A piston of an air compressor contains at least one fixing bolt configured to fix a plane of a top of a head of the piston in at least one air stop sheet. A respective one of the at least one air stop sheet includes at least one bending section and at least one acting zone opposite to the at least one bending section and configured to cover at least one air orifice, and a back surface of the at least one acting zone of the respective one air stop sheet turns on relative to the plane of the top of the head at an open angle θ, thus producing an air flowing space. A pressure of a cylinder balances with atmosphere, and the piston is not stopped by a back-pressure resistance to move smoothly in upward and downward moving strokes after the air stop sheet moves again.

An air stop sheet of a piston of a cylinder, the piston is accommodated in an air compressor, and an air stop sheet is accommodated on a head of the piston. The air stop sheet includes a bending section having a positioning zone and an acting zone and configured to be a boundary line of the acting zone and the positioning zone. The acting zone backing the cylinder turns on relative to the plane of the head at an open angle θ, thus producing an air flowing space. A piston rod extends downward from the head and includes a cavity, an air conduit, a column, and a spring configured to abut against the acting zone of the air stop sheet. The air stop sheet is pushed by the spring to turn on at an open angle θ, and the air conduit and the air channel communicate with atmosphere.

An air stop sheet of a piston of a cylinder, the piston is accommodated in a compressor, and an air stop sheet is accommodated on a head of the piston. The air stop sheet includes a bending section having a positioning zone and an acting zone. The bending section is a boundary line of the acting zone and the positioning zone so that a positive surface of the air stop sheet forms an obtuse angle less than 180 degrees, and a back surface of the acting zone of the air stop sheet backing the top of the cylinder turns on relative to the plane of the top of the head at an open angle θ, thus producing an air flowing space. A piston rod extends downward from the head and includes an air conduit communicating with the air channel.

A piston of an air compressor is actuated by a motor to move in a cylinder. The piston includes a head, an air stop sheet having a first bending section which is a boundary line of an acting area and a positioning zone of the air stop sheet, and a back surface of the acting zone backing the top of the cylinder turns on relative to a plane of a top of the head at an open angle θ1. The acting zone has a noncircular spacing groove, a neck, and a second bending section. The head includes a piston rod having a cavity, an air conduit, a column, and a spring. The air stop sheet is forced by the spring to locate in the acting zone backing the cylinder and a plane of a top of the head at an open angle θ1.

An air compressor contains a piston actuated by a motor to move in a cylinder. The piston includes an air stop sheet mounted on a top support plate thereof. The air stop sheet includes a bending section having a positioning zone and an acting zone located opposite to the positioning zone and configured to cover an air channel of the piston. The bending section is a boundary axis of the acting area and the positioning zone of the air stop sheet so that a top of the air stop sheet facing the cylinder forms an obtuse angle less than 180 degrees, and a back surface of the acting zone of the air stop sheet backing a top of the cylinder turns on relative to a plane of a top of the top support plate at an open angle θ, thus producing an air flowing space.

A piston of an air compressor, the air compressor including the piston actuated by a motor to move upward and downward in a cylinder. The piston contains a head accommodating an air stop sheet which has a first bending section being a boundary line of an acting area and a positioning zone of the air stop sheet. The acting zone has a noncircular spacing groove configured to separate an external portion and a circular portion, a neck, and a second bending section, such that an axial line between the circular portion and the external portion is the second bending section at an obtuse angle less than 180 degrees, and the second bending section is defined between a bottom of the circular portion and a top of the external portion at an acute angle θ2.

An example pressure-driven metered mixing dispensing pump includes a housing, a fluid inlet, a piston disposed in the housing at least partially defining first, second and third chambers, the first and second chambers each in fluid communication with the third chamber, the piston to, in response to first fluid entering the first chamber via the fluid inlet, move in a first direction to decrease the volume of the second chamber thereby ejecting second fluid from the second chamber into the third chamber, a spring to move the piston in a second direction to decrease the volume of the first chamber thereby ejecting at least some of the first fluid from the first chamber into the third chamber thereby mixing the at least some of the first fluid and the second fluid to form a mixture, and an outlet to discharge the mixture from the third chamber.

A vehicle-mounted electric oil-free air compressor, including a motor, a box body, a piston, and a flywheel shaft. The motor is fixed on the box body, a cylinder cover is at the top of the box body, a main shaft of the motor includes a coupling driving end, the flywheel shaft is driven by an elastic body to rotate. The piston includes a primary intake valve piece and a primary exhaust valve piece, the box body is provided with a secondary cavity, a secondary exhaust valve piece is provided at a vent hole on one side of the cavity, and the primary exhaust valve piece is also a secondary intake valve piece of the compressor, increasing the exhaust pressure. When the piston reciprocates, the stress is balanced and the vibration is small, and with the assistance of a high-efficiency flywheel, the operation of the air compressor is stable.

A foam pump has dual, coaxial air and liquid cylinders, each having a respective air and liquid piston which move together during a dispensing operation. One or more air passageways between the air cylinder and a liquid-air mixing chamber are configured to impart rotation to an airstream passing from the air cylinder to the mixing chamber to increase turbulent mixing of the air and liquid in the mixing chamber. The liquid cylinder is axially aligned with the air cylinder to provide a low profile pump which does not require a dip tube or sleeve to communicate with the bottom of the liquid source when used in an inverted application wherein the foam pump is positioned below the source of liquid. A resilient valve member in the liquid outlet is biased to close on its own to prevent leaking in the event the air and liquid pistons do not fully return to the home position.

A cylinder piston for an air compressor, in particular for a two-stage air compressor, has at least two channel openings integrated in the piston surface of the cylinder piston, which are designed as an inlet valve and/or as an outlet valve for air in a compression chamber of the cylinder. A coherent, one-piece and flexible bending sealing element is provided inside or covering the channel openings. The sealing element for the at least two or a plurality of channel openings enables an inflow into a channel opening or outflow from a channel opening, wherein the at least two channel openings through the flexible bending sealing element can be designed independently of one another as an inlet valve or as an outlet valve. Also provided is a cylinder with at least one cylinder piston and an air compressor with such a cylinder.