HONING JIG
The honing jig has a base on which a whetstone or other abrasive substance is mounted. A pair of spaced guide rods extends the length of the base. A carriage is mounted to tubes which slide along the rods and through which the guide rods extend. The blade to be sharpened is held to the carriage by a clamp and the clamp swivels on the carriage to allow the inclination of the blade relative to the whetstone to be adjusted. The angle of the guide rods can be adjusted to permit fine adjustment of the inclination of the blade.
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This invention relates to honing jigs and more particularly to a jig for sharpening the cutting edge of a blade in a tool such as a plane and a chisel. In one embodiment of the invention, the jig has provision for adjustment of the inclination of the blade according to the angle of its cutting surface. In another embodiment, the jig has provision for honing a secondary bevel on the cutting edge.
BACKGROUND OF THE INVENTIONThe conventional method of sharpening a blade of a chisel or a plane is to clamp the blade to a honing tool having a roller and to push the tool across an abrasive surface such as that of a whetstone. Such a method has a number of shortcomings, one of which is that skill is required to operate the tool properly. Many carpenters and particularly hobbyists lack such skill and do more harm that good to a blade when they attempt to sharpen it by this method.
Anther shortcoming of the method is that the tool tends to run off the whetstone as it is pushed back and forth. Unless particular care is taken to prevent this, the blade can be damaged as it is being pushed. Furthermore, the operator may injure himself since his hand may be struck by the blade if his hand is in its path.
SUMMARY OF THE INVENTIONIn one aspect of the present invention, a honing jig for use in sharpening an object generally comprises a base adapted to support an abrasive substance thereon and a carriage assembly constructed for releasably mounting the object to be sharpened. The base and carriage assembly are mounted with respect to each other for obtaining relative translational movement of the object mounted on the carriage assembly and the abrasive substance on the base so that a portion of the object engaging the abrasive substance is sharpened.
In another aspect of the present invention, a honing jig for use in sharpening a blade generally comprises a base adapted to support a whetstone thereon, and guide rails pivotally mounted on the base at one end of each guide rail. A carriage assembly comprises a slider and a fixture pivotally mounted on the slider. The slider is mounted on the guide rails for movement along the guide rails with respect to the base. The fixture is adapted to mount the blade thereon. The slider and fixture include alignable apertures, where at least some of the apertures are located in positions so that the fixture must assume different angles with respect to the slider to align different apertures. A pin receivable in selected aligned apertures can thereby fix the angular orientation of the fixture relative to the slider. A stepped pedestal is adapted to support the guide rails in a first position in which the guide rail makes a first angle with the base, and in a second position in which the guide rail makes a second angle with the base different from the first angle.
In yet another aspect of the present invention, a method of honing a blade generally comprises pivotally moving a blade fixture at a selected angle for the blade. The blade fixture is secured at the selected angle mounting the blade in the fixture at the selected angle, and then the securement of the fixture is released. The blade is moved into engagement with an abrasive substance, and the blade is translated across the abrasive substance to hone the blade.
The honing jig of the invention is described with reference to the accompanying drawings in which:
Like reference characters refer to like parts throughout the description of the drawings.
With reference to
The whetstone is seated on base 10 and is located on the base by stop members 40a,b at each of its ends. Stop member 40a is immovably fixed to the base while stop member 40b is moveable in a T-slot 42 in the base 10 by loosening thumbscrew 44 so that the spacing between the two stop members can be adjusted to accommodated whetstones of different lengths. Whetstones of different lengths can be commonly encountered in the market, and the honing jig of the illustrated embodiment is capable of accommodating them.
