WO2007139549A1

WO2007139549A1 - Self-aligning blade angle guide

Info

Publication number: WO2007139549A1
Application number: PCT/US2006/020919
Authority: WO
Inventors: Ronald Swartz
Original assignee: Ronald Swartz
Priority date: 2006-05-31
Filing date: 2006-05-31
Publication date: 2007-12-06

Abstract

A device for use in the manual sharpening of arrow broadheads, razor blades and the like includes a unique symmetrical clamp-and-axle assembly having interchangeable, matched pairs of special purpose jaw members for gripping blades of differing configurations. When coupled to the frame, the clamp-and-axle assembly is freely rotatable, and this free rotation automatically aligns the length of the edge of the blade with the surface of a sharpening medium. Additionally these rotational and self-aligning capability enables the user to service both sides of the blade's edge with a single blade clamping operation, by manually rotating the clamp 180 degrees between passes along the surface of the sharpening medium.

Description

TITLE:

SELF-ALIGNING BLADE ANGLE GUIDE

INVENTOR: RONALD F. SWARTZ

FIELD OF THE INVENTION

[0001] The present invention generally relates to a device for use in the manual sharpening of arrow broadheads, razor blades, and specialty blades.

BACKGROUND OF THE INVENTION

[0002] The need to sharpen or re-sharpen blades of cutting instruments is ancient.

While in theory the actions involved in the sharpening process are fairly simple, in practice a good deal of skill is required, and sharpening has been a difficult task for the average person. This is particularly true of smaller blades. This is evidenced by the countless devices that have been designed to aid the user in the sharpening process, and by the fact that entire industries exist solely to manufacture disposable blades of widely varying styles and purposes.

[0003] Various prior art devices for aiding in the manual sharpening of blades generally have had a common goal of maintaining a fixed angle between an abrasive sharpening surface and a blade as the blade is moved across the sharpening surface, or more recently, as the abrasive surface is moved across the blade. While this aspect of the sharpening process is critical, to efficiently sharpen any blade requires that the following actions take place in concert:

1) The blade to be sharpened must move smoothly across an abrasive surface while being held at a fixed angle to the surface.

2) The entire length of the blade edge must come in contact with the abrasive surface at a uniform rate each time the blade is moved across the surface.

3) The blade must be turned over after each completed "pass" across the abrasive surface and a similar pass must be made on the opposite side of the blade. [0004] Step 3 is necessary to insure that a uniform bevel is maintained, because the action of moving the dull blade across the abrasive surface, such as a whetstone, has the following two separate effects on the blade: 1) The portion of the blade edge that is in contact with the abrasive surface or the "underside" is ground away. Defects and deformities are removed and a clean smooth surface is created.

2) As the underside of the blade edge is ground away, microscopic burrs and filings are formed on the opposite or "top" side of the edge.

[0005] These burrs and filings are detrimental to the desired effect of sharpening as they continue to build up with each pass across the abrasive surface. In order to minimize this undesirable effect, the blade must be turned over after each completed pass across the abrasive surface and a similar pass must be made on the opposite side. This process is repeated until the blade is sharp. Accordingly, both sides of the blade edge bevel are uniformly ground, burrs and filings are not permitted to build up, and a greater degree of sharpness is achieved. [0006] Various devices that hold blades at fixed angles to a sharpening surface are known in prior art and are known to consist of basically familiar, expected and obvious structural configurations. However, there has been a long-standing need for a device that is capable of performing all of the following functions:

1) securely hold the blade to be sharpened at a fixed angle to the sharpening surface;

2) ensure that the entire length of the blade edge is uniformly ground on each pass across the sharpening surface;

3) easily facilitate the superior process of alternately passing each side of the blade across the sharpening surface; and 4) enable the user to service both sides of the blades edge with a single blade clamping operation.

[0007] For example, Longbrake, U.S. Pat. No. 3,819,170, describes a hand-held device for the sharpening of knives and arrow broadheads consisting of a vise for securing the blade to be sharpened, two individual guide bars mounted at the rear top and bottom of the vise, with each guide bar having a series of holes indicating several angle options, through which a length of rod with a sharpening stone attached to one end is passed, and the stone then is passed across the blade. This device secures the blade at a fixed angle to the sharpening stone but discourages the user from employing the process of alternately passing the stone over each side of the blade's edge, as the rod/stone must be withdrawn from one guide bar, the entire device inverted and the rod/stone reinserted in the corresponding angle hole of the opposite guide bar with each pass of the stone.

[0008] Alsch, U.S. Pat. No. 5,431,068, describes a device wherein a blade vise is horizontally mounted midway along a vertical main shaft which is topped with an assembly through which a single rod with multiple sharpening stones of varying grit mounted on one end is semi-permanently attached. Again, this devise does maintain a fixed angle between the blade and the sharpening surface; however, the drawback of this system is that the blade must be undamped, removed, turned over and re-clamped to sharpen the opposite side. This makes the process of sharpening more difficult and time- consuming than necessary. Further, passing the stone alternately over each side of the blade is impractical.

