Field of the Disclosure

This disclosure relates to a safety device for use with a panel return and an edgebander. This disclosure further relates to a panel return and/or an edgebander comprising such a safety device.

Background

In order to cover the edges of a panel, substrate or work piece such as particle board or MDF panels for example, such as those used for kitchens and furniture, an edging strip, such as a plastic or wood veneer, is commonly applied to these edges. Machines for this purpose are commonly called edgebanders or edgebanding machines, and a relatively wide range is available. These machines grip the top and bottom surfaces of the panel, along the panel margin, and move the panel in a work direction along the edgebander as the edging strip is applied.

Related to these edge-banders are machines commonly called panel returns which typically comprise a substrate driving device to assist in driving the substrate or work piece along a predetermined path, to support the panel at a start position prior to entering the edge banding machine and after the panel has exited the edge banding machine. The panel returns typically overlap with the edgebanding machine such that at the beginning and end of the panel travel along the edgebander, the panel is supported by both the edge banding machine and the panel return. Once the panel has exited the edgebander, the panel return returns the edged panel to the start position.

The predetermined path is linear, and initially is in the work direction, that is, the same direction as the movement of the panel along the edgebanding machine. The panel return typically comprises an infeed area, which receives the panel from the edgebander in the work direction, once the edge has been applied to the panel. Typically, the panel return is then configured to transfer to the panel, in a direction transverse to the work direction, from the infeed area onto a return path defined by an adjacent part of the panel return. The panel return therefore also typically comprises a transfer area which transfers the edged panel from the infeed area transversely onto the primary panel return area. The return path along the primary panel return area transports the panel back along the panel return back to the start, in a direction generally parallel to, but in the opposite direction to, the work direction, to a region adjacent the inlet of the edge banding machine, so that the next margin of the panel can be edged, or the panel can be removed from the panel return by an operator.

The panel return typically comprises a plurality of rollers, or other rotary elements, typically some driven and some passive, arranged in three arrays, corresponding to the infeed, transfer, and return areas. These arrays of rotary elements move the panel along a substantially‘n’ shaped path when viewed from above: an initial direction being the work direction (first roller array), a second direction (second roller array) being transverse to the work direction, and a third direction (third roller array) being parallel with, but opposite to, the work direction. In some cases the rotary elements could comprise conveyor belts, or wheels, or any combination of belts, wheels and rollers.

In practice the edgebander is typically a separate machine from the panel return, with the two machines being configured to work together. There may be a common controller, usually on the edgebander, which controls both machines. Typically, there is an elongate gap between the two machines. As the panel is edged by the edgebander it moves along the elongate gap, with the panel being supported at one end by the edgebander, and at the other end by the panel return. The elongate gap can sometimes be large enough for a user to fit in it. In practice this can happen when handling a large or at least long panel which requires two users to lift it. In that circumstance, one of the users can walk into the elongate gap to help lift the panel into an initial position so that edging can begin. Further, once in that initial position, the edgebander exerts a significant grip force on the panel, that grip force typically being too great for a user to overcome. Consequently, it is possible for a user to be trapped in the elongate gap by the panel, such that during edging, the panel can move along the gap and crush the user. Due to the significant forces exerted by the edgebander on the panel, this can cause severe injury to the user that is trapped.

Object of the Invention

It is therefore an object of the invention to provide a safety device for a panel return and an edgebander which overcomes or at least ameliorates one or more of the above problems, or alternatively to provide improved safety, or alternatively to at least provide the public with a useful choice. Further objects of the invention will become apparent from the following description.

Summary of Invention

According to one aspect of this disclosure, there is provided a safety device for use with an edgebander and a panel return which are together configured to move a panel along a first path in a work direction to edge the panel, and to return the panel along a return path in an opposite direction, the safety device comprising a safety actuator configured to detect relative movement between the edgebander and the panel return, and to generate a safety signal when that relative movement is detected, the safety signal being configured to be used to deactivate the edgebander and/or the panel return. The safety signal may be used directly by a controller of the safety device, or by a controller of the edgebander and/or panel return. The safety device may comprise a guide configured to allow movement of the panel return relative to the edgebander along a predetermined path between first and second positions such that the panel return moves away from the edgebander when moving from the first to the second positions;

a) wherein the safety actuator is configured to generate the safety signal when the panel return has moved along the guide to the second position;

b) the safety device is configured to transmit the signal to an emergency stop system of the edgebander and/or the panel return such that the edgebander and/or panel return are deactivated by the emergency stop system when the signal has been received.

