IMPROVEMENTS IN MECHANISM FOR CUTTING OR SHEARING SHEET METAL INTO VARIOUS SHAPES AND FOR MADE FROM SHEET METAL" ADRIAT TO TADIOTIS STAD PROVISIONAL SPECIFICATION
Year: 1883

page_text: LETTERS PATENT to Alfred Nind Hopkins of the firm of J. H. Hopkins and
Sons of Granville Works, Birmingham in the County of Warwick Tin-plate
workers and Japanners for an Invention of "IMPROVEMENTS IN MECHANISM
FOR CUTTING OR SHEARING SHEET METAL INTO VARIOUS SHAPES AND FOR
MADE FROM SHEET METAL"
ADRIAT TO
TADIOTIS STAD
PROVISIONAL SPECIFICATION left by the said Alfred Nind Hopkins at
the Office of the Commissioners of Patents on the 10th April 1883.
ALFRED NIND HOPKINS, of the firm of J. H. Hopkins and Sons [sic] of Granville
Works, Birmingham in the County of Warwick, Tin-plate workers and Japanners,
"IMPROVEMENTS IN MECHANISM FOR CUTTING OR SHEARING SHEET METAL INTO
VARIOUS SHAPES AND FOR TRIMMING UP ARTICLES OF VARIOUS SHAPES
FROM SHEET METAL
"
MADE
This invention has for its object a considerable saving in the cost of tools, by
the employment of improved mechanism for (1) cutting or shearing sheet metal
into blanks of any desired shapes, with the exception of such shapes as have
re-entrant angles, and (2) trimming or shearing such edges, as lie in a common
plane, of any articles made from sheet metal, with the exception of those parts of
such edges of any such articles which bound any re-entrant angles, thereof and lie
at and near the apices of such angles.
In the case of any such re-entrant angles, as aforesaid, the blanks or articles,
as aforesaid, are cut, trimmed or sheared, by my improved mechanism, to the
nearest shape possible to that desired, and the re-entrant angles are afterwards cut
by hand or in any convenient manner.
A machine, constructed for the purposes aforesaid, consists essentially of a set of
rotary shears of the ordinary type for cutting or shearing sheet metal into circular
blanks, with the ordinary holding apparatus for the sheet metal, but having the
framing of the circular cutters carried in a slide so as to be capable of an in-
and-out movement to and from the holder, the inward movement being effected by

page_text: means of a weight on the end of a cord or chain passing over a pulley and
connected to the said frame, or by means of a weighted lever or in any convenient
manner, and, such machine, having also a "former" fixed upon the holder-spindle
so as to rotate therewith and act during the revolution of such spindle against a
roller in the inner end of the cutter-frame so as to effect the outward movement
of such frame. The contour of such "former" corresponds exactly in shape and
size to the contour of the blank to be cut or the article to be trimmed, and
therefor, of course, when a different size or shape of blank or article is to be cut
or trimmed the "former is changed for one corresponding to such difference.
The upper end of the holder-spindle is screwed on to the part below and the
"former" is carried upon a plain part of such part below and immediately below
the screwed joint so as to be readily removed and a fresh one substituted when the
upper part of the holder-spindle is unscrewed. When fixed in place the "former
is held between a shoulder formed by the upper-part of the holder-spindle and a
collar on the part below.
