US Patent 7470076 Pen retention apparatus

A pen retention device for releasably securing a pen to a tether is disclosed. The device includes a pen having an end, a collar defining an internal cavity surrounding the end and an orifice having a diameter, an elastic retainer disposed within the internal cavity, and an anvil securedly attached to the tether. An outer surface of the elastic retainer defines an internal dimension and an external dimension of the elastic retainer, the external dimension greater than the diameter of the orifice such that the internal cavity retains the elastic retainer. The anvil includes an angled retention surface having an external diameter greater than the internal dimension of the elastic retainer and less than the diameter of the orifice.