Patent ID: 6443239
Filing Date: 2002-09-03
Classification: B25B,B25F

Abstract:
A pneumatic rotary hand tool comprising a housing having an air motor therein, said housing having an inlet passage for flow of air to the motor for driving it, a valve for controlling the flow of air through the inlet passage, said inlet passage having a upstream-facing valve seat, said valve comprising members in the passage upstream of the seat one of which has a stem extending downstream therefrom past the seat, a spring biasing said members in downstream direction to a closed position, said stem extending generally axially in said passage in said closed position of said members, a deflector for the stem operable by one holding the tool for deflecting the stem angularly from said generally axial position to a first angularly deflected position wherein said valve members establish flow of air to the motor at a relatively low rate for low-speed operation thereof and farther to a second farther angularly deflected position wherein said valve members establish flow of air to the motor at a relatively high rate for high-speed operation thereof, said one of said members having upstream and downstream faces, said stem extending downstream from its downstream face generally from the center thereof, a second one of said members comprising a generally annular member positioned between the downstream face of said one member and the valve seat, said annular member having a generally central opening and said stem extending downstream through said opening past the seat, said spring biasing said one member downstream toward said second member and biasing said second member toward said closed position against said seat, said stem having a part thereon spaced downstream of said second member when the stem is in its said generally axial position, said part being movable with the stem as said stem is deflected from its said generally axial position to said first angularly deflected position without moving said second member away from the seat, said one member being angled away from said second member as said stem is deflected from its said generally axial position to said first angularly deflected position for said low-rate flow between said members and through the generally central opening of said second member, said part moving said second member away from said seat on farther deflection of the stem to said second angularly deflected position to establish said relatively high-rate flow past said second member, said part extending radially outwardly from the stem.