Precision position indicator

Claim 2

Apparatus for sensing the position of a movable object along a predetermined path relative to pre-established limits comprising: first and second sensing stations establishing corresponding limits along the path of a movable object, said stations cooperatively establishing three zones along said path including a zone between said stations and zones beyond each of said stations; each said sensing station including first and second independent sensing elements cooperatively establishing a reference limit, each sensing element providing separate sensing and non-sensing output condition signals in response to the position of said movable object relative thereto, the spacing between said sensing elements being less than the dimension of said movable object, whereby said sensing elements may independently sense said object and at one position said sensing elements will simultaneously sense the presence of said object; a separate signal circuit operatively connected for response to each sensing station and providing first and second output signal states representing positions of said movable object relative to the respective reference limit; each said signal circuit including means for changing the respective circuit output from one state to the other in response to changes in said station element output condition signals and providing a unique relationship of said circuit output signal states in response to the positioning of said movable object in each of said zones; first, second and third signal means respectively representing each of said zones operatively connected to said signal circuits and responsive to said output signal states; enabling means operatively connected to said signal circuits and to said signal means for enabling the representative zone of said signal means while simultaneously disabling the remaining signal means in response to the relationship between the outputs of said signal circuits and the zone in which said object lies.

Claim 3

Apparatus set forth in claim 1 in which each said means for changing said output signal states further comprises: inverting means respectively connected to each of said first and second sensing elements and responsive thereto providing inverted output condition signals relative to the signal of the respective element; cross coupled NAND gates operatively connected to said inverting means and providing said output signal states from one of said gates, each of said gates having two inputs and a single output and providing a gate output signal determined by said inputs, one input of each gate being operatively connected to one of said inverting means for response to inverted output condition signals therefrom, each of said gate output signals being connected to and providing the second input to the other said gate whereby said signal circuit output signal state is determined by state of said cross coupled gates; and said enabling means including a logic circuit providing a logic signal enabling said second signal means only when said first cross coupled gate provides a first circuit output having a first signal state and said second cross coupled gate provides a second circuit output having a second signal state.

Claim 4

Apparatus as set forth in claim 2 in which said logic circuit comprises: a first NAND gate providing a first input connected to a positive power source and a second input connected to a first cross coupled NAND gate output signal, said NAND gate providing output signal states to enable and disable said third signal means in response to the staTe of said first cross coupled NAND gate; a second NAND gate providing a first input connected to said positive power source and a second input connected to a second cross coupled NAND gate output signal; a third NAND gate providing a first input connected to the output of said second NAND gate and a second input connected to said first cross coupled NAND gate output signal; and a fourth NAND gate providing a first input connected to the output of said third NAND gate and a second input connected to said power source, said fourth NAND gate providing a signal enabling said signal means.

Claim 5

Apparatus for sensing and indicating, relative to pre-established limits, the location of an object positionable along a flow path in response to the characteristic of a body being measured, said measuring means comprising: a transparent flow tube vertically connected between said air supply and said outlet; a float in said tube positioned therealong in accordance with the flow upward through said tube; first and second sensing stations along said tube establishing corresponding limits on said tube and along the path of said float, said stations cooperatively establishing a first zone above said first station, a second zone between said stations, and a third zone below said second station, each said station comprising a light source providing a beam of light across said tube; first and second photodetectors spaced apart along said tube less than the dimension of said float and cooperatively establishing a reference limit, each photodetector being operatively responsive to said beam and providing separate sensing and non-sensing output condition signals in response to the position of said float relative thereto, whereby said photodetectors may independently sense said float and at one position said photodetectors will simultaneously sense the presence of said float; a separate signal circuit operatively connected for response to each sensing station and providing first and second output signal states representing positions of said float relative to the respective reference limit; each said signal circuit including means for changing the respective circuit output from one state to the other in response to changes in said station photodetector output condition signals and providing a unique relationship of said circuit output signal states in response to the positioning of said movable object in each of said zones; first, second and third indicator means respectively representing each of said zones operatively connected to said signal circuits and responsive to said output signal states; enabling means operatively connected to said signal circuits and to said indicator means for enabling the representative zone of said indicator means while simultaneously disabling the remaining indicator means in response to the relationship between the outputs of said signal circuits and the zone in which said object lies.

