Improvements in Lock Nuts and Bolts.
Year: 1891

page_text: Date of Application, 25th Feb., 1891
Complete Specification Left, 25th Nov., 1891-Accepted, 9th Jan., 1892
PROVISIONAL SPECIFICATION.
[Communicated from abroad by WALTER GLEDHILL, of 625, Chestnut Street,
Philadelphia, in the United States of America, Manufacturer.]
Improvements in Lock Nuts and Bolts.
I, JAMES SMETHURST of Holywell Green Halifax in the County of York,
Manufacturer, do hereby declare the nature of this invention to be as follows :-
This invention relates to lock nuts and bolts.
According to these improvements, the bolt is screwed in the ordinary manner
with a right hand thread and in addition, the outer end of the bolt is screwed
with a left hand thread having a greater pitch in order not to weaken the screwed
part of the bolt to any considerable extent.
The inner nut is tapped with a right hand thread and the outer or lock nut
with a left hand thread, each of the same pitch as the corresponding threads on
the bolt. On the outer face of the inner nut there is formed an annular projection
around the eye of the nut, and on the contiguous face of the lock nut an annular
recess is formed to receive the projection on the face of the inner nut. The outer
face of the annular projection of the inner nut is preferably serrated, and a small
set screw is passed at an angle or longitudinally through the lock nut so that when
the nuts are screwed up, the end of the set screw may be caused to engage in one
of the serrations.
With this arrangement, even without the set screw, any motion of the nuts
tending to loosen them will only cause them to bind more firmly together and lock
themselves upon the bolt. The set screw is however preferred to be used as an
additional precaution.
D
1
30
1
1
4
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1001
WILLIAM E. HEYS,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Lock Nuts and Bolts.
I, JAMES SMETHURST of Holywell Green, Halifax in the County of York,
Manufacturer, 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 lock-nuts and bolts.
According to these improvements, the bolt is screwed in the ordinary manner
with a right hand thread, and in addition, the outer end of the bolt is also screwed
with a left hand thread having a greater pitch than the right hand thread, in
order not to weaken the screwed part of the bolt to any considerable extent.
The inner nut is tapped with a right hand thread and the outer or lock-nut
with a left hand thread, each of the threads being of the same pitch as those of
the corresponding parts of the bolts. On the outer face of the inner nut there is
formed an annular projection around the eye of the nut, and on the contiguous face
of the lock-nut an annular recess is formed to receive the projection on the face
of the inner nut. The outer face of the annular projection of the inner nut is
preferably serrated, and a small set-screw may be passed at an angle or longi-
tudinally through the lock-nut so that when the nuts are screwed up the end of
the set-screw may be caused to engage with one or other of the serrations.

page_text: With this arrangement, even without the set-screw any motion of the nuts
tending to loosen them will only cause them to bind more firmly together and lock
themselves upon the bolt. The set screw is however preferred to be used as an
additional precaution.
The accompanying drawings illustrate in what manner this invention may be
carried into practical effect, and will be hereinafter referred to. In each of the
figures similar parts or details are indicated by similar letters of reference.
Figure 1 represents a longitudinal sectional elevation ;
Figure 2 a plan of the lock nut;
Figure 3 a plan of the inner mut; and
Figure 4 an elevation of the inner nut.
A is the bolt which is screwed throughout with a right hand thread in the
ordinary manner, and is afterwards screwed with a left hand thread of the same
diameter but of a coarser pitch to about the point where the faces of the nuts will
meet in use, as indicated by Figure 1.
B is the inner nut on which the annular projection E is formed around the eye
of the bolt. This projection is preferred to be radially notched or serrated,
each of the notches being capable of receiving the point of the set screw D. In
use this annular projection E is on the side of the nut further from the head of
the bolt.
C is the lock nut having an annular recess formed in it corresponding with the
projection E which fits into it in use. Through this nut a hole is drilled and
tapped for the set-screw D, the hole being drilled in such a direction and position
that the point of the set-screw may engage with one or other of the notches in E
after the nut C has been screwed into contact with the nut B.
From the construction of the nuts and of the bolt it will be obvious that when
they are in contact, with the head face of the nut B in contact, for example, with
a fish plate, that any motion tending to rotate either of the nuts will only cause
them to tend to lock more securely.
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. The construction combination and arrangement with the nuts B and C
respectively tapped with a right hand and a left hand screw thread the left hand
thread having a coarser pitch than the right hand thread, and of the bolt screwed
with a right hand thread and additionally screwed at the point with a coarser
left hand thread; substantially as and for the purpose hereinbefore described and
as illustrated by the accompanying drawings.
2. The construction combination and arrangement with the nuts BC respec-
tively tapped with right hand and with left hand screw threads the left hand screw
thread having a coarser pitch than the right hand thread, with a bolt screwed
with a right hand screw thread and additionally screwed at the point with a left
hand thread of coarser pitch, a notched annular projection E on the inner nut, a
corresponding recess on the outer nut, and the set screw D; substantially as
and for the purpose hereinbefore described and as illustrated by the accompanying
drawings.
Dated this 23rd day of November A.D. 1891.
WILLIAM E. HEYS,
Agent for the Applicant.