Rail-Based Floor Conveyor System

Abstract

A rail-based floor conveyor system, with a floor conveyor with concavely grooved wheels and rails having a surface which, when in contact, dips at least partially into the grooved area of the wheels, thereby producing at least two load-bearing lines during the movement of the floor conveyor, wherein a wheel holder is provided for each wheel, with at least one horizontal axis of rotation for each wheel and a vertical axis of rotation to a bearing connected to the floor conveyor, and wherein the wheels can be moved by drives or manually on the rail, bearing including a first bearing part and a second bearing part, wherein one of the bearing parts has a concave surface section, which is at least partially in contact with a convex surface section of the respective other bearing part, and wherein both bearing parts are movable relative to one another while maintaining contact.

Claims

1. A rail-based floor conveyor system, comprising: at least one floor conveyor with concavely grooved wheels around a circumference thereof and rails having an outer surface which, when in contact with the wheels, dip at least partially into a grooved area of the wheels, thereby producing at least two load-bearing lines on the rails during movement of the floor conveyor, a wheel holder for each wheel or pair of wheels, with at least one horizontal axis of rotation for each wheel and a vertical axis of rotation to a bearing which connects the wheel holder to the floor conveyor, wherein the wheels are adapted to be moved by drives or manually on the rail, and the bearing including at least a first bearing part and a second bearing part, one of the bearing parts having a concave surface portion which is at least partially in contact with a convex surface portion of the respective other bearing part, and wherein both bearing parts are movable relative to one another while maintaining contact.

2. The rail-based conveyor system of claim 1, wherein the convex and concave surface sections of the first and second bearing parts are formed by arcs of the same radius.

3. The rail-based conveyor system of claim 1, wherein the convex surface portion of a said bearing part of at least one said bearing is adapted to be swiveled in the direction of an arc transversely to the direction of the rail on the concave surface portion of the respective other bearing part.

4. The rail-based conveyor system of claim 1, wherein the bearing is a spherical bearing.

5. The rail-based conveyor system of claim 1, wherein centers of a circular arc of at least one of the concave surface portion and the convex surface portion lie in alignment with the rail.

6. The rail-based conveyor system of claim 1, wherein a higher one of the bearing parts is provided with said concave surface portion and a lower one of the bearing parts is provided with said convex surface portion.

7. The rail-based conveyor system of claim 6, wherein the higher bearing part is firmly connected with one of a supporting structure and a loading area of the floor conveyor.

8. The rail-based conveyor system of claim 1, further comprising an arrangement for preventing the swiveling at least at one bearing, so that only a relative rotational movement of the wheel holder about the vertical axis of rotation is feasible for the bearing.

9. The rail-based floor conveyor system of claim 8, wherein some bearings of the floor conveyor are provided with an arrangement for preventing swiveling and others are not.

10. The rail-based conveyor system of claim 1, wherein at least one of the surface portions is one of: finished with a slippery coating or includes a material different from that of the respective other surface portion, so that a coefficient of friction between the two surface portions is less than 0.1.

11. The rail-based conveyor system of claim 1, wherein at least one bearing has an additional shock-absorbing elastomeric layer.

Description

[0038] The invention will be explained in the following with reference to the illustrative drawings.

[0039] FIG. 1 shows a corner portion of a floor conveyor and a length of a rail in a basic construction

[0040] FIG. 2 shows a corner section of a floor conveyor and a section of rail with a central vertical section through the wheel

[0041] FIG. 3 shows the behavior of the inventive bearing when there is a lack of constancy in the rail track

[0042] FIG. 4 shows the behavior of the inventive bearing when there is overloading of the loading area of the floor conveyor

[0043] FIG. 5 shows a bearing with means to prevent swiveling

[0044] FIG. 6 shows a bearing with an additional elastomeric layer

[0045] A vertical section is shown in FIGS. 2 to 6 in order to be able to illustrate the features better. For reasons of clarity, cross-hatching was also dispensed with (except for the elastomeric layer).

[0046] FIG. 1 shows an embodiment of the basic structure of a rail-based floor conveyor system 1. In this case, only one corner of the floor conveyor 3 and a portion of a round rail 2 are shown. The floor conveyor 3 has a supporting construction 8, on which a loading area 9 is located.

