Hand truck World

A toe jack, comprising: a base member having a bottom surface and a base side wall peripherally disposed about said base member; a lift member having a top surface; a toe jack bellows disposed between said base member and said lift member, said bellows comprising a flexible member having an upper end a lower end and one or more convolutions disposed between said upper end and said lower end;

a top plate sealably connected to said upper end of said bellows and connected to said lift member;

a bottom plate sealably connected to said lower end of said bellows and connected to said base member, said top plate, said bellows and said bottom plate forming a pressurizable chamber; and

inlet means in communication with said chamber for admitting pressurized air into said chamber to raise said lift member relative to said base member and for withdrawing pressurized air from said chamber to lower said lift member, said inlet means suitable for connection to a source of pressurized air.

2. The toe jack according to claim 1, wherein said base member further comprises a plurality of support members.

3. The toe jack according to claim 1, wherein said lift member further comprises a lift side wall peripherally disposed about said lift member.

4. The toe jack according to claim 1, wherein said lift member further comprises a plurality of support members.

5. The toe jack according to claim 1 further comprising a first connecting means for sealably connecting said upper end of said bellows to said top plate.

6. The toe jack according to claim 1 further comprising a second connecting means for sealably connecting said lower end of said bellows and said bottom plate.

7. The toe jack according to claim 1 further comprising valve means disposed between said inlet means and said source of pressurized air for controlling the admittance of pressurized air into said chamber and the withdrawal of pressurized air from said chamber.

8. The toe jack according to claim 7, wherein said valve means comprises pressure relief means for releasing air from said chamber when pressure in said chamber exceeds a predetermined amount.

9. The toe jack according to claim 1 further comprising venting means in communication with said chamber for releasing air from said chamber whenever pressure therein exceeds a predetermined value.

10. The toe jack according to claim 9, wherein said venting means comprises at least one vent valve and an actuating member interconnecting said vent valve and an inner wall of said chamber.

11. The toe jack according to claim 10, wherein said vent valve is disposed in said top plate and pressurized air from said chamber is released peripherally between said top plate and said lift member to the atmosphere.

12. The toe jack according to claim 10, wherein said vent valve is disposed in said bottom plate and pressurized air from said chamber is released peripherally between said bottom plate and said base member to the atmosphere.

13. A toe jack, comprising:

a base member having a bottom surface and a plurality of support members;

a lift member having a top surface;

a bellows disposed between said base member and said lift member, said bellows comprising a flexible member having an upper end, a lower end and one or more convolutions disposed between said upper end and said lower end;

a top plate sealably connected to said upper end of said bellows and connected to said lift member;

a bottom plate sealably connected to said lower end of said bellows and connected to said base member, said top plate, said bellows and said bottom plate forming a pressurizable chamber; and

inlet means in communication with said chamber for admitting pressurized air into said chamber to raise said lift member relative to said base member and for withdrawing pressurized air from said chamber to lower said lift member, said inlet means suitable for connection to a source of pressurized air.

14. The toe jack according to claim 13, wherein said lift member further comprises a lift side wall peripherally disposed about said lift member.

15. The toe jack according to claim 13, wherein said lift member further comprises a plurality of support members.

16. The toe jack according to claim 13 further comprising valve means disposed between said inlet means and said source of pressurized air for controlling the admittance of pressurized air into said chamber and the withdrawal of pressurized air from said chamber.

17. The toe jack according to claim 13 further comprising venting means in communication with said chamber for releasing air from said chamber whenever pressure therein exceeds a predetermined value, said venting means comprising at least one vent valve disposed in said top plate and an actuating member interconnecting said vent valve and an inner wall of said chamber, said vent valve configured to release pressurized air from said chamber to the atmosphere peripherally between said top plate and said lift member.

18. The toe jack according to claim 13 further comprising venting means in communication with said chamber for releasing air from said chamber whenever pressure therein exceeds a predetermined value, said venting means comprises at least one vent valve disposed in said bottom plate and an actuating member interconnecting said vent valve and an inner wall of said chamber, said vent valve configured to release pressurized air from said chamber to the atmosphere peripherally between said bottom plate and said lift member.

19. A toe jack, comprising:

a base member having a bottom surface;

a lift member having a top surface and a lift side wall, said lift side wall peripherally disposed about said lift member;

a bellows disposed between said base member and said lift member, said bellows comprising a flexible member having an upper end, a lower end and one or more convolutions disposed between said upper end and said lower end;

a top plate sealably connected to said upper end of said bellows and connected to said lift member;

a bottom plate sealably connected to said lower end of said bellows and connected to said base member, said top plate, said bellows and said bottom plate forming a pressurizable chamber; and

inlet means in communication with said chamber for admitting pressurized air into said chamber to raise said lift member relative to said base member and for withdrawing pressurized air from said chamber to lower said lift member, said inlet means suitable for connection to a source of pressurized air.

20. The toe jack according to claim 19, wherein said lift member further comprises a plurality of support members.

21. The toe jack according to claim 19 further comprising valve means disposed between said inlet means and said source of pressurized air for controlling the admittance of pressurized air into said chamber and the withdrawal of pressurized air from said chamber.

22. The toe jack according to claim 19 further comprising venting means in communication with said chamber for releasing air from said chamber whenever pressure therein exceeds a predetermined value, said venting means comprising at least one vent valve disposed in said top plate and an actuating member interconnecting said vent valve and an inner wall of said chamber, said vent valve configured to release pressurized air from said chamber to the atmosphere peripherally between said top plate and said lift member.

