CA2160622A1 - Adjustable angle knife - Google Patents
Adjustable angle knifeInfo
- Publication number
- CA2160622A1 CA2160622A1 CA002160622A CA2160622A CA2160622A1 CA 2160622 A1 CA2160622 A1 CA 2160622A1 CA 002160622 A CA002160622 A CA 002160622A CA 2160622 A CA2160622 A CA 2160622A CA 2160622 A1 CA2160622 A1 CA 2160622A1
- Authority
- CA
- Canada
- Prior art keywords
- knife
- counter
- counter knife
- leading edge
- further characterized
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27L—REMOVING BARK OR VESTIGES OF BRANCHES; SPLITTING WOOD; MANUFACTURE OF VENEER, WOODEN STICKS, WOOD SHAVINGS, WOOD FIBRES OR WOOD POWDER
- B27L11/00—Manufacture of wood shavings, chips, powder, or the like; Tools therefor
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Wood Science & Technology (AREA)
- Forests & Forestry (AREA)
- Milling, Drilling, And Turning Of Wood (AREA)
Abstract
A knife and counter knife is disclosed for a chipping machine that is provided with a knife holder having means for fixing the counter knife in place, and a clamping plate for clamping the knife firmly against the counter knife. The counter knife has a leading edge profiled to permit rotation of the knife. The bottom surface of the knife is complementarily profiled to rotate about the leading edge of the counter knife.
Description
21 6~B~
.
The present invention relates to the field of sawmill equipment, and provides a novel knife and counter knife combination for use with wood chipping apparatus. The present invention also provides a modified clamp for holding the knife in place against the counter knife, and a novel device for permitting the knife on a chipping machine or the like to be angled over a range of angles.
In this specification, reference will be made to chipping r-~h i nPc including disk chippers, drum chippers, chipper canters, chipper slabbers, chipper edgers, or chipper reman (remanufacturing) machines. It will be understood that these machines each utilize essentially the same type of knife, so no distinction will be made between them, and the present invention will be understood as extending to each of the foregoing ~--h;n~, and any other machinery utili7;n~ the same or similar knives.
Now, using a disk chipper as an example, the chipper comprises a monolithic massive steel disk into which pockets are formed on the outer surface. Each pocket extends radially from near the centre to near the perimeter of the disk, and includes a knife holder bolted into the pocket over a thin plate known as a control plate, a counter knife bolted onto the knife holder, a clamping plate over the knife holder, and between the clamping plate and the counter knife, a knife keyed 216~22 to the counter knife and forcibly held on the counter knife by the clamping plate. This form of system, that is generally considered the industry standard is shown for instance, in U.S.
Patent No. 4,997,018. The knife is fairly compact, double edged, with hardened edges. Unlike conventional chipper knife designs that utilized a massive knife equivalent to the clamping plate and knife of the above described system, the knife of the above described system is not considered re-grindable. It has a hardened edge for long life and can be honed, but is not of sufficient size or thickness for re-grinding involving stock removal to change the profile thereof.
It is sometimes necessary to change the angle of the knife blade to the surface of the disk. This is usually from 29 -31, for most softwoods and hardwoods, but for harder woods, such as very knotty wood, dry hardwood, or frozen wood, angles of up to about 35 or 36 are desired. To change the angle of the knife blade in a conventional solid blade system, the back surface of the blade is ground down, from about 1 to about 5O~
as required. This provides a correctly angled blade, but uses 2 0 up valuable stock on the blade . In the system described in U.S. Patent No. 4,997,018, referred to above, control plates having wedge shaped profiles are utilized, to angle the blade holder assembly resting on the control plate. Therefore, changing the angle of the blade holder requires substantially complete ~ pmhly of the pocket assembly, and use of a 21 6~B22 specialized, expensive, thin, wedge-shaped part. Moreover, since the blade holder will then be at an angle to the bottom surface pocket, the tapped hole in the blade holder will be at a slight angle to the bolt ~Yt~nr~; ng from through the disk.
When that bolt is torqued down, then, its head will not seat perfectly flatly against the back of the disk. This may create problems in tightening the blade holder securely in the pocket.
The object of the present invention, therefore, is to provide a knife for a system compatible with the knife holders of the system shown in U.S. Patent No. 4,997,018, which knife can be angled at from about 29 to about 36 from the face of a disk without the need to change for knives of different angles or to use a wedge-shaped control plate located under the knife holder to control the infeed force of the knife or lliF~i'lFF' ~,le all components in the pocket of the disk.
