Patent ID: 12240075

DETAILED DESCRIPTION

The disclosed example grinder tools and accessories are versatile and allow for improved productivity, accurate control, and improved safety. In the past, a portion of a sanding or grinding abrasive disc surface was removed to allow a user to visibly attach the disc to a grinder tool. As described in this disclosure, by providing a blind mounting technique, the entire surface of the disc may be used for the abrasive surface. The blind mounting mechanism for a grinder tool may include a center alignment mechanism having a first contact and a second contact. A rotational device may include an axle that is movable with respect to the center alignment mechanism. A hub may be mounted to the axle and may include a first coupling interface. The disc may have a second coupling interface for mating with the first coupling interface. The center alignment mechanism may be movable a first mounting distance relative to the hub and may contact the disc with the first contact and the second contact to center align the first coupling interface with the second coupling interface. The rotational device may be configured to slowly rotate the hub to angle align the first coupling interface with the second coupling interface to thus allow the disc to mate and attach to the hub.

There are at least three main mechanical portions of the example grinder and accessories: (1) a set of segments in a backplate (or more generally a plate) surrounding the grinder disc that are used for loading the disc and that also may be used for vacuuming particles from sanding operations; (2) multiple fences used with a work table to allow positioning of work articles at various angles to the grinder tool; and (3) a tool holder for sharpening woodworking or other hand tools.

The backplate may be comprised of the set of segments and may be attached to a motor or a hand crank with a magnetic or another attachment hub that holds a sanding or grinding disc. To allow a disc to be easily mounted and unmounted, there may be adaptions to the back plate to allow for movement between the disc and the hub. A semi-circular top segment may be used to encircle the disc partially. A partial-circular bottom segment partially may encircle the disc but may be movable towards the hub a short mounting distance to allow the disc when resting in the bottom segment partial-circle to align a center protrusion in the hub with a center hole in the disc. The hub may also have a set of one or more satellite protrusions to align with a set of one or more corresponding holes in the sanding disc. A motor or hand crank may be slowly rotated until the hub satellite protrusions align with the holes in the disc, thereby allowing the disc to “snap” flatly onto the hub. With a motor, the slow rotation may be done via a special ‘mounting mode’ routine in a motor controller and may be activated by a user. With a hand crank, the user may just rotate the hub with the hand crank slowly.

The top segment and bottom segment may have recessed cavities to allow waste material from a work object or grinding disc to be vacuumed and collected by a vacuum system.

The backplate may have a ledge that prevents the disc from being tilted and accidentally removed when force is applied to it during grinding. To aid in removal of the disc, a demounting lever may be attached to the back plate to allow the disc to tip out and break the coupling with the hub and thus allow a user to grab the disc easily.

A work table accessory may be attached to the grinder tool, and the work table may be adjustable at different angles and movable in an in/out direction. Various fence accessories may be used to adjust the working angle of work items to the disc surface. A first fence accessory may have a dual clamp that allows clamping the fence to the front or side of the work table with a first clamp while also allowing a second clamp to clamp a working guide at various angles and in/out to the disc surface. The second clamp may be reversible to allow for different thicknesses of work guides to be used. A second fence accessory may have magnets to allow attachment to the front or sides of the work table and magnets in the work guide to allow for holding the work guide to the surface of the work table during aligning, before being clamped down with a screw knob. Magnets may be added to the first fence as well.

A tool sharpening accessory may allow for various angles of attack in placing tool edge surfaces to the grinding disc. The tool sharpening accessory may be adjusted up/down and rotationally with respect to the sanding disc. The tool sharpening accessory may have a tool holder bar with multiple pins for holding the base of a tool during sharpening. The tool holder bar may be held in place with a special binding plate system that allows for adjusting the tool holder bar along up/down a pair of parallel rails that can also rotate the tool holder bar with respect to the plane of the sanding disc to change the angle of the grinding of the tool being sharpened. The mounting attachment points that hold the pair of parallel rails to the grinder tool are formed with a shaped opening to allow a tool that is to be sharpened, such as a long blade, to approach the disc surface from the sides of the grinder tool.

Accordingly, to improve the sharpening of tools, several different tool alignment mechanism accessories are shown and described herein. Further, to help improve productivity and safety, several integrative vacuum systems may also be incorporated to allow for the removal of work material and abrasive grit. More detailed information and examples follow within the detailed description of the drawings.

FIGS.1A and1Bare front and rear perspective views, respectively, of an example manual grinder tool10A having a rotational device70with a hand-crank72.FIG.2is an exploded view of the example manual grinder tool10A shown inFIGS.1A and1Bwith the backside of the disc90shown.

A rotational device70, in this example a crank handle72, is attached or otherwise mounted to a back plate100having a first segment opening. In other examples, such as shown in other figures, the rotational device70may be a brushless DC motor (BLDC)74, an AC motor, a gearbox attached to a remote power unit, and the like. The rotational device70has an axle shaft the extends through the back plate100and is attached to a hub80, preferably magnetic, on an opposing side of the back plate100from the rotational device70.

