1. Field of the Invention
The present invention pertains generally to power masonry tools and related devices for cutting and grinding. More specifically, the present invention relates to portable type power saws driven by an internal combustion engine or electric motor and having dust abatement while cutting cinder block, concrete, brick, clay, stone, tile, and the like.
2. Description of the Prior Art
Circular saws using a rotating circular saw blade have been known for some time. Early versions include those employed by saw mills to make lumber. Hand-held circular saws have also been known for many decades that were first used mainly in woodworking applications. Improvements to saw blade design and material have lead to expanded applications for portable saws including masonry, plastic and even metal. Many such saws are currently powered by electric motors; however internal combustion motors may also be employed.
Also known, is a problem of uncontrolled release of and exposure to airborne dust and particulate matter resulting from cutting a workpiece. Accordingly, government agencies such as OSHA have promulgated safety and health requirements for wet and dry cutting. The California Occupational Safety and Health Act of 1973 requires employers to provide a safe and healthful work place and gives Cal/OSHA regulatory jurisdiction over all public and private employers in California. Henceforth, employers must be compliant with all regulations set forth in Title 8 of The California Code of Regulations. In addition to health issues, the dust by-products present a clean-up challenge, even if all individuals in a contained environment have donned respirators.
Development of wet cutting devices and methods is one solution to dust abatement. In doing so, water is applied at a blade cutting edge where dust is entrained to a fluid and directed to a holding area. While most wet cutting methods work relatively well, they create additional problems of waste water pollution and environmental concerns. Further, the slurry created will adhere to cutting tool materials and components that also require periodic cleaning.
Many prior art solutions have been proposed that specifically employ dry means to control dust in a portable hand-held saw. Two examples proposed by Yamami et al., U.S. Pat. Nos. 6,047,693 and 6,155,246, entitled “Dust Collector-Equipped Power Cutter,” and “Power Cutter,” both assigned to the Kioritz Corporation, describe a portable power saw having a vacuum fan for removing dust. More specifically, a conventional portable power saw includes a main body having a motor, a circular cutting blade with a safety cover surrounding upper and lower portions of the blade. The safety cover further provides a passageway for dust removal. One problem with these and other numerous examples is that an external bag is required to collect dust that reduces the portability of the apparatus. Another problem in the prior art is that dusty air is sucked through the fan continually that increases wear on the moving components. Another feature missing in the prior art is a design having a retractable shroud for maintaining proper alignment while moving along a stationary work piece.
In light of the above, it is an object of the present invention to provide a Power Saw Apparatus with Integrated Dust Collector that is highly portable and lighter in weight as compared prior art solutions. More specifically, it is an object of the present invention to provide a power saw that integrates dust collection to a single portable unit. It is still a further object of the present invention to provide a dry dust collection design that is easily maintained as dust accumulates. It is additionally an object of the present invention to more efficiently control dust by implementing a filter to a hand-held power saw design. It is further an object of the present invention to provide a retractable blade guard providing more flexibility while moving along a work piece. It is still further an object of the present invention to provide a design that includes a variety of innovative features over prior designs.