Patent ID: 7726895

Claim:
A method for releasably securing a pen to a tether, the method comprising: providing in the pen an end and an annular interior surface defining a bore; providing a cap comprising an expandable retention interface, the expandable retention interface disposed within the bore proximate the end and comprising a radially outwardly directed surface in contact with the annular interior surface; and securedly attaching an anvil to the tether; wherein the expanding retention interface further comprises a radially inwardly directed surface in operable communication with the anvil; wherein the expanding retention interface is responsive to an application of force less than a release force by the tether via the anvil to the radially inwardly directed surface to expand and secure cap to the pen, wherein the expanding retention interface is responsive to an application of force greater than the release force by the tether via the anvil to the radially inwardly directed surface to release the cap from the pen, and wherein the anvil is securedly attached to a first end of the tether and the pen retention device further comprising a tether retracting reel in operable communication with a second end of the tether.