6840 results about "Check valve" patented technology

An automotive emergency start power supply with an inflation function includes: an inflation pump, an internal power supply, and a first circuit board. The inflation pump is provided with a first power device, a detection assembly, and a first check valve; the first power device includes a first driving assembly and a first inflation assembly including a first transmission assembly, first cylinder assembly and connecting pipe; the first driving assembly is configured to provide power to the first inflation assembly, and the first inflation assembly is configured to provide first airflow to the first air outlet portion; the detection assembly is configured to detect air pressure information; and the first check valve is disposed in a first accommodating space formed by the first cylinder assembly and the connecting pipe, and is configured to allow the first power device to provide the first airflow to the first air outlet portion.

A pump system includes a housing defining a first internal volume and a second internal volume, a first piston positioned to separate the first internal volume into a first chamber and a second chamber, a second piston positioned to separate the second internal volume into a third chamber and a fourth chamber, a first inlet check valve configured to permit fluid flow into the first chamber, a second inlet check valve configured to permit fluid flow into the third chamber, a directional control valve (DCV) repositionable between (a) a first position where the DCV is configured to fluidly couple the second chamber to a high pressure fluid source and (b) a second position where the DCV is configured to fluidly couple the fourth chamber to the high pressure fluid source, and a relief valve configured to supply a fluid to the DCV through an orifice to move the DCV.

A rotating check valve is disclosed for improved debris collection within a wellbore. The check valve can be part of a debris removal tool that includes a motor, pump, gearbox, bailer, milling bit, the check valve, rotational shafts. On its uphole end, the check valve can be coupled with the bailer such that the check valve can rotate relative to the bailer. Also on the uphole end, the check valve can be rotationally coupled to a shaft that passes through the bailer and couples with the gearbox. On the downhole end, the check valve can be rotationally coupled to the milling bit. The check valve can include a torque transfer mechanism that transfers torque generated by the motor and gearbox to the milling bit. The check valve can include a unidirectional flow control mechanism that restricts the flow of fluid and debris to the uphole direction.

The invention relates to the technical field of bearings, and provides a hydrostatic bearing gas supply system which comprises a first gas supply subsystem and a second gas supply subsystem, the first gas supply subsystem comprises a first pipeline, a first check valve, a first reaction mechanism, a second reaction mechanism and a degassing structure, and the first reaction mechanism, the second reaction mechanism and the first pipeline are sequentially connected; a reactant is arranged in the first reaction mechanism, a catalyst is arranged in the second reaction mechanism, and the first check valve and the degassing structure are arranged on the first pipeline; the second gas supply subsystem is connected with the first pipeline; when the gas source is cut off, the reactant and the catalyst are subjected to chemical reaction in the second reaction mechanism to generate water vapor and oxygen, the degassing structure is used for consuming the oxygen and generating superheated steam, and the superheated steam enters the hydrostatic bearing. The air supply system for the hydrostatic bearing provides the pure water vapor working medium for the hydrostatic bearing, so that the normal operation of the hydrostatic bearing is ensured, and the hydrostatic bearing is prevented from being damaged.

A milling bit valve is disclosed for improved debris collection within a wellbore. The check valve can be part of a debris removal tool that includes a motor, pump, gearbox, bailer, milling bit, check valve, and rotational shafts. In an example, on its uphole end, the milling bit can be coupled with the check valve. On its downhole end, the milling bit can be configured for debris removal with cutting edges. The downhole end can also include openings that provide access to an internal cavity of the milling bit. The internal cavity can extend the entire length of the milling bit. This allows the pump to pull drilling fluid into the bailers through the milling bit and check valve. As a result, the debris removal tool can simultaneously remove obstructions in a wellbore and collect debris from the obstruction removal.

Embodiments of a manifold of a hydraulic fracturing system include a junction having an inlet flow bore. The junction can include an integrated flow junction and valve check assembly having a body including a central portion and one or more side portions. The central portion can be positioned between a pair of manifold sections of the manifold and attached thereto. The one or more side portions extend radially from the central portion and include an inlet bore through which a pressurized fluid is received and supplied to the manifold. One or more check valves is positioned along the inlet bore so as to be integrated within the body of the junction.

