IMPROVEMENTS IN LOCK-NUTS AND SCREW BOLTS
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 IMPROVEMENTS IN LOCK-NUTS
AND SCREW BOLTS communicated to him from abroad by Benjamin Sampson
Crocker of Topeka in the County of Shawnee, William Harrison Hill also of
Topeka in the County of Shawnee and Alexander Monroe, of Lawrence in the
County of Douglas, both in the State of Kausas, United States of America
COMPLETE SPECIFICATION filed by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 10th July 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
"IMPROVEMENTS IN LOCK-NUTS AND SCREW BOLTS communicated to me from
abroad by Benjamin Sampson Crocker of Topeka in the County of Shawnee,
William Harrison Hill, also of Topeka in the County of Shawnee, and Alexander
Monroe of Lawrence in the County of Douglas, both in the State of Kansas,
United States of America.
This
The object of this Invention is to provide an absolute lock nut for screws.
end is attained by the contrivance shown in the accompanying drawing forming
part of this specification, in which Figure 1 shows the end of a bolt with a right
and left screw cut upon the same portion of it. Figures 2 and 3 show longitudinal
sections of the same taken through diametrical planes cutting the circumference at
the lines y,.y and x, x of figure 1, respectively and at the corresponding opposite
points. Figure 4 shows the two nuts employed upon the screw, just in position to
be locked, and Figure 5 shows the nut locked upon the screw. Figure 6 shows an
underside view of the lock nut.
A is the thread of a right hand screw first cut upon the bolt of any required
diameter having any desired. pitch. B is the thread of a left hand screw cut upon
the entire, or as much as is desired of the right hand screw. C is a right hand or
support nut turned upon the right hand thread, and D is a left hand or locking

page_text: nut turned upon the left hand thread of the screw. Now when the right hand
nut is turned to its place and followed to a snug contact by the left hand nut, any
tendency of the right hand or support nut to unscrew will equally tend to tighten
the left hand or lock nut so that by the law of reciprocal antagonisms the nut C
is positively and securely locked.
E represents a projection of any form, like which there may be two or more on
the lock nut contact side of the support nut. F represents a furrow or depression
in the support nut contact side of the lock nut just fitted to receive the
projection E. When the nuts are constructed in this form, the support nut must
be turned past the point at which it is ultimately to rest to just half the length of
the projections E. The lock nut is then turned almost to contact with the
projections E of the support nut and so that these projections shall coincide with
their respective depressions F, at which position, if the nuts have been properly
constructed, their wrench surfaces will be in the same plane. Now by turning
both at once with the wrench, the support nut will turn down to its resting place
and the lock nut will turn up to a contact with the support nut, when, as in the
former case, every tendency of the support nut to unscrew will only force the lock
nut more snugly against it, and as by no means can any jolt or continuous jar now
turn down the lock nut, the support nut is absolutely locked. It can only be
unlocked now by turning both nuts backward at once with the wrench until the
projections are lifted out of their respective depressions, when by turning, down
the lock nut as in the former case, the support nut can be unscrewed.
The left hand thread may be cut first if desired and the projections may be upon
the lock nut, and the depressions upon the support nut.
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.
The combination of a bolt having intersecting right and left hand threads A
and B with the nuts C and D having corresponding threads, one nut being provided
with projections and the other with corresponding depressions on their meeting
faces, as and for the purpose hereinbefore described.
In witness whereof I the said Alexander Melville Clark have hereunto set my
hand and seal this seventh day of July, A.D. 1883.
AT DI