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EP 1 099 509 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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06.10.2004 Bulletin 2004/41 |
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Date of filing: 16.10.2000 |
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Marking workpieces
Verfahren und Vorrichtung zum Markieren von Werkstücken
Méthode et appareil pour marquer des pièces de travail
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Designated Contracting States: |
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FR GB IT |
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Priority: |
14.10.1999 DE 19949552 07.10.2000 DE 10049701
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Date of publication of application: |
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16.05.2001 Bulletin 2001/20 |
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Proprietor: Mate Precision Tooling Inc. |
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Anoka,
Minnesota 55303 (US) |
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Inventor: |
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- Schneider, Albrecht
61440 Oberursel (DE)
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Representative: Erb, Henning, Dipl.-Ing. et al |
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Patentanwälte Beyer & Jochem,
Klettenbergstrasse 13 60322 Frankfurt am Main 60322 Frankfurt am Main (DE) |
(56) |
References cited: :
DE-A- 3 735 422 US-A- 5 682 657
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JP-A- 8 281 340
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] The present invention relates to a method and apparatus for marking workpieces on
a punching press, wherein the marking tool is forced by means of the punching stroke
either against the surface of the workpiece to form a mark on the surface thereof
or a certain depth into the surface of the workpiece to form the marking by inscribing.
The workpiece, which is generally a piece of flat sheet metal is displaced within
its plane in order to create a straight or curved marking line.
[0002] There is an increasing demand for providing the workpiece with individual identifications.
In this connection the use of stamping dies is not always practical because the stamping
is often also visible on the back of sheet metal workpiece. Difficulties in connection
with stamping dies occur particularly when it is intended to punch parts of different
lengths out of a sheet metal workpiece (e.g., in order to minimize waste) and wherein
a certain orientation of the marking on the workpiece is desirable.
[0003] A known method for marking sheet metal consists of embossing dot matrices for producing
an alpha-numeric symbol with the aid of a pointed embossing tool. The workpiece must
be moved stepwise after each dot has been embossed. This results in a multitude of
required stamping stroke cycles, just to represent a single symbol. Besides the large
amount of required time and the increased wear of the driving mechanism for the stroke,
which is driven in a quasi load-free manner, the loud noise is considered to be a
disadvantage. A coarser dot matrix does simplify the marking process, but it also
results in a more unsatisfactory matrix.
[0004] From US-A-5682657 and JP-A-08281340 it is known to avoid the repetitive striking
of the striker by means of an additional pneumatic device acting on the marking tool
high frequently while the striker is lowered. However, during marking a dot-matrix
still some noise is to be expected. Further, the additional device is space demanding.
The synchronization of the high-frequent movement of the marking tool and the stepwise
displacement of the workpiece is difficult to achieve when high speed marking is required.
[0005] A qualitatively appealing marking can be achieved by inscribing markings into the
surface of the workpiece, wherein no waviness or "rear embossing" will occur. Borries
Markiersystem GmbH of Pliezhausen, for example, offers a machine, by means of which
inscribing of the desired identification is possible by displacing a tip forced into
the surface of the workpiece in accordance with the contours of the marking.
[0006] It would seem that in principle one could employ such a known marking device in a
punch press. However, if this were done, the space available for the main punching
operation would be reduced and the progress of the main punching operation would be
made more difficult. Also, such a prior marking device could only operate within a
limited portion of the area of the punch press so that movement of the sheet metal
workpiece in order to apply markings on different areas thereof would become more
difficult.
[0007] It is an object of the present invention to create a new improved method and apparatus
for marking a sheet metal workpiece, which method and apparatus can be integrated
into a punching processes in a punch press with no additional driving means for the
marking tool.
[0008] This object is attained in accordance with the invention by a method and apparatus
in accordance with claims 1 and 7, respectively.
[0009] The production of visually pleasing markings of any arbitrary symbol on or in the
workpiece surface is made possible by means of the marking tool being placed on the
punch press without any additional, space-consuming devices. At the same time the
marking method is optimally integrated into the punching process so that, for example
with a turret punch press, a sheet metal workpiece is first marked at the desired
locations and thereafter is finished by means of the tools seated in other holders
of the punch press. The marking tool may be arranged in a punch tool holder or in
a holder on the workpiece support table of the punch press, so that the marking can
be made from above or below the workpiece, as required. The orientation of the marking
can be determined by means of the software which controls the workpiece driving mechanism.
[0010] It is also advantageous in connection with the method of the invention that the tool
tip need be moved only once into its marking position, so that the number of punch
strokes which must be performed by the punch press is considerably reduced. The results
are reduced noise generation and reduced wear of the stroke driving mechanism.
[0011] In one preferred embodiment of the invention, at least a portion of the punch stroke
is absorbed by an elastic element which extends between a table for seating the workpiece
and the punch tool holder.
