Expandable mandrel
OwnerDavid T. Grayinventor
Life of this patent
Estimating the term…
Abstract
A workpiece holder features a grip post having an interior wall structure and an exterior wall structure defining a plurality of expandable sections adapted to engage the wall of a bore formed on a workpiece. The grip post houses a cam arrangement abutting the interior wall structure. A pin arrangement is movably mounted in the grip post and has a tapered head engageable with the cam arrangement. A fluid system is provided for instantaneously imparting longitudinal movement to the pin arrangement whereby the exterior wall structure of the grip post is expanded into gripping relationship with the workpiece bore by the progressive engagement of the tapered head with the cam arrangement.
Claims20
A workpiece holder comprising in combination:
- a grip post having an interior wall structure and an exterior wall structure defining a plurality of expandable sections adapted to engage the wall of a bore formed on a workpiece, the grip post having a cam arrangement abutting the interior wall structure;
- a pin arrangement movably mounted in the grip post and having a tapered head engageable with the cam arrangement;
- means for instantaneously imparting longitudinal movement to the pin arrangement whereby the exterior wall structure of the grip post is expanded into gripping relationship with the workpiece by the progressive engagement of the tapered head with the cam arrangement, and
- a base assembly comprised of a base having a fluid passageway formed therein in communication with a source of fluid pressure, a cap joined to the base and formed with a central through hole for receiving the pin arrangement, and a gland sealably interposed between the base and the cap and provided with a bore for receiving the pin arrangement, the bore being in aligned communication with the fluid passageway and the through hole.
A workpiece holder comprising in combination:
- a grip post having an interior wall structure and an exterior wall structure defining a plurality of expandable sections adapted to engage the wall of a bore formed on a workpiece, the grip post having a cam arrangement abutting the interior wall structure and a first resilient means acting directly upon the cam arrangement;
- a pin arrangement movably mounted in the grip post and having a tapered head engageable with the cam arrangement and a second resilient means surrounding the pin arrangement;
- and
- means for instantaneously imparting longitudinal movement in one direction to the pin arrangement against forces of the first and second resilient means whereby the exterior wall structure of the grip post is expanded into gripping relationship with the workpiece by the progressive engagement of the tapered head with the cam arrangement, the first and second resilient means acting to return the pin arrangement in an opposite direction to the one direction causing the grip post sections to retract from the workpiece.
An expandable mandrel comprising:
- a base assembly having a fluid passageway in communication with a source of fluid pressure;
- a grip post having a plurality of expandable sections adapted to engage the wall of a bore formed on a workpiece and a central chamber having an interior wall for accommodating a retainer formed of a series of races, each race provided with a first resilient means for retaining a bearing component therein, and
- a movable pin arrangement having an upper tapered end engageable with the bearing components and a lower end supported in communication with the fluid passageway and surrounded by a second resilient means,
- such that when the wall defining the bore of the workpiece is positioned upon the grip post, fluid pressure delivered to the passageway will force the pin arrangement axially against the force of the second resilient means, whereby the tapered end of the pin arrangement deforms each first resilient means and forces the bearing components radially outward from their races against the interior wall of the central chamber causing the grip post sections to expand against the workpiece bore wall so that the workpiece is positively supported and gripped.
In a workpiece holder having a plurality of components disposed in respective races engageable with a tapered end of an elongated member, the improvement residing in:
- means for supplying and regulating fluid pressure in the workpiece holder such that, upon application of fluid pressure, the elongated member moves axially in one direction so as to force the bearing components out of the races to enable the workpiece to be gripped on the holder;
- and
- resilient means in the workpiece holder acting directly upon the bearing components and the elongated member, and operable upon release of fluid pressure to move the elongated member axially in an opposite direction to the one direction so as to return the bearing components to their races to enable the workpiece to be released from the holder.
Dependencies are inferred from the claim text.