23. The toe jack according to claim 19 further comprising venting means in communication with said chamber for releasing air from said chamber whenever pressure therein exceeds a predetermined value, said venting means comprises at least one vent valve disposed in said bottom plate and an actuating member interconnecting said vent valve and an inner wall of said chamber, said vent valve configured to release pressurized air from said chamber to the atmosphere peripherally between said bottom plate and said lift member.

24. A toe jack, comprising:

a base member having a bottom surface;

a lift member having a top surface and a plurality of support members;

a bellows disposed between said base member and said lift member, said bellows comprising a flexible member having an upper end, a lower end and one or more convolutions disposed between said upper end and said lower end;

a top plate sealably connected to said upper end of said bellows and connected to said lift member;

a bottom plate sealably connected to said lower end of said bellows and connected to said base member, said top plate, said bellows and said bottom plate forming a pressurizable chamber; and

inlet means in communication with said chamber for admitting pressurized air into said chamber to raise said lift member relative to said base member and for withdrawing pressurized air from said chamber to lower said lift member, said inlet means suitable for connection to a source of pressurized air.

25. The toe jack according to claim 24 further comprising valve means disposed between said inlet means and said source of pressurized air for controlling the admittance of pressurized air into said chamber and the withdrawal of pressurized air from said chamber.

26. The toe jack according to claim 24 further comprising venting means in communication with said chamber for releasing air from said chamber whenever pressure therein exceeds a predetermined value, said venting means comprising at least one vent valve disposed in said top plate and an actuating member interconnecting said vent valve and an inner wall of said chamber, said vent valve configured to release pressurized air from said chamber to the atmosphere peripherally between said top plate and said lift member.

27. The toe jack according to claim 24 further comprising venting means in communication with said chamber for releasing air from said chamber whenever pressure therein exceeds a predetermined value, said venting means comprises at least one vent valve disposed in said bottom plate and an actuating member interconnecting said vent valve and an inner wall of said chamber, said vent valve configured to release pressurized air from said chamber to the atmosphere peripherally between said bottom plate and said lift member.

28. A toe jack, comprising:

a base member having a bottom surface;

a lift member having a top surface;

a bellows disposed between said base member and said lift member, said bellows comprising a flexible member having an upper end, a lower end and one or more convolutions disposed between said upper end and said lower end;

a top plate sealably connected to said upper end of said bellows and connected to said lift member;

a bottom plate sealably connected to said lower end of said bellows and connected to said base member, said top plate, said bellows and said bottom plate forming a pressurizable chamber;

inlet means in communication with said chamber for admitting pressurized air into said chamber to raise said lift member relative to said base member and for withdrawing pressurized air from said chamber to lower said lift member, said inlet means suitable for connection to a source of pressurized air; and

venting means in communication with said chamber for releasing air from said chamber whenever pressure therein exceeds a predetermined value, said venting means comprising at least one vent valve disposed in said top plate and an actuating member interconnecting said vent valve and an inner wall of said chamber, said vent valve configured to release pressurized air from said chamber to the atmosphere peripherally between said top plate and said lift member.

29. The toe jack according to claim 28, wherein said base member further comprises a base side wall and a plurality of support members, said base side wall peripherally disposed about said base member.

30. The toe jack according to claim 29, wherein said lift member further comprises a lift side wall peripherally disposed about said lift member.

31. The toe jack according to claim 30, wherein said lift member further comprises a plurality of support members.

32. The toe jack according to claim 28 further comprising valve means disposed between said inlet means and said source of pressurized air for controlling the admittance of pressurized air into said chamber and the withdrawal of pressurized air from said chamber.

33. A toe jack, comprising:

a base member having a bottom surface;

a lift member having a top surface;

a bellows disposed between said base member and said lift member, said

bellows comprising a flexible member having an upper end, a lower end and one or more convolutions disposed between said upper end and said lower end;

a top plate sealably connected to said upper end of said bellows and connected to said lift member;

a bottom plate sealably connected to said lower end of said bellows and connected to said base member, said top plate, said bellows and said bottom plate forming a pressurizable chamber;

inlet means in communication with said chamber for admitting pressurized air into said chamber to raise said lift member relative to said base member and for withdrawing pressurized air from said chamber to lower said lift member, said inlet means suitable for connection to a source of pressurized air; and

venting means in communication with said chamber for releasing air from said chamber whenever pressure therein exceeds a predetermined value, said venting means comprises at least one vent valve disposed in said bottom plate and an actuating member interconnecting said vent valve and an inner wall of said chamber, said vent valve configured to release pressurized air from said chamber to the atmosphere peripherally between said bottom plate and said lift member.

34. The toe jack according to claim 33, wherein said base member further comprises a base side wall and a plurality of support members, said base side wall peripherally disposed about said base member.

35. The toe jack according to claim 34, wherein said lift member further comprises a lift side wall peripherally disposed about said lift member.

36. The toe jack according to claim 35, wherein said lift member further comprises a plurality of support members.

37. The toe jack according to claim 33 further comprising valve means disposed between said inlet means and said source of pressurized air for controlling the admittance of pressurized air into said chamber and the withdrawal of pressurized air from said chamber.

1. Field of the Invention

The field of the present invention relates generally to devices for use in lifting objects. In particular, the present invention relates to portable pneumatically-operated lifting devices. Even more specifically, the present invention relates to low profile portable toe jacks that utilize one or more pressurizable bellows.

