US3718167A

US3718167A - Limb stub-cutting mechanism

Info

Publication number: US3718167A
Application number: US00220328A
Authority: US
Inventors: P Cervenak
Original assignee: Nicholson Manufacturing Co
Current assignee: Nicholson Manufacturing Co
Priority date: 1972-01-24
Filing date: 1972-01-24
Publication date: 1973-02-27
Anticipated expiration: 1990-02-27

Abstract

The rotary ring of a log barker has a flaring mouth carrying bits in radial planes for cutting limb stubs. Hooked ends of swinging arms rotate around a log as it is moved lengthwise to scrape off the bark.

Description

0 United States Patent 1 [1 3,718,167

ervenak [4 1 Feb. 27, 1973 LIMB STUB-CUTTING MECHANISM [56] References Cited Inventor: Peter J- Cervenak, Seattle, Wash. d [73] Assiglee Nichlsn Manufacmring 314,876 3/1885 Poole etal. ..l44/208 E a wash- 2,s02,494 8/1957 Nicholson ....l44/208 E [22] Filed: Jan. 24, 1972 3,333,615 8/1967 Robbins ..l44/208 E [21] Appl' 220328 Primary Examiner-Gerald A. Dost Related US. Application Data Attorney-Robert Beach [62] I Division of Ser. No. 84,056, Oct. 26, 1970, which is a division of Ser; No. 627,067, March 30, 1967, Pat. [57] ABSTRACT 3,536,265- The rotary ring of a log barker has a flaring mouth carrying bits in radial planes for cutting limb stubs. [52] US. Cl ..l44/2 Z, 144/208 E Hooked ends of Swinging arms rotate around a l as [51] Int. Cl. ..A0lg 23/02 it is moved lengthwise to scrape off the bark [58] Field of Search ..l44/208 R, 208 E, 2 Z

3 Claims, 7 Drawing Figures sum 1 OF 2 PATENTEI] FEB 27 I973 PATENTED FEB 2 7 I973 SHEET 2 OF 2 LIME STUD-CUTTING MECHANISM This application is a division of my application Ser. No. 084,056, for Log Barker Delimber and Refuse- Reducing Mechanism, filed Oct. 26, 1970, which is a division of my earlier application Ser. No. 627,067, for Log Barker Refuse-Reducing Mechanism, filed Mar. 30, I967, which issued as U.S. Pat. No. 3,536,265.

A principal object of the invention is to remove limbs from logs being barked more readily and effectively and with less interference with the barking operation than has been experienced previously.

More particularly, the invention relates. to an improved type of limb and knot paring mechanism having inclined bits with an obtuse-angled cutting edge.

FIG. 1 is a longitudinal vertical section through a log barker of the present invention.

FIG. 2 is an elevation of the barker ring assembly viewed from the discharge side, with parts broken away; and FIG. 3 is a corresponding elevation of the barker ring assembly viewed from the feed side.

FIG. 4 is an enlarged vertical longitudinal section through the barker ring assembly.

FIG. 5 is a detail bottom plan of a portion of a limb cutter bit taken on line 55 of FIG. 4;

' FIG. 6 is a detail section on line 66 of FIG. 5; and

FIG. 7 is a section on line 7-7 of FIG. 5.

The limb-cutting mechanism of the present invention can be applied to various types of rotary ring log barkers, representative examples of which are shown in Nicholson US. Pat. No. 2,802,494 and in FIGS. 1, 2, 3 and 4, in particular, of the drawings of this application. Logs L are fed lengthwise to such a barker by a feed conveyor 1 and the barked log is withdrawn from the barker by a discharge conveyor 2. The barker ring assembly is mounted on a plate 3 which can be suitably mounted and guided for elevational movement so that the center of the rotary barker ring 4 will coincide with the axis of the log L being barked. The barker ring is rotated around the log by a drive chain 5 engaging a drive sprocket 6 and teeth provided around the circumference of the barker ring.

Each log is fed through the throat 7 of the barker ring 4 to be engaged by scraper tips of the barker arms 8 which are mounted on the barker ring by pivots 9. These barker arms are swung in a direction about such pivots to press their scraping ends against the log by hydraulic jacks 10. Pressure of the barking tips of the arms against the log is maintained by air under pressure in expandible air chambers 11 which are in communication with the respective jacks 10. Such log barker mechanism described thus far in detail is not part of the present invention, but is simply representative of a typical rotary ring barker to which the present invention can be applied.

Projecting from the feed side of the rotary barker throat 7 is an annular flange or collar 12 forming a flared mouth through which a log L is moved by the feed conveyor 1 into the barker ring throat. The angle between any portion of such mouth in a radial plane and the axis of the barker ring 4 should be between 45 and 60 and preferably is about 55. On the flaring inner face of collar 12 are mounted elongated cutter bits 13 having their lengths disposed substantially in radial planes. These cutter bits are spaced circumferentially of the barker ring substantially equidistantly, and their inner cutting ends project inward beyond the cylindrical surface of the throat 7.

