Pumps for noncontact tonometry are provided. In one embodiment, a pump for noncontact tonometry includes a compression pump, a compression chamber, a first pressure sensor in communication with the compression chamber, a surge chamber, and a valve separating the compression chamber and surge chamber. The compression pump compresses a first volume of gas into the compression chamber. When the first pressure sensor detects a threshold pressure in the compression chamber, the valve opens and releases the gas into a surge chamber, where it combines with a gas residing in the surge chamber to form a puff of gas that escapes from the surge chamber through a flow-limiting nozzle. The components of the pump, which relies on passive rather than active components to create the controlled puff, can be assembled to have a profile that is portable and fit for home use.

Provided is a pump device and a hydraulic actuator that can reduce the number of steps of performance measurement. The pump device includes: a switching valve for switching a flow of oil to a first chamber or a second chamber of a cylinder device, the inside of which is segmented into the first chamber and the second chamber by a piston; an up blow valve (first chamber-side relief valve) that relieves pressure of a first chamber-side flow path connected to the first chamber; and a down blow valve (second chamber-side relief valve) that relieves pressure of a second chamber-side flow path connected to the second chamber.

The invention relates mainly to a pumping system (1) which comprises an alternating distribution device comprising at least one shut-off device (7) comprising four mobile shut-off members (70-73) for shutting off first and second inlets (E1, E2; E1a, E2a) and first and second outlets (S1, S2; S1a, S2a) of the pumping system (1) and at least one trigger (8, 9) configured to actuate said shut-off members (70-73) between two positions, respectively a shutting-off position and an open position, which alternating distribution device can be actuated between a first arrangement associated with a first fluid distribution cycle and a second arrangement associated with a second fluid distribution cycle.

A pump includes a fluid outflow mechanism that causes the brake fluid in the discharge chamber to flow out into the suction chamber in accordance with decrease in the volume of the discharge chamber when the feed ring of the valve portion decreases the volume of the discharge chamber in cooperation with the increasing movement of the volume of the first pump chamber in a state where the first pump chamber and the discharge chamber are filled with brake fluid in the suction step.

The invention relates mainly to a pumping system (1) which comprises an alternating distribution device comprising at least one shut-off device (7) comprising four mobile shut-off members (70-73) for shutting off first and second inlets (E1, E2; E1a, E2a) and first and second outlets (S1, S2; S1a, S2a) of the pumping system (1) and at least one trigger (8, 9) configured to actuate said shut-off members (70-73) between two positions, respectively a shutting-off position and an open position, which alternating distribution device can be actuated between a first arrangement associated with a first fluid distribution cycle and a second arrangement associated with a second fluid distribution cycle.

The invention relates to a hydraulic device for a rail vehicle including a tank region for a hydraulic fluid, a motor having a pump for pumping the hydraulic fluid, a hydraulic connection panel for providing hydraulic fluid paths and for holding hydraulic components, a control region for controlling the hydraulic components, and a housing. The tank region and the control region are arranged on opposite sides of the hydraulic connection panel. The motor is arranged together with the pump on one side of the hydraulic connection panel.

The inflating device has a body, a large cylinder, a small cylinder, a handle, a switching mechanism, and a switching device. The large cylinder is mounted moveably in the body and has an upper input gap, an inner bottom base, and a bottom base. The upper input gap is defined between an outer surface of a bottom end of the large cylinder and an inner surface of a first chamber of the body. The bottom base is connected with the large cylinder, is located below the inner bottom base, and has a first annular holding recess and a first O-ring. The small cylinder is mounted moveably in a second chamber of the large cylinder and has a piston base. The handle is mounted on the top end of the small cylinder. The switching mechanism is mounted on the top end of the large cylinder.

Pumps for noncontact tonometry are provided. In one embodiment, a pump for noncontact tonometry includes a compression pump, a compression chamber, a first pressure sensor in communication with the compression chamber, a surge chamber, and a valve separating the compression chamber and surge chamber. The compression pump compresses a first volume of gas into the compression chamber. When the first pressure sensor detects a threshold pressure in the compression chamber, the valve opens and releases the gas into a surge chamber, where it combines with a gas residing in the surge chamber to form a puff of gas that escapes from the surge chamber through a flow-limiting nozzle. The components of the pump, which relies on passive rather than active components to create the controlled puff, can be assembled to have a profile that is portable and fit for home use.

Compressor for generating compressed air for a commercial vehicle, having a housing with a piston chamber in a crankcase and a dead space which is configured at least in the cylinder head. The compressor has a valve device with a valve element which has an actuating section and a shut-off body for separating the dead space from the piston chamber, wherein the shut-off body can be lifted up from a valve seat in the direction of the piston chamber in order to open the valve device. The valve element is configured in one piece with the actuating section.

A control unit 6 of a bellows pump device 1 determines whether or not a second bellows 14 (first bellows 13) is in a predetermined expanded state when the first bellows 13 (second bellows 14) contracts to a mid-contraction state, on the basis of respective detection signals of a first detection unit 29 and a second detection unit 31, and when a determination result of the determination is negative, the control unit 6 performs next pressure increase control of controlling a second electropneumatic regulator 52 (first electropneumatic regulator 51) such that an air pressure of a pressurized air to be supplied to a second suction-side air chamber 26B (first suction-side air chamber 26A) of a second driving unit 28 (first driving unit 27) at next expansion of the second bellows 14 (first bellows 13) is increased.