Patent Description:
A known system for conveying products has a conveyor with which products are moved in a conveying direction. The known system also has a supply conveyor which connects at a supply location to the conveyor with which products are moved in a supply direction and are transferred to the conveyor. A control device ensures that in use, a product is transferred from the supply conveyor to a predetermined position on the conveyor. An example of a known system of this kind is disclosed in <CIT>. <CIT> discloses a system for conveying products according to the preamble of claim <NUM>.

One objective of the present invention is to provide a system for conveying products that is suitable for application with a large variety of products. Another objective of the invention is to provide a system for conveying products, with an increased capacity. Another objective of the invention is to provide a system for conveying products, with increased reliability.

One or more of said objectives are achieved with the system according to the invention, for conveying products, comprising.

wherein the supply conveyor comprises a positioning portion and the supply drive device is configured to speed up or to slow down a product at the location of the positioning portion in order to ensure that the product, on being transferred from the supply conveyor to the conveyor, moves to the predetermined position on the conveyor; wherein the system further comprises:.

One effect of the system according to the invention is that through application of said blowing device even relatively light products, for example such as letterbox packets including products in envelopes, can be conveyed effectively with the system and can be transferred with the supply conveyor to the conveyor. Because the products are forced against the supplying carrying surface by the air stream, in operation the products, in particular relatively light products, during said acceleration or deceleration, will not or will at least to a considerably smaller extent have a tendency to slide relative to the accelerating or decelerating supplying carrying surface thereunder, or even, under the influence of air resistance, come away from the supplying carrying surface and possibly even land up next to the supply conveyor. Light products of this kind can thus be conveyed effectively with the system by employing said blowing device. The system according to the invention is therefore suitable for a large variety of products, in particular also relatively light products. Owing to said blowing device, the reliability of the system also increases, since any undesirable sliding of a product relative to the accelerating or decelerating supplying carrying surface thereunder makes it more difficult or even impossible to allow the product to move to a predetermined position on the conveyor. Application of said blowing device also makes it possible to increase the capacity of the system. This is possible because a conveying speed of products on the conveyor and on the supply conveyor can be increased since owing to the blowing device, as explained, products do not have or at least have to a considerably smaller extent a tendency to slide relative to the accelerating or decelerating supplying carrying surface thereunder so that even at an increased speed, reliable transfer of products can be achieved.

In one embodiment the conveyor may be a sorting conveyor, for example such as a transverse-belt conveyor or a tilt-tray conveyor or possibly also a conveyor wherein products are pushed with pushing shoes in the transverse direction of the conveyor.

In one embodiment the blowing device comprises two successive blowing units in the supply direction. The blowing device, and if using said two blowing units each of the blowing units, is in one embodiment configured to generate an air stream that extends over a width of the positioning portion. "A width" means a width of the supplying carrying surface, in a transverse direction transverse to the supply conveying direction, of the supply conveyor. Application of two successive blowing units increases a length of the supply conveyor, more particularly of the positioning portion, on which the products are, in operation, subjected to the air stream, and therefore further increases the reliability of the system.

In one embodiment the blowing device is configured to generate the air stream in such a way that this also is directed in the supply direction. By thus directing the air stream slanting forwards and downwards, products are to an even greater extent subjected effectively to the air stream and products can, in particular when accelerating, be subjected to greater acceleration. One angle of the air stream is in one embodiment located at an acute angle in the range from <NUM> to <NUM> degrees, preferably from <NUM> to <NUM> degrees, to the supplying carrying surface, seen in side view of the supply conveyor. Said angle relates to a main direction of the air stream, i.e. the average angle. The air stream itself may extend/fan out over a range of angle.

In one embodiment the blowing device is configured to generate the air stream with an air speed component in the supply direction that is at least roughly equal to a speed of movement of products on the conveyor. Therefore the products are subjected to the air stream very effectively and coordinated with the speed of movement of the conveyor.

In one embodiment the control device is configured to control the blowing device in such a way that in operation the blowing device generates the air stream only during acceleration and deceleration of a product, preferably only during acceleration. Only generating the air stream at said times lowers the energy consumption of the system.

In one embodiment the system further comprises a transfer portion between the positioning portion and the conveyor, said transfer portion being arranged in such a way that at the location of the transfer portion the supply direction, seen in top view, makes an acute angle with the conveying direction. Therefore products are already partly transferred to the conveyor in the desired conveying direction. Said acute angle may in one embodiment be in the range from <NUM> to <NUM> degrees, preferably from <NUM> to <NUM> degrees.

In one embodiment the supply drive device is configured such that a speed of movement of products in the supply direction on the transfer portion is at least substantially equal to a speed of movement of products in the conveying direction on the conveyor. This leads to a controlled and therefore reliable transfer of products from the supply conveyor to the conveyor.

The invention also relates to a method for conveying products, making use of a system as described above according to the present invention. The method comprises:.

wherein the method further comprises:
c) for the purpose of step b), generating with the blowing device, under the influence of the control device, an air stream from above the supplying carrying surface in the direction of the supplying carrying surface at the location of the positioning portion, so that products are forced against the supplying carrying surface.

