Abstract:
A hydraulic vehicle jack system that safely lifts vehicles without using the vehicle as a power source power source and without moving mechanical parts. The system comprises: (a) a hydraulic vehicle jack mounted to the chassis of a vehicle near one of its wheels; (b) a hydraulic pump system to provide pressurized fluid to the hydraulic vehicle jack; and (c) a control device to activate the hydraulic pump system. Also disclosed is a method for lifting a vehicle.

Description:
[0001]     This application claims the benefit of U.S. Provisional Application No. 60/647,480, filed Jan. 27, 2005, which is incorporated herein by reference. 
     
    
     BACKGROUND OF INVENTION  
       [0002]     1. Technical Field  
         [0003]     The present invention relates generally to jack systems for lifting vehicles and, more particularly, to a hydraulic vehicle jack system that safely lifts vehicles without using the vehicle as a power source and without moving mechanical parts.  
         [0004]     2. Description of Related Art  
         [0005]     Jacks are used to raise a variety of vehicles such as automobiles and trucks from the ground. Most commonly, these devices are used when the vehicle must be lifted to repair or perform maintenance upon it. For example, a portion of an automobile must be raised in order to change a tire.  
         [0006]     Many of these jacks are stowed in the vehicle, usually in the trunk. To remove the jack, the user is typically required to remove various items from the trunk first. Once the jack is removed, users that are not familiar with the jack may find it difficult to position beneath the vehicle and operate the jack. Often, the inexperienced or unfamiliar user may need to consult the jack&#39;s instruction manual.  
         [0007]     Self-contained jack systems or systems integrated into the vehicle itself eliminate the need for the user to remove the jack from storage and position it beneath the vehicle in order to operate it. Some of these devices include hydraulic systems that further increase the device&#39;s ease of use by reducing, or eliminating, the amount of physical effort needed to operate the jack and lift the vehicle.  
         [0008]     However, much of the prior art uses the vehicle as the source of power for operating the jack. In addition, many of the prior art jacks rely on moving mechanical parts. Eliminating the need for moving mechanical parts would reduce the opportunity for the device to malfunction or require repair and would makes the jack safer to use.  
         [0009]     What is needed is a self-contained jack system that is not supplied with power from the vehicle and has no moving mechanical parts.  
       SUMMARY OF INVENTION  
       [0010]     The present invention addresses the foregoing problems by eliminating the use of moving mechanical parts and the need for power from the vehicle to be supplied to the jack. Thus, the hydraulic vehicle jack system is a device that is safer when used, requires less maintenance, and facilitates easier repairs. The hydraulic vehicle jack system comprises a hydraulic vehicle jack mounted to the chassis of a vehicle near one of its wheels, a hydraulic pump system to provide pressurized fluid to the hydraulic vehicle jack, and a control device to activate the hydraulic pump system.  
         [0011]     The hydraulic vehicle jack comprises an outer cylinder with an inner piston rod that slides vertically within the outer cylinder. The lower end of the inner piston rod is pivotably attached to a ground pad that engages the surface beneath the vehicle.  
         [0012]     The hydraulic pump system is comprised of a pump, a fluid reservoir connected to the pump, a valve connected to the pump and fluid reservoir, and a plurality of hydraulic lines emanating from the valve. The lines are connected to ports formed in the outer cylinder of the hydraulic vehicle jack and supply hydraulic fluid to the vehicle jack. The pump system, preferably powered by a source independent of the vehicle, is integrated into the vehicle where it can be operated safely.  
         [0013]     To operate the hydraulic vehicle jack, the control device, preferably a keyed unit in a location easily accessible to the vehicle&#39;s driver, activates the hydraulic pump system. The pump system sends pressurized fluid, preferably an oil, to the outer cylinder of the jack. As the outer cylinder fills with fluid, the inner piston rod extends vertically and raises the vehicle off the ground. All this achieved without the use of gears, cranks or belts; thus, eliminating mechanical moving parts and increasing the safety of the device.  
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0014]     The novel features believed characteristic of the main invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following summary of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:  
         [0015]      FIG. 1  is front view of a hydraulic vehicle jack in accordance with the present invention;  
         [0016]      FIG. 2  is a side view of a hydraulic vehicle jack shown in  FIG. 1 ;  
         [0017]      FIG. 3  is front view of a hydraulic vehicle jack shown in  FIG. 1  that includes the position of an additional mounting plate; and  
         [0018]      FIG. 4  is a perspective view of a hydraulic pump system in accordance with the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0019]     In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized. It is also to be understood that structural, procedural and system changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents. For clarity of exposition, like features shown in the accompanying drawings are indicated with like reference numerals and similar features as shown in alternate embodiments in the drawings are indicated with similar reference numerals.  
         [0020]     Referring to  FIG. 1 , shown is hydraulic vehicle jack  10 . Hydraulic vehicle jack  10  includes mounting plate  12 , extension port  22 , retraction port  23 , outer cylinder  24 , inner piston rod  26 , removable safety pin  30 , swivel pin  18 , ground pad  20 , and pump system  31  shown in  FIG. 4 .  
