US4633419A — Angle measuring device

Claim 1

Independent Claim 233 words

An angle measuring device comprising: a disc rotating at a constant speed; a reference point provided for said disc, said reference point being fixedly secured a housing; a reference region including said reference point; an angle measuring arm concentric with said disc and rotatable; first and second measuring points provided on said arm in such a manner that said first and second measuring points are positioed symmetrically with respect to the center of rotation of said arm; arithmetic means for multiplying a ratio of an angle measuring time required for said disc to turn from said reference point to said first or second measuring point to a one-revolution time required for said disc to make one complete rotation through 360°; determining means for determining whether or not said first measuring point is in said reference region; change-over means for switching measuring operations in such a manner that when said first measuring point is in said refernce region a period of time required for said disc to turn from said reference point to said second measuring point is measured and when said first measuring point is out of said reference region a period of time required for said disc to turn from said reference point to said first measuring point is measured; and measured angle correcting means for subtracting 180° from a measured angle when said first measuring point is in said reference region.

Claim 2

Dependent Claim 233 words

An angle measuring device comprising: a disc rotating at a constant speed; a reference point provided for said disc, said reference point being fixedly secured a housing; a reference region including said reference point; an angle measuring arm concentric with said disc and rotatable; first and second measuring points provided on said arm in such a manner that said first and second measuring points are positioed symmetrically with respect to the center of rotation of said arm; arithmetic means for multiplying a ratio of an angle measuring time required for said disc to turn from said reference point to said first or second measuring point to a one-revolution time required for said disc to make one complete rotation through 360°; determining means for determining whether or not said first measuring point is in said reference region; change-over means for switching measuring operations in such a manner that when said first measuring point is in said refernce region a period of time required for said disc to turn from said reference point to said second measuring point is measured and when said first measuring point is out of said reference region a period of time required for said disc to turn from said reference point to said first measuring point is measured; and measured angle correcting means for subtracting 180° from a measured angle when said first measuring point is in said reference region.

Claim 3

Dependent Claim 86 words

The angle measuring device as claim in claim 1, further comprising: angle measuring time integrating means of integrating data corresponding to said angle measuring time every revolution of said disc; one-revolution-time integrating means for integrating data corresponding to said one revolution time every revolution of said disc; arithmetic means for computing a measured angle according to a ratio of the integration value of said angle measuring time to the integration value of said one revolution time after said disc has made a predetermined number of revolutions.

Claim 4

Dependent Claim 33 words

The angle measuring device as claimed in claim 1, wherein said arithmetic means, said determining means, said change-over means and said measured angle correcting means operate when said disc has made one revolution.

Claim 5

Dependent Claim 204 words

In an angle measuring device which includes a disc having a slit and rotating at a constant speed, a reference point provided for said disc fixedly secured to a housing, an angle measuring arm substantially concentric with said disc and rotatable, and a measuring point on said angle measuring arm, and in which a reference point pulse is produced when said slit of said disc passes through said reference point and a measuring point pulse is generated when said slit of said disc passes through said measuring point, the improvement comprising: first time detecting means for detecting a first time which elapses from the rise of said reference point pulse until the rise of said measuring point pulse; second time detecting means for detecting a second time which elapses from the fall of said reference point pulse until the fall of said measuring point pulse; average value calculating means for calculating an average time of said first and second times; one-revolution-time detecting means for detecting a period of time required for said disc to make one revolution; and arithmetic means for multiplying a ratio of said average time to said period of time required for said disc to make one complete revolution through 360°.

Claim 6

Dependent Claim 204 words

In an angle measuring device which includes a disc having a slit and rotating at a constant speed, a reference point provided for said disc fixedly secured to a housing, an angle measuring arm substantially concentric with said disc and rotatable, and a measuring point on said angle measuring arm, and in which a reference point pulse is produced when said slit of said disc passes through said reference point and a measuring point pulse is generated when said slit of said disc passes through said measuring point, the improvement comprising: first time detecting means for detecting a first time which elapses from the rise of said reference point pulse until the rise of said measuring point pulse; second time detecting means for detecting a second time which elapses from the fall of said reference point pulse until the fall of said measuring point pulse; average value calculating means for calculating an average time of said first and second times; one-revolution-time detecting means for detecting a period of time required for said disc to make one revolution; and arithmetic means for multiplying a ratio of said average time to said period of time required for said disc to make one complete revolution through 360°.

Claim 7

Dependent Claim 88 words

The angle measuring device as claimed in claim 4, wherein said first and second time detecting means comprise: means for inverting polarities of said reference point pulse and said measuring point pulse; change-over means for selectively outputting said reference point pulse and said measuring point pulse directly or said referece point pulse and said measuring point pulse the polarities of which have been inverted; and a circuit for generating an angle measuring pulse corresponding to said first and second times according to output signals of said change-over means.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1989-12-29	1990-06-30	1990-12-30	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1993-12-29	1994-06-30	1994-12-30	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1997-12-29	1998-06-30	1998-12-30	$7700.00	Window Closed / Lapsed

Angle measuring device

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