Abstract: A power unit includes a frame having a handle with a control knob, and a pair of pivotal lift arms elevated by pushing the rearward ends by a push bar of a hydraulic cylinder. The cylinder has a control valve attached to a control shaft extending from the control knob. A pair of guide rail are attached to the bottom of the frame; and a pair of rack bars are slidably mounted on each guide rail, and has a forward end pivotally linked to the push bar. A pair of dogs are positioned above the rack bar, each having a rearward end pivotally attached to the frame and a forward end engaging a tooth of the rack bar. The forward end of each dog engages the rack bar as the lift arms are elevated; and in the event of a hydraulic failure, the dogs lock the lift arms in the elevated position. A release includes a cam tube having a V slotted opening in the underside thereof. A swing plate has a cam follower stud slidably engaged within the V slotted opening.

Abstract: A floor jack includes a frame having a handle with a control knob, and a pair of pivotal lift arms elevated by pushing the rearward ends by a push bar of a hydraulic cylinder. The cylinder has a control valve attached to a control shaft extending from the control knob. A pair of guide rail are attached to the bottom of the frame; and a pair of rack bars are slidably mounted on each guide rail, and has a forward end pivotally attached to the push bar. A pair of dogs are positioned above the rack bar, each having a rearward end pivotally attached to the frame and a forward for engaging a tooth of the rack bar. The forward end of the dogs engage the rack bar as the lift arms are elevated; and in the event of a hydraulic failure, the dogs lock the lift arms in the elevated position. A release includes a cam tube having a V slotted opening in the underside thereof. A swing plate has a cam follower stud slidably engaged within the V slotted opening.

Abstract: Each jack stand includes a rectangular bottom plate having a pair of rectangular openings therein. The rack has a rectangular platform having a lateral loading side, a width a little larger than the jack-stand-length, and a length equal to a multiple of the jack stand widths. A plurality of L-shaped fingers are located on the platform at points corresponding to the opening in the bottom plate, and extends upwardly and laterally toward the non loading side of the platform. Each finger has a rectangular upper surface thereon having a width and length slightly smaller than the width and length of the openings in the bottom plates; and creates an opening between the platform and the finger that is slightly greater that the thickness of the bottom plates of the jack stands.

Abstract: A bridge traverses along lift arms of a power unit, having leveling pads with inner rectangular plates and roller bearings; and each lift arms has an inner slide plate. The bridge has the general shape of a rectangular block and has a first longitudinal recess in each side, having a width slightly larger than the width of the slide rail, and a depth equal to the thickness of the slide rail. The bridge has a second longitudinal recess in each side having a width slightly larger than the diameter of the roller bearings and a depth slightly larger than the thickness of the roller bearings. The bridge is biased in the forwardly direction along the slide rails by a rectangular pusher frame. The pusher frame has a pair of side plates, with each outer side having a longitudinal recess therein slightly larger than the width of the slide rail and a depth equal to the thickness of the slide rail.

Abstract: A power unit has a frame with a bottom and a pair of lift arms with a cover plate, and a bridge. A lower latch member has a forward end, a middle portion and a rearward end with the middle portion pivotally connected near the lower inner side of one of the lift arms. The rearward end is angled downward, extending below the lower side of the lift arm. The rearward end is biased downwardly and is engagable with the bottom of the frame. The forward end has an upward finger with a beveled-up nose thereon that is engagable with a downward lateral flange at the forward end of the bridge. The bridge is retained by the forward end of the lower latch member, and whereby when the lift arm is lowered to the lowermost position, the forward end is automatically released. An upper latch member has a forward end, a middle portion and a rearward end, with the middle portion pivotally connected to a pivot arm extending downwardly from the cover plate.

Abstract: A power unit includes a rectangular frame having a forward end for operating the jack stand; a middle portion for retaining the lifting mechanism; a rearward end for controlling the power unit. A pair of lift arms acting in parallel have forward ends, central portions and rearward ends and are interconnected at the rearward ends thereof by a lateral push bar. A pair of horizontally oriented U-shaped leveling pads each having an outer rectangular plate and an inner rectangular plate providing an open rearward end with the opening equal to the thickness of the lift arm, and forming a closed U-shaped forward end, and are pivotally attached at the rearward end thereof around the inner and outer sides of the forward end of the respective lift arm. Each outer rectangular plate of the leveling pad has a downwardly extended lever arm at the forward end thereof for connecting to a leveling link.

