Abstract:
A inflatable product for an inflatable body includes a casing with an airway adapted to communicate with an interior of the inflatable body, a resilient element movably positioned inside the casing to define with the casing a space therebetween, an on/off switch adapted to connect to an air pump, a driving element movably positioned inside the casing to be in response to the movement of the resilient element so as to selectively activate the on/off switch to activate the air pump and a recoil element positioned around the driving element and a distal end of which is abutted against the resilient element, wherein the spring is compressed/decompressed when the resilient element moves in response to pressure inside the inflatable body so that activation/deactivation of the on/off switch is controlled via the movement of the resilient element as well as the compression of the spring.

Description:
[0001]    The present invention is a continuation application claiming the benefit of U.S. application Ser. No. 11/472,460 filed on Jun. 21, 2006. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a pressure switch, and more particularly to a pressure switch adapted to be driven by pressure inside an inflatable body so as to selectively and automatically activate operation of a pump to inflate the object and to maintain the pressure inside the inflatable body within a predetermined range. 
         [0004]    2. Description of the Prior Art 
         [0005]    There are various inflatable bodies in our daily life, such as mattresses, sofas and animal figured toys. Due to temperature factors around the inflatable body, load factors on top of the inflatable body and sealing effect inside the inflatable body, all these inflatable bodies may require inflation from time to time, for safety and comfort reasons, after continuously using the inflatable body for a period of time. Because there is no monitoring device to keep track of pressure variations inside the inflatable body, every now and then the user will have to check the inflatable body&#39;s pressure to ensure that the inflatable body is suitable for use. If the inflatable body&#39;s pressure is low or is not suitable for use, the user will have to inflate the inflatable body. Currently, every inflation process is processed manually. Therefore, the operator needs to constantly inflate the inflatable body to maintain pressure inside the inflatable body and to provide comfort to the user, which is quite labor inefficient. 
         [0006]    To overcome the shortcomings, the present invention provides an improved pressure switch to mitigate the aforementioned problems. 
       SUMMARY OF THE INVENTION 
       [0007]    The primary objective of the present invention is to provide an improved pressure switch to selectively and automatically activate/deactivate operation of a pump to start/stop pumping the inflatable body to maintain pressure of the inflatable body within a predetermined range. 
         [0008]    Another objective of the present invention is to provide a load adjusting assembly inside the pressure switch to adjust pressure sensitivity of the pressure switch so as to allow the pressure to be adapted to fit to different applications. 
         [0009]    A still further objective of the present invention is to provide an exchanging chamber inside the casing of the pressure switch of the present invention and having a sliding block movably received inside the exchanging chamber to communicate the interior of the pressure switch with the interior of the inflatable body to allow inflation/deflation to the inflatable body via a pump. 
         [0010]    A further objective of the present invention is that the sliding block is driven by a server motor inside the casing of the pressure switch of the present invention via a worm shaft directly connected to a gear which is integrally formed with the sliding block. 
         [0011]    Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a schematic cross sectional view showing the structure of the present invention; 
           [0013]      FIG. 2  is a schematic cross sectional view showing that the load adjusting assembly is modified and a leverage is employed; 
           [0014]      FIG. 3A  is a cross sectional view showing that the pressure switch of the present invention as well as a pump is assembled inside the inflatable body; 
           [0015]      FIG. 3B  is a schematic top cross sectional view of  FIG. 3A ; 
           [0016]      FIG. 4A  is a cross sectional view showing the arrangement of the pressure switch of the present invention and the pump inside the inflatable body, which is not the same as that shown in  FIG. 3A ; 
           [0017]      FIG. 4B  is a schematic top cross sectional view of  FIG. 4A ; 
           [0018]      FIG. 5  is a schematic cross sectional view showing that the pressure switch is installed inside the inflatable body and a plug extending from the pump is connected to and controlled by the switch of the pressure switch of the present invention; 
           [0019]      FIG. 6  is a schematic cross sectional view showing that the pressure switch of the present invention is integrated with the pump; 
