Improvements in Lock Nuts.
Year: 1890

page_text: Date of Application, 5th Nov., 1890
Complete Specification Left, 5th Aug., 1891-Accepted, 26th Sept., 1891
PROVISIONAL SPECIFICATION,
Improvements in Lock Nuts.
I, HARRY THOMAS MINNITT, Egerton Villa Horn Lane Acton London W.,
Draughtsman, do hereby declare the nature of this invention to be as follows:--
In fastening by bolts and nuts two pieces of plate or metal together, it is some-
times necessary owing to the jarring it is subjected to, that the nuts should be
prevented from shaking loose or in other words should be locked. This end is
sometimes accomplished by constructing the nut with a saw nick on one side, and
by compressing the one part, the spring of the nut bears on the thread of the bolt,
and friction then prevents the slacking back of the nut.
My improvements relate to the class of lock nuts, in which two nuts are used.
The first for the purpose of tightening up and the second for jamming it or fixing
it in position, so that it cannot shake back, the latter nut generally being a. thin
one and is termed the lock nut, the other the main nut.
One method of carrying out my improvements, consists in making a short
screwed cone on the face of a nut, and through this cone tapping the ordinary
thread of the bolt, then making a saw nick on one side entirely severing that side
longitudinally.
This is the nut that is screwed onto the bolt after the other or cone nut is
fixed in position against the plate or plates. In tightening up this outer nut, the
saw nick allows it to compress & tighten round the bolt end when screwing into
the cone nut.
In place of slitting the entire nut to the full depth, a modification would be, to
cross cut the cone down to the depth of the coned screw, and by compressing the
nut by the four wings achieve the same result.
.
A second modification, is to dispense entirely with the screw thread on the
cone.
Dated thin 5th day of Novembar 1800.
SAML. HANNAH,
Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in Lock Nuts.
I, HARRY THOMAS MINNITT, Egerton Villa, Horn Lane, Acton, London W.,
Draughtsman, 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 :-
In fastening by bolts and nuts, two pieces of plate or metal together, it is
sometimes necessary, owing to the jarring it is subjected to, that the nuts should
be prevented from shaking loose, or in other words, should be locked. This end
is sometimes accomplished by constructing the nut with a saw nick on one side,
and by compressing the one part, the spring of the nut bears on the thread of the
bolt, and friction then prevents the slacking back of the nut.
My improvements relate to the class of locknuts in which two nuts are used.
The first for the purpose of tightening up and the second for jamming it, or fixing
it in position so that it cannot shake back, the latter nut generally being a thin
one and is termed the locknut, the other, the main nut.
One method of carrying out my improvements, consists in making a short screwed
cone on the face of a nut and through this cone tapping the ordinary thread of

page_text: the bolt, then making a saw nick on one side entirely severing that side
longitudinally.
This is the nut that is screwed into the bolt after the other or coned nut is
fixed in position against the plate or plates. In tightening up this outer nut, the
saw nick allows it to compress and tighten round the bolt end when screwing into
the cone nut.
In place of slitting the entire nut to the full depth, a modification would be to
cross cut down to the depth of the coned screw and by compressing the nut by
the four wings achieve the same result.
A second modification is to dispense entirely with the screw thread on the cone,
making it a plain wedge or cone, and splitting it down one side, as previously
described with the screwed cone, or making three or more cuts, but the depth of
the cone only.
Referring to the accompanying drawings ;
Fig. 1. shows the plain coned lock nut.
Fig. 2. shows the screwed coned lock nut.
Fig. 3. shows a section of the same.
Fig. 4. shows the plain coned lock nut, but with four slits.
Fig. 5. shows a plan of the same with one of the parts removed.
In Fig. 1. (a) is the coned nut tapped, with a thread as usual, this is shown in
dotted lines (b). It is split on one side the entire depth as shown at (c). (d) is
the lower plain nut, it is coned internally to fit the male cone on the top nut.
In using it, the lower nut (d) is first placed over the bolt end, the top nut is then
screwed on and the cone on entering the lower nut, is by the wedge action com-
pressed round the bolt and thus effectually prevents its return by shaking or any
ordinary means.
Fig. 2. is the screwed coned nut, similar in all respects to Fig. 1. with the
exception that the cone is threaded, with a pitch or distance apart, of the threads
exactly the same as the tapped part (e), its action also is similar to Fig. 1., except
that the top nut enters the screwed cone and so tightens the split nut on the bolt
end, this is better seen in section Fig. 3.
Fig. 4. shows the top nut split by four or any convenient number of nicks
but down only to the extended part of the top nut (h).
Its action is similar to the others, with the exception that the four wings
only are compressed round the bolt in place of the full depth as in Fig. 1 and
Fig. 2.
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:
1st. A lock nut composed of an ordinary nut, with a split screwed cone on one
side screwed into a cap nut, the whole forming a lock nut as shown & described.
2nd. A lock nut composed of an ordinary nut with a plain split cone on one
side fitting into a cap nut, the whole forming a lock nut as shown and described.
3rd. A lock nut composed of an ordinary nut with either plain or screwed
cone, but with three or more splits the depth of the cone as shown and described.
Dated this 5th day of August 1891.
SAML. HANNAH,
51, Lincoln's Inn Fields, London, W.C., Agent for Applicant.