IMPROVEMENTS IN NUTS AND SCREWS."
Year: 1879

page_text: LETTERS PATENT to Jeremiah Cowdy, of the City of London, and Henry
Andrews, of Hammersmith, in the County of Middlesex, for the Invention
of "IMPROVEMENTS IN NUTS AND SCREWS."
PROVISIONAL SPECIFICATION left by the said Jeremiah Cowdy and
Henry Andrews at the Office of the Commissioners of Patents on the 2nd
May 1879.
JEREMIAH COWDY, of the City of London, and HENRY ANDREWS, of Hammersmith,
in the County of Middlesex. IMPROVEMENTS IN NUTS AND SCREWS."
It has heretofore been proposed to form the bedding side of bolt heads and of
nuts and screws with a series of peculiarly formed projecting teeth equally
distributed all round with the view of preventing the slackening or unscrewing of
such bolts, nuts, or screws, which commonly takes place from the jarring or vibration
of those parts of a structure or machine in which they are employed; the slackening
or unscrewing is prevented by the peculiar form of the teeth, which are so inclined as
to hinder or prevent loosening or turning back in one direction, but so as to permit
the further tightening up by turning forward or in the opposite direction.
Now the object of this Invention is to produce an increased gripping action for
the purpose aforesaid and also to decrease the cost of manufacture as compared with
the method just referred to.
According to this Invention we produce such increased gripping action by forming
one tooth (or say two or three) of the one sided description above referred to in
one part or portion of the bedding or underside of the nut only, and with the other
part plain; we thereby cause a one sided hold or grip tending to very slightly
bend the bolt or screw or to cant it in its hole. The rise of the inclined side of
tooth may be very gradual or as it were screw shape. The other side is vertical or
of a slight incline. When a washer under the nut is required or desirable (say,

page_text: because of a too large or uneven hole or uneven bedding surface) we make the
underside of such washer with several equidistant teeth all round or so as to make
an even grip or bearing, and we make the other or upper side plain for the tooth of
our improved nut to bed itself in.
For screws which are fastened into tapped holes we form the under or bedding
side of the head similarly with one tooth or, say, two teeth in one place or portion
of the same.
The nut and the screw head or the side of same which is to be formed with the
tooth (or teeth) are to be of a harder substance or surface than the material against
which they bed themselves, so that the tooth (or teeth) may to a certain extent
imbed or indent itself therein.
This Invention is particularly applicable to the fastening of fish plates to rails or
.girder sleepers.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Jeremiah Cowdy and Henry Andrews in the Great Seal Patent Office
on the 1st November 1879.
JEREMIAH COWDY, of the City of London, and HENRY ANDREWS, of Hammersmith,
in the County of Middlesex. "IMPROVEMENTS IN NUTS AND SCREWS."
It has heretofore been proposed to form the bedding side of bolt heads and of
nuts and screws with a series of peculiarly formed projecting teeth equally
distributed all round with the view of preventing the slackening or unscrewing of
such bolts, nuts, or screws, which commonly takes place from the jarring or vibration
of those parts of a structure or machine in which they are employed; the slackening
or unscrewing is prevented by the peculiar form of the teeth which are so inclined
as to hinder or prevent loosening or turning back in one direction, but so as to
permit the further tightening up by turning forward or in the opposite direction.
These nuts have heretofore usually been made of steel.
Now the object of this Invention is to produce an increased gripping action for
the purpose aforesaid, and also to decrease the cost of manufacture as compared with
the method just referred to.
According to the Invention we produce such increased gripping action by forming
one tooth, or say two or three of the one sided description above referred to in one
part or portion of the bedding or under side of the nut only, and with the other
part plain, we thereby cause a one sided hold or grip tending to very slightly bend
the bolt or screw or to cant it in its hole. The rise of the inclined side of tooth
may be very gradual, or as it were screw shape. The other side is vertical or of a
slight inward incline. When a washer under the nut is required or desirable (say,
because of a too large or uneven hole or uneven bedding surface) we make the
underside of such washer with several equidistant teeth all round or so as to make
an even grip or bearing, and we make the other or upper side plain for the tooth
of our improved nut to bed itself in.
For screws which are fastened into tapped holes we form the under or bedding
side of the head similarly with one tooth or say two teeth in one place or portion of
the same.
The nut and the screw head or the side of same which is to be formed with the
tooth (or teeth) are to be of a harder substance or surface than the material against
which they bed themselves, so that the tooth (or teeth) may to a certain extent
embed or indent itself therein.
This Invention is particularly applicable to the fastening of fish plates to rails or
girder sleepers.
Figure 1 of the accompanying Drawings is a side elevation of a bolt fitted with
a square nut made according to this Invention, and Figure 2 is plan of the under-
side of the nut. The tooth a is placed near one corner where the nut is strongest,
and has in this case an incline of about one fourth the circumference, the rest of the
end surface of the nut being level; Figure 3 is an elevation of the same bolt and
aut showing the mode of action but rather exaggerated, the tooth while more or less
embedded giving the bolt a tendency to assume a slanting or bent position in the
hole through the two pieces c and d united thereby.
Figure 4 is a plan of a hexagon nut formed with a similar tooth.
Figure 5 shows the Invention applied to a washer d under a nut or bolt head; it
is formed with a tooth on each side or face but shallower than in the other cases so
as not to cant or bend the bolt too much; or one side of the washer may be formed
with three or more equidistant teeth.
Figure 6 shows a bolt with nut having two teeth a which are also shown in the
plan Figure 7. The teeth are shown close together so as to produce the desired one
sided or canting or bending tendency.

page_text: Figure 8 illustrates the Invention as applied to the underside of the head of a
screw; Figure 9 is plan of same, and Figure 10, a plan of a square head of
a screw..
The bolts, nuts, and washers made according to this Invention may be made of
steel; but we find. that they may advantageously be made of iron case-hardened on
the tooth side, and we thus cheapen the manufacture. We prefer in all cases to
make the short side of the tooth as vertical as possible, or if the manufacture admits
of it, even undercut so as to give the best possible grip and to enable it to embed
itself well.
And having thus described and ascertained the nature of this Invention, and in
what manner the same is to be performed, we declare that we claim,—
The tooth or teeth a on the side or face or faces of a nut or screw head or
washer for the purpose of embedding itself effectually, and also for imparting a
one sided or canting or bending tendency to the bolt or screw, and thus prevent
it from getting loose, substantially as set forth.
In witness whereof, I, the said Jeremiah Cowdy, for myself and on behalf
of the said Henry Andrews, have hereunto set my hand and seal, this
Thirtieth day of October, in the year of our Lord' One thousand eight
hundred and seventynine.