[0009] Juranitch, U.S. Pat. No. 3,654,823, discloses a device for the sharpening of arrowheads consisting of a two-piece clamp, which grips the arrowhead, and through its shape, also maintains a fixed angle to a sharpening surface, such as a whetstone. However, achieving uniform blade-to-stone contact on both sides of the blade with this device is difficult because the blade must be precisely positioned in the clamp, and any misalignment or structural anomaly of the clamp will result in a portion of the blade edge being held above the surface of the whetstone. Additionally, the clamp body rides the surface of the stone, which wears the device itself and clogs the porous surface of the sharpening stone with additional metal filings. [0010] Accordingly, objects and advantages of the present invention are to provide a sharpening system which:

1) enables the user to maintain a fixed angle between a blade to be sharpened and the sharpening surface;

2) is capable of sharpening blades of varying sizes and configurations with equal efficiency,

3) enables and encourages the user to utilize the superior process of alternately passing each side of the blade across the sharpening surface;

4) insures uniform blade-to-sharpening surface contact throughout the length of the blade; 5) enables the user to service both sides of the blade with a single blade clamping operation; and 6) enables the user, regardless of skill, knowledge or experience, to sharpen blades accurately and proficiently, with minimal effort and minimal opportunity for error.

100 [0011] These and other objects and advantages of the present invention will become apparent to readers from a consideration of the ensuing description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Fig. 1 is a side view of the clamp-and-axle assembly 30 with the razor

105 blade gripping jaw members 1, 2 installed.

[0013] Fig. 2 is a side view of the clamp-and-axle assembly 30 with the arrow broadhead gripping jaw members 13, 14 installed and the jaws 13, 14 in an open position.

[0014] Fig. 3 is a perspective front/top/side view of a razor blade gripping jaw member 1.

110 [0015] Fig. 4 is a perspective rear/bottom/side view of a razor blade gripping jaw member 1.

[0016] Fig. 5 is a perspective front/top/side view of an arrow broadhead gripping jaw member 13.

[0017] Fig. 6 is a perspective rear/bottom/side view of an arrow broadhead

115 gripping j aw member 13.

[0018] Fig. 7 is a perspective view of a preferred embodiment of the invention.

[0019] Fig. 8 is a cut away side view of a preferred embodiment of the invention, showing the clamp-and-axle assembly 30 partially inserted into the frame 9, with the frame 9, roller 10, and bracket 11 shown in cross section.

120 [0020] Fig. 9 is an exploded view of a preferred embodiment of the invention, with the razor blade gripping jaw members 1, 2.

[0021] Fig. 10 is a perspective operational view of a preferred embodiment of the invention, with an arrow broadhead secured in the jaws 13, 14.

[0022] Figs. 11 and 12 are perspective views of a preferred embodiment of the

125 invention illustrating the rotational capability of the clamp-and-axle assembly, with the razor blade gripping jaws 1, 2 installed. [0023] Similar reference characters denote corresponding features consistently throughout the attached drawings.

[0024] Although every reasonable attempt is made in the accompanying drawings

130 to represent the various elements of the embodiments in relative scale, it is not always possible to do so with the limitations of two-dimensional paper. Accordingly, in order to properly represent the relationship of various features among each other in the depicted embodiments and to properly demonstrate the invention in a reasonably simplified fashion, it is necessary at times to deviate from the absolute scale in the attached

135 drawings. However, one of ordinary skill in the art would fully appreciate and acknowledge any such scale deviations as not limiting the enablement of the disclosed embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Referring to Figs. 1 and 2, there is shown the self-aligning blade angle

140 guide of the present invention, which includes a clamp-and-axle assembly 30, which is designed to interchangeably retain a matched pair of jaw members. There are various matched pairs of special purpose jaw members, with differing configurations and purposes.

[0026] Referring to Figs. 3 and 4, a first pair of jaw members 1, 2 is designed to

145 grip razor blades and other small flat-bodied blades. A second pair of jaw members 13, 14 (Figs. 5 and 6) is designed to grip arrow broadheads. Either pair of jaw members 1, 2 (Figs. 3 and 4) or 13, 14 (Figs. 5 and 6) may be selectably installed in the clamp-and-axle assembly 30 by the user, depending on the type of blade to be sharpened.

[0027] Referring to Fig. 9, the clamp-and-axle assembly 30 further includes a bolt

150 3 having at its first end a bolt head 3a, which is standard hexagonal in configuration. Extending from the bolt head 3a is a threaded bolt shaft 3c. Mounted on the bolt shaft 3c is a base plate 4, a spacing washer 5, a cylindrical bearing 6, and a tensioning nut 7. Further, a recessed channel 3b encircles the bolt shaft 3c near its terminal end.

[0028] Referring generally to Figs. 7 and 8, a preferred embodiment of the

155 present invention further includes a hand-held frame 9 to which the clamp-and-axle assembly 30 is removably coupled by a semi-circular compressible ring 8 (Fig. 9) which is engaged in the recessed channel 3b of the bolt shaft 3c. Additionally, a bracket 11 and roller 10 assembly (Fig. 9) is secured to the underside of the frame 9. When coupled to the frame 9 the clamp-and-axle assembly 30 is freely rotatable within the frame 9 (Figs. 160 7, 11, and 12).

[0029] Fig. 1 shows the clamp-and-axle assembly 30 comprised of two individual jaw members 1, 2 of like profile and dimension, arranged in opposition with the head 3a of the bolt 3 captured in a recess between the jaw members 1, 2 and the bolt shaft 3c extending out through an aperture in the base of the jaw members 1, 2. The base plate 4

165 captures and retains the jaw members 1, 2 and bolt head 3a in combination. The base plate 4 has a hole 4a in its center through which the bolt shaft 3c extends. Following the base plate 4 on the bolt shaft 3c is a large spacing washer 5 followed by a cylindrical bearing 6, a tensioning nut 7 and the recessed channel 3b encircling the bolt shaft 3c near its terminal end. Fig.2 is a side view of the clamp-and-axle assembly 30 with the arrow

170 broadhead gripping jaws 1, 2 installed and in an opened position.

