Abstract:
A manual liquid pump has a drawing device, a connecting tube, an outlet gun and a detecting device. The drawing device is inserted into a container to draw liquids and has a caution shaft. The connecting tube has an inner and outer pipe. The inner pipe is mounted in the outer pipe and is connected to and actuates the caution shaft. The outlet gun has a returning valve being selectively actuated to close and prevent liquid from flowing through the outlet gun, instead forcing the liquid down the inner pipe and actuating the caution shaft to warn users to stop pumping. The detecting device is mounted in the nozzle and actuates the return valve when a liquid level is too high to prevent overfilling and spillage for safer operation.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a manual liquid pump, and more particularly to a manual liquid pump having an auto shut-off valve to prevent overfilling. 
         [0003]    2. Description of Related Art 
         [0004]    Conventional manual liquid pumps usually comprise a drawing device, a joint pipe and an outlet gun. The drawing device is used to fill gas or air into a storage container by hand to draw the liquid out of the storage container. The joint pipe is connected to the drawing device to transport the liquid drawed out of the storage container. The outlet gun is connected to the joint pipe opposite to the drawing device and is used to fill the liquid drawed out of the storage container into a bucket or a can. 
         [0005]    The conventional manual liquid pump can be used to transport liquid from the storage container to a bucket or can. However, the conventional liquid pump cannot detect the liquid level of the liquid that filling the bucket or can. When the liquid has filled the bucket or can, and the user still operates the conventional manual liquid pump to transport the liquid into the bucket or the can, the liquid will continue to be added causing overflow. If the liquid is a volatile liquid such as the gasoline, such overflow is dangerous liquid. 
         [0006]    To overcome the shortcomings, the present invention provides a manual liquid pump to mitigate or obviate the aforementioned problems. 
       SUMMARY OF THE INVENTION 
       [0007]    The main objective of the present invention is to provide a manual liquid pump having an auto shut-off valve to prevent overfilling. 
         [0008]    The manual liquid pump in accordance with the present invention has a drawing device, a connecting tube, an outlet gun and a detecting device. The drawing device is inserted into a container to draw liquids and has a caution shaft. The connecting tube has an inner and outer pipe. The inner pipe is mounted in the outer pipe and is connected to and actuates the caution shaft. The outlet gun has a returning valve being selectively actuated to close and prevent liquid from flowing through the outlet gun, instead forcing the liquid down the inner pipe and actuating the caution shaft to warn users to stop pumping. The detecting device is mounted in the nozzle and actuates the return valve when a liquid level is too high to prevent overfilling and spillage for safer operation. 
         [0009]    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 
         [0010]      FIG. 1  is a perspective view of a manual liquid pump in accordance with the present invention; 
           [0011]      FIG. 2  is an enlarged, exploded perspective view of a drawing device of the manual liquid pump in  FIG. 1 ; 
           [0012]      FIG. 3  is an enlarged side view in partial section of the drawing device of the manual liquid pump in  FIG. 1 ; 
           [0013]      FIG. 4  is an enlarged exploded view of an outlet gun of the manual liquid pump in  FIG. 1 ; 
           [0014]      FIG. 5  is an enlarged top view of the outlet gun of the manual liquid pump in  FIG. 1 , showing internal elements; 
           [0015]      FIG. 6  is an enlarged exploded view of a detecting device of the manual liquid pump in  FIG. 4 ; 
           [0016]      FIG. 7  is enlarged side view in partial section of the detecting device of the manual liquid pump in  FIG. 6 ; 
           [0017]      FIG. 8  is an operational side view of the detecting device of the manual liquid pump in  FIG. 7 ; and 
           [0018]      FIG. 9  is an operational side view in partial section of the drawing device of the manual liquid pump in  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]    With reference to  FIGS. 1 ,  2  and  4 , a manual liquid pump in accordance with the present invention comprises a drawing device ( 10 ), a connecting tube ( 20 ), an outlet gun ( 30 ) and a detecting device ( 40 ). 
         [0020]    The drawing device ( 10 ) has a body ( 11 ), a drawing mount ( 12 ), a piston rod ( 13 ), a pushing block ( 14 ), a pivot seat ( 15 ) and a caution shaft ( 16 ). 
