Improvement in Drive Screw.
Year: 1892

page_text: Date of Application, 27th Dec., 1892
Complete Specification Left. 8th Sept. 1893—Accepted. 27th Dec., 1893
PROVISIONAL SPECIFICATION.
Improvement in Drive Screw.
I, ROBERT LINKLETTER, of 27 Gardener Avenue, Jersey City, Hudson County,
New Jersey, United States of America, Gentleman, do hereby declare the nature
of this invention to be as follows :-
This invention relates to a drive screw provided with two intertwisted spiral
shanks, that are joined to a common nicked head.
At their lower ends, each shank is provided with an inner bevel and with a
lateral bevel. The two inner bevels form a V-shaped groove between them, while
the two lateral bevels extend in opposite directions.
The result of this construction is, that as the screw is driven into the wood, the
shanks will separate and uncoil to increase the diameter of the screw, which is thus
firmly held in place.
When the screw is withdrawn in the ordinary manner by a screw driver, the
shanks will be gradually lapped one upon the other and the screw, when entirely out
of the wood, will have again assumed its normal appearance.
Dated this 27th day of December 1892.
ALLISON BROS.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvement in Drive Screw.
I, ROBERT LINKLETTER, of 27 Gardener Avenue, Jersey City, Hudson County,
New Jersey, United States of America, Gentleman, 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 :-
This invention relates to a drive screw provided with two intertwisted spiral
shank sections that will spread and uncoil as the screw is driven home.
The invention consists in the various features of improvement more fully pointed
out in the claims.
In the accompanying drawing:
Figs. 1 and 2 are elevations of the screw, taken at right angles to each other.
Figs. 3 and 4 are similar views showing the screw driven home.
Figs. 5 and 6 are detail views at right angles to each other of the tip of one of
the shank sections.
The letter a, represents the nicked head of the screw and a¹, a', are the two
sections of the split shank, which are connected to the head on top and are discon-
nected from each other at the bottom. The sections a', a', are made in the form
of a tapering spiral, which when wound upon each other, form together a solid
tapering shank.
The sections a¹, a³, are at their lower ends provided with two bevels viz.: an
inwardly slanting bevel a³, and a laterally slanting bevel at. The two inner
bevels a, form a V-shaped groove between them (Fig. 1) and when the screw is
driven home, they have a tendency to cause the shank sections to spread
apart. The two lateral bevels at, extend in opposite directions on the two shank
sections (Fig. 2) and they have for their object to cause the shank sections to
revolve or unwind from each other. The result of the construction is that as the
screw is driven into the wood A, (Fig. 3) the shank sections will separate and
uncoil, to increase the diameter of the screw, which is thus firmly held in place.
D

page_text: When the screw is withdrawn in the ordinary manner by a screw driver, the
shank sections will be gradually lapped one upon the other and the screw, when
entirely out of the wood will have again resumed its normal appearance.
The screw can be manufactured in many different ways. prefer to manufacture
it in the ordinary way, but instead of threading it, I point and split it by dies and
wrap or twist it by revolving dies.
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 1
claim is:
1. A drive screw provided with two spirally coiled shank sections, wound one
upon the other, each section terminating in a separate point, substantially as
specified.
2. A drive screw provided with two spirally coiled shank sections wound one
upon the other and having an inner bevel a³, substantially as specified.
3. A drive screw provided with two spirally coiled shank sections wound one
upon the other and having lateral bevels a', extending in opposite directions,
substantially as specified.
4. A drive screw provided with two spirally coiled shank sections wound one
upon the other and having the inner bevel a³, and the lateral bevel a', substantially.
as specified.
Dated this 8th day of September 1893.
ALLISON BROS.,
Agents for the Applicant.