Motorized trenching apparatus are widely utilized in a variety of construction industries for formation of deep, wide, and often extensive trenches. Most such trenchers are dedicated vehicular machinery (see, for example, U.S. Pat. No. 4,195,427) or large complex attachments for plows, tractors, loaders and the like (see, for example, U.S. Pat. No. 7,096,609).
In the field, however, various contractors often need only small, narrow trenches created with a minimum of surface/soil disturbance. For example, electrical and telecommunications contractors often need to install small (½ to 3/4  inch) PVC conduits under concrete slabs such as factory, warehouse or store floors and the like. Likewise, plumbers often run small water lines under slabs for waste pipe, supply lines, LP lines, and the like. Usually trenches for such purposes need only be a few inches deep. Larger trenching or digging machinery is thus typically impractical for these installations, and manual trench formation is often made very difficult due to worksite soil compaction (requiring pickaxes and the like to form the trench).
Narrow, shallow but extensive trenching is also utilized by landscape contractors for installation or replacement of sprinkler systems and low voltage landscape lighting. Small trenches can also be utilized by landscaping installers for vinyl edging and erosion cloth installation or replacement. Large trenching units are again typically impractical for use in many such installations (retrofit installations in existing yards and existing installation repair, for example). Heretofore utilized trenchers are not readily maneuverable in small areas and are difficult to utilize when barriers or impediments such as building walls, landscaping and/or fences are near the trench being created. Curved trenches are also difficult for these larger machines to accommodate.
Maintenance of such machinery is involved and extensive, and the ability to perform on-site trenching chain maintenance or replacement is limited by chain size and/or repair tool requirements (the chain being the main wear item in such machinery, maintenance thereof is common). Additionally, the bulk and power of such heretofore known trenching machinery requires trained operators and great care for safe use. The low speed operation of most such machinery means that material removed from the trench is often more difficult to backfill.
Moreover, moving heretofore known trenching machinery from one site to another usually requires trailering, and storage and maintenance of such machinery requires large yard areas, making their maintenance and use impractical for many contractors and/or for smaller jobs. Do-it-yourself and contractor rental facilities would also benefit from smaller and more readily transportable and storable trenching units. Thus, a trencher design for small (narrow and shallow) trench formation that is easy to use and store, and that is readily portable could be utilized.
USPTO Backgrounds
USPTO Backgrounds