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.
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.
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
As seen for example in
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
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
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
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.
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4131263 | John | Dec 1978 | A |
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Number | Date | Country | |
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20110101295 A1 | May 2011 | US |