US 3392763 A
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July 16, 1968 K. LEDERGERBER WOOD CHIPPER CONSTRUCTION Filed May 15, 1967 IN VEN TOR.
I; /Kwu Z. EOFRGERBER JM .i@ Y 32 7701?! Y5 United States Patent 3,392,763 WOOD CHIPPER CONSTRUCTION Karl Ledergerber, Box 556, Wadley, Ga. 30477 Continuation-impart of application Ser. No. 439,325,
Mar. 12, 1965. This application May 15, 1967, Ser.
6 Claims. (Cl.,144176) ABSTRACT OF THE DISCLOSURE A wood chipper apparatus is provided with an improved mounting of a chipper disc, and an improved feed spout construction is provided for receiving whole logs for a chipping action. The chipper disc is mounted on a shaft which is wholly supported by bearings on one side of the disc only, and this arrangement permits a mounting of longer cutting knives on a face of the disc. The feed spout is constructed to receive whole logs, and a plurality of anvils carried by the feed spout are arranged on a curved path to coact with the chipper disc.
Related application This application is a continuation-in-part of my copending application Ser. No. 439,325, filed Mar. 12, 1965, now Patent No. 3,332,461.
Background of invention This invention relates' to an improvement in rotary disc chippers and is particularly concerned with an improved feed spout and chipper disc arrangement for use with rotary disc wood chippers.
In the wood pulp industry it is necessary to reduce wood stock such as logs or slabs of wood to a chip form. It is desirable in producing such chips to obtain a-chip product which has certain uniform characteristics of size and quality in order to provide for better cooking characteristics of the chip product. Therefore, it is important that the wood stock be cut cleanly with little bruising or squeezing of the resulting product, and it is important to obtain a uniform chip product at a maximum rate of production.
As described in my copending application Ser. No. 439,325, now Patent No. 3,332,461, it has been the practice in producing such a chip product from wood stock to utilize a rotary disc chipper apparatus of the type shown in US. Patents 1,438,943 and 3,047,244. Such apparatus includes a chipper disc mounted for rotation in a vertical plane, and a number of cutting knives are mounted on one face of the disc. The cutting knives coact with a stationary bed knife, or anvil, in such a way that a scissors action results between the rotating knives and the stationary knife. Wood stock in the form of logs or slabs is conveyed to the vicinity of the chipper apparatus, and the wood is then delivered into a feed spout associated with the chipper apparatus. The feed spout communicates with the face of the chipper having the cutting knives, and the feed spout serves to support the wood stock while the stock is being delivered and drawn into the cutting face of the rotary disc. Other prior art on this subject as developed in the examination of my copending application, includes the U5. Patents 1,942,675, 2,712,974, 3,069,101 and 3,123,311.
Summary of invention The present invention is directed to improved feed spout and chipper disc constructions for use in apparatus of the type described above. It has been found that the improved structures of this invention result in better support for logs so that a maximum cutting efiiciency is attained and a more uniform chip product is produced.
In accordance with the present invention, the feed spout of a chipper is constructed to carry a plurality of stationary anvils. These stationary anvils are arranged in a curved path which approximates the curvature of a log at a plane which is cut at an angle to the longitudinl axis of the log. Further, the plurality of anvils provides for a construction which is more economically and easily produced for log handling chippers, and relatively large diameter stock material can be handled at an improved cutting rate for a given apparatus.
In addition, the present invention provides for an improved mounting of chipper discs associated with any rotary disc apparatus of the type described above. Prior chipper disc mounting arrangements have provided for a bearing support at each end of a shaft which carries a chipper disc for rotational movements within a housing of the wood chipper apparatus. The cutting knives which are normally positioned on one face of the chipper disc have been limited in their individual lengths because it was necessary to permit the passage of the shaft through the entire disc structure and past the mounted positions of the knives. Also, prior art bearing supports have interfered with the size and location of feed spouts. The present invention provides for a novel mounting of a chipper disc within a housing wherein the shaft upon which the disc is carried for rotational movements is mounted in bearing supports located on one side only of the disc. This means that the surface of the disc which is used for carrying cutting knives may be a surface which is opposed to the positions of the bearing support members. Thus, the knives may be longer in length and may approach the center axis of rotation for the disc in an arrangement which provides for substantially improved cutting action for each individual knife. Also, the positioning of the feed spout relative to the housing may be substantially improved for chipper apparatus of this type.
Other advantages of the improved feed spout and chipper disc constructions of this invention will become apparent in the more detailed discussion which follows, and in the discussion reference will be made to the following drawings.
Brief description of the drawings FIGURE 1 is a top plan view of a wood chipper apparatus, showing a top section of the apparatus removed so as to illustrate an improved mounting of a chipper disc within a housing of the apparatus, and
FIGURE 2 is an elevational view of the chipper apparatus of FIGURE 1, illustrating an improved feed spout construction for handling logs.