A water flosser with a unidirectional sealing device includes a shell and a second check valve. A water storage chamber and a liquid outlet communicated to the water storage chamber are provided inside the shell. The liquid outlet is arranged at a bottom of the water storage chamber. The shell downwards extends along an edge of the liquid outlet to form a first abutment block. A protruding second abutment block is arranged in the shell; the second abutment block is arranged towards the first abutment block. The second check valve is provided with an abutment board. The first abutment block abuts against an upper surface of the abutment board. The second abutment block abuts against a lower surface of the abutment board, to limit the second check valve between the first abutment block and the second abutment block.

The invention discloses a reverse anti-blocking check valve, and relates to the technical field of valve bodies, the reverse anti-blocking check valve comprises a check valve body, and an expansion part is arranged on the surface of a valve plate, facing the fluid direction, of the check valve body; the expansion component comprises a bearing column fixed to the center axis of the surface of the valve plate, and a limiting ring is fixed to the axial top end of the bearing column. The expansion part is arranged on the incident flow side of the valve plate, the dynamic response function in the valve opening and closing process is achieved, when fluid is impacted in the forward direction, the expansion part is unfolded under the fluid pressure effect, the contact arc plate is automatically attached to the inner wall of a pipeline, an auxiliary sealing ring is formed, and the sealing performance is effectively improved; when the fluid pressure is weakened, the expansion component retracts by means of the spring, so that the contact arc plate is separated from the inner wall of the pipeline and generates relative motion, the cleaning effect similar to that of a scraper is achieved, dirt attached to the pipe wall and the surface of a key structure can be effectively peeled off, and the self-cleaning capacity and the anti-blocking effect of the valve are improved.

The invention relates to the technical field of hydrogen storage system testing, and discloses a one-way valve combined hydrogen storage system durability test bench and a test method. A main control computer of the rack is used for configuring test task parameters, coordinating operation of subsystems and processing test data; the high-pressure hydrogen supply subsystem comprises a pressure-adjustable hydrogen source and a pressure closed-loop control module, and can apply accurate and controllable hydrogen pressure to the inlet end of the tested system according to test task parameters; the multi-channel valve state acquisition subsystem acquires the inlet and outlet pressure of the valve, the surface temperature of the valve body and vibration spectrum data in real time through pressure, temperature and vibration sensor arrays arranged at the valves, and transmits the data to the main control computer; the valve action driving subsystem comprises a high-speed electromagnetic actuator array and a displacement feedback module and can drive all valves to execute a preset opening degree sequence and opening and closing frequency. And the durability evaluation subsystem is embedded into the main control computer, calculates the accumulated damage degree of the valve and predicts the residual life cycle.

The invention belongs to the field of hydrogen filling, and relates to an automatic hydrogen filling system for a hydrogenation mother station, which comprises a hydrogen purification device, a plurality of hydrogen compressors, a plurality of filling main pipes, a plurality of branch pipelines, a plurality of emptying pipelines, a plurality of filling hoses and a control system, an outlet of each hydrogen compressor is connected with a compressor outlet pressure gauge and a check valve, each branch pipeline is provided with a branch stop valve, and each emptying pipeline is provided with an emptying adjusting valve. And the control system is in signal connection with the compressor outlet pressure gauge, the branch stop valve, the emptying regulating valve and a long pipe vehicle pressure gauge arranged on the long pipe vehicle, and is used for automatically executing the actions of boosting, depressurizing, filling and stopping filling according to the pressure difference. Compressor pressure, filling header pipe pressure and long pipe vehicle pressure cooperate with one another, full automation and full flow of filling boosting and depressurization are achieved, and the working efficiency is improved.

Disclosed is a hydraulic control system for safe rapid opening or closing of a valve. The hydraulic control system comprises a hydraulic cylinder (71), a pressure oil line (141), an oil return line (151), an oil drain line (161), a quick oil return line (171) and a valve manifold (181), wherein the inside of the valve manifold is provided with a three-position four-way directional control valve (51), a bidirectional hydraulic lock (31), a first two-position four-way directional control valve (61) and an energy accumulator (191); a first cartridge valve (101) is connected between the oil drain line and a rod cavity of the hydraulic cylinder, and a pilot port of the first cartridge valve is connected to a port A of the first two-position four-way valve; an oil inlet of the energy accumulator is connected to each of the pressure oil line and the oil return line, a first check valve (81) is connected between the oil inlet of the energy accumulator and the pressure oil line, and a second cartridge valve (102) is connected between the first check valve and the energy accumulator; and the second cartridge valve is connected to a rodless cavity of the hydraulic cylinder, and a pilot port of the second cartridge valve is connected to the port A of the first two-position four-way directional control valve. The hydraulic control system for safe rapid opening or closing of a valve allows for safe rapid opening or closing of a valve.

