Patent Document

BACKGROUND 
     The present invention relates to hydraulic jacks for lifting loads such as motorized vehicles and other heavy objects and equipment. Specifically, the invention relates to a versatile modular hydraulic floor jack adapted to lift different types of vehicular load, while being configured at the same time to provide enhanced lateral stability. 
     Hydraulic floor jacks are known in the art. Typically, a hydraulic floor jack includes a hydraulic ram that is given a mechanical advantage by known means, namely, in which a hydraulic press is harnessed to convert a manual input force into an output force delivered by a piston, the output force being considerably magnified over the input force. The magnified piston force may be applied directly to elevate a load, or it may be utilized to pivot an elevation arm of the floor jack, which elevates the load in a pivoting action. 
     A number of different types of floor jack have been developed, each for a specialized purpose. For example, a point lift hydraulic jack has been developed which is useful for elevating a motor vehicle. This kind of hydraulic jack applies an upward load to the motor vehicle on what is effectively an upwardly applied point load. (In reality of course, the upwardly applied load is not a precise “point,” but rather a flat plate having a relatively small area, hence it is an “effective” a point load.) An effective point load is desirable, firstly, because a motor vehicle that has been elevated will always have at least two wheels on the ground. These two wheels may be braked so that, in combination with the effective point load, a stable and immovable three point support exists and the motor vehicle will not move or tip while elevated. However, the undercarriage of a motor vehicle typically has a complex shape so that, if a multiple point ram were used to elevate the vehicle, or if a large flat plate were used on the end of the ram, it is likely that the point of lift may shift from one point to another as the vehicle is elevated. This is highly undesirable because the user may not know which point on the underside of the vehicle will eventually be the point of load when the vehicle is fully elevated. Thus, the user may find out too late that an inappropriate point on the underside of the vehicle has become the point of load. The point at which load is applied may be inappropriate because it may buckle, or even worse, may break. For example, a user will try to avoid applying a point of hydraulic lift to a flat floor panel of the motor vehicle because the floor panel may bend out of plane or may be punctured by the hydraulic lift. Therefore, a hydraulic lifting jack with an effective point support is always desirable when lifting motor vehicles because this enables the user to position that point under a strengthened portion of the undercarriage of the vehicle that he knows will sustain the load. 
     On the other hand, other types of motorized vehicles require a floor lifting jack with different characteristics to allow a workman to gain access to their undercarriage. For example, snowmobiles, motor bikes, and some all-terrain-vehicles each have a relatively small and narrow plan area, and neither type can be lifted at one point to leave two other points on the ground to stabilize the vehicle. Rather, the shapes of these vehicles may require that they be lifted entirely and bodily off the floor while stability against tipping over is provided entirely by the jack itself. To this end, such vehicles are often constructed so that the undercarriage has a flat portion at the center of gravity, and, for this kind of case, hydraulic floor jacks have been developed that have a relatively wide and long “footprint” in contact with the floor. They also have relatively wide and long planar lifting platforms that allow the lifted vehicle to balance on the platform while under elevation. However, where the jack is the only point of support for the vehicle, there is always an increased risk that the jack itself may tipple over, with disastrous consequences. In this regard, some of the prior art jacks that perform this specialized lifting function are made with side wheels that are spaced as widely apart as possible to give as much lateral stability as possible. However, this solution results in a hydraulic jack that occupies a very large area “footprint,” which may add to the overcrowding of a small workshop. 