Effects of the method according to the invention are similar to effects of the system according to the invention described above. Embodiments of the system according to the invention are similar in application to the method according to the invention, and vice versa.

In one embodiment, during step c), with the blowing device, the air stream is generated with an air speed component in the supply direction that is at least roughly equal to a speed of movement of products on the conveyor. Therefore the products are subjected to the air stream very effectively and coordinated with the speed of movement of the conveyor.

In one embodiment, for the purpose of step c) the control device controls the blowing device in such a way that the blowing device generates the air stream only during acceleration and deceleration of a product, preferably only during acceleration. Only generating the air stream at said times lowers the energy consumption of the system.

The present invention will be explained hereunder on the basis of the description of preferred embodiments of a system and method according to the invention, referring to the following figures.

The figures show a system <NUM> for conveying products <NUM>, <NUM>. For this purpose the system <NUM> comprises a conveyor <NUM>, being, in the example shown in <FIG>, a transverse-belt conveyor, which has successive, driven transverse belts <NUM> with which products can be sorted at the location of sorting locations, not shown further in the figures, by moving products off of the conveyor in the transverse direction by activating a drive of a transverse belt at the location of a sorting location. The conveyor <NUM> is actually only shown partly in <FIG> and is in practice endless. The conveyor has a carrying surface <NUM> for the products <NUM>, <NUM> and a drive device <NUM> (shown very schematically) for moving products <NUM>, <NUM> located on the carrying surface <NUM> in a conveying direction <NUM>.

The system <NUM> also has a supply conveyor <NUM>, which connects to the conveyor <NUM> at a supply location <NUM>. The supply conveyor has a supplying carrying surface 14a, 14b, 14c for products <NUM> and a supply drive device <NUM> for moving in a supply direction <NUM> products <NUM> located on the supplying carrying surface 14a-c and transferring these products <NUM> to the conveyor <NUM>. The supply conveyor <NUM> has an upstream belt conveyor <NUM>, which has a part 14a of the supplying carrying surface, for supplying products <NUM> to a positioning portion <NUM>, to be defined in more detail hereunder. The belt conveyor <NUM> is only shown very schematically in <FIG>. The supply conveyor <NUM> also has a transfer portion <NUM>, which has a part 14c of the supplying carrying surface, between the positioning portion <NUM> and the conveyor <NUM>. The transfer portion <NUM> is arranged in such a way that at the location of the transfer portion <NUM>, the supply direction, seen in top view, makes an acute angle "a" with the conveying direction <NUM>. The supply drive device <NUM> may be configured so that a speed of movement of products <NUM> in the supply direction <NUM> on the transfer portion <NUM> is at least substantially equal to a speed of movement of products <NUM>, <NUM> in the conveying direction <NUM> on the conveyor <NUM>.

The system <NUM> has a control device <NUM> (shown very schematically and in practice connected actively, such as wired or wireless, to the conveyor and the supply conveyor), said control device <NUM> being configured to control the supply drive device <NUM> in operation in such a way relative to the drive device <NUM> that a product <NUM> is transferred from the supply conveyor <NUM> at a predetermined position <NUM>, <NUM>' onto the conveyor <NUM>. This position may, as shown in <FIG> for position <NUM>', be an empty position on the conveyor <NUM> between two products <NUM> already present on the conveyor. The product indicated with reference number <NUM>" in <FIG> is transferred earlier from the supply conveyor <NUM> to the conveyor <NUM>. Position information like this can be stored in the control device or may be passed on to the control device by a high-level system controller. The position of each product on the conveyor and the desired position of a product to be transferred to the conveyor may be known and available via the control device. The position of products on the supply conveyor <NUM> may be known and may for example be observed by a detector such as a camera connected to the control device.

For the purpose of transferring a product <NUM> on the supply conveyor <NUM> at a predetermined position <NUM>, <NUM>' onto the conveyor <NUM>, the supply conveyor <NUM> has a positioning portion <NUM>. The positioning portion <NUM> has, at least in the example shown in the figures, four successive conveyor belts <NUM> drivable independently of each other. The supply drive device <NUM> is configured to speed up or to slow down a product <NUM> at the location of the positioning portion <NUM> in order to ensure that on transfer from the supply conveyor <NUM> to the conveyor <NUM>, the product <NUM> moves onto the conveyor <NUM> at the predetermined position <NUM>. For this purpose, the product indicated with reference number <NUM>' is for example already accelerated by means of one or more of the conveyor belts <NUM> so that the product <NUM>' is transferred to position <NUM>'. The product <NUM> located on belt conveyor <NUM> must for example still be accelerated at the positioning portion <NUM> to be able to arrive correctly at position <NUM> on the conveyor <NUM>.