[0047] In the embodiment, a bearing 10 is provided exactly at the corner of the support construction, in which a wheel holder 6 is mounted with at least one wheel about a vertical axis of rotation D. The wheel (there may also be several wheels) has a wheel axle 7, which also forms the horizontal axis of rotation W, about which the wheel may rotate.

[0048] FIG. 2 shows a vertical section through the bearing, the wheel and the rail of FIG. 1. It may be seen clearly that the bearing 10 is divided into a first bearing part 11 and a second bearing part 12. The first bearing part 11, which is disposed above the second bearing part 12, has a concave surface section 14, while the bearing part 12 has a convex surface section 13, which is adapted to the concave surface section 14 of bearing part 11. The two surface sections 13 and 14 abut one another, but still allow one or more degrees of freedom of movement relative between bearing parts 11, 12. At least the rotation of the wheel support to a vertical axis of rotation D should be preserved. Moreover, a slippery coating 16 may be provided on one or on both surface sections 13, 14. In some cases, it makes sense to design these surface sections 13, 14 as spherical surface sections, so that one is dealing with a spherical bearing. The possibility of swiveling movements relative to one another between the bearing parts 11, 12 is explained in more detail in the description of FIGS. 3 and 4.

[0049] However, with regard to FIG. 2, reference is still made to the effect of the grooving 5 of the wheel or of all wheels of the floor conveyor 3. The convex surface portion of the rail 2 dips into groove 5, so that there are two points of contact, which form a support perimeter 19 on the wheel 4, while the wheel is running around the wheel axle 7. They engage the rail 2 slightly laterally, so that the wheels are held securely in their track on the rail. The contact area is therefore minimal so as to reduce friction.

[0050] FIGS. 3 and 4 show how the two bearing parts 11 and 12 swivel relative to one another in certain situations.

[0051] In FIG. 3, the rail 2 does not run true to the track of the second rail for the floor conveyor 3, which is not shown. The correct position would be shown, for example, by the dashed line 2. In this case, the bearing parts 11 and 12 swivel slightly towards each other, which has the positive consequence that the wheel does not run on one side of the rail and the burden of the one-sided load does not negatively affect the advantages of the invention. Due to the swiveling motion, the two peripheral contact lines in the groove region of the wheel are retained.

[0052] A similar case, in which swiveling between the first bearing part 11 and the second bearing part 12 is advantageous, is shown in FIG. 4, in which a deflection of the supporting structure 8 is brought about by a high load on the loading area 9. Here also, the normal position of the supporting structure is shown by a dashed line 8. Thus, the bearing 10 can compensate for this deflection and, with that, avoid a lateral stress on the round rail 2. In this case, it is even possible to keep the wheel axle 7 horizontal. In both cases, that is, the ones shown in FIGS. 3 and 4, it is also seen that it makes sense if the center of the radius' R of the concave surface section of the upper bearing portion 11 and the center of the radius' R of the convex surface section of bearing part 12 lie in the region of the rail 2.

[0053] A special feature of the bearing 10 is shown in FIG. 5. In an advantageous embodiment, the bearing may be provided with means to prevent swiveling 15, in this embodiment in the form of a bolt 20 passing vertically through the first and the second parts of the bearing. If a bearing is provided with such means to prevent swiveling 15, this bearing can only allow a rotational movement of the wheel holder about a vertical axis of rotation D. With that, the stability of the floor conveyor can be increased significantly by allowing only one bearing on a rail to swivel, but preventing it on a second rail.

[0054] Finally, it should still be mentioned thatas shown by way of example in FIG. 6elastomeric layers or components 17 may also be used in the bearing to avoid shocks and vibrations and thus to increase the life of the rail 2 or of the wheel 4.

LIST OF REFERENCE SYMBOLS

[0055] 1 Rail-based floor conveyor

[0056] 2, 2 Rail, round rail

[0057] 3 Floor conveyor, carriage

[0058] 4 Wheel

[0059] 5 Wheel groove

[0060] 6 Wheel holder

[0061] 7 Wheel axle

[0062] 8, 8 Supporting construction

[0063] 16 Slippery coating

[0064] 17 Elastomeric coating

[0065] 18 Convex rail surface

[0066] 19 Contact point or peripheral line

[0067] 20 Bolt

[0068] W Horizontal axis of rotation

[0069] D Vertical axis of rotation

[0070] R Radius