[0001] The apparatus relates to an apparatus for bending sheet material, including a die
having at least one longitudinally extending groove and a stamp having at least one
linear contact zone for contacting the sheet material to be bent, the die and the
stamp being movable towards each other.
[0002] In the known apparatus of this sort regularly a different die has to be mounted in
order to accommodate the groove extending in the die as to its shape and size in accordance
with the kind and the thickness of sheet material to be bent and the desired shape
to be bent. Exchanging the die, however, is relatively time consuming.
[0003] The invention has the object of providing an apparatus of the kind indicated hereinabove
in which this drawback has been overcome in a simple but nevertheless efficient manner.
[0004] For this purpose the apparatus according to the invention is characterized in that
the die includes at least one reciprocable die part adapted to define the size and
the shape of the groove.
[0005] In this manner it is possible to adjust the size and the shape of the groove in the
die simply by moving the reciprocable die part so that accommodating the groove in
accordance with the kind and thickness of the material to be bent and the desired
shape to be bent can take place very quickly.
[0006] In a favourable embodiment of the invention the die includes two die parts disposed
on either side of a vertical centre plane in which the contact zone of the stamp is
situated, each of said die parts being reciprocable relative to said vertical centre
plane, and preferably both die parts are simultaneously reciprocable with equal speed.
[0007] An other serious draw back of the known apparatus is that during bending of the sheet
material the surface thereof slides along the groove defining edges of the die whereby
a strong wear of the die is effected, while the accuracy of the dimensions of the
shape to be bent is reduced. Furthermore, the sliding of the surface of the sheet
material to be bent along the said edges of the die requires large forces for the
deformation of the sheet material, while furthermore the surface of the sheet material
may be easily damaged.
[0008] In a preferred embodiment of the apparatus of the invention this draw back is overcome
in that the (each) die part starting from a position in which the stamp has its contact
zone just contacting the sheet material to be bent, in dependency of the relative
movement of the stamp and the die, are movable relative to the contact zone of the
stamp in such a manner that the distance between the contact zone of the stamp and
the linear contact zone of the (each) die part with the sheet material to be bent
remains substantially constant during bending.
[0009] Thereby it is reached that the surface of the sheet material to be bent during bending
does not substantially slide along the or each die part so that no wear of the die
parts takes place and the surface of the sheet material cannot be damaged. Furthermore,
the accuracy of the dimensions will be maintained during the bending.
[0010] In a favourable embodiment of the invention the (each) die part is movable to a position
in which the groove of the die is fully closed and the stamp includes at least one
reciprocable stamp part adapted to define the size and the shape of a groove in the
stamp.
[0011] In this manner it is reached that the die may be used as a stamp and the stamp as
a die, so that for bending of a Z-profile, for example, there is no necessity of turning
the sheet material.
[0012] .In this manner such profiles requiring bending to be done in two opposite directions
may be formed without turning the sheet material, which considerably increases the
accuracy of the obtained profile.
[0013] i In this embodiment in accordance with the invention it is to be preferred that
the (each) stamp part starting from a position in which the die brought into the closed
position has a contact zone just contacting the sheet material to be bent, in dependency
of the relative movement of the stamp and the die, is movable relative to the contact
zone of the die in such a manner that the distance between the contact zone of the
die and the contact zone of the (each) stamp part with the sheet material to be bent
remains substantially constant during bending.
[0014] In the apparatus of the kind mentioned hereinabove the turning of the sheet material
to be bent also may be avoided in that the die and the stamp each include a pivotably
supported carrier, said carriers each carrying at least a die part and a stamp part
which may be positioned into a working position by pivoting of the carrier.
[0015] In a favourable embodiment of the apparatus of the invention the stamp is mounted
for pivoting about an axis lying in the vertical centre plane and has at least one
longitudinal end coupled to an operating means for pivoting the stamp, said stamp
being pivotable through such an angle that with the stamp parts moved from each other
the contact zone of at least one stamp part may be positioned into the vertical centre
plane.
[0016] Thereby the one stamp part of which the contact zone is pivoted into the vertical
centre plane, may be used as a stamp so as to enable the bending of certain profiles,
wherein a part of the already bent profile is received into the groove between the
stamp parts.
