NL2037587B1 - Section for an accumulating roller transporter - Google Patents

Abstract

1 9 The invention relates to a section for an accumulating roller transporter. It comprises a series of rollers, a section drive mechanism, configured to drive the series of rollers in rotation, and a motive power input. The section drive mechanism is switchable between a transport state and a stopping state. According to the invention, in the transport state, the section drive mechanism is coupled to each of the series of rollers, and is coupled to the motive power input to transfer motive power from the motive power input to each of the series of rollers, and in the stopping state, the section drive mechanism is coupled to each of the series of rollers, and is decoupled from the motive power input. A roller transporter with such sections is also disclosed. 1 <fig. 2B>

Description

SECTION FOR AN ACCUMULATING ROLLER TRANSPORTER

The invention relates to a section for an accumulating roller transporter, the section being configured to form together with one or more further sections, a complete accumulating roller transporter, the section comprising a series of rollers arranged in a transport direction, configured for transporting an object placed on some of the series of rollers in the transport direction by rolling, and for temporarily storing said object by stopping the rolling, a section drive mechanism, configured to drive the series of rollers in rotation, and a motive power input, configured to receive motive power for the section, wherein the section drive mechanism is switchable between a transport state and a stopping state.

Accumulating roller transporters are used in warehouses for the transportation and temporary holding of pallets with objects. The pallets can be placed on the rollers, in order to be transported by rolling. Typically, the pallets are transported from an upstream entry position to a downstream unloading position. In between, the pallets are lined up back-to-back, thus temporarily being accumulated, so they can be picked up one-by-one and when desired, from the unloading position, using for example a forklift.

To create modular designs of roller transporters, it is customary to divide them in sections, each section corresponding to one position for a pallet. It is principally possible to drive some or all rollers independently, in order to accurately position the pallet on the sections. However, the required driving arrangements and control systems are rather complicated. Leaving some rollers undriven removes complexity, however only at the expense of accuracy. Accuracy problems for instance arise when relatively heavy pallets slide onwards even after driving has stopped, due to the inertia of the heavy pallets. This problem is exacerbated when some or all rollers are freely rotating, and can thus not be used for braking the pallet.

A solution exists that combines driving all rollers in a section with a relatively simple control, by selectively coupling or decoupling a motive power input on the one hand with the collection of rollers on the other hand. While control of such systems is simpler, the rollers can, in the decoupled state, not easily be used to brake the pallet. As a result, pallets of different weight, due to their different inertia, have a different brake distance. To account for even the heaviest pallets, with the longest brake distance, accumulating roller transporters are therefore made oversized.

It is an object of the invention to at least partially address these problems. More specifically, it is an object of the invention to provide a section for an accumulating roller transporter wherein the transported pallets can be placed relatively closely to each other, preferably regardless of pallet weight, and which is easily controlled.

The object is achieved by a section for an accumulating roller transporter according to the preamble. wherein in the transport state, the section drive mechanism is coupled to each of the series of rollers, and is coupled to the motive power input to transfer motive power from the motive power input to each of the series of rollers; and in the stopping state, the section drive mechanism is coupled to each of the series of rollers, and is decoupled from the motive power input.

Using a central motive power input which can be selectively coupled and decoupled to and from the individual sections can provide to a more elegant system of providing movement to the individual sections, and thus easy control over the placement of the pallets. Once decoupled from the motive power input, the section drive mechanism is no longer powered. However, it is still coupled to the rollers, so that these rollers are hindered in their rotation by each other and the drive mechanism, thereby causing a braking effect on each roller.

This contrasts sharply to the prior art solution decoupling the rollers. because in the system described herein the rollers are not left free to rotate. In fact, they are still coupled to each other via the section drive mechanism.

It should be noted that while the term drive mechanism is used, this mechanism could also be a mechatronic or an electronic system. In particular however, the section drive mechanism may be entirely or substantially mechanical in nature. In examples presented below, it will be shown the section drive mechanism comprises a chain, which is selectively coupled to the motive power input via a clutch. Of course, a belt could also be used, or some other drive mechanism.

Furthermore, while the object that is transported is referred to as a pallet for the purpose of explaining the prior art and in some cases the invention, the accumulating roller transporter as described herein can be used for any object. In particular, but not necessarily, the objects may be carrier for other products, such as pallets, trays, boxes, sleds, carts, etc.

It is further noted that some particular features described below may be applied even if in the stopping state the section drive mechanism is not coupled to each of the series of rollers, regardless of whether or not it 1s coupled to the motive power input. In other words, the invention also relates to the preamble of claim 1, wherein the section drive mechanism selectively couples some or all of the series of rollers to the motive power input in the transport state and the stopping state respectively, combined with any suitable dependent claim (with or without the characterizing portion of claim 1).

In particular, in the stopping state, the section drive mechanism rotationally fixes the series of rollers with respect to each other. This may be particularly advantageous, because by coupling the series of rollers with respect to each other, the resistance to rotation of all rollers together may increase. As such, the rollers are able to impart a larger braking force on the object. In particular, even rollers which do not directly contact the object may still contribute to the total braking force.