Detailed description of invention The wood chipper apparatus of the present invention may be of any typical construction, and may include the constructional features described in my copending application Ser. No. 439,325. The descriptive material in my copending application is intended to be included as part of the present description by reference thereto. Such a wood chipper apparatus is shown generally at 10 in the drawings. The chipper apparatus 10 includes a housing having a base portion 12 and a cover portion which may be made up of sections 14 and 16. The cover section 14 may be pivotally mounted by a hinge 18 so that it may be tilted and opened relative to the section 16. Thus, the cover section 14 may swing open to permit an easy access to the interior of the chipper apparatus. When the section 14 is in a closed position it may be clamped or locked to the adjoining cover section 16 by any suitable means. A chip removing stack 22 is provided for removing the chip product out of the apparatus.
Within the housing, a rotating chipper disc 24 is mounted on a horizontal axis for rotation in a vertical plane. A horizontally disposed axle means 26 carries the chipper disc 24 and provides the axis of rotation for the disc. The axle means 26 may pass into a central portion of the disc 24, but the axle does not extend beyond a front face 32 of the disc which carries knife elements 34. A pair of bearing supports 36, such as pillow block bearings of well known construcfion, may be provided for supporting the entire axle and disc assembly for rotation about a horizontal axis. An important feature of the present invention is to mount the entire axle and chipper disc assembly with all bearing supports located on one side only of the chipper disc. This feature provides for the use of longer knife elements 34 on a cutting face 32 of a chipper disc without any interference from an axle shaft or bearing supports on the cutting side of the disc. The chipper disc 24 may include a hub element 38 which is secured to the disc for providing a tight mounting of the disc on an end of the axle 26. Means for rotating the disc may include a motor and drive belt means of well known constructions, as exemplified in the above mentioned patents or in my copending application. The driving means is preferably positioned on the same side of the chipper disc as are the pillow block bearings 36.
Because of the improved arrangement for mounting a chipper disc with all bearing support means located on one side only of the disc, it is possible to provide a better placement and construction for knife elements 34 on a cutting face of a disc. Referring to FIGURE 2, it can be seen that the knife elements 34 are relatively long, compared to prior art arrangements, and the illustrated embodiment shows four knife elements 34 placed about a disc face, although any suitable number of knives may be used. The four knife elements 34 are placed at substantially right angles to one another, however, each knife element is offset slightly from a perfectly aligned position with the central axis of the chipper disc. Each knife element 34 is fixed to the face of the disc so that a cutting edge 40 leads the knife in its movement with the rotation of the disc. The end 42 of each cutting edge slightly leads an end 44 of the same knife as related to a line drawn through the central axis of the disc and along the plane of the cutting face 32. The knife element 34 may be bolted or otherwise affixed to the front face of the disc so as to be replaceable when worn. Also, each knife element 34 may be mounted over an opening 46 which is formed completely through the chipper disc in a well known manner to provide for a movement of chips away from the cutting edge of the knives and through the disc.
In addition to the elements just described, the chipper apparatus further includes an inlet means for feeding stock material to the cutting face of the rotating chipper disc. The inlet means is in the form of a feed spout 50 which is shown as a horizontally disposed tubular member which leads into a side wall of the chipper apparatus housing so as to communicate at an angle with the lower half of the rotating disc face 32, In this manner, an opening is provided for feeding logs or other stock material into the cutting face of the rotating disc.
The feed spout 50 is preferably circular or oval in its cross section so as to handle the circular configurations of whole logs which are to be reduced in the chipper apparatus. A terminal end of the feed spout enters the housing of the chipper apparatus so as to present the end of a log against the rotating face 32 of the disc 24. With the disc rotating clockwise, as viewed in FIGURE 2, it can be seen that the cutting edges 40 of the disc move across the exposed end of the log generally from right to left so as to slice chips from the log. As already discussed, the cutting action of chipper devices of this type results from a movement of a plurality of knives past fixed anvils so as to accomplish a scissors-like action between the knives and the anvils. The present invention is concerned with providing a novel arrangement of a plurality of anvils so as to improve the cutting action against whole logs, as
. '4 compared to previous arrangements for cutting slabs and other forms of wood stock.
Although it is kown to provide feed spouts having tubular inlet members which introduce stock material into chipping apparatus, the usual function of such feed spouts is to merely carry or convey stock material, and there has been no provision for an improved cutting action or cooperation of an end of such feed spouts with a chipper disc rotating in a vertical plane. Also, it is known to provide single piece anvil elements having curved surfaces for assisting in the support and conveying of curved stock material into some form of chipper apparatus. However, prior devices have not been as efficient to operate nor as economical to produce as the improved feed spout and anvil structure of the present invention. Referring to FIGURE 2, it can be seen that the feed spout 50 is horizontally disposed to enter the chipper apparatus housing at an angle, and thus, a circular feed spout will form a communication through an opening in the vertical housing wall. The opening which is formed through the housing wall to receive the feed spout 50, and to carry logs therethrough, has essentially an elliptical shape, as illustrated. As viewed in FIGURE 2, the left hand side of the elliptical opening through the housing Wall is provided r with a series of separate anvil elements 52 which are disposed about the curved inner terminal end of the feed spout 50 so as to provide fixed surfaces against which the cutting knives 34 can move a log which is being reduced to chips. The elements 52 make up the anvil means for the feed spout construction, and the anvil elements start at a top point of the feed spout and are placed downwardly and outwardly, as illustrated, until they reach a midpoint of the longitudinal axis of the feed spout. From there, the elements 52 are placed downwardly and inwardly until they reach a bottom point on the circular opening formed through the housing wall. Thus the fixed anvil means of the present invention is in the form of an anvil which is made up of a plurality of single anvil elements placed along a curved path which describes an ellipse or some other preferred curve. The single anvil elements 52 are easily manufactured and heat-treated because they are formed with straight surfaces, and thus, no costly machining and treating operations are required in the manufacture of the elements 52. However, even though the elements 52 are formed with straight surfaces, they are disposed about the inner end of the feed spout 50 so as to form an essentially curved anvil surface against which a log may be placed While it is being reduced to chips. The anvil elements 52 may be mounted at the inner end of the feed spout 50 in any convenient manner, and a preferred construction has been illustrated. Plate members 54 are affixed to a vertical portion of the chipper housing wall, and each plate element 54 includes a curved inner edge which defines a portion of the elliptical opening formed through the housing wall. The anvil elements 52 are then bolted, or otherwise afiixed directly to the plate members 54 so as to follow the curved edges of the plates. When all elements are in place, an essentially curved anvil means is presented toward the inside of the chipper apparatus so as to cooperate with the movement of knives 34 past the position of the anvil.
Also, it can be seen from FIGURE 2 that the feed spout 50 and the opening through which it communicates into the chipper apparatus may be ideally positioned so as to receive a full sweep of the cutting edges of each knife element 34. This positioning is further made possible by the removal of any bearing support structures which would otherwise interfere with the location of a feed spout into one side of a housing for a chipper apparatus.
With the apparatus which has been described and illustrated, a log can be introduced into the feed spout 50 for reduction to chips. Once the log is moving along the length of the feed spout, one end of the log will be introduced into the rotating, cutting face 32 of the chipper disc 24. As soon as the knife elements 34 contact an end of the log, the log will be pushed against the anvil means which is formed from the plurality of anvil elements 52, and then, a scissors action will cause the log to be reduced to chips as the knives sweep past the log end in a clockwise direction. It has been found that the cutting action of the knives, as coupled with the cooperation of the curved anvil means 52 results in the log being drawn into the chipper apparatus. Thus, the entire log is advanced into the cutting face of the chipper disc 24 until it has been completely reduced to chips.
With the invention just described, it is possible to handle logs without first reducing them to slabs or other configurations, and a more efficient and economical chipping action and rate are attained. Although the invention has been described with reference to a preferred embodiment, variations will become apparent to those skilled in the art, and such variations are intended to be included within the scope of the present invention, as claimed.
What is claimed is:
1. In a wood chipper apparatus of the type having a chipper disc which rotates in a vertical plane, said disc having a plurality of cutting knives mounted on a face thereof, the improvement comprising:
a tubular feed spout extending into the wood chipper apparatus for delivering a log into the face of the chipper disc having the plurality of knives mounted thereon, said feed spout being disposed on a substantially horizontal plane and at an angle to the chipper disc so that logs being fed through the feed spout are drawn into the chipper apparatus and reduced to chips by the action of the knives on the chipper disc, and
a curved anvil means carried by a side wall of the feed spout for coacting with the cutting knives of the chipper disc, said curved anvil means further comprising a plurality of anvil elements which are arranged on a curved path which essentially follows a portion of the curvature of the tubular feed spout at its terminal end portion which extends into the wood chipper apparatus.
2. The improvement of claim 1 wherein said plurality of anvil elements are arranged on a curved path which describes a portion of an ellipse.
3. The improvement of claim 1 wherein said plurality of anvil elements are mounted on vertical portions of a housing which encloses said chipper disc.
4. The improvement of claim 1 wherein said chipper disc is mounted at an end of a horizontally disposed axle means which is mounted for rotation in bearing means, said bearing means being positioned only on a side of the chipper disc which is opposed to the face of the disc which carries the cutting knives.
5. In a wood chipper apparatus of the type having a chipper disc which is mounted for rotation within a housing, and a plurality of knives mounted on a first face of the chipper disc, the improvement in the mounting of said disc which comprises:
an axle means which is mounted for being driven so as to rotate the chipper disc, and means to secure the chipper disc to a terminal end of the axle means so that the axle does not extend beyond said first face of the chipper disc, and
bearing means for supporting said axle means, said bearing means being positioned only on an opposite side of the chipper disc from said first face.
6. The improvement of claim 5 and including driving means for rotating said axle means and said chipper disc, said driving means being positioned on said opposite side of the chipper disc.
References Cited UNITED STATES PATENTS 1,942,675 1/1934 Wigger et al.
2,174,593 10/1939 Pelot et al 144176 XR 2,299,248 10/ 1942 Ottersland 144-176 XR 3,061,207 10/1962 Clark 241-92 WILLIAM W. DYER, JR., Primary Examiner. W. D. BRAY, Assistant Examiner.