[0017] In an embodiment of the invention wherein a base is provided having a support surface
for the sheet material to be bent, the stamp and the die according to the invention
are tiltable relative to the base about a longitudinal axis which substantially coincides
with the contact zone between the die part disposed at the side of the support surface
and the sheet material to be bent.
[0018] Thereby it is reached that the part of the sheet material to be bent, which during
bending is disposed on the support surface, remains supported on this support surface.
[0019] In accordance with the invention in an apparatus including an abutment for the sheet
material to be bent it is to be preferred that the abutment is supported by a frame
which is pivotably connected with one of said die parts about a pivoting axis which
substantially coincides with the contact zone between said one die part and the sheet
material to be bent.
[0020] In this case it is advantageous that two abutment jaws are provided in which the
respective end edge of the sheet material to be bent may be clamped.
[0021] In this manner an apparatus is obtained which is capable of keeping the sheet material
to be bent during the whole process of the formation positioned in the right manner
so as to make possible particularly exact dimensions.
[0022] In accordance with the invention the frame includes a support beam which is parallel
to the pivoting axis, and two arms are mounted on the support beam for sliding motion
in parallel to said pivoting axis, each arm at its end carrying an abutment jaw, and
the support beam is slidable transversely of said pivoting axis.
[0023] In this case preferably the frame is connected with a base of the apparatus by an
actuating means which effects the pivotal motion of the frame in dependency of the
relative movement of the stamp and the die. Thereby it is reached that the pivoting
movement of the frame in accordance with the movement of the stamp relative to the
die may be controlled whereby when using a suitable control unit the complete bending
process for obtaining a desired profile may be performed completely automatically.
[0024] When for bending certain profiles the sheet material to be bent should be turned
in a horizontal plane, the frame in a favourable embodiment includes a rotary platform
substantially disposed in the centre for retaining the sheet material to be bent thereon.
[0025] ) The costs of manufactoring the apparatus of the invention may be kept low, when
the movable die parts and the movable stamp parts, if any, are similar to each other.
[0026] The invention will hereinafter be explained by reference to the drawing schematically
illustrating some embo-5 diments.
Fig. 1 -is a schematically represented perspective view of a first embodiment of the
apparatus of the invention.
Fig. 2 is a schematically partially represented side view of a second embodiment of
the apparatus of the invention, wherein the movable die parts and the stamps are represented
in two positions.
Fig. 3 is a partially represented section of a third embodiment of the apparatus of
the invention, representing the stamp and the die only.
Fig. 4 is a partly represented schematical side view of the die of fig. 3.
Fig. 5 is a part of the lower side of the die of fig. 3 represented in side view.
Fig. 6 is a schematically represented side view of a fourth embodiment of the apparatus
of the invention.
Fig. 7 is a schematically represented side view of a pivotally mounted stamp of the
invention.
Fig. 8 is a side view, partly in section, of an embodiment of the die of the apparatus
of the invention including a pivotal abutment.
Fig. 9 is a view according to the line IX-IX of fig. 8, partly in section.
Fig. 10 is a view according to the line X-X of fig. 8.
Fig. 11 is a schematically represented side view of an alternative embodiment of the
apparatus of the invention.
[0027] In fig. 1 a first embodiment of the apparatus for bending sheet material is designated
with the reference number 1, and includes a stamp 3 carried by an upper beam 2, the
stamp being downwardly movable by hydraulic cylinders 4 for bending the sheet material.
The piston position of the cylinders 4 is determined by potentiometers 5 disposed
at either side of the upper beam 2 and of which only one is shown in fig. l.The upper
beam 2 for that purpose is connected by a wire 6 with the runners of the potentiometers
5. The electric signals delivered by the runners of the potentiometers 5 and corresponding
with the position of the upper beam 2 can be used by a suitable electronic control
unit for controlling the hydraulic cylinders 4.
