Abstract:
A temperature switch electrically interconnects a first wire and a second wire, and includes a conducting mechanism and a temperature control mechanism controlling electrical connection between the first and second wires using the conducting mechanism in a normal condition. The conducting mechanism includes a safety unit composed of a conducting resilient bracket and a deformable component abutting against the conducting resilient bracket, thereby enabling the conducting resilient bracket to electrically interconnect the first and second wires. The deformable component is deformed upon reaching a specific temperature, such that interconnection between the first and second wires made via the conducting resilient bracket is broken.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a switch, and more particularly to a temperature switch that may cut off power supply of an electric device when an abnormal temperature condition exists. 
         [0003]    2. Description of the Related Art 
         [0004]    A common electrical appliance configured for heating, such as a water dispenser, a coffeemaker, an electrical iron, a hairdryer, etc., employs a heater for heating. 
         [0005]    Such an electrical appliance usually includes a temperature switch and a fuse to keep a desired temperature and to prevent danger resulting from abnormal operation of the heater. Although safety may be ensured, installation of the two components (i.e., the temperature switch and the fuse) in a limited space of the electrical appliance may disfavor assembly process. Referring to  FIGS. 1 and 2 , commonly owned co-pending U.S. patent application Ser. No. 13/406,946 discloses a temperature switch  1  that abuts against a heating component  10 , that electrically interconnects two wires  11 , and that includes a base  12 , a conducting mechanism  13  and a temperature control mechanism  14 . 
         [0006]    The base  12  includes a base body  121 , and a cap body  123  that is connected to the base body  121  to form an accommodating chamber  122  therebetween and that has a limiting hole  124 . The conducting mechanism  13  includes two conducting pieces  131 ,  132  respectively and electrically connected to the wires  11 , a fixed conducting rod  133  installed on the base body  121  and electrically connected to the conducting piece  131 , a conducting resilient piece  135  installed within the accommodating chamber  122  via a coupling component  134 , and two fuses  136  electrically interconnecting the conducting piece  132  and the conducting resilient piece  135 . The temperature control mechanism  14  includes a temperature sensing cap  142  that cooperates with the cap body  123  to form a deformation space  141 , a temperature-sensing control plate  143  disposed in the deformation space  141 , and a linking rod  144  disposed movably in the limiting hole  124 . The linking rod  144  is biased between the temperature-sensing control plate  143  and the conducting resilient piece  135 . 
         [0007]    In a normal operation state, the linking rod  144  is biased by the temperature-sensing control plate  143 , such that the conducting resilient piece  135  is biased to abut against the fixed conducting rod  133 , thereby permitting current flow through the conducting piece  131 , the fixed conducting rod  133 , the conducting resilient piece  135 , the fuses  136 , and the conducting piece  132 . When the heating component  10  reaches a specified temperature, the temperature-sensing control plate  143  deforms as shown in  FIG. 2 , and the conducting resilient piece  135  restores and is separated from the fixed conducting rod  133 . When the temperature is abnormally high, and the temperature-sensing control plate  143  is disabled from deformation or the conducting resilient piece  135  loses its restoring ability, the fuses  136  are melted, so as to cut off current flow between the conducting piece  132  and the conducting resilient piece  135 . 
         [0008]    Ideally, the aforesaid temperature switch  1  may ensure safety. However, in practice, since each of the fuses  136  stands as a pillar, the fuses  136  are apt to melt incompletely, thereby failing to break electrical connection. 
       SUMMARY OF THE INVENTION 
       [0009]    Therefore, an object of the present invention is to provide a temperature switch that may have a relatively high reliability to cut off current flow. 
