Improvements in Locking, the Screw Nuts of Sorew Bolts and other Screws.
Year: 1891

page_text: Date of Application, 23rd May, 1891
Complete Specification Left, 16th Feb., 1892-Accepted. 19th Mar., 1892
PROVISIONAL SPECIFICATION.
Improvements in Locking, the Screw Nuts of Sorew Bolts and
other Screws.
We TANGYES LIMITED of Cornwall Works Soho in the County of Stafford
Engineers and JAMES RICHARD WILLIAMS of Station Road Handsworth in the
County of Stafford Mechanical Engineer do hereby declare the nature of this.
invention to be as follows:-
The said invention has for its object to prevent the accidental unscrewing of
screw nuts from the screws of screw bolts or other screws on which the said nuts
may have been screwed.
On the top or outer face of the screw nut we make a series of ratchet teeth
extending all round the said face of the screw nut. We make a short sleeve or
tubular piece having on its lower or inner face a series of ratchet teeth .corre-
sponding to those on the face of the screw nut. The internal diameter of this
sleeve is somewhat greater than the diameter of the end of the screw so that when
the sleeve is placed on the end of the screw the annular space between them is
sufficient for the reception of a helical spring. A shoulder at the bottom of the
interior of the sleeve serves as a bearing for the bottom of the said spring. A.
cotter passed through a cross hole or one of a series of cross holes near the upper
end of the screw serves for the upper bearing of the said spring. At the upper end
of the sleeve two slots are formed at opposite points and parallel with the axis of
the sleeve. These slots extend nearly to the bottom of the sleeve and permit of.
the sliding of the sleeve on the screw. the cross cotter entering these slots and while
permitting of the sliding of the sleeve prevent its rotation.
After the screw nut lías been screwed on the screw of the screw bolt or other
screw the sleeve containing the coiled spring is passed onto the end of the screw
and the spring being compressed the cotter is passed through the cross hole near
the end of the screw and engaged in the slots in the sleeve. The ratchet teeth of..
the sleeve engaging with those of the screw nut the said nut is prevented from
rotating in the direction necessary to withdraw it from the screw.
The said screw
nut can however be advanced on the screw the ratchet teeth permitting the rotation
of the screw nut in the required direction. In order to remove the screw nut
from the screw it is necessary to withdraw the cotter and remove the spring and
sleeve.
,
In some cases we dispense with the sleeve the lower end of the coiled spring.
bearing on the ratchet teeth of the nut its upper end bearing against the cotter.
Where it is desirable to.be able to rotate the screw nut in either direction by the
exertion of a moderate force we do not employ ratchet teeth on the nut and on the
sleeve but we employ teeth the two sides of each of which make with each other
preferably a right angle. In this case the screw nut can be made to move on the
screw in either direction by the use of a spanner there being no risk of the nut
accidentally unscrewing.
Or the parts may be modified in the following manner. The end of the screw
may have fixed to it a cap in which the screw nut moves in one or other direction as
it is moved on the screw. The open lower end of this cap is divided by longitudinal
slits into a series of spring arms; the ends of these arms bear on the hexagonal.
faces of the nut and offer such resistance to its motion that while it may be turned >
on.the screw with the exertion of a moderate force there is no risk of its accidental
removal. Or the nut may have a sleeve with a series of ribs or long teeth all round *