Said contribution would be imparted on the object via the section drive mechanism and another roller, which at that point is still in contact with the object. The resulting braking distance may bring about a significant economic advantage, as the total accumulating roller transporter may be made shorter (with the same amount of sections) or may include more sections for the same length, or both. More effective use can therefore be made of space inside a warehouse, e.g. a cooled warehouse. Needless to say, the reduced amount of materials for a shorter accumulating roller transporter may also be advantageous in itself.

The series of rollers may, in at least the stopping state and optionally also in the transport state, be rotatable in a direction corresponding to the transport direction, e.g. when overcoming a braking force, but not in the opposite direction. The series of rollers being rotatable may herein mean that they are free to rotate collectively, for instance when overcoming the braking force, as in the stopping state they may still be coupled to each other via the section drive mechanism as explained above. The braking force may be applied via a brake, but can also result from friction in the system.

Accordingly, when an object is being transported and the section drive mechanism is switched to the stopping state. the rollers may allow an overshoot. though optionally small as explained above, of the object due to the inertia of the object. When the object is however offloaded using e.g. a forklift, the blocking of the rollers in the opposite direction allows easier pickup. The pickup using a fork lift thus benefit from a free-wheeling behaviour of the rollers. The free-wheeling behaviour may be provided by a free-wheel for instance for each and every roller (e.g. connecting the roller to the section drive mechanism, but is preferably provided for the section drive mechanism as a whole. As an example, a coupling could be used to power the section drive mechanism from the motive power input, the coupling providing the free-wheeling behaviour. Of course, the free-wheeling behaviour includes at least sufficient braking force to bring the objects to a stand still, for instance from friction.

In order to switch the section between its transport state and its stopping state, the section can further comprise a stopper switch which is movable between an activated and a non-activated state.

Practically, the stopper switch protrudes above the series of rollers so as to be activated when contacted by an object, such as a pallet, transported by the series of rollers in the transport direction. Further, the stopper switch is connected to the section drive mechanism via a transfer mechanism. Via the transfer mechanism, the stopper switch can facilitate switching the drive mechanism from its transporting state to its stopping state. Due to the stopper switch being activated when contacted by an object, an automatic triggering of the stopper switch is obtained.

Use can be made of this automatic triggering for the actual switching of the section drive mechanism without requiring active control or user involvement.

Another or an alternative advantage of the stopper switch protruding above the rollers, is that even relatively light objects, for instance unloaded or lightly loaded pallets, still cause activation of the stopper switch. The stopping system as described herein is thus suitable not only for heavy objects. but also for the lighter ones.

Aside from the stopper switch, the section can also further comprise an input switch, which is movable between an activated and a non-activated state, wherein the input switch is connected to the transfer mechanism, and wherein the transfer mechanism is configured to switch the section drive mechanism from the transport state to the stopping state only when both the stopper switch and the input switch are activated.

This particular combination of input switch and transfer mechanism features may be used to introduce more automated functioning of the transporter. In particular, the input switch can be used to provide a further prerequisite, further to activation of the stopper switch, for switching the section drive mechanism. It can therefore be used to switch the drive mechanism when an object triggers the stopper switch only when the further prerequisite is fulfilled. Depending on the configuration of further components, the prerequisite may be used to further automate control. As an example, the input switch could be activated by default, so that any triggering of the stopper switch would switch the section drive mechanism, e.g. to stop the object. As another example, the input switch could be disengaged, so that even if the stopper switch is triggered, the section drive mechanism is not, and the object may proceed.

Advantageously, the input switch is manipulated such that objects proceed automatically along the accumulating roller transporter to the next section, until the end of the transporter where the first object is brought to a halt. Then, the next object preferably halts before the last section, and so on. In this way, the entire accumulating roller transporter can be filled using suitable control of the input switch of each section.

The transfer mechanism can possibly be biased to switch the section drive mechanism to the transport state. This bias causes a consistent tendency of the section to move objects along when possible. As an example, once a pallet has been unloaded from the downstream unloading position, the accumulating roller transporter should move pallets from upstream sections further downstream, filling up the downstream unloading position again. For this purpose it is desired that the rollers start rolling again, which is done by switching the section drive mechanism to its transport state. This can be achieved by biasing the transfer mechanism, for example with a spring, so that it switches the section drive mechanism to the transport state and returns the stopper switch back to its original position. Of course other biasing means may be used, but a spring is mentioned here specifically because it allows a purely mechanical solution which requires no complex control.

In particular, the transfer mechanism can be configured to switch the section drive mechanism to the transport state when the stopper switch and/or the input switch is in its respective non-activated state. By configuring the transfer mechanism in such a way, the section will be moved to the transport state as soon as either the section is clear of any pallets (de-activating the 5 stopper switch), or when the input switch is in its non-activated state, which can increase system automation.

In some embodiments, the section further comprises an output switch, which is switchable between an activated and a non-activated state, e.g. for switching an input switch of a further section for an accumulating roller transporter, wherein the stopper switch is coupled to the output switch to activate the output switch when the stopper switch is activated, wherein optionally said coupling is made by the transfer mechanism.

