Note: Descriptions are shown in the official language in which they were submitted.
f~d 2 8
Grip~er for a conveying device for conveying single-
sheet or multiple-sheet Printed ~roducts
The present invention relates to a gripper for
a conveying device for conveying single-sheet or
multiple-sheet printed products, such as newspapers,
magazines and parts thereof, according to Claim 1.
Preferred further developments of the gripper
according to the invention form the subject-matter of
the dependent claims.
Exemplary embodiments of the subject-matter of
the invention are explained in detail below with refer-
ence to the purely diagrammatical drawing, in which:
Figure 1 shows a lateral view of a conveying device
for carrying printed products away in the
transfer region,
Figures 2 and 3 show a gripper of the conveying device
according to Figure 1 in the open and closed
states respectively,~0 Figure 4 shows a plan view of a gripper according to
Figures 2 and 3, partially in section along
the line IV-IV in Figure 5,
Figure 5 shows a section along the line V-V in Figure
4,
Figure 6 shows a lateral view of the gripper in the
direction of the arrow A in Figure 4,
Figures 7 and 8 show a gripper in an illustration
corresponding to Figures 2 and 3 in a
different pivot position in the open and
closed states respectively, and
Figures 9-12 show different conveying devices with a
different arrangement of the grippers.
Figure 1 shows the transfer region of a convey-
ing device 1 which has grippers 2 which are fastened at
regular intervals to a continuous link chain (not
shown) guided in a chain duct 3. Said link chain is
guided over a deflection wheel 4 in the transfer
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region. The grippers 2 move in the direction of the
arrow B along a closed circulation path.
Each gripper 2, whose construction and mode of
functioning will be described in detail with reference
to Figures 2-6, has a first gripper part 5 and a second
gripper part 6. In the opened state of the grippers 2,
the two gripper parts 5, 6 define a gripper opening 7
which faces towards the rear relative to the conveying
direction B in the conveying device according to Figure
10 1.
Each gripper 2 grips a printed product 8 at its
leading edge 8a (fold edge). The printed products 8 are
fed in the direction of the arrow C by a belt conveyor
9 in a manner known per se in an imbricated formation
S. As can be seen in Figure 1, each printed product
lies in this imbricated formation S on the preceding
printed product 8. A pressure roller 10 lies loosely on
the printed products 8 fed by the belt conveyor 9.
The construction of the grippers 2 is now
explained in detail below with reference to Figures
2-4.
The second gripper part 6 is of integral con-
struction with a bearing part 11 which is mounted so as
to be pivotable on a shaft 12 whose longitudinal axis
is denoted by 12'. As emerges, in particular, from
Figures 5 and 6, this shaft 12 is provided with longi-
tudinal grooYes. The shaft 12 is mounted rotatably in a
holder 13 which is U-shaped in cross-section and is
fastened to a link chain 13 which is guided in the
guide duct already mentioned. This link chain 14 is of
known design and is very similar to the link chain such
as is described, for example, in DE-A-2,629,528 or the
corresponding document US-A-4,294,345. Figure 4 shows
in each case half of a link chain 14 of a lighter con-
struction and of a link chain 14' of heavierconstruction.
The first gripper part 5 is likewise of
integral construction with a bearing part 15 which is
arranged inside the holder 13 and i8 mounted so as to
be pivotable on the shaft 12. The longitudinal axis 12'
of this shaft 12 thus forms the common pivot axis for
the bearing parts 11, 15 and thus for the gripper parts
6 and 5. A resting part 16 is connected to the shaft 12
so as to' be fixed against rotation, specifically via a
spreader ring 17 which is integral with the resting
part 16 and engages with projections in the longitu-
dinal grooves of the shaft 12 (Figure 5). Supported on
the resting part 16 is a compression spring 18 which is
supported at the other end on a journal 19 which is
inserted in the bearing part 15 for the first gripper
part 5. As can readily be seen in Figure 5, a rotary
movement of the shaft 12 in an anticlockwise rotary
movement, i.e. in the direction of the arrow F, is
transmitted via the compression spring 18 to the bear-
ing part 15 and thus the first gripper part 5, which
results in pivoting of the first gripper part 5 from
the open position shown in Figures 2 and 5 into the
clamping position illustrated in Figure 3.
