|
Description: |
| Abstract:
In order to accurately test or calibrate precision electromechanical rotary transducers it is necessary to determine precisely the rotation of the shaft relative to the body thereof, i.e., the support for the shaft. For example, precision potentiometers are tested in a voltage bridge circuit by comparison with a calibrated standard potentiometer. For this purpose it is necessary to know the angular setting of both potentiometers within very close limits. Therefore, it is an object of the present invention to provide an indexing head for determining within a fraction of a minute of arc the angular setting of the shaft of a potentiometer or other electromechanical rotary transducer.
For convenience of explanation it will be assumed that the indexing head is constructed for use with precision potentiometers; however, it should be understood that the device can be used anywhere it is desired to index a shaft relative to its support.
In accordance with the invention there is provided an indexing head for accurately indexing a shaft relative to its support, the indexing head comprising a frame, an indexing wheel in the form of a precision gear mounted for axial rotation upon said frame, means for fixedly securing a support for a shaft relative to said frame, means for coupling to said indexing wheel for conjoint rotation a shaft supported by said support, a carriage member mounted on said frame for movement adjacent the periphery of said indexing wheel, control means for determining the movement of said carriage member, a slide block mounted on said carriage member for parallel movement relative thereto, an indexing block carrying a toothed rack, adjustable means joining said indexing block to said slide block in a manner permitting selective tangential operative engagement of said rack with the teeth of said indexing wheel, the movements of said carriage member and said slide block paralleling the line of said tangential engagement, a calibrated micrometric adjustment member carried by said carriage member for micrometric positioning of said slide block relative to said carriage member, and an indicator carried by said indexing block for cooperating with indiciating said indexing wheel, said indicia defining equiangular increments of said indexing wheel which are equal to a given multiple of the circular pitch of the teeth thereon.
Claims:
1. An indexing head for accurately indexing a shaft relative to its support, said indexing head comprising a frame, an indexing wheel in the form of a precision gear mounted for axial rotation upon said frame, means for fixedly securing a support for a shaft relative to said frame, means for coupling to said indexing wheel for conjoint notation a shaft supported by said support, a carriage member mounted on said frame for movement adjacent the periphery of said indexing wheel, control means for determining the movement of said carriage member, a slide block mounted on said carriage member for parallel movement relative thereto, an indexing block carrying a toothed rack, adjustable means joining said indexing block to said slide block in a manner permitting selective tangential operative engagement of said rack with the teeth of said indexing wheel, the movements of said carriage member and said slide block paralleling the line of said tangential engagement, a calibrated micrometric adjustment member carried by said carriage member for micrometric positioning of said slide block relative to said carriage member, and an indicator carried by said indexing block for cooperating with indicia on said indexing wheel, said indicia defining equiangular increments of said indexing wheel which are equal to a given multiple of the circular pitch of the teeth thereon.
2. An indexing head for accurately indexing a shaft relative to its support, said indexing head comprising a frame, an indexing wheel in the form of a precision gear mounted for axial rotation upon said frame, means for fixedly securing a support for a shaft relative to said frame, means for coupling to said indexing wheel for conjoint rotational shaft supported by said support, a slide block, a carriage member supporting said slide block in the plane of said indexing wheel radially spaced from the periphery thereof for movement relative to said carriage member along a line parallel to a tangent to said periphery, 'said carriage member being mounted on said frame for independent movement parallel to said line, control means for determining the movement of said carriage member, a toothed rack, a plunger secured at one end to said rack and supported for longitudinal sliding motion in said slide block such as to position said rack for selective operative engagement with the teeth of said indexing wheel along said tangent, a calibrated micrometric adjustment member carried by said carriage member for micrometric' positioning "of said slide block relative to said carriage member, and an indicator joined to said rack for cooperating with indicia on said indexing wheel, said indicia defining equiangular increments of said indexing wheel which are equal to a given multiple of the circular pitch of the teeth thereon.
3. An indexing head according to claim 2, wherein said plunger has a rectangular cross-section, said slide block has a rectangular bore therethrough of larger cross-sectional dimension to receive said plunger, and a pair of pressure plates engaging two of the intersecting faces of said plunger are disposed in the space between the plunger and the walls of the bore in the slide block for firmly positioning said plunger relative to the slide block.
4. An indexing head for accurately indexing a shaft relative to its support, said indexing head comprising a frame, an indexing wheel in the form of a precision gear mounted for axial rotation upon said frame, means for fixedly securing a support for a shaft relative to said frame, means for coupling to said indexing Wheel for conjoint rotation a shaft supported by said support, a slide block supporting a toothed rack in the plane of said indexing Wheel for selective operative engagement with the teeth of said indexing Wheel along a tangent to the periphery thereof, a calibrated micrometric adjustment member, a carriage member supporting both said slide block and said adjustment member for micrometric positioning of said slide block relative to said carriage member, said indexing Wheel being rotated by movement of said rack with said slide block under the control of said adjustment member, an indicator joined to said rack for cooperating with indicia on said indexing wheel, said indicia defining equiangular increments of said indexing wheel which are equal to a given multiple of the circular pitch of the teeth thereon, and means supported by said frame for adjusting the position of said carriage thereby rotating said indexing wheel Without changing either the setting of said adjustment member or the relationship between said indicator and said indicia.
5. An indexing head for accurately indexing the shaft relative to the body of an electro-mechanical rotary transducer, said indexing head comprising a frame, an indexing Wheel in the form of a precision gear mounted for axial rotation upon said frame, a piloted mounting member for supporting the body of an electro-mechanical rotary transducer relative to said frame with the shaft of the transducer aligned co-axially with the axis of said indexing Wheel, means for coupling said shaft to said indexing Wheel for conjoint rotation, a slide block supporting a toothed rack in the plane of said indexing Wheel for selective operative engagement with the teeth of said indexing Wheel along a tangent to the periphery thereof, a calibrated micrometric adjustment member, a carriage member supporting both said slide block and said adjustment member for micrometric positioning of said slide block relative to said carriage member, said indexing Wheel being rotated by movement of said rack with said slide block under the control of said adjustment member, an indicator joined to said rack for cooperating with indicia on said indexing Wheel, said indicia defining equiangular increments of said indexing wheel which are equal to a given multiple of the circular pitch of the teeth thereon, and means supported by said frame for adjusting the position of said carriage thereby rotating said indexing wheel Without changing either the setting of said adjustment member or the relationship between said indicator and said indicator.
|
|
){kind=link}
){kind=link}
){kind=link}