The utility model relates to a liquid hydrogen storage tank with a vaporizer. Comprising an inner shell used for containing liquid hydrogen; the pressurizing unit comprises a pressurizing pipeline, and a pressurizing valve, a pressurizer and a pressurizing and pressure regulating valve which are sequentially arranged on the pressurizing pipeline in the medium flowing direction; one end of the pressurizing pipeline is connected with the bottom end of the inner shell, and the other end is communicated with the gas-phase space of the inner shell; the pressurizing unit is used for maintaining the pressure of the inner shell at a first pressure; the air supply unit comprises an air supply pipeline, and an air supply valve, a vaporizer, a pressure reducing valve and a check valve which are sequentially arranged on the air supply pipeline in the medium flowing direction; one end of the gas supply pipeline is connected with the bottom end of the inner shell, and the other end is connected with external gas utilization equipment; the vaporizer is used for converting liquid hydrogen into hydrogen, and the pressure reducing valve is used for reducing the pressure of the gasified hydrogen to the pressure required by gas equipment; and the exhaust unit is communicated with the gas phase space of the inner shell and is used for exhausting the overpressure gas. According to the storage tank, gas supply parameters can be changed according to gas use requirements of users, and the applicability is high.

A check valve assembly can include a housing including an inlet port, an outlet port, and a flow chamber defined by the housing and fluidly coupling the inlet port to the outlet port, an actuation chamber, and a piston assembly movable between a closed position and an open position. The piston assembly can include a poppet positioned in the flow chamber and can be configured to sealingly engage the housing in the closed position to fluidly separate the inlet port from the outlet port, and a flange positioned in the actuation chamber. The flange can contain a sealing member positioned between the flange and the housing to fluidly separate a forward actuation chamber from a rearward actuation chamber. A shaft can extend between the poppet and the flange. A biasing member can be operably coupled to the piston assembly wherein the biasing member biases the poppet assembly closed.

The invention belongs to the technical field of dampers, and particularly provides a shock-absorbing damper for a high-rise building, which comprises supports fixedly mounted on an upper boss and a lower boss, a damper body is hinged between the two supports, a spiral pipe is arranged on the outer side of the damper body, one support is connected with a sleeve, and the other support is connected with a spring. An air outlet one-way valve and an air inlet one-way valve are arranged on the sleeve, the air outlet one-way valve is connected with a pressurizing box through a hose, a conveying pipe is arranged in the pressurizing box, and the conveying pipe is communicated with an inlet of the spiral pipe through a hose. In the reciprocating motion process of the damper body, the sleeve and the inflating piston rod are matched to pressurize the pressurizing box, cooling liquid in the pressurizing box is pressed into the spiral pipe, heat of the damper body is taken away, the temperature of the damper body is kept within a proper range, and the situation that the energy dissipation capacity of the damper body is affected by too high temperature is avoided; the problem that in the prior art, the energy dissipation capacity of a damper is weakened due to high temperature is solved.

A ratcheting setting tool can use wellbore fluid to inflate expandable seals positioned downhole in a wellbore. For example, the ratcheting setting tool can include a piston within a first chamber. The piston can move from a first position to a second position in the first chamber when a pressure is applied to the piston. The ratcheting setting tool can include a first check valve in a second chamber. The first check valve can transmit wellbore fluid from the wellbore into the second chamber. The ratcheting setting tool can include a second check valve. The second check valve can transmit the wellbore fluid in the second chamber into an inflatable valve when the piston moves from the first position to the second position. In some examples, the ratcheting setting tool may be a hydraulic ratchet.

The invention relates to a gas injection device of a foaming injection molding machine, and belongs to the technical field of injection molding machines. The gas injection device comprises a gas source; a pressure reducing valve; an air inlet one-way valve; injecting air cylinders; a gas injection piston; the connecting rod mechanism is used for connecting the gas injection piston and the injection screw rod; the gas injection head is communicated with the gas storage chamber and the injection charging barrel; the gas injection one-way valve is located between the gas injection head and the gas injection cylinder, and gas in the gas storage chamber enters the injection charging barrel in a one-way mode through the gas injection one-way valve; and when the injection screw retreats in a pre-plasticized mode, the gas injection piston is driven by the connecting rod mechanism to slide in the gas injection cylinder, the volume of the gas storage chamber is compressed, after the gas pressure rises to exceed the melt pressure, the gas injection head is opened, and inert gas enters the injection charging barrel through the gas injection head. The gas injection system is simplified, the gas injection flow and pre-plasticizing of the injection screw are synchronously carried out, and the manufacturing cost of equipment is reduced.

The invention discloses a check valve device adopting a dynamic pressure detection and compensation algorithm, and relates to the technical field of automatic control. The device comprises a valve, a pressure sensor group and a control part, the pressure sensor group comprises two pressure sensors which are respectively arranged at the upstream and the downstream of the valve and are used for continuously acquiring instantaneous pressure data; the control part is used for calculating the instantaneous pressure difference inside and outside the valve according to the obtained instantaneous pressure data, and performing nonlinear correction on the reference opening degree by using a correction factor to obtain the final command opening degree; the method comprises the following steps: constructing a kinetic equation of a valve core to represent an actual valve opening constraint under torque-free control; and torque control is conducted according to the deviation between the final command opening degree and the actual valve opening degree. The opening degree can be adjusted in real time to respond to the complex fluid environment, and the dynamic response performance, the energy utilization efficiency and the adaptability to complex working conditions are remarkably improved.

The application relates to the technical field of liquid control check valves, and discloses a plug-in type large-flow liquid control check valve structure with an adjustable pilot ratio, which comprises a pilot valve block and a main valve core, the pilot valve block is provided with a protective cap, one end of the protective cap is provided with a first base, a limiting rod is movably connected in the first base, a guide plunger is in contact connection with one end of the limiting rod, a top rod is in contact connection with the bottom of one end of a rotating lever, a steel ball is in contact connection with the bottom of the top rod, the steel ball is movably connected in the second base, the second base is provided with a third return spring, the pilot valve block and the main valve core are composed of two-stage structures, the pilot valve block adopts a unique mechanical structure, the control pilot ratio of the liquid control check valve is changed by adjusting the limiting rod, the main valve core adopts a two-way plug-in valve, the characteristics of high flow capacity of the two-way plug-in valve are fully utilized, the problem of large flow is solved, and the designed flow of the application can reach 5000 L / min.

The low-resistance range hood check valve comprises a driving ring, a longitudinal guide ring, connecting rods and a valve plate, the longitudinal guide ring is arranged in an inner ring of the driving ring, the valve plate is arranged in the inner ring of the driving ring, a plurality of inclined guide grooves are formed in the positions, corresponding to the connecting rods, of the driving ring, and a plurality of longitudinal guide grooves are formed in the positions, corresponding to the connecting rods, of the longitudinal guide ring. The connecting rod sequentially penetrates through the oblique guide groove and the longitudinal guide groove and is hinged to the valve plate. According to the low-resistance check valve for the range hood, through rotation of the driving ring and matching and limiting of the oblique guide groove and the longitudinal guide groove, the connecting rod moves up and down, the valve plate is dragged to be switched between the opening state and the closing state, and the requirement for conducting or cutting off a pipeline channel is effectively met; the movement trend that the valve plate covers the fixed base due to the dead weight or the torsion spring is avoided, it is effectively guaranteed that no pressure loss is caused to the air pressure of the draught fan in the opening state, and the oil smoke suction and exhaust effect of the range hood is improved.

The invention relates to a plunger pump system, a control method and a filter press. The plunger pump system comprises an oil storage container, an oil pump device, a plunger device and a hydraulic device. The hydraulic device comprises two hydraulic assemblies, each hydraulic assembly comprises an oil cylinder and a piston, the piston divides the oil cylinder into a rod cavity and a rodless cavity, and the rod cavities of the two hydraulic assemblies or the rodless cavities of the two hydraulic assemblies are communicated with each other. The oil pump device and the hydraulic device are connected through an oil supply pipeline, a liquid flow reversing device and a one-way valve are connected to the oil supply pipeline, the flow direction of hydraulic oil in two branch pipelines of the oil supply pipeline is controlled by the liquid flow reversing device to be periodically switched, and the flow directions of the hydraulic oil in the branch pipelines are opposite at the same moment. One end of the electric control overflow device is connected between an oil pump device and a one-way valve, the other end of the electric control overflow device is connected with an oil storage container, and the electric control overflow device is controlled to conduct an oil outlet of the oil pump device and the oil storage container during reversing of the liquid flow reversing device and discharge impact of hydraulic oil reversing on the plunger pump system.

