An Improved Means for Locking the Heads of Screws or Screw Nuts.
Year: 1892

page_text: Date of Application, 4th Oct., 1892-Accepted, 5th Nov., 1892
COMPLETE SPECIFICATION.
An Improved Means for Locking the Heads of Screws or
Screw Nuts.
We, LEOPOLD RICHARD BLUMSTENGEL of Loschwitz near Dresden, Lieu-
tenant-Colonel, and ERNST LUDWIG ROEHN of Humboldtstrasse, Dresden, in the
German Empire, Architect, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to a means or device for the simultaneous locking of two
screw heads or two screw nuts and is more especially designed for application to
the connections of railway rails.
In the accompanying drawing the invention is shewn employed for locking the
screw nuts of fish plate bolts, Fig. 1 being a front view, Fig. 2 an end view, Fig. 3
a top view, Fig. 4 a back view of the device and Fig. 5 a sectional view of a
lock nut.
The screw or nut locking device consists of a curved stay or stretcher a, the
ends 6 of which, engage in corresponding recesses c in the screw heads or nuts,
bearing against the latter in such a way that in the event of the screws or nuts
turning in the direction to become loose, the stay a will be the more tightly
compressed between the screw heads or nuts, or if one only of the screws or nuts
should slacken the other screw or nut will be the more tightly screwed up.
This action will be clearly understood from Fig. 1 in which the screw thread is
supposed to be right handed. The result is due partly to the particular curved
form of the stay or stretcher a which allows of its being pressed against and
between each screw head or nut when these turn in the slackening direction,
and partly to the location of the recesses c (Fig. 4) relatively to the axis of the
screw thread in such a way that the ends of stay a cannot of themselves spring
out of the same upon the occurrence of shocks or vibrations.
The stay a is applied to the screw heads or nuts by first introducing one end of
the same into that recess of a screw head or nut which is near the foot of the
rail and then the other end into the corresponding recess of the other head or
The introduction of the
nut being that which is near the head of the rail.
second end may be effected by means of a slight blow upon the upper curved
surface of the stay. To this end the stay is made of such a length that after
one end of the same has, as described, been introduced into a recess of the one
screw head or nut, the other end can only be introduced into the corresponding
recess of the other screw head or nut by causing the stay to extend by means of a
slight blow on the corresponding curved part. The stays so placed in position
may be removed by the use of a slight force without rendering them unfit for
re-use, although they will not be displaced by blows, shocks or vibrations. In
view of possible irregularities in the metal of the fish plates and in the screw
threads or other parts, recesses c are provided on all the sides or corners of the
screw heads or nuts, so that upon the head or nut being screwed down into the
fastening position, one of the said recesses may always be brought into the requisite
position.
This locking device has been shewn in practice to be safe, durable, simple and
inexpensive, and not affected by the most inclement weather, properties that render
the device of considerable value for the permanent way of railways.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
A means or device for the simultaneous locking of two screw heads or screw

page_text: nuts, in which a curved stay a engages by its ends in corresponding recesses in
said screw heads or screw nuts and is jammed between these in such a way that
if they work loose it becomes more tightly fixed, or if one of such screw heads or
screw nuts works loose the other is made tighter, substantially as described and
shewn..
Dated this 4th day of October 1892.
THOMAS R. SHILLITO,
89, Chancery Lane, London, W.C., Agent for the Applicants.