[0012] Since punch presses are designed for very high processing forces, it can be very
difficult under certain circumstances to move the stroke driving mechanism almost
load-free into a precisely defined position. To compensate for this, it is possible
by an elastic element to achieve considerably more precise movement of the tool tip
on or into the surface of the workpiece. In the process, the elastic element translates
the relatively large punch stroke of the punch press into an exactly defined contact
pressure force of the tool tip, which leads to the desired marking position.
[0013] In a further preferred embodiment of the invention at least one marking is formed
as center mark, wherein, following pressing the tool tip, the workpiece is maintained
in its predefined position until the marking tool is retracted.
[0014] It is desirable for some applications to be able to set a center mark on the workpiece,
for example in order to be able to position or center bolts or pins which are to be
welded onto the workpiece. The provision of the center mark can be integrated into
the marking process and apparatus in accordance with the invention, wherein it might
be advantageous if, in connection with a center mark, the tool tip were pressed deeper
into the workpiece than the usual inscribing depth.
[0015] For example, when making a center mark it is possible in a further development of
the invention that by different positioning of the tool tip with respect to a counter-support,
for example, the spring travel of the tool tip reaches its maximum before it has reached
the deepest depth in the workpiece. While the inscribing of markings is performed
by means of a resilient tool tip, the latter rests against a stop when making a center
mark.
[0016] It has been shown to be practical to guide the workpiece by means of at least one
support roller in the area of the workpiece table and/or the punch tool holder since,
among other things, the support rollers or support balls provide the required counter
support while not hampering the displacement of the workpiece.
[0017] In accordance with the invention, an apparatus as disclosed in claim 7 is provided.
The counter-support can be fixed in place on the punch holder, in the table or on
the punch holder. It is possible with the aid of the at least one marking tool with
its resilient tool tip and the appropriate counter-support to execute the marking
or center marking operations on a punch press with its workpiece which is movable
in its plane. It is basically of no significance whether the marking tool is arranged
below or above the workpiece, or whether marking tools are provided on both sides
of the workpiece in order to mark both sides thereof in cooperation with appropriate
counter-supports. With such an apparatus, one marking tool and one counter-support
in combination can constitute one half of the apparatus above or below the workpiece.
[0018] The counter-support preferably has at least one rotatable support roller or support
ball for the movable support of the workpiece. As previously mentioned, balls or rollers
as the support offer the possibility of a dependable support, with mobility provided
without damage to the surface or at least limiting frictional losses to occur only
at the contact points.
[0019] The marking tool preferably has, besides the tool tip, rotatable support rollers
or support balls, which are seated in an elastically spring-loaded manner.
[0020] With an arrangement of this type, during a punching stroke the workpiece first comes
into contact with the support rollers or support balls, which subsequently yields
elastically until, prior to reaching bottom dead center, the tool tip comes into contact
with the surface of the workpiece. Contact pressure is then built up during the further
downward movement.
[0021] In this case the spring travel of the support rollers or support balls is preferably
greater than the spring travel of the tool tip. In this way it is possible when setting
a center mark that the tool tip rests against a stop, because of which an exactly
defined center mark depth results. Center marking requires a precise approach to its
final position.
[0022] The resilience of the elastic elements of the support rollers is suitably less than
that of the elastic element of the tool tip in order to achieve a sufficient contact
pressure when applying the marking symbols, and in order to introduce only small forces
into the workpieces by means of the support rollers or support balls, noting that
the sheet metal workpiece can be comparatively thin. However, the resilience of the
support roller or support balls should be sufficient for supporting the workpiece
during the operation.
[0023] A cone-shaped tip of the inscribing element is preferably forced into the workpiece
surface, so that an inscribing force is achieved regardless of the direction of movement.
However, shapes which are not round are also conceivable which, when required, can
be rotated in accordance with the direction of movement of the workpiece, or which
can also specifically cut grooves of different thicknesses into the workpiece surface.
[0024] In accordance with yet another preferred embodiment, the marking tool has an adjustable
support, by means of which the position of the tool tip and/or the prestress of its
elastic element can be adjusted.
[0025] The adjustable support makes possible the individual adaptation of the contact depth,
for example in order to improve the clarity of the symbols in the same material of
the workpiece, or to make possible an adaptation to the material of the workpiece.
[0026] As mentioned above, with the present invention, it is possible to make a marking
such as an ink marking or the like on the surface of the sheet metal instead of inscribing
the marking into the sheet metal. Making an ink marking would use the same method
and apparatus as described above with respect to inscribing except that the method
and the equipment would be adjusted such that the marking tools such as a pen or the
like would simply be forced with sufficient pressure against the surface of the workpiece,
as opposed to entering into the surface of the workpiece. Any suitable pen could be
used including for example, a ball-point pen, a roller ball pen, a felt tip pen or
a grease pencil.
