Improvements in Nuts for Screw Bolts.
Year: 1896

page_text: Date of Application, 9th Jan., 1896-Accepted, 7th Mar., 1346
COMPLETE SPECIFICATION.
Improvements in Nuts for Screw Bolts.
We, JOHN WHITEHEAD WILSON DRYSDALE, of the Firm of Drysdale & Co.,
Engineers, Bou-Accord Engine Works, London Road, in the City of Glasgow,
and MATTHEW STODDART, Draughtsman with said Firm, 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 invention has for its object to provide self-tightening nuts of improved
construction for use mainly in securing the bolts in connecting rod end bearings to
compensate for wear of the brasses and it is also applicable in other cases in which
it is desirable that the nuts employed should be self-tightening.
The invention is illustrated by the accompanying drawings in which
Figure 1 is a vertical section of the improved nut showing the bolt in elevation,
Figure 2 is a plan of the same, Figure 3 is a side elevation at right angles to
Figure 1, and Figure 4 is a horizontal section on the line - in Figure 3.
The bolt A of which only the screw-threaded end is shown as carried through
the cap or cover C of the bearing terminates in a reduced portion A' in which is
cut a slit or saw drift a, and the screw-threaded nut B which is fitted on the bolt
in the usual way to draw it up and bear on the cover C is maintained in close
contact with said cover by means of a spring D coiled within a cap or box E fitted
over the outer end of the nut. A washer H is interposed between the upper end
of the nut B and the coiled spring. One end of the spring is passed through the
elit a in the end of the bolt A and the other is passed through or otherwise attached
to the enclosing cap or box E, and when the nut is screwed up the cap E is turned
so as to coil the spring. Catch levers F which are pivoted on the cap E and are
turned up out of the way while the spring is being coiled are thereafter dropped
into engagement with slots b formed in a collar b' on the nut so as to clamp or hold
the cap on the nut with the spring in tension or compression.
The spring then applies a torsional strain between the bolt and its nut and tends
to turn the nut B upon the bolt A against the resistance of the bearing cover C;
and as wear of the brasses occurs and the cover C yields the nut is turned to
tighten up the bolt. Split pins G are passed through snugs on the cap E and in
a groove g formed around the nut to prevent the cap slipping off whilst not
interfering with the free turning movement of the nut or cap.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. A compensating nut for screw bolts constructed and arranged to operate
substantially as described with reference to the drawings annexed.
2. The combination with a nut for a screw bolt of a coiled spring interposed
between the nut and a cap thereon so as to apply torsional strain on the nut
relatively to the bolt substantially as described.
Dated this 8th day of January 1896.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicants.