The Warner & Swasey Company

Gary E Englander

Richard P Chase

Donald P Anderson

Guy D Metcalf

Roger H Fournier

Joseph F Volk

Martin A German

The present invention relates to a method of dressing a complex contour onto a grinding surface of at least one grinding wheel of a two-axis grinding machine for grinding a workpiece. The method comprises the steps of causing at least one dressing diamond to traverse the grinding surface of said grinding wheel along a first axis parallel to the axis of rotation of the workpiece while simultaneously causing movement of the dressing diamond with respect to said grinding surface along a second axis; and employing a programmable controller to control said traversing and said movement, so as to automatically dress a complex contour onto said grinding surface.

Dual wheel cylindrical grinding center

An improved method and grinding machine are used to grind lobes on a camshaft. The grinding machine includes a longitudinally extending rocker bar which is pivotally mounted on a work table or carriage. A headstock and tailstock are connected with the rocker bar to rotatably support the camshaft as the cam lobes are ground by a grinding wheel. A control assembly includes a motor which is operated to pivot the rocker bar from a retracted or loading position through an index position to an operating position in a range of operating positions. Immediately before the rocker bar reaches the range of operating positions, the speed of the motor is reduced to effect a corresponding reduction in the speed of movement of the rocker bar. In addition, the motor actuates a biasing assembly to urge the rocker bar toward the camshaft with a relatively large force during a rough grinding operation and a reduced force during a finish grinding operation. During the rough and finish grinding operations, a master cam assembly and follower cooperate to move the rocker bar in the range of operating positions as a function of the desired cam lobe configuration. The cam follower is movable into alignment with a selected one of a plurality of cam elements in the master cam assembly by a motor which is mounted on the carriage. A stop member is utilized to stop the rocker bar when it has moved away from the grinding wheel to the index position. This enables the cam follower to be aligned with a selected master cam element between the grinding of successive lobes on the camshaft without moving the rocker bar all the way back to the loading position. When the grinding of the camshaft is completed, the stop member is retracted to enable the rocker bar to be pivoted to the loading position.

Grinding machine and method

An improved grinding machine includes a grinding wheel which is moved along a path extending at an acute angle to the axis of rotation of a workpiece. The workpiece is movable along its axis of rotation. During plunge grinding operations, the workpiece can be reciprocated along its axis of rotation. During traverse grinding operations, it is necessary to compensate for the acute angle of the path along which the grinding wheel is moved relative to the axis of rotation of the workpiece. This may be done between traverse grind strokes by initiating movement of the grinding wheel toward the workpiece from a position in which the edge surface of the grinding wheel is offset from the plane of a radially extending shoulder surface. Upon completion of a grinding operation, the wheel is retracted to a clear point. Different clear points are used so that the grinding wheel is retracted to only the extent necessary when finishing portions of a workpiece having different diameters. The position of an edge surface of the grinding wheel along the axis of rotation of the workpiece is indicated by data stored in a Z-axis register. Data corresponding to the distance a face surface on the grinding wheel is spaced from the axis of rotation of the workpiece is stored in an X-axis register. The data stored in both registers is changed when the grinding wheel is moved toward and away from the workpiece along the path which extends at an acute angle to the axis of rotation of the workpiece. However, the data in only the Z-axis register is changed when the workpiece is moved along its axis of rotation relative to the grinding wheel. The data in the Z-axis register is adjusted to compensate for the distance which a reference surface on the workpiece is offset from a zero datum position during an initial workpiece locating operation. To reduce the likelihood of wheel breakage, operation of the grinding machine is automatically interrupted when the current required to drive the grinding wheel exceeds a relatively low predetermined amount during high speed positioning movements of either the grinding wheel or the workpiece. If the current required to drive the grinding wheel exceeds a rated operating load by a predetermined amount during a grinding operation, the grinding operation is also interrupted. Fine and coarse pulse generators are provided in association with drive shafts for moving the grinding wheel and the workpiece. The output from the pulse generators are compared and if there is a predetermined difference in the outputs of the fine and coarse pulse generators associated with a particular drive shaft due to a malfunctioning of the grinding machine, operation of the grinding machine is interrupted.

Grinding machine

An improved grinding machine includes a grinding wheel which is moved along a path extending at an acute angle to the axis of rotation of a workpiece. The workpiece is movable along its axis of rotation. During plunge grinding operations, the workpiece can be reciprocated along its axis of rotation. During transverse grinding operations, it is necessary to compensate for the acute angle of the path along which the grinding wheel is moved relative to the axis of rotation of the workpiece. This may be done between traverse grind strokes by initiating movement of the grinding wheel toward the workpiece from a position in which the edge surface of the grinding wheel is offset from the plane of a radially extending shoulder surface. Upon completion of a grinding operation, the wheel is retracted to a clear point. Different clear points are used so that the grinding wheel is retracted to only the extent necessary when finishing portions of a workpiece having different diameters. The position of an edge surface of the grinding wheel along the axis of rotation of the workpiece is indicated by data stored in a Z-axis register. Data corresponding to the distance a face surface on the grinding wheel is spaced from the axis of rotation of the workpiece is stored in an X-axis register. The data stored in both registers is changed when the grinding wheel is moved toward and away from the workpiece along the path which extends at an acute angle to the axis of rotation of the workpiece. However, the data in only the Z-axis register is changed when the workpiece is moved along its axis of rotation relative to the grinding wheel. The data in the Z-axis register is adjusted to compensate for the distance which a reference surface on the workpiece is offset from a zero datum position during an initial workpiece locating operation. To reduce the likelihood of wheel breakage, operation of the grinding machine is automatically interrupted when the current required to drive the grinding wheel exceeds a relatively low predetermined amount during high speed positioning movements of either the grinding wheel or the workpiece. If the current required to drive the grinding wheel exceeds a rated operating load by a predetermined amount during a grinding operation, the grinding operation is also interrupted. Fine and coarse pulse generators are provided in association with drive shafts for moving the grinding wheel and the workpiece. The outputs from the pulse generators are compared and if there is a predetermined difference in the outputs of the fine and coarse pulse generators associated with a particular drive shaft due to a malfunctioning of the grinding machine, operation of the grinding machine is interrupted.

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Shrewsbury, MA, United States of America

Gary E Englander