page_text: it on which the ends of the spring arms bear and offer sufficient resistance to
prevent the accidental removal of the screw nut.
Dated the 23rd day of May 1801
W. T. WHITEMAN,
Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in. Locking the Screw Nuts of Screw Bolts and
other Screws.
We, TANGYES LIMITED; of Cornwall Works Soho, in the County of Stafford
Engineers, and JAMES RICHARD WILLIAMS, of Station Road, Handsworth, in
the County of Stafford, Mechanical Engineer, do hereby declare the nature of
the said invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
-:
The said invention has for its object to prevent the accidental unscrewing of
screw nuts from the screws of screw bolts or other screws on which the said nuts
may have been screwed.
:
On the top or outer face of the screw nut we make a series of ratchet teeth
extending all round the said face of the screw nut. We make a short sleeve or
tubular piece having on its lower or inner face a series of ratchet teeth corre-
sponding to those on the face of the screw nut. The internal diameter of this
sleeve is somewhat greater than the diameter of the end of the screw so that when
the sleeve is placed on the end of the screw the annular space between them is
sufficient for the reception of a helical spring. A shoulder at the bottom of the
interior of the sleeve serves as a bearing for the bottom of the said spring. A
cotter passed through a cross hole, or one of a series of cross holes, near the upper
end of the screw serves for the upper bearing of the said spring. At the upper
end of the sleeve, two slots are formed at opposite points and parallel with the axis
of the sleeve. These slots extend nearly to the bottom of the sleeve and permit
of the sliding of the sleeve on the screw, the cross cotter entering these slots and
while permitting of the sliding of the sleeve prevent its rotation.
After the screw nut has been screwed on the screw of the screw bolt or other
screw the sleeve containing the coiled spring is passed onto the end of the screw
and the spring being compressed the cotter is passed through the cross hole near
the end of the screw and engaged in the slots in the sleeve. The ratchet teeth of
the sleeve engaging with those of the screw nut, the said nut is prevented from
rotating in the direction necessary to withdraw it from the screw.
The said screw
nut can however be advanced on the screw the ratchet teeth permitting the rotation
of the screw nut in the required direction. In order to remove the screw nut
from the screw it is necessary to withdraw the cotter and remove the spring and
sleeve.
Where it is desirable to be able to rotate the screw nut in either direction by the.
exertion of a moderate force we do not employ ratchet teeth on the nut and on
the sleeve but we employ teeth the two sides of each of which make with each
other preferably a right angle. In this case the screw nut can be made to move on
the screw in either direction by the use of a spanner, there being no risk of the nut
accidentally unscrewing.
Or the parts may be modified in the following manner. The end of the screw
may have fixed to it a cap in which the screw nut moves in one or other direction
as it is moved on the screw.
The open lower end of this cap is divided by longitudinal slits into a series of
spring arms; the ends of these arms bear on the hexagonal faces of the nut and
offer such resistance to its motion that while it may be turned on. the screw with
the exertion of a moderate force, there is no risk of its accidental removal. Or the nut
may have a sleeve with a series of ribs or long teeth all round it on which the ends

page_text: of the spring arms bear and offer sufficient resistance to prevent the accidental
removal of the screw nut.
We will now proceed to describe with reference to the accompanying drawings
the manner in which the said invention is to be performed.
Figure 1 represents in elevation one of the locking arrangements of the said
invention in which the top or outer face of the screw nut is provided with a series
of ratchet teeth in which one or more ratchet teeth on the lower or inner face of the
locking sleeve or tubular piece engage
Figure 2 represents a plan of the toothed face of the screw nut.
a is the screw holt and the screw nut working thereon; the said screw nut having
ratchet teeth c on its top or outer face; d is the sleeve or short tubular piece
surrounding the lower part of the screw bolt and used for locking the screw nut.
The lower or inner face of the locking sleeve is provided with ratchet teeth at
opposite points; one of these teeth is marked e in Figure 1. It will be seen by
reference to the drawing that the internal diameter of the locking sleeve d is some-
what greater than the diameter of the end of the screw bolt so that an annular
space is left between them. In this annular space the coiled spring is situated
one end of the spring bearing against the bottom of the interior of the sleeve and
the other end of the spring bearing against the cotter 7 passed through a cross hole
in the screw bolt and working in longitudinal slots h, at opposite sides of and
parallel with the axis of the sleeve . These slots h, h and the pin or cotter g
working in them, permit of the sliding of the locking sleeve on the screw bolt, but
the said pin or cross cotter while permitting of the sliding of the sleeve, prevents its
rotation. The slots h, hand the cross cotter g are repeated in the modification
hereinafter described and represented in Figures 3 and 4 and the parts enumerated
are very clearly shown in the last mentioned figures.
the
After the screw nut has been screwed to the required distance on the screw bolt a,
the locking sleeve d containing the coiled spring is passed onto the end of the screw.
bolt and the spring being compressed, the cotter g is passed through the cross hole
near the end of the screw and engaged in the slots h, in the locking sleeve. By
engagement of the ratchet teeth on the sleeve with those on the face of the
screw nut the said screw nut is prevented from rotating in the direction necessary
to withdraw it from the screw bolt. The said crew nut can however be
advanced on the screw bolt, the ratchet teeth permitting the rotation of the
screw nut in the required direction. When it is required to remove the screw
nut from the screw bolt a it is necessary to withdraw the cotter g and remove
the spring and sleeve d.
Figure 3 represents in elevation and Figure 4 in section and end elevation, the
locking arrangement in which the screw nut is made capable of rotating in either
direction on the screw bolt by the exertion of a moderate force;
Figure 5 represents an end elevation of the screw nut and
Figure 6 represents an end elevation of the locking sleeve; and
Figure 7 represents the coiled spring separately.
In this arrangement, teeth or depressions are arranged on the face of the locking
sleeve and the face of the screw nut is provided with two projections or
teeth at opposite points. It will be seen that the teeth, both of the screw nut and
locking sleeve, in this arrangement are not ratchet teeth but the two sides of each
of the teeth make with each other a right angle; that is, the teeth are of a V shape.
By the use of this kind of teeth the screw nut can be made to move on the screw
in either direction by the use of a spanner, there being no risk of the screw nut b
accidentally unscrewing.
By referring to the drawing it will be seen that two V shaped projections
marked b², 2 are made on the face of the screw nut and correspondingly shaped
recesses marked , d' are made in the face of the locking sleeve for engaging with
the V projections of the screw nut, and locking the said nut.
The locking sleeve d is fitted on the end of the screw a and its spring made to
take a bearing against the bottom of the sleeve and against the cross cotter g,

page_text: Ipassed through the screw and working in the slots h, h of the sleeve as herein before
described with respect to the arrangement Figures 1 and 2. The position of the
V shaped teeth may be reversed, that is, the recesses may be made in the face
of the nut and the projections for engaging with them made on the face of the
locking sleeve.
When lock nuts of large size are used, the V shaped projections or teeth
instead of being made solid with the mut may be dowelled or otherwise fixed in
the nut.
When the improved locking arrangement is applied to screws requiring a
considerable range of adjustment such as the stuffing box screws of marine engines,
steam hammers and the like, we prefer to make a series of adjusting holes in the
screw as represented in Figure 8 for facilitating the following up of the locking
sleeve to the nut to be locked.
Figure 9 represents in section and Figure 10 in elevation a modification of our
improved locking arrangement, applied to the fixing, by a set screw, of a collar or
the boss of a pulley or the like on a shaft.
is the shaft and k is the collar or boss to be fixed to the said shaft by the set
screw working in the screw nut or screwed shouldered part of the collar or
boss. The said screwed shouldered part is provided at opposite sides with
✓ shaped projections or teeth m, m; p is the spring sliding sleeve having in its face
V shaped depressions n, to engage upon the V shaped projections or teeth m on the
screw nut part of the boss or collar : 7 is the spring and the cross cotter. By
the engagement of the teeth of the sleeve with the teeth of the screw nut pert³
of the collar or boss, the latter is locked to the set screw, the action being
substantially the same as that of the arrangement before described.
Figure 11 represents in elevation and Figure 12 in horizontal section the locking
arrangement in which a series of spring arms is used for clipping the screw nut and
thereby locking it to the screw: is the screw and t the screw nut without teeth
on its face. The end of the screw has fixed to it the cap in which the screw nut t
'moves in one or other direction as the said nut is rotated on the screw. The.
greater part of the cap is divided by longitudinal slits into a series of spring
arms u², u which arms bear upon the faces of the nut (see Figure 12) and offer
such resistance to its motion that while the nut may be turned on the screw with
the exertion of a moderate force, there is no risk of its accidental removal.
The inner faces of the spring arms have preferably the angular shape represented
in the section Figure 12 for enabling them to engage with or lock upon the angular
edges of the nut.
In place of using a plain nut with the locking spring arms, a nut having a series
of ribs or teeth on its faces. may be employed. The spring arms bear upon these
ribs and offer sufficient resistance to prevent the accidental removal of the screw
nut.
Having now particularly described and ascertained the nature of the said inven-
tion and the manner in which the same is to be performed we declare that we
claim as the said invention of "Improvements in locking the screw nuts of screw
bolts and other screws"
-
First The combination with a screw nut having a tooth or teeth on its outer
face of a spring sliding locking sleeve or tubular piece having corresponding
teeth on that face presented to the toothed face of the screw nut for engaging with
the tooth or teeth on the screw nut and thereby locking the latter on the screw bolt
or other screw substantially as hereinbefore described and illustrated in Figures 1
to 8 both inclusive of the accompanying drawings; whether the teeth on the screw
nut and locking sleeve permit of the rotation of the screw nut in one direction only
or in either direction on the screw bolt or other screw substantially as described
and illustrated.
Secondly-The modified locking arrangement herein before described and
illustrated in Figures 9 and 10 of the accompanying drawings for locking a colla

page_text: or boss or equivalent part to the set screw by which the said collar, boss or part is
secured to a shaft or the like.
Thirdly-The locking arrangement herein before described and illustrated in
Figures 11 and 12 of the accompanying drawings, the said locking arrangement
consisting of a series of spring arms, carried by a cap fixed to the screw bolt or
other screw, made to bear upon the faces of the screw nut, either plain or ribbed,
for locking the said screw nut.
Dated the Twelfth day of February 1892.
TANGYES LIMITED,
W. J. Parkins, Secretary.
JAMES RICHARD WILLIAMS..