FEEDING ASSIST MEANS FOR A WOOD CHIPPER
United States Patent 3856212
In a wood chipper having a power-driven, knife-carrying disk there is provided a freely rotatable roller positioned closely adjacent the path of such knives for supporting and guiding the piece being chipped into position for chipping. While in some embodiments, the roller is permitted to move backwardly against a resilient force away from the path of said knives, it is normally held sufficiently close thereto as to constitute also the bedplate or anvil with which the knives cooperate in the chipping operation. Thus, the surface of the feeding roller and the path of the knives provide a pair of converging surfaces into which the material being chipped is drawn by the chipping operation, whereby, as a result of the freely rolling characteristics of the roller, a substantial degree of self-feeding is obtained.
US Patent References:
/3123311.html
Fontaine - March 1964 - 3123311
Forage harvester
Waldrop - September 1967 - 3342231
Knife disc wood cutting machine
Kirsten - October 1967 - 3346027
Wood chipper
Eklund et al. - May 1968 - 3384311
EAR CORN ADAPTER FOR FORAGE HARVESTERS
Witt - January 1971 - 3552463
/3123311.html
Fontaine - March 1964 - 3123311
Forage harvester
Waldrop - September 1967 - 3342231
Knife disc wood cutting machine
Kirsten - October 1967 - 3346027
Wood chipper
Eklund et al. - May 1968 - 3384311
EAR CORN ADAPTER FOR FORAGE HARVESTERS
Witt - January 1971 - 3552463
Application Number:
05/385185
Publication Date:
12/24/1974
Filing Date:
08/02/1973
View Patent Images:
Export Citation:
Assignee:
Royer Foundry and Machine Co. (Kingston, PA)
Primary Class:
Other Classes:
241/222, 241/101.710, 241/92, 241/278.100, 144/176
International Classes:
B27L11/02; B27L11/00; B02C23/02
Field of Search:
241/55,56,91,92,101.7,11M,221,222,224-225,277,278R 144/162R,176
US Patent References:
| 3635410 | PULPWOOD CHIPPER | January 1972 | Smith |
Primary Examiner:
Custer Jr., Granville Y.
Assistant Examiner:
Goldberg, Howard N.
Attorney, Agent or Firm:
Woodhams, Blanchard & Flynn
Claims:
I claim
1. In a wood chipping device having a rotatable disk, cutting knives on a face thereof and openings through said disk at locations adjacent the cutting edges of said disk, air blast creating means on the side of the disk opposite said knives for drawing a current of air through said openings and expelling said air and said chips through discharge means, the improvement comprising feeding assist and anvil means comprising:
2. The device of claim 1 including within said mounting device a fixed bracket projecting away from the cutting surface of said disk, a shaft coaxial with said roller for supporting same and said bracket including a pair of parallel, upwardly facing support surfaces for supporting said shaft; and
3. The device of claim 1 including within said mounting device resilient means for permitting said roller to move toward and away from said disk surface in a direction substantially perpendicular thereto, means for resiliently urging said roller toward said disk and means positively limiting the travel of said roller toward said disk.
4. The device of claim 1 including within said mounting device a bracket mounted fixedly with respect to the axis of said disk and projecting away from said disk;
5. The device of claim 3 wherein said roller is positioned with its axis substantially parallel to the surface of said disk which is normal to the disk axis and wherein said roller is arranged for movement toward and away from said surface in a direction substantially perpendicular thereto.
6. The device of claim 3 wherein said roller is positioned with its axis at least substantially parallel with the axis of said disk and is mounted for movement toward and away from said disk along a line including a projecting radius of said disk.
1. In a wood chipping device having a rotatable disk, cutting knives on a face thereof and openings through said disk at locations adjacent the cutting edges of said disk, air blast creating means on the side of the disk opposite said knives for drawing a current of air through said openings and expelling said air and said chips through discharge means, the improvement comprising feeding assist and anvil means comprising:
2. The device of claim 1 including within said mounting device a fixed bracket projecting away from the cutting surface of said disk, a shaft coaxial with said roller for supporting same and said bracket including a pair of parallel, upwardly facing support surfaces for supporting said shaft; and
3. The device of claim 1 including within said mounting device resilient means for permitting said roller to move toward and away from said disk surface in a direction substantially perpendicular thereto, means for resiliently urging said roller toward said disk and means positively limiting the travel of said roller toward said disk.
4. The device of claim 1 including within said mounting device a bracket mounted fixedly with respect to the axis of said disk and projecting away from said disk;
5. The device of claim 3 wherein said roller is positioned with its axis substantially parallel to the surface of said disk which is normal to the disk axis and wherein said roller is arranged for movement toward and away from said surface in a direction substantially perpendicular thereto.
6. The device of claim 3 wherein said roller is positioned with its axis at least substantially parallel with the axis of said disk and is mounted for movement toward and away from said disk along a line including a projecting radius of said disk.
Description:
FIELD OF THE INVENTION
This invention relates to a wood chipper and particularly to a type thereof having feeding assist means.
