280 PC PASSENGER-BRAKE EQUIPMENT 



the emergency cylinder operates during an emergency applica- 

 tion, but does not operate during a service application. Thus, 

 in emergency applications, the maximum service braking power 

 is doubled not by increased brake-cylinder pressure, as in the 

 other equipments, but by the use of the second cylinder. 

 Each cylinder is provided with a slack adjuster, and both 

 adjusters are connected to the slack-adjuster hole in the serv- 

 ice-brake cylinder; thus, they will operate simultaneously and 

 take up the slack evenly in the two brake cylinders and in 

 accordance with the requirements of the service cylinder. 



Two reservoirs are used with this equipment. The service 

 reservoir supplies air to the service-brake cylinder; the emer- 

 gency reservoir supplies air to the emergency cylinder during 

 emergency applications; also, in service operations, it furnishes 

 the air used in obtaining graduated release and quick recnarge 

 of the equipment. A third reservoir, forming part of the con- 

 trol valve, has three chambers called the pressure chamber, the 

 application chamber, and the reduction-limiting chamber. 



NO. 3-E PASSENGER CONTROL VALVE 



The No. 3-E passenger control valve, superseding the No. 

 3-D control valve, is standard for and regularly furnished with 

 PC (two-cylinder) schedules for very heavy passenger cars; i. e., 

 PC-2-12, PC-2-14, PC-2-16, and PC-2-18. In Fig. 1 (a) is 

 shown the release portion of this valve and in (fe), the applica- 

 tion portion; the equalizing portion is shown in Fig. 2 and 

 the emergency and quick-action portion in Fig. 3. The piece 

 number of the control valve, complete, is 37,896. The piece 

 and reference numbers of the various parts are given in the 

 accompanying list. 



PC. No.Ref. No. Name of Part 



32,873 Equalizing portion, complete. 



32,143 Application portion, complete. 



36,435 Emergency portion, complete. 



35,598 Quick-action portion, complete. 



37,849 2 Equalizing body, complete, includes one 



each of 19 and 37. 



36,420 3 Release piston, complete, includes one of 9. 

 37,042 4 Release-slide valve. 