[0030] Now in greater detail, the specific configuration of the individual razor blade gripping jaw members 1, 2 is shown in perspective views in Fig. 3 (top view) and Fig.4 (bottom view). While Figs. 3 and 4 designate the illustrated jaw member 1, the jaw member 2 is a precise duplicate of jaw member 1 and a matched pair is arranged in 175 opposition when installed in the clamp-and-axle assembly 30. Constructed of rigid material and being of like profile and dimension, the jaw members 1, 2 are of appropriate width to securely grip a razor blade, small straight edged specialty blade, and the like.

[0031] The specific configuration of the individual arrow broadhead gripping jaw members 13, 14 is shown in perspective views in Figs.5 (top view) and 6 (bottom view).

180 Figs. 5 and 6 show that the broadhead gripping jaw members 13, 14 are precisely similar to the razor blade gripping jaw members 1, 2 with a single exception: the terminal ends of the razor blade gripping jaw members 1, 2 are perpendicular to the sides of the jaw members 1, 2 whereas the terminal ends of the broadhead gripping jaw members 13, 14 are cut or formed at an angle to the sides of the jaw members 13, 14. The angle is such

185 that when the jaw members 13, 14 are installed in the clamp-and-axle assembly 30, a conventional two-bladed arrow broadhead may be secured in the jaws 13, 14 in an orientation which positions one blade of the arrow broadhead between the blade gripping surfaces 22 and the opposite blade roughly parallel with the base edge of the jaws' 13, 14 outside planar surfaces 20 (Fig. 10). 190 [0032] While Figs. 5 and 6 designate the illustrated jaw member 13, the jaw member 14 is a precise duplicate of jaw member 13 with one exception: to create a working pair, the terminal ends of the jaw members 13, 14 are cut or formed at opposite angles from one another so that when the two are arranged in opposition, inside to inside, the terminal ends are parallel and aligned.

195 [0033] Figs. 3-6 show that each jaw member 1, 2, 13, 14 has an outside planar surface 20 a base planar surface 21 and two separate inside planar surfaces; a blade gripping surface 22 at the forward end, and a shelf edge 23 at the base end, the two being separated by a two sided recess which forms a structural shelf 24 at the base of each jaw member 1, 2, 13, 14. The sides of the recess are of substantially differing widths. The

200 narrower side 25 of the recess is perpendicular to the shelf edge 23 and sufficiently deep to accommodate one half of the width of the bolt head 3 a, and the wider side 26 of the recess is parallel with the outside planar surface 20. Furthermore, Figs. 4 and 6 show that the shelf edge 23 is perpendicularly bisected by a semi-elliptical recess 27. The width of the recess 27 is similar to the diameter of the bolt shaft 3c. The depth of the recess 27 is

205 less than one-half of the diameter of the bolt shaft.

[0034] Fig.7 shows the clamp-and-axle assembly 30 with the razor blade gripping jaws 1, 2 installed and the clamp-and-axle assembly 30 coupled to the hand-held, hollow- bodied frame 9. The cylindrical roller 10 is securely mounted in the bracket 11 which is attached to the frame 9 with two screws.

210 [0035] Referring to Figs.l and 9 to further detail the clamp-and-axle assembly 30,

Fig. 1 shows the arrangement of components in the assembly 30, and Fig. 9 provides perspective views of each individual component. Fig. 1 shows two individual jaw members 1, 2 arranged in opposition inside to inside, with the bolt head 3 a captured in the enlarged recess formed between the jaw members 1, 2, the underside surface of the

215 bolt head 3 a resting on each structural shelf 24 and the bolt shaft 3c captured between the two semi-elliptical recesses 27.

[0036] Figs. 1 and 9 further show that the jaw members 1, 2 and bolt head 3a in combination are captured and held in position by the base plate 4 which is rectangular in shape and constructed of stiff, flexible material. The bolt shaft 3c extends out through 220 the hole 4a in the center of the base plate 4. The diameter of the hole 4a closely matches the diameter of the bolt shaft 3c. Additionally, each long edge of the rectangular base plate 4 has a continuous narrow extension 4b, 4c, which is folded or formed to capture the base portion of each jaw member's outside planar surface 20. The span of the base plate 4 between the extensions 4b, 4c is such that each jaw member's semi-elliptical 225 recess 27 is held tightly against the bolt shaft. The width of the base plate 4 is similar to the width of the jaw members 1, 2, 13, 14.

[0037] Continuing with Figs. 1 and 9, the spacing washer 5 is constructed of rigid material with a low friction finish. The spacing washer 5 is positioned on the bolt shaft 3c against the outside surface of the base plate 4. The spacing washer 5 has an inside

230 diameter closely matching the outside diameter of the bolt shaft 3c, and an outside diameter that is slightly less than the height of the base plate 4. The cylindrical bearing 6 is constructed of rigid material with a low friction finish and is positioned on the bolt shaft 3c against the spacing washer 5. The inside diameter of the bearing 6 closely matches the primary diameter of the bolt shaft 3c, and the outside diameter of the bearing

235 6 closely matches the diameter of the hole 9a in the forward end of the frame 9. The threaded tensioning nut 7 is engaged on the threads of the bolt shaft 3c and positioned against the cylindrical bearing 6. The tensioning nut 7 has an outside diameter, which is smaller than the outside diameter of the cylindrical bearing 6. Shortly beyond the tensioning nut 7 on the bolt shaft 3c, the threads terminate and the remaining portion of

240 the bolt shaft 3c is slightly reduced in diameter. The recessed channel 3b encircles the bolt shaft 3c near its terminal end. The channel 3b is sufficiently deep to permit the ring 8 to compress into the channel 3b to the point where the ring 8 is sufficiently reduced in diameter to pass through the hole 9b in the frame 9.

