MENTS IN LOCK NUTS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Richard David Sanders at the Office
of the Commissioners of Patents on the 16th August 1883.
RICHARD DAVID SANDERS, of Glasgow, in the County of Lanark.
MENTS IN LOCK NUTS;"
"IMPROVE-
The object of this Invention is so to construct and secure nuts upon screw bolts
that they shall be prevented from shaking loose when screwed up to the work.
According to one modification of the Invention adapted for ordinary bolts such
as are used in securing fish-plates of railways, a loose nut blank or washer, or a
nut having no screw thread is fitted on the bolt, and into a shallow recess in the
fish plate which prevents it from turning; and a nut of ordinary form is screwed
on the end of the holt to bear against the first nut. The faces of the nuts which
bear against each other are grooved, slotted, or indented radially at different points,
or between the faces holes are drilled, and when the nuts are tightened up, one (or
more) of the grooves in the one nut comes opposite the corresponding grooves in
the other nut and forms a hole (or holes) into which a plug of lead or solder or other
suitable material is driven. The grooves may be so formed that the holes formed
between the nuts may be slightly tapered to prevent the plug slipping out, or the
grooves may be notched or indented laterally for this purpose. The plug when
inserted prevents the one nut turning on the other, and as the inner nut is held in
a recess in the fish plate, or in the work, the outer nut is securely locked. The
bolt head fits in a recess in the fish plate on the opposite side of the rail, and
prevents the bolt turning in the nuts.
In a modified arrangement adapted to bolts having screwed on them both a
right hand and a left hand thread, two nuts with screw threads to correspond to
those of the bolt are fitted on the end of the bolt. Between the bearing faces of
the nuts, holes are drilled, or corre-ponding grooves, slots, or indentations are
formed, one or more of which come opposite each other when the nuts are tightened
up and form holes into which the plug of lead or other material is driven. The
bolt is by preference reduced in diameter at its extreme end which is screwed in
the direction opposite to that of the thread on the thicker portion.
In a further modification, a single screw nut is used, and is formed with a flange
round its inner or bearing edge. In this flange, a number of holes are drilled or
formed, and into the face of the work one or more holes is or are drilled, so that
D

page_text: when the nut is tightened up, one of the holes in the flange may come opposite a
hole in the work. Into this hole a plug of lead or slder or other suitable material
is driven. The bole in the flange of the nut is slightly tapered, conical, or counter-
sunk, and when the soft metal plug is driven in to take the shape of the hole it is
securely retained.
If the work to be secured by such bolts and nuts, he of timber, a metal washer is
interposed between the flange of the nut and the work, and in the flange and
washer one or more holes are drilled, into which a metal plug is driven to prevent
the nut turning on the washer.
When the bolt and nut are fitted near the edge of the work, and when a flange
could not be used, a hole or holes is or are drilled from the side between the bearing
surfaces of the nut and of the work, and into the hole a plug of soft metal is
driven.
In each case the lock nut is unscrewed by turning it with a screw key with such
force as to shear the metal plug which otherwise prevents the nut shaking loose.
This mode of securing nuts on screw bolts by a plug of soft metal or other
material driven into a hole or recess formed between the screw nut and the work,
or between the screw nut and a second nut or washer held from turning by the
work may be adapted to suit any circumstances in which screw bolts and nuts
are used.