Patent Description:
Such roller conveyors are frequently used in the transport of products, such as luggage items or parcel items in a warehouse.

German Utility Model <CIT> discloses a method for assembling a roller conveyor having a plurality of successive, driven rollers mounted at a predefined pitch on a frame of the roller conveyor, the successive rollers supporting and conveying products in use of the roller conveyor. This method comprises the steps of:.

An object of the invention is to provide an efficient manner of assembling a roller conveyor.

The above object is achieved by the method according to the invention, as defined in claim <NUM>, for assembling a roller conveyor having a plurality of successive, driven rollers mounted at a predefined pitch on a frame of the roller conveyor, the successive rollers supporting and conveying products in use of the roller conveyor,.

An effect of the method according to the invention is that a very efficient assembling of the roller conveyor is achieved by first only mounting the first support element of the roller to the frame and passing the mentioned drive elements over the pulley means of the roller, after which the drive element is tensioned using a tensioning device and the second support element is mounted to the frame while the drive element is kept tensioned, after which the tensioning device is removed. This way, each time a further roller can be mounted in the same and highly efficient manner, thereby efficiently and quickly assembling the roller conveyor.

Such tensioning of the flexible drive element is relevant for the drive element being able to transfer a drive torque between first and a second pulley means of respective neighbouring rollers. Tensioning the drive element by forcing the roller away from a previously mounted neighbouring roller results in the second support element being brought in the position in which it can be mounted to the second frame part in a very easy manner. After said mounting, the tensioning device can be removed, wherein the drive element remains tensioned so that it can effectively be used to drive a roller.

The driven rollers of the roller conveyor may be driven by a drive motor, preferably an electric motor, coupled to one of the rollers such as via a further endless flexible drive element. The rollers may be coupled in a series configuration, with each time two neighboring rollers being drivingly coupled via an endless flexible drive element. This way, a single drive motor may drivingly rotate the plurality of rollers of the roller conveyor.

In an embodiment, the pulley means may comprise one pulley over which two drive elements may be passed, or may comprise two individual pulleys over each of which a drive element may be passed. The endless flexible drive elements may be drive belts, such as flat belts, V-belts, or poly-V belts. The latter are preferred.

In an embodiment, the first mounting provisions of the first frame part are formed by a plurality of first passages spaced apart at the pitch in a first base part of the first frame part, each passage for receiving therein a first support element of one of the plurality of rollers and for preventing the first support element from moving perpendicular to a longitudinal direction of the roller. This provides for a very simple and robust mounting of the roller to the first frame part. The first support element may have a pin which is received in the passage when mounted.

In an embodiment, the second frame part has a plurality of second passages spaced apart at the pitch, through each of which passages a roller body can pass, wherein for the purpose of the step of mounting the first support element, the roller is at least temporarily moved with at least a part of its roller body through a passage of said series of passages. Such second passages make a very easy mounting of the first support element possible, while at the same time providing a guard preventing access from above the rollers to the pulley means. The second passages may be holes which are slightly larger than an outer diameter of the roller bodies, such as having a diameter of between <NUM> and <NUM> percent larger than that of the roller bodies.

In an embodiment, for the purpose of the step of tensioning the drive element by exerting a force on the roller, a force is exerted on the roller body. Since the roller bodies are easily accessible at least from above, this increases the ease of the mounting of the roller to the frame.

In an embodiment, for the purpose of the step of tensioning the drive element by exerting a force on the roller, the tensioning device is placed between the roller and a previously mounted neighbouring roller thereof.

In an embodiment, each second mounting provision has a removable bracket which can be fixated onto a second base part of the second frame part, wherein for the purpose of the mounting of the second support element of the roller to the second mounting provision while keeping the drive element tensioned by the tensioning device, the bracket is fixated to the base part. Such removable brackets make the mounting of the second support element very easy. Also, they make maintenance very efficient. The bracket may in an embodiment be mounted to the second base part by means of a screw connection.

In an embodiment, the removable bracket has a bracket passage for receiving therein the second support element of the roller and for preventing the second support element from moving perpendicular to a longitudinal direction of the roller. In an embodiment, the bracket and the second base part enclose the pulley means of the roller between them at least in a fixated condition of the bracket on the second base part, increasing the safety of the conveyor. The second support element may comprise a pin which is received in the bracket passage when mounted.

In an embodiment, the bracket and the second base part enclose the pulley means between them at least in a fixated condition of the bracket on the second base part, wherein the second base part has a C-shaped cross section wherein the bracket, in said fixated condition, bridges a gap between ends of legs of the C-shape. Such a construction provides a relatively stiff second base part, while at the same time forming a guard for the pulley means, which increases the safety of the conveyor.