[0038] Completing the description of the clamp-and-axle assembly 30, Figs. 8

245 and 9 show the compressible ring 8. The ring 8 is constructed of flexible, resilient material and is circular in cross section. The outside diameter of the ring 8 is similar to the primary diameter of the bolt shaft 3c, and the inside diameter of the ring 8 is larger than the diameter of the bolt shaft 3c within the recessed channel 3b. The width of the ring 8 is similar to the width of the channel 3b. The opening in the ring 8 is small enough

250 to require the ring 8 to be snapped into the channel 3b, while large enough to allow the ring 8 to be compressed to match the inside diameter of the hole 9b in the rear of the frame 9. [0039] Referring to Figs. 7-12, the frame 9 for the clamp-and-axle assembly 30 is constructed of rigid material and is basically a tubular rectangular block of which the 255 corners have been rounded top and bottom at one end creating an elongated "D" shape. The height and width of the frame 9 are similar to the height and width of the base plate 4.

[0040] Referring to Fig. 8, the hole 9a is centered in the square end of the frame

9. The diameter of the hole 9a closely matches the outside diameter of the cylindrical

260 bearing 6. The second hole 9b is centered in the rounded end of the frame 9, and the diameter of the hole 9b is slightly smaller than the outside diameter of the compressible ring 8. Further, the hole 9b shares a common centerline with the hole 9a in the square end of the frame 9. Additionally, the inner orifice 9c and the outer orifice 9d of the hole 9b are conically enlarged or reamed to match the outside diameter of the compressible

265 ring 8. The length of the frame 9 is such that when the clamp-and-axle assembly 30 is fully inserted into the frame 9, the spacing washer 5 will rest against the outside of the square end of the frame 9 and the compressible ring 8 will be captured in the rear tapered orifice 9c of the hole 9b.

[0041] Referring to Fig. 9, it can be seen that the cylindrical roller 10 is similar in

270 length to the width of the frame 9. An axle 10a extends from each end of the roller 10.

The roller 10 is retained by the bracket 11 which extends through the forward base section of the frame 9. The bracket 11 is bent 90 degrees at each end to form two arms

11a, lib, which extend down beyond the base of the frame 9. Each arm 11a, lib has a hole lie, Hd near its terminal end which captures an axle 10a of the roller 10. Each arm

275 11a, 1 Ib has a second hole 1 Ie, 1 If positioned above the axle holel Ic, 1 Id, the diameter of which is suitable to accept the mounting screws 12a, which attach the bracket 11 to the frame 9. Further preferably, the terminal ends of both bracket arms lla, 1 Ib are rounded to a radius which is smaller than that of the cylindrical roller 10, and are angled along their back edges from the radius to the point where the bracket arm lla, lib meets the

280 frame 9. Fig. 9 further shows that the portion of the bracket 11 that extends through the frame 9 is reduced in width so that the bracket 11 can be moved forward to position the forward edge of each bracket arm 1 Ia, 1 Ib flush with the forward edge of the frame 9.

[0042] The invention utilizes a unique symmetrical clamp-and-axle assembly 30, which is designed to interchangeably retain a pair of special purpose jaw members. This assembly 30 is removably coupled to a hand-held frame 9, which has a cylindrical roller 10 mounted in a bracket 11 below the forward end of the frame 9. While coupled to the frame 9, the clamp-and-axle assembly 30 is freely rotatable within the frame.

[0043] As shown in Figs. 1, 2 and 9, a pair of jaw members 1, 2 or 13, 14 are arranged in opposition with the bolt head 3a captured in the recess between the jaw members 1, 2, or 13, 14, and with the bolt shaft 3c captured between the two semi- elliptical recesses 27. The semi-elliptical recesses 27 serve to align the jaw members 1, 2 or 13, 14 and to prevent linear movement of the individual jaw members 1, 2 or 13, 14 within the base plate 4. The jaw members 1, 2 or 13, 14 and the bolt 3 in combination are captured by the base plate 4. The base plate 4 has a hole 4a in its center through which the bolt shaft 3c extends and through which the bolt shaft 3c can be reciprocally moved. Each long edge of the base plate 4 has a continuous narrow extension 4b, 4c which serves to tightly capture the base portion of each jaw member's outside planar surface 20. The base plate 4, the semi-elliptical recesses 27, and the bolt shaft 3c, in combination, serve to position and retain the jaw members 1, 2 or 13, 14 within the clamp-and-axle assembly 30.

[0044] Continuing with Figs. 1, 2 and 9, it can be seen that, when the clamp-and- axle assembly 30 is coupled to the frame 9, the large diameter spacing washer 5 serves to maintain rotational clearance between the base plate 4 and the frame 9 against the base plate 4 on the bolt shaft 3c. The spacing washer 5 also serves to support and stiffen the base plate 4 when the nut 7 is tightened. The cylindrical bearing 6 is positioned on the bolt shaft 3c against the spacing washer 5 and serves to support the forward end of the clamp-and-axle assembly 30 when the assembly 30 is inserted into the frame 9, and permits the clamp-and-axle assembly 30 to freely rotate in either direction within the frame 9. The nut 7 is engaged on the threads of the bolt shaft 3c and positioned against the bearing 6. The nut 7 is tightened to close the jaw members and loosened to open the jaws members. Shortly beyond the nut 7, the threads of the bolt shaft 3c terminate and the bolt shaft 3c is slightly reduced in diameter. The channel 3b encircles the bolt shaft 3c near its terminal end. The channel 3b serves as a seat for the ring 8, and provides a recess for the ring 8 to compress into, permitting the ring 8 to pass through the hole 9b in the rear of the frame 9. [0045] Referring to Figs. 7, 11 and 12, the portion of the bolt shaft 3c which is reduced in diameter and the bearing 6 provide smooth surfaces on which the clamp-and- axle assembly 30 rotates within the frame 9, and in combination provide support for, and stabilized rotation of, the clamp-and-axle assembly 30 within the frame 9.

