Recoil mechanism for track-type tractors

Claim 2

In combination with first and second members movable relatively toward and away from each other, recoil means comprising: cylinder means associated with the first member and movable therewith, and comprising a first cylindrical portion and a second cylindrical portion of greater crosssectional area than the first cylindrical portion and communicating with the first cylindrical portion; a first piston sized to fit within the first cylindrical portion of the cylinder means; a second piston associated with the second member and movable therewith relative to the first member and cylinder means, the First and second pistons and the cylinder means defining a closed chamber; reaction means associated with the first member for movement therewith; compressible and extensible resilient means associated with the reaction means and first piston to urge them apart; and, substantially incompressible fluid filling the chamber, so that the amount of movement of the first piston relative to the cylinder means is greater than the corresponding amount of movement of the second piston relative to the cylinder means, whereby, upon relative movement of the first and second members toward each other, the amount of compressing movement of the resilient means is greater than the corresponding amount of relative movement of the first and second members toward each other.

Claim 3

The recoil means of claim 1 wherein the first piston defines a continuous cross-sectional surface which substantially completely fills in the cross-sectional area of the first cylindrical portion.

Claim 4

The recoil means of claim 2 wherein every portion of the chamber is in continuous open communication with every other portion of the chamber.

Claim 5

The recoil means of claim 3 wherein the resilient means comprise helical springs.

Claim 6

In a vehicle having a track frame comprising first and second track frame portions movable relatively toward and away from each other, first and second rotatable members mounted to the first and second track frame portions and movable relatively toward and away from each other upon such relative movement of the first and second track frame portions, and a track entrained about the first and second rotatable members, recoil apparatus comprising: cylinder means associated with the first track frame portion and movable therewith, and comprising a first cylindrical portion and a second cylindrical portion of greater cross-sectional area than the first cylindrical portion and communicating with the first cylindrical portion; a first piston sized to fit within the first cylindrical portion of the cylinder means; a second piston associated with the second track frame portion and movable therewith relative to the first track frame portion and cylinder means, the first and second pistons and the cylinder means defining a closed chamber; reaction means associated with the first track frame portion for movement therewith; compressible and extensible resilient means associated with the reaction means and the first piston to urge them apart; and, substantially incompressible fluid filling the chamber, so that the amount of movement of the first piston relative to the cylinder means is greater than the corresponding amount of movement of the second piston relative to the cylinder means, whereby, upon relative movement of the first and second track frame portions toward each other the amount of compressing movement of the resilient means is greater than the amount of corresponding relative movement of the first and second track frame portions toward each other.

Claim 7

In a vehicle having a track frame comprising first and second track frame portions movable relatively toward and away from each other, first and second rotatable members mounted to the first and second track frame portions and movable relatively toward and away from each other upon such relative movement of the first and second track frame portions, and a track entrained about the first and second rotatable members, recoil apparatus comprising: cylinder means associated with the first track frame portion and movable therewith, and comprising a first cylindrical portion and a second cylindrical portion of greater cross-sectional area than the first cylindrical portion and communicating with the first cylindrical portion; a first piston sized to fit within the first cylindrical portion of the cylinder means; a second piston associated with the second track frame portion and movable therewith relative to the first track frame portion and cylinder means, the first and second pistons and the cylinder means defining a closed chamber; reaction means associated with the first track frame portion for movement therewith; compressible and extensible resilient means associated with the reaction means and the first piston to urge them apart; and, substantially incompressible fluid filling the chamber, so that the amount of movement of the first piston relative to the cylinder means is greater than the corresponding amount of movement of the second piston relative to the cylinder means, whereby, upon relative movement of the first and second track frame portions toward each other the amount of compressing movement of the resilient means is greater than the amount of corresponding relative movement of the first and second track frame portions toward each other.

Claim 8

The vehicle of claim 5 and further comprising means for selectively introducing pressurized substantially incompressible fluid into the chamber to move the second piston relatively outwardly of the cylinder means, to in turn move the first and second track frame portions relatively apart, in turn moving the rotatable members apart to tension the track.

Claim 9

The vehicle of claim 6 wherein the first piston defines a continuous cross-sectional surface which substantially completely fills in the cross-sectional area of the first cylindrical portion.

Claim 10

The vehicle of claim 7 wherein every portion of the chamber is in continuous open communication with every other portion of the chamber.

Claim 11

The vehicle of claim 8 wherein the resilient means comprise helical springs.

Claim 12

The vehicle of claim 9 and further comprising a sleeve, having tubular portion surrounding said first cylindrical portion, a first flange member extending radially inwardly of the tubular portion, and a second flange member Connected to the first flange member and extending radially outwardly of the first flange member, and wherein the helical springs comprise a first helical spring disposed between the first flange member and the reaction means, and in contact with the first flange member, and a second helical spring disposed between the second flange member and the reaction means, and in contact with the second flange member.

Claim 13

The vehicle of claim 10 wherein the first track frame portion comprises a casing which houses the first and second helical springs and first and second flange members, with the outer edge of the second flange member in intimate relation with the inner surface of the casing, the cylinder means being fixed to said casing.

Claim 14

The vehicle of claim 11 and further comprising locking means associated with the inner surface of the casing positioned to contact the second flange member upon urging thereof by the first and second helical springs, to limit movement of the first and second flange members under such urging of the first and second helical springs.

Claim 15

The vehicle of claim 12 wherein the locking means comprise a plurality of locking members seatable in an annular groove defined by the inner surface of the casing.

Claim 16

The vehicle of claim 13 wherein the first track frame portion comprises a first tubular body, and wherein the casing comprises an extended portion of said first tubular body, and wherein the second track frame portion comprises a second tubular body, with the first tubular body disposed within the second tubular body and slidable inwardly and outwardly thereof.

Claim 17

The vehicle of claim 14 wherein the reaction means comprise a plate fixed within the first tubular body and contacting the first and second helical springs.

Claim 18

The vehicle of claim 15 wherein the first and second rotatable members comprise idlers.