     Another example of a vehicle lifting jack is one required for certain lawn tractors or other vehicles that have a wheel base that is too wide to permit a jack to lift the entire vehicle off the floor as in the case of a motorbike or snowmobile. Rather, the front end must be lifted by the front two wheels while the vehicle pivots about the back two wheels. In cases such as this, the front two wheels are driven onto slings or stirrups that are tied into a central lifting arm, and the lifting load is applied to the wheels via the stirrups. The reason that the load is taken by the wheels in this design and not by a central platform to the undercarriage, is that the wheel base of such vehicles may be so short that, when fully lifted in front about the pivoting back wheels, the vehicle slopes upward at a considerable angle. Thus, any surface on the tractor that was flat when parked will slope at the same large angle when the tractor is elevated. This would tend to create a dangerous situation if the lifting were caused by a load applied to the undercarriage because the point of contact will substantially realign itself from horizontal as the vehicle is elevated, producing the possible very undesirable result that the jack slips out of engagement with the tractor. Therefore, loops or stirrups are provided to capture the wheels of the tractor. When elevated, the tractor wheels may freely realign themselves by rotating, without any adverse result on safety. 
     A noticeable problem that has arisen in the art is that many workshops, both commercial and private, may be required to possess all three types of hydraulic jack described above to deal with the various types of vehicle that must be serviced. This gives rise to issues of financial expense, and also to issues of overcrowding and storage in the workshop for a host of different hydraulic jacks. Moreover, even where all three types of jack are provided in a workshop, the kind that elevates a vehicle entirely off the floor always suffers the risk of instability for which no suitable solution is available. 
     Thus there is a need in the art for a solution to problems found in the prior art as described above. The present invention addresses these and other needs. 
     SUMMARY OF THE INVENTION 
     The present invention is a novel and unique kit of components that extends the useful range operation of a hydraulic jack so that it is able to perform the functions that are typically required to be performed by more than one hydraulic jack. The invention also includes a novel feature for stabilizing a jack to elevate a load completely off the ground, with no portion of the load remaining on the ground. 
     In a preferred embodiment, the kit comprises a lifting jack that has a left side arm and a right side arm. A set of wheels is provided for moving the hydraulic jack on a floor surface. The jack has a first platform having a first horizontal flat surface with an area of first magnitude for supporting an object balanced on the flat surface, without any portion of the object remaining on the floor. Significantly, a hole is defined in the first platform, the hole being adapted for removably receiving an object inserted from above. A hydraulic lift is provided, configured to elevate the platform. A handle is provided, configured to be removably engaged with the jack for providing an input force into the hydraulic lift whereby the hydraulic lift elevates the platform. 
     In a preferred embodiment, each side arm defines an opening configured to allow the handle to be snugly passed through both openings at the same time. This arrangement provides for added stability when the jack is being used to elevate a load entirely, with no portion of the load remaining on the floor. 
     A second platform is provided having an area of second magnitude that is smaller than the first magnitude of the first platform. The second platform defines a downwardly extending protrusion configured to be removably positioned in the hole in the first platform, whereby the first platform is configured to support the second platform above the first platform. The second platform is configured to be rotatable about an axis passing vertically through the hole in the first platform. This feature permits any load on the second platform to realign to take into account strain induced realignments when load is applied. 
     In a further aspect of the invention, a third platform may be provided, having components extending beyond left and right lateral edges of the first platform. Each component is configured with an opening to receive and support a wheel of a vehicle. The third platform also defines a downwardly extending protrusion configured to be removably positioned in the hole in the first platform, whereby the first platform is configured to support the third platform. 
     The arrangement thus described permits the user to use the first platform alone to elevate loads entirely, so that no portion of the load remains on the floor. Such loads might be smaller vehicles such as motor bikes and snowmobiles. Optionally, the user may insert the handle used to actuate the jack into openings on either side of the jack in order to provide added stability to the jack under this load condition. 
     Alternatively, the user may engage the second smaller platform with the first platform, so that the second platform is positioned above the first platform load is taken entirely by the second platform, and no load is applied to the first platform. This arrangement is suitable for large motor vehicles that require a relatively small point of contact from the jack that must be positioned precisely on a reinforced point on the undercarriage of the motor vehicle. 
     Further alternatively, the user may remove the second smaller platform from the first platform, and instead engage the third platform with the first platform. The third platform, having portions that extend laterally beyond the edges of the first platform, are suitable for receiving and supporting two wheels of a small wheel base vehicle such as a lawn tractor. The wheels are lifted, and may realign themselves by rotation as the vehicle adopts a large angle of inclination to the floor. 
