Recumbent Bicycle with Direct Underseat Steering

Abstract

The invention allows a rider to operate a bicycle in a recumbent position, and steer the bicycle using a direct underseat steering system. The recumbent position, compared to the typical upright riding position, greatly reduces air resistance and required effort. The direct underseat steering system is mechanically simple, which makes is less costly to manufacture, and the direct steering system is also less likely than linkage-based systems to be damaged in a crash. The frame geometry allows the manufacturer to use inexpensive materials and techniques, while still providing the rider adequate stiffness and durability.

Claims

1. A double-pyramid recumbent bicycle frame comprising: a) a rear pyramid formed by a rear seat tube, a left seat stay, a right seat stay, a left chain stay, and a right chain stay; b) a forward pyramid formed by a left main side stay, a right main side stay, a main tube, a left front side stay, a right front side stay, and a front down tube; c) a head tube that forms part of the forward pyramid and connects to the front end of the left main side stay, the front end of the right main side tube, the front end of the front down tube, the rear end of the left front side stay, the rear end of the right front side stay, and the rear end of the front down tube; d) a left rear dropout that connects to the left seat stay of the rear pyramid, the left chain stay of the rear pyramid, and the left main stay of the forward pyramid; e) a right rear dropout that connects to the right seat stay of the rear pyramid, the right chain stay of the rear pyramid, and the right main stay of the forward pyramid; f) a connection between the left side of the midsection of the rear seat tube of the rear pyramid and the left main stay of the forward pyramid; and g) a connection between the right side of the midsection of the rear seat tube of the rear pyramid and the right main stay of the forward pyramid.

2. A steering assembly for a bicycle comprising: a) a left front fork and a right front fork that are connected to each other, said front forks rotatably attached and removably attached to a head tube, and b) a handlebar that is operably connected to the front forks, said handlebar mounted so that it rotates freely in the vertical space between an upper frame component and a lower frame component, said upper frame component being connected to said head tube, and said lower frame component being connected to said head tube.

3. The steering assembly of claim 2, wherein the handlebar is mounted so that it rotates freely in the vertical space between an upper frame component and a lower frame component, wherein said upper frame component consists of left and right main side stays, and wherein said lower frame component consists of a down tube.

4. The steering assembly of claim 2, further comprising a vertical fork extender stem, said vertical fork extender stem connected to one or both of the front forks and attached to a wraparound connector, said wraparound connector attached to the handlebar.

5. The steering assembly of claim 4, wherein said wraparound connector is removably attached to the vertical fork extender and said wraparound connector is removably attached to the handlebar.

6. The frame of claim 1, further comprising a bottom bracket shell, wherein said bottom bracket shell forms the point of the forward pyramid and is connected to the front end of the left front side stay, the front end of the right front side stay, and the front end of the front down tube.

7. The frame of claim 1, wherein a rear bicycle wheel is removably attached and rotatably attached to the left rear dropout and the right rear dropout.

8. The frame of claim 1, further comprising a jockey wheel connected to the side of the frame.

9. The frame of claim 1, further comprising a front seat mount connected to the midsection of the left main side stay and the midsection of the right main side stay, and a rear seat mount connected to the top of the rear seat tube, the top of the left seat stay, and the top of the right seat stay.

10. The frame of claim 9, wherein the front and rear seat mounts are removably and adjustably attached to a seat.

11. The frame of claim 8, further comprising a drivetrain, with said drivetrain comprising a bottom bracket, pedals and crankarms, a chainring, a rear sprocket, and a chain, wherein the chain path runs around the chainring, over the jockey wheel, around the rear sprocket, and back to the chainring.

12. The frame of claim 11, further comprising an internally geared hub rotatably attached to the rear sprocket and rotatably attached to the rear wheel, and operated by a shifting device mounted either on the frame or the handlebar.

13. The steering assembly of claim 2, further comprising a braking system consisting of a braking mechanism, such as rim calipers or a disc brake, that is operated by a controlling device mounted on the handlebar or on the frame.

