Abstract:
A dual-purpose hydraulic electric jack comprises a hydraulic lifting mechanism ( 1, 2 ), an oil pump ( 12 ), an oil tank ( 9 ), an oil conveying pipeline and an electric motor ( 14 ). The lifting mechanism, the oil pump and the oil tank are all connected with the oil conveying pipeline. A transmission mechanism is arranged between the oil pump and the electric motor. A one-way valve ( 10 ) is provided between the oil tank and the oil pump. The oil pump ( 12 ) is equipped on one end side of the electric motor ( 14 ), and an air pump ( 15 ) is equipped on the other end side of the electric motor ( 14 ). A transmission mechanism is arranged between the air pump and the electric motor. The air pump is communicated with an air conveying pipeline ( 35 ) and the electric motor is equipped with a trigger mechanism for controlling the connection of the electric motor with the transmission mechanism between the electric motor and the air pump or oil pump. The function of the hydraulic electric jack is enhanced greatly and the hydraulic electric jack is convenient to use.

Description:
CROSS REFERENCE TO RELATED PATENT APPLICATION 
     The present application is the US national stage of PCT/CN2010/070304 filed on Jan. 21, 2010, which claims the priority of the Chinese patent application No. 200910301429.3 filed on Apr. 9, 2009, which application is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     This invention relates to a special jack mechanism, particularly to a dual-purpose hydraulic electric designed for jacking vehicles droved by hydraulic oil jack. 
     BACKGROUND OF THE INVENTION 
     A broke down has always been part of driving, so jack will be a necessity for a driver, when he or she meets some broke down issues. 
     It is applied for an invention patent on hydraulic electric Jack for vehicles (patent number: 200620357377.8), this kind of jack is composed of oil tank, motor, oil pump, piston push rod, which are connected with each other by complicated oil pipelines, in which valve cavity shall be added. The inside of the valve cavity is divided into two parts by steel ball-shape one-way valve, the upper valve cavity and the lower valve cavity. Inside the valve cavity is a movable object, on which there is one ejector rod used for pushing the steel ball. When the jack works, the rotation direction of the motor decides the flow direction of the hydraulic oil in the valve cavity in order to keep the piston ejector rod moving accordingly. While the jack is different to produce and assemble during its actual producing, assembling and using process, and its stability is not good as well. Investigating its reason, it is due to the complicated structure in the valve cavity and higher request for the position and movement relations between each component inside the valve cavity, as well as the complicated structure of the oil pipeline connected to the valve cavity. What&#39;s more, this kind of jack lacks of versatile functions, and can&#39;t be used for other purpose. 
     SUMMARY OF THE INVENTION 
     In order to solve the said shortcomings of the existing dual-purpose hydraulic electric jack, the technical problems to be solved for this invention are: to offer a new style of dual-purpose hydraulic electric jack, which has simple structure and versatile functions. 
     In order to solve the technical problems mentioned above, the measures of this invention takes are: a new style of dual-purpose hydraulic electric jack, which consists of hydraulic jacking mechanism, oil pump, oil tank, oil pipeline and motor. The hydraulic jacking mechanism, oil pump and oil tank are all connected to the oil pipelines. Between the oil pump and the motor is assembled the first drive mechanism with a one-way valve between the oil tank and the oil pump. On one end of the motor is the said oil pump and a air pump positioned on the other end. Between the air pump and the motor is assembled the second drive mechanism, and the air pump is connected to the air pipe. At the location of the motor is a pull mechanism, which is assembled to control the drive mechanism between the motor and the air pump or the oil pump. The pull mechanism can control the motor to connect to air pump or oil pump, but the air pump and oil pump can&#39;t be working at the same time. When the motor drives the oil pump, the hydraulic oil will be pumped into the oil cylinder in the jacking mechanism from the oil tank, and then it can&#39;t flow back into the tank due to the one-way valve. So the increasing hydraulic oil in the jacking mechanism will push the jacking mechanism to lift the heavy object. When the drive mechanism works between the motor and the air pump, the motor will drive the air pump to work to supply compressed air, which can be used for the air inflation for vehicles. 
