Pneumatic spring devices

Claim 2

A pneumatic spring device including at least one cylinder assembly with opposed ends, a piston assembly movably mounted in the or each cylinder assembly, at least one variable-volume compartment defined by the cylinder assembly and the piston assembly, a rod in the piston assembly extending out of at least one of said opposed ends of the cylinder assembly, attachment means provided on the rod for attaching the rod to a device which is to be actuated by the pneumatic spring device, at least one seal located between the cylinder assembly and the piston assembly, and a gas filling said compartment, said gas, under normal conditions of temperature and pressure, having a density less than that of nitrogen, and being under high pressure.

Claim 3

A pneumatic spring device according to claim 1, in which the gas is helium.

Claim 4

A pneumatic spring device according to claim 1, in which the gas is compressed between 300 and 1000 bars.

Claim 5

A pneumatic spring device according to claim 1, including an hydraulic jack arrangement connected with the piston assembly, the cylinder assembly being common to both the piston assembly and the hydraulic jack arrangement.

Claim 6

A pneumatic spring device according to claim 1, in which the rod extends out of both of said opposed ends of the cylinder assembly.

Claim 7

A pneumatic spring device according to claim 1, in which the or each seal is in the form of a spring packing.

Claim 8

A pneumatic spring device including at least one cylinder assembly with opposed ends, a piston assembly movably mounted in the or each cylinder assembly, at least one variable-volume compartment defined by the cylinder assembly and the piston assembly, a rod in the piston assembly extending out of at least one of said opposed ends of the cylinder assembly, attachment means provided on the rod for attaching the rod to a device which is to be actuated by the pneumatic spring device, at least one seal located between the cylinder assembly and the piston assembly, and a gas filling said compartment, said gas, under normal conditions of temperature and pressure, having a density less than that of nitrogen, and being under high pressure, the piston assembly comprising a first piston integral with said rod, a first variable-volume compartment defined by said first piston at one of said opposed ends of the cylinder assembly, a second piston connected with said rod, a second compartment defined by said second piston at the other of said opposed ends of the cylinder assembly, one of said first and second compartMents being filled with said gas at high pressure, and aperture means in said apparatus defining an inlet communicating with the other compartment for the entry of hydraulic fluid under pressure to said other compartment.

Claim 9

A pneumatic spring device including at least one cylinder assembly with opposed ends, a piston assembly movably mounted in the or each cylinder assembly, at least one variable-volume compartment defined by the cylinder assembly and the piston assembly, a rod in the piston assembly extending out of at least one of said opposed ends of the cylinder assembly, attachment means provided on the rod for attaching the rod to a device which is to be actuated by the pneumatic spring device, at least one seal located between the cylinder assembly and the piston assembly, and a gas filling said compartment, said gas, under normal conditions of temperature and pressure, having a density less than that of nitrogen, and being under high pressure, the piston assembly comprising a first piston integral with said rod, a first variable-volume compartment defined by said first piston at one of said opposed ends of the cylinder assembly, a second piston connected with said rod, a second compartment defined by said second piston at the other of said opposed ends of the cylinder assembly, one of said first and second compartMents being filled with said gas at high pressure, and aperture means in said apparatus defining an inlet communicating with the other compartment for the entry of hydraulic fluid under pressure to said other compartment.

Claim 10

A pneumatic spring device according to claim 7, including an element interposed between said first and second pistons to space them apart, said element being of a length at least equal to the length of travel of the pistons, an intermediate compartment defined between said first and second pistons, and orifice means in the cylinder assembly defining a passage extending between said intermediate compartment and the atmosphere.

Claim 11

A pneumatic spring device according to claim 7, in which the rod has opposed ends, and the first and second pistons are adjacent one another at one of said opposed ends of the rod, recess means define an intermediate compartment between the first and second pistons, and an axial bore in the rod forms a channel communicating between said intermediate compartment and the atmosphere.

Claim 12

A pneumatic spring device according to claim 7, in which the gas is helium.

Claim 13

A pneumatic spring device according to claim 7 in which the gas is compressed between 300 and 1000 bars.