         [0010]    According to the present invention, a temperature switch is adapted to be electrically connected with a first wire and a second wire. The temperature switch comprises: 
         [0011]    a base body; 
         [0012]    a cap body connected to the base body to form an accommodating chamber therebetween; 
         [0013]    a conducting mechanism including a first conducting piece adapted to be electrically connected to the first wire, a second conducting piece adapted to be electrically connected to the second wire, a fixed conducting component, a conducting resilient piece that is disposed in the accommodating chamber, that is electrically connected to the first conducting piece, and that is contactable with the fixed conducting component, and a safety unit, the safety unit including a conducting resilient bracket, and a temperature-dependent deformable component abutting against the conducting resilient bracket to bias the conducting resilient bracket into a conducting state where the conducting resilient bracket electrically interconnects the fixed conducting component and the second conducting piece, 
         [0014]    wherein the temperature-dependent deformable component is configured to be deformed upon reaching a specific temperature, such that the conducting resilient bracket is changed to a non-conducting state where the conducting resilient bracket is separated from one of the second conducting piece and the fixed conducting component; and 
         [0015]    a temperature control mechanism configured to control contact between the conducting resilient piece and the fixed conducting component with a sensed temperature. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which: 
           [0017]      FIG. 1  is an exploded perspective view illustrating a temperature switch disclosed in U.S. patent application Ser. No. 13/406,946; 
           [0018]      FIG. 2  is a sectional view of the temperature switch shown in  FIG. 1 ; 
           [0019]      FIG. 3  is an exploded perspective view illustrating a preferred embodiment of a temperature switch according to the present invention; 
           [0020]      FIG. 4  is a fragmentary top view of the preferred embodiment, a temperature control mechanism and a cap body of the preferred embodiment being omitted for the sake of clarity; 
           [0021]      FIG. 5  is a sectional view taken along line V-V in  FIG. 4 ; 
           [0022]      FIG. 6  is a sectional view taken along line VI-VI in  FIG. 4 , showing that the preferred embodiment is in a conducting condition; and 
           [0023]      FIG. 7  is a sectional view similar to  FIG. 6 , showing that the preferred embodiment is in a non-conducting condition. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0024]    Referring to  FIG. 3  to  FIG. 5 , the preferred embodiment of the temperature switch  20  according to the present invention is to be installed on an electrical appliance (not shown), and is in contact with a heating component  21 . The temperature switch  20  is adapted to electrically interconnect a first wire  22  and a second wire  23 , and comprises a base  3 , a conducting mechanism  4  installed on the base  3 , and a temperature control mechanism  5  installed on the base  3 . 
         [0025]    In this embodiment, the base  3  includes a base body  31  made of an insulating and high temperature resistant material, such as a ceramic material or a plastic material, and a cap body  32  connected to the base body  31  to form an accommodating chamber  30  therebetween. The base body  31  has a base wall  311 , a surrounding wall  312  extending upwardly from a periphery of the base wall  311  toward the cap body  32 , a platform  313  extending upwardly from the base wall  311 , a mounting hole  314  that passes through the base wall  311  and the platform  313 , an isolating ring  315  that protrudes from the platform  313  and that surrounds the mounting hole  314 , and a receiving space  316  that passes through the platform  313  and the base wall  311 . The cap body  32  has a limiting hole  321  formed in a central portion of the cap body  32 . 
         [0026]    The conducting mechanism  4  includes: a first conducting piece  41  adapted to be electrically connected to the first wire  22 ; a second conducting piece  42  adapted to be electrically connected to the second wire  23 ; a conducting rod  43  that electrically interconnects the first conducting piece  41  and a conducting resilient piece  40  in the accommodating chamber  30  and that mounts the first conducting piece  41  and the conducting resilient piece  40  to the base wall  31 ; a fixed conducting component  44 ; an insulating spacer  45  that is made of an insulative material and that is disposed above and abuts against the fixed conducting component  44 ; a mounting component  46  that has a head and that extends through the mounting hole  314  to mount the insulating spacer  45 , the fixed conducting component  44 , and the second conducting piece  42  to the base body  31 ; and a safety unit  47  received in the receiving space  316  of the base  3 . In this embodiment, the fixed conducting component  44  is sleeved on the isolating ring  315  for preventing the inner surface of the fixed conducting piece  44  from coming into contact with the outer surface of the mounting component  46 , and the insulating spacer  45  is disposed between the head of the mounting component  46  and the fixed conducting component  44  so as to prevent the fixed conducting component  44  from coming into contact with the mounting component  46 . 
         [0027]    The conducting resilient piece  40  has a resilient arm  401 . The resilient arm  401  has a movable contact  402  proximate to a free end thereof, and a biased portion  403  disposed on a middle part thereof. The fixed conducting component  44  has a fixed contact  441  aligned with the movable contact  402  of the conducting resilient piece  40 . The safety unit  47  includes a conducting resilient bracket  471 , and a temperature-dependent deformable component  472 . The conducting resilient bracket  471  has two contact walls  473  spaced apart from each other, and a connecting wall  474  interconnecting the contact walls  473 . The contact walls  473  extend slantingly toward each other from two ends of the connecting wall  474  in an original shape of the conducting resilient bracket  471 . The temperature-dependent deformable component  472  is made of an alloy material that is bendable and deformable when heated to a specific deforming temperature designed as required. The temperature-dependent deformable component  472  is disposed between and abuts against the contact walls  471 . Two ends  475  of the temperature-dependent deformable component  472  respectively bias the contact walls  473 , thereby deforming the conducting resilient bracket  471  such that the contact walls  473  extend slantingly away from each other from the two ends of the connecting wall  474 , as shown in  FIG. 6 . Therefore, the deformed conducting resilient bracket  471  has a restoring force applied on the two ends  475  of the temperature-dependent deformable component  472 . 