The output switch generally allows the section of the accumulating roller transporter to communicate to other sections about the status of its stopper switch. This information can be used to control and/or automate other sections, particularly upstream sections. In practice, the output switch is used by individual sections to communicate about the presence of pallets on top of that section. As an example, if the stopper switch is activated in a section, the output switch of it will correspondingly also be activated. The output switch can thus be used to ascertain that a pallet has reached that particular section.

The skilled person will recognize that a particularly modular section is created when both the output and the mput switch are present. In that case, the output switch of a downstream section can be coupled to the input switch of an upstream section.

In this manner, the sections may behave almost fully automatically. As an example, an object placed on the upstream section is presumed. When the object first enters the upstream section, it may not vet trigger the stopper switch. As such, the section drive mechanism is still in its transport state (e.g. by being biased or switched towards it). The rollers of the upstream section are thus driven to transport the object. Similarly, the rollers of the downstream section are driven, but as they are not vet in contact with the object, this is of no importance for this example.

When the object encounters and triggers the stopper switch of the upstream section, nothing changes still. After all, the transfer mechanism is configured only to switch the section drive mechanism to the stopping state when the stopper switch is activated, and when the input switch is also activated. Since the stopper switch of the downstream section however is not yet activated, neither is the output switch of the downstream section, and consequently neither is the mput switch of the upstream section. The section drive mechanism of the upstream section is thus kept in its transport mode. Accordingly, the object is transported downstream to the downstream section.

At some point, the object will trigger the stopper switch of the downstream section. This will in turn trigger the corresponding output switch and the input switch of the upstream section. If at this time a further object on the upstream section is introduced, this further object will come to a standstill as follows. The further object will trigger at some point the stopper switch of the upstream section. At this time, the input switch of the upstream section is still triggered by the former object on the downstream section. Thus, the section drive mechanism is switched to the stopping state by the transfer mechanism. As a result, rollers of the upstream section are no longer driven, and thus stop, along with the object.

In summary, an upstream object is automatically stopped when a downstream object blocks its path.

When the downstream object is removed or transported further, the further object may be transported again. For this purpose, it is advantageous to bias the switches to their de-activated states. It may be sufficient to bias the stopper switch only, the output switch only, or the input switch only. Of course, any combination can also be made.

It can be particularly advantageous for the transfer mechanism to be separate from the section drive mechanism.

Accordingly, the transfer mechanism can be made relatively light-weight and easy to manipulate, as it is not subject to the same design constraints that may apply to the section drive mechanism. In a way, the transfer mechanism being separate from the section drive mechanism causes a decoupling between the drive line and the control of the drive line. This facilitates control.

It is possible for the series of rollers to define a downstream end and an upstream end of the section as seen in the transport direction, and wherein the stopper switch is arranged closer to the downstream end than to the upstream end, preferably at less than 15% of a section length defined between the upstream and downstream ends from the downstream end, more preferably at less than 10% of the section length from the downstream end, even more preferably at less than 7% of the section length from the downstream end.

By moving the stopper switch towards the downstream end. any unusable space beyond the stopper switch is limited. Accordingly, the actual usable area of the section relative to its total size is larger, thus increasing the space efficiency of the section.

Each section may comprise one or more rollers between the downstream end and the stopper switch. It is preferable if only one roller is present in this position, so as to limit the space between stopper switch and downstream end. This is possible because of the features described in claim 1.

As an example, in a roller transporter for pallets of 1200 mm in length along the transport direction, prior art section lengths are typically in the range of 1450 — 1475 mm. This allows some space between pallets on adjacent sections, but also allows a heavy pallet to slow down over a relatively large braking distance due to their inertia. According to the invention however, it is possible to shorten the section, e.g. to approximately 1330 mm, although anywhere between 1300 and 1400 mm is already an improvement, or between 1320 and 1350 mm. As an example, less rollers may be needed. Of course, depending on the diameter chosen, the amount of rollers may be less than 10, for instance 9 or 8, in this case for rollers with a 166 mm centre distance.

In one embodiment of the section, the section can comprise a first actuator connected to the section drive mechanism, the first actuator being switchable between an engaged state, in which it moves the section drive mechanism to the stopping state or keeps the section drive mechanism in the stopping state, and a non-engaged state, in which it leaves the section drive mechanism free to move towards or remain in the transport state.

Additionally or alternatively, the first actuator can be coupled to the output switch, optionally via the transfer mechanism, and can be configured to activate the output switch or keep the output switch activated.

Including the first actuator allows selectively stopping transport of upstream objects. After all, if the output switch is activated via the first actuator, upstream sections will stop automatically transporting further objects. In the section including the first actuator itself, the first actuator can also be used to delay the section drive mechanism from switching to the transport state if desired. for instance during unloading.

As an example, when an operator lifts the pallet from the section, it, and the previous section, may be biased back to the transport state because the stopper switch is no longer activated.