     As the preferred alternative, the said air pipeline has a air cock, which is provided with exhausting duct and inflatable duct. The air inlets of both ducts are connected to the said air pipeline, and the air outlets are both connected to each other. 
     The exhausting valve is assembled between the inlet and outlet of exhausting duct, while a T-shape air bar is assembled between the inlet and outlet of inflatable duct. The air cock can be used for air inflation for vehicle tires, which increases the scope of application of the jack. The stretch end of the exhausting valve props up the relevant interface in the exhausting duct. When the pressure of the compressed air gets higher in the air pipe, the air will press the exhausting valve open to enter the inflatable duct, then the air pump will start working, while the T-shape air bar will fit the relevant interface in the exhausting duct as well. When the air inflation begins, the air cock will fit the inflation cock in the vehicle tire first, and then the air bar is pushed away from the interface of the inflatable duct, finally the compressed air could smoothly enter the vehicle tire. 
     The said air pump and oil pump are connected to their relevant connection bases that are linked with each other, while the motor is assembled and can slip well on a coupling bar. By operating the pull mechanism, the motor can selectively slip to the air pump or the oil pump to drive it. 
     As the preferred alternative, the end of the said motor has a connection board that interstitially hitches the coupling bar. While the said pull mechanism is assembled on the oil pump base or the air pump base. Connected with the coupling bar, meanwhile the motor could move by the connection board on the motor, making its structure simple and easy to operate. 
     As the preferred alternative, the said pull mechanism is assembled on the connection base of the air pump, but there is only such one connection board close to the connection base of the oil pump. The coupling bar is hitched by a backspring assembled between the connection board and the connection base of the oil pump. The slipping direction of the motor on the coupling bar can be controlled by their cooperation between the backspring and the pull mechanism, making the structure simple. 
     As the preferred alternative, the pull mechanism has a knob on the connection base of the air pump and one rotatable block assembled inside the connection base of the air pump, which is linked with the knob, as well as a driving mechanism assembled outside of the rotatable block, which can touch the circumferential outside interface of the rotatable block. The driving mechanism can push the motor to the connection base of the oil pump as the circumferential outside interface of the rotatable block slips on it. When the rotatable block turns, its circumferential outside interface could change the position of the motor on the coupling bar. 
     As the preferred alternative, the rotatable block has a sector cross section, and the said driving mechanism has one driving spring, which hitches on the coupling bar, as well as one slurcork that can slip on the coupling bar. One end of the driving spring presses on the connection board, and the other on the slurcork that could touch the outside circumferential interface of the said rotatable block; on the connection base of the air pump is a limit bolt, whose end could reach the rotation range of the rotatable block. The stability of the motor can be improved by the driving spring during the slipping process, making it easy to connect to the drive mechanism. The rotation angle of the rotatable block can be set by the limit bolt to keep the position of the moved motor on the coupling bar, which can ensure the stability of the power transmission for the drive mechanism. 
     As the preferred alternative, the drive mechanism has one projecting insert on the connection base of the air pump or the oil pump, and a slot in the relevant position of the motor end. The insert bears on the end of the motor, could interstitially get in the slot, and its length is consistent with the max moveable displacement of the motor on the coupling bar. The power transmission could be finished by the cooperation between the insert and the slot, offering a simple structure and nice transmission stability. 
     As the preferred alternative, the end of the insert closed to the motor is sharp pointed, which could promote the inserting operation between the insert and the slot and improve the stability of the jack during its working process. 
     As the preferred alternative, the jacking mechanism is assembled with some overload protection on it. When the heavy object is lifted to come to a head, the protection could control the motor to stop working in order to protect the oil pump. 
     Accordingly, the advantages of this invention are: 
     As the air pump is assembled, it could be driven by the motor to offer the vehicle tires compressed air for air inflation, which improves the application range of the jack. The pull mechanism can be used to control the connection between the motor and the oil pump or air pump to ensure their working condition and the reliability of the jack. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is the perspective view of the dual-purpose hydraulic electric jack construction proposed by the present invention. 
         FIG. 2  is the amplificatory longitudinal section view of the air cock. 