         [0021]    The body ( 11 ) has a drawing barrel ( 111 ) and a mounting ring ( 113 ). The drawing barrel ( 111 ) is used to insert into a container (not shown) and has a top, a bottom, a center and a drawing pipe ( 112 ). The drawing pipe ( 112 ) is formed on the bottom of the drawing barrel ( 111 ). The mounting ring ( 113 ) is hollow, is detachably connected to the drawing barrel ( 111 ) and has a bottom and a top. The bottom of the mounting ring ( 113 ) is detachably mounted around the top of the drawing barrel ( 111 ). 
         [0022]    With further reference to  FIG. 3 , the drawing mount ( 12 ) is formed on the body ( 11 ) and has a top, a bottom, a sidewall, an internal surface, a chamber ( 121 ), a rod hole ( 122 ), two drawing holes ( 123 ), a dovetail groove ( 124 ), a shaft hole ( 125 ), an output tube ( 126 ) and a pivotal recess ( 127 ). The bottom of the drawing mount ( 12 ) is formed on the top of the mounting ring ( 113 ) of the body ( 11 ). The chamber ( 121 ) is defined in the drawing mount ( 12 ). The rod hole ( 122 ) is formed in the top of the drawing mount ( 12 ) and communicates with the chamber ( 121 ) and aligns with the center of the drawing barrel ( 111 ). The drawing holes ( 123 ) are formed in the bottom of the drawing mount ( 12 ) and communicate with the chamber ( 121 ) and the drawing barrel ( 111 ). The dovetail groove ( 124 ) is formed in the bottom of the drawing mount ( 12 ) near the drawing holes ( 123 ). The shaft hole ( 125 ) is formed in the top of the drawing mount ( 12 ) and communicates with the chamber ( 121 ). The output tube ( 126 ) is formed on and protrudes from the sidewall of the drawing mount ( 12 ) and communicates with the chamber ( 121 ). The pivotal recess ( 127 ) is formed in the internal surface of the drawing mount ( 12 ) near the output tube ( 126 ). 
         [0023]    The piston rod ( 13 ) is movably mounted in the body ( 11 ) and the drawing mount ( 12 ) and the piston rod ( 13 ) has an inner end, an outer end, an external surface, a check valve ( 131 ) and an operating head ( 132 ). The inner end of the piston rod ( 13 ) extends into the body ( 11 ) through the rod hole ( 122 ) and into the chamber ( 121 ) of the drawing mount ( 12 ). The check valve ( 131 ) is connected to the inner end of the piston rod ( 13 ) and mounted between the drawing barrel ( 111 ) and the mounting ring ( 113 ). The outer end of the piston rod ( 13 ) extends out of the top of the drawing mount ( 12 ) from the rod hole ( 122 ). The operating head ( 132 ) is formed on the outer end of the piston rod ( 13 ) to allow the piston rod ( 13 ) to be moved up or down relative to the drawing mount ( 12 ) and the body ( 11 ). 
         [0024]    The pushing block ( 14 ) is mounted securely in the drawing mount ( 12 ) and has a top, a bottom, a sidewall, an inserting hole ( 141 ), a pushing axle ( 142 ) and a returning conduit ( 143 ). The inserting hole ( 141 ) is formed in the top of the pushing block ( 14 ). The pushing axle ( 142 ) is movably mounted in the inserting hole ( 141 ) of the pushing block ( 14 ) and has a top end. The returning conduit ( 143 ) is formed on and protrudes from the sidewall of the pushing block ( 14 ) and aligns with the output tube ( 126 ) of the drawing mount ( 12 ). 