This would cause the sections to start transporting again, and thus pallets from upstream sections would start moving immediately. By including the actuator, this can be temporarily be prevented, thus allowing the operator to safely remove the pallet before pallets from previous sections will be transported to the section forming the downstream unloading position again.

The section may further comprise a sensor configured to register deactivation of the stopper switch and a timer connected to the first actuator to disengage the actuator when a predefined amount of time has passed after the stopper switch has been deactivated.

This combination of features may increase safety by preventing transport for the predetermined amount of time after an object has been taken from the accumulating roller transporter.

The section may comprise a second actuator connected to the section drive mechanism for switching it to the transport state.

Accordingly, it is possible to force the section to restart transport on command. Depending on the configuration, this is useful for instance, perhaps exclusively, at the most downstream section.

The section drive mechanism can comprise a first endless drive element connected to each of the series of rollers. The endless drive element may for instance be a belt or a chain, or similar.

The first endless drive element can act as the coupling between the motive power input and the series of rollers, whilst the same component can maintain the rotational fixation between multiple rollers at once.

The invention also relates to an accumulating roller transporter comprising at least two sections as described herein, e.g. according to any of the previously discussed variations and embodiments. As stated before, the sections mentioned above can be disposed in such a way that they connect to each other in the transport direction, thus creating a complete accumulating roller transporter.

One possible setup of sections would be for a first section of the at least two to comprise at least an output switch for switching an input switch of a further section for an accumulating roller transporter, and for a second section of the at least two sections to comprise an Input switch, wherein the output switch of the first section is coupled to the input switch of the second section.

This way, the presence of a pallet on a section that is closer to the downstream unloading position can activate the input switch of a section that is located to its upstream end, so that when a pallet enters this upstream section, and engages the stopper switch, will be switched to its stopping state as well, thus successfully aligning the pallets back-to-back on adjacent sections.

When the sections are combined into an accumulating roller transporter, the transporter can also comprise a second endless drive element and a drive connected to the second endless drive element to move the second endless drive element, the second endless drive element being connected to the motive power input of each section. Preferably, the drive is continuously engaged regardless of whether objects are to be moved by any one particular section or not.

As a result, all sections can be driven by a single system, and the sections themselves can selectively engage by coupling to the motive power input or not. This removes the requirement for convoluted control at the system level, because the sections themselves may be better able to handle said control.

The invention will be further elucidated with reference to the drawings, in which:

Figure 1 shows schematically a perspective view of an accumulating roller transporter;

Figures 2A and 2B show schematically and in perspective a section of an accumulating roller transporter and details thereof;

Figure 3 shows schematically a side view of details of a portion of an accumulating roller transporter;

Figure 4 shows schematically a perspective view of details of the section drive mechanism of a section of an accumulating roller transporter;

Figures SA and 5B show schematically perspective views of details of the section drive mechanism of a section of an accumulating roller transporter; and

Figures 6A — 6H show schematically how objects are transported and temporarily stored on an accumulating roller transporter.

Across the figures, like elements are referred to using like reference numerals. Like elements of different embodiments are indicated using reference numerals increased by one hundred (100).

Figure 1 shows an accumulating roller transporter 1. The accumulating roller transporter 1 consists of several sections 2, 3, 4 one behind another in a transport direction T. The first section 3 as seen in the transport direction T, is arranged on the upstream end 11 of the accumulating roller transporter 1. The last section 4 as seen in the transport direction T is at the downstream end 12. In between are middle sections 2. As an example a total of five sections 2. 3. 4 is shown in figure 1, butitis principally possible to create a roller transporter 1 of a desired length by using a desired number of sections. Typically, and also the case in this example, the middle sections 2 are identical.

The first section 3, at the upstream end 11, is different in that it comprises a drive motor (not shown), for driving a second endless drive element 50, 51 which will be introduced below. Of course, the drive motor could be placed anywhere suitable. The last section 4, at the downstream end, is also different from the middle sections 2, in that it is modified to show some behaviour specific for the downstream end 12. The modifications will be described below. Each section 2, 3, 4, comprises a series of rollers 5 (not all rollers are numbered for the sake of clarity) arranged in parallel and one behind another in the transport direction T. Each roller 5 itself is transversal to the transport direction T. The collective of rollers 5 of all sections 2, 3, 4 combines to form a movable transport surface 6. Accordingly, an object can be carried by the rollers 5 and moved in the transport direction T from one section 2, 3, 4, to another section 2, 3, 4 by rotation of the rollers 5.

The sections 2, 3, 4 comprise a frame 7 that holds the rollers 5. The frame 7 itself is held at a certain height using legs 8, most of which are used to carry two adjacent sections 2, 3, 4. Each section is oriented such that an upstream end 9 of the section and a downstream end 10 of that section align with the transport direction. Throughout the figures, details of each section will be described in each case with reference to one section only. The features are optionally present in all sections. The last section 4 at the downstream end 12 differs slightly from the others, as will be explained further below.

