Gas springs

Claim 2

A gas spring comprising a cylinder body having one end closed, a piston rod reciprocable into and out of the cylinder body through the other end thereof between a retracted and an extended position of said spring, gas under pressure in said cylinder body operating at all times against the cross sectional area of said rod to urge it towards the extended position of said spring, and mechanical latching means operative in said extended position to prevent substantial relative movement between said piston rod and said cylinder body, said latching means being manually releasable to permit such relative movement.

Claim 3

A gas spring according to claim 1, wherein said latching means, comprises a gEnerally tubular member carried by said piston rod and telescopically co-operable with said cylinder body, said tubular member being axially separated from said cylinder body in the extended position, and releasable means preventing telescoping of said tubular member and said cylinder body.

Claim 4

A gas spring according to claim 2, wherein said releasable means comprises at least one inherently resilient arm having a portion which extends laterally between said tubular member and said cylinder body in said extended position, said arm being manually movable against said inherent resilience to permit telescoping of said cylinder body and said tubular member.

Claim 5

A gas spring according to claim 3, wherein said releasable means is mounted on said cylinder body, and wherein said tubular member is movable telescopically over both said releasable means and said cylinder body to said retracted position upon release of said latching means.

Claim 6

A gas spring according to claim 3, wherein said tubular member is normally axially spaced from the or each said laterally extending portion in said extended position.

Claim 7

A gas spring for lifting and supporting a hinged tailgate part of a vehicle relative to a vehicle body part, said gas spring comprising a cylinder body for connection to one of said parts, a piston rod for connection to the other of said parts, gas under pressure in said cylinder body operating at all times against the cross sectional area of said rod to urge it towards the extended position of said spring, said piston rod being reciprocable into and out of said cylinder between a fully retracted position in which the tailgate is fully open, and mechanically latching means which prevents substantial movements of said piston rod into said cylinder from said fully extended position in the event of failure of gas pressure in said spring, wherein said latching means includes means providing an indication of such failure.

Claim 8

A gas spring for lifting and supporting a hinged tailgate part of a vehicle relative to a vehicle body part, said gas spring comprising a cylinder body for connection to one of said parts, a piston rod for connection to the other of said parts, gas under pressure in said cylinder body operating at all times against the cross sectional area of said rod to urge it towards the extended position of said spring, said piston rod being reciprocable into and out of said cylinder between a fully retracted position in which the tailgate is fully open, and mechanically latching means which prevents substantial movements of said piston rod into said cylinder from said fully extended position in the event of failure of gas pressure in said spring, wherein said latching means includes means providing an indication of such failure.

Claim 9

A gas spring in accordance with claim 5 including visual gas pressure failure indicating means provided by the elimination of said normal axial spacing due to the sinking of said tubular member into engagement with said laterally extending portion upon failure of the gas pressure in said spring.