22
The holder-spindle is rotated by mechanism which throws itself out of gear with
the driving power immediately such spindle has made one revolution; and the
nechanism I prefer to employ for this purpose consists of an adaptation of
mechanism which has been employed previously for an analogous purpose, and is
described as follows:-A horizontal shaft (hereinafter termned the first-motion
shaft) has a pulley mounted loosely thereon which receives the driving belt, and a
spur pinion fixed thereon which imparts motion, through the medium of a spur
wheel, to a second horizontal shaft (hereinafter termed the second-motion shaft)
which latter imparts motion to the holder-spindle, through the medium of mitre
spur wheels fixed respectively on the end of such second-motion shaft and the
lower end of the holder-spindle. One revolution of the second-motion shaft thus
produces one revolution of the holder-spindle, and therefor of the sheet metal
or articlo, as aforesaid, being operated upon by the machine. A disc or block
is fixed upon the first-motion shaft a short distance from the pulley aforesaid, and
a clutch is made to slide upon such shaft on the opposite side of the block to that
on which the pulley is placed. Two lugs, opposite to one another circumferentially,
project from the pulley towards the block aforesaid, and pins corresponding thereto
project from the clutch through the block, which acts as a guide therefor. A cross
spindle, carried in bearings upon the framing of the machine, has a lever goaring
at one end with an annular groove in the clutch and at its opposite end formed to
bear against the face of and be actuated by an inclined or curved stud or cam on
the boss of the wheel on the second-motion shaft. To start the machine, the lever
aforesaid is actuated by means of a suitable handle and lever, the latter bearing
against the first-mentioned lever, so as to throw the clutch forwards, when the
ends of the pins projecting therefrom aro engaged with the lugs projecting from
the pulley and the working parts of the machine are put in motion, the circular
cutters rotating and cutting the sheet metal as such sheet metal, or article, made
therefrom is rotated between them, and the "former" and weight (or equivalent)
acting together to move the cutters in and out from the centro of the sheet metal,
or article, as such is revolved, or to keep such cutters at any desired distance from
such centre, as may be necessary for the desired shape of the sheet or article being
operated upon. As the second-motion shaft, and by consequence the holder-
spindle, completes one revolution, the cam .upon the face of the wheel on the
second-motion shaft forces back one end of the lever bearing theroagainst, thus
throwing back the opposite end of such lever and drawing back the clutch and
therefor stopping the machine. The slight swing of the machine carries the
cam sufficiently to allow the lever to be moved in again by means of the handle to
re-start the machine for cutting another sheet or trimming another article.
The employment of the mechanism herein-before described for the purposes
stated effects a considerable saving in the cost of tools, over the ordinary mothod
of cutting out various shaped blanks and trimming up various shaped articles of
sheet metal.
j

page_text: The machine as described is not, of course, intended for cutting out rectangular-
shaped blanks or trimming such shaped articles, as such may be best performed
with plain shears, nor is there any special advantage in employing the machine
for circular blanks and articles over the employment for such purposes of ordinary
circular shears, but the machine may be used for this latter purpose with equal
convenience to that of the ordinary circular shears.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alfred Nind Hopkins' in the Great Seal Patent Office on
the 9th October 1883.
ALFRED NIND HOPKINS, of the firm of J. H. Hopkins and Sons, of Granville
Works Birmingham in the County of Warwick, Tin-plate workers and Japanners,
"IMPROVEMENTS IN MECHANISM FOR OUTTING OR SHEARING SHEET METAL INTO
VARIOUS SHAPES AND FOR TRIMMING UP ARTICLES OF VARIOUS SHAPES MADE
FROM SHEET METAL
"2
This invention has for its object a considerable saving in the cost of tools by the
employment of improved mechanism for, (1) cutting or shearing sheet metal into
blanks of any desired shapes, with the exception of such shapes as have re-entrant
angles, and, (2) trimming or shearing such edges as lie in a common plane of any
articles made from sheet metal, with the exception of those parts of such edges of
any such articles which bound any re-entrant angles thereof and lie at and near
the apices of such angles.
In the case of any such re-entrant angles as aforesaid the blanks or articles as
aforesaid are cut, trimmed or sheared, by my improved mechanism to the nearest
sliape possible to that desired, and the re-entrant angles are afterwards cut by
hand or in any convenient manner.
A machine, constructed for the purposes aforesaid, consists essentially of a set of
rotary shears of the ordinary type for cutting or shearing sheet metal into circular
blanks, with the ordinary or analogous holding apparatus for the sheet metal or
article made therefrom, but having the framing of the circular cutters carried in a
slide so as to be capable of an in-and-out movement to and from the holder, the
inward movement being effected by means of a weight on the end of a cord or
chain passing over a pulley and connected with the said frame, or by means of a
weighted lever, or in any convenient manner, and, such machine, having also a
"former" fixed upon the holder-spindle (or other spindle as will be explained) so
as to rotate therewith and act, during the revolution of such spindle, against a
roller at the inner end of the cutter frame, so as to effect the outward movement of
such frame. The contour of such "former" corresponds exactly in shape and size
to the contour of the blank to be cut or the article to be trimmed, and therefor, of
course, when a different size or shape of blank or article is to be cut or trimmed the
former" is changed for one corresponding to such differenco.
