Patent GB-1316243-A (GB)
Title: Tyre fitting apparatus
IPC: B60C25/132
Filed: 1971-09-27
Abstract: 1316243 Tyre fitting apparatus HOFMANN GmbH Gebr [trading as HOFMANN K G Gebr] 27 Sept 1971 [5 Feb 1971] 44973/71 Heading B7C A tyre fitting apparatus comprises at least one wheel carrier 32 for carrying a wheel 22 below a fitting head 21 which can be lowered into a working position over the wheel and which carries at least one tyre fitting device which can be moved around the uppermost rim flange of the wheel on the carrier to fit a tyre 20 onto the wheel, the carrier 32 comprising a fixed pair of claws 2 and a movable pair of claws 3 displaceable rectilinearly towards and away from the claws 2 so that a wheel can be clamped between the pairs of claws, and the fitting head 21 including a guide bar 10 movably carrying a pressure plate 9 which presses down onto the wheel during a tyre fitting operation to hold the wheel firmly on the corner 32. Preferably several wheel carriers 32 are provided, each comprising a base member 1 connected to the movable part of a conveyer system. The pair of claws 3 is movable against the action of springs 4, each connected at one end to the claws 3 and at the other end to the base 1, by means of a lever system 6 which may comprise a quadrilateral of four pivotally interconnected levers 23, which are also connected, as shown, to the claws 3, to the base member 1, and to guide rollers 5, so that when, in use, a carrier 32 moves along the conveyer and the rollers 5 contact control bars 7 which are stationary with respect to the conveyor, separation of the claws 2, 3 occurs to allow a wheel to be placed on, or removed from, the carrier, the claws 2, 3 otherwise being urged together by the springs 4 to grip a wheel. Alternatively the lever system may comprise a centre lever carrying a roller at its middle engaging a guide in the base member, and shorter levers pivotally connected to the ends of the centre lever and to the claws 3 and base member 1 respectively, the pivotal connections of the shorter levers to the centre lever carrying the rollers 5. The fitting head 21 includes a carriage 33 having a guide rail 10 which carries the pressure plate 9 by means of rollers, the plate 9 having a guide 27 and/or rollers 28, for holding down a tyre 20 in use, and being connected to a spring system 34 through a cable 29 and pulley assembly 19, such that in use the plate 9 may be moved along the rail 10 when in contact with a wheel moving along the conveyer, and may be returned to its starting position by the spring system 34. The fitting head 21 also has a shaft 31 pivotally mounting two arms 14 movable against the action of pressure elements 15, each arm 14 carrying at its free end a fitting roller assembly movable against the action of springs 16, each assembly consisting of a tyre stretching roller 12 and two support rollers 13 on a carrier 11 pivoted to the arm, and a fitting roller 18, in use, the rollers 13 gripping the uppermost rim flange of a wheel 22 as it passes below the fitting head and causing the assemblies 30 to travel round the periphery of the wheel whilst the rollers 12 stretch the tyre outwardly over the wheel rim flange and the rollers 18 press the tyre downwardly.