         FIG. 3  is the perspective view of the oil pump, motor and air pump when they are connected together and the power is transmitted to air pump from the motor. 
         FIG. 4  is the incompact perspective view of the oil pump, motor and air pump when they are connected together and no power is transmitted to air pump or oil pump from the motor. 
         FIG. 5  is the end face perspective view of the motor side closed to the air pump. 
         FIG. 6  is the end face perspective view of the connection base with air pump. 
         FIG. 7  is the perspective view of the rotatable block. 
         FIG. 8  is the perspective view of the overload protection mechanism. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIG. 1 , the dual-purpose hydraulic electric jack, proposed by the present invention, is comprised of hydraulic jacking mechanism  40 , oil pump  12 , oil tank  9  and motor  14 , all of which are connected to the oil pipeline, but the motor  14 . The said oil pump is gear oil pump, and the motor is permanent magnet DC motor. 
     The jacking mechanism is comprised of ejector rod  1  and oil cylinder  2 , and the ejector rod  1  is a two-stage construction in the oil cylinder  2 . Between the oil pump  12  and the oil cylinder  2  is assembled a one-way control valve  3  that has a partition  5  inside, and the one-way control valve  3  is divided into two parts: oil entering cavity and oil returning cavity, both of which are connected to the oil hole in the partition  5 . In the oil entering cavity near the oil hole is one steel ball  4 , which can block off the mouth of the oil hole. Between the steel ball  4  and the one-way control valve is one spring connected with them. The oil pipeline joins the oil pump  12  and the oil cylinder  2 , successively connecting oil pump  12 , oil returning cavity, oil hole, oil entering cavity and oil cylinder  2 . In the oil returning cavity there is a movable object  7 , which has a thimble on its end near the steel ball  4 . The thimble  6  is corresponding with the position of the oil hole, and its diameter is less than the oil hole diameter. So that the thimble  6  can insert the oil hole in order to push the steel ball  4  away. The oil returning cavity is divided into upper oil cavity and lower oil cavity by the movable object  7 , and the thimble  6  is assembled in the upper oil cavity struck by the oil pipeline. Between the oil tank  9  and the lower oil cavity of the one-way control valve is assembled some oil returning pipeline  8 , and at the bottom of the lower oil cavity is assembled stage  11 , on which the moveable object  7  will get to cover the oil entrance in the oil returning pipeline  8  when the jacking mechanism is working. Between the oil pump  12  and the oil tank  9  is assembled one-way valve  10  in the oil pipeline. 
     When the jacking mechanism works in the jack, the hydraulic oil is pumped from the oil tank  9  by the oil pump and gets into the upper oil cavity of the oil returning cavity through the one-way valve  10 , and then it pushes the said steel ball  4  away, finally go through the oil entering cavity and enter in the oil cylinder  2  to drive the ejector rod to jack the heavy object. When the heavy object gets the right place, the motor  14  stops working, and the steel ball  4  covers the oil hole under the pressure of the hydraulic oil, then the hydraulic oil will keep still in the oil cylinder  2  and the oil-entering cavity, so the heavy object will be kept at the certain height. When the heavy object slowly falls, the motor  14  will take contra rotation, while the hydraulic oil in the upper oil cavity will not flow back into the oil tank  9  through the oil pipeline between the oil pump  12  and oil tank  9 , but into the said lower oil cavity as result of the one-way valve  10  under the pressure of the oil pump  12 . Along with the decrease of the hydraulic oil in the upper oil cavity, the hydraulic oil will push the moveable object  7  to the partition  5 , then the thimble  6  will push the steel ball  4  away, so that the working hydraulic oil could flow back to the upper oil cavity through the clearance between the steel ball  4  and the oil hole. When the moveable object moves some certain distance, the oil entrance of the said oil returning pipeline will be revealed, then the hydraulic oil will go back into the oil tank  9  through the oil pipeline to reduce the height of the heavy object. While it has strict demand of the position of the oil entrance of oil returning pipeline  8  on the one-way control valve  3  wall, it is that the distance between the oil entrance and the stage  11  shall be slightly longer than that between the end of thimble  6  and the steel ball  4 . So that the thimble  6  can fully push the steel ball  4  away during the oil returning process to ensure the hydraulic oil can flow back smoothly through the oil returning pipeline. 
