Information
-
Patent Grant
-
6302678
-
Patent Number
6,302,678
-
Date Filed
Friday, March 27, 199826 years ago
-
Date Issued
Tuesday, October 16, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Nguyen; Nam
- Nguyen; Thu Khanh T.
Agents
-
CPC
-
US Classifications
Field of Search
US
- 162 197
- 162 270
- 425 374
- 425 335
- 493 459
- 493 461
-
International Classifications
-
Abstract
For levelling webs of paper (3) gaps (20) are provided, each defined by a deflection roll (17) and a stationary bending face (16). For changing the wrap angle at the bending face (16) and also for non-bended passage of the web (3) through the device (1) the deflection roll (17) is transferable into varying positions powered by a positioning device (30). Thereby high speed operation with reliable function and simple construction are achieved.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a device with which flexural or elastic materials can be worked in achieving a desired non-stressed shape, such as a flat shape. Such materials may be substrates or other rollable materials having a constant thickness which are worked as individual sheets or as an endless material web.
2. Description of the Background
Due to it being supplied as a reeled material, for instance, paper tends to curl, i.e. a portion of the web spread out flat is subject to an inherent bending stress and thus tends to curve or curl to relieve the stresses on release of external forces. However, it may also be wanted to bend or work a flat layer which is planar when free of stress so that it assumes a curved position. In any case, bending breaks a predetermined stress by moving the material on its face to which it is to be curved relative to a bending face. In this arrangement the material defines an angle of wrap in the portion coming into contact with the bending face. This angle of wrap is determined by the position of a deflector or guide for the material next the bending face. This deflector may be provided upstream and/or downstream of the bending face. For modifying the angle of wrap or for optionally working both faces of the material the deflector arrangement and the bending face means are expediently adjustable relative to each other. For this purpose the bending face may be positioned on the device frame so that it can be adjusted relative to the deflector during the entire bending operation, e.g. to transpose material sections in sequence having continuously changing tendencies into the same, non-stressed planar shape or the like. Such an adjustment may, however, result in a bulky configuration involving complicated control and inertia in control movements which makes it difficult to quickly react to varying curl tendencies or other properties of the material. If the length of the material section tensioned freely or linearly between the bending face and the deflection face is greater than the deflection radius of the deflection face the aforementioned drawbacks are likewise given and in addition to this material section may oscillate at high running speeds to the detriment of consistent good quality working.
OBJECTS OF THE INVENTION
An object is to overcome the drawbacks of known configurations or of the kind described. A wide variety of stresses should be introduceable into the material by simple constructional means.
SUMMARY OF THE INVENTION
In accordance with the invention the guiding face forming the deflection face and the bending face define as boundaries a relatively narrow gap which permits material to pass preferably free of compression stress. The clear width or the like of the gap is variable so that its minimum width is many times smaller than the cited deflection radius when the material wraps the bending face. This width can be measured in an axial plane of the deflection passing through the center of the bending face or of the angle of wrap. The minimum width may also be smaller than half, a quarter or a tenth of the deflection radius or smaller than 50 or 30 times the thickness of the material so that the free running zone between the two guiding faces is maximally as large as the deflection radius or smaller as compared thereto corresponding to one of the cited values.
Although in this case too, the bending face is positionally adjustable during bending operation it is, however, particularly expedient when thereby only the deflection is adjusted transverse to the deflection axis since then the distances and time required maximally for positioning are relatively small. The deflection face can thus be set tangentially to the plane of a flank connecting to the bending face and the tangential point can be continuously displaced from a position remote from the flank and opposing the bending face up to the flank face and a zone behind the bending face. This is especially achieved when the associated positioning axis is located away from the deflection axes of the deflection face upstream or downstream next to the bending face and thus the gap width is slightly altered by the positioning motion.
A web of paper to be subsequently worked is expediently secured with its leading edge to the overlapping trailing edge of an advanced paper web, e.g. by an adhesive tape before these ends or the seam reaches the working station. If the seam is passed on an arc or angle of wrap through the working engagement at the bending face or the like it may easily tear. This is why the guiding faces are mutually displaceable in a sudden short impulse such that the seam can be guided past one or both guiding faces without curvature or even contact, thus excluding damage.
