Abstract:
The present invention relates to a type of pressure switch, particularly a type of pressure switch having a hand-controlled device, using a control rod on the hand control device to directly drive a second driving plate to move up and down, thereby to effortlessly open and close a release valve and power of the pressure switch.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    A pressure switch is the electrical switch of pressure operation, used to control the pressure inside the air cylinder of an electrically driven air compressor, to turn it between two preset pressure settings. The pressure switch has a release vale, serving to avoid overload starting of the air compressor, and a control rod to manually open the release valve of the air compressor cylinder, to execute release operation, meanwhile cut off power to the air compressor, to stop operation of the air compressor. A four-way base connector opening facilitates installation of the release valve and pressure gage. 
         [0002]    The present invention relates to a type of pressure switch, particularly a type of pressure switch having a hand-controlled device, using a control rod on the hand control device to directly drive a second driving plate to move up and down, thereby to effortlessly turn on and off the release valve and power. 
         [0003]    As shown in  FIGS. 1 to 4 , the conventional pressure switch  1  comprises a base  11 , a lower casing  12 , an upper casing  13 , an exterior casing  14 , a first driving plate  21 , a second driving plate  22 , a third driving plate  23 , a tension spring  24 , a pressure adjustment spring set  25 , a fine-tune spring set  26 , a release valve  27  and a control rod  28 ; wherein the base  11  has an air inlet  111 , a first pressure release hole  112 , a second pressure release hole  113  and a third pressure release hole  114 , and a pneumatic rubber block  1120  is joined to an outside of the first pressure release hole  112 , wherein the lower casing  12  has a through hole  121  on its bottom, the first side wall  122  of the lower casing  12  has a mobile hole  123 , protruding outwardly on top of the mobile hole  123  is a hole unit  124 , protruding outwardly on bottom of the mobile hole  123  is a flapper  125 ; positioned on the second side wall  126  of the lower casing  12  is a shaft hole  127 , the bottom of the lower casing  12  is joined to the top of the base  11 , the through hole  121  on the bottom of the lower casing  12  is positioned on top of the pneumatic rubber block  1120  joined externally to the first pressure release hole  112  of the base  11 ; wherein the upper casing  13  is made of plastic material, positioned at the center on top of the upper casing  13  is a mobile hole  131 , positioned on the front side of the mobile hole  131  are two spring troughs  132 ,  133 , positioned inside the spring trough  132  are two matching snap troughs  1321 ,  1322 , the upper outlet  1323  of the spring trough appropriately retracts inwardly, positioned in the upper section of the spring trough  133  is an inside screw thread  1331 , the inside margin of the lower outlet  1332  of the spring trough  133  appropriately retracts inwardly, positioned on one side of the mobile hole  131  is an on off circuit  134 , the on off circuit  134  comprising of a contact point  1341  and a conductive piece  1342 ; positioned on another side of the mobile hole  131  is also an on off circuit  135 , the on off circuit  135  comprising of a contact point  1351  and a conductive piece  1352 . On the inside margin of the upper casing, between the two on off circuits  134 ,  135  are two matching slide rails (not shown in the drawings); the upper casing  13  is fitted to the top of the lower casing  12 , the upper casing  13  and the lower casing  12  are combined and screwed to the top of the base  11 ; wherein the exterior casing  14  is fitted to the top of the upper casing  13  and the lower casing  12 , the exterior casing  14  and the lower casing  12  are combined and screwed to the top of the base  11 ; wherein the bottom at the center of the first driving plate  21  forms downwardly a protrusion  211 , positioned at the front section of the first driving plate  21  is a sleeve  212 , one side of the sleeve  212  bending upwardly 90 degrees to have a snap trough  213 , another side of the sleeve  212  bending upwardly 90 degrees then bending outwardly 90 degrees to form a wing part  214 ; the first driving plate  21  is positioned inside the lower casing  12 , the protrusion  211  of the first driving plate  21  is justly accommodated in the through hole  121  on bottom of the lower casing  12 , and is pressed against the pneumatic rubber block  1120  at a bottom side of the through hole  121  on the bottom of the lower casing  12 ; wherein one side of the second driving plate  22  extends outwardly to form an extension arm  221 , positioned at the center of the second driving plate  22  is a spring piece  222  at