Improvements in Screw Nuts.
Year: 1889

page_text: Date of Application, 5th Jan., 1889
Complete Specification Left, 19th Sept., 1889-Accepted, 2nd Nov, 1889
PROVISIONAL SPECIFICATION.
Improvements in Screw Nuts.
I, JAMES EDWARD RANSOME of Orwell Works Ipswich in the County of Suffolk
Engineer do hereby declare the nature of this invention to be as follows
This Invention has for its object improvements in screw nuts.
In order that the nut when screwed up may grip the bolt and not be liable to shake
loose I form a slit diametrically across it from side to side or from angle to angle.
This slit extends from the top or outer side of the nut part of the way through
it towards the base or inner side. The top of the nut is thus converted into a pair
of jaws and these by the yielding of the metal at the base are able to close together
or to approach each other sufficiently to tightly grip the bolt on to which the nut is
screwed. In order to cause this closing of the jaws the base of the nut is so formed
that it does not bear uniformly on the surface opposed to it but on the under and
outer side of each jaw there is a projection. When the nut is screwed up it is these
projections which alone take the pressure whilst the part of the nut below the slit
yields to the pressure and the jaws are forced together and grip the bolt as before
stated. The grip is obtained without damage to the thread of the nut or the thread
of the bolt. When unscrewed the pressure is released and the nut again turns freely
on the bolt.
ΟΙ
Dated this 4th day of January 1889.
COMPLETE SPECIFICATION.
Improvements in Screw Nuts.
I, JAMES EDWARD RANSOME of Orwell Works, Ipswich, in the County of Suffolk,
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.:-
This Ivention has for its object improvements in screw nuts.
In order that the nut when screwed up may grip the bolt and not be liable to shake
loose I form a slit diametrically across it from side to side or from angle to angle.
This slit extends from the top or outer side of the nut part of the way through it
towards the base or inner side. The top of the nut is thus converted into a pair of
jaws and these by the yielding of the metal at the base are able to close together or
to approach each other sufficiently to tightly grip the bolt on to which the nut is
screwed. In order to cause this closing of the jaws the base of the nut is so formed
that it does not bear uniformly on the surface opposed to it but on the under and
outer side of each jaw there is a projection. When the nut is screwed up it is these
projections which alone take the pressure whilst the part of the nut below the slit
yields to the pressure and the jaws are forced together and grip the bolt as beforo
stated. The grip is obtained without damage to the thread of the nut or the thread
of the bolt. When unscrewed the pressure is released and the nut again turns freely
on the bolt.
.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.

page_text: Figures 1 and 2 are respectively a plan and elevation of a hexagon nut, in which "a
is the slit: "b, b," the two parts of the nut which form jaws to grip the bolt: "c, c,"
are the projections on the bottom of the nut which take the bearing when the nut is
screwed up,
and which are placed on either side of the slit "a," so that the upper
parts ", " of the nut are forced towards the centre and thus grip the bolt.. In
these figures the slit is shewn across the angles. Figures 3 and 4 are respectively
a plan and elevation of a hexagon nut but formed according to my invention with
the slit across the sides of the nut. Figures 5 and 6 are respectively a plan and
elevation of a square nut with a slit across the sides, and Figures 7 and 8 shew also
a square nut but with the slit across the angles. Figures 9 and 10 shew a flanged
nut similarly formed. In Figures 11 and 12 the projecting pieces "c, c," on each side
of the bottom of nut instead of being formed with a shoulder are made so as to form
a curved surface for the bottom of the nut. In all these figures the parts referred
to in the description of Figures 1 and 2 are marked with the same letters.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I would remark that I
am aware that lock nuts have been made with a slit or slits at the top and the separated
parts forced inwards by mechanical means before the nut is applied to the bolt so as to
make the upper part of the nut fit more tightly on the bolt, but in such nuts the grip
upon the bolt is not increased by being screwed up hard on its bearing but rather the
reverse and I declare that what claim is :-
1. Making self tightening lock nuts with a slit across the top and with two projec-
tions on the bottom, one on either side of the slit, so disposed relatively to each other
that the top of the nut is converted into a pair of jaws which are automatically forced
together to grip the bolt when the projections on the bottom of the nut take the
pressure caused by screwing the nut home hard on its bearing and so that when the
nut is unscrewed the pressure is released and the nut can again turn freely on the bolt,
substantially as described and shown in the drawings.
2. A self tightening lock nut having a slit across the top and two projections on the
bottom, one on either side of the slit, substantially as described and shewn in the
drawings.
Dated this 18th day of September 1889.