2. Background

The most commonly available jacking system currently used today are mechanical jacking devices that require the user to place the jack under the object to be lifted, such as one side or end of a motor vehicle, and mechanically operate the jack to extend the lifting axis and raise the object. Mechanical jacking devices have a number of commonly known disadvantages, including lack of stability and strength and the requirement of mechanical effort on part of the user. Another disadvantage of mechanical lifting devices is the amount of space required for the user to effectively utilize the mechanical jack. The space requirement limits the usefulness of these devices in situations where there is not much room for the user to operate the mechanical jack.

toe jacks overcome many of the limitations of mechanical jacking devices and are commonly used to lift various objects in many different situations. A number of such jacks are portable to allow use at locations other than at fixed facilities, such as repair workshops or garages. One common use for portable toe jacks is to lift one side or end of a motor vehicle or trailer off the ground surface to enable a person to replace a damaged tire or get under the motor vehicle to perform other repair work. For such use, the unextended toe jack must have a low profile to allow the user to easily place the jack under the disabled vehicle. Once placed under the portion of the vehicle the user desires to raise, air or hydraulic fluid is directed toward the jack to extend it and raise the vehicle. In general, toe jacks are suitable for lifting relatively heavy objects without requiring an undue amount of space or effort on part of the jack user.

A number of low profile toe jacks are known. The known toe jacks generally utilize a telescopically extendable lifting axis that extends in response to the introduction of air or hydraulic fluid into the jack. These type of jacks have a number of disadvantages, including known problems with the telescopic member sticking or even jamming during lifting or lowering operations.

toe jacks that rely on a telescoping member to obtain the desired lift have an inherent limit on the maximum amount of lift that can be obtained. The maximum lift of these type of toe jacks is limited by the design of the telescoping member. A toe jack that relies on flexible bellows for lift, such as the present invention, is not so limited. Although this could have some benefits in certain situations, the ability of the jack to obtain very high lift can result in an overturned vehicle or other object that is being lifted. To prevent over-filling and the potential for such problems, toe jacks often incorporate an automatic pressure release valve that vents pressurized air to the atmosphere. Unfortunately, persons have been known to attempt to overcome the JACK automatic pressure release valves (i.e., by blocking the release port or other means) in order to obtain lift that is outside the range in which the toe jack is designed.

3. Related Art

A number of related art devices exist that identify themselves as pneumatic or air-controlled lift devices. Such devices include U.S. Pat. No. 3,730,481 to Ekonen, U.S. Pat. No. 3,743,248 to Moor, U.S. Pat. No. 3,751,007 to Hollerith, U.S. Pat. No. 3,993,286 to Greene, U.S. Pat. No. 4,021,018 to Dasan, and U.S. Pat. No. 4,913,402 to McJunkin. None of these related art devices solve the problems identified and solved by the present invention in the manner solved by the present invention. Each of the aforementioned patents present toe jacks that utilize a telescoping member. Only the Moor patent discloses the use of a bellows in conjunction with a low profile, portable toe jack. The rubber bellows in the Moore patent, shown as 28 in FIG. 1 therein, merely serves as a casing to enclose the telescoping member and protect it against soiling and damage.

SUMMARY OF THE INVENTION

The toe jack of the present invention solves the problems identified above. That is to say, the present invention provides a low profile, portable toe jack utilizing a flexible bellows that extends in response to the introduction of air from a source of compressed air outside the jack to raise an object off a surface. The object is lowered by releasing air from the bellows. The toe jack of the present invention utilizes multiple safety systems to prevent over-extension of the bellows that could result in damage to the toe jack or overturning of the object being lifted (i.e., a motor vehicle).

In the primary embodiment of the present invention, the toe jack comprises a bellows made from a reinforced flexible member having at least one convolution (i.e., the part of the flexible member that forms an annular protrusion larger than the outside diameter of the ends of the bellows) therein. The bellows is located between a lift member that abuts the object to be lifted and a base member that abuts the surface from which the object is being lifted. The bellows is connected to the lift member and base member by a top plate and bottom plate, respectively, that sealably connect to the bellows through use of a connecting member at each plate. When configured, the bellows provides an air-tight chamber that expands or contracts with the introduction or release of pressurized air from within the chamber. A valve assembly controls the introduction and release of air from an outside pressure source, such as an air compressor or equivalent. A safety valve system prevents over-extension of the bellows.

The bellows can be made from any number of available rubber or polymer materials that can be reinforced with various fiber, steel or other strengthening materials that allows the flexible member to extend while

maintaining peripheral strength in the bellows. Bellows suitable for use in the toe jack of the present invention can include those commonly available as air springs. The ends of the bellows sealably attach to top and lower plates that form the pressurizable chamber.

The valve assembly comprises a fitting that provides communication between an external source of pressurized air and the chamber formed by the bellows. The fitting can connect to an air line that is suitable for transmitting pressurized air from the air source. A spring-controlled dual valve assembly is disposed between the source of air and the fitting to control the flow of air into the chamber and the release of air from the chamber. The dual valve assembly comprises a safety system to prevent over-pressurizing of the chamber by preventing the air pressure inside the chamber from exceeding a predetermined level.

Inside the chamber formed within the bellows, the toe jack can comprise a safety system that prevents over-filling, and therefore over-extension, of the bellows. In the preferred embodiment, the safety system comprises a pop-type valve in the top plate or the bottom plate, or both. When the bellows extends to the design limit, based on the construction of the toe jack itself and the need to prevent the motor vehicle or other object from overturning, the pop valve activates to release air from the pressurized chamber. In the preferred embodiment, the air exits the chamber through one or more passageways that allow air to be released peripherally between the lift member and the top plate and/or between the base member and the bottom plate. Air exiting in the manner described above provides relatively rapid release of air and prevents the user from blocking a single exit port in an attempt to obtain additional lift from the toe jack.