"

page_text: A machine constructed according to this invention is illustrated by the accom-
panying drawings, of which, figure 1 is a side elevation, figure 2 a plan, figure 3 an
end elevation looking in the direction of the arrow a figure 1, and figure 4 a
transverse section on line xx of figure 1, such figure 4 shewing for the sake of
simplicity only the parts necessary to make the illustration clear. The same
letters of reference occurring upon different views indicate corresponding parts.
A is the foundation-plate of the machine, B the machine-bed and C C standards
upon the plate A supporting the bed B. D D¹ are a pair of ordinary rotary
cutters mounted upon a frame E. This frame E is fixed upon a sliding-plate F
which is carried within V-slides G G upon a sliding-rest or plate H so as to be
capable of a sliding-movement therein. The sliding-rest or plate H is carried
within V-slides I I upon a saddle K, and the saddle K is carried upon V-slides LL
forming the top of the bed B as shewn. M is the holder-spindle mounted
vertically in the bearings N N (shewn by dotted lines figure 1) and O a centre
thrust-pin to adjust the level of the spindle. P P¹ are the holders for the sheet
(or in a modified form as will be presently explained for the article to be trimmed).
Qis a "former," which is made of exactly the same size and shape on plan as the
blank to be produced or article to be trimmed. In order to fix the "former" in
place so that it may readily be removed and replaced by a "former" of different
size or shape, or both, the spindle M is constructed in two parts, the upper part M¹
being provided with a socket A', square or polygonal-sided outside so as to be
easily operated by means of a spanner, and screwed internally; and the lower
part of such spindle having a collar B for the "former" Q to lie upon, a plain
part B2 (shewn by dotted lines figure 1) immediately above the collar, around which
the "former" fits, and a screwed part C' (also shewn by dotted lines figure 1) upon
which the socket A¹ is screwed and thus the whole upper part M¹ of the spindle M
and the holder P' is firmly fixed. The plain part B is somewhat shallower than
the "former" Q, as shewn, so that the lower edge of the socket A' tightens down
upon the top of the "former" as it is screwed home. a is a feather-key upon the
part B and prevents the "former" turning otherwise than with the spindle.
The holder P is carried and tightened down as in the ordinary construction of
circular cutting machines. R. is a roller (shewn by dotted lines figure 2) carried in
a frame fixed to the front of the sliding-rest or plate H. S is a weight connected
to a cord T which passes over a pulley U turning upon a pin fixed on the underside
of the saddle K. The back end of the cord T is connected to a stud V fixed to the
underside of the sliding-rest H. The saddle K is moved to any position along the
bed B, as may be best to suit the size of "former" employed, and is held fixed in
such position, by means of the screw W carried at its back end in a bearing Y
fixed to the bed B, and held by means of collars from moving endways in such
bearing, and screwed through a bracket E¹ fixed to the saddle K. As will be
readily seen, the weight S acts to pull the sliding-rest H forwards and keep the
roller R continually against the edge of the "former" Q.-As the holder-spindle
is made to revolve (by mechanism hereinafter described) the "former" Q will
operate, as its edge increases in distance from its centre, to push back the roller R
and sliding-rest H and consequently raise the weight S, and, as such distance
lessens, the weight will bring back the sliding-rest so that under all circumstances
(save as herein-before excepted) the front edge of the roller R will bear against the
outer edge of the "former" Q; and it is manifest that if the cutters D D' are
fixed with their cutting edges vertically over the front edge of the roller R, the
blank (or article) will be sheared exactly to the shape of the "former." The
cutters are adjusted in the position described, in the case of shearing blanks, by
means of a screw a' carried in a bearing b upon the sliding-rest H so as not to
be movable end ways in such bearing, such screw a¹ being screwed through a
block cupon the plate F. d is a hand-wheel for operating the screw a'. The
saddle K has a slotted opening through it to allow of the endway movement of
the stud V.
A special vertical adjustment of the cutters is provided for, in this machine, as

page_text: the holders (which have usually a vertical adjustment in ordinary circular shears)
are preferably fixed as to their vertical position when screwed up to hold a sheet
(or article). To provide for this vertical adjustment, the upper cutter-spindle is
carried in a frame F¹ and the lower cutter-spindle in a frame Ġ³. These frames Fl
and G are held against the frame E by means of screw bolts e e etc. which pass
through vertically slotted holes in the frame E and are screwed into the frames F¹
and G respectively. The frames F¹ and G' fit endways between edges or flanges ff
which stand forward at each end of the frame E. The frame E is bolted to the
plate F by means of bolts passing through a flange H' cast on one side of the
frame E. I is a wedge or cotter between the plate F and the lower edge of the
frame G. In transverse section (figure 4) this wedge is shewn to have a tongue
projecting upwards into a groove in the frame G³, in order to keep the wedge from
slipping out sideways. g is a bar bolted on to the top of the frame E, and
projecting over the upper edge of the frame F'. hh are set bolts screwed through
the bar g and bearing upon the upper edge of the frame F¹ as shewn. The lower
cutter is raised or lowered by slackening the lower bolts ee and then tightening up
or slackening back the wedge I', and afterwards tightening up the bolts e e. The
upper cutter may be raised or lowered by hand after slackening the upper bolts ee
and (when the cutter is to be raised) the bolts h h also. i is a small distance-bolt
to assist in adjusting the back ends of the cutter spindles and keep them the proper
distance apart. This bolt is screwed into a part of the frame G₁ and bears against
a part of the frame F', and must of course be screwed in or out as required as the
vertical position of the cutters is being adjusted in the manuer before-described.
The endway adjustment of the cutters relatively to one another is effected in the
ordinary manner, as shewn,
The holder-spindle may be rotated by mechanism which throws itself out of
gear with the driving power and causes the spindle to stop immediately such
spindle has made one revolution. The machine illustrated by the accompanying
drawings, and which I prefer to employ for this purpose, consists of an adaptation
of mechanism which has been employed previously for an analogous purpose. This
mechanism is described as follows:-K' is a first motion shaft mounted in suitable
bearings, as shewn, and has a pulley L' mounted loosely thereon which receives the
driving belt. M³ is a spur pinion fixed on the shaft K', and imparts motion to a
shaft N through the mediuin of the spur wheel O¹ fixed thereon. The shaft N'
imparts motion to the holder-spindle M through the medium of the spur mitro
wheels QQ One revolution of the shaft N' thus produces one revolution of the
spindle M, and therefor of the sheet metal or article being operated upon by the
machine. A disc or block R' is fixed upon the shaft K' a short distance from the
pulley L', and a sliding clutch S' is mounted upon the shaft K' in the position
shown. Two lugs k k¹, opposite to one another circumferentially, are held to the
boss of the pulley L' by means of shanks having nuts on the back ends thereof, as
shewn, and these lugs project from the boss of the pulley L' towards the block R',
as shewn; and pins corresponding to such lugs, project from the clutch S¹
through the block R' which acts as a guide and support therefor. m (shewn by
dotted lines figure 1) is a cross-spindle carried in bearings upon the framing of the
machine, as shewn. n is a vertical lever which is carried at or near its centre by
the spindle m, and is forked at its upper end (see dotted lines figure 3) and provided
with pins o o to gear into a groove p around the clutch S¹, and is curved at its
lower end, as shewn, to bear against the face of, and be actuated by, an inclined
or curved stud or cam t on the boss of the wheel O¹. T' is a vertical spindle
carried in bearings q q on the framing of the machine. Near the upper end of this
spindle T is fixed a horizontal handle lever r, and to the lower end of such spindle
is fixed a horizontal lever s passing backwards transversely of the machine so as
to bear against the lower end of the lever n on the side thereof which is towards
the pulley L'.
To start the machine;-the lever r is pulled forwards thus causing the lever 8
to move back the lower end of the lever n, and thus move the upper end of the

page_text: lever n so as to slide the clutch S¹ towards the pulley L' and shoot forwards the
pins so as to engage with the lugs kk. As the shaft N¹, and by consequence
the holder-spindle M, nearly completes one revolution, the cam t on the boss of the
wheel O' forces outwards the lower end of the lever n thus throwing the pins l'
back out of contact with the lugs kk, and therefor stopping the machine. The
slight swing of the machine carries the cam round sufficiently to allow the lower
end of the lever n to be moved in again by means of the handler and levers to
re-start the machine, for cutting out another blank or trimming another article.