In an embodiment of the method in which several of the above mentioned embodiments are combined, for the purpose of the step of mounting the first support element of the roller,.

The invention also relates to the use of a tensioning device in a method according to the invention, which method is for assembling a roller conveyor having a plurality of successive, driven rollers mounted at a predefined pitch on a frame of the roller conveyor, the successive rollers supporting and conveying products in use of the roller conveyor,.

Such a tensioning device is a very simple and easy-to-use device for effectively tensioning the drive element upon mounting the roller to the frame. Effects relating to the method of the invention described above also apply in a similar manner to the tensioning device of the present invention.

In an embodiment, the first and second pusher bodies are configured for contacting the respective roller bodies of the two rollers. Since the roller bodies are easily accessible at least from above, this increases the ease of the mounting of the roller to the frame.

In an embodiment, the second pusher body is spring loaded on the cam. This way, upon taking away the force by pivoting the cam, the second pusher body removes itself from the roller as a result of a spring force, which makes the positioning of the device between two rollers and the removal of the device from between two rollers very easy and user-friendly.

The cam of the tensioning device may be operated by means of a drive motor such as a servo motor or a stepper motor, for example, or by means of an hydraulic or pneumatic cylinder, for example. In an embodiment for manual operation, the tensioning device may have a lever connected to the cam, which lever is configured be manually operated and is configured such that upon pivoting the lever about a pivot axis thereof, the cam pivots about its pivot axis as well.

In an embodiment, the lever and cam have been designed such that a force ratio between a pivoting force on a free end of the lever and a force exerted by the cam on the second pusher body is at least <NUM>, preferably at least <NUM>.

The present invention is described hereinafter with reference to the accompanying schematic figures in which embodiments of the present invention are shown and in which like reference numbers indicate the same or similar elements.

<FIG> shows a roller conveyor <NUM> assembled using an example of a method according to the present invention. The roller conveyor <NUM> has a plurality of successive, driven rollers <NUM> (only a few of the total of <NUM> rollers have been given a reference numeral). The rollers <NUM> are mounted at a predefined pitch p (see <FIG>) on a frame <NUM> of the roller conveyor <NUM>. Although the conveyor <NUM> has a 'length' of <NUM> rollers, in practice a shorter conveyor or a (much) longer conveyor may be used. The conveyor <NUM> as shown in <FIG> may form a module of a conveyor system having multiple successive such conveyors forming a conveying path. The successive rollers <NUM> are configured to support and convey products, like product <NUM>. Although conveyor <NUM> has an additional series of lower rollers <NUM> below the plurality of rollers, the presence of such lower rollers is not relevant for the present invention. The conveyor <NUM> may or may not have further provisions below the rollers <NUM>, like the shown series of lower rollers. A height of the frame may be set in dependence on application requirements.

The example of the method of the invention comprises providing the plurality of rollers <NUM> and providing the frame <NUM>. Each of the successive rollers <NUM> has a cylindrical roller body <NUM>, and a first supporting element <NUM> and a second support element <NUM> on respective opposite ends <NUM> and <NUM>, respectively, of the roller body <NUM>. The second support element <NUM> has pulley means for coupling the roller <NUM> with both its neighbouring rollers <NUM> via respective endless flexible drive elements, at least in the present example formed as drive belts <NUM>. The drive belts <NUM> may for example be poly-V belts as shown in the figures. The pulley means are formed as one pulley <NUM> over which two drive belts <NUM> may be passed. The frame <NUM> has a first and a second, mutually parallel, elongate frame part <NUM> and <NUM>, respectively, for mounting therebetween the plurality of successive rollers <NUM>. The first <NUM> and second <NUM> frame part each have a plurality of mounting provisions <NUM> and <NUM>, respectively, spaced apart at the pitch p.

The first mounting provisions <NUM> of the first frame part <NUM> are formed by a plurality of first passages spaced apart at the pitch p in a first base part <NUM> of the first frame part, each passage for receiving therein a first support element <NUM> of one of the plurality of rollers <NUM> and for preventing the first support element <NUM> from moving perpendicular to a longitudinal direction <NUM> of the roller <NUM>. The first support element <NUM> is formed as a pin which merely needs to be slid through a passage formed in the base part <NUM> of the first frame part <NUM>. The roller body <NUM> can rotate with respect to the pin. The roller body <NUM> is coupled for rotation to the pulley <NUM>.