BACKGROUND OF THE INVENTION
While wood chippers of a wide variety of types, designs and constructions have been known for a great many years, and same have been highly successful in many situations, there has been a problem in the designing of a wood chipper for a small or medium-size application which, insofar as I am aware, has not been satisfactorily solved prior to the present invention. In designing the wood chipper of small or medium size, such as for use in cleaning up brush or fallen limbs in a small park or on a golf course, it is not possible to provide the large and substantially automatic chippers which are commonly used by municipalities and power companies in chipping wood picked up from streets and/or right of ways. Instead, it is desired to have a small unit, preferably one small enough to be moved from place to place by hand and utilizing for driving the chipping mechanism a relatively small gasoline engine. In such a device, the feeding is normally by hand inasmuch as the provision of automatic or power-feed means would render the device physically too large as well as too expensive for the uses for which it is intended.
However, purely hand-feed means, such as has been tried on some machines of the prior art, are relatively slow in overall operation inasmuch as the operator must stay with the machine when same is chipping a given piece of wood and cannot go after another piece until such chipping operation is completed. Further, such hand-feeding means is often dangerous to the operator who may be tempted to permit his hands to go too close to the chipping knives. While gravity feeds are known in which the wood to be chipped is inserted into a hopper or similar device in a substantially vertical alignment, gravity is relied upon for feeding thereof, same is not always convenient, particularly where long tree branches of 3 or 4 inches in diameter are involved, in view of their weight. Hence, feeding at a lower angle with respect to the horizontal, such as 30° or 40° is preferred and in some cases it would even be desirable to design equipment for feeding in a horizontal direction if suitably automatic or semi-automatic feeding means could be devised. Therefore, it is desirable to provide a chipping device which can be constructed in a simple manner and which can be provided and which will have feeding means of a sufficiently simple nature as to be both inexpensive to make and economical of space and yet which will require only the initial insertion of a piece of wood thereinto. After such insertion, or at least shortly after such insertion where a piece of wood is so long so as to require at least temporary hand guidance, the wood will then be automatically drawn into the chipper under such suitably controlled conditions that it will feed to, or at least close to, the end thereof and will become converted to chips as desired.
It is further desirable in order to provide design flexibility in the design of units of different sizes or for different precise purposes, that such feeding means be capable of some flexibility without material change in design in order to accommodate pieces of wood, as tree branches, being fed thereinto in directions forming several angles with the horizontal, which angles are however normally greater than the horizontal and less than the vertical.
Accordingly, the objects of the invention include:
1. To provide a wood chipper which is particularly applicable to medium or small-size embodiment.
2. To provide a wood chipper adapted for handling small brush and branches and particularly for handling pieces of wood of approximately 4 inches in diameter or less.
3. To provide a wood chipper having at least semi-automatic feeding assist means, particularly such means as to enable an operator to feed a piece of wood for chipping with only minor manual guidance thereof at the beginning of the operation with respect to a single piece of wood and with no guidance at all near the end thereof.
4. To provide a wood chipper having at least semi-automatic feeding assist means which will be equally operable in a horizontal position, a vertical position or in an angular position therebetween.
5. To provide a wood chipper having at least semi-automatic feeding assist means which means are of such simplicity as to add very little to the manufacturing cost of the equipment and virtually nothing to the maintenance thereof.
6. To provide a wood chipper which throughout will be of such simplicity as to be capable of manufacturing at a relatively low cost and yet which will be sturdy and capable of extended use with a minimum of maintenance.
Other objects and purposes of the invention will be apparent to persons acquainted with apparatus of this general type upon reading of the following specification and examination of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a wood chipper embodying the invention.
FIG. 2 is an end view taken from the righthand side of FIG. 1.
FIG. 3 is a section taken on the line III--III of FIG. 2.
FIG. 4 is a section taken on the line IV--IV of FIG. 1.
FIG. 5 is a section taken on the line V--V of FIG. 2.
FIG. 6 is a fragmentary view of a modification.
FIG. 7 is a fragmentary and sectional view of a modification taken on a section plane corresponding to that of FIG. 3.
SUMMARY OF THE INVENTION
In carrying out the objects and purposes above set forth, there is provided a rather heavy rotatably mounted disk driven by any suitable prime mover and arranged for easy portability upon any suitable wheeled platform. Said disk is provided on one face thereof with knives for cutting the workpiece and openings extend through the disk immediately below said knives by which the chips may pass to the opposite side of the disk. Said opposite side of the disk carries means for both physically throwing said chips out a discharge chute and for generating an air stream which assists the travel of the chips by entering through the above-mentioned disk openings and passing out through said discharge chute.
