THE INDIA RUBBER WORLD 



563 



in proper place by one revolution of the core. This is again 

 shifted to the first position, the opposite bead set in place and 

 the end of the fabric taken from the pressure bar and drawn 

 down until the cone-roll rests on the core and the core revolved 

 to apply the third ply. After this is stitched down, the core 

 is again shifted to receive the fourth ply, which completes the 

 process for a small tire. (The Knight Manufacturing Co., Can- 

 ton, Ohio.) 



AN IMPROVED AUTOMATIC MIXER. 



Enclosed mi.xers of the type here shown are now considered 

 as standard rubber-mill equipment and have demonstrated their 

 superiority on the softer stocks, all black tread stocks and many 

 mixtures that are injurious 

 to workmen. 



The important improve- 

 ments embodied in this new 

 machine include a large 

 cooling area to reduce the 

 temperature of the material 

 being mixed; it is practi- 

 cally dust proof; the dis- 

 charge door easily slides so 

 that small eiTort is required 

 to discharge the material 

 that leaves the machine in 

 comparatively small pieces ; 

 tlie shafts, bearings, and 

 general construction are of 

 a rugged design to with- 

 stand the severest strain ; 

 and the motor drive is 

 substantial in construction 

 and quiet in operation. 



This machine handles 



batches from 75 to 150 



pounds, depending on the 



capable of successfully mixing batches 



. (Birmingham Iron Foundry, Derby, 



The E.\neukv 



.gravity. A laryer size 

 of 450 pounds, gravity 

 Connecticut.) 



COLLAPSIBLE TIRE-BUILDING FORM. 



The D. M. B. collapsible tire-building form shown in two views 

 is unique in design and simple in operation. It is specially 

 adapted for use in making tires which are cured in molds on air- 

 bags, because by its collapsable constructidn it can be so folded 



Closed 



The D. M. B. Tike-Builmnu Form. 



Ope> 



upon itself that the unvulcanized tire can be removed with little 

 effort from the form without stretching the beads or otherwise 

 damaging it. 



It is claimed that the use of this form will greatly lessen the 

 cost and labor of tire building. In fact, its introduction has made 

 possible the employment of women as tire builders on account 

 of the simplicity and ease of its operation. 



Referring to the illustrations the view on [lie left shows the 

 form in closed position ready for building llie lire, the view on 

 the right shows it in open or collapsed po.-,iuon for removal of 

 the tire. This building form is very easily and quickly changed 

 from closed to collapsed position by drawing inwardly the upper 

 sliding section by means of a rack and pinion actuated by a hand 

 socket wrench. 



The section is then folded over toward the center on a hinge 

 and each hinged side section is in turn folded, as shown in the 

 view on the right. When the form is in this position the tire 

 can be easily lifted from it without strain or distortion. (De 

 Mattia Bros., Inc., Garfield, New Jersey.) 



PNEUMATIC CHUCKS FOR TIRE-BUILDING MACHINES. 



Air-operated chucks have recently come into use for holding 

 the bases of solid tires and the cores of pneumatic tires during 

 building operations. 



The 12-jaw chuck shown on the left in the illustration is a 

 special chuck designed for use in connection with a solid rub- 

 ber tire-trimming machine. It will take tires from 28 to 

 36 inches in diameter, each of the jaws having a movement of 

 over 4 inches. Owing to the narrow width of the small tires, 

 it is necessary to make the chuck only 31/^ inches wide on 

 the outside diameter. The chuck has 12 jaws, which are neces- 

 sary to avoid springing the tire ring out of shape, which is 

 the main difiilculty with a four-jawed chuck. All working parts 

 are fully enclosed, making them dust-proof and eliminating 

 danger to the workman. 



The movement of the jaws is obtained through a rack-and- 

 pinion movement that is operated by a 12-inch standard double- 

 acting air cylinder. This chuck can also be made for external 

 gripping by using false jaws. 



.AiR-OrER.\TED Chi. 



Twelve-Jaw Chi 



Three-J-\w Chuck. 



The three-jaw chuck shown in the illustration on the right 

 is used on pneumatic tire-making machines and the interior 

 construction is similar to that of the twelve-jaw chuck. It has 

 a range from 17 to 24 inches, to accommodate regular-sized 

 cores. These chucks are operated by a standard 10-inch double- 

 acting air cylinder. The three-jaw chuck can also be used on 

 tire-building stands, there being four chucks to each stand. 

 (.American Pneumatic Chuck Co.; Neidow & Payson Co., 9 

 South Clinton Street, Chicago, Illinois, general sales agents.) 



P. I. W. TIRE-BUILDING STANDS. 



Both of these stands are built alike, with the exception that 

 the ratchet holding the arm in position is operated by a foot- 

 lever on one machine while the other is hand-controlled. 



The spider revolves on a turned shaft, riveted into the arm, 

 and is provided with three adjusting screws capable of accom- 

 modating cores for any size of tire from 28 to 44 inches jn 

 diameter. The ratchet catch on the spider is reversible, enab- 



