September 1. 1916] 



THE INDIA RUBBER WORLD 



659 



New Machines and Appliances. 



A UODERN GRINDER AMD MIXER. 



LARGER ami better machines are now being designed and con- 

 structed by rubber machinery manufacturers to keep pace 

 with the steadily increasing requirements of the rubber in- 

 dustry. Tlie accompanying illustration shows a modern type of 

 mill now being manufactured for the grinding and mi.xing of rub- 

 ber and is particularly adapted to handling tire stocks. The bed- 

 plate is heavy and sul)stantial, having twelve foundation bolts 

 with the necessary plates, and is provided with two solid pedestals 

 that arc lined with babbitt metal and arranged for grease lubri- 

 cation. 



The housings and cai)s are made of semi-steel, of a rugged 

 design for heavy duty, and the journal boxes which are also of 

 heavy construction are provided with wide seats on the housings. 

 Full bronze liners of special bearing bronze are fitted in the 

 boxes, and arranged for direct water cooling circulation. 



The rolls are not equal in diameter, one being 22 inches and 

 the other 26 inches, while the length of both is (54 inches. They 

 are made of chilled iron, the journals gfround true, and bronze 

 stuffing boxes with distributing pipes are furnished for con- 

 trolling the temperature. The adjusting screws and nuts are of 

 steel, easily removable at all times and provided with a locking 

 device. Breaking cups for overloads are placed ))etween the 

 screws and boxes, and automatic cast-iron guides, compensating 

 for the opening of the rolls, are mounted on the journal boxes. 

 A bronze sight feed oiler and an accessible grease pocket 

 are provided for each journal for the purpose of lubrication. 



The shafting is of hammered steel turned true and smooth. 

 Roth drive gear and pinion have cut spur teeth, the gear being 

 made of semi-steel in one piece ; the steel pinion is made in 

 halves with machined joint, and heavy holding bolts. 



The connecting gears are of steel, and liave cast spur teeth 

 with sta«i;ercrl face Tlie ci .niu-ctinii 'jiars nitrate in .i deep 



been made to remedy the trouble, 

 objection to the use of herringbone 



slush pan of cast iron and ait riKl.i-til li\ a luavy sheet steel 

 cover provided with hand holes for inspection. A balanced bar 

 with throw-out switcli provides means for instantly stopping 

 the mill in case of an emergency. | I'arrcl l-"nundry & >tachinc 

 Co.. Ansonia, Connecticut.] 



EXTENSIBLE COUPLING FOR MILL DRIVES 



All users of herringbone gears are familiar with the bad ef- 

 fect of end thrust, or any constraint which does not leave the 

 gears perfectly free to align themselves. The resulting noise, 

 vibration and wear arc very objectionable, especially in the 

 case of rubber calender rolls where a very smooth action is de- 



sired. Many efforts hav 

 which has always been a 

 gears. 



The use oi any fixed end thrust causes too much constraint, 

 and the lack of it allows the lateral motion due to the drift of 

 the motor armature or any other external forces acting on the 

 shaft to be transmitted directly to the pinion, with the disagree- 

 able results before mentioned. Flexible couplings have been, 



and are being, widely used with the idea of relieving the gears 

 from these end thrusts and some form of connection between 

 the motor and herringbone pinion was desired which would 

 (1) transmit the necessary power; (2) leave the pinion free to 

 align itself with the gear, and (3) leave the pinion unaffected 

 by any end thrust, caused by lateral motion of the shaft. 



Such a coupling has been recently designed, and is here shown, 

 in connection with the well-known magnetic safety clutch which 

 has been in use on calender rolls for some time. 



The mechanical construction of the coupling is very simple. 

 the principal object being to make the disks D strong enough 

 to transmit the torque, and at the same time secure the utmost 

 ilexibility. It may easily be seen that the amount of torque 

 transmitted is only dependent on the thickness of the disks, and 

 tlic size of the bolts. The extensibility is only dependent on thi 

 Ilexibility of the disks, and is absolutely independent of the 

 amount of torque transmitted, in that it is the same when n 

 Ii'ad is being transmitted as when the load is maximum. 



In order to secure the utmost extensibility the disks are 

 laminated, each disk consisting of several thin disks bolted to- 

 gether. The deflection of a thin circular plate under a given 

 load varies inversely as the cube of the thickness. Three J^-inch 

 ili-ks will transmit the same torque as one ^-inch disk, but the 

 three thin disks will deflect nine times as easily as the one thick 

 disk. Piactice has demonstrated the correctness of this theor\ 

 and in the case of a 32-incli coupling recently built, the iorc 

 necessary to cause a deflection of a large part of an inch, wa- 

 much less than the end sliding friction in the bearings. 



While this coupling has only been applied to rubber calender 

 work, where it has met instant approval, it is not limited to this 

 field, and may be applied in any case where a truly extensible 

 coupling is desired. [The Cutler-Hammer Clutch Co., Milwau- 

 kee. Wisconsin.] 



PORTABLE MOTOR DRIVEN ALLIGATOR SHEARS. 



.Mligator shears are indispensable to the rubber scrap and re- 

 claiming industries ; moreover, the great variety of refractory 

 material to be cut generally requires a heavily constructed and 

 powerful shear. The illustration and description of the lighter 

 portable type that follows are offered as a suggestion for doubt- 



