Patent ID: 7891101

Claim:
A jamb saw comprising: a saw blade housing including a horizontal roof and a cylindrically shaped side wall structure defining an open bottom, an open front, a closed rear side and partially open laterally opposite sides, said roof having a vertical annular opening, an upstanding bushing having a vertical bore aligned with said vertical annular opening and a vertically extending circumferential gap between circumferentially confronting segments, said bushing having a bottom portion not forming parts of said confronting segments, said bottom portion being rigidly secured to said roof, a vertically adjustable cylindrical shaft housing concentrically positioned in said vertical bore of said bushing, a vertical shaft rotatably mounted coaxially in said cylindrical shaft housing having an upper end adapted for a driving connection to an output shaft of a reversibly attachable hand held power tool and a lower end extending downward into said cylindrical shaft housing, a circular saw blade secured coaxially to said lower end of said shaft, a support roller on said rear side of said saw blade housing, a pair of roller support arms having corresponding inward ends pivotally connected on vertical axes at laterally opposite portions of said blade housing and having corresponding outward ends, a support roller mounted on each of said corresponding outward ends of said roller support arm, a biasing spring interposed between each of said arms and said saw blade housing urging said arms to extend radially outward in relation to said vertical axes, and a threaded tension device connected to said confronting segments of said bushing including a tensioning handle pivotable about a horizontal axis and disposed for gripping by a hand of a person using said jamb saw, said tension device being operable by said lever to control relative vertical movement between said bushing and said cylindrical shaft housing.