         [0025]    The pivot seat ( 15 ) is pivotally mounted in the drawing mount ( 12 ), abuts the pushing block ( 14 ) and has a top, a bottom, a mounting segment ( 151 ), an engaging hole ( 152 ), a pushing segment ( 153 ) and a lifting segment ( 154 ). The mounting segment ( 151 ) is defined in the bottom of the pivot seat ( 15 ) and is pivotally mounted in the mounting recess ( 127 ) of the drawing mount ( 12 ). The engaging hole ( 152 ) is formed through the top and the bottom of the pivot seat ( 15 ) and is mounted around the piston rod ( 13 ). The pushing segment ( 153 ) is defined in the top of the pivot seat ( 15 ) and abuts the top end of the pushing axle ( 142 ) of the pushing block ( 14 ). The lifting segment ( 154 ) is defined in the bottom of the pivot seat ( 15 ) opposite to the mounting segment ( 151 ) and aligns with the shaft hole ( 125 ) of the drawing mount ( 12 ). 
         [0026]    The caution shaft ( 16 ) is mounted in the chamber ( 121 ) of the drawing mount ( 12 ), abuts the pivot seat ( 15 ) and has a lower end, an upper end and a mounting spring ( 161 ). The lower end of the caution shaft ( 16 ) abuts the lifting segment ( 154 ) of the pivot seat ( 15 ) to hold the caution shaft ( 16 ) in the chamber ( 121 ) of the drawing mount ( 12 ). The upper end of the caution shaft ( 16 ) is mounted in the shaft hole ( 125 ) of the drawing mount ( 12 ). The mounting spring ( 161 ) is mounted around the caution shaft ( 16 ) between the internal surface of the drawing mount ( 12 ) and the lower end of the caution shaft ( 16 ). 
         [0027]    With further reference to  FIG. 6 , the connecting tube ( 20 ) is connected to the drawing device ( 10 ) and has a distal end, an outer pipe ( 21 ), and an inner pipe ( 22 ). The outer pipe ( 21 ) is connected to the drawing mount ( 12 ) of the drawing device ( 10 ) and has a rear end and a front end. The rear end of the outer pipe ( 21 ) is mounted around the output tube ( 126 ) of the drawing mount ( 12 ) and communicates with the chamber ( 121 ) of the drawing mount ( 12 ) and the drawing barrel ( 111 ) of the body ( 11 ). The inner pipe ( 22 ) is mounted in the outer pipe ( 21 ) and is connected to the pushing block ( 14 ) of the drawing device ( 10 ) and has a rear end and a front end. The rear end of the inner pipe ( 22 ) is mounted in the returning conduit ( 143 ) of the pushing block ( 14 ) through the output tube ( 126 ) and communicates with the inserting hole ( 141 ) of the pushing block ( 14 ). 
         [0028]    With further reference to  FIG. 5 , the outlet gun ( 30 ) is implemented with two half-casings and is connected to the distal end of the connecting tube ( 20 ) and has a rear end, a middle, a front end, a handle ( 31 ), an interior ( 32 ) and a nozzle ( 33 ). 
         [0029]    The handle ( 31 ) is formed in the rear end of the outlet gun ( 30 ) and is mounted around the front end of the outer pipe ( 21 ) of the connecting tube ( 20 ). 
         [0030]    The interior ( 32 ) is defined in the middle of the outlet gun ( 30 ) and receives the front ends of the outer pipe ( 21 ) and the inner pipe ( 22 ). 
         [0031]    The nozzle ( 33 ) is formed in the front end of the outlet gun ( 30 ) and has a free end, an opening ( 331 ) and a holding panel ( 332 ). The opening ( 331 ) is defined in the free end of the nozzle ( 33 ) and communicates with the interior ( 32 ). The holding panel ( 332 ) is semicircular and is mounted in the opening ( 331 ) of the nozzle ( 33 ) and has a holding hole ( 333 ). The holding hole ( 333 ) is formed in the holding panel ( 332 ). 
         [0032]    With further reference to  FIG. 7 , the detecting device ( 40 ) is mounted in the outlet gun ( 30 ) and has a mounting jacket ( 41 ), a returning seat ( 42 ), a returning valve ( 43 ), an actuating element ( 44 ), a returning spring ( 45 ), a flow pipe ( 46 ) and a floating shaft ( 47 ). 
