Slide opening system for a tool system for compacting powdery materials

A slide opening system for a tool system for compacting powdery materials having an upper ram, a lower ram and an insertable tool frame in which punch holders are moved relative to the base-plate from their filling position downward to the pressing position and from the pressing position upward to the ejection position which corresponds to the filling position (ejection method), and a further punch holder is moved from the filling position downward to the pressing position and from the pressing position downward to the withdrawal position (withdrawal method), with plungers acting on slides for releasing the withdrawal plate for the withdrawal motion, whereby the plungers of the slide opening system each act on a preferably stepped slide via a pivoted lever in the form of a cam disk with leverage that changes during the opening process and at least one roll located on the lever.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a slide opening system for a tool system for 
compacting powdery materials, in particular a slide opening system for a 
press for producing compacts from powdery materials having an upper ram 
and lower ram and a multiplate system formed as an adapter unit which can 
be installed in and dismounted from the press in a tool frame. 
Specifically, the present invention relates to a slide opening system for 
a tool system wherein a lever arm is activated by plungers to translate a 
stepped slide. 
2. Description of the Prior Art 
Such a press with a multiplate adapter is known from German laid-open print 
DE-OS 39 09 757. In this press three punch holding plates are movable via 
hydraulic piston/cylinder units from a base-plate fixed relative to the 
press, two of which work by the ejection method, i.e. are moved from the 
filling position downward to the press end position and from the press end 
position upward to the ejection position. 
For producing a broad diversity of stepped compacts in a great variety of 
forms the third punch holding plate works by the withdrawal method, 
whereby the punch holding plate or withdrawal plate is likewise movable 
via a hydraulic piston/cylinder unit. 
The motion of the withdrawal plate from the pressing position in which the 
withdrawal plate rests on a fixed stop to the withdrawal position is 
coupled with the motion of the lower ram, since stops present on the die 
plate come to rest against the withdrawal plate. Simultaneously with the 
downward motion of the die holding plate slides are moved away laterally 
outward via corresponding stops so as to create thereunder a space for the 
downward motion of the withdrawal plate to the withdrawal position. 
Since the die motion is to be executed as quickly as possible, an equally 
quick power transmission is necessary for the lateral moving away of the 
slides. The power transmission is provided by a wedge which is operated at 
its upper end by a stop disposed on the die plate. This wedge is beveled 
at an angle of 45.degree. at its lower end and urges the slide outward via 
a roll with the slanting surface when moving down. 
This gives rise to very great diverting forces in the slide opening 
mechanism and thus high stress on the roll. That leads to quick wear of 
the roll bearing, so that this construction can no longer be used as of a 
tonnage of approx. 150 t. 
SUMMARY OF THE INVENTION 
The problem of the invention is accordingly to prevent these disadvantages 
and provide a slide opening system for a tool system for compacting 
powdery materials which is also suitable for large occurring forces or 
tonnages. 
This problem is solved according to the invention by providing a lever 
that, in response to translation of a plunger, functions to translate a 
stepped slide. 
According to the invention one provides a slide opening system comprising a 
plurality of cooperating components, whereby a stop or spindle located on 
the die holding plate and adjustable relative thereto operates, during the 
withdrawal motion, a plunger having at its lower end a unilaterally 
slightly rounded contact surface via which the plunger in turn causes a 
lever to swivel. 
The lever, whose leverage changes during the opening process, is pivoted in 
the punch holding or withdrawal plate and includes on one side a segment 
of a curve connected with the lever via which the lever urges the slide 
radially outward. 
This motion takes place until the stop or rod rests on a plate and the 
plunger is no longer moved downward. At this time the slide overcomes a 
divided step, so that a tangential motion downward takes place 
simultaneously with the stopping of the radially outward motion. 
This causes a roll located on the lever to reach a slope connected with the 
base-plate of the press, on which it rolls downward thereby causing the 
further radially outward opening motion of the slide via the cam disk. 
