Improvements in Screws.
Year: 1892

page_text: Date of Application, 22nd Feb., 1892
Complete Specification Left, 22nd Dec., 1892-Accepted, 28th Jan., 1893
Improvements in Screws.
I, ELLIS PARR, of Brazil House, Isleworth, in the County of Middlesex,
Gentleman, do hereby declare the nature of this invention to be as follows:-
My present invention relates to the screws ordinarily used for the purpose of
screwing into wood in carpentry and joinery work.
In using such screws it is generally necessary to make a hole in the wood with
a gimlet or equivalent tool before screwing in the screw, and my invention has for
its object a novel method of making screws by which the use of a gimlet is rendered
unnecessary, the screw itself being provided with a device by which the hole in
the wood is made at the same time when the screw is screwed into it.
Supposing that my invention is to be applied to an ordinary wood screw having
a conical or other head to receive a screw driver the body of the screw being
cylindrical or somewhat taper and having a helical projecting thread round its
lower end for a sufficient distance from the point I form upon the body of the
screw and through the projecting thread one or more helical grooves of semi-
circular or other suitable section extending from the point to, or nearly to, or
passing through, the conical head.
The edge of the semi-circular or other grooves described, serves as a cutting
instrument and cuts away the wood in the same manner as an ordinary gimlet, the
part removed passing into and up the helical groove or grooves and the edges of
the thread cutting a path instead of forcing aside and tending to split the wood.
Instead of the groove or grooves being helical, they may be straight, or partly
helical and partly straight or of any other suitable form, and their number, size,
and shape, may be varied more or less as may be found advisable according to the
size and character of the screws and the purposes for which they are to be used.
The screw threaded part of the screw may be either at the lower end only of the
latter, or at its upper end, or at the central part only, or it may extend from the
point to the head, or it may be in separate interrupted parts.
In a modified form of my improved screws, I omit the screw thread or threads
described altogether, the screw then consisting of a cylindrical or tapering body
having a conical head for a screw driver, and one or more helical grooves extending
from the point, to, and through, the conical head. The extreme point of the screw
is however preferably formed with a short conical screw thread, through which the
helical groove or grooves may pass. Such screws are cheaply made and are easily
screwed into the wood which is to receive them.
By my invention great facility is provided for driving in the screws, and the
wood is not injured.
Dated this 92nd dow of Rahmarn 1009

page_text: COMPLETE SPECIFICATION.
Improvements in Screws.
I, ELLIS PARR, of Brazil House, Isleworth, in the County of Middlesex, do
hereby declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement and accompanying drawing, that is to say :-
My present invention relates to the screws ordinarily used for the purpose of 5
screwing into wood in carpentry and joinery work.
In using such screws it is necessary generally to make a hole in the wood with
a gimlet or equivalent tool before screwing in the screw, and my invention has for
its object a novel method of making screws by which the use of a gimlet or other
tool is rendered unnecessary, the screw itself being provided with a device by which 1
the hole in the wood is made at the same time that the screw is screwed into it.
The accompanying drawing is in illustration of my invention.
Figure 1 represents my improved screw with a screw thread at its lower end or
point;
Figure 2 shews (the screw with the screw thread at the middle of its length, and 1
Figure 3 with the screw thread at the upper end under the head,
Figure 4 shews my improved screw without a screw thread.
Similar letters refer to similar parts in the several figures.
Supposing that my invention (as shewn in Figure 1) is to be applied to an
ordinary wood screw having a conical or other head b having a transverse nick to
receive a screw driver, the body of the screw a being cylindrical or somewhat
taper and having a helical projecting thread c round its lower end for a sufficient
distance from the point I form upon the body of the screw and through the
projecting thread one or more helical grooves d of semi-circular or other suitable
section extending from the point to, or nearly to, or passing through, the conical
head.
The edge of the semi-circular or other grooves d described serves as a cutting
instrument and cuts away the wood in the same manner as an ordinary gimlet, the
part removed passing into and up the helical groove or grooves, and the edges of
the thread c cutting a path instead of forcing aside and tending to split the wood.
The screw threaded part of the screw may be either at the lower end only of the
latter (as shewn in Figure 1) or at its upper end (as shewn in Figure 3), or at
the central part only (as shewn in Figure 2), or it may extend from the point to
the head. Or it may be in separated interrupted parts.
In a modified form of my improved screw (as shewn in Figure 4) I omit the
screw thread or threads described altogether, the screw then consisting of a
cylindrical or tapering body a having a conical head b for a screw driver, and one
or more helical grooves d extending from the point to, and through, the conical
head. The extreme point of the screw is however preferably formed with a short
conical screw thread c, through which the helical groove or grooves may pass.
Such screws are cheaply made and are easily screwed into the wood which is to
receive them.
Instead of the groove or grooves being helical, they may be straight, or partly
helical and partly straight or of other suitable form, and their number, size, and
shape, may be varied more or less as may be found advisable according to the size
and character of the screws and the purposes for which they are to be used.
By my invention great facility is provided for driving in the screws, and the
wood is not injured.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. The combination in a
BOHAM

page_text: driver, screw thread c and helical groove d passing through the body of the
screw a, the screw-thread c, and the conical head b, substantially as set forth and
illustrated in Figures 1, 2, and 3.
2. The combination in a screw, of the body a, the conical head b nicked for a
screw-driver, and the helical groove d passing through the body of the screw a and
the conical head b, and its edges forming a screw-thread, substantially as set forth,
and shewn in Figure 4.
Dated this gond dow of November 1809
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.