4o.' 



THE INDIA RUBBER WORLD 



March 



1921 



New Machines and Appliances 



CrCYCLE TIRE TRIMMING MACHINES 



ORIGINALLY wlioii bicyclc tires were lirst manufactured, they 

 were inacic in two-piece molds and only two lines of over- 

 tiow had to be removed. Today, practically ninety-five per 

 cent of the tires contain fancy non-skid treads and to perfectly pro- 

 duce these non-skid designs, three-piece molds are used. Con- 

 sequently, three lines of overflow must be removed and the 

 combined length of the three circular overflow lines on each 

 tire equals nearly 21 feet. To do this by hand is a slow and 

 expensive proposition, and the automatic trimming machines 

 shown in the illustrations are claimed to be rapidly replacing 

 the hand method. 



Referring to Fig. 1, the machine is removing the overflow 

 from the tread ni a bicycle tire which rests on a grooved rollei 

 in front of the cutters. The shaft supporting this roller is 

 driven from the counter-ihaft which is fastened to the base 

 of machine, and as the tire travels with the grooved roller the 

 overflow is removed. It is held in a vertical position by two 

 idle rollers, the grooves of which are made large enough to 



Each machine is complete with a motor and necessary cord 

 with connecting plug for attaching to the lighting system. 1 he 

 tire starts revolving as soon as it is placed in positinn on the 



Fig. 1 Trimming Bicycle Tire — Tread Overflow 



accommodate all sizes of tires. They are held in position by 

 steel rods fastened to the mounting board and can be adjusted 

 to tires of diflferenl diameters. 



Fig. 2 is a side view of a horizontal niacliinc. showing the 

 overflow being removed from the inside of tin- lire which is 

 supported by idle rollers on each side and in the rear. The 

 shaft and grooved roller in front of the cutters are held in 

 place by an extension arm bearing. The extension arm is con- 

 nected to a steel supiKjrt which is securely fastened to the 

 mounting board by a rod running through its hub. The rod is 

 threaded on one end and enters the knob on the left side of 

 the support. By turning the knob, the extension arm and the 

 tire is moved into or away from the cutters as desired, cither 

 trimming the tire very closely or allowing a small margin of 

 rib. From the e.xtcnsion arm, a projection extends downward 

 with a rod attached to the end. The rod hooks into a disk which 

 is fastened to the mounting board. A lever extends from the 

 side of the disk and by moving this lever the extension arm 

 and the tire are raised or lowered as desired. A spring is at- 

 tached on the shaft between the bearings of the extension arm 

 and this presses the tire against the cutters and acts as a 

 cushion, allowing the tire to give and take as it revolves 



¥ic. 2. Trimming Bicycle Tire — Inside Overflow 



machine and it can be stopped or taken away at any time while 

 the machine is running. The average production of a skilled 

 operator is 20 to 25 tires an hour. Under the same conditions 

 the machine is claimed to trim 100 tires per hour. — T. \V. Morris, 

 3304 Warren avenue, Chicago, Illinois. 



GIANT TRUCK-TIRE BUILDING STAND 



Every rubber tire manufacturer will be interested in this new 

 model tire-building stand which has been particularly designed 

 for use in the construction of heavy pneumatic truck tires. If 

 is strongly built of cast iron, and provided w'ith bolt holes for 

 attaching to the floor. It is fitted throughout with Timken 

 roller bearings. The core upon which the tire is built is placed 

 in the rotatablc chuck attached to the arm, and as the tire is 

 built up, layer upon layer, the operator can easily turn the core 

 around, as the result of perfectly balanced bearings. The arm 

 ■support can be moved in any direction which will enable the 



Rev.'voi.ds Tire-Bl'ilding Stand 



operator to perform the work better and quicker. A foot lever 

 on the right-hand side of the stand is connected with two 

 powerful springs which are part of the operating mechanism. 



