ARRANGEMENT AT TREE FELLING UNIT

• US 3,688,816 A
• Filed: 06/15/1970
• Issued: 09/05/1972
• Est. Priority Date: 06/19/1969
• Status: Expired due to Term

• Current Assignee: N/A
• Original Assignee: N/A
• Primary Examiner(s): Donald R. Schran
• Application Number:
  US05/046,180
• Time in Patent Office: 813 Days
• Field of Search: 143/32,32N 144/34R,34B,34E,3D,309AC
• US Class Current: 83/743
• CPC Class Codes: A01G 23/091 Sawing apparatus specially adapted for felling trees A01G23/081, A01G23/083, A01G23/093 take precedence
• CPC Class Codes: Y10T 83/667 Tool carrier or guide affixed to work during cutting
• CPC Class Codes: Y10T 83/7083 With cutter other than endlessly orbiting type
• CPC Class Codes: Y10T 83/7108 Including ground-traversing vehicle
• CPC Class Codes: Y10T 83/7507 Guide for traveling cutter
• CPC Class Codes: Y10T 83/8884 Disc

Abstract

The invention relates to a tree felling unit of the type at which a frame supports arms for pressing the tree stem against a stop member on the frame, whereafter cutting is effected by means of a cutting device supported by the frame. The invention shows the improvement that the cutting device is an endless saw chain driven along a guiding edge of a disc slidable along a straight track in the frame and drivable against the tree stem with the guiding disc edge facing the stem. Hereby a unit is obtained having the advantages of the shear knife, such as compact dimensions and directed felling effect, but not its disadvantages, such as damages on the surface wood and requirements on a very high driving effect.

Claims

1. In a tree felling unit arrangement comprising gripping or counterholding arms for catching a tree stem and pressing it against a stop member on the frame of the felling unit and thereafter crosscutting it by a cutting device in the form of a saw guide bar with saw chain, sprocket wheel and drive means for said wheel, which cutting device is movable against the stem held caught, the improved construction wherein the sides of the frame are designed to form for the lateral parts of a carrier means a straight slide and guide track directed to the stop member, which carrier means serves as a holder for a disc acting as saw guide bar and having an extension in the longitudinal and transverse direction of said track exceeding the expected maximum stem diameter, and supports a sprocket wheel with drive means and that drive means are provided for driving the carrier means in the direction against the stop member, and which carrier means is shaped like a yoke, the legs of which are slidably mounted along the lateral edges of the frame and hold between themselves the respective lateral edges of the disc supporting the saw chain, the yoke portion serving as a mounting for the disc and as a holder for the sprocket wheel with drive means.

2. Arrangement according to claim 1, wherein the drive means for the sprocket wheel is a hydraulic motor supporting said wheel, and the drive means for driving the carrier means comprises hydraulic means preferably placed on both sides of the disc and engaging between respective fixed points on the frame and the movable carrier means.

3. Arrangement according to claim 1 or 2, characterized in that the drive means for The sprocket wheel is a hydraulic motor supporting said wheel, and the drive means for driving the carrier means comprises hydraulic means preferably placed on both sides of the disc and engaging between respective fixed points on the frame and the movable carrier means.

4. Arrangement according to claim 3, wherein it comprises two additional hydraulic means each placed adjacent one of the two hydraulic means for operating respective counterholding arms mounted in the frame.

5. Arrangement according to claim 4, wherein the outer ends of the counterholding arms are provided with knives for effecting a marking cut immediately above the action plane of the saw chain.

6. Arrangement according to claim 5, in which the counterholding arms engage above the action plane of the saw chain, and the frame is pivotally suspended for participating in the felling motion of the tree, characterized in that the knife is completed by an overlying claw for fixing the felled tree when it is being drawn in.

7. Arrangement according to claim 1, characterized in that the disc is substantially circular.

8. Arrangement according to claim 1, characterized in that the disc at least locally has a thickness successively increasing towards the rear end.

9. Arrangement according to claim 8, wherein a wedge element is attached on the lower surface of the disc for effecting said increase in thickness.

10. Arrangement according to claim 2, in which it comprises two additional hydraulic means each placed adjacent one of the two hydraulic means for operating respective counterholding arms mounted in the frame.

11. Arrangement according to claim 1, wherein the outer ends of the counterholding arms are provided with knives for effecting a marking cut immediately above the action plane of the saw chain.

12. Arrangement according to claim 4, at which the counterholding arms engage above the action plane of the saw chain, and the frame is pivotally suspended for participating in the felling motion of the tree, characterized in that the knife is completed by an overlying claw for fixing the felled tree when it is being drawn in.

13. Arrangement according to claim 1, wherein the disc is substantially circular.

14. Arrangement according to claim 1, wherein the disc at least locally has a thickness successively increasing towards the rear end.

15. Arrangement according to claim 7, wherein a wedge element is attached on the lower surface of the disc for effecting said increase in thickness.