Improvements in connection with Look Nuts.
Year: 1893

page_text: Date of Application, 3rd Feb., 1893
Complete Specification Left, 2nd Nov.. 1893-Accepted. 2nd Dec.. 1893
PROVISIONAL SPECIFICATION.
Improvements in connection with Look Nuts.
I JOHN SMITH of 195 Windmill Lano Smethwick in the County of Stafford
Engineer do hereby declare the uature of this invention to be as follows :—
My invention relates to adjusting stops and lock nuts.
The object of my invention is the construction of a stop or lock nut whereby the
adjustment can be quickly, easily, and most accurately regulated, and the lock made
absolutely certain.
My invention consists of two stops or nuts, both screwed with two differently
pitched threads, one thread forming the main screw, and the other thread creating
the tension and forming the stop or lock.
The stops or nuts can be made of any material, and the threads of any pitch
providing sufficient allowance be made between the two threads to create the tension
necessary to form the compensating adjusting stop and lock nut.
By way of illustration, I will describe one way of carrying my invention into
effect, but it must be understood that other methods of applying the two nuts and
the two threads may be adopted without departing from the essence of my
invention.
Two nuts "A" and "B" nro screwed through the contre to the same pitch, one
nut "A" is turned down on the outside to a diameter for one half the length of
the nut, and this diameter is screwed all its longth by a thread of a different pitch
to that through the centre of the nut; the other nut "B" has its bore increased
for one half the length of the nut to the same size as the external diametor of the
first nut "A," and this increased bore is scrowed all its length by the same thread
and pitch as the external diameter of the first nut "A," so that the one nut “A”
shall screw into the other nut "B."
"
The difference between the pitch of the threads, that is to say, between the
thread passing through the centro of both nuts and the thread screwing one nut
into the other, is sufficient to compensate for any slackness in the fit of the two
nute on the bolt or spindle, and to form a tension whereby the adjustment or
lock is made.
This adjustment or lock can be made with equal facility by screwing the outer
nut "A" either forward or backwardl.
This stop or lock nut is specially adapted for all kinds of connecting-rod bolts,
slide valve spindles, cut-off valves, Meyers oxpansion gear, and for scouring the
buckets or plungers of steam pumps on to their rods.
It can also be used with the greatest efficiency for any other duty for which an
adjustable stop or lock nut is required.
Dated this 2nd day of February 1893.
COMPLETE SPECIFICATION.
Improvements in connection with Look -Nuts.
I, JOHN SMITH, of 195 Windmill Laue, Smethwick, Staffordshire, 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:-
My invention relates to adjusting stops and lock nuts.
The object of my invention is the construction of an. adjusting stop or lock-nut

page_text: whereby the adjustment can be quickly, easily, and accurately regulated, and a
secure lock made upon the thread without jambing against the work, distorting the
thread, or using split pin or cotter.
My invention consists of two stops or nuts both screwed with two differently
pitched threads, one thread forming the main screw, and the other thread creating
the tension and forming the stop or look.
The stops or nuts can be made of any suitable material and the threads of any
pitch providing sufficient allowance be made between the two threads to create the
tension necessary to form the adjusting stop or lock nut.
The annexed drawings show more clearly the application of the invention.
A and B are two nuts of any desired form, both screwed through the centre by
the same pitched thread (a) so that they will fit on the same bolt.
Nut A for a portion of its length (a¹) is reduced externally to a diameter, and
this reduced external diameter is screwed by a thread (a') of a different pitch to
that running through the centre of the nut.
Nut B for a portion of its length (b) corresponding to the length of the reduced
external diameter of nut A, is increased in the bore, and this increased boró is
screwed by the same pitched thread as the reduced external diameter of nut A, so
that nut A кcrews into nut B.
It is obvious that the difference in the speed or travel of the two threads corre-
sponds to the difference in their respective pitches, so that when the pitch of the
thread scrowing nut A into nut B is finor than the pitch of the thread passing
through the centre of the nuts, the speed of the two nuts running into each other
will be slower than the speed of the nuts along the bolt. Therefore when nut B
is at rest on the bolt and nut-A is run on the bult and screwed into nut B, nut A
will travel along the bolt quicker than it screws into nut B. This will cause nut B to
be drawn towards out A, and, as the nuts are drawn together any slackness there
may be in the fit of the nuts on the bolt thread will be taken up, and each of the
threads running through the centre of the uuts will be pressed against the corre-
sponding bolt threads in the direction of the bolt-end and away from where the
work would be placed, so that the lock is made upon the bolt thread without
jambing the nut against the work. When required the unt can be as firmly screwed
against the work as any ordinary nut without, in any degree, taking from its looking
efficiency.
"
As nut A is screwed home into nut B the pressure upon the bolt thread will be
increased until a secure lock is made upon the bolt thread for the whole length of
the two combined nuts.
The speed of locking is merely a matter of detail and is capable of being varied
as circunstances may require, without departing from the essence of the invention
which consists in the application of differential threads for the adjusting and
tightening of stops or nuts. In the application of this principle to the adjusting
and tightening of stops or nuts it is possible to arrange the stops or uuts inversely
to the manner above described, that is to say the pitch of the thread running
through the centre of the nut may be finer than the pitch of the thread screwing
nut A into nut B.
The locking can be varied so that it may be effected by turning nut A eithor
forward or backward, at the will of the operator, or by turning nut A forward only,
as circumstances may require. When it is required to effect the lock by turning
nut A either forward or backward, put.A is screwed into nut B for nearly the
whole length of its reduced external diameter (see Fig. 2) before the nuts are
placed upon the bolt thread, the two combined nuts are then placed upon the bolt
and run along the thread as one nut until nut B is in the position in which it is
required to be locked. The look is then effected upon the bolt thread by turning
nut A either forward or backward at the will of the operator.
When the look is to be effected by turning nut A forward only, each nut is run
along the bolt thread separately (see Fig. 3) just as two ordinary nut. Nut B is
first run on the bolt, thread to the, position. in which it is required to be locked.

page_text: Nut A is then run on the bolt thread and screwed into nut B, and, as the operator
tightens nut A so the look is effected upon the bolt thread in the manner as above
set forth.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination of parts forming two stops or nuts, each stop or nut being
Borewed with two differently pitched threads running parallel to each other, the
difference between the pitch of the two threads being sufficient to create a tension
and form a secure lock upon the bolt thread.
2. The arrangement of the two stops or nuts and the two differently pitched
threads as above described and claimed in Claim 1. in such a manner as to effect the
lock upon the bolt thread by turning the outward stop or nut either forward or
backward.
"
3. The arrangement of the two stops or nuts and the two differently pitched
threads as above described and claimed in Claim 1. in a way other than described
and claimed in Claim 2. so that the lock upon the thread is made by turning the
outward stop or nut in one direction only, as described in reference to Fig. 3.
The whole to be substantially as and for the purposes described and illustrated in
the accompanying drawings.
Dated this lat day of Novembo 1902