Screw driver and screw head system Patent #: 4311071
ApplicationNo. 06/554140 filed on 11/21/1983
US Classes:81/460, Inserted portion having plural, noncollinear blades (e.g., Phillips)411/407Having driver retaining means
ExaminersPrimary: Smith, Gary L.
Assistant: Whitcomb, Adrian H. Jr.
Attorney, Agent or Firm
International ClassesB25B 15/00 (20060101)
F16B 23/00 (20060101)
Foreign Application Priority Data1982-11-22 FR
AbstractA non-slip screw of the type having a threaded shank and a slotted head, including a locking surface defined in the screw head by a central transverse slot which extends across the top of the head for engagement with a screwdriver blade tip. The locking surface includes a pair of radially outwardly extending inclined walls extending downwardly from each end of the transverse slot. An especial screwdriver having its exterior blade tip configured complementally with the pairs of radially outwardly extending inclined walls is engageable with the locking surface, so as to rotate the screw head in either direction. The screw head is characterized by its positive grip with the screwdriver blade tip, notwithstanding actual screwdriving or unscrewing and removal of the screw.