Connected to the shaft 12 so as to be fixed
against rotation is a closing lever 20 whose pivot axis
20' coincides with the longitudinal axis; 12' of the
shaft 12. At its free end, the closing lever 20 bears a
follower roller 21 which is freely rotatable about the
axis of rotation 21'. The closing lever 20 is provided
with a projecting blocking arm 22. The closing lever 20
is now arranged in such a way that the connecting line
denoted by 23 between the pivot axi~3 20' and the axis
of rotation 21' of the follower roller 21 runs trans-
versely to the direction of movement B or B' of the
grippers 2 (Figure 2). Furthermore, together with the
plane D which is formed by the flat first gripper part
5, this connecting line 23 forms an angle ~ which i~
less than 90~ (Figure 2). This is important so that the
first gripper part 5 can be moved from the open posi-
tion into the clamping position during a movement in
both directions of movement B and B'.
For blocking the first gripper part 5 in its
clamping position, there is a locking device which has
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a locking lever 24 which is mounted on the bearing part
11 90 as to be pivotable about the axis 24'. This lock-
ing lever 24 has at one end a blocking projection 25
which interacts with the blocking arm 22 on the closing
lever 20 to lock the first gripper part 5, as is shown
in Figure 3. The locking lever 24 is pivoted by means
of a spring 26 into its blocking position and held
therein. At the other end, the locking lever 24 has a
follower roller 27 which is mounted so as to be freely
rotatable about the axis of rotation 27'. In the block-
ing position of the locking lever 24, the axis of
rotation 27' of this follower roller 27 is flush with
the longitudinal axis 12' of the shaft 12. It is
ensured by this arrangement that release of the locking
lever 24, i.e. pivoting into its release position by an
unlocking force P acting on the follower roller 27
(Figure 3), is ensured in all pivot positions of the
gripper 2.
Arranged on the bearing part 11 for the second
gripper part 6 on the side opposite the locking lever
24 is a positioning follower roller 28 which is mounted
so as to be freely rotatable about the axis 28'. In
this case, the axis of rotation 28' is flush with the
pivot axis 24' of the locking lever 24. The positioning
follower roller 28 interacts with positioning links 29,
by means of which the pivot position of the second
gripper part 6 and thus of the open and closed gripper
2 is- defined. This second gripper part 6 is pivotable
between two end positions which enclose with one
another an angle of about 90~. One end position of the
second gripper part 6 is illustrated in Figures 2 and
3, in which this second gripper part 6 runs approxi-
mately in the direction of movement B, B' of the
grippers 2. In the other end position shown in Figures
7 and 8, the second gripper part 6 extends approxi-
mately perpendicular to the direction of movement B, B'
of the grippers 2. By means of these end positions of
the second gripper part 6, the end positions of the
open and closed gripper are also defined, which gripper
2 8
-- 5 --
can assume any intermediate position depending on the
design of the positioning links 29. It should also be
mentioned in this context that the second gripper part
6 defining a plane E (Figure 2) is offset relative to
the common pivot axis 12' of the two gripper parts 5,
6. In other words, the said plane E runs with spacing
from this common pivot axis 12', as can readily be seen
in Figure 2.
For closing the grippers 2, there are fixed
closing links 30 which act on the follower roller 21 of
the closing lever 20 and bring about pivoting of the
latter in the closing direction, i.e. anticlockwise in
the illustration according to Figure 2. These closing
links 30 can be constructed in a manner known per se to
correspond to the particular requirements. These clos-
ing links 30 are illustrated only diagrammatically in
the figures.
With reference to the closing links indicated
by 30a and 30b in Figure 2, it is to be made clear that
the gripper 2 can be closed in both conveying direc-
tions B and B' by virtue of the arrangement and con-
struction of the closing lever 20 described above. If
the gripper is moved in the direction of the arrow B,
the closing link 30a is to be provided. If, in con-
trast, the gripper 2 is moved in the opposite direction
B', the closing link is to be constructed as indicated
by 30b.
The mode of functioning of the gripper 2 is now
explained below with reference to Figures 2 and 3.
