Improvements relating to Nut-locks.
Year: 1889

page_text: Date of Application, 18th July, 1889
Complete Specification Left, 16th Apr., 1890-Accepted, 17th May, 1890
PROVISIONAL SPECIFICATION.
Improvements relating to Nut-locks.
I, EMIL OBERWARTH, of 33 Zimmerstrasse, Berlin, in the Empire of Germany,
Merchant, do hereby declare the nature of this invention to be as follows:-
This invention is intended to be applied for locking the nuts of bolts which have
either right and left handed screw threads or two threaded parts of a different pitch
and a nut to each thread so that by turning the nuts an equal part of a revolution
they are caused to move so as to become locked. The friction between the nuts is
often regarded as sufficient to prevent the two nuts working loose, especially with
bolts having right and left handed screw threads but in practice it is frequently
found that this is not the case.
According to this invention I provide a washer having flanges or clamps which
bear against the sides of the two nuts (i.e. the primary nut and the lock nut) whereby
they are firmly locked in position and prevented from turning.
Instead of a washer placed between the nuts a hexagonal or other suitably shaped
sleeve or tube can be placed over the two nuts such tube being prevented from
slipping off by a bend in the middle of one of its sides, or by other suitable means,
and thereby preventing the nuts working loose.
One form of the washer forming the nut-lock consists of a double ring made in one
picce the openings being for the passage of the screw bolt. The rings are turned
over upon each other in such a manner that the openings therein coincide and then
one part of the ring is bent to form a clamp. On the primary nut being screwed
tight the washer is applied thereto the clamp bearing against its side, the lock nut is
then screwed up tight and the washer is bent over against its side to form the other
clamp whereby the nuts are both locked in position.
It will be obvious that my invention admits of various modifications, for example,
a single ring is sometimes employed instead of a double ring; the two clamps are
sometimes divided by a slit and an additional clamp is provided, and in some cases
several double clainps and single clamps are employed.
Dated the 18th day of Tule 1880
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to Nut-locks.
I, EMIL OBERWARTH, of 33 Zimmerstrasse, Berlin, in the Empire of Germany,
Merchant, 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 nut-locks and is intended to be applied for locking the
nuts of bolts which have either right and left handed screw threads or two threads of
different pitch and nuts having threads which correspond with the threads of the bolts,
the two nuts coming into contact at the meeting point of the two bolt-threads. The
friction between the nuts is often regarded as sufficient to prevent the two nuts
working loose, but in practice it is frequently found that this is not the case.
According to this invention I provide a washer having clamps which bear against the
sides of the two nuts, whereby the nuts are firmly locked in position and prevented
from turning, it being immaterial whether the nuts are in contact with each other
or not.

page_text: Instead of employing a washer between the nuts the clamps can be formed integral
with one of the nuts and bent down against the sides of the other nut after both nuts
have been screwed on their bolt.
Or, a hexagonal or other suitably shaped tube can be passed over the nuts to
prevent them turning.
In order to enable iny invention to be fully understood I will proceed to describe
the same by reference to the accompanying drawing, in which,
Figure 1 represents an elevation of a screw-bolt d with right and left hand
threads.
Figure 2 is a similar view of the bolt d with the two nuts e and fand the washer P
provided with clamps a and b placed between them. The clamp bis first made to
bear against one side of the nut e and after having secured the nuts in their proper
position the other clamp a is bent over in the direction of the arrow so as to bear
against one of the sides of the nut fas shewn in Figure 3 which is an elevation of the
bolt d with the nuts and clamping washer applied thereto.
If
To allow the clamp to be bent over where the sides of the two nuts are at an angle
of 30° the clamping washer P is formed as shown in plan at Figure 4, that is to say,
a radial split c is made in one of the clamps so as to allow the two halves a of the
divided clamp, when placed between the two nuts as shown in plan at figure 5-
which also represents a longitudinal section of the clamping washer-to be bent
over and bear against two adjacent sides of the nut f. It will be seen by reference
to the longitudinal section of the washer figure 7, that the washer P can be prepared
and the clamp he bent before applying the washer. When it is applied the bent
clamp bears, as shown in plan at Figure 6, against one of the sides of the nut.
the clamp a is split the clamp can be omitted as in the plan figure 8 and it is in this
case also immaterial what may be the relative positions of the sides of the two nuts e
and ; they can, as before, form an angle of 30° shewn in figure 9 which represents
similar views to figure 5 but illustrating the washer shewn in Figure 8. In use the
one part a of the clamp is, in this case, bent in one direction as shown in the plan at
figure 10 and in the longitudinal section at figure 11, and the other part a is bent in
the opposite direction, so that the one bears against the nut e, figure 10, and the other
against the nut f. To obtain greater security the washer P can be made with as
many clamps as there are sides to the nuts say, for example, 6. Of the six clamps
three may be split as shown in plan at figure 12. In figure 13, which is a longi-
tudinal section of this form of washer and a plan illustrating its application to two
nuts, the clamps are shown in the most suitable position relatively to the sides of the
nuts e and f. Figure 14, is a plan of the nuts è and fand Figure 15 is an elevation
of the nut e shewing the position of the washer after the three unsplit clamps have
been bent over. These three clamps can however be bent before inserting the
washer P.
Instead of providing a washer with clamps an ordinary circular ring or washer can
be used provided it is large enough to allow the edges to be bent over the sides of
the nuts in a similar way to the herein before described clamps. Figures 16, 17
and 18 represent this kind of washer P, figure 16 being a plan and figure 17 a
longitudinal section shewing it with two opposite edges a and b bent over, and
figure 18 being a longitudinal section through the washer before the edges have been
so bent.
Instead of an ordinary round washer a double one can be employed formed by
bending a suitably punched or cut plate as shewn in figures 19. 20 and 21.
It con-
sists of two ring shaped parts connected together at h, as shewn in plan at figure 19;
the holes are intended for the passage of the bolt. The plate punched into the
shape shown in Figure 19 is bent so that the holes i cover one another as in the
longitudinal section, figure 20, the edges being then bent over (as shown at a and b
in the longitudinal section, figure 21) to form the clamps.
Figure 22 is a sectional elevation illustrating the use of a double washer of this
description on a screw bolt having a right hand thread r and a left hand thread l.
After the nut e is tightened up the washer P is placed on the bolt and the part 6 of

page_text: the periphery is bent over; this bending can however be effected before hand in
which case the washer is placed so that the clamp 6 bears against one side of the
nute after which the lock nut is tightened and the clamp a bent as shewn in dotted
lines so as to bear against one side of the nut f.
The double washer can also be made of small rings provided with special clamps
like those of the first herein described washers as shewn in plan at Figure 23 and
in longitudinal sections at figures 24 and 25. Each half is provided with a clamp
one of which a bears against the nut and the other against the nut f
As has already been mentioned the clamps can be formed integral with either one
of the two nuts figure 27 is a plan and a vertical section of a nut with one of such
clamps and figure 28 represents similar views of a nut with two of such clamps.
The nuts are secured in the following manner :-The nut e corresponding to the
right hand thread is first screwed onto the bolt d figure 26 (which is a sectional
elevation illustrating the application of this form of my invention) after it has been
passed through the holes of the parts to be connected and the nut e is then tightened,
the threaded part of the bolt being so regulated that the outer face of the nut e
reaches to or past the point of junction of the two threaded parts and l. The nut f,
corresponding to the left hand thread and having at the edge of its inner face one or
more clamps g. is then screwed on the bolt as far as possible towards or up to the nut e
with the sides of the two nuts coinciding and the clamps g are bent over so as to bear
against the sides of the nut e.
It will be obvious from the foregoing description that, whether the washers with
clamps or clamps formed on the nuts be employed, it is immaterial whether the two
nuts are brought to bear against each other or have a small space between them as in
either case a thoroughly secure nut lock is obtained because the nuts cannot turn
independently of each other and a simultaneous movement of the two nuts is rendered
It will also be
impossible by reason of the two different kinds of screw threads.
obvious that if the bolts be made with two right hand or two left hand threads of
different pitch, a similar result will be obtained. Figure 29 is a sectional elevation
illustrating a bolt with two right hand screw threads 1 and 2 of different pitch and
different diameter and with nuts e and screwed thereon. Figure 30 is an elevation
of a bolt shewing how the left hand thread for the nut can be cut over the right
hand thread of the bolt d so as to have the same diameter for both screw threads.
Or, as shewn in the elevation of a bolt at figure 31, a second right hand thread of
the same diameter can be cut over the first but having a different pitch and the
clamps as before described are used in this case in a like manner. The two threads
on the bolt and the corresponding nuts may be cut of the same depth or one may
be slightly flat or less deep than the other according to the purpose for which they
are required.
Instead of a washer placed hetween the nuts, a hexagonal tube such as m can be
passed over the two nuts as shewn in Figure 32 which is an elevation of a bolt and
nuts provided with such a tube shewn in section. The tube m is prevented from
slipping off by a bend in the middle of one of its sides or by other suitable means and
thereby prevents the nuts working loose.
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.) A nut-lock for screw bolts having threads of different hand or pitch and fitted
with corresponding nuts, consisting of a single or double washer placed between the
nuts and having the edges or clamps formed thereon bent over so as to bear against
the sides of the two nuts substantially as herein before described.
(2.) A nut-lock, for screw bolts having threads of different hand or pitch and two
corresponding nuts, formed by providing one of such nuts with clamps which are
bent over to bear against the sides of the other nut, the two nuts being regulated so

page_text: that their sides can be brought to coincide with each other substantially as herein-
before described.
(3.) The improved nut-locks herein before described with reference to the various
figures of the accompanying drawing.
Dated the 16th day of April 1890.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.