Oc-niBER I, 1913.] 



THE INDIA RUBBER WORLD 



13 



Two New Solid Tire Machines. 



Sol, II) rublicr tires were for a long time— and are now, in 

 most instances — mannfactiircd by means of the old method, 

 in which the rubber is forced out through a die. or by 

 means of the alternative method of building up the entire rubber 



l'"i(;. 1. — Side Ki.f.vatiox of Bridge Tire Machine. 



portion of the tire by hand, in preparation for the mould. 1 wo 

 recent British patents, relating to a new method of building up 

 solid rubber tires by means of specially constructed machiner\. 

 are briefly described herewith. The first of these, the invention 

 of Robert and Jonathan Bridge, of the firm of David Bridge & 

 Co.. Limited. Lastlcton, England, relates to the building up of a 

 tire in continuous layers of rubber taken from a calender which 

 furnis the rubber in sheets as it comes from the heating mill; 

 of an adjustable mandrel upon which the metal base of the tire 

 is placed, and of a cutting apparatus by means of which the tire 

 is turned to the desired shape after wrapping. 



The rubber is first passed from the heating mill to the calender 

 A (Fig. 1), which is provided with three rollers B B. From this 

 point the sheets of rubber may be cut into strips and conducted 

 to more than one mandrel, altho only one is shown herewith. 



Fig. 2. — Top View of Bridge Tire Machine. 



.At C is shown the strip of rubber pa.ssing from the lower roller 

 B to the mandrel D. This mandrel is usually of the split ring 

 type, so that it may be collapsed for the purpose of removing 



the rubber tread after the wrapping process is completed. It is 

 held in place by means of an adjustable expanding ring E which 

 is manipulated by the hand wheel F. 



The speed regulating mechanism is the most interesting feature 

 of this machine. It consists of two cone-shaped pulleys G and H 

 ( l'"ig. 2), connected by a belt 1 which is automatically moved over 

 the pulleys as the tire increases in size. This is accomplished 

 by means of a fork K carried on the rods L L and connected 

 with a lever M pivoted to the frame at X. This lever engages 

 with the slotted end of the lever O, the opposite end of which 

 has a roller P which bears against the tire as it is being built up 

 on the mandrel. As the tire increases in size during the winding 

 process the series of levers causes the belt I to be moved across 

 the cone-shaped pulleys so as to reduce the speed of the pulley H. 

 This pulley, having a pinion Q which engages the large gear R. 

 the speed of the tire periphery is kept constant throughout the 



Fig. 3.— Price Solid Tire Wrapping Machine. 



winding process. The shaft S also has a clutch T by means of 

 which tlic mandrel D may be thrown out of gear without stopping 

 the calender. 



The heavy roller U is employed to press the strips of rubber 

 together so that all air is excluded from the tire. In addition 

 to the roller a vacuum pump is sometimes used, with the open 

 end of the air pipe placed in -the angle V so as to withdraw 

 the air away from the rubber strip as the latter is being wound. 



After the winding is continued until the tire is of the desired 

 thickness, the tread may be turned to the required shape by means 

 of the cutting apparatus W. This cutter may be of the com- 

 pound type .so that the knife may be operated in any direction, 

 and it may also include a buffing or finishing wheel to follow the 

 cutter. The clutch T may be disengaged from the gear R and 

 engaged with the gear X which is driven by a chain Y from the 

 gear Z. This also gives a higher speed in the shaft S which is 

 desirable for the cutting and finishing process. 