Although the device can be made for bending engagement only on one face of the material, it is expediently configured for alternating bending engagement on both faces. For this purpose two separate deflecting faces are displaceable in common and two separate bending faces are mutually and separately adjustable relative to the device frame. The deflecting faces provided for this purpose, on the one hand, and the bending faces on the other are facing each other and are minimally spaced from each other by a spacing which is maximally as large as the deflection radius or smaller. The deflecting faces may be formed by rotational faces or rollers, the clear width there between as measured in their common axial plane being smaller than their radius. At both deflecting faces and at the bending face the material may be simultaneously guided and thus curved alternatingly in opposite directions.
In accordance with the invention fluid or suction means is provided with which particles of dust, paper or the like can be permanently exhausted more particularly in the region of the guiding faces or gap. A suction port adjoining the gap or the guiding faces is shaped expediently, as viewed axially, other than circular, more particularly oblong so that in the associated gap boundary only a single suction orifice extending over the full gap length is necessary. Such a configuration is substantially simpler to produce than orifices arranged in a grid pattern.
The bending face is expediently arranged on a plate or slat-like or similar type reversible body which can be replaced as a module without needing to destroy any part of it or its fastener means and can be thus reinserted in reversed positions so that a further bending face of three, four or more such faces is in place for workingly engaging the material. Accordingly, these bending faces working alternatingly may be configured in one part. However, the bending face may also be formed by a rotational face, for example, a round rod, instead of an edged face.
To facilitate changing the bending body, together with a support body such as a rod, where necessary, its fastening to the device frame is suitable for radial removal, i.e. for removal transversely to the longitudinal direction of the bending face or to the width extension of the material. Removing or changing can thus also be done when the material regularly passes through the device, the same applying also to the deflector arrangement or the individual deflector bodies.
In a further aspect of the invention the guiding faces are slantingly adjustable relative to each other or relative to the material or the running direction or the like, more particularly as viewed at right angles to the longitudinal direction of the guiding faces so that varying wrap angles or gap widths can be achieved over the width of the material. This adjustment is possible during bending operation.
BRIEF DESCRIPTION OF THE INVENTION
Example embodiments of the invention are explained in more detail in the following and illustrated in the drawings in which:
FIG. 1
is a side view of a device for a multi-ply material web,
FIG. 2
is a partially sectioned view as seen from the right of a single subdevice of the arrangement as shown in
FIG. 1
,
FIG. 3
is a section through the bending tools as shown in
FIG. 2
,
FIG. 4
is a view of a bending body as shown in
FIGS. 2 and 3
,
FIG. 5
is a longitudinal section through the bending body as shown in
FIG. 4
,
FIG. 6
is a scrap view of the bending body as shown in cross-section in
FIG. 3
on an enlarged scale,
FIG. 7
is a scrap view of the suction connection of the bending body,
FIG. 8
is a cross-sectional view of the mounting arrangement of one end of the bending body,
FIG. 9
is a cross-sectional view of the bearing means of the other end of the bending body, and
FIG. 10
is a scrap view of a further embodiment of the subdevice as shown in FIG.
1
.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in
FIG. 1
multiple equal bending or subdevices
1
are arranged in a station
2
horizontally juxtaposed and spaced from each other by an amount which is smaller relative to the space requirement for a device
1
, each of which is designed to work a separate material
3
in a working zone. In these working zones the materials
3
have parallel running directions
4
inclined downwards in running planes
5
parallel to each other. Each device
1
is arranged as a module for facilitated removal from a frame
6
. A multi-layer material web
7
from which the webs
3
located initially congruently on each other is fed horizontally and above the devices
1
to station
2
from separate reel stands, firstly aligned at a deflection
9
and then downstream thereof the individual materials
3
are each deflected in sequence from the web
7
at an upper deflection
8
and fed extended directly to the associated device
1
. From the working zone each material
3
is fed extended to devices
11
located below at which the materials
3
are placed one on the other in sequence to again form the web
7
.
In front and behind of the devices
1
the frame
6
comprises a portal
12
and
13
respectively each composed of rods, the vertical supports of these portals being connected to each other via horizontal girders
14
located on both sides of the material
3
. On their tops these members
14
mount the device modules
1
and can be removed together therewith as a unit from the remaining frame
12
,
13
. The upper ends of portals
12
,
13
are likewise interconnected with girders on which the deflectors
8
or rolls are rotatively mounted in sequence.