Claim 6

Apparatus for sensing and indicating, relative to pre-established limits, the location of an object positionable along a flow path in response to the characteristic of a body being measured, said measuring means comprising: a transparent flow tube vertically connected between said air supply and said outlet; a float in said tube positioned therealong in accordance with the flow upward through said tube; first and second sensing stations along said tube establishing corresponding limits on said tube and along the path of said float, said stations cooperatively establishing a first zone above said first station, a second zone between said stations, and a third zone below said second station, each said station comprising a light source providing a beam of light across said tube; first and second photodetectors spaced apart along said tube less than the dimension of said float and cooperatively establishing a reference limit, each photodetector being operatively responsive to said beam and providing separate sensing and non-sensing output condition signals in response to the position of said float relative thereto, whereby said photodetectors may independently sense said float and at one position said photodetectors will simultaneously sense the presence of said float; a separate signal circuit operatively connected for response to each sensing station and providing first and second output signal states representing positions of said float relative to the respective reference limit; each said signal circuit including means for changing the respective circuit output from one state to the other in response to changes in said station photodetector output condition signals and providing a unique relationship of said circuit output signal states in response to the positioning of said movable object in each of said zones; first, second and third indicator means respectively representing each of said zones operatively connected to said signal circuits and responsive to said output signal states; enabling means operatively connected to said signal circuits and to said indicator means for enabling the representative zone of said indicator means while simultaneously disabling the remaining indicator means in response to the relationship between the outputs of said signal circuits and the zone in which said object lies.

Claim 7

A position indicator for indicating the position of a body relative to a reference location comprising: first detector means operative to produce a first signal in response to the presence of said body at said reference location and operative to produce a second signal in response to the absence of said body from said reference location; means producing a first indicator signal in response to said detector means second signal whenever said body is positioned away from said reference location in one direction and producing a second indicator signal in response to said detector means second signal whenever said body is positioned away from said reference location in another direction, and further including means producing one of said indicator signals in response to said first signal; said means producing said first and second indicator signals including a second detector means producing a third signal in response to the approach of said body towards said reference location in one of said directions anD further includes means controlling the response of said means producing said first and second indicator signals to said first signal in response to said third signal, whereby indications of the positions of said body along said directions relative said reference location are provided.

Claim 8

A position indicator for indicating the position of a body relative to a reference location comprising: first detector means operative to produce a first signal in response to the presence of said body at said reference location and operative to produce a second signal in response to the absence of said body from said reference location; means producing a first indicator signal in response to said detector means second signal whenever said body is positioned away from said reference location in one direction and producing a second indicator signal in response to said detector means second signal whenever said body is positioned away from said reference location in another direction, and further including means producing one of said indicator signals in response to said first signal; said means producing said first and second indicator signals including a second detector means producing a third signal in response to the approach of said body towards said reference location in one of said directions anD further includes means controlling the response of said means producing said first and second indicator signals to said first signal in response to said third signal, whereby indications of the positions of said body along said directions relative said reference location are provided.

Claim 9

The indicator of claim 5 wherein said first detector means includes a detector positioned so as to produce said first and second signals in the presence and absence of said body from said reference location, respectively, and wherein said second detector means includes a second detector positioned spaced from said first detector along the path of one said directions a distance less than a dimension of said body and producing said third signal when said body passes said second detector.

Claim 10

The indicator of claim 6 wherein said detectors are photoelectric detectors and said first and second detector means includes a light source positioned so that said body intercepts a portion of the light which normally impinges a said photoelectric detector in passing said detectors.

Claim 11

The indicator of claim 6 wherein said second detector also produces a fourth signal when said body is not positioned by said second detector and wherein said first, second, third, and fourth signals are high-low logic signals, and wherein both said means producing indicator signals includes cross-coupled NAND gates, with the output of said first detector being one input to one of said NAND gates, the outputs of the second detector being one input to the other of said NAND gates, and the outputs of said NAND gates being cross-coupled to the other inputs of said NAND gates, and wherein said means producing said indicator signals includes means responding to the output of said one NAND gate to produce said indicator signals.