Sack Truck News

Most hydraulic machine jacks, such as those used as automobile machine jacks or the like, comprise a load-bearing plate or support which is mounted to pivot upwardly about a stationary pin or shaft, so that the support will move both vertically and laterally during the raising and lowering thereof. For this reason it is not uncommon to mount such machine jacks on wheels, so that as the load-bearing plate moves upwardly beneath a load the entire jack will be free to shift or roll on its wheels forwardly or rearward in a horizontal direction to compensate for the torque or lateral loading factor which results from the swinging movement of the load-bearing plate.

It is, of course, possible to produce a machine jack which has its operating cylinder disposed in a vertical position so that the load-bearing plate will be moved directly vertically in response to the reciprocation of the associated piston rod of the cylinder. However, this design minimizes to a great extent the utility of the jack, because when the load-bearing plate is in its lowermost position it is supported on the upper end of the fully retracted piston rod, so that as a practical matter it is not possible to lower the load-bearing surface far enough to enable it to be used on items which have relatively low clearances, for example extremely low-swung automobile frames.

It is an object of this invention, therefore, to provide an improved machine jack which obviates the advantages of prior hydraulic machine jacks of the type which utilize pivotal load-bearing supports, or vertically disposed cylinders for operating the machine jacks.

A more specific object of this invention is to provide a hydraulically operated jack which is capable of being collapsed to an extremely low position, and yet which is capable of being readily elevated to an operating height several times the height of its lowermost position.

A further object of this invention is to provide an improved machine jack of the type described, which utilizes a plurality of pivotally-connected links that form two, collapsible, parallelogram-shaped sections mounted one above the other for operation by a cylinder which is disposed horizontally between them.

Still another object of this invention is to provide an improved machine jack of the type described in which the operating cylinder is mounted within the collapsible frame for both vertical and lateral movement during the operation of the jack, while the upper, lower-bearing surface of the jack is mounted to move only vertically during such operations.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawings.

A load-bearing plate is mounted by a plurality of pivotal links above a base plate, and solely for vertical movement toward and away from the base plate. An intermediate frame including two, spaced, parallel side bars is supported by the links between the two plates for swinging movement on the base plate about a pair of spaced, parallel axes. Driving means, such as a hydraulic screw jack is mounted between the two side bars for swinging movement therewith, and has a reciprocal piston rod attached to one of two, parallel shafts mounted at opposite ends in slots in the side bars to reciprocate longitudinally of the bars during the raising and lowering of the load-bearing plate. The reciprocal movement of the two shafts oscillates the links which in turn cause the load-bearing plate to reciprocate only vertically relative to the base plate.

1. Machine jacks, comprising

a base,

an intermediate frame,

a first plurality of links pivotally connected to said base and said frame to support said frame on said base for translational movement in an arc about a pair of spaced axes and between first and second limit positions,

a load-bearing member,

a second plurality of links pivotally connected to said frame and said load-bearing member to support said load-bearing member on said frame for movement relative thereto,

drive means mounted on said frame for arcuate movement therewith and having a reciprocable driver,

a third plurality of links pivotally connected to said frame and to at least certain of said first and second pluralities of links for translational movement with said frame relative to said base and said load-bearing member, and

means pivotally connecting said third plurality of links to said driver and operative to impart said arcuate movement to said frame, and to reciprocate said load-bearing plate linearly toward and away from said base plate upon reciprocation of said driver.

2. Machine jacks as defined in claim 1, wherein

said frame includes a pair of spaced, parallel side members,

said connecting means comprises at least one shaft extending transversely between said side members and slidably guided at opposite ends thereof in registering slots in said side members for reciprocation parallel to said driver,

said driver is connected to said one shaft to impart reciprocation thereto, and

each of said third plurality of links is pivotally connected at one end to said one shaft and at its opposite end to one of said certain links of said first and second pluralities thereof.