The feeding assist means comprise a roller mounted adjacent the surface of the disk upon which the knives are mounted, the axis of said roller being parallel with, but normally offset from, a diameter of said disk. In the principal preferred embodiment illustrated, said roller is rotatably mounted on a horizontal axis which is offset somewhat below the horizontal diameter of the disk. The roller is preferably mounted for a normal position close to the disk to function normally also as the anvil but is in some embodiments movable against a resilient resistance away therefrom. Means are provided for limiting the distance the roller can move toward the disk in response to said resilient means. The workpiece is, in the embodiment where the disk is in a vertical plane, introduced to the disk at an approximately 45° angle and rests upon the roller. The roller thus supports the workpiece during the chipping operation but since the work face of the workpiece forms a wedge with the surface bearing against the roller, such wedging action tends to move said roller back against its resilient mounting. Thus, the roller accommodates itself to a variety of sizes of workpiece and yet holds the workpiece at all times in operating position against the disk. A fixed anvil may also be provided where the roller is movable away from the cutting disk more than a relatively small distance. Further, the action of the knives being at an acute angle with respect to the lengthwise extent of the workpiece tend to draw the workpiece in toward the disk and thus provide the desired self-feeding function. Thus, while the operator may support and guide a workpiece during the initial portion of the chipping operation, particularly if the workpiece is an especially long one, as same becomes shorter it can then be permitted to self-feed into and through the apparatus.
DETAILED DESCRIPTION
Referring now to the drawings in more detail, there is provided a base plate 1 which may be supported in any convenient manner such as on wheels 2. A housing 3 comprises front and rear plates 4 and 6 which are mounted onto said base plate 1 in any convenient manner, such as by welding. A shroud-like closure 16 is positioned at the side edges of said front and rear plates and serves both to stiffen same and to close the sides of the housing. Same further assists in guiding the chips and leads through a discharge opening 19 to an external spout 21. Suitable means such as the bearing structure 7 is mounted on the rear plate 4 for supporting a shaft 9 in a cantilevered manner on said plate 4. Same may, if desired, be supplemented by a further bearing (not shown) extending rearwardly from said support plate 4 and/or by a further bearing on the front plate 6. Said shaft rotatably supports a chipper disk 11 which will be described further hereinafter. Said shaft is suitably connected as by the coupling 12 to a prime mover 13 which is also mounted in any convenient manner on the platform 1. Said prime mover may be of any convenient type, such as a gasoline engine or electric motor.
The disc 11 is, in line with conventional practice, made fairly heavy to provide a good fly wheel effect for overcoming the intermittent resistance applied thereto by the action of the knives. In one preferred embodiment said fly wheel is made of steel and is approximately 26 inches in diameter and 1 inch thick, although these dimensions are given only as examples and are in no way limiting. Radially elongated knives 22 are circumferentially spaced around the disk and are provided on their leading edges with suitable cutting edges 23 which are spaced from the surface of the disk a distance equal to the desired thickness of the chip. In the illustrated embodiment, each of the knives extends a little over one-half of the radius of the disk and are radially spaced to cover mostly different but slightly overlapping circumferential paths. In this embodiment, only two knives are shown and such has been found to be sufficient. However, different numbers of knives may be utilized at appropriate radial lengths and circumferential spacings as desired. Likewise in this embodiment the knives are angled somewhat, here 15°, with respect to a radius through said knives, with the inner knife facing slightly radially outwardly and the outer knife facing slightly radially inwardly.
Openings 24 are provided in the disk adjacent the cutting edges of each knife for the passage therethrough of the sliced off chip. Means 26 project axially from the rearward side of the disk 11 and are aligned radially for creating an air blast which acts both to draw the chip in through the openings 24 and discharge same to the discharge spout 21.
While in the illustrated embodiment, the knives 22 are shown as each extending substantially one-half the full radial cutting distance and the openings 24 are shown as similarly positioned and aligned, it will be understood that the particular details of the knife and opening form no part of the invention and same may be varied widely as desired.
A roller 31 which functions both as a feeding device and as a bedplate or anvil is mounted by means further hereinafter described in a position close to but spaced from the front face of the disk 11 with its axis of rotation substantially parallel to that of the radius upon which the knife is located at the moment of cutting. In the illustrated embodiment, said roller 31 is mounted on a horizontal axis which is spaced below the horizontal diameter of the disk 11. Said roller is mounted through resilient means which tend constantly to push same toward the disk with an adjustable force and the movement of said roller toward the disk is limited by suitable means, such as that described below. The space 30, which is the minimum spacing between the roller and the disk, should be only enough to clear the knives 22 but little if any more.
In the form of the invention shown in FIGS. 1-5, the roller 31 is rotatably mounted upon a fixed shaft 33 which is mounted for horizontal sliding movement upon the upper surface 34 of a pair of spaced side plates 36 and 37. Desirably and as shown in the embodiment of FIGS. 1-5, the side plates 36 and 37 extend upwardly to comprise partial covers, of which one is shown at 38, for the roller and chipping zone and to define along with the upper surface 34 a guide slot 39. The shaft 33 is received into and is horizontally slidable in said guide slot 39. A pair of long bolts 41 and 42 extend through fixed brackets 43 and 44, respectively, said latter being rigidly mounted onto the side plates 36 and 37, and thence through the respectively opposite ends of the shaft 33. Springs 46 and 47 encircle said bolts between the brackets 43 and 44 and the respective ends of the shaft 33 and the nuts 48 and 49 limit movement of the shaft 33 in response to the springs 46 and 47 toward the disk 11.