an upward angle of approximately 45 degrees, at the center of the second driving plate  22  and one side of the spring piece  222  is a snap hole  223 ; the second driving plate  22  is positioned on top of the first driving plate  21 , the extension arm  221  of the second driving plate  22  extends out of the mobile hole  123  on the first side wall  122  of the lower casing  12 , and between the hole unit  124  protruding outwardly on top of the mobile hole  123  and the flapper  125  protruding outwardly from the bottom of the mobile hole  123 ; wherein the hook end  241  of the tension spring  24  is hooked to the snap trough  213  of the first driving plate  21 , another hook end  242  of the tension spring  24  is hooked to the snap hole  223  of the second driving plate  22 ; wherein the third driving plate  23  is an insulating plate made of bakelite, the top of the third driving plate  23  is a slide block  231  protruding upwardly, the bottom of the third driving plate  23  is an activation block  232  protruding downwardly, the front of the third driving plate  23  is a slide block  233  protruding forwardly, the rear of the third driving plate  23  is a slide block  234  protruding backwardly, the left and right sides of the third driving plate  23  extend outwardly to form respectively a pressure rod  235 ,  236 ; the third driving plate  23  is positioned between the upper casing  13  and the second driving plate  22 , the slide block  231  of the third driving plate  23  is fitted into the mobile hole  131  of the upper casing, the slide blocks  233 ,  234  at the front and rear of the third driving plate  23  are correspondingly fitted to two corresponding slide rails (not shown in the drawings) of the upper casing  13 , the pressure rod  235  of the third driving plate  23  is pressed against the lower margin of the conductive piece  1342  of the on off circuit  134  of the upper casing  13 , the pressure rod  236  of the third driving plate  23  is pressed against the lower margin of the conductive piece  1352  of the on off circuit  135  of the upper casing, the bottom end of the activation block  232  of the third driving plate  23  is pressed against the upper margin of the spring plate  222  at the center of the second driving plate  22 ; wherein the pressure adjusting spring set  25  comprises of a pressure adjusting screw  251 , a double-wing nut  252  and a compression spring  253 , the pressure adjusting spring set  25  is positioned inside the spring trough of the upper casing  13 , the bottom of the pressure adjusting screw  251  of the pressure adjusting spring set  25  is fitted to the outside margin of the sleeve  212  at the front section of the first driving plate  21 , using the depth penetrated by the pressure adjusting screw  251  into the double-wing nut  252  to adjust the pressure applied by the compression spring  253  on the first driving plate  21 ; wherein the fine-tune spring set  26  comprises of a pressure adjusting screw  261 , a compression spring  262  and a plastic terminal  263 , the fine-tune spring set  26  is positioned inside the spring trough of the upper casing, the plastic terminal  263  of the fine-tune spring set is pressing against the upper margin of the wing part  214  at the front section of the first driving plate  21 , using the depth penetrated by the pressure adjusting screw  261  into the inside screw thread  1331  in upper section of the spring trough  133 , to adjust the pressure applied by the fine-tune applied by the compression spring  262  through the plastic terminal  263 ; wherein the release valve is joined to the hole unit  124  of the first side wall  122  of the lower casing by a nut  270 , the air release piston rod  271  of the release valve  27  appropriately extends toward the lower part of the hole unit  124 , at the front of the mobile hole  123  of the first side wall  122  of the lower casing  12 , and pressing against the upper margin of the extension arm  221  of the second driving plate  22 ; the air cylinder (not shown in the drawings) of the air compressor (not shown in the drawings) is joined to the air inlet hole  111  of the base  11 , the air from the air cylinder enters through the air inlet hole  111  of the base  11  to the first pressure release hole  112 , the second pressure release hole  113  and the third pressure release hole  114  of the base  11 , with an air pipe (not shown in the drawings) connected to the pressure release hole  113  and the release valve  27  of the base  11 , and a air pipe (not shown in the drawings) connected to the third pressure release hole  114  and the pressure gage (not shown in the drawings) of the third pressure release hole  114  of the base  11 ; wherein the control rod  28  is shaped in a figure of “7”, the hook end  281  of the control rod  28  penetrates into the shaft hole  127  of the second side wall  126  of the lower casing  12 , pressing against the lower margin of the wing part  214  at the front section of