Improvements in Mechanism for Cutting or Shearing Sheet Metal into Various Shapes, and for Trimming up Articles of Various Shapes Made from Sheet Metal.
Year: 1890

page_text: Date of Application, 19th July, 1890
Complete Specification Left, 20th Apr., 1891-Accepted, 23rd May, 1891
PROVISIONAL SIEVITICATION.
Improvements in Mechanism for Cutting or Shearing Sheet Metal
into Various Shapes, and for Trimming up Articles of Various
Shapes Made from Sheet Metal.
We, J. H. HOPKINS AND SONS (LIMITED), of Granville Works, in the City of
Birmingham, Tinplate Workers and Japanners, and CHARLES WILLIS, Fitter in
the employment of the said Company, do hereby declare the nature of this invention
to be as follows:-
This invention relates to certain improvements in mechanism for cutting out
sheet metal blanks of various shapes and for trimming up articles of various shapes
made from sheet metal, of the character of that described in the Specification filed
in pursuance of the conditions of Letters Patent, number 1804 dated 10th April
1883, granted to Alfred Nind Hopkins, that is to say, mechanism for the purpose
in which the position of the cutters is controlled by the aid of a revolving "former;"
and has for its object means whereby the circular cutters of such mechanism may
be automatically vibrated, as required, so as to be constantly in position, or
approximately so, to cut in a line tangential to the periphery of the blank which
is being cut or article which is being trimmed, that is to say, in a line at right
angles, or approximately so, to a line drawn from the centre of such blank or article
to the point of such periphery at which at the moment the cutters are operating;
the purpose of the invention being to avoid the tendency to tear the metal which is
experienced with cutters which are merely moved in and out in a direct line, owing
to their cutting portions of the edge while in a position oblique thereto.
In describing this invention it will be convenient to refer to parts of the
mechanism described in the said former Specification, by the letters of reference
used on the drawings accompanying such Specification.
According to this invention, the cutter spindles are mounted in a frame (hereinafter
distinguished as the cutter frame) which is pivoted vertically within a frame
(hereinafter distinguished as the sliding frame) which is carried in the V guides of
the saddle K, and thus while the sliding frame is capable of endway movement in
the saddle, the cutter frame is capable of being vibrated sideways in the sliding
frame. The cutter frame is pivoted upwards and downwards to the inner end of
the sliding frame, and the common centre of the pivots is in line, or approximately
80, with the plane of the cutting edges of the cutters. The lower pivot pin is
carried down somewhat below its bearing in the sliding frame, and carries a cross-
piece or head on the ends of which, respectively, are mounted two friction rollers.
These rollers are pressed against the "former "Q to move back the cutters, which
are pressed in thereagainst by a weight acting, preferably, through the medium of
an L-shaped lever and connecting rod, and thus the two rollers answer the purpose
of the single roller R, which is dispensed with. These rollers, however, operate
also, by vibrating the cutter frame as required, to constantly maintain the cutters in
position, or approximately so, to cut in a line tangential to the periphery of the
blank which is being cut or of the corresponding portion of the article which is
being trimmed. The shape of the "former" is modified somewhat at its curved
parts (or throughout, if it is curved throughout) from the exact shape of the blank
to be cut or of the corresponding portion of the article to be trimmed, as the pair of
rollers allow of the cutters approaching nearer the centre of the work when an
outwardly curved portion of the edge of the "former is presented to them than
when such portion of the edge is presented to a single roller, as in the case of the
mechanism described in the said former Specification, in consequence of such
portion of the edge of the "former" projecting somewhat into the space between
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page_text: the rollers; and, in the case of an inwardly curved portion of the edge of the
❝ former
being presented to the rollers, the effect on the position of the cutters
(as compared with their position when a single roller is used) is, of course,
reverse of that above described, that is to say, they will not approach so near to the
centre of the work.
the
Dated this 18th day of July 1890.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.
COMPLETE
SPECIFICATION.
Improvements in Mechanism for Cutting or Shearing Sheet Metal
into Various Shapes, and for Trimming up Articles of Various
Shapes Made from Sheet Metal.
