text: 1. Field of the Invention
  The present invention relates to a fastener driver and, in particular, to an anti-slip fastener driver that prevents or reduces the tendency of a driving portion to slip out of the head of a stripped screw.
  2. Description of the Related Art
  A screw is a threaded fastener that is used to attach a workpiece or help keep a workpiece in position. The screw has a head specially formed section on one end thereof and designed to fit a certain type of screw driver, which allows users to insert or remove the screw. A stripped or damaged screw is one on which the head is damaged and, thus, difficult or impossible to turn using conventional screw drivers. This damage of screws can occur through normal wear and tear, or by using the wrong type or size of driver for the screw.
  Screws have several types of head designs, depending on the manner in which the screw is intended to be used. Some heads of the screws are more susceptible to stripping than others, particularly when being driven by machine-guided tools. The simplest and least expensive screws often are manufactured with slot heads, which can be driven with a variety of tools. These types of heads also are easily damaged if too much torque is applied, often leading to a stripped screw.
  When a screw does become damaged, a user can attempt several methods to remove the stripped screw. If the stripped screw is made from a softer metal, then the user can try cutting a new slot in it with a rotary tool or removing the head of the screw with a power drill. However, it needs more tools for cutting a new slot in the stripped screw. Actually, that is too much trouble for users.
  The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.