Improvements in Lock Nuts and Bolts.
Year: 1893

page_text: Date of Application, 19th Sept., 1893
Complete Specification Left, 19th June, 1894-Accepted, 21st July, 1894
Improvements in Lock Nuts and Bolts.
I, JAMES SMETHURST of Bandon Terrace, Denton's Green, St. Helens, in the
County of Lancaster, Manufacturer, do hereby declare the nature of this invention
to be as follows:
According to this invention which relates to lock nuts and bolts the bolt is
screwed in the ordinary manner with a right hand thread. The end of the screwed
part or all of it if desired is then screwed in the reverse direction. This reversed
or left hand thread may be of any but is preferably of a coarser pitch than the right
hand thread.
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 thread on the bolt.
The outer face of the inner nut is formed with a series of recesses and the outer nut
is provided with one or more spring pins or bolts the heads of which project from
the inner side and are shaped and adapted to come into engagement with the
recesses on the outer face of the inner nut. These recesses are placed at equal
radial distances from the centre of the nut when only one spring pin is employed on
the lock nut but may be placed at unequal radial distances when more than one
spring pin is employed the pins being placed in corresponding positions on the lock
aut. By this latter arrangement greater nicety of adjustment may be obtained.
The spring pins or bolts are arranged to slide within holes or recesses preferably
at right angles to the face of the lock nut so that their heads may project from the
face and be contained within the recesses on the outer face of the inner nut or may
be entirely contained within the lock nut when they are subjected to pressure.
Outward motion is imparted to the pins or bolts when pressure is removed by means
of suitable springs. For this purpose it is preferred to use an indiarubber ring or
collar which surrounds the stem of the pin and is compressed when the pin is forced
into the lock nut. Other forms of spring may however be used such for instance
as a spring washer or a helical spring.
In use the right hand nut is screwed upon the bolt and is followed by the left
hand nut. When the first nut has been screwed into place and the lock nut is
forced up against it the spring pin or pins or one of them engages with one of the
recesses on the face of the inner nut. Any tendency to outward motion of the inner
nut thus only causes the two nuts to bind more firmly together.
If desired of course the inner nut might be provided with a left hand thread and
the outer or lock nut with a right hand thread the bolt being correspondingly
screwed.
As an alternative method of manufacture the spring pin or pins may be contained
within the inner nut and project from its outer surface the corresponding recesses
being formed on the inner face of the outer or lock nut.
Dated this 18th day of Sentember 1803
WILLIAM E. HEYS,
Agent for the Applicant.

page_text: .
"
Improvements in Lock Nuts and Bolts.
I, JAMES SMETHURST, of Bandon Terrace, Denton's Green, St. Helens, in the
County of Lancaster, Manufacturer, do hereby declare the nature of this invention,
and in what manuer the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
According to this invention which relates to lock-nuts and bolts, the bolt is
screwed in the ordinary manner with a right hand thread. The end of the screwed
part, or all of it if desired, is also screwed in the reverse direction. This reverse or
left hand thread may be of any pitch, but is preferably coarser than the right hand
thread.
The thinner
There are two nuts, of which the inner one is the thicker, and fits upon the right
hand thread. This nut has on its outer face a series of recesses concentric with the
nut, or there may be more than one series of such concentric recesses.
outer nut fits upon the left hand thread and has arranged in its inner face one or
more spring pins or dogs capable of engagement with the recesses on the outer face
of the inner nut. When the inner nut. has been screwed up, the outer nut is screwed
down upon it, whereupon the spring pin ultimately engages with one of the recesses.
As an alternative, the positions of the recesses and the spring pins may be reversed,
the pins being in the inner nut and the recesses in the outer nut.
The accompanying drawings illustrate in what manner my invention may be
carried into effect. In these drawings:
Figure 1 is a sectional elevation of a bolt and nut-lock constructed according to
these improvements.
Figure 2 is a plan of the inner nut, shewing two concentric rows of recesses.
Figure 3 is a plan of the inner side of the outer nut, shewing two spring pins
or dogs at different distances from the centre and adapted respectively to engage
with the inner and outer circle of recesses on the face of the inner nut.
Figure is a plan of a spring pin which may be employed, the spring being
constituted of the indiarubber ring shewn, fitting upon the shank of the pin.
Figures 5 and 6 respectively shew modifications of the spring pin.
A is the bolt screwed with a right and left hand threads. B is in the inner or
working nut, and C is the outer or locking nut. Preferably the nut B is tapped
with a right hand thread, and C with a left hand thread to fit upon the threads
of the bolt, but this arrangement may be reversed, in which case the working nut
will be left handed and the locking nut right handed.
In the outer face of the working nut, the circle of recesses E is formed. These
may be equidistant from the centre of the nut, but in order to obtain closer adjust-
ment I prefer to arrange them in two circles, the recesses in one circle breaking
pitch with those in the other circle, as shewn by the Figure. In the inner face
of the locking nut I arrange as many spring pins F as there are circles of
recesses in the working nut. Thus, in Figure 3, there are two spring pins
respectively arranged at the same distances from the centre as the circles of
recesses shewn by Figure 2. The pins are therefore in such positions that when
the faces of the nuts are brought together they can engage any of the recesses
of the inner and outer circles respectively.
The spring pins F may be variously constructed, and three modifications are
shewn by the drawings. In Figure 4, the pin has, and has in all cases, a
conical head G, under which is a shoulder H, and a cylindrical shank J. Ou
this shank there fits an indiarubber ring L which acts as a spring. In the
inner face of the nut C a recess is formed, as shewn in Figures 5 and 6, for the
head of the pin, and a central hole from the recess for the reception of the shank.
The indiarubber ring has such internal and external diameters that it will fit

page_text: closely upon the shank of the pin and within the recess in the locking nut, so that
when the pin is inserted it cannot accidentally drop out, but may move longitudinally
by the compression and re-expansion of the rubber. Alternative forms of spring
are illustrated by Figures 5 and 6, that in Figure 5 being a bow spring of steel, I,
and that in Figure 6 being a spiral spring . When the bow spring is used, it alone will
suffice to prevent the pin falling accidentally out of the nut, but when the spiral spring
is employed, the shank of the pin may extend through the nut and be secured
by a small cross pin passing through it as shewn.
When the working nut has been screwed up, and the locking nut is screwed
down upon it, the spring pin moves in and out as it rides over the recesses, and
finally remains in one of them when the locking nut is screwed fully up. This
engagement of the pin with one of the recesses tends to lock or fasten the nuts
together and thus to prevent their becoming loosened.
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 :-
As a nut locking device, the combination and arrangement of a right and a left
handed thread upon the bolt a right handed and a left handed nut respectively
fitting upon the bolt threads, and in the contiguous faces of the nuts a circular series
of holes and a spring pin or spring pins, the recesses being in one nut and the spring
pin or pins in the other nut and adapted to engage with each other, substantially
as hereinbefore described and as illustrated by the accompanying drawings.
Dated this 18th day of June A.D. 1894.
WILLIAM E. HEYS,
Agent for the Applicant.