Improvements in Washers and Nuts for Effecting the Locking or Securing of Nuts on Screw Bolts.
Year: 1888

page_text: Improvements in Washers and Nuts for Effecting the Locking or
Securing of Nuts on Screw Bolts.
I. ADOLPH VOGT of Hameln in the Empire of Germany, Civil Engineer do hereby
declare the nature of this Invention to be as follows
The object of my Invention is to provide means whereby nuts can be readily and
efficiently locked or secured in their screwed up position on their bolts without
liability to their working loose by reason of vibration or from other cause.
The nut or a loose washer turning with the nut by reason of its fitting on it or
being secured to it has on its inner surface a wedge shaped radial projection or several
(preferably three) such projections the thicker ends of the wedges being towards the
centre of the nut or washer. There is also provided a second washer which intervenes
between the surface through which the bolt passes and the face of the nut or washer
carrying the wedge shaped projections. The surface of the said second washer which
is opposed to the said projections has a corresponding number of curved recesses the
curves thereof being disposed eccentrically of the centre of the washer, bolt and nut
and in planes parallel to the planes of the surfaces or faces of the washer in which
they are formed. At the end of each such curved recesses furthest from the centre
of the washer the recesses terminate in radial lines also in planes parallel to the planes
of the faces of the said washer.
The eccentricity of the recesses is so calculated that when the nut is being screwed
home the wedges on the first washer or nut after slipping for a certain angle on these
outlines get a firm bold on them and exercise such a pressure upon the second washer
and consequently on the surface behind it that neither nut nor washer can further.
turn.
The projections and recesses aforesaid are of such a degree that they exceed in a
given part of a rotation the pitch of the screw of the bolt and nut and therefore
the tightening of the nut increases if an endeavour be made to screw back the nut.
In order to be able to unscrew the nut after it has been tightened in this way the
second washer has a number of sides or has such a form that it may be turned by

page_text: means of a key or other suitable means.
As soon as the second washer is turned in
the direction in which the nut has to be unscrewed the pressure between nut and
_washer_ceases and the nut becomes loose.
The second washer instead of having excentrically curved recesses may be provided
with curved projections whose upper lines are disposed eccentrically of the centre of
the washer, bolt and nut and in planes parallel to the planes of the surfaces or faces
of the washer on which they are projecting. At the end of each such curved projections
furthest from the centre of the washer the projections terminate in radial lines also
in planes parallel to the planes of the faces of the said washer.
In this case to produce the same effect of gripping the nut the eccentricity of these
upper lines must have an opposite direction to that employed in the first arrangement
and also the wedge shaped projections of the nut or its washer must have their thin
ends near the centre of the washer.
The curved recesses or projections may be on the first washer or on the nut and
the wedge shaped projection may be on the second washer.
The second washer instead of having wedge shaped projections may be provided
with one or more radially situated ribs, the upper surfaces of which are parallel to
the plane of the washer. The first washer or the nut may have on its lower surface
opposite to the ribs of the second washer a corresponding number of projecting
inclined flanges. The inclinations of this flange are so calculated that when the nut
or its washer turns in the direction for unscrewing the nut these inclined surfaces
get a firm hold on the ribs so that at last the nut is so firmly tightened that it cannot
be unscrewed without the second washer being loosened as in the previous
arrangements.
It will be evident that the details for obtaining the same effect of gripping the
nut may be varied for example. Both washers or one washer and the nut may be
provided on their opposite surfaces with projections radially or tangentially disposed
to the washer and straight or curved the upper surfaces or outlines of two such
opposite projections being either both inclined or one inclined and the other in
parallel plane to the plane of the washer. The inclination of these projections may
be directed either towards the centre or towards the circumference of the washers.
From this it will be seen that the arrangements may be considerably varied but
in any event the opposite projections should cross each other and one or both of
them should be inclined towards the centré and so that the locking effect is obtained
by the greater extent of the incline over the pitch of the screw in a given portion of
a rotation.

page_text: I ADOLPH VOGT of Hameln in the Empire of Germany 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 object of my Invention is to provide means whereby nuts can be readily and
efficiently locked or secured in their screwed up position on their bolts without liability
to their working loose by reason of vibration or from other cause.
The nut or a loose washer turning with the nut by reason of its fitting on it or
being secured to it has on its inner surface a wedge shaped radial projection or soveral
(preferably three) such projections.
Figure 1 of the accompanying drawings shows in plan of underside and side view
the projections a on the nut A and Figure 2 shows in corresponding views a washer A
separate from the nut with the projections a upon it the said washer having two or
moro sides at a² which embrace the nut so that the washer and nut form virtually one
as far as rotary movement is concerned.
The thicker ends of the wedges are in these cases as shown towards the centre of
the nut or washer. There is also provided a second washer B shown in plan and
vertical section in Figure 3 which washer occupies a position between the surface
through which the bolt passes and the face of the nut A or the washer A2 carrying
the wedge shaped projections a. The surface of the said second washer which is
opposed to the said projections a has a corresponding number of curved recesses
the outer curves thereof being disposed eccentrically of the centre of the washer bolt
and nut and in planes parallel to the planes of the surfaces or faces of the washer in
which they are formed. At the end of each such curved recesses furthest from the
centre of the washer the recesses terminate in radial lines also in planes parallel to
the planes of the faces of the said washer.
The eccentricity of the recesses is so calculated that when the nut A is being
screwed home the wedges a on the first washer A2 or on the nut A after slipping for
a certain distance on the outer curved edges of the recesses get a firm hold on them
and exercise such a pressure upon the second washer B and consequently on the
surface behind it that neither nut nor washer can further turn. Figure 4 shows in
elevation partly in section the bolt with the washers in place and the nut screwed up,
the loose washer A being used in the example here illustrated.
The projections and recesses aforesaid are of such a degree of inclination and
eccentricity respectively that they exceed in a given part of a rotation the pitch of
the screw of the bolt and nut and therefore the tightening of the nut increases if an
endeavour be made to screw back the nut.

page_text: In order to be able to unscrew the nut after it has been tightened in this way the
second washer B has a number of sides (as shown for example) or has such a form
that it can be turned by means of a key or other suitable incans. As soon as the
second washer is turned in the direction in which the nut has to be unscrewed the
pressure between nut and washer ceases and the nut becomes loose.
When I use
the washer A2 the Invention can be readily applied to existing bolts and nuts.
It is to be understood that in referring to the second washer I mean the washer
which is next the surface through which the bolt passes whether there be another
separate washer or not. Instead of there being eccentrically curved recesses bas in
Figure 3 bearing against wedge shaped projections a the first washer or the next
may have thereon curved projections whose upper surfaces are disposed eccentrically
to the centre of the washer bolt and nut and in planes parallel to the planes of the
surfaces or faces of the washer on which they project. This is shown in Figure 5 in
plan of underside and in section on the line 1, 2. At the end of each such curved
projection (c) furthest from the centre of the washer they terminate in radial lines c²
also in planes parallel to the planes of the faces of the said washer. In this case to
produce the same effect of gripping the nut the eccentricity of these projections c
must have a direction opposite to that employed in the first arrangement and also the
wedge shaped projections a³ of the second washer must have their thin ends near the
centre of the washer as shown in Figure 6. Figure 7 shows the bolt washers and nut
in place.
The curved recesses or the projections c and the wedge shaped projections a³
may be on either the first washer (or on the nut) or on the second washer as may be
desired.
The second washer instead of having wedge shaped projections may be provided
with one or more radially situated ribs d as shown in Figure 8 the upper surfaces of
which are parallel to the plane of the washer. And the first washer or the nut may
have on its lower surface opposite to the ribs d of the second washer a corresponding
number of projecting inclined or wedge shaped projections at as shown in plan and
section on the line 3, 4 in Figure 9. The inclination of these projections a' is so
calculated that when the nut or its washer turns in the direction for unscrewing the
nut these inclined surfaces a get a firm hold on the ribs d so that finally the nut is
so firmly tightened that it cannot be unscrewed without the second washer being
loosened as in the previous arrangements. Figure 10 shows this last arrangement
with the bolt washers and nut in place.
It will be evident that the details for obtaining the described effect of gripping the
nut may be varied for example:
Both washers or one washer and the nut may be provided on their opposite surfaces
with projections radially or tangentially disposed to the washer and straight or curved
the upper surfaces or outlines of two such opposite projections being either both
inclined or one inclined and the other in parallel plane to the plane of the washer.
The inclination of these projections may bo directed either towards the centre or
towards the circumference of the washers. Figures 11, 12 and 13 show some examples
according to these modifications, the full lines showing the bearing parts on one surfaco
and the dotted lines the bearing parts on the opposed surface.
From this it will be seen that the arrangements may be considerably varied but in
any event the opposite projections should cross each other and one or both of them
should be inclined towards the contre so that the locking effect is obtained by the
greater extent of the incline over the pitch of the screw in a given portion of a
rotation.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is:
1. Providing washers or washers and nuts for screw bolts with their opposed surfaces
provided with inclined and eccentrically situated surfaces such that the nut is locked
in position on the bolt substantially as hereinbefore described.

page_text: 2. Providing washers or washers and nuts for screw bolts with opposed surfaces
provided with parts such that the nut is locked in position on the bolt owing to the
greater difference in degree of elevation of such parts over the pitch of the screw
substantially as herein beforo described.
3. A nut locking device in which the nut and the washer are provided on their
opposed surfaces with wedge shaped radial projections and with eccentrically curved
recesses or projections such that after the nut is screwed home tendency to backward
movement of the nut is prevented substantially as herein before described.
4. A nut locking device consisting of two washers provided on their opposed
surfaces with projections as and for the purpose hereinbefore described and claimed
one of the washers being formed so that it embraces the nut or becomes engaged
therewith substantially as herein before described.