[0028] The apparatus 1 is further provided with a die 7 including two movable die parts
8. The die parts 8 which define a groove 9 between them, at their side remote from
the groove 9 each are provided with a saw teeth-like side cooperating with a complementary
saw teeth-like side of a slidable operating rod 10 as designated with 11. By the sliding
of the operating rod the die parts 8 can be reciprocated so that the size of the groove
9 in dependency of the kind and thickness of the sheet material to be bent and the
profile to be shaped can be adjusted. Both die parts 8 are disposed at either sides
of a vertical centre plane designated by a broken line 12, a linear contact zone 13
of the stamp 3 being disposed in said plane, the stamp 3 with said contact zone 13
contacting the sheet material to be bent. Both die parts are simultaneously reciprocable
relative to the said vertical centre plane with equal speed.
[0029] Fig. 2 schematically represents a side view of a second embodiment of the apparatus
for bending the sheet material and mainly shows a die 14 and a stamp 15. The die 14
consists of an elongate beam of U-shaped cross section. The stamp 15 is of equal length
as the die 14 and in this case is provided with a tip 16 of V-shaped cross section
forming a linear contact zone 17, with which the stamp 15 contacts the sheet material
18 to be bent.
[0030] In fig. 2 two different working positions of the apparatus have been drawn, a broken
line designating the starting position and a drawn line the end position. The die
14 in this embodiment is provided with two die parts 18 which are pivotally mounted
in the die 14 and which define a groove 19 in the die. By pivoting of the die parts
18 the size and the shape of the groove 19 can be defined. Furthermore it is possible
to control the pivoting motion of the die parts 18 in dependency of the movement of
the stamp 15 so as to realize important advantages. The pivoting motion of the die
parts 18 can be obtained in various manners, for example by supporting the die parts
18 on a series of support blocks 20with interposition of a cylindrical cavity bearing
21, while the support blocks at the lower side each are provided with a surface inclined
in the direction perpendicular to the plane of the drawing and cooperating with an
inclined surface formed in the fixed die part 22. By movement of the support blocks
12 perpendicular to the plane of the drawing with a suitabe operating means the die
parts 18 may be pivoted upwardly and downwardly.
[0031] The control unit may control the pivoting motion of each die part 18 starting from
a position designated by the broken line, in which the stamp 15 with its contact zones
17 just contacts the sheet material 23 to be bent, in such manner relative to the
contact zone 17 of the stamp 15 that the distance between this contact zone 17 and
the linear contact zone 24 of each die part 18 with the sheet material 23 to be bent
remains substantially constant during bending. The movement of the stamp 15 may be
determined with potentiometers in the same manner as hereinabove described.
[0032] Hereby it is reached that the sheet material will not substantially slide over the
contact zones 24 of the die parts 18 during bending whereby wear of the die parts
18 and damage to the sheet material is avoided. Furthermore the desired profile can
be shaped in this manner with high accuracy.
[0033] Under circumstances, for example when a profile to be shaped is already partially
bent, it is possible to cause the die parts 18 to perform relatively different pivoting
motions, in which case each die part 18, of course, requires a separate operating
mechanism.
[0034] Fig. 3 schematically represents a section of an embodiment of the apparatus of the
invention for bending sheet material and mainly shows a die 25 and a stamp 26. A single
line 29 designates the connection between an upper beam 27 and a lower beam 28, which
connection, of course, will always be present. The die 26 is provided with a die carrying
member 30 supported by the lower beam 27 and two movable die parts 31 disposed at
either side of the vertical centre plane designated by a broken line 32.
[0035] For each movable die part 30 the die carrying member 30 includes a longitudinally
extending bearing cavity 33 in which the respective die part 31 is pivotably supported
with an extension 34 of partly circular section. Furthermore each movable die part
31 by a ball-joint 35 is connected with the ends of a plurality of arms 36 spaced
throughout the length of the die 25. The arms have their other ends also connected
by a ball-joint 37 with an operating rod 38 (see also fig. 4), which in the represented
embodiment is common to both die parts 3l. The operating rod is longitudinally slidably
mounted in the die carrying member 30 and at one end coupled to an operating means
in a manner not illustrated. By the operating means sliding the operating rod 38 the
die parts 31 may be pivoted back and forth so that the size and the shape of the groove
39 defined between the die parts 31 may be adjusted. Thereby the die parts 31 may
be positioned with their ends 40 against each other so that the groove 39 is fully
closed. Thereby the die 25 may also be used as a stamp.
