Adjustable Grinding Platform and Mounting Assembly
A grinding platform with an axis of rotation that is on the plane of the abrasive when used with belt grinders and on the plane that is vertical and tangent to the curvature of the abrasive when used with wheel grinders; such grinder having an angle gauge and possibly a vernier scale that allow for accurate determination of the angle of the tool rest in relation to the grinding surface. The grinding platform can also be continuously adjusted horizontally to compensate for wheel wear.
This application claims the benefit of U.S. Provisional Patent Application No. 61/478,342, filed on Apr. 22, 2012, which is incorporated by reference herein in its entirety for all purposes.
BACKGROUND OF THE INVENTION1. Field of the Invention
Embodiments of the present invention relate to adjustable grinding platforms or tool rests used in conjunction with grinding wheels and abrasive belts.
2. Description of Related Art
Grinding platforms, also called work rests, are commonly used in conjunction with belt sanders, belt grinders, and grinding wheels for the mechanized abrasive removal, or grinding, of materials. Just about any material can be grinded, such as: metal, wood, or plastic. Grinders and belt sanders are often used for the shaping and sharpening of metal tools, such as woodworking tools. This is typically accomplished by using a vertical grinding wheel mounted on a bench or a stand, but can also be accomplished by using abrasive belts which are part of a belt grinder or sander. The following discussion will discuss grinding platforms for sharpening woodworking tools; however, this invention is not limited to use in the context of sharpening tools.
Sharpening woodworking tools is typically accomplished by resting the tool on the grinder platform such that the longitudinal axis of the tool is parallel to the plane created by the top of the platform surface. The tool is then pressed toward the abrasive surface by hand. Employing this handheld method requires a tool platform that adequately supports the workpiece as well as having the platform set to the correct angle and position to obtain the desired angle of the sharpened edge of the workpiece.
It is fairly common for grinding platforms to incorporate a fixture to assist with making angular measurements between the grinding platform and the abrasive surface. A problem common to such fixtures is that they measure the angle of the platform, not the angle of the point of impact of the workpiece placed upon the grinding platform with the grinding wheel, which is where the true angle of the edge of the workpiece is created. This problem increases with grinding wheels because they vary in diameter over time due to wear and attrition.
There are several methods commonly used for determining the variable angular relationship between a grinding surface and a grinding platform or tool rest and workpiece. One method involves a trial and error process of grinding the workpiece and measuring the resulting angle of the sharpened workpiece. Another method involves several prepared blocks of wood, called jigs, with the desired angle cut on one of the corners. This method is quick, but requires many jigs to accommodate many angles. Another method involves placing a protractor on the grinding platform and flat along the side of the grinding wheel, or belt, such that the center point of the angle of the protractor is on the plane of abrasion; however, this method requires adjustment of the protractor in addition to adjustment of the grinding platform. Additionally, the size of the protractor may introduce error in the measurement of the angle created on the tip of the workpiece by failing to measure the angle where the workpiece actually comes into contact with the arc length of the perimeter of the grinding wheel. Yet another method involves using a digital angle gauge which provides fast angular measurement, but does not allow for nearly simultaneous setting of the platform angle. Additionally, such digital angle gauges require a power source and are subject to loss of calibration through use.
SUMMARYAccording to embodiments of the present invention, the present invention may comprise: a platform and a mounting assembly; said platform having an axis of rotation capable of being on the plane of a surface when the grinding platform is adjacent to a planar surface and on the plane that is vertical and tangent to the curvature of a surface when adjacent to a curved surface; and the mounting assembly of which has a platform pivoting centerline coincident with the plane that is defined by the top surface of the platform and is capable of continuous or indexed horizontal and vertical movement of a platform.
The platform or mounting assembly may also comprise a fixed angle gauge capable of accurately determining the angle of the platform relative to a planar or curved surface, such angle gauge may incorporate a vernier scale. Embodiments of the platform and mounting assembly may also have removable platform supports, interchangeable platforms of various dimensions, and be capable of an angular adjustment of one hundred and sixty five degrees or more.
