Abstract: A spindle of an oil hydraulic cylinder includes a main body and a circular ring shaped copper coat. The main body defines a central axis and has a large diameter segment and a small diameter segment integrally extended from the large diameter segment. The copper coat is brazed on an outer surface of the large diameter segment. The center of the copper coat is arranged at the central axis, and the radius of the spindle is greatest at a portion of the spindle coated by the copper coat. The abrasion resistance of the copper coat is greater than the abrasion resistance of the main body. Thus, the spindle of the instant disclosure is a composite structure and is provided for reducing abrasion. Additionally, the instant disclosure also provides an oil hydraulic cylinder.

Abstract: A spindle of an oil hydraulic cylinder includes a main body and a circular ring shaped copper coat. The main body defines a central axis and has a large diameter segment and a small diameter segment integrally extended from the large diameter segment. The copper coat is brazed on an outer surface of the large diameter segment. The center of the copper coat is arranged at the central axis, and the radius of the spindle is greatest at a portion of the spindle coated by the copper coat. The abrasion resistance of the copper coat is greater than the abrasion resistance of the main body. Thus, the spindle of the instant disclosure is a composite structure and is provided for reducing abrasion. Additionally, the instant disclosure also provides an oil hydraulic cylinder.

Abstract: A pump piston structure of a hydraulic cylinder includes a pump piston having an aslant circular groove formed on a circumferential surface of the pump piston and interconnected to a through hole on a distal surface, a movable O-ring installed at the aslant circular groove, a penetrating hole formed between a distal surface of the pump piston and a piston rod and blocked by a pressure valve, and an oil suction hole formed separately on the pump piston and the piston rod for sucking hydraulic oil to push the hydraulic cylinder in the reciprocal movements of the pump piston, and when the hydraulic cylinder is loaded with a heavy object, some of the hydraulic oil at the pump piston returns to the piston rod to reduce the resistance of operating the pump.

Abstract: A jack structure for a clutch contains a main hydraulic cylinder to push a movable arm to move vertically, and a holder including a support rod actuated by an auxiliary hydraulic cylinder of the movable arm to move vertically and horizontally relative to the holder. The main hydraulic cylinder is a single acting hydraulic cylinder, and the auxiliary cylinder is a double acting hydraulic cylinder. The main hydraulic cylinder communicates with an inlet tube of the auxiliary hydraulic cylinder. A valve seat includes a pump hole to draw hydraulic oil via a valve seat cylinder, an inlet connected with the inlet tube, an outlet coupled with an outlet tube of the auxiliary hydraulic cylinder, and a bore connected with an oil tank. A control post is axially connected with the valve seat and includes plural grooves to selectively communicate with the pump hole, the inlet, the outlet, and the bore after rotation.

Abstract: A carrying rack of an engine includes a main hydraulic cylinder to move a swing arm upward and downward, and the swing arm including a seat disposed on a front end thereof, the seat including a support post axially mounted therein, wherein the support post includes a fixed peg axially inserted to a U-shaped receiving member to form a L shape, and the receiving member includes a pillar axially fixed on a bottom end thereof by using a retaining bolt, the support post also includes a rotating holder axially connected to the seat; an auxiliary hydraulic cylinder is axially disposed in an inner side of the swing arm by using its distal end so that a hydraulic lifter axially couples with the rotating holder via a connecting rod, and the swing arm includes a shaft mounted thereon to contact with the connecting rod.

Abstract: A jack structure for a clutch contains a main hydraulic cylinder to push a movable arm to move vertically, a holder including a support rod actuated by an auxiliary hydraulic cylinder of the movable arm to move vertically and horizontally relative to the holder, wherein the main hydraulic cylinder is a single acting hydraulic cylinder, the auxiliary cylinder is a double acting hydraulic cylinder, pipes of the main hydraulic cylinder communicate with an inlet tube of the auxiliary hydraulic cylinder; a valve seat includes a pump hole to draw hydraulic oil via a cylinder, an inlet connected with the inlet tube, an outlet coupled with an outlet tube of the auxiliary hydraulic cylinder, and a bore connected with an oil tank; a control post axially connected with the valve seat and includes plural grooves to selectively communicate with the pump hole, the inlet, the outlet, and the bore after rotation.

Abstract: A check valve for use in a pump of a hydraulic cylinder includes a tubular member having a sheath member received therein. The pump includes a chamber provided in an output pipe thereof for receiving the check valve. The tubular member is constructed in the form of a hollow cylinder and includes a sealing sleeve fitted therearound. The tubular member includes an oil seal mounted on the front end thereof for the engagement with a hollow screw element in the chamber. The sheath member includes a hollow cap member, a first spring element, a ball, a hollow disc element, and a second spring element which are placed into the tubular member in turn. By using the hollow disc element and the second spring element, the tubular member may be fixed in the chamber, and by way of the screw element, the tubular member is enclosed in the chamber.

