Apparatus and method for transporting flexible, planar products

Printed products (10) are conveyed to a transfer portion (22) by means of the grippers (14) of the gripper conveyor (12). The vacuum belt conveyor (26) suctions with its active strand (28) the respective end region (32) of the printed products (10), after which, close to the end of the (34) of the transfer portion (22), the grippers (14) respectively release the printed products (10). The motional path (38) of the gripper jaws (16) runs in the transfer portion (22) in the shape of an arc. The active strand (28) of the vacuum belt conveyor (26) runs in the transfer portion (22) at an approximately constant distance to the motional path (38). In the case of large processing capacities and correspondingly high velocities, a reliably secure, positionally stable transfer of the printed products (10) from the gripper conveyor (12) to the vacuum belt conveyor (26) is thereby ensured.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Swiss Application No. 2010 0716/10, filed May 10, 2010.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus and a method for transporting flexible, planar products, as claimed in patent claims1and13respectively.

In particular in mailrooms of printing houses, the printed products are frequently transported by means of gripper conveyors. In this context, it frequently happens that the printed products are delivered from the gripper conveyors to the belt conveyor for further processing. In the case of large processing capacities and the high conveying velocities associated therewith, the problem exists that the printed products flap when transferred from the gripper conveyor to the belt conveyor and, in particular, behave erratically after being released by the grippers of the gripper conveyors, with the risk of losing their ordered arrangement.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is therefore to provide an apparatus and a method for transporting flexible, planar products, which apparatus/method ensures a secure and reliable transfer of the products from a gripper conveyor to a belt conveyor, even at high conveying velocities.

This object is achieved with an apparatus having the features of patent claim1and a method having the features of patent claim13.

The grippers of the gripper conveyor are designed to, with their gripper jaw, hold and transport a flexible, planar product, in particular a printed product such as a newspaper, a magazine or the like, by its holding region, which lies contiguous to a holding edge. Since the products are secured in the gripper jaw, they have a precisely defined position. According to the invention, the motional path of the gripper jaws, i.e. of the free end of the gripper jaws, has in a transfer portion, in which the products are transferred from the gripper conveyor to a belt conveyor, an arc-shaped course. The course may be arc-shaped over the whole of the transfer portion.

The grippers can respectively be loaded with a single product. It is also possible, however, for the grippers to be loaded with more than one product, for example two products, these products being arranged in an imbricated formation, so that the holding regions of the products are exposed.

According to embodiments of the invention, the belt conveyor is configured as a vacuum belt conveyor having a perforated belt, the active strand of which runs in the transfer portion at a distance to the motional path of the gripper jaws.

The arc-shaped course of the motional path of the gripper jaws leads to a secure bearing contact of the products, with their free end region facing away from the holding edge, against the active strand of the vacuum belt conveyor. The vacuum belt conveyor suctions the end region of the particular products to the active strand, whereby said products are stabilized and held in a defined position, so that, when the particular grippers are subsequently opened, they can no longer alter this position.

Since the motional path of the gripper jaws has an arc-shaped course and the active strand of the vacuum belt conveyor runs in the transfer portion at a distance to the motional path, the mutual spacing of the products, or the overlapping thereof, is also altered in the course of the transfer. If the arc-shaped course of the motional path is convex, the distance between the free end edges of successive products, which free end edges lie opposite the holding edges of the products, is increased. Correspondingly, this distance is reduced in the case of a concave course.

Vacuum belt conveyors have at least one self-contained perforated belt, which is driven such that it rotates in the direction of conveyance and the holes of which, in the suction portion of the active strand, are connected to a vacuum source. The suction portion can here extend around virtually the entire length of the active strand. It is also possible, however, for the suction portion to be divided, in the direction of conveyance, into successive sub-portions.

Usually, vacuum belt conveyors are provided with a vacuum pan, which is connected to the vacuum source and over whose opening the active strand of the perforated belt is moved. The holes of the perforated belt which are respectively located in the region of the opening are hence connected to the vacuum source.

The gripper jaws have in the transfer portion a speed—measure of their vectorial velocity—which, according to embodiments of the invention, is less than the speed—and thus the rotational velocity—of the perforated belt.

