I. Field of the Invention
The present invention pertains to machines for collecting, reducing, compacting and removing wooden materials, and more particularly to drum chippers and shredders.
II. Description of the Background
Urban removal of wood and debris at the curbside is presently accomplished using a number of labor intensive or environmentally unfriendly methods. These methods include burning, bundling at curbside with rope or twine, and collection by city crews using portable shredders.
Burning, although less used today than years past, results in smoke and pollutants being discharged into the air. This method is particularly a problem during days of high pressure which forces smoke to hover at low altitudes and create a nuisance. As a result, burning has been banned by law in many communities.
Most urban collection of wood is currently done by bundling twigs and branches with rope or twine and setting then at the curbside for collection. The bundles are collected by crews, placed in trucks and transported to land fills or compost piles for disposal. One problem with bundling is that compliance with proper collection rules is low. Compliance problems typically arise when people bundle branches in excess of the size or weight designated by collection crews. Problems can also arise when people fail to properly tie the bundles. Bundles that fail to comply with collection rules are typically left at the curbside by collection crews and may sit for weeks thereby becoming an eye sore and a road hazard.
Another method of removing wood debris is with portable high-speed shredders. To remove curbside debris, crews hand-feed branches into a shredder. The hand-fed branches are quickly reduced and blown into the back of a truck, often with the aid of a high-powered blower system. Although this method is fairly effective at reducing wood debris, the method fails in many other respects. First, the method provides an inefficient use of labor, as it requires multiple crewmembers to drive the truck and handle the branches. Secondly, present day chippers and shredders generate large amounts of noise pollution. Excessive noise pollution arises from both the high speed cutting implements and from the high power blower systems. Noise pollution also arises from high speed impacting of the cutting implements upon the material being shredded.
Present day shredders also are very dangerous. When branches are hand fed into rotating high-speed blades, the blades quickly grab and pull the branches. If an operator fails to pay close attention to the job at hand, the operator can be pulled into the shredder and severely injured. Another hazard arises from flying debris. Flying debris occurs from splintered wood being ejected back towards the operator from the high-speed cutting blades. Because of the dangers involved in using high-speed portable shredders, the inefficient use of labor, and the excessive noise pollution generated, methods of urban wood removal are in need of improvement. Furthermore, by improving the reducing efficiency of present day drum shredders, smaller engines can be used to accomplish the same job that used to take larger, less fuel-efficient machines. Therefore, there exists a need for a more efficient drum shredder.