     An overload protection is also added into the said jacking mechanism. It includes a mechanical part, which is connected to the one-way control valve  3 , and a commutation switch, which is connected to the control circuit of the motor  14 . For the mechanical part, it can be assembled on the one-way control valve  3  or kept separately. The mechanical part is comprised of the casing  36  and the T-shape piston  37  in the casing  36 , as well as the pressure spring  38  between them. On the piston  37  is the ejector rod protruding from the casing  36 , and the casing  36  is connected to the said oil returning cavity of the one-way control valve  3  through the oil pipeline. The said commutation switch is assembled in the control circuit of the motor  14 , when the heavy object is jacked up to the top point, the hydraulic oil pressure will go up in the oil returning cavity, if the oil pump keeps on working driven by the motor, as the casing  36  is connected to the oil returning cavity, so the hydraulic oil will push the piston  37  to overcome the elasticity derived from the spring  38 , then the ejector rod on the piston  37  will touch the commutation switch to cut the control circuit off and stop the motor  14 . When the heavy object needs to fall, the motor  14  will go reversal by the control switch, and then the heavy object will fall. The commutation switch and the control switch can be used to realize forward rotation, reversal and brake control. However, it must be noted that the elasticity, loading on the piston  37  from the pressure spring  38 , shall be slightly greater than the pressure on the piston  37  from the hydraulic oil when the heavy object is jacked to the top point, this can be easily obtained by testing. One end of the motor is assembled the oil pump  12 , and the other end is air pump  15 , meanwhile both of the pumps have drive mechanism connected to the motor for power transmission. At the location of the motor  14  is a pull mechanism, which shall be assembled to control the connection between the motor and the air pump or the oil pump, while the air pump and oil pump can&#39;t get working at the same time. The said air pump and oil pump are connected to each relevant massive connection base that is linked with each other by four coupling bars  23 . The end of the motor has a connection board  13  near the connection base of the oil pump  22 , and there are through holes at the four corners of the motor, which are inserted by coupling bars. In this way, a combination forms, which is comprised of the oil pump  12  with its connection base  22 , air pump  15  and its connection base  28 , as well as the motor  14 , while the motor  14  is situated in the middle of the combination with the two pumps situated on the either side. What is more, the motor  14  can axially slip to the air pump  15  or the oil pump  12  along a coupling bar  23 . 
     The said pull mechanism is assembled on the flank of the connection base  28  of the air pump, which has a knob  26  on its outside and an eccentric rotatable block  32  inside the connection base of the air pump. One end of the rotatable block  32  is connected with knob  26 , and the other is a shaft  33 , which is on the connection base of the air pump  28 , and the knob  26  can drive the rotatable block to rotate together. The rotatable block has a cross section sector. On the connection base of the air pump  28  is assembled the limit bolt  25 , whose end could reach the rotation range of the rotatable block. When the rotatable block  32  rotates, both of the upper flanks can touch the limit bolt, so that the two positions of the rotatable block  32  can be limited. 
     Outside of the rotatable block  32  is assembled the driving mechanism that can touch the circumferential outside interface of the rotatable block  32 . The driving mechanism can push the motor to the connection base of the oil pump  22  when the circumferential outside interface of the rotatable block slips on it. The said driving mechanism has one driving spring  34 , which is hitches on the coupling bar  23 , as well as one slurcork  27  that can slip on the coupling bar  23 , and one end of the driving spring can press the said connection board  13 , while the other for the slurcork  27  that could touch the outside circumferential interface of the said rotatable block. The said driving mechanism can also be one thrust pole, which is on the end of the motor  14  near the connection base of the air pump. The structure of the thrust pole is one bolt, whose position is corresponding with the position of the rotatable block  32 , and its outer end can touch the camber cylinder of the rotatable block  32 . When the rotatable block rotates, the thrust pole will slip on the camber cylinder of the rotatable block  32 . The thrust pole is assembled on the motor  14  and could move, that is the thrust pole can move axially on the motor  14 , and is hitched by the screw spring that presses on both the motor  14  and the thrust pole. 
