An Improvement in Nut-locking Devices.
Year: 1889

page_text: Date of Application, 6th May, 1889-4ccepted, 15th June, 1889
COMPLETE SPECIFICATION.
An Improvement in Nut-locking Devices.
I, ADOLPH VOGT, of 69 Boulevard Waterloo, Bruxelles, kingdom of Belgium,
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
-
My invention relates to devices for locking the nuts of screw-bolts, and the improve-
ment consists in the combination with the bolt and the nut, of an auxiliary or
pinching screw, smaller in diameter than the bolt, and having threads of the same
pitch as those of the latter, but inclined in contrary direction, the said screw being
arranged rotatively in or upon the nut, or a check-nut, and meshing with the threads
of the bolt.
In the annexed drawing are shown different modes of carrying out my invention.
According to Figs. 1 to 5 the auxiliary or pinching screw S is connected by a pin
or pivot to a piece A, having a hole a with inside screw-threads that fit to the threads
of the bolt C, so that it forms a kind of check-nut to the nut B, and the screw S is
pivoted to the piece A in such position that it will mesh with the threads of the bolt
when the said piece is screwed on the latter Provided the bolt has a right-hand
screw-thread, as usual, the screw S is made with left-hand thread, and it is fitted at the
top with notches e, or other suitable means, for applying a screw-driver or key thereto.
Preferably the piece A is made with a recess b for receiving the screw S, and a sleeve
c corresponding to a recess h in the latter, and the pin f, about which the screw turns,
is riveted at both ends so as to prevent the screw from shifting lengthwise but without
hindering its rotation
After the nut B and the piece A have both been screwed tight, the screw S is
rotated to the left until it is also drawn tight, the upper surfaces of the threads of the
When the
screw then pressing against the lower surfaces of the threads of the bolt.
parts are in this condition it is impossible to turn the piece A backward, because any
power applied thereto to cause such rotation, would tend to rotate the screw about the
bolt in the same direction, .e to the left, by the triction of its threads on those of the
bolt But as, on account of the screw S being of smaller diameter than the bolt, the
threads of the former are steeper than those of the latter, and as the screw cannot
shift downward, any such rotation of the screw to the left would only cause the
pinching action of the screw on the bolt to be increased. This action is greater in
proportion to the difference of diameter of the screw and the bolt, and to the force
originally applied to the screw for tightening it.
Instead of being mounted on a separate piece A, the screw S may, however also be
connected by its pivot to the nut B, as shown by Figs. 6 and 7 the arrangement
being for the rest analogous to that described, and consequently operating with like
effect
Figs 8, 9 and 10 represent another modification. In this case the screw S has a
diameter which is considerably smaller than that of the bolt C, it is made slightly
conical and located in a round or oval recess in provided for on the inner face of the
nut, the said recess being parallel to the axis of the bolt, and its depth, vertically
thei eto, being such that when the screw is inserted into the recess, its threads will
first engage loosely with the threads of the bolt and that, in the measure as it is
screwed further down, the threads will engage more deeply with each other, on
account of the conical form of the screw, until finally the screw is jammed.
The recess is made laterally somewhat wider than the upper diameter of the screw,
in order that, when any force tends to slacken the nut, the screw S may roll on the
back wall of the recess, and screw itself further into the same so as to press more

page_text: strongly against the threads of the bolt. For the purpose of allowing the nut to be
released, the screw S is withdrawn by means of a sciew-driver as in the other cases.
If the recess m is made slightly inclined, as shown by Fig. 10, the jamming action
of the screw S ensues still sooner and with greater certainty than when the recess is
parallel to the axis of the bolt.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed, I declare that what I claim is :-
=
A nut-locking device consisting in the combination, with a screw-bolt and a nut,
of a screw S, smaller in diameter than the bolt and having threads of like pitch as
those of the latter, but inclined in contrary direction, the said screw being arranged
rotatively upon the nut, or in a recess thereof, or on a piece A forming a check-nut,
so that the threads of the screw mesh with those of the bolt, substantially as described.
Dated 6th May 1889
J. H. JOHNSON & Co,
Agents.