Fluid cylinder

Claim 2

A fluid cylinder comprising a first tubular member, a piston mounted for reciprocal movement within said first tubular member to divide the interior thereof into a first chamber and a second chamber, a rod member having one end connected to said piston for movement therewith and an opposite end extending exteriorly of said second chamber, a second tubular member telescopically received by said first tubular member and spaced therefrom to define a third chamber, said second tubular member being so connected to said piston to produce relative movement of said first and second tubular members resulting in said third chamber contracting upon contraction of said second chamber and said third chamber expanding upon expansion of said second chamber, means closing the ends of said inner and outer tubular members, means for providing fluid pressure and exhausting fluid from said chambers, the improvement comprising valve means carried within said fluid cylinder connected with said chambers to vary fluid flow to said chambers and fluid exhaust from said chambers in a manner which varies the rate of expansion of at least one of said chambers intermediate its fully contracted and fully expanded positions.

Claim 3

The fluid cylinder as defined in claim 1, and in which said valve means is normally operable to block fluid flow to one of said chambers during expansion and to supply fluid flow to that chamber upon being actuated.

Claim 4

The fluid cylinder as defined in claim 1 and including a fourth chamber defined by said closing means, said fourth chamber expanding and contracting with said first chamber in which said valve means is normally operable to block fluid pressure to one of said chambers during expansion and to supply fluid pressure to that chamber upon a predetermined pressure being produced in the corresponding expanding chamber.

Claim 5

The fluid cylinder as defined in claim 1, and in which said valve means are disposed intermediate said first chamber and said second chamber, said valve means being normally open during initial expansion of said first chamber and being operable to close at a predetermined pressure being produced in said first chamber to reduce the rate of expansion of said first chamber.

Claim 6

The fluid cylinder as defined in claim 1, and in which said valve means connects said first and second chambers during initial expansion of said first chamber, moves to a position isolating said first chamber from said second chamber and exhausting said second chamber upon a predetermined expansion of said first chamber.

Claim 7

The fluid cylinder as defined in claim 1, and in which said valve means is operable to connect one of said second and third chambers to said fluid pressure source and the other to exhaust during initial expansion of said second and third chambers and to connect said chambers together after a predetermined expansion of said second and third chamber.

Claim 8

A fluid cylinder as defined in claim 1, and in which said valve means are disposed intermediate said first, said second and said third chambers and are operable in one position to open fluid communication between saiD first and second chamber during initial expansion of said first chamber and upon a predetermined pressure increase in said first chamber to a position closing communication between said first and second chamber and opening communication between said second and third chambers.

Claim 9

The fluid cylinder as defined in claim 7, and in which said valve means are further operable upon a predetermined increase in the pressure in said third chamber to close communication between said first and second chambers and to open communication between said second and third chambers.

Claim 10

The fluid cylinder as defined in claim 7, and including means for selectively actuating said valve means to close communication between said first and second chambers and to open communication between said second and third chambers regardless of the position of said valve means to thereby vary the rate of expansion of said chambers.

Claim 11

The fluid cylinder as defined in claim 1, and in which said valve means are disposed intermediate said first, second and third chambers and are operable in one position to open fluid communication between said first chamber and said second chamber upon expansion of said first chamber to a predetermined position and are selectively operable to move to a position closing communication between said first and second chambers and opening communication between said second and third chambers.

Claim 12

A fluid cylinder as defined in claim 1, and including a fourth chamber defined by said closing means, said fourth chamber expanding and contracting with said first chamber, in which said valve means comprises a normally closed valve member disposed intermediate said first and said fourth chambers and operable upon a predetermined expansion of one of said chambers to open to thereby reduce the rate of expansion of said chambers.

Claim 13

A fluid cylinder comprising a first tubular member, a piston mounted for reciprocable movement within said first tubular member to divide the interior of said first tubular member into a first chamber and a second chamber, a rod member having one end connected to said piston for movement therewith and an opposite end extending exteriorly of said second chamber, a second tubular member telescopically received by said first tubular member and spaced therefrom to define a third chamber, said second tubular member being so connected to said piston to produce relative movement of said first and second tubular members resulting in said third chamber contracting upon contraction of said second chamber, and said third chamber expanding upon expansion of said second chamber, means closing the ends of said inner and outer tubular members, means for providing pressure fluid and exhausting pressure fluid from said chambers, the improvement comprising first valve means carried by said rod member, said first valve means being operable in a first position to prevent fluid communication between said first and second chambers when said first chamber is provided with said pressure fluid and operable in a second position to open fluid communication between said first and second chambers when said pressure fluid is exhausted from said first chamber, whereby a portion of the pressure fluid in said first chamber is exhausted to said second chamber and another portion of said fluid pressure in said first chamber is exhausted through said fluid exhausting means; and second valve means being operable in a first position to open fluid communication between said second and third chambers when said first chamber is provided with said pressure fluid, and operable in a second position to close fluid communication between said second and third chambers when said fluid is exhausted from said first chamber, whereby the rate of contraction of said first chamber is less than the rate of expansion of said first chamber.

Claim 14

A fluid cylinder comprising a first tubular member, a piston mounted for reciprocable movement within said first tubular member to divide the interior of said first tubular member into a first chamber and a second chamber, a rod member having one end connected to said piston for movement therewith and an opposite end extending exteriorly of said second chamber, a second tubular member telescopically received by said first tubular member and spaced therefrom to define a third chamber, said second tubular member being so connected to said piston to produce relative movement of said first and second tubular members resulting in said third chamber contracting upon contraction of said second chamber, and said third chamber expanding upon expansion of said second chamber, means closing the ends of said inner and outer tubular members, means for providing pressure fluid and exhausting pressure fluid from said chambers, the improvement comprising first valve means carried by said rod member, said first valve means being operable in a first position to prevent fluid communication between said first and second chambers when said first chamber is provided with said pressure fluid and operable in a second position to open fluid communication between said first and second chambers when said pressure fluid is exhausted from said first chamber, whereby a portion of the pressure fluid in said first chamber is exhausted to said second chamber and another portion of said fluid pressure in said first chamber is exhausted through said fluid exhausting means; and second valve means being operable in a first position to open fluid communication between said second and third chambers when said first chamber is provided with said pressure fluid, and operable in a second position to close fluid communication between said second and third chambers when said fluid is exhausted from said first chamber, whereby the rate of contraction of said first chamber is less than the rate of expansion of said first chamber.