     Thus, the invention allows up to three potential lifting capabilities to be provided by one jack, in addition to added lateral stability derived from components of the jack that are necessarily present for operation of the jack. Thus, no additional material is required to create this additional stability, and the only additional fabrication needed is to cut two openings in the sides of the jack. 
     In a further aspect of the invention, the handle, when passed through the openings, includes a fixed ridge at one end of the handle and a movable ridge at an opposite end of the handle, each ridge being configured to reduce wobble of the jack on a floor surface. Preferably, the movable ridge comprises a cylindrical portion slidable over the handle, and an annular portion protruding outwardly from the cylindrical portion. 
     In another aspect of the invention, the second magnitude (of the second platform) is less than twenty percent the first magnitude (of the first platform). This allows the second platform, when present, to assume all the load when elevating a motor car, with reduced likelihood of a portion of the car undercarriage contacting the first platform. To further reduce this likelihood, the second platform preferably has an aspect ratio of one, and no horizontal dimension of the second platform exceeds six inches. Furthermore, the second platform is preferably positioned above the first platform by at least one inch in order to increase clearance of the load undercarriage from the first platform. 
     These and other advantages of the invention will become more clearly apparent with reference to the figures and the detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a hydraulic jack having features of the present invention, shown in a depressed condition, and shown with certain selected components. 
         FIG. 2  is an exploded view, shown in perspective, of the hydraulic jack of  FIG. 1 . 
         FIG. 3  is a perspective view of the jack of  FIG. 1 , shown in an elevated condition. 
         FIG. 4  is the view of the jack shown in  FIG. 3 , in a partially disassembled condition. 
         FIG. 5  is a perspective view of the hydraulic jack having features of the present invention, shown in a depressed condition, and shown with different selected components than those shown in  FIG. 1 . 
         FIG. 6  is a perspective view of the jack of  FIG. 5 , shown in elevated condition. 
         FIG. 7  is a perspective view of the jack in  FIG. 6 , shown in partially disassembled condition. 
         FIG. 8  is a further perspective view of a hydraulic jack having features of the present invention, shown in a first stability condition. 
         FIG. 9  is a perspective view the jack of  FIG. 8 , shown in a second stability condition. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the figures, which are shown by way of exemplification and not limitation, a modular hydraulic jack having features of the present invention is described. The present invention initially comprises a specialized lifting jack  20  specially configured for use in combination with other components, under a variety of load and stability conditions. 
     The specialized jack  20  of the present invention may be seen as one of the invention components in each of  FIGS. 1-9 . Initially,  FIG. 2  shows the specialized jack  20  in an exploded view as comprising two opposing left and right outer side arms  22 ,  24  extending from the front end to the back end of the jack. At the front of the side arms, two front wheels  26 ,  28  are situated and connected to each other by an axle  30  which also serves to stiffen the jack. Two rear wheels  50  (only one rear wheel visible in the figures) are situated at the rear end of the jack, capable of swiveling independently of each other for providing the jack with stearability. In a preferred embodiment, the side arms are bent so that they are spaced wider apart at the front end of the jack than at the rear end, in order to provide enhanced lateral stability. As will be noted below, stability provided by this spacing of the wheels may be insufficient for some lifting operations, so that a novel and inventive feature is introduced to enhance lateral stability. A hydraulic lift  32  is positioned between the side arms towards the back end of the jack, operable by a hand held lever  300  (seen in  FIG. 8 ) that is adapted to be removably inserted into a pivotable yoke  34  configured to apply a pumping action to a hydraulic press in the lift  32 . Manual actuation of the lever causes a piston  36  in the lift to extend forwardly with considerable force, with the result that a lifting arm  38  is caused to pivot upwardly, thereby lifting a platform  40  that may have a load positioned on it. Two stabilizer pivoting arms  42 ,  44  are also connected between the platform  40  and the side arms  22 ,  24  so that the platform always assumes a horizontal orientation under all stages of elevation. 