If magnetic, the hub80may be a round-shaped aluminum disc with magnets inserted into or in some examples may be a magnetic material. In other examples, there may be multiple layers of non-magnetic and magnetic materials, such a carbon fiber or epoxy fiber as some example non-magnetic materials. The hub80may include a center protrusion82and a set of one or more satellite protrusions84surrounding the center protrusion82to form a first coupling interface86.

With a magnetic hub80, a disc90having a magnetic affinity is used for holding a grinding surface that covers its front side, and on its backside, has matching holes to align with the center protrusion82and the set of one or more satellite protrusions84. The height of the center protrusion82and the set of one or more satellite protrusions84are less than the thickness of the disc90to ensure that the grinding surface, when attached to the front side of the disc90, forms a substantially flat surface across the entire front surface of the disc90. The magnetic affinity may be accomplished by using a disc90made of ferromagnetic material such as an iron or iron alloy material. Alternatively, the disc90may be made of a non-ferromagnetic material such as aluminum and embedded with iron or ferromagnetic material to allow the disc90to be magnetically attracted to a magnetic hub80. Generally, a magnetic hub80may be made of a hard-magnetic material such as a neodymium or an alnico alloy (an iron alloy with aluminum, nickel, and cobalt) or another strong permanent magnet. Other strong permanent magnetic materials may include ferrite, a ceramic compound composed of iron oxide and other metallic elements. In some examples, a magnetic hub80may be designed to be an electromagnet that can be energized with electricity flowing through copper or aluminum wires surrounding a core made of iron, nickel, or cobalt.

The back plate100may be formed of a non-magnetic material such as aluminum, plastic, epoxy, ceramic, or other material and formed from a single or multiple pieces. The radius of the first segment102is greater than the radius of the disc90. In some examples, the first segment102may not be truly circular but may be an elliptical or another shaped segment in which the opening is still sufficient to encompass a first portion of the disc90within.

A second segment112is mounted to the first segment102and has a second segment opening114(FIG.7C) aligned with the first segment opening104to form a substantially circular opening having a diameter larger than the diameter of the disc90. In some examples, the second segment opening114may not be truly circular but may be a partial, an elliptical, or another shaped segment in which the opening is still sufficient to encompass a second portion of the disc90within. Together, the first segment opening104and the second segment opening114form a substantially circular opening surrounding the hub80and allows for receiving the disc90when mounted on the hub80. The second segment112may be made of a non-magnetic material such as aluminum, plastic, epoxy, ceramic, or other material. The second segment112may be made of the same or different material than the first segment102.

With respect to blind mounting, as noted, the disc90has a diameter96less than a diameter110(seeFIG.7c) of the combined first104and second114segment openings. The disc90has a second coupling interface88, for mating with first coupling interface86on the hub. Because the disc90is designed to have its front surface covered with grinding material, there is no visible human reference for where the second coupling interface openings are on the disc90when it is to be mounted to the hub80. To help a user of the grinder tool reliably and safely mount the disc90onto the hub80, a center alignment mechanism99allows the back plate100to be movable towards the hub80a mounting distance98such that the disc90when in contact with the second segment opening114at its first contact14and second contact15, the disc90has a central opening of the second coupling interface88aligned with a center protrusion of the first coupling interface86formed in the hub80. However, the set of satellite openings94in the disc90may not be aligned with a set of one or more satellite protrusions84on the magnetic hub80. To help align the set of satellite openings94with the set of one or more satellite protrusions84, the rotational device70is configured to rotate the hub80slowly to align the set of satellite openings94to the set of one or more satellite protrusions84on the hub80.

When using a magnetic hub80and it is aligned with the disc90, the disc90is magnetically attracted to the magnetic hub80, and the disc90will “snap” to the magnetic hub80to allow the disc to magnetically mate to the magnetic hub80. In some examples, the rotational device70is a crank handle72. In these examples, a user can slowly rotate the crank handle72until the disc90snaps to the hub80. In other examples, the rotational device70may be a motor74. The motor74in these examples may include a “mounting mode” routine78such that when a button (not shown) is pressed (or initiated by other means) the motor74begins to rotate at a slow speed (for example, less than about 30 to 50 RPM) until and when the satellite openings94are aligned with the satellite protrusions84and the disc90snaps to the magnetic hub80and the motor70continues to rotate slowly until the mounting mode routine78is disabled, such as releasing the button (or disabled by other means). In some examples, slow speed may be set as a ratio such as 2%-5% or less of the full operating speed. Accordingly, by having a disc mounting system with the movable back plate100relative to the hub80, and the ability to slowly rotate the hub80, the disc90may be blind-mounted to the hub80. This blind mounting feature allows the disc90to have its entire front surface be overlaid with grinding material and does not require a user to screw, bolt, clamp or otherwise mount the disc90onto the hub80as is done with most grinder tools. Once the disc90is mounted and mated to the hub80, the back plate is allowed to move the mounting distance away from the hub80by gravity or other means.

In some examples, the back plate100may include a set of vacuum openings116that can be used to attach a vacuum or another waste material collector. The front cover125may include a first recessed channel120extending from the first14and second15contacts to the set of vacuum openings116to form a vacuum cavity when at least one of the set of vacuum openings116is coupled to a vacuum source. Accordingly, the first recessed channel120forms a vacuum cavity designed to balance airflow across the face of disc90and to collect and remove waste from the grinding surface of the disc90to the set of vacuum openings116. In other examples, there may be an additional second recessed channel122in the back plate100extending around the first segment102and extending towards the first recessed channel120to extend the vacuum cavity to encompass the circumference of the disc90substantially.

