Improvements in Locking Bolts and Nuts for Vibrating and Moving Machinery.
Year: 1895

page_text: Date of Application, 24th Oct., 1895-Accepted, 14th Dec.. 1895
COMPLETE SPECIFICATION.
Improvements in Locking Bolts and Nuts for Vibrating and
Moving Machinery.
I JAMES CARROLL of Kilmacthomas in the County of Waterford, Ireland,
Gentleman do hereby declare the nature of this invention (a communication to me
from abroad by Edward Larcomb, and Henry S. Fitzherbert, of Palmerston
North, New Zealand) and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
This invention relates to a new or improved lock nut and washer for bolts for
vibrating and moving machinery and in accordance therewith I provide a nut
which used in conjunction with the washer of a particular construction to be
hereinafter described is locked upon the bolt sufficiently to prevent any risk of
loosening by vibration. The lock nut and washer constructed in accordance with
this invention are particularly adapted for use upon fish bolts for railways, or for
fastenings for agricultural implements rolling stock, pumping engines or any other
machinery moving at a high rate of speed. It can as required be unlocked and
relocked without injury to either the nut or washer and the full strength of the
bolt and nut are retained to the same extent as the ordinary screw bolt without the
facilities for locking.
And in order that this my invention may be fully understood I will now describe
same with reference to the accompany sheet of drawings and to the letters
aud figures of reference marked thereon, that is to say :-
Fig. 1. is a view of the lock nut and washer screwed up in the locked position
upon a bolt.
Fig. 2. is a plan view of underside of nut.
Fig. 3. is a plan of the washer.
Fig. 4. an inverted plan of the same, and
Fig. 5. shews the application of the invention to the head of a set screw.
Similar letters of reference indicate like parts in each of the figures.
a is the bolt with head a¹ and screwed at a². The nut screws upon the
thread a. Upon the under side of nut 6 I cut or otherwise form teeth or
notches c. d is the washer which is used in conjunction with the nut 6 and serves
to lock same in its screwed up position. This washer d I form (see particularly
Figs. 3 and 4) with a slit or catch d' from the outside edge towards the centre and
then at an angle with said cut d¹ I make the slit d². The portion of the washer
bounded by the slits or cuts d' d' is then sprung out and serves as a pawl (see
Fig. 1) taking into the ratchet teeth c of the nut b. Upon the undersider of the
washer d I form cuts e similar to those of a bastard file the projections from such
cuts forming a roughened surface which bites, or engages with the surface of the
material it is screwed up to. The washer d 1 make of tempered steel so that the
points or projections are much harder than the surface against which it acts. In
Fig. 5 the teeth c are shewn as formed upon the bolt head a'; the washer d then
being placed under such head a' and acting similarly as when used with the nut b.
When screwed up into position the pawl portion d of the washer d engages with
the teeth c and the roughened surface of the washer d engaging with the surface of
the material against which it is screwed up, the bolt is prevented becoming
unscrewed without assistance. The bolt however can be immediately unlocked by
placing a panner on the nut (or head as the case may be) and pressing down the
pawl d and then turning when the whole is loosened, entirely obviating the

page_text: necessity of using double nuts, split keys through bolts, or other devices heretofore
employed.
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
1. The new or improved lock nut and washer for bolts substantially as herein-
before described and shewn.
2. In combination the nut b (or head a¹) formed with teeth c upon its under or
inner side, and the washer d formed with a roughened under surface and having the
split portion d acting as a pawl, substantially as and for the purposes hereinbefore
described and shewn.
Dated this 24th day of October 1895.
HUGHES, ELI & HUGHES,
76, Chancery Lane, W.C., Agents for the Applicant.