Accordingly, the primary objective of the present invention is to provide a toe jack that utilizes pressurized air to lift heavy loads having the features generally described above and more specifically described below in the detailed description.

It is also an important objective of the present invention to provide a portable toe jack that has a low profile when not pressurized. It is also an important objective of the present invention to provide a toe jack that is of durable, extremely sturdy construction having substantially high lift capacity.

It is also an important objective of the present invention to provide a toe jack that utilizes a bellows made of a flexible member that forms a pressurizable chamber in conjunction with top and bottom plates.

Yet another important objective of the present invention is to provide a toe jack that has one or more safety systems to prevent over-filling and over-extension of the toe jack wherein at least one of those safety systems is not able to be by-passed by the user of the jack.

It is a further objective of the present invention to provide a toe jack having a dual valve assembly that facilitates filling and release of air from a pressurizable chamber while preventing any over-filling or over-extension of the jack.

The above and other objectives of the present invention will be explained in greater detail by reference to the attached figures and the description of the preferred embodiment which follows. As set forth herein, the present invention resides in the novel features of form, construction, mode of operation and combination of parts presently described and understood by the claims.

A stable toe jack comprising a base adapted to be supported by the ground, an elongated piston extending from the base and defining an axis, a generally cylindrical toe housing having a closed end and an open end, the toe housing defining an inner surface surrounding a portion of the piston and having a fluid inlet in the inner surface adjacent the closed end, the toe housing being movable relative to the piston along the axis, and the toe housing including a toe projecting from the open end of the toe housing, the toe including a lifting surface, and supporting means for supporting the toe housing on the piston for movement relative to the piston along the piston axis, the supporting means including interengaging means on the inner surface of the toe housing and on the piston for preventing rotation of the toe housing relative to the piston about the axis, the supporting means including an upper bushing fixed to the piston, and a lower bushing fixed to the toe housing and having there through a bore surrounding and slidably engaging the piston, the lower bushing and the inner surface of the toe housing defining an expandable cavity communicating with the fluid inlet.

2. A toe jack as set forth in claim 1 wherein the interengaging means includes a keyway that is located in the inner surface of the toe housing and that extends in the direction of the axis, and a key that is fixed to the piston and that extends into the keyway.

3. A toe jack as set forth in claim 2 wherein the lower bushing sealingly engages the piston.

4. A toe jack as set forth in claim 1 wherein the interengaging means includes a keyway that is located in the piston and that extends in the direction of the axis, and a key that is fixed to the inner surface of the toe housing and that extends into the keyway.

5. A toe jack as set forth in claim 1 wherein the inner surface of the toe housing includes a first portion having a longitudinally extending recess and a second portion that is adjacent the open end of the toe housing.

6. A toe jack as set forth in claim 5 wherein the inner surface of the toe housing has a step extending radically between the first portion of the inner surface and the second portion of the inner surface, and wherein radial extent of the step is greater than the radial extent of the recess.

7. A toe jack as set forth in claim 1 wherein the piston has a first end fixed to the base, a second end spaced from the base and an outer surface extending between the first and second ends, wherein a portion of the inner surface of the toe housing is spaced from the outer surface of the piston and is non-circular in a plane perpendicular to the piston axis, and wherein the supporting means includes a bushing fixed to the piston adjacent the distal end and having a peripheral surface that is sized and configured to slidingly mate with the non-circular portion of the inner surface of the toe housing.

8. A toe jack as set forth in claim 1 wherein the lower bushing is seemingly engaged with the piston.

9. A toe jack as set forth in claim 1 wherein the piston has a first end fixed to the base, a second end spaced from the base and an outer surface extending between the first and second ends, wherein a portion of the outer surface of the piston and is non-circular in a plane perpendicular to the piston axis, and wherein the supporting means includes a bushing fixed to the toe housing and having therethrough a non-circular bore that slidingly engages the non-circular portion of the outer surface of the piston.

10. A toe jack as set forth in claim 1 wherein the piston has an outer surface cantered on the axis defined by the piston, and wherein the supporting means includes a bushing fixed to the piston and having an outer surface engaged with a portion of the inner surface of the toe housing, the outer surface of the bushing that is fixed to the piston and the portion of the inner surface of the toe housing that is engaged by the bushing fixed to the piston both being centered on an axis that is offset from the axis defined by the piston.

11. A toe jack as set forth in claim 1 and further comprising a pump assembly removably mounted on the toe housing, the pump assembly including a reservoir adapted to contain a supply of fluid and a fluid passage communicable with the reservoir and adapted to communicate with the fluid inlet.

12. A toe jack as set forth in claim 11 wherein the toe housing includes a fluid outlet passage communicable with the cavity and further including an outlet valve on the toe housing for opening and closing the fluid outlet passage, the outlet valve being operable when used either with the pump assembly or when used with an alternative high-pressure fluid supply.

13. A toe jack as set forth in claim 1 and further including a remote source adapter irremovably mounted on the toe jack and adapted to be connected to a source of high pressure fluid.