The single-layer material
3
is fed as an endless web to the working zone of the individual devices
1
via a cylindrical guide and deflection face
15
which the material
3
wraps over an angle of maximally 90°. From face
15
the material passes stretched directly to a guide or bending face
16
formed by a corner edge rounded in cross-section. Guide face
15
is formed by a rotating roll or deflector body
17
and the bending face
16
by a stationary bending body
18
comprising rectangular flat cross-sections throughout, which like deflector body
17
covers the full width of the material. Any soilage appearing in the working zone or in the vicinity of gap
20
is continuously removed pneumatically by a flow, for example by suction means
19
. The plane
10
of gap
20
slanting downwards in the direction
4
coincides with the bending flank of the bending face
16
which directly opposes guiding face
15
and is formed by an entirely planar larger face
21
of body
18
. The running plane
5
is steeper than face
21
so that the material
3
passes through the gap
20
from one gap boundary
15
to the opposite gap boundary
16
at an acute slanting angle before then being deflected on bending face
16
downwards and away from face
15
over an angle of less than 90°. The free length of material
3
between the two boundaries
15
,
16
is extremely short, but continuously variable. This length is smaller than the largest cross-sectional extension of body
17
or
18
or is half or a quarter thereof.
Guiding face
15
is curved about a horizontal deflector axis
22
, oriented parallel to running plane
5
and at right angles to direction
4
. Bending face
16
is curved about a bending axis
24
orientable parallel thereto. The two convex curved faces
15
,
16
greatly differ in their radius of curvature, the radius of face
15
being at least 10 to 20 times or 30 times larger than the radius of face
16
. Face
15
is adjustable about a positioning axis
25
oriented parallel to axis
22
, the positioning axis
25
being fixed on frame
6
and located on the side of axis
22
or of body
17
facing away from gap
20
or plane
10
.
The two ends of body
17
are secured or rotationally mounted on two supporting cheeks
26
, each of which is rotationally mounted about axis
25
over at least 120° or 360° with a bearing
28
and
29
respectively located at the corresponding outer side. Unit
17
,
26
,
27
can be radially removed from frame
6
, where necessary, together with bearings
28
,
29
. For precise, continuous adjustment about axis
25
positioning means
30
are provided which comprise an upright rotational motor
31
and a gear such as an angular gear
32
directly flanged thereto. Gear
32
is secured to the upper side of one member
14
and operates self-locking. The corresponding cheek
26
is secured directly to the freely protruding output journal of gear
32
so that the latters gear bearing directly forms the corresponding sole bearing
28
for positioning unit
17
,
26
,
27
, eliminating the need for any further separate or frame-fixed bearing on this side. The positioning means
30
,
40
,
42
,
43
or the suction means
19
may be arranged optionally on both sides of gap
20
by e.g. arranging gear
32
optionally on each one of members
14
and the connection
52
,
53
,
54
,
55
optionally in the region of each one of members
14
. Due to this arrangement the operator side of the device
1
may be located optionally on either the one side or the other and, where necessary, maintained free of means
19
,
30
,
42
.
For adjusting unit
17
,
26
,
27
control means
33
are provided on the side of gear
32
facing away from this unit. Means
33
comprise a control cam
34
located in axis
25
of the journal and arranged directly on the other journal of the same gear shaft. The periphery of cam
34
acts on a sensor
35
, such as an inductive transducer, so that by setting a variable signal value the positioning means
30
is stopped when the corresponding position of guiding body
17
is attained. An analog indication of the position is provided by an optical display
36
on the outer side of the other bearing
29
.
The flat or rod-type body
18
having constant outer cross-sections full-length is secured replaceably to a rod or supporting body
37
which is larger in cross-section and which is cross-sectionally configured as a flat rectangular tubular body carrying intimately adjoined body
18
on one of its two wider outer faces. Due to this the edge faces of body
18
adjoining edges
16
are located in the planes of the two outer faces of body
37
which are narrower or located at right angles thereto. The ends of unit
18
,
37
, more particularly only the ends of body
37
are rigidly connected with circular disk-shaped flanges
38
which are replaceably fixed to plate-shaped supporting flanges
38
′ of frame
2
by axial bolts which can be screwed into place toward outside. Once the axial bolts have been released unit
18
,
37
can be removed radially from supporting flanges
38
′ or conversely reinstalled.
