| 摘要 |
<p>793,024. Rasping &c. tyres. ZANGL, K. April 17, 1956 [Oct. 24, 1955], No. 11615/56. Class 31 (1). [Also in Group XXII] In a method of buffing or paring non-inflated pneumatic rubber tyres for re-trueing and retreading in which the tyre is clamped centrally on a mandrel and is operated on during rotation by a tool guided against the tyre surface, the tyre is driven with such a speed of rotation that it is extended radially by centrifugal force to provide a counter pressure against the action of the tool. As shown, a tyre 1 is clamped by means of a mandrel comprising clamping jaws 7 pivoted to spreader levers 2, 3, the levers 2 being mounted on a fixed support 4 and the levers 3 on a nut 5 which is adjustable by means of a hand wheel 6. Alternatively, the levers 2 may be mounted on the nut 5 and the levers 3 on the support 4. Each jaw 7 has fixed and adjustable stops 8 against which the beads of the tyre bear. The mandrel is carried by a shaft 9 mounted in a machine pedestal 10 containing a driving motor and change-speed gear. Tools in the form of buffing rollers 11 are mounted with their driving motor 12 on a common shaft 13 which is mounted in a hollow fork 14 having a hollow spindle 15 which is rotatably mounted in a bracket 16 pivoted to the pedestal 10 so that either of the buffing rollers can be brought into operation as desired. The ends of the fork 14 are provided with suction hoods 19 extending over the buffing rollers and provided with automatically-locking valves, that associated with the operative buffing roller being held open and that associated with the inoperative buffing roller being held closed. The spindle 15 is connected to a suction duct 20 and to increase the suction effect that portion of the fork 14 leading to the inoperative buffing roller can be closed by means of an adjustable valve 21, Fig. 3. In a modification, Fig. 5 (not shown), the buffing rollers and their driving motor are mounted for pivoting about a vertical axis. In a further modification, Fig. 6 (not shown), the buffing rollers are concave to correspond with the doming of the tyre tread. A steel brush, or buffing rasp, secured to a handle may be used instead of the buffing rollers. Alternatively, the tools may be in the form of paring blades which are each clamped between two fixed or adjustable rollers which are adapted to run on the tyre tread and thereby regulate the cutting depth of the blades.</p> |
