A Lock Bolt or Improved Device for Preventing the Unscrewing of Nuts on Bolts.
Year: 1890

page_text: Date of Application, 20th Nov., 1890
Complete Specification Left, 19th Aug., 1891-Accepted, 3rd Oct., 1891
PROVISIONAL SPECIFICATION.
A Lock Bolt or Improved Device for Preventing the Unscrewing of
Nuts on Bolts.
1, DUGALD DRUMMOND, of 186 Bath Street, Glasgow, in the County of
Lanark, North Britain, Engineer, do hereby declare the nature of this invention to
be as follows, that is to say —
My said invention has for its object to provide an improved, simple, and satis-
factory device for preventing the unscrewing of nuts on bolts; and whereas in most
devices heretofore used or proposed for the same purpose, the nut has been the
part which has been modified, according to my invention it is the bolt which is
dealt with. A very important application of my invention is to the bolts by which
are secured the fish plates of railway rails; but my improved device is also applicable
with advantage in other cases.
In carrying out my invention I make the screwed end of the bolt tubular or with
a tubular recess extending from the end inwards at least so far as to be in the
part on which the nut is situated when screwed up. After the nut has been
screwed up on the bolt a tapering or conical steel drift or pin is driven into the
end of the bolt, and expands the bolt so as to make it fill the nut and become so
tight therein as to prevent the nut from unscrewing or loosening by vibration. The
bolt is thus made a reliable lock bolt, by means of which a permanently firm rail
joint is obtained, wear and tear is reduced to a minimum, security from accident is
increased, and economy in maintenance is obtained.
Dated this Nineteenth day of November 1890.
EDMUND HUNT,
Applicant's Agent.
COMPLETE SPECIFICATION.
A Lock Bolt or Improved Device for Preventing the Unscrewing of
Nuts on Bolts.
I, DUGALD DRUMMOND, of 186, Bath Street, Glasgow, in the County of
Lanark, North Britain, 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, that is to say :-
My said invention has for its object to provide an improved simple, and satis-
factory device for preventing the unscrewing of nuts on bolts; and whereas in
most devices heretofore used or proposed for the same purpose, the nut has been
the part, which has been modified, according to my invention it is the bolt which is
dealt with. A very important application of my invention is to the bolts by which
are secured the fish plates of railway rails; but my improved device is also applicable
with advantage in other cases.
In carrying out my invention I make the screwed end of the bolt tubular or with
a tubular recess extending from the end inwards at least so far as to be in the
part on which the nut is situated when screwed up. After the nut has been screwed
up on the bolt a tapering or conical steel drift or pin is driven into the end of the
bolt, and expands or distends the bolt so as to make it fill the nut and become
so tight therein as to prevent the nut from unscrewing or loosening by vibration.
And in order that my said invention and the manner of performing the same
may be properly understood I hereunto append a sheet of explanatory drawings to

page_text: be hereinafter referred to and showing,, by way of example, my improved device
as applied in securing the fish plates of a railway rail.
Figure, I, on the accompanying sheet of drawings is a transverse vertical section
of parts of a railway railtand fisli plates with my improved device in position but
before expansion of the bolt.. Figure, 2, is a similar view. but, with the bolt expanded
and Figure, 3, is a side elevation of the tapering steel drift or pin. In these
drawings the same reference letters are used to mark the same parts wherever thiey
are repeated.
As shown in the drawings the screwed end of the bolt, B, for securing the fish
plates, P, of the railway rail, R, is made with a. tubular recess, T, extending from
the end inwards slightly further than the part on which the nut, N, is situated
when screwed up as shown in Figure, 1. After the nut, N, has been screwed up
on the bolt, B, a tapering or conical steel drift. or pin, D, such as is.shown in
Figure, 3, is driven into the end of the bolt, B, as indicated by dotted lines in
Figure, 2, and expands or distends the bolt, B, so as to make it fill the nut, N, and
become so tight therein as to prevent the nut, from unscrewing or loosening by
vibration. The bolt, B, is thus made a reliable lock bolt, by means of which a
permanently firm rail joint is obtained, wear and tear is reduced to a minimum,.
security from accident is increased, and economy in maintenance. is obtained.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
The lock bolt or improved device for preventing the unscrewing of nuts-on bolts
the screwed end of the bolt being made tubular and locking the nut by being
expanded or distended in it substantially as herein before described.
Dated this Eighteenth day of August 1891.
EDMUND HUNT,
Applicant's Agent.