Claim 14

A pneumatic spring device according to claim 7, in which the or each seal is in the form of a spring packing.

Claim 15

A pneumatic spring device according to claim 7, in which the rod extends out of both of said opposed ends of the cylinder assembly.

Claim 16

A control installation for an electric circuit breaker, comprising at least one pneumatic spring device including at least one cylinder assembly with opposed ends, a piston assembly movably mounted in the or each cylinder assembly, at least one variable-volume compartment defined by the cylinder assembly and the piston assembly, a rod in the piston assembly extending out of at least one of said opposed ends of the cylinder assembly, attachment means provided on the rod for attaching the rod to a device which is to be actuated by the pneumatic spring device, at least one seal located between the cylinder assembly and the piston assembly, and a gas filling said compartment, said gas, under normal conditions of temperature and pressure, having a density less than that of nitrogen, and being under high pressure.

Claim 17

A control installation for an electric circuit breaker, comprising at least one pneumatic spring device including at least one cylinder assembly with opposed ends, a piston assembly movably mounted in the or each cylinder assembly, at least one variable-volume compartment defined by the cylinder assembly and the piston assembly, a rod in the piston assembly extending out of at least one of said opposed ends of the cylinder assembly, attachment means provided on the rod for attaching the rod to a device which is to be actuated by the pneumatic spring device, at least one seal located between the cylinder assembly and the piston assembly, and a gas filling said compartment, said gas, under normal conditions of temperature and pressure, having a density less than that of nitrogen, and being under high pressure.

Claim 18

A control installation for an electric circuit breaker, comprising at least one pneumatic spring device, at least one cylinder assembly with opposed ends, a piston assembly movably mounted in the or each cylinder assembly, at least one variable-volume compartment defined by the cylinder assembly and the piston assembly, a rod in the piston assembly extending out of at least one of said opposed ends of the cylinder assembly, attachment means provided on the rod for attaching the rod to a device which is to be actuated by the pneumatic spring device, at least one seal located between the cylinder assembly and the piston assembly and a gas filling said compartment said gas, under normal conditions of temperature and pressure, having a density less than that of nitrogen, and being under high pressure, the piston assembly comprising a first piston integral with said rod, a first variable-volume compartment defined by said first piston at one of said opposed ends of the cylinder assembly, a second piston connected with said rod, a second compartment defined by said second piston at the other of said opposed ends of the cylinder assembly, one of said first and second compartments being filled with said gas at high pressure, and aperture means in said apparatus defining an inlet communicating with the other compartment for the entry of hydraulic fluid under pressure to said other compartment, and the circuit breaker has a movable contact with which said rod is mechanically connected.

Claim 19

A control installation for an electric circuit breaker, comprising at least one pneumatic spring device, at least one cylinder assembly with opposed ends, a piston assembly movably mounted in the or each cylinder assembly, at least one variable-volume compartment defined by the cylinder assembly and the piston assembly, a rod in the piston assembly extending out of at least one of said opposed ends of the cylinder assembly, attachment means provided on the rod for attaching the rod to a device which is to be actuated by the pneumatic spring device, at least one seal located between the cylinder assembly and the piston assembly and a gas filling said compartment said gas, under normal conditions of temperature and pressure, having a density less than that of nitrogen, and being under high pressure, the piston assembly comprising a first piston integral with said rod, a first variable-volume compartment defined by said first piston at one of said opposed ends of the cylinder assembly, a second piston connected with said rod, a second compartment defined by said second piston at the other of said opposed ends of the cylinder assembly, one of said first and second compartments being filled with said gas at high pressure, and aperture means in said apparatus defining an inlet communicating with the other compartment for the entry of hydraulic fluid under pressure to said other compartment, and the circuit breaker has a movable contact with which said rod is mechanically connected.

Claim 20

A control installation for an electric circuit breaker according to claim 14, which includes a cylinder-piston arrangement and a dielectric gas provided therein, the circuit breaker having fixed cOntacts, and the piston of said cylinder-piston arrangement being mechanically connected to said rod of the piston assembly, such that, at the moment the movable contact is released from said fixed contacts, said dielectric gas is blown between the contacts.