Year: 1887

page_text: Date of Application, 19th Dec., 1887
Complete Specification Left, 15th Sept., 1888
Complete Specification Accepted, 19th Oct., 1888
EDWIN PHILANDER PRINCE of Myrtle Villa Dudley Road Birmingham in the
County of Warwick Manager of Works do hereby declare the nature of this Invention
to be as follows:-
1
My invention consists of the combination of parts hereinafter described for locking
the screw nuts of screw bolts and other screws.
I will describe my invention in connection with a screw bolt.
I make the shank of the screw bolt of different diameters at different parts that is
the greater part of the shank is made of the usual diameter while a portion near the
end of the shank is made of smaller diameter. The end of the shank of larger diameter
is screwed with a left hand screw thread and the extreme end of the shank of reduced
diameter is screwed with a right hand screw thread. The screw nuts to be used with
the screw bolt described are tapped with screw threads corresponding with the parts
of the screw bolt on which they are to be fitted. The screw nut to be fitted on the left
hand screw on the larger diameter of the bolt I will call the back screw nut and that
nut which is to be fitted on the right hand screw on the part of the bolt of reduced
diameter will call the front screw nut. The outer face of the back nut is formed
with stepped inclines or teeth resembling the teeth of a ratchet wheel and the inner
face of the front nut or that face which is to be presented to the stepped or ratchet face
of the back nut is provided with similar stepped inclines or teeth so that the teeth or
inclines on the said front nut can he engaged or locked with those on the back nut.
I use with the improved screw bolt and lock nuts described a spring washer for the
purpose of exerting a binding action on the back nut the said spring washer being
placed between the back nut and the block or part through which the screw bolt is
passed or placed underneath the head of the bolt. The spring washer consists of a
convex disc having a radial slot or opening in it for engaging with the stem of the
bolt or of a convex ring. Instead of a convex washer a flat washer may be used
when a binding action is not required. In this case the screw nuts cannot be
unscrewed

page_text: In order to fasten the bolt and lock the screw nuts the back screw nut having the
left hand screw thread is first screwed on the corresponding screw thread on the bolt
until the said back nut bears against the elastic washer. The front nut having the
right hand screw thread is next screwed upon the corresponding screw thread on the
smaller end of the bolt the front screw nut being screwed up to the back screw nut.
The back screw nut being held in its position by a spanner a half turn is given to
the front screw nut. By this motion of the front screw nut its steps or ratchet teeth
are made to engage with those on the back screw nut. By now easing or unscrewing
the back screw nut by turning it through about one twelfth of a rotation the shoulders
of the teeth on the faces of the respective screw nuts are engaged together and the two
nuts are locked together and motion in them prevented that is the shoulders on the
back or left hand screw nut prevent the motion of the front or right hand screw nut in
the direction proper to unscrew it and the shoulders on the front or right hand screw
nut prevent the motion of the back screw nut in the direction proper to unscrew it.
To unfasten the bolt the back screw nut is turned so as to cause it to advance on its
screw compressing the convex washer. The front screw nut can now be turned and
unscrewed from its screw and the back scrow nut can then be unscrewed from its
screw.
Dated this Nineteenth day of December 1887.

page_text: I EDWIN PHILANDER PRINCE of Myrtle Villa, Dudley Road, Birmingham in the
County of Warwick, Manager of Works, do hereby declare the nature of my 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 consists of the combination of parts herein after described for locking
the screw nuts of screw bolts and other screws.
I will describe my invention in connection with a screw bolt.
I make the shank of the screw bolt of different diameters at different parts, that is,
the greater part of the shank is made of the usual diameter while a portion near the
end of the shank is made of smaller diameter. The end of the shank of larger
diameter is screwed with a left hand screw thread and the extreme end of the shank
of reduced diameter is screwed with a right hand screw thread. The screw nuts to be
used with the screw bolt described are tapped with screw threads corresponding with
the parts of the screw bolt on which they are to be fitted. The screw nut to be fitted
on the left hand screw on the larger diameter of the bolt I will call the back screw
nut and that nut which is to be fitted on the right hand screw on the part of the bolt
of reduced diameter I will call the front screw nut. The outer face of the back nut is
formed with stepped inclines or fecil resembling the teeth of a ratchet wheel and the
inner face of the front nut or that face which is to be presented to the stepped or
ratchet face of the back nut is provided with similar stepped inclines or teeth so that
the teeth or inclines on the said front nut can be engaged or locked with those on the
back nut.
I use with the improved screw bolt and lock nuts described a spring washer for the
purpose of exerting a binding action on the back nut the said spring washer being
placed between the back nut and the block or part through which the screw bolt is
passed or placed underneath the head of the bolt. The spring washer consists of a
convex disc having a radial slot or opening in it for engaging with the stem of the
bolt, or of a convex ring. Instead of a convex washer a flat washer may be used
when a binding action is not required.
In order to fasten the bolt and lock the screw nuts the back screw nut having the
left hand screw thread is first screwed on the corresponding screw thread on the
bolt until the said back nut bears against the elastic washer. The front nut having
the right hand screw thread is next screwed upon the corresponding screw thread
on the smaller end of the bolt the front screw nut being screwed up to the back
screw nut.
The back screw nut being held in its position by a spanner a half turn is given
to the front screw nut. By this motion of the front screw nut its steps or ratchet teeth
are made to engage with those on the back screw nut. By now casing or unscrewing