We J. H. HOPKINS AND SONS (LIMITED) of Granville Works, in the City of
Birmingham, Tinplate Workers and Japanners, and CHARLES WILLIS, Fitter in
the employment of the said Company, 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 certain improvements in mechanism for cutting out
sheet metal blanks of various shapes and for trimming up articles of various shapes
made from sheet metal, of the character of that described in the Specification filed
in pursuance of the conditions of Letters Patent, number 1804, dated 10th April
1883, granted to Alfred Nind Hopkins, that is to say, mechanism for the purpose
in which the position of the cutters is controlled by the aid of a rotating "former;"
and has for its object means whereby the circular cutters of such mechanism may
be automatically vibrated, as required, so as to be constantly in position, or
approximately so, to cut in a line tangential to the periphery of the blank which
is being cut or article which is being trimmed, that is to say, in a line at right
angles, or approximately so, to a line drawn from the centre around which such
blank or article is being turned to the point of such periphery at which at the
moment the cutters are operating; the purpose of the invention being to avoid the
tendency to tear the metal which is experienced with cutters which are merely
moved in and out in a direct line, owing to their cutting portions of the edge while
in a position oblique thereto.
In describing this invention we will, for the sake of convenience, in referring to
parts of the mechanism described in Hopkins' said Specification, use the same letters
of reference as are employed to indicate such parts in the drawings accompanying
such Specification.
In the drawings herewith,
Figure 1 is a side elevation of Hopkins' machine with our improvements applied
thereto;
Figure 2 is a transverse section of the same taken on line x x of Figure 1 ;
Figures 3, 4 and 5 are detached plan views of the "former" and cross-piece
hereinafter described, shewing the relation of the studs or rollers hereinafter
described to the "former" in three of its positions; and
Figure 6 is a detached plan view, partly in section, shewing the pivoted cutter
frame, hereinafter described, in position at an angle with the axis of the machine
due to the position in which the "former" is shewn by such view.
A is the foundation plate, and B is the bed plate of the machine supported on
said plate by legs or standards C. The holder spindle M which carries the blank
or article to be cut or trimmed, is mounted in suitable bearings and is driven from
shaft N' through the medium of the mitre or bevel wheels Q¹ Q, the shaft N'
being itself driven by suitable gear from the engine or other motor. The two parts
or discs P P of the holder between which-the sheet metal, or sheet-metal article,

page_text: is held and rotated as it is being sheared or trimmed, are of the usual character
employed in rotary cutting machines, and the outer disc is drawn back and also
tightened
A pair of ordinary rotary
are mounted in the usual manner on a frame or part E; but, according
to this invention, the frame E is pivoted at a a', (the latter pivot being shewn by
broken lines only), in the forward ends of a sliding frame E', in such a manner that
the frame E is capable of being vibrated sideways on its pivots. The frame E' is
carried upon a sliding rest or plate H which slides in V-guides J on a saddle K;
and this saddle is carried to be capable of sliding on V slides L forming the top of
the bed B. The saddle K is adjusted into any desired position along the bed B, by
means of a screw W, and remains fixed in such position while the machine is at
work, but the sliding frame E' is free to slide to-and-fro, together with the plate H,
along the saddle as the machine is at work. A "former" Q is fixed on the
spindle M, and rotates therewith. The lower pivot pin a' of the cutter frame E is
prolonged downward somewhat below its bearing in the sliding frame E¹, and
carries a cross-piece or head in which are fixed two studs c arranged on opposite
sides of the pivot axis, and each stud preferably carries a surrounding friction roller.
The sliding frame E is constantly pressed inwards, under yielding pressure, by
means of a weight S which acts, preferably, through the medium of an L-shaped
leverd d' and connecting rod e, and thus the studs c are constantly pressed against
the edge of the former Q. The cutters are constantly pressed outwards by means
of the former Q, and inwards by means of the weight S, the weight yielding
upwards as the rollers are moved outwards by the "former," and reacting to move
the rollers in again as the periphery of the former recedes; and thus the cutters
will cut out metal blanks of various shapes, or trim up articles of various shapes,
depending on the shapes of the "formers" which are employed. The studs c,
however, as will be obvious on reference to the detached views Figures 3, 4 and 5,
operate not only in conveying the outward thrust of the "former" to the sliding
frame E, and controlling the inward movement of such frame, (as in the case of
the single stud or roller r of Hopkins' machine), but also cause the vibration of the
cutter frame as required, and thus constantly maintain the cutters in position, or
approximately so, to cut in a line tangential to the periphery of the blank which is
being cut, or of the corresponding portion of the article which is being trimmed,
and for this purpose the point at which the cutters operate upon the sheet should be
in the line of the common axis of the pivots.
cutters Dn the usual or any convenient manner.
The "former" Q (as shewn in the drawings) has the form of an oblong
quadrilateral with rounded corners, and in Figure 6 the pivoted cutter frame E is
shewn in the oblique position it will assume with reference to a line through the
axis of the sliding frame E' when the "former" is presented to the studs c c in
the position as seen in the figure. When so presented, one stud bears on the
straight edge of the "former" and the other on the rounded corner. When the
"former is presented to the studs in the positions as represented in Figures 3
and 4, the axes of the cutter frame E and sliding frame E' will coincide. Figure 5
shews the angle of obliquity of the two frames when one stud c has passed off
from the rounded corner of the "former" and the other roller has just come on.