     As seen for example in  FIG. 1 , the platform  40  has left and right lateral edges or side members  54 ,  56  that are parallel with each other, and are spaced apart so as to fit snugly between the forward portions of the side arms  22 ,  24 . The side members  54 ,  56  each have a length that extends from the front end of the jack to a point where the side arms start to bend inwards. The side members are connected to each other via at least one cross beam  58 . The side members and cross beams may be covered with non-slip rubber matting, or the like. Thus, the platform  40  provides what is essentially a square planar support surface suitable for lifting motor bikes or all-terrain vehicles, by which action these vehicles are lifted entirely off the floor and balance on the large support surface of the platform  40  without any portion of the vehicle touching the floor. To facilitate stability of the vehicle on the platform, strap lugs  60  may be provided for tying down straps that are looped around the vehicle to prevent it from tipping off the platform due to accidental bumping while balanced on the platform. Recesses  61  are also provided in the axle  30  that are configured for receiving a strap without slipping. As will be discussed below, one of the remaining problems in the art is the danger of the entire jack plus its strapped on load tipping over if bumped. A novel solution to reducing this danger is identified and described below. 
     The specialized jack  20  with platform  40  thus far described is suitable for lifting smaller vehicles like snowmobiles, motorbikes, and all-terrain-vehicles entirely off the floor so that the vehicles balance on the wide platform  40 . However, the large platform  40  is not suitable for lifting a larger vehicle like a motor car. As noted above, modern motor cars typically have a complex shaped undercarriage, and only a few isolated points on the undercarriage are sufficiently reinforced to receive an upward lifting force from a hydraulic jack. If the large platform  40  is positioned below these points, the uplifting platform does not necessarily apply its uplift force to the reinforced point on the undercarriage, but may spread its force to other adjacent points that are not reinforced, such as the floor of the car. These unreinforced points may bend, or may even be punctured or broken with considerably disadvantageous results. 
     Thus, in order to solve this problem, a second smaller platform or saddle  100  is provided (seen in  FIGS. 1 ,  3  and  4 ) that may be installed and removed from the platform  40  as desired, and which protrudes above the level of the platform  40  by an amount “H” (as indicated in  FIG. 3 ) so that it may be positioned to connect with reinforced points on the undercarriage of the car without any point on the platform  40  coming into contact with the undercarriage. In order to achieve this result, a hole  62 , is provided in one of the cross beams  58  of the platform  40 . The hole is configured to receive a protrusion or nib  102  that extends downwardly from the saddle  100 . When the nib  102  is positioned in the hole  62  in the platform, the upper surface of the saddle protrudes above the upper surface of the platform by an amount “H” ( FIG. 3 ) that preferably exceeds one inch. Under this configuration, the saddle  100  is also configured to be capable of rotating about an axis extending vertically through the hole  62 . This aspect is useful for allowing the saddle to realign itself to a small degree as the car is lifted, because it frequently occurs that small strain adjustments take place as a heavy load is lifted, and surfaces that were in contact before the load is applied may be removed from contact by these small strains after load is applied. Thus, rotation of the saddle  100  about the nib  102  is an important capability in the present invention. Also importantly, the area of the saddle (within the perimeter of the saddle) is substantially less than the area of the wide platform  40  (within the perimeter of the platform  40 ), preferably being less than 20% of the area of the platform  40 . Further preferably, no horizontal dimension of the saddle  100  should exceed six inches and also, the platform should preferably be symmetrical about two orthogonal axes, as seen in the figures, so that it has an aspect ratio of one. Thus, when the saddle  100  is positioned on the platform  40  for elevating a load, and the platform is elevated by hydraulic jacking action while positioned under a car, the saddle  100  will find the desired point of load on the undercarriage of the car before any portion of the platform  40  can come into contact with any other portion of the undercarriage. Any realignment due to strain is accommodated by the rotating saddle  100 . Thus, the same specialized jack  20  can be used to lift cars using selected component in the form of the saddle  100  as can be used to lift small vehicles such as snowmobiles, motorbikes, and all-terrain-vehicles using only the larger platform  40 . This aspect results in considerable cost savings because a workshop needs to acquire only one specialized hydraulic jack  20 , to be used in combination with a special mating saddle  100 , whereby the combination is configured to expand the utility of the hydraulic jack to be capable of use with a broader range of vehicles. 