The active strand may have in the transfer portion an at least approximately arc-shaped course which is equidirectional to the motional path. An at least approximately arc-shaped course means that the arc can be imitated also by successive, chord-like portions.

In an embodiment of the apparatus according to the invention, the motional path of the gripper jaws has in the transfer portion, and preferably over the entire length of the transfer portion, a circular-arc shaped course. The distance between the products, or their free end edges, in the transfer portion hence remains at least approximately constant.

The distance between the motional path of the gripper jaws and the active strand of the vacuum belt conveyor may be adjustable. The optimal processing of printed products of different thickness and different length is thereby made possible.

In a further embodiment of the apparatus according to the invention, the clamping tongues of the grippers, which respectively form a gripper jaw, and thus the gripper jaws per se, are mounted pivotably about a gripper axis running transversely, in particular at right angles, to the direction of conveyance. This makes it possible, for example by means of a link motion, to control the desired pivotal position of the gripper jaws upon reaching the transfer portion, and within this. More particularly, the gripper axis runs parallel to the conveying surface defined by the vacuum belt conveyor.

The gripper jaws, upon reaching the transfer portion and within the transfer portion, can be directed obliquely rearward with respect to the direction of conveyance. The free end edge of the products is hence trailing with respect to their holding edge located in the gripper jaw.

The gripper conveyor may have a conveying member guided in a guide channel. This is in the form of a link chain in one embodiment, which is capable of withstanding tensile and compressive load. On the conveying member, cantilever-like carrying members are arranged at a predetermined carrier spacing, which carrying members reach through the gap of the guide channel of C-shaped cross section. These carrying members respectively carry, outside the guide channel, a gripper. In such an embodiment, the exact position and location of each product, and thus the location of the products relative to one another, is always predefined and known.

In an embodiment of the apparatus according to the invention, in the transfer portion the motional path of the gripper jaws is convex and, correspondingly, the active strand of the vacuum belt conveyor is concave. This embodiment allows the centrifugal forces to be utilized, which force the free end region of the products into bearing contact against the active strand of the vacuum belt conveyor.

If, in such an embodiment, the motional path of the gripper jaws, in the transfer portion, is located radially on the outside with respect to the conveying member to which the grippers are fastened by carrying members, the distance between the free end edges of the successive products in relation to the carrier spacing, and thus to the distance which these end edges adopt in a rectilinear course of the gripper conveyor, is additionally increased.

The active strand may be divided in the transfer portion into rectilinear segments, which succeed one another in the direction of conveyance, and thus forming chords of the arc, allow a concave course of the active strand in the transfer portion. This embodiment offers the possibility, between successive segments, of holding the perforated belt radially to the outside with respect to the arc.

At least some of the segments are assigned a vacuum pan, which is connected to a vacuum source and over which runs the active strand. At least those segments which are located in the suction portion of the vacuum belt conveyor are configured in this way. All—possibly apart from the first or the last segment, viewed in the direction of conveyance—may be realized in this way.

The perforated belt can be guided between respectively successive segments in a Ω shape around deflexion rollers. This allows a low-friction operation.

Moreover, the perforated belt is shored in the region of the vacuum pans, by means of supporting rollers, against the movement into the vacuum pans.

In a further embodiment of the apparatus according to the invention, the vacuum belt conveyor has, in addition to the perforated belt, at least one further perforated belt driven at the same speed, preferably one on each of the two sides. The segments of the further perforated belt or belts are preferably arranged offset, in the direction of conveyance, in relation to the segments of the perforated belt, so that the region between successive segments of the perforated belt is bridged by a segment of the further perforated belt or belts. Uninterrupted holding of the end regions of the products, despite segmentation of the active strand, is thereby ensured.

In the transfer portion, the motional path of the gripper jaws can be shaped concavely and the active strand of the vacuum belt conveyor correspondingly convexly. A rectilinear course of the active strand is also conceivable. In these embodiments, segmentation of the vacuum belt conveyor is unnecessary.

It should be mentioned that the distance between the motional path of the gripper jaws and the active strand of the vacuum belt conveyor prevents the formation of a nip for the products. The transfer portion is thus nipless. The distance is greater than the thickness of the products and, should these overlap, greater than the overall thickness of the overlapping products.