Description

SUMMARY OF THE INVENTION

Brief Description Of The Drawings

[0014] FIG. 1a right side perspective view of an example vehicle

[0015] FIG. 2a top side elevation view of an example vehicle

[0016] FIG. 3a front side elevation view of an example vehicle

[0017] FIG. 4a rear side elevation view of an example vehicle

[0018] FIG. 5a partial right side view of the jockey wheel and steering assembly

[0019] FIG. 6a partial left side view of the steering assembly with the front wheel turned to the right

[0020] FIG. 7a partial left side view of the steering assembly with the front wheel turned to the left

[0021] FIG. 8a partial view of the front seat mount

[0022] FIG. 9a partial view of the rear seat mount

DETAILED DESCRIPTION OF THE INVENTION

[0023] A recumbent bicycle 10 of this invention is shown in FIG. 1. As shown in FIG. 1, a down tube 12 is connected to a rear seat tube 14. The lower end of the rear seat tube 14 is connected to the right rear dropout 24 by a right chain stay 20. The lower end of the rear seat tube 14 is also connected to the left rear dropout 26 by a left chain stay 22. As shown in FIG. 1 and FIG. 4, the upper right end of the rear seat tube 14 is connected to a right rear dropout 24 by a right seat stay 16. The upper left end of the rear seat tube 16 is also connected to a left rear dropout 26 by a left seat stay 18. The rear wheel and tire 28 are removably connected to the right rear dropout 24 and the left rear dropout 26.

[0024] A right main side stay 30 is connected to the right rear dropout 24 and connected to the right side of the rear seat tube 14 and connected to the right side of the front seat tube 66 and connected to the right side of the head tube 34 and connected to the rear end of the right front side stay 38. A left main side stay 32 is connected to the left rear dropout 26 and connected to the left side of the rear seat tube 14 and connected to the left side of the front seat tube 66 and connected to the left side of the head tube 34 and connected to the rear end of the left front side stay 40.

[0025] As shown in FIG. 1 and FIG. 2 and FIG. 3, a front down tube 36 connects the front center of the head tube 34 to the underside of the bottom bracket shell 42. The rear end of the right front side stay 38 is connected to the front end of the right main side stay 30 and the upper right side of the head tube 34. The front end of the right front side stay 38 is connected to the right upper side of the bottom bracket shell 42. The rear end of the left front side stay 40 is connected to the front end of the left main side stay 32 and the upper left side of the head tube 34. The front end of the left front side stay 40 is connected to the left upper side of the bottom bracket shell 42. The bottom bracket shell 42 is rotatably connected to a chainring 44 and pedals and crankarms 46.

[0026] As shown in FIG. 5, a jockey wheel 50 is connected to the lower right side of the head tube 34. A chain 48 passes around the chainring 44 then over the top of the jockey wheel 50 then around the rear sprocket 52 then back to the chainring 44. The right front fork 54 is connected to the left front fork 56 and both forks are removably connected to a front wheel and tire 58. The right front fork 54 and left front fork 56 are rotatably connected to the head tube 34.

[0027] As shown in FIG. 6 and FIG. 7, the left front fork 56 is connected to a vertical fork extender stem 60 that, when the bicycle is assembled, runs parallel to the head tube 34. The left end of wraparound connector 62 slips over and is removably clamped to the vertical fork extender stem 60. The rear end of the wraparound connector 62 slips around and is removably clamped to the handlebar 64. The wraparound connector 62 is shaped and positioned on the vertical fork extender stem 60 and clamped to the handlebar 64 in an arrangement that ensures that the right front fork 54 and left front fork 56 can rotate freely without interfering with the chain 48 or the down tube 12 or the right main side stay 30 or the left main side stay 32.

[0028] As shown in FIG. 8, the front seat tube 66 is connected to the down tube 12 and connected to the right main side stay 30 and connected to the left main side stay 32. A front seat post 68 is inserted into and removably clamped to the front seat tube 66. The front seat post 68 is removably clamped to a front seat clamp 70 which is removably clamped to the front seat rails 72. The front seat rails 72 are connected to the seat 74.

[0029] As shown in FIG. 4 and FIG. 9, a rear seat post 74 is inserted into and removably clamped to the rear seat tube 14. The rear seat post 76 is removably clamped to a rear seat clamp 78 which is removably clamped to the rear seat rails 80 which are connected to the seat 74.

[0030] Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.