Improvements in Machinery or Apparatus for Cutting out Circular Sheet Metal Blanks.
Year: 1888

page_text: Date of Application, 7th July, 1888
Complete Specification Left, 6th Apr., 1889-Accepted, 15th June, 1889
PROVISIONAL SPECIFICATION.
Improvements in Machinery or Apparatus for Cutting out Circular
Sheet Metal Blanks.
I, JOHN PINSON, of Finchfield near Wolverhampton in the County of Stafford.
galvanized iron manufacturer, do hereby declare the nature of this invention to be as
follows
This invention relates to machinery which operates to cut out sheet metal blanks by
means of circular cutters, and has for its chief object such improvements therein as
will facilitate manipulation on the part of the attendant and greatly increase the
efficiency of the machine, whereby the output will be very considerably increased.
In a machine constructed according to this invention for cutting out sheet metal
blanks by means of circular cutters one of the gripping discs, for holding the sheet
metal under treatment is fixed on the inner end of a spindle which is driven by a band
around a pulley thereon or in other convenient manner, and the other disc is carried
by, and so as to be capable of revolving upon, the inner end of a spindle mounted in
a suitable poppet or carriage so as to be capable of an endway sliding movement. The
latter spindle is moved inwards, so as to grip the sheet metal under treatment between
the discs, and is afterwards moved outwards to release the cut blanks, by means of a
toggle joint operated by a lever handle, or in other convenient manner. The circular
cutters are carried upon a block fitted to a suitable fixed guide along which it may be
moved inwards or outwards towards the axis of the spindles by means of a screw and
to which it may be fixed firmly in any desired position by means of a bolt or bolts.
The adjustable cutter is carried upon a rest mounted in slides upon the block and
capable of being moved therealong by means of a screw and firmly fixed thereto in
any desired position by means of a bolt or bolts.
As will be seen from the foregoing description, the discs and sheet metal are driven
and the movement of the sheet metal itself drives the cutters.
A tumbler gauge is used for setting the blanks in position.
The driving spindle carrying the first-mentioned disc is put into gear with the
driving mechanism by the foot or otherwise.
It is preferred to arrange the mechanism above described so that the spindles which
carry the gripping discs are horizontal and the cutters in position vertically below the
axis of the spindles; in such case the sheet metal is placed vertically in place between
the discs and against the cutters and gauge, this being the most convenient method of
fixing the work. This arrangement of the spindles and cutters is not, however,
essential as they will of course work in other positions if desired, for instance, the
axis of the spindles may be vertical and the cutters be placed in position corresponding
thereto.
Wolverhampton and Walsall, Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Machinery or Apparatus for Cutting out Circular
Sheet Metal Blanks.
I, JOHN PINSON, of Finchfield near Wolverhampton in the County of Stafford,
galvanized iron manufacturer, 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 machinery which operates to cut out sheet metal blanks by
means of circular cutters, and has for its chief object such improvements therein as

page_text: will facilitate manipulation on the part of the attendant and greatly increase the
efficiency of the machine, whereby the output will be very considerably increased.
In a machine constructed according to this invention, for cutting out sheet metal
blanks by means of circular cutters, one of the flat discs or grippers for holding the
sheet metal under treatment is fixed on the inner end of a spindle which is driven by
a band around a pulley thereon or in other convenient manner, and the other disc or
gripper is carried by, and so as to be capable of revolving upon, the inner end of a bar
mounted in a suitable poppet or carriage so as to be capable of an endway sliding
movement. This bar is moved inwards, so as to grip the sheet metal under treatment
between the discs and is afterwards moved outwards to release the cut blanks, by means
The
of a toggle-joint operated by a handle-lever, or in other convenient manner.
circular cutters are carried by a block fitted to a suitable fixed guide along which it
may be moved inwards or outwards towards the axis of the discs by means of a screw
and to which it may be fixed firmly in any desired position by means of a bolt. The
adjustable cutter is carried upon a holder or rest mounted on a guide upon the block,
and such holder is capable of being adjusted along the block by means of a screw and
firmly fixed thereto in any desired position by means of a bolt or bolts in a manner
analogous to that previously adopted for a like purpose.