         [0033]    The mounting jacket ( 41 ) is mounted in the interior ( 32 ) of the outlet gun ( 30 ), is connected to the outer pipe ( 21 ) of the connecting tube ( 20 ) and has a rear end, a front end, an external surface, an attachment tube ( 411 ), a mounting chamber ( 412 ), a gap ( 413 ) and a hook ( 414 ). The attachment tube ( 411 ) is formed on the rear end of the mounting jacket ( 41 ) and mounted in the front end of the outer pipe ( 21 ). The mounting chamber ( 412 ) is defined in the mounting jacket ( 41 ) near the front end and communicates with the attachment tube ( 411 ) and the inner pipe ( 22 ) extends into the mounting chamber ( 412 ) of the mounting jacket ( 41 ). The gap ( 413 ) is formed through the external surface of the mounting jacket ( 41 ) in the front end and communicates with the mounting chamber ( 412 ). The hook ( 414 ) is formed on and protrudes from the external surface of the mounting jacket ( 41 ) near the rear end and aligns with the gap ( 413 ). 
         [0034]    The returning seat ( 42 ) is mounted in the mounting jacket ( 41 ), is connected to the inner pipe ( 22 ) of the connecting tube ( 20 ) and has a center, a central tube ( 421 ) and multiple fins ( 422 ). The central tube ( 421 ) is formed on the center of the returning seat ( 42 ) and communicates with the attachment tube ( 411 ) and the mounting chamber ( 412 ) of the mounting jacket ( 41 ) and is mounted in the front end of the inner pipe ( 22 ). The fins ( 422 ) are parallelly formed around the central tube ( 421 ) in at even intervals. 
         [0035]    The returning valve ( 43 ) is connected to the mounting jacket ( 41 ) and has a base ( 431 ), a cover ( 432 ) and a pivot shaft ( 433 ). The base ( 431 ) is connected to the front end of the mounting jacket ( 41 ) and has an inner end, an outer end, an external surface, a through hole ( 434 ), a pivot hole ( 435 ) and a slit ( 436 ). The inner end of the base ( 431 ) is mounted in the mounting chamber ( 412 ) of the mounting jacket ( 41 ). The through hole ( 434 ) is formed through the base ( 431 ) and communicates with the mounting chamber ( 412 ) of the mounting jacket ( 41 ). The pivot hole ( 435 ) is formed through the base ( 431 ) and communicates with the through hole ( 434 ). The slit ( 436 ) is formed through the external surface of the base ( 431 ) and communicates with the through hole ( 434 ) and the pivot hole ( 435 ) and aligns with the gap ( 413 ) of the mounting jacket ( 41 ). 
         [0036]    The cover ( 432 ) is pivotally connected to the inner end of the base ( 431 ) to selectively close the through hole ( 434 ) of the base ( 431 ) and has a bottom face and two guiding tracks ( 437 ). The bottom face of the cover ( 432 ) faces the through hole ( 434 ) of the base ( 431 ). The guiding tracks ( 437 ) are formed parallelly on the bottom face of the cover ( 432 ). The pivot shaft ( 433 ) is mounted in the pivot hole ( 435 ) of the base ( 431 ). 
         [0037]    The actuating element ( 44 ) may be number-3 shaped, is pivotally connected to the returning valve ( 43 ) and has a connecting end ( 441 ), a middle, a mounting end ( 442 ), two guiding posts ( 443 ) and a circular hole ( 444 ). The connecting end ( 441 ) of the actuating element ( 44 ) passes through the through hole ( 434 ) of the base ( 431 ) and is connected to the cover ( 432 ). The middle of the actuating element ( 44 ) is mounted in the slit ( 436 ) of the base ( 431 ) and is pivotally connected to the pivot shaft ( 433 ). The mounting end ( 442 ) of the actuating element ( 44 ) extends out of the outer end of the base ( 431 ). The guiding posts ( 443 ) are formed on the connecting end ( 441 ) and are movably mounted in guiding tracks ( 437 ) of the cover ( 432 ). The circular hole ( 444 ) is formed through the middle of the actuating element ( 44 ) and is mounted around the pivot shaft ( 433 ). 