To not require a large magnetic hub80and reduce mass as well as cost, a magnetic hub80is generally desired to have as small a diameter as needed to support the magnetic material and the center82and satellite84protrusions. However, having a small diameter hub may allow a user to apply a large force on the edge of the disc90and perhaps cause the disc90to de-mount from the magnetic hub80. To prevent such an occurrence, back plate100may have a ledge105raised to be just below the back surface of the disc90once mounted onto the hub80. With the ledge105, a user is unable to tilt the disc90sufficiently to break the magnetic coupling with the magnetic hub80as it is prevented from further tilting once the back of the disc touches the surface of the ledge105.

To remove the disc90once it has been mounted on or mated with the hub80, the back plate100may have a demounting lever28attached to it. The demounting lever28may be biased in a first position where it does not touch the back side of the disc90and is movable by the user to a second position to tip the disc90by breaking the attraction between the disc90and the hub80and thus allow a user to grab the disc. When the user pulls the disc90away from the tool, the center protrusion82and the set of one or more satellite protrusions84on the hub80unmate from the center opening92and the set of satellite openings94in the disc90.

The rotational device70is counterbalanced with a counterweighted crank arm73. The rotational device70may be rotated clockwise or counter-clockwise at a speed determined by a user. The crank handle72in this example screws into a hole in a distal end of the counter-weight73. The counterweight73is attached to an axle106and tightened with a screw79and washer5. The counterweight73is positioned a distance from the manual grinder tool10A with a spacer3. The axle106rotates within a pair of bearings4that are mounted into an adjustment mount block9. The adjustment mount block9is affixed to a set of guide rods24between coupling plate31and upper plate39for vertical positioning of the manual grinder tool10A. Back-plate shield101is held to upper plate39and coupling plate31by a plurality of screws2inserted through apertures (holes)93in plate101as shown inFIG.2. The adjustment mount block9may include an accessory attachment23with a mounting post8used to mount various accessories such as light sources, laser pointers, fans, etc. The set of guide rods24may be mounted to a first table mount20. The table mount20may include a mount clamp knob26connected to a slip plate21. The table mount20may be coupled to the set of guide rods24via a mounting rod29and a coupling plate31.

The manual grinder tool10A for a blind mounting a disc90may include a back plate100having a recessed opening103with first segment102and a second segment112with a first contact14and a second contact15. The first segment102and the second segment112may be mounted together with screws95,97and77to a back-plate shield101or the first segment102, the second segment112and the back-plate shield101may be a wholly formed solid piece or combination of several pieces.

The rotational device70includes the axle106and is movably mounted to the back plate100, in this example to backplate shield101. A magnetic hub80may be mounted to the axle106and may include a first coupling interface86, shown here as a center protrusion82and a satellite protrusion84as just one example. The disc90may be ferromagnetic and has a disc diameter96less than a diameter of the recessed opening103and a second coupling interface88for mating with the first coupling interface86. The second coupling interface88is shown here as a center opening92, and a satellite opening94sized to accept the center protrusion82and the satellite protrusion84, respectively. The back plate100is movable a mounting distance98relative to the magnetic hub80with a center alignment mechanism99such as to contact the disc90with the first segment102and the disc centering support pads, the first contact14and the second contact15, of the second segment112to center align the first coupling interface86with the second coupling interface88. That is, the center alignment mechanism99includes a recessed opening103larger than the diameter of the disc90. The rotational device70is configured to rotate the magnetic hub80to angle-align the first coupling interface86with the second coupling interface88to allow the disc90to mate to the magnetic hub80magnetically. In some examples, the hub80may be non-magnetic and have another type of attachment device as an alternative disc mounting assembly. The alternative disc mounting assembly should maintain enough resistance against rotation to facilitate the engagement of whatever coupling members are used. In this example, the satellite protrusion84. The center alignment mechanism99may be biased to move the first contact14and the second contact15the mounting distance98away from the disc90once the disc90is mated to the hub80.

To allow for the mounting distance98movements, the back plate100, the back-plate shield101in this example, may have a shield opening107larger than the axle106to facilitate relative movement of the back plate100to the rotational device70. The back plate100may also have a set of vacuum openings116to allow coupling to a vacuum source via one or more vacuum couplers118. In some configurations or examples, one or more of the set of vacuum opening116may have a vacuum plug119to seal a respective vacuum opening116. Accordingly, the back plate100may include a set of vacuum openings116and an opposing front cover125spanning a portion of the recessed opening103. The opposing front cover125includes a first recessed channel120extending from the first contact14and the second contact15to the set of vacuum openings116. When at least one of the set of vacuum openings116is coupled to a vacuum source, the first recessed channel120forms a vacuum cavity for collecting and removing material from the tool10. Additionally, the back plate100may include a second recessed channel122extending around the recessed opening103and extending towards the first recessed channel120to extend the vacuum cavity.

