A New or Improved Machine for Cutting Tin Plate and the like.
Year: 1898

page_text: Date of Application, 23rd Mar., 1898-Accepted, 19th Nov., 1898
COMPLETE SPECIFICATION.
A New or Improved Machine for Cutting Tin Plate and the like.
I, TRAUGOTT EMIL RICHTER-SIPS, of Kurze Strasse 2, Leutzsch, in the German
Empire, Master Locksmith, do hereby declare the nature of this invention, and in
what manner the same is to be performed, to be particularly described and ascer
tained in and by the following statement:-
This invention relates to a machine for cutting triangular pieces of tin plate o
similar material such as are used in the corners of window frames in some system"
of glazing.
Triangular pieces have hitherto usually been punched or stamped out and as a
result have had rough edges and have not been flat, which has necessitated subse-
quent rolling or pressing.
By the use of this improved machine the triangular pieces are cut from a strip
of metal by means of two knives which operate alternately at a suitable angle to
each other, and the severed portions are perfectly flat and have straight edges.
The improved machine consists essentially of three parts, viz.:-Means for
conveying or feeding the strip of tin plate; two longitudinally movable knives or
supports for the plate; and two rotating knives, both the rotating knives and the
supporting knives being arranged at suitable angles with each other.
In order that my invention may be more readily understood I have hereto
appended a sheet of drawings to which I will hereinafter refer and which illustrato
a machine constructed to embody my improvements.
Figure 1 represents the machine in plan.
Figure 2 shows it as seen from underneath.
Figure 3 illustrates a longitudinal section.
On the table 1 are arranged the two guide rails 2 and 3 between which passes the
strip of tin plate 4 from which the triangular pieces are to be cut. The distance
between the rails may be varied to suit different widths of strips by means of the
slots 5 and the screws or bolts 6. At the front end of the table is a cross rail or
piece 7 between which and the table there is just room for the passage of the strip 4
which is thus held more securely.
At the front end of the table two knives or cutters 8, 9, are arranged at an angle
to each other and each is longitudinally movable in a horizontal direction. They
are provided with extensions or projections 11 and 12 which extend under or
through the guide rails 10, and by means of which the knives are alternately pushed
under and withdrawn from the strip of metal 4.
The required horizontal motion is imparted to the knives by means of the bent
levers 13 and 14 which are pivotted at 15 and 16 and are connected to the knives,
one to each, at the points 17 and 18. The free ends of the levers carry pins or
bowls 19 and 20 which engage with cam grooves in the peripheries of the discs 21
and 22. These grooves are in one plane for the greater part of their lengths but
each is provided with a swell or cam 23 or 24, the cam in one disc being arranged
at an angle of 180° with the cam upon the other disc. It will be easily seen on
reference to the drawings that the rotation of the discs, which are mounted upon
a common shaft, will effect the alternate reciprocation of the knives.

page_text: Mounted upon or within the frame 25 are the two rotary knives or cutters 26
and 27 which are secured to suitable shafts geared together by the bevel wheels 28
and 29. The two knives are mounted at an angle of 180° apart and are so arranged
that each of them forms a pair of shears with one or other of the reciprocating
knives 8 or 9. The cutting of the pieces from the strip of tin is effected by feeding
the strip forward to the desired extent over one of the reciprocating knives, for
example, 8, which occupies its most forward position under the strip. The rotary
knife 26 then comes down and shears off the triangular piece. The knife 8 is then
withdrawn, the rotary knife 26 moves away, the strip is fed forward, the knife 9
moves forward and comes under the strip, and the knife 27 comes round and cuts a
piece from the strip. The knives on each side of the strip thus alternately come
into action, the strip of tin being fed forward intermittently.
The apparatus for feeding forward the strip of tin is constructed and arranged as
follows. A crank disc 30 has attached to it a link or rod 31 which passes over a
pin or support 32 and is pressed constantly down towards the table by a spring 33.
The front end or part 35 of the link is preferably covered with indiarubber and
comes over the strip of tin.
When the disc 30 rotates in the direction of the arrow and after the link 31 has
been moved forward to its furthest position as indicated by Figure 3, continued
rotation depresses the attached end of the link 31 and raises the outer end 35 owing
to the engagement of the link with the pin 32. Thus for half a rotation of the disc
the link is withdrawn with its end 35 raised. During the next half rotation,
however, the end 35 of the link is pressed downwards upon the tin strip which is
tlius fed forward. If desired the strip 4 may be mounted upon rollers to facilitate
its movement. The crank pin of the disc 30 may be adjustable relatively to the
centre of the disc so as to vary the amount of throw and consequently the feed of
the strip.
When the machine is to be used a strip of tin is placed between the guide rails 2
and 3 and is pushed forward under the cross rail 7. The main wheel 34 is now
rotated and drives the bevel wheel 36 by means of which the rotary knives 26
and 27 are operated, as well as the wheels 37 and 38 for driving the strip feeding
device and the grooved discs 21 and 22. The different wheels are so proportioned
and geared together that the knives 26 and 27 and the discs 21 and 22 perform one
revolution while the crank disc 30 completes two.
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. In a machine for cutting triangular pieces of tin plate and the like, two
reciprocating knives and two rotary knives which together form two pairs of shears,
constructed arranged and operated substantially as hereinbefore described and as
illustrated by the accompanying drawings.
2. In a machine for cutting triangular pieces of tin plates and the like, devices
for feeding the strip of tin intermittently in a forward direction and consisting of a
crank disc, an attached link, a stop or support upon which the link rests, a
downwardly pressing spring, and a foot to come into contact with the tin strip, all
constructed and arranged substantially as herein before described and as illustrated
by the accompanying drawings.
3. A machine for cutting triangular pieces of tin plate and the like, constructed
arranged and operated substantially as hereinbefore described and as illustrated by
the accompanying drawings.