Abstract: A power unit includes a frame having a handle with a control knob, and a pair of pivotal lift arms elevated by pushing the rearward ends by a push bar of a hydraulic cylinder. The cylinder has a control valve attached to a control shaft extending from the control knob. A pair of guide rail are attached to the bottom of the frame; and a pair of rack bars are slidably mounted on each guide rail, and has a forward end pivotally linked to the push bar. A pair of dogs are positioned above the rack bar, each having a rearward end pivotally attached to the frame and a forward end engaging a tooth of the rack bar. The forward end of each dog engages the rack bar as the lift arms are elevated; and in the event of a hydraulic failure, the dogs lock the lift arms in the elevated position. A release includes a cam tube having a V slotted opening in the underside thereof. A swing plate has a cam follower stud slidably engaged within the V slotted opening.

Abstract: A floor jack includes a frame having a handle with a control knob, and a pair of pivotal lift arms elevated by pushing the rearward ends by a push bar of a hydraulic cylinder. The cylinder has a control valve attached to a control shaft extending from the control knob. A pair of guide rail are attached to the bottom of the frame; and a pair of rack bars are slidably mounted on each guide rail, and has a forward end pivotally attached to the push bar. A pair of dogs are positioned above the rack bar, each having a rearward end pivotally attached to the frame and a forward for engaging a tooth of the rack bar. The forward end of the dogs engage the rack bar as the lift arms are elevated; and in the event of a hydraulic failure, the dogs lock the lift arms in the elevated position. A release includes a cam tube having a V slotted opening in the underside thereof. A swing plate has a cam follower stud slidably engaged within the V slotted opening.

Abstract: A jack stand for use with a power unit having a slide forward bridge for positioning by the jack stand; and having a pair of leveling pads with inner roller bearings thereon for engaging an upper lifting plate of the jack stand, and a bottom plate having openings therein for engaging a mobile rack for transporting the jack stands. The jack stand has the bottom plate with a series of telescopic frames extendable therefrom, and the upper lifting plate extending from the upper frame, having side flanges with a rectangular bottom surface thereon for engaging the roller bearing of the power unit. A pair of bumpers are attached to the lowermost vertical frame with one extending forwardly and one extending rearwardly (one of which is always positioned) for engaging the slide forward bridge, as the jack stand is loaded into the power unit.

Abstract: A power unit (or a hydraulic floor jack) includes a rectangular frame with side flanges and has a tubular handle enclosing a control shaft and a control knob. A pivotal lifting mechanism is mounted on the frame including a pair of parallel lift arms having rearward ends interconnected by a lateral push bar. The forward ends (with the bridge) are rotatable upward for lifting a load as the push bar is translated forward within a pair of U channels tracks attached to the inner side flanges. A hydraulic cylinder has a ram for pushing the lateral push bar forward along the tracks for raising the forward ends of the lift arms, and has a releasable control valve for retracting the ram to lower the forward ends of the lift arms. The safety mechanism includes a toothed rack bar secured in the vertical wall of the racks. The lateral push bar has bore holes in the ends thereof.

Abstract: A bridge traverses along lift arms of a power unit, having leveling pads with inner rectangular plates and roller bearings; and each lift arms has an inner slide plate. The bridge has the general shape of a rectangular block and has a first longitudinal recess in each side, having a width slightly larger than the width of the slide rail, and a depth equal to the thickness of the slide rail. The bridge has a second longitudinal recess in each side having a width slightly larger than the diameter of the roller bearings and a depth slightly larger than the thickness of the roller bearings. The bridge is biased in the forwardly direction along the slide rails by a rectangular pusher frame. The pusher frame has a pair of side plates, with each outer side having a longitudinal recess therein slightly larger than the width of the slide rail and a depth equal to the thickness of the slide rail.