To help in preventing the disc90from being separated from the hub80by the pressure of a tool or work article on the disc90during use, a ledge105is formed in the back plate100to prevent tipping of the disc90. To facilitate removal of the disc90, a demounting lever28may be configured to the back plate100to allow the disc90to be tipped away from the hub80. Accordingly, one or more ledges105are within the recessed opening103. The ledges105are configured to prevent the disc90from being tipped when a force is applied to a face of the disc90during operation and thereby preventing the first coupling interface86to unmate from the second coupling interface88. The demounting lever28may be attached to the back plate100and biased in a first position that is not in contact with a backside of the disc90and movable to a second position to contact the backside of the disc90to tip the disc90. This tipping allows the first coupling interface86to unmate from the second coupling interface88in the disc90and to allow further a user to grab the disc90for removal. The biasing of the demounting lever28may be spring biased, gravity biased, or other.

For additional safety when rotating the rotational device70, a safety shield may be mounted between the counterweight73and spacer3to prevent an operator's fingers from being caught between the counterweight73and the adjustment mount block9. The safety shield71may be constructed of a transparent, partially transparent, or opaque plastic, glass, ceramic, or metal material. A transparent or partially transparent (such as a screen material) may help to allow a user to view adjustment clamps25when moving the adjustment mount block9up and down.

FIGS.3A and3Bare front and rear perspective views, respectively, of an example motor grinder tool10B with a motor rotational device70and a work shelf30accessory. The work shelf30may also be attached to the example manual grinder tool10A ofFIGS.1A,1B and2.FIG.4is an exploded view of the example motor grinder tool10B shown inFIGS.3A and3Bwithout the work shelf30.FIGS.5A and5Bare front and rear perspective views, respectively, of the example motor grinder tool10B inFIGS.3A and3Bwith the work shelf30in alternate positions.

In this example, guide rods24are attached to adjustment mount block9which is further supporting the mounting of a motor74. Adjustment block9allows for vertical up-down positioning of the motor74. An adjustment clamp25may be used to fix the height of the motor74to the guide rods24. A second table mount22is used to attach the guide rods24to a workbench, work table, or another work area. The motor74has an axle106that when mounted to adjustment mount block9extends through an opening and may be extended by a coupler13and set screw11to a center protrusion82. The center protrusion82extends through the hub80which is mounted to the coupler13with screws2. A satellite protrusion84may be press-fitted to hub80to form a first coupling interface86with the center protrusion82. Shown inFIG.4is the backside of the disc90with center opening92and satellite opening94forming the second coupling interface88for mating with the first coupling interface86. Other coupling interfaces may be used.

The work shelf30may be attached to the back plate100and extends in an orthogonal direction to the back plate100. The work shelf30may be adjustable at multiple angles from the normal in the orthogonal direction with a first shelf adjustment clamp32. The work shelf30may also be adjustable toward and from the back plate100with a second shelf adjustment clamp33. By having an adjustable work shelf30, the approach of a workpiece to the grinding surface can be varied as required for any particular grinding task.

FIGS.6A,6B,6C, and6Dare front perspective views of an example motor grinder tool10B illustrating the steps in mounting a disc90to the motor grinder tool10B. InFIG.6A, the work shelf30is adjusted down and away from the back plate100. The motor74is coupled to a motor controller76having a mounting mode routine78. To blind load the disc90to the motor grinder tool10B, the disc90with a first coupling interface86is inserted into a recessed opening103of the back plate100as shown inFIG.6B. The back plate100is attached to a rotational device70, motor74in this example, further coupled to a hub80having a second coupling interface88. InFIG.6C, the back plate100is moved a mounting distance98to contact the disc90at a first contact14and a second contact15(seeFIG.4) of the recessed opening103to center and vertically align the first coupling interface86to the second coupling interface88. The rotational device70, motor74in this example or rotational device70in the example ofFIGS.1A,1B and2, is slowly rotated to align the first coupling interface86further to the second coupling interface88to allow the disc90to attach firmly to the hub80. In this example, this rotation allows the satellite opening94on the hub80to align with the satellite protrusion84on the backside of the disc90. The slow rotation can be done by a user finesse with the hand crank or by the mounting mode routine78of motor controller76. In the mounting mode, the motor controller76instructs the mounting mode routine78to rotate slowly (such as less than 50 RPM). This can be initiated by a user pressing a disc mount button (not shown) readable by the motor controller76. If a magnetic hub80is used and the disc90is ferromagnetic, the disc90will “snap” flush or flatly to the magnetic hub80. If an alternative disc attachment system is used, the hub80may not be required to rotate. Once mounted, the back plate100may be moved opposite the mounting distance98as shown inFIG.6D. The work shelf30may be moved back to the desired working position as shown.

The disc centering support pads, first contact14and second contact15, can also be fixed in position to center the disc90on the vertical axis of the center protrusion82, and with the center opening92of the disc90a distance below the center protrusion82small enough to allow a user to grasp and raise the disc90to blindly engage the center protrusion82in the center opening92hole of disc90.

To remove the sanding or grinding disc90, a demounting lever28attached to the back plate100may be moved to a first position to allow the disc90to decouple from the hub80. A user then may grab the disc and pull it away from the tool.