           [0020]      FIG. 7A  is a schematic cross sectional view showing that the casing of the present invention is provided with an exchanging chamber, wherein the sliding block is moved to allow inflation to the inflatable body; 
           [0021]      FIG. 7B  is a schematic cross sectional view showing that the sliding block is moved to allow deflation to the inflatable body; 
           [0022]      FIG. 7C  is an exploded perspective view showing parts of the embodiment shown in  FIG. 7A ; 
           [0023]      FIG. 8A  is a cross sectional view showing a different exchanging chamber from that shown in  FIG. 7A , wherein the inflatable body is inflating; 
           [0024]      FIG. 8B  is an operational view showing that the inflatable body is deflating; 
           [0025]      FIG. 8C  is an exploded perspective view of the parts shown in  FIG. 8A ; 
           [0026]      FIG. 8D  is a perspective view showing the gear employed in this embodiment; 
           [0027]      FIG. 9A  is a schematic cross sectional view showing the application of the pressure switch with the exchanging chamber shown in  FIG. 7A ; 
           [0028]      FIG. 9B  is a schematic cross sectional view showing that the inflatable body is deflating via a different driving element of the present invention; 
           [0029]      FIG. 9C  is an exploded perspective view showing parts of the embodiment in  FIG. 9A ; 
           [0030]      FIG. 10A  is a schematic cross sectional view showing the inflation of the inflatable body, wherein the driving element is the same as that used in  FIG. 8A ; 
           [0031]      FIG. 10B  is a schematic cross sectional view showing that the pressure switch is in deflating status; 
           [0032]      FIG. 10C  is an exploded perspective view showing parts of the embodiment in  FIG. 10A ; 
           [0033]      FIG. 10D  is a perspective view showing the gear in  FIG. 10C ; 
           [0034]      FIG. 11A  is a schematic cross sectional view showing that the pressure switch of the present invention is in an inflation process; 
           [0035]      FIG. 11B  is a schematic cross sectional view showing that the pressure switch of the present invention is in a deflation process; and 
           [0036]      FIG. 12  is a schematic side plan view showing the embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0037]    With reference to  FIG. 1 , it is noted that the pressure switch ( 1 ) in accordance with the present invention includes a casing ( 11 ), a resilient element ( 12 ), a driving element ( 13 ), a spring ( 14 ), a load adjusting assembly ( 15 ) and an electrical on/off switch ( 16 ). 
         [0038]    The casing ( 11 ) is composed of a U-shaped top casing ( 111 ), an inverse U-shaped mediate casing ( 112 ) and a U-shaped bottom casing ( 113 ) interrelated to the mediate casing ( 112 ) in such a manner that a space is defined therebetween. The mediate casing ( 112 ) is provided with a recess ( 1120 ) defined in an inner periphery of the mediate casing ( 112 ) and a centrally defined through hole ( 1121 ) defined through a top face of the mediate casing ( 112 ) and having a first threading ( 1122 ) defined in an inner periphery defining the through hole ( 1121 ). To correspond to the recess ( 1120 ) of the mediate casing ( 112 ), the bottom casing ( 113 ) is provided with a step ( 1130 ) to be received in the recess ( 1120 ) and an airway ( 17 ) defined through a bottom face of the bottom casing ( 113 ) so as to allow a space confined by the bottom casing ( 113 ) and the mediate casing ( 112 ) to communicate with air inside the inflatable body after the pressure switch of the present invention is positioned inside the inflatable body. 
         [0039]    The resilient element ( 12 ) is substantially U shaped and has two ends ( 121 ) respectively supported by the step ( 1130 ) of the bottom casing ( 113 ) and engaged with a top inner face defining the recess ( 1120 ) of the mediate casing ( 112 ). The driving element ( 13 ) has a bowl like bottom ( 132 ) and a central rod ( 131 ) extending from a bottom face of the bowl like bottom ( 132 ) and out of the through hole ( 1121 ) of the mediate casing ( 112 ). The bowl like bottom ( 132 ) is part of the resilient element ( 12 ) and the spring ( 14 ) is positioned around the central rod ( 131 ). The load adjusting assembly ( 15 ) includes a sliding block ( 151 ) inserted into the through hole ( 1121 ) of the mediate casing ( 112 ) and positioned around the central rod ( 131 ). The sliding block ( 151 ) has a second threading ( 1511 ) formed on an outer periphery thereof to correspond to and mate with the first threading ( 1122 ) of the mediate casing ( 112 ) and a shoulder ( 1513 ) to abut a distal end of the spring ( 14 ), wherein the proximal end of the spring ( 14 ) is abutted against a bottom face of the mediate casing ( 112 ). A knob ( 152 ) is rotatably positioned on top of the top casing ( 111 ) and has a rod ( 1521 ) integrally extending from the knob ( 152 ) and a gear ( 153 ) formed on a distal free end of the rod ( 1521 ) to correspond to beveled teeth ( 1512 ) formed on an outer periphery of the sliding block ( 151 ) to be adjacent to the second threading ( 1511 ). The switch ( 16 ) is an ordinary on/off switch and has a pushbutton ( 161 ) formed on a bottom of the switch ( 16 ) to correspond to and engage with a top face of the central rod ( 131 ). 
