Felling head structure

Claim 2

A tree shear comprising: a frame having a forward side and a bottom; a pair of blade support arms being pivotally connected to the frame adjacent the bottom thereof for swinging about an axis extending generally perpendicular to said forward side; said pair of arms respectively including a pair of support members extending forwardly beyond said main frame in general parallelism to said axis; a pair of plate-like cutting blades respectively being fixed to said pair of blade support arms, and having opposed cutting edges extending substantially parallel to said axis; said pair of blades, as viewed in a direction parallel to said axis, being arcuately curved about said axis; a pair of crankshafts being rotatably mounted in said main frame for movement about respective axes extending parallel to and being equally spaced from the opposite sides of said axis; motor means being drivingly connected to said crankshafts for selectively rotating the latter and a pair of drive links having first ends respectively pivotally connected to said pair of crankshafts and having second ends respectively pivotally connected to said pair of blade support arms.

Claim 3

The tree shear defined in claim 1 wherein said pair of support members respectively comprise a pair of tubular members having opposite closed ends; said blade support arms each including a pair of spaced, parallel strap-like members passing crosswise through a respective tubular member and having respective protruding ends; each pair of strap-like members being fixed to the tubular member through which they pass by first reinforcement members fixed to one side of the tubular member and to the protruding ends of the strap-like members and by second reinforcement members fixed to an opposite side of the tubular member and to the strap-like members; and said strap-like members being pivotally connected to the frame for movement about said axis.

Claim 4

The tree shear defined in claim 1 wherein said pair of support members respectively comprise a pair of tubular members having opposite closed ends; and a pair of opposed tree-receiving receptacles being respectively fixed integrally with opposed inner portions of said tubular members above said cutting blades and being arranged to clamp a tree after the latter has been sheared by said cutting blades.

Claim 5

The tree shear defined in claim 2 wherein said tubular members are cylindrical.

Claim 6

The tree shear defined in claim 3 wherein said tubular members are cylindrical.

Claim 7

A tree shear comprising: a main frame having a front side portion which defines an upright surface disposed for contacting a standing tree when the latter is being sheared; a pair of blade supporting arms comprising a first pair of members being respectively pivotally connected at one of their ends to the main frame for swinging towards and away from each other about an axis extending substantially perpendicular to said upright surface and a second pair of members being respectively rigidly joined to said first pair of members and extending substantially parallel to said axis beneath and forwardly of said main frame; a pair of blade structures each including a plate-like cutting blade curved arcuately between cutting and trailing edges and having forward and rearwaRd edges joining said cutting and trailing edges; each blade structure further including upright member means secured to said cutting blade adjacent its trailing, forward and rearward edges and defining forward and rearward upright corner structures respectively adjacent the intersections of the forward and rearward edges with said trailing edge; said second pair of members of said blade supporting arms each including a pair of depending mounting brackets having angular portions shaped complementary to and received in the upright corner structures of one of said pair of blade structures; releasable fastener means securing said upright corner structures and said depending mounting brackets together; said cutting edges of said blades extending generally parallel to said axis; said blades being curved such that they lie along the path swept by said cutting edges as they move about said axis between an open spaced-apart position defining a tree-receiving zone and a closed position wherein the edges are adjacent the center of said zone; and power means connected to said blade supporting arms for selectively effecting movement of the cutting edges between said open and closed positions.

Claim 8

A tree shear comprising: a main frame having a front side portion which defines an upright surface disposed for contacting a standing tree when the latter is being sheared; a pair of blade supporting arms comprising a first pair of members being respectively pivotally connected at one of their ends to the main frame for swinging towards and away from each other about an axis extending substantially perpendicular to said upright surface and a second pair of members being respectively rigidly joined to said first pair of members and extending substantially parallel to said axis beneath and forwardly of said main frame; a pair of blade structures each including a plate-like cutting blade curved arcuately between cutting and trailing edges and having forward and rearwaRd edges joining said cutting and trailing edges; each blade structure further including upright member means secured to said cutting blade adjacent its trailing, forward and rearward edges and defining forward and rearward upright corner structures respectively adjacent the intersections of the forward and rearward edges with said trailing edge; said second pair of members of said blade supporting arms each including a pair of depending mounting brackets having angular portions shaped complementary to and received in the upright corner structures of one of said pair of blade structures; releasable fastener means securing said upright corner structures and said depending mounting brackets together; said cutting edges of said blades extending generally parallel to said axis; said blades being curved such that they lie along the path swept by said cutting edges as they move about said axis between an open spaced-apart position defining a tree-receiving zone and a closed position wherein the edges are adjacent the center of said zone; and power means connected to said blade supporting arms for selectively effecting movement of the cutting edges between said open and closed positions.