14. A toe jack comprising

a base assembly including an elongated piston defining an axis,

a generally cylindrical toe housing supported by the piston for movement relative to the piston along the axis, the toe housing and the piston defining an expandable cavity, and the toe housing having extending therein a fluid inlet passage communicating with the expandable cavity,

a fluid source attachment including a fluid reservoir adapted to contain a fluid supply, a fluid passage communicable with the reservoir and communicating with the fluid inlet passage and a hand pump operable to cause a flow of fluid from the reservoir through the fluid passage into the cavity, and

mounting means for removably supporting the fluid source attachment on the toe housing to afford fluid communication between the fluid passage and the fluid inlet passage and alternatively to afford ready removal of the fluid source attachment and to permit fluid communication between the fluid inlet passage and an alternative high-pressure fluid supply.

15. A toe jack as set forth in claim 14 wherein the toe housing has extending therethrough a fluid outlet passage communicable with the cavity, and wherein the toe housing includes an outlet valve for selectively opening and closing the fluid outlet passage to control flow of hydraulic fluid, the outlet valve remaining with the toe housing when the pump assembly is removed from the toe housing.

16. A toe jack as set forth in claim 14 wherein the mounting means includes a port adapter extending between the fluid inlet passage and the fluid passage in the fluid source attachment when the fluid source attachment is mounted on the toe housing.

17. A jack as set forth in claim 14 wherein the toe housing has extending therethrough a fluid outlet passage communicating with the cavity, wherein the fluid inlet passage and the fluid outlet passage respectively have a fluid inlet port and a fluid outlet port terminating at a mounting face on the exterior of the toe housing.

18. A toe jack as set forth in claim 17 wherein the fluid source attachment includes a mounting face having therein a fluid passage port communicating with the fluid passage and a reservoir port communicating with the reservoir, the mounting face on the pump assembly and the mounting face on the toe housing mating so that the fluid inlet port and fluid passage port register and so that the fluid outlet port and reservoir port register.

19. A toe jack as set forth in claim 18 wherein the fluid source attachment is a pump assembly.

20. A toe jack as set forth in claim 18 wherein the fluid source attachment is a remote source adapter.

21. A toe jack comprising

a base including an elongated piston,

a generally cylindrical toe housing supported by the piston for movement along a portion of the length of the piston, the toe housing and the piston defining therebetween an expandable cavity, and

a pump assembly mounted on the toe housing, the pump assembly including a fluid reservoir communicable with the cavity and adapted to contain a fluid supply and including a hand operable pump for pumping a flow of fluid from the reservoir to the cavity, the pump including a first handle that is moveable relative to the toe housing to pump fluid and a second handle that is selectively moveable relative to the first handle between a lifting position wherein the second handle prevents movement of the first handle relative to the toe housing and an operating position wherein the second handle affords movement of the first handle relative to the toe housing.

22. A toe jack comprising

a base adapted to be supported by the ground,

an elongated piston extending from the base and defining an axis,

a toe housing having a closed end and an open end, the toe housing defining an inner surface surrounding a portion of the piston, the toe housing and the piston defining there between an expandable cavity adapted to contain a supply of fluid under pressure,

means for supporting the toe housing for movement relative to the piston along the axis between a retracted position and an extended position, the means for supporting the toe housing including a first bushing fixed to the piston and a second bushing fixed to the toe housing,

interengaging means on the inner surface of the toe housing and on the piston for preventing rotation of the toe housing relative to the piston about the axis,

a seal sealingly fixed to the toe housing adjacent the open end of the toe housing and slidably sealingly engaged with the piston, and

a fluid inlet communicating with the cavity and adapted to communicate with a supply of fluid under pressure for moving the toe housing relative to the piston.

23. A toe jack comprising

a base adapted to be supported by the ground,

an elongated piston extending from the base and defining an axis,

a generally cylindrical toe housing having a closed end and an open end, the toe housing defining an inner surface surrounding a portion of the piston, the toe housing being movable relative to the piston along the axis, and the toe housing including a toe projecting from the open end of the toe housing, the toe including a lifting surface,

supporting means for supporting the toe housing on the piston for movement relative to the piston along the piston axis, the supporting means including interengaging means on the inner surface of the toe housing and the on piston for preventing rotation of the toe housing relative to the piston about the axis, the interengaging means including a keyway in the piston that extends in the direction of the axis and a key that is fixed to the inner surface of the toe housing and that extends into the keyway and a bushing sealingly fixed to the piston and sealingly slidably engaging the inner surface of the toe housing.

24. A toe jack comprising

a base adapted to be supported by the ground,

an elongated piston defining a piston axis, the piston having a first end fixed to the base, a second end spaced from the base and an outer surface extending between the first and second ends, a portion of the outer surface of the piston being non-circular in a plane perpendicular to the piston axis,

a generally cylindrical toe housing having a closed end and an open end, the toe housing defining an inner surface surrounding a portion of the piston, the toe housing being movable relative to the piston along the axis, and the toe housing including a toe projecting from the open end of the toe housing, the toe including a lifting surface,

interengaging means on the inner surface of the toe housing and the on piston for preventing rotation of the toe housing relative to the piston about the axis, the interengaging means including a bushing fixed to the toe housing and having therethrough a non-circular bore that slidingly engages the non-circular portion of the outer surface of the piston, and

a bushing sealingly fixed to the piston and sealingly slidably engaging the inner surface of the toe housing.