As will be seen from the foregoing description, the discs and sheet metal are driven,
and the movement of the sheet metal itself drives the cutters.
An important feature of this invention consists in the combination with the machine
of means whereby the back disc or gripper is moved forwards to grip the sheet metal
by a quick-acting mechanism, such as the toggle-joint and handle-lever aforesaid,
instead of by the screw usually employed for the purpose and which causes the
operation to be an extremely slow one.
This invention will be readily understood on reference to the accompanying
drawings, of which figure 1 is a front elevation of a machine constructed according
to this invention for cutting out sheet metal blanks, figure 2 a plan of the same, and
figure 3 a section taken on liue of figure 1. One of the discs or grippers A for
holding the sheet metal under treatment is fixed on the inner end of a spindle B
carried in bearings on the tops of standards C. The spindle B is driven, when the
machine is at work, by means of a band passing around the cone-pulley D, or it may
be driven by any suitable mechanism. The other disc or gripper A¹ is carried so as
to be capable of revolving upon the inner end of a bar a which is itself carried within
a guide block so as to be capable of being moved end ways therein in order to move
the disc A¹ towards or from the disc A; and this bar a is formed square or other
shape in section which will prevent it from being turned axially within the guide b, or
a round bar or spindle may be employed in combination with a feather-key and groove
to prevent it turning. An endway movement is given to the bar a through the
medium of a handle-lever c and toggle-joint d d, the connection between the lever c
and toggle-joint being effected by means of an arm e on the inner end of the lever
and a link between the outer end of such arm and the toggle-joint. It will be seen
that as the handle-lever c is moved to the left-hand the links of the toggle-joint will be
brought more directly into line with one another, and will thus not only move the
disc A¹ against a sheet metal blank placed between the discs, but that the leverage
exerted by the operator will, owing to the position of the links of the toggle-joint, be
so great as to cause a very tight grip of the blank between the discs. When the
handle is moved back again to the right-hand the links of the toggle-joint will be
drawn outwards so as to be considerably out of line with one another (as shewn), and
thereby the disc A¹ is of course drawn back. A very quick motion may be given in
an endway direction to the disc A¹ by means of the lever and toggle-joint. The
hinder link of the toggle-joint is pivotted to a part. carried by a vertical arm or
support G, and such support and the guide b and an arm G' by which it is carried may
form together a back poppet, as shewn, which may be carried to slide upon a bed H
as in the case of a lathe-poppet, and be fixed in position thereupon by means of a
v bolt n.just as a lathe poppet is fixed. This poppet may be set up along the bed H by
means of a set-pin o screwed through the end of the bed and bearing against the back

page_text: or outwards towards
or
edge of the poppet. The degree to which the sheet metal is gripped between the discs
depends on the approximation which the links d d of the toggle-joint may make to
being in a straight line with one another, and hence it is desirable to bring the links
practically into line with one another when the disc A' is in its most forward position.
This renders it necessary or advisable to employ a stop to prevent the links from being
forced too far in a backward direction and thus drawing back the disc just when it is
intended to be gripping tightly against the sheet metal. Such a stop is formed by the
set-pin carried by the bar m' fixed to both the guide and the upper end
of the support G. The circular cutters 9 g¹ are carried by means of a block E
which is itself fitted to a vertical guide F along which it may be slid inwards
from the axis of the discs. This block E is
held against the face of the vertical guide F by means of a holt r (see
specially figure 3) which has a head s let into a countersunk hole in the block
and which passes through a vertical slot in the guide and is tightened up by means
of a nut and washer, as shewn. The part t of the holt r which passes through the
guide is square, or otherwise flat-sided, so as to be a good sliding fit within the vertical
slot in the guide, and the part of such bolt which is within the block is round to
allow of the block being turned thereon in an analogous manner to that previously
adopted for the purpose hereinafter described. A vertical screw h, having a hand-
wheel on its lower end, and carried in the bed of the machine so as to be held from
moving in an end way direction, is screwed through the part t of the bolt r, and thus
when the nut on the end of the bolt is slackened the block E may be readily raised
or lowered along the guide F, to suit different sizes of blanks, by means of the
screw h; and when it has been thus moved into the desired position it may be rigidly
is fitted to
fixed again to the guide by tightening up the nut. The circular cutter
turn on the end of a spindle p which is fixed in a supplementary block E' which
is itself fixed to the block E by means of bolts q. The adjustable cutter g₁ is mounted
upon a holder or rest i which is carried upon, and so as to be capable of being moved
along, an inclined guide block k, formed with or fixed to the main block E. The
endway adjustment of the cutter g' is effected by means of a set-pin I screwed through
a lug on the end of the holder, with its point bearing against the end of the block k;
and when this cutter has been properly adjusted the holder i is fixed rigidly to the
block k by means of bolts m which pass through slotted holes in the holder and are
screwed into the guide block. The block E has a flange a projecting across the front
edge of the guide F but at a short distance forwards therefrom thus leaving space
between the flange and guide, and set-pins are screwed through the flange and
their inner ends bear against the guide. This arrangement is adopted, in combination
with the round part of the bolt r which is within the block E, for the purpose of
adjusting the set of the cutters to receive the metal as it is turned in towards
them in being cut; and this adjustment is effected by first slackening somewhat the
nut on the bolt and then slackening one of the set-pins b¹ and tightening the other
to turn the block E on the round part of the bolt ràs may be required. To fix the
block E in its proper axial position on the pin r both the set-pins 61 must, of course,
be tightened up. The guide F which carries the block E may be adjusted in a
direction parallel with the axis of the spindle B by means of set-pins c¹ passing through
the foot d of the guide and hearing at their inner ends against a part of the bed or
framing of the machine. The bolts e¹ by which the foot d' is fixed to the bed H pass,
of course, through slotted holes in such foot.
до
Each cutter is fixed on the end of its respective spindle in the usual manner,
and the spindles revolve with the cutters. As there is a considerable downward
pressure on the cutter g a centre-pin k², screwed through a part l¹ of the block E, is
employed to take the thrust and for taking up the wear.
A rough blank, usually of a square shape, from which it is intended to cut out a
circular one, is first placed in position against the face of the disc A, with one of its
edges resting upon the cutter g and another edge resting against a gauge f¹, and the
disc A¹ is then brought up against the blank so as to grip such blank firmly between
itself and the disc A. The spindle B is then caused to rotate so as to drive the disc A.

page_text: and consequently also the blank and disc A', on account of the friction caused by the
pressure of the parts together, and thus the blank is cut into a circular form by the
cutters. The gauge f1 is what is known in the trade as a lifting or tumbler
gauge, that is to say, it is hinged or pivotted in such a manner that it can be raised
and will fall again to a fixed point upon being released, so that it is simply moved up
as a corner or other projecting edge of the rough blank comes in contact with it, and
as such part passes out of contact therewith the gauge falls again into its normal
position. Immediately the circular blank has been cut the disc A¹ is drawn back, in
the manner above described, and the circular. blank is then removed and replaced with
a rough blank to be cut. The starting and stopping of the machine may be effected
in any convenient manner such as is employed in analogous cases. The method I
have adopted for this purpose, and which I find very convenient, is to mount the
cone-pulley D as a loose pulley upon the spindle B, and to carry within a groove in
the spindle a turning key which when the spindle is desired to be driven is projected
somewhat edgeways into a key-way cut therefor in the nave of the pulley and which
is withdrawn from such key-way when it is desired that the machine shall stop. I
have not illustrated this arrangement in detail as it is one in common use in machines
employed in working sheet metal, though I am not aware of its having been applied to
a machine which operates to cut out blanks by means of circular cutters. When it is
desired to start the machine a stop-piece 2 of the usual character is moved to the
right, so as to be clear of the usual arm which projects sideways from the turning
key, by the operator pressing his foot on a pedal j, and thus the arm i¹ falls backwards
slightly in the usual manner, as the key-way in the pulley comes opposite the key,
and thus moves the key partially into the key-way and causes the spindle B to revolve
with the pulley; and the machine is stopped, on the completion of cutting a blank, by
lifting the foot from the pedal and allowing the overbalancing weight of the connections
to bring back the stop-piece 2 into the position shewn so as to catch the arm i¹, in the
usual manner at a point in the revolution of the spindle, and cause the key to move
out of the key-way in the pulley.