         [0040]    When the pressure switch of the present invention is employed in an inflatable body ( 4 ), the top casing ( 111 ) is integrally formed with a periphery of the inflatable body ( 4 ) such that the resilient element ( 12 ) is affected by pressure inside the inflatable body ( 4 ) via the airway ( 17 ). When the pressure inside the inflatable body ( 4 ) is larger than a recovery force of the spring ( 14 ), the driving element ( 13 ) is pushed by the resilient element ( 12 ), which results in that the central rod ( 131 ) of the driving element ( 13 ) is moved to engage with the pushbutton ( 161 ) of the switch ( 16 ) to turn off the switch ( 16 ). After the switch ( 16 ) is off, a pump responsible for inflation of the inflatable body ( 4 ) stops operation and the pressure inside the inflatable body ( 4 ) is maintained. 
         [0041]    However, when the pressure inside the inflatable body ( 4 ) is decreased, the recovery force of the spring ( 14 ) overcomes the pressure inside the inflatable body ( 4 ) so that the central rod ( 131 ) is moved away from the pushbutton ( 161 ), which activates the operation of the pump to inflate the inflatable body ( 4 ). Further, rotation of the knob ( 152 ) is able to drive the central rod ( 131 ) to move upward or downward relative to the casing due to the engagement between the gear ( 153 ) and the beveled teeth ( 1512 ). When the central rod ( 131 ) is moved upward, the load on the spring ( 14 ) is lessened and the pressure required to push the driving element ( 13 ) to move is reduced. However, when the central rod ( 131 ) is moved downward, the load on the spring ( 14 ) is increased and thus the pressure required to push the driving element ( 13 ) to move is also increased. 
         [0042]    With reference to  FIG. 2 , the pressure switch of the present invention is configured substantially the same as that shown in  FIG. 1 . The only difference therebetween is that the load adjusting assembly ( 15 ) is now provided with a sliding block ( 151 ) having the same structure as that in the first embodiment, a knob ( 152 ) threadingly and rotatably positioned on the top casing ( 111 ) and having a rod ( 1521 ) extending downward from the knob ( 152 ) and a leverage ( 154 ) having a first end loosely positioned around a neck ( 1522 ) formed on a distal free end of the rod ( 1521 ) and a second end securely connected to an outer periphery of the sliding block ( 151 ). In this embodiment, the sliding block ( 151 ) is provided with an indent ( 1515 ) defined in the outer periphery of the sliding block ( 151 ). A mediate portion of the leverage ( 154 ) is positioned on a top face of the mediate casing ( 112 ). Therefore, rotation of the knob ( 152 ) is able to adjust load on the spring ( 14 ). That is, when the knob ( 152 ) is moved upward, the central rod ( 131 ) as well as the bowl like bottom ( 132 ) is depressed and the load on the spring ( 14 ) is increased. When the knob ( 152 ) is moved closer to the top casing ( 111 ), which substantially lifts the central rod ( 131 ) as well as the bowl like bottom ( 132 ), the load on the spring ( 14 ) is lessened. 
         [0043]    With reference to  FIGS. 3A and 3B , the pressure switch ( 1 ) of the present invention is installed inside an air pump ( 2 ), which all together are installed inside the inflatable body ( 3 ). The electrical connector (not numbered) of the air pump is connected to the switch ( 16 ) so that it is noted that the air pump ( 2 ) operation is totally controlled by the activation/deactivation of the pressure switch ( 1 ) of the present invention. 
         [0044]    With reference to  FIGS. 4A and 4B , it is seen that the air pump ( 2 ) and the pressure switch ( 1 ) of the present invention are respectively installed inside the inflatable body ( 3 ). The electrical connector of the air pump ( 2 ) is connected to the switch ( 16 ) of the pressure switch ( 1 ) such that when the switch ( 16 ) is initiated, the air pump ( 2 ) is activated and when the switch ( 16 ) is deactivated, the air pump ( 2 ) operation is thus stopped. 
         [0045]    With reference to  FIG. 5 , the pressure switch ( 1 ) of the present invention in connection with a power source is installed inside the inflatable body ( 3 ) and provided with an electrical connector ( 18 ) in connection with the switch ( 16 ) so as to provide electricity to the air pump ( 2 ) outside the inflatable body ( 3 ). 
         [0046]    With reference to  FIG. 6 , the pressure switch ( 1 ) of the present invention is installed inside the air pump ( 2 ) and the switch ( 16 ) of the pressure switch ( 1 ) is connected to the electrical connector of the air pump ( 2 ). Furthermore, the pressure switch ( 1 ) has a tube ( 19 ) extending from the airway ( 17 ) to an outlet ( 21 ) of the air pump ( 2 ) such that when the air pump ( 2 ) is inflating the inflatable body ( 3 ) with the outlet ( 21 ) extended into the inflatable body ( 3 ), the pressure inside the inflatable body ( 3 ) may still be sensed by the resilient element ( 12 ) via the tube ( 19 ). 