         [0038]    The returning spring ( 45 ) is attached to the mounting jacket ( 41 ) and the actuating element ( 44 ) and has two ends. One of the ends of the returning spring ( 45 ) is mounted on the hook ( 414 ) of the mounting jacket ( 41 ). The other end of the returning spring ( 45 ) is mounted on the mounting end ( 442 ) of the actuating element ( 44 ). 
         [0039]    The flow pipe ( 46 ) is mounted in the nozzle ( 33 ) of the outlet gun ( 30 ), is connected to the returning valve ( 43 ) and the holding panel ( 332 ) of the nozzle ( 33 ) and has a rear end and a front end. The rear end of the flow pipe ( 46 ) is mounted around the outer end of the base ( 431 ) of the returning valve ( 43 ). The front end of the flow pipe ( 46 ) is mounted in the holding hole ( 333 ) of the holding panel ( 332 ). 
         [0040]    The floating shaft ( 47 ) is movably mounted in the nozzle ( 33 ) of the outlet gun ( 30 ) parallel to the flow pipe ( 46 ) and has an inner end and an outer end. The inner end of the floating shaft ( 47 ) is mounted in the nozzle ( 33 ) near the outer end of the base ( 431 ) and abuts the actuating element ( 44 ) near the mounting end ( 442 ). The outer end of the floating shaft ( 47 ) extends to the free end of the nozzle ( 33 ). 
         [0041]    When the manual liquid pump is used to transport liquid from a container to another one, the mounting barrel ( 111 ) and the drawing pipe ( 112 ) of the body ( 11 ) are placed in a container and the nozzle ( 33 ) of the outlet gun ( 30 ) is placed in a tank. Then, the operating head ( 132 ) of the piston rod ( 13 ) is moved reciprocatorily to make the check valve ( 131 ) move relative to the mounting barrel ( 111 ). Then, the liquid will draw and transport liquid from the container to the tank through the drawing pipe ( 112 ), the mounting barrel ( 111 ), the drawing holes ( 123 ), the chamber ( 121 ), the output tube ( 126 ), the outer pipe ( 21 ), the attachment tube ( 411 ), the returning seat ( 42 ), the through hole ( 434 ) of the base ( 431 ) and the flow pipe ( 46 ). 
         [0042]    With reference to  FIGS. 8 and 9 , when the liquid is drawn to fill the tank, the liquid in the tank will flow back up the nozzle ( 33 ) and make the floating shaft ( 47 ) move further into the nozzle ( 33 ). Then, the inner end of the floating shaft ( 47 ) will push the mounting end ( 442 ) of the actuating element ( 44 ) to rotate relative to the base ( 431 ) and the connecting end ( 441 ) of the actuating element ( 44 ) will make the cover ( 432 ) close the through hole ( 434 ) of the base ( 431 ). 
         [0043]    Should the piston rod ( 13 ) remain in operation, liquid flowing into the mounting jacket ( 41 ) will be stopped by the cover ( 432 ) closing the through hole ( 434 ) of the base ( 431 ) and will flow into the inserting hole ( 141 ) of the pushing block ( 14 ) via the central tube ( 421 ), the inner pipe ( 22 ) and the returning conduit ( 143 ). As the inserting hole ( 141 ) fills up with the liquid, the pushing axle ( 142 ) will move upward relative to the pushing block ( 14 ) and the top end of the pushing axle ( 142 ) will push the pushing segment ( 153 ) of the pivot seat ( 15 ) upward. Then, the mounting segment ( 151 ) of the pivot seat ( 15 ) will move relative to the mounting recess ( 127 ) to make the pivot seat ( 15 ) rotate relative to the drawing mount ( 12 ). With rotation of the pivot seat ( 15 ) relative to the drawing mount ( 12 ), the engaging hole ( 152 ) of the pivot seat ( 15 ) will engage the external surface of the piston rod ( 13 ) and the upper end of the caution shaft ( 16 ) will extend out of the shaft hole ( 125 ) of the drawing mount ( 12 ). This reminds a user to stop moving the piston rod ( 13 ) to prevent the liquid from flowing over the container. Therefore, the manual liquid pump can be operated safely. 
         [0044]    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 features of the invention, the disclosure is illustrative only. Changes may be made in the details, 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.