Patent ID: 12207597

DETAILED DESCRIPTION

FIG.1illustrates a timber-working system comprising a carrier10for use in forest harvesting. The carrier10comprises an operator cab12from which an operator (not shown) controls the carrier10. The carrier10further comprises a boom assembly14, to which a timber-working device in the form of a forestry head16is connected.

Connection of the head16to the boom assembly14comprises a rotator18, configured to rotate the head16about the generally vertical axis of rotation marked by dashed line20. A tilt bracket22further allows rotation of the head16between a prone position (as illustrated) and a standing position.

The head16comprises a frame24to which the tilt bracket22is pivotally attached. Right hand (RH) and left hand (LH) delimb arms26are pivotally attached to the frame24, as are opposing RH and LH feed arms28. RH and LH feed wheels30are attached to the respective RH and LH feed arms28, which together with RH and LH frame-mounted feed wheels may be controlled to feed one or more stems (not illustrated) along a longitudinal feed axis of the head16. It should be appreciated that while the head16is described as having two frame-mounted feed wheels, in exemplary embodiments the head may have one frame-mounted feed wheel, or none, as known in the art. The arm and frame mounted feed wheels may collectively be referred to as the ‘feed mechanism.’ It should be appreciated that reference to the feed wheels is intended to comprise the hydraulic rotary drives propelling them. A measuring wheel may be used to measure the length of the stem as it passes.

Saw apparatus in the form of a main chainsaw30is attached to the frame24. In examples, a topping chainsaw may be provided at the other end of the head16. The main saw30is typically used to fell a tree when the head16is in a harvesting position, and to buck stems into logs in the processing position of the head16. The topping saw may be used to cut off a small-diameter top portion of the stem(s) to maximize the value recovery of the trees.

FIG.2Ashows an exemplary feed arm arrangement200, comprising LH and RH feed arms300, each having a hydraulic motor302to which feed wheels304are mounted. The LH and RH feed arms300are driven by hydraulic actuators202to close and open in order to grasp and release a tree stem being felled and/or processed. The LH and RH feed arms300are interconnected by timing link204, which acts as a physical guide to assist in having the LH and RH feed arms300open and close at similar rate.

Referring toFIG.2B, a frame100of the head comprises longitudinal walls102extending along the feed axis of the head—i.e. perpendicular to the timing link204. In examples, support members in the form of nylon guide blocks250are secured to the longitudinal walls102in a position inferior to the timing link204when the feed arm arrangement200is tilted into a harvesting/felling orientation, as shown.

As shown inFIG.2C, the nylon guide block250comprises a main body252, having a plurality of fastener holes254through which fasteners (e.g. bolts) may be passed in order to secure the nylon guide block250to the longitudinal wall102. In this example, a lip256extends from the main body252, such that in use the lip256overhangs heads of the fasteners, and increases the surface area of support surface258against which the timing link204bears.

Referring toFIGS.3A and3B, each feed arm300comprises a feed arm frame350having a first pivot pin mounting portion and a second pivot pin mounting portion in the form of pin barrels352. First and second pivot pins310are received in the respective barrels352, aligned along a common longitudinal axis. An air gap is provided between the between the pivot pins310along the common longitudinal axis. Hoses and/or cables between the motor302and the frame100(or components mounted thereto) may pass through this air gap, reducing the length required—and therefore exposure during operation which may otherwise be vulnerable to damage.

Referring toFIG.3C, each pivot pin310is held relative to the frame100using a first pivot pin retainer320, and a second pivot pin retainer322is provided at a distal end of the pin barrel352. C-clips324inside the pin retainers320and322, respectively, prevent longitudinal movement—with shims326taking up any excess play. In use, the pivot pin310remains stationary relative to the frame100, while the pin barrel352rotates about the pivot pin310.

Referring toFIGS.3D and3E, the feed arm frame350comprises a motor mounting portion354to which the motor302is mounted. The feed arm frame350further comprises a first side portion356between the motor mounting portion354and the first pin barrel352, and a second side portion (not shown inFIG.3DorFIG.3E) between the motor mounting portion354and the second pin barrel352. The feed arm frame350further comprises a posterior portion358between the motor mounting portion354, and the side portions356. A superior bridge portion360extends between the pin barrels352, on their anterior side. In the exemplary embodiment illustrated, the feed arm frame350comprises a first doubler portion362on the posterior portion358, and a second doubler portion364on the superior bridge portion360.

The feed arm frame350further comprises gusset portions366between the superior bridge portion360and the respective pin barrels352, offset from the respective side portions356. A bracing bridge portion368is provided between the side portions356, inferior to the pin barrels352. The bracing bridge portion368comprises a bent plate extending from the posterior portion358in an anterior direction, and bending in an inferior direction.

The feed arm frame350further comprises a superior strong-back portion370between the superior bridge portion360and the side portions356. The superior strong-back portion370is perpendicular to the superior bridge portion360. An inferior strong-back portion372is provided between the motor mounting portion354and the side portions356. The inferior strong-back portion372is perpendicular to the motor mounting portion354.

FIG.4AandFIG.4Billustrate an exemplary pin retention assembly400, which in use retains a pin410inserted through a structural member402. In the illustrated example, the pin410comprises an annular retention groove412, having locating features in the form of a straight planar surface414on opposing sides of the pin410. The pin retention assembly400comprises a pin retainer420having first and second legs422defining a slot therebetween. The pin retainer420is configured to be slid relative to the pin410such that in use the first leg422is positioned in the first locating feature414and the second leg422is positioned in the second locating feature414.

The pin retention assembly400comprises a locating recess416in the structural member402, the locating recess416having inwardly facing planar side surfaces418. The pin retainer420is disposed within the locating recess416such that an outer side surface of each leg422is proximal a respective side surface418of the locating recess416, wherein the outer side surface of each leg422at least partially overlaps the recess side surface418. The pin retainer420is fastened to the structural member402—in this example using at least one bolt430. In use, the overlap between the outer side surface of each leg422and the recess side surfaces418prevents the pin keeper legs422from spreading under rotational loading from the pin410, reducing the likelihood of failure.

No admission is made that any reference disclosed herein constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the field of endeavour, in New Zealand or in any other country.

Throughout this specification, the word “comprise” or “include”, or variations thereof such as “comprises”, “includes”, “comprising” or “including” will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Embodiments described herein may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the disclosure and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present invention.

Embodiments have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.