         [0021]     Mounting plate  12  is fixedly attached to a vehicle and may have holes  14  for use in securing mounting plate  12  to the vehicle. A bolt or screw for example may be passed through holes  14  to secure mounting plate  12  to the vehicle. Preferably, mounting plate  12  is secured on or near to the vehicle&#39;s axle case, proximate to at least one of the wheels and surrounding frame on the vehicle.  
         [0022]      FIG. 2  shows mounting plate  12  attached to axle case  46  using U-bolt  28 . Axle case  46  is a typical axle case on a vehicle, such as an automobile or pickup truck. U-bolt  28  has a profile sufficient to surround at least a portion of axle case  46  and is strong enough to secure mounting plate  12  to axle case  46 . Mounting plate  12  is fixedly attached to outer cylinder  24 .  
         [0023]     Outer cylinder  24  contains at least a portion of inner piston rod  26 . Inner piston rod  26  has an upper end (not shown) and an opposing lower end  42 . Inner piston rod  26  slides vertically within outer cylinder  24 . Opposing lower end  42  of inner piston rod  26  contains swivel pin  18 .  
         [0024]     Swivel pin  18  is attached to ground pad  20  such that ground pad  20  is pivotally attached to lower end  42  of piston rod  26 . Ground pad  20  is relatively flat, capable of supporting at least a portion of a vehicle&#39;s weight, and will engage the surface beneath the vehicle when jack  10  is in use for lifting the vehicle.  
         [0025]     In another embodiment, mounting plate  12  contains two parallel side walls  44  which extend perpendicularly from mounting plate  12 . Side walls  44  contain mounting cylinder  16  which extends through side walls  44  and outer cylinder  24 .  
         [0026]     Jack  10  is actuated by a hydraulic pump system  31  shown in  FIG. 4 . Pump system  31  comprises of activation switch  35 , pump  32 , fluid reservoir  34 , valve  36 , at least one hydraulic line  38 , and power source  39 , that powers pump  32 . Power source  39  is preferably independent of vehicle&#39;s power system and may be a battery for example. Preferably, power source  39  is a rechargeable battery that can be recharged by the vehicle&#39;s alternator.  
         [0027]     Valve  36  is attached to pump  32  and reservoir  34  either directly or by the use of flexible tubing such as hydraulic line  38 . Hydraulic lines  38  of pump system  31  are attached to intake port  22  and outlet port  23  in outer cylinder  24 . Hydraulic pump system  31  can be located anywhere in the vehicle where it can be operated safely.  
         [0028]     Activation switch  35  is used to activate or deactivate pump  32  and open or close valve  36 . Preferably, activation switch  35  is a keyed unit in a location that is easily accessed by the vehicle&#39;s driver.  
         [0029]     To lift a vehicle, the user first activates hydraulic pump system  31  via activation switch  35  which may be conveniently located within the passenger compartment of the vehicle. Pump system  31  generates pressurized fluid, preferably a non-compressible fluid such as oil, and valve  36  opens allowing the pressurized fluid to fill outer cylinder  24  of hydraulic vehicle jack  10 . When filled, inner piston rod  26  is forced downward and raises the corner of the vehicle where hydraulic vehicle jack  10  is mounted.  
         [0030]     Upon completion of jack  10 &#39;s use, activation switch  35  is used to deactivate hydraulic pump system  31 . The pressurized fluid returns to the pump system&#39;s fluid reservoir  34 . As the fluid drains from outer cylinder  24 , the vehicle is lowered to the ground. To prevent hydraulic jack  10  from extending when not in use, a removable safety pin  30 , traversing laterally through outer cylinder  24  and inner piston rod  26 , may be employed.  
         [0031]     In addition to be used to raise the vehicle for replacement of a wheel, hydraulic vehicle jack  10  may be operated to raise a portion of the vehicle from ground to render it immobile. Thereby, the theft of a vehicle having an activated jack  10  is deterred, if not prevented.  
         [0032]     As detailed above, hydraulic vehicle jack  10  is raised and lowered by the use of pressurized fluid, provided by hydraulic pump system  31 , filling into or draining from the jack&#39;s outer cylinder  24 . Thereby, no gears, cranks or belts are used in the preferred embodiment. In addition, the hydraulic vehicle jack system itself is mounted onto the vehicle. No wheels or other means with which to move the system into position prior to operating the device is required. Therefore, the present invention eliminates moving mechanical parts that are inherently prone to failure.  
         [0033]     While the invention has been particularly shown and described with reference to the preferred embodiment, it will be understood by those skilled in the art that variations in size, materials, shape, form, function and manner of operation, assembly and use, may be made without departing from the spirit and scope of the invention. Further, it is to be understood that the present invention is not limited to the sole embodiment described above but also may encompasses any and all embodiments within the scope of the following claims.