The motor controller76may include one or more processors having one or more cores and be made up of one or multiple processor architectures such as x86™, x64™, ARM™, PowerPC™, and the like. The processor(s) are coupled to computer readable medium (CRM) to read and execute instructions that implement the mounting mode routine. In other examples, the mounting mode routine may be partially or fully implemented using logic and digital and/or analog circuitry. The motor controller's76main memory and the processor memory may each constitute computer-readable medium. The term “computer-readable medium” may include single medium or multiple media (centralized or distributed) that store the instructions or data structures. CRM may be implemented to include, but not limited to, solid-state, optical, and magnetic media whether volatile or non-volatile. Such examples include, semiconductor memory devices (e.g. Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), and flash memory devices), magnetic discs such as internal hard drives and removable discs, magneto-optical discs, and CD-ROM (Compact Disc Read-Only Memory) and DVD (Digital Versatile Disc) discs.

FIG.7Ais a side perspective view of an example motor grinder tool10B illustrating where cut views ofFIGS.7B and7Coccur.FIGS.7B and7Care cut views of the example motor grinder tool10B shown inFIG.7Ato illustrate vacuum channels in one example.FIG.7Bshows the cut through section A-A ofFIG.7A.FIG.7Cshows the cut through section B-B ofFIG.7A.

InFIG.7B, the front cover125is shown as transparent and has a first recessed channel120to allow first vacuum airflow115to extend from the front surface of the disc90to under the disc90to a second recessed channel122(FIG.7C) behind the mounted disc90on back plate100. InFIG.7C, beneath the disc90, the waste particles and air are transported by the second vacuum flow117to at least one of the set of vacuum openings116.

In addition, a second vacuum airflow117draws material from the front surface of disc90to the back surface and second recessed channel122. The second vacuum airflow117is drawn into any of the set of vacuum openings116that are coupled to a vacuum source. The second recessed channel112is defined by the shape of the first segment102and second segment112of the back plate100. The distance between the disc90and edges of the first segment102form a first segment opening104. Likewise, the distance between the disc90and the edges of the second segment112form a second segment opening114leading to the second recessed channel122.

FIGS.8A and8Bare front perspective views of a motor grinder tool10B with an example adjustable fence40accessory in different positions.FIG.9is an exploded view of the example adjustable fence40shown inFIGS.8A and8B. In one example, the adjustable fence40is couplable to the work shelf30with a first fence clamp41with a bottom knob47, shelf clamp48, and shelf edge aligner49. The first fence clamp41has a screw mount43extending in a direction normal to the top surface of the work shelf30. A second fence clamp42has first and second opposing surfaces on a channel guide45, the surfaces extending normal from the screw mount and the first and second opposing surfaces each have a channel guide45of different heights to accommodate different thicknesses of an elongated portion44. The adjustable fence40has at least one elongated portion44with a thickness and a fence channel46to couple to a respective channel guide45. The second fence clamp42is adjustable about a rotational axis around the screw mount43. The elongated portion44is also adjustable in a linear direction back and forth along the channel. The screw mount43accepts a tightening screw top knob47to clamp the elongated portion44once positioned.

Accordingly, a first fence clamp41to fasten the adjustable fence40the work shelf30. A screw mount43extends in a direction normal to the top surface of the work shelf30. A second fence clamp42has a channel guide45and first and second opposing surfaces extend normal from the screw mount43. The first opposing surface has a first height from the center of the channel guide45and the second opposing surface has a different second height from the center of the channel guide45. A first elongated portion44has a thickness about the height of the first height. In some examples, a second elongated portion44has a thickness about the height of the second height and may be swapped with the first elongated portion44. The first and second elongated portions44have a fence channel46to couple to a respective side of the channel guide45. The second fence clamp42is adjustable in a rotational axis around the screw mount43. The first and second elongated portions44may be adjusted in a linear direction back and forth along the fence channel46. The screw mount43accepts a tightening screw knob47to clamp the first or second elongated portion44once positioned on the work shelf30.

FIG.10is a front perspective view of a motor grinder tool10B with an example magnetic fence50accessory.FIGS.11A and11Bare an exploded view and an assembled view, respectively, of the example magnetic fence50shown inFIG.10. To help in positioning a workpiece on the work shelf30, in one example, the work shelf30is coupled to a magnetic fence50. The magnetic fence50has a first clamp having a screw mount53extending in a direction normal to the top surface of the work shelf30and a first portion of the magnetic fence50, a magnetic shelf edge aligner59, is magnetically coupled to a side edge of the work shelf30. The magnetic fence50has a second portion, magnetic elongated portion54, with an elongated opening56encircling the screw mount53and adjustable in a rotational axis around the screw mount53. The magnetic elongated portion54of the magnetic fence50is also adjustable in a linear direction back and forth along the elongated opening56. The magnetic elongated portion54of the magnetic fence50is magnetically coupled to the top side of the work shelf with magnets52. The screw mount53accepts a tightening screw knob51to clamp the magnetic elongated portion54once positioned.