In order to accomplish the foregoing object, the present invention provides a novel knife and counter knife combination, preferably for use with a modified clamp, as will be described. Also provided are novel spacers for effecting angulation between the knife and counter knife.
In a broad aspect, then, the present invention relates to a knife and counter knife for a chipping machine that is provided with a knife holder having means for fixing said 216~622 counter knife in place, and a clamping plate for clamping said knife firmly against said counter knife, characterized in that said counter knife has a leading edge profiled to permit rotation of said knife, the bottom surface of said knife being complementarily prof iled to rotate about the leading edge of said counter knife.
In drawings that illustrate the present invention by way of example:
Figure 1 is a cross-sectional view through a knif e blade of a first PrhQrl;r-nt of the present invention, mounted in a knife holder; and Figure 2 is a cross-sectional view through a knife blade of a second ~ nt of the invention.
Referring now to Figure 1, a knife holder 4, for insertion into, e.g., the knife pocket of a chipper disk, is shown Pqll;rpPd with the knife of the present invention. The knife holder 4 is provided at its forward upper edge with a counter knife 2, the forward edge of which has a semi-circular pro~ection 21 extending its length. Just behind the projection 21 is a groove 9 which may, for instance, be a shallow squared groove, as shown in the drawings.
The knife 1 of the present invention is provided with a pair of symmetrically disposed;emi-circular grooves 11 on its ~ 2l~n~2~
under surface. Each of these grooves is dimensioned to provide a close fit with semi-circular projection 21 on the counter knife. Therefore, with the knife 1 mounted on the counter knife 2, the knife 1 can rotate forwardly, as shown in Figure 1. In the figure, the knife 1 shown in solid lines is set at 35 to the face of the disk, the angle of which is shown as a horizontal line above the figure. The actual face of the disk would, of course be below the cutting edge of the knife.
Maintaining the knifQ at a 35 angle is a spacer rod 7 inserted in shallow square groove 9 in the counter knife 2, extending into the rearward groove 11 of the knife 1. As will be seen in Figure 1, the lowermost surface of rod 7 is machined way to form a smooth flat surface, and to provide the rod with a precise width, whereby the angle setting of the knife can be reliably duplicated. In order to provide a wide range of possible angular settings of the knife, a number of rods, e.g., one for each degree or half degree between 29 and 35 is provided. shown in Figure 1 is a second angular setting, 30 of the knife, la, in phantom. It will be seen that the rearward groove 11 on the knife is lifted, and the space for rod 7 is wider. A different rod would, therefore, be inserted and the clamp bolt 6 tightened, to tighten clamp 5 against the knife 1. As shown in Figure 1, the forward edge of clamp 5 will be shortened, to ensure that clamping pressure, without creating a gap between the forward edge of the clamp and the knife 1 is exerted on the top surface of the knife 1, between the grooves on the lower surface thereof. This ensures that the clamping pressure does not act to rotate the knife 1.
Referring now to Flgure 2, an alternative form of the present invention is disclosed. In this form, the spacer rod 7 is replaced with a spacer wedge 8 having a head 81, and a wedge-shaped tail 82. The tail 82 is provided with apertures for set screws 83 to secure the tails to the counter knife.
The head 81 and tail 82 are dimensioned to provide the angulation of knife 1 desired. As is the case with rods 7 for the form of invention shown in Figure 1, the spacer wedges 8 are provided in sets of incremental angles, an entire set permitting a user to set the blade of a chipper at any desired angle. Preferably, the angle setting associated with a spacer rod 7 or wedge 8 is stamped on it, permanently.
It will be understood that the knife of the present invention is double edged, with back grind bevels under each edge, so it can be reversed for usage of each edge before re-honing .
It is to be understood that the examples described above are not meant to limit the scope of the present invention. It is expected that nl~l uus variants will be obvious to the person skilled in the f ield of wood chipping equipment design without any departure from the spirit of the invention. The 21~622 appended claims, properly con6trued, form the only limitation upon the scope of the invention.
.
The present invention relates to the field of sawmill equipment, and provides a novel knife and counter knife combination for use with wood chipping apparatus. The present invention also provides a modified clamp for holding the knife in place against the counter knife, and a novel device for permitting the knife on a chipping machine or the like to be angled over a range of angles.