With reference to
A number of apertures 56 extend through the adjustment plate 26. The apertures 56 are spaced apart from each other and extend from the front wall 26b through the rear wall 26a. A series of apertures 60 extend inward from the curved area of the block 54 and are arranged, as illustrated in
In
In summary, each aperture 56 in the adjustment plate 26 will align with only one aperture 60 in the angle-adjusting block 54 at any one time and when an aperture in one is in alignment with an aperture in the other, no other apertures will be in alignment. Only by pivoting the block will other the apertures 56, 60 in turn be brought into alignment. Pivoting of course causes jaws 46, 48 to conjointly pivot with resulting pivoting of the blade 32 so that the inclination of the blade relative to the whetstone 34 will vary according to which apertures 56, 60 in the plate 26 and block 54 are in alignment. The shank of a locating pin 64 is receivable in any one of the pairs of apertures 56, 60 in alignment. The pin 64 acts to rotationally lock the block 54 relative to the plate 26. Such immobilization causes a like immobilization of the blade 32.
With reference to
The operation of the locating pin 64 is as follows: first an operator immobilizes the swiveling clamp 30 relative to the adjustment plate 26 at a predetermined angle by inserting the pin through selected aligned apertures 56, 60. He then positions the cutting edge of a blade 32 to be sharpened on the whetstone 34 and secures the blade to the swiveling clamp 30. He then removes the pin 64 to allow him to force the cutting edge into firm and solid contact with the whetstone so that the whetstone can sharpen the edge. the angle of the blade 32 relative to the whetstone set by the pin 64 is not materially changed. The operator can then move the blade 32 back and forth on the whetstone in order to sharpen the cutting edge. Friction between the cutting edge 32a and the whetstone 34 will hold the blade at the same angle.
Should the operator desire to alter the existing angle of the cutting edge 32a, he would disconnect the blade 32 from the swiveling clamp 30, set the swiveling clamp at the new angle by means of the locating pin 64, place the blade so that its cutting edge 32a is in contact with the whetstone 34, secure the blade to the swiveling clamp and finally, remove the locating pin. The cutting edge 32a of the blade 32 is then ready to be sharpened as before, but at a new angle.
As previously indicated, the location of the apertures 60 in the block 54 will determine the angle of the blade 32 at each stop point. It is preferred that the angle at each stop point be an integer and the angle between successive stop points be always the same. For example the angle at the stop points can be 15, 20, 25, 30 degrees and so on. However, other angles may be used without departing from the scope of the present invention. In
With reference again to
The dual supporting block 20 has a pair of apertures 76 for receipt of studs 74. Knobs 78 are threadably received on the upper ends of the studs 74. Tightening of the knobs 78 immobilizes both the supporting block 20 and the pedestal 68. Loosening of the knobs 78 allows the supporting block 20 to be raised so that the pedestal 68 is free to slide forward or backward with the studs 74 moving in the slots 72. The pedestal 68 can be slid from the position illustrated in
The ends of the guide rods 18a, 18b opposite the dual supporting block 20 are pivotally connected by end members 14 to supporting blocks 12a,b as previously indicated. Sliding of the pedestal 68 from the position illustrated in
In
It will be further understood, of course, that modifications can be made in the structure of the honing jig of the invention without departing from the scope of the invention as defined in the following claims.
Claims
1. A honing jig for use in sharpening an object, the honing jig comprising:
- a base adapted to support an abrasive substance thereon;
- a carriage assembly constructed for releasably mounting the object to be sharpened, the base and carriage assembly being mounted with respect to each other for obtaining relative translational movement of the object mounted on the carriage assembly and the abrasive substance on the base so that a portion of the object engaging the abrasive substance is sharpened.
2. A honing jig as set forth in claim 1 wherein the carriage assembly is mounted for selectively adjusting the angle of the object held by the carriage assembly with respect to the abrasive substance on the base.
3. A honing jig as set forth in claim 2 wherein the carriage assembly comprises a fixture for releasably mounting the object and a plate, the fixture being pivotally mounted on the plate for selectively adjusting the angle of the fixture relative to the plate.
4. A honing jig as set forth in claim 3 wherein the carriage assembly further comprises a connector for releasably connecting the fixture and the plate together at a fixed angle.