320 [0046] Referring to Fig. 8, it can be seen that the semi-circular compressible ring

8 is engaged in the recessed channel 3b encircling the bolt shaft 3c. The compressible ring 8 serves to removably couple the clamp-and-axle assembly 30 to the frame 9 while permitting the assembly to freely rotate in either direction within the frame 9.

[0047] When changing from sharpening razor blades to sharpening arrow

325 broadheads or vice versa, removal and installation of the different styles of jaw members is performed by the user, as presently described. To remove a set of jaw members, the clamp-and-axle assembly 30 is first removed from the frame 9 and the nut 7 is loosened to the extreme rear of the threaded portion of the bolt shaft 3c. The bolt 3 is then pushed backward through the hole 4a in the base plate 4, forcing the jaw members to open 330 widely as the bolt head 3 a moves into the narrow opening between the gripping surfaces 22. The user then grips one jaw member in each hand and continues to open the clamp even further, which causes the individual jaw members to disengage both the base plate 4 and the bolt shaft 3c, and snap out of the assembly.

[0048] To install either set of jaws 1, 2 or 13, 14, the clamp-and-axle assembly 30

335 is removed from the frame 9 and the tensioning nut 7 is loosened to the extreme rear of the threaded portion of the bolt shaft 3c. The bolt shaft 3c is then pushed backward through the base plate 4 to a point which permits a chosen pair of jaw members to be arranged in opposition inside the base plate 4 with the bolt head 3 a positioned between the blade gripping surfaces 22, with each semi-elliptical recess 27 straddling the bolt

340 shaft 3c, and with the base edge of each jaw member's outside planar surface 20 contacting the inside surface of the base plate 4. The bolt shaft 3c is then pulled back through the hole 4a until the underside surface of the bolt head 3 a contacts the structural shelves 24. The bolt 3 is then rotated to position two opposing flat sides of the bolt head

3a parallel with the shelf edges 23. Continuing to pull the bolt 3 through the hole 4a in

345 the base plate 4 causes the individual jaw members to pivot towards each other on the base edges of their outside planar surfaces 20, and snap into place, capturing the bolt head 3a in the recess between the jaw members in a position that prevents the bolt head 3a from turning inside the recess. The tensioning nut 7 is then tightened into its working range.

350 [0049] The tolerance between the bolt head 3a and the recess created by arranging two jaw members in opposition is close enough to prevent the bolt 3 from turning with the nut 7, as the nut 7 is tightened or loosened, while loose enough to permit the jaw members to close. Regardless of which particular pair of jaws 1, 2 or 13, 14 is installed in the clamp-and-axle assembly 30, as the nut 7 is tightened, the bolt head 3a is drawn

355 down on the structural shelves 24 forcing the jaw members to pivot towards each other, closing the terminal ends of the jaws members tightly on the blade.

[0050] To sharpen a razor blade, or other straight-edged, flat-bodied blade, the razor blade gripping jaw members 1, 2 are installed in the clamp-and-axle assembly 30 as outlined above, and the nut 7 slightly loosened to allow the jaw members 1, 2 to open. A 360 blade is then placed between the jaw members 1, 2 and oriented with the edge of the blade positioned roughly parallel to the front and rear edges of the jaw members' outside planar surfaces 20, and extending approximately one quarter of one inch out of the terminal ends of the jaw members 1, 2. The nut 7 is then tightened to secure the blade in the assembly 30.

365 [0051] To sharpen a conventional two-bladed arrow broadhead, the broadhead gripping jaw members 13, 14 are installed in the clamp-and-axle assembly 30 (Fig. 2) as outlined above, and the nut 7 slightly loosened to allow to the jaws 13, 14 to open. The broadhead is then positioned with one blade between the jaw members 13, 14, and the opposite blade (the blade to be sharpened) oriented roughly parallel with the base edge of

370 the jaw members' outside planar surfaces 20. The nut 7 is then tightened to secure the broadhead in the assembly 30.

[0052] Fig. 7 shows the clamp-and-axle assembly 30 coupled to the frame 9, and shows the roller 10 mounted in the bracket 11 below the forward end of the frame 9. The bracket 11 serves to position and retain the roller 10, while permitting the roller to turn in 375 either direction. The roller 10 supports the frame 9 during the sharpening process, and provides a durable point of contact with the sharpening surface, which insures that the sharpening angle does not change over the life of the device.

[0053] Referring now to Fig. 8, to couple the clamp-and-axle assembly 30 to the frame 9, the user takes the clamp-and-axle assembly 30 in one hand, and the frame 9 in 380 the other hand and inserts the terminal end of the bolt shaft 3c into the frame 9 through the hole 9a and on into the hole 9b. As the terminal end of the bolt shaft 3c enters the hole 9b at the rear of the frame 9, the compressible ring 8 engages the enlarged orifice 9c of the hole 9b, resisting further travel of the bolt shaft 3c. Simultaneously, the bearing 6 begins to enter the hole 9a. The user then applies light pressure to force the ring 8 into,

385 and through, the hole 9b, where it is first compressed to a reduced diameter by the enlarged orifice 9c, which serves as a forcing cone, then passes through the cylindrical core of the hole 9b, and expands to its original diameter in the orifice 9d upon exiting the hole 9b, thereby coupling the clamp-and-axle assembly 30 to the frame 9 in snap-in, snap-out fashion. As the ring 8 passes through the hole 9b, the bearing 6 seats in the hole

390 9a, and the washer 5 comes to rest against the forward end of the frame 9.

