April 1, 1917.] 



THE INDIA RUBBER WORLD 



383 



the stand C is journaled the driving shaft D and in the stand 

 B is an adjustable center E which supports one end of the 

 mandrel F, the other end of which is centered in the chuck G 

 on the end of the driving shaft D. H is an eccentric rotary 

 knife journaled in an adjustable bearing attached to the knife 

 carriage /. This carriage slides on the shaft / and is moved 



Fig. 4. — Automatic Trimmixg .\Nn Wr.\ppi.vg M.\chine. 



longitudinally by the screw shaft A.'. The shaft / is driven 

 from the driving shaft D by spur gears L and the cutting 

 knife is revolved by means of the gears M. An intermittent 

 feeding movement is given the threaded shaft K by means of 

 the ratchet wheel A^. This ratchet is turned a short distance 

 each time one of the rollers O strikes a roller P on the pawl 

 carrier. The strikers O are mounted on a disk Q on the end 

 of the shaft /. The operation of the machine is as follows : 

 The mandrel with the rubber tube upon it is placed in posi- 

 tion, the knife support is adjusted and power is applied to 

 the driving pulley, which revolves the mandrel and also the 

 elliptical knife. When that part of the knife of the least radius 

 comes opposite the tube on the mandrel, the feed shaft K 



Fig. 5. — "Push" M.\ndrel M.\chixe. 



moves the knife carriage / lengthwise a distance equal to the 

 thickness of the ring required. In this way tlic tube is cut 

 into rings while the knife is in constant rotation. 



Further development of the principle embodied in the above 

 original invention has resulted in the following complete line 

 of highly specialized machines for the manufacture of jar rings. 



THE IMPROVED PI.\N.\ROS.\ J.^K RING M.\CHINES. 



These machines show the progress that has been made in 



specialized machinery used in modern rubber mills for the 



manufacture of jar rings. They include an automatic machine 



for trimming and cloth wrapping the unvulcanized tube on the 



curing mandrel ; a machine operated by compressed air that 

 removes the cut rings and at the same time forces another un- 

 cut tube upon the same mandrel; a duplex jar ring lathe that 

 automatically cuts the rings ; and a special alternating grinding 

 machine for grinding the elliptical cutters. 



The uncured tube on its mandrel is placed in the right-hand 

 end of the machine shown in Fig. 4, and the ends of the tube 

 are accurately squared and at the same time the length deter- 

 mined by automatic cutters. The tube is then placed on the wet 

 wrapper and the end brought over the tube when it is released 

 and rolls down the incline by gravity — thereby loosely wrapping 

 itself — to the two parallel gear driven rollers on which it rests. 

 The upper presser roller, being automatically raised to permit 

 the entry of the wrapped tube, is now brought down in contact 

 with it, the power applied and after 16 revolutions the cloth is 

 smoothly and evenly wrapped around the tube. The upper 

 presser roller is then released and the wrapped tube rolls down 

 the inclined plane to the end of the machine and is ready for 

 curing. 



After the tube has been vulcanized, it is blown off the mandrel 

 by compressed air and placed on the cutting mandrel by tlie 



Fig. 6. — Automatic Jar Ring Lathe. 



machine shown in Fig. 5. This machine serves a double pur- 

 pose bj' removing the cut jar rings from the mandrel and at 

 the same time applying another tube to the same mandrel. 



This "push" mandrel machine consists of a horizontal cylin- 

 der containing a piston that is operated by compressed air. A 

 mandrel and tube that has been cut on the jar ring lathe is 

 placed on the concave bed of the machine and the end ad- 

 justed to the outer end of the piston. One end of an uncut 

 cured tube is slipped over the free end of the mandrel, the 

 other tube end being attached to the automatic compressed air 

 valve shown at the extreme left of the illustration. Compressed 

 air is automatically released by this valve and rigidly distends 

 the tube while the piston is operated, forcing the mandrel into 

 the uncut tube and at the same time removing the cut rings. 



The jar rings are cut on the automatic lathe shown in Fig. 

 6, the mandrel being placed between the centers and revolved 

 at a lixed speed. The cutting is performed by two rotary, 

 elliptical knives or cutters mounted on separate carriages that 

 arc driven in the same direction by a lead screw. The knife 

 on the right starts on the right end of the tube and cuts to 

 the left, while the other knife starts at the center and cuts in 

 the same direction. There is no reciprocatory motion, which 

 is the most important feature, as it permits running the machine 