[0036] In the apparatus of fig. 3 the stamp 27 is mainly embodied in the same manner as
the die 25 and is provided with a stamp carrying member 41 connected with the upper
beam 28 and having two longitudinally extending bearing cavities 42 in which movable
stamp parts 43 may be pivotably supported with an extension 44 of partly circular
section. The pivoting motion of the stamp parts 43 is effected in a similar way by
arms 45 and an operating rod 46. By the stamp parts 43 being pivoted into the open
position a groove may be defined in the stamp 26 so that the stamp 26 may function
as a die.
[0037] In this manner it is reached that with the apparatus illustrated in fig. 3 sheet
material can be bent in two directions without the necessity of turning the sheet
material, whereby the use of the apparatus is considerably facilitated and the accuracy
of the profile to be shaped is increased.
[0038] The pivoting motion of the movable die parts 31 and the movable stamp parts 43, respectively,
can be controlled by a suitable control unit in dependency of the movement of the
stamp 26 relative to the die 25 starting from a position in i which the stamp 26 respectively
the die 25 with the contact zones just contacts the sheet material to be bent in such
manner relative to the contact zone of the stamp 26 respectively the die 25 that the
distance between the various contact zones remains substantially constant during bending.
[0039] It is known that in an apparatus for bending sheet material, in particular with a
great length of the sheet material to be bent, the work piece from the centre thereof
towards the ends is bent through an ever increasing angle by deformation or deflection
of the stamp and the die. This deformation or deflection can be compensated, for example
by cambering the die, that is making it somewhat round intentionally. In the apparatus
of fig. 3 and 4 the cambering is relatively simple.
[0040] The die carrying member 30 at the lower side is provided with a channel 47 of inverted
U-shaped section, in which the upper end of the lower beam 27 is received. In this
upper end are arranged bores 48 spaced regularly throughout the length and designated
in fig. 3 by a dotted line. In the side walls 49 of the channel 47 slots 50 are formed
at each bore 48 as may be seen in the fig. 3 and 5. In each bore 48 a shaft 51 is
fitted and this shaft 51 at both ends carries excentric stub axles 52 projecting into
the slots 50. The stub axles 52 are pivotably journaled in slide blocks 53 mounted
in the slots 50. On one of the stub axles 52 in a manner not illustrated a drivable
operating arm 54 is secured for rotating the respective shaft 51. When the operating
arms 54 are pivoted, the shaft 51 will turn whereby the die 25 locally as a result
of the excentric stub axles will somewhat move downwardly or upwardly. Thereby it
is possible to camber the die 25 in a relatively simple manner.
[0041] Fig. 6 represents an alternative embodiment of the apparatus which is embodied in
such manner that the sheet material to be bent also can be bent in two directions
without turning of the sheet material. The apparatus of fig. 6 for that purpose is
provided with a die 55 having a rotatably supported carrier 56 and a stamp 57 having
a rotatably supported carrier 58. The pivoting motion of the carrier 56, 58 is effected
by an associated operating means 59, 60 which by an arm 61 is connected with the respective
carrier. Each carrier 56, 58 includes a die part 62 and a stamp part 63 which may
be positioned into a working position by the rotation of the respective carrier. The
radial distances of the pivoting axis of the carrier 56, 58 to the contact zone of
the stamp part 63 respectively the support surface of the die part 62 preferably are
equal so that the heigth of the not illustrated support surface supporting the sheet
material does not have to be adjustable. The angular distance between the die part
62 and the stalmp part 63 is larger than 90° as appears from fig.
6.
[0042] It is noted that the above-described embodiment of the die carrying member 30 and
the lower beam 27 with the shafts 51 mounted therein for cambering the die also can
be used in the embodiment of the apparatus of fig. 6.