[0054] Similarly, to remove the clamp-and-axle assembly 30 from the frame 9, the user grasps the frame 9 in one hand and the clamp-and-axle assembly 30 in the other hand, and simply pulls the two apart. The enlarged orifice 9d acts as a forcing cone to compress the ring 8, permitting the ring 8 to be pulled back through the hole 9b, and 395 releasing the clamp-and-axle assembly 30 from the frame 9.

[0055] This "snap connection," while securely coupling the clamp-and-axle assembly 30 to the frame 9, also permits free rotation of the clamp-and-axle assembly 30 within the frame 9. The bolt shaft 3c is supported at the front of the frame 9 by the cylindrical bearing 6 in its corresponding hole 9a, and is further supported at the rear of 400 the frame 9 by the bolt shaft 3c in the hole 9b.

[0056] A preferred method for sharpening blades in accordance with the present invention is the same regardless of which particular pair of jaw members are installed in the clamp-and-axle assembly 30. Moreover, regardless of the particular blade configuration, any blade to be sharpened is oriented in the jaw members with the edge to 405 be sharpened positioned roughly parallel with the base edge of the jaw members' outside planar surfaces 20.

[0057] Referring now to Fig. 10, after installing the desired jaw members 1, 2 or

13, 14 in the clamp-and-axle assembly 30, and after securing a blade to be sharpened in the jaw members, the user snaps the assembly 30 into the frame 9 and grasps the frame 9 410 in a manner which places the sides of the frame 9 between thumb and middle finger and places the index finger on the top surface of the frame 9 back from the base plate 4 (to avoid interfering with the rotation of the clamp-and-axle assembly 30). The device is then placed on a flat abrasive surface, such as a whetstone, with only the roller 10 contacting the surface of the stone. The weight of the frame 9 and any added pressure 415 applied by the user is evenly distributed along the length of the roller 10, which stabilizes the frame 9 on the surface of the whetstone.

[0058] The user next tips the device forward to bring the blade's edge into contact with the whetstone. As the blade's edge contacts the stone, a portion of the pressure being born by the roller 10 is shifted to the blade, and transferred through the blade to the

420 clamp-and-axle assembly 30. If the blade is not properly aligned in the jaw members, or if the clamp-and-axle assembly 30 is rotated to any position which presents the blade's edge to the stone at an angle which is not parallel with the surface of the stone, one end of the blade's edge will contact the surface before the other, causing the clamp-and-axle assembly 30 to rotate on its axis, until the entire length of the blade's edge contacts the

425 surface of the whetstone. The device is then rolled forward along the length of the stone with light pressure being applied to lap the first side of the blade's edge. Next, the user lifts the device from the whetstone, and with the free hand, rotates the assembly 30 approximately 180 degrees within the frame 9 to present the opposite side of the blade's edge for a similar pass across the stone. Again, as the blade contacts the surface of the

430 whetstone, the assembly 30 automatically rotates to the point where the entire length of the blade is uniformly contacting the stone. This process is repeated, rotating the assembly 180 degrees after each pass until the blade is sharp.

[0059] This self-aligning feature ensures continuous, uniform contact between the entire length of the blade's edge and the surface of the whetstone, and pressure being 435 equally distributed to all points along the length of the blade's edge at all times during the sharpening process. Further, the rotational capability of the clamp-and-axle assembly permits the user to service both sides of the blade's edge in a single blade clamping operation.

[0060] As such, each side of the blade is ground equally, burrs and filings are not

440 permitted to build-up on either side of the blade's edge, a uniform double bevel is maintained, and a superior method of sharpening is easily utilized, resulting in a superior edge with a greater degree of sharpness. [0061] Thus, the reader will see that the present invention provides a significant technological advancement in the field of manual sharpening devices and a simplification 445 of the manual sharpening process for both skilled and unskilled users while encouraging the user to utilize a superior method of sharpening.

[0062] While the preceding description contains many specificities, these should not be construed as limitations to the spirit or scope of the invention but rather to serve as an exemplification of one or more preferred embodiments. Many other variations in 450 design are possible.

[0063] For example, the mechanical design of the clamp may be changed to any configuration that achieves the goal of securely gripping the blade, such as a clamp having two jaw members, of which at least one is pivotable towards the other, with one jaw member having a hole through which a threaded fastener is passed to engage a 455 similarly threaded receiver in the opposite jaw member, whereby tightening the threaded fastener pulls the jaw members towards each other to grip the blade.

[0064] Another possible clamp configuration comprises one fixed jaw member and one pivotable jaw member, wherein a fulcrum and threaded set screw are used to pivot one jaw member towards the other to capture and secure the blade between the 460 jaws.

[0065] Yet another possible clamp configuration is a spring-type clamp that grips the blade by means of an internal or external spring that applies constant pressure to close the jaws and is forcibly opened by applying pressure to the rear portion of the jaws or to a leveraged extension of the jaw or jaws.

465 [0066] An equally functional clamp construction utilizes two flexible springs or spring plates which are joined at one end and press against each other at the other end, whereby a narrow opening is created between the springs or spring plates at the front of the clamp, and the blade forced into the opening and held in place by spring tension.