It is not, of course, essential (though it is much preferred) that a toggle-joint be
employed in moving forward and backward the disc A', as any means may be adopted
which will give both an endway movement (preferably a quick one) to the disc A¹
and also the required leverage for producing the necessary grip of the blank between
the discs; for instance, a cam operated by the lever may be employed to move the
bar a and to press the disc A firmly against the sheet metal. It will be obvious also
that it is not essential that the bar or spindle a which carries the disc A' be prevented
from turning on its axis, as the disc A may be fixed upon the end of a spindle which
is capable of revolving in the guide b and such spindle may be moved endways by the
aid of pins or a collar operating between a pair of collars or within a circular groove
around the spindle so that the spindle may revolve without carrying such pins or
collar around with it, and such pins or collar be operated by means of a toggle-joint or
other convenient means, as will be readily understood.
The mechanism above described is shewn by the drawings to have the spindle and
bar which carry the gripping discs in a horizontal position and the cutters in position
vertically below the axis of the discs, the sheet metal being placed vertically in place
between the discs and against the cutter g and gauge f', this being the most convenient
method of fixing the work. Such arrangement, however, of the spindle and bar and
cutters is not essential, as they will of course work in other positions if desired, for
instance, the axis of the discs may be vertical and the cutters be placed in position
corresponding thereto.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The general arrangement and combination of parts constituting a machine for
cutting out circular sheet metal blanks, substantially as described and shewn by the
drawings herewith.

page_text: 2. In a machine for cutting out circular sheet metal blanks, a spindle carrying a
disc or gripper fixed on its inner end, with means by which such spindle may be
caused to revolve and be stopped at pleasure, a part carried by a fixed guide in such a
manner that it may be slid along such guide endways, said part carrying a dise or
gripper which is capable of being revolved, and with means by which such part may
be readily moved inwards by a quick-acting movement so as to bring the face of the
dise or gripper carried thereby against a thickness of sheet metal placed between the
discs, and by which the disc carried by such part may be held firmly against such
sheet metal and be moved backwards again therefrom by a reversal of the quick-acting
movement, in combination with a pair of cutters carried in position to cut the sheet
metal as the same is revolved whilst held between the discs, all constructed and
arranged to operate substantially in the manner and for the purpose described
and shewn.
3. In a machine for cutting out circular sheet metal blanks, the combination of the
spindle B, disc or gripper A, sliding-bar a carried by a guide b, disc A¹, toggle-
joint d d and means of operating the same; and cutters 9 g¹ carried by a sliding block
capable of adjustment towards and from the axis of the discs or grippers, all
substantially as and for the purpose described.
4. A machine for cutting out circular blanks in which the sheet metal to be cut is
placed vertically between discs or grippers capable of turning on a horizontal axis,
substantially as described for the purpose set forth.
5. In a machine for cutting out circular blanks, the means, substantially as
described, by which a block carrying the cutters may be adjusted towards or from the
axis of the discs or grippers which hold the sheet metal.
6. In a machine for cutting out circular blanks the application of a toggle-joint
actuated by a lever for the purpose of giving endway movement to the back disc or
gripper and of causing a firm grip of the sheet metal between the pair of discs or
grippers, substantially as described.
Dated this 5th do- CA
1 1000
STEPHEN WATKINS,
Wolverhampton and Walsall, Agent for the Applicant.