The swivel of the lever and thus the slide opening motion is thus 
expediently executed in two steps. The first step takes place through the 
lowering of the plunger, while the second step is brought about by the 
rolling of the roll on the slope after the slide has overcome the divided 
step. 
This construction of the slide opening system permits an improved power 
transmission by the plunger in comparison to the prior art, because at the 
beginning of the opening motion, when the greatest forces occur, there is 
area contact instead of line contact between plunger and lever and in 
particular also between the bearing shell and the shoulder of the lever. 
Due to the form of the pivoted lever the leverage changes additionally 
during the opening process, so that the greatest force is applied at the 
beginning and the smallest toward the end of the opening motion. It is 
therefore readily possible to use a roll since only small forces act on 
the roll, in particular restoring forces of the slide caused by a spring. 
The providing of a step divided into two supporting surfaces furthermore 
permits a high surface compression and a small opening path, which avoids 
a long withdrawal and permits the inventive slide opening system to be 
utilized with great tonnages.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The tool frame shown in FIG. 1 includes a base-plate designated as 1 which 
is connected with the press in stationary and fixed fashion after 
installation of the tool frame. Guided displaceably in base-plate 1 is a 
framework which is constructed from lower coupling plate 2 and die holding 
plate 3 interconnected rigidly via tie rods 4. The displaceable guidance 
of the framework in base-plate 1 takes place via tie rods 4. 
Lower coupling plate 2 is coupled or connected with the lower ram of the 
press. The connection of the tool frame to the upper ram of the press 
takes place via upper connection piece 5. Connection piece 5 is 
displaceable on guide rods 6 which are connected firmly with die holding 
plate 3. 
Punch holder 7 is movable starting from base-plate 1. It works by the 
ejection method, i.e. is lowerable from the filling position to a pressing 
position and movable from the pressing position to an ejection position 
which corresponds to the filling position. The motion of punch holder 7 
relative to base-plate 1 takes place via two piston/cylinder units 8 which 
are operated hydraulically. Pistons 9 of the piston/cylinder units are 
guided in cylinders 10 of base-plate 1 and act on plate 11 which is part 
of punch holder 7. 
Further punch holder 12 is movable from base-plate 1 by two piston/cylinder 
units 13, the pistons designated as 14 being guided in cylinders 15 formed 
in base-plate 1. Punch holder 12, also referred to as a bridge, works like 
punch holder 7 by the ejection method. For reasons of simplification punch 
holders 7 and 12 will thus be designated as ejection plates in the 
following. 
In contrast, third punch holder or punch holding plate 16 works by the 
withdrawal method, as does die holding plate 3, which is lifted by the 
lower ram of the press (not shown) to the filling position via tie rod 4 
due to the coupling with lower coupling plate 2, moved downward in 
controlled fashion from the filling position during the pressing 
operation, and moved downward by the lower ram, after the upper punch is 
lifted off the compact, far enough for the compact to be released. 
Punch holder 16, also designated as withdrawal plate 16 in the following, 
is displaceable relative to base-plate 1, whereby cylinders 18 of the two 
piston/cylinder units 19 are formed in withdrawal plate 16 itself. The 
lower ends of pistons 20 are connected to base-plate 1. 
The filling position of punch holder 7 working by the ejection method is 
limited by nuts 22 which are disposed on plate 11 and come to rest against 
underside 23 of base-plate 1. Nuts 22 are adjustable relative to each 
other to guarantee a possibility of adjusting the stop. The pressing 
position of ejection plate 7 is defined by shoulder 24 resting against an 
inside bore of base-plate 1. 
The filling position of ejection plate 12 is defined by an adjustable stop 
ring not shown in FIG. 1 which strikes underside 23 of base-plate 1 in the 
filling position. 
The filling position of withdrawal plate 16 is defined by stops (not 
apparent from FIG. 1) on withdrawal plate 16, whereby a threaded rod 
screwable relative to base-plate 1 is provided for the purpose of 
adjustment, defining with a head as a stop shoulder the motion of 
withdrawal plate 16 and thus the filling position. In the pressing 
position withdrawal plate 16 is urged over the powder column and is also 
supported thereby relative to base-plate 1 via stop 39 shown in FIG. 2. 
Alternatively, withdrawal plate 16 can also be moved from its filling 
position to the pressing position by adjustable stops 28, which are 
fastened to upper connection piece 5 via rods 29, pressing on rods 30 
connected with withdrawal plate 16 via pressure medium cushion 31. 
Since the motion of withdrawal plate 16 from the filling position to the 
pressing position is coupled with the motion of upper connection piece 5 
via the upper ram of the press, pressure medium from cylinder 32 can be 
let off for pressure medium cushion 31 via an outlet valve (not shown) 
when withdrawal plate 12 has already reached its pressing position before 
the upper ram reaches the pressing position. Otherwise the downward motion 
of the upper ram would be prevented by pressure medium cushion 31, which 
could lead to the destruction of press components. 
Die holding plate 3 is moved to the filling position via the motion of the 
lower ram due to the coupling of the framework with lower coupling member 
2. During the pressing operation die holding plate 3 is brought downward 
in controlled fashion, again due to the coupling with the lower ram via 
the framework, whereby die holding plate 3 is supported in the press end 
position in the press, namely via the lower ram. 
In the prior art device, during the withdrawal motion of die holding plate 
3 slides 33, here two slides 33, are moved away laterally outward, only 
right slide 33 being shown in FIG. 2. Left slide 33 is disposed 
mirror-symmetrically on the other side of the tool frame. This lateral 
motion away of slides 33 is obtained in the following way. When die 
holding plate 3 is transferred to the withdrawal position, adjustable 
stops 34 disposed on die holding plate 3 press on movable wedge 35 mounted 
in withdrawal plate 16 which urges, with its surface sloped at angle 
.alpha., slide 33 laterally outward via roll 36 so that the path downward 
is free for withdrawal plate 16, which is brought into the withdrawal 
position in conjunction with the downward motion of die holding plate 3. 
As soon as the path is free for withdrawal plate 16 by slides 33 being 
moved away, withdrawal plate 16 is brought into the withdrawal position 
via stops 34 with the further downward motion of die holding plate 3. 
FIG. 2 further shows the relation of forces in slide opening system 38 
functioning via wedge 35 and roll 36. F.sub.a designates the component of 
withdrawal force which acts on withdrawal plate 16 via the associated 
punch at the time when slides 33 begin to open. F.sub.o is the force 
necessary for opening slide 33 with which die holding plate 3 acts via 
stops 34 on wedge 35 and thus on roll 36 of slide 33. The frictional force 
which counteracts the opening motion is characterized as F.sub.r, while 
F.sub.l is the force resulting from F.sub.r and F.sub.o which is taken up 
by roll 36. 
An embodiment of inventive slide opening system 40 is shown in FIG. 3, 
whereby one can see only the part of slide opening system 40 on the left 
side of the tool frame. The other part of slide opening system 40 is 
constructed mirror-symmetrically and disposed on the right side of the 
tool frame. 
In contrast to wedge system 38 from FIG. 2, when die holding plate 3 moves 
the die down to the withdrawal position it acts via adjustable stops or 
rods 34 not on wedges 35, but on plunger 41. Stops 34 can be adjusted 
relative to die holding plate 3 since they are formed e.g. as spindles 34. 
Plunger 41 engages bore 42 in punch holding plate or withdrawal plate 16 
and has, unlike wedge 35 from FIG. 2, no sloped wedge surface but almost 
even connection surface 43 with a small outwardly directed radius 
conceived for the following swivel motion. Via connection or contact 
surface 43 plunger 41 acts on pivoted lever 44 with shoulder 45 formed 
therein which lies against bearing shell 46 disposed or formed on 
withdrawal plate 16 and forming a pivot bearing with shoulder 45 of lever 
44. Pivoted lever 44 is connected with punch holding plate or withdrawal 
plate 16 in center 47 of the rotation. 
