Patent US4490941A successfully refreshed from Google Patents.
US4490941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spindle door operator
Assignee: Mark IV Transportation Products Corp
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Filing: 1981-08-13
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Granted: 1985-01-01
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Expires: 2001-08-13
Abstract
Abstract A door operator for opening and closing doors on transit vehicles and the like includes an actuator (50) secured to the transit vehicle (10). The actuator houses a worm drive and a reciprocating air cylinder (52) for imparting rectilinear motion to the worm drive. A door shaft (18) is coupled to a door (14) and mechanically coupled to the worm drive such that rectilinear motion of the system is transmitted by the worm drive into rotary motion to the drive shaft to open and close the door. A cam (90) is secured to the vehicle and adjacent to a cam follower (108) that is secured to the door shaft. The cam follower engages the cam during approximately the initial 80% motion during closing of the door and approximately the final 80% of the door opening. A recycling switch (200) for the door may be mounted in the vehicle adjacent to the cam in a position to be engaged upon engagement of the door with an object to recycle the door.
Inventors
- 👤 Harry E. Mamach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:40
CPC Classifications
E; E05; E05F; E05F15/00; E05F15/50; E05F15/53; E05F15/54; E05Y; E05Y2900/00; E05Y2900/50; E05Y2900/51
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
126 words
A door operator for opening a door of transit vehicles and the like, comprising: an actuator, a worm drive in said actuator, a piston reciprocally mounted in said actuator and coupled to said worm drive, a door shaft coupled to a door mounted on a vehicle, said door shaft mechanically coupled to said worm drive wherein rectilinear motion of said piston is transmitted as rotary motion to said door shaft to open and close said door, a cam assembly on said vehicle, including a cam, a cam follower coupled to said door and engaging said cam during approximately the last 80% of travel of said door during opening of said door and approximately the initial 80% of travel of said door during closing of said door.
Claim 2
Dependent Claim
126 words
A door operator for opening a door of transit vehicles and the like, comprising: an actuator, a worm drive in said actuator, a piston reciprocally mounted in said actuator and coupled to said worm drive, a door shaft coupled to a door mounted on a vehicle, said door shaft mechanically coupled to said worm drive wherein rectilinear motion of said piston is transmitted as rotary motion to said door shaft to open and close said door, a cam assembly on said vehicle, including a cam, a cam follower coupled to said door and engaging said cam during approximately the last 80% of travel of said door during opening of said door and approximately the initial 80% of travel of said door during closing of said door.
Claim 3
Dependent Claim
24 words
The door operator claimed in claim 1 further comprising cushioning means for cushioning the motion of said piston at end positions of said door.
Claim 4
Dependent Claim
45 words
The door operator claimed in claim 1 further comprising a switch for recycling said door upon engagement of said door with an object, said switch mounted on said vehicle adjacent said cam assembly, and means biasing said cam assembly out of engagement with said switch.
Claim 5
Dependent Claim
175 words
A door operator for opening and closing doors on transit vehicles and the like, comprising: an actuator mounted in a vehicle adjacent to a door on said vehicle to be opened by said actuator, said actuator includes a worm drive, a piston reciprocally mounted in said actuator and coupled to said worm drive to impart rectilinear motion to said worm drive, a door shaft coupled to said door and to said worm drive wherein said worm drive translates the rectilinear motion from said piston to rotary motion to said door shaft, a cam assembly including an arcuate cam mounted on said vehicle, a cam follower movably secured to said door engaging said cam during approximately the first 80% of the closing motion of said door and approximately the last 80% of travel during opening of said door, a switch for recycling said door upon engagement with an object mounted in said vehicle in a position to be actuated by said cam assembly, and means for biasing said cam assembly out of engagement with said switch.
Claim 6
Dependent Claim
175 words
A door operator for opening and closing doors on transit vehicles and the like, comprising: an actuator mounted in a vehicle adjacent to a door on said vehicle to be opened by said actuator, said actuator includes a worm drive, a piston reciprocally mounted in said actuator and coupled to said worm drive to impart rectilinear motion to said worm drive, a door shaft coupled to said door and to said worm drive wherein said worm drive translates the rectilinear motion from said piston to rotary motion to said door shaft, a cam assembly including an arcuate cam mounted on said vehicle, a cam follower movably secured to said door engaging said cam during approximately the first 80% of the closing motion of said door and approximately the last 80% of travel during opening of said door, a switch for recycling said door upon engagement with an object mounted in said vehicle in a position to be actuated by said cam assembly, and means for biasing said cam assembly out of engagement with said switch.
References Cited (Backward Citations)
US4055023A
Cited
US4308691A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-01 | 1988-07-02 | 1989-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-01 | 1992-07-02 | 1993-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-01 | 1996-07-02 | 1997-01-01 | $7700.00 | Window Closed / Lapsed |