Improvements in Wood Screws.
Year: 1889

page_text: COMPLETE SPECIFICATION.
Improvements in Wood Screws.
1. CHARLES DAKE ROGERS of 21 Stevens Street, Providence in the State of Rhode
Island, United States of America, Works Superintendent 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 :-
(:
Heretofore in the manufacture of wood screws it has been usual to prolong the
threads from the cylindrical portion of the screw to the extreme end of the point
portion, thereby producing upon the screw the well know. gimlet point." In certain
classes of screws as for example "drive-screws," the entire point portion is unthreaded,
the thread terminating at the base of the point, while in other forms of drive-screws
the thread, which is in the form of a quick spiral, is formed on both the cylindrical
and point portions.
An objection to the use of the gimlet-pointed wood screw is that it does not
readily enter into the wood in starting unless a hole be first made for its reception. If
a hammer is used for starting such a screw into wood, the thread upon the screw point
obviously acts to prevent its ready entrance, as it can enter only by rupturing the
fibres of the wood, at the same time the spiral thread also acts to foace the screw to
one side or laterally, thereby rendering it somewhat difficult to enter the screw
centrally into the wood.
it
The object of my present improvement is to overcome the disadvantages just
named, and to that end I provide a wood screw with a point-portion which combines
a plain or unthreaded centering part which first enters the wood or material into which
may be inserted and a screw-thread which commences at the base of the plain part
of the point and extends rearwardly in a gradually increasing depth until it reaches
the base of the point where it unites with and forms a part of the full thread formed
on the cylindrical or body portion of the screw. By means of a point thus formed the
screw may he first entered true and centrally into the wood by a slight blow, the
resistance offered being very small, after which the screw may be driven home by a
screw-driver or other means as usual.
in the appended drawings. Figure 1 is a perspective view of my improved wood
screw, the diameter across the threads exceeding the size of the wire or unthreaded
portion of the shank. Fig. 2 is a similar view, the threaded and unthreaded portions
of the screw shank being of the same diameter, and Fig. 3 is a portion of a screw
having a sharpened polygonal point provided with a thread which vanishes about
midway of the point's length.
wood-screw complete. designates the
t the screw-thread; the root or core at
The head of the screw may be provided
therein as usual, or the screw may
be
In the drawings a indicates my improved
unthreaded shank portion of the screw, and
the base of the threads being indicated by r.
with a head having a screw-driver nick
provided with any well known form of head.
My invention resides in the novel construction of the point-portion p of the
screw, this portion I preferably make tapering, terminating at the end in a sharpened
point e. The screw-thread t extends froin the body portion of the screw, past the base
of the point portion and terminating about midway thereof, as clearly shown by the
drawings.
The normal
The thread is, as before stated, a continuation of the main thread t.
size of the thread practically ceases at the base of the point portion and is continued
therefrom towards the point at substantially the same pitch but gradually decreasing
in width and depth until it vanishes at a point into the point's surface. The
remaining part e of the point portion p being plain or unthreaded and terminating in
the sharpened point e, as represented in Figs. 1 and 2.

page_text: Without departing from the spirit of my invention I may make the point portion p
of the screw polygonal and form a more or less connected diminishing thread & thereon,
terminating at el, substantially as shown in Fig. 3.
"
My improved screw may be made by cutting away the metal, as in making
cut screws," or it may be produced by suitably operated swaging dies by what is
known as the "rolling process."
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. As a new article of manufacture a wood screw having the point portion thereof
provided with a sharpened unthreaded part for entering the wood and centering itself
therein and having the other part of the point portion provided with a thread gradually
increasing in width and depth until it forms a part of the normal thread at the base of
the point, substantially as herein before described.
.
2. A wood screw having a sharpened cone-shape point portion provided with a
diminishing thread and a plain or unthreaded part e extenling from the termination
of said thread to the end e of the point, substantially as shown and for the purpose
herein before described.
Dated this 15th day of October 1889.
CHARLES DAKE ROGERS,
Inventor.