Road structure – process – or apparatus – Traffic steering device or barrier
Reexamination Certificate
1999-09-24
2001-01-30
Lillis, Eileen D. (Department: 3673)
Road structure, process, or apparatus
Traffic steering device or barrier
C049S026000, C049S028000, C049S049000
Reexamination Certificate
active
06179517
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to access control systems and more particularly to electrically controlled systems for opening and closing one or more obstructions to traverse of a vehicle or an individual through a passage.
DESCRIPTION OF THE PRIOR ART
It is well known to apply barriers of one sort or another to passage of a vehicle. These barriers may require payment of a fee for temporary removal such as on a toll road. They may require entry of a secret or identifier code, application of a code card, display of a pass, or the like, such as in gated communities. There may be a complete secondary barrier, such as a door, and a primary gate, such as a bar that rotates about a horizontal axis through an angle of 90 degrees. It is useful to delay opening the secondary gate until the barrier is fully open. Gates of the prior art are often subject to damage when the gate is forced open. Their use may be lost while repairs are awaited. These are not the sort of items whose loss of use, even temporarily, is tolerated. Some provision should also be provided for opening the gate in case of power failure. These gates require a non-uniform motion for best operation. They often use a non-circular rotary actuator for this purpose, but this results in undesirable variable forces on the gear system as well as more costly structure. It also wears the gears irregularly because only a fraction of the gear teeth are ever used. In the case of a fire, and/or power loss it is especially important that the access barrier remain open or be openable or by fire fighters from outside, or by people trapped inside, even with loss of power.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a traffic access control system that overcomes some of the deficiencies of the prior art. The system of the invention may be applied to a variety of access barriers, including, but not limited to, vertically or horizontally swinging bars and gates, vertically and horizontally rolling doors and grilles and the like. It may be applied to traffic by vehicles or individuals. It is another object that the control system of the invention anticipate many of the maintenance problems of the prior art, and provide means for rapid and simple repair that reduce the time that the apparatus is out of operation and the cost of many repairs. The system of the invention includes a high ratio gearmotor whose output may turn an output gear through only about 90°, when moving a barrier between open and closed positions. The gear drives an output shaft through a slip clutch. The output shaft is directly attached to a barrier connecting member that holds the barrier bar and to shaft position sensors. When the motor drives the output gear in normal operation between open and closed positions, the system automatically senses whether the bar is up or down. If the bar is down, and someone lifts the bar to gain access, the shaft will rotate with the bar and the system will sense the bar position. An optional output trigger may be generated to notify the system of such an event. However, the clutch will slip so that there will be no turning of the output gear, and no damage to the apparatus. Once a close signal is received, the barrier automatically realigns the barrier to the horizontal position. Another advantage is that a different quadrant of the gear is now in use. For routine maintenance, one need only lift the bar periodically to ensure uniform wear of the gear. It is necessary to provide some means of allowing access in case of power failure. The system provides a backup battery on continuous charge. The system senses when power fails. It provides a signal to open the gate if the power has been off for more than a preset time. It may include means requiring a trigger before the backup opens the gate. The system may also be provided with battery charge sensing means and means to elevate the gate when power fails and the battery charge falls below a pre-selected value.
The motor drive is a reversing DC gearmotor. It is driven by a series of DC pulses of variable width so that the output rotary motion can be non-uniform. This results in the same motion as provided by non-circular drive components such as the sinusoidal drives well known in this art, but with numerous cost and function advantages enjoyed by uniform circular components.
Alternatively, the motor drive may be an AC motor with variable frequency power to achieve non-uniform motion.
A principal application of the invention will be to operate vehicular barriers that pivot through about 90° about a horizontal axis from a horizontal closed position to vertical open position. Other applications operate barriers such as doors that slide, raise, or pivot about a vertical axis.
These and other objects, features and advantages of the invention will become more apparent when the detailed description is studied in conjunction with the drawings, in which like reference characters indicate like elements in the various drawing figures.
REFERENCES:
patent: 3964704 (1976-06-01), Karr
patent: 3975861 (1976-08-01), Baump et al.
patent: 4035955 (1977-07-01), Burnett
patent: 4232484 (1980-11-01), Buchman
patent: 4313281 (1982-02-01), Richmond
patent: 4364200 (1982-12-01), Cobb
patent: 4392392 (1983-07-01), Perisic et al.
patent: 4403449 (1983-09-01), Richmond
patent: 4434578 (1984-03-01), Rumpz
patent: 4531325 (1985-07-01), Phillips
patent: 4632598 (1986-12-01), Richards
patent: 4665650 (1987-05-01), Hall
patent: 4711608 (1987-12-01), Ghusn
patent: 4916859 (1990-04-01), Butler
patent: 4916860 (1990-04-01), Richmond et al.
patent: 4934097 (1990-06-01), Quante
patent: 5076012 (1991-12-01), Richmond et al.
patent: 5101595 (1992-04-01), Rhoades
patent: 5123204 (1992-06-01), He
patent: 5136809 (1992-08-01), Richmond et al.
patent: 5136810 (1992-08-01), DeWitt, III
patent: 5230179 (1993-07-01), Richmond et al.
patent: 5263281 (1993-11-01), Osborn
patent: 5415055 (1995-05-01), Henfrey
patent: 5438799 (1995-08-01), Le Faucheur
patent: 5671563 (1997-09-01), Marcum
patent: 5813796 (1998-09-01), Kocznar
patent: 5869940 (1999-02-01), Parsadayan
patent: 5878530 (1999-03-01), Eccleston et al.
patent: 5884432 (1999-03-01), Delillo
patent: 6025685 (2000-02-01), Parsadayan
Blum Alvin S.
Lillis Eileen D.
Pechhold Alexandra
LandOfFree
Traffic access control system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Traffic access control system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Traffic access control system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2497910