Improvements in Lock Nuts.
Year: 1891

page_text: Date of Application, 31st Jan., 1891
Complete Specification Left, 27th Oct., 1891-Accepted, 5th Dec. 1891
PROVISIONAL SPECIFICATION.
Improvements in Lock Nuts.
I, ROBERT LETHBRIDGE TAPSCOTT of 62 Croxteth Road, Liverpool in the
County of Lancaster Civil Engineer do hereby declare the nature of this invention
to be as follows: -
Improvements in lock nuts, consisting of a combination of screw nuts, to prevent
the ordinary screw nut, from becoming loose while subjected to concussion.
Referring to the accompanying drawings
:―
Figure 1, represents a front elevation of the screw nuts and screw bolt in
position.
Figure 2, represents a vertical sectional detail view of the screw nuts on the
screw bolt.
Figure 3, represents screw nut Y.
Nut Ymay have either a right hand or left hand screw thread cut on its
surface, but it will in any case be different from that on the screw bolt.
Assuming for the purpose of this description that the screw bolt has a right
hand screw thread cut on it then nut Y will have a left hand screw thread cut on
its surface.
In carrying my invention into effect, the ordinary screw nut X is first screwed
on to the bolt A B, then nut Y is screwed onto the bolt A B, but leaving a
space G I. HJ. between it and nut X. Nut Z is then screwed on to nut Y
and tightened up into contact with nut X as shown at OI and J P.
•
If any upward movement of nut X were possible it would be in the direction
necessary to move nut Z, downwards and tighten them.
So that nut X is prevented from moving upwards by nut Z.
Thus nut Z locks nut X.
COMPLETE SPECIFICATION.
Improvements in Lock Nuts.
1, ROBERT LETHBRIDGE TAPSCOTT of 62 Croxteth Road, Liverpool in the
County of Lancaster, Civil 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 :-
The object of my invention is to provide means whereby a screw nut is
prevented from working loose. For this purpose I make a screw nut of small
diameter to work on the screw bolt, having on part of its outer surface the faces
of the nut and on the other part I cut a screw thread of opposite character from
that on the screw bolt, that is to say, if the bolt has a right handed screw thread
cut on it, the nut will have a left handed screw thread cut on part of its outer
surface.
The nut faces will be within a circle of less diameter than the least diameter of
the screw thread. I then make another screw nut having a screw thread cut
through it to work on the screw thread cut on the outer surface of the screw nut
first mentioned the diameter of this second nut being suitable to its surface
meeting and pressing against the surface of the ordinary screw nut.
The drawings left with the Provisional Specification show a screw bolt A B and
three screw nuts X. Y. Z. in position according to my invention.

page_text: Figure 1, shows the screw nuts in position on the screw bolt.
Figure 2, shows the screw bolt with the screw nuts in section, and
Figure 3, shows the outer surface of screw nut Y.
The part CEF D'of the outer surface of the screw nut Yhas faces cut on it in
the ordinary way, the other part E G H F has a screw thread cut on it of opposite
character to that on the screw bolt, that is to say, if the screw bolt has a right
handed screw thread cut on it, the nut Y'will have a left handed screw thread cut
on its outer surface E G H F, it has also a screw thread cut through it to work on
the screw bolt.
The screw nut Z has the ordinary faces cut on its outer surface R M N L and
through it a screw thread to work on the screw thread E G H F of the screw
nut. The screw nut X denoted by OQR P is an ordinary screw nut working
on the screw bolt and is the nut to be locked.
When the nuts are all in position and properly screwed up there will be a
space GIJ H between nut X and nut Y; and nut Z will be pressing against
nut X on the surface denoted by OI and JP.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is
A combination of screw nuts substantially as and for the purpose herein
described and shown upon the drawings.
Dated this Twenty-sixth day of October 1891
R. LETHBRIDGE TAPSCOTT.