US3673584A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Position-measuring transformer having end-detecting windings useful for positioning a magnetic head of a disc drive system
Assignee: Inductosyn Corp
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Filing: 1971-03-08
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Granted: 1972-06-27
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Expires: 1991-03-08
Abstract
Abstract Disclosed is a position-measuring transformer formed from two relatively movable members. The transformer is particularly useful for selecting and defining track positions in a magnetic disc drive system which may be used as a memory in a digital computer. One stationary member of the transformer includes cofunction windings and end-detecting windings. Those windings magnetically coupled to a reference winding on another relatively movable member of the transformer. The reference winding, which is the continuous winding of the transformer, is formed from a plurality of equally spaced active conductors. The active conductors are interconnected such that alternate ones conduct in opposite directions so that each pair of adjacent active conductors define a reference cycle. The end-detecting windings consist of one or more pairs of active conductors where the active conductors in each pair have full-cycle spacing, that is, the separation between each active conductor in a pair equals one reference cycle. The full-cycle spacing of the end-detecting winding superposed over the half-cycle spacing of the enddetecting winding induces a substantially zero resultant signal in the end-detecting winding except when the end-detecting winding is positioned over the end conductor of the reference winding as may occur when the reference winding is moved. When over the end, a limit signal is generated as a result of the unequal coupling between the end-detecting winding active conductors and the end conductor of the reference winding. The limit signal thus generated typically defines the inner or outer limit of a read/write head. Cofunction windings are formed from four winding sections with equal numbers of active conductors per section. The cofunction windings are formed using an efficient winding pattern which minimizes the number of welded or soldered connections required.
Inventors
- 👤 Clair L Farrand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:39
CPC Classifications
H; H01; H01F; H01F29/00; H01F29/08; H01F29/12; G; G05; G05D; G05D3/00; G05D3/12; G05D3/20; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
106 words
A position-measuring transformer including first and second relatively movable members comprising, a first winding, on said first member, formed by first active conductors spaced at halfcycle positions of a reference cycle and interconnected to cause adjacent ones of said first active conductors to conduct in opposite directions, a second winding on said second member inductively coupling said first winding, said second winding formed by second active conductors spaced at full-cycle positions and interconnected to cause adjacent ones of said second active conductors to conduct in opposite directions, said second winding producing a non-zero resultant signal only when said second active conductors unequally couple said first winding.
Claim 2
Dependent Claim
106 words
A position-measuring transformer including first and second relatively movable members comprising, a first winding, on said first member, formed by first active conductors spaced at halfcycle positions of a reference cycle and interconnected to cause adjacent ones of said first active conductors to conduct in opposite directions, a second winding on said second member inductively coupling said first winding, said second winding formed by second active conductors spaced at full-cycle positions and interconnected to cause adjacent ones of said second active conductors to conduct in opposite directions, said second winding producing a non-zero resultant signal only when said second active conductors unequally couple said first winding.
Claim 3
Dependent Claim
18 words
The transformer of claim 1 wherein said second active conductors are substantially parallel to said first active conductors.
Claim 4
Dependent Claim
29 words
The position-measuring transformer of claim 1 further including, a signal generator for energizing said first winding, and, a signal detector for detecting any signal induced in said second winding.
Claim 5
Dependent Claim
30 words
The position-measuring transformer of claim 1 wherein said second member further includes, a first polyphase winding spaced from said second winding for detecting cyclic positions relative to said reference cycle.
Claim 6
Dependent Claim
62 words
The position-measuring transformer of claim 4 further including a second polyphase winding spaced relative to said first polyphase winding any odd integral multiple of one-quarter of said reference cycle and wherein each of said polyphase windings includes two winding sections having a positive coupling effect to said reference winding and two winding sections having a negative coupling effect to said reference winding.
Claim 7
Dependent Claim
48 words
The position-measuring transformer of claim 5 wherein each of said first and second polyphase windings has one positive coupling and one negative coupling winding section symmetrically disposed on either side of a center line whereby the number of conductor crossovers interconnecting the winding sections does not exceed four.
Claim 8
Dependent Claim
28 words
The position-measuring transformer of claim 6 wherein said polyphase windings include terminals through-connected to the back of said second member whereby the number of conductor crossovers equals one.
