An Improved Lock-nut.
Year: 1889

page_text: Date of Application, 14th Feb., 1889
Complete Specification Left, 14th Nov., 1889-Accepted, 8th Feb., 1890
NOVIDIONAL DIUIFICATION.
An Improved Lock-nut.
I, JAMES WILLIAM SMALLMAN, of Nuneaton, in the County of Warwick, and
Brixton, in the County of Surrey, Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention consists of an improved lock-nut so constructed that, without
adding an extra piece or employing a special bolt, the loosening of the parts by
vibration is prevented.
In carrying out this invention, I employ a nut having a base lying in a plane
which cuts the axial plane of the bolt otherwise than at right-angles; that is, a
nut a portion only of the base of which arrives in contact with the washer until
the nut is screwed home, the effect being to gradually bend the bolt to one side,
and thus lock the parts in position.
10
1
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1000
COMPLETE SPECIFICATION.
An Improved Lock-nut.
I, JAMES WILLIAM SMALLMAN, of Nuneaton, in the County of Warwick, and
Mostyn Road, Brixton, in the County of Surrey, 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 :—
This invention consists of an improved lock-nut so constructed that, without
adding an extra piece or employing a special bolt, the loosening effects of vibra-
tion are overcome.
In carrying out this invention, I employ a nut having a base lying in a plane
which cuts the axial plane of the bolt otherwise than at right angles; that is, a
nut a portion only of the base of which arrives in contact with the washer until
the nut is fully screwed home; the effect being to gradually bend the bolt to one
side, and thus lock the parts in position.
In the accompanying drawings, Fig. 1 is a view partly in plan and partly in
horizontal section shewing a fish-bolt furnished with a nut made in accordance
with the present invention and applied to a rail-joint; the nut being only loosely
screwed up. Fig. 2 is a similar view; the nut being fully screwed home and
securely locked in position.
In Fig. 1, the base of the nut A is in a plane which cuts the axial plane of
the belt B otherwise than at right angles; only one point a in the base of the
nut being in contact with the washer C. in Fig. 2, the bolt, instead of being
straight as in Fig. 1, is bent and the base of the nut is parallel with the washer C
and is, therefore, in a plane approximately at right angles to the axial plane of
that part of the bolt passing through the rail D and the fish-plates E and E'; the
relative position of the plane of the base of the nut with respect to the axial plane of
that part of the bolt actually passing through the nut being of course practically
unchanged.
The action of the parts is as follows:-The point a¹ (opposite the point a) in the
base of the nut rotates in a plane indicated by the line xy. In Fig. 2, therefore, both
the points a and a¹ being in contact with the washer, that part of the nut below the
line xy serves to prevent the movement of the nut in either direction until sufficient
force is exerted to vary the extent to which the bolt is bent. Whilst the nut is being

page_text: screwed home or unscrewed, the projecting end b of the bolt describes a volute; com-
mencing, in the former case, at the inner end and, in the latter case, at the outer end
of the volute. After the bolt is bent by the rotation of the nut in one direction,
it is straightened or nearly straightened by the rotation of the nut in the other
direction.
By way of contrast, it may be pointed out that although an ordinary nut would, if
screwed up against an inclined surface, bend the bolt to one side, it would not whilst
being unscrewed straighten or nearly straighten the bolt, neither would the end of the
bolt travel in a spiral line, nor would there be any locking effect on the nut.
On account of the slight extent to and the gradual manner in which the bolt is bent
by the rotation of the lock-nut above described, frequent removals of the nut do not
affect the efficiency of the bolt, neither is any difficulty experienced in screwing home
or in unscrewing the nut itself.
A lock-nut constructed as above set forth may, therefore, be employed in all cases
where it is desirable for the nuts to be securely fastened.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim as a new manufacture in lock-nuts is :-
1. The improved lock-nut formed or operating substantially as set forth.
2. A lock-nut in which the locking effect is produced by reason of the nut, when
screwed home, being unable to rotate without varying the extent to which the bolt
has been previously bent, substantially as described.
Dotad the Lith day of November 1889
JAMES W. SMALLMAN.