December 1. 1920 



THE INDFA RUBBER WORLD 



177 



New Machines and Appliances 



SAFETY DEVICE FOR TOGGLE PRESSES 



TiiGCi.E I'RESSES used for making small rubber molded articles 

 arc continuous running machines, and operate at a certain 

 number of cycles per hour. A dct'uiite time is allowed during 

 each cycle for changing the molds l)etore the platen of the press 

 starts upward. Occasionally an operator does not remove his 

 hand from the platen soon enough, resulting in a severe injury 

 when the platen moves toward the upper head of the press. 



That these conditions can be overcome has been successfully 

 demonstrated by a prominent rubber company who installed the 

 safety device shown in the diagram on all their toggle presses. 

 Production is now limited only by the speed of the operator. 



To eliminate the personal hazard, a magnetic clutch is installed 

 on the driving shaft. One member of the clutch drives the press 

 through a pinion and is bushed on the main driving shaft to 

 which is keyed the other clutch member. Upon disengaging the 

 clutch while the press is operating, the platen comes to rest almost 

 instantly, making it unnecessary to stop the motor and flywheel. 



Connected in each circuit to the clutch are two push button 

 switches and a limit switch of the rotating cam type, the latter 



Sfi B.I.I) 1 lJl,(,I.E PrES.S 



being directly connected to the driven member of the press 

 and makes a complete cycle for each cycle of the press. 

 The push buttons are mounted on the front of the 

 press, convenient to the operator. 



To start the press, the operator puts his hands on 

 the push buttons for a moment or so. This keeps his 

 hands out of danger and at the same time starts the 

 clutch, the circuit for which is maintained by the 

 limit clutch. 



The platen completes the upward stroke, .^s soon 

 as it starts downward the operator removes the mold and inserts 

 another. If his work is completed before the platen starts on the 

 upward stroke he depresses both push buttons for an instant, imtil 

 the switch has time to mainta-n again the circuit for the rlutch. 

 However, should he fail to complete his work before the platen 

 starts the upward stroke, the liinit switch automatically releases 

 the clutch and consequently stops the press. In case he fails to 



keep up with the press, it automatically stops. There is no pos- 

 sibility of the operator becoming caught in the press. Upon fail- 



rO START BOTH BUTTON! 

 MUST Bt ■pRLSit.D 



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ROTflTirtG C«M 

 LiniT SWITCH 



l)i.\c.k,\M OK Connections Between Push Buttons, Limit 

 Switch .^ND Clutch 



ure of power, it also automatically stops and it can be started only 

 by pressing both push buttons. — Cutler-Hammer Manufacturing 

 Co.. Milwaukee, Wisconsin. 



MACHINE FOR SIFTING COMPOUNDING MATERIAJ-S 



Sifting machines have demonstrated their utility in removing 

 trash, specks, or foreign matter from materials used in com- 

 pounding, thereby insuring uniformity in the sifted product. The 

 Kote.x sifter here shown is unicjue in that it operates with a level 

 rotary sieve motion and includes a patented ball cloth cleaning 

 device, making it particularly efficient in sifting fine, soft or sticky 

 materials. 



The sieve box is made lighi in wciglit to avoid excessive 

 vibration and strongly braced to withstand the driving strains. 

 The sieve motion is level and rotary at the head end. elliptical 

 in the center and reciprocating at the extreme tail end. The 

 sieves and also the dust cover frame which holds them in place 

 are readily removed, making the sifter box accessible for clean- 

 ing or changing sieves of different mesh. Each sieve consists of 

 a frame having a sieve cloth on its upper side, a hall supporting 



K- TEX Sifter 



screen nn its lower side and a set of ball cloth cleaners. The 

 balls are confined in pockets below the sifting cloth and being 

 deflected upward by beveled divisions they strike the sieve cloths 

 very lightly l)ut frequently, thereby cleaning the cloths without 

 wearing them. 



These machines are made in .several sizes and capable of mak- 

 ing the necessary ninnber of separations in handling a wide range 



