Patent Publication Number: US-2009237857-A1

Title: Hydraulic stun gun

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical discharge weapons and more particularly, to a hydraulic self-defense stun gun for disabling a target at a distance by discharging high voltage, low current into the target through two jets of water. 
     2. Description of the Related Art 
     A regular self-defense stun gun user must have the positive and negative electrodes of the stun touch the target so that electrical high voltage can be discharged into the target to disable the target. However, it is dangerous to approach to the target within a short distance. Therefore, hydraulic stun gun for disabling a person at a distance is developed.  FIG. 1  illustrates a hydraulic stun gun according to the prior art (Taiwan Patent Publication Number 493735). According to this design, as shown in  FIG. 1 , the hydraulic stun gun comprises a housing  100  having installed therein two water tanks  10  (see  FIG. 2 ), two metal nozzles  20 , two lead wires  30 , a micro switch  40  and a piston set  50 . The two water tanks  10  are arranged in parallel, and respectively connected to the metal nozzles  20  by a respective water tube  101 . The two lead wires  30  each have one end respectively connected to the metal nozzles  20  and the other end respectively connected to the micro switch  40 . Further, a button  60  is provided at one side of the micro switch  40 . The piston set  50  is operable to provide an air pressure to the water tanks  10 . When operating the button  60  to switch on the micro switch  40  after a certain number of reciprocating cycles of the piston set  50 , two jets of water are driven out of the metal nozzles  20  to the target, and at the same time a high voltage is discharged to the target through the two jets of water, disabling the target. Therefore, this design of hydraulic stun gun is capable of disabling a target at a distance. 
     However, the aforesaid hydraulic stun gun is still not satisfactory in function. When the button  60  is not operated, a compression spring  602  supports the button  60  in the off position where the top stop rods  601  of the button  60  are stopped at the water tubes  101  against a respective stop member  1001  inside the housing  100  to flatten the water tubes  101 , blocking the water passage of the water tubes  101 . The compression spring  602  may start to wear quickly with use. When the spring force of the compression spring  602  drops below a certain level, the pressure provided by the top stop rods  601  of the button  60  against the water tubes  101  and the respective stop members  1001  becomes insufficient. In this case, water will leak out of the water tanks  10 . Therefore, an improvement is necessary to eliminate this water leakage problem. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a hydraulic stun gun, which uses needle valves to control the output of jets of water positively, preventing a water leakage. 
     To achieve this and other objects of the present invention, the hydraulic stun gun comprises a housing, two water tanks mounted in the housing, two metal nozzles provided at a front side of the housing, two water tubes respectively connected between the water tanks and the metal nozzles, a first battery set, a voltage converter adapted for converting DC battery power of the first battery set into a high voltage, two lead wires electrically connecting positive and negative terminals of the first battery set and the voltage converter to the metal nozzles, a micro switch electrically connected between the two lead wires and the first battery set, a high pressure air source mounted in the housing and adapted for providing a compressed air pressure into the water tanks to force water out of the water tanks into the water tubes, a button operable to switch on/off the micro switch and the high pressure air source, wherein two needle valves are respectively mounted in the water tubes and operable to close/open the water tubes, each needle valve comprising a valve hole and a valve needle movable with the button to close/open the valve hole. When the user depresses the button to close the circuit of the lead wires, battery set, voltage converter circuit and metal nozzles, and at the same time the valve needles of the needle valves are respectively opened from the associating valve holes. 
     Further, the button comprises a slide fixedly connected thereto. The slide has two rod members respectively coupled to the valve needles of the needle valve for enabling the valve needles of the needle valves to be moved with the button to close/open the respective valve holes. 
     Further, the high pressure air source can be a piston set. The piston set has one end connected to the two water tanks through an air tube. The air tube has mounted therein a check valve to prevent reverse flow of air. Further, a compression spring is connected between the check valve and the slide of the button. 
     Further, the high pressure air source can be a high-pressure air container controllable to provide a compressed air pressure to the water tanks to force water out of the water tanks into the water tubes. 
     Further, the high pressure air source can be a power air pump mounted in the housing. In this case, a second battery set is mounted in the housing and electrically connected to the power air pump for causing the power air pump to pump compressed air into the water tanks. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         FIG. 1  is a schematic sectional plain view of a hydraulic stun gun according to the prior art. 
         FIG. 2  is a top view in an enlarged scale of a part of  FIG. 1 , showing the arrangement of the water tanks and the metal nozzles. 
         FIG. 3  is a schematic plain view of a hydraulic stun gun in accordance with a first embodiment of the present invention. 
         FIG. 4  is similar to  FIG. 3 , but showing the voltage converter circuit provided with a voltage regulator. 
         FIG. 5  is a schematic drawing showing an electrical discharge operation of the hydraulic stun gun according to the present invention. 
         FIG. 6  is a schematic plain view showing the structure of a needle valve used in the hydraulic stun gun in accordance with the present invention (the valve needle closed the valve hole). 
         FIG. 7  corresponds to  FIG. 6  but showing the valve needle opened from the valve hole). 
         FIG. 8  is a schematic plain view of an alternate form of the hydraulic stun gun in accordance with the present invention. 
         FIG. 9  is a schematic plain view showing the operation of the piston set of the hydraulic stun gun in accordance with the present invention. 
         FIG. 10  is a schematic plain view of another alternate form of the hydraulic stun gun in accordance with the present invention (a power air pump used to substitute for the piston set). 