[0027] Thus, it is an object of the present invention to provide a new and improved method
and apparatus for marking a workpiece, wherein the apparatus is incorporated within
a punch press.
[0028] It is another object of the present invention to provide a new and improved method
and apparatus for marking a sheet metal workpiece in conjunction with a punch press,
wherein the marking can be either inscribed into the surface of the workpiece or made
as an ink marking on the surface of the workpiece.
[0029] It is still another object of the present invention to provide a new and improved
method and apparatus for marking a sheet metal workpiece in conjunction with a punch
press, wherein the marking can be made on either side of the workpiece, with suitable
support provided on the other side of the workpiece.
[0030] These and other objects of the present invention will become more apparent from the
detailed description to follow.
[0031] The invention will now be described in detail with respect to preferred embodiments
of the invention wherein:
Fig. 1 is a central cross sectional view of a marking tool for insertion into a punch
holder,
Fig. 2 is a central cross sectional view of a marking tool for insertion into a holder
on a workpiece supporting table of a punch press, wherein the right and left sides
show two different positions,
Fig. 3 is a central cross sectional view of a marking tool similar to Figure 2, but
showing a modification thereof, and
Fig. 4 is an enlarged view of a portion of Figure 1, but showing a modification thereof.
[0032] Referring now to the drawings, like elements are represented by like numerals throughout
the several views.
[0033] Referring to Figure 1, the marking tool has a guide bush 14, in which a support 16
is axially guided, and a driving head 20, which are in engagement with each other
via a threaded connection 22. By means of a guide insert 24, the support 16 holds
an inscribing tool 26, which is axially movable with respect to the support 16 and
has a tool shaft 28 which is guided in an appropriately fitted bore 30 of the guide
insert 24, a pressure plate 32, formed at the top of the shaft 28, as well as an inscribing
element 34, seated on the free lower end of the shaft 28. The inscribing element 34
is embodied as a pointed cone and can be made, for example, of a diamond, boron nitride,
a hard metal, or an otherwise suitable material for inscribing the respective workpiece.
[0034] The axial mobility of the inscribing tool 26 in relation to the support 16 is limited
by a first shoulder 36 of a bore 38 in the support 16, and by the top 40 of the guide
insert 24 inserted into the bore 38. A compression spring 44, arranged under prestress
between a second shoulder 42 and the pressure plate 32, urges the pressure plate 32
downwardly against the top 40 of the guide insert 24.
[0035] In the exemplary embodiment represented, the workpiece 12 is a sheet metal plate
which rests on a tool holder 46 with a rotatably seated ball 48, wherein the contact
point between the workpiece 12 and the ball 48 lies exactly in alignment with the
inscribing element 34.
[0036] To inscribe a symbol on the workpiece 12, the workpiece is first appropriately aligned
with the marking tool 10. Thereafter, lowering of the inscribing tool 26 is started
by actuating the stroke driving mechanism of the punch press, which acts on the driving
head 20, wherein the guide bush 14 is urged against the support 16 by means of a shoulder
50. In the course of the downward movement of the support 16 the inscribing tool 26
is initially moved along until the inscribing element 34 rests on the surface of the
workpiece. The continued downward movement of the support 16 leads to compression
of the compression spring 44, and therefore the pressure exerted on the pressure plate
32 steadily increases. Because of the pressure exerted by the compression spring,
the inscribing element 34 penetrates the surface of the workpiece and reaches its
maximum penetration depth at the end of the punch stroke.
[0037] An adjustment of the penetration depth of the inscribing element 34 can be performed
by a relative turning of the driving head 20 in relation to the support 16. This changes
the effective total combined length of support 16 and driving head 20. With this increased
length of the support 16 and driving head 20 the inscribing element 34 reaches the
surface of the workpiece earlier in the punch stroke, and the pressure built up by
means of the compression spring 44 becomes correspondingly greater.
[0038] As soon as the inscribing element 34 reaches its inscribing position, the stroke
driving mechanism of the punch press is blocked. Conversely, if the stroke driving
mechanism of the punch press did not permit the marking tool to stop in the inscribing
position, a separate detent device must be provided between the support 16 and the
guide bush 14. With the inscribing element 34 held down, the workpiece 12 is now displaced
in its plane in order to form the contours of the symbol to be inscribed, wherein
any arbitrary orientation of the symbol is possible by an appropriate control of the
workpiece driving mechanism. When the symbol has been completely inscribed in the
workpiece, the stroke driving mechanism is reversed, wherein first the support 16
is moved away from the workpiece 12 because of the diminishing pressure force by the
spring 44 and, following the contact of the pressure plate 32 with the top 40 of the
guide insert 24, the inscribing element 34 is lifted off the workpiece 12. The workpiece
12 is appropriately horizontally displaced within its plane and the inscribing process
is repeated for inscribing additional symbols.