page_text: the back screw nut by turning it through about one twelfth of a rotation, the
shoulders of the teeth on the faces of the respective screw nuts are engaged together
and the two nuts are locked together and motion in them prevented; that is, the
shoulders on the back or left hand screw nut prevent the motion of the front or right
hand screw nut in the direction proper to unscrew it and the shoulders on the front or
right hand screw nut prevent the motion of the back screw nut in the direction proper
to unscrew it.
To unfasten the bolt the back screw nut is turned so as to cause it to advance on
its screw, compressing the convex washer. The front screw nut can now be turned
and unscrewed from its screw and the back screw nut can then be unscrewed from
its screw.
Figure 1 of the accompanying Drawing represents in section the screw nut of a screw
bolt locked according to my invention; Figure 2 represents the screw bolt detached ;
Figure 3 represents a front elevation of the back screw nut and Figure 4 represents a
front elevation of the front screw nut.
The same letters of reference indicate the same parts.
a is the shank of the screw bolt made of different diameters at different parts, the
end of the shank of different diameters being screwed with right and left hand screw
threads, that is, the end of the shank of larger diameter is screwed with the left hand
screw thread c and the extreme end of the bolt of reduced diameter is screwed with
the right hand screw thread d: e. fare the back and front screw nuts to be used with
the screw bolt a, c, d the said screw nuts being tapped respectively with screw threads
corresponding with the parts c, d of the screw bolt on which they are to be fitted.
The outer face of the back nut e is formed with stepped inclines or ratchet teeth e and
the inner face of the front ant is provided with similar stepped inclines or ratchet
teeth. By constructing the opposed faces of the back and front screw nuts e, fin
the manner represented, the teeth or inclines f2 on the front nut can be engaged or
locked with the teeth or inclines e on the back nut e as hereinafter explained. is a
spring washer consisting of a convex ring or disc for engaging with the stem of
the bolt. The said spring washer is placed between the back nut e and the block
or part through which the screw bolt is passed. By means of the spring washer g
a binding action is exerted on the back nut e. The clastic washer may consist of
a continuous ring as represented in Figure 5, or a ring having a radial slot or
opening in it as represented in Figure 6. Or a flat washer may be used when a
binding action is not required.
Figure 7 represents my method of locking the screw nut applied to a screw
bolt used for fastening the fish plates of the rails of railways the parts in the
said Figure 7 being marked with the same letters of reference as corresponding
parts in Figure 1.
The
The parts are used for locking the screw nut of the screw bolt in the following
manner. The back nut having the left hand screw thread is first screwed on the
screw thread c on the bolt a until the said back nut bears against the elastic
washer. The front nut having the right hand screw thread is now screwed
upon the screw thread d 'on the bolt a and screwed up to the back nut e.
back nut e being held in its position by a spanner a half turn is given to the
front screw nut. This motion of the front screw nut causes the faces of its
stepped or ratchet teeth to engage with the faces of the stepped or ratchet
teeth of the back screw nut e. The back screw nut e is now cased or unscrewed
by turning it through about one eighth of a rotation. By the back motion of
the screw nut e the shoulders of the teeth on the opposed faces of the respective
screw nuts e, f are engaged together and the two nuts are locked together and
motion in them prevented and the screw bolt effectually fastened in its place as
will be understood by an examination of Figures 1 and 7.
For the purpose of unfastening the screw bolt the back screw nut e is turned
so as to cause it to advance on its screw c, the convex spring washer g being
compressed. The shoulders of the teeth or inclines of the back screw nut e are
thereby removed from the shoulders of the teeth or inclines of the front screw

page_text: nut. The front screw nut may now be turned and unscrewed from its screw d
and the back screw nut e afterwards unscrewed from its screw c.
Instead of making the stem of the screw bolt of two diameters as represented
in Figure 2 the stem of the bolt may be made of the same diameter throughout
the end of the bolt being first made with a left hand screw thread and the
extreme end of the stem afterwards made with a right hand screw thread the thread
of the right hand screw crossing that of the left hand screw.
This modification of the bolt is represented in Figure 8, where c² represents
that part of the screw bolt having a left hand screw thread only, while the part <
represents the end of the screw bolt having a right and left hand screw thread
cut upon it. In making the screw bolt Figure 8 the left hand screw thread c² is
first cut on the whole of the screwed part of the screw bolt and afterwards a
right hand screw thread is cut on the part d². On the screw thread
nute is fitted and on the screw thread the screw nut is fitted. The screw
bolt made in the manner represented in Figure 8 is somewhat stronger than the
bolt having different diameters represented in Figure 2 and the manufacture of
the bolt is simplified.
the back
The two screw nuts e, f having stepped or inclined faces are placed upon the
modified screw bolt Figure 8 and the said nuts locked together in the manner
herein before described.
My improvements may be applied to screw bolts and screws generally where
nuts are required to be fixed upon them.
Having now particularly described and ascertained the nature of my Inven-
tion and the manner in which the same is to be performed I declare that I
claim as my invention of "Improvements in locking the screw nuts of screw
bolts and other screws
"
The combination of a screw bolt or screw having a right and left hand screw
thread with screw nuis having corresponding screw threads, the opposed faces of
the said screw nuts being made with stepped inclines or ratchet teeth for engaging
or locking with one another; whether the screw bolts or screws and screw nuts
be used with or without an elastic or spring washer substantially as herein before
described and illustrated in the accompanying Drawing.
Dated the Fourteenth day of September 1888.
EDWIN PHILANDER PRINCE.