An Improved Nut Looking Device.
Year: 1896

page_text: Date of Application, 25th Apr., 1896-Accepted, 15th Aug., 1896
COMPLETE SPECIFICATION.
An Improved Nut Looking Device.
A communication by ERNST MELLER, of 5 Podmanicky-utcza, Buda Pesth, in
the Kingdom of Hungary, Civil Engineer.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester both in the County of Lancaster, 118 New Street, Birmingham in
the County of Warwick and 322 High Holborn in the County of Middlesex,
Civil Engineer, 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 :-
The improved nut locking device which forms the object of this invention is
shown in the accompanying drawings; Figures 1 and 2 being sile views and
Figure 3 an end view.
The screw or bolt A, which is provided with a head and with the ordinary
right hand screw thread, has a rectangular wedge-shaped slot cut transversely
through it near one end vertical to the longitudinal axis, said slot being of smaller
diameter than the screw. One side or end of said slot runs right up to the last
thread of the screw. In this slot a wedge C is fitted on which wedge at each
end a flat left-hand screw-thread is cut, adapted to be engaged by a lock nut D
having also a left hand thread. D' is an ordinary tightening nut out to
correspond with the thread of the screw A.
In use the screw A after the removal of the wedge C is inserted in the piece or
work which is to be fastened or connected, and an ordinary nut D' is screwed on
its thread and screwed tight in the ordinary manner with a screw key. The
wedge C is then inserted in the wedge-shaped slot iu such a way, that seen from
the front, the screw thread cut thereon inclines to the right (the wedge is in
any case so made that it cannot be mounted incorrectly as it will not fit the wrong
way into the wedge opening) the thread ou each ond of the wedge projecting
from the screw. Finally a lock nut D, which, in case of need, for the purpose of
firmness may be also of larger size than the tightening nut (for instance in the
case of a sorow a nut corresponding to a 1 screw of Whitworth's tables) is
scrowed on the threaded wedge in an opposite direction to the hands of a watch
until it reaches the tightening nut D¹ and rests against this latter firmly and yet
not too firmly.
By this device the ordinary tightening uut D' is entirely prevented from
becoming loose as if it tends to turn to the left by strong vibration and shaking
or jolting (whereby the connection is loosened) it carries with it by friction, the
lock nut D and tends to turn the latter also to the left, the turning in which
direction however corresponds as regards this out to a movement inwards, that is
to say, the connection is made still firmer. The lock uut cannot become loose
seeing that vibration is only communicated to it through a very small surface (the
thread of the wedge) and that turning is much more difficult on an incomplete
thread than on a full thread, which has been practically proved and can be
shown.
In order that the lock uut may be further prevented from becoming loose, the
contact surfaces of the tightening nut D' and lock nut D may also be provided
with teeth so that a stronger tendency to turn is prevented by the engagement of
the teeth. The tightening nut is really in this case also tightened up."

page_text: In order that the look nut by subsequent tightening may remain in contact
with the ordinary tightening nut the bore of the former is made somewhat greater
than the greatest diameter of the screw in order that it may pass over the
latter.
Figure 1 shows the lock nut in its innermost position. It cannot be screwed
further on, as otherwise the wedge would not be entirely within the nut and would
not be sufficiently secure or firm.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
'by my foreign correspondent, I declare that what I claim is :-
An improved nut locking device, consisting of a wedge threaded on each end
and adapted to be inserted transversely through the bolt or screw (A) which is
provided with a slot to receive it and a nut (D) adapted to be screwed on the said
threaded wedge when in position after the ordinary nut (D') has been screwed up,
the contact surfaces of the two screw nuts if desired being formed with teeth for
.greater security, substantially as described.
Dated this 24th day of April 1896.
WM. P. THOMPSON & Co.,
Agonte.