A single section 2 is depicted in figures 2A and 2B. This section 2 would be repeated to form a complete transporter. Brief reference is made to the legs 8, which are shared between adjacent sections 2. Figure 2A shows that the section 2 has a total of nine rollers 5. It is also possible to use some other number of rollers 5 per section 5. It is particularly envisaged to use eight rollers 5. The rollers 5 are arranged in parallel and behind one-another in the transport direction T, which is aligned with the upstream end 9 and the downstream end 10 of the section. A stopper switch 13 is seen to protrude above the rollers 3, 1.e. above the transport surface 6 defined by the rollers 5. The stopper switch in this case consists of a bar 15 extending transversally with respect to the transport direction, and carried by three brackets 16 which extend around one of the rollers 5. Accordingly, an object being transported will inevitably interact with the stopper switch 13. Of course another type of stopper switch 13 could be employed. The stopper switch 13 is arranged near the downstream end 10 of the section 2. In this case, the stopper switch 13 is shown two rollers 5 down from the downstream end 10, whilst seven rollers are on the upstream side of the stopper switch 13. However, it is principally possible and particularly envisaged, to use eight rollers 5 and place the stopper switch 13 between the last roller 5 nearest the downstream end 10 and the other seven rollers. Of course, other numbers of rollers 5 could be used. In this example, and regardless of the number of rollers 5, the stopper switch 13 is arranged close to the downstream end 10. As compared to the length of the section 2 in the transport direction T the stopper switch is at ca. 11 % of that length. When eight rollers are used. the stopper switch can be arranged at less than 7% of the length.

To show details of the section 2, the rollers 5 have been made invisible in figure 2B, exposing roller mounts 19 that still indicate where the invisible rollers would be arranged. The thusly revealed details will be explained further below, at the same time referencing figure 3. In figure 3 the rollers are visible from their sides, because a part of the frame 7 otherwise blocking view of the rollers 5 and other details has been made invisible.

The section is driven by a section drive mechanism. In this case, the section drive mechanism comprises a first endless drive element 17, in this case a section chain 17, but another type of element could be used. The section chain 17 runs along the section 2 in the transport direction T and is coupled to each roller 5. The section chain 17 is kept on track by a system of pulleys 20, and by the rollers 5 themselves. Along the top of the section 2, the section chain 17 is protected by a cover 18, and is therefore not visible along its entire length in figure 3. It is also protected along the bottom of the section 2 by another cover 25. Both covers 18, 25 are carried by the frame 7. A coupling 35 is provided, attached via a plate 36 to the cover 25. The coupling 35 in this case is a clutch, but could be any suitable type of coupling 33. In the definition of this application, the coupling includes two sides, which can be connected or disconnected from another, thereby providing switching behaviour for the section drive mechanism, of which the coupling is part. Brief reference is made to figure 4, in which can be seen that the coupling 35 comprises a main drive sprocket 47 on one end. On the other, opposite end another sprocket is present (not visible), which engages the section chain 17. Between the two ends are features 48, for causing the coupling to engage or disengage, which will be explained later. For now, it suffices to note that the sprocket 47 acts as a motive power input to the section 2. Referring back to figures 2B and 3, it can be seen that when the coupling 35 is switched to be engaged. any power from the motive power input 47 is transferred to the section chain 17. and thus to the rollers 5. When the coupling 35 is not engaged, no motive power from the motive power input 47 is transferred to the section chain 17.

Nevertheless, the section chain 17 is still coupled to the rollers 5, which are thus rotationally fixed with respect to each other.

Of course section drive mechanism in this case consists of the section chain 17 and the coupling 35, which takes input from the motive power input 47 in the form of a sprocket 47 fixed to the coupling 35, any other type of suitable drive mechanism could be used. As described herein, the drive mechanism can thus be switch between a transport state, when the drive mechanism is coupled to each of the series of rollers and to the motive power input 47, so that the rollers are driven via the section drive mechanism by the motive power input 47, and a stopping state, in which the section drive mechanism is still coupled to each of the series of rollers 5, but not to the

I5 motive power input 47.

The stopper switch 13 is rotatable about an axle 16 mounted in bearing blocks 49 attached laterally to the frame 7. When activated by an object, the stopper switch 13 moves to the left in figure 3. The stopper switch 13 is connected to the section drive mechanism via a transfer mechanism which will be elucidated further below. For now, reference is made to linkage 30, which moves together with the stopper switch 13 to the left when activated, so that an output rod 26, also slides left. The output rod 26 is held by gliding bearings 27, and comprises at its end an output switch 24. The output switch 24 thus moves from left to right depending on the position of the stopper switch 13. As such, the section 2 can signal upstream whether or not its stopper switch 13 is active, i.e. whether or not an object is present on the rollers 5 of the section. The output rod 26, and thus the output switch 24. is pretensioned to the right. to its inactivated state, via a spring 28 acting between stop 29 fixed to the output rod 26 and one of the gliding bearings 27. The spring 29 accordingly also biases the stopping switch 13 upwards, towards its non-activated state. Of course another form of biasing could be used, and the bias for the stopper switch 13 could be separate and/or independent from any optional biasing of the output switch 24.

