Mower Blade Sharpening Angle Grinder Adaptor

Abstract

An adaptor for mower blade sharpening, the adaptor incorporating a U bracket having a proximal leg having upper and lower ends, a distal leg having upper and lower ends, and a web spanning laterally between the legs'upper ends; the adaptor further incorporating a table underlying the U bracket's web, the table spanning laterally between the U bracket's proximal and distal legs; the adaptor further incorporating mounting flanges for mounting the table upon the U bracket, the mounting flanges forwardly extending the table from the U bracket's proximal and distal legs; the adaptor further incorporating an annular clamp which is fixedly attached to the U bracket's web.

Claims

1. An adaptor for mower blade sharpening, the adaptor comprising: a. A U bracket comprising a proximal leg having upper and lower ends, a distal leg having upper and lower ends, and a web spanning laterally between said legs'upper ends; b. A table underlying the U bracket's web, the table spanning laterally between the U bracket's proximal and distal legs; c. Means for mounting the table upon the U bracket, said means forwardly extending the table from the U bracket's proximal and distal legs; and d. An annular clamp fixedly attached to the U bracket's web.

2. The adaptor of claim 1, wherein the annular clamp comprises a grinder neck encircling member, said member extending rearwardly from the U bracket's web.

3. The adaptor of claim 2, wherein the annular clamp further comprises an over-center latch fixedly connected operatively to the grinder neck encircling member.

4. The adaptor of claim 3, wherein an end of the annular clamp's grinder neck encircling member is fixedly attached to the U bracket's web, and further comprising a hook fixedly attached to another end of the grinder neck encircling member, the hook being adapted for releasable engagement with the over-center latch.

5. The adaptor of claim 4, wherein the annular clamp is supported at the U bracket's web.

6. The adaptor of claim 5, wherein the annular clamp's over-center latch is connected operatively to an extendable and retractable member.

7. The adaptor of claim 1, wherein the means for mounting the table upon the U bracket comprise proximal and distal travel slots respectively extending along the U bracket's proximal and distal legs.

8. The adaptor of claim 7, wherein the means for mounting the table upon the U bracket further comprise proximal and distal eyed flanges, said flanges being respectively fixedly attached to or formed wholly with proximal and distal ends of the table.

9. The adaptor of claim 8, wherein the means for mounting the table upon the U bracket further comprise proximal and distal bolts, said bolts respectively extending through the proximal and distal eyed flanges and through the proximal and distal travel slots.

10. The adaptor of claim 9, wherein the proximal and distal eyed flanges angularly extend the table between 30 and 40 from the U bracket's proximal and distal legs.

11. A mower blade sharpening assembly comprising: a. An angle grinder having a neck and a rotating grinding wheel; b. A U bracket having an upper web, and having proximal and distal legs fixedly attached to and extending downwardly from proximal and distal ends of the web; c. An annular clamp adapted for engaging the angle grinder's neck and for securing said neck at a rearward side of the web, and for securing the rotating grinding wheel beneath the web; d. A table spanning between the U bracket's proximal and distal legs, the table underlying the grinding wheel; and e. Means for mounting the table upon the U bracket, said means forwardly extending the table from the U bracket's proximal and distal legs.

12. The mower blade sharpening assembly of claim 11, wherein the annular clamp comprises an over-center latch and grinder neck encircling member combination, said combination's grinder neck encircling member engaging the grinder's neck.

13. The mower blade sharpening assembly of claim 12, wherein the annular clamp's over-center latch is adapted for tightening the grinder neck encircling member about the angle grinder's neck and for anchoring the angle grinder at the rearward side of the U bracket's web.

14. The mower blade sharpening assembly of claim 13, wherein the means for mounting the table forms a V cleft between upper surface of the table and a lower surface of the grinding wheel.

15. The mower blade sharpening assembly of claim 14, wherein the means for mounting the table upon the U bracket further comprise proximal and distal eyed flange and travel slot combinations, said combinations'travel slots respectively opening at the U bracket's proximal and distal legs.

16. The mower blade sharpening assembly of claim 15, further comprising proximal and distal feet respectively fixed attached to and extending rearwardly from lower ends of the U bracket's proximal and distal legs.