3. Machine jacks as defined in claim 2, wherein said drive means is mounted between said side members of said frame, and between said base and said load-bearing member, respectively, and for movement in the same direction as said driver.

4. Machine jacks as defined in claim 1, wherein said first plurality of links comprise two pairs of spaced links pivotally connected at their lower ends to opposite ends, respectively, of said base for pivotal movement about said spaced axes, one of said pairs being pivotally connected at their upper ends to one end of said frame adjacent opposite sides thereof, and the other of said pairs being longer than said one pair and being pivotally connected intermediate their ends to the opposite end of said frame at opposite sides thereof,

said two pairs of links being operative to maintain a plane surface on said load-bearing member parallel at all times to a plane containing said spaced axes.

5. Machine jacks as defined in claim 4, wherein

said second plurality of links include a third pair of spaced links pivotally connected at their lower ends to said one end of said frame coaxially of the upper ends of said one pair of links and at their upper ends to opposite sides of said load-bearing plate at one end thereof, and a fourth pair of spaced links equal in length to said second pair, and pivotally connected intermediate their ends to opposite ends of said frame at said opposite ends thereof, and coaxially off the pivotal connections of said second pair with said frame, and being pivotally connected at their upper ends to opposite sides of said load-bearing plate at the opposite end thereof.

6. Machine jacks as defined in claim 5, wherein said third plurality of links include two additional pairs of spaced links positioned adjacent each end of said frame, and pivotally connected at one end thereof to said first and second pluralities of links, and mounted at their opposite ends for pivotal and reciprocal movement relative to said frame.

7. Machine jacks, comprising

a pair of rigid plates,

a first plurality of pivotal links interposed between said plates for supporting one plate movably above the other,

a pair of spaced, parallel side members positioned between said plates and having a first pair of spaced, parallel pins extending transversely therebetween, and slidable at opposite ends thereof in elongate slots formed in said side members adjacent opposite ends thereof,

drive means mounted on said side members between said plates and having a drive element reciprocal selectively in opposite directions between a retracted and an extended position,

means connecting said drive element to one of said pins to impart reciprocation thereto, and

a second plurality of pivotal links connecting said pins to said first plurality of links to impart pivotal movement thereto,

said links being operative during pivotal movement thereof to swing said side members about a first pair of spaced, parallel axes fixed with respect to said other plate, and about a second pair of spaced, parallel axes fixed with respect to said one plate and movable with said one plate in spaced, parallel planes containing said first pair of axes, whereby said one plate is moved linearly between raised and lowered positions with respect to said other plate.

8. Machine jacks as defined in claim 7, wherein

each of said second plurality of links is pivotally connected at one end to one of said pins and at its opposite end is pivotally connected to one of said first plurality of links, and

said side members comprise a pair of elongate, parallel members equi-spaced from said one and said other plate, respectively.

9. Machine jacks as defined in claim 7, wherein

a second pair of parallel pins extend transversely between said side members adjacent opposite ends thereof and are fixed at their ends to said side members,

said first pair of pins are mounted to reciprocate toward and away from said second pair of pins during the raising and lowering, respectively, of said one plate, and

a manually-operable locking member is pivoted at one end on one of said second pair of pins and has a notch therein adjacent its opposite end engageable over one of said first pair of pins, when said one plate is in its raised position, thereby releasable to lock said one plate in said raised position.

10. Machine jacks as defined in claim 8, wherein

each of said first plurality of links is pivotally connected adjacent one end to one of said side members and at its opposite end to one of said plates, and

said first plurality of links include two pairs at one end of said plates, each of which is equal in length, and two further pairs at the opposite end of said plates, each of which is equal in length, and longer than each of said two pairs at said one end of the plates, whereby said two further pairs of links are pivoted at points intermediate their ends to said side members.

This invention relates to machine jacks, and more particularly to an improved machine jack having a load-supporting platform which rises and falls vertically without any lateral movement in horizontal direction.

