Patented Sept. 22, 1931
United States Patent Office
Peter L. Robertson, of Milton, Ontario, Canada
Application filed January 10, 1929. Serial No. 331,516.
The principal objects of this invention are to provide
a screw driver which may be readily adapted for use
with various sizes or types of screws and which may
be altered very quickly to suit the requirements of
A further object is to improve the construction of
the holder of the removable bits to enable their more
ready adjustment and rearrangement.
The principal feature of the invention consists in
the novel arrangement of a plurality of individual bits
to be utilized in various combinations and in the novel
construction of the bit holder whereby the bits are
readily adjusted or replaced therein.
This invention is an improvement in screw drivers to
be used principally in conjunction with my co-pending
invention for improvements in tool holders, filed in
the United States Patent Office July 2, 1928 under Serial
In the accompanying drawings, Figure 1 is a perspective
view of my improved screw driver showing the multiple
bit arrangement for use with large slotted screws.
Figure 2 is a perspective view of the bit end of the
screw driver showing the arrangement of the bits with
a smaller screw.
Figure 3 is a perspective view of the bit end of the
screw driver showing an arrangement of the bits for
use with a perforated screw, such as a wheel spoke nipple.
Figure 4 is a perspective detail of the inner bit holder
Figure 5 is an enlarged longitudinal sectional detail
through the bit holder showing the bits in position,
as shown in Figure 1.