Between plunger 41, or between its lower contact surface 43, and the 
corresponding upper contact surface of lever 44 facing plunger 41, as well 
as between lever 44 and slide 48 there is thus no line contact but flat 
contact, in contrast to wedge system 38 (wedge 35/roll 36). There is in 
particular area contact between shoulder 45 of lever 44 described below 
and bearing shell 46 at the time when the swivel motion breaks out, i.e. 
when the highest forces occur. 
The downward motion of plunger 41 causes lever 44 to swivel outward around 
center 47 and urge slide 48 outward via cam disk 57, which is connected 
here with lever 44 by means of a screw or the like, with a suitable arc at 
58 for supporting the swivel motion. 
This likewise moves inner surface 49 of slide 48 facing the tool frame 
radially outward over step 50, so that punch holding plate or withdrawal 
plate 16 can be moved further downward. During this first radial outward 
motion, i.e. while slide 48 moves radially outward over step surface 51 up 
to the edge of step 50, stop or rod 34 covers path y. After that, stop 34 
lies with its shoulder 55 on plate 56 which is disposed on withdrawal 
plate 16, so that no further plunger motion is possible relative to 
withdrawal plate 16. 
Upon further downward motion of withdrawal plate 16 slide 48 must be moved 
further outward. This motion now takes place no longer via plunger 41 but 
via roll 53 mounted in lever 44, which rolls under constraint over slope 
54, slope 54 being connected for example with base-plate 1. Instead of 
roll 53 one can also provide in particular two rolls mounted in lever 44, 
namely in front of and behind lever 44. 
FIG. 3 shows the relations of force or leverage in inventive slide opening 
system 40 with the help of arrows and the letters a and b. F.sub.a 
designates the component of withdrawal force which acts on slide 48 at the 
time when slide 48 begins to open. F.sub.o is the force necessary for 
opening slide 48 with which die holding plate 3 acts via stop or rod 34 on 
plunger 41 and thus on lever 44. Frictional force F.sub.r, which 
counteracts the opening motion, and F.sub.o yield resulting force F.sub.l 
which acts in center 47 of the swivel motion and is transmitted via 
shoulder 45 of lever 44 to bearing shell 46. 
During the swivel motion the leverage changes. While at the beginning of 
the motion lever arms a and b are about equally long, i.e. a=b, lever arm 
a initially decreases and thereafter slightly increase continuously while 
lever arm b increases. This means that toward the end of the swivel 
motion, when the forces acting on slide 48 lessen, the radially outward 
motion of slide 48 is guaranteed by increasing lever arm b. 
In inventive slide opening system 40 it is possible to use roll 53 even at 
great tonnages, in comparison to the use of roll 36 in wedge system 38, 
because no forces act on roll 53 with the exception of the slide restoring 
forces, which occur via a spring (not shown) with the help of which slide 
48 is moved inward again. 
The supporting surface of step 50 in the embodiment example shown in FIG. 3 
is divided into two surfaces, namely upper step surface 51 and lower step 
surface 52. Since opening path y available is very small in order to avoid 
a long withdrawal, it suffices to move slide 48 outward without step 50 
only at small tonnages. In contrast, the inventive slide opening system 
can be utilized through step 50 also at great tonnages. 
Due to the arrangement of step surfaces 51 and 52 only half the required 
path is needed by the die motion and thus via plunger 41 during opening of 
slide 48, namely the path of inner surface 49 of slide 48 from its 
starting position via upper step surface 51 up to the step edge. The 
remaining path is covered under constraint via roll 53 in conjunction with 
slope 54. 
The size of step surfaces 51 and 52 is equal in the present embodiment 
example. When dimensioning upper step surface 51 one must make sure that 
slide 48 can move downward further relative to base-plate 1 when inner 
surface 49 of slide 48 has reached its end position on step 50 forced by 
the plunger motion via lever 44.