Industrial truck with load rollers located in swiveling load roller carriers

Abstract

An industrial truck (1) has a drive section (2) and a movable load section (4). The load section (4) has at least one wheelarm (5) with at least one load roller (6) rotatably mounted in a load roller carrier (12) which is mounted by a swivel bearing (13) on the wheelarm (5). The swivel-bearing (13) is a bearing pin (20). A linkage (10) is connected with the load roller carrier (12) by a coupling pin (21). The load roller carrier (12) has two outer bearing levers (12a, 12b) with bearing flanges (32a, 32b) for mounting the bearing pin (20) and bearing flanges (33a, 33b) for mounting the coupling pin (21), and an additional web (30) located between the outer bearing levers (12a, 12b) and having a bearing flange (32c) for mounting the bearing pin (20) and/or a bearing flange (33c) for mounting the coupling pin (21).

Claims

1. An industrial truck, comprising: a drive section; a load section movable relative to the drive section; at least one wheelarm connected to the load section and including at least one load roller, wherein the load roller is rotatably mounted in a load roller carrier and the load roller carrier is swivel-mounted by a swivel bearing on the wheelarm, wherein the swivel bearing of the load roller carrier comprises a bearing pin mounted on the wheelarm; a linkage operatively connected with the load roller carrier, wherein the linkage is connected in an articulated manner by a coupling pin with the load roller carrier; at least one stopping projection extending from an outer surface of the load roller carrier, the at least one stopping projection being located between the load roller carrier and the wheelarm for a lowered position of the wheelarm, and a through-hole formed in a vertical sidewall of the at least one wheelarm to define a stop surface for receiving and contacting the at least one stopping projection when the wheelarm is lowered, wherein the load roller carrier includes two outer bearing levers including bearing pin bearing flanges for mounting of the bearing pin and coupling pin bearing flanges for mounting of the coupling pin and the load roller carrier includes at least one web located between the outer bearing levers, and wherein the web includes a bearing flange for mounting of the bearing pin and a bearing flange for mounting of the coupling pin.

2. The industrial truck of claim 1, wherein the wheelarm includes outer bearing flanges for mounting of the bearing pin and inner bearing flanges for mounting of the bearing pin, wherein the outer bearing levers of the load roller carrier are located respectively between the outer bearing flange and the inner bearing flange of the wheelarm.

3. The industrial truck of claim 1, wherein the web of the load roller carrier is located between the two inner bearing flanges of the wheelarm.

4. The industrial truck of claim 1, wherein the linkage comprises a bearing fork including two bearing segments for mounting of the coupling pin, wherein the bearing fork is located between the outer bearing levers of the load roller carrier, and wherein the web of the load roller carrier is located between the two bearing segments of the linkage.

5. The industrial truck of claim 1, wherein the wheelarm, in a fully lowered position of the load section, has a wheelarm height of less than 50 mm above a road surface.

6. A system comprising: an industrial truck of claim 1 having a maximum wheelarm height in a fully lowered position of the load section of 50 mm; and a special pallet, wherein the special pallet has an entry height of a pickup opening for the wheelarms of the industrial truck of 50 mm between a road surface and an underside of a load-bearing surface of the special pallet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional advantages and details of the invention are explained in greater detail below with reference to the exemplary embodiment which is illustrated in the accompanying schematic figures in which like reference numbers identify like parts throughout.

(2) FIG. 1 shows as schematic illustration of an industrial truck of the invention with the load section in the lowered position;

(3) FIG. 2 shows the industrial truck illustrated in FIG. 1 with the load section fully raised;

(4) FIG. 3 is a view of the tip of a wheelarm of the industrial truck of the invention illustrated in FIGS. 1 and 2 from above;

(5) FIG. 4 is a section along line A-A in FIG. 3;

(6) FIG. 5 is a side view of the tip of a wheelarm of the invention;

(7) FIG. 6 is a section along line B-B in FIG. 5;

(8) FIG. 7 is a perspective view of a linkage of the industrial truck of the invention;

(9) FIG. 8 is a perspective view of a load roller carrier of the industrial truck of the invention; and

(10) FIG. 9 is a section of the load roller carrier along line C-C in FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(11) The industrial truck 1 illustrated in a side view in FIGS. 1 and 2, such as a lift truck in the form of a low-lift truck or a high-lift truck, for example, has a drive section 2 which is provided with a steerable drive wheel 3, and a load section 4 which can be raised and lowered relative to the drive section 2. The load section 4 preferably comprises two wheelarms 5 which are at a spaced lateral distance from each other and are supported on a roadway F by load rollers 6 located at or near the tip of the respective wheelarms 5. The drive section 2 is supported on the roadway F by means of the drive wheel 3. To increase stability, the drive section 2 can be supported on the roadway F by support rollers, which are not illustrated in any further detail. The upper side of the wheelarms 5 forms a load-bearing surface LF, which can be driven under a pallet to lift the pallet, which is not illustrated in any further detail.

