AU2014250628A1 - Tandem - Google Patents

Abstract

A tandem for two riders has a triangulated bicycle frame linking a pair of unicycles with handlebars for the front unicycle rear handlebars in the middle of the frame, a seat for the front unicycle mounted between the front handlebars and the rear handlebars. The front handlebars ride on shock absorbers. 2014-10-14,C:\Usrs\Shaflen ocuments\SPEClFfCATIONS\pamrhantcap2_wpd,7 C)w OC o (N C *) -Io

Description

TITLE OF INVENTION Tandem TECHNICAL FIELD [0001] This invention concerns tandems for cyclists. BACKGROUND [0002] Tandems of standard length are too long to be carried on the rear carrier of a car. Although well suited to road travel they are not regarded as a recreation bicycle and are rarely seen off road. SUMMARY OF INVENTION [0003] The apparatus aspect of the invention provides a tandem for two riders comprising a bicycle frame linking a pair of unicycles with steering means for the front unicycle. [0004] The frame may support handlebars for the rear rider. [0005] The front rider has handlebars and the rear rider has handlebars. [0006] The frame may support a seat for the front unicycle. [0007J The frame may have the shape of an inverted triangle divided into front and rear sections by a central upright tube. A horizontal crossbar may form the triangle base, the sides of the triangle being formed by inclined tubes such that the inclined tubes and the central upright tube meet at the lower apex of the frame. The front section has a headstock for the front forks and the rear section has a headstock for the rear unicycle. 2014-I 0-t4,C-.Useus\Sharke\Docurments\SPECIFICATIONSIpamnha.cap2.wd I 2 [0008] The seat for the front unicycle may be adjustable by sliding in an upright seat tube fixed to the crossbar between the central tube and the front headstock. [0009] The handlebar support may further comprise a pair of telescopic forks attached to their lower ends to the top of the forks of the front unicycle. [0010] The telescopic forks may be pivoted to the forks of the front unicycle and additionally supported by a bifurcated component extending from the front unicycle wheel spindle in advance of the unicycle forks. The purpose of the telescopic forks is to provide absorption of road shocks transmitted through the handlebars. Advantageous Effects of Invention [0011] 1. Drive to both wheels without sprockets and chains. Good traction in off road conditions. [0012] 2. Light weight compared to a conventional tandem. One rider can ride the tandem. [0013] 3. Fits on a car's rear bicycle rack. BRIEF DESCRIPTION OF DRAWINGS [0014] One embodiment of the invention is now described with reference to the accompanying drawings, in which: [0015] Figure 1 is a side view of the tandem. [0016] Figure 2 is a perspective of the front half of the tandem to show construction. 2014-10-14,C:\Usrs\Shudne\DocumenIs\SPECIFICATIONS'pamhamcap2 wpd,2 3 DESCRIPTION OF EMBODIMENTS [0017] Referring now to the drawings, the tandem frame is substantially triangular with a front headstock 2 and a rear headstock 4 connected by a common crossbar 6 and a pair of inclined down tubes 8,10 which meet at a central upright tube 12, the purpose of which is to support the rear pedallers handlebars 14. [0018] The rear headstock 4 supports a rear unicycle assembly consisting of a pair of forks 16 connected by a fork bridge 18, a pair of fork ends 20 which support a wheel 22, a pair of cranks 24 with pedals 26 and a caliper brake assembly 28. [0019] The front part of the crossbar 6 has a sectional seat tube 30 which permits the rise and fall of the steerer's seat 32. [0020] The front headstock 2 supports a front unicycle assembly also consisting of a pair of forks 34 connected by a fork bridge 36, a pair of fork ends 38 which support a wheel 40, a pair of cranks 42 with pedals 44 and a caliper brake 46. [00211 The front forks 34 are steerable by handlebars 48 at the end of the bifurcated mounting tube 50 of a pair of spring activated telescopic forks 52. The lower ends of telescopic forks 52 are connected to bridge 36 by brackets (welds) 54. These cushion the rider who steers against road stocks. As the telescopic forks point forwardly at 60 degrees they require support from front wheel 40. This is provided by bifurcated strut 56 which straddles the front wheel and is connected to the telescopic forks by clamps 58. This creates a rigid triangle which still permits the handlebars to soften road bumps. [0022] The rear pedaller's seat 60 is height adjustable in rear headstock 4. The seat is different from the steerer's seat 32 in that it has a concave surface when seen in side view. The rear pedaller sits more uprightly than the steering rider whose pedals and handlebars 48 lie forwardly of the seat 32. 2014-10-14,C:\Users\Shadene\Documenis\SPECIFICATIONSpamharncap2.wpd,3 4 [0023] Brake lever 62 on handlebar operates rear brake 28. Brake lever 64 on handlebar 48 operates front brake 46 while it is practical to build the tandem from two existing frames joined together commercial production will utilise purpose-built tandem frames. [0024] It is to be understood that the word "comprising" as used throughout the specification is to be interpreted in its inclusive form, ie. use of the word "comprising" does not exclude the addition of other elements. [0025] It is to be understood that various modifications of and/or additions to the invention can be made without departing from the basic nature of the invention. These modifications and/or additions are therefore considered to fall within the scope of the invention. 2014-10-14,CAUsers\Sharlene\Documnts\SPECIFICATONSpamTai cap2 wpd,4

Claims (14)

1. A tandem for two riders comprising a bicycle frame linking a front unicycle to a rear unicycle with steering means for the front unicycle.

2. A tandem as claimed in Claim 1, wherein the frame supports handlebars for the rear rider.

3. A tandem as claimed in Claim lor 2, wherein the front unicycle is pivotally mounted in the frame and has handlebars which steer the front wheel,

4. A tandem as claimed in any one of Claims 1-3, wherein the frame has a support for the seat of the front unicycle.

5, A tandem as claimed in any one of Claims 1-4, wherein the frame is the shape of an inverted triangle divided into front and rear sections by a central upright tube,

6. A tandem as claimed in Claim 5, wherein a horizontal crossbar forms the triangle base and the sides of the triangle are inclined tubes such that the inclined tubes and the central upright tube meet at the lower apex of the frame.

7. A tandem as claimed in any one of Claims 4-6, wherein the seat support for the front unicycle is an upright seat tube extending from the crossbar to the front inclined tube.

8. A tandem as claimed in any one of Claims 5-7, wherein the front section has a headstock for the front forks and the rear section has a headstock for the rear unicycle.

9. A tandem as claimed in any one of Claims 3-8, wherein the handlebars extend from the upper end of a telescopic fork, the lower end of the fork being fixed to the fork of the front unicycle. 6

10. A tandem as claimed in Claim 9, wherein the telescopic fork is inclined forwardly and is additionally supported by a pair of struts connected between the upper end of the telescopic fork and the lower end of the fork of the front unicycle.

11. A tandem as claimed in Claim 9, wherein the telescopic fork is inclined forwardly and is additionally supported by a pair of struts connected between the upper end of the telescopic fork and the wheel spindle of the front unicycle.

12. A tandem as claimed in any one of Claims 2-11, wherein rear handlebars do not steer but are height adjustable by rise and fall in the upright central tube.

13. A tandem as claimed in any one of Claims 8-12, wherein the rear seat is supported by the headstock.

14. A tandem as claimed in any one of Claims 1-13, wherein the rear seat has a longitudinally concave, contact surface in order to centralise the torso of the rear rider.

2014-10-14,C:\Usershadene\Documems\SPECTFICATIONSipamam cap 2 n pd6