropriate height. 
       FIG. 7  shows an enlarged view of an embodiment with regard to the mounting between the guide portions  131  of the opposing bars  13  and the engagement portions  22  of the protective shell  20 , wherein each stop portion  131  defines a plurality of notches  131   a  being arranged at regular intervals. In addition to the guide portions  131  being formed into a tooth-like surface, the engagement portions  22  are formed into an elastic hook  22   a , for example, through a punching process, wherein the elastic hook  22   a  has one end being curved towards to the guide portions  13  so that it can be inserted into one of the notches  131   a , thereby allowing the elastic hook  22   a  to engage with the notches  131   a . As such, the position of the engagement portions  22  of the protective shell  20  relative to the stop portions  131  of the opposing bars  13  can be adjusted, so that the protective shell  20  can be mounted to the valve body  10  at an appropriate height. 
       FIG. 8  shows an enlarged view of another embodiment with regard to the mounting between the guide portions  131  of the opposing bars  13  and the engagement portions  22  of the protective shell  20 , wherein each stop portion  131  defines a plurality of rounded grooves  131   b  being arranged at regular intervals. In addition, the engagement portions  22  is provided with an elastically driven ball  22   b  that can provide elasticity through an elastic member  22   b   1 , such as a compression spring, to allow the ball  22   b  to engage with one of the rounded grooves  131   b . As such, the position of the engagement portions  22  of the protective shell  20  relative to the stop portions  131  of the opposing bars  13  can be adjusted, so that the protective shell  10  can be mounted to the valve body  10  at an appropriate height. 
       FIGS. 9 through 12  show enlarged views of different embodiments of ventilation hole for the protective shell of the fire sprinkler. As shown, the protective shell  20  can be defined with at least one ventilation hole  26 , which can be formed through a punching process and can be shaped as a circular hole (see  FIG. 9 ), a rectangular hole (see  FIG. 10 ), a number of elongated rectangular holes (see  FIG. 11 ), or an array of square holes (see  FIG. 12 ). The ventilation hole  26  can speed up the heated ambient air flowing into the protective shell  20  to allow the glass bulb  12  therein to get broken more easily, so that the time required to break the glass bulb  12  can be shortened, and thus the capability of the fire sprinkler to detect a fire emergency can be increased. 
       FIG. 13  shows a second embodiment of the present invention, wherein the guide portions  21  and the engagement portions  22  are designed to project from the top end of the protective shell  20  instead of the inwardly extending flange  25  provided in the first embodiment. The projected guide portions  21  of the protective shell  20  can guide the opposing bars  13  to move relative to the protective shell  20  and to facilitate the engagement portions  22  of the protective shell  20  to be engaged with the stop portions  131  of the opposing bars  13 . With such structure, in addition to the convenience of the protective shell  20  being mounted to the valve body  10 , due to a larger opening existed between the two projected guide portions  21 , the ambient air flowing into the protective shell  20  can be significantly increased, so that the response time of the heat-activated glass bulb  12  can be shortened, and thus the response speed of the fire sprinkler to a fire emergency can be increased. 
     In light of the foregoing, the protective shell can be moved linearly, rather than being moved rotationally as in the conventional devices, to adjust the height of the protective shell while installing the fire sprinkler. This feature allows the position of the protective shell to be adjusted more quickly and conveniently as compared with the conventional one. Furthermore, through the confining function of the guide portions of the protective shell, the protective shell can be mounted to the valve body more securely, and thus the protective shell can resist vibrations or impacts resulting from construction activity or earthquake more effectively. 
     Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure is made by way of example only and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention hereinafter claimed.