Face
16
is manually adjustable by positioning means
39
or
40
relative to unit
17
,
26
,
27
and frame
6
separately about two positioning axes
45
,
46
located at right angles to each other, namely by the positioning means
40
during operation and by the positioning means
39
when operation is stopped. Axis
46
oriented parallel to face
16
and to axes
22
,
25
is located on the side of face
16
facing away from gap
20
,
10
roughly in the center axis of supporting body
37
or of the associated flanges
38
. For passage of the cited axial bolts these flanges
38
comprise slots curved about axis
46
so that the inclination of the face
16
and gap flank
21
can be steadily varied and then locked in place by clamping action of the axial bolts. The flank
21
is located in one position of unit
15
,
26
,
27
at right angles to the common axial plane
47
of axes
22
,
25
, this axial plane intersecting flank
21
directly adjacent to face
16
. From this position planes
10
,
47
can be steadily displaced in both opposing directions. Also so that plane
47
spacedly opposes face
16
and thus slants relative to plane
10
. In the cited center position the clear width of gap
20
is at a minimum, it increasing steadily when varied in both directions as is evident from the positions indicated dot-dashed in FIG.
3
. The minimum gap width is expediently more than one millimeter and less than three or five millimeters. Positioning movements of both positioning means
30
,
39
result in such changes, it only being the positioning means
39
which establishes the smallest possible gap width.
Positioning means
40
permit mutually slanting adjustment of face
16
and axes
24
,
46
, on the one hand, and of guiding face
15
and axes
22
,
25
on the other. The cited gap width settings remain constant over the positioning length of positioning means
40
. Positioning means
40
set the one end, remote from positioning means
30
, of unit
18
,
37
about positioning axis
25
whilst the other end of this unit merely privots about frame-fixed axis
45
, i.e. including the corresponding supporting flange
38
′ in each case. Axis
45
is always located in the same axial plane of axis
25
and is laterally juxtaposed with the axial planes of axes
22
,
24
,
46
oriented parallel thereto. It is possible by the positioning means
30
to translate axis
22
also in this common axial plane. The supporting flange
38
′ for the one flange
38
is adjustable by a guide
41
curved about axis
25
, this guide comprising a guide pin engaging a curved slot with zero diametral clearance and rigidly connected to supporting flange
38
′. The mounting about axis
45
oriented transverse or inclined to flank
21
or plane
10
is formed by a joint
42
or a mount comprising a joining pin located fixed to frame
6
in axis
45
.
Each of the bearings
41
,
42
comprises a mounting body
48
fixed to frame
6
laterally on the inside of the corresponding member
14
. The one mounting body carries guide
41
and the other, in a bifurcated arrangement, the joining pin which passes through the corresponding supporting flange
38
′ between the forked arms of the corresponding mounting body
48
. After this adjustment the unit
18
,
37
needs to be locked only in the region of guide
41
by suitable means
43
, for example by clamping. For this purpose a manually lever-operable clamping device is provided with which guide
41
can be axially tensioned relative to the corresponding mounting body
48
. To facilitate manual adjustment along the guide
41
the corresponding supporting flange
38
′ is provided with a radially protruding handle
44
adjoining the inner side of this mounting body
48
. Clamp
43
is accessible directly on the underside of the corresponding member
14
.
Body
18
as shown in
FIGS. 4
to
6
consists of an integral metal body the surface of which is coated overall or at least in the region of the four longitudinal edges
16
e.g. with a vacuum-deposited film of a harder substance, such as ceramic oxide film or the like maximally a tenth or half a tenth of a millimeter thick, for example. Body
18
is optionally turnable about its longitudinal center axis and about its transverse axis oriented at right angles thereto so that with respect to member
37
each of its four edges
16
can be optionally brought into the same working position for engaging the material
3
. For this purpose fastening means
49
for reversible tool
18
comprise on both flat sides of reversible bit
18
countersinks for fastener bolts with which tool
18
can be tensioned optionally with both flat sides against the corresponding flat side of member
37
. Edges
16
may have different radii of curvature so that one and the same tool
18
has working edges
16
for adapting to various working requirements.