The position is substantially the reverse of that seen in Figure 6. In Figure 5,
is a broken line indicating the axis of the cutter-frame E, while indicates the
axis of the sliding frame.
The studs e may bear direct against the edge of the "former," instead of
through the medium of the rollers, but it is much preferred to use the rollers;
and, where the term "studs" is used in this Specification it includes the rollers,
as if parts of the studs, in cases in which the rollers are used.
The contour of the "former" is modified somewhat from the exact shape of the
blank to be cut or of the corresponding portion of the article to be trimmed, as
the pair of studs c allow of the cutters approaching nearer the centre of the work
when a curved portion of the edge of the "former" is presented to them than when

page_text: such portion of the edge is presented to a single stud as used, for instance, in Hopkins'
mechanism, in consequence of such portion of the edge of the "former" projecting
somewhat into the space between the studs. This is clearly shewn in Figures
and 5; and in Figure 6 the difference in the shape of the blank, or article which
has been cut or trimmed, from that of the " former," is shewn by the broken line
curves g.
In describing the above invention, we have taken, as a type of the mechanism
to which the invention relates, the mechanism described in Hopkins' said
Specification, and have illustrated our invention as applied to one of his machines,
and have marked the parts corresponding to those of Hopkins' machine by the
letters of reference employed in his said Specification. The novelty of our
invention consists in the means for automatically adjusting the cutters to the line
to be cut.
It will be seen that the holder discs P P' are shewn in position to hold a blank.
Their position will, of course, be altered vertically when used to hold an article,
such as a stamped pie dish, of which the edge is to be trimmed up by the cutters.
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. In a machine for cutting out sheet metal blanks or for trimming up articles
made from sheet metal, a rotating
"
"former operating, in combination with a
pair of bearing surfaces carried on opposite sides of an axis on which they are
capable of turning, to produce a vibratory movement in endway-moving rotary
cutters, substantially as described for the purpose set forth.
2. In a machine for cutting out sheet metal blanks, or for trimming up articles
made from sheet metal, in which a rotating "former" is employed in imparting
endway movement to rotary cutters, through the medium of a sliding frame, the
combination of a frame or part carrying such cutters and pivoted to the sliding
frame, with a head carried on the pivot axis of the cutter frame and provided with
a pair of studs (preferably surrounded with rollers) through which endway
movement is imparted by the "former" to the cutter frame and by which such
frame is vibrated, substantially as described for the purpose set forth.
3. In a machine for cutting out sheet metal blanks, or for trimming up articles
made from sheet metal, in which a rotating "former" carried by the holder
spindle is employed in imparting end way movement to rotary cutters, through the
medium of a sliding frame, the combination of a frame or part carrying such
cutters and pivoted to the sliding frame, with a head carried on the pivot axis of
the cutter frame and provided with a pair of studs (preferably surrounded with
rollers) through which endway movement is imparted by the "former" to the
cutter frame and by which such frame is vibrated, substantially as described for
the purpose set forth.
4. In a machine for cutting out sheet metal blanks, or for trimming up articles
made from sheet metal, in which a rotating "former" is employed in imparting
endway movement to rotary cutters, through the medium of a sliding frame, the
combination of a frame or part carrying such cutters and pivoted to the sliding
frame, with a head carried on the pivot axis of the cutter frame and provided with
a pair of studs (preferably surrounded with rollers) through which endway move-
ment is imparted by the "former" to the cutter frame and by which such frame is
vibrated, the pivot axis of the cutter frame passing through (or approximately
through) the point at which the cutters operate on the sheet metal, substantially as
described for the purpose set forth.
5. In a machine for cutting out sheet metal blanks, or for trimming up articles
-made from sheet metal, the combination of a rotating "former," of a sliding
frame carrying a pivoted frame or part on which are mounted the rotary cutters,
of a pair of bearing pieces carried on the pivot axis of the cutter frame and

page_text: maintained in constant contact with the "former" under yielding pressure, such as
by a weighted lever and suitable connections, all substantially as and for the
purpose described and shewn.
23
6. In a machine for cutting out sheet metal blanks, or for trimming up articles
made from sheet metal, in which a rotating "former is employed in imparting
endway movement to rotary cutters, through the medium of a sliding frame, the
means substantially as described and shewn by the drawings herewith, by which
vibratory movement is imparted to the cutters for the purpose set forth.
Dated this Seventeenth day of April 1891.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.