5. A honing jig as set forth in claim 4 wherein the connector comprises a pin, the plate having openings sized to receive the pin and the fixture having corresponding openings sized to receive the pin.
6. A honing jig as set forth in claim 5 wherein the openings in the fixture are arranged generally along a line that is angled with respect to a line along which the openings in the plate are arranged whereby the angle of the fixture is determined by which of the openings in the fixture receives the pin.
7. A honing jig as set forth in claim 2 further comprising at least one guide rod, the carriage assembly being slidably mounted on the guide rod for movement therealong with respect to the guide rod and base.
8. A honing jig as set forth in claim 7 wherein the guide rod is mounted with respect to the base for adjustment of the angle of the guide rod with respect to the base and the abrasive substance on the base.
9. A honing jig as set forth in claim 8 further comprising a first support pivotally mounting the guide rod generally at one end, and a second support mounting an opposite end of the guide rod.
10. A honing jig as set forth in claim 9 wherein the second support comprises a pedestal and a support block releasably mounted on the pedestal, the pedestal being formed to mount the support block at different distances from the base thereby to change the angle of the guide rod relative to the base.
11. A honing jig as set forth in claim 10 wherein the pedestal is formed with steps each sized and shaped for engaging and mounting the support block.
12. A honing jig as set forth in claim 10 wherein the pedestal is adapted to be releasably secured to the base in different locations on the base.
13. A honing jig as set forth in claim 12 wherein the pedestal further comprises a handle for use in moving the pedestal relative to the base.
14. A honing jig as set forth in claim 8 wherein the carriage assembly comprises a fixture for releasably mounting the object and a plate, the fixture being pivotally mounted on the plate for selectively adjusting the angle of the fixture relative to the plate.
15. A honing jig as set forth in claim 1 wherein the carriage assembly is mounted on the base for movement relative to the base, the honing jig further comprising at least one adjustable stop for limiting the travel of the carriage assembly relative to the base.
16. A honing jig as set forth in claim 15 further comprising at least one guide rod, the carriage assembly being slidably mounted on the guide rod for movement therealong with respect to the guide rod and base, the adjustable stop being adapted for selective positioning along the guide rod to engage the carriage assembly to limit its travel.
17. A honing jig as set forth in claim 1 wherein the base comprises a lower member and an abrasive substance support, the abrasive substance support being constructed for mounting on the lower member at different selected locations.
18. A honing jig for use in sharpening a blade, the honing jig comprising:
- a base adapted to support a whetstone thereon;
- guide rails pivotally mounted on the base at one end of each guide rail;
- a carriage assembly comprising a slider and a fixture pivotally mounted on the slider, the slider being mounted on the guide rails for movement along the guide rails with respect to the base, the fixture being adapted to mount the blade thereon, the slider and fixture including alignable apertures, at least some of the apertures being located in positions so that the fixture must assume different angles with respect to the slider to align different apertures;
- a pin receivable in selected aligned apertures thereby to fix the angular orientation of the fixture relative to the slider;
- a stepped pedestal adapted to support the guide rails in a first position in which the guide rail makes a first angle with the base, and a second position in which the guide rail makes a second angle with the base different from the first angle.
19. A method of honing a blade comprising:
- pivotally moving a blade fixture at a selected angle for the blade;
- securing the blade fixture at the selected angle;
- mounting the blade in the fixture at the selected angle;
- releasing the securement of the fixture;
- moving the blade into engagement with an abrasive substance;
- translating the blade across the abrasive substance to hone the blade.
Type: Application
Filed: Dec 14, 2007
Publication Date: Jan 1, 2009
Applicant: JessEm Tool Company (Greeneville, TN)
Inventor: Darrin E. Smith (Greeneville, TN)
Application Number: 11/956,823
International Classification: B24B 19/00 (20060101); B24B 1/00 (20060101);