(12) To lift the load section 4, a lifting device 7 is provided which includes one or more hydraulic cylinders, for example, and is located between the drive section 2 and the load section 4. To transmit the lifting motion of the load section 4 to the load rollers 6 on the ends of the wheelarms 5, for each wheelarm 5 there is a linkage 10 which is in an operative connection with the load rollers 6 and also with a lever system 11 which actuates the linkage 10. The lever system 11 can also act as a guide to guide the load section 4 during the lifting and lowering movements.

(13) On an industrial truck 1 operated by an electric battery, the load section 4 can also include a battery compartment 8 for a traction battery, which supplies electrical power to an electrical traction drive of the drive wheel 3 and to an electrical drive system of the lifting device 7.

(14) The load rollers 6 are located so that they can rotate in load roller carriers 12, which are located so that they can swivel on the corresponding wheelarms 5. For the swivel-mounting of the load roller carriers 12, a swivel bearing 13 is provided on each wheelarm 5. In the illustrated exemplary embodiment the linkages 10 are in the form of connecting rods. The swivel bearing 13 is located in the vertically upper portion of the wheelarms 5. The linkages 10, which are in the form of connecting rods, are connected by coupling points 14 in an articulated manner with the load roller carrier 12. The coupling points 14 are located in a vertical direction below the swivel bearing 13.

(15) When the load section 4 is raised by the lifting device 7, the load roller carriers 12 (which are actuated by the lever system 11 and the linkage 10 and are provided with the load rollers 6) are swiveled downwardly in the counterclockwise direction around the swivel bearing 13 so that the wheelarms 5 are lifted upwardly. FIG. 2 shows the load section 4 in the fully raised position. Accordingly, when the load section 4 is lowered, the load roller carriers 12 are swiveled in the clockwise direction around the swivel bearing 13, so that the wheelarms 5 are lowered.

(16) The wheelarms 5 of the industrial truck 1 of the invention, in the fully lowered position of the load section 4, have a wheelarm height H of less than 50 mm, so that the industrial truck 1 of the invention can be used to handle special pallets which have an entry height of 50 mm for the wheelarms 5.

(17) FIGS. 3 to 9 illustrate a constructive embodiment of the wheelarms 5 of the industrial truck 1 illustrated in FIGS. 1 and 2.

(18) In the illustrated exemplary embodiment, the swivel bearing 13 of the load roller carrier 12 on the wheelarm 5 has a bearing pin 20. For the articulated connection of the linkage 10 to the load roller carrier 12, there is a coupling pin 21 which forms the coupling point 14.

(19) To achieve the low wheel height H of less than 50 mm in the lowered position of the wheelarms 5, the bearing pin 20 is supported at a plurality of bearing points (in the illustrated exemplary embodiment at four bearing points) on the wheelarm 5 and at a plurality of bearing points (in the illustrated exemplary embodiment at three bearing points) on the load roller carrier 12, so that the bearing pin 20 can have a relatively small diameter compared with the bearing pin of conventional load roller carriers. The coupling pin 21 is also connected with the load roller carrier 12 in a plurality of bearing points (in the illustrated exemplary embodiment at three bearing points) so that the coupling pin 21 can also have a smaller diameter compared with the coupling pin of conventional load roller carriers.

(20) For this purpose, the fork-shaped load roller carrier 12 (as illustrated in FIGS. 6, 8, and 9) includes two lateral, outside bearing levers 12a, 12b, between which rockers 25a, 25b are swivel-mounted and in which the load rollers 6 (in the illustrated exemplary embodiment three load rollers 6) are mounted so that they can rotate. In each of the outer bearing levers 12a, 12b, for the swivel mounting of the rockers 25a, 25b, there are respective bearing flanges 26a, 26b for a bearing 27, by means of which the rockers 25a, 25b are swivel-mounted on the bearing levers 12a, 12b. The bearing flanges 26a, 26b for the rockers 25a, 25b are formed by a through bore in the bearing levers 12a, 12b.

(21) In addition, the load roller carrier 12 includes an additional central web 30 in the vicinity of the swivel bearing 13 and the coupling point 14, with the at least one additional central web 30 located between the outer bearing levers 12a, 12b and parallel to them. The web 30 is located and fastened by means of a connecting plate 31 between the outer bearing levers 12a, 12b.

(22) In the outer bearing levers 12a, 12b, bearing flanges 32a, 32b are formed for the mounting of the bearing pin 20 and bearing flanges 33a, 33b for the mounting of the coupling pin 21. In the web 30 of the load roller carrier 12 located between the outer bearing levers 12a, 12b, an additional bearing flange 32c is formed for the mounting of the bearing pin 20 and/or an additional bearing flange 33c for the mounting of the coupling pin 21. The bearing flanges 32a, 32b, 32c for the bearing pin 20 and the bearing flanges 33a, 33b, 33c for the coupling pin 21 are each formed by a through bore in the bearing levers 12a, 12b and the web 30 of the load roller carrier 12. The through bores in the load roller carrier 12, which form the bearing flanges 32a, 32b, 32c for the bearing pin 20, the bearing flanges 33a, 33b, 33c for the coupling pin 21, and the bearing flanges 26a, 26b for the rockers 25a, 25b, are aligned parallel to one another.