The utility model discloses a rocker arm type quick closing check valve in the technical field of check valves, which comprises a valve body of the check valve, a valve seat is embedded on one side in the valve body, a cavity is arranged on the inner side of the valve body, a valve cover is mounted at the top of the valve body through a plurality of bolt columns, nuts are mounted at the tops of the bolt columns in a threaded manner, and the valve cover is provided with a rocker arm. A check piece used for preventing backflow is installed on the inner side of the valve body, the valve seat is annularly embedded in a cavity of the valve body, the upper surface of the valve deck is in an arc shape, a plurality of bolt columns penetrate through the valve deck, and then nuts are in threaded connection with the bolt columns to install and fix the valve deck. And the non-return piece in the valve body can enable the fluid penetrating through the valve seat to perform anti-backflow non-return operation, so that the anti-backflow efficiency and accuracy are improved.

A chemical canister is configured to be placed in a wellbore. The chemical canister includes the following features. A housing defines a chemical reservoir. A check valve regulates flow between the reservoir and an outside environment.

The invention provides an excavator crushing working condition double-pump flow matching method, device, medium and system. Under the condition that the excavator carries out crushing working condition operation, the pressure difference between the auxiliary pump and the main pump is obtained, and a first pressure difference is obtained; under the condition that the first pressure difference is smaller than a pressure difference threshold value, a current control signal of the auxiliary pump is gradually increased; under the condition that the current control signal of the auxiliary pump is increased every time, the pressure difference between the auxiliary pump and the main pump is obtained again, and a second pressure difference is obtained; and under the condition that the second pressure difference is larger than or equal to the pressure difference threshold value, the current control signal of the auxiliary pump is kept the same as the current control signal of the auxiliary pump at the current moment under the current crushing working condition. The problem that the confluence effect of two hydraulic pumps in an existing scheme is sometimes affected by volume efficiency difference and abrasion failure of the hydraulic pumps under different boundary conditions, so that the flow of an auxiliary pump cannot be converged with a main pump through a confluence one-way valve, and the crushing operation effect is affected is solved.

The invention discloses an integrated electro-hydraulic driving unit of a marine anchor and mooring machine. The integrated electro-hydraulic driving unit comprises an oil supplementing system, a main driving system, a control system, a safety system and a hydraulic motor, an oil supplementing pump in the oil supplementing system is connected with an oil drainage tank and communicated with a pressure oil tank in the main driving system, the pressure oil tank is communicated with a main pump in the main driving system through two third one-way valves, a port A and a port B of the main pump are communicated with a port A and a port B of a hydraulic motor respectively, and one ends of two safety valves in the safety system are connected with the port A and the port B of the main pump respectively. The other ends of the two safety valves are connected in parallel to a pipeline between the oil outlet of the pressure oil tank and the inlets of the two third one-way valves; a controller of the control system is in electric signal connection with the main motor; and an output shaft of the hydraulic motor is connected with an input shaft of the anchor windlass. Therefore, according to the design, the hydraulic pump station, the control valve and the hydraulic motor can be integrated, and the integration degree is high.

The utility model discloses a double-adjustment check valve, which belongs to the technical field of check valves, and comprises a valve body, a check assembly and an adjustment assembly, two ends of the valve body are respectively provided with a water inlet channel and a water outlet channel, a valve hole is arranged in the valve body and between the water inlet channel and the water outlet channel, the top of the valve body is fixedly provided with a valve cover, and the valve cover is fixedly provided with a valve core. The non-return assembly comprises a limiting block installed in the valve deck in a sliding mode, a spring is fixedly connected to the bottom of the limiting block, a valve element is fixedly connected to the lower end of the spring, the adjusting assembly comprises a supporting cylinder fixedly connected to the valve deck, and the inner top wall of the supporting cylinder is in threaded connection with a screw rod. The screw rod is inserted into the limiting block and is in threaded connection with the limiting block; through the arrangement of the adjusting assembly, the initial compression amount of the spring can be controlled, the pressure needed for overcoming the elastic force of the spring can also change, and the opening water pressure corresponding to the check valve can be adjusted so as to adapt to various requirements under different working conditions.