The limit brackets 50 and 51 fasten, as with screws, to the side plates 36 and 37, carry limit screws 52 and 53 which are threadably adjustable to limit the distance said bolts 41 and 42, and consequently the shaft 33, may move backwardly in response to rearward movement of the roller 31. The heads of the bolts 41 and 42, acting against the brackets 43 and 44, limit the distance the shaft 33 can move toward the disk 11.
A hopper 54 is mounted partly on the rear housing plate 6 and partly on a bracket 56 which in turn is connected to the upper portions 38 extending upwardly form the side plates 36 and 37. The bottom surface 57 of the hopper 56 is tangent, or approximately tangent, to the roller 31 when same has moved back somewhat away from the disk 11 and entered into a normal operating position.
The knives 22 are mounted into said disk 11 in any convenient manner such as being held against a wedge-shaped bar 61 which bar is firmly fixed by screws, welding or otherwise to the rear face of the disk 11 and said knives are held agianst said bar by a clamp bar 62 which is held in position by appropriate screws 63. An adjustment screw 64 is provided in a conventional manner for advancing the knife downwardly.
A bed knife 32 may be provided, if desired, especially where the roller 31 is permitted to move backwardly away from the knives more than a very limited distance, namely, a distance sufficient to destroy the functioning of said roller as a bedplate or anvil, or where relatively small brush is being cut such as under 1/2 inch in diameter, so that it might tend to be drawn past the curved surface of the roller 31. If and where such a fixed anvil is required, it may be provided between the side plates 36 and 37 and below the center of the feed roller 31. Said bed knife will comprise a blade 56 which is adjustably received into a bed knife base 57, said latter being rigidly fixed at its respective ends to said side plates 36 and 37. A screw 58 will in a conventional and presently known manner be tightenable to hold the bed knife 56 in any adjusted position.
OPERATION
The operation of the foregoing-described equipment will be readily understood from the description and drawings already given but will be reviewed to insure a full understanding of the invention.
With the prime mover started and the disk 11 rotating rapidly, as at a normal engine output speed, a workpiece W is placed on the roller 31 and urged downwardly toward the disk 11. Same is preferably held at an angle of approximately 45° to the horizontal and will normally be further guided by the edge of the hopper 54. The roller 31 is at this point held by its resilient mounting against the stop provided by the heads of the limit bolts 41 and 42 and only slightly spaced from the disk 11. As the knives 22 successively strike the leftward end of said workpiece, chips are sliced off and drawn by the airstream above mentioned through the openings 24, around the disk 11 and out through the discharge spout 21. The action of the knife against the end of the workpiece tends to pull the workpiece downwardly against the roller 31. The pressure thus created of the workpiece against the roller acts against the portion of the roller whose tangent forms an acute angle with respect to the face of the disk (namely, the tangent which is coincident, or parallel, with the surface 57 of the hopper) and thus the roller tends to urge the workpiece toward the disk. Thus, the action of the cutting knives tends to pull the workpiece still further into cutting position. This combined with the action of gravity on the workpiece insures that same will be carried all the way to its end to the cutting knives and the workpiece completely chipped. Where the spring 39 is a relatively heavy spring it will hold the roller 31 close to the paths of the knives and thus in effect function as an anvil or bed with which the knives cooperate and in such case the bed knife assembly 32 may in many instances be eliminated. It should be understood, however, that in this arrangement the spring 39 is sufficiently heavy as to permit very little yielding and consequent movement of the roller 31 away from the disk 11 so that the function of said spring is largely to absorb shock and minimize the likelihood of breaking of parts of the equipment.
It will be apparent that with a very long workpiece the operator will often find it desirable to support and guide same in the initial portion of the chipping thereof but that as same becomes shorter he can soon let it go and the self-feeding operation will take over.
While the illustrated embodiment is shown with the disk in a vertical position and the feeding at a substantially 45° angle to the horizontal, it will be apparent that this is a function of the most simple and therefore inexpensive manner of mounting the motor and disk. However, it will be apparent that the motor and disk can also be mounted so that the disk itself makes an acute angle to the horizontal, such as a 45° angle, and in such case the workpiece may be fed thereto in a substantially horizontal manner. This, of course, eliminates the use of gravity to assist the feeding operation but it has some advantage in ease of feeding in that the workpieces are then fed substantially horizontally rather than being lifted as is necessary when same are to be fed at a downwardly sloping 45° angle. Of course, a combination of the foregoing concepts is also possible, namely to slope the disk at approximately 60° or 70° to the horizontal with the feeding then sloping at approximately 20° or 30° to the horizontal.
MODIFICATIONS
In FIG. 6 there is shown a modification wherein the drum 31 is mounted by a shaft 33 onto an adjustable screw 71 which is received into a fixed bracket 72, said latter being mounted on the side plate 36. Obviously, a screw and bracket similar to the screw 71 and bracket 72 will be provided on the opposite side of the roller 31 and will be fixed to the side plate 37. Thus, the spacing of the roller 31 from the disk 11 may be adjusted by suitable adjustments of the nuts 73 and 74 but no resilience is here provided for the mounting. Here again the roller 31 itself functions essentially as the anvil or bedplate against which the knives operate and the bed knife assembly 32 may, if desired, be omitted.
In FIG. 7 there is shown the use of a roller 31a in association with a disk, or drum 76. Said drum 76 functionally corresponds to the disk 11 excepting that in this case the knives 77 are mounted on the peripheral surface thereof rather than on a face surface as in the case of the disk 11. The drum 76 is driven in any convenient manner, not shown, such as the same manner as that in which the disk 11 is driven. The hopper structure 78 is provided having, in this embodiment, a horizontal wall surface 79 for the support and feeding of workpieces for chipping to the drum. The roller is mounted so as to project a short distance above the plane of the wall 79 whereby to receive the end of the workpiece and feed same to the knives of the drum. Said roller 31a together with the drum 76 again, as in the embodiments of FIGS. 1-6 form converging walls whereby to form an acute angle on the end of a workpiece. This in turn assists in urging the workpiece into the chipping zone as the chipping operation progresses. The drum 31 may be mounted in either manner shown above in FIGS. 1-, 6, namely either for movement downward against resilient force as in FIG. 5 or as in FIG. 6 an adjustable positioning which is fixed for any given adjusted position. Finished chips are discharged through the conduit 81, partly by being thrown therethrough from the chipping drum 76 and partly by the air blast drawn in from the hopper 78 by the knives on the chipping drum and from thence expelled as an air blast through the discharge conduit 81.
Testing of machines embodying the foregoing described invention have shown that they are highly effective on relatively dry wood so that the necessity for frequent resharpening of the blades, as distinguished from previously known somewhat similar machines which when used on dry wood required frequent resharpening of the cutting blades.
Although a specific embodiment of the invention has been disclosed for illustrative purposes it will be recognized that a variety of variations may be made therein in addition to those above expressly referred to which variations will still be within the scope of the hereinafter appended claims and same will accordingly be considered as covered by said claims excepting as the claims by their own terms expressly provide otherwise.
This invention relates to a wood chipper and particularly to a type thereof having feeding assist means.
BACKGROUND OF THE INVENTION
While wood chippers of a wide variety of types, designs and constructions have been known for a great many years, and same have been highly successful in many situations, there has been a problem in the designing of a wood chipper for a small or medium-size application which, insofar as I am aware, has not been satisfactorily solved prior to the present invention. In designing the wood chipper of small or medium size, such as for use in cleaning up brush or fallen limbs in a small park or on a golf course, it is not possible to provide the large and substantially automatic chippers which are commonly used by municipalities and power companies in chipping wood picked up from streets and/or right of ways. Instead, it is desired to have a small unit, preferably one small enough to be moved from place to place by hand and utilizing for driving the chipping mechanism a relatively small gasoline engine. In such a device, the feeding is normally by hand inasmuch as the provision of automatic or power-feed means would render the device physically too large as well as too expensive for the uses for which it is intended.
However, purely hand-feed means, such as has been tried on some machines of the prior art, are relatively slow in overall operation inasmuch as the operator must stay with the machine when same is chipping a given piece of wood and cannot go after another piece until such chipping operation is completed. Further, such hand-feeding means is often dangerous to the operator who may be tempted to permit his hands to go too close to the chipping knives. While gravity feeds are known in which the wood to be chipped is inserted into a hopper or similar device in a substantially vertical alignment, gravity is relied upon for feeding thereof, same is not always convenient, particularly where long tree branches of 3 or 4 inches in diameter are involved, in view of their weight. Hence, feeding at a lower angle with respect to the horizontal, such as 30° or 40° is preferred and in some cases it would even be desirable to design equipment for feeding in a horizontal direction if suitably automatic or semi-automatic feeding means could be devised. Therefore, it is desirable to provide a chipping device which can be constructed in a simple manner and which can be provided and which will have feeding means of a sufficiently simple nature as to be both inexpensive to make and economical of space and yet which will require only the initial insertion of a piece of wood thereinto. After such insertion, or at least shortly after such insertion where a piece of wood is so long so as to require at least temporary hand guidance, the wood will then be automatically drawn into the chipper under such suitably controlled conditions that it will feed to, or at least close to, the end thereof and will become converted to chips as desired.
It is further desirable in order to provide design flexibility in the design of units of different sizes or for different precise purposes, that such feeding means be capable of some flexibility without material change in design in order to accommodate pieces of wood, as tree branches, being fed thereinto in directions forming several angles with the horizontal, which angles are however normally greater than the horizontal and less than the vertical.
