Improvements in Mechanism for the Manufacture of Sheet Metal Cramps and for Making Connections therewith.
Year: 1897

page_text: Date of Application, 23rd Aug., 1897-Accepted, 18th Dec., 1897
Improvements in Mechanism for the Manufacture of Sheet Metal
Cramps and for Making Connections therewith.
I, HEINRICH WOLLHEIM, of Villa Simmig, No. 334 Wilhelminenstrasse, Loschwitz,
near Dresden, in the Kingdom of Saxony and German Empire, 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 machines in which sheet metal cramps are formed
automatically and fixed to the parts to be connected; the sheet metal strip which
has been cut off, being bent into the shape of the cramp by a punch. The object of
the invention is to form the punch so that the sheet metal cramp is finished by such
punch without the use of an anvil required hitherto.
In order that my invention may be 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 vertical section through the Machine.
Figure 1 is a detail view.
Figure 2. shows the sections of the sheet metal cramps at different periods during
the manufacture.
Figures 3 to 8 are details which show the cycle of operations by which the cut off
sheet metal piece is formed to a cramp and ultimately fixed on the parts to be
united.
According to the construction shown in the drawings, a sheet metal strip is fed
transversely into the machine by means of rollers a a. Knives b b cut pieces of the
sheet metal strip, one piece after another, which are pushed over the bending punch h
and under the bending and fixing dies d d¹.
The punch h shown to an enlarged scale in Figures 3 to 7 consists according to
this invention of fixed cheeks h¹ h¹ and of a middle piece h2 which is inserted between
them so that it can make a prescribed movement in vertical direction. The
operating mechanism for this device may be constructed in various ways.
As shown
in the drawings, a middle piece h² has a serrated lower edge, and below the same a
correspondingly formed bar is arranged between the cheeks h¹ h¹³, see Figure 1.
The middle piece h² is guided vertically by bolts which engage in slots of the middle
piece ².
At the movement of the bar the middle piece h2 ascends on the teeth of
the former. The movement of the bar is effected by means of a wedge shaped
rod 1, Figure 1, which is pushed forwards by the machine perpendicularly to the
bending punch h, and which act with the oblique face at its end on the edge of
recess of the bar l.
The middle piece 2 is shaped like an inverted V, the angle of the faces is
somewhat more oblique than the slope of the finished sheet metal cramp, see
Figure 2. The upper edges of the two cheeks h¹ h¹ at the sides of the middle piece
are bevelled inwards, the bevel corresponding to the desired inclination of the side
serrated teeth of the metal cramps.

page_text: The transverse sections Figures 3-8 serve to illustrate the successive phases of the
transformation of the cut off sheet metal strip into cramps.
Figure 2 illustrates the preliminary intermediate and final shape of the sheet metal
cramp.
Figure 3 shows the cut off sheet metal strip fed over the bending punch.
The bending die and the fixing die d are situated somewhat over the punch.
In Figure 4 both dies have descended. The bending die d' has preceded the
fixing die d and has bent the edges of the sheet metal strip over the recessed edges of
the punch h.
Figure 5 shows the middle piece h² when lifted. The bending die and fixing die
have reascended. The middle piece 2 has bent the sheet metal strip upwards along
the middle and has given a converging position to the side serrated teeth.
In figure 6 the middle piece of the bending punch has returned into its former
low position, the two dies have descended, the bending die has again preceded the
fixing die. The side serrations of the sheet metal cramp, carried down by the dies,
have struck on the bevelled edges of the cheeks h¹ h¹ of the bending punch and the
side serrations have thus been bent inwards.
Figure 7, Both dies have ascended simultaneously and have lifted the sheet metal
cramp held between them from the bending punch, the latter is withdrawn.
Figure 8. Both dies have descended. The attaching die continues its descent and
drives the cramp into the card-board.
The bending die serves as a guide for this purpose.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
A machine for the manufacture of sheet metal cramps and for forming connections
therewith, having a bending punch, consisting of a fixed trough shaped part h¹¹
having its upper faces bevelled inwards and of a middle piece h2 sliding vertically in the
trough of h h having its upper face formed like an inverted V, the said punch being
arranged and coacting with dies d d for bending the cut off cramps, so that after the
teeth of the cramps have been pressed downwards by the descending bending punch,
the middle piece h² receives an upward movement, lifts the cramp over the side
pieces h¹h bends them upwards along the centre and gives at the same time a
converging position to the serrations, the upper stamp (descending while the middle
piece h² retires) presses the serrations of the cramp on the upper faces of the side
pieces and forms the serrations into the correct form, substantially as
described.
Dated this 92–1 day of tuus 1407