         [0047]    With reference to  FIGS. 7A ,  7 B and  7 C, the pressure switch in this embodiment is substantially the same as that shown in  FIG. 1 . The only difference therebetween is that the top casing ( 111 ) is provided with an exchanging chamber ( 1111 ) having three holes (A, B, C). The hole (A) is provided to communicate the exchanging chamber ( 1111 ) with the interior of the top casing ( 111 ). The hole (B) is provided to communicate the exchanging chamber ( 1111 ) with an interior of the inflatable body ( 3 ). An air tube ( 33 ) is extending from the hole (C) to communicate with the airway ( 17 ). The top casing ( 111 ) is provided with at least one track ( 32 ) formed therein and a sliding block ( 31 ) is movably received inside the exchanging chamber ( 1111 ) with the confinement of the track ( 32 ) such that the sliding block ( 31 ) is able to alternately block the hole (A) and the hole (C). That is, when the sliding block ( 31 ) is moved to the right (seen in  FIG. 7A ) and to communicate hole (B) with hole (C) via the exchanging chamber ( 1111 ), the pressure switch is ready for inflation. When the sliding block ( 31 ) is moved to the left (seen in  FIG. 7B ) and communicate hole (B) with hole (A), the pressure switch is ready for deflation. That is, the air inside the inflatable body is able to escape from hole (A) and hole (B) to be away from the inflatable body. When the pressure switch of the present invention is ready for inflation, the pressure inside the inflatable body ( 3 ) may still be sensed by the resilient element ( 12 ) via hole (B), hole (C), tube ( 33 ) and the airway ( 17 ). When the pressure switch of the present invention is ready for deflation, i.e. the sliding block ( 31 ) is moved to the left in the exchanging chamber ( 1111 ), the pressure inside the inflatable body ( 3 ) is sensed by the resilient element ( 12 ) via hole (B) and hole (A). 
         [0048]    With reference to  FIGS. 8A˜8D , it is noted that a motor ( 35 ) is positioned inside the pressure switch ( 1 ) of the present invention and a worm shaft ( 36 ) is extending out of the motor ( 35 ) to mate with a gear ( 34 ) which is received inside the exchanging chamber ( 1111 ) and mated with the sliding block ( 31 ) so that rotation of the worm shaft ( 36 ) as a result of the operation of the motor ( 35 ) is able to drive the sliding block ( 31 ) to move inside the exchanging chamber ( 1111 ) to accomplish the desired goals as stated above. 
         [0049]    With reference to  FIGS. 9A to 9C , the driving element ( 13 ) is now composed of two T shaped rods. A leaf spring ( 18 ) has a first end connected to one of the two rods of the driving element ( 13 ) and a second end connected to the on/off switch ( 16 ). The other rod of the driving element ( 13 ) is connected to the resilient element ( 12 ). When in operation, the air inside the inflatable body enters the pressure switch of the present invention via the airway ( 17 ) to force the resilient element ( 12 ) to move. As a result of the movement of the resilient element ( 12 ), the driving element ( 13 ) is moved. Therefore, when the pressure inside the inflatable body is larger than that of the recovery force of the leaf spring ( 18 ), the on/off switch ( 16 ) is stopped to stop inflation. However, when the pressure inside the inflatable body is less than that of the recovery force of the leaf spring ( 18 ), the on/off switch ( 16 ) is activated due to the influence of the leaf spring ( 18 ) to force the driving element ( 13 ) back to its original position. Thus the pump ( 2 ) is activated to increase the pressure inside the inflatable body. When in deflation, the sliding block ( 31 ) is moved to the right to communicate the interior of the pressure switch with the ambient air. Thus, reverse operation of the air pump ( 2 ) draws air out of the inflatable body until a negative pressure inside the inflatable body is large enough to overcome the recovery force of the leaf spring ( 18 ) so as to turn off the on/off switch ( 16 ) to stop operation of the air pump ( 2 ). 
         [0050]    With reference to  FIGS. 10A to 10D , it is noted that the pressure switch ( 1 ) is substantially the same as that shown in the ninth embodiment shown in  FIGS. 9A to 9C . Furthermore, the motor ( 35 ), the worm shaft ( 36 ) as well as the gear ( 34 ) are provided to drive the sliding block ( 31 ) to move, which has already been described in the embodiment shown in  FIGS. 8A to 8D . 
         [0051]    With reference to  FIGS. 11A and 11B , two pressure switches ( 1 , 11 A) are provided to be responsible for inflating and deflating respectively. As operations thereof are substantially the same as those described in the previous embodiments, detailed description thereof is thus omitted. 
         [0052]    With reference to  FIG. 12 , the sliding block ( 31 ) is not connected to the gear ( 34 ). But the gear ( 34 ) is now provided with an arcuate recess ( 341 ) to receive therein a positioning rod ( 311 ) formed on the sliding block ( 31 ) such that when the gear ( 34 ) is rotated due to the driving of the motor ( 35 ), the sliding block ( 31 ) is moved. 
         [0053]    It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.