Radial arm saw control mechanism

Saw control mechanism for a radial arm saw assembly of the type provided with an upwardly extending support post, an elongate arm supported by the post, a saw unit supported upon the elongate arm and movable along the arm, comprising a base member, attachment means attaching the base member to the post for support by the post, a housing attached to the base member for support of the housing by the base member, the housing being provided with an elongate cavity, the cavity being adapted to contain fluid, the cavity having a first portion and a second portion, the housing also having a passage adjacent the cavity and in fluid communication with the first portion of the cavity and the second portion of the cavity, an orifice joining the first portion of the cavity to the passage, a valve adjustable within the orifice for adjustably controlling the rate of flow of fluid from the first portion of the cavity to the passage, a piston within the cavity and axially movable within the cavity, a piston rod attached to the piston and axially movable with the piston, the piston rod extending from the cavity and including a threaded portion, a wheel rotatably supported by the base member, a threaded member attached to the wheel, the threaded member being in threaded meshed engagement with the threaded portion of the piston rod, a cable wound upon the wheel and extending therefrom, means attaching the cable to the saw unit, whereby movement of the saw unit in a direction from the post forces movement of the cable as the cable partially unwinds from the wheel and forces rotation of the wheel, whereby rotation of the wheel forces rotation of the threaded member, whereby rotation of the threaded member forces axial movement of the threaded portion of the piston rod and axial movement of the piston rod and axial movement of the piston, axial movement of the piston forcing movement of fluid in the cavity and forcing flow of fluid from the first portion of the cavity through the orifice and into the passage, the valve controlling the rate of flow of fluid from the cavity and thus controlling the rate of movement of the piston and thus controlling the rate of rotation of the wheel and thus controlling the rate of travel of the cable and thus controlling the rate of travel of the saw unit upon the arm.

Saw movement control mechanism for a radial arm saw assembly of the type provided with a substantially vertical post, a substantially horizontal arm supported by the post and extending therefrom, the arm being angularly movable about the vertical axis of the post, a saw unit supported by the arm and movable along the arm, comprising a base member, connection means attaching the base member to the post for pivotal movement of the base member upon the post, a housing attached to the base member for support of the housing by the base member, the housing having a cavity provided with a first portion and a second portion, there being a first port at the first portion of the cavity, there being a second port at the second portion of the cavity, a piston within the cavity and movable between the first portion of the cavity and the second portion of the cavity, a resilient member engaging the piston and urging movement thereof toward the first portion of the cavity, a conduit extending between the first portion and the second portion of the cavity and in communication therewith, the cavity and the conduit being adapted to contain fluid, the ports providing fluid communication between the cavity and the conduit, a piston rod attached to the piston and extending from the cavity, the piston rod including a threaded section exterior of the cavity, a wheel rotatably supported by the base member, a shaft having a hollow portion, the shaft being attached to the wheel, the hollow portion of the shaft having internal threads, the threaded section of the piston rod being within the hollow portion of the shaft and in meshed engagement with the internal threads of the hollow portion of the shaft, a coil spring encompassing the shaft and urging rotative movement of the shaft and the wheel, a cable having a portion wound upon the wheel and a portion extending from the wheel, the cable having an attachment portion attachable to the saw unit, the saw unit being movable upon the arm in a direction away from the post, movement of the saw unit in a direction from the post forcing movement of portions of the cable from the wheel and forcing rotative movement of the wheel, whereby the shaft is rotated, and the piston rod and the piston are moved axially in a direction from the first portion of the cavity and toward the second portion of the cavity, whereby fluid is forced through the second port and into the conduit, whereby the rate of travel of the piston is controlled by the volumetric rate of flow of the fluid from the cavity and through the second port, the rate of rotation of the wheel thus being controlled by the volumetric rate of flow of the fluid from the cavity through the second port, the rate of travel of portions of the cable and the saw unit thus being controlled by the volumetric rate of flow of the fluid from the cavity and through the second port.

Saw movement control mechanism for a radial arm saw assembly of the type having an elongate substantially vertical post, an arm supported by the post and pivotally movable about the central axis of the post, a saw unit supported by the arm and movable along the arm, comprising:

• a support member attached to the post, a housing attached to the support member, the housing having a cavity, the cavity having an outlet opening, a piston within the cavity and axially movable within the cavity, a piston rod attached to the piston and axially movable with the piston, the piston rod having a threaded extension portion exterior of the cavity, a rotatable wheel rotatably supported by the support member, a threaded member attached to the wheel and threadedly joining the wheel to the threaded extension portion of the piston rod, whereby the threaded member is in meshed relationship with the threaded extension portion of the piston rod, a cable wound upon the wheel and extending therefrom, the cable extending from the wheel to the saw unit and attachable to the saw unit, whereby movement of the saw unit in a direction from the post forces movement of portions of the cable as portions of the cable unwind from the wheel and rotate the wheel, whereby rotation of the wheel forces axial movement of the piston rod and axial movement of the piston and forces fluid from the cavity through the outlet opening, the wheel and the cable thus moving at a rate in accordance with the rate of movement of the piston as the piston forces fluid flow from the cavity through the outlet opening.