For an even more detailed view, reference is now made to figure 4. The bracket 16 of the stopper switch 13 is seen to carry a blocking wheel 32, which moves with the bracket 16 approximately from left to right in figure 4 when the stopper switch is activated. The blocking wheel 32 engages a stop plate 31 fixed to an input rod 33 which is slidably held by gliding bearings 34, 44. The input rod 33 is biased using a spring 46 to the left in figure 4. The spring 46 provides a force between the gliding bearing 34 and a protrusion 45 fixed to the rod. As a result of the spring 46, the input rod 33 is allowed to move to the left in the shown figure, whenever the blocking wheel 32 permits said movement upon activation of the stopper switch. The input rod 33 has at its other end (left of figure 4) an input switch 23, which in this example is has the form of a disk 23 fixed to the input rod 33. The disk 23 acts as an input switch by allowing movement of the input rod 33 to the left when the disk is free to translate to the left, and blocks movement of the input rod 33 when itis obstructed. Accordingly, whether or not the input switch 23 is activated (1.e. the disk 23 is unblocked) and whether or not the stopper switch 13 is activated, determines whether the input rod 33 is moved to the left by the spring 46. Although not strictly necessary, it is proposed the output switch of one section 2 is connected to the input switch of another. Emerging behaviour caused by this coupling will be described in more detail below. First however, attention is drawn to bar 38 attached to the input rod 33. The bar 38 comprises an arcuate track 39 which interacts with a push wheel 42, which in turn is held by a lever 40. The lever 40 rotates around the gliding bearing 34 and rotates around its axis of rotation 41 in the gliding bearing 34. The push wheel 42 rotates about its own axis of rotation 43 towards the end zone of the lever 40. Due to the arcuate track 39, the push wheel 42 is pushed down together with the lever 40 when the input rod 33 is moved to the left. The push wheel 42 thus acts as a follower to the track 39 of the bar 38. Downward movement of the wheel 42 causes a force from the wheel 42 onto the coupling 35. specifically onto a jacket 48 thereof. Force on the jacket 48 causes the coupling 35 to disengage. Accordingly, the coupling 35 is disengaged if and only if, the stopper switch 35 is activated and when the input switch 23 is activated. When either is not activated, the coupling 35 is remained engaged. In this manner, the section 2 is powered from the motive power input or not. The motive power input, as mentioned before here in the form of a sprocket 47, is driven in turn by a second endless drive element 50, 51 which in figure 4 is shown to run right to left (50) to interact with the sprocket. A retum section 51 of the same endless drive element 50, 51 runs left to right in figure 4. The second endless drive element 50, 51 in this case is a main chain 50, 51, but could be any suitable drive element. The main chain 50, 51 runs along all sections 2 to power each of their respective sprockets 47.

As a result, the section drive mechanism provides motive power to the series of rollers 5 normally, because it is biased to a transport state, but moves to the stopping state when the stopper switch 13 and the input switch 23 are both activated. If the stopper switch 13 is activated, the output switch 24 1s also activated.

Figure SA shows details of a section 4 that can be used as a last section 4, at the downstream end of an accumulating roller transporter 1. Of course, these modifications can be used in other sections 2 as well, if desired. As an example however, only the last section 4 includes these modifications. The first modification is made visible in figure 5A, by again excluding visibility of some rollers 5 and some components belonging the second modification described below with reference to figure 5B. The first modification concems the provision of a first actuator 34, in this specific example a solenoid 54 fixed to the frame 7. and a ferromagnetic activation plate

52 fixed via a ring fixture 53 to the output rod 26 of the section 4. The solenoid 54 can be activated to force the activation plate 52, and thus the output rod 26 to the left in figure SA. This position ensures that the section drive mechanism remains in the stopping state. At the same time, the output switch 23 is activated. because the solenoid 54 operates on the output rod 26 which is part of the transfer mechanism. Of course, the solenoid 54 could be arranged elsewhere or function differently, as long as it allows keeping the transfer mechanism in the stopping state or allows moving it to the stopping state.

Figure 5B shows a second modification, which is exemplary in nature and is not strictly needed. The modification concerns the provision of a backstop 55 near the upstream end 9 of the section 4. The backstop 55 is carried by a series of brackets 57 and can be tilted around an axle 56 carried by bearings 60 arranged on the frame. The brackets 57 are connected to a transversal beam 58 fixed to the frame 7 via a springs 59, so that the backstop 55 is pretensioned upwards. An object being transported in the transport direction T interacts with the backstop 55 by pushing the backstop 55 downwards, so that the object may pass over it. Movement of the backstop 35 causes extension of the springs 59, which after the object has passed along return the backstop upwards.

Opposite movement of the backstop 55 is prevented by a stop 61 fixed to the transversal beam 58.

Accordingly, if an object is moved against the transport direction T, the backstop 55 will not move downward and blocks the object. The provision of this second modification is expressly optional, as similar functionality can be achieved by providing a one-way free-wheel connected to or as part ofthe section drive mechanism. As an example, the coupling 35 may be manufactured such that it allows free movement of the section chain 17 in a direction corresponding to the transport direction, but blocks movement in the other direction.

