Piston type accumulator

Claim 2

An accumulator comprising a cylinder closed at both ends and having an inner cylindrical surface, a main piston slidable in the cylinder in sealed engagement with said surface, said main piston having a bore forming a piston chamber open at each end to the interior of the cylinder, an axially extending cylindrical member mounted in the main piston, and an auxiliary piston slidably mounted on the member and in sealed engagement at its outer periphery with said bore.

Claim 3

The accumulator of claim 1 in which the main piston has axially spaced bearing portions engageable with said surface and said auxiliary piston has axially spaced bearing portions engageable with said member, the axial spacing of the main piston bearing portions being greater than that of the auxiliary piston.

Claim 4

The accumulator of claim 1 in which the auxiliary piston is sealed relative to said member.

Claim 5

The accumulator of claim 1 in which said member carries a stop means at one end for limiting travel of said auxiliary piston within said main piston.

Claim 6

The accumulator of claim 1 in which there is a means for limiting the travel of the auxiliary piston in the main piston in each direction.

Claim 7

The accumulator of claim 1 in which said main piston has a transverse portion at one end thereof upon which said member is mounted, and said transverse portion provides a stop for travel of the auxiliary piston in one direction.

Claim 8

The accumulator of claim 1 in which the auxiliary piston has a small radial clearance with said member and in which the auxiliary piston carries sealing means at its outer periphery for making sealing contact with said bore, and said periphery otherwise has a radial clearance with said bore that is greater than said small radial clearance.

Claim 9

The accumulator of claim 1 in which said auxiliary piston has a peripheral portion having a close radial clearance with said bore and has a central opening that receives said member with a close radial clearance, said central opening being of greater axial length than said peripheral portion.

Claim 10

An accumulator comprising a cylinder closed at both ends, an elongated main piston slidable in the cylinder in sealed engagement therewith, said main piston having an elongated piston chamber having substantially unrestricted communication at each end with the interior of the cylinder, an auxiliary piston mounted for slidable axial movement in said piston chamber between opposite ends of said chamber and in sealed engagement with said main piston whereby said pistons cooperate for dividing the cylinder into a chamber for gas and a single chamber for liquid.

Claim 11

An accumulator comprising a cylinder closed at both ends, an elongated main piston slidable in the cylinder in sealed engagement therewith, said main piston having an elongated piston chamber having substantially unrestricted communication at each end with the interior of the cylinder, an auxiliary piston mounted for slidable axial movement in said piston chamber between opposite ends of said chamber and in sealed engagement with said main piston whereby said pistons cooperate for dividing the cylinder into a chamber for gas and a single chamber for liquid.

Claim 12

An accumulator comprising a cylinder closed at its ends, an elongated main piSton in said cylinder having axially spaced bearing surfaces in sliding contact with said cylinder, means sealing said main piston relative to said cylinder, said main piston having an elongated inner cylindrical surface, an auxiliary piston within said main piston and in free floating sealed sliding engagement with said inner cylindrical surface and of shorter axial length than said main piston for movement from one end of said cylindrical surface to the other end, said pistons cooperating to divide the cylinder into two chambers, one on each side of said pistons with each chamber being in substantially unrestricted communication with an adjacent side of the auxiliary piston, and means at each end of said main piston for retaining said auxiliary piston within said main piston.

Claim 13

An accumulator comprising a cylinder closed at its ends, an elongated main piSton in said cylinder having axially spaced bearing surfaces in sliding contact with said cylinder, means sealing said main piston relative to said cylinder, said main piston having an elongated inner cylindrical surface, an auxiliary piston within said main piston and in free floating sealed sliding engagement with said inner cylindrical surface and of shorter axial length than said main piston for movement from one end of said cylindrical surface to the other end, said pistons cooperating to divide the cylinder into two chambers, one on each side of said pistons with each chamber being in substantially unrestricted communication with an adjacent side of the auxiliary piston, and means at each end of said main piston for retaining said auxiliary piston within said main piston.

Claim 14

An accumulator comprising a cylinder closed at its ends, an elongated main piston in said cylinder having axially spaced bearing surfaces in sliding contact with said cylinder, means sealing said main piston relative to said cylinder, said main piston having an elongated inner cylindrical surface, an auxiliary piston within said main piston and in sealed sliding engagement with said inner cylindrical surface and of shorter axial length than said main piston for movement from one end of said cylindrical surface to the other end, said pistons cooperating to divide the cylinder into two chambers, one on each side of said pistons with each chamber being in communication with an adjacent side of the auxiliary piston, means at each end of said piston for retaining said auxiliary piston within said main piston, one of said chambers being for liquid and the other for gas, and said main piston has a transverse support member at the end of the main piston that is adjacent the chamber for liquid, said support member carrying an axially extending member, and said auxiliary piston having an opening therethrough that receives said axially extending member and is in sealed sliding engagement therewith.

Claim 15

An accumulator comprising a cylinder closed at its ends, an elongated main piston in said cylinder having axially spaced bearing surfaces in sliding contact with said cylinder, means sealing said main piston relative to said cylinder, said main piston having an elongated inner cylindrical surface, an auxiliary piston within said main piston and in sealed sliding engagement with said inner cylindrical surface and of shorter axial length than said main piston for movement from one end of said cylindrical surface to the other end, said pistons cooperating to divide the cylinder into two chambers, one on each side of said pistons with each chamber being in communication with an adjacent side of the auxiliary piston, means at each end of said piston for retaining said auxiliary piston within said main piston, one of said chambers being for liquid and the other for gas, and said main piston has a transverse support member at the end of the main piston that is adjacent the chamber for liquid, said support member carrying an axially extending member, and said auxiliary piston having an opening therethrough that receives said axially extending member and is in sealed sliding engagement therewith.