The second frame part <NUM> has a plurality of second passages <NUM> spaced apart at the pitch p, through each of which passages <NUM> a roller body <NUM> can pass as <FIG> shows. Each second mounting provision <NUM> has a removable bracket <NUM> which can be fixated onto a second base part <NUM> of the second frame part <NUM>. The removable bracket <NUM> has a bracket passage <NUM> for receiving therein the second support element <NUM>, more specifically a pin <NUM> of the second support element <NUM>, of the roller <NUM> and for preventing the second support element <NUM> from moving perpendicular to the longitudinal direction <NUM> of the roller <NUM>. As can be understood from <FIG>, the hexagonal pin <NUM> merely needs to pass through the correspondingly shaped bracket passage <NUM> and the same holds for the first support element <NUM> mounted to the first mounting provision <NUM>. That means, in principle, no lock nut or the like needs to be mounted to either of the first and the second support elements <NUM>, <NUM>. The bracket <NUM> and the second base part <NUM> enclose the pulley <NUM> of the roller <NUM> between them at least in a fixated condition of the bracket <NUM> on the second base part <NUM>, as <FIG> and <FIG> show in particular. The second base part <NUM> has a C-shaped cross section wherein the bracket <NUM>, in said fixated condition as shown in the figures, bridges a gap G between ends <NUM> of legs of the C-shape. The bracket may easily be mounted to the second frame part <NUM> by a screw connection as shown.

The example of the method of the invention further comprises, for the purpose of mounting a roller <NUM> of the plurality of rollers <NUM> to the frame <NUM>, the following steps. See in particular <FIG>.

<FIG> shows that a first roller <NUM>' has already been mounted. The use of the reference numerals <NUM>' and <NUM> is merely for the purpose of explaining the method. The rollers <NUM>' and <NUM> are identical. The first roller <NUM>' may be connected to a drive means, such as a drive motor, of the conveyor. The first support element <NUM> of a roller <NUM> is mounted to a first mounting provision <NUM> of the first frame part <NUM>, by sticking a pin of the first support element <NUM> through a passage forming the first mounting provision <NUM>, while leaving the opposite second support element <NUM> of that roller <NUM> free from a second mounting provision <NUM> of the second frame part <NUM>. In more detail, the roller <NUM> is at least temporarily moved with at least a part of its roller body <NUM> through a second passage <NUM>, after which the first support element <NUM> is moved towards the first frame part <NUM> such that the first support element <NUM>, or at least the mentioned pin thereof, is received in a passage forming the first mounting provision <NUM> in the first base part <NUM>.

A drive belt <NUM> and a further drive belt <NUM>' are passed over the pulley <NUM> of the roller <NUM> (<FIG>). As shown, drive belt <NUM> couples the roller <NUM> to the first roller <NUM>', which is its previously mounted neighbouring roller, so that the rollers <NUM>' and <NUM> are drivingly connected. The drive belt <NUM>' is still to be passed about another neighbouring roller still to be mounted (on the right side of roller <NUM> in the view of <FIG>). The drive belt <NUM> is tensioned by exerting a force on the roller <NUM> by means of a tensioning device <NUM>. <FIG> shows a first state of the tensioning device <NUM> in which it is placed in between the roller <NUM> and the previously mounted neighbouring roller <NUM>'. <FIG> shows a second state of the tensioning device <NUM> in which it exerts a force on the roller <NUM>. The construction of the tensioning device <NUM> will be further explained below. The second support element <NUM> of the roller <NUM> is then mounted to the second mounting provision <NUM> while keeping the drive belt <NUM> tensioned by the tensioning device <NUM>. See <FIG>, showing that a bracket <NUM> is placed over the pin <NUM> of the second support element <NUM> and fixated to the base part <NUM> of the second frame part <NUM> while keeping drive belt <NUM> tensioned. Then, the tensioning device <NUM> is removed from the roller <NUM>. These steps are repeated until the plurality of rollers have been mounted to the frame <NUM> of the roller conveyor <NUM>, thereby assembling the roller conveyor <NUM>. For the purpose of the step of tensioning the drive belt <NUM> by exerting a force on the roller <NUM>, a force is exerted on the roller body <NUM> as the figures show.

The mentioned tensioning device <NUM> for use in the above described example of a method according to the invention, is configured for tensioning an endless flexible drive element passed about respective pulley means of two neighbouring rollers <NUM>', <NUM> of the roller conveyor of which a first roller <NUM>' has already been mounted to the frame of the device and the other roller <NUM> is to be mounted to the frame, as described in more detail above. The tensioning device <NUM> is shown in more detail in <FIG>.