Accordingly, the objects of the invention include:
1. To provide a wood chipper which is particularly applicable to medium or small-size embodiment.
2. To provide a wood chipper adapted for handling small brush and branches and particularly for handling pieces of wood of approximately 4 inches in diameter or less.
3. To provide a wood chipper having at least semi-automatic feeding assist means, particularly such means as to enable an operator to feed a piece of wood for chipping with only minor manual guidance thereof at the beginning of the operation with respect to a single piece of wood and with no guidance at all near the end thereof.
4. To provide a wood chipper having at least semi-automatic feeding assist means which will be equally operable in a horizontal position, a vertical position or in an angular position therebetween.
5. To provide a wood chipper having at least semi-automatic feeding assist means which means are of such simplicity as to add very little to the manufacturing cost of the equipment and virtually nothing to the maintenance thereof.
6. To provide a wood chipper which throughout will be of such simplicity as to be capable of manufacturing at a relatively low cost and yet which will be sturdy and capable of extended use with a minimum of maintenance.
Other objects and purposes of the invention will be apparent to persons acquainted with apparatus of this general type upon reading of the following specification and examination of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a wood chipper embodying the invention.
FIG. 2 is an end view taken from the righthand side of FIG. 1.
FIG. 3 is a section taken on the line III--III of FIG. 2.
FIG. 4 is a section taken on the line IV--IV of FIG. 1.
FIG. 5 is a section taken on the line V--V of FIG. 2.
FIG. 6 is a fragmentary view of a modification.
FIG. 7 is a fragmentary and sectional view of a modification taken on a section plane corresponding to that of FIG. 3.
SUMMARY OF THE INVENTION
In carrying out the objects and purposes above set forth, there is provided a rather heavy rotatably mounted disk driven by any suitable prime mover and arranged for easy portability upon any suitable wheeled platform. Said disk is provided on one face thereof with knives for cutting the workpiece and openings extend through the disk immediately below said knives by which the chips may pass to the opposite side of the disk. Said opposite side of the disk carries means for both physically throwing said chips out a discharge chute and for generating an air stream which assists the travel of the chips by entering through the above-mentioned disk openings and passing out through said discharge chute.
The feeding assist means comprise a roller mounted adjacent the surface of the disk upon which the knives are mounted, the axis of said roller being parallel with, but normally offset from, a diameter of said disk. In the principal preferred embodiment illustrated, said roller is rotatably mounted on a horizontal axis which is offset somewhat below the horizontal diameter of the disk. The roller is preferably mounted for a normal position close to the disk to function normally also as the anvil but is in some embodiments movable against a resilient resistance away therefrom. Means are provided for limiting the distance the roller can move toward the disk in response to said resilient means. The workpiece is, in the embodiment where the disk is in a vertical plane, introduced to the disk at an approximately 45° angle and rests upon the roller. The roller thus supports the workpiece during the chipping operation but since the work face of the workpiece forms a wedge with the surface bearing against the roller, such wedging action tends to move said roller back against its resilient mounting. Thus, the roller accommodates itself to a variety of sizes of workpiece and yet holds the workpiece at all times in operating position against the disk. A fixed anvil may also be provided where the roller is movable away from the cutting disk more than a relatively small distance. Further, the action of the knives being at an acute angle with respect to the lengthwise extent of the workpiece tend to draw the workpiece in toward the disk and thus provide the desired self-feeding function. Thus, while the operator may support and guide a workpiece during the initial portion of the chipping operation, particularly if the workpiece is an especially long one, as same becomes shorter it can then be permitted to self-feed into and through the apparatus.
DETAILED DESCRIPTION
Referring now to the drawings in more detail, there is provided a base plate 1 which may be supported in any convenient manner such as on wheels 2. A housing 3 comprises front and rear plates 4 and 6 which are mounted onto said base plate 1 in any convenient manner, such as by welding. A shroud-like closure 16 is positioned at the side edges of said front and rear plates and serves both to stiffen same and to close the sides of the housing. Same further assists in guiding the chips and leads through a discharge opening 19 to an external spout 21. Suitable means such as the bearing structure 7 is mounted on the rear plate 4 for supporting a shaft 9 in a cantilevered manner on said plate 4. Same may, if desired, be supplemented by a further bearing (not shown) extending rearwardly from said support plate 4 and/or by a further bearing on the front plate 6. Said shaft rotatably supports a chipper disk 11 which will be described further hereinafter. Said shaft is suitably connected as by the coupling 12 to a prime mover 13 which is also mounted in any convenient manner on the platform 1. Said prime mover may be of any convenient type, such as a gasoline engine or electric motor.
