Claims
- 1. A drawbridge apparatus comprising:
- (a) first base;
- (b) a second base;
- (c) a first cantilevered beam having an extended end and a base end slidably coupled to the first base, wherein sliding of the first cantilevered beam projects the beam in a direction that is toward the second base;
- (d) a first bascular leaf having a first counterweight portion and a first span portion, said first bascular leaf being pivotally coupled to the first base at an intersection of the first counterweight portion and the first span portion; and
- (e) a first hinged leaf having a first base end pivotally coupled to the first span portion of the first bascular leaf and a first extended end coupled to the first cantilevered beam.
- 2. The apparatus of claim 1, further comprising:
- (a) a second cantilevered beam having an extended end and a base end slidably coupled to the second base, wherein sliding of the second cantilevered beam projects the beam in a direction that is toward the first base;
- (b) a second bascular leaf having a second counterweight portion and a second span portion, said second bascular leaf being pivotally coupled to the second base at an intersection of the second counterweight portion and the second span portion; and
- (c) a second hinged leaf having a second base end pivotally coupled to the second span portion of the second bascular leaf and a second extended end coupled to the second cantilevered beam.
- 3. The apparatus of claim 2, wherein the first cantilevered beam and the second cantilevered beam are arranged and configured opposite each other on intersecting paths so that as each projects from the bases the first cantilevered beam and the second cantilevered beam interconnect at their extended ends, the base ends of the cantilevered beams being coupled to the bases.
- 4. The apparatus of claim 3, wherein the extended end of the first cantilevered beam further comprises an interlocking shaft, and wherein the extended end of the second cantilevered beam further comprises an interlocking sleeve sized to receive the interlocking shaft of the first cantilevered beam.
- 5. The apparatus of claim 1, wherein the extended end of the first hinged leaf is pivotally coupled to the extended end of the first cantilevered beam so that the first hinged leaf and the first bascular leaf move in response to sliding of the first cantilevered beam.
- 6. The apparatus of claim 1, wherein the extended end of the first hinged leaf is slidably coupled to the extended end of the first cantilevered beam.
- 7. The apparatus of claim 6, further comprising a leaf drive means coupled to the first base and the first bascular leaf for pivoting the first bascular leaf relative to the first base.
- 8. The apparatus of claim 7, wherein said leaf drive means comprise:
- (a) a curved rack secured to the first base;
- (b) a leaf drive motor secured to the first bascular leaf; and
- (c) a leaf pinion gear coupled to the drive motor and to the counterweight portion of the first bascular leaf, said pinion gear operatively engaging the curved rack.
- 9. The apparatus of claim 1, further comprising a beam drive means coupled to the first base and the first cantilevered beam for sliding the first cantilevered beam relative to the first base.
- 10. The apparatus of claim 1, wherein said beam drive means comprise:
- (a) a beam rack secured to the first cantilevered beam;
- (b) a beam drive motor secured to the first base; and
- (c) a beam pinion gear coupled to the drive motor and operatively engaging the rack.
- 11. The apparatus of claim 1, wherein the first base comprises a roadbed having a top surface, the first cantilevered beam being slidably coupled to the first base above the top surface of the roadbed.
- 12. The apparatus of claim 1, wherein the first base comprises a roadbed having a top surface, the first cantilevered beam being slidably coupled to the first base beneath the top surface of the roadbed.
- 13. The apparatus of claim 12, further comprises a plurality of wheel trucks disposed beneath the top surface of the roadbed, wherein the first cantilevered beam is slidably coupled to the first base beneath the top surface of the roadbed with said wheel trucks.
- 14. The apparatus of claim 1, wherein the first cantilevered beam has a curved shape.
- 15. A drawbridge apparatus comprising:
- (a) a first base;
- (b) a second base;
- (c) a cantilevered beam slidably coupled to the first base, wherein sliding of the cantilevered beam projects the beam at least partially from the first base to the second base;
- (d) a bascular leaf having a counterweight portion and a span portion, said bascular leaf being pivotally coupled to the first base; and
- (e) a hinged leaf having a base end pivotally coupled to the span portion of the bascular leaf and an extended end coupled to the cantilevered beam.
- 16. A drawbridge apparatus comprising:
- (a) a first pier;
- (b) a second pier;
- (c) first and second cantilevered beams slidably coupled to the first and second piers, respectively, wherein said beams are arranged and configured to project from the first and second piers to a location between the two piers at which location said beams interconnect;
- (d) beam drive means for sliding the first and second cantilevered beams from and into first and second piers, respectively;
- (e) first and second bascular leaves having first and second counterweight portions and first and second span portions, respectively, said first and second bascular leaves being pivotally coupled to first and second bases, respectively, at the intersections of the respective counterweight portion with the respective span portion;
- (f) first and second hinged leaves having first and second base ends pivotally coupled to the respective first and second span portions of the bascular leaves, said hinged leaves also having first and second extended ends slidably coupled to the first and second cantilevered beams, respectively; and
- (g) leaf drive means for pivoting the first and second bascular leaves.
- 17. A drawbridge apparatus comprising:
- (a) a first base;
- (b) a second base;
- (c) a first cantilevered beam having an extended end and a base end slidably coupled to the first base, wherein sliding of the first cantilevered beam projects the beam in the direction of the first base to the second base; and
- (d) a first bascular leaf pivotally coupled to the first base wherein said first bascular leaf is adapted to pivot between a retracted position, wherein said first bascular leaf extend from its pivotal coupling with the first base at an angle relative to the cantilevered beam, and an extended position, wherein the first bascular leaf rests on and extends along the cantilevered beam.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 07/680,943, filed Apr. 5, 1991, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (2)
Number |
Date |
Country |
324342 |
Jun 1963 |
FRX |
387897 |
Jan 1924 |
DEX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
680943 |
Apr 1991 |
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