Suction means
19
are stationary or not exposed to positional changes in operation and comprise a slot-shaped fluid or suction orifice
50
passing transversely through tool
18
in the middle between edges
16
. Opening
50
is oriented parallel to edges
16
and in line between countersinks
49
. The corresponding wall of member
37
is provided with a coincidental fluid orifice connecting the port of orifice
50
located in flank
21
to a flow passage
51
. Passage
51
is bounded solely by the inner sides of profile
37
, runs full length over the latter and has at one or both ends constricted connectors
52
which are provided for both gaps
20
at the remote outer sides of support flanges
38
′ and laterally adjacent to
41
or axis
45
. To connectors
52
a flexible tube
53
, e.g. a hose, connects and traverses the underside of the corresponding member
14
. The other end of this tube is connected via a slanting connection
55
to a longitudinal passage
54
. Secured to the other longitudinal section of each member
14
is one such longitudinal passage
54
! having a rectangular or square cross-section, into the side wall of which the connection
55
issues at an acute angle inclined to the flow direction in passage
54
to eliminate flow losses. The end of passage
54
located nearer to the frame part of deflector
9
translates via a bend into a passage
56
oriented vertically upwards, the upper end of which is connected to a suitable pressure/suction source, such as a blower.
As shown in
FIGS. 1 and 2
only one single simultaneously effective tool edge
16
is provided for each working zone or device
1
so that tool engagement is possible on one face only of the corresponding material
3
. The configuration as shown in
FIG. 3
is suitable for providing tool engagement optionally on both faces of the material
3
. For this purpose identical units
18
,
37
are secured separate to the same support flanges
38
′ on both sides of axial plane or axis
45
and adjustable about axis
46
independently of each other as as removable independently of each other. The working faces
16
of these two units spacedly oppose each other symmetrically to plane
45
. Flanks
21
are counter inclined so that their planes
10
are oriented at an obtuse angle in a V-formation to each other. Cheeks
26
,
27
likewise support two separate deflecting faces
15
,
15
′ or identical deflection bodies
17
having separate deflection axes
22
,
23
arranged symmetrically on both sides of an axial plane of positioning axis
25
. In one position this axial plane coincides with plane
45
so that the material
3
is able to pass from deflector
8
to deflector
11
without contact between rolls
17
and tools
18
, i.e. without being deflected in the working zone. By pivoting unit
17
,
26
,
27
in the one direction into the position as shown in
FIG. 3
the material
3
is transferred from the deflection on one guiding face
15
with one material face into bending engagement of the other material face with the one bending face, namely the right-hand face
16
. By pivoting in the opposite direction the material
3
is correspondingly brought into engagement with the other bending edge
16
by the other deflection face
15
′.
Due to pivoting about axis
25
the angle of wrap at the corresponding edge
16
can be varied dynamically and continuously during operation. Thereby the wrap angle at the corresponding deflection face
15
,
15
′ as well as the width of gap
20
are also changed. Gear
32
automatically locks each setting by the inner obstruction of its gear members. Independently of this, this wrap angle and gapwidth can be altered by positioning means
39
. In this respect also the two flanges
38
could be displaced relative to each other in torsional deformation of unit
18
,
37
to achieve differing wrap angles along the length of edge
16
, as is possible by positioning means
40
. However, the dynamic variation is undertaken not with tools
18
but with deflections
17
resulting in a very simple configuration of the suction means
19
. Each passage
51
is connected to one of the connectors
52
. All subdevices
1
are connected to a common longitudinal header passage
54
. The cited ends of the two passages
54
are connected to the common riser passage
56
via the cited bend, configured as a Y-connector. Since the deflectors
17
cannot come into contact with tools
18
or other components of the device
1
even when fully rotated about axis
25
no means for restricting travel such as limit switches are needed. Each tool
18
or the tool edge
16
thereof may also be replaced by a rotating rod, the bearings of which are to be flanged to the support flanges
38
′ or provided on flanges
38
. All components are located freely accessible thus greatly facilitating maintenance or insertion of the material
3
.