Prior to closing the gripper 2, the latter,
i.e. the second gripper part 6, is moved by the posi-
tioning link 29 into the desired product-receiving
position and held therein (Figure 2). To pivot the
first gripper part from the open position into the
clamping position, the closing link 30 (30a or 30b
respectively) begins to act on the follower roller 21
on the closing lever 20 which is thus pivoted anti-
clockwise. This results in a corresponding rotation of
the shaft 12 and thus also of the resting part 16. This
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rotary movement of the resting part 16 is transmitted
via the compression spring 18 to the bearing part 15 of
the first gripper part 5, as a result of which the
latter is pivoted towards the clamping position. When
the closing lever 20 has now reached a position denoted
by the connecting line 23a in Figure 3, the first
gripper part 5 comes into contact with the second
gripper part 6. In this position, the compression
spring 18 already exerts a certain clamping force. In
this position of the closing lever 20, the blocking arm
22 also already begins to run up against the blocking
projection 25 of the locking lever 24. When the closing
lever 20 is rotated further, the locking lever 24 is
now pressed back out of the blocking position by the
blocking arm 22, continuing to act on the blocking pro-
jection 25, counter to the force of the spring 26, i.e.
is pivoted anticlockwise. When the closing lever 20 has
now reached its end position denoted by the connecting
line 23 in Figure 3, locking of the closing lever 20 is
effected by the blocking projection 25 of the locking
lever 24 acting on the blocking arm 22. This means
that, for locking the first gripper part 5 in its
clamping position, the closing lever 20 has to travel
only a short way which is illustrated in Figure 3 by
the pivot angle ~. During the pivoting of the closing
lever 20 through the abovementioned angle ~, the com-
pression spring 18 is compressed, which obviously
results in the clamping force exerted by the first
gripper part 5 being increased accordingly. The magni-
tude of this clamping force also depends on the thick-
ness of the printed product 8 clamped between the
gripper parts 5, 6.
The short pivot path (angle ~), as mentioned,
which the closing lever 20 has to travel until it is
locked, is possible because the compression spring 18
already exerts a clamping force, as already mentioned,
as soon as the first gripper part 5 comes into contact
with the second gripper part 6 or with the printed
- 7 _ ~ 2 ~
product 8 to be gripped which has run into the gripper
opening 7.
To unlock the closing lever 2 0 and thus the first
5 gripper part 5, i.e. to open the gripper 2, an opening
arrangement comprising fixed opening links (not shown in
Fig. 3) is provided which acts on the follower roller 27 of
the locking lever 24 thus exerting an unlocking force P on
the follower roller 27, causing the locking lever 24 to be
pivoted anticlockwise. After a short pivot path (small
pivot angle ~ in Figure 3), the blocking projection 25 is
released from the blocking arm 22 on the closing lever 20
which is pivoted clockwise under the effect of the
compression spring 18 becoming relaxed. As soon as the
15 blocking arm 22 is outside the range of action of the
blocking projection 25 and the unlocking force no longer
acts on the follower roller 27, the locking lever 24 is
pivoted back into its blocking position again by the spring
26.
In illustrations corresponding to Figures 2 and 3,
Figures 7 and 8 show a gripper 2 in the other end position
in which the second gripper part 6 runs approximately
perpendicular to the direction of movement B, B' of the
gripper 2. The gripper 2 is moved into this end position
25 by a correspondingly constructed positioning link 29 which
differs in construction from the positioning link 29 in
Figures 2 and 3. Figure 7 shows the first gripper part 5
in its extreme open position in which it is held by a
holding-open link 31 which interacts with the follower
roller 21 on the closing lever 20.
The closing, locking and opening of the gripper 2 are
effected in the end position illustrated in Figures 7 and
8 in the same manner as described with reference to Figures
2 and 3, in which case, however, the different links must
35 be constructed accordingly, as mentioned.
It can be seen by comparing Figures 2 and 3 with
Figures 7 and 8 that the grippers 2 can be opened and
closed in both end positions and thus also in any
intermediate position, specifically irrespective to
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whether they are moved in the direction of the arrow B or
in the direction of the arrow B'.
With reference to Figures 9-12, different
possibilities of use of the grippers 2 are now described,
as have been explained in conjunction with Figures 1-8.
In the embodiment according to Figure 9, the printed
products 8 are brought in a suspended position by a feed
conveyor 32 and are taken over and conveyed further by a
delivery conveyer 33. As described with reference to
Figures 7 and 8, the grippers 2 of the feed conveyor 32 are
held by positioning links 29 in an end position in which
the second gripper part 6 runs approximately perpendicular
to the conveying direction approximately perpendicular to
the conveying direction G of the feed conveyor 32. The
grippers 2 of the delivery conveyor 3, which are moved in
the same direction G, are likewise held in this end
position, but the gripper opening 7 is directed upwards and
the second gripper part 6 forms the trailing part of the
grippers 2.