the first driving plate  21 , the shaft rod  282  of the control rod is fitted to the shaft hole  127  of the second side wall  126  of the lower casing  12 , the handle  283  of the control rod  28  is positioned outside the shaft hole  127  of the second side wall  126  of the lower casing  12 ; lifting up the handle  283  of the control rod  28  will make the hook end  281  of the control rod  28  push the first driving plate  21  to move upward, the compression spring  253  of the pressure adjusting spring set  25  and the compression spring  262  of the fine-tune spring set  26  drive the extension arm  221  of the second driving plate  22 , push up the air release piston rod  271  of the release valve  27  to open the release valve  27  to leak air; and push the third driving plate  23  to move upward, drive the pressure rod  235  of the third driving plate  23 , push the conductive piece  1342  away from the contact point  1341  of the on off circuit  134  of the upper casing  13  to move upward, meanwhile driving the pressure rod  236  of the third driving plate  23 , pushing the conductive piece  1352  away from the contact point  1351  of the on off circuit  135  of the upper casing  13  to move upward, to turn off power and stop operation of the air compressor (not shown in the drawings). 
         [0004]    As described above, in the conventional type of pressure switch  1 , lifting the handle  283  of the control rod  28  requires a very powerful force to make the hook end  281  of the control rod  28  push the first driving plate  21  to move the first driving plate  21  upward, counteracting the compression spring  253  of the pressure adjusting spring set  25  and the compression spring  262  of the fine-tune spring set  26 , resulting in oblique inclination of the compression spring  253  of the pressure adjusting spring set  25  after being compressed, and cracking of the upper casing  13  made of plastic material after being compressed. 
       SUMMARY OF THE INVENTION 
       [0005]    To make improvement on the shortcoming of the aforementioned conventional pressure switch, the present invention provides a type of pressure switch comprising of a base, a lower casing, an upper casing, an exterior casing, a first driving plate, a second driving plate, a third driving plate, a tension spring, a pressure adjusting spring set, a fine-tune spring set, a release valve and a control rod, characterized in the hand control device comprising of the control rod and the second driving plate, wherein the hook end of the control rod is joined to the second driving plate, using the control rod to directly drive the second driving plate to move up and down, to effortlessly turn on and off the release valve and power of the pressure switch; which can make improvement on the shortcoming in the hand control device of the conventional type of pressure switch comprising of a control rod and a first driving plate, which requires an extremely large force to turn on and off the release valve and power of the pressure switch, counteracting the pressure adjusting spring set on the first driving plate and the compression spring of the fine-tune spring set, resulting in oblique inclination of the compression spring of the pressure adjusting spring set after being compressed, and cracking of the upper casing made of plastic material after being compressed. 
         [0006]    The primary objective of the present invention is to provide a type of pressure switch that is capable of making improvement on the shortcoming of the conventional type of pressure switch using a hand control device comprising of a first driving plate and a control rod and requiring an extremely large force to turn on and off the release valve and power of the pressure switch, counteracting the compression spring of the conventional pressure switch positioned on top of the first driving plate, resulting in oblique inclination of the compression spring of the pressure adjusting spring set after being compressed, and cracking of the upper casing made of plastic material after being compressed. 
         [0007]    Another objective of the present invention is to provide a type of pressure switch which uses a hand control device to turn off the release valve and power of the pressure switch, without touching the compression springs of the pressure adjusting spring set and fine-tune spring set installed in the pressure switch. 
         [0008]    A further objective of the present invention is to provide a type of pressure switch that is equipped with a hand control device comprising of a hook end of a control rod joined to a second driving plate, wherein the hook end of the control rod is joined to the second driving plate, using to the control rod to directly drive the second driving plate to move up and down, to effortlessly turn on and off the release valve and power of the pressure switch. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an exploded view of the conventional pressure switch. 
