Packmaster Container System
A rare shot of the 25 cubic yard version of second generation Packmaster
1955 was breakthrough year for the detachable container, with new front loader designs from Dempster and Towner feeding modern packer trucks. In cooperation with a Chicago area hauler named Harold Vandermolen, Leach designed an economical method to adapt detachable containers to be serviced by the new Packmaster. The genius of the Leach system was that it required only the simplest of modifications to the tailgate, and no independent lift mechanism; the Packmaster blade would do all of the lifting.
Receiver slots and clamps were affixed to the sides of the hopper opening, to mate with a trunnion welded to the front of the container boxes. A riser plate was added to increase the height of the hopper sill to match that of the one cubic yard Leach wheeled containers. A pair of cables, or chains, which were affixed to the packer blade, were then hooked to the sides of the container to raise and empty the contents. The images below will better illustrate the procedure:
The container is wheeled in place in the receivers, and clamped in place to prevent it falling off the tailgate. Workers then take the ends of cables (attached to packer blade) and hook them on the handles on either side of the container. Note how the packer blade is stopped at its low point in the hopper:
Next, the packer blade is started from mid-cycle, and begins to travel up into the body. As it packs the previous load, the cables begin lifting the container up to dump the contents into the hopper, which is being cleared by the ascending packer blade:
As the packer blade stops at the end of the cycle, reaching the 'home' position, the container is now almost fully inverted. Note how the sill riser plate prevents refuse falling out on to the street. To complete the process, the packer is started again, and as the blade descends over the newly loaded refuse, the cables begin to lower the container, which returns to the ground at the mid point of the cycle. The blade is stopped here, and the cables removed:
After unhooking the container, the crew would simply leave the blade in the lowered position if another container was to be emptied. Or, the packer cycle could be restarted and completed for normal hand loading of the hopper. This was the beauty of the Leach system; one truck could effortlessly switch from containers to hand loading all day long.
For hand loading, the sill riser could be easily folded down to provide a lowered sill height. However, some users actually preferred leaving the sill riser up, to increase the fillable height of the hopper and thus increase the time between packing cycles. Though overfilling the hopper was not officially sanctioned by Leach, it was a somewhat common practice, as demonstrated by this St. Petersburg, Florida crew:
Leach Packmasters, with their spacious hoppers were often used as 'mother' trucks to receive refuse from satellite vehicles, as with the scooter system from Cushman Motors shown here
© 2009 Eric Voytko
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Photos from factory brochures/advertisements except as noted
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