[0067] Other clamp designs too numerous to list may be substituted as the

470 particular clamp configuration is not critical to the function of the invention.

[0068] Likewise, the specific mechanical configuration and interaction of parts which enables the clamp to freely rotate may be changed and remain within the intended spirit of the disclosure. For example, the axle can be secured to the frame in a manner which prevents the axle from rotating and the clamp configured to rotate on or about the 475 fixed axle, as the spirit of the disclosure is the rotational capability of the clamp, rather than the specific mechanical configuration used to achieve rotational capability.

[0069] Further variations in the means of coupling the clamp to the axle and/or the axle to the frame are similarly possible. For example, the axle may be integral to the clamp and removable from the frame, or the axle may be integral to the frame and 480 removable from the clamp, or the axle can be removable from both the clamp and the frame, or the axle may be permanently attached to both the clamp and the frame, or any combination that provides for rotational capability of the clamp.

[0070] The shaft used to pivot the jaws does not need to double as the axle, the shaft may be shortened and a separate axle used to join the clamp assembly to the frame 485 assembly, nor does the axle necessarily need to extend completely through the frame, the axle may be attached permanently or removably to the frame at only the front, or an offset bracket and axle assembly could be mounted anywhere on the frame and continue to function as intended.

[0071] The length and/or diameter of the axle relative to the clamp and to the

490 frame could be increased or reduced to accommodate the particular clamp/axle/frame construction used. Likewise the shaft-type axle can be replaced by a spherical ball and socket joint for the purpose of connecting the clamp to the frame while providing for rotational capability of the clamp.

[0072] Furthermore, the spacing washer, cylindrical bearing and the tensioning

495 nut could be consolidated into a one-piece construction or, if an alternative clamp configuration is used, the spacing washer, cylindrical bearing and tensioning nut may be eliminated entirely from the construction.

[0073] The semicircular compressible ring on the bolt shaft and its corresponding receptacle in the rear of the frame could be replaced by any number of mated fitting 500 designs, which would serve the purpose of removably or permanently coupling the clamp to the frame, while providing for rotational movement of the clamp.

[0074] Likewise, the frame can be modified in numerous ways and continue to function within the spirit of the invention. For example, the shape of the frame may be rectangular, square, or round, elliptical or any other shape. The frame could also be solid,

505 rather than hollow. A simple elongated grip or handle having an axle, or configured to accept an axle, could be substituted for the preferred frame and would function adequately as described in the operation of the preferred embodiment.

[0075] The cylindrical roller may be changed to one or more wheels mounted on an axle or axles with appropriate mounting hardware used, or a spherical roller or rollers 510 with appropriate mounting hardware may be substituted, or the cylindrical roller and its bracket may be eliminated entirely and a solid bar or shoulder substituted, which would serve to establish and maintain the sharpening angle.

[0076] The roller bracket may be modified as well by utilizing two separate bracket plates, one mounted on either side of the frame to capture the roller, or the 515 bracket or brackets could be mounted elsewhere on the frame, or the bracket may be formed into the frame in a one-piece construction. The bracket may be constructed in any configuration designed to retain a particular style of roller or wheel for the purpose of supporting and positioning the frame during the sharpening process as outlined in the disclosure.

520 [0077] In sum, it is to be understood that modifications may be made to the invention which do not exceed the scope of the appended claims and modified forms of the present invention done by others skilled in the art to which the present invention pertains will be considered infringement of this invention when those modified forms fall within the claimed scope of this invention.

525 [0078] With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are

530 intended to be encompassed by the present invention.

[0079] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and 535 equivalents may be resorted to, falling within the scope of the invention.

Claims

What is claimed is:

1. A self-aligning blade angle guide, comprising: 540 (a) an axle having a first end and a second end;

(b) a clamp attached to said first end of said axle; and

(c) a frame operatively attached to said second end of said axle in a manner that allows free rotational movement of said clamp relative to said frame.

545 2. The self-aligning blade angle guide of claim 1, further comprising a support structure for selecting a sharpening angle relative to a sharpening medium.

3. The self-aligning blade angle guide of claim 2, in which said support structure comprises:

550 (a) a bracket attached to said frame; and

(b) a roller operatively coupled to said bracket in a manner that allows said roller to freely turn within said bracket.

4. The self-aligning blade angle guide of claim 1, wherein said clamp comprises:

555 (a) a base having a hole through which said first end of said axle extends; and

(b) a pair of opposing jaw members coupled in combination with said base and said first end of said axle, whereby said opposing jaw members are releasably retained by said base and said first end of said axle. 560

5. The self-aligning blade angle guide of claim 4, further comprising a means for tightening and loosening said opposing jaw members.

6. The self-aligning blade angle guide of claim 5, further comprising a support structure 565 for selecting a sharpening angle relative to a sharpening medium.

570 7. The self-aligning blade angle guide of claim 6, in which said support structure comprises:

(a) a bracket attached to said frame; and

575

8. A self-aligning blade angle guide, comprising:

(a) a clamp for securing a blade to be sharpened;

(b) a frame operatively associated with said clamp so as to enable free rotational movement of said clamp relative to said frame;

580 (c) a means for selecting a sharpening angle; and

(d) a means for coupling said clamp to said frame in a manner which provides for free rotational capability of said clamp relative to said frame, whereby the weight of said self-aligning blade angle guide, combined with any added pressure applied by the user, causes said clamp to rotate on its axis when said self-

585 aligning blade angle guide is placed in an operational position on the surface of a sharpening medium, thereby aligning the edge of a blade secured in said clamp with the surface of the sharpening medium, said rotational capability further enables the user to service both sides of a blade's edge with a single blade clamping operation by manually rotating said clamp 180 degrees between passes along the surface of the

590 sharpening medium.