[0039] During the horizontal displacement of the workpiece 12, the roller body 48 of the
counter-support 46 follows this movement, wherein an optimal counter-support directly
in alignment with the inscribing element 34 always exists. Because the roller ball
48 turns, sliding movements against the underside of the workpiece 12 are prevented,
so that the underside of the workpiece 12 is not detrimentally affected.
[0040] Where the marking tool of Figure 1 is used in a punch press the guide bush 14 is
adapted to the tool holder and the driving head 20 is adapted to the stroke driving
mechanism of the punch press.
[0041] The compression spring 44 can be replaced with a pneumatically or hydraulically operating
pressure spring.
[0042] Figure 2 illustrates a marking tool 100, which can be inserted into a support on
the workpiece supporting table of a punch press. The marking tool 100 has a housing
102, which has a circular bore 104, in which is received a ring-shaped holder 106.
The ring-shaped holder 106 is resiliently axially supported in the punching direction
by means of several helical springs 110, which are located within the circumference
of a first shoulder 108. The holder 106 has two or more recesses 112, in which inserts
116, which rotatably receive support balls 118, have been fixed in place by means
of threaded bolts 114. Even in the maximum retracted resilient state, as shown on
the right side of Figure 2, the support balls 118 project upwardly past the upper
edge of the housing 102. In its uppermost position, as shown on the left side of Figure
2, the upward movement of holder 106 is limited by a retaining ring 120, against which
an annular shoulder 122 of the ring-shaped holder 106 rests. It would also be within
the invention to provide a separately embodied holder with an associated helical spring
in place of a ring-shaped holder 106.
[0043] The marking tool 100 moreover has a cone-shaped tool tip 124 made of a suitable material,
for example a hard alloy. The tool tip 124 has been inserted via a screw thread 126
into a bore 128 of a tool holder 130, which is resiliently supported by means of a
helical spring 132 on a bottom cover 134. In this embodiment, the cover 134 has been
screwed into a screw thread in the bottom of housing 102. This arrangement allows
the replacement of the tool tip 124 without the necessity to completely dismantle
the marking tool.
[0044] The tool holder 130 is guided in a guide bore 135 of a housing element 136, which
is screwed together with the housing 102 by means of a screw connection. A rotation
guard 138 in the form of a bolt prevents relative rotation between the tool holder
130 and the housing element 136.
[0045] A detent flange 142 provided on the tool holder 130, together with its detent face
144 on the housing element 136, limits upward movement of the tool holder 130. In
the other direction, the maximum retracted resilient position of the tool holder 130
with the tool tip 124 is limited by the bottom face 146 of the tool holder 130 engaging
the bottom cover 134, wherein the travel of the springs 110 of inserts 116 is greater
than the travel of spring 132 the of tool holder 130. In the uppermost position of
the springs 110 and 132 and the inserts 116 the support balls 118 project upwardly
past the tool tip 124, while in the maximum retracted resilient state of the inserts
116 and of the tool holder 130, the tool tip 124 projects upwardly slightly past the
tops of the support balls 118.
[0046] A tool corresponding to the marking tool 100 and having a further tool tip can be
provided in the area of the punch holder of the respective punch press. It is also
within the invention to provide only a simple counter-support with support balls,
which can be aligned with the support balls 118 of the marking tool 100. A reverse
arrangement is also within the invention, wherein only a counter-support with support
balls 118 is provided on the table side, and a tool similar to the tool 100 is provided
in the punch holder.
[0047] During operation, a workpiece to be marked, normally a sheet metal piece, initially
rests on the support balls 118 of the tool 100 and is not in contact with the tool
tip 124. In this position the sheet metal workpiece can be displaced horizontally
in its plane without the tool tip 124 causing damage to the surface. After the sheet
metal workpiece has been moved into a position in which it is to be marked, a punch
stroke is initiated. In the course of this stroke, the sheet metal workpiece is moved
downwardly, for example by pressure balls on the top of the workpiece, wherein the
inserts 116 are lowered against the force of the helical springs 110. The tool tip
124 reaches the surface of the sheet metal workpiece, and the prestressed spring 132
of the tool holder 130 is compressed by means of continued lowering, because of which
a contact pressure force of the tool tip 124 is built up on the surface of the sheet
metal workpiece. The tip 124 slightly penetrates into the material of the workpiece
under this contact pressure force. If symbols are to be inscribed into the surface
of the workpiece, the bottom dead center position is set in such a way that the tool
holder 130 does not yet rest against the bottom cover 134. Therefore the penetration
depth of the tool tip 124 remains relatively slight. Thereafter the sheet metal workpiece
is displaced horizontally in its plane in accordance with the contours of a symbol
to be inscribed. The top dead center position of the punch holder is then again approached.
