An Improved Machine for Making Metal Nuts for Screw Bolts.
Year: 1891

page_text: Date of Application, 7th May, 1891-Accepted, 1st Aug.,
1891
COMPLETE SPECIFICATION.
An Improved Machine for Making Metal Nuts for Screw Bolts.
GEORGE STONES and JOHN STONES, of the Atlas Works Brook Street,
Smethwick, Staffordshire, Bolt and Nut Manufacturers, 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 :-
In describing our invention we will refer to the accompanying drawings.
Many kinds of machines are now used for making nuts, all of which are con-
structed in such a manner as to allow a certain amount of spring, so that as the
heat of the bar from which the nuts are made varies, so does the thickness of the
nuts vary, and to avoid this we have invented a machine of such solid construction
and design as to reduce this variation to a minimum.
In the first place the main crank shaft in existing machines has to depend on
bolts or pins to keep it in position, and when the necessary pressure is brought to
bear to form the nut, the bolts or pins stretch or spring and therefore the requisite
even pressure to form a perfect nut is not obtainable.
In our improved machine we dispence intirely with bolts and pins for this purpose,
and form a solid bearing by boring a round hole in the main casting A. (Fig. 1) to
admit a round shaft B (Fig. 2) of sufficient diameter for the crank C to be formed
giving the required stroke.
Another defect in existing machines is that the bearing surfaces of the main
slide D are formed parallel and the same length as the slide, and we find from
experience that the wear on the end E is so slight that it will last for years, wereas
the other end F will be found defective in a few months or even weeks. This is
caused in the first place that, as the nut is made at the end F the strain on this end
of the slide is much greater than on the other end, and secondly the scale or oxide
of iron, dust, water &c., which get on the bearings wear or cuts them away, this
inequality of wear between one end of the slide and the other end is a source of
much trouble, because the bearings of the slide in a short time become taper from
end to end, and however tight the slide bars are set up, the slide at one end of the
stroke will be tight, and at the other end loose.
To avoid this we have constructed a slide (Fig. 3 & 4) with bearings at each
end (not all along the slide) so that four slide bars are required instead of two. It
will be readily seen that each end of the slide can be adjusted independently. The
end of the slide where the nut is made is much wider than the other for two
reasons, the wear on this end being much greater than the other, and also being
farther away from where the nut is made, is more easily protected from the scale
water &c.
As the greatest strain occurs when the cut off G enters the die box H, we have
extended the bearings of the slide to project beyond the end of the slide so as to
take a more equal bearing.
Another improvement we have made is in the mode of securing the punches,
which is usually done by screwing the end of the punch and using a lock nut or set
screw to prevent it turning, this method is costly and the screws are liable to get
out of order.
J
To remedy this we enlarge the end of the punch L (Fig. 5) making a suitable
recess in the punch holder N, and after the punch is put in, a solid block O is
inserted and the punch is fixed, the working position of the punch being readily
adjusted by putting liners or packing pieces the required thickness in the spaces
and K. Assuming the space J to be in. and the space K to be in., to fix the
punch L it would be nescessary to put a packing piece in. thick in the space J, and
a packing piece in. thick in the space K, and after the punch becomes worn, by

page_text: changing the packing piece from J to K and visa versa, the punch would be
moved forward in. A set of packing pieces consists of 16, from 1 in. to 1 in.
thick.
As the strain on the punch is horizontally only, the weight of the punch and the
holder N is sufficient to keep it in its place, as we find from experience that the
punch has no tendency to rise in the box I. This arrangement applies to both
the main slide D and the back slide M.
The last improvement we have made is a compact simple and efficient method of
working the back slide M. As the punch L is piercing the nut, to save wasting
the metal it is nescessary to have another punch to meet it and reduce the thickness
of the wad or punching, to do this we use a rocking shaft P (Fig. 6 and 7) which
is actuated by the crank Q, through the connecting rod R. (The connecting rod R
is the full length of the machine, but only the ends of it are shewn, the one end on
the crank Qand the other end on the crank pin of the rocking shaft P). As the
main slide & punch move forward it is nescessary that the back punch should
advance and recede very quickly at the point required, and as the stroke of the
main slide is five and half inches, and the stroke of the crank Q thirteen inches it
will be readily seen how this is accomplished. The top of the arm S (Fig. 6
and 7) on the shaft P coming into actual contact with the back slide M, no links
or connection of any kind is required. The rod T is for the purpose of pulling
back the slide M to eject the punching, and also for preventing damage to the
punches by coming in contact with each other when the machine is running without
being used.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :
1. A machine, the main casting of which is constructed to take a shaft and form
bearings without bolts or pins as shewn and described.
2. A main slide for said machine with separate bearings at each end, the
bearings at one end being wider and extending beyond the end of the slide as shewn
and described.
3. An improved method of securing and adjusting the punches for the said
machine as shewn and described.
4. A compact, simple and efficient method of working the back slide of the said
machine as shewn and described.
Dated this 6th day of May 1891.
GEORGE STONES.
JOHN STONES.