AN IMPROVED MACHINE FOR CUTTING SHEET METAL INTO OVAL AND OTHER FORMS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, HERBERT JOHN ALLISON, of the firm of Allison Brothers, of 52 Chancery
Lane, London, in the County of Middlesex, Patent Agents, do hereby declare the
nature of my Invention for "AN IMPROVED MACHINE FOR CUTTING SHEET
METAL INTO OVAL AND OTHER FORMS" and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
Figure 1 is a plan view partly broken away, of the machine for cutting sheet
metal embodying my Invention.
Figure 2 is a side elevation thereof.
Figure 3 is a vertical section in line x, x, Figure 1.
Similar letters of reference indicate corresponding parts in the several Figures.
This Invention consists of a machine for cutting sheet metal, etc., into oval and
other forms, whereby the work is accomplished in a true, uniform and expeditions
manner.
Referring to the Drawings:-
A represents a table which is properly supported and on which is mounted a two
part shaft B, the inner ends whereof carry heads C between which the sheet of
metal to be cut is clamped.
One part of the shaft B rotates in fixed bearings and has connected with it a
crank handle for operating purposes, and the other part is adapted to slide and
rotate in its bearings, and has in contact with it a spring D and lever D¹, which
operate in reverse order, for opening and closing the heads C for the application
and removal of the sheet, said lever being attached to a treadle Du.
Fitted to the table A is a horizontally arranged carriage E, and secured to the
shaft B is a former or shaping piece F, which bears against a roller G on said
carriage E, the contour of the piece F coinciding with that which it is desired to
impart to the sheet. To the table is pivoted a weighted lever E¹, which is
connected with the carriage E, the object whereof is to hold the roller G constantly
in contact with the former or shaping piece F.

page_text: To the carriage E at the end adjacent to the shaft B is pivoted a yoke. H, to
whose lower end are secured the cutters J of the machine, which are so disposed
that when the sheet is clamped to the heads C, they occupy positions on opposite
sides of said sheet.
Connected with the yoke H is an arm K, to which is pivoted a weighted
lever L, the bearings whereof are on the table A, said lever carrying a stud or
roller L, which rests against a cam M, the latter being secured to the shaft B and
imparting its motion to the yoke H, said weighted lever L being held constantly
engaged with the cam M.
The operation is as follows:-
The head on the sliding part of the shaft B is held separated from the other head
by the action of the spring D, and the sheet or plate of metal to be cut is placed
between the two heads and rested on the gage and support N, which latter is
'secured to the table A below said heads. The treadle D is then depressed
whereby the heads firmly clamp the metal between them. The crank handle on
the shaft B is now rotated whereby the metal is carried around with the shaft, and
owing to the former or shaping piece F, the carriage E is moved in accordance with
the contour of said former or shaper.
As said former is in the present case of oval shape, the cutters J which are
connected with the carriage E are moved nearer to and further from the centre of
said cutters, due to the oval contour of the former, and thus the rotary cutters or
shears are presented to and act upon the rotating piece of metal in such manner
that it is cut in oval form.
As the curvature of the shaped or cut metal changes, due to. the oval form
imparted to the same, it is important to present the cutters thereto at different
angles relatively to the greater and less curves of the same as is practiced in
cutting with hand shears, it being noticed that while said angles may increase or
decrease they are nevertheless tangential to the metal, hence the yoke to which
the cutters are directly attached and which is pivoted to the carriage receives
motion from the cam M in such manner that the cutting edges of the cutters
assume angles more or less obtuse or acute as they act upon the metal while
cutting the greater or less curves so that the cut is made smooth and without
buckling.
When the crank shaft has completed its rotation, the treadle is let go, and as the
heads C are relieved, the shaped metal may be readily removed, after which a fresh
sheet or piece of metal is applied to the heads and the subsequent operations are
similar to those previously stated.
It will be seen that the sheets are shaped or cut true and uniform and with
smooth edges and the work is rapidly and expeditiously accomplished.
In order to cut larger sheets or plates into oval form, the yoke H is set back
from the heads the required extent so as to adjust the position of the cutters
relatively to the required dimensions of the shaped metal, it being seen that the
carriage E is longitudinally slotted to receive bolts which are passed through the
slots into the base of the yoke and tightened by nuts, whereby the yoke and
connected parts are securely held in adjusted position, the bar or arm K being also
adjustably connected to the yoke.
The former or shaping piece F may be of other rounded forms than oval, as is
evident, without departing from the Invention.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A sliding carriage having cutters attached thereto, a former or shaper
engaging with said carriage, and a rotary holder for the metal located adjacent to
the cutters, said parts being constructed, combined and operating substantially as
and for the purpose set forth.

page_text: 2. A machine for cutting metal into oval form having cutters which are attached
to a yoke or support which has pivotal motions on a sustaining carriage,
substantially as and for the purpose set forth.
3. A carriage supporting a pivotal yoke and cutters connected with said yoke, in
combination with a shaft carrying a holder for the metal, a former or shaper
controlling the action of the cutters, and a cam imparting motions to the pivotal
yoke, substantially as and for the purpose set forth.
4. The holder, former or shaper, cutters and carriage, in combination with the
yoke H, arm K, lever L with stud or roller L' and cam M, substantially as and for
the purpose set forth.
5. In a machine of the order stated, the holder, consisting of heads C, the two
part shaft B, the spring D, and lever D¹, said parts being constructed and operating
substantially as and for the purpose set forth.
6. A machine for cutting sheet metal in oval and irregular forms constructed and
operating substantially as herein described.
Dated th: TAL 1
T17002
HERBERT J. ALLISON.