25. A toe jack comprising

a base adapted to be supported by the ground,

an elongated piston defining a piston axis, the piston having a first end fixed to the base, a second end spaced from the base and an outer surface extending between the first and second ends and being centered on the piston axis,

a generally cylindrical toe housing having a closed end and an open end, the toe housing defining an inner surface surrounding a portion of the piston, the inner surface of the toe housing having a first portion that is centered on the piston axis and a second portion that is centered on a second axis offset from the piston axis, the toe housing being movable relative to the piston along the axis, and the toe housing including a toe projecting from the open end of the toe housing, the toe including a lifting surface, and

interengaging means on the inner surface of the toe housing and the on piston for preventing rotation of the toe housing relative to the piston about the axis, the interengaging means including a first bushing fixed to first portion of the inner surface of the toe housing and having therethrough a bore that sealingly slidingly engages the piston and a second bushing fixed to the piston and slidably engaging the second portion of the inner surface of the toe housing.

1. Technical Field

The invention relates to jacks for lifting loads, and more particularly to hydraulic toe jacks.

2. Related Prior Art

Toe jacks are used for lifting loads in general industrial applications such as the rigging of machinery, automotive maintenance and material handling, and in the maintenance of railroad rails and beds. A toe jack typically includes a base and a lifting surface or “toe” that is moveable to a retracted position wherein the toe is flush or closely spaced with the base. Because the toe can be positioned so as to be closely spaced to the base, toe jacks are well-suited for use in close quarters and in applications wherein the object to be lifted provides minimal clearance for the jack.

Toe jacks can be either hydraulically or mechanically operated and can be used to lift extremely heavy loads over a relatively small distance. Because of the mechanical advantages that can be realized by using hydraulic fluid as a medium for operating a toe jack, hand operable hydraulic toe jacks can be used to lift loads exceeding several tons. However, a toe jack that is subjected to such heavy loading, must contain and maintain relatively high hydraulic fluid pressures within the toe jack.

Since the introduction of concrete as a material used for railroad ties, toe jacks used for the maintenance and repair of railroad beds must have an increased lifting capacity. For example, a concrete tie may weigh approximately 800 lbs. whereas a wooden tie may weight approximately 200 lbs. However, it is desirable for such toe jacks to be relatively easily portable. Also, a toe jack subjected to heavy loading should remain stable as it extends to lift the load.

In general, the invention provides a relatively light weight, high capacity hydraulic toe jack that is well-suited for the maintenance and repair of railroad beds. The toe jack has few components, thereby providing a portable toe jack, and also has a relatively high lifting capacity.

In one embodiment, the invention provides a toe jack including a base adapted to be supported by the ground, an elongated piston extending from the base and defining an axis, a generally cylindrical toe housing having a closed end and an open end, the toe housing defining an inner surface surrounding a portion of the piston, the toe housing being movable relative to the piston along the axis, and the toe housing including a toe projecting from the open end of the toe housing, the toe including a lifting surface, and supporting means for supporting the toe housing on the piston for movement relative to the piston along the piston axis, the supporting means including interengaging means on the inner surface of the toe housing and on the piston for preventing rotation of the toe housing relative to the piston about the axis and a bushing fixed to the toe housing and having therethrough a bore surrounding and slidably engaging the piston.

In another embodiment, the invention provides a toe jack including a base assembly including an elongated piston defining an axis, a generally cylindrical toe housing supported by the piston for movement relative to the piston along the axis, the toe housing and the piston defining an expandable cavity, and the toe housing having extending therein a fluid inlet passage communicating with the expandable cavity, a fluid source attachment including a fluid reservoir adapted to contain a fluid supply, a fluid passage communicable with the reservoir and communicating with the fluid inlet passage and a hand pump operable to cause a flow of fluid from the reservoir through the fluid passage into the cavity, and mounting means for removably supporting the fluid source attachment on the toe housing to afford fluid communication between the fluid passage and the fluid inlet passage and alternatively to afford ready removal of the fluid source attachment and to permit fluid communication between the fluid inlet passage and an alternative high-pressure fluid supply.

In another embodiment, the invention provides a toe jack including a base including an elongated piston, a generally cylindrical toe housing supported by the piston for movement along a portion of the length of the piston, the toe housing and the piston defining therebetween an expandable cavity, and a pump assembly mounted on the toe housing, the pump assembly including a fluid reservoir communicable with the cavity and adapted to contain a fluid supply and including a hand operable pump for pumping a flow of fluid from the reservoir to the cavity, the pump including a first handle that is moveable relative to the toe housing to pump fluid and a second handle that is selectively moveable relative to the first handle between a lifting position wherein the second handle prevents movement of the first handle relative to the toe housing and an operating position wherein the second handle affords movement of the first handle relative to the toe housing.

In another embodiment, the invention provides a toe jack including a base adapted to be supported by the ground, an elongated piston extending from the base and defining an axis, a toe housing having a closed end and an open end, the toe housing defining an inner surface surrounding a portion of the piston, the toe housing and the piston defining therebetween an expandable cavity adapted to contain a supply of fluid under pressure, means for supporting the toe housing for movement relative to the piston along the axis between a retracted position and an extended position, interengaging means on the inner surface of the toe housing and on the piston for preventing rotation of the toe housing relative to the piston about the axis, a seal sealingly fixed to the toe housing adjacent the open end of the toe housing and slidably sealingly engaged with the piston, and a fluid inlet communicating with the cavity and adapted to communicate with a supply of fluid under pressure for moving the toe housing relative to the piston.

