Improvements in Sheet Metal Drawing Presses.
Year: 1891

page_text: Date of Application, 17th June, 1891
Complete Specification Left, 15th Mar., 1892-Accepted, 16th Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in Sheet Metal Drawing Presses.
1, ERDMANN KIRCHEIS of Aue, Saxony in the Empire of Germany Machinery
Manufacturer do hereby declare the nature of this invention to be as follows:-
This invention relates to presses for drawing or stamping up sheet metal and the
improvement consists in certain mechanism or mechanisms by which the three
principal constituents of the press, namely the inatrix, the pressing stamp and the
blank holder are caused respectively to be moved and to remain stationary at the
times and in the manner required for their co-operation in draw-stamping.
The nature of the mechanism or mechanisms above referred to is as follows.
The blank holder is movable in guides parallel to the pressing stamp and is
suspended from toggle-jointed levers moving on pivots on the frame of the machine.
On the pressing stamp, or connected to move therewith are plates in which are
suitably arranged grooves engaged in a convenient manner with the toggle joints of
the levers so that the latter are forced to follow the grooving and are consequently
bent or straightened respectively during the movement of the pressing stamp.
The grooves are such that during the commencement of the downward movement
of the pressing stamp, the toggles are straightened and the blank holder descends
with the pressing stamp towards the stationary matrix. At the moment when the
downward movement of the blank-holder is to cease and the latter is to remain
stationary the toggle joints will arrive into grooves parallel with the line of move-
ment of the pressing stamp and parts connected thereto. The latter may therefore
descend further while the blank holder is held immoveable.
The construction may be modified by arranging on trunnions by which the upper
members of the toggles are connected or pivoted to the frame of the press, plates
moving with said trunnions engaging by pin and groove with the plate or member
attached to the pressing stamp so that the toggles are straightened through their
trunnions. In place also of pin and groove in this construction racks and segments
may be employed the segments being fixed upon the trunnions and the racks upon
the plate or member attached to the pressing stamp. In this case the teeth of the
segments will pass out of gear with the teeth of the racks when the blank-holder
has arrived in its lowest position to allow of the further movement of the pressing
stamp, while a straight continuation of the plate beyond the segment on each toggle
trunnion lies against a similar straight continuation above the rack teeth on the
pressing stamp plate.
In the above constructions the matrix is stationary. When the matrix is movable
the blank-holder is stationary and a fixed part of the press.
In carrying out this construction the matrix block is suspended upon jointed levers
whose trunnions or pivots are in the frame of the press but as it is necessary for
the matrix to rise or meet the pressing stamp the pin and groove connections with
the plate or member attached to the pressing stamp are arranged so that their
action is to fold the jointed levers together while the pressing stamp is moving
through the first portion of its movement to meet the matrix block, and thus move
the latter in a direction towards the pressing stamp.
Dated this 17th day of June 1891.
HERBERT & Co.,
Agents to Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Sheet Metal Drawing Presses.
I ERDMANN KIRCHEIS of Aue. Saxony in the Empire of Germany Machinery
Manufacturer 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 presses for drawing or stamping up sheet metal and the
improvements consist in certain mechanism or mechanisms by which the three
principal constituents of the press, namely the matrix, the pressing stamp and the
blank holder are caused respectively to be moved and to remain stationary at
the times and in the manner required for their co-operation in draw stamping. The
nature of the mechanism or mechanisms above referred to is as follows.
The blank holder is movable in guides parallel to the pressing stamp and is
suspended from toggle jointed levers moving on pivots on the frame of the machine.
On the pressing stamp or connected to move therewith are plates in which are
suitably arranged grooves engaged in a convenient manner with the toggle joints
of the levers so that the latter are forced to follow the grooving and are consequently
bent or straightened respectively during the movement of the pressing stamp.
The grooves are such that during the commencement of the downward movement
of the pressing stamp the toggles are straightened and the blank holder descends
with the pressing stamp towards the stationary matrix. At the moment when the
downward movement of the blank holder is to cease and the latter is to remain
stationary the toggle joints will arrive into grooves parallel with the line of move-
ment of the pressing stamp and parts connected thereto. The latter may therefore
descend further while the blank holder is held immovable.
The construction may be modified by arranging on trunnions by which the upper
members of the toggles are connected or pivoted to the frame of the press, plates
moving with said trunnions engaging by pin and groove with the plate or member
attached to the pressing stamp so that the toggles are straightened through their
trunnions. In place also of pin and groove in this construction, racks and segments
may be employed, the segments being fixed upon the trunnions and the racks upon
the plate or member attached to the pressing stamp. In this case the teeth of the
segments will pass out of gear with the teeth of the racks when the blank holder
has arrived in its lowest position to allow of the further movement of the pressing
stamp while a straight continuation of the plate beyond the segment on each toggle
trunnion lies against a similar straight continuation above the rack teeth on the
pressing stamp plate.
In the above constructions the matrix is stationary. When the matrix is movable
the blank holder is stationary and a fixed part of the press.
In carrying out this construction the matrix block is suspended upon jointed
levers whose trunnions or pivots are in the frame of the press but as it is necessary
for the matrix to rise or meet the pressing stamp the pin and groove connections
with the plate or member attached to the pressing stamp are arranged so that their
action is to fold the jointed levers together while the pressing stamp is moving
through the first portion of its movement to meet the matrix block and thus move
the latter in a direction towards the pressing stamp.
The accompanying drawings illustrate modes of carrying this invention into
practice.
Fig. 1 is a front elevation and Fig. 2 a side elevation of the improved press.
Fig. 3 is a detail view thereof these three figures showing the pressing stamp and
blank holder raised. Fig. 4 is a section showing the said parts in their lowest
positions. Fig. 5 is a plan view and Fig. 6 a cross section of this press. is the
blank holder carried on the member p'. kh are the toggle jointed levers, d the slot
on the member which is movable with the pressing stamp e, m is the matrix. Fig. 7

page_text: is a front elevation of part of the press in which the levers hk hk are moved by or
through ears on the trunnions n n of the levers hh. Fig. 8 is a front elevation
of part of the press in which the trunnions n n are moved, toothed segments meshing
with rack teeth on the member d¹.
Figs. 9 to 13 show constructions in which the blank holder is stationary and the
pressing stamp and matrix are movable. Fig. 9 is a front elevation and Fig. 10 a
sectional view of such press with the pressing stamp e raised and the matrix carrier t
lowered. Fig. 11 is a side elevation of the same press with the stamp lowered and
matrix raised. Fig. 12 is a modification in which the slots d are made in arms
on the trunnions of levers instead of in the member d' attached to the pressing
stamp as in Figs. 9 to 11. The rods are attached to the matrix carrier t. Fig. 13
shows the modified construction of Fig. 12 in the position assumed when the stampe
is lowered and the matrix carrier t raised.
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
1. In a drawing press the combination of the pressing stamp, the blank holder
and the matrix carrier one of said parts being stationary, toggle jointed levers / k
connected to the frame of the press and to either of the movable parts and a
member d' connected to the other movable part and adapted to operate the toggle
jointed lever substantially as and for the purpose specified.
2. The constructions of drawing presses herein described and illustrated.
Dated this 15th day of March 1892.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.