As shown in
FIG. 3
on the side of the deflector
17
facing away from tool
18
, namely between deflectors
8
,
17
or
11
,
17
a further material guide
57
may be provided located nearer to deflector
17
. Guide
57
does not deflect during bending but when the material
3
is guided past without contacting bending face
16
or at the most slightestly touching it. For each deflection face
15
,
15
′ material guide
57
comprises a corresponding frame-fixed deflector
58
,
58
′ or cylindrical rod or the like. In one position deflection face
15
forms with deflector
58
a tight passage gap for S-shaped reversing deflection of the material
3
and in the other position for likewise oppositely deflecting in the region of an equal deflector gap between deflection face
15
′ and deflector
58
′. The material passes through the deflection gap in each case without any clamping pressure so that only one material face has deflector contact at any moment. Deflectors
58
,
58
′ are secured to flanges
59
and thus secured adjustable and removable at a support flange
59
′ as already described with respect to flanges
38
. Accordingly, here too, positioning means may be provided corresponding to means
39
,
40
, the deflectors
58
,
58
′ like the deflectors
16
each being located eccentrically to the corresponding positioning axis.
In the embodiment shown in
FIG. 10
the deflectors
17
are provided spacedly downstream of bending faces
16
and deflector
8
is located upstream of faces
16
as shown in FIG.
1
. To engage and disengage passage control mode for non-worked passage of material
3
past the faces
16
the drive
31
is a power of fluid cylinder. Drive cylinder
31
comprises two separate cylinders each separately controllable and rigidly connected to each other in series. The pistons rods face away from each other. Each cylinder can be transposed separately into two end positions so that four stop-limited working strokes, namely that of each individual cylinder and the two working cylinders are achieved. Instead of the deflectors
17
being fixedly mounted to the frame the units
18
,
37
or the supporting flange
38
′ are pivoted about axis
25
of deflector
8
by drive
31
. Thereby each of the two tools
18
too, can optionally be brought into engagement with the material
3
. Fine adjustment of the tool
18
or of its wrap angle is done manually via gearing such as a worm gear.
Claims
- 1. A setting device for bending layer material defining remote first and second layer faces, said setting device comprising:a stationary base frame; a running path defining a running direction and a cross-sectional running plane, and first and second guide faces for guiding the layer material, said first guide face including a bending face and said second guide face including a deflection face, said first and second guide faces being operationally directly interconnected by the layer material when passing between said first and second guide faces, and wherein dusting means are included for conveying dust away from said running path.
- 2. The setting device according to claim 1, wherein said dusting means include suction means directly connecting to at least one of said first and second guide faces.
- 3. A setting device for bending layer material defining remote first and second layer faces, said setting device comprising:a stationary base frame; a running path defining a running direction and a cross-sectional running plane, and first and second guide faces for guiding the layer material, said first guide face including a bending face and said second guide face including a deflection face, said first and second guide faces being operationally directly interconnected by the layer material when passing between said first and second guide faces, said first and second guide faces bounding a gap defining a gap shape for passing the layer material, said gap shape being operationally variable by displacing said first guide face with respect to said second guide face, between said first and second guide faces said gap defining a gap plane, and wherein an air port connects directly to said gap, said air port being positionally displaceable with said bending face and with respect to said deflection face.
- 4. A setting device for bending layer material defining remote first and second layer faces, said setting device comprising:a stationary base frame; a running path defining a running direction and a cross-sectional running plane, and first and second guide faces for guiding the layer material, said first guide face including a bending face and said second guide face including a deflection face, said first and second guide faces being operationally directly interconnected by the layer material when passing between said first and second guide faces, and a bending body including said bending face and exchangeably mounted on a support rod, wherein said support rod includes a hollow profile including angular internal cross-sections.
- 5. A setting device for bending layer material defining remote first and second layer faces, said setting device comprising:a stationary base frame; a running path defining a running direction and a cross-sectional running place, and first and second guide faces for guiding the layer material, said first guide face including a bending face and said second guide face including a deflection face, said first and second guide faces being operationally directly interconnected by the layer material when passing between said first and second guide faces, and a bending rod including said bending face, wherein said bending rod includes a fluid duct for operationally passing a fluid.
Priority Claims (1)
Number |
Date |
Country |
Kind |
197 13 207 |
Mar 1997 |
DE |
|
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Foreign Referenced Citations (8)
Number |
Date |
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623 285 |
May 1981 |
CH |
4 83 673 |
Oct 1929 |
DE |
26 46 281 |
Apr 1977 |
DE |
38 33 804 |
Jun 1989 |
DE |
296 00 403 |
Mar 1996 |
DE |
195 06 465 |
Aug 1996 |
DE |
0 374 827 |
Jun 1990 |
EP |
WO9421546 |
Sep 1994 |
WO |