Although determination of the position of a product on the supply conveyor may take place in various ways, including for example with a vision system, i.e. with a camera system, a vertical photocell unit <NUM> is employed in the example shown in the figures. A vertical photocell unit refers to a horizontal row of transmitterreceiver photocells that are active vertically and, in the present example, are directed vertically downward through a gap <NUM> between two successive conveyors and an opposing unit is provided. The horizontal row of photocells preferably extends over the whole width of the supply conveyor <NUM> so that even products that are located completely on one side on the supplying carrying surface can be observed. The output signal of the photocell unit is then only "on" (with no interruption of the light beams at all) or "off" (one or more of the light beams are interrupted). These photocell units are also suitable for detecting low products. These low products are generally also relatively light products, which, as described, are forced by the blowing device in an effective manner against the supplying carrying surface, thus significantly reducing the chance of undesirable displacement or even coming away.

In this way, position information of products on the supply conveyor can thus be observed and be passed on to the control device <NUM> so that, based thereon, for example one or more of the conveyor belts <NUM> of the positioning portion <NUM> may be driven in such a way that this accelerates a product so that it is moved onto the conveyor <NUM> at a desired position.

The system <NUM> further comprises a blowing device <NUM>, which is configured for generating, in operation, under the influence of the control device <NUM>, an air stream from above the supplying carrying surface 14b in the direction of the supplying carrying surface 14b at the location of the positioning portion <NUM>, for forcing, in operation, products <NUM> against the supplying carrying surface 14b. At least in the example shown, the blowing device <NUM> has two successive blowing units <NUM> in the supply direction <NUM>, each configured to generate an air stream <NUM> that extends over a width b of the positioning portion <NUM>. The blowing units are provided on a frame <NUM> above the supplying carrying surface 14a, 14b. The blowing device <NUM> is configured to generate the air stream <NUM> in such a way that this also is directed in the supply direction <NUM>, at least in the example shown in the figures at an acute angle c of about <NUM> degrees to the supplying carrying surface 14b, seen in side view of the supply conveyor <NUM>. In <FIG>, the air streams <NUM> are only indicated by means of the dashed arrows shown, which represent the main air stream. In practice, the air streams <NUM> will fan out. The blowing device <NUM> is configured to generate the air stream <NUM> with an air speed component in the supply direction <NUM> that is at least roughly equal to a speed of movement of products on the conveyor <NUM>. It is advantageous in this case if the control device <NUM> is configured to control the blowing device in such a way that the blowing device only generates the air stream in operation during acceleration and deceleration of a product, preferably only during acceleration.

The system <NUM> as described above is used in a method for conveying products <NUM>, <NUM>. The method comprises the moving of products <NUM>, <NUM>, located on the carrying surface <NUM>, with the conveyor <NUM> in the conveying direction <NUM>, and the moving of products, located on the supplying carrying surface 14a-c, with the supply conveyor <NUM> in a supply direction <NUM>. The control device <NUM> controls the supply drive device <NUM> in such a way relative to the drive device <NUM> that a product <NUM> is transferred from the supply conveyor <NUM> at a predetermined position <NUM>, <NUM>' onto the conveyor <NUM>, for which the supply drive device <NUM> is configured to speed up or to slow down a product <NUM> at the location of the positioning portion <NUM> in order to ensure that the product <NUM> on transfer from the supply conveyor <NUM> to the conveyor <NUM> moves over onto the conveyor <NUM> at the predetermined position <NUM>, <NUM>'.

The method further comprises generating, with the blowing device <NUM>, under the influence of the control device <NUM>, an air stream <NUM> from above the supplying carrying surface 14b in the direction of the supplying carrying surface 14b at the location of the positioning portion <NUM>, so that products <NUM> are forced against the supplying carrying surface 14b.

Claim 1:
System (<NUM>) for conveying products (<NUM>, <NUM>), comprising
- a conveyor (<NUM>) with a carrying surface (<NUM>) for the products (<NUM>, <NUM>) and with a drive device (<NUM>) for moving products (<NUM>, <NUM>), located on the carrying surface (<NUM>), in a conveying direction (<NUM>);
- a supply conveyor (<NUM>) that is connected to the conveyor (<NUM>) at a supply location (<NUM>), with a supplying carrying surface (14a-c) for products (<NUM>) and with a supply drive device (<NUM>) for moving products located on the supplying carrying surface (14a-c) in a supply direction (<NUM>) and transferring these products to the conveyor (<NUM>);
- a control device (<NUM>) that is configured for controlling, in operation, the supply drive device (<NUM>) in such a way relative to the drive device (<NUM>) that a product (<NUM>) is transferred from the supply conveyor (<NUM>) to a predetermined position (<NUM>, <NUM>') on the conveyor (<NUM>);
wherein the supply conveyor (<NUM>) comprises a positioning portion (<NUM>) and the supply drive device (<NUM>) is configured to speed up or to slow down a product (<NUM>) at the location of the positioning portion (<NUM>) in order to ensure that the product (<NUM>), on being transferred from the supply conveyor (<NUM>) to the conveyor (<NUM>), moves to the predetermined position on the conveyor (<NUM>);
characterized by:
- a blowing device (<NUM>), configured for generating, in operation, under the influence of the control device (<NUM>), an air stream (<NUM>) from above the supplying carrying surface (14b) in the direction of the supplying carrying surface (14b) at the location of the positioning portion (<NUM>), for forcing, in operation, products (<NUM>) against the supplying carrying surface (14b).