Now the position of the sheet metal workpiece can be moved and, if desired, further
symbols can be inscribed.
[0048] The provision of a center mark in a workpiece is also possible by means of the marking
tool 100, for example as an alignment aid for pins or bolts to be welded onto the
workpiece during subsequent work steps. To this end the sheet metal workpiece at bottom
dead center is moved further downward by means of an increased punch stroke, or by
means of a tool tip 124, which can be adjusted in a suitable manner, or by means of
a position adjustment of the pressure balls, or the like, because of which the bottom
face 146 rests against the bottom cover 134 before bottom dead center has been reached.
By means of the subsequent lowering by a further short distance, a center mark of
a desired depth is made which clearly extends to a depth which is deeper than the
inscribed symbols.
[0049] Figure 3 illustrates another embodiment 200 of a marking tool. The embodiment of
Figure 3 is similar to the embodiment of Figure 2 except for certain modifications.
Accordingly, those elements in Figure 3 which are identical to Figure 2 are represented
by the same numeral. Those elements which have been modified have been raised by 100
relative to the numeral used to describe the related part in Figure 2.
[0050] In contrast to Figure 2, Figure 3 shows a diamond tool tip 224 which is seated in
a shaft 226. This shaft 226 has been fixed in place by means of an attachment screw
228 on a tool holder 230. The essential difference of the tool holder 230 in comparison
with the tool holder 130 of Fig. 2 is that the tool holder 230 has an increased free
space between its bottom face 246 and the bottom cover 234, so that even with the
holder 106 being maximally retracted resiliently and resting against the first shoulder
108, the spring travel of the tool holder 230 is not at its maximum compression. Therefore
the marking tool represented in Fig. 3 is only suitable for inscribing symbols wherein
the greater hardness of the diamond tip 224 provides a longer service life, while
the increased travel of spring 132 protects the diamond tip from shocks caused by
engaging the detent 142.
[0051] As described above, the described tools for marking and possibly providing center
marks can be used on the workpiece supporting table side as well as on the punch holder
side, so that processing of both sides of the workpiece is possible.
[0052] Figure 4 illustrates a modification of the present invention wherein, instead of
an inscribing element, there is provided an ink point 334 for marking the surface
of the workpiece 12 without penetrating same. Ink point 334 is shown at the lower
end of a shaft 334 mounted in guide insert 24 of Figure 1. All of the above described
features of all embodiments of the invention can utilize an ink element 134 to mark
the surface of a workpiece in place of the previously described elements for inscribing
the workpiece and/or forming a center mark. As would be understood by one of ordinary
skill in the art, when using an ink marking point 334, one would simply adjust movements
of all of the other movable parts such that instead of penetrating the workpiece,
the apparatus would move the ink point 334 to a position whereat it exerted sufficient
force onto the workpiece to form an ink marking. As with the other embodiments, the
workpiece 12 could then be displaced horizontally within its plane so as to form an
ink symbol of straight or curved lines. Any type of known ink point could be used
such as a ball-point, a roller ball point, a felt tip or a grease pencil.
[0053] Although the invention has been described in considerable detail with respect to
preferred embodiments thereof, it will be apparent that the invention is capable of
numerous modifications and variations, apparent to those skilled in the art, without
departing from the scope of the invention, as defined by the appended claims.
1. A method for marking workpieces on punch presses, wherein a marking tool (34, 124,
224, 334) is forced by means of a punch stroke onto or into the surface of a sheet-shaped
workpiece, which is displaceable in its plane, characterized in that the marking tool has a tool tip (34, 124, 224, 334) which, after being forced onto
or into the workpiece, is maintained in a marking position, the workpiece is displaced
in its plane with the tool tip (34, 124, 224, 334) held down corresponding to the
contours of the symbol to be marked or inscribed, and subsequently the tool tip (34,
124, 224, 334) is moved back into its position of rest wherein, if required, after
an appropriate movement of the position of the workpiece, the marking process is repeated
in accordance with the number of markings to be made.
2. The method in accordance with claim 1, characterized in that marking tools (34, 124, 224, 226, 334) are arranged in a punch holder of the punch
press and/or in a holder of the workpiece support table.
3. The method in accordance with claim 1 or 2, characterized in that at least a portion of the punch stroke is absorbed by an elastic element (44, 132)
which is provided extending between a workpiece supporting table and the punch tool
holder.
4. The method in accordance with claim 3, characterized in that at least one marking is set as a center mark, wherein, after the tool tip (34, 124,
224) has entered the workpiece, the tool tip is maintained in its predetermined position
until the marking tool is retracted.
