| 摘要 |
A gas spring comprises a cylinder (1) which is closed at one end and within which a piston (2) works, the piston being carried by a piston rod (3) extending sealingly through the other end of the cylinder. The cylinder contains gas and liquid and the piston has passageways (12, 13) which permit the passage of liquid from one side to another of the piston. To overcome the problem of known gas springs in which the passageways restrict flow in both directions and in which substantial effort may be required to overcome the resistance of liquid passing through the passageways when compressing the spring, which is disadvantageous for example when the spring is supporting a vehicle tailgate, a restrictor plate (9) is provided which co-operates with the passageways (12, 13) and is arranged to restrict the flow of liquid through the piston (2) during an extension stroke of the spring and to permit substantially unrestricted flow during a compression or retraction stroke. <IMAGE> |
