Sealed mechanical configuration for electronic calipers for reliable operation in contaminated environments
First Claim
1. A capacitive electronic caliper having reduced sensitivity to environmental contaminants, comprising:
- an elongated main beam mechanically coupled to a first position determining member, said main beam having a hollow interior thereby forming an elongated cavity;
a first set of electrodes fixed within said elongated cavity in said main beam, said first set of electrodes forming a pattern extending over a measuring range along the length of said main beam;
a slider mechanically coupled to a second position determining member, said slider being slidably mounted on said main beam so that the position of said slider on said main beam is indicative of the relative distance between said first and second position determining members;
a second set of electrodes fabricated on a substrate operably positioned in the cavity of said main beam so that said second set of electrodes can move along the length of said first set of electrodes to form an operable set of capacitive encoder electrodes;
a coupling mechanism mechanically coupling said slider to said substrate so that the relative movement between said first and second position determining members corresponds to the relative movement between said first and second set of electrodes;
a sealing mechanism to isolate said cavity from the external environment while allowing said coupling mechanism to mechanically couple said slider to said second set of electrodes; and
electronic circuitry connected to one of said sets of electrodes, said electronic circuitry applying signals to and receiving signals from said set of electrodes in order to provide an indication of the relative position between said first and second position determining members as a function of the capacitive coupling between said first and second sets of electrodes.
1 Assignment
0 Petitions
Accused Products
Abstract
An electronic caliper configuration making such calipers more reliable in the presence of liquid and particulate contaminants. Included in the caliper configuration is an elongated cavity added to the main beam of the caliper. The cavity is sealed with a cover. The measuring scale element of the measuring transducer, and the associated shorter pickoff element are mounted in this cavity. The depth bar, ordinarily attached to the sliding jaw in conventional calipers, is inserted into the cavity through a hole or holes aligned parallel to the longitudinal axis of the caliper and internally joined to the moving transducer element. A conventional lip seal provides an effective seal around the diameter of the depth bar. An external portion of the depth bar is coupled to the sliding jaw of the caliper via axially rigid linkage or alternately an axially rigid flexure. In this way, the internally isolated transducer elements can be actuated by the external sliding caliper jaw. As a result, the measuring transducer elements, which are contamination sensitive, may be isolated within a cavity in a caliper which nearly maintains the preferred, historically proven form and functions to provide an electronic caliper with greatly improved reliability when operating in the traditional industrial shop environment. In one embodiment, the neutral axis of the depth bar is positioned to coincide with the neutral axis of the linkage bars, so that bending of the linkage bars and depth bar does not significantly affect the measurement accuracy.
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Citations
38 Claims
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1. A capacitive electronic caliper having reduced sensitivity to environmental contaminants, comprising:
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an elongated main beam mechanically coupled to a first position determining member, said main beam having a hollow interior thereby forming an elongated cavity; a first set of electrodes fixed within said elongated cavity in said main beam, said first set of electrodes forming a pattern extending over a measuring range along the length of said main beam; a slider mechanically coupled to a second position determining member, said slider being slidably mounted on said main beam so that the position of said slider on said main beam is indicative of the relative distance between said first and second position determining members; a second set of electrodes fabricated on a substrate operably positioned in the cavity of said main beam so that said second set of electrodes can move along the length of said first set of electrodes to form an operable set of capacitive encoder electrodes; a coupling mechanism mechanically coupling said slider to said substrate so that the relative movement between said first and second position determining members corresponds to the relative movement between said first and second set of electrodes; a sealing mechanism to isolate said cavity from the external environment while allowing said coupling mechanism to mechanically couple said slider to said second set of electrodes; and electronic circuitry connected to one of said sets of electrodes, said electronic circuitry applying signals to and receiving signals from said set of electrodes in order to provide an indication of the relative position between said first and second position determining members as a function of the capacitive coupling between said first and second sets of electrodes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A capacitive transducer for measuring the position between first and second objects, said transducer comprising:
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an elongated main beam mechanically coupled to said first object, said main beam having a hollow interior thereby forming an elongated cavity; a first set of electrodes mounted within said elongated cavity to form a pattern extending along the length of said main beam; a substrate positioned in said cavity adjacent said first set of electrodes, said substrate being slidably mounted in said cavity so that said substrate can move along a measurement axis extending from one end of said cavity to another; a second set of electrodes fabricated on said substrate, said second set of electrodes having a pattern that allows the relative position between said first and second set of electrodes along the length of said main beam to be determined by the capacitive coupling between said first and second sets of electrodes; an elongated mechanical coupling member extending from the substrate axially inside said elongated cavity and through an aperture formed in one of the end walls of said cavity, said mechanical coupling member being mechanically coupled to said second object so that the relative movement between said first and second sets of electrodes corresponds to the relative movement between first and second objects; a seal positioned at said aperture to isolate said cavity from the external environment while allowing said coupling member to move axially through said aperture; and electronic circuitry connected to one of said sets of electrodes, said electronic circuitry applying signals to and receiving signals from said set of electrodes in order to provide an indication of the relative position between said first and second objects as a function of the capacitive coupling between said first and second sets of electrodes. - View Dependent Claims (15, 16, 17)
