AN IMPROVED NUT-LOCK
Year: 1883

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A. M and
W. Clark of 53 Chancery Lane in the County of Middlesex Fellow of the
Institute of Patent Agents for an Invention of AN IMPROVED NUT-LOCK
communicated to him from abroad by Henry Schwarzwalder of the City of
New York in the County and State of New York, United States of America
COMPLETE SPECIFICATION filed by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 13th November 1883.
"
ALEXANDER MELVILLE CLARK of the firm of A. M and W. Clark of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents. "AN
IMPROVED NUT-LOCK communicated to me from abroad by Henry Schwarzwalder
of the City of New York in the County and State of New York, United States of
America
This Invention relates to means for preventing nuts from working loose on bolts
or screws, whether used on vehicles, such as railroad cars, or on stationary
contrivances, such as, railroad rails or in other places. The invention consists in
slitting the threaded end of the bolt, and in combining therewith a nut and a
washer, which carries a yoke that enters the slit in the end of the bolt, all as
hereinafter more fully described.
Figure 1 of the accompanying drawing is a plan or top view of the Improved
nut-lock Figure 2 is a side view of the same and Figure 3 a central section
.thereof.
In the drawing, the letter A represents a bolt or screw, and B is the nut, which
is threaded to fit said bolt or screw. C is a washer or plate, having a yoke-likė
top piece D. The upper or threaded end of the bolt or screw A, has a longitudinal
slot a cut into it, into which the central portion of the yoke D enters, when the
device is in use. The nut will be between the body C, of the washer and the
yoke D when the parts are properly on the bolt..
In screwing the nut home it forces the washer along with it and thereby draws
the yoke D farther down into the slot a of the bolt, the effect of which is that the

page_text: yoke acting as a wedge, will finally spread the slitted end of the bolt, as is shown
in figure 3. In this position it will be impossible for the nut to become jarred
loose, as it cannot ride up on the expanded thread of the spread bolt, and the yoke
at the same time is held fast in the jaws of said spread bolt. A very strong
wrench and great power will be needed to start the nut B on its backward motion,
and as it is started, the person who does it will have to take care to cause the
washer C, to follow it, so as thus gradually to move the yoke D out of the slot, and
get the bolt A, back into normal cylindrical form by the operation of unscrewing
the nut.
The yoke D may either be of the form shown in figure 2, or may be a projection 1
on or attachment of the washer C of any-other form, provided it is adapted to
enter the slit in the bolt, while the nut is between the said entering portion and
the body of the washer. Where the yoke-or its equivalent enters into the slot a it
may either be of rectangular form, as shown in figure 3, in which case the slot
may be tapering, or it may be wedge-like, in which case the slot may have parallel
sides.
Having described the nature of the said Invention and the manner of performing
the same I declare that what I claim as new and desire to secure by Letters
Patent is:
1st The combination of the nut B with the travelling washer C, yoke D, and
bolt A, having slit a substantially as described.
2nd The nut-lock constructed to secure the nut to the bolt by spreading the bolt,
substantially as specified.
In witness whereof I the said Alexander Melville Clark have hereunto set my
hand and seal this fifth day of November A.D. 1883.