In the method according to embodiments of the invention, a flexible, planar product is transported by means of a gripper conveyor into a transfer portion. To this end, the product is secured, by a holding region of the product, in the gripper jaw of grippers arranged one behind another. The grippers arranged one behind another are driven rotatingly in a direction of conveyance F. The product transported into the transfer portion is in this portion, in an end region facing away from its holding region, suctioned by an active strand, driven in the direction of conveyance F, of a perforated belt of a vacuum belt conveyor. After the product, in its end region, has been suctioned to the active strand of the vacuum belt conveyor, the grippers of the gripper conveyor open and the product is transported onward by means of the vacuum belt conveyor. The active strand here runs at a distance A to the motional path of the gripper jaws. The motional path of the gripper jaws has an arc-shaped course. The perforated belt is driven at a belt speed which is greater than the speed at which the gripper jaws are driven.

In embodiments of the method, in the transfer portion the active strand runs in the same direction as the motional path of the gripper jaws and at least approximately in an arc shape.

In further embodiments, the motional path of the gripper jaws in the transfer portion runs in the shape of a circular arc.

In a further embodiment of the method, the motional path of the gripper jaws runs convexly and the active strand of the vacuum belt conveyor runs concavely.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows a region, relating to the present invention, of an apparatus for transporting flexible, planar products10, in the present case printed products such as newspapers, magazines or the like. It has a gripper conveyor12, serving as a feed conveyor, whose grippers14, which are driven rotatingly in a direction of conveyance F and are arranged one behind another, are designed to, with their gripper jaw16, respectively secure a product10by its holding region18adjoining a holding edge20and transport it to a transfer portion22.

Arranged downstream of the gripper conveyor12is an evacuation conveyor24configured as a belt conveyor, which in the transfer portion22is configured as a vacuum belt conveyor26. The vacuum belt conveyor26, which is disposed in the transfer portion22beneath the gripper conveyor12, is designed to, in the transfer portion22, with its active strand28of the perforated belt30, which active strand28is driven in the direction of conveyance F, suction the products10, held by the gripper conveyor12, in their end region32facing away from the holding edge20and, following subsequent release by the grippers14, transport them onward. The release takes place close to the downstream-situated end34of the transfer portion22and the vacuum belt conveyor26conveys the received products10to a belt conveyor36of the evacuation conveyor24, which belt conveyor36is arranged downstream of the first-named conveyor in the direction of conveyance F and is provided with parallel conveyor bands.

The motional path38of the gripper jaws16has in the transfer portion22an arc-shaped course, in the illustrative embodiment represented in the drawing a circular-arc-shaped course which is convex with respect to the self-enclosed gripper conveyor. The vacuum belt conveyor26is arranged radially on the outside with respect to the arc of the gripper conveyor12such that the active strand28in the transfer portion22has an at least approximately constant distance A to the motional path38.

Each gripper14has two interacting clamping tongues40forming the gripper jaw16, one of the clamping tongues40, in the present case the leading one viewed in the direction of conveyance F, determining the pivotal position of the grippers14and thus of the gripper jaw16, and the other, trailing clamping tongue40being pivoted relative to the leading clamping tongue40for the opening and closing of the gripper jaw16.

The motional path38is given by the movement of the free end of the clamping tongue40defining the position of the grippers14, in the shown illustrative embodiment of the leading clamping tongue40.

At this point it should be noted that the distance A between the motional path38and the vacuum belt conveyor26is greater than the thickness of the products10to be conveyed, and should these overlap, as in the shown illustrative embodiment, greater than the overall thickness of the products10in the region of overlap. The products10are thus, in the transfer portion22, not held in a nip.

In particular, embodiments as are known, for example, from printed publications EP 0 600 183 A1, EP 0 557 680 A1 and EP 0 557 679 A1 are suitable as grippers14. The clamping tongues40, which respectively form a gripper jaw16, can be pivoted relative to one another about a gripper axis42running at right angles to the direction of conveyance F and parallel to the conveying surface defined by the vacuum belt conveyor26and, in the closed setting of the gripper jaw16, are locked under spring load by means of a locking lever44, seeFIG. 3.

One of the clamping tongues40, in the present case the one which is leading in the direction of conveyance F, is fixedly connected to a positioning follower roller46, which is guided in a positioning link48to control the rotational position of the grippers14and thus of the gripper jaw16.

The other one of the clamping tongues40, in the shown illustrative embodiment the one which is trailing in the direction of conveyance F, is connected by a spring to a closing lever50, which on the one hand bears a follower roller52, mounted such that it is freely rotatable, and, on the other hand, is designed to interact with the locking lever44; seeFIG. 3.

For the closing of the grippers14, or of the gripper jaw16, the follower roller52is moved by means of a closing link (not shown) such that the clamping tongue40connected by the spring to the closing lever50is pivoted toward the other clamping tongue40held in its position by the positioning follower roller46and the positioning link48, to be precise to the point where, following the bearing contact of the clamping tongues40one against another, or against a product10arranged therebetween, the spring is tensioned and the closing lever50is interlocked with the locking lever44for the generation of the clamping force. For the opening of the grippers14, close to the end34of the transfer portion22, the locking lever44is pivoted by means of an opening apparatus54such that it releases the closing lever50and the clamping tongue40connected thereto can move into the opening setting. The structure and the working method of such grippers14is explained in detail in the aforementioned printed publications and the pertinent disclosure should herewith be integrated into the present description.

For the sake of completeness, it should be mentioned that the opening apparatus54is arranged such that it opens the grippers14which are respectively moved past it, if the clamping tongue40which determines the motional path38is close to the downstream-situated end34of the transfer portion22.

Each of the grippers14is fastened in a known manner to a cantilever-like carrying member56. The carrying members56, for their part, are fastened with a predetermined carrier spacing to a self-enclosed conveying member58, which is preferably formed by a link chain capable of withstanding tensile and compressive load. The conveying member58is guided in a guide channel60of C-shaped cross section, the carrying members56reaching through the gap62of the guide channel60, so that the grippers40are outside the guide channel60; in the shown illustrative embodiment, with respect to the arc-shaped course, radially outside the guide channel60.

Viewed in the direction of conveyance F, the guide channel60, which in the shown region of the apparatus according to the invention extends in a vertical plane, runs vertically downward, then in a 90° circular-arc portion61through the transfer portion22, the end34of the transfer portion22being followed by a short rectilinear portion64. This leads the conveying member58tangentially up to a continuously driven deflexion and drive wheel66mounted on a horizontal axis. In an upward vertical direction, the deflexion and drive wheel66is followed, in turn, by a rectilinear portion68of the guide channel60. The deflexion and drive wheel66driven in the rotational direction D drives the conveying member58and thus the grippers rotatingly in the direction of conveyance F.

The grippers14are aligned in their pivotal position by means of the positioning link48such that, upon reaching the transfer portion22and up to the end34thereof, the gripper jaws16are directed obliquely rearward with respect to the direction of conveyance F. Hence, the holding edges20of the products10, with respect to the end edges32′ situated opposite them, are leading, and in the transfer portion22the holding edges20, viewed in the radial direction, are located further in than the end edges32′ and the thereto adjoining end region32.

In the shown illustrative embodiment, in the transfer portion22, the pivotal position of the grippers14is maintained with respect to the direction of conveyance F, so that the motional path38runs at a constant distance to the guide channel60and thus, in the transfer portion22, has a circular-arc-shaped course.

It should be mentioned that the gripper conveyor12is assigned guide rods70, which at a fixed distance to the guide channel60and to the motional path38, viewed in the direction of conveyance F, extend as far as the vacuum belt conveyor26. The products10held by the grippers40slide with their end region32along these guide rods70, which ensure that the products10maintain their obliquely rearward running, possibly curved position, as represented inFIG. 1, also in the vertically downward running portion and during standstill of the gripper conveyor12.

The vacuum belt conveyor26is realized so as to be vertically adjustable in order to be able to adjust the distance A between the motional path38and the active strand28, in dependence on the thickness of the products10to be processed.