The tensioning device <NUM> has a body part <NUM>, a first pusher body <NUM> for contacting the first <NUM>' of the two rollers, fixated on the body part <NUM> such as by means of a screwed connection as shown or fixated on the body part <NUM> by manufacturing the body part and the first pusher body <NUM> as one integral part, for example, or by welding it to the body part. The device <NUM> also has a second pusher body <NUM> movably provided on the body part <NUM>, for contacting the roller to be mounted to the frame <NUM> of the roller conveyor <NUM>. The second pusher body <NUM> has upward extending pins <NUM> passing through slots <NUM> in the body part <NUM> for the purpose of being movable with respect to the body part <NUM>.

The tensioning device <NUM> further has a cam <NUM> between the first <NUM> and second <NUM> pusher body, such that pivoting the cam <NUM> about a pivot axis <NUM> thereof results in the cam <NUM> forcing the second pusher body <NUM> away from the first pusher body <NUM> thereby exerting a force on the roller to be mounted when provided in between two neighbouring rollers, thereby tensioning the drive belt <NUM> as explained above. As <FIG> show in particular, the cam is shaped such that upon a counterclockwise pivoting movement about the pivot axis <NUM>, the second pusher body <NUM> is forced away from the first pusher body <NUM>. <FIG> shows a first state of the tensioning device <NUM> in which the second pusher body <NUM> is closer to the first pusher body <NUM> and <FIG> shows a second state of the tensioning device <NUM> in which the second pusher body <NUM> is further from the first pusher body <NUM>. The first and second pusher bodies <NUM>, <NUM> are configured for contacting the respective roller bodies <NUM> of the two neighbouring rollers <NUM>', <NUM>. For that purpose, they have respective concave outer surfaces <NUM> and <NUM>, respectively, the concave surfaces preferably being adapted to the shape of the roller bodies <NUM>.

The second pusher body <NUM> is spring loaded on the cam <NUM>. This is realised by the two coil springs <NUM> mounted between fixed mounting pins <NUM> on the base body and the pins <NUM> on the second pusher body <NUM>, and exerting a pulling force on the pins <NUM> such that the second pusher body <NUM> is pulled towards the first pusher body <NUM> and thereby against the cam <NUM>. The tensioning device <NUM> further has a lever <NUM> connected to the cam <NUM>, which lever <NUM> is configured be manually operated and is configured such that upon pivoting the lever <NUM> about a pivot axis thereof, which is in the present example the pivot axis <NUM>, the cam <NUM> pivots about the pivot axis <NUM> as well.

Claim 1:
Method for assembling a roller conveyor (<NUM>) having a plurality of successive, driven rollers (<NUM>) mounted at a predefined pitch (p) on a frame (<NUM>) of the roller conveyor (<NUM>), the successive rollers supporting and conveying products (<NUM>) in use of the roller conveyor,
the method comprising the steps of:
- providing the plurality of successive rollers each having a cylindrical roller body (<NUM>) and a first and a second support element (<NUM>, <NUM>) on respective opposite ends of the roller body, the second support element (<NUM>) having pulley means (<NUM>),
- providing a frame (<NUM>) having a first and a second, mutually parallel, elongate frame part (<NUM>, <NUM>) for mounting therebetween the plurality of successive rollers, wherein the first and second frame part each have a plurality of mounting provisions (<NUM>, <NUM>) spaced apart at the pitch (p),
the method being characterized in that it comprises for the purpose of mounting a roller of the plurality of rollers to the frame, the further steps of:
- mounting the first support element (<NUM>) of a roller to a first mounting provision (<NUM>) of the first frame part while leaving the opposite second support element (<NUM>) of that roller free from a second mounting provision (<NUM>) of the second frame part,
- passing an endless flexible drive element (<NUM>) and a further endless flexible drive element (<NUM>') over the pulley means (<NUM>) of the roller (<NUM>),
wherein the drive element (<NUM>) also passes over the pulley means (<NUM>) of a previously mounted neighbouring roller (<NUM>) and wherein the further drive element (<NUM>') is still to be passed about another neighbouring roller (<NUM>) still to be mounted,
- tensioning the drive element (<NUM>) by exerting a force on the roller (<NUM>) by means of a tensioning device (<NUM>),
- mounting the second support element (<NUM>) of the roller (<NUM>) to the second mounting provision (<NUM>) while keeping the drive element (<NUM>) tensioned by the tensioning device (<NUM>), and then
- removing the tensioning device (<NUM>) from the roller (<NUM>).