Although not shown, it is possible to provide the section 4 with a sensor, for instance infrared or pressure, or other suitable sensor, to register when the stopper switch is activated and/or deactivated. A timer can then be included and coupled to the first actuator 54 to keep the drive mechanism in the stopping state while the timer runs after the stopper switch 13 has been deactivated.

It is also possible to provide a further actuator connected to the section drive mechanism for switching it to the transport state. This option is also not shown m the figures.

Finally, the last section 4 may or may not have an input switch. It does not strictly require the input switch, at least not for receiving input from a downstream section, because there is none.

In the example shown in these figures. the input switch is activated when the input rod is free to move. Since no downstream components are present for the last section 4, the input switch is always activated and any object transported stops upon activating the stopper switch 13. After all, with the input switch activated, the stopper switch 13 directly switches the drive mechanism.

It is noted that in the accumulating roller transporter 1 of the figures 1 — 5B, which is exemplary in nature, the section drive mechanism comprises the section chain 17, and the coupling 35. The motive power input is formed by the sprocket 47 of the coupling 35. The transfer mechanism comprises the input rod 33, the output rod 26, the linkage 30, the system of the blocking wheel 32 and stop plate 31. the bar 38 with track 39 and push wheel 39 to cooperate with the coupling 35. As can be recognized, the transfer mechanism is separate from the drive mechanism. Due to the exemplary nature, the section drive mechanism and transfer mechanism may be built up differently.

The emergent behaviour of the accumulating roller transporter 1 described herein will be further elucidated with a highly schematic representation of the roller transporter in figures 6A —

GH. In this case, the roller transporter 101 consists of four sections 103, 102a, 102b, 104 arranged in that order in a transport direction T. A first object is a first pallet 162 with goods 163 and a second object 1s a second pallet 164 with goods 165 and a third object is a third pallet 166 with goods 166. These items, if present, are the same across all figures 6A — 6H, and are therefore not always referenced in each figure. In normal operation, a first pallet 162 is placed on the accumulating roller transporter 101 in the first section 103, i.e. at the upstream end 111. At this time, the stopper switch of only the first section 103 is activated. It is activated by the first pallet 162. In particular, the output switch of the section 102a directly downstream of the first section 103 is not activated, so the input switch of the first section 103 is also not activated. Accordingly, the transfer mechanism keeps the section drive mechanism of the first section in the transport state.

This couples the rollers of the first section 103 to the motive power input, which is continuously driven using a drive motor. Accordingly, the rollers are driven and start transporting the object. As a side note, it is remarked that similarly the rollers of other sections 104, 102b, 1024 are also driven at this time, because none of their directly downstream sections has activated their input switch.

Thus, all rollers are moving.

Even though the first pallet 162 triggers each stopper switch in turn, the above described conditions continue to apply, so that all rollers keep moving and the first pallet is as can be seen in figure 6B.

These conditions continue to apply until the first pallet 162 reaches the last section 104, a situation which is shown in figure 6C. At this time, the stopper switch of the last section 104 is triggered. Since no input switch needs to be triggered to stop this section 104 (either it is already triggered or absent), the last section 104 stops transporting. This is brought about by the transter mechanism transferring activation of the stopper switch to the section drive mechanism, which is switched to the stopping sate. At the same time, the output switch of the last section 104 is also activated, which in turn activates the input switch of the section 102b directly upstream of the last section 104. At this time, the rollers of the last section 104 are thus stopped, and the rollers of the other sections 103, 102a, 102b are driven.

In the next figure 6D, a second pallet 164 is added. This typically is done at the first section 103, although not strictly necessary. As was the case with the first pallet 162. the second pallet is transported from one section to the next, meanwhile activating stopping switches one after the other. The first sections 103, 1024 remain activated even when their stopper switch is activated, because their respective downstream sections 102b, 1024 have not activated their respective input switches. Accordingly, the second pallet is moved until it triggers the stopper switch at the section 102b directly upstream of the last section 104. When this stopper switch is activated, it fulfils, together with its input switch being activated by the output switch of the last section 104, the criteria necessary for switching the section drive mechanism to the stopping state. As a result, the second pallet 164 stops ahead of the first pallet 162. This process can be continued with as many sections in a transporter and equally many pallets. All the pallets will line up in the most downstream position possible, there being accumulated until needed.

In figure 6F this has been summarized by the addition of a third pallet 166, which will stop at the section 1024 directly downstream of the first section 103.

When the first pallet 162 is taken off the last section (i.e. at the downstream end of the transporter), it leaves an empty space on that section. The first actuator is used to temporarily hold the section 102b directly upstream of the last section 104 in the stopping state for a predetermined time period. At the same time, the last section 104 is also kept in the stopping state. Accordingly, the first pallet 162 can be safely taken off.

Then, and as shown in figure 6H transport is resumed by release of the first actuator, and if needed by the second actuator bringing the section drive mechanism of the last section 104 to the transport state. This releases also the output switch of the last section 104, thereby releasing in turn the upstream input and output switches, thereby thus automatically switching the section drive mechanisms of the section 102b directly upstream of the last section 104b to the transport state.

