Jack

Claim 2

A jack having, in combination, a lifting cylinder, a pump for pumping liquid, such as oil, for example, to said lifting cylinder, a compressed-air motor for operating said pump, said compressed-air motor and said pump comprising a unitary structure, a frame, means for mounting said lifting cylinder on said frame, means for detachably connecting said unitary structure on said frame, said frame having passageway means for conducting liquid between said lifting cylinder and said pump, said frame having a base, and attaching means associated with a lifting device for detachably mounting said base in an operative position on the device.

Claim 3

The combination set forth in claim 1 including additional attaching means each associated with a different lifting device, each of said attaching means being capable of coacting with said base for detachably mounting said base on a particular lifting device.

Claim 4

The combination set forth in claim 1 in which said pump includes a part at the end of said unitary structure which has several passageways and said frame has several passageways forming said passageway means and includes a first part formed with a recess in which said pump part is disposed, means including a hollow screw for securing said pump part to said first frame part, said screw having a passageway extending therethrough in communication with one of the passageways in said pump part and one of the passageways in said frame, respectively, when said pump part is secured to said first frame part, said recess having at least one groove when said pump part is disposed therein which is in communication with another of said passageways in said pump part and another of said passageways in said frame.

Claim 5

The combination set forth in claim 3 in which the frame has a second recess in which an end of said lifting cylinder is disposed, a passageway in said frame being in communication with said cylinder at the vicinity of said second recess.

Claim 6

The combination set forth in claim 4 comprising a circuit for circulating liquid, such as oil, for example, through and between said pump and said lifting cylinder, said circuit including said passageways and said groove, and said lifting cylinder including structure defining a reservoir for holding a body of the liquid, said reservoir being in communication with a passageway in said frame and with said lifting cylinder.

Claim 7

The combination set forth in claim 1 in which said compressed-air motor comprises control means including first valve structure for controlling the operation of said motor, said lifting cylinder including a lifting piston, a circuit including said passageway means for circulating liquid, such as oil, for example, through and between said pump and said lifting cylinder, control means including second valve structure for controlling the circulation of liquid in said circuit, said unitary structure being enclosed by a casing, a rotatable shaft, means including said casing and said frame for supporting said shaft, said shaft having an operating handle and eccentric sections for operating said first and second valve structures to render said compressed-air motor operable or inoperable and to render said circuit operable or inoperable to supply liquid to said lifting cylinder for lifting purposes, and said second valve structure functioning, when said circuit is inoperable to supply liquid to said lifting cylinder for lifting purposes, to provide a path of flow for liquid in said circuit from said lifting cylinder which permits said piston to move when said jack is being lowered.

Claim 8

The combination set forth in claim 1 which includes a handle for carrying said unitary structure, said handle comprising a hollow tubular member fixed to said frame, said tubular member having an inlet adapted to be connected to a source of supply of compressed air, said compressed-air motor having an inlet for compressed air, and conduit means for conduction compressed air from said tubular member to the compressed air inlet of said motor, said conduit means and said tubular member being so constructed and arranged that the latter functions as a water separator and a pressure equalizing chamber for the compressed air.

Claim 9

The combination set forth in claim 1 which includes a carriage having wheels, means including said base and said attaching means for fixing the jack to said carriage, a supporting plate on said carriage, and said supporting plate and said wheels being so constructed and arranged that, when said jack is stationary, substantially all of the dead-weight load on the jack will be carried by said supporting platE.

Claim 10

The combination set forth in claim 8 in which said attaching means comprises a bracket, one end of said base engaging said bracket, means on said carriage comprising a pivoted locking arm movable between locking and unlocking positions, and said locking arm in its locking position bearing against the opposite end of said base at the upper edge thereof.

Claim 11

The combination set forth in claim 6 which includes a carriage having wheels, means including said base and said attaching means for fixing the jack to said carriage, a supporting plate on said carriage, and said supporting plate and said wheels being so constructed and arranged that, when said jack is stationary, substantially all of the dead-weight load on the jack will be carried by said supporting plate, an operating shaft having a plurality of sections, one of said sections being axially movable with respect to the other, said operating shaft being turnable, means on said carriage for rotatably supporting said operating shaft, one end of said operating shaft coacting with the operating handle of said shaft having eccentric sections whereby turning movement of said operating shaft effects turning of said shaft having eccentric sections.

Claim 12

The combination set forth in claim 8 which includes a lifting arm provided with a lifting platform, an operating shaft, said lifting cylinder being disposed horizontally on said carriage, said lifting cylinder and operating shaft and lifting arm being so constructed and arranged that said operating shaft, responsive to said lifting cylinder, displaces the lower end of said lifting arm horizontally, a first linked arm pivotally connected to said carriage and lifting arm, respectively, and a second linked arm pivotally connected to said lifting platform and said first linked arm, respectively, to impart a parallel motion displacement of said lifting platform during lifting movement thereof.

Claim 13

The combination set forth in claim 8 in which said means for fixing the jack to said carriage includes structure for turnably mounting said base thereon, a lifting rod, a lifting arm, the jack cooperating with said lifting rod which in turn acts on said lifting arm, means including two linked arms for pivotally connecting said lifting arm to said carriage to develop a lifting movement, means for articulatedly connecting one of said linked arms to the other of said linked arms, a lifting platform, means for coupling the other of said linked arms to said lifting platform, and means for pivotally attaching said lifting platform to said lifting arm to impart a parallel motion displacement of said lifting platform during lifting movement thereof.