The guide means may be configured to guide a support structure of the panel return, the support structure supporting the panel return relative to the edgebander.

The support structure may comprise a leg or foot of the panel return.

The guide may be elongate and may comprise an elongate base and at least one side wall upstanding from the base and configured to guide the support structure along the base. The guide may comprise an elongate channel configure to be affixed to a floor or other immovable substrate, the channel comprising a pair of opposed side walls upstanding from the base.

The safety device may comprise an end stop against which a part of the panel return abuts when in the second position. The safety actuator may be provided on the end stop.

The safety actuator may comprise any one or more of:

a) a contact switch, activated by contact from the panel return, or by removal of contact by the panel return or the edgebander;

b) a pressure switch, activated by pressure applied by the panel return, or by removal of pressure by the panel return or the edgebander;

c) an optical switch, activated by the presence or absence of light when the panel return is in the second position;

d) a proximity switch, activated when the panel return is proximate the switch.

The safety switch may be configured to be mounted on the panel return, on the edgebander,

or on an intermediate structure, the panel return being movable relative to the intermediate structure.

The guide may be configured to allow movement of the panel return between the first and second positions between 5 and 50mm, and preferably between 10 and 20mm.

A plurality of safety actuators may be provided, each located on or at a different part of the panel return. The safety device may be located on or at a part of the panel return that is adjacent the edgebander. The safety device may be configured to transmit the safety signal to an e-stop chain of the edgebander.

The safety device may further comprise a barrier configured to extend across at least part of the panel return and across the work direction so as to be impacted by a panel above a predetermined size.

The barrier may comprise, or is configured to work with, an actuator configured to generate a safety signal used to deactivate the panel return, when a panel contacts the barrier. The safety signal may be generated when the panel moves the barrier.

The barrier may be movably mounted on the panel return, movement of the barrier between closed and open positions, generating the safety signal.

The barrier may be hingedly mounted on the panel return.

The barrier may comprise a standalone safety device, separate to the safety device of any one of the above statements.

The barrier may comprise an integral safety device, integral with the safety device of any one of the above statements.

According to another aspect of this disclosure there is provided a safety device for use with an edgebander and a panel return which are together configured to move a panel along a first path in a work direction to edge the panel, and to return the panel along a return path in an opposite direction, the safety device comprising: a. a barrier configured to at least partially extend across the first path and across the work direction; b. and a safety actuator configured to:

i.detect movement of the barrier when contacted by the panel, and

ii.to generate a safety signal when that movement is detected, the safety signal being configured to be used to deactivate the edgebander and/or the panel return.

According to another aspect of this disclosure, there is provided a panel return comprising the safety device of any one of the above statements.

According to a further aspect of this disclosure, there is provided an edgebanding system comprising: a. a panel return;

b. an edgebander; and

c. the safety device of any one of the above statements.

Brief Description of Drawings A number of embodiments of the disclosure will now be described by way of example with reference to the drawings in which:

Figure 1 is a plan view of a prior art panel return and edgebander.

Figure 2 is a perspective view of the panel return and edgebander of Figure 1 , in use with a plurality of panels, and showing the transfer area of the panel return in the foreground.

Figures 3a and 3b are perspective views of the panel return and edgebander of Figures 1 and 2, showing examples of how a user may become trapped in the elongate gap between the panel return and edgebander.

Figure 4 is an enlarged perspective view of a support structure, being a leg and foot in this example, of a panel return, and an edgebander, in accordance with the present disclosure.

Figure 5 is an enlarged perspective view of two legs of a panel return in accordance with the present disclosure.

Figure 6 is an enlarged perspective view of a leg of a panel return in accordance with the present disclosure, showing the leg in a first condition.

Figure 7 is an enlarged perspective view of a leg of a panel return in accordance with the present disclosure, showing the leg in a second condition.

Figure 8 is an example safety chain of a panel return and edgebander in accordance with the present disclosure.

Figure 9 is a perspective view of a panel return in accordance with this disclosure with another safety feature in a first position.

Figure 10 is a perspective view of the panel return of Figure 9 with the safety feature in a second position.