     Extending the same principle as described above, the specialized jack may be used by selecting yet another lifting platform which is uniquely configured to be removably added to the specialized hydraulic jack  20  as part of the present invention. In this case, with reference to  FIGS. 5 ,  6 , and  7 , a lateral lifting platform  200  is provided having the characteristic that it too has a downwardly extending nib  202  at a center of symmetry of the platform  200 . When the nib is inserted in the hole  62  in the cross beam  58 , the lateral lifting platform  200  lies across the wide planar platform  40  and extends beyond either lateral edge  54 ,  56  of the platform  40 . Each side of platform  200  terminates in a opening, or stirrup  204 ,  206  configured to receive and support a wheel of a lawn tractor or similar vehicle. Thus, when the jack  20  is in a lowered configuration (as seen in  FIG. 6 ), the stirrups  204 ,  206  rest on the floor surface, allowing a small lawn tractor to drive up to the jack and rest a front wheel within each stirrup. When the jack  20  is elevated, as seen in  FIG. 7 , the lawn tractor is lifted upwards by its wheels. Because the wheels are able to rotate, they are able to realign as the tractor is lifted, thereby avoiding the danger that would arise if the point of lift were applied against a fixed point on the tractor. 
     In yet another aspect of the invention, a feature is provided that adds lateral stability to the specialized jack  20  while adding no additional material or moving parts to the specialized jack. As will be appreciated by one of ordinary skill, the lifting condition described above that creates the greatest danger of instability is where the wide platform  40  is used to support a snowmobile or motorbike whereby the entire vehicle is lifted off the floor, and the jack  20  alone provides stability to the elevated load because the only support for the load is the jack itself. Typically, this lifting is for only a short period while oil is being drained or the like, but occasionally lifting may be required for a longer period and in this case the question of stability becomes more important because the danger of inadvertently bumping the elevated vehicle is increased. 
     Accordingly, the specialized jack of the present invention is configured to have two holes  302 ,  304  in each side arm  22 ,  24  as seen in  FIG. 8 . The holes are sized to permit the removable activation handle  300 , which is normally planted in the yoke  34 , to be removed from the yoke and passed snugly through both holes  302 ,  304  so that about the same length of handle extends from each side of the jack, as seen in  FIG. 9 . By “snugly” it is meant that the handle passes easily, but once in position any wobble of the jack about the handle does not appreciably diminish safety. In order to bring the ends of the handle flush with the floor level, a first ridge  306  is attached on one end of the handle. On the other side of the handle, a second movable ridge  308  is provided. Preferably, the second movable ridge  308  is in the form of a cylinder with an annular portion that protrudes radially outwardly, as seen in  FIGS. 8 and 9 . The cylinder may slide along the handle  300  so that it may be removed while the handle  300  is being introduced into the openings  302 ,  304 . Once the handle is in the desired position within the openings, the movable ridge  308  is slipped on the free end of the handle. Thus, the handle  300  positioned across the jack  20  provides extra stability to the jack, and the two ridges  306 ,  308  reduce any wobble in the event the jack plus load is bumped, and the handle resists any overturning moment that might be applied to the loaded jack. Once the need for added stability for the jack has passed, the movable ridge  308  may be removed from the handle  300  and the handle removed from its position lying across the jack  20 . The movable ridge  308  is then reinstalled on the handle  300  for safekeeping, as seen in  FIG. 8 , and the handle is inserted in the yoke  34  where it will reside until next required to provide lateral stability to the elevated jack. 
     Thus, the present invention addresses with novel and useful features needs that are found in the art of hydraulic lifting jacks. The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Technology Category: b