Classic Refuse Trucks

Paxit Tippers

Dennis Brothers began building motor vehicles in 1904, and has a rich history well beyond the scope of CRT, including the manufacture of specialized vehicles such as refuse collectors, fire appliances, buses, and even lawn mowers.

In the early 1950's, the introduction of the Paxit Major refuse collector, based on their "Pax" commercial chassis, would establish them as one of the premiere builders of compression-type refuse vehicles. The Paxit utilized the "inverted drawer" type compression ram as pioneered by Swiss inventor Jacob Ochsner in the 1930's. The Paxit and other variations of this simple and effective method (including SD and Glover, Webb and Liversidge) were to remain popular in European rear loaders through the early 1970's, and likely influenced the North American half-pack type side loaders which first appeared in the late 1950's.

The earliest Paxit models were "intermittent" type packers, with power being used to compress the load in the hopper as required. Though not the best of images, the illustration at left shows a glimpse of the working end of the early Paxit Major, as equipped with a Harbilt portable bin and lift system.

Early models appear to have incorporated the tailgate mechanism into a top-opening "clamshell" type assembly similar to the old Haller screw-type collectors. A picture of an early fleet of Paxits used by Aylesbury Vale District Council may be seen by clicking here.

The later Paxit II featured a swing-away tailgate, a feature also pioneered by Ochsner in the 1930's. This ingenious design automatically swings the packing mechanism up and out of the way as the body is tipped. In the 1958 version pictured at right, a cable affixed to the frame is acted upon by the rising body, causing the cable to draw the end gate upward on side mounted pivot arms. Rival SD used a set of solid links to achieve the same result with their Pakamatic.

The Ochsner design lent itself particularly well to conversion from intermittent cycling, to continous, automatic cycling of the packer, as used on the Paxit III by the 1960's. With automatic-continuous loaders, the hydraulic control system is designed so that refuse is constantly packed by the mechanism, typically in small increments as the collection crew loads the vehicle. With either version, there is no reload time; the crew may continue to add refuse even as the mechanism operates, providing there is sufficient room in the hopper.

The diagram below illustrates the push & pack Ochsner system as used by Dennis:

(1) Refuse is loaded into hopper (2) Plunger pushes refuse from below, "inverted drawer" shape of plunger prevents refuse from falling behind mechanism (3) Pivoting panel sweeps and packs refuse into body (the SD Pakamatic used a similar method, but excluded upper packer panel and instead forced refuse beneath fixed tines)

The Paxit III (above) competed toe-to-toe with rival SD Pakamtic through the 1960's, and the Paxit series remained one of the UK's best sellers both at home and abroad. The use of light alloys in their construction (to reduce dead weight) also gave these trucks a particularly attractive look, at least when new.

One critical difference with U.S. designs of the period was the hight of the hopper sill (or loading rave), which was approximately 4' 6" on the Paxit. One reason often given for the relatively high sill was that it was advantageous to collectors who typically carried barrels at a relatively high height. However, the physical layout of the mechanism, with its rearward mounted packer box required the high rave height, without which the hopper would probably be far too shallow. Folding steps provided additional lift for the loaders as required.

The Paxit was available with a host of bin-lift configurations including a Dennis-patented device for the "Paladin" type barrels (shown at right) once popular with businesses and multiple dwellings.

6/4/05