Abstract: A carrying rack of an engine includes a main hydraulic cylinder to move a swing arm upward and downward, and the swing arm including a seat disposed on a front end thereof, the seat including a support post axially mounted therein, wherein the support post includes a fixed peg axially inserted to a U-shaped receiving member to form a L shape, and the receiving member includes a pillar axially fixed on a bottom end thereof by using a retaining bolt, the support post also includes a rotating holder axially connected to the seat; an auxiliary hydraulic cylinder is axially disposed in an inner side of the swing arm by using its distal end so that a hydraulic lifter axially couples with the rotating holder via a connecting rod, and the swing arm includes a shaft mounted thereon to contact with the connecting rod.

Abstract: A check valve for use in pump of hydraulic cylinder comprises a check valve including a tubular member disposed therein and having a sheath member received therein, a pump including a chamber provided in an output pipe thereof for receiving the check valve, wherein the tubular member is constructed in the form of a hollow cylinder and includes a sealing sleeve fitted therearound, and includes an oil seal mounted on the front end thereof for the engagement with a hollow screw element in the chamber; the sheath member is comprised of a hollow cap member, a first spring element, a ball, a hollow disc element which are placed into the tubular member in turn, and a second spring element. By using the disc element and the second spring element, the tubular member may be fixed in the chamber, and by way of the screw element, the tubular member is enclosed in the chamber.

Abstract: A multi-stage telescoping transmission jack with a high flow, lower pressure air-over-oil pump.

Abstract: A portable lifting jack having a wheeled frame (1), a lifting arm (10), a handle (11) and a hydraulic pump (2), which includes a multipurpose block (20) formed as an octogonal column member, and a releasing device (40) and a piston pump (50) respectively defined in a rear side of the multipurpose block. A hydraulic actuator (60) is connected at a threaded hole defined in a front side of the multipurpose block. Two oil chambers (24) are defined in opposite ends of the multipurpose block and communicate with each other. Particularly, an equalizing valve (30) is disposed on a top of the multipurpose block and in communication with the oil chamber to equalize the external and internal pressures of the hydraulic pump so as to increase the efficiency of the hydraulic portable lifting jack.

Abstract: A multi-stage telescoping transmission jack with a high flow, lower pressure air-over-oil pump.

Abstract: A portable lifting jack having a wheeled frame (1), a lifting arm (10), a handle (11) and a hydraulic pump (2), which includes a multipurpose block (20) formed as an octogonal column member, and a releasing device (40) and a piston pump (50) respectively defined in a rear side of the multipurpose block. A hydraulic actuator (60) is connected at a threaded hole defined in a front side of the multipurpose block. Two oil chambers (24) are defined in opposite ends of the multipurpose block and communicate with each other. Particularly, an equalizing valve (30) is disposed on a top of the multipurpose block and in communication with the oil chamber to equalize the external and internal pressures of the hydraulic pump so as to increase the efficiency of the hydraulic portable lifting jack.

Abstract: A hydraulic jack includes a first cylinder, a handle pivotally connected to the first cylinder to activate the first cylinder, a second cylinder in communication with the first cylinder and having a piston received in the second cylinder to connect to an arm so as to support a seat on top of the arm. A pivotal shaft is provided at a joint between the first cylinder and the second cylinder so that the first cylinder is pivotally connected to the second cylinder by way of the pivotal shaft.

Abstract: A hydraulic jack includes a first cylinder, a handle pivotally connected to the first cylinder to activate the first cylinder, a second cylinder in communication with the first cylinder and having a piston received in the second cylinder to connect to an arm so as to support a seat on top of the arm. A pivotal shaft is provided at a joint between the first cylinder and the second cylinder so that the first cylinder is pivotally connected to the second cylinder by means of the pivotal shaft.

Abstract: A pneumatically driven hydraulic pump in accordance with the present invention is comprised of a cylindrical body, a front end cap, a rear end cap, a division wall, a piston, a control valve, a pneumatic valve, an air bladder and a pedal. The pneumatically piston and the air bladder also connected to the air source are used to quickly pump hydraulic fluid to an external hydraulic lifting device. Consequently, a heavy object can be lifted or lowered quickly.

Abstract: A hydraulic jack includes a moveable base seat. A lift arm, a handle and a hydraulic driver each mounted on the base seat. The hydraulic driver is driven by the handle to push the lift arm to lift an object. The hydraulic jack has a compound piston assembly and a hydraulic driver with fluid paths by which the jack can adjust the lift capacity so as to lift quickly and lower slowly.