A method for setting up an embodiment of the grinder platform and mounting assembly comprising; providing adequate vertical clearance between the mounting assembly and an abrasive surface; aligning the longitudinal centerline of the mounting assembly with the center of the face of the abrasive surface; and allowing for the horizontal extension of the mounting assembly to be toward the abrasive surface.
A method for setting up an embodiment of the grinder platform and mounting assembly for a planar or convex surface comprising; establishing the vertical position of the platform such that a workpiece's thickness midline is at the same height as a horizontal line created by a vertical plane that is tangent to the convex surface; establishing the horizontal position of the platform such that the tilting axis of the platform is in the vertical plane that is tangent to the convex abrasive surface; and adjusting the angle of the platform to the desired angle.
A method for manufacturing an embodiment of the grinder platform and mounting assembly comprising primarily machining extrusions.
While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
OBJECTS AND ADVANTAGESNone of the particular objects or advantages that follow must be entirely satisfied as they are non-exclusive alternatives and at least one of the following objects is met; accordingly, several objects and advantages of the present invention are:
(a) to provide a platform having an axis of rotation capable of being on the plane of a surface when the grinding platform is adjacent to a planar surface and on the plane that is vertical and tangent to the curvature of a surface when adjacent to a curved surface;
(b) to provide a mounting assembly that has platform pivoting centerline coincident with the plane that is defined by the top surface of the platform;
(c) to provide a mounting assembly which is capable of continuous or indexed horizontal and vertical movement of a platform;
(d) to provide a work rest with a fixed angle gauge capable of accurately determining the angle of the platform relative to a planar or curved surface;
(e) to provide a work rest with a fixed angle gauge incorporating a vernier scale;
(f) to provide a work rest capable of an angular adjustment of one hundred and sixty five degrees or more;
(g) to provide a work rest with interchangeable platforms of various dimensions;
(h) to provide a work rest with removable platform supports;
(i) to provide a method for manufacturing an embodiment of the grinder platform and mounting assembly that comprises of primarily machining extrusions;
(j) to provide a method for setting up an embodiment of the grinder platform and mounting assembly comprising; providing adequate vertical clearance between the mounting assembly and an abrasive surface; aligning the longitudinal centerline of the mounting assembly with the center of the face of the abrasive surface; and allowing for the horizontal extension of the mounting assembly to be toward the abrasive surface;
(k) to provide a method for setting up an embodiment of the grinder platform and mounting assembly for a planar or convex surface comprising; establishing the vertical position of the platform such that a workpiece's thickness midline is at the same height as a horizontal line created by a vertical plane that is tangent to the convex surface; establishing the horizontal position of the platform such that the tilting axis of the platform is in the vertical plane that is tangent to the convex abrasive surface; and adjusting the angle of the platform to the desired angle;
(l) these and other objects and advantages of the invention will be apparent from the detailed description and drawings.
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- 1 Platform
- 1a Platform Pin
- 1b Platform Wheel Clearance
- 1c Platform Pivot Range—typical
- 1d Platform Pivot Range—special
- 1e Platform Pivoting Centerline
- 1f Workpiece Thickness Midline
- 1g Workpiece Thickness Maximum
- 1h Short Half-Round Platform Design
- 1i Slotted Platform Design
- 1j Slot Detail in the Slotted Platform
- 1k Long Platform Design
- 1L Platform Assembly Lateral Movement
- 2 Left Upright
- 2a Left Upright Angle Indicator Scale
- 3 Right Upright
- 3a Right Upright Angle Indicator Scale
- 4 Sliding Baseplate
- 4a Vertical Travel of Uprights and Platform
- 5 Fixed Baseplate
- 5a Fixed Baseplate Mounting Screws
- 6 Platform Pivot Locking Screw
- 7 Angle Indicator Plate
- 7a Angle Indicator Plate Edge
- 7b Angle Indicator Vernier Scale
- 8 Table Pin Bushing
- 9 Sliding Baseplate Locking Screws
- 10 Threaded Connector
- 11 Upright Locking Screws
- 12 Baseplate Clamping Plate
- 13 Baseplate Clamping Plate Retaining Screw
- 14 Flat Abrasive Surface
- 15 Convex Abrasive Surface
- 16 Bottom Mounting Base
- 17 Convex Abrasive Surface Maximum Outside Diameter
- 18 Convex Abrasive Surface Minimum Outside Diameter
- 19 Workpiece Thickness
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. However, the illustrated embodiments are merely exemplary and many additional embodiments of this invention are possible. It is understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the illustrated devices, and such further application of the principles of the invention as illustrated herein are contemplated as would normally occur to one skilled in the art to which the invention relates.
