Motorcycle seat with convertible backrest

1. A convertible motorcycle seat including:

(a) an elongated saddle having a driver seat portion and a rear passenger portion and including a platform, cushioning material and a cover;

(b) a backrest hinge assembly having a base plate secured to the rear portion of said platform, said base plate having upstanding ears spaced transversely of said platform, an elongated pivotable arm having transversely spaced depending ears disposed between said upstanding ears of said base plate, a pivot member extending transversely of, and journalled in, said upstanding ears, said pivotable arm being pivotable into an erect position extending generally vertically and into a collapsed position extending generally forwardly of said saddle, said depending ears having a lower surface portion providing a cam surface including a pair of spaced recesses spaced arcuately about said pivot member with a convexly arcuate lobe therebetween, an indexing pin extending transversely of said base plate, and biasing means on said base plate biasing said indexing pin against said cam surfaces of said depending ears and into one of said recesses whereby said pivotable arm is firmly held in an erect position or in a collapsed position; and

(c) a backrest mounted on said pivotable arm.

2. The convertible motorcycle seat in accordance with claim 1 wherein said biasing means comprises a compression spring bearing on said base plate and upwardly against said indexing pin.

3. The convertible motorcycle seat in accordance with claim 1 wherein a plurality of said biasing means is provided along the length of said indexing pin.

4. The convertible motorcycle seat in accordance with claim 2 wherein said spring is seated in a recess in said base plate.

5. The convertible motorcycle seat in accordance with claim 1 wherein said pivotable arm has a reduced width between said upstanding ears.

6. The convertible motorcycle seat in accordance with claim 1 wherein said backrest has cushioning material thereon about said pivotable arm and a cover disposed thereabout.

7. The convertible motorcycle seat in accordance with claim 6 wherein said backrest has a cover plate on the rear surface of said pivotable arm when said backrest is in said erect position.

8. The convertible motorcycle seat in accordance with claim 6 wherein said rear passenger portion of said saddle is configured to provide a recess in which said hinge assembly and backrest are disposed in the collapsed position of said pivotable arm.

9. The convertible motorcycle seat in accordance with claim 8 wherein said backrest is dimensioned and configured to blend into the contours of said saddle about said recess.

10. The convertible motorcycle seat in accordance with claim 9 wherein the rear end of said base plate has a forwardly inclined upstanding tang.

11. The convertible motorcycle seat in accordance with claim 10 wherein a cover plate is secured to said upstanding tang and is dimensioned and configured to cover said hinge assembly.

12. The convertible motorcycle seat in accordance with claim 11 wherein said backrest has cushioning material thereon about said pivotable arm and a cover disposed thereabout, and a cover plate thereon configured and dimensioned to bend into said first mentioned cover plate secured to said tang.

13. The convertible motorcycle seat in accordance with claim 1 wherein said recesses of said cam surfaces are concavely arcuate.

14. A convertible motorcycle seat including:

(a) an elongated saddle having a driver seat portion and a rear passenger portion and including a platform, cushioning material and a cover;

(b) a backrest hinge assembly having a base plate secured to the rear portion of said platform, said base plate having upstanding ears spaced transversely of said platform, an elongated pivotable arm having transversely spaced depending ears disposed between said upstanding ears of said base plate, a pivot member extending transversely of, and journalled in, said upstanding ears, said pivotable arm being pivotable into an erect position extending generally vertically and into a collapsed position extending generally forwardly of said saddle, said depending ears having a lower surface portion providing a cam surface including a pair of spaced recesses spaced arcuately about said pivot member with a convexly arcuate lobe therebetween, an indexing pin extending transversely of said base plate, and a plurality of biasing means on said base plate along the length of said indexing pin biasing said indexing pin against said cam surfaces of said depending ears and into one of said recesses whereby said pivotable arm is firmly held in an erect position or in a collapsed position, said biasing means comprising compression springs; and

(c) a backrest mounted on said pivotable arm;

wherein said biasing means comprises a compression spring bearing on said base plate and upwardly against said indexing pin, said rear passenger portion of said saddle being configured to provide a recess in which said hinge assembly and backrest are disposed in the collapsed position of said pivotable arm.

15. The convertible motorcycle seat in accordance with claim 14 wherein said pivotable arm has a reduced width between said upstanding ears, and said backrest has cushioning material thereon about said pivotable arm and a cover disposed thereabout.

16. The convertible motorcycle seat in accordance with claim 15 wherein said backrest has a cover plate on the rear surface of said pivotable arm when said backrest is in said erect position.

17. The convertible motorcycle seat in accordance with wherein said backrest is dimensioned and configured to blend into the contours of said saddle about said recess, and the rear end of said base plate has a forwardly inclined upstanding tang, and a cover plate is secured to said upstanding tang, said cover plate being dimensioned and configured to cover said hinge assembly.

18. The convertible motorcycle seat in accordance with claim 14 wherein said backrest has cushioning material thereon about said pivotable arm and a cover disposed thereabout and is configured and dimensioned to bend into said first mentioned cover plate.