[0043] Fig. 7 represents a side view of the stamp 26. The stamp 26 by a cylindrical bearing
64 is connected with the upper beam 28 so that the stamp 26 is pivotal about the axis
65 of this cylindrical bearing 64, which axis is disposed in the vertical centre plane
32. At both ends the stamp 26 is provided with a coupling plate 66 through which the
stamp 26 is coupled with an operating arm 67 and for that purpose a slot 68 is disposed
in the coupling plate 66 and traversed by a connecting bolt 69. The other end of the
operating arm 67 is coupled with an actuating rod 70 which is common to both operating
arms.
[0044] Thereby the stamp 26 from the normal position shown in the left part of fig. 7, in
which the contact zone 71 of the stamp parts 43 positioned in the closed position
is disposed in the vertical centre plane 32, may be pivoted to the position shown
in the right parts of fig. 7, in which the contact zone 72 of one of the stamp parts
43 positioned to the fully open position is disposed in the vertical centre plane.
The stamp may also be pivoted to the right in the drawing so that the contact zone
of the other stamp part 43 will be positioned in the vertical centre plane. In this
position of the stamp 26 only one stamp part 43 is used as a stamp whereby it is possible
to bend profiles in such manner that part of the sheet material to be bent may be
received into the groove 73 between both stamp parts 43.
[0045] Fig. 8 represents a section, partly in side view, of the die 25, in which an adjustable
abutment is provided which as a whole is designated with 74. As also appears from
fig. 9 and 10 the abutment 74 includes two abutment jaws 75 in which an end edge of
the sheet material to be bent can be clamped. For this purpose the one jaw part 76
of both abutment jaws 75 in a manner not illustrated may be operated by a rod 77.
The abutment jaws 75 are disposed each on the one end of an arm 78, which arms 78
are mounted on slide blocks 79 which are slidably ranged on a support beam 80. The
support beam 80 is part of a frame 81 which is pivotably connected with this die part
31 about a pivoting axis substantially coinciding with the contact zone 82 between
the one die part 31 and the sheet material to be bent. The support beam 80 extends
in parallel to the pivoting axis designated with 83 in fig. 10 so that the arms 78
are slidable in parallel to this pivoting axis across the support beam 80 for accommodating
the width of the sheet material to be bent.
[0046] The frame 81 is provided with two arms 84, of which the first ends are pivotably
connected with the said die part 3J;. On the other ends of the arms 84 a box beam
85 is secured, which extends beyond the one arm 84 and supports a drive motor 87 on
this extending end 86. On the box beam 85 two boxes 88 are mounted and in each of
them a screw spindle 89 is rotatably journaled. Each box 88 carries a guide rod 90
in parallel to the screw spindle 89. The support beam 80 at both its ends is provided
with an extension 91 in which a threaded bore 92 is formed cooperating with the respective
screw spindle 89, and with a guide element 93 cooperating with the respective guide
rod 90.
[0047] The screw spindles 89 with their one end project into the box beam 85 and at this
end are provided with toothed-belt pulleys 94, through which the screw spindles 89
are coupled to the drive motor 87 by toothed belts 95. In this manner the support
beam 80 by the actuation of the motor 87 can be moved transversely of the pivoting
axis 83 so that the distance between the abutment jaws 75 and the die 25 is adjustable
in accordance with the desired location of the shape to be bent into the sheet material.
[0048] The frame 81 by an actuating mechanism 97 is connected with the lower end of the
lower beam 27 or a base (not illustrated) of the apparatus, which carries this lower
beam 27. In the embodiment represented in fig. 8-10 this actuating mechanism 97 consists
of two not visible screw spindles which are rotatably journaled in boxes 97 which
are coupled to the boxes 88. The screw spindles are drivable by a motor 98 through
not visible toothed belts running in a protective box 99. In this manner the pivoting
motion of the frame 81 may be effected.
