Im- PROVEMENTS IN LOCK BOLTS
Year: 1873

page_text: LETTERS PATENT to Alfred John Dobson, of Camden Road, Camden
Town, in the County of Middlesex, for the Invention of "Im-
PROVEMENTS IN LOCK BOLTS.”
Scaled the 2nd April 1874, and dated the 2nd October 1873.
PROVISIONAL SPECIFICATION left by the said Alfred John Dobson-
at the Office of the Commissioners of Patents, with his Petition,
on the 2nd October 1873.
I, ALFRED JOHN DOBSON, of Camden Road, Camden Town, in the,
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN LOCK BOLTS," to be as follows:-
My Invention relates to a-bolt-made of any metal or material, in the
worm of which is cut a slot, the size of which varies according to
the size of the bolt, and can be applied to the smallest or largest sized

page_text: bolts made. This slot not being cut deeper than the worm of the screw
does not detract from the strength of the bolt as in other cases of lock
bolts where holes are bored right through the centro, and in which holes
are placed pins, thereby detracting from the strength of the bolt; in this
slot (previously to screwing on tho nut) is placed a plain picco of wire
copper or any other soft metal, the nut then being screwed on, forming
its own worm in the soft metal wire placed in the slot. The nut boing
screwed up to its position tightly is prevented going further if it were
possible, as it could not cut the worm any further in the soft metal
without force of screw wrenches or other tools being applied, and it is also:
locked from coming off by vibration, by turning back on to tho nut tho
wire over which the said nut has passed, the end of the wire then being
clenched on to the end of the nut prevents it from coming off except by
the aid of great force such as screw wrenches. A bolt made in this
manner prevents any loosening of the nut, thereby preventing accidents
on railroads by loose plates on tho lines, and is applicablo to various uses
in railway work, building, ship-building, and gencral construction.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred John Dobson in the Groat Seal Patent
Office on the 2nd April 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
JOHN DOBSON, of Camden Road, Camden Town, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of October, in the year
of our Lord One thousand eight hundred and seventy-three, in
the thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Dobson, Her
special licence that I, the said John Dobson, my executors, admi-
nistrators, and assigns, or such others as I, the said John Dobson,
my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter

page_text: during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN LOCK BOLTS," upon the condition (amongst others)
that I, the said John Dobson, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said John Dobson, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement:-
My Invention relates to a bolt made of any metal or material, in the
worm of which is cut a slot; the size of this slot varies according to the
size of the bolt, and it can be applied to the smallest or largest sized bolt
made. This slot not being cut deeper than the worm of the sorew
does not detract from the strength of the bolt as in other cases of lock
bolts where holes are bored right through the centre, and in which holes
are placed pins, thereby detracting from the strength of the bolt; in this
slot (previously to screwing on the nut) is placed a plain piece of wire
of malleable iron, copper, or any other soft metal, the nut then being
screwed on, forming its own worm in the soft metal wire placed in the
slot. The nut being screwed up to its position tightly is prevented
going further if it were possible, as it could not cut the worm any
further in the soft metal without force of screw wrenches or other tools
being applied, and it is also locked from coming off by vibration by
turning back on to the nut the wire over which the said nut has passed,
the end of the wire then being clenched on to the end of the nut
prevents it from coming off except by the aid of great force such as

page_text: Figures 3 and 4 illustrate the method of locking the nut by means of
the wire or pin when the nut is screwed up.
A is the bolt in which is the slot B; C, the nut; D, locking wire or
pin. In fixing this bolt the bolt is first passed through the plate or
other object to be secured, the wire or pin D is laid in the slot B, the '5
nut C is screwed tight up, and the end of the wire being bent over it as
at D', Figures 3 and 4, the nut is securely fixed. More than one slot B
might be made in the bolt A. and an equal number of locking wires or
pins be used, but I deem more than one unnecessary and undesirable.
It will be evident that the nut of a bolt thus made and fixed cannot 1
work loose, therefore accidents resulting from loose plates on railways
need no longer be feared.
The application of my improved lock bolt also gives a great saving in
labour as the bolts do not need the constant supervision and tigthening
up of the nuts exacted in the present style of plain bolt and nut which 1
is only fixed securely by the oxydation of the metal.
My improved lock bolt is not only applicable for tightening fish
plates and railway chairs, but also for building purposes, railway
carriages, both freight and passenger, ship-building purposes, where bolts
are used and which from the motion are liable to work loose if not 2
locked. It is also applicable for machinery, and where large quantities
of bolts are used obviates the necessity of stoppages of the machinery
for screwing-up purposes. It will be found very advantageous for
bridges and every construction subject to vibration. In short it may be
substituted with advantage in lieu of the ordinary bolt and nut wherever 2
this lattter is used.
Having now described and ascertained the nature of my said Inven-
tion and in what manner the same is or may be performed, I would have
it understood that I do not limit myself to any dimensions of bolt, nut,
or locking wire or pin, or slot, nor to the use of any particular metal or 3
material in their construction, excepting that the wire should be of
metal soft enough to permit the nut to cut a screw thread upon it, and
sufficiently pliable to admit of its end being turned down upon tho nut,
and what I claim as secured to me by the herein-before in part recited
Letters Patent is, the uso of a lock bolt having a slot to receive a 3

page_text: locking pin or wire by which its nut is locked, substantially as herein.
before set forth.
In witness whereof, I, the said Alfred John Dobson, have hereunto
set my hand and seal, this Thirtieth day of March, in the year
of
our Lord One thousand eight hundred and seventy-four.
ALFRED JOHN DOBSON. (L.S.)