US3667398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear induction motor secondary member
Assignee: Tracked Hovercraft Ltd
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Filing: 1971-06-25
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Granted: 1972-06-06
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Expires: 1991-06-25
Abstract
Abstract The secondary member in or for a linear induction motor of the single-sided and short stator variety is mounted generally horizontally for co-operation with a linear induction motor primary member carried above it. The secondary member comprises an aluminum reaction plate disposed above magnetic material which supports it from the track. The reaction plate is wider than the magnetic material and extends beyond it along either side of the secondary member at side portions which in operation provide the longitudinally extending parts of the current paths in the reaction plate. The reaction plate is clamped down on to the track by clamping devices which produce clamping forces on the undersides of the side portions immediately adjacent the magnetic material.
Inventors
- 👤 Christopher Durrant English
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:58
CPC Classifications
B; B60; B60L; B60L13/00; B60L13/03; H; H02; H02K; H02K41/00; H02K41/02; H02K41/025
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
149 words
In combination a prepared track and generally horizontal linear induction motor secondary member extending along the track for co-operation with a single-sided linear induction motor primary member carried above it by a vehicle arranged for operation along the track whereby to propel the vehicle, the linear induction motor secondary member comprising an electrically conductive reaction plate, magnetic material between the reaction plate and the track, the reaction plate being wider than the magnetic material so as along the sides of the secondary member to extend beyond the magnetic material in side portions for providing longitudinal paths for secondary member current, and clamping means for separate co-operation with the said side portions and attached to the track to secure the reaction plate into position, the co-operation of the clamping means with the side portions being at the undersides of the side portions remote from the edges of the reaction plate.
Claim 2
Dependent Claim
23 words
A combination according to claim 2, wherein the co-operation of the clamping means with the side portions is by abutment of co-operating surfaces.
Claim 3
Dependent Claim
52 words
A combination according to claim 1, wherein the side portions extend downwardly so as in the vertical sense to overlap part of the magnetic material, and the co-operation of the clamping means with the side portions is at the undersides of the side portions remote from the edges of the reaction plate.
Claim 4
Dependent Claim
62 words
A combination according to claim 4, wherein longitudinally extending grooves are formed along inside faces of the overlapping parts, and the clamping means have arms which extend into the grooves so as to bear downwardly upon the lower surfaces of the grooves in abutting relationship therewith, and downwardly extending portions which extend downwardly from the said arms for transmitting clamping forces thereto.
Claim 5
Dependent Claim
37 words
A combination according to claim 5, wherein the arms are slidable in the grooves for at least partly accommodating differential thermal expansion and contraction between the reaction plate and the track at least in the longitudinal direction.
Claim 6
Dependent Claim
34 words
A combination according to claim 4, wherein the clamping means comprises downwardly extending portions which extend downwardly from the side portions for transmitting clamping forces thereto and which are integral with the side portions.
Claim 7
Dependent Claim
91 words
A combination according to claim 4, wherein the reaction plate comprises a rolled sheet of electrically conductive material of generally uniform thickness which extends beyond the magnetic material on either side, the combination further comprising electrically conductive angled members having arms thereof secured in generally parallel and contiguous relation to the projecting parts along their undersides, the arms of the angled members and the projecting parts together forming the side portions, the angled members having downwardly extending portions which extend downwardly from the said arms for transmitting the clamping forces thereto.
Claim 8
Dependent Claim
61 words
A combination according to claim 2, wherein the clamping means comprise portions extending downwardly from the co-operation with the side portions and turned outwardly at their bases, and resilient members which bear downwardly upon the top surfaces of the said outwardly turned bases in abutting relation therewith and are secured to the track to produce clamping forces on the side portions.
Claim 9
Dependent Claim
95 words
A combination according to claim 2, wherein the magnetic material is formed of a plurality of blocks of magnetic material extending along the track with gaps between the adjacent ends of successive blocks for accommodating differential thermal expansion and contraction relative to the track, the combination including, for each said gap, a magnetic member disposed in overlapping relationship beneath the magnetic blocks forming the gap so as magnetically to bridge the gap, at least one of the magnetic blocks being arranged for longitudinal movement with respect to the magnetic member where they overlap one another.
Claim 10
Dependent Claim
23 words
A combination according to claim 2, which includes a sheet of resin bonded asbestos paper separating the reaction plate from the magnetic material.
Claim 11
Dependent Claim
67 words
A combination according to claim 2, wherein the secondary member is received in a channel formed in the track, and filler members are disposed in the channel between the side portions and the adjacent sides of the channel, the reaction plate including the side portions, the filler members, and the track at either side of the channel in combination presenting an upwardly facing and generally plane surface.
Claim 12
Dependent Claim
48 words
A combination according to claim 2, wherein by means of the reaction plate the clamping means are effective for counteracting substantially all of any net upward force which in operation may be exerted on the secondary member due to attraction of the magnetic material to the primary member.
Claim 13
Dependent Claim
36 words
The combination claimed in claim 1 when further combined with gas cushion vehicle arranged for operation along the track and carrying beneath it a linear induction motor primary member for co-operation with the said secondary member.
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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |