AX IMPROVED MODE OF MANUFACTURING NUTS FOR SCREW BOLTS
Year: 1877

page_text: LETTERS PATENT to George Greenwood, of Leeds, in the County of York,
Machine Maker, and William Horsfall, of the same Place, Foreman, for the
Invention of AX IMPROVED MODE OF MANUFACTURING NUTS FOR SCREW
BOLTS."
Sealed the 7th May 1878, and dated the 19th November 1877.
PROVISIONAL SPECIFICATION left by the said George Greenwood and
William Horsfall at the Office of the Commissioners of Patents on the 19th
November 1877.
GEORGE GREENWOOD, of Leeds, in the County of York. Machine Maker, and
WILLIAM HORSFALL, of the same Place, Foreman. "AS IMPROVED MODE OF MANU-
FACTURING NUTS FOR SCREW BOLTS,
This Invention relates to the manufacture of nuts for screw bolts by the adapta-
tion to that purpose of machinery now used for forging bolts and spikes, and more
particularly of the machinery which forms the subject of a Patent granted to one
of the present applicants, dated 5th Oct. 1869. No. 2882. In that machine the
rod, whether round or square, was submitted while in a heated state to a pair of
grippers which held it firmly while a die advanced to ** upset the end of the metal
to form a hump for conversion into the head of the bolt. The rod was then withdrawn
and placed between a pair of gripping dies, which, together with a second or finishing
heading die, completed the bolt head.
It is now proposed to form bolts in a similar manner, either with square or hexa-
gonal heads, but by preference in one set of heading dies: and in place of the second
heading die, to provide a punch of a diameter equal to the diameter of the hole to
be formed in the nut. The bolt is then to be submitted to a pair of grippers or
laterally compressing dies which will reduce that portion of the stem of the bolt
which is close to the head to a diameter corresponding to that of the punch. The
punch is then caused to strike the centre of the head, and force out the metal
T071

page_text: opposed to it in the form of a core, thereby converting the buit head into a nut
blank. The metal thus forced out forms a continuation of the rod under treatment,
and is used in the manufacture of the next following nut, thus no meial is wasted
in our improved process of manufacture.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Greenwood and William Horsfall in the Great Seal Patent
Office on the 18th May 1878.
GEORGE GREENWOOD, of Leeds, in the County of York, Machine Maker, and
WILLIAM HORSFALL, of the same Place, Foreman. AS IMPROVED MODE OF MANY-
FACTURING NUTS FOR SCREW BOLTS."
This Invention relates to the manufacture of nuts for screw bolts by the adapta-
tion to that purpose of machinery now used for forging bolts and spikes, and more
particularly of the machinery which forms the subject of the Patent granted to one
of the present applicants, dated Fifth October, One thousand eight hundred and
sixty-nine, No. 2882. In that machine the rod, whether round or square, was sub-
mitied while in a heated state to a pair of grippers which held it firmly while a
die advanced to upset the end of the metal to form a lump for conversion into the
head of the bolt. The rod was then withdrawn and placed between a pair of
gripping dies, which, together with a second or finishing heading die, completed the
bolt head.
In carrying out our improved manufacture of unis, we propose, first, to form bolts
in a similar manner to that above-described, and either with square or hexagonal
heads, but by preference in one set of heading dies, and by fitting the machine with
a punch in place of the second heading die, and by submitting the head of the bolt
to the action of the punch while the bolt is held between à pair of grippers or
laterally compressing dies, the punch will strike the centre of the head and force
out the metal opposed to it in the form of a core, thereby converting the bolt head
into a nut blank. The metal thus forced out forms a continuation of the rod under
treatment, and is used in the manufacture of the next following nut.
In the accompanying Drawings we have shown in several views the arrangement
of machinery which we employ for manufacturing nuts according to our Invention.
This machinery is in its general characteristics substantially like that which forms
the subject of the Patent above mentioned, it will not be necessary therefore to enter
minutely into the details of its construction.
Fig. 1. Sheet L., represents in plan view, a bolt forging machine, fitted to make
nuts for screw bolts according to our Invention.
Fig. 2: Sheet II., is a longitudinal sectional elevation of the same, taken in the
line 1, 2, of Fig. 1: and Fig. 4. Sheet III., is a transverse section taken in the
line 3. 4. of Fig. 1.
In these Figures, A is the main driving shaft, receiving its motion from band
pulleys B. This shaft has its bearings in blocks C, C, cast on the bed of the machine,
and it is fitted with cams for working the gripping dies, the side hammers and the

page_text: slide carrying the heading die and the punch; D, D, is the bed plate of the machine
and to it are fitted the blocks E. E', which blocks serve to carry a pair of gripping
dies c. The block is free to slide in guides on the bed plate, and the block E' is
stationary on the bed plate.it being held in position bymeans of a breaking piece 1º
of cast iron, which, when any undue pressure is put upon the gripping dies will break
up,and thus relieve the dies and prevent strain or injury to any permanent part of
the machine. In the contact faces of these gripping dies, two semicircular horizon-
tal recesses are formed to hold the heated bolt at two different elevations.the one in
line with the heading die f, and the other in line with the punch g.
these recesses is clearly shewn in Fig. 8.
The form of
The lower opening in the die, which is opposite the heading die, is contracted at
its inner end, in order that, by pressing on the stem of the holt immediately
below the head, it may reduce its diameter to a size corresponding to that of the
punch.
The upper opening in the gripping dies is enlarged laterally to receive the head
of the bolt when it is brought under the action of the punch g.
Both the
punch and heading die are carried by the same sliding block F, which is sup
ported in suitable guides on the bed plate: h., are side hammers carried by
slides H. and serve, when the bolt is headed, to put lateral pressure upon the
head and thereby to bring it to shape, preparatory to
the head being pre-
sented to the punch g.
When a rod of heated iron is submitted to the machine, it is brought, first,
opposite to the heading die, and thrust forward into contact therewith, the
heading die serving as a gauge to regulate the amount of metal passed into the
machine. The gripping dies will then close on the heated metal, and hold it
firmly while the heading operation is being effected. The sliding block E of the
gripping dies is formed (see the plan view Fig. 1) with an incline on its rear end.
to receive the pressure of a sliding bar I, which lies at right angles thereto, and is
held in guides on the bed plate. This bar receives an endway motion from a cam l'
on the shaft A. and when driven forward by its cam, it will cause the block E to
The
advance, and ensure the gripping of the heated metal between the dies e
pressure of these dies will be maintained until the heading die F and the side
hammers have successively acted upon the metal which protruded from the
gripping dies.
When the head of the bolt is completed, and the slide E is relieved of pressure.
the spring will come into action and draw it back to its quiescent position.
So soon as the heated metal is gripped between the dies, the heading F will
advance. This is effected by a cam F¹ on the shaft A, which cam, hearing on the
rear end of the slide will cause the heading die to upset the end of the rod, and
compress it into the shape of a bolt head.
For the purpose of determining the amount of metal which shall be presented to
the heading die. the limit of the back traverse of the slide is made adjustable.
This is effected by connecting the slide through an adjusting coupling rod F
with a rock lever F³ pivotted to the back of the machine, and having a hooked
finger which bears against a cam P5 on the shaft A.
By elongating the rod F. the back motion of the slide will be contracted, and
cice versa, and as the heated metal is fed into the machine, when the heading die
has completed its back traverse.the amount of metal passed into the machinebeyond
the grip of the dies e may be regulated with the greatest exactness.
So soon as the heading die has acted on the metal, it is withdrawn to allow of
the side hammers finishing the head, and bringing it up to a square or hexagonal
shape, as may be desired. The slides H which carry these hammers have vertical
inclined surfaces formed thereon to receive the pressure of bars which lie at right
angles thereto, and slide in guides on the bed plate. These sliding bars receive an
endway motion from cams H2 on the shaft A. and the slides which they actuate are
withdrawn to their quiescent positions by means similar to that shewn for with-
drawing the slide E.

page_text: When the head of the bolt is completed, the attendant withdraws the heated
metal, and places it in the upper recess of the gripping dies which grip the head
firmly, and present it to the action of the punch g. The punch now advancing by
reason of the continued rotation of the cami F will strike the centre of the head of
the bolt, and push out the central portion of the metal which still adheres to the
stem of the holt, and will serve to form a portion of the next succeeding head that
is to be formed on the rod thus, no metal is wasted in our improved process of
manufacture.
In order to remove all tendency to overrunning in the machine, when the driving
clutch (as explained in the Specification of the before-mentioned Patent) is disen-
gaged, we now apply to this mechanism a friction brake, which as the treadle is
depressed, will be brought to bear upon the clutch disc, and effectually prevent its
moving independently.
This contrivance is shewn in side elevation and back view at Figures 1ª and
Sheet T., where K is a weighted lever carrying a friction block, that bears upon
the periphery of the dise L, which carries the clutch bolt M that takes into the hub
of the driving pulley B.
Fig. 4. Sheet III., shews an arrangement of dies for forming the head of the bolt
by the aid of a preparatoryheader or "bunting" die,as described in the Patent before
referred to. This bunting die is represented at f*, and serves to taper the end of
the rod while upsetting it, and thus to prepare it for the subsequent operations of
the heading die F, and slide hammers.
Having now set forth the nature of our Invention of "An Improved Mode of
Manufacturing Nuts for Screw Bolts," and explained the manner of carrying the
sume into effect, we wish it to be understood that under the above in part recited
Letters Patent, we claim the mode hereindescribed of producing nuts from the heads
of bolts and utilizing the scrap obtained therefrom.
In witness whereof. T. the said George Greenwood, have hereunto set my hand
and seal, the Sixteenth day of May, in the year of our Lord One thousand
eight hundred and seventy-eight.
GEORGE GREEN WOOD. (1..8.)