A speed controller capable of controlling an action speed of an external cylinder in one stroke in a step-wise manner. The speed controller includes a first flow path and a second flow path that allow a first port and a second port to be in communication with each other. The first flow path is provided with a first check valve for allowing flow from the first port to the second port. The second flow path is provided with a first needle valve, and an opening hole of the first check valve is constituted as a part of a flow path. The first needle valve adjusts the flow rate by changing an opening area of the opening hole with a tip portion fixed on a piston in the cylinder chamber. The speed controller further includes a third flow path allowing the first port and the cylinder chamber to be in communication with each other. The third flow path is provided with a second check valve for allowing flow from the first port to the cylinder chamber.

A valve assembly includes a housing having an inlet and an outlet spaced from each other, a first chamber defining the inlet, a second chamber defining the outlet, and a valve seat disposed between the first and second chambers, wherein fluid communicates between the first and second chambers. A valve head is disposed in the housing and moveable relative to the housing between an open position spaced from the valve seat and a closed position engaged with the valve seat. A valve stem is coupled to the valve head for moving the valve head between the open and closed positions. The valve stem is coupled to the valve head and rotatably and reciprocally movable for moving the valve head between the open and closed positions. A retainer plate is coupled to the valve head and a valve seal is disposed between the valve head and the retainer plate. The valve head includes an integrally formed rivet that secures the retainer plate to the valve head, thereby retaining the valve seal to the valve head.

A speed controller capable of controlling an action speed of an external cylinder in one stroke in a step-wise manner. The speed controller includes a first flow path and a second flow path that allow a first port and a second port to be in communication with each other. The first flow path is provided with a first check valve for allowing flow from the first port to the second port. The second flow path is provided with a first needle valve, and an opening hole of the first check valve is constituted as a part of a flow path. The first needle valve adjusts the flow rate by changing an opening area of the opening hole with a tip portion fixed on a piston in the cylinder chamber. The speed controller further includes a third flow path allowing the first port and the cylinder chamber to be in communication with each other. The third flow path is provided with a second check valve for allowing flow from the first port to the cylinder chamber.

A valve assembly comprises a housing having a first chamber, a second chamber, and a valve seat disposed between the first and second chambers. A valve head is disposed in the housing and is moveable relative to the housing between an open position spaced from the valve seat and a closed position engaged with the valve seat. The valve head defines a bore therethrough along an axis. A valve stem is coupled to the valve head for moving the valve head between the open and closed positions. The valve stem is disposed in the bore and is moveable relative to the valve head from a sealed position preventing fluid communication through the bore to an unsealed position allowing fluid communication through the bore for relieving pressure differences between the first chamber and the second chamber when the valve head is in the closed position. An intermediate member is separate from and coupled to the valve seat and the valve head in the bore. The intermediate member is axially fixed to one of the valve stem and the valve head. The other of the valve stem and the valve head defines a travel space with the intermediate member retained in the travel space between the valve stem and the valve head. The travel space is sized larger than the intermediate member along the axis for allowing selective movement of the valve stem relative to the valve head between the sealed and unsealed positions.

A valve assembly includes a housing having a first chamber, a second chamber, and a valve seat disposed therebetween. A valve head disposed in the housing and is moveable between an open position and a closed position. The valve head defines a bore extending along an axis from the first chamber to the second chamber when the valve head is in the closed position. A valve stem is disposed in the bore and is coupled to the valve head in the bore for moving the valve head between the open and closed positions. The valve assembly allows for selective fluid communication between the first and second chambers to alleviate pressure differences between the first and second chambers. In one embodiment, the valve stem moves in the bore between a sealed position and an unsealed position. In another embodiment, a check valve is disposed in the bore.