[0049] The pivoting motion in this case is dependent of the relative movement of the stamp
26 and the die 25. The movement of the stamp 26, for example, can be determined in
the manner described in connection with fig. 1 with a potentiometer which is coupled
to a control unit. The control unit controls the motor 98 in such manner that the
pivoting movement of the frame 81 exactly follows the movement of the sheet material
during bending. When the desired shape has been bent into the sheet material, the
control unit subsequently may control the motor 87 in order to move the sheet material
for bending the sheet material in a next desired location. Since the abutments jaws
75 may continuously retain the end edge of the sheet material, a profile may be fabricated
from the sheet material with very high accuracy. Furthermore the described apparatus
thereby is very suitable for completely automatically bending desired profiles under
control of a suitable computer.
[0050] As appears from fig. 10, the frame 81 furthermore includes a rotary platform 100
which is disposed nearly in the centre and which is movable upwardly and downwardly
and which is capable of rotating the sheet material in a horizontal plane. For that
purpose the sheet material with the abutment jaws 75 is positioned over the rotary
platform 100, whereafter the sheet material is retained thereon. This may take place
for example by applying a vacuum to openings formed in the rotary platform of by a
rotatably mounted clamping means pressing the sheet material on the rotatary platform
100. After the rotation of the sheet material the end edge of the sheet material turned
towards the abutment jaws 75 may be grasped whereafter the subsequent bending operations
may be carried out.
[0051] Furthermore it is possible to provide the other die part 31 with an abutment 74 supported
by a frame 81 which in the manner described above is pivotably connected with this
die part 31.
[0052] Fig. 11 represents an alternative for the abutment 74 supported by the pivotable
frame 81.In fig. 9 the apparatus is drawn in thick lines in a starting position, while
the apparatus is represented in thin lines in an end position in which the sheet material
(not illustrated) is bent over 90° and the stamp 101 and the die 102 have been tilted
over an angle of 45°. The die 102 which in the same manner as in the apparatus of
fig. 1 is provided with movable die parts 8 and the stamp 101 are mounted in one or
more C-shaped frames 103 which at the upper side are connected together by a plate
104 and at the lower side by a die table 105. The die table 105 is rotatably supported
by a base 106, the axis of rotation substantially coinciding with the contact zone
107 of the right die part 8.
[0053] The pivoting motion of the C-shaped frames 103 with the stamp 101 and the die 102
are effected by a hydraulic cylinder-piston assembly 108 which is pivotably connected
with one of the frames 103 and the base 106. The pivoting motion is dependent of the
movement of the stamp 101, which as in the embodiment of fig. 1 is determined by a
potentiometer 5.
[0054] In the embodiment of the apparatus illustrated in fig. 11 the sheet material during
the whole bending operation is supported by a table 109.
[0055] It is noted that the drive of various members by screw spindles as mentioned hereinabove
of course can also be effected by other drive means like hydraulic cylinder-piston
assemblies, for example.
[0056] The invention is not limited to the embodiments described hereinabove which may be
modified in various manners within the scope of the invention.
[0057] The embodiment of the apparatus represented in fig. 6 may also be provided with an
abutment 74 supported by the pivotable frame 81 as illustrated in the fig. 8-10. For
this purpose at either side of the die 55, for example, a support is mounted and the
arms 84 are pivotably connected therewith. The pivoting axis of the frame 81 thereby
may be adjusted in the area situated substantially between the contact zone of the
stamp part 63 positioned in the working position and the contact zones of the die
part 62 with the die part positioned in the working position.
[0058] Since the sheet material in the apparatus of fig. 6 during bending will slide, the
abutment jaws 65 will have to follow this sliding motion. For this purpose the abutment
jaws 75 may be mounted so as to be slidable against the effect of a spring. As an
alternative the motor 87 may be controlled by the control unit for moving the abutment
jaws 75 in dependency of the relative movement of the stamp 57 and the die 55. This
movement in a manner as described hereinabove may be determined by a potentiometer.
1. Apparatus for bending sheet material, including a die having at least one longitudinally
extending groove and a stamp having at least one linear contact zone for contacting
the sheet material to be bent, the die and the stamp being movable towards each other,
characterized in that the die includes at least one reciprocable die part adapted
to define the size and the shape of the groove.
2. Apparatus according to claim 1, characterized in that the die includes two die
parts disposed on either side of a vertical centre plane in which the contact zone
of the stamp is situated, each of said die parts being reciprocable relative to said
vertical centre plane.