Detailed Description of the Drawings

Throughout the description like reference numerals will be used to refer to like features in different embodiments as appropriate. Referring initially to Figures 1 and 2, an edgebander 1 and panel return 3 are shown. The panel return 3 is configured to:

a) support one end of a panel to be edged, as it is moved in the work direction W by the edgebander l ;

b) transfer the panel, in a direction T transverse to the work direction W, onto a return path R defined by an adjacent part of the panel return 3;

c) to transport the panel back along return path R to a region adjacent the inlet of the edge bander 1, so that the next part of the panel can be edged, or the panel removed from the panel return 3 if all edging is complete.

Thus a panel travels along a plurality of roller arrays 3 A, 3B, 3C of the panel return 3 along a substantially ‘n’ shaped path when viewed from above: an initial direction being the work direction W which terminates at the outlet end of the edgebander 1 at an infeed end 5 of the panel return 3 by a first roller array 3A, a second direction T (provided by a transfer area 7 of second roller array 3B of panel return 3) being transverse to the work direction W, and a third, return direction R (provided by third roller array 3C) being parallel with the work direction W but with the panel moving in the opposite direction.

As can be seen from Figures 1 and 2, the edgebander 1 and panel return 3 are shown in a typical configuration in which there is an elongate gap 9 between the two machines, which extends along the entire length of the edgebander 1, from the infeed area 5 to the transfer area 7. As further illustrated by Figure 3, it is possible for a user U to become trapped in the gap 9 when lifting a panel P into position in the infeed area 5. In Figure 3a, one user Ul is in the gap 9, perhaps attending to a maintenance or checking task, whilst second user U2 loads a panel P into the infeed area 5. Once panel P has been gripped by the edgebander 1 to begin edging, the edgebander 1 will drive the panel P along the work direction W into contact with first user Ul, who could become trapped between the panel P and transfer area 7. In Figure 3b, a larger panel P requires lifting into position by the two users Ul, U2, with user Ul backing into gap 9 and potentially becoming trapped as described above. This example is potentially more serious because the panel P is larger and the gripping force exerted onto the panel P by the edgebander 1 will be significant, and far greater than can be overcome by user U 1. This could cause significant injury or death to the first user U 1.

Referring additionally to Figures 8 and 9, the edgebander 1, and most if not all edgebanders, include an emergency stop, or e-stop, system 51. The e-stop, sometimes known as the safety relay, typically includes a safety controller 53 and a safety chain 55 which includes one or more emergency stop buttons 11, one of which is shown in Figure 3. Sometimes an emergency stop button is provided at each end of the edgebander 1, at each end of gap 9. Sometimes the e-stop includes an emergency stop cord extending along all or part of the gap 9. The e-stop system 51 provided on the edgebander 3 also controls the panel return 3 such that activation of the e-stop not only stops the edgebander 1 but also the panel return 3. The e-stop 51 is designed such that when activated, all energy into the edgebander 1 and panel return 3 is stopped. This could be electrical energy, but also any energy from pneumatic or hydraulic systems, such as compressed air for example. The e-stop system 51 typically comprises a safety chain 55 comprising a plurality of switches in series, one such switch being the e-stop button 11. If any of the switches is activated, the e-stop 51 activates. Further, the e-stop system 51 typically comprises two such safety chains 55 A, 55B, as shown in Figure 8. Further, each safety chain 55A, 55B is typically subject to cyclic testing via one or more applied electrical pulses. The controller controls these pulses and any return signals to check if the switches are functional.

As can best be seen in Figures 3 and 4, the panel return 3 comprises a plurality of support structures which support the panel return 3 on the floor of the building in which it is used. In the illustrated example, these support structures comprise legs 13 each of which comprises a respective foot 15.

Referring to Figures 4 to 7, in accordance with the present disclosure, each foot 15 is configured to be able to move relative to the floor, such that the panel return 3 can also move relative to the floor, in a direction parallel with the work direction W, and parallel with the longitudinal axis of the gap 9. In the illustrated embodiment, each foot 15 is configured to be received in a channel 17. Each channel 17 is affixed to the floor. Each channel 17 has a base 18 and upstanding side walls 19 configured to resist transverse movement of the foot 15 in the channel 17, but to allow at least limited movement of the foot 15 along the channel 17 in a direction parallel to the work direction W. In this example the limited movement is a sliding movement of the foot 15 along the channel 17.

As can best be seen in Figure 6, one of the combinations of legs 13, feet 15 and channels 17 is provided with a safety device 21. The safety device 21, in this example, comprises an intermediate structure comprising an end stop 23 upstanding from the channel 17 at or near one end of the channel 17. The end stop 23 is provided with a safety actuator such as a switch or button 25 which projects from the part of the end stop 23 that faces the adjacent leg 13. The safety actuator 25 is connected into the e-stop system 51 as described above - the safety actuator 25 is connected so as to comprise an additional safety switch in the e-stop system.

The channels 17 allow longitudinal movement of the feet 15 along each channel 17. Once such movement reaches a predetermined magnitude, say 20mm, the leg 13 engages and activates the safety actuator 25. This causes the switch associated with the safety actuator 25 to close, activating the e-stop 51 and stopping the edgebander 1 and panel return 3. Thus, if the panel return 3 moves, or is moved, the edgebander 1 and panel return 3 shuts down. In any of the circumstances described above, where a user is trapped in gap 9, this means that if the panel P is driven into the user U by the edgebander 1 , this will force the user U into contact with the panel return 3. If the user U is sandwiched between the panel P and panel return 3, any further movement of the panel P towards the user U will transfer force through the user U into the panel return 3, moving the panel return 3 in the work direction W via the feet 15 moving along channels 17. Continued such movement causes the panel return 3 leg 13 to contact the safety actuator 25, activating the e-stop 51. Referring to figures 6 and 7, the initial and final positions of the feet 15 in each channel 17 are respectively shown.

This arrangement therefore prevents the user U from being significantly squashed between the panel P and panel return 3, or at least minimises or reduces any damage to the user U, if the user U becomes trapped in gap 9. This arrangement could also be used by the user to proactively activate the e-stop 51, by leaning on the panel return 3 to move the panel return 3 to activate the e-stop 51.

Safety actuator 25 could comprise any device configured to be able to generate a signal indicative of the presence of the leg 13 or foot 15, or indicative of relative movement between the edgebander 1 and panel return 3. In the example illustrated the safety actuator 25 comprises a push switch or button. However, the safety actuator 25 could comprise any other suitable device including a light sensor, a pressure sensor, or any other type of proximity sensor, or any combination of multiple sensors. The safety actuator 25 could be provided on the upstanding end stop 23, or could be provided elsewhere on the channel 21. For example, a pressure or light sensor could be provided on the base of the channel 21, onto which the foot 15 moves.

More than one safety actuator 25 can be provided, with such an actuator 25 being provided for two or more feet 15, or even for each foot 15.

The safety actuator 25 could be positioned anywhere else on the panel return, for example on one or more of the housings which house each roller array, provided that the safety actuator can respond to relative movement between the edgebander 1 and the panel return 3. In practice the edgebander 1 is a relatively large and heavy piece of machinery and will not move.

A practical advantage of such an actuator 25 is that it can be relatively simply wired into the e-stop chain 55, which is typically configured to allow additional safety switches to be added. As can be seen in figure 8, the two chains 55 A, 55B of the e-stop system 51 comprise a plurality of switches S in series, and a plurality of unused nodes N. At least one of the switches comprises the user activated safety switch 11. The other switches S are elsewhere in the edgebander 3 or panel return 3 and relate to other safety aspects of each device. The safety actuator 25 can be wired into an unused node N, effectively adding another switch S to one or both chains 55 A, 55B.

Figure 8 further illustrates this arrangement in a different way, schematically. The e-stop system 51 comprises a central controller/relay 53 which is electrically connected to the switch chains 55 A, 55B. The switch chains 55A, 55B comprise switches Sl associated with the panel return 3, and a switch S2 associated with safety actuator 25. In effect the e-stop 51 comprises a composite safety switch system which is electrically connected to and responsive to any number of switches of the edgebander 1 , panel return 3 and safety device 21.

The safety device 21, or at least the safety switch 25, could comprise a separate standalone device such as an intermediate structure, or be integral with one or both of the panel return and the edgebander.

Referring now to Figures 9 and 10, a further safety device 81 is provided which may comprise a standalone safety device, or may be used in conjunction with, or as part of, safety device 21. Safety device 81 may be configured to generate its own safety signal and to deactivate one or both of edgebander 1 and panel return 3, or some of panel return 3. Safety device 81 may be configured to activate safety device 21, either by generating a signal used by safety device 21, or simply by causing relative movement between the edgebander 1 and panel return 3 such that safety device 81 is activated.