The vacuum belt conveyor26has at least one self-enclosed perforated belt30, which is driven such that the active strand moves in the direction of conveyance F at a rotational velocity and thus belt speed |w| which is greater than the speed |v| of the gripper jaws14. In some embodiments, for the gripper jaws14and the active strand28, the angular velocity ω, in the transfer portion22, is at least approximately equal.

If a single perforated belt30is provided, this can be arranged symmetrically to the plane in which the motional plane38extends. If two perforated belts30are provided, one of the perforated belts30can be located on each side with respect to this plane. In particular, the vacuum belt conveyor26is configured as represented inFIGS. 2 and 3, with a perforated belt30in the middle and, on each side of this perforated belt30, a further perforated belt30′.

The active strand28of the centrally arranged perforated belt30is formed by four rectilinear, at least approximately equally long segments72, which follow on from one another in the direction of conveyance F and which are arranged at angles to one another and, forming chords, imitate the concave arc. Viewed in the direction of conveyance F, the second, third and fourth segments72are respectively assigned a vacuum pan74, as is described in greater detail further below. The first segment72thus serves exclusively for the guidance of the end regions32of the products10, while the second, third and fourth segments72form a suction portion76of the active strand28of the perforated belt30.

In the shown illustrative embodiment, the active strand28extends over an angle of about 40°.

The two further perforated belts30′ arranged to the side of the perforated belt30form in the region of the active strand28, in a similar manner to the perforated belt30, rectilinear segments72′, which succeed one another in the direction of conveyance F and are arranged at angles to one another in order, forming chords of the arc, likewise to imitate the concave course. The first and last segments72′, viewed in the direction of conveyance F, are configured roughly half as long as the particular segments72of the perforated belt30, while the further three segments arranged between these segments72′ have roughly the same length as the segments72of the perforated belt30.

The segments72′ of the further, likewise self-enclosed perforated belts30′ thus bridge the short gaps between the segments72of the perforated belt30, and the segments72correspondingly bridge the short gaps between the successive segments72′ of the further perforated belts30′.

As is additionally described further below, the middle three segments72′ of the further perforated belts30are respectively assigned a vacuum pan74′. The suction portion76′ of the active strand28of the further perforated belts30′ thus lies in the region of the middle three segments, while the respectively first segment72′ and last segment72′, viewed in the direction of conveyance F, serve for the guidance of the end regions32of the products10.

The suction portion76″ of the vacuum belt conveyor26—see also FIG.4—formed by a combination of the suction portions76and76′ of the first perforated belt30and of the further perforated belts30′, thus extends, viewed in the direction of conveyance F, from approximately the middle of the first segment of the perforated belt30to toward the end of the last segment72of this perforated belt30.

The vacuum belt conveyor26is directly followed, in the direction of conveyance F, by the belt conveyor36, which, in the shown illustrative embodiment, has four conveying bands78, which are arranged side by side and are driven at the same velocity as the perforated belts30,30′.

InFIG. 4, the centrally arranged perforated belt30and the two perforated belts30′ arranged to the side thereof, with the associated drive rollers80and deflexion rollers82, as well as the vacuum pans74,74′ assigned to the particular segments72,72′, are shown in perspective representation. The machine frame provided with a casing—compare FIGS.1to3—on which the drive rollers80, deflexion rollers82and the further rollers mentioned further below are mounted and to which the vacuum pans74,74′ are fastened, is not represented.

The endless perforated belt30—see also FIG.5—and the endless further perforated belts30′—compare also FIGS.7and9—are provided with a continuous hole pattern, so that a multiplicity of continuous suction holes84are always present in the region of the vacuum pans74,74′. In the present case, the perforated belts30,30′ are provided with transverse rows of suction holes84, which rows are arranged successively one behind another in the direction of rotation U, a plurality of such rows respectively being located in the region of each vacuum pan74,74′.

