IMPROVEMENTS IN LOCK NUTS, BOLTS, AND SCREWS, AND IN MODES OF AND MACHINERY FOR ManufacturinG THE SAME
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by William Phillips Thompson
at the Office of the Commissioners of Patents, with his Petition,
on the 8th December 1875.-A communication from abroad by
F. M. F. Cazin, of Colorado, one of the United States of America.
I, WILLIAM PHILLIPS THOMPSON, of 6, Lord Street, Liverpool, in the
County of Lancaster, Consulting Engineer and Patent Agent, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN LOCK
NUTS, BOLTS, AND SCREWS, AND IN MODES OF AND MACHINERY FOR ManufacturinG
THE SAME, a communication to me from abroad by F. M. F. Cazin, of
Colorado, one of the United States of America, to be as follows:
"
This lock nut. is distinguished from all lock nuts previously Patented
by the absence of any third part besides bolt and nut constituting the
lock, as the shape of bolt and nut in this improvement lock without
extra parts. The thread of the bolt differs from that of ordinary bolts
similar in other respects (whether its shape be square, pointed, or
otherwise), in its lower face (that facing the bolt head, forming a
continuous zig-zag line dividing each circumferential turn of the thread
into as many offsets as will be deemed expedient, usually two or four,
the offsets being either 180 degrees or ninety degrees apart. Each
•

page_text: offset on one turn of the thread has a corresponding one in every turn
of thread of the same bolt, being all arranged in lines parallel to the
axis of the bolt. The perpendicular face of each offset faces in the
direction of the screw line toward the head of the bolt. The nuts are
formed with similar offsets facing in the opposite direction. The con-
sequences are that in screwing on the nut neither offset affords any
resistance (nor indeed in screwing off the nut so long as the pressure of
the nut is exerted towards the screw head). The instant however the
nut has been screwed tight-up and the sets of offsets have passed each
other, they can never be turned back so long as the pressure causes the
under surface of the bolt thread, and the upper surface of the nut thread
to press against each other as the offsets interlock. The offsets can be
usually very small from 1 to 10 of the pitch in a single threaded
halt

page_text: that gear into the vacant spaces between the dies on the die roll.
A square or rectangular bar of iron at a great heat is introduced
between these rolls, and is by them bent into a sinuous form round the
protruding dies of the die roll. The bar then passes between the die
roll and a third roll with sharp pointed cogs, between each of which is
an indentation the exact requisite shape and size of the future semi-nut
blank; this cuts off the bar between each die and squeezes it against the
die, and at the same time forming its outer surface into the requisite shape
for a half nut. Two of these half nut blanks are now rolled or pressed
so as to gain the requisite thread, and are duly put together (on a bolt or
screwed mandril so as to ensure their accurate fitting), and a red hot
hexagonal ring stamped to fit is placed round them. The whole shrunk
tight in water forms the nut.