This invention relates to rolls for feeding logs through tree handling equipment such as delimbers, tree processors and the like.
Some tree delimbers include a pair of curved knives that can be brought into contact with the outer surface of a log. The log is pulled past the knives which shear off any limbs projecting from the log. In typical tree delimbers the log is moved by compressing it between a pair of counter-rotating feed rollers. The feed rollers grip the log and move it along. Examples of tree delimbers which work in this general manner are the SIDEWINDER™ and LIM-MIT™ delimbers made by Risley Manufacturing Ltd. of Grande Prairie, Alberta, Canada.
Some existing feed rollers are faced with spikes to enable them to better grip the outer surface of a log. These spikes can incise the outer layer of wood of the log, which is undesirable.
Other commonly-used feed rollers comprise a rubber-coated cylinder having a chain mesh stretched over its outer surface. These feed rollers, while reducing damage to the log surface, suffer from relatively short service lives and can be undesirably expensive.
Commonly-owned U.S. Pat. No. 4,972,890 describes a type of feed roller which comprises a cylindrical drum having contour-edged bars bolted to its outer surface. The contour-edged bars are relatively widely spaced apart. These feed rollers have not been completely successful, because they can cause chipping of the outer surface of logs.
Despite the variety of feed rollers available for use in tree processing machinery there remains a need for feed rollers which improve on the performance and/or cost effectiveness of current feed rollers.
One aspect of the invention provides a feed roller for handling trees. The feed roller comprises a rotatable support member and a plurality of elongated strips coupled to the support member. The strips extend substantially parallel to one another in a cylindrical configuration. Each of the strips has a leading edge having a plurality of spaced apart projections. The leading edge projections interdigitate with projections on a trailing edge of an adjacent one of the strips.
Another aspect of the invention provides a feed roller for tree handling. The feed roller comprises a drum having a longitudinal axis and a substantially cylindrical surface. A plurality of strips are spaced apart around a circumference of the drum. The strips extend substantially parallel to the longitudinal axis. Each strip has a leading edge and a trailing edge. Each strip has projections on its leading and trailing edges. The projections on the leading edge of each strip interdigitate with projections on a trailing edge of an adjacent strip. Each strip has a first end extending into a first pocket at a first end of the surface and a second end extending into a second pocket at a second end of the surface.
Yet another aspect of the invention provides a feed roller for tree handling. The feed roller comprises a substantially cylindrical drum having a longitudinal axis and a plurality of metal strips spaced apart around a circumference of the drum. The strips extend substantially parallel to the longitudinal axis. Each metal strip has a leading edge and a trailing edge. The leading edge is shaped to provide projections. The trailing edge has a shape complimentary to the shape of the leading edge of an adjacent one of the strips. The projections on the leading edge of each metal strip interdigitate with projections on a trailing edge of an adjacent one of the metal strips. The strips are coupled to the drum by a coupling. The coupling permits the strips to rock from side to side.
A further aspect of the invention provides a replacement tree gripping member for a feed roll for tree handling. The tree gripping member comprises a strip of metal having a textured outer face. An inner face of the strip bears a band of a material. The material of the band is resilient, has a static coefficient of friction with steel not exceeding 1, or is both resilient and has a static coefficient of friction with steel not exceeding 1. The strip has a wavy leading edge comprising a plurality of projections, and a wavy trailing edge comprising a plurality of projections complementary to the leading edge projections. The band of material is narrower than the strip.
Further features and aspects of the invention are described below.
In Figures which illustrate non-limiting embodiments of the invention:
Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
This invention relates to feed rollers for feeding logs. Such feed rollers may be used in various applications. Feed rollers may be used, for example, in roll-stroke delimbers.
Roll-stroke delimber 10 may be actuated by its operator to tightly close grapple 14 about the butt of a felled tree and to retract boom 12 and, with it, the tree, toward log feed roller mechanism 22. Once grapple 14 is released, log feed roller mechanism 22 grips the tree and feeds it backwardly through tree guide tube 45. The tree is delimbed as its branches strike the arms of grapple 14 or cutters (not shown) mounted at the forward end of tube 45. Once the tree has been delimbed, log feed roller mechanism 22 may be actuated to propel the delimbed tree forwardly through tree guide tube 45. Saw 16 may then be actuated at selected intervals to buck the delimbed tree into desired lengths.
Log feed roller mechanism 22 (
In the illustrated embodiment, rings 118 and 119 each comprise a plurality of arc-shaped sectors 120 which can be independently dismounted from drum 112. Sectors 120 are held in place by bolts 122 or other suitable fasteners.