Unless otherwise indicated, the drawings are intended to be read (e.g., arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.
The details for the sliding baseplate 4 can be seen in
Uprights 2 and 3 are attached to the sliding baseplate 4 as illustrated in
A platform 1 is then affixed between the two uprights, 2 and 3, as illustrated in
One means for preparing the assembly of platform 1 with the uprights 2 and 3 is through the addition and attachment of platform pins 1a, as shown in
With the uprights, 2 and 3, and platform 1 assembled together; this assembly can be attached to a sliding baseplate 4. One means for attaching the platform subassembly and uprights, 2 and 3, to the sliding baseplate 4 is by placing upright locking screws 11 through slots in the lower portion of the uprights, 2 and 3; such upright locking screws 11 can then be threaded into oppositely threaded ends of the threaded connector 10 which can pass through sliding baseplate 4. This assembly then makes up the movable portion of the grinding platform that slides laterally in relation to a fixed baseplate 5.
The movable assembly can then be fitted into a fixed baseplate 5 by inserting the sliding baseplate 4 into an opening as shown in
Use of the entire adjustable grinding platform and the platform mounting assembly can be accomplished by mounting it to a bottom mounting base 16, the bottom mounting base 16 may be of a variety of shapes and materials, examples of which are shown in
Care should be taken during the installation of the adjustable grinding platform and the platform mounting assembly so that several alignment requirements are assured. First, there should be adequate vertical clearance between the bottom mounting base 16 and the abrasive belt, or wheel, to allow for the installation of a fixed baseplate 5. Second, the centerline of the adjustable grinding platform and the platform mounting assembly; that is, the longitudinal centerline of the sliding baseplate 4; should be coincident with approximate center of the face width of the abrasive belt or wheel. Third, this same longitudinal centerline of the sliding baseplate 4 should be at a 90 degree horizontal angle to the axis of rotation of the wheel of the abrasive unit regardless of whether that wheel is part of a belt grinder as illustrated in
This available lateral longitudinal adjustment 1L is particularly necessary when the adjustable grinding platform and platform mounting assembly is used in conjunction with the straight vitrified wheel of a bench or pedestal grinder; as illustrated in
Setup of the platform as shown in
A possible range of platform angles for this embodiment can be seen in
The right hand side of
The second step involved in setup for a convex surface is positioning the platform pivoting centerline 1e at a horizontal position that places 1e in the vertical plane that is tangent to the convex abrasive surface (abrasive belt 15 in
The grinding angle (40 degrees in this example) is easily determined. The angle is read directly from the scales 2a and 3a that are printed on the top ends of the uprights 2 and 3, as shown most clearly in the close-up isometric perspective view illustrated in
With a proper setup arrangement, two important aspects of the platform become more apparent. First, the platform angle can be changed without any other adjustments being required. This would apply if the wedge angle of the sharpened tool was to be changed or if additional tools of a different type but of the same thickness were to be ground during the same sharpening session. The second aspect of importance is that the attrition of the abrasive and the subsequent reduction of the grinding wheel diameter does not require a major revision to the setup. The entire sliding baseplate subassembly is simply moved towards the wheel as indicated by 1L until the platform pivoting centerline 1e again becomes coplanar with the vertical plane that is now tangent to the new wheel size. This latter aspect is particularly advantageous to the user who has many tools of approximately the same thickness. In a matter of seconds the sliding baseplate subassembly can be changed to accommodate the sharpening of any tool in this thickness range.
Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.
CONCLUSIONThis adjustable grinding platform and mounting assembly invention provides quick, easy, and accurate platform adjustments using a scale that defines the platform's angular axis of adjustment which is on the surface of a planar abrasive or the vertical plane tangent to the radius of a curved surface; continuous compensation for abrasive wheel diameter attrition; advantageous incremental or continuous height adjustment; exchangeable platforms; and stability that can be used with a variety of mechanical abrasive processes. While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. Accordingly, the scope of this invention should be determined not by the embodiments, but by the applied claims and their legal equivalents.
Claims
1. A work rest, the work rest comprising:
- a platform having a top surface, wherein the platform is capable of having an axis of rotation on a plane of a planar surface when the platform is adjacent to the planar surface or on a plane that is vertical and tangent to a curvature of a surface when the platform is adjacent to the curved surface;
- a mounting assembly, wherein the mounting assembly is capable of having a platform pivoting centerline on a plane of the top surface of the platform and is capable of horizontal or vertical movement of a platform;
- wherein the platform is fixed or removably attached to the mounting assembly.
2. The work rest of claim 1, wherein the platform or mounting assembly has a fixed angle gauge capable of accurately determining the angle of the top surface of the platform relative to a plane of a planar surface when the platform is adjacent to the planar surface or to a plane that is vertical and tangent to a curvature of a surface when the platform is adjacent to the curved surface.
3. The work rest of claim 2, wherein said angle gauge incorporates a vernier scale.
4. The work rest of claim 1, wherein the platform comprises interchangeable platforms of various dimensions.
5. The work rest of claim 1, wherein the platform is capable of an angular adjustment of one hundred and sixty five degrees or more.
6. The work rest of claim 1, wherein the mounting assembly has removable upright platform supports.
7. The work rest of claim 1, wherein the work rest is aluminum.
8. The work rest of claim 1, wherein the platform has a bottom surface with slots thereon.
9. The work rest of claim 1, wherein the platform has a bottom surface platform wheel indenture.
10. A method for using a work rest having a tilting platform with a top surface attached to a mounting assembly capable of horizontal extension adjacent to a planar or curved surface comprising:
- providing adequate vertical clearance between the mounting assembly and the surface;
- aligning the longitudinal centerline of the mounting assembly perpendicular to the center of the face of the surface; and
- allowing for the horizontal extension of the mounting assembly to be toward the abrasive surface.
11. The method of claim 10, further comprising:
- establishing the vertical position of the top surface of the platform such that a workpiece's thickness midline is at the same height as a horizontal line created by a vertical plane that is tangent to a curved surface.
12. The method of claim 11, further comprising:
- establishing the horizontal position of the platform such that the tilting axis of the platform is in the vertical plane that is tangent to a curved surface.
13. The method of claim 12, further comprising:
- adjusting the angle of the platform to the desired angle.
14. The method of claim 10, further comprising:
- establishing the horizontal position of the platform such that the tilting axis of the platform is in the vertical plane that is tangent to a curved surface.
15. The method of claim 14, further comprising:
- establishing the vertical position of the top surface of the platform such that a workpiece's thickness midline is at the same height as a horizontal line created by a vertical plane that is tangent to a curved surface.
16. The method of claim 15, further comprising:
- adjusting the angle of the platform to the desired angle.
Type: Application
Filed: Apr 23, 2012
Publication Date: Oct 25, 2012
Inventor: Stuart Batty (Boulder, CO)
Application Number: 13/454,011
International Classification: B24B 41/06 (20120101); B24B 49/00 (20120101);