A machine toe jack for mounting on a machine body, the toe jack having an extensible leg projectable from a hollow toe jack housing and attached to the machine body along the length of the housing. A piston cooperating in a cylinder in the extensible leg extends the leg from the housing. A hydraulic fluid reservoir is formed in the extensible leg in an annular space surrounding the cylinder. A valve block is coextensive with the extensible leg at the foot of the leg and contains the valves and pumping piston for the toe jack. Valving in the valve block permits manual extension and retraction of the extensible leg.

1. An extensible toe jack comprising:

a piston hydraulically operable in a cylinder;

a hydraulic fluid reservoir surrounding the cylinder along a substantial portion of its length;

a housing connected to the piston;

a valve block coextensive with the reservoir and at the base of the cylinder, said valve block fitting telescopically within the housing and comprising at least one hydraulic conduit therein in fluid communication between the reservoir andcylinder and having at least one check valve in the conduit, said valve block further comprising means for accessing the check valve through the exterior of the valve block, said accessing means being essentially flush with the exterior surface of thevalve block so as to permit substantially all of the valve block to be recessed telescopically into the housing so as to permit the housing to slidably cover the valve block when the piston is fully retracted into the cylinder; and

hydraulic fluid pumping means for pumping fluid from the reservoir to the cylinder.

2. An extensible toe jack comprising:

a piston hydraulically operable in a elongated cylinder;

a hydraulic fluid reservoir formed by a space between the cylinder and a wall of an extensible leg of the toe jack;

a housing connected to the piston;

a valve block coextensive with the extensible leg and at the base of the cylinder, said valve block fitting telescopically within the housing and comprising first hydraulic fluid communication means having first and second check valves thereinfor unidirectionally conducting fluid from the reservoir to the cylinder, said first hydraulic fluid communication means further comprising first and second plugs, said plugs being essentially flush with the external surface of the valve block so as topermit the extensible leg and substantially all of the valve block to be recessed telescopically into the housing when the piston is fully retracted, said plugs also having means adapted to receive a tool for removal of the plugs to provide access to thefirst and second check valves, said valve block further comprising second hydraulic fluid communication means operable between the cylinder and the reservoir having a manually controlled valve interposed therein; and

hydraulic fluid pumping means in communication with the first fluid communication means and between the first and second check valves.

1. Field of the Invention

The present invention relates to toe jacks which are mountable on a machine body and are useful for loading, removal, and/or leveling of the machine body.

2. The Prior Art

Currently there is a plethora of machine jacks available on the market ranging from simple mechanical toe jacks to sophisticated hydraulic units and are either demountable or are permanently mounted on the machine body.

One prior art machine toe jack, in particular, is attachable to a machine body only along a relatively short distance of the mid-section of the toe jack. An enlarged hydraulic fluid reservoir precludes snug engagement of the machine toe jack to the machinebody, and brackets must be used to bridge the resultant gap at the mid-section of the toe jack. Accordingly, the toe jack is attached to the machine body in a relatively insecure manner, particularly since attachment at the hydraulic fluid reservoir itself isnot possible. The reservoir also occupies a segment of the toe jack body which would otherwise be occupied, to some extent, by the extensible leg of the toe jack resulting, therefore, in a shorter extensibility of the toe jack.

With the valving mechanism and hydraulic fluid pumping apparatus of the toe jack located on top of the reservoir, the working level of the pump is elevated and is continually changing during operation of the toe jack. The constantly changing elevationof the working level is inconvenient and subjects to toe jack attachment point to undue stresses when the machine body tends to wobble.

A further problem arises from the upper hydraulic fluid reservoir because leaks, when they occur, result in hydraulic fluid staining a substantial portion of the length of the toe jack and thus serving to collect dust and debris on the toe jack.

Generally, manual extension of prior machine skates is possible only to a limited extent. Lowering of the extensible leg of the toe jack to contact with the ground so as to support a machine is, therefore, possible only through operation of the pumpingmechanism. This is both tedious and inconvenient, particularly if the extensible leg must be extended a considerable distance before it contacts the ground surface.