In another embodiment, the invention provides a toe jack comprising a base adapted to be supported by the ground, an elongated piston extending from the base and defining an axis, a generally cylindrical toe housing having a closed end and an open end, the toe housing defining an inner surface surrounding a portion of the piston, the toe housing being movable relative to the piston along the axis, and the toe housing including a toe projecting from the open end of the toe housing, the toe including a lifting surface, supporting means for supporting the toe housing on the piston for movement relative to the piston along the piston axis, the supporting means including interengaging means on the inner surface of the toe housing and the on piston for preventing rotation of the toe housing relative to the piston about the axis, the interengaging means including a keyway in the piston that extends in the direction of the axis and a key that is fixed to the inner surface of the toe housing and that extends into the keyway and a bushing sealingly fixed to the piston and sealingly slidably engaging the inner surface of the toe housing.

In another embodiment, the invention provides a toe jack including a base adapted to be supported by the ground, an elongated piston defining a piston axis, the piston having a first end fixed to the base, a second end spaced from the base and an outer surface extending between the first and second ends, a portion of the outer surface of the piston being non-circular in a plane perpendicular to the piston axis, a generally cylindrical toe housing having a closed end and an open end, the toe housing defining an inner surface surrounding a portion of the piston, the toe housing being movable relative to the piston along the axis, and the toe housing including a toe projecting from the open end of the toe housing, the toe including a lifting surface, interengaging means on the inner surface of the toe housing and the on piston for preventing rotation of the toe housing relative to the piston about the axis, the interengaging means including a bushing fixed to the toe housing and having therethrough a non-circular bore that slidingly engages the non-circular portion of the outer surface of the piston, and a bushing sealingly fixed to the piston and sealingly slidably engaging the inner surface of the toe housing.

In another embodiment, the invention provides a toe jack including a base adapted to be supported by the ground, an elongated piston defining a piston axis, the piston having a first end fixed to the base, a second end spaced from the base and an outer surface extending between the first and second ends and being centered on the piston axis, a generally cylindrical toe housing having a closed end and an open end, the toe housing defining an inner surface surrounding a portion of the piston, the inner surface of the toe housing having a first portion that is centered on the piston axis and a second portion that is centered on a second axis offset from the piston axis, the toe housing being movable relative to the piston along the axis, and the toe housing including a toe projecting from the open end of the toe housing, the toe including a lifting surface, and interengaging means on the inner surface of the toe housing and the on piston for preventing rotation of the toe housing relative to the piston about the axis, the interengaging means including a first bushing fixed to first portion of the inner surface of the toe housing and having therethrough a bore that sealingly slidingly engages the piston and a second bushing fixed to the piston and slidably engaging the second portion of the inner surface of the toe housing.

A feature of the invention is the provision of a hydraulic toe jack that remains relatively stable under heavy loading. The toe jack includes a toe that cannot rotate relative to the base of the toe jack as the toe moves away from the base of the toe jack.

Another feature of the invention is the provision of a hydraulic toe jack having a simple construction and having hydraulic seals that are configured to contain hydraulic fluid under high pressure.

Another feature of the invention is the provision of a toe jack that is adapted to be operated with a hand operable pump assembly that can be mounted on the toe jack or alternatively operated by connecting the toe jack to another source of high pressure hydraulic fluid, such as a mechanically operated pump.

Another feature of the invention is the provision of a hydraulic toe jack including a carrying handle that is moveable into a carrying position to allow the jack to be lifted and carried and to prevent operation of the pump of the toe jack, and that is movable away from the carrying position to afford operation of the pump of the toe jack.

Another feature of the invention is the provision of a relatively light weight hydraulic toe jack that can be hand carried and that has a high lifting capacity.

Another feature of the invention is the provision of a hydraulic toe jack that is easily repaired and maintained. The toe jack includes a toe housing that is easily removable for repair and maintenance or replacement, even when the toe jack is located in the field. Also, the toe housing is made of a wear resistant material.

A pedestal supported hydraulic toe jack arrangement, and a kit for adapting a commercially available hydraulic bottle toe jack to use at selectively adjustable relatively elevated locations includes a first elongated hollow tubular member having a floor engaging based fixed on one end thereof and at least one transverse aperture extending there through near the other end thereof. A second elongated tubular member having a first set of generally parallel generally equally spaced transverse apertures and a second set of generally parallel generally equally spaced transverse apertures generally orthogonal to the first set. The second elongated member has a transverse dimension sufficiently small that it may be telescopically slidingly positioned inside the first hollow tubular member. There is a toe jack adapter plate fixed to one end of the second elongated tubular member, and a plurality of bolts for fastening a hydraulic toe jack to the toe jack adapter plate. A pin adapted to extend simultaneously through one transverse aperture of each tubular member to fix the relative locations of the first and second elongated tubular members. There is an optional saddle for adapting an object engaging end of a movable ram portion of a hydraulic toe jack to support a convexly curved heavy object. The saddle has an upwardly opening convex rest and a downwardly opening hollow cylindrical adapter for passing over and laterally securing the saddle to the object engaging end of the ram.

1. A kit for adapting a commercially available hydraulic bottle toe jack for use at selectively adjustable relatively elevated locations comprising:

a first elongated tubular member having a floor engaging base fixed on one end thereof, a first transverse aperture extending there through near the other end thereof, and a second transverse aperture longitudinally spaced from the first aperture and extending generally orthogonal thereto;

a second elongated tubular member having a first set of generally parallel generally equally spaced transverse apertures and a second set of generally parallel generally equally spaced transverse apertures with the second set of apertures extending generally orthogonal to the first set, one of the elongated members having a transverse dimension sufficiently small that it may be telescopically slidingly received within the other tubular member;

a toe jack adapter plate fixed to one end of the second elongated tubular member;

a plurality of bolts for fastening a hydraulic toe jack to the toe jack adapter plate; and

a pin adapted to extend simultaneously through said first elongated tubular member transverse aperture and a selected one of said first and second sets of apertures to fix the relative locations of the first and second elongated tubular members.

