Movable or removable closures – With traffic director or controller; e.g. – one-way
Reexamination Certificate
2000-06-28
2001-04-10
Redman, Jerry (Department: 3634)
Movable or removable closures
With traffic director or controller; e.g., one-way
C049S358000, C049S029000
Reexamination Certificate
active
06212825
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the field of gates for highway-rail grade crossings and in particular to a gate which deploys a secondary arm as, or after, a primary gate arm is lowered so as to cover both lanes of a highway crossing a railway grade.
BACKGROUND OF THE INVENTION
A highway-rail grade crossing presents a unique and potentially dangerous traffic obstacle for inexperienced motorists. The fact is that many drivers do not cross railroad tracks often enough to be familiar with the warning devices including safety gates which are there for their own safety. Such drivers are often unaware that trains cannot stop nearly as quickly as motor vehicles in order to avoid a collision. Other drivers for whatever reason, including impatience, simply ignore all warning signs and attempt to defeat railroad crossing warning devices in order to cross over before a train arrives. Combined, driver inattention and impatience are the most common factors contributing to collisions between motor vehicles and trains at highway-rail grade crossings according to Operation Lifesaver, a non-profit public education program having the object of eliminating collisions, deaths and injuries at highway-rail intersections and on railroad rights of way.
Operation Lifesaver reports that thousands of people are seriously injured and hundreds are killed in about 4,000 highway-rail grade crossing crashes each year involving collisions between motor vehicles and trains. Also according to Operation Lifesaver, this translates into a collision between a person or a vehicle and a train approximately every 100 minutes in the United States, thus making it 40 times more likely that a motorist will die in a collision with a train than a collision with another motor vehicle. It is important to keep in mind that, again according to Operation Lifesaver, there are approximately 270,000 highway-rail grade crossings in the United States and that over 50% of crashes at public grade crossings occur where active warning devices such as gates, lights and/or bells exist. In 1996, collisions at public highway-rail crossings between trains and automobiles accounted for approximately 40 percent of all forms of collisions with trains at such crossings.
Many railroad public crossings at grade, specifically highway crossings used by automobiles, have protection gates that are actuated automatically by an approaching train. The gates rotate down into a horizontal position from a vertical position to prevent vehicles from entering onto the tracks as the train approaches and passes by. In many instances these gates only span across half the roadway, usually a single lane. Thus one-half of the roadway is left open. Vehicles often will, rather than wait for an approaching train to pass, go around the lowered gate and proceed into the path of the approaching train if the driver of the vehicle thinks he or she can get over the crossing before the train arrives.
When applicant inquired of those who maintain these gates as to the reason for the gates only spanning half the roadway, he was informed that in a situation where a vehicle arrives at the crossing to find the gates moving down and successfully goes under the gate in that vehicles lane, the vehicle may then still proceed straight ahead to clear the crossing without being immediately blocked on the other side of the track by a lowered gate intended to prevent traffic crossing from the opposite direction.
Consequently, it is an object of the present invention to provide a secondary section of gate of sufficient length to span the half of the roadway not blocked by a primary gate, the secondary gate rotatably mounted at the tip or free end of the primary gate and rotatable 180 degrees into a lowered position by means of a small motor and gearbox.
In the prior art, Applicant is aware of the following United States patents which deal with improvements to single arm railway crossing gates so as to deal with the problem of vehicles striking the gates, none of which teach the use of a secondary gate extension: U.S. Pat. No. 2,874,493 which issued Feb. 24, 1959 to Mandel for an Automatic Signal and Barrier Device for Railroad Crossings, U.S. Pat. No. 3,994,457 which issued Nov. 30, 1976 to Teasel for a Crossing Gate, U.S. Pat. No. 5,469,660 which issued Nov. 28, 1995 to Tamenne for a Self-Restoring Railroad Highway Crossing Gate Device, and U.S. Pat. No. 5,884,432 which issued Mar. 23, 1999 to DeLillo for a Breakaway Assembly for Vehicle Barrier Device.
Applicant is also aware of U.S. Pat. No. 4,666,108 which issued on May 19, 1987 to Fox for an Extensible Railroad Grade Crossing Gate Arm and U.S. Pat. No. 5,671,563 which issued Sep. 30, 1997 to Marcum for a Vehicle Control Arm Device. Both Marcum and Fox disclose the use of a secondary gate arm extension, Marcum providing a breakaway end section addressing the problem of the gate being struck and damaged by vehicles, Fox disclosing a telescoping second arm member telescopically inserted in a first arm member. Neither Fox nor Marcum teach nor suggest the advantages of the present invention as set out herein.
SUMMARY OF THE INVENTION
Consequently, it is an object of the present invention to provide a secondary section of gate of sufficient length to span the half of the roadway not blocked by a primary gate, the secondary gate rotatably mounted at the tip or free end of the primary gate and rotatable 180 degrees over the primary gate into a lowered position by means of a small motor and gearbox. Rotating the secondary gate in a generally vertical plane over the primary gate provides oncoming car traffic with a large, moving and highly visible cue that the approach of the train is imminent.
When not actuated the secondary section of gate would normally be in a retracted position beside or on top of the primary gate. The secondary section of gate is rotated into an extended position after the primary gate is rotated down, so as to approach, its fully lowered position. The lowering of the secondary gate is timed to include enough delay so that a vehicle which drives under a primary gate on one side of a crossing as the primary gate is lowering would have sufficient time to proceed across the crossing and under the secondary gate section on the other side before the secondary section on the other side is rotated into its horizontal, extended position. The timing of the delay is adjusted to allow time for a vehicle to clear, depending on the size, i.e. number of tracks across the crossing. Prior art sensors, known to one skilled in the art, may be employed to detect a vehicle's presence in the crossing to help coordinate the delay. Secondary gate sections thus effectively block vehicles from going around the tip or free end of the primary gate and into the path of an oncoming train during the critical seconds before a collision would be inevitable.
In one embodiment, not intended to be limiting, the secondary gate section is fitted with a double acting spring-type hinge, advantageously near the end mounted to the tip of the primary gate. The hinge allows the secondary gate to be pushed aside by a vehicle in circumstances which would otherwise result in a collision. The spring then urges the secondary gate back into position. Alternatively the secondary gate may be rigid, and it may be mounted to the primary gate in a similar manner to how the primary gate is now mounted to the gate actuating mechanism, for example a Safetran™ Model S-40 gate actuating mechanism, so as to break away when ran into by a vehicle.
The secondary gate section may be of the same type of material (for example, wood, aluminum or fiberglass) as the primary gate, have the same dimensions (although length may vary) and have lights mounted in the same manner as the primary gate.
The rotation assembly for rotation actuation of the secondary gate may be a small motor and gearbox which is capable of rotating a drive shaft 180 degrees. Rotation of the shaft is controlled by relays and limit switches. The motor and gearbox may be mounted at the free end of th
Edwards Antony C.
Redman Jerry
Sentinel Innovative Technologies Incorporated
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