Claim 9

The tree shear defined in claim 6 wherein each of the forward and rearward corner structures of each blade structure includes first and second sides respectively extending generally parallel and perpendicular to the cutting edge of the blade structure of which the corner structures form a part; and said first sides having opposed inner edges which are spaced apart to define an opening for permitting the passage of material.

Claim 10

A tree shear comprising: a support frame defining an elongate, horizontally extending, open-ended, tubular housing; a pair of crankshafts being respectively rotatably mounted to said frame at opposite ends of said housing for rotation about a pair of parallel horizontal axes extending crosswise to the length of said housing; a first extensible and retractable motor means being located in said housing and being connected to said pair of crankshafts for effecting simultaneous rotation thereof; a tree-engaging surface means being located on the exterior of said housing between said parallel axes for engaging a tree stem extending crosswise to said parallel axes and crosswise to the length of said housing; said pair of crankshafts each extending from said frame beyond said tree-engaging surface means; a pair of blade structures rotatably mounted to said support frame for rotation about a third axis located equidistant from and extending parallel to said pair of parallel axes; said pair of blade structures extending from said frame beyond said tree-engaging surface means and respectively including cutting edges elongated in a direction substantially parallel to said third axis and arranged so as to be movable with the respective blade structures about said third axis between an open position wherein they are spaced apart a distance greater than the diameter of a tree stem to be sheared, and a closed position wherein they are closely adjacent each other; and a pair of link means respectively connecting said pair of crankshafts to said blade structures for effecting the movement of said cutting edges between said open and closed positions upon selective actuation of said extensible and retractable motor means.

Claim 11

A tree shear comprising: a support frame defining an elongate, horizontally extending, open-ended, tubular housing; a pair of crankshafts being respectively rotatably mounted to said frame at opposite ends of said housing for rotation about a pair of parallel horizontal axes extending crosswise to the length of said housing; a first extensible and retractable motor means being located in said housing and being connected to said pair of crankshafts for effecting simultaneous rotation thereof; a tree-engaging surface means being located on the exterior of said housing between said parallel axes for engaging a tree stem extending crosswise to said parallel axes and crosswise to the length of said housing; said pair of crankshafts each extending from said frame beyond said tree-engaging surface means; a pair of blade structures rotatably mounted to said support frame for rotation about a third axis located equidistant from and extending parallel to said pair of parallel axes; said pair of blade structures extending from said frame beyond said tree-engaging surface means and respectively including cutting edges elongated in a direction substantially parallel to said third axis and arranged so as to be movable with the respective blade structures about said third axis between an open position wherein they are spaced apart a distance greater than the diameter of a tree stem to be sheared, and a closed position wherein they are closely adjacent each other; and a pair of link means respectively connecting said pair of crankshafts to said blade structures for effecting the movement of said cutting edges between said open and closed positions upon selective actuation of said extensible and retractable motor means.

Claim 12

The tree shear defined in claim 8 wherein each of said blade structures includes a plate-like blade curved on a radius about said third axis; and said cutting edge of each blade structure forming one edge of each blade.

Claim 13

The tree shear defined in claim 8 wherein said first extensible and retractable motor means comprises a unitary cylinder loosely received in said housing and having a pair of pistons slidably mounted therein; and a pair of piston rods respectively having first ends connected to said pair of pistons and second ends connected to said pair of crankshafts, said motor means thus being supported solely by said pair of crankshafts.

Claim 14

The tree shear defined in claim 10 wherein said motor means and said housing have cooperating abutment means for preventing said cylinder from undergoing shifting movement along the length of the housing during extension and retraction of the motor means.

Claim 15

The tree shear defined in claim 8 wherein said pair of blade structures are pivotally connected to said frame at a location which is directly beneath said housing and forms a lowermost part of said frame when the latter is disposed such that said pair of parallel axes lie in a common horizontal plane; a pair of grapple tongs being rotatably mounted on said frame for swinging towards and away from each other about a second pair of parallel axes which extend perpendicular to said first-mentioned parallel axes; said grapple tongs being mounted to said frame at locations respectively equidistant from the opposite ends of said housing and on that side of the housing which is opposite from the side whereat said blade structures are pivoted; and a second extensible and retractable motor means being connected between said main frame and said grapple tongs for selectively swinging the latter towards and away from each other.

Claim 16

The tree shear defined in claim 10 wherein said first extensible and retractable motor means comprises a first pair of double-acting hydraulic actuators; a pair of grapple tongs being rotatably mounted on said support frame for swinging towards and away from each other respectively about a second pair of parallel axes which are located equidistant from and extend in a direction perpendicular to said third axis; and a second pair of double-acting hydraulic actuators being respectively connected between said support frame and said pair of grapple tongs; combined horizontal pivot pin and manifold means being mounted on said support frame rearwardly of said housing and including surface means, adapted for establishing a horizontal pivot connection between one end of a boom structure and the support frame, and including fluid passage means connected to said first and second pairs of double-acting hydrauluc actuators for conveying pressure and exhaust fluid to and from said first and second pairs of hydraulic actuators.

Claim 17

A tree shear comprising: a main frame having a front side portion defining a surface adapted for engagement with a side of a standing tree trunk when the latter is being sheared; a pair of blade support arms being pivotally connected to said main frame for swinging movement toward and away from each other about an axis extending crosswise to said surface; said blade support arms including forwardly extending portions extending beyond the front side portion of said main frame and being adapted to be positioned on opposite sides of a tree trunk engaged by said surface; a pair of cutting blade structures; connection means respectively releasably securing said cutting blade structures to said pair of blade support arms for movement with the arms to shear a tree trunk positioned therebetween; said pair of blade structures respectively including a pair of cylindrically curved, plate-like blades respectively having a pair of cutting edges extending parallel to said axis and respectively terminating at front and rear pairs of edges extending crosswise to said pair of cutting edges; and said connection means including first adjustable means for prestressing said blades in a direction parallel to said cutting edges.

Claim 18

A tree shear comprising: a main frame having a front side portion defining a surface adapted for engagement with a side of a standing tree trunk when the latter is being sheared; a pair of blade support arms being pivotally connected to said main frame for swinging movement toward and away from each other about an axis extending crosswise to said surface; said blade support arms including forwardly extending portions extending beyond the front side portion of said main frame and being adapted to be positioned on opposite sides of a tree trunk engaged by said surface; a pair of cutting blade structures; connection means respectively releasably securing said cutting blade structures to said pair of blade support arms for movement with the arms to shear a tree trunk positioned therebetween; said pair of blade structures respectively including a pair of cylindrically curved, plate-like blades respectively having a pair of cutting edges extending parallel to said axis and respectively terminating at front and rear pairs of edges extending crosswise to said pair of cutting edges; and said connection means including first adjustable means for prestressing said blades in a direction parallel to said cutting edges.

Claim 19

The tree shear defined in claim 14 wherein said pair of cutting blade structures each include a pair of upright brackets secured to the top surface of the blade adjacent said front and rear edges and each upright bracket including a side extending substantially perpendicular to said cutting edge; said forwardly extending portions of said blade support arms each including a pair of spaced depending brackets having said upright brackets of a respective blade structure located therebetween and respectively having sides positioned in closely spaced facing relationship to said sides of said upright brackets of a respective blade when the blade is in an unstressed condition; and threaded fastener means extending through said opposed sides of said upright and depending brackets and being tightened to prestress said blades.

Claim 20

The tree shear defined in claim 15 and further including shim means sandwiched between said opposed sides of said upright and depending brackets for limiting the amount that the blades can be prestressed.

Claim 21

The tree shear defined in claim 14 wherein said plate-like blades are disposed so as to overlap when the blades are in a closed position; and said connection means including a second adjustable means for adjusting the amount that said blades will overlap when closed.

Claim 22

The tree shear defined in claim 14 wherein the cutting edges of the blades are arranged so as to occupy predetermined desired positions relative to each other when the blades are closed; and said connection means including a second adjustable means for adjusting said blades so as to dispose the same in said desired positions.