The printed products 8 held in the region of their one
edge 8a by the grippers 2 of the feed conveyor 32 are
gripped at the opposite edge 8b by the grippers 2 of the
delivery conveyor 3. As soon as the printed products 8 are
clamped in the grippers 2 of the delivery conveyor 3, the
grippers 2 of the feed conveyor 32 are opened by means of
an opening arrangement 34 which has an opening link 35
which acts on the follower roller 27 on the locking lever
24.
The locking device 24, 25, the first gripper part 5
and the stationary opening arrangement 34, 35 can be
referred to, in general terms, as "a locking device for
blocking the first gripper part in its clamping position,
the locking device being releasable by a stationary opening
arrangement along the path of travel of the gripper.
The embodiment according to Figure 10 is very similar
to that according to Figure 9 and differs from the latter
by a different position of the grippers 2 during transfer
of the printed products 8. In the embodiment according to
Figure 10, the gripper openings 7 are namely not directed
downwards or upwards, but obliquely towards the rear in the
feed conveyor 32 and obliquely towards the front in the
delivery conveyor 33.
The embodiment shown in Figure 11 is related to a
certain extent to the embodiment according to Figure
g
1. ~owever, in contrast to the variant according to
Figure 1, the printed products 8 fed by the belt
conveyor 9 in an imbricated formation S are not gripped
at the leading edge 8a, but at the trailing edge 8b.
This requires a different position of the grippers 2 in
the transfer region than in the embodiment shown in
Figure 1. In Figure 11, 36 shows a guide for the
printed products 8.
In the embodiment according to Figure 12 which
is similar to that according to Figure 1, the belt con-
veyor 9 brings the printed products 8 in an imbricated
formation S' in which each printed product 8 lies on
the following printed product. This means that the
leading edges 8a of the printed products 8 lie at the
bottom in the imbricated formation S'.
The printed products 8 are gripped by the con-
veying device lb at this leading edge 8a. This means
that the gripper openings 7 must point towards the rear
in the transfer region.
It can readily be seen in Figure 1 and in
Figures 9-12 that the same gripper construction as was
described with reference to Figures 2-8 can be used for
conveying devices 1, la, lb, 32, 33 with different
tasks. By virtue of their special construction, the
grippers 2 can be moved into different pivot positions
and can be closed and opened satisfactorily in any
pivot position without requiring constructive adapta-
tions of the grippers 2 to the respective purpose. It
is understood that the positioning links 29, the open-
ing links 35 and any holding-open links 31 must be
adapted to the particular purpose of the conveying
devices. The corresponding links are indicated diagram-
matically in Figures 9-12.
A further advantage of the gripper construction
described is that the grippers 2 can be made and
assembled in a simple manner. The two gripper parts 5
and 6, together with their bearing parts 11 and 15
respectively can be made of plastic, which results in a
light construction. Since the closing force is
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primarily applied by the compression spring 18, the
first gripper part 5 only has to have a limited flexi-
bility. In order to secure the shaft 12 against dis-
placement in the direction of its longitudinal axis
12', the shaft 12 is provided in the region of the
spreader ring 17 with a circumferential groove in which
a rib on the inside of the spreader ring 17 engages in
the manner of a snap-on connection in the assembled
state. This easy-assembly solution obviates the need
for mounting separate securing rings or the like.
It is also conceivable to connect the first
gripper part 5 to the shaft 12 directly via a spring
element which bears the first gripper part 5 at one end
and is connected to the shaft 12 at the other end. This
spring element then forms both the bearing part for the
first gripper part 5 and the closing spring which is
stressed when the gripper is closed. Such an embodiment
is described, for example, in DE-A-3,102,242 and the
corresponding document US-A-4,381,056.
Instead of fastening the grippers 2 at fixed
intervals on a link chain 14, as shown with reference
to Figure 4, it is also possible to mount them on bear-
ing elements which, though coupled to one another, can
be varied, however, in their spacing. Such a solution
with bearing elements which can be varied in their
spacing is described, for example, in EP-A-0,323,557
and the corresponding document US-A-5,007,629.