5. The method in accordance with claim 4, characterized in that in connection with center marks the tool tip (34, 124, 224) is pushed deeper into
the workpiece than during the inscribing process, and preferably in the course of
providing a center mark the spring travel of the tool tip (34, 124, 224) reaches its
maximum before the lowest depth penetration into the workpiece has been reached.
6. The method in accordance with one of the preceding claims, characterized in that the workpiece is guided by at least one support roller or support ball (48, 118)
in the area of the workpiece support table and/or the punch holder.
7. An apparatus for executing a method in accordance with one of the preceding claims,
wherein the apparatus consists of at least one marking tool (34, 124, 224, 334) and
at least one counter-support on the side of the workpiece located opposite the marking
tool, wherein the marking tool has a tool tip (34, 124, 224, 334), which can be pressed
in against the restoring force of an elastic element (44, 132) and can be fixed in
place on a punch holder or the holder at the workpiece supporting table of a punch
press, and the counter-support can be fixed in place on the other side of the workpiece,
characterized in that the at least one marking tool (34, 124, 224, 334) can be forced by means of a punch
stroke onto or into the surface of a sheet-shaped workpiece and arranged to be held
down in its marking position during displacement of the workpiece in its plane.
8. The apparatus in accordance with claim 7, characterized in that the counter-support has at least one rotatable support roller or support ball for
the movable support of the workpiece.
9. The apparatus in accordance with claim 7 or 8, characterized in that, besides the tool tip (34, 124, 224, 334), the marking tool has rotatable support
rollers or support balls (118), which are seated in an elastically spring-loaded manner,
the spring travel of the support rollers or support balls (118) preferably being greater
than the spring travel of the tool tip (34, 124, 224, 334).
10. The apparatus in accordance with claim 9, characterized in that in the rest position the tool tip (124, 224) projects less than the support rollers
or support balls (118), but wherein the latter can be resiliently retracted into a
lower position than the tool tip (124, 224), the resiliency of the elastic elements
(110) of the support rollers (118) preferably being less than the resiliency of the
elastic element (132) of the tool tip (124, 224).
11. The apparatus in accordance with one of claims 7 to 10, characterized in that the tool tip (34, 124, 224) consists of diamond, boron nitride or a hard alloy.
12. The apparatus in accordance with one of claims 7 to 11, characterized in that the tool tip (34, 124, 224) is cone-shaped.
13. The apparatus in accordance with one of claims 7 to 12, characterized in that an adjustable support (16, 18, 20, 22, 126, 130, 226, 228) is associated with the
marking tool (34, 124, 224, 334), by means of which the position of the tool tip (34,
124, 224, 334) and/or the prestress of its restoring spring can be adjusted.
14. The apparatus in accordance with one of claims 7 to 13, wherein the tool tip is an
ink point for marking the surface of the workpiece.
1. Verfahren zum Markieren von Werkstücken auf Stanzmaschinen, wobei mittels des Stanzhubes
ein Markierwerkzeug (34, 124, 224, 334) gegen oder in die Oberfläche eines in seiner
Ebene verfahrbaren, tafelförmigen Werkstückes gedrückt wird, dadurch gekennzeichnet, daß das Markierwerkzeug über eine Werkzeugspitze (34, 124, 224, 334) verfügt, die nach
dem Drücken gegen oder in das Werkstück in einer Markierstellung gehalten wird, das
Werkstück bei niedergehaltener Werkzeugspitze (34, 124, 224, 334) entsprechend der
Kontur eines zu markierenden Zeichens verfahren wird und anschließend die Werkzeugspitze
(34, 124, 224) in ihre Ruhestellung zurückbewegt wird, wobei im Bedarfsfall der Markiervorgang
entsprechend der Anzahl gewünschter Zeichen nach einer geeigneten Bewegung der Lage
des Werkstückes wiederholt wird.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß in einer Stanzstempelhalterung der Stanzmaschine und/oder in einer Halterung am Tisch
Markierwerkzeuge (34, 124, 224, 334) angeordnet werden.
3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß wenigstens ein Teil des Stanzhubes von einem sich zwischen einem Tisch zur Auflagerung
des Werkstückes und der Stanzstempelhalterung erstreckenden vorgesehenen elastischen
Element (44; 132) aufgenommen wird.
4. Vorrichtung nach Anspruch 3, dadurch gekennzeichnet, daß wenigstens eine Markierung als Körnerpunkt gesetzt wird, wobei das Werkstück nach
dem Eindringen der Werkzeugspitze (124) in seiner vorgegebenen Lage bis zum Zurückbewegen
des Markierwerkzeuges gehalten wird.
