Fluid type accumulator spring with emergency back-up spring

Claim 2

A spring system comprising a combination of a main spring and an associated back-up spring: said main spring having first and second spaced apart sections, which said sections are movable toward one another; said main spring including elastically operating means for biasing said first and second sections apart; said back-up spring having a stressing surface; said back-up spring being normally prestressed; means for normally prestressing said back-up spring; said back-up spring stressing surface being normally spaced a first distance from said main spring first section; said backup spring stressing surface and said main spring first section being shiftable toward one another upon application of forces to either of them and said main spring first section and said back-up spring stressing surface being so positioned that after movement of said main spring first section over said first distance relative to said stressing surface, said main spring first section engages said stressing surface, and further movement of said first main spring section in the same direction further stresses the prestressed said back-up spring.

Claim 3

The spring system of claim 1, wherein said stressing surface of said back-up spring further comprises a lateral sliding surface to cooperate with said main spring first section to enable relative lateral sliding when said main spring first section and said back-up spring stressing surface are engaged.

Claim 4

The spring system of claim 1, wherein said back-up spring is interposed between said first and said second sections of said main spring.

Claim 5

The spring system of claim 1, wherein said main spring is a fluid accumulator and the fluid is located between said spaced apart first and second sections; means for maintaining said accumulator normally pressurized and for regulating its pressure.

Claim 6

The spring system of claim 4, wherein said first and said second sections of said main spring respectively comprise a first and a second surface which cooperate in defining said fluid filled accumulator.

Claim 7

The spring system of claim 4, wherein said accumulator is a gas accumulator.

Claim 8

The spring system of claim 6, wherein said back-up spring is located inside said accumulator and is interposed between said first and said second sections of said main spring.

Claim 9

The spring system of claim 6, wherein said back-up spring is a spring formed of solid, resilient material.

Claim 10

The spring system of claim 8, wherein said back-up spring is comprised of a block of resilient material and its said stressing surface is at one end of said block.

Claim 11

A spring system of claim 4, wherein said back-up spring is comprised of a solid block of resilient material and its said stressing surface is at one end of said block.

Claim 12

A spring system of claim 4, wherein said back-up spring is located inside said accumulator and is interposed between said first and said second sections of said main spring.

Claim 13

The spring system of claim 11, wherein said accumulator is annular in shape, said back-up spring is annular in shape, and said accumulator and said back-up spring are coaxial.

Claim 14

The spring system of claim 12, wherein said first and said second sections of said main spring respectively comprise a first and a second surface which cooperate in defining said fluid filled accumulator.

Claim 15

The spring system of claim 13, wherein said stressing surface of said back-up spring further comprises a lateral sliding surface to cooperate with said main spring first surface to enable relative lateral sliding when said main spring first surface and said back-up spring stressing surface are engaged.

Claim 16

In combination, the spring system of claim 13 and means for pressing said spaced apart first and second surfaces toward one another; said means for maintaining and regulating pressUre normally maintaining pressure in said accumulator at a level to maintain said first main spring surface and said back-up spring stressing surface apart and permitting those elements to engage upon failure of pressure in said accumulator.

Claim 17

In combination, the spring system of claim 4 and means for pressing said spaced apart first and second sections toward one another; said means for maintaining and regulating pressure normally maintaining pressure in said accumulator at a level to maintain said first main spring section and said back-up spring stressing surface apart and permitting those elements to engage upon failure of pressure in said accumulator.

Claim 18

A parallel spring system, comprising a combination of a main spring and an associated back-up spring: a main spring; a main spring support surface on which said main spring is supported; spaced from said main spring support surface are engaging means for engaging an object to be supported by said parallel spring system; said main spring extending between and normally holding apart said main spring support surface and said engaging means; said engaging means being movable toward and away from said main spring support surface thereby alternately tensioning and relaxing said main spring; a back-up spring in parallel with said main spring; a back-up spring support surface positioned such that said main spring engaging means is movable toward and away from said back-up spring support surface; said back-up spring sitting upon said back-up spring support surface; said back-up spring having a stressing surface at the opposite end thereof from said back-up spring support surface, such that application of force to said back-up spring stressing surface stresses said back-up spring and moves its said stressing surface towards said back-up spring support surface; said back-up spring stressing surface being normally spaced a preselected distance from said main spring engaging means, such that normal shifting of said engaging means, which results in tensioning and relaxing of said main spring, still leaves said main spring engaging means and said back-up spring stressing surface separated and also applies no stress to said back-up spring, but upon failure of said main spring to hold said main spring engaging means and said back-up spring stressing surface apart, said main spring engaging means presses upon said back-up spring stressing surface and stresses said back-up spring.

Claim 19

A parallel spring system, comprising a combination of a main spring and an associated back-up spring: a main spring; a main spring support surface on which said main spring is supported; spaced from said main spring support surface are engaging means for engaging an object to be supported by said parallel spring system; said main spring extending between and normally holding apart said main spring support surface and said engaging means; said engaging means being movable toward and away from said main spring support surface thereby alternately tensioning and relaxing said main spring; a back-up spring in parallel with said main spring; a back-up spring support surface positioned such that said main spring engaging means is movable toward and away from said back-up spring support surface; said back-up spring sitting upon said back-up spring support surface; said back-up spring having a stressing surface at the opposite end thereof from said back-up spring support surface, such that application of force to said back-up spring stressing surface stresses said back-up spring and moves its said stressing surface towards said back-up spring support surface; said back-up spring stressing surface being normally spaced a preselected distance from said main spring engaging means, such that normal shifting of said engaging means, which results in tensioning and relaxing of said main spring, still leaves said main spring engaging means and said back-up spring stressing surface separated and also applies no stress to said back-up spring, but upon failure of said main spring to hold said main spring engaging means and said back-up spring stressing surface apart, said main spring engaging means presses upon said back-up spring stressing surface and stresses said back-up spring.

Claim 20

The parallel spring system of claim 17, wherein said main spring is a fluid accumulator and the fluid is located between said main spring engaging means and said main spring support surface; means for maintaining said accumulator normally pressurized and for regulating its pressure.

Claim 21

The parallel spring system of claim 18, wherein said accumulato is a gas accumulator.

Claim 22

The parallel spring system of claim 19, wherein said back-up spring is located inside said accumulator and is thereby positioned between said main spring engaging means and said main spring support surface.

Claim 23

The parallel spring system of claim 19, wherein said back-up spring is a spring formed of solid, resilient material.

Claim 24

The parallel spring system of claim 18, wherein said back-up spring is located inside said accumulator and is thereby positioned between said main spring engaging means and said main spring support surface; said accumulator being annular in shape, said back-up spring being annular in shape, and said accumulator and said back-up spring being coaxial.

Claim 25

The parallel spring system of claim 17, wherein said back-up spring is normally pre-stressed; means for normally pre-stressing said back-up spring.

Claim 26

The parallel spring system of claim 23, wherein said stressing surface of said back-up spring further comprises a lateral sliding surface to cooperate with said main spring engaging means, to enable relative lateral sliding when said main spring engaging means and said back-up spring stressing surface are engaGed.