Accordingly, a first portion, the magnetic shelf edge aligner59, has a screw mount53that extends in a direction normal to a top surface the first portion. The first portion is configured to magnetically couple to a side edge of the work shelf30. A second portion, the magnetic elongated portion54, has an elongated opening56to encircle the screw mount53and may be adjusted about a rotational axis around the screw mount53. The second portion may also adjust in a linear direction back and forth along the elongated opening56. The second portion is configured to magnetically couple to a top side of the work shelf30. A tightening screw knob51on the screw mount53is configured to clamp the second portion once positioned.

FIGS.12A and12Bare front and rear perspective views, respectively, of an example tool sharpening accessory60for a manual grinder tool10A or a motor grinder tool10B.FIG.13is an exploded view of the example tool sharpening accessory60ofFIGS.12A and12B.FIGS.14A and14Bare front perspective views of the example tool sharpening accessory60mounted to the motor grinder tool10B illustrating different positions and placement of a tool170to be sharpened.FIGS.14C and14Dare front and side perspective views, respectively, of the example tool sharpening accessory60showing additional example adjustments of the example tool sharpening accessory60. Finally,FIG.14Eis a front perspective view of the example tool sharpening accessory60and positioning of a tool170to be sharpened from the side of the example tool sharpening accessory60. The tool sharpening accessory60may be used to improve productivity and efficiency when using a grinder tool to sharpen a work working or another hand tool170. The tool sharpening accessory60allows for multiple positioning of a tool surface to the disc surface to ensure fast and effective sharpening and ability to sharpen various wood cutting, curved, flat-bladed, or other tool surfaces.

The tool sharpening accessory60may be attached to the guide rods24of table mount22of the manual grinder tool10A or the motor grinder tool10B. The tool sharpening accessory60includes a first arm136extending in a first direction and a second arm137extending parallel in the first direction. The first and second arms136,137are disposed on opposing sides of the disc90. A tool holding rod138extends between the first arm136and the second arm137. The tool holding arm138has one or more sets of pins140located at predetermined positions. The pins140may be arranged to allow for left and right-hand operation during sharpening of a tool170. The set of pins140allow for interfacing with a tool170to be sharpened as shown inFIGS.14A-E. The tool holding rod138is adjustable along the first direction. The tool sharpening accessory60includes a pair of mounting brackets142each attached to the first arm136and the second arm137separately. The mounting brackets142allow the tool sharpening accessory60to be rotatable around an axis where the tool sharpening accessory60is mounted to the guide rods24with mount plate143and mounting clamp132to adjust the pivot point of the tool170to the disc90surface (FIG.14D). The mounting brackets142are formed with a shaped opening146to allow the tool170to be sharpened to approach the disc90in a direction along the plane of the disc90from a side of the motor grinder tool10B as shown inFIG.14E, such as with a long-bladed knife. The tool sharpening accessory60may include a support rod154orthogonal to and at the distal end of the first and second arms136,137for structural support. The support rod154may be used to connect the first arm136to the second arm137to provide stiffness in the movement of the first and second arms136,137.

The tool sharpening accessory60may also include a top vacuum collector130formed by a movable cover139and side enclosures131. One or more of the side enclosures131may include a vacuum coupler118for attachment to a vacuum source. The tool sharpening accessory60may also include a bottom shield134to prevent inadvertent contact with the disc90during sharpening operations. The tool holding rod138may be moved up and down the first and second arms136,137by pressing on a binding plate release bar150that releases a set of binding plates152that prevent the tool holding rod138movement. The tool holding rod138may also be rotated to and from the disc90to change the angle of sharpening by adjusting the mounting brackets142with adjustment knob144. To aid in placing the tool at the correct location on the disc90during the adjustment of the tool holding rod138, a position indicator160may be moved in front of the disc90and the surface of the tool170to be sharpened placed at the location of the alignment aid162, shown here as a teardrop opening within the position indicator160and that locates the tool cutting edge at the axis of sharpening angle rotation.

Accordingly, a tool sharpening accessory60for a grinder tool10A,10B includes a first arm136extending in a first direction and a second arm137extending parallel in the first direction and the first and second arms136,137opposite opposing sides of the grinder tool10A,10B. A tool holding rod138extends between the first arm136and the second arm137. The tool holding rod138includes a set of pins140located at predetermined positions for interfacing to a tool170to be sharpened. The tool holding rod138is configured to be adjustable in the first direction.

The tool sharpening accessory60may also include a pair of mounting brackets142each attached to the first arm136and the second arm137separately. The mounting brackets142allow the tool sharpening accessory60to be rotatable around a tool sharpening angle axis when the tool sharpening accessory60is mounted to the grinder tool10A,10B. The mounting brackets142may be formed with a shaped opening146to allow the tool170to approach the disc90in a direction along the plane of the disc90from a side of the grinder tool10A,10B. In some examples, the tool holding rod138includes two binding plates152each having an opening encircling a respective first arm136and second arm137. When the two binding plates152are in a first position, they are biased to contact the first and second arms to prevent descending linear adjustment of the tool holding rod138. When the two binding plates152are in a second position, the two binding plates152are positioned to allow the tool holding rod138to be linearly adjusted in ascension or descension along the first direction. In one example, the tool holding rod138includes a binding plate release bar150parallel to the tool holding rod138and connected to the two binding plates152. In another example not shown, the two binding plates152are separately biased with a spring, and each has a lever to allow de-biasing of the spring thereby requiring two-handed operation. To ease proper positioning of a tool170, the tool sharpening accessory60may include an alignment aid160having an indicator162to align an end of the tool170on a disc90when the tool holding rod138is adjusted. Finally, the tool sharpening accessory60may also include a vacuum collector130between the first arm136and the second arm137to collect waste material and grinder surface grit.

