Document VGLaNkEYLd8NXmeEG3Yj5ae28

6 As early as 1937 Caterpillar was conducting research work to identify operating characteristics of all known types of brake lining material. It, is a. necessity that Caterpillar provide its customers with the best performing and safest brakes pos sible. So far, a material superior to asbestos-type that fulfills all the requirements needed for the heavy-duty brakes required on earthmoving equipment has not been found. TO'nbUI-TIMK DIAGRAM FOR TWO DIFFERENT FRICTION MATIRIALS TORQUE CURVE B M .i BEGIN SLIP TIME END FIGURE NO. 2 TORQUE CURVES OF FRICTION MATERIALS Figure No. 2 i3 a strip chart recording of the torque-time re lationship for two different friction materials. These two traces illustrate the frictional behaviour throughout a brake application. In curve A, note the smooth deceleration or brak ing as the wheel speed is reduced to zero, from beginning to end of stop. This is one of the characteristics we expect from asbestos-type material. On the other hand, curve B of a non asbestos friction material shows undesirable speed change conditions. The trace exhibits considerable frictional vibration. This results CAT-1007371 015