GB570110A - Improvements in telescopic suspension applied to front wheels of motor cycles - Google Patents

Abstract

570,110. Spring forks for motor-cycles. WHITEHOUSE, A. W. June 24, 1943, No. 10171. [Class 136 (iii)] [Also in Group XXXII] Front wheel spring suspension means for a motor cycle comprise a pair of upper tubes 7 within which slide a pair of lower tubes 8 under spring control, the upper tubes 7 being secured together by stays 17, 18 which pass across in front of the steering-head 19 and are provided with arms 14a, 11, clamped to laterallyextending members 16, 12 of the steering spindle 13 above and below the steering-head. The upper arms 14a are adjustable on the tops of the tubes 7 so that the distance between the two sets of arms 14a, 11 may be varied to suit existing members 16, 12 on the cycle. In the construction shown the lower tubes 8 are provided with sockets or lugs 9a on which the front wheel spindle is mounted. The front mudguard 44 is pivoted to a rod 43 sliding in a tube 45 extending between the stays 17, 18, and is further supported by rods 41 fixed to the lugs 9a. Outer telescopic casing tubes 5, 6 are secured respectively to the tubes 7, 8. Shock absorbers. The load is transmitted from the upper tube 7 to the lower tube 8 by a strong spring 24 compressed between the head 20 of tube 7 and a flange 23 on the tube 8. A bush 25 is a push fit in the tube 7 and forms a lower bearing between the tubes 7, 8. A flange 26 on the bush 25 is a sliding fit in the casing 6 and is provided with packing 26a to form an oil seal between the tube 8 and the casing 6. A tube 27 is screwed to the head 20 of tube 7 and passes freely through the flange 23 on tube 8, its lower end having a bush 29 on which rests a rebound spring 30 adapted to act on a valve 31 which can close the passage between the tube 27 and flange 23. A spring 33 rests on the lower end of tube 8 and is normally free at its upper end as shown, but comes into action to assist the main spring 24 in the case of severe shocks. A series of holes 36 increasing in diameter upwardly are formed in the tube 8 to put its lower end in communication with the space 35. A hole 37 in the upper end of tube 8 communicates with the space 34 above the bush 25, and holes are formed in the inner tube 27 near the top. Oil is supplied through a filling plug 40 at the top of an oil container tube 39 and fills the lower end of the tube 8 and the space 35 up to the packing 26a. When a load compresses the strut.7, 8 the tube 7 is depressed and forces oil from the space 35 into the tube 8, through the hole 37 into the space 34, and also up the tube 27 and through the holes thus lubricating the various parts. On the rebound the' tubes 7, 27 and the spring 30 all rise. If the recoil goes beyond the normal position the spring 30 closes the valve 31 so that oil is trapped in the upper part of the tube 8 and can leave it only through small holes 42 leading to the space 34. The oil in this space returns through hole 37 into tube 8 and through holes 36 to space 35.