Some embodiments disclosed herein relate to a device for transferring precise amounts of fluid from at least one source container to at least one target container. In some embodiments, the fluid is first transferred from the source container (e.g., a vial) through a connector to an intermediate measuring container (e.g., a syringe). In some embodiments air can pass through an air inlet and enter the vial to compensate for the volume of fluid withdrawn from the vial. An air check valve or a bag or a filter can prevent the fluid from escaping through the air inlet. The precisely measured amount of fluid can then be transferred from the intermediate measuring container to the target container (e.g., an IV bag). In some embodiments the connector can include a source check valve and a target check valve to direct fluid first from the source container to the intermediate measuring container and then from the intermediate measuring container to the target container. Some embodiments of the device can include a motor and a controller for automatically actuating a plunger of the syringe to transfer the desired amount of fluid.

The utility model discloses a semi-automatic backwashing laminated filter. The external structure of the semi-automatic backwashing laminated filter comprises a handle, a filter base body, a water inlet, a water outlet, a laminated shell, a blow-down valve, a blockage indicator, a filter screen flushing valve and the like, the internal structure comprises a flow direction selector, a butterfly check valve, a laminated filter element, a rotational flow centrifugal disc, a laminated compression inner cover, a laminated compression outer cover, a spring between the laminated compression inner cover and the laminated compression outer cover and the like. The channel position of the flow direction selector is switched by rotating the handle, so that the switching between the filtering mode and the backwashing mode is realized. In a filtering mode, muddy water flows into a raw water cavity outside the lamination after being accelerated by the rotational flow centrifugal disc, impurities are intercepted, and clear water flows into a downstream pipeline; and in a backwashing mode, the water flow is sprayed out from the spraying holes in the filter element frame by pressing the position of the lamination for compressing the inner cover and loosening the lamination, so that impurities are eluted from the lamination and discharged through the blow-down valve. In addition, a filter screen is arranged on the flow direction selector to intercept impurities of flushing water, and the filter screen can be flushed in a filtering mode. The utility model has the advantages of convenient use and simple structure.

The invention relates to the technical field of pipeline filters, in particular to a self-cleaning filter and a check valve, the self-cleaning filter comprises a pipe body and an annular filter screen, a bottom plate is coaxially fixed at one end of the annular filter screen, a water guide column is arranged on one side of the bottom plate, one end of the annular filter screen is fixedly connected with the inner wall of the pipe body through a fixing ring, and a central column is coaxially arranged at the water inlet end of the pipe body; a spiral flow channel is arranged between the central column and the inner wall of the pipe body, a slag discharging opening and a slag discharging pipe are arranged on the bottom plate, one end of the slag discharging pipe is communicated with the slag discharging opening, the other end of the slag discharging pipe penetrates through the pipe body and then is located outside the pipe body, and a cleaning mechanism is further arranged in the pipe body. Through cooperation of the spiral flow channel, the water guide column, the annular filter screen and the cleaning mechanism, the automatic cleaning of the annular filter screen is synchronously realized in the fluid filtering process, so that the filtering effect of the annular filter screen is ensured.

The invention relates to the technical field of valves, in particular to a duplex check valve. Comprising a valve body, a circulation opening formed in the valve body, a valve seat arranged on the valve body and located in the circulation opening, a first through hole formed in the valve seat, a sealing valve clack arranged in the valve body in a lifting mode, a guiding piece arranged between the valve seat and the sealing valve clack, and a compression spring arranged between the guiding piece and the sealing valve clack. The auxiliary sleeve is arranged on the valve body and located at the circulation opening, the second through hole is formed in the valve body, the auxiliary valve clack is arranged on the valve body in a lifting mode and located in the circulation opening, the lower end of the auxiliary guide rod is fixedly arranged on the sealing valve clack, the linkage shaft is arranged at the lower end of the sealing valve clack and located in the auxiliary sleeve, and the lower end of the linkage shaft makes contact with the upper end of the auxiliary guide rod. Through the design of the double valve clacks, the double-sealing effect is achieved, the reliability and the sealing performance of the check valve are improved, the linkage shaft structure ensures that the main valve clack and the auxiliary valve clack move synchronously, and response is rapid.

An inflatable cushion that is orally inflatable using exhaled air. The inflatable cushion also can be inflated by breathing into an inflation chamber portion of the cushion and then squeezing the inflation chamber (e.g., with a user's hands and fingers), thereby increasing the pressure, to push additional air into the passages and channels to fill the seat cushion. A separate deflation chamber of the seat cushion can have a tubular check valve designed to be squeezed that opens the valve to deflate. The deflation chamber can be used to adjust the comfort of the inflatable cushion or to empty the inflatable cushion after use. The inflatable cushion can be made of thin plastic or similar material that is lightweight and can be folded, creating a structure that can be used several times before disposal.