2. The kit of claim 1 further comprising a saddle for adapting an object engaging end of a movable ram portion of a hydraulic toe jack to support a convexly curved heavy object.

3. The kit of claim 2 wherein the saddle comprises an upwardly opening convex rest and a downwardly opening hollow cylindrical adapter for passing over and laterally securing the saddle to the object engaging end of the ram.

4. A kit for adapting a commercially available hydraulic bottle toe jack for use at selectively adjustable relatively elevated locations comprising:

a first elongated tubular member having a floor engaging base fixed on one end thereof, a first transverse aperture extending there through near the other end thereof, and a second transverse aperture longitudinally spaced a first distance from the first aperture and extending generally orthogonal thereto;

a second elongated tubular member having a first set of generally parallel generally equally spaced transverse apertures and a second set of generally parallel generally equally spaced transverse apertures with the second set of apertures extending generally orthogonal to the first set, each said aperture of said first set being longitudinally spaced a second distance from an adjacent one of said second set of apertures, said second distance being unequal to said first distance, the elongated members having a transverse dimension sufficiently small that it may be telescopically slidingly received within the other tubular member;

a toe jack adapter plate fixed to one end of the second elongated tubular member;

a plurality of bolts for fastening a hydraulic toe jack to the toe jack adapter plate; and

a pin adapted to extend simultaneously through said first elongated tubular member transverse aperture and a selected one of said first and second sets of apertures to fix the relative locations of the first and second elongated tubular members.

5. The kit of claim 4 wherein said first distance is less than said second distance.

6. The kit of claim 5 wherein said second distance is less than twice said first distance.

The present invention related generally to toe jacking devices for raising heavy objects and more particularly to such toe jacking devices for further raising already elevated heavy objects. In particular, the present invention provides a device for raising vehicle components on vehicles resting on a raised hydraulic lifts.

Several lifting devices for already elevated objects are known. For example, a pedestal transmission toe jack comprises a hydraulic ram toe jack supported at an elevated location on a four leg castered base. The lift range of this device is relatively limited, for example, between 50-70 inches, and the heavy weight and large base makes it nearly impossible to use in a pit beneath a lift.

Hydraulic under hoist utility toe jacks having a conventional floor supported toe jack with an adjustable pipe arrangement extending upwardly from the movable top of the toe jack are also known. These devices, which are essentially extensions to the upper end of a conventional toe jack improve the lift range as compared to the previously mentioned transmission toe jack, but are extremely difficult to use since the upper end of the toe jack must be accurately located while the toe jack is being raised by operating the toe jack handle, which is located about six feet beneath the toe jack upper end, to engage the heavy object.

The hydraulic toe jack stand of the present invention is a hydraulic toe jack mounted on the upper end of an adjustable stand. It is made of two pipes, one telescopically received inside the other, with holes drilled in both pipes to vary the height of the stand. A pin extending through one hole of each pipe holds the toe jack in position at the desired height.

This tool is well suited to use by mechanics when a vehicle is on a lift in a repair shop. It is used under the vehicle. Examples of uses are: to lift or lower an engine or hold an engine in position while removing or installing an oil pan or motor mounts, or to lower or raise an engine to remove or install a transmission; also to hold a transmission in place to remove or install an engine. The hydraulic toe jack stand can be used to hold exhaust pipes in place, or a drive shaft in place while removing or installing the shaft.

The hydraulic toe jack stand of the present invention is light weight and can be moved about easily. It does not take up much room while under the vehicle, and is easy to work around while in use; air hoses and electrical cords can not get caught on the stand because of its design. This tool is safe, because the operator can control the toe jack while at the work being done, instead of raising or lowering a lift the vehicle is on onto a stationary stand, which is very dangerous.

Among the several objects of the present invention may be noted the provision of an easily deployed toe jack stand for use beneath hydraulic lifts; the provision of a kit for assembling a toe jack stand; the provision of a hydraulic toe jack arrangement where the hydraulic portion thereof is located relatively close to the objecting to be raised thereby facilitating operation by one person; the provision of a toe jack stand which located a hydraulic toe jack at an elevated location close to an object to be raised; and the provision of a hydraulic toe jack stand which may be positioned in a pit beneath a vehicle. These as well as other objects and advantageous features of the present invention will be in part apparent and in part pointed out hereinafter.

In general, a pedestal supported hydraulic toe jack arrangement has a floor engaging base with a hollow tubular member fixed thereto and extending upwardly there from. A second selectively movable tubular member is telescopically received in the hollow tubular member generally coaxial therewith. The movable tubular member may be selectively positioned at a any one of several different discrete locations along the axis relative to the hollow tubular member. The movable tubular member includes a first set of generally parallel generally equally spaced transverse apertures and a second set of generally parallel generally equally spaced transverse apertures which extend generally orthogonally to the first set. The hollow tubular member includes at least one, and preferably two, transverse apertures which are selectively alignable with any aperture of the first and second sets. A steel pin may then be simultaneously passed through one aperture in each tubular member to fix the elevation of the hydraulic toe jacking structure at a preferred level. A hydraulic toe jacking structure such as a commercially available hydraulic bottle toe jack has a base fixed to an upper end of the movable tubular member and an upwardly extending ram movable continuously throughout a limited longitudinal range along the common axis. The primary function of the hydraulic toe jack arrangement is to further raise already substantially elevated heavy object such as vehicle components already located on conventional hydraulic lifts.