December 1, 1912.] 



THE INDIA RUBBER WORLD 



135 



A MODEL CALENDER ROOM. 



By Morris .1. Pearson. 



IN preparing this article on this important subject, the writer 

 *■ has dealt solely with the mechanical side of the question. 

 During the past ten years, he has had an excellent opportunity to 

 study the mechanical details of a great majority of the important 

 installations in this country, and has incorporated in this article 

 the most desirable features, as well as a few new ideas. 



The general layout of the room, as shown, is practically the 

 same as one recently installed by a large rubber factory in the 

 Middle West, though it differs materially in many details. The 

 various mechanical features, however, are applicable to almost 

 any sized installation. 



The room is 75 feet wide by ISO feet long, with a IJ^-inch maple 

 floor laid on concrete. On either side of the room is located a 

 line of six mills with rolls 20-inch diameter by 60-inch face. Each 

 line is driven by a 300 horsepower motor, with reducing gear, 

 located midway between the mills, there being three on each side 

 of the drive. Located between the mill lines, are twelve 3-roll 

 calenders, with rolls 24-inch diameter by 66-inch face, and 

 equipped with individual motor drives. A central passageway, 

 8 feet wide, e.\tends the whole length of the room. 



MILL LINE DETAILS. 



The original drive for the mill line consisted of a motor, directly 

 connected with the line shaft, running at about 100 r. p. m. The 

 size of the motor, to give the power required at this slow motor 

 speed, necessitated a pit in the floor about 17 feet by 14 feet 

 by 3J4 feet deep. 



The drive shown here is one of recent design and has the 

 motor located directly over the line shaft, where it is easily 

 accessible. The power is transmitted from the motor to the line 



The motor is connected with the reducing gear by a magnetic 

 coupling, providing for a safety stop, which is absolutely in- 

 stantaneous and which can be operated by hand or foot trips 

 from any mill on the line. A magnetic brake, used in connection 

 with this coupling, is automatically applied when the coupling is 

 cut off. The power required for energizing a 300 horsepower 

 magnetic coupling is only 2 amperes at 120 volts, and for the 

 brake 1.75 amperes at 120 volts— both continuously. It will thus 

 be seen that the operating cost is comparatively nothing. 



.Ml line shafting is 6}^-inch diameter, providing for duplicate 

 pinions and bearings throughout. It is located high enough to 

 allow everything connected with the mill line to clear the floor. 



MILL DETAILS. 



The mill housings are of cast iron, with caps of O. H. cast 

 steel, giving the greatest strength possible to both frame and cap 

 at the joint where they are fitted. This style of construction 

 appears to be preferable mechanically to the present method, 

 where the cap is made of cast iron and separate bars of steel are 

 fitted between the frame and cap to secure the same results. The 

 adjusting screw nut is so held in the housing that both the nut 

 and screw can be removed from the frame at a moment's notice, 

 without disturbing any other part of the mill. The rolls are of 

 chilled iron, turned smooth and fitted with steam connections of 

 the improved type, where the inlet pipe is located exactly on the 

 center of the roll. 



The roll bearings are full brass-lined and are interchangeable 

 throughout. They are designed to carry automatic guides, which 

 allow for the greatest possible working space on the rolls. 



Special attention has been given to the gearing, the involute 

 shape of tooth being used throughout. The drive pinion is split 

 and flanged on the outer side only, so that it may be drawn out 

 of mesh from the drive gear when it is desired to "cut a mill 



Plan of a Model Calender Room. 



shaft by cut double helical gears enclosed in oil-tight casings. 

 Automatic lubrication is provided by means of an oil pump, 

 connected with the lower part of the casing, which delivers the 

 oil to the gears directly at the point where needed. Gearing of 

 the cut double helical type is far superior to spur gearing, in that 

 it allows a more compact design and reduces vibration, wear and 

 noise to a minimum. The only part of the drive to extend below 

 the floor is the lower part of the gear casing. 



out." The connecting gears are of ample pitch, with no flanges, 

 both being of O. H. cast steel. The large pitch and involute 

 shape of tooth result in satisfactory service on a large range of 

 centers, which fact will be found to be a distinct advantage as 

 the rolls wear down. Both connecting and drive gears are fitted 

 with slush-pans and gear-guards of convenient design. 



The speed of the back roll is 24 r. p. m. and the front roll 

 16 r. p. m., giving a friction of IJ^ to 1. 