         [0028]    The temperature control mechanism  5  includes a temperature-sensing cap  51  made of a heat-conductive material and connected to the cap body  32  of the base  3  to form a deformation space  52  between the cap body  32  and the temperature-sensing cap  51 , a linking rod  53  that passes through the limiting hole  321  of the cap body  32 , and a temperature-sensing control plate  54  that is disposed in the deformation space  52 , that contacts the temperature-sensing cap  51 , and that has a deforming part  541  disposed at a central portion thereof and deformable due to temperature change in such a manner to move between a proximate position and a distal position farther away from the conducting resilient piece  40  than the proximate position. The linking rod  53  is made of a heat-insulating ceramic material and is disposed movably in the limiting hole  321 . The linking rod  53  is aligned with the deforming part  541 , and is disposed between and in contact with the temperature-sensing control plate  54  and the biased portion  403  of the conducting resilient piece  40 . 
         [0029]    Referring to  FIGS. 3 ,  5  and  6 , in this embodiment, when the temperature switch  20  is in a conducting condition, the deforming part  541  of the temperature-sensing control plate  54  is at the distal position, and the linking rod  53  is not pressed against the conducting resilient piece  45 , so that the movable contact  402  on the resilient arm  401  of the conducting resilient piece  45  is in contact with the fixed contact  441 . Furthermore, in the conducting condition, the temperature-dependent deformable component  472  biases the contact walls  473  of the conducting resilient bracket  471 , such that the contact walls  473  are respectively and electrically connected to the second conducting piece  42  and the fixed conducting component  44 . In other words, each of the contact walls  473  has a conducting portion that abuts against a respective one of the second conducting piece  42  and the fixed conducting component  44 , thereby resulting in a closed circuit through the first wire  22 , the first conducting piece  41 , the conducting resilient piece  40 , the fixed conducting component  44 , the safety unit  47 , the second conducting piece  42  and the second wire  23 . 
         [0030]    When the heating component  21  is heated to reach a pre-determined first temperature, the deforming part  541  of the temperature-sensing control plate  54  moves from the distal position to the proximate position, so that the linking rod  53  is pressed against the biased portion  403  of the conducting resilient piece  40 , and the movable contact  402  on the resilient arm  401  of the conducting resilient piece  45  is spaced apart from the fixed contact  441 , such that electrical connection between the first and second wires  22 ,  23  is broken. When temperature of the heating component  21  drops to a predetermined second temperature, the deforming part  541  of the temperature-sensing control plate  54  moves from the proximate position back to the distal position, such that the heater of the electrical appliance will perform a heating operation once again. 
         [0031]    Referring to  FIGS. 3 ,  5  and  7 , when the temperature switch  20  is in the conducting condition, if the temperature of the heating component  21  is higher than the predetermined first temperature while the temperature-sensing control plate  54  is disabled from deformation, or the conducting resilient piece  40  is abnormally in contact with the fixed contact  441  of the fixed conducting component  44 , the heater of the electrical appliance will keep on heating to thereby result in an increase in the temperature of the temperature-sensing cap  51  and the environmental temperature thereof. When the environmental temperature rises to a specific temperature, the temperature-dependent deformable component  472  is deformed, so as to change the conducting resilient bracket  47  to a non-conducting state where the resilient conducting bracket  47  is resiliently restored to its original shape such that one of the contact walls  473  is separated from a corresponding one of the second conducting piece  42  and the fixed conducting component  44 , as shown in  FIG. 7 . In detail, the contact walls  473  bend toward the connecting wall  474  such that the conducting portion of one of the contact walls  473  is separated from the corresponding one of the second conducting piece  42  and the fixed conducting component  44 . That is, the temperature switch  20  is converted from the conducting condition as shown in  FIG. 6  into the non-conducting condition as shown in  FIG. 7 . 
         [0032]    As mentioned above, the temperature switch  20  according to the present invention uses the temperature-dependent deformable component  472  that abuts against the conducting resilient bracket  471  to cause the contact walls  473  of the conducting resilient bracket  471  to be respectively and electrically connected to the second conducting piece  42  and the fixed conducting component  44  in the conducting condition. When the environment temperature rises to a specific temperature and the temperature switch  20  operates abnormally, the electrical connection between the first and second conducting pieces  41 ,  42  can be broken by virtue of deformation of the temperature-dependent deformable component  472  and the restoring force of the conducting resilient bracket  471 . Since the electrical connection is broken by the restoring force of the conducting resilient bracket  471 , the drawback of the abovementioned prior art can be effectively overcome. In addition, in the preferred embodiment, both of the isolating ring  315  and the insulating spacer  45  are designed to prevent the fixed conducting component  44  from coming into contact with the mounting component  46 . However, if the mounting component  46  is made of a non-conductive material, it is not necessary for the temperature switch  20  of the pre sent invention to include the isolating ring  315  and the insulating spacer  45 . 
         [0033]    While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.