           [0010]      FIG. 2  is a perspective view of the conventional pressure switch. 
           [0011]      FIG. 3  is a schematic view of the conventional pressure switch in switching off operation. 
           [0012]      FIG. 4  is a schematic view of the conventional pressure switch in switch on operation. 
           [0013]      FIG. 5  is an exploded view of the present invention of pressure switch. 
           [0014]      FIG. 6  is a perspective view of the present invention of pressure switch. 
           [0015]      FIG. 7  is a schematic view of the present invention of pressure switch in switching off operation. 
           [0016]      FIG. 8  is a schematic view of the present invention of pressure switch in switching on operation. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    As shown in  FIGS. 5 through 8 , the present invention of pressure switch  5  comprises a base  51 , a lower casing  52 , an upper casing  53 , an exterior casing  54 , a first driving plate  61 , a second driving plate  62 , a third driving plate  63 , a tension spring  64 , a pressure adjusting spring set  65 , a fine-tune spring set  66 , a release valve  67  and a control rod  68 ; wherein the base  51  has an air inlet hole  511 , a first pressure release hole  512 , a second pressure release hole  513  and a third pressure release hole  514 , the first pressure release hole  512  of the base  51  is joined externally to a pneumatic rubber block  5120 ; wherein the lower casing  52  has a through hole  521  on its bottom, the first side wall  522  of the lower casing  52  has a mobile hole  523 , the mobile hole  523  has a hole unit  524  protruding outwardly on its top side, the mobile hole  523  has a flapper  525  protruding outwardly on its bottom side, the second side wall  526  of the lower casing  52  has a shaft hole  527 , the bottom of the lower casing  52  is joined to the top of the base  51 , the through hole  521  on the bottom of the lower casing  52  is joined to the top side of the pneumatic rubber block  5120  which is joined externally to the first pressure release hole  512  of the base  51 ; wherein the upper casing  53  is made of plastic material, at the center on top of the upper casing  53  is a mobile hole  531 , on the front side of the mobile hole  531  are two spring troughs  532 ,  533 , inside the spring trough  532  are two matching snap troughs  5321 ,  5322 , the inner margin of the upper outlet  5323  of the spring trough  532  retracts appropriately inward, on the upper section of the spring trough  533  is an inside screw thread  5331 , the lower outlet  5332  of the spring trough  533  retracts appropriately inward, on one side of the mobile hole  531  is an on off circuit  534 , the on off circuit  534  consisting of a contact point  5341  and a conductive piece  5352 ; on the inside margin of the upper casing  53  and between the on off circuits  534 ,  535  are two corresponding slide rails (not shown in drawings); the upper casing  53  is fitted on top of the lower casing  52 , the upper casing and the lower casing  52  are jointly screwed to the top of the base  51 ; wherein the exterior casing  54  is fitted to the top of the upper casing  53  and the lower casing  52 , the exterior casing  54  and the lower casing  52  are jointly screwed to the top of the base  51 ; wherein the central bottom of the first driving plate  61  curves downward to form a protrusion  611 , the front section of the first driving plate  61  has a sleeve  612 , one side of the sleeve  612  bending upward  90  degrees to form a snap trough  613 , another side of the sleeve  612  bending upward 90 degrees then again bending outwardly 90 degrees to form a wing part  614 ; the first driving plate  61  is positioned inside the lower casing  52 , the protrusion  611  of the first driving plate  61  is justly accommodated in the through hole  521  on the bottom of the lower casing  52  and in contact with the pneumatic rubber block  5120  below the through hole  521  on the bottom of the lower casing  52 ; wherein one side of the second driving plate  62  has an extension arm  621  extending outwardly, another side of the second driving plate  62  forms a wing part  622  bending slightly downward, the center of the second driving plate  62  has a spring plate  623  at an upward angle of approximately 45 degrees, the center part of the second driving plate  62  and one side of the spring plate  623  has a snap hole  624 ; the second driving plate  62  is positioned on top of the first driving plate  61 , the second driving plate  62  is slightly wider than the first driving plate  61 , the wing part  622  of the second driving plate  62  extends further than the wing part  614  of the first driving plate  61 , the extension arm  621  of the second driving plate  62  extends out of the mobile hole  523  of the first side wall  522  of the lower casing  52 , between the hole unit  524  protruding outwardly on top of the mobile hole  523  and the flapper  525  protruding outwardly on bottom of the mobile hole  523 ; wherein the hook end  641  of the tension spring  64  is hooked to the snap trough  613  of the first driving plate  61 , and another hook end of the tension spring  64  is hooked to the snap hole  623  of the second driving plate  62 ; wherein the third driving plate  63  is an insulated plate made