(23) For mounting of the bearing pin 20 (as illustrated in FIGS. 3 and 6) the wheelarm 5 is provided on each of its outer sides with a bearing fork, each of which forms an outer bearing flange 35a, 35b and an inner bearing flange 36a, 36b for the bearing pin 20. The outer bearing levers 12a and 12b, respectively, of the load roller carrier 12 are each located between the outer bearing flange 35a or 35b, respectively, and the inner bearing flange 36a or 36b, respectively, of a bearing fork of the wheelarm 5. The bearing flanges 35a, 35b, 36a, 36b for the mounting of the bearing pin 20 are formed by a through bore which is located in the corresponding bearing forks of the wheelarm 5.

(24) The additional central web 30 of the load roller carrier 12 is located between the two inner bearing flanges 36a, 36b of the wheelarm 5.

(25) The bearing pin 20 is therefore mounted and supported in alternation in a bearing flange 35a, 36a, 36b, 35b of the wheelarm 5 and a bearing flange 32a, 32c, 32b of the load roller carrier 12.

(26) The industrial truck 1 is also provided in the vicinity of the swivel bearing 13 of the load roller carrier 12 on the upper side of the respective wheelarm 5 with an entry guide to facilitate driving the truck under the pallet. The entry guide is formed by at least one roller 41, 42, 43, 44 mounted so that it can rotate on the bearing pin 20. The rollers 41, 42, 43, 44 have a diameter such that the peripheral surface U of the rollers 41, 42, 43, 44 projects slightly beyond (above) the load-bearing surface LF on the upper side of the corresponding wheelarm 5.

(27) In the illustrated exemplary embodiment, one roller is located between each inner bearing flange 36a, 36b of the wheelarm 5 and the central web 30 provided with the central bearing flange 32c of the load roller carrier 12, and between each inner bearing flange 36a, 36b of the wheelarm 5 and the outer bearing lever 12a, 12b provided with the outer bearing flange 32a, 32b of the load roller carrier 12, so that two rollers are arranged in pairs on both sides of the inner bearing flange 36a, 36b of the wheelarm 5. The roller 41 is therefore located between the outer bearing lever 12a of the load roller carrier 12 and the inner bearing flange 36a of the wheelarm 5. The roller 42 is located between the inner bearing flange 36a of the wheelarm 5 and the central web 30 of the load roller carrier 12. The roller 43 is located between the central web 30 of the load roller carrier 12 and the inner bearing flange 36b of the wheelarm 5. The roller 44 is located between the inner bearing flange 32b of the wheelarm 5 and the outer bearing lever 12b of the load roller carrier 12.

(28) The linkage 10 (as illustrated in FIG. 7) is provided for articulated coupling with the load roller carrier 12. The linkage 10 is a bearing fork that includes two bearing segments 10a, 10b, in which there is a through bore 50 for the mounting of the coupling pin 21. The bearing segment 10a is located between the outer bearing lever 12a and the central web 30 of the load roller carrier 12 and the bearing segment 10b is located between the outer bearing lever 12b and the central web 30 of the load roller carrier 12. The web 30 of the load roller carrier 12 is located between the two bearing segments 10a, 10b of the linkage 10.

(29) Stop means 60 are located between the load roller carrier 12 and the wheelarm 5 for the lowered position of the wheelarm 5. The stop means 60 are formed by wing-like projections 61a, 61b on the outer sides of the bearing levers 12a, 12b of the load roller carrier 12, which interact with stop surfaces 62 on side plates of the wheelarm 5. The stop means 60 limit the swiveling movement of the load roller carriers 12 upwardly in the fully lowered position of the wheelarms 5 and in connection with the design of the linkage 10 which actuates the corresponding load roller carrier 12, make it possible to leave an open space in the fully lowered position between the rollers 41, 42, 43, 44 and the linkage 10, which permits rotation of the rollers 41, 42, 43, 44 on the bearing pin 25. In addition, when the wheelarms 5 are lowered, whereby the wing-like projections 61a, 61b of the load roller carrier 12 are supported by the stop surfaces 62 directly on the wheelarms 5, the forces exerted on the bearing pin 20 and the coupling pin 21 are reduced.

(30) The mounting of the bearing pin 20 and of the coupling pin 21 of the invention and the design of the load roller carrier 12 of the invention with the additional central web 30, on which there are additional bearing flanges 32c, 33c for the bearing pin 20 and the coupling pin 21, make it possible to reduce the diameter of the bearing pin 20 and the coupling pin 21 compared with conventional industrial truck, so that the height H of the wheelarms 5 can be reduced, thereby making it possible to handle special pallets with a low entry height.

(31) It will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed in the foregoing description. Accordingly, the particular embodiments described in detail herein are illustrative only and are not limiting to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof.