Patent GB-419244-A (GB)
Title: Improvements in or relating to tire building apparatus
IPC: B29D30/36
Filed: 1934-02-21
Abstract: 419,244. Moulding wheel tyres. FIRESTONE TYRE & RUBBER CO., Ltd., Great West Road, Brentford, Middlesex.-(Firestone Tire & Rubber Co. ; Akron, Ohio, U.S.A.) Feb. 21, 1934, No. 5743. [Class 87 (ii).] In the type of tyre-building apparatus in which a flat band is shaped to tyre form by fluid pressure applied to its interior and an expansible core is fed in a collapsed condition into the tyre, the band is held between a stationary head and a movable head in the form of a hollow-cylinder provided with means for drawing the collapsed core into its interior and subsequently expelling it into the inflated band, while gradually inflating it during the process. After assembly, the fluid-pressure within the band is released, and the movable head retracted leaving the assemblage ready for vulcanizing. In the form shown the band is clamped between a fixed conical head 113, Figs. 1 and 2, and the movable head 39 raised and lowered by rack-and-pinion gear from a two-speed motor 33. The band and the two heads form an airtight chamber into which compressed air can be introduced from a pipe 122 leading to the interior of the member 23 and thence through holes 51 into the chamber. The bags are manipulated by a piston 47 carrying an adjustable hook 54, the piston being raised and lowered by screw-mechanism 58 driven from the motor 69. Both motors are stopped automatically and the compressed-air supply for the tyre controlled by the moving parts of the apparatus during the cycle of operations. In operation, an air-bag is hung on the hook 54 and a flexible pipe 142 leading to a hand-operated four-way valve 145 is attached to the inflating valve. The valve 145 then is manipulated to apply suction and completely deflate the bag. Motor 69 is then operated to lift the deflated bag into the interior of the member 23. A band is then mounted between the heads and motor 33 operated to lower the movable head 39. A cam 125 in sequence opens a valve in the pipe 122 and admits compressed air to inflate the band, then operates a switch 103 to change the motor 33 from high to low speed and a second switch 104 to stop the motor, and, if necessary, finally operates a third limit switch 105 to apply a brake 35 to the motor. A fourth limit switch 102 operates to stop the motor and apply the brake when the head 39 is moved upwardly. At the next stage the upper head is raised to a small extent by reversing the motor by hand, thus allowing the inflated tyre to expand sufficiently to insert the bag. Motor 69 is then started by hand to lower the bag into the inflated tyre. The spring-mounted yielding central portion 120 of the lower head 113, acts as a deflector to conduct the falling bag to the interior of the bowed tyre. At the end of the movement the hook disengages the bag and passes into a recess in the head 113. The valve 145 is then manipulated to disconnect the bag from the suction-apparatus and connect it to a source of carbon dioxide under pressure. As the bag expands, the interior of the tyre is opened to the atmosphere through a vent pipe 138. A cam 77 raised and lowered by geared screw-mechanism operates upper and lower limit switches 84, 85 to stop the motor 69.