Abstract: An electronic hollow grinder bevel angle indicator wherein a microprocessor calculates the grinding bevel angle that will be obtained when a tool is placed flat upon a tool rest and presented to the periphery of a rotating grinding wheel. The calculated bevel angle is the acute angle of intersection between the tool rest plane and a plane tangent to the grinding wheel periphery at the line of intersection between the grinding wheel periphery and the tool rest plane. The microprocessor also calculates the air-gap between the tool rest and grinding wheel, and warns the operator when the air gap exceeds a specified safety threshold.

Abstract: An electronic hollow grinder bevel angle indicator wherein a microprocessor calculates the grinding bevel angle that will be obtained when a tool is placed flat upon a tool rest and presented to the periphery of a rotating grinding wheel. The calculated bevel angle is the acute angle of intersection between the tool rest plane and a plane tangent to the grinding wheel periphery at the line of intersection between the grinding wheel periphery and the tool rest plane. The microprocessor also calculates the air-gap between the tool rest and grinding wheel, and warns the operator when the air gap exceeds a specified safety threshold.

Abstract: An improved hollow grinder bevel angle control wherein a height-attitude coupling mechanism links the height and attitude motions of an adjustable tool-rest, and a scale on a stationary portion of the grinder cooperates with a pointer on the height-attitude coupling mechanism to indicate a relationship between bevel angle and grinding wheel radius. The coupling mechanism is implemented with a linkage mechanism that provides a wide range of tool-rest adjustment, subject to the height-attitude relationship defined by the linkage. The pointer is mounted for rotation with the linkage mechanism about its fixed pivot point, and is user-adjustable so that a dimension from the fixed pivot point to the tip of the pointer coincides with the radius of the grinder wheel. The bevel angle scale is stationary with respect to movement of the linkage mechanism, and arranged so that the tip of the pointer sweeps across the scale as the linkage mechanism is adjusted through its full range of movement.