Classic Refuse Trucks SMV /SITA PLUS

SMV / SITA PLUS (SITA Matériel de Voirie)

By the early 1980s, SITA had introduced a modern slide-sweep loader that combined elements of the Leach 2-R, The Heil Mark IV/Mark V and the Gar Wood LP-900. This unusual packer is known as the Sita Plus, or the SMV (SITA Matériel de Voirie), which appears to have been the new name for the truck equipment manufacturing division. This name change may reflect the fact that Sita was becoming one of Europe's leading waste haulers, and their management may have concluded that the Sita name would be an impediment to commercial sales of the new body, since many potential customers for the Sita Plus packer would be their rivals in the collection business. The acronym SMV is more of a neutral designation.

The Sita Plus seems quite conventional at a distance, but a look inside the packer mechanism reveals some interesting features:

First drawing shows packer in 'home' position, ready for loading. The slide and sweep panels (red highlights) are connected together at hinge C and sweep rams (yellow highlights) are located inside the body, with lower ends connected to sweep panel arms at B, and upper ends anchored atop the slide panel.

The shaft at B extends outwardly and passes through a roller, guided by the curved tracks, terminating in stubs just outside the hopper walls to which the slide cylinders (not shown) are also connected. Top of slide panel is guided by rollers at A

Start of Cycle: The sweep rams (yellow highlights) retract and sweep panel opens over load. Note how pivot point B is held captive within the curved roller tracks. Thus, as sweep panel opens, lower edge of slide panel swings out slightly at hinge point C.

Compare with other slide-sweep rear loaders, where it is hinge point C that is carried in the tracks

Packer cylinders (not shown) then begin extending, lowering the sweep panel, which is supported by rollers A and B

Slide cylinders (green highlights) are now fully extended. Note how slide panel is nearly vertical at this phase in the packing cycle.

The slide cylinders are located outside of the hopper sidewalls. The piston ends are connected at the top of the tailgate, while the rod ends are clamped to the stub shafts extending through the tracks at B

Sweep cylinders now extend, and refuse is swept from the hopper as slide panel is forced inward slightly. Slide cylinders then retract, packing load into the body.

The articulated slide panel movement is unique, found only on the SITA Plus and the Heil Mark IV/Mark V

This packer is currently produced in France by CTI, in Spain by SITA S.A. (where it is sold as the Sita Plus) and also by Zenith Engineering in Singapore. Sita currently concentrates its business in water and waste management. They provide waste collection services for 50 million people, with 430,000 commercial customers.

Detail of external slide plate cylinder and curved roller track

Version built by Zenith Engineering, Singapore

The current French-built version by CTI

SELECTED PATENTS

Patent #	Description	Inventor	Assignee	Date
US4551055	Apparatus for charging solids under compression into a receptacle	Demenais	SITA	July 23, 1982

7/4/11