Improvements in and connected with the Manufacture of Lock Nuts.
Year: 1895

page_text: Date of Application, 5th .Mar., 1895
Complete Specification Left, 3rd Jan., 1896-Accepted, 5th June, 1895
PROVISIONAL SPECIFICATION.
Improvements in and connected with the Manufacture of
Lock Nuts.
We, THOMAS GARE, of 25, Booth Street, Edgeley, Stockport, in the County
of Chester, Engineer, and THOMAS SEPTIMUS HARDEMAN, of 137, Withington
Road, Whalley Range, Manchester, in the County of Lancaster, Cloth Merchant,
do hereby declare the nature of this invention to be as follows :—
This invention relates to improvements in and connected with the manufacture
of that class of lock nuts which are made from coiled metal bara.
Our invention has for its object in the first place to provide an improved section
of material or bar which will facilitate the tapping and finishing of the exterior of
the nut and save material and labour.
Bars heretofore used in the manufacture of coiled lock nuts have been rolled
with flat sides. In the coiling of the said bars the external as well as internal side
is disturbed, i.e. the side of the bar externally becomes concave and internally
convex which, change in shape, is specially noticeable in coiling wide sections of
bars, say for nuts which will possess only 14 or two coils.
This disturbance of metal producing a coil uneven internally as well as externally
necessitates on the one hand, when coiled in a cold state, the rimmering out of the
same to enable the tapping of a durable thread, and on the other hand the cutting
off of a greater amount of material externally than otherwise which in each case
is a loss of material and time.
To this end our invention consists in employing in the manufacture of the said
Duts taper or other suitably sectioned bars the wide or external side and the
narrow or internal side of which are rolled convex and concave respectively, so
that on the bar being coiled the disturbance in the metal will cause the said convex
and concave sides to become straight and thus form a coil with an even surface
externally as well as internally.
In lieu of tapping the said nuts and shaping them externally by cutters we may
coil the bar in a hot state onto a threaded mandrel and afterwards pass the coil in
its hot state through a pair or pairs of rotary or reciprocating dies adapted to
shape the same hexagon or otherwise as may be required; or the bar may be
coiled onto a plain mandrel and on the same or after by substituting the latter by
a threaded mandrel be passed in a hot state through either one or the other of the
said dies. When on a threaded mandrel the pressure of the said dies imbeds the
interior of the coil into the thread on the said mandrel and thus forms: a thread in
the coil. The bar may be run in a hot state from the roller mill direct through
the guide or former hereinafter 'described onto the said mandrels or it may be
heated in or passed through a furnace. The said rotary and reciprocating dies
may form a separate apparatus or the rotary dies may be mounted onto the slide
rest which carries the said guide or former so as to move jointly therewith whereby
the coil is wound and shaped externally simultaneously, the said dies being formed
conical so as to press the coil to shape gradually.
:
Our invention has for its object in the second place to provide an improved
guide or former for the coiling of taper sectioned bars specially applicable for wide
Bections and heated bars for nuts. "The said guide or former consists of a block
adapted to slide on the mandrel upon which the bar is coiled and carried by Ja
bracket or plate secured to a slide rest. The said bracket or plate is furnished