Abstract: A jack stand for use with a power unit having a slide forward bridge for positioning by the jack stand; and having a pair of leveling pads with inner roller bearings thereon for engaging an upper lifting plate of the jack stand, and a bottom plate having openings therein for engaging a mobile rack for transporting the jack stands. The jack stand has the bottom plate with a series of telescopic frames extendable therefrom, and the upper lifting plate extending from the upper frame, having side flanges with a rectangular bottom surface thereon for engaging the roller bearing of the power unit. A pair of bumpers are attached to the lowermost vertical frame with one extending forwardly and one extending rearwardly (one of which is always positioned) for engaging the slide forward bridge, as the jack stand is loaded into the power unit.

Abstract: A power unit includes a rectangular frame having a forward end for operating the jack stand; a middle portion for retaining the lifting mechanism; a rearward end for controlling the power unit. A pair of lift arms acting in parallel have forward ends, central portions and rearward ends and are interconnected at the rearward ends thereof by a lateral push bar. A pair of horizontally oriented U-shaped leveling pads each having an outer rectangular plate and an inner rectangular plate providing an open rearward end with the opening equal to the thickness of the lift arm, and forming a closed U-shaped forward end, and are pivotally attached at the rearward end thereof around the inner and outer sides of the forward end of the respective lift arm. Each outer rectangular plate of the leveling pad has a downwardly extended lever arm at the forward end thereof for connecting to a leveling link.

Abstract: Each jack stand includes a rectangular bottom plate having a pair of rectangular openings therein. The rack has a rectangular platform having a lateral loading side, a width a little larger than the jack-stand-length, and a length equal to a multiple of the jack stand widths. A plurality of L-shaped fingers are located on the platform at points corresponding to the opening in the bottom plate, and extends upwardly and laterally toward the non loading side of the platform. Each finger has a rectangular upper surface thereon having a width and length slightly smaller than the width and length of the openings in the bottom plates; and creates an opening between the platform and the finger that is slightly greater that the thickness of the bottom plates of the jack stands.

Abstract: A power unit has a frame with a bottom and a pair of lift arms with a cover plate, and a bridge. A lower latch member has a forward end, a middle portion and a rearward end with the middle portion pivotally connected near the lower inner side of one of the lift arms. The rearward end is angled downward, extending below the lower side of the lift arm. The rearward end is biased downwardly and is engagable with the bottom of the frame. The forward end has an upward finger with a beveled-up nose thereon that is engagable with a downward lateral flange at the forward end of the bridge. The bridge is retained by the forward end of the lower latch member, and whereby when the lift arm is lowered to the lowermost position, the forward end is automatically released. An upper latch member has a forward end, a middle portion and a rearward end, with the middle portion pivotally connected to a pivot arm extending downwardly from the cover plate.

Abstract: A hydraulic floor jack has a tubular handle with a yoke at the distal end thereof with lateral axels pivotally attached to a pair of vertical side brackets. One side brackets has a series of arcuate upper surfaces concentric with the lateral axel of the yoke, including a large radius forward portion, then a small radius arcuate notch portion, then an intermediate radius rearward portion. The yoke has a barrel aligned radially over the circular upper surfaces of the side bracket, with a plunger therein having an upper end extending above the barrel and a lower end for extending below the barrel and into the arcuate notch portion. A plunger control level has a rectangular distal end that is pivotally attached to the upper end of the plunger.

Abstract: A two-position lift bridge is used with a jack-stand power unit including a forward end, a rearward end, a pair of upward side flanges, with the rearward end having a hydraulic cylinder. A rear cover plate extends horizontally from the side flanges and over the cylinder, and has vertical apertures for positioning the lift bridge, and has a threaded vertical aperture for securing the lift bridge. The frame has a pair of parallel lift arms having forward end that are extendable by the cylinder. Each forward end has a leveling pad pivotally attached having an outwardly extended flange, and one having a vertical aperture and a threaded aperture. The lift bridge includes a rectangular plate one side having downward extending corner flanges with horizontal openings for engaging one of the outwardly extended flanges of the leveling pad.