Magnetic caliper with reference scale on edge
First Claim
1. A compact electronic caliper comprising an elongated scale member that extends along a measuring axis direction, a slider assembly that slides along the scale member, and a signal processing circuit that is fixed relative to the slider assembly,the scale member comprising:
- a reference edge surface that extends along the measuring axis direction and that has a first narrow dimension orthogonal to the measuring axis direction;
a loading edge surface that extends along the measuring axis direction and that has a second narrow dimension orthogonal to the measuring axis direction;
a top surface located between the reference edge surface and the loading edge surface, the top surface having a wide dimension orthogonal to the measuring axis direction that is wider than the first and second narrow dimensions; and
a scale track that extends along the measuring axis direction, the scale track comprising magnetic field modulating elements arranged in a scale track pattern corresponding to a scale pitch PT along the measuring axis direction, andthe slider assembly comprising;
a slider;
a reference edge interface configuration comprising an internal reference surface of the slider, the internal reference surface comprising at least one sliding surface portion that slides along the reference edge surface during operation;
a loading edge interface configuration comprising an internal loading surface of the slider that opposes the loading edge surface, and at least one sliding surface portion that slides along the loading edge surface during operation; and
a sensor assembly comprising a plurality of respective sensing elements that are positioned along the scale track and that are responsive to the magnetic field modulating elements and that are connected to provide a plurality of respective output signals to the signal processing circuit, the plurality of respective output signals indicative of the displacement of the slider assembly relative to the scale member along the measuring axis direction, andthe compact electronic caliper comprises at least one of the configurations A and B, wherein;
in the configuration A the scale track is arranged along the reference edge surface within the first narrow dimension, the internal reference surface comprises first and second sliding surface portions that slide against the reference edge surface during operation and that are spaced apart from one another along the measuring axis direction, and the sensor assembly is included in the reference edge interface configuration with the plurality of respective sensing elements positioned along the scale track between the first and second sliding surface portions; and
in the configuration B the scale track is arranged along the loading edge surface within the second narrow dimension, the at least one sliding surface portion that slides along the loading edge surface comprises first and second sliding surface portions that are spaced apart from one another along the measuring axis direction, and the sensor assembly is included in the loading edge interface configuration with the plurality of respective sensing elements positioned along the scale track between the first and second sliding surface portions.
1 Assignment
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Accused Products
Abstract
An electronic hand tool type caliper includes a scale track located along a scale member reference edge that forms a sliding bearing with a mating surface of the caliper slide, thereby maintaining proper alignment of the slide jaw. Placing the scale track along the reference edge is advantageous in that the reference edge surface is inherently precisely machined and particles are excluded by the inherently close fit and the wiping action of the sliding bearing. A readhead sensor is mounted within the slide surface that mates to the reference edge to provide the sliding bearing. Thus, a very small readhead sensor may be reliably positioned at an extremely small gap relative to the scale in a protected operating environment, without detrimentally affecting cost, slider friction, or signal strength. High resolution digital signals may be provided.
63 Citations
23 Claims
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1. A compact electronic caliper comprising an elongated scale member that extends along a measuring axis direction, a slider assembly that slides along the scale member, and a signal processing circuit that is fixed relative to the slider assembly,
the scale member comprising: -
a reference edge surface that extends along the measuring axis direction and that has a first narrow dimension orthogonal to the measuring axis direction; a loading edge surface that extends along the measuring axis direction and that has a second narrow dimension orthogonal to the measuring axis direction; a top surface located between the reference edge surface and the loading edge surface, the top surface having a wide dimension orthogonal to the measuring axis direction that is wider than the first and second narrow dimensions; and a scale track that extends along the measuring axis direction, the scale track comprising magnetic field modulating elements arranged in a scale track pattern corresponding to a scale pitch PT along the measuring axis direction, and the slider assembly comprising; a slider; a reference edge interface configuration comprising an internal reference surface of the slider, the internal reference surface comprising at least one sliding surface portion that slides along the reference edge surface during operation; a loading edge interface configuration comprising an internal loading surface of the slider that opposes the loading edge surface, and at least one sliding surface portion that slides along the loading edge surface during operation; and a sensor assembly comprising a plurality of respective sensing elements that are positioned along the scale track and that are responsive to the magnetic field modulating elements and that are connected to provide a plurality of respective output signals to the signal processing circuit, the plurality of respective output signals indicative of the displacement of the slider assembly relative to the scale member along the measuring axis direction, and the compact electronic caliper comprises at least one of the configurations A and B, wherein; in the configuration A the scale track is arranged along the reference edge surface within the first narrow dimension, the internal reference surface comprises first and second sliding surface portions that slide against the reference edge surface during operation and that are spaced apart from one another along the measuring axis direction, and the sensor assembly is included in the reference edge interface configuration with the plurality of respective sensing elements positioned along the scale track between the first and second sliding surface portions; and in the configuration B the scale track is arranged along the loading edge surface within the second narrow dimension, the at least one sliding surface portion that slides along the loading edge surface comprises first and second sliding surface portions that are spaced apart from one another along the measuring axis direction, and the sensor assembly is included in the loading edge interface configuration with the plurality of respective sensing elements positioned along the scale track between the first and second sliding surface portions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification