Apparatus for felling trees

Claim 2

In a tree cutting apparatus including a frame, a cutter bar pivotally attached to said frame, a saw chain mounted for rotation around said cutter bar, power means for driving said chain about said cutter bar, and means for pivoting said cutter bar into and out of engagement with a tree to be cut; the improvement comprising: a pusher assembly mounted on said frame and engageable with said tree, said pusher assembly comprising: a support member pivotally mounted at one end to said frame, a pusher bar adapted to engage the trunk of said tree attached to the free end of said support member, and a pressure cylinder acting between said frame and said support member for moving said support member between a first position adjacent said frame to a second position pivoted upwardly therefrom to urge said pusher bar into engagement with said tree, said support member comprising a three-sided member defining a cavity enclosing said pressure cylinder when said support member is in said first position.

Claim 3

The improvement according to claim 1, in which said means for moving said support member comprises a hydraulic cylinder, and accumulator means operable to selectively pressurize said hydraulic cylinder.

Claim 4

The improvement according to claim 2, in which said accumulator means comprises an accumulator cylinder, a gas chamber within said cylinder, and means associated with said hydraulic cylinder and a source of hydraulic pressure for introducing pressurized hydraulic fluid into said accumulator cylinder, thereby compressing said gas in said chamber.

Claim 5

The improvement according to claim 3, including means for relieving pressure within said accumulator when said support member is in said first position.

Claim 6

The improvement according to claim 1, in which the relative locations of the pivot point of said support member, said pusher bar, and said saw chain are such that said pusher bar always moves upward away from said frame as said saw chain cuts through a tree and the tree tends to pivot on its stump under the influence of a felling force applied by said pusher assembly.

Claim 7

In a tree cutting apparatus adapted for attachment to a vehicle, including: a frame, a cutter bar pivotally attached to said frame, a saw chain mounted for rotation around said cutter bar, power means for driving said chain about said cutter bar, means for pivoting said cutter bar into and out of cutting engagement with a tree, attachment means pivotally attached at one end to said vehicle and at an opposite end to said frame, and means for pivoting said frame on said attachment means from a substantially horizontal operative position to a substantially vertical inoperative position; the improvement comprising: a pusher assembly operable to exert a felling force against a tree engaged by said saw chain, said pusher assembly comprising: an elongated support member pivotally mounted on said frame, a pusher bar attached to said support member in position to engage a tree being cut by said saw chain, and a pressure cylinder acting between said frame and said support member for urging said pusher bar into engagement with the tree, said urging means being operable to retract said support member to a position substantially flat against said frame, whereby movement of said frame from its operative to its inoperative position is not inhibited, said support member having a cavity formed therein capable of enclosing said pressure cylinder when said support member is in its retracted position.

Claim 8

In a tree cutting apparatus adapted for attachment to a vehicle, including: a frame, a cutter bar pivotally attached to said frame, a saw chain mounted for rotation around said cutter bar, power means for driving said chain about said cutter bar, means for pivoting said cutter bar into and out of cutting engagement with a tree, attachment means pivotally attached at one end to said vehicle and at an opposite end to said frame, and means for pivoting said frame on said attachment means from a substantially horizontal operative position to a substantially vertical inoperative position; the improvement comprising: a pusher assembly operable to exert a felling force against a tree engaged by said saw chain, said pusher assembly comprising: an elongated support member pivotally mounted on said frame, a pusher bar attached to said support member in position to engage a tree being cut by said saw chain, and a pressure cylinder acting between said frame and said support member for urging said pusher bar into engagement with the tree, said urging means being operable to retract said support member to a position substantially flat against said frame, whereby movement of said frame from its operative to its inoperative position is not inhibited, said support member having a cavity formed therein capable of enclosing said pressure cylinder when said support member is in its retracted position.