page_text: with a bowl or roller positioned below the said mandrel and in front thereof with a
pair of bowls or rollers between which the bar to be coiled passes onto the periphery
of the aforesaid bowl or roller and then onto the mandrel. The bar to be coiled in
passing over the said bowl or roller is curved or cranked thereby so as to conform
with the pitch at which it is coiled and thus effect a complete closing of the coil. 5
The said pair of bowls or rollers are rendered adjustable so as to suit the various
widths of bars used as well as the said plate or bracket to accomodate the said
bowls or rollers to the angle at which the bar coils onto the said mandrel.
Dated this 4th day of March 1895.
Improvements in and connected with the Manufacture of
Lock Nuts.
:
We, THOMAS GARE, of 25 Booth Street, Edgeley, Stockport, in the County
of Chester, Engineer, and THOMAS SEPTIMUS HARDEMAN, of 137 Withington
Road, Whalley Range, Manchester, in the County of Lancaster, Cloth Merchant,
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 relates to improvements in and connected with the manufacture
of that class of lock nuts which are made from coiled metal bars as described in
our previous Specification No. 6215* of 1892,
Our invention has for its object to provide an improved section of material or
bar which will facilitate the tapping and finishing of the exterior of the nut and
save material and labour.
Bars heretofore used in the manufacture of coiled lock nuts have been rolled.
with flat sides, as shewn in section in Fig. 1 of the accompanying drawings. In
the coiling of the said bars the external as well as the internal side undergoes
change of form, that is to say, the side of the bar externally becomes concave and
internally convex which change of shape is specially noticable in coiling wide bars,
say for nuts which will possess one coil and a half or two coils, as shewn in Fig. 2,
which is the longitudinal section of a coil made from bars of the section Fig. 1 in
which it is seen that each convolution is externally concave at a and internally
⚫ convex at b.
This change of forin producing a coil uneven internally as well as externally
involves labour and expense in boring or reamering the interior to provide for the
tapping of a durable thread, and in cutting off material externally.
According to our present invention, we employ in the manufacture of coiled_nuts,
bars of taper section determined as hereinafter set forth having the wide or
external side rolled convex, and the narrow or internal side rolled concave, so that,
on the bar being coiled, the convolutions fit closely against each other throughout
the depth and the outer and inner sides of the bar become straight and thus a close
coil is formed with an even surface both externally and internally.
Fig. 3 shews by way of example the form of the section suited for a coil of certain
diameter.
Fig. 4 is a part side elevation and part longitudinal section of the coil, and
Fig. 5 is a longitudinal section of the screw threaded nut.
Figs. 6 and 7 are diagrams shewing how the depths of the bar may be
determined.
Referring first to Figs. 6 and 7, in which the circle A indicates a transverse
section of the bolt at the bottom of the thread, the dotted circle around it indicating

page_text: the section over the top of the thread. The width of the nut across flats being
given, the square or hexagon outline is drawn in the usual way and a radius is
drawn from the centre C to one of the angles. In order to allow for finishing the
nut, this radius is extended a little, practically about th of an inch, to the point O.
The length of the line I O, from the point I where this radius cuts the circle A to
the terminal point O of the slightly extended radius, is the depth of the bar which.
has to be coiled in order to make a nut of the dimensions shewn in Figs. 6 and 7..
When the nut is to be round, of a given diameter, the depth of bar should exceed
the distance from the circle A to the exterior of the nut by a small amount say
3th of an inch to allow for finishing.
Referring now to Fig. 3 the form of the bar is determined as follows. The
depth I determined as described with reference to Figs. 6 and 7 is divided into
5 equal parts; through B, the second division from I and the third from O, is.
drawn a line E N at right angles to IO and the lengths B E and B N each equal
to B I are set off, these determining the width NE of the bar at what may be-
termed its neutral line, it having been found by experiment that by the coiling,.
that part of the bar which is outside N E becomes narrowed and the part inside
becomes widened, so that the width of each convolution is uniform throughout its
depth. In order to determine the slope of the sides of the bar, twice the depth OI
is set off from I fixing a point P whence lines are drawn through N and E.
determining the sloping sides of the bar. And, finally, from a centre D set off
from I such that DI is equal to I O circular arcs are struck through O and I
determining the outside and inside curvatures of the bar. Although we have
described the width N E as being double the depth B I, it might be somewhat.
wider or narrower according as the number of convolutions may be less or greater.
As shewn in Figs. 4 and 5 the bar is coiled so as to form a left hand helix, this.
being for a nut having a right hand thread, so that, when the nut has been screwed
down, any tendency for it to unscrew itself has the effect of locking it more firmly
on the bolt. For a nut having a left hand thread the coil is preferably, for the
same reason a right hand helix.
Having now particularly described and ascertained the nature of this inven--
tion and in what manner the same is to be performed, we declare that what we
claim is:-
In the manufacture of coiled lock nuts, the use of a bar the section of which has
two opposite sides sloped, the wider of its other two sides convexly curved and the
narrower concavely curved, substantially in the manner and for the purpose set
forth.
Dated thie Bud dex of Jenner 100A
ABEL & IMRAY,
Agents for the Applicants..