In this specification, reference will be made to chipping r-~h i nPc including disk chippers, drum chippers, chipper canters, chipper slabbers, chipper edgers, or chipper reman (remanufacturing) machines. It will be understood that these machines each utilize essentially the same type of knife, so no distinction will be made between them, and the present invention will be understood as extending to each of the foregoing ~--h;n~, and any other machinery utili7;n~ the same or similar knives.
Now, using a disk chipper as an example, the chipper comprises a monolithic massive steel disk into which pockets are formed on the outer surface. Each pocket extends radially from near the centre to near the perimeter of the disk, and includes a knife holder bolted into the pocket over a thin plate known as a control plate, a counter knife bolted onto the knife holder, a clamping plate over the knife holder, and between the clamping plate and the counter knife, a knife keyed 216~22 to the counter knife and forcibly held on the counter knife by the clamping plate. This form of system, that is generally considered the industry standard is shown for instance, in U.S.
Patent No. 4,997,018. The knife is fairly compact, double edged, with hardened edges. Unlike conventional chipper knife designs that utilized a massive knife equivalent to the clamping plate and knife of the above described system, the knife of the above described system is not considered re-grindable. It has a hardened edge for long life and can be honed, but is not of sufficient size or thickness for re-grinding involving stock removal to change the profile thereof.
It is sometimes necessary to change the angle of the knife blade to the surface of the disk. This is usually from 29 -31, for most softwoods and hardwoods, but for harder woods, such as very knotty wood, dry hardwood, or frozen wood, angles of up to about 35 or 36 are desired. To change the angle of the knife blade in a conventional solid blade system, the back surface of the blade is ground down, from about 1 to about 5O~
as required. This provides a correctly angled blade, but uses 2 0 up valuable stock on the blade . In the system described in U.S. Patent No. 4,997,018, referred to above, control plates having wedge shaped profiles are utilized, to angle the blade holder assembly resting on the control plate. Therefore, changing the angle of the blade holder requires substantially complete ~ pmhly of the pocket assembly, and use of a 21 6~B22 specialized, expensive, thin, wedge-shaped part. Moreover, since the blade holder will then be at an angle to the bottom surface pocket, the tapped hole in the blade holder will be at a slight angle to the bolt ~Yt~nr~; ng from through the disk.
When that bolt is torqued down, then, its head will not seat perfectly flatly against the back of the disk. This may create problems in tightening the blade holder securely in the pocket.
The object of the present invention, therefore, is to provide a knife for a system compatible with the knife holders of the system shown in U.S. Patent No. 4,997,018, which knife can be angled at from about 29 to about 36 from the face of a disk without the need to change for knives of different angles or to use a wedge-shaped control plate located under the knife holder to control the infeed force of the knife or lliF~i'lFF' ~,le all components in the pocket of the disk.
In order to accomplish the foregoing object, the present invention provides a novel knife and counter knife combination, preferably for use with a modified clamp, as will be described. Also provided are novel spacers for effecting angulation between the knife and counter knife.
In a broad aspect, then, the present invention relates to a knife and counter knife for a chipping machine that is provided with a knife holder having means for fixing said 216~622 counter knife in place, and a clamping plate for clamping said knife firmly against said counter knife, characterized in that said counter knife has a leading edge profiled to permit rotation of said knife, the bottom surface of said knife being complementarily prof iled to rotate about the leading edge of said counter knife.
In drawings that illustrate the present invention by way of example:
Figure 1 is a cross-sectional view through a knif e blade of a first PrhQrl;r-nt of the present invention, mounted in a knife holder; and Figure 2 is a cross-sectional view through a knife blade of a second ~ nt of the invention.
Referring now to Figure 1, a knife holder 4, for insertion into, e.g., the knife pocket of a chipper disk, is shown Pqll;rpPd with the knife of the present invention. The knife holder 4 is provided at its forward upper edge with a counter knife 2, the forward edge of which has a semi-circular pro~ection 21 extending its length. Just behind the projection 21 is a groove 9 which may, for instance, be a shallow squared groove, as shown in the drawings.
The knife 1 of the present invention is provided with a pair of symmetrically disposed;emi-circular grooves 11 on its ~ 2l~n~2~
under surface. Each of these grooves is dimensioned to provide a close fit with semi-circular projection 21 on the counter knife. Therefore, with the knife 1 mounted on the counter knife 2, the knife 1 can rotate forwardly, as shown in Figure 1. In the figure, the knife 1 shown in solid lines is set at 35 to the face of the disk, the angle of which is shown as a horizontal line above the figure. The actual face of the disk would, of course be below the cutting edge of the knife.