3. Apparatus according to claim 2, characterized in that both die parts are simultaneously
reciprocable with equal speed.
4. Apparatus according to anyone of the preceding claims, characterized in that the
(each) die part starting from a position in which the stamp has its contact zone just
contacting the sheet material to be bent, in dependency of the relative movement of
the stamp and the die, are movable relative to the contact zone of the stamp in such
a manner that the distance between the contact zone of the stamp and the linear contact
zone of the (each) die part with the sheet material to be bent remains substantially
constant during bending.
5. Apparatus according to anyone of the preceding claims, characterized in that the
(each) die part is movable to a position in which the groove of the die is fully closed
and the stamp includes at least one reciprocable stamp part adapted to define the
size and the shape of a groove in the stamp.
6. Apparatus according to claim 5, characterized in that the stamp includes two stamp
parts situated on either side of the vertical centre plane, each stamp part being
reciprocable relative to said vertical centre plane.
7. Apparatus according to claim 5, characterized in that both stamp parts are simultaneously
movable with equal speed.
8. Apparatus according to anyone of the claims 5-7, characterized in that the (each)
stamp part starting from a position in which the die brought into the closed position
has a contact zone just contacting the sheet material to be bent, in dependency of
the relative movement of the stamp and the die, is movable relative to the contact
zone of the die in such a manner that the distance between the contact zone of the
die and the contact zone of the (each) stamp part with the sheet material to be bent
remains substantially constant during bending.
9. Apparatus according to anyone of the preceding claims, characterized in that the
die is provided with a die carrying member supported on a lower beam and including
for each movable die part a longitudinally extending bearing cavity in which the respective
die part is pivotably supported with an extension of partly circular section.
10. Apparatus according to claim 9, characterized in that each movable die part is
pivotably connected with the ends of arms spaced throughout the length of the die
and having their other ends pivotably connected with an operating rod common to the
movable die parts, said operating rod being longitudinally slidably mounted in the
die carrying member and having one end coupled to an operating means.
11. Apparatus according to anyone of the claims 5-10, characterized in that the stamp
is provided with a stamp carrying member secured to the upper beam and having for
each movable stamp part a longitudinally extending bearing cavity in which the respective
stamp part is pivotably ? supported with an extension of partly circular section.
12. Apparatus according to claim 11, characterized in that each pivotal stamp part
is connected with the ends of arms spaced throughout the length of the stamp and having
their other ends pivotably connected with an opera- ) ting rod common to the movable
stamp parts, said operating rod being longitudinally slidably mounted in the stamp
carrying member and having one end coupled to an operating means.
13. Aggaratus according to anyone of the claims 6-12, characterized in that the stamp
is mounted for pivoting about an axis lying in the vertical centre plane and has at
least one longitudinal end coupled to an operating means for pivoting the stamp, said
stamp being pivotable through such an angle that with the stamp parts moved from each
other the contact zone of at least one stamp part may be positioned into the vertical
centre plane.
14. Apparatus according to anyone of the claims 9-13, characterized in that the die
carrying member at the lower side is provided with a channel of inverted U-shaped
section, the upper end of the lower beam being received into the channel and including
longitudinally spaced bores, the adjacent side-walls of the channel being provided
with slots at each bore, and a shaft is fitted in each bore, said shaft at both ends
carrying excentric stub axles projecting into the slots and being pivotably journaled
in slide blocks mounted in the slots, and a drivable operating arm is secured on one
of the stub axles for rotating the respective shaft.
15. Apparatus according to anyone of the preceding claims including a base having
a support surface for the sheet material to be bent, characterized in that the stamp
and the die are tiltable relative to the base about a longitudinal axis which substantially
coincides with the contact zone between the die part disposed at the side of the support
surface and the sheet material to be bent.
16. Apparatus according to claim 15, characterized in that the stamp and the die are
mounted on one or more C-shaped frames tiltable about the longitudinal axis, at least
one of which is connected with the base by an actuating means.
