The Janney Passenger couplers that were used are the older rotary lock design that was intended to be used with a seperate yoke or draft bolt conected by a vertical pivot pin. They also have a riveted shank so one body casting could be used to make the length coupler dictated by the car design.
The Sharon couplers are a newer gravity lock design that has a short shank that was designed to be riveted directly to the yoke.
The draft gear for Sharon freight couplers, as used in the AC&F built 5500 stock for example, was mounted driectly inside the end beam. The coupler head was located close enough to the centerplate that the coupler and yoke could move enough to keep the pulling force is a relitively straight line.
The draft gear on a passenger car if mounted under the platform would sooner or later tear off the platform or derail the car on curves beacuse of the forces involved. (Think about pulling a trailer around an interstate cloverleaf, when the angle of the trailer gets sharp enough the back of the towing vehicle wants to slide out of the curve.) The solution was to move the draftgear inside the ensill of the body and closer the the centerplate and giving the head a certian amount of swing and a centering device. That way the the couplers can follow the curve and minimise the tearing forces on the end of the car.
The Janny coupler also requires a "buff" gear that is located in the platform it self. the buff gear holds the cars seperated so the couplers tend to remain in a straight line. It also improves the passenger comfort by limiting the slack action on the train. (That is one of the reason C&TS train handling can be a bit rough at times, since now of those cars were equipped with any kind of slack control. A standard type E coupler had 1-2 inches on slack depending on wear. Lets play crack the whip.)
The slack on post WWII passenger car is accomplished bu the type H coupler which has a machined face and knuckle and interlocking portions thatlimit the slack in the coupling to under 1/4" in new couplers. This also makes the two couplers function as a single straight drawbar so no centering device is needed. It does require a longer shank and a horizontal and vertical pivot pin.
I'll stop babbling now. I'd post some better pictures of the new Janneys we had cast but our webmaster is burried with work. There should be one of the head and centering blocks down the page