17. An adaptor for mower blade sharpening, the adaptor comprising: a. A U bracket comprising a proximal leg having upper and lower ends, a distal leg having upper and lower ends, and a web spanning laterally between said legs'upper ends; b. A table underlying the U bracket's web, the table spanning laterally between the U bracket's proximal and distal legs; c. Means for mounting the table upon the U bracket, said means forwardly extending the table from the U bracket's proximal and distal legs; and d. An annular clamp fixedly attached to the U bracket's web; wherein the annular clamp comprises a flexible strap, the flexible strap looping rearwardly from the U bracket's web.

18. The adaptor of claim 17, wherein the annular clamp further comprises an over-center latch fixedly attached to the U bracket's web.

19. The adaptor of claim 18, wherein an end of the annular clamp's flexible strap is fixedly attached to the U bracket's web, and further comprising a hook fixedly attached to the opposite end of the flexible strap, the hook being adapted for releasable engagement with the over-center latch.

20. The adaptor of claim 19, wherein the annular clamp further comprises a slot extending through the U bracket's web, and wherein the annular clamp's flexible strap extends through the slot.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0016] FIG. 1 is a perspective view of a preferred embodiment of the instant inventive mower blade sharpening angle grinder adaptor.

[0017] FIG. 2 is an alternative perspective view of the adaptor of FIG. 1.

[0018] FIG. 3 re-depicts the structure of FIG. 2, the view of FIG. 3 showing engagement of free end of a strap component to form an angle grinder neck clamping space.

[0019] FIG. 4 is a proximal side view of the structure of FIG. 1.

[0020] FIG. 5 re-depicts the structure of FIG. 4, the view of FIG. 5 showing a dulled mower blade in engagement with table and grinding wheel components of the instant invention.

[0021] FIG. 6 re-depicts the structure of FIG. 5, the view of FIG. 6 showing a completion of mower blade sharpening grinding.

[0022] FIG. 7 is an alternative frontal perspective view of the instant inventive adaptor, the view further showing attached angle grinder and grinder wheel components.

[0023] FIG. 8 re-depicts the structure of FIG. 7, the view of FIG. 8 showing a mower blade distally extended over an upper surface of an adaptor table component.

DETAILED DESCRIPTION OF THE INVENTION

[0024] Referring now to the drawings, and in particular to FIG. 1, a preferred embodiment of the instant inventive mower blade sharpening angle grinder adaptor is referred to generally by reference arrow 1. The adaptor 1 preferably comprises a U bracket which incorporates a proximal leg 8, a distal leg 6, and a web 2 which spans between and rigidly interconnects upper ends of said legs. In a preferred embodiment, the U bracket 2,6,8 is composed of durable steel.

[0025] Travel slots 10 and 12 preferably extend into and through the U bracket's legs 6 and 8, and a strap receiving slot 4 preferably extends into and opens downwardly at the U bracket's web 2. Feet 15 and 17 preferably extend horizontally and rearwardly from the lower ends of the U bracket's legs 6 and 8, and permanent magnets 16 and 18 may be suitably fixedly attached to lower surfaces of the U bracket's feet 15 and 17. The magnets 16 and 18 may advantageously stabilize the adaptor 1 during use upon a steel topped work bench. Elastomeric friction pads (not shown within views) may be suitably substituted for magnets 16 and 18.

[0026] A steel mower blade supporting and guiding table 20 is provided in combination with table mounting means which securely mount proximal and distal ends of the table 20 upon the U bracket's proximal and distal legs 8 and 6. In the preferred embodiment, the table mounting means are adapted for vertically adjustably mounting the table 20 upon the Ubracket's legs 6 and 8.

[0027] Referring simultaneously to FIGS. 1, 2, and 4, the table mounting means may suitably comprise proximal and distal eye and travel slot combinations. Referring in particular to FIG. 4, mounting flange apertures or eyes 33 are represented by dashed lines drawn upon the table's proximal mounting tab 24, such aperture 33 constituting the eye component of the adaptor's proximal eye and travel slot combination. A similarly configured eye (not shown within views) extends through the table's distal mounting tab 22. The adaptor's eye components 33 may align with and may respectively forwardly overlie the legs'proximal and distal travel slot components 12 and 10, thereby completing the adaptor's proximal and distal eye and travel slot combinations.