17. Apparatus according to anyone of the preceding claims 1-14 including an abutment
for the sheet material to be bent, characterized in that the abutment is supported
by a frame which is pivotably connected with one of said die parts about a pivoting
axis which substantially coincides with the contact zone between said one die part
and the sheet material to be bent.
18. Apparatus according to claim 17, characterized in that two abutment jaws are provided
in which the respective end edge of the sheet material to be bent may be clamped.
19. Aparatus according to claim 18, characterized in that the frame includes a support
beam which is parallel to the pivoting axis, and two arms are mounted on the support
beam for sliding motion in parallel to said pivoting axis, each arm at its end carrying
an abutment jaw, and the support beam is slidable transversely of said pivoting axis.
20. Apparatus according to claim 19, characterized in that the frame carries two guide
rods extending transversely of the pivoting axis and guiding the respective ends of
the support beam.
21. Apparatus according to claim 20,characterized in that the frame is provided with
two drivable screw spindles extending in parallel to the guide rods and each cooperating
with a threaded bore in the respective end of the support beam.
22. Apparatus according to claim 21, characterized in that the frame includes a box
beam which at both ends is pivotably connected with the die part about the pivoting
axis by an arm, said box beam carrying a drive motor which drives the screw spindles
through toothed belts extending in the box beam.
23. Apparatus according to claim 21 or 22, characterized in that the screw spindles
each are rotatably journaled in a box.
24. Apparatus according to anyone of the claims 17-23, characterized in that the frame
is connected with a base of the apparatus by an actuating means which effects the
pivotal motion of the frame in dependency of the relative movement of the stamp and
the die.
25. Apparatus according to anyone of the claims 17-24, characterized in that the frame
is provided with a platform disposed substantially centrally and movable upwardly
and downwardly, said platform being adapted to thereon retain the sheet material to
be bent.
26. Apparatus according to anyone of the claims 17-25, characterized in that both
die parts pivotably support a frame including an abutment in accordance with one of
the claims 17-25.
27. Apparatus according to anyone of the preceding claims 2-26, characterized in that
the movable die parts and the movable stamp parts, if any, are similar to each other.
28. Apparatus for bending sheet material, including a die having at least one longitudinally
extending groove and a stamp having at least one linear contact zone contacting the
sheet material to be bent, the die and the stamp being movable towards each other,
characterized in that the die and the stamp each include a pivotably supported carrier,
said carriers each carrying at least a die part and a stamp part which may be positioned
into a working position by pivoting of the carrier.
29. Apparatus according to claim 28, characterized in that the radial distances of
the pivoting axis of the carriers to the contact zone of the stamp part respectively
the support surface of the die part are equal.
30. Apparatus according to claim 28 or 29, characterized in that the angular distance
between the stamp part and the die part is larger than 90°.
31. Apparatus according to claim 28, 29 or 30, characterized in that the die is provided
with a die carrying member which at the lower side is provided with a channel of inverted
U-shaped section the upper end of the lower beam being received into the channel and
including longitundinally spaced bores, the adjacent side-walls of the channel being
provided with slots at each bore, and a shaft is fitted in each bore, said shaft at
both ends carrying excentric stub axles projecting into the slots and being pivotably
journaled in slide blocks mounted in the slots, and a drivable operating arm is secured
on one of the stub axles for pivoting the respective shaft.
32. Apparatus according to anyone of the claims 28-31 including an abutment for the
sheet material to be bent, characterized in that the abutment is supported by a frame
which is pivotably connected with the apparatus, and the pivoting axis is adjustable
within the area situated substantially between the contact zone of the stamp part
of the one carrier when the stamp part is in the working position and the contact
zones of the die part of this carrier when the die part is in the working position,
the pivoting axis extending in parallel to the respective contact zones.
33. Apparatus according to claim 32, characterized in that the abutment against the
effect of a spring is slidable transversely of the pivoting axis of the frame.
34. Apparatus according to claim 32, characterized in that the abutment is slidable
transversely of the pivoting axis of the frame in dependency of the relative movement
of the stamp and the die.
35. Apparatus of claim 32, 33 or 34, characterized in that the abutment and the frame
are embodied as specified in one of the claims 18-25.