Patent US4105027A successfully refreshed from Google Patents.
US4363980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear motor
Assignee: Polaroid Corp
•
Filing: 1981-08-24
•
Granted: 1982-12-14
•
Expires: 2001-08-24
Abstract
Abstract A linear motor which utilizes the magnetic attraction between a washer formed from a ferrous material, e.g., steel, and a magnetic pole of an armature for automatically returning the armature to its original position upon the deenergization of a field coil. The washer is originally located in alignment with and in surrounding relation to one of the effective poles of the armature. The stroke of the armature is limited to a distance which insures that at the end of the stroke the one effective pole will be located closer to the washer than any other effective pole. Upon deenergizing the field coil, the magnet attraction between the one effective pole and the washer will cause the armature to return to its original position.
Inventors
- 👤 Christian C. Petersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:40
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/08; G03B9/28; G03B9/32; H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/16; H01F7/1607; H01F7/1615; H02; H02K; H02K33/00; H02K33/12; H02K33/16; H01F7/121; H01F7/122; H01H; H01H51/00; H01H51/22; H01H51/2209; H01H2051/2218
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
235 words
A linear motor comprising: means formed from a non-magnetic material for supporting electrically conductive means, said supporting means including means defining a passageway extending axially of said supporting means; an armature mounted within said passageway for axial movement relative to said supporting means between first and second positions, said armature including a pair of permanent magnets and a core, said core being located between said first and second permanent magnets with common poles of said magnets in engagement with opposite axial end faces of said core thereby forming an armature having effective common poles at the axial ends of said armature and an effective pole of opposite polarity located at a point substantially one-half the distance between the ends of said core; electrically conductive means wound upon said supporting means for moving said armature from said first position to said second position upon being electrically energized; output means mounted on one end of said armature for transmitting the movement of said armature to an apparatus to be driven thereby; means for limiting the movement of said armature along said passageway upon energization of said electrically conductive means; and means formed from a ferrous material mounted on said supporting means substantially in alignment with one of the effective poles of said armature when said armature is in said first position for automatically returning said armature to said first position upon deenergization of said electrically conductive means.
Claim 2
Dependent Claim
235 words
A linear motor comprising: means formed from a non-magnetic material for supporting electrically conductive means, said supporting means including means defining a passageway extending axially of said supporting means; an armature mounted within said passageway for axial movement relative to said supporting means between first and second positions, said armature including a pair of permanent magnets and a core, said core being located between said first and second permanent magnets with common poles of said magnets in engagement with opposite axial end faces of said core thereby forming an armature having effective common poles at the axial ends of said armature and an effective pole of opposite polarity located at a point substantially one-half the distance between the ends of said core; electrically conductive means wound upon said supporting means for moving said armature from said first position to said second position upon being electrically energized; output means mounted on one end of said armature for transmitting the movement of said armature to an apparatus to be driven thereby; means for limiting the movement of said armature along said passageway upon energization of said electrically conductive means; and means formed from a ferrous material mounted on said supporting means substantially in alignment with one of the effective poles of said armature when said armature is in said first position for automatically returning said armature to said first position upon deenergization of said electrically conductive means.
Claim 3
Dependent Claim
34 words
A linear motor as defined in claim 1 wherein said means formed from a ferrous material comprises a disc having an aperture therein through which a portion of said armature is adapted to pass.
Claim 4
Dependent Claim
39 words
A linear motor as defined in claim 2 wherein the distance traveled by said armature in moving from said first position to said second position is less than one-half the distance between the effective opposite poles of said armature.
Claim 5
Dependent Claim
41 words
A linear motor as defined in claim 2 wherein the distance traveled by said armature in moving from said first position to said second position is less than one-half the length between the magnetic poles of one of said permanent magnets.
Claim 6
Dependent Claim
18 words
A linear motor as defined in claim 4 wherein said limiting means is formed from a non-magnetic material.
Claim 7
Dependent Claim
45 words
A linear motor as defined in claim 4 further including second output means mounted on an end of said armature opposite to that at which said first-mentioned output means is mounted for transmitting the movement of said armature to an apparatus to be driven thereby.
Claim 8
Dependent Claim
54 words
A linear motor as defined in claim 6 wherein said electrically conductive means is energizable so as to move said armature from said first position to a third position, said third position being in a direction generally opposite to that taken by said armature in moving from said first position to said second position.
Claim 9
Dependent Claim
98 words
A linear motor as defined in claim 7 further including a second apertured disc formed from a ferrous material through which a portion of said armature is adapted to be moved as said armature moves between said first and third positions, said discs being mounted on said supporting structure in transverse relation to said armature and substantially in alignment with and in surrounding relation to opposite ends of said armature when said armature is in said first position for automatically moving said armature from said third position to said first position upon deenergization of said electrically conductive means.
Claim 10
Dependent Claim
56 words
A linear motor as defined in claim 8 wherein said electrically conductive means includes first and second field coils, said first field coil being energizable to move said armature from said first position to said second position and said second field coil being energizable to move said armature from said first position to said third position.
Claim 11
Dependent Claim
19 words
A linear motor as defined in claim 4 wherein said permanent magnets are formed from a rare earth material.
Claim 12
Dependent Claim
18 words
A linear motor as defined in claim 3 wherein said limiting means is formed from a non-magnetic material.
Claim 13
Dependent Claim
45 words
A linear motor as defined in claim 3 further including second output means mounted on an end of said armature opposite to that at which said first-mentioned output means is mounted for transmitting the movement of said armature to an apparatus to be driven thereby.
Claim 14
Dependent Claim
54 words
A linear motor as defined in claim 12 wherein said electrically conductive means is energizable so as to move said armature from said first position to a third position, said third position being in a direction generally opposite to that taken by said armature in moving from said first position to said second position.
Claim 15
Dependent Claim
51 words
A linear motor as defined in claim 13 wherein said an effective pole of said armature is a magnetic pole located substantially half way between the opposite ends of said core and said disc is located in alignment with said an effective pole when said armature is in said first position.
Claim 16
Dependent Claim
56 words
A linear motor as defined in claim 14 wherein said electrically conductive means includes first and second field coils, said first field coil being energizable to move said armature from said first position to said second position and said second field coil being energizable to move said armature from said first position to said third position.
Claim 17
Dependent Claim
19 words
A linear motor as defined in claim 1 wherein said permanent magnets are formed from a rare earth material.
References Cited (Backward Citations)
GB817381A
Cited
US3022400A
Cited
US3202886A
Cited
US3149255A
Cited
US3495147A
Cited
US3549917A
Cited
US3728654A
Cited
US3755699A
Cited
US3860300A
Cited
US3874750A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-13 | 1986-06-14 | 1986-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-13 | 1990-06-14 | 1990-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-13 | 1994-06-14 | 1994-12-14 | $7700.00 | Window Closed / Lapsed |