Improvements in and in the Manufacture of Sheet Metal Cramps for Securing the Parts of Boxes Together.
Year: 1894

page_text: Date of Application, 31st Dec., 1894
Complete Specification Left, 30th Sept., 1895-Accepted, 16th Nov., 1895
PROVISIONAL SPECIFICATION.
Improvements in and in the Manufacture of Sheet Metal Cramps
for Securing the Parts of Boxes Together.
I, HEINRICH WOLLHEIM, of Villa Simmig, 344 Wilhelminen Strasse,
Loschwitz Dresden, Germany, Gentleman, do hereby declare the nature of this
invention to be as follows:-
This invention relates to sheet metal cramps, to their manufacture and to making
connections with such cramps in the manufacture of card board boxes. These
sheet metal cramps have teeth made from the body of the sheet metal by stamping
cross-shaped or angular incisions into the body of the metal crap and bending the
small angular pieces thus produced, so as to form projecting teeth.
These cramps are made of a strip or ribbon of sheet metal, the width of which
corresponds to the length of the cramps to be manufactured.
The apparatus which I use in this manufacture is designed to produce two
successive rows of the desired teeth at one end of the strip of sheet metal, to cut
off this end piece with either serrated, undulated or straight edges, and to press the
same on to the parts of the box which are to be united and are situated on an
anvil, while bending it simultaneously into the shape required for the cramp or
connection. All these steps are carried out in one continuous operation.
The strip of sheet metal is pushed on to a plate or table, the back end of which
is formed with a shearing edge. The upper face of this plate is provided with
holes, corresponding to the punches designed for effecting the incisions required to
produce the desired projecting teeth. The upper or moving stamp is provided
with a second shearing edge so as to form a pair of shears with the before mentioned
shearing edge of the plate or table. The upper stamp carries a holder parallel to
it, which holds at its lower end the punches for effecting the incisions and bending
the teeth. The corresponding holes in the lower plate or table are opposite to
these punches and form matrices thereto.
on
If the sheet metal strip is pushed forward it strikes against a spring provided
the back of the upper stamp.
When then the upper stamp descends its shearing
edge cuts off the piece which is to form the cramp, at its further descent it
actuates the device holding the punches, the edges of which cut through the
sheet metal while their shanks, bend the angular pieces thus producing and forming
projecting teeth thereby.
The before mentioned spring now holds the cut off piece of sheet metal strip on
to the upper stamp, and at the further descent of the latter the piece of sheet metal
is brought down to the anvil on which is situated the box of which the edges are to
be connected. The counter pressure of the anvil bends the sheet metal piece into
cramp shape and presses it on to the edges to be connected together. At the
following ascent of the stamp the device holding the punches is left behind to be
again operated afterwards by the upper stamp.
In order to prevent the projecting teeth from interfering with the movement of
the sheet metal strip by remaining in the matrice holes of the plate or table, the sheet
metal strip passes over two or more bridges inserted in the table or plate. These
bridges are supported by springs which lift the sheet metal strip after the stamping
has been effected.
The incision may be conveniently in the form of a cross this allowing of four

page_text: projecting teeth being formed or it may be an incision forming only an angle and
If flat surfaces are to be
producing only one angular tooth for each incision.
connected the anvil and stamps must be formed accordingly.
Dis 21st dow of December 1894
FELL & WILDING,
Agents for the Applicant.
Improvements in and in the Manufacture of Sheet Metal Cramps
for Securing the Parts of Boxes Together.
I, HEINRICH WOLLHEIM, of Villa Simmig, 344 Wilhelminen Strasse,
Loschwitz Dresden, Germany, Gentleman, 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 the manufacture of sheet metal cramps as means for
making connection between edges and flat surfaces of boxes of card board, leather,
thin wood, or similar material, the said cramps being produced by stamping cross
shaped or angular incisions into the body of the sheet metal and bending over the
sheet metal piece formed by the incisions.
The invention relates further to making such connections by means of such sheet
metal cramps..
The invention consists in apparatus for manufacturing the said sheet metal cramps
and for making connections therewith.
The apparatus is designed to cut pieces, corresponding to the width of a finished
cramp, off a sheet metal strip fed thereto, to stamp the before mentioned incisions
into the piece of sheet metal strip and to press the piece of sheet metal strip on the
edges or surfaces to be connected.
In order that my invention may be the better understood, I now proceed to describe
the same, reference being had to the accompanying drawings and to the letters and
figures marked thereon.
Figure 1 is a side elevation of the upper part of the machine.
Figure 2 is a cross section through the same.
Figures 3, 4 and 5 show details drawn to an enlarged scale.
Figures 6 to 11 show sheet metal cramps as they are produced in various forms
by the machine.
2
The strip of sheet metal from which the pieces to form the sheet metal cramps
are cut is fed forwards by rollers a a Figures 1 and 2, which are operate.l from
the disc m by means of a rod n, a withdrawing spring, a changing mechanism
and a pair of conical wheels o o, see Figure 1.
The strip is fed forwards on a plate 6 Figures 2, 3 and 5, the front of which is
formed as a shearing edge c with which corresponds an upper shearing plate c'
arranged on a stamp d. The shearing plates have straight cutting edges, if the
sheet metal cramps are to have straight longitudinal sides, or they have serrated
or undulated cutting edges, if the sides of the cramps are to have serrations or
undulations.
The plate is provided with holes ee in the direction of movement of the punches
or stamps. The object of these holes in combination with punches is to stamp
cross-shaped or angular incisions into the sheet metal and to bend over the pieces
formed thereby, so that they protrude as teeth from the sheet metal surface.
The punches which are pointed at their ends and of a section corresponding to
the incisions to be made, are fixed to a slide g, (Figures 2, 3 and 5) which has a
pin g which engages into a longitudinal slot of the stamp d. The latter is
from
operated by means of the bell crank g, which rotates around the axle P:

page_text: the camt fixed to the driving axle s on which is also situated the pulley r, see
Figure 2.
When the strip of sheet metal has been fed forwards by the before mentioned
mechanism, the stamp d descends and its cutting edge c cuts off the piece which is
to be pressed on the edges or surfaces to connect them. Then, the end of the
longitudinal slot in the stamp strikes the ping of the slide g. The latter is compelled
to join the movement and the punches fixed to it perforate the sheet metal strip,
which lies on the plate b, and the sides of the punches bend over the teeth formed
by the incisions. Therefore, in the course of the operation that end of the sheet
metal strip, which comes up for cutting at the next descent of the stamp, is provided
with the teeth with which the cramp inust be provided for fixing it.
The cut off piece of sheet metal strip is fed by the further descending stampd to
the anvil u, on which is situated the box to be finished and pressed on the edges to
be connected, and bent at the same time to the corresponding angle or shape. The
surface of the stamp is recessed, and the anvil is roof shaped, as shown, when elge
connections are to be made, both parts have plane surfaces when flat surfaces are
to be connected.
It is necessary in the described operation that the cut off piece of sheet metal
strip adheres to the face of the stamp d. Hooks are provided for this purpose,
the number of such hooks corresponding to the number of teeth or undulations of
the cramp. These hooks are fixed to a slide w which can move to a certain extent
in a flat groove of the stamp, see Figures 3 and 4. Before the commencement of
the descent these hooks are in their lowest position, see Figure 5, and are so far
removed from the face of the stamp that the strip of sheet metal can advance to
them. When the stamp descends, the slide to is retained in position by the pressure
of a bolt a which is under the pressure of a spring y, adjustable by means of a
screw y', so that the space between the face of the stamp and the hooks v disappears
and the cut off piece of sheet metal strip is held or supported. When this position
has been reached, the stamp takes with it the slide w with the hooks. During the
ascent the spring pressed bolt a comes again into action so that the slide a does not
follow the stamp to at once and that the hooks stand again away from the face of
the stamp.
Into the rest plate bare inserted bridges i, Figures 3 and 5, which, by means of
pinsk, rest on a plate ', which is situated on a spring . The piece of sheet metal
strip which is being fed forwards passes over these bridges.
When the stamping
operation commences, the sheet metal strip and bridges i are pressed down on the
resting plate and the dies fenter into the holes e. When the stamping operation
is finished and the dies ascend again, the bridges and the sheet metal strip are
returned by the spring into their former position, the teeth of the sheet metal
piece leaves the holes e and the sheet metal strip can be again fed forwards.
Figures 6 to 11 illustrate the sheet metal strip which is operated upon. Figure 6
shows a piece of sheet metal strip into which have been stamped triangular holes
from which one tooth is bent off the plane of the strip, see also cross section,
Figure 10. Further, Figures 7, 8, 9 and 11 show a piece of sheet metal strip into
which have been stamped two rows of round, or approximately round holes, from
the circumference of which have been bent over three small teeth so as to be at an
angle to the sheet metal strip (see also transverse sectional view, Figure 11).
The various operations upon the sheet metal strip differ also in that the cut of
the shearing plate may be straight, as shown by a dotted line in Figures 6 and 7, or
that it may be undulated or serrated, as shown in Figures 8 and 9 respectively,
the edges of the sheet metal cramps being formed accordingly.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
An apparatus for the manufacture of sheet metal cramps with teeth stamped
therein for making connections between edges or flat surfaces with them,

page_text: consisting of a stamp d with a straight, serrated or undulated shearing edge c'
in combination with a similarly formed shearing edge on the resting plate b
adapted to cut off, at the descent of the stamp d, a piece of sheet metal strip with
either straight, serrated or undulated sides, punches adapted to stamp, at the
descent of the stamp g two rows of incisions corresponding to the shape of teeth
with which the cramp is to be formed and an anvil u adapted to press the piece of
sheet metal strip, held on the face of the stamp by hooks v fixed on a slide w, on to
the parts of the box to be connected, while bending them simultaneously into cramp
form, substantially as described.
Dated the 30th day of September 1895.
FELL & WILDING,
Agents for the Applicant.