[0028] The adaptor's table mounting means preferably further comprise proximal and distal bolt fasteners 32 and 28 which may be respectively extend rearwardly through the eyes 33 which open at mounting flanges 24 and 22. Such fasteners 32 and 28 respectively further extend rearwardly through the immediately rearwardly underlying travel slots 12 and 10. Wing nuts 34 and 30 may be threadedly mounted over the rearward helically threaded ends of the fasteners 32 and 28, and such nuts may be tightened against the rearward faces of the U bracket's legs 8 and 6. Tightening of the wing nuts 34 and 30 advantageously secures the table 20 at a selected elevation beneath the U bracket's web 20, and loosening of such nuts allows selective repositioning of the table.

[0029] Referring simultaneously to FIG. 1-6, the instant inventive adaptor 1 preferably further comprises a grinder neck encircling member, suitably a flexible strap 36 which has a high tensile strength and is capable of exerting a high pulling force against a circular structure such as the perpendicularly extending neck 74 of a hand operated angle grinder 70. The angle grinder 70 has a perpendicularly extending neck 74 which houses and rotatably supports a rotary output shaft 76 having a lower helically threaded end 79. A circular grinding disc or cutting wheel 78 is mounted over the rotary output shaft 76, and such disc is secured thereon by an internally helically threaded nut 82.

[0030] In the depicted embodiment, the flexible strap 36 functions as a rearward segment or section of an annular clamp, the medial portion 3 of the U bracket's web 2 advantageously constituting and functioning as such clamp's forward section. A first end 37 of the annular clamp's strap 36 is fixedly attached to a rearward surface of the U bracket's web 2 by means of an L bracket 38 which is attached by bolts or rivets 40 and 42. The opposite end or free end 39 of the strap 36 presents a second L bracket 46 which functions as a hook flange, such hook flange 46 being securely attached to the strap 36 by means of bolts or rivets 48.

[0031] As shown in FIG. 3, the free end 39 of the strap 36 may be extended forwardly through the opening or gap 14 beneath the web 2 and above the table 20. Thereafter, the upper edge of the strap 36 may be extended upwardly into slot 4. Upon such engagement of the strap 36 within the slot 4 an annular clamping space 35 is advantageously formed.

[0032] The instant inventive adaptor 1 further incorporates tightening means which may engage the hook 46 and which may forcefully draw the free end 39 of the strap 36 forwardly through the slot 4, thereby constricting the annular clamping space 35. In a suitable embodiment, as depicted, the tightening means may comprise an over-center latch assembly 55 which includes a base plate 60 mounted upon the forward face of the web 2 by bolts or rivets 62, upper and lower clevis ears 58 wholly formed with and extending forwardly from upper and lower edges of the base plate 60, a U configured lever 56 pivotally mounted upon the clevis ears 58, an internally helically threaded nut 54 spanning between and rotatably mounted upon the open and lower arms of the U configured lever 56, and a loop 50 and threaded shaft 52 combination threadedly engaging the nut 54.

[0033] Upon engagement of the loop 50 of the over-center latch assembly 55 with hook 46 as depicted in FIG. 3, the lever 56 may be pivoted from the proximally retracted position depicted in FIG. 3 to a distally extended position as depicted in FIG. 7. Upon full distal extension of the lever 56 to the FIG. 7 position, the strap 36 is forcefully drawn forwardly through slot 4 and clamping space 35 is simultaneously forcefully constricted. Also upon such distal extension of lever 56, the pivot axis 53 of the helically threaded nut 54 is advantageously displaced rearwardly from the ears'pivot axis 57. While the lever 56 occupies its distal position, proximally directed pulling forces applied by the helically threaded shaft 52 to the rotatable nut 54 tend to further distally pivot the lever 56 toward the base 60, advantageously locking the lever 56 at its fully distally pivoted position. Accordingly, full distal pivoting of the lever 56 locks the strap 36 at an annulus constricting position.

[0034] Referring simultaneously to FIGS. 3 and 4, the angle grinder's neck 74 may have varying diameter depending on the make and model of the tool. Where a provided angle grinder neck 74 has a relatively small diameter, the effective length of the threaded shaft 52 may be reduced by rotatably screwing the shaft 52 distally through nut 54, thereby constricting the clamping space 35. Alternatively, to accommodate annular clamping about a larger diameter angle grinder neck, the loop 50 and threaded shaft 52 may be proximally unscrewed, correspondingly increasing the size of the clamping space 35.

[0035] In a suitable alternative embodiment, the clamping grinder neck encircling member may comprise a hingedly opening C configured ring (not depicted within views), such ring having a forward section which is fixedly attached to the U bracket's web, and has a rearward section which curves and extends around the rearward aspect of the angle grinder's neck. In such suitable embodiment a tightenable and releasable fastener, such as an over-center latch may span between ends of such hinged C configured ring, such fastener effectively annularly clamping holding the grinder's neck at the rearward side of the web.

[0036] Referring simultaneously to all figures, in use of the suitable embodiment 1 of the instant inventive adaptor, an operator may initially loosen wing nuts 30 and 34 and may temporarily slidably move the table 20 downwardly to a grinder installation facilitating position, such table height adjustment temporarily increasing the size of the adaptor's grinder wheel passage space 14.

[0037] Thereafter, the forward aspect or end of the grinding wheel 78 of the angle grinder 70 may be extended forwardly through space 14, and the strap 36 may be extended about the neck 74 of the angle grinder 70. Thereafter, the upper edge of the free end 39 of the strap 36 may be extended upwardly into slot 4, and the loop 50 of the over-center latch assembly 55 may be engaged with the strap's free end hook 46.

[0038] Thereafter, the operator may forcefully pivot the lever 56 distally from the FIG. 3 position to the FIG. 9 position. Such lever pivoting constricts the clamping space 35, forcefully driving the strap 36 radially inwardly toward the rotation axis of the neck 74, and forcefully driving the rearward face of the web 2 against the front surface of the neck 74. Such over-center latch driven web and strap tightening of the annular clamp 2,3,36 about the angle grinder's neck 74 securely fastens the adaptor 1 to the angle grinder 70.

[0039] Thereafter, the operator may slidably move the table 20 upwardly along travel slots 10 and 12 until the upper and rearward edge of the table 20 immediately underlies and parallel's the asperous grinding surface 80 of the grinding wheel 78. Thereafter, wingnuts 30 and 34 may be tightened, securing the table 20 in place.

[0040] Thereafter, the adapter 1 may be placed upon a level surface such as a top of a work bench. Where the work bench has a steel surface, the preferably provided permanent magnets 16 and 18 extending downwardly from feet 15 and 17, advantageously magnetically stabilize the adapter 1. Thereafter, the operator may actuate the angle grinder 70 while holding the angle grinder's rear hand grip (not shown within views) with one of his or her hands. The operator may utilize his or her other hand to place a mower blade 90 having a dulled cutting edge 92d upon the upper surface of the table 20.

[0041] Thereafter, the operator may use such other hand to drive such dulled cutting edge 92d rearwardly into the V cleft or valley, formed by the table 20 and the grinder wheel 78. Simultaneously with such rearward driving of the blade 90, the operator may slidably move the blade 90 distally beneath such wheel. Repetitions of such actions advantageously produces a sharpened edge 92s within blade 90, as indicated in FIG. 6.

[0042] The bevel angle of the blade's sharpened edge 92s substantially matches the angle between the forward extension of the grinder wheel 78 and the table 20. The adaptor's annular clamp 2,3,36 will typically hold the adaptor 1 upon an angle grinder 70 to form an approximate 90 degree or perpendicular extension of the grinder wheel 78 with respect to the U bracket's legs 6 and 8. With such perpendicular extension of the grinder wheel, an extension of table's mounting tabs or flanges 22 and 24 at an a angle between 50 and 60 will extend the table 20 at a corresponding angle b between 30 and 40 from the grinding wheel 78. Such 30-40 range of the adaptor's grinding angles or bevel a includes commonly desired bevel angles of mower blades, with a 30 bevel being provided for cutting fine bladed lawns and a 40 bevel being used for mowing rough vegetation. Accordingly, the preferred angle b between the mounting tabs 22 and 24 and the table 20 is preferably between 50 and 60. The angles of the feet 15 and 17 with respect to the legs 6 and 8 preferably match such angle b so that the table 20 is held at a substantially horizontal orientation upon placement of the feet 15 and 17 upon a horizontal work surface.

[0043] A permanent magnet 26 may be advantageously mounted at the proximal end of the table 20, such magnet resisting vibration induced separations of the blade 90 from the table 20 during grinding operations.

[0044] While the principles of the invention have been made clear in the above illustrative embodiment, those skilled in the art may make modifications to the structure, arrangement, portions and components of the invention without departing from those principles. Accordingly, it is intended that the description and drawings be interpreted as illustrative and not in the limiting sense, and that the invention be given a scope commensurate with the appended claims.