The second pallet 164 will then move further downstream, to the last section 104b, in turn switching the section drive mechanism below the third pallet 166 on, so that this pallet 166 will therefore be transported to the section 102b directly upstream of the last section 104b (see arrow 99). The second pallet 164 will then be ready for offloading.

The present invention is not limited to the embodiment shown. but extends also to other embodiments falling within the scope of the appended claims.

As an example, the rollers 5 of each section need not be parallel, and can for instance be arranged along an arcuate transport direction.

Claims (18)

Conclusions 1. A section for an accumulating roller conveyor, the section being configured to form, together with one or more further sections, a complete accumulating roller conveyor, the section comprising: - a series of rollers arranged in a conveying direction, and configured for conveying an object placed on some of the rollers in the series in the conveying direction by rolling, and for temporarily storing the object by stopping the rolling, - a section drive mechanism configured to drive the series of rollers in rotation, and - a motive power input configured to receive motive power for the section, the section drive mechanism being switchable between a conveying state and a stop state, characterised in that : - in the conveying state, the section drive mechanism is coupled to each of the series of rollers, and is coupled to the motive power input for transmitting motive power from the motive power input to each of the series of rollers; and - in the stop state, the section drive mechanism is coupled to each of the series of rollers and disengaged from the motive power input. 2. Section for an accumulating roller conveyor according to the preceding claim, wherein in the stop state, the section drive mechanism fixes the series of rollers in rotation relative to each other. 3. Section for an accumulating roller conveyor according to the preceding claim, wherein the series of rollers in the stop state of the drive mechanism are free to rotate in a direction corresponding to the conveying direction, but not in the opposite direction. A section for an accumulating roller conveyor according to any preceding claim, the section further comprising a stop switch movable between an activated and a deactivated state, the stop switch projecting above the roller array so as to be activated when touched by an object conveyed by the roller array in the conveying direction, the stop switch being connected to the section drive mechanism via a transfer mechanism. The accumulating roller conveyor section of claim 1, further comprising an infeed switch movable between an activated and deactivated state, the infeed switch being connected to the transfer mechanism, and the transfer mechanism being configured to switch the section drive mechanism from the transport state to the stop state when both the stop switch and the infeed switch are activated. 6. A section for an accumulating roller conveyor according to the preceding claim, wherein the transfer mechanism is inclined to move the section drive mechanism to the conveying state. 7. An accumulating roller conveyor section as claimed in claim 5 or 6, wherein the transfer mechanism is configured to switch the section drive mechanism to the conveying state when the stop switch and/or the feed switch is in its respective inactivated state. 8. An accumulating roller conveyor section as claimed in any one of claims 4 to 7, further comprising an output switch switchable between an on and off state, for example for switching an input switch of a further accumulating roller conveyor section, the stop switch being coupled to the output switch for activating the output switch when the stop switch is activated, optionally the coupling being made by the transfer mechanism. 9. An accumulating roller conveyor section as claimed in any one of claims 4 to 8, wherein the transfer mechanism is separate from the section drive mechanism. A section for an accumulating roller conveyor according to any one of claims 4 to 9, wherein the series of rollers defines a downstream end and an upstream end of the section as viewed in the conveying direction, and wherein the stop switch is arranged closer to the downstream end than to the upstream end, preferably at less than 15% of a section length defined between the downstream end and the upstream end from the downstream end, more preferably at less than 10% of the section length, even more preferably at less than 7% of the section length from the downstream end. An accumulating roller conveyor section according to any preceding claim, comprising a first actuator connected to the section drive mechanism, the first actuator being switchable between an engaged state, in which it moves the section drive mechanism to the stop state or holds the section drive mechanism in the stop state, and a disengaged state, in which it leaves the section drive mechanism free to move to or remain in the transport state. 12. An accumulating roller conveyor section as claimed in the preceding claim, wherein the first actuator is further coupled to the output switch, optionally via the transfer mechanism, and is configured to activate the output switch or to maintain the output switch activated. 13. An accumulating roller conveyor section as claimed in claim 11 or 12, further comprising a sensor configured to sense deactivation of the stop switch and a timer connected to the first actuator to release the actuator when a predefined amount of time has passed after the stop switch has been deactivated. 14. An accumulating roller conveyor section as claimed in any preceding claim, comprising a second actuator connected to the section drive mechanism for switching it to the conveying state. 15. An accumulating roller conveyor section as claimed in any preceding claim, wherein the section drive mechanism comprises a first endless drive element connected to each of the series of rollers. 16. Accumulating roller conveyor comprising at least two sections according to any of the preceding claims. Accumulating roller conveyor according to the preceding claim, wherein a first section of the at least two sections is according to at least claim 8, and a second section of the at least two sections is according to at least claim 3, wherein the output switch of the first section is coupled to the input switch of the second section. An accumulating roller conveyor according to any one of claims 16 to 17, comprising a second endless drive element and a drive connected to the second endless drive element for moving the second endless drive element, the second endless drive element being connected to the drive input of each section.