Both the perforated belt30and the further perforated belts30′ are guided at the upstream-situated end around deflexion rollers82, which are mounted coaxially in a freely rotatable manner, and at the downstream-situated end around drive rollers80, which are likewise coaxially mounted, yet are connected to one another and to a drive motor M—seeFIGS. 6 and 8. Between two respectively successive segments72,72′, the perforated belts30,30′ are respectively deflected in a Ω-like manner around three further deflexion rollers86, which have parallel axes, are arranged in the isosceles triangle and are mounted such that they are freely rotatable. Two of these three further deflexion rollers86, viewed in the direction of conveyance F, are respectively arranged directly one after the other, the upstream-situated one of these further deflexion rollers86being arranged close to the downstream-situated end of a segment72,72′ and the adjacent deflexion roller82being arranged at the upstream-situated end of the following segment72,72′. The third of these further deflexion rollers86is arranged such that it is offset, with respect to the two others, downward in the direction of the return strand88.

The return strand88of each perforated belt30,30′ is guided adjacent to the particular drive roller80and adjacent to the associated deflexion roller82in an S-shape around a roller pair90in order, on the one hand, to increase the angle of wrap about the drive roller80or deflexion roller82and, on the other hand, to increase the distance of the return strand88to the active strand28and make space for the vacuum pans74,74′ arranged therebetween. Roughly midway between these roller pairs90, the perforated belt30and the further perforated belts30′ are guided around a respective tensioning roller92in order to keep the perforated belts30,30′ taut. Acting between the machine frame and the tensioning rollers92is a respective tension spring94, seeFIGS. 6 and 8.

The vacuum pans74,74′ are connected by a piping96to a commonly known vacuum source (not shown). On the side facing the active strand28, the vacuum pans74,74′ are open and the perforated belt30or the particular further perforated belt30′ runs over this opening. The suction holes84respectively located in the region of these openings are connected to the vacuum source.

The vacuum pans74,74′ each have a planar flange98, which encircles the opening and protrudes radially outward, which flanges, on the one hand, support the active strand28and, on the other hand, prevent false air from being sucked into the vacuum pans74,74′. For the sake of completeness, it should be mentioned that the width of the openings of the vacuum pans74,74′ is less than the width of the associated perforated belt30, or of the further perforated belt30′.

In the shown illustrative embodiment, the width of the further perforated belts30′ is greater than the width of the perforated belt30. Preferably, the vacuum pans74′ assigned to the further perforated belts30′ are provided with supporting rollers100, mounted in a freely rotatable manner, to prevent the particular regions of the further perforated belts30′ from being sucked into the vacuum pans74′. As can be deduced, in particular, fromFIG. 8, each particular vacuum pan74′ can be assigned, for example, three supporting rollers100, which extend over at least a part of the width of the opening of the vacuum pans74′ and are seated in a freely rotatable manner on bearing shafts, which latter extend at right angles to the direction of conveyance F and direction of rotation U through the vacuum pans74′ and are fastened to the side walls thereof. The supporting rollers100can be narrowly configured, so that they rather form supporting wheels. Naturally, it is also possible to arrange a plurality of narrow supporting rollers100or supporting wheels side by side on a bearing shaft. It is also conceivable, of course, to provide supporting rollers100in the vacuum pans74assigned to the perforated belt30.

The radius with which the guide channel60is curved in the transfer portion22can measure, for example, about 500 mm. The deflexion and drive wheel66can have a radius of, for example, 250 mm. On the conveying member58, the carrying members56are arranged, for example, with a center-to-center spacing of 100 mm. Furthermore, the grippers24can be controlled in their pivotal position such that the motional path38in the transfer portion22has a radius of about 600 mm. If the distance between the motional path38of the gripper jaws16and the active strand28of the vacuum belt conveyor26here amounts to a distance A of about 75 mm, the products10are taken up by the gripper conveyor with a distance of 135 mm between the end edges32′ of successive products10and carried off in the direction of evacuation W. In the rectilinear portions of the motional path38, this distance amounted to 100 mm.

If, based on the above-specified dimensions, the conveying member58is driven at a rotational velocity of, for example, 1000 mm/s, the gripper jaws16move at a speed |v| of 1200 mm/s and the active strand28moves at a speed |w| (and rotational velocity) of 1350 mm/s.

The motional path38may run in the transfer portion22in the shape of a circular arc, the radius of the circular arc for the processing of printed products being in some embodiments less than one meter. The length of the transfer portion22measures, for example, between 300 mm and one meter, and can be about 500 mm.

