Stable toe jack
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.