5. Verfahren nach Anspruch 4, dadurch gekennzeichnet, daß die Werkzeugspitze (34, 124, 224) bei Körnerpunkten tiefer in das Werkstück eingedrückt
wird als bei einem Ritzvorgang und vorzugsweise beim Einbringen einer Körnung der
Federweg der Werkzeugspitze (34, 124, 224) aufgebraucht wird, bevor die tiefste Eindrückstellung
erreicht wird.
6. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß das Werkstück durch wenigstens eine Auflagerrolle oder -kugel (48; 118) im Bereich
des Tisches zur Auflagerung des Werkzeuges und/oder der Stanzstempelhalterung geführt
wird.
7. Vorrichtung zur Durchführung eines Verfahrens nach einem der vorhergehenden Ansprüche,
wobei die Vorrichtung aus wenigstens einem Markierwerkzeug (34, 124, 224, 334) und
wenigstens einem Gegenhalter auf der dem Markierwerkzeug gegenüberliegenden Seite
des Werkstückes besteht, wobei das Markierwerkzeug eine gegen die Rückstellkraft eines
elastischen Elements (44; 132) eindrückbare Werkzeugspitze (34, 124, 224, 334) aufweist
und an einer Stanzstempelhalterung oder einem Halter an dem Tisch einer Stanzmaschine
zur Auflagerung des Werkstückes festlegbar ist und der Gegenhalter auf der anderen
Werkstückseite festlegbar ist, dadurch gekennzeichnet, daß das wenigstens eine Markierwerkzeug (34, 124, 224, 334) mittels eines Stanzhubes
gegen oder in die Oberfläche eines tafelförmigen Werkstückes drückbar und während
einer Verlagerung des Werkstückes in seiner Ebene in seiner Markierstellung niederhaltbar
ist.
8. Vorrichtung nach Anspruch 7, dadurch gekennzeichnet, daß der Gegenhalter wenigstens eine drehbare Auflagerrolle oder -kugel zur beweglichen
Auflagerung des Werkstückes aufweist.
9. Vorrichtung nach Anspruch 7 oder 8, dadurch gekennzeichnet, daß das Markierwerkzeug (34, 124, 224, 334) neben der Werkzeugspitze (124, 224) drehbare
Auflagerrollen oder -kugeln (118) aufweist, die elastisch federnd gelagert sind, wobei
der Federweg der Auflagerrollen oder - kugeln (118) vorzugsweise größer als der Federweg
der Werkzeugspitze (34, 124, 224, 334) ist.
10. Vorrichtung nach Anspruch 9, dadurch gekennzeichnet, daß die Werkzeugspitze (124, 224) im Ruhezustand weniger weit hervorsteht als die Auflagerrollen
oder -kugeln (118), dieser aber in eine tiefere Lage einfederbar sind als die Werkzeugspitze
(124, 224), wobei die Federrate der elastischen Elemente (110) der Auflagerrollen
(118) vorzugsweise kleiner als die Federrate des elastischen Elements (132) der Werkzeugspitze
(124, 224) ist.
11. Vorrichtung nach einem der Ansprüche 7 bis 10, dadurch gekennzeichnet, daß die Werkzeugspitze (34, 124, 224) aus Diamant, Bornitrid oder Hartmetall besteht.
12. Vorrichtung nach einem der Ansprüche 8 bis 14, dadurch gekennzeichnet, daß die Werkzeugspitze (34; 124; 224) kegelförmig ist.
13. Vorrichtung nach einem der Ansprüche 7 bis 12, dadurch gekennzeichnet, daß dem Markierwerkzeug (34, 124, 224, 334) ein verstellbarer Träger (16, 18, 20, 22;
126, 130; 226, 228) zugeordnet ist, mit welchem die Lage der Werkzeugspitze (34, 124,
224) und/oder die Vorspannung von deren Rückstellfeder verstellbar ist.
14. Vorrichtung nach einem der Ansprüche 7 bis 13, dadurch gekennzeichnet, daß die Werkzeugspitze eine Schreibstelle zum Markieren der Oberfläche des Werkstückes
ist.
1. Procédé de marquage de pièces de travail sur des presses à poinçonner, selon lequel
un outil de marquage (34, 124, 224, 334) est poussé de force au moyen d'un coup de
poinçon sur ou dans la surface d'une pièce de travail en forme de feuille qui peut
être déplacée dans son plan,
caractérisé en ce que
l'outil de marquage a une pointe d'outil (34, 124, 224, 334) qui, après avoir été
poussée de force sur ou dans la pièce de travail, est maintenue dans une position
de marquage, la pièce de travail est déplacée dans son plan avec la pointe d'outil
(34, 124, 224, 334) maintenue abaissée conformément aux contours du symbole à marquer
ou à inscrire, puis la pointe d'outil (34, 124, 224, 334) est rétractée dans sa position
de repos, l'opération de marquage étant si nécessaire répétée conformément au nombre
de marquages à faire, après un mouvement approprié de la position de la pièce de travail.