InFIG. 10a, the course of the motional path38of the gripper jaws is shown in heavily simplified representation, the direction of conveyance being denoted by F. In the shown example, the course of the motional path39of the active strand of the perforated belt of the vacuum belt conveyor is rectilinear. The course of the motional paths38and39is here divided into an inlet portion I, a transfer portion II and an outlet portion III. The inlet portion I refers to that part of the motional paths38and39which leads to the transfer portion II. The outlet portion III refers to that part of the motional paths38and39which leads away from the transfer portion II. Radii of curvature102and103of the motional path38of the gripper jaws in the transfer portion II and in the outlet portion III respectively are likewise shown. As can be seen fromFIG. 10b, in the transfer portion II the active strand of the perforated belt is driven at a speed |w| which is greater than the speed |v| of the gripper jaws. In the outlet portion III, a sharp increase in speed |v| occurs due to the smaller radius of curvature103.

InFIG. 11a, a further example of the course of the motional path38of the gripper jaws is shown, once again, in heavily simplified representation. The direction of conveyance is denoted by F. In the shown example, the course of the motional path39of the active strand of the perforated belt of the vacuum belt conveyor is concavely curved. The course of the motional paths38and39is here divided into an inlet portion I, a transfer portion II and an outlet portion III. The inlet portion I once again refers to that part of the motional paths38and39which leads to the transfer portion II. The outlet portion III refers to that part of the motional paths38and39which leads away from the transfer portion II. The radii of curvature104,105and106are likewise shown. As can be seen fromFIG. 11b, in the transfer portion II the active strand of the perforated belt is driven at a speed |w| which is greater than the speed |v| of the gripper jaws. In the outlet portion III, a sharp increase in speed |v| occurs due to the smaller radius of curvature106.

FIG. 12illustrates the relationship between the angular velocity and the velocities v and w or the speeds |v| and |w| at a point on the respective path course. Here too, it can be seen that, at the respectively shown point (blackened circle) on the motional paths38and39, the speed |w| of the perforated belt is greater than the speed |v| of the gripper jaws on the motional path38.

The working method of that embodiment of the apparatus according to the invention which is shown in the figures is as follows. The grippers14are continuously driven such that they rotate in the direction of conveyance F. The grippers14are each loaded in a loading station with a product10, the grippers14, with their gripper jaw16, respectively grasping the product10in its holding region18contiguous to the holding edge20, and securing the same. The grippers14are supplied to the transfer portion22with a pivotal position such that that free end edge32′ which lies opposite the holding edge20, and thus the thereto adjoining end region32, viewed in the direction of conveyance F, is trailing with respect to the holding edge20. In the direction of the transfer portion22, the products10slide with their end region32along the guide rods70and then, aided by the centrifugal forces and as a result of the convex course of the motional path38of the gripper jaws16, come to bear with their end region32against that active strand28of the vacuum belt conveyor26which lies radially on the outside with respect to said motional path38.

In the region of the first segments72,72′ of the vacuum belt conveyor26, the end regions32of the products10are extensively supported, whereby they stabilize. In the adjoining suction portion76″, the end regions32are suctioned to the perforated belt30and the further perforated belt30′ and are thereby secured. At the end34of the transfer portion22, the grippers14which run past there are respectively opened, whereby the particular products10are released. Since they are held at this moment by the vacuum belt conveyor26, they cannot alter their position to the perforated belt30,30′ and relative to one another. The products10are held stable when their holding region18is released. Despite an airstream, a stable delivery of the products10onto the vacuum belt conveyor26with a defined altered spacing between the holding edges20of successive products10is realized. The stabilized products10are released from the vacuum belt conveyor26close to the downstream-situated end of the suction portion76and are carried off in an ordered formation by means of the downstream belt conveyor36.

The length of the transfer portion22, measured in the direction of conveyance F, is greater than the extent of the largest products10to be transported. The width of the suction-active region of the vacuum belt conveyor26, measured at right angles to the direction of conveyance F, is chosen smaller than the width of the, in this regard, smallest products10to be transported.