The clutch S¹ is shewn upon the drawings to be in about its mid-position.
Although an automatic mechanism is preferred for stopping the machine this
may be effected by any convenient means operated by the attendant.
The machine as above described with reference to the drawings, is so described
rather in its special application for shearing blanks, and is slightly modified there-
from for the purpose of being employed for trimming articles made from sheet
metal. For this latter purpose the screw a¹ is removed from the block C, and a
lever b (shewn by dotted lines figure 2 only) is carried upon a fulcrum pin con
one of the slides of the sliding rest H. The inner end of this lever is slotted to
work around a pin d fixed to the sliding-plate F and the outer end is formed into
a handle.
An adjustable stop is formed to the forward movement of the sliding-
plate F, relatively to the sliding-rest H, by means of the pin e³ (shewn by dotted
lines figure 2 only) screwed through the bracket f which is bolted (preferably by
two bolts one being below the one shewn) to the front end of the sliding-rest H,
as shewn. When an article to be trimmed is to be fixed in position, the cutters
are moved back by means of the lever b³, so as to bring them outside the edge of
the metal to be trimmed off, and are then returned gradually by means of the lever
as the article revolves, thus cutting into the metal to be trimmed off, until the
plate F is against the pin e³ (in which position it is held by means of the lever)
when the cutting edges of the cutters will be vertically over the front edge of the
roller R and the article therefor be trimmed to the desired shape as the revolution
of such article is continued. The article which is being trimmed may be caused
to revolve more than one revolution, if desired (either in the case of automatic
stopping mechanism or otherwise) or so as to be revolved sufficiently to complete
the trimming of the edge. When inore than one revolution is to be produced for
each article, in the case of automatic stopping mechanism, the attendant may
re-start the machine for each revolution, or the mechanism may be constructed to
stop the machine only after the desired number of revolutions (such as one and a
half, two etc.).
In the case of articles to be trimmed the lower holder P¹ is shaped to fit within
the hollow of the article, which is consequently turned with its hollow upwards.
This will frequently involve a greater head-room for the holders than is shewn
on the drawings and this is provided for by turning the head g² upside down.
Instead of the "former" Q being mounted upon the holder-spindle, as shewn, it
may, if desired, be mounted upon a separate spindle, and in such case may, if
desired, be arranged to act in pushing the cutter frame inwards, the weight or
equivalent being arranged to act in pulling such frame outwards.
The employment of the mechanism herein-before-described for the purposes
stated, effects a considerable saving in the cost of tools, over the ordinary method
of cutting out various shaped blanks and trimming up various shaped articles of
sheet metal.
4
The machine as described is not, of course, intented for cutting out rectangular- 5
shaped blanks or trimming such shaped articles, as such may be best performed
with plain shears, nor is there any special advantage in employing the machine for
circular blanks and articles, over the employment for such purposes of ordinary
circular shears, but (preferably by fixing the cutter-frame and dispensing with the
"former," in which case the machine is substantially of the ordinary type of 5
circular cutters) the machine may be used for this latter purpose with equal
convenience to that of the ordinary circular shears.

page_text: Having now stated the nature of my said invention and particularly described
and ascertained the manner of performing the same; I declare that I do not limit
myself to the exact details herein-described and shewn by the drawings, as such
may be varied without departing from the nature of the invention, but what I
claim as my invention and desire to secure by the herein-before in-part-recited
Letters Patent, is :—
First-In a machine employed in cutting or shearing sheet metal into various
shaped blanks, or trimming the edges of articles of various shapes made from sheet
metal, or in performing both these operations, the combination of a set of rotary
shears or cutters with a "former" fixed and operated to produce, in conjunction
with a weight or equivalent, a reciprocating movement of the cutter frame,
substantially as and for the purpose herein described and shewn by the
accompanying drawings.
Second: The combination of parts forming a complete machine of the
description referred to in the foregoing claim, constructed and operating sub-
stantially as and for the purpose herein-described and shewn by the accompanying
drawings.
In witness whereof I the said Alfred Nind Hopkins have hereunto set my
hand and seal this eighth day of October in the year of our Lord one
thousand night bundand th
Witness
FRANK H. PARKYN
Stephen Watkins'
Patent Office
Wolverhampton.
ALFRED N HOPKINS (L.S.)