Safety device 81 comprises, in this example, a movable end barrier 83 mounted on the panel return 3, and more specifically on a part of the infeed 5 which is spaced apart from the edgebander 1. In this example, the barrier 83 is provided at the end of the infeed 5 distal from the edgebander 1, but the barrier 83 could be provided at any position between the end of the infeed 5 and the outlet end of the edgebander 1. The barrier 83 extends transversely across the infeed 5, and transversely across the work direction W.

In addition to movable barrier 83, in this example, there is also provided a fixed wall or fence 85 which comprises a side barrier extending along all or part of the length of the infeed 5, in the work direction 5.

The barrier 83 in this example is movable via a side hinge 87 at the end of side wall 85, about a vertical pivot axis projecting vertically from the infeed 5. A latching or other retention device may be provided at the non-hinged end of the barrier 83 to releasably retain that end of the barrier 83 to the panel return 3.

The barrier 83 is movable between a closed position in which the barrier 83 extends at least partially across the infeed 5 and blocks panels P moving in the work direction as shown with reference to Figure 9, and an open position in which the barrier 83 does not extend across the infeed 5 and work direction W, as shown with reference to Figure 10.

In other examples the barrier 83 could be movable in any other way across, or partly across, the infeed 5 to block panels P moving in the work direction when in the closed position as shown in Figure 9, and to the open position in which the barrier 83 does not extend across infeed 5 and does not block the path of the panel P in the work direction, as shown in Figure 10. As with safety device 21, device 81 in this example comprises an actuator, such as a switch or sensor, configured to generate a signal when the barrier 83 is in, or is moving towards, the open position. The actuator could comprises any one or more of:

a. a contact switch;

b. a pressure switch;

c. an optical switch;

d. a proximity switch.

The signal generated by the actuator is used to deactivate at least the panel return 3, or at least the infeed 5 of the panel return 3. The signal may also be used to deactivate the panel return 3 and the edgebander 1 using e-stop system 51 , and indeed the actuator may be wired into the e-stop system 51 , as per the safety device 21 described above.

When the barrier 83 is opened, or partially or fully open, the panel P is no longer driven along at least the panel return 3.

Therefore, in the circumstance where a longer than usual panel P is being edged, with prior art apparatus, the panel P can project from the end of the infeed 5, as shown in Figure 10, potentially making contact with a person or object that might be located at the end of the infeed. For example, it is often the case that a fork-lift truck, or other factory apparatus, be parked at the end of the panel return 3. If a particularly long panel P is then processed, the end of the panel P can project beyond infeed 5 so as to impact the factory apparatus, damaging it, and potentially severely injuring a human stood in that position.

In contrast, with the safety device 81 of the current disclosure, if a panel P impacts the barrier 83, further movement of the panel P opens the barrier 83. This movement of barrier 83 from the closed position, causes the actuator to generate the signal which is then used to deactivate at least the infeed 5 of panel return 3. Thus, further movement of panel P in the work direction W is halted, and any projection of panel P beyond the end of infeed 5 is minimised.

It will be noted that in a majority of cases the panel P being processed will not be long enough to reach barrier 83. Flowever, where longer/wider panels P are processed, safety device 81 enhances the safety of the panel return 3 and/or edgebander 1.

As noted above, safety device 81 could comprise a standalone device configured to be integral with or removably mounted on the panel return 3/infeed 5. In alternative embodiments safety device 81 could comprise part of the larger e-stop system 51 and thus be used to also deactivate edgebander 1. The safety device 81 could be configured to be retrofitted to existing panel returns 3. In one embodiment the safety device 81 is used in conjunction with safety device 21 in the sense that contact by the panel P with the barrier 83 causes movement of the panel return 3 relative to the edgebander 1. As described above, this relative movement between the panel return 3 and the edgebander 1 activates safety device 21, and shuts down the panel return 3 and the edgebander 1 using the e-stop system 51. In that example, the barrier 83 may be movable, but could alternatively be fixed so as to extend permanently across the work direction W and across infeed 5.

Unless the context clearly requires otherwise, throughout the description, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of“including, but not limited to”.

Although this invention has been described by way of example and with reference to possible embodiments thereof, it is to be understood that modifications or improvements may be made thereto without departing from the scope of the invention. The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features. Furthermore, where reference has been made to specific components or integers of the invention having known equivalents, then such equivalents are herein incorporated as if individually set forth.

Any comment regarding prior art is not to be taken as an admission or acknowledgement that the prior art forms part of the common general knowledge in the art.