         FIG. 11  corresponds to  FIG. 10 , showing another power circuit arrangement of the power air pump. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 3 , a hydraulic stun gun in accordance with a first embodiment of the present invention is shown comprising an electrically insulative pistol-like housing a, two water tanks  1 , two metal nozzles  2 , two lead wires  3 , a micro switch  4  and a piston set  5 . The electrically insulative pistol-like housing a is formed of two symmetrical hollow halve shells, having a grip a 1  and a button a 2  slidably coupled to the grip a 1  for trigging control. 
     The two water tanks  1  are mounted in the housing a and arranged in parallel. 
     The metal nozzles  2  are mounted in the front side of the housing a and respectively connected to the water tanks  1  through a respective water tube  21 . 
     The two lead wires  3  are the positive pole lead wire and the negative pole lead wire connected in series with a battery set  31  and a voltage converter circuit  32 , each having one end, each respectively connected to the metal nozzles  2 . Further, a voltage regulator  33  may be provided for regulating the output voltage of the voltage converter circuit  32  (see  FIG. 4 ). 
     The micro switch  4  is mounted in the housing a at one side of the button a 2  and electrically connected to the circuit of the lead wires  3 , battery set  31 , voltage converter circuit  32  and metal nozzles  2 , and controllable by the button a 2  to open/close the circuit. When the button a 2  is depressed to close the circuit of the lead wires  3 , battery set  31 , voltage converter circuit  32  and metal nozzles  2 , high voltage and low current jets of water are driven out of the housing  2  into the target (see  FIG. 5 ). 
     The piston set  5  is mounted in the housing a. The reciprocating motion of the piston set  5  provides a compressed air pressure to the water tanks  1 , forcing water out of the water tanks  1  into the water tubes  21 . 
     Further, a needle valve  6  is respectively mounted in each water tube  21  between the respective water tank  1  and the respective metal nozzle  2  (see  FIG. 3 ), and movable with the button a 2 . The needle valve  6  comprises a valve hole  62 , and a valve needle  61  movable with the button a 2  to close/open the valve hole  62 . When the button a 2  is depressed to close the circuit of the lead wires  3 , battery set  31 , voltage converter circuit  32  and metal nozzles  2 , the valve needle  61  is moved backward to open the valve hole  62  (see  FIG. 7 ), allowing compressed water to pass through the associating water tube  21  out of the associating metal nozzle  2 . On the contrary, when the button a 2  is returned to its former position, the valve needle  61  is returned to close the valve hole  62  (see  FIG. 6 ). 
     Further, the button a 2  is fixedly mounted with a slide a 3 . The slide a 3  has two rod members a 4  respectively coupled to the valve needles  61  of the needle valves  6  in the water tubes  21 . Therefore, when the button a 2  is depressed, the slide a 3  is moved with the button a 2 , and the valve needles  61  of the needle valves  6  are respectively moved by the rod members a 4  to open the associating valve holes  62  (see  FIG. 7 ). 
     Further, the piston set  5  has one end connected to the water tanks  1  through an air tube  51 . A check valve  7  is mounted in between the piston set  5  and the air tube  51  to prevent reverse flow of air. Further, a compression spring  8  is connected between the check valve  7  and the slide a 3 . When the button a 2  is released from the operator&#39;s hand, the compression spring  8  automatically returns the slide a 3 , and therefore the button a 2  is returned and the valve needles  61  of the needle valves  6  are returned by the rod members a 4  to close the associating valve holes  62 . 
     Referring to  FIG. 8 , a high-pressure air can  9  may be used to substitute for the piston set  5  shown in  FIG. 3 , and operable by an operating button  91  to discharge a compressed air to the water tanks  1 . 
     When in use, operate the piston set  5  to provide a compressed air pressure into the water tanks  1  through the air tube  51  (see  FIG. 9 ), forcing air out of the water tanks  1  into the respective water tubes  21 . At this time, the valve needles  61  of the needle valves  6  respectively close the associating valve holes  62  (see  FIG. 6 ). Thereafter depress the button a 2  to open the valve needles  61  from the associating valve holes  62  (see  FIG. 7 ), allowing water to be driven out of the water tubes  21  through the metal nozzles  2 . When depressing the button a 2 , the micro switch  4  is switched on, causing a high voltage and low current electrical discharge to be carried with the jets of water and driven into the target when the two jets of water touched the target. 
     Further, if a high-pressure air can  9  is used to substitute for the aforesaid piston set  5 , and the user can operable the operating button  91  to discharge a compressed air into the water tanks  1 , forcing air out of the water tanks  1  into the respective water tubes  21 . 
     Further, as stated above, a voltage regulator  33  (rotary knob) may be provided for regulating the output voltage of the voltage converter circuit  32  (see  FIG. 4 ) subject to the target encountered. For example, when encountering a robber carrying a weapon, the output voltage can be adjusted to the highest level; otherwise the output voltage can be adjusted to a relatively lower level, avoiding a fatal electric shock. 
     Referring to  FIG. 10 , a power air pump  5 ′ may be used to substitute the aforesaid piston set  5 , and a second battery set  52  may be installed to provide the necessary working voltage to the power air pump  5 ′. Alternatively, the power air pump  5 ′ may be electrically connected to the circuit of the lead wires  3 , micro switch  4 , battery set  31 , voltage converter circuit  32  and metal nozzles  2  (see  FIG. 11 ). When the power air pump  5 ′ is started, a compressed air pressure is provided to the water tanks  1  to force water out of the water tanks  1  into the water tubes  21 . In case second battery set  52  is used, the second battery set  52  must be switched on to start the power air pump  5 ′ before depressing the button a 2 . If the power air pump  5 ′ is electrically connected to the battery set  31 , the power air pump  5 ′ is started when the user depresses the button a 2  to switch on the micro switch, i.e., when the button a 2  is depressed, high voltage and low current jets of water are driven out of the housing  2  into the target. 
     Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention.