530 



THE INDIA RUBBER WORLD 



[July 1, 1916. 



Automatic Control of Time, Temperature and Exhaust in Tire 



Vulcanizers. 



PERFECT vulcanization is the final achievement in the many valve, through passage F, is increased, and the consequent clos- 



important steps that are necessary in making automobile ing movement of the steam valve checks the excess steam. The 



tires. A uniform curing temperature is vitally essential in opposite eflfect occurs, of course, when the temperature tends to 



the production of a guaranteed product. Dependence on the diminish and more steam is needed, 



carefulness and experience of an operator invariably challenges '^' ^ -•"- -°^~-' 



the well-known fallibility of human skill, and an automatic con- 

 trol that neither forgets nor becomes tired and careless is 

 incomparable. 



Such devices are doubtless well known m general to the trade ; 

 however, the following description of the principle and methods 

 of operating that are 

 characteristic of the Tag- 

 liabue system will be of 

 undoubted interest. The 

 operating principle of 

 these controllers is em- 

 bodied in the primary 

 parts that are described 

 in the following text and 

 illustrated in Figure 1 : A 

 capsular spring which ex- 

 pands and contracts in 

 direct ratio with the tem- 

 perature tendency within 

 apparatus to which con- 

 troller is attached; a 

 transmitting lever for 

 multiplying and transmit- 

 ting this movement; a 

 ball valve which is oper- 

 ated by the transmitting 

 lever and which allows 

 more or less air pressure 

 to open or close the steam 

 valve to a greater or 

 lesser extent; air inlet 

 and outlet connections for 

 the air pressure which 

 does the actual work of 

 regulating the steam valve. 

 The capsular spring A 

 is a phosphor bronze shell 

 with a flexible top that 

 when a temperature con- 

 troller is involved is connected by flexible tubing with a ther- 

 mostatic bulb, partly filled with ether. When the bulb tempera- 

 ture varies, the pressure of the vapor above the ether varies in 

 accordance and moves the top of A in response to the merest 

 tendency toward a change at the bulb. In the case of a pressure 

 controller the capsular spring is directly connected to the con- 

 trolled steam pressure. 



The transmitting lever B is provided with an adjusting screw 

 at the point where it contacts with the capsular spring. Ad- 

 vancing or withdrawing this screw, in connection with a dial and 

 pointer arrangement, provides an ideal adjustment for higher 

 or lower temperature maintenance. 



The ball valve is extremely simple; it is sensitive and positive 

 because frictionless and self-cleansing. When the temperature 

 tends to go too high the consequent slight expansion of the 

 capsular spring A and the resulting movement of the transmit- 

 ting lever B allow the valve stem D to move upward. This 

 increases the opening for the incoming air, which enters through 

 G, and restricts the opening for the air which escapes past the 

 pin D. Thus the air pressure on the diaphragm-motor steam 



isequent change 



-/g) Transmitting lever, which multiplies 

 ^~^ aq well as transmits the move- 

 e flexible top of the 

 capsular spring A, 



:rew, for temperature 

 ing, as determined by extent 

 to which this screw projects — 

 through lever B. 



valve pin which floats in a cur- 



nt of air as it follows the move- 



f the transmitting lever B. 



Figure 1. The .Principle of the 

 TAGLiABtm System. 



The compressed air affords an instant, flexible and powerful 



means for doing any amount of work required, especially when 



the steam temperature shows a mere tendency to change and 



when, therefore, the capsular spring moves only an infinitesimal 



extent. 



The actual operation of the Tagliabue control system applied 



to a tire press is briefly 



as follows, with reference, 



however, to Figure 2: 



Figure 2 shows a tire 

 vulcanizing press to which 

 the following Tagliabue 

 units are applied. The first 

 is a compound controller 

 which consists of two con- 

 trollers housed in one 

 case. One of these con- 

 trollers maintains a uni- 

 form steam temperature 

 within the press, while the 

 other portion of the con- 

 troller takes care of the 

 exhausting or venting at 

 the bottom of the press by 

 periodically and frequent- 

 ly relieving the heater, not 

 only of the water con- 

 densation, but of the su- 

 persaturated steam also. 

 Another controlling unit 

 is the automatic time 

 controller which, after the 

 vulcanizing period is at an 

 end, automatically shuts 

 off the steam supply and 

 opens the exhaust wide. 

 This can also be arranged 

 to turn on cold water for 

 ^_motor_stj;am_vaive. _ _ ^__ , ^ ._ flooding and cooling the 

 contents of the press when 

 desired At the same time this controller rings a bell, or other- 

 wise signals the operator, that he may know the heater is 

 blowing off and be ready to open and re-charge it with the least 

 waste of time. Another unit is the recording thermometer, 

 which gives a graphic record of just what the controllers have 

 accomplished in the way of uniform temperature maintenance, 

 the final units being the mercurial thermometers, which serve as 

 a check on the recorder. 



Assuming now that the operator has charged the heater and 

 is ready to start the cure, he first steps up to his time con- 

 troller and by means of the setting key turns the hand clockwise 

 from the starting point to the exact time period required for the 

 cure. Then he opens the hand valve which is between the steam 

 supply source and diaphragm motor valve B, shown in the "Side 

 View Showing Arrangement of By-pass." Steam now enters 

 the heater and the hand of the time controller K will commence 

 to travel backward, or counter-clockwise. At the start dia- 

 phragm-motor valve B will be wide open, but will gradually 

 close as the temperature builds up within the heater until finally 

 it will assume the exact throttling position required to maintain 



top 



outlet for this auxil- 



'hich does the actual 



ng the diaphragm- 

 valve. 



pressed air at 15 

 pounds per square inch pressure, 

 only a nominal amount of which 

 is needed. 



bushing which not only 



ides valve-pin D, but also ai- 



passage for relief of air 



on top of diaphragm- 



