A conveying system

The invention relates to a conveying system provided with a rail system with a trolley or the like, which is movable along said rail system and with a switch device by means of which a trolley can be diverted from said rail track to another rail track connected to said first rail track, wherein said trolley or the like is provided with two guide members which are arranged some distance apart in the intended direction of movement of a trolley along a rail track and which cooperate during operation with a fixed guide rail extending in the longitudinal direction of a rail track, whilst said trolley is furthermore provided with two further guide members, which are arranged some distance apart in the intended direction of movement of a trolley along a rail track.

EP-A-0 367 972 shows such a conveying system with a trolley having four guide rollers arranged in the corner of a rectangle. If the trolley has to be diverted the guide rollers at one side of the trolley has to be displaced out of engagement with the rail track, whereby the guide rollers at the other side of the trolley are guided in a curved rail track.

The object of the invention is to obtain a conveying system of the above kind wherein a reliable divertion from one rail track to the other rail track can be realized by simple means, if desired.

According the invention this can be achieved in that said further guide members are furthermore arranged in staggered relationship with respect to each other, transversely to the intended direction of movement for cooperating with guide rails and a switch tongue forming part of said switch device for diverting said trolley from one rail track to the other, whereby said guide rails and said switch tongue are disposed near the connection between said two rail tracks.

The invention will be explained in more detail with reference to the accompanying Figures.

• Figure 1 is a diagrammatic perspective view of a part of the conveying system according to the invention.
• Figure 2 is a larger-scale view of the switch portion that is encircled at II in Figure 1.
• Figure 3 is a larger-scale view of a switch tongue forming part of the switch device.
• Figures 4 and 5 are diagrammatic bottom views of a trolley, with a switch device sketched in, when the trolley passes the switch device without being diverted from one rail track to another rail track by the said switch device.
• Figures 6 - 8 show various stages during the diversion of a trolley from one rail track to another rail track.
• Figure 9 is a diagrammatic perspective view of a part of the conveying system, at the point where two rail tracks meet.
• Figure 10 is a larger-scale view of the encircled portion X in Figure 9.

The conveying system shown in Figure 1 comprises a first rail track 1, which comprises a pair of rails 2 and 3 extending parallel to each other.

A trolley 4 is movable over said rails. The trolley 4 is thereby supported by four self-adjusting running wheels 5 (Figure 4) provided at its bottom side, which roll over the upper surfaces of the rails 2 and 3.

In order to ensure that the trolley 4 keeps moving in the longitudinal direction of the rails 2 and 3 thereby, a guide means 6 is provided between the rails, said guide means being formed by a strip-shaped means extending parallel to the longitudinal direction of the rails. Said strip-shaped means 6 cooperates with two guide means arranged some distance apart in the intended direction of movement of the trolley according to arrow A, which are each formed by a pair of rollers 7, 8 and 9, 10 respectively, and which are rotatable about upwardly extending axes of rotation. The arrangement is thereby such that when the trolley 4 moves along rails 2 and 3 both rollers 9 and 10 of the one guide means and rollers 7 and 8 of the other guide means will be positioned on either side of the guide means formed by the elongated strip 6, thereby effecting that the trolley 4 can only move in the longitudinal direction of the rails 2 and 3. Linear motors 11, which are known per se, may be provided for driving the trolley 4.

A conveying system of this type may for example be used at airports for conveying the luggage 12 of air passengers.

Generally the luggage or the trolley are thereby provided with electronically read codes, by means of which the trolley can be transported to a predetermined station. For that purpose additional rail tracks 13 are connected to the main rail track 1, generally at several points, via which a trolley may for example be guided to a predetermined station so as to deliver the luggage 12. Such an additional rail track 13 is again provided with a pair of rails 14 and 15 extending parallel to each other, which correspond with the rails 2 and 3.

A switch device 16 is provided near the connection of the rail track 13 to the rail track 1 for diverting a trolley from the rail track 1 to the rail track 13. The switch device 16 comprises a plate-shaped means 17 arranged between the rails 2 and 3, in which guide grooves 18 and 19 extending parallel to the longitudinal direction of the rails 2 and 3 are provided. Guide grooves 20 and 21 respectively provided in the plate 17, which include an angle with the guide grooves 18 and 19, are connected to said grooves 18 and 19 between the ends of said grooves. A switch tongue 22 is disposed near the end of the connection of the guide groove 20 to the guide groove 18, said switch tongue at its downstream end, seen in the intended direction of movement of a trolley 4 according to arrow A, being pivotal to and fro in the direction of arrow B, by suitable setting means 22'', about an upwardly extending pivot pin 22'.