Maintaining the knifQ at a 35 angle is a spacer rod 7 inserted in shallow square groove 9 in the counter knife 2, extending into the rearward groove 11 of the knife 1. As will be seen in Figure 1, the lowermost surface of rod 7 is machined way to form a smooth flat surface, and to provide the rod with a precise width, whereby the angle setting of the knife can be reliably duplicated. In order to provide a wide range of possible angular settings of the knife, a number of rods, e.g., one for each degree or half degree between 29 and 35 is provided. shown in Figure 1 is a second angular setting, 30 of the knife, la, in phantom. It will be seen that the rearward groove 11 on the knife is lifted, and the space for rod 7 is wider. A different rod would, therefore, be inserted and the clamp bolt 6 tightened, to tighten clamp 5 against the knife 1. As shown in Figure 1, the forward edge of clamp 5 will be shortened, to ensure that clamping pressure, without creating a gap between the forward edge of the clamp and the knife 1 is exerted on the top surface of the knife 1, between the grooves on the lower surface thereof. This ensures that the clamping pressure does not act to rotate the knife 1.
Referring now to Flgure 2, an alternative form of the present invention is disclosed. In this form, the spacer rod 7 is replaced with a spacer wedge 8 having a head 81, and a wedge-shaped tail 82. The tail 82 is provided with apertures for set screws 83 to secure the tails to the counter knife.
The head 81 and tail 82 are dimensioned to provide the angulation of knife 1 desired. As is the case with rods 7 for the form of invention shown in Figure 1, the spacer wedges 8 are provided in sets of incremental angles, an entire set permitting a user to set the blade of a chipper at any desired angle. Preferably, the angle setting associated with a spacer rod 7 or wedge 8 is stamped on it, permanently.
It will be understood that the knife of the present invention is double edged, with back grind bevels under each edge, so it can be reversed for usage of each edge before re-honing .
It is to be understood that the examples described above are not meant to limit the scope of the present invention. It is expected that nl~l uus variants will be obvious to the person skilled in the f ield of wood chipping equipment design without any departure from the spirit of the invention. The 21~622 appended claims, properly con6trued, form the only limitation upon the scope of the invention.
Claims (8)
1. A knife and counter knife for a chipping machine that is provided with a knife holder having means for fixing said counter knife in place, and a clamping plate for clamping said knife firmly against said counter knife, characterized in that said counter knife has a leading edge profiled to permit rotation of said knife, the bottom surface of said knife being complementarily profiled to rotate about the leading edge of said counter knife.
2. A knife and counter knife as claimed in claim 1 further characterized in that means are provided behind the profiled leading edge of said counter knife to maintain said knife at a desired angle, against the pressure of said clamping plate.
3. A knife and counter knife as claimed in claim 2, further characterized in that said leading edge of said counter knife has a semi-circular profile and the lower surface of said counter knife is provided with symmetrically disposed grooves complementary to said semi-circular leading edge of said counter knife.
4. A knife and counter knife as claimed in claim 3, further characterized in that there is provided in the surface of said counter knife behind said semi-circularly profiled leading edge, a groove to accommodate said means to maintain said knife at a said desired angle.
5. A knife and counter knife as claimed in claim 4, further characterized in that said means to maintain said knife at a said desired angle is a rod insertable between said groove in said counter knife and the rearward most groove in the undersurface of said knife.
6. A knife and counter knife as claimed in claim 5, further characterized in that said rod has a longitudinally flattened surface, there being a plurality of rods of selected widths provided whereby a desired width corresponding to a desired angulation of said knife can be selected.
7. A knife and counter knife as claimed in claim 6, wherein said rods are provided with wedge-shaped projections extending along the length thereof, at angles corresponding to the angulation of said knife, to fill the space between the knife and the counter knife.
8. A knife and counter knife as claimed in any preceding claim, wherein said clamp seats firmly against the top surface of said knife when said knife is at maximum angulation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002160622A CA2160622A1 (en) | 1995-10-16 | 1995-10-16 | Adjustable angle knife |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002160622A CA2160622A1 (en) | 1995-10-16 | 1995-10-16 | Adjustable angle knife |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2160622A1 true CA2160622A1 (en) | 1997-04-17 |
Family
ID=4156775
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002160622A Abandoned CA2160622A1 (en) | 1995-10-16 | 1995-10-16 | Adjustable angle knife |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2160622A1 (en) |
-
1995
- 1995-10-16 CA CA002160622A patent/CA2160622A1/en not_active Abandoned
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |
Effective date: 19991018 |