A plurality of longitudinally extending strips 124 substantially cover the face of feed roller 110. Each strip 124 has a first end 124A engaged under first ring 118 and a second end 124B engaged under second ring 119. Strips 124 have leading edges 126 and trailing edges 128. Leading edges 126 are shaped to have a plurality of longitudinally spaced-apart projections 130. Each trailing edge 128 has a shape which is complementary to leading edge 126 of the adjacent strip 124. Projections 130 on leading edges 126 interdigitate with complementary projections 132 on trailing edges 128.
It can be seen that, in general, feed roller 110 comprises a rotatable support member to which are coupled a plurality of elongated strips 124. In the illustrated embodiment, the support member comprises drum 112. Strips 124 extend substantially parallel to one another and to an axis of rotation of drum 112. Strips 124 are arranged in a cylindrical configuration.
In the illustrated embodiment, leading and trailing edges 126, 128 have wavy shapes such that projections 130 and 132 are rounded. Strips 124 may be called “contour-edged”.
Outer faces 133 of strips 124 are textured to enhance frictional contact with a log. In the embodiment of
An inner face 136 (see
The construction of feed roller 110 permits strips 124 to rock slightly from side to side, as indicated by arrows 142 (
Strips 124 are preferably fabricated of a material which, if bent slightly, will spring back to its original shape. In one embodiment, strips 124 are fabricated from QT-100 steel (as defined by CSA standard 640.21/M). The resilience of strips 124 and the ability of layer 140 to yield under pressure permits strips 124 to flex inwardly and outwardly, as indicated by arrows 143 (
Strips 124 are captured by rings 118 and 119, but are free to float slightly. Longitudinal movement of strips 124 is limited by abutment surfaces on strips 124. In the illustrated embodiment of
Strips 124 may be dimensioned so that, when strips 124 are equally spaced-apart around drum 112, leading edge 126 of each strip 124 is separated from the trailing edge 128 of an adjacent strip 124 by a narrow gap 146 (
Each strip 324 has end portions 325A and 325B. End portions 325A and 325B are received in pockets 350 in retaining members 352 and 353. In the illustrated embodiments, each retaining member 352, 353 comprises a plurality of removable segments 356. Each segment 356 has recesses 350A which provide pockets 350 when the segment is affixed to drum 310. A strip 324 may be removed for servicing or replacement by removing the segments 356 at one or both of its ends.
In the illustrated embodiment, segments 356 are held in place by fasteners, in particular bolts 357A and nuts 357B. Segments 356 may be affixed to drum 310 by other types of fastener or in any other suitable manner.
In some embodiments band 360 has a low static coefficient of friction with a material of the surface of drum 312. For example, in some embodiments the static coefficient of friction does not exceed 1. In some embodiments the static coefficient of friction between the material of drum 312 and the material of band 360 does not exceed 4×10−1. Bands 360 are narrow enough and/or longitudinal edge portions of bands 360 are compressible enough to permit strips 324 to rock from side to side as shown in
Pockets 350 provide a means for positively driving strips 324. Preferably as shown in
In the illustrated embodiments, strips 324 have abutment surfaces 344 which, when the ends of strips 324 are engaged in pockets 350, can bear against corresponding surfaces 345 of segments 356. Preferably abutment surfaces 344 are spaced somewhat more closely than surfaces 345 so that strips 324 are not prevented from sliding slightly longitudinally relative to drum 312.
Retaining members 352 and/or 353 may have patterns of projections on their surfaces. Retaining members 352 and/or 353 optionally have faces which are angled inwardly toward strips 324. This may help to maintain logs in engagement with strips 324 in some cases.
Strips as described in relation to any of the above embodiments may be supplied as replacement parts for feed rollers according to the invention.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example:
Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.
This is a continuation-in-part of application Ser. No. 10/345,212 filed on 16 Jan. 2003 now U.S. Pat. No. 6,684,923 and entitled Feed Rolls for Tree Handling Equipment.
Number | Name | Date | Kind |
---|---|---|---|
2588121 | Johnston | Mar 1952 | A |
3821076 | Stenberg et al. | Jun 1974 | A |
4047274 | Lehmann | Sep 1977 | A |
4901778 | Fenton | Feb 1990 | A |
4930179 | Wright et al. | Jun 1990 | A |
4972890 | Isley | Nov 1990 | A |
5806130 | Pascoe | Sep 1998 | A |
6394259 | Alhainen | May 2002 | B1 |
6764456 | Doherty | Jul 2004 | B1 |
Number | Date | Country |
---|---|---|
WO 9916598 | Apr 1999 | WO |
Number | Date | Country | |
---|---|---|---|
20040211489 A1 | Oct 2004 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 10345212 | Jan 2003 | US |
Child | 10766081 | US |