     On the coupling bar  23  is a backspring  30 , which is equipped between the connection board  13  and the connection base of the oil pump  22 . Meanwhile the backspring elasticity shall be less than the elasticity of the screw spring and the driving spring  34 , that is when the rotatable block  32  rotates, it will press the thrust pole or the slurcork  27  to force the motor  14  by the screw spring or driving spring  34 , and overcome the elasticity from the backspring  30 , finally promote the motor to slip to the oil pump. When the motor  14  reverses, the pressure will relieve on the driving pole or slurcork  27  from the rotatable block  32 , and the motor  14  moves to the air pump  15  under the elasticity of the backspring  30 . When the motor  14  moves to the oil pump  12  or air pump  15 , it will connect to the relevant pump to realize its power transmission from the motor  14  to the relevant pump. 
     The said drive mechanism above has one projecting insert  29  on the connection base of the air pump  28  or the connection base the oil pump  22 , and one slot in the end centre position of the motor  14 . The insert  29  can reach to the outside of the connection base of the air pump  28  or the connection base of the oil pump  22 , and has a sharp point, which can get in the said slot  31  when the motor  14  moves like above to realize its power transmission from the motor  14  to the air pump  14  or oil pump  12  that can be driven by the motor  14 . The projecting length of the insert  29  fits to the max moveable displacement of the motor  14  on the coupling bar  23 , that is the max moveable displacement of the motor  14  is slightly longer than the projecting length of the insert  29 . The motor  14  is connected to the air pump  15  and oil pump  12  by the pull mechanism. The max moveable displacement of the motor  14  on the coupling bar  23  depends on the shape and size of the rotatable block  32 . 
     The air pump  15  has been assembled with air pipeline  35 . While one end of the air pipeline is assembled with the air cock  16 , which is a connected detachable structure and comprised of the air cock body  18 , as well as the concave adapter connector  17  that is connected to the air pipeline  35 . Inside the air cock body  18  are assembled the exhaust pipe and inflation pipe, whose air inlets are both connected with the air pipeline  35  and air outlets are connected to each other. The exhaust pipe has one exhausting valve  19 , which is between the air inlet and the air outlet, and one stage structure, to which the taper end of the exhausting valve is fitted. On the other end of the exhausting valve  19  is assembled the spring  20 , under its elasticity, the exhausting valve  19  will have a tight fit to the exhaust pipe  19  when the compressed air is only a little in the air pipeline  35 . Normally the elasticity of the spring  20  shall be slightly greater than the pressure in the air cylinder  9  on state, so that the compressed air could push the exhausting valve  19  open to vent outside through the exhaust pipe when the air cylinder  9  completes its working. Between the air inlet and the air outlet is assembled a T-shape air bar  21  and a relevant stage in the inflation pipe, the T-shape air bar could slip axially along the inflation pipe. If the air pipeline  35  is filled with compressed air, the compressed air will press the air bar  21  to have a tight fit with the stage interface in the inflation pipe. While the air cock  16  fits the inflation in the vehicle tire, the air bar will be pushed an axial displacement by the inflation valve, so as to offer a clearance between the air bar  21  and the said stage interface, through which the compressed air could flow in the vehicle tire. 
     In order to quantitatively show the working condition of the air pump  15 , the air pump  15  is assembled with a air manometer  24 , which could show the pressure of the compressed air derived from the air pump  15 , so as to avoid a blowout during the air inflating process. 
     When the dual-purpose hydraulic electric jack is working, the motor can be controlled by the three-state controller, which has three keys as “Up”, “Down” and “Pause”. The “Up” key could be series-wound with some control circuit of the motor  14  for forward rotation; while the “Down” key could be series-wound with other control circuit of the motor  14  for the contra rotation; and the last “Pause” key can be used to cut off the power of the motor  14 . Furthermore, the said “Down” key could also be used as the control key for inflation, or assemble another “Inflation” key, which can be parallel with the “Down” in the controller. When the motor  14  is 
     connected with the air pump  15  by the pull mechanism, the motor  14  will take contra rotation if the “Inflation” key is pressed, so as to drive the air pump  15  to offer compressed air.