9. The self-aligning blade angle guide of claim 8, wherein the means of coupling said clamp to said frame comprises:

(a) an axle having a first end and a second end;

595 (b) said clamp further providing a means for attaching said first end of said axle to said clamp; and

(c) said frame further providing a means of attaching said second end of said axle to said frame, whereby said clamp, said axle, and said frame may be coupled in combination, in a 600 manner which enables said clamp to freely rotate on its axis in either direction with, or about said axle.

10. A self-aligning blade angle guide, comprising:

(a) an axle having a first end and a second end;

605 (b) a clamp including, in combination, a pair of similar jaw members of predetermined shape arranged in opposition, means for attaching said first end of said axle to at least one said jaw member, a base having a hole through which said axle extends and releasably retaining said jaw members in combination with said first end of said axle, thereby forming a clamp-and-axle assembly, and

610 means for imparting reciprocal movement to said axle, whereby said each jaw member is caused to pivot towards and away from the opposite said jaw member, thereby enabling the clamp to securely grip and release a blade;

(c) a frame removably coupled to the clamp-and-axle assembly so as to enable free rotational movement of the clamp-and-axle assembly through an angle of at

615 least 180 degrees with respect to said frame; and

(d) means for establishing and maintaining a predetermined sharpening angle, whereby a weight of said self-aligning blade angle guide, combined with any added pressure applied by the user, causes said clamp to rotate on its axis as the self-aligning blade angle guide is placed in operational position on the surface

620 of a sharpening means, thereby aligning the edge of a blade secured in said clamp with the surface of the sharpening means, said rotational capability further enabling the user to sharpen both sides of a blade's edge with a single blade clamping operation by manually rotating said clamp at least 180 degrees between passes along the surface of the sharpening means.

625

11. The self-aligning blade angle guide of claim 10, wherein said means for attaching said first end of said axle to said jaw members comprises:

(a) said axle having a head of predetermined size and configuration at said first end of said axle; and

630 (b) each said jaw member having an inside surface and an outside surface, and each said jaw member further having a similar recess formed in its said inside surface, each said recess being configured to accept approximately one half of said head of said axle, whereby said jaw members may be arranged in opposition with said head of said axle captured in said recesses, with said jaw

635 members and said axle being retained in combination by said base.

12. The self-aligning blade angle guide of claim 10, wherein said clamp further includes:

(a) a plurality of matched pairs of jaw members, each matched pair of said jaw members being configured and adapted to securely grip a different style of

640 blade; and

(b) means for releasably retaining said matched pair of jaw members in said clamp, whereby the user may selectably interchange said matched pairs of jaw members within said clamp, thereby enabling the user to sharpen blades of differing styles and configurations.

645

13. The self-aligning blade angle guide of claim 8, wherein the means of selecting a sharpening angle comprises:

(a) a bracket;

(b) a roller;

650 (c) a means of retaining said roller within said bracket in a manner that permits said roller to freely turn within said bracket; and

(d) a means of attaching said bracket and said roller, in combination, to said frame in a manner which enables a user to present both said roller and a blade secured in said clamp to an abrasive surface,

655 thereby enabling said roller, in combination with a blade secured in said clamp, to select a sharpening angle, when the self-aligning blade angle guide is placed in its operational position.

14. The self-aligning blade angle guide of claim 11, wherein said means for imparting 660 reciprocal movement to said axle comprises:

(a) said axle being threaded; and

(b) a tensioning nut having threads which are compatible with said threads of said axle, said tensioning nut being engaged on said second end of said axle, whereby tightening or loosening said tensioning nut moves said axle

665 reciprocally through said hole of said base, whereby said jaw members are caused to pivot towards or away from each other, thereby enabling said jaw members to grip and release a blade.

15. A self-aligning blade angle guide, comprising:

670 (a) an axle having a first end and a second end;

(b) a clamp for securing a blade to be sharpened, said clamp configured to operatively couple to said first end of said axle;

(c) a frame configured to operatively couple to said second end of said axle; and

675 (d) a support structure for positioning the self-aligning blade angle guide on the surface of a sharpening medium for selecting a sharpening angle, whereby said axle, said clamp, said frame, and said support structure are coupled in combination in a manner which provides for free rotational capability of said clamp, enabling said clamp to freely rotate as the self-aligning blade angle guide is placed on

680 the surface of a sharpening medium, thereby aligning the edge of a blade secured in said clamp with the surface of the sharpening medium, and further enabling the user to service both sides of a blade's edge with a single blade clamping operation by manually rotating said clamp 180 degrees between passes along the surface of the sharpening medium.

685

16. The self-aligning blade angle guide of claim 10, wherein the means for establishing and maintaining a predetermined sharpening angle comprises:

(a) a bracket fixedly attached to the underside of said frame; and

(b) a roller operatively retained by said bracket. 690

17. The self-aligning blade angle guide of claim 10, wherein said frame is adapted to be held in one hand of the user.

18. The self-aligning blade angle guide of claim 10, further comprising means for 695 maintaining rotational clearance between said base and said frame.

19. The self-aligning blade angle guide of claim 10, further comprising means for supporting the clamp-and-axle assembly when the clamp-and-axle assembly is inserted into said frame, and for stabilizing rotation of the clamp-and-axle assembly

700 within said frame.

20. The self-aligning blade angle guide of claim 10, further comprising means for removably coupling the clamp-and-axle assembly to said frame while permitting the clamp-and-axle assembly to freely rotate in either direction within said frame. 705