FIG.15Ais an example set of operations200for a method of making a grinder tool10A,10B.FIG.15Bare example additional operations250that can be included in the example method ofFIG.15A. In block202a rotational device70having an axle106is mounted to a center alignment mechanism99that has a first contact14and a second contact15that are movable in a direction with respect to the rotational device70. In block204, a hub80is mounted to the axle106to create a first coupling interface86. In block206, the first contact14and the second contact15are configured to be movable with respect to the hub80a mounting distance98such that a disc90having a second coupling interface88for mating with the first coupling interface86, when in contact with first contact14and the second contact15center aligns the first coupling interface86with the second coupling interface88. The rotational device70is configured to rotate the hub80to angle-align the first coupling interface with the second coupling interface.

Additional operations250may be included in the method of making a grinder tool10A,10B. In block252, the rotational device70may be mounted to a back plate100. In block254, a set of vacuum openings116may be made in the back plate100. In block256, a first recessed channel120may be created in an opposing top cover125extending from the first contact14and the second contact15to the set of vacuum openings116in the back plate100. In block258, a second recessed channel122may be created in the back plate100where the disc is mounted and the second recessed channel122extends toward the first recessed channel120.

FIGS.16A and16Bare two rear perspective views, respectively, of another example grinder tool10C with a control box180, motor rotational device70and a counterbalance182in an upper (FIG.16A) and lower (FIG.16B) position. In this example, the grinder tool10C has a table base184that distributes the weight of grinder tool10C from mount rods29across a larger area than the first table mount20ofFIGS.1A and1Band the second table mount22ofFIGS.3A and3B. This table base184provides good stability and the ability to move the ginder tool10C on the table. The various table mounts and table base may be interchanged on the grinder tool10B and10C examples.

The control box180includes the motor controller76and mounting mode routine78along with other motor controller firmware. In this example, the control box180is positioned above motor rotational device70but in other examples, the control box180may be positioned in different locations and may also be positioned away from the grinder tool10C but connected with an electrical cable. The motor rotational device70and the control box180may weigh a considerable amount in some examples, and manual adjustment may be assisted by the counterbalance182, shown in this example as a coiled spring. In other examples, the counterbalance182may be a pneumatic lift assist, a vertical coiled spring, a magnetic lift assist device, a spring and pulley system, or other lift assist device. The purpose of the counterbalance182to help offset the weight of the movable members on the guide rods24so that during adjustment safety is enhanced.

FIGS.17A and17Bare an example illustration (FIG.17A) and detail (FIG.17B) of the example grinder tool10C ofFIGS.16A and16Bshowing two-handed release levers188and a spare disc holder190. The control box180has been removed to show another example adjustment clamp25, and a work shelf30is attached to the tool for illustration.

In this example, a couple of screws with spring washers186are used to provide the clamping force of the adjustment clamp25to the guide rods24. An operator uses both hands, one on each release lever188to move the mounting block9of adjustment clamp25away from guide rods24to allow movement of the assembly. When the release levers are let go by the operator, the spring washers apply pressure of the mounting block9to the guide rods24to prevent movement. The disc holder190may be mounted to the table base184and used to store alternate discs91, which may be of different grits or types of abrasive surfaces.

FIGS.18A-18Dare different views of the grinder tool10C ofFIG.17Ain the lower position with a work shelf30, a spare disc holder190and alternate discs91, and control box180. The control box180contains the motor controller76and may include one or more knobs, buttons, switches, lights, displays, etc. used to set operational parameters and monitor the operation of the motor controller76.FIG.18Ais a front view showing the disc90, front cover125, table base184, work shelf30, release levers188, guide rods24, and mount rods29.FIG.18Bis a right-side view andFIG.18Cis a front-right perspective view andFIG.18Dis a back-right perspective view all showing the components ofFIG.18Afrom different angles.

FIGS.19A and19Bare left and right perspective views of a motor74on a hinged downward motion-damping motor base220. The hinged downward motion-damping motor base220is attached to a left guard201and a right guard202. The guards201,202are rotationally attached to a left base member203and a right base member204near the rear of each guard201,202so that the hinged downward motion-damping motor base220and supports201,202can pivot upwards or downwards around a central rotational point when a user causes the motor base220to raise or lower. Some embodiments are provided with a release lever206that frees the motor base220so that the motor base220is free to rotate up or down. When the grinder is at the desired angle, the user re-engages the lever206to lock the guards201,202in place. This means that the grinder can be used in any position throughout the angular range of motion, not just at the top or bottom of the rotational arc.