of bakelite, the top of the third driving plate  63  is a slide block  631  protruding upwardly, the bottom part of the third driving plate  63  is an activation block  632  protruding downward, the front of the third driving plate  63  is a slide block  633  protruding forward, the rear of the third driving plate  63  is a slide block  634  protruding backward, the left and right sides of the third driving plate  63  extending outwardly to form respectively a pressure rod  635 ,  636 ; the third driving plate  63  is positioned between the upper casing  53  and the second driving plate  62 , the slide block  631  of the third driving plate  63  is fitted into the mobile hole  131  of the upper casing  53 , the slide blocks  633 ,  634  on the front and rear of the third driving plate  63  are correspondingly fitted to the two corresponding slide rails (not shown in drawings) of the upper casing  53 , the pressure rod  635  of the third driving plate  63  is pressed against the lower margin of the conductive piece  5342  of the on off circuit  534  of the upper casing  53 , the pressure rod  636  of the third driving plate  63  is pressed against the lower margin of the conductive piece  5352  of the on off circuit  535  of the upper casing  53 , the activation block  632  of the third driving plate  63  is pressed against the upper margin of the spring piece  622  at the center of the second driving plate  62 ; wherein the pressure adjusting spring set  65  comprises a pressure adjusting screw  651 , a double-wing nut  652  and a compression spring  653 , the pressure adjusting spring set  65  is positioned inside the spring trough  532  of the upper casing  53 , the bottom of the pressure adjusting screw  651  of the pressure adjusting spring set  65  is fitted to the outer margin of the sleeve  612  in the front section of the first driving plate  61 , using the depth penetrated by the pressure adjusting screw  651  into the double-wing nut  652  to adjust the pressure applied by the pressure the compression spring  653  on the first driving plate  61 ; wherein the fine-tune spring set  66  comprises a pressure adjusting screw  661 , a compression spring  662  and a plastic terminal  663 , the fine-tune spring set  66  is positioned inside the spring trough  533  of the upper casing  53 , the plastic terminal  663  of the fine-tune spring set  66  is pressed against the upper margin of the wing part  614  at the front section of the first driving plate  61 , using the depth penetrated by the pressure adjusting screw  661  into the screw thread  5331  in the upper section of the spring trough  533 , to fine tune the pressure applied by the compression spring  662  through the plastic terminal  663  on the first driving plate  61 ; wherein the release valve  67  is joined by a nut  670  to the hole unit  524  on the first side wall  522  of the lower casing  52 , the air release piston rod  671  of the release valve  67  appropriately extends downward toward the hole unit  524 , at the front of the mobile hole  523  of the first side wall  522  of the lower casing  52 , and is pressing against the upper margin of the extension arm  621  of the second driving plate  62 ; the air cylinder (not shown in the drawings) of the air compressor (not shown in the drawings) is joined to the air inlet hole  511  of the base  51 , air in the air cylinder enters through the air inlet hole  511  of the base  11  into the first pressure release hole  512 , the second pressure release hole  513  and third pressure release hole  514  on the base  51 , there is a air pipe (not shown in drawings) connected to the second pressure release hole  513  and the release valve  67  on the base  51 , there is an air pipe (not shown in the drawings) connected to the third pressure release hole  514  and the pressure gauge (not shown in the drawings) on the base  51 ; wherein the control rod  68  is formed in the shape of figure “7”, the hook end  681  of the control rod  68  penetrates the shaft hole  527  of the second side wall  526  of the lower casing  52 , and is pressed against the lower margin of the wing part  622  of the second driving plate  62 , the shaft rod  682  of the control rod  68  is fitted to the shaft hole  527  of the second side wall  526  of the lower casing  52 , the handle of the control rod  68  is positioned outside the shaft hole  527  of the second side wall  526  of the lower casing  52 ; lifting the handle  683  of the control rod  68  upward will make the hook end  681  of the control rod  68  push the second driving plate  62  to move upward, driving the extension arm  621  of the second driving plate  62 , and pushing the air release piston rod  671  of the release valve  67  to open up the release valve  67  to leak air; and push up the third driving plate  63  to move upward, thereby driving the pressure rod  635  of the third driving plate  63 , pushing the conductive piece  5342  away from the contact point  5341  of the on off circuit  534  of the upper casing  53  to move upward, meanwhile driving the pressure rod  636  of the third driving plate  63 , and pushing the conductive piece  5352  away from the contact point  5351  of the on off circuit  535  of the upper casing  53  to move upward, thereby turning off power of the pressure switch, and stop operation of the air compressor (not shown in the drawings). 
