 
SM-3 Sanivan (1945-1950) 
The model SM-3 Sanivan is one of the great unsung pioneers in refuse truck design, and appears to be the first commercially successful refuse truck from Sicard. Ronaldo Boissonnault of Montreal filed the patent in 1945, which was assigned to Arthur Sicard. Production likely began that year or shortly thereafter, and the SM-3 was advertised in the 1946-47 Municipal Index. Boissonnault improved greatly on Sicard's unloading method by adding hydraulic power directly to the moveable barrier within the body, thus making the SM-3 the first rear loader with direct hydraulic ejection, more than a decade before this feature appeared on a competitive rear loader !
The "Yard-by-Yard", pre-compaction system of the SM-3 was another departure from the 1943 Irenne Sicard refuse truck. 
SM-3 Packing Cycle Loading Position Cutaway drawing sequence shows packing panels, with hydraulics omitted for clarity. The SS3 utilized twin pivoting panels with a "pre-crushing" action taking place in the tailgate. Packing panel A is shown here in the full open position, ready to receive refuse in the hopper B. Retainer panel C is fully lowered, forming a barrier between hopper and previously compacted load. Unlike the Gar Wood Load-Packer, there was no "loading level" in the hopper B; It could be loaded until no more refuse would fit. First Stage Operator commences cycle by pulling and holding a control lever for packing panel A, causing rotation through the hopper. As the hopper is swept, the load is "pre-crushed" against the rear face of retainer panel C. When maximum pressure is achieved, the packing panel stops and the lever is then released. A hydraulic oil pressure gauge was also provided, which would cue the operator that a particular panel had reached it's respective limit. Second Stage Operator next pulls lever controlling retainer panel C, which raises the panel and opens the passageway from the hopper to the storage body. The packing panel A is then further actuated, pushing the pre-crushed load into storage body until it reaches it's maximum travel limit. Lever is released, which stops packing panel in this position. Final Stage Operator reverses retainer panel C, thereby closing off passageway and scraping the forward face of packing panel A. Compacted load is now retained in body, and packing panel may be reversed through hopper to the loading postion. 
SM-3 Packing Cylinder Location Cutaway drawing shows location of key features. Packing panel cylinders, mounted outside of hopper sidewalls are normally concealed by protective covers. 1 Packing Panel 2 Packing Panel Cylinder 3 Packing Panel Sector and 4 Gear 5 Retainer Panel Cylinder and 6 Bellcrank 7 Tailgate Clamp and Lever 8 Packer Control Levers 
11/6/04 © 2004 Eric Voytko All rights reserved Photos from factory brochures/advertisements except as noted Logos shown are the trademarks of respective manufacturers |