A double action hydraulic jack has a primary hydraulic pump in fluidic communication with the hydraulic fluid reservoir and with the lift cylinder. The hydraulic jack has an auxiliary hydraulic pump also in fluidic communication with the hydraulic fluid reservoir and the lift cylinder. The auxiliary hydraulic pump operates at light-load conditions to drive the jack ram upwards at a rate at least three times faster than at heavy lift-load conditions with only the primary hydraulic pump in operation.

A double action hydraulic jack has a primary hydraulic pump in fluidic communication with the hydraulic fluid reservoir and with the lift cylinder. The hydraulic jack has an auxiliary hydraulic pump also in fluidic communication with the hydraulic fluid reservoir and the lift cylinder. The auxiliary hydraulic pump operates at light-load conditions to drive the jack ram upwards at a rate at least three times faster than at heavy lift-load conditions with only the primary hydraulic pump in operation.

A hydraulic oil-circuit system and a hydraulic jack are proposed. The hydraulic oil-circuit system includes a hydraulic cylinder, an oil loading chamber, a storage oil chamber and an oil unloading pipeline; a piston is arranged in the hydraulic cylinder and divides the hydraulic cylinder into a first hydraulic oil chamber and a second hydraulic oil chamber; the first hydraulic oil chamber has a first oil port, and the second hydraulic oil chamber has a second oil port; the first oil port and the second oil port are both in unidirectional communication with the oil loading chamber and are both in unidirectional communication with the storage oil chamber; and the oil unloading pipeline connects the oil loading chamber and the storage oil chamber.

A hydraulic oil-circuit system and a hydraulic jack are proposed. The hydraulic oil-circuit system includes a hydraulic cylinder, an oil loading chamber, a storage oil chamber and an oil unloading pipeline; a piston is arranged in the hydraulic cylinder and divides the hydraulic cylinder into a first hydraulic oil chamber and a second hydraulic oil chamber; the first hydraulic oil chamber has a first oil port, and the second hydraulic oil chamber has a second oil port; the first oil port and the second oil port are both in unidirectional communication with the oil loading chamber and are both in unidirectional communication with the storage oil chamber; and the oil unloading pipeline connects the oil loading chamber and the storage oil chamber.

A clamp contains: a body, an actuation rod, and a slow descending device. The body includes a first support sheet, and the actuation rod includes a second support sheet. The body further includes a drive grip, a driven mechanism, and a limitation mechanism. The limitation mechanism has a first spring, multiple first fixing protrusions, and a release lever. The slow descending device includes a second spring, multiple second fixing protrusions, a guide element, and a micro-adjustment handle. The micro-adjustment handle has a pull lever and the second spring 31 surrounds around the actuation ro. The multiple second fixing protrusions accommodate the actuation rod and are pushed by the second spring. The micro-adjustment handle has a third spring and a control lever pushed by the third spring and contacting with the multiple second fixing protrusions.

A clamp contains: a body, an actuation rod, and a slow descending device. The body includes a first support sheet, and the actuation rod includes a second support sheet. The body further includes a drive grip, a driven mechanism, and a limitation mechanism. The limitation mechanism has a first spring, multiple first fixing protrusions, and a release lever. The slow descending device includes a second spring, multiple second fixing protrusions, a guide element, and a micro-adjustment handle. The micro-adjustment handle has a pull lever and the second spring 31 surrounds around the actuation ro. The multiple second fixing protrusions accommodate the actuation rod and are pushed by the second spring. The micro-adjustment handle has a third spring and a control lever pushed by the third spring and contacting with the multiple second fixing protrusions.

A self-contained electric double-acting hydraulic cylinder jack for lifting objects is provided, comprising a vertically elongated upper housing section and lower housing section, which are slidably assembled on each other to form a self-contained assembly, a hydraulic electric linear actuator placed between the upper housing and lower housing sections, which actuator comprises an integrated motor, pump, valve, and double-acting cylinder, an on-board battery for supplying power to the hydraulic electric linear actuator, and a momentary on-off-on toggle switch conjugated in electrical connection with the battery to actuate the actuator.

A self-contained electric double-acting hydraulic cylinder jack for lifting objects is provided, comprising a vertically elongated upper housing section and lower housing section, which are slidably assembled on each other to form a self-contained assembly, a hydraulic electric linear actuator placed between the upper housing and lower housing sections, which actuator comprises an integrated motor, pump, valve, and double-acting cylinder, an on-board battery for supplying power to the hydraulic electric linear actuator, and a momentary on-off-on toggle switch conjugated in electrical connection with the battery to actuate the actuator.

A vehicle system includes a chassis and a lift assembly. The chassis includes a frame defining a first aperture and a second aperture. The lift assembly includes an adapter assembly and a lift device. The adapter assembly includes (a) an adapter defining a first pin aperture, a second pin aperture, and an adapter aperture, (b) a first pin extending through the first aperture and the first pin aperture and a second pin extending through the second aperture and the second pin aperture to selectively couple the adapter to the frame, and (c) a cross member configured to be received by the adapter aperture. The lift device includes a pair of receivers configured to engage the cross member of the adapter assembly to support the cross member. The first pin aperture and the adapter aperture each extend laterally when the adapter is coupled to the frame.

A vehicle system includes a chassis and a lift assembly. The chassis includes a frame defining a first aperture and a second aperture. The lift assembly includes an adapter assembly and a lift device. The adapter assembly includes (a) an adapter defining a first pin aperture, a second pin aperture, and an adapter aperture, (b) a first pin extending through the first aperture and the first pin aperture and a second pin extending through the second aperture and the second pin aperture to selectively couple the adapter to the frame, and (c) a cross member configured to be received by the adapter aperture. The lift device includes a pair of receivers configured to engage the cross member of the adapter assembly to support the cross member. The first pin aperture and the adapter aperture each extend laterally when the adapter is coupled to the frame.