2. Procédé selon la revendication 1,
caractérisé en ce que
les outils de marquage (34, 124, 224, 226, 334) sont disposés dans un porte-poinçon
de la presse à poinçonner et/ou dans un support de la table de support de pièce de
travail.
3. Procédé selon la revendication 1 ou 2,
caractérisé en ce qu'
au moins une partie du coup de poinçon est absorbée par un élément élastique (44,
132) qui s'étend entre une table de support de pièce de travail et le support d'outil
de poinçonnage.
4. Procédé selon la revendication 3,
caractérisé en ce qu'
au moins un marquage est défini comme une marque centrale, selon laquelle, après que
la pointe d'outil (34, 124, 224) a pénétré dans la pièce de travail, la pointe d'outil
est maintenue dans sa position prédéterminée jusqu'à ce que l'outil de marquage soit
rétracté.
5. Procédé selon la revendication 4,
caractérisé en ce qu'
en connexion avec des marques centrales, la pointe d'outil (34, 124, 224) est poussée
plus profondément dans la pièce de travail que pendant l'opération d'inscription,
et de préférence au cours de la réalisation d'une marque centrale, la course de ressort
de la pointe d'outil (34, 124, 224) atteint son maximum avant que la pénétration à
la profondeur la plus basse dans la pièce de travail ait été atteinte.
6. Procédé selon une des revendications précédentes,
caractérisé en ce que
la pièce de travail est guidée par au moins un galet de support ou bille de support
(48, 118) dans la zone de la table de support de pièce de travail et/ou du porte-poinçon.
7. Appareil pour mettre en oeuvre une méthode selon l'une des revendications précédentes,
l'appareil étant constitüé d'au moins un outil de marquage (34, 124, 224, 334) et
au moins un contre-support sur le côté de la pièce de travail opposé à l'outil de
marquage, l'outil de marquage ayant une pointe d'outil (34, 124, 224, 334) qui peut
être enfoncée contre la force de restauration d'un élément élastique (44, 132) et
peut être fixée en place sur un porte-poinçon ou le support de la table de support
de pièce de travail d'une presse à poinçonner, alors que le contre-support peut être
fixé en place sur l'autre côté de la pièce de travail,
caractérisé en ce que
l'outil d'usinage ou les outils d'usinage (34, 124, 224, 334) peut/peuvent être poussés
de force au moyen d'un coup de poinçon sur ou dans la surface d'une pièce de travail
en forme de feuille et disposés pour être maintenus abaissés dans leur position de
marquage pendant le déplacement de la pièce de travail dans son plan.
8. Appareil selon la revendication 7,
caractérisé en ce que
le contre-support a au moins un galet de support ou bille de support rotatif pour
le support mobile de la pièce de travail.
9. Appareil selon la revendication 7 ou 8,
caractérisé en ce que,
outre la pointe d'outil (34, 124, 224, 334), l'outil de marquage a des galets de support
ou billes de support rotatifs (118) qui sont montés de manière élastique sur ressort,
la course de ressort des galets de support ou billes de support (118) étant de préférence
plus grande que la course de ressort de la pointe d'outil (34, 124, 224, 334).
10. Appareil selon la revendication 9,
caractérisé en ce que
dans la position de repos, la pointe d'outil (124, 224) dépasse moins que les galets
de support ou billes de support (118), mais dans lequel ces derniers peuvent être
rétractés de manière résiliente dans une position plus basse que la pointe d'outil
(124, 224), la résilience des éléments élastiques (110) des galets de support (118)
étant de préférence inférieure à la résilience de l'élément élastique (132) de la
pointe d'outil (124, 224).
11. Appareil selon une des revendications 7 à 10,
caractérisé en ce que
la pointe d'outil (34, 124, 224) est constituée de diamant, de nitrure de bore ou
d'un alliage dur.
12. Appareil selon une des revendications 7 à 11,
caractérisé en ce que
la pointe d'outil (34, 124, 224) est en forme de cône.
13. Appareil selon l'une des revendications 7 à 12,
caractérisé en ce qu'
un support ajustable (16, 18, 20, 22, 126, 130, 226, 228) est associé avec l'outil
de marquage (34, 124, 224, 334), au moyen duquel la position de la pointe d'outil
(24, 124, 224, 334) et/ou la tension initiale de son ressort de restauration peut
être ajustée.
14. Appareil selon l'une des revendications 7 à 13,
caractérisé en ce que
la pointe d'outil est une pointe encreuse pour marquer la surface de la pièce de travail.