As is furthermore diagrammatically illustrated in Figure 3 the switch tongue 22 can furthermore pivot from its normal operating position, against the action of a spring, about a substantially horizontally extending pivot pin 23 provided near the upper end of pivot pin 22', for a purpose yet to be described in more detail hereafter.

With a view to cooperating with the guide means formed by the guide grooves 18 - 20 the trolley is provided with additional guide means, which are formed by cams 24 and 25 secured to the bottom side of the trolley, which cams are connected to the trolley, being freely rotatable about axes of rotation extending perpendicularly.

As will be apparent from Figures 4 - 8 cam 25 is thereby arranged some distance before cam 24, seen in the intended direction of movement according to arrow A, whilst cams 24 and 25, seen in the direction of movement according to arrow A, are staggered relative to each other, in a direction transversely to the intended direction of movement according to arrow A.

Near the switch device the strip-shaped guide means 6 is interrupted, in order to be able to divert trolley 4 from rail means 1 to rail means 13.

When the trolley 4 is to stay on rail track 1 near the connection of rail track 13 to rail track 1, the switch tongue 22 will take up a position in which the switch tongue 22 blocks the access to guide groove 20. Near the switch device 16 the guide cams 24 and 25 will guide the trolley in the longitudinal direction of the rail track 1, since the guide cams 24 and 25 forming guide means move through the guide grooves 18 and 19 forming guide means, as is shown in Figures 4 and 5. By means of the guide cams 24 and 25 the trolley 4 is thus caused to follow the track 1, in spite of the fact that the guide means formed by the rollers 7, 8 and 9, 10 respectively have lost contact with the guide means formed by the strip-shaped means 6 upon passing the switch device.

When the trolley is to be diverted from rail track 1 to rail track 13, setting means 22'' will move the switch tongue 22 to a position in which the switch tongue 22 releases the access to the guideway 20 and blocks the access to the downstream part of the guide groove 18 located past the switch. Upon passing the switch device 16 the front guide cam 25 will be able to move within the guide groove 18 along a certain distance and will subsequently be diverted into the guide groove 20 by the switch tongue 22. At the moment when the front guide cam 25 arrives at the switch tongue 22, the front rollers 9 and 10 have already lost contact with the guide strip 6, as will be apparent from Figure 6. Upon further movement of the trolley 4 said trolley 4 is thus guided by cam 25 and the two rollers 7 and 8.

At some point of time also cam 24 will first move through the upstream part of the guide groove 19 initially, and then be guided into the guide groove 21, whereby the trolley 4 pivots about the axis of the connecting line between rollers or wheels 7 and 8, , as it were, whilst the guide rollers 7 and 8 lose contact with guide means 6, so that at some point of time during the diversion of the trolley from rail track 1 to rail track 13 said trolley 4 is only guided by the two guide rollers 24 and 25 moving through the guide grooves 20 and 21, as is illustrated in Figure 8. At some point of time the guiding of the trolley will be taken over again by the guide means formed by rollers 9 and 10 and subsequently also by rollers 7 and 8, which will cooperate with a strip-shaped guide means 26 corresponding with strip-shaped guide means 6, which extends parallel to and between the rails 14 and 15.

If the cam 25 would strike the tip of the switch tongue, whose height gradually increases, as a result of the switch tongue not having reached an intended end position yet, the cam 25 may run onto the rounded upper edge of the switch tongue, whereby the tongue is pivoted about the pin 23. At some point of time the cam will thereby fall from the rounded upper edge of the tongue, as a result of which jamming of the trolley 4 in question will be prevented.

A simple switch means may be used for guiding the trolley back from rail track 13 to rail track 1, said switch means being diagrammatically illustrated, more particularly in sectional view, in Figure 10. As appears from this Figure said switch means 27 comprises a plate-shaped part 28, in which guide grooves 29 and 30 being in line with rail track 1 are provided for guiding guide cams of trolleys 4 moved along rail track 1. Furthermore curvilinear guide grooves 31 and 32 are provided, which guide the guide cams 24 and 25 of a trolley coming from rail track 13 when the trolley in question is being diverted from rail track 13 to rail track 1.