The disc 11 is, in line with conventional practice, made fairly heavy to provide a good fly wheel effect for overcoming the intermittent resistance applied thereto by the action of the knives. In one preferred embodiment said fly wheel is made of steel and is approximately 26 inches in diameter and 1 inch thick, although these dimensions are given only as examples and are in no way limiting. Radially elongated knives 22 are circumferentially spaced around the disk and are provided on their leading edges with suitable cutting edges 23 which are spaced from the surface of the disk a distance equal to the desired thickness of the chip. In the illustrated embodiment, each of the knives extends a little over one-half of the radius of the disk and are radially spaced to cover mostly different but slightly overlapping circumferential paths. In this embodiment, only two knives are shown and such has been found to be sufficient. However, different numbers of knives may be utilized at appropriate radial lengths and circumferential spacings as desired. Likewise in this embodiment the knives are angled somewhat, here 15°, with respect to a radius through said knives, with the inner knife facing slightly radially outwardly and the outer knife facing slightly radially inwardly.
Openings 24 are provided in the disk adjacent the cutting edges of each knife for the passage therethrough of the sliced off chip. Means 26 project axially from the rearward side of the disk 11 and are aligned radially for creating an air blast which acts both to draw the chip in through the openings 24 and discharge same to the discharge spout 21.
While in the illustrated embodiment, the knives 22 are shown as each extending substantially one-half the full radial cutting distance and the openings 24 are shown as similarly positioned and aligned, it will be understood that the particular details of the knife and opening form no part of the invention and same may be varied widely as desired.
A roller 31 which functions both as a feeding device and as a bedplate or anvil is mounted by means further hereinafter described in a position close to but spaced from the front face of the disk 11 with its axis of rotation substantially parallel to that of the radius upon which the knife is located at the moment of cutting. In the illustrated embodiment, said roller 31 is mounted on a horizontal axis which is spaced below the horizontal diameter of the disk 11. Said roller is mounted through resilient means which tend constantly to push same toward the disk with an adjustable force and the movement of said roller toward the disk is limited by suitable means, such as that described below. The space 30, which is the minimum spacing between the roller and the disk, should be only enough to clear the knives 22 but little if any more.
In the form of the invention shown in FIGS. 1-5, the roller 31 is rotatably mounted upon a fixed shaft 33 which is mounted for horizontal sliding movement upon the upper surface 34 of a pair of spaced side plates 36 and 37. Desirably and as shown in the embodiment of FIGS. 1-5, the side plates 36 and 37 extend upwardly to comprise partial covers, of which one is shown at 38, for the roller and chipping zone and to define along with the upper surface 34 a guide slot 39. The shaft 33 is received into and is horizontally slidable in said guide slot 39. A pair of long bolts 41 and 42 extend through fixed brackets 43 and 44, respectively, said latter being rigidly mounted onto the side plates 36 and 37, and thence through the respectively opposite ends of the shaft 33. Springs 46 and 47 encircle said bolts between the brackets 43 and 44 and the respective ends of the shaft 33 and the nuts 48 and 49 limit movement of the shaft 33 in response to the springs 46 and 47 toward the disk 11.
The limit brackets 50 and 51 fasten, as with screws, to the side plates 36 and 37, carry limit screws 52 and 53 which are threadably adjustable to limit the distance said bolts 41 and 42, and consequently the shaft 33, may move backwardly in response to rearward movement of the roller 31. The heads of the bolts 41 and 42, acting against the brackets 43 and 44, limit the distance the shaft 33 can move toward the disk 11.
A hopper 54 is mounted partly on the rear housing plate 6 and partly on a bracket 56 which in turn is connected to the upper portions 38 extending upwardly form the side plates 36 and 37. The bottom surface 57 of the hopper 56 is tangent, or approximately tangent, to the roller 31 when same has moved back somewhat away from the disk 11 and entered into a normal operating position.
The knives 22 are mounted into said disk 11 in any convenient manner such as being held against a wedge-shaped bar 61 which bar is firmly fixed by screws, welding or otherwise to the rear face of the disk 11 and said knives are held agianst said bar by a clamp bar 62 which is held in position by appropriate screws 63. An adjustment screw 64 is provided in a conventional manner for advancing the knife downwardly.
A bed knife 32 may be provided, if desired, especially where the roller 31 is permitted to move backwardly away from the knives more than a very limited distance, namely, a distance sufficient to destroy the functioning of said roller as a bedplate or anvil, or where relatively small brush is being cut such as under 1/2 inch in diameter, so that it might tend to be drawn past the curved surface of the roller 31. If and where such a fixed anvil is required, it may be provided between the side plates 36 and 37 and below the center of the feed roller 31. Said bed knife will comprise a blade 56 which is adjustably received into a bed knife base 57, said latter being rigidly fixed at its respective ends to said side plates 36 and 37. A screw 58 will in a conventional and presently known manner be tightenable to hold the bed knife 56 in any adjusted position.
OPERATION
The operation of the foregoing-described equipment will be readily understood from the description and drawings already given but will be reviewed to insure a full understanding of the invention.