         [0018]    As described above, the components comprising the present invention of pressure switch  5 , including the base  51 , the lower casing  52 , the upper casing  53 , the exterior casing  54 , the first driving plate  61 , the third driving plate  63 , the tension spring  64 , the pressure adjusting spring set  65 , the fine-tune spring set  66  and the release valve  67  are exactly the same as the components comprising the conventional pressure switch  1 , including the base  11 , the lower casing  12 , the upper casing  13 , the exterior casing  14 , the first driving plate  21 , the third driving plate  23 , the tension spring  24 , the pressure adjusting spring set  25 , the fine-tune spring set  26  and the release valve  27 ; the preferred embodiment of the present invention of pressure switch  5  is characterized in that, in the hand control device composed by the control rod  68  and the second driving plate  62 , the second driving plate  62  is slightly wider than the first driving plate  61 , one side of the second driving plate  62  forms a wing part  622 , and the hook end  681  of the control rod  68  being positioned on the lower margin of the wing part  622  of the second driving plate  62 , using the control rod  68  to directly push the second driving plate  62  to move up and down, thereby to drive the extension arm  621  of the second driving plate  62 , push the air release piston rod  671  of the release valve  67  to turn on or off the release valve  67  of the pressure switch; and drive the pressure rods  635 ,  636  of the third driving plate  63  and turn on and off power of the pressure switch. 
         [0019]    Since the preferred embodiment of the present invention of pressure switch  5  uses the control rod  68  to directly push the second driving plate  62  to move up and down, driving the extension arm  621  of the second driving plate  62 , pushing the air release piston rod  671  of the release valve  67  to turn on and off the release valve  67  of the pressure switch, thereby driving the pressure rods  635 ,  636  of the third driving plate  63  to turn on and off power of the pressure switch, which will not involve contact with the compression spring  651  of the pressure adjusting spring set  65  and the compression spring  661  of the fine-tune spring set  66 , therefore it requires not much effort to turn on and off the control rod  68 ; which is capable of making improvement on the shortcomings in the conventional type of pressure switch  1  that requires an extremely large force by using a hand control device comprising of the control rod  28  and the first driving plate  21  to push the first driving plate  21  to move upward, to counteract the compression tension  253  of the pressure adjusting spring set  25  and the compression spring  262  of the fine-tune spring set  26 , resulting in oblique inclination of the compression spring  253  of the pressure adjusting spring set  25  after being compressed, and cracking of the upper casing  13  made of plastic material after being compressed. 
         [0020]    The above description serves to describe some of the preferred embodiments of the present invention, which should not be used to restrict or limit the present invention which may include a variety of transformations, modifications and applications without departing from the spirit of the present invention, including the hand control device with equivalent performance by production of the control rod in one of many different geological configurations, joined to the second driving plate by one of various mechanical means, and other similar methods should be included in the scope of the subject patent right.