US4056882A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a dimensionally stable commutator
Assignee: Ametek Airtechnology Group Ltd
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Filing: 1976-06-07
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Granted: 1977-11-08
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Expires: 1996-06-07
Abstract
Abstract This invention describes a method of making a commutator, for a high speed electric machine, (1) embedding a number of conductive bars in insulating plastics material to form a moulded commutator (2) the moulded commutator defining at least one annular seat (3) placing a ring of high tensile material on the seat whereby to stress the ring in tension and thereby apply a radially inward load to each bar which is greater than the centrifugal force on the bar at maximum running speed. The invention also includes a commutator made by this method.
Inventors
- 👤 Robert Arthur Letts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:56
CPC Classifications
H; H01; H01R; H01R39/00; H01R39/02; H01R39/04; H01R39/06; H01R43/00; H01R43/06; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49009; Y10T29/49011; Y10T29/49826; Y10T29/49863; Y10T29/49865; Y10T29/49874
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
81 words
A method of making a high speed commutator, comprising embedding a number of conductive bars in insulating plastics material to form a moulded commutator while simultaneously providing the moulded commutator with at least one annular seat, and then subsequently placing a ring of high tensile material on the seat, stressing the ring in tension and thereby applying a radially inward load to each conductive bar which is three times greater than the centrifugal force on the bar at maximum running speed.
Claim 2
Independent Claim
81 words
A method of making a high speed commutator, comprising embedding a number of conductive bars in insulating plastics material to form a moulded commutator while simultaneously providing the moulded commutator with at least one annular seat, and then subsequently placing a ring of high tensile material on the seat, stressing the ring in tension and thereby applying a radially inward load to each conductive bar which is three times greater than the centrifugal force on the bar at maximum running speed.
Claim 3
Dependent Claim
41 words
A method as claimed in claim 1 wherein the commutator is cylindrical and two annular seats are formed one at either end of the cylinder under the brush-engaging outer surface and wherein one of said rings is located on each seat.
Claim 4
Dependent Claim
30 words
A method as claimed in claim 1 wherein a single annular seat is formed on the underside of brush-engaging surfaces of the commutator and a single ring is mounted thereon.
Claim 5
Dependent Claim
15 words
A method as claimed in claim 1 wherein each ring is force-fitted on its seat.
Claim 6
Dependent Claim
16 words
A method as claimed in claim 1 wherein each ring is heat shrunk on its seat.
Claim 7
Dependent Claim
30 words
A method as claimed in claim 1, wherein the bars are disposed about a central tube and the plastics material is molded around the tube as it embeds the bars.
Claim 8
Independent Claim
96 words
A method of making a commutator, comprising 1. embedding a number of conductive bars in insulating plastics material to form a moulded commutator the bars having recesses in their ends which are circumferentially aligned 2. the mouled commutator defining and annular seat at each end within the recesses 3. expanding a ring of high tensile material 4. placing said ring on each seat whereby to stress the ring in tension and thereby apply a radially inward load to each bar which is greater than three times the centrifugal force on the bar at maximum running speed.
Claim 9
Independent Claim
96 words
A method of making a commutator, comprising 1. embedding a number of conductive bars in insulating plastics material to form a moulded commutator the bars having recesses in their ends which are circumferentially aligned 2. the mouled commutator defining and annular seat at each end within the recesses 3. expanding a ring of high tensile material 4. placing said ring on each seat whereby to stress the ring in tension and thereby apply a radially inward load to each bar which is greater than three times the centrifugal force on the bar at maximum running speed.
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) | 1980-11-07 | 1981-05-09 | 1981-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-07 | 1985-05-09 | 1985-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-07 | 1989-05-09 | 1989-11-08 | $7700.00 | Window Closed / Lapsed |