Claim 9
Dependent Claim
151 words
A disc drive system for positioning a magnetic head at a Plurality of track locations including an inner limit and an outer limit, on a magnetic disc, comprising, a first member rigidly-fixed with respect to said magnetic head and relatively movable with respect to said magnetic disc, said first member having a reference winding formed by first active conductors spaced at half-cycle positions of a reference cycle and interconnected to cause adjacent ones of said first active conductors to conduct in opposite directions. a second member rigidly fixed with respect to said magnetic disc having first and second end-detecting windings each having second active conductors spaced at full-cycle positions and interconnected to cause adjacent ones of said second active conductors to conduct in opposite directions, said first and second end-detecting windings operative to detect ends of said reference winding to thereby define said inner and outer limits on said magnetic disc.
Claim 10
Dependent Claim
151 words
A disc drive system for positioning a magnetic head at a Plurality of track locations including an inner limit and an outer limit, on a magnetic disc, comprising, a first member rigidly-fixed with respect to said magnetic head and relatively movable with respect to said magnetic disc, said first member having a reference winding formed by first active conductors spaced at half-cycle positions of a reference cycle and interconnected to cause adjacent ones of said first active conductors to conduct in opposite directions. a second member rigidly fixed with respect to said magnetic disc having first and second end-detecting windings each having second active conductors spaced at full-cycle positions and interconnected to cause adjacent ones of said second active conductors to conduct in opposite directions, said first and second end-detecting windings operative to detect ends of said reference winding to thereby define said inner and outer limits on said magnetic disc.
Claim 11
Dependent Claim
107 words
The disc drive system of claim 8 wherein said second member further includes, first and second polyphase windings each spaced relative to each other by any odd integral multiple of one-quarter of said reference cycle and wherein each of said polyphase windings includes two winding sections having a positive coupling effect to said reference winding and two winding sections having a negative coupling effect to said reference winding, the said polyphase winding sections formed from active conductors having a nominal spacing equal to one-half said reference cycle where said track locations are defined by the null positions of said polyphase windings with respect to said reference winding.
Claim 12
Dependent Claim
51 words
The disc drive system of claim 9 further including, a signal generator for energizing said reference windings, first and second signal detectors for detecting any signals induced in said first and second end-detecting windings, respectively, third and fourth detectors for detecting the signals in said first and second polyphase windings, respectively.
Claim 13
Dependent Claim
105 words
Position-measuring transformer comprising relatively movable inductively related members in close space relation, one of said members having a single-phase winding, another of said members having a polyphase winding and a limit winding with first and second active conductors at one end of said polyphase winding, said limit winding being in close space, non-inductive relation with said single phase winding when said single phase winding is juxtaposed to both said active conductors of said limit winding, said limit winding being inductively related to said single phase winding and supplying a limit signal when said single phase winding is juxtaposed to only one of said active conductors.
Claim 14
Dependent Claim
105 words
Position-measuring transformer comprising relatively movable inductively related members in close space relation, one of said members having a single-phase winding, another of said members having a polyphase winding and a limit winding with first and second active conductors at one end of said polyphase winding, said limit winding being in close space, non-inductive relation with said single phase winding when said single phase winding is juxtaposed to both said active conductors of said limit winding, said limit winding being inductively related to said single phase winding and supplying a limit signal when said single phase winding is juxtaposed to only one of said active conductors.
Claim 15
Dependent Claim
114 words
Position-measuring transformer comprising relatively movable inductively related members in close space relation, one of said members having a single-phase winding formed by reference active conductors spaced at half-cycle position of a reference cycle, another of said members having a limit winding with first and second active conductors spaced at full-cycle positions of said reference cycle, said limit winding being in close-space, non-inductive relation with said single phase winding when said single-phase winding is juxtaposed to equally couple both said active conductors of said limit winding, said limit winding being inductively related to said single phase winding and supplying a limit signal when said single phase winding is juxtaposed to unequally couple said single-phase winding.
Claim 16
Dependent Claim
114 words
Position-measuring transformer comprising relatively movable inductively related members in close space relation, one of said members having a single-phase winding formed by reference active conductors spaced at half-cycle position of a reference cycle, another of said members having a limit winding with first and second active conductors spaced at full-cycle positions of said reference cycle, said limit winding being in close-space, non-inductive relation with said single phase winding when said single-phase winding is juxtaposed to equally couple both said active conductors of said limit winding, said limit winding being inductively related to said single phase winding and supplying a limit signal when said single phase winding is juxtaposed to unequally couple said single-phase winding.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |