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Adapted Humphrey Valve Solves Truck Trailer Problem

January 19, 2015 | written by twg

Truck trailers have a mechanical device called a “slider,” which allows the operator to manually adjust the position of the axles and suspension to balance the trailer, or shorten its turning radius for tight maneuvering. To change the position, the driver must pull the actuation rod, which retracts the locking pins, move the truck, and then re-engage the pins in the new position.

Unlike mechanical linkage that often takes great strength to operate, the pneumatic system requires very little force. Using truck system air fed through a Humphrey P5014D valve to an air cylinder, the operator can easily retract and re-engage the locking pins in seconds.

To eliminate the possibility of air building up in the cylinder and causing the pins to retract, Humphrey designed the valve with a larger exhaust orifice, so any pressure bypassing the inlet will always vent to the atmosphere. Instead ofa separate in-lineair system filter, Humphrey incorporated the filter into the valvebody. This helped lower the total system cost. In addition, using a die cast body eliminated the need for expensive machining of bar stock. And the quantities ordered enabled Humphrey to achieve the exact cost target.

After studying the market, a major manufacturer of suspension systems for truck trailers saw an opportunity to introduce a new, pneumatically operated suspension lock pin retraction system that would take almost no effort to operate. This would make the new system very attractive to companies looking for ways to reduce their potential worker compensation claims, especially among women and older male drivers.

The system for both O.E.M.’s and the aftermarket had to meet an exact cost target, but standard components either didn’t fit the allowable space, didn’t provide the required features or cost too much.

Then the manufacturer contacted Humphrey,and the Engineered Solutions team established the engineer-to-engineer process necessary to arrive at the optimal custom pneumatic solution. Since the most expensive part of a valve assembly is the extensive machining needed to create the ports and passages,

Humphrey suggested a custom die cast body incorporating the proven, reliable Humphrey diaphragm valve principle. This allowed Humphrey to deliver the assembled valve with all the desired features at the target cost.