The preferred shape of the cutter bit 13 is shown in detail in FIGS. 5, 6 and 7. Each bit is of trapezoidal cross section, as shown in FIG. 7, having two parallel sides 13a and 13b disposed in planes parallel to the axis of the barker ring, a side 13c perpendicular to such parallel sides and in contiguous engagement with collar 12 and an inclined face 140. The face 14a of the bit connecting such parallel sides is inclined relative to them in a direction such that the leading side of the bit in the direction of barker rotor rotation is wider than the trailing side of the bit. Consequently, the leading face 13b of the bit and such inclined joining face 14a converge to form an acute-angled cutting edge 15a which preferably is approximately 60.

The inner end of the bit is beveled to provide an end surface 14b, shown in FIGS. 5 and 6, which will form a cutting edge 15b that is substantially parallel to the axis of the rotary ring. The bevel between the leading face 13b of the bit and the bit end face 14b again is such that the angle of the cutting edge 15b is acute and preferably about 60. The two cutting edges 15a and 15b intersect to form an obtuse angled corner 15c, having an angle between and 135, depending upon the slope of the inner face of collar 12. Such angle preferably is approximately As a log L is fed by the conveyor 1 into themouth of the barker ring as shown in FIG. 1, the cutting edges 15a and 15b will engage and trim off any branch stubs or other protuberances projecting outward to a distance beyond the circle defined cooperatively by the cutting edges 15b of the several bits. A sufficient number of these bits should be provided to cut such projections effectively, and 16 of such bits has been found to be a satisfactory number. Disposition of the lengths of the cutting bits substantially in radial planes of the barker rotor parallel to the axis of the rotor provides a strong cutting end, and one which does an effective cutting job. In particular, a long cutting edge is afforded by arranging the cutting edge sections 15a and 15b at an obtuse angle, as shown best in FIG. 6, instead of the cutting edge sections forming a right angle like the cutting edge sections of the cutter bits shown in the prior Nicholson US. Pat. No. 2,802,494.

The limb refuse cut by the bits 13 and the bark refuse scraped from the log by the barker arms 8 in the form of discrete fragments falls into the circular pit 16 shown in FIG. 1, which is located directly beneath the barker. Across the lower portion of this pit extends a bridge 17 which may be in the form of a channel having its edge flanges extending upwardly. This bridge preferably extends diametrically across the pit so that it serves to support a bearing for the upper end of an upright shaft 18 located centrally of the pit. This shaft carries a hub 19 on which is mounted a rotor disk 20 of a hog.

The upright shaft 18 carries a pulley 21 which is connected by several V-belts 22 to a drive pulley 23.This drive pulley can be driven by any suitable drive mechanism such as represented by a shaft 24.

On opposite sides and opposite ends of the bridge 17 are mounted stationary shearing bars 25, the lower edges of which constitute shearing edges. Movable shearing bars 26 are carried by the rotor plate 20 in positions to coact with the stationary shearing bars 25 as the rotor rotates.

Beneath each movable shearing bar 26 is a vane 28 extending radially of the rotor, which acts to sweep the hogged waste material rotationally within the casing of the hog including an upright circumferential wall 29, preferably of considerably greater extent than the wall of the pit 16, a bottom wall 30 and an annular top wall 31 bridging between the pit and the circumferential wall 29 of the hog.

To prevent limb and bark refuse from lodging on the bridge 17, it is preferred that it be capped by a ridged cover 33 held in place by bolts 34. The ridge shape of such cover deters accumulation of refuse on the bridge, but in addition, flow of air drawn through the hog by movement of the vanes 28 will tend to sweep downward past opposite sides of the bridge and remove material from the ridged cover.

I claim:

1. Limb stub-cutting mechanism for a log barker having a rotary barker ring through which a log can be fed lengthwise, comprising a flange having a generally frustoconical surface flaring outwardly from the infeed side of the barker ring toward logs being fed to the barker ring and carried by the barker ring, and a plurality of elongated cutter bits carried by said flaring flange with their lengths inclined generally parallel to said flaring surface and in substantially radial planes of the barker ring for cutting limb stubs from a log moving through the barker ring.

2. The limb stub-cutting mechanism defined in claim 1, in which each cutter bit has a cutting edge including a first section on the inner end of the bit extending substantially parallel to the axis of the barker ring and a second section inclined outwardly from said first section toward the feed end of the barker ring, said two cutting edge sections being disposed at an obtuse angle.

3. The limb stub-cutting mechanism defined in claim 2, in which the obtuse angle between the two cutting edge sections of each bit is approximately

Claims

3. The limb stub-cutting mechanism defined in claim 2, in which the obtuse angle between the two cutting edge sections of each bit is approximately 125* .