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18. In a capacitive electronic caliper of the type having an elongated main beam mechanically coupled to a first position measuring member, a first set of electrodes mounted on said main beam form a pattern extending along the length of said main beam, a slider mechanically coupled to a second position measuring member, said slider being slidably mounted on said main beam so that the position of said slider on said main beam is indicative of the relative position between said first and second position measuring members, and a second set of electrodes having a pattern that allows the relative position between said first and second set of electrodes along the length of said main beam to be determined by the capacitive coupling between said first and second sets of electrodes, a method of making said caliper less sensitive to contaminants, said method comprising:
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positioning said first and second set of electrodes in an enclosed cavity extending along the length of said main beam so that said second set of electrodes can move along the length of said scale while capacitively interacting with said first set of electrodes; and mechanically coupling said slider to said second set of electrodes. - View Dependent Claims (19, 20)
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21. A capacitive electronic caliper having reduced sensitivity to environmental contaminants, comprising:
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an elongated main beam mechanically coupled to a first position measuring member, said main beam having a hollow interior thereby forming an elongated cavity; a first set of electrodes fixed within said elongated cavity in said main beam, said first set of electrodes forming a pattern extending over a measuring range along the length of said main beam; a slider mechanically coupled to a second position measuring member, said slider being slidably mounted on said main beam so that the position of said slider on said main beam is indicative of the relative position between said first and second position measuring members; a second set of electrodes fabricated on a substrate positioned in the cavity of said main beam so that said second set of electrodes is operably positioned relative to said first set of electrodes and said substrate can move along the length of said main beam; a bar extending from an aperture in an end wall of said cavity axially along said main beam into said cavity, said bar being mechanically coupled to said slider outside said cavity and to said substrate inside said cavity so that said bar mechanically couples said substrate to said slider whereby the relative movement between said first and second sets of electrodes corresponds to the relative movement between said main beam and said slider; a seal positioned at said aperture to isolate said cavity from the external environment while allowing said bar to move axially through said aperture; and electronic circuitry connected to one of said sets of electrodes, said electronic circuitry applying signals to and receiving signals from said set of electrodes in order to provide an indication of the relative position between said first and second position measuring members as a function of the capacitive coupling between said first and second sets of electrodes. - View Dependent Claims (22, 23, 24, 25, 26, 27)
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28. An electronic caliper having reduced sensitivity to environmental contaminants, comprising:
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an elongated main beam mechanically coupled to a first position measuring member, said main beam having a hollow interior thereby forming an elongated cavity; an elongated first position transducer element fixed within said elongated cavity in said main beam, said first position transducer element extending over a measuring range along the length of said main beam; a slider mechanically coupled to a second position measuring member, said slider being slidably mounted on said main beam so that the position of said slider on said main beam is indicative of the relative position between said first and second position measuring members; a second position transducer element positioned in the cavity of said main beam so that said second position transducer element is operably positioned relative to said first position transducer element and can move along the length of said first position transducer element; a bar extending axially along said main beam and into said cavity through an aperture in an end wall of said cavity, said bar being mechanically coupled to said slider outside said cavity and to said second position transducer element inside said cavity so that said bar mechanically couples said second position transducer element to said slider whereby the relative movement between said first and second position transducer elements corresponds to the relative movement between said main beam and slider; a seal positioned in said aperture to isolate said cavity from the external environment while allowing said bar to move axially through said aperture; and electronic circuitry operably connected to at least one of said first and second position transducer elements to provide signals to and receive signals from said position transducer element to provide an indication of the relative position between said first and second position measuring members as a function of an interaction between said first and second position transducer elements. - View Dependent Claims (29, 30, 31, 32, 33, 34)
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35. A method for manufacturing a capacitive electronic caliper having reduced sensitivity to environmental contaminants, comprising:
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mechanically coupling an elongated main beam to a first position determining member, the main beam having a hollow interior forming an elongated cavity; fixing a first set of electrodes within the elongated cavity, the first set of electrodes forming a pattern extending over a measuring range along the length of the main beam; mechanically coupling a slider to a second position determining member, the slider slidably mounted on the main beam, a position of the slider on the main beam indicative of a relative distance between the first and second position determining members; fabricating a second set of electrodes on a substrate operably positioned in the cavity of the main beam, the second set of electrodes movable along the length of the first set of electrodes to form an operable set of capacitive encoder electrodes; mechanically coupling the slider to the substrate by a coupling mechanism, relative movement between the first and second position determining members corresponding to relative movement between the first and second set of electrodes; providing a sealing mechanism to isolate the cavity from the external environment, the sealing mechanism allowing the coupling mechanism to mechanically couple the slider to the second set of electrodes; and connecting electronic circuitry to one of the sets of electrodes, the electronic circuitry applying signals to and receiving signals from the set of electrodes to provide an indication of the relative position between the first and second position determining members as a function of the capacitive coupling between the first and second sets of electrodes.
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36. A method for manufacturing a capacitive electronic caliper having reduced sensitivity to environmental contaminants, the capacitive transducer measuring a position between first and second objects, the method comprising:
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mechanically coupling an elongated main beam to the first object, the main beam having a hollow interior forming an elongated cavity; mounting a first set of electrodes within the elongated cavity to form a pattern extending along the length of the main beam; positioning a substrate in the cavity adjacent the first set of electrodes, the substrate slidably mounted in the cavity, the substrate moveable along a measurement axis extending from one end of the cavity to another; fabricating a second set of electrodes on the substrate, the second set of electrodes having a pattern, a relative position between the first and second set of electrodes along the length of the main beam determined by capacitive coupling between the first and second sets of electrodes; mechanically coupling a mechanical coupling member to the second object, the elongated mechanical coupling member extending from the substrate axially inside the elongated cavity and through an aperture formed in one of the end walls of the cavity, relative movement between the first and second sets of electrodes corresponding to relative movement between first and second objects; positioning a seal at the aperture to isolate the cavity from the external environment, the seal allowing the coupling member to move axially through the aperture; and connecting electronic circuitry to one of the sets of electrodes, the electronic circuitry applying signals to and receiving signals from the set of electrodes to provide an indication of the relative position between the first and second objects as a function of the capacitive coupling between the first and second sets of electrodes.
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37. A method for manufacturing a capacitive electronic caliper having reduced sensitivity to environmental contaminants, comprising:
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mechanically coupling an elongated main beam to a first position measuring member, the main beam having a hollow interior forming an elongated cavity; fixing a first set of electrodes within the elongated cavity in the main beam, the first set of electrodes forming a pattern extending over a measuring range along the length of the main beam; mechanically coupling a slider to a second position measuring member, the slider slidably mounted on the main beam, a position of the slider on the main beam indicative of relative position between the first and second position measuring members; fabricating a second set of electrodes on a substrate positioned in the cavity of the main beam, the second set of electrodes operably positioned relative to the first set of electrodes, the substrate moveable along the length of the main beam; mechanically coupling a bar to the slider outside the cavity and to the substrate inside the cavity, the bar extending from an aperture in an end wall of the cavity axially along the main beam into the cavity, relative movement between the first and second sets of electrodes corresponding to relative movement between the main beam and the slider; positioning a seal at the aperture to isolate the cavity from an external environment while allowing the bar to move axially through the aperture; and connecting electronic circuitry to one of the sets of electrodes, the electronic circuitry applying signals to and receiving signals from the set of electrodes in order to provide an indication of the relative position between the first and second position measuring members as a function of the capacitive coupling between the first and second sets of electrodes.
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38. A method for manufacturing an electronic caliper having reduced sensitivity to environmental contaminants, comprising:
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mechanically coupling an elongated main beam to a first position measuring member, the main beam having a hollow interior forming an elongated cavity; fixing an elongated first position transducer element within the elongated cavity in the main beam, the first position transducer element extending over a measuring range along the length of the main beam; mechanically coupling a slider to a second position measuring member, the slider slidably mounted on the main beam, a position of the slider on the main beam indicative of relative position between the first and second position measuring members; positioning a second position transducer element in the cavity of the main beam, the second position transducer element operably positioned relative to the first position transducer element and moveable along the length of the first position transducer element; mechanically coupling a bar to the slider outside the cavity and to the second position transducer element inside the cavity, the bar extending axially along the main beam and into the cavity through an aperture in an end wall of the cavity, relative movement between the first and second position transducer elements corresponding to relative movement between the main beam and slider; positioning a seal in the aperture to isolate the cavity from an external environment while allowing the bar to move axially through the aperture; and operably connecting electronic circuitry to at least one of the first and second position transducer elements to provide signals to and receive signals from the position transducer element to provide an indication of the relative position between the first and second position measuring members as a function of an interaction between the first and second position transducer elements.
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Specification