The left and right base members203,204provide a stable support platform when a user uses the invention, regardless of whether the hinged downward motion-damping motor base220is in a raised or lowered position. The base members203,204are attached to a front and rear mounting plates209,207, respectively, that serve to secure embodiments of the invention to a worktable or the like. The mounting plates209,206provide support surfaces so that the invention is less prone to sliding, tipping, or unwanted motion during use. The mounting plates209,207allow the embodiments of the invention to sit freely on a worktable, or, alternatively, holes or other attachments are provided so that the mounts can be bolted or otherwise attached to the worktable.

A damper208is provided that provides resistance when the hinged downward motion-damping motor base220is lowered. The damper208smooths the rotational motion of the base220and prevents rapid changes in position, falling of the base220, damage to the grinder, or injury to a user that may occur through uncontrolled descent of the grinder. That is, when the release lever206is disengaged and the base220allowed to move, the damper208resists translation of the base220from a first position to a second position.

FIGS.20A and20Bshow the hinged downward motion-damping motor base220and hinged left and right supports201,202in a lowered position. In this lowered position the orientation of the motor74and the axle106are such that a grinding disc attached to the axle74is roughly perpendicular to worktable or bench upon which the invention is mounted. This lowered position orients the frontal plane of the grinding disc at approximately 90 degrees from the surface of the worktable or bench.

FIG.21Ashows a front view of an example tool sharpening accessory with an example tool height alignment sighting surface210, with cutout211, incorporated into a top vacuum collector130for use in conjunction with the example tool sharpening accessory. The tool sharpening accessory can also include, in some embodiments, a bottom shield134that prevents inadvertent contact with the sharpening disc when a user is sharpening tools.

A plurality of pins140are located on a tool holding rod138that accommodate a tool170that is being sharpened. The pins170can be used to hold the tool170in place or provide a point of contact to stabilize the tool170. The tool holding rod138is attached to the tool sharpening accessory by way of a first arm136and a second arm137that allow the rod138to be slid toward or away from the sharpening disc. The movement of the rod138allows tools of different sizes to be sharpened as well as providing for the proper positioning of the tool170in relation to the sharpening disc.

FIG.21Bshows a detail view of the tool height alignment sighting surface210with cutout211and a tool170placed under the cutout211so that it may be properly positioned during sharpening. In some embodiments, the plane of the tool height alignment surface210is aligned with the plane of the tool support (299). This causes tools170placed along the bottom of the height alignment surface210to be positioned near to the centerline of the axis of rotation of the invention. This further causes the tool170being sharpened to be oriented as closely to 90 degrees from the direction of the disc's rotation as possible. That is, the sharpening motion of the disc is approximately from the top of the tool to the bottom, or vice versa depending on the side of the disc that the tool170is positioned on.

FIG.22Ais a front perspective view of the example tool sharpening accessory60and positioning of a tool170to be sharpened from the bottom of the example tool sharpening accessory60. This embodiment of the tool sharpening accessory60includes an example tool height alignment sighting surface210with cutouts211above the alignment sighting surface210. The top of the tool height alignment surface210is aligned with the plane of the tool support299. It can be seen from this view how the tool to be sharpened170lays at an angle to the sharpening disc. The cutouts211allow a user to have a top-down view of the tool170so that it may be positioned accurately.

FIG.22Bshows a rear perspective view of the example tool sharpening accessory60and positioning of a tool170to be sharpened from the bottom of the example tool sharpening accessory60. This embodiment of the tool sharpening accessory60may also include a top vacuum collector130formed by a movable cover and side enclosures. The tool sharpening accessory60may also include a bottom shield134to prevent inadvertent contact with the disc90during sharpening operations. The tool holding rod138may be moved up and down the first and second arms136,137. The tool holder may also be rotated to and from the disc90to change the angle of sharpening by adjusting the mounting brackets with adjustment knob144.

Accordingly, a tool sharpening accessory60for a grinder tool10A,10B includes a first arm136extending in a first direction and a second arm137extending parallel in the first direction and the first and second arms136,137opposite opposing sides of the grinder tool. A tool holding rod138extends between the first arm136and the second arm137. The tool holding rod138includes a set of pins140located at predetermined positions for interfacing to a tool170to be sharpened. The tool holding rod138is configured to be adjustable in the first direction.

To ease proper positioning of a tool170, the tool sharpening accessory60may include an alignment aid160having an indicator210to align an end of the tool170on a disc when the tool holding rod138is adjusted. Finally, the tool sharpening accessory60may also include a vacuum collector130between the first arm136and the second arm137to collect waste material and grinder surface grit.

The tool sharpening accessory60may be used to improve productivity and efficiency when using a grinder tool to sharpen a wood working or another hand tool170. The tool sharpening accessory60allows for multiple positioning of a tool surface to the disc surface to ensure fast and effective sharpening and ability to sharpen various wood cutting, curved, flat-bladed, or other tool surfaces.

All publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) should be considered supplementary to that of this document. For irreconcilable inconsistencies, the usage within this document controls.

While the claimed subject matter has been particularly shown and described regarding the foregoing examples, those skilled in the art will understand that many variations may be made therein without departing from the intended scope of subject matter in the following claims. This description should be understood to include all novel and non-obvious combinations of elements described herein, and claims may be presented in this or a later application to any novel and non-obvious combination of these elements. The foregoing examples are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application. Where the claims recite “a” or “a first” element of the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.