GB686421A - Improved tandem bicycle frame construction - Google Patents

Abstract

686,421. Convertible cycles. COVENTRYEAGLE CYCLE & MOTOR CO., Ltd. July 10, 1951 [July 10, 1950], No. 17152/50. Class 136 (iii) In a tandem bicycle which can readily be converted into a solo machine and vice versa, the cross bar and/or like longitudinal frame members of the front and rear parts of the frame have a detachable connection with appropriate lugs or the like on the front and rear seat pillars and bottom brackets respectively, so that on disconnection of said detachable connections the front seat pillar and longitudinal frame members extending rearwardly therefrom can be removed to enable the rear seat pillar to be detachably connected to the cross bar and/or like longitudinal frame members of the said front part to form a frame for a solo machine. In Fig. 1, the cross bar 1 and the frame member 2 have detachable connections at 3, 4 with lugs 5, 6 on the pillar tube 7, and bottom bracket 8 respectively, and the frame members 9, 10 have detachable connections at 11, 12 with lugs 13, 14 on the pillar tube 15 and bracket 16 respectively, whilst the tube 15 has a lug 17 to receive the rear end of the cross bar 1. To convert to a solo machine, the bar 1 and member 2 are disconnected from the tube 7 and bracket 8, and the members 9, 10 from the tube 15 and bracket 16. The sprocket chain 18 is removed and also a section of the rear brake operating rod (not shown), thus enabling the tube 7 and members 9, 10 to be removed as a whole. The cross bar 1 and member 2 can then be connected to the tube 15 and bracket 16 respectively, and upon re-connection of the rear brake rod linkage a solo bicycle is formed. Each detachable connection comprises a forked part 21 on one lug such as 13 adapted to receive a projection 22 on a lug 23, the lugs being secured together be a bolt 24. The projection 22 is of I section, the flanges of which have surfaces 25 engaging the bevelled edges of the part 21. Alternatively, the connection comprises a socket portion on one lug adapted to receive a complementary end portion.