With the prime mover started and the disk 11 rotating rapidly, as at a normal engine output speed, a workpiece W is placed on the roller 31 and urged downwardly toward the disk 11. Same is preferably held at an angle of approximately 45° to the horizontal and will normally be further guided by the edge of the hopper 54. The roller 31 is at this point held by its resilient mounting against the stop provided by the heads of the limit bolts 41 and 42 and only slightly spaced from the disk 11. As the knives 22 successively strike the leftward end of said workpiece, chips are sliced off and drawn by the airstream above mentioned through the openings 24, around the disk 11 and out through the discharge spout 21. The action of the knife against the end of the workpiece tends to pull the workpiece downwardly against the roller 31. The pressure thus created of the workpiece against the roller acts against the portion of the roller whose tangent forms an acute angle with respect to the face of the disk (namely, the tangent which is coincident, or parallel, with the surface 57 of the hopper) and thus the roller tends to urge the workpiece toward the disk. Thus, the action of the cutting knives tends to pull the workpiece still further into cutting position. This combined with the action of gravity on the workpiece insures that same will be carried all the way to its end to the cutting knives and the workpiece completely chipped. Where the spring 39 is a relatively heavy spring it will hold the roller 31 close to the paths of the knives and thus in effect function as an anvil or bed with which the knives cooperate and in such case the bed knife assembly 32 may in many instances be eliminated. It should be understood, however, that in this arrangement the spring 39 is sufficiently heavy as to permit very little yielding and consequent movement of the roller 31 away from the disk 11 so that the function of said spring is largely to absorb shock and minimize the likelihood of breaking of parts of the equipment.
It will be apparent that with a very long workpiece the operator will often find it desirable to support and guide same in the initial portion of the chipping thereof but that as same becomes shorter he can soon let it go and the self-feeding operation will take over.
While the illustrated embodiment is shown with the disk in a vertical position and the feeding at a substantially 45° angle to the horizontal, it will be apparent that this is a function of the most simple and therefore inexpensive manner of mounting the motor and disk. However, it will be apparent that the motor and disk can also be mounted so that the disk itself makes an acute angle to the horizontal, such as a 45° angle, and in such case the workpiece may be fed thereto in a substantially horizontal manner. This, of course, eliminates the use of gravity to assist the feeding operation but it has some advantage in ease of feeding in that the workpieces are then fed substantially horizontally rather than being lifted as is necessary when same are to be fed at a downwardly sloping 45° angle. Of course, a combination of the foregoing concepts is also possible, namely to slope the disk at approximately 60° or 70° to the horizontal with the feeding then sloping at approximately 20° or 30° to the horizontal.
MODIFICATIONS
In FIG. 6 there is shown a modification wherein the drum 31 is mounted by a shaft 33 onto an adjustable screw 71 which is received into a fixed bracket 72, said latter being mounted on the side plate 36. Obviously, a screw and bracket similar to the screw 71 and bracket 72 will be provided on the opposite side of the roller 31 and will be fixed to the side plate 37. Thus, the spacing of the roller 31 from the disk 11 may be adjusted by suitable adjustments of the nuts 73 and 74 but no resilience is here provided for the mounting. Here again the roller 31 itself functions essentially as the anvil or bedplate against which the knives operate and the bed knife assembly 32 may, if desired, be omitted.
In FIG. 7 there is shown the use of a roller 31a in association with a disk, or drum 76. Said drum 76 functionally corresponds to the disk 11 excepting that in this case the knives 77 are mounted on the peripheral surface thereof rather than on a face surface as in the case of the disk 11. The drum 76 is driven in any convenient manner, not shown, such as the same manner as that in which the disk 11 is driven. The hopper structure 78 is provided having, in this embodiment, a horizontal wall surface 79 for the support and feeding of workpieces for chipping to the drum. The roller is mounted so as to project a short distance above the plane of the wall 79 whereby to receive the end of the workpiece and feed same to the knives of the drum. Said roller 31a together with the drum 76 again, as in the embodiments of FIGS. 1-6 form converging walls whereby to form an acute angle on the end of a workpiece. This in turn assists in urging the workpiece into the chipping zone as the chipping operation progresses. The drum 31 may be mounted in either manner shown above in FIGS. 1-, 6, namely either for movement downward against resilient force as in FIG. 5 or as in FIG. 6 an adjustable positioning which is fixed for any given adjusted position. Finished chips are discharged through the conduit 81, partly by being thrown therethrough from the chipping drum 76 and partly by the air blast drawn in from the hopper 78 by the knives on the chipping drum and from thence expelled as an air blast through the discharge conduit 81.
Testing of machines embodying the foregoing described invention have shown that they are highly effective on relatively dry wood so that the necessity for frequent resharpening of the blades, as distinguished from previously known somewhat similar machines which when used on dry wood required frequent resharpening of the cutting blades.
Although a specific embodiment of the invention has been disclosed for illustrative purposes it will be recognized that a variety of variations may be made therein in addition to those above expressly referred to which variations will still be within the scope of the hereinafter appended claims and same will accordingly be considered as covered by said claims excepting as the claims by their own terms expressly provide otherwise.