The present invention is a machine toe jack for mounting upon movable bodies such as machine bodies for facile raising, lowering, and leveling of the movable bodies. The toe jack is securely attachable to a machine body. Snug securement is possible sincethe hydraulic fluid reservoir is an integral part of the extensible leg and is formed in the annular space surrounding the toe jack cylinder. An elongated piston cooperates in the cylinder and is attached to a housing which completely enclosed theextensible leg upon retraction. A valve block coextensive with the extensible leg and at the base thereof contains the hydraulic fluid valving and pumping mechanisms. Access to all of the hydraulic fluid valving and pumping apparatus is easilyavailable from the external periphery of the valve block.

Facile manual extension and retraction are possible since the valving mechanism is located below the hydraulic fluid reservoir and the toe jack cylinder easily permitting transfer of hydraulic fluid from one to the other without operation of thepumping mechanism. Additionally, leaks, if they occur, stain only a small portion of the base of the toe jack and not the entire length thereof.

Not only does the housing serve to protect the toe jack apparatus during transit but also presents a uniform profile since the cross-sectional area of the toe jack is uniform along its entire length.

It is, therefore, a primary object of this invention to provide improvements in machine toe jacks.

It is another object of this invention to provide a machine toe jack wherein a substantial portion of the operating mechanism of the toe jack is retractable within a protective housing.

It is a further object of this invention to provide a machine toe jack wherein the operating level of the hydraulic pumping mechanism remains constant at ground level.

Another object of this invention is to provide a toe jack with an extensible leg that is manually extensible and retractable.

Another object of this invention is to provide a hydraulic toe jack with a hydraulic valve block wherein all hydraulic fluid control devices are readily accessible from the external periphery of the valve block.

These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawing.

The pedestal supported hydraulic machine jacks arrangement, and a kit for adapting a commercially available hydraulic bottle machine jacks 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 machine jacks to the machine jacks 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 machine jacks 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 machine jacks 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 therethrough 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 machine jacks adapter plate fixed to one end of the second elongated tubular member;

a plurality of bolts for fastening a hydraulic machine jacks to the machine jacks 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 machine jacks 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 machine jacks 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 therethrough 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 machine jacks adapter plate fixed to one end of the second elongated tubular member;

a plurality of bolts for fastening a hydraulic machine jacks to the machine jacks 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 machine jacksing devices for raising heavy objects and more particularly to such machine jacksing 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 machine jacks comprises a hydraulic ram machine jacks 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 machine jackss having a conventional floor supported machine jacks with an adjustable pipe arrangement extending upwardly from the movable top of the machine jacks are also known. These devices, which are essentially extensions to the upper end of a conventional machine jacks improve the lift range as compared to the previously mentioned transmission machine jacks, but are extremely difficult to use since the upper end of the machine jacks must be accurately located while the machine jacks is being raised by operating the machine jacks handle, which is located about six feet beneath the machine jacks upper end, to engage the heavy object.

The hydraulic machine jacks stand of the present invention is a hydraulic machine jacks 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 machine jacks 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 machine jacks stand can be used to hold exhaust pipes in place, or a drive shaft in place while removing or installing the shaft.

The hydraulic machine jacks 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 machine jacks 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 machine jacks stand for use beneath hydraulic lifts; the provision of a kit for assembling a machine jacks stand; the provision of a hydraulic machine jacks 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 machine jacks stand which located a hydraulic machine jacks at an elevated location close to an object to be raised; and the provision of a hydraulic machine jacks 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 machine jacks arrangement has a floor engaging base with a hollow tubular member fixed thereto and extending upwardly therefrom. 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 machine jacksing structure at a preferred level. A hydraulic machine jacksing structure such as a commercially available hydraulic bottle machine jacks 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 machine jacks arrangement is to further raise already substantially elevated heavy object such as vehicle components already located on conventional hydraulic lifts.