Positive feed tool with improved shift from forward to retract
AssigneeApex Brands, Inc.
InventorsJeremy Watford, Kevin Myhill, Marc Djabri
Life of this patent
Estimating the term…
Abstract
Feed tools and methods of use for initiating a change in a spindle feed direction from an advance direction that moves the spindle towards a workpiece to a retract direction that moves the spindle away from the workpiece. The tool and methods may use a thrust overload force that is generated on one or more of the components to initiate the shift from forward to retract and/or a lift ring that acts on one or more of the components. The tool and methods may also include a two-stage piston to accomplish the shift. The various components may be used independently or in combination within the tool.
Claims15
A positive feed tool configured to operate in a first mode and a second mode, the feed tool comprising:
- an elongated spindle adapted to carry a tool bit and to rotate and to move axially along a feed path, the spindle configured to operate in a first mode to move axially along the feed path in a first direction and a second mode to move axially along the feed path in an opposing second direction, the spindle further configured to prevent movement in the first direction beyond a stop position;
- a spindle drive mechanism connected to the spindle to rotate the spindle;
- a differential feed gear that engages with and is rotated by the spindle drive mechanism, the differential feed gear spaced away from the spindle;
- a spindle feed gear connected to the spindle to axially move the spindle along the feed path, the spindle feed gear engaged with and rotated by the differential feed gear;
- the first mode including the spindle drive mechanism engaged with the spindle to rotate the spindle and engaged with the differential feed gear to rotate the spindle feed gear, the spindle feed gear being located at a first axial position along the feed path, the spindle drive mechanism and the differential feed gear being a first axial distance apart;
- the second mode including the spindle feed gear moves to a different second axial position along the feed path and the differential feed gear a greater second distance axially apart from and disengaged from the spindle drive mechanism;
- the spindle configured to transition from the first mode to the second mode in response to the spindle feed gear axially being moved along the feed path from the first position to the second position.
A method of initiating a shift in a spindle direction in a positive feed tool, the method comprising:
- rotating a spindle drive mechanism that is connected to a spindle thereby rotating the spindle;
- rotating the spindle drive mechanism thereby rotating a differential feed gear that is engaged with the spindle drive mechanism;
- rotating the differential feed gear thereby rotating a spindle feed gear that is engaged with the differential feed gear;
- rotating the spindle feed gear that is connected to the spindle while the spindle is rotating and moving the spindle in a first direction along a feed path;
- preventing the spindle from moving in the first direction while continuing to rotate the spindle and the spindle feed gear and begin moving the spindle feed gear axially along the spindle in an opposing second direction along the feed path;
- moving the spindle feed gear axially along the spindle in the second direction and moving the differential feed gear away from the spindle drive mechanism and disengaging the differential feed gear from the spindle drive mechanism;
- and
- stopping rotation of the spindle feed gear while continuing to rotate the spindle and moving the spindle in the second direction along the feed path.
Dependencies are inferred from the claim text.