WILBUR L SHEFFIELD
Engineering in Needham, MA
License number
Massachusetts 14893
Expiration Date
Jun 30, 1984
Type
Mechanical Engineer
Address
Address
Needham, MA 02492
Professional information
Disposable Propel-Repel Pencil
US Patent:
4544296, Oct 1, 1985
Filed:
Oct 27, 1980
Appl. No.:
6/200786
Inventors:
William A. Jarvis - Dunwoody GA
John Kirby - S. Hamilton MA
Alan J. Lane - Lexington MA
John P. Pokorski - Chelmsford MA
Wilbur L. Sheffield - Needham MA
John Kirby - S. Hamilton MA
Alan J. Lane - Lexington MA
John P. Pokorski - Chelmsford MA
Wilbur L. Sheffield - Needham MA
Assignee:
Scripto, Inc. - Atlanta GA
International Classification:
B43K 2108
US Classification:
401 73
Abstract:
A mechanical pencil is disclosed that includes a barrel with a non-circular internal bore, a helical coil member that is fitted within the bore and attached to an externally positioned driving member, and a lead positioning means or pusher member that is positioned about and threadably engaged with the coil and constrained by the non-circular bore of the barrel for sliding longitudinal movement therein. The lead positioning means or pusher member includes fins that extend through the coil turns and act as a positioning stop for the writing lead and a lead gripping means for propelling and repelling the centrally disposed writing lead upon the manual rotation of the external driving member that is attached to the coil disposed within the barrel.