Abstract
A spreader for lifting an intermodal transport container includes a main beam extending in a longitudinal direction, the main beam formed of a first, upper C-beam of a relatively thicker material thickness and a second, lower C-beam of a relatively thinner material thickness; and an indicator configured to provide an indication if a distance in a transversal direction between a pair of twist-locks is set in a wide-body position when lowered onto respective lifting castings provided with top openings separated by a transversal distance corresponding to a standard position.
Claims
1. A top-lift spreader for lifting an intermodal transport container, the top-lift spreader comprising: a first pair of twist-locks and a second pair of twist-locks, wherein each pair of twist-locks comprises a first twist-lock and a second twist-lock, said first and second pairs of twist-locks being arranged in a rectangular pattern, a long side of which defines a longitudinal direction and a short side of which defines a transversal direction, the twist-locks being configured to engage with lifting castings arranged in a mating rectangular pattern on a top face of the container, each of said twist-locks comprising a male locking insert configured to be inserted into a top opening of the respective lifting casting, the male locking insert comprising an insert end portion which is twistable about a vertical rotation axis to a lock position for engaging with the respective lifting casting, wherein each pair of twist-locks is reconfigurable between a standard position mode, in which a distance between a rotation axis of the male locking insert end portion of the first twist-lock and a rotation axis of the male locking insert end portion of the second twist-lock is a first distance, and a wide twist-lock position (WTP) mode, in which the distance between the rotation axis of the male locking insert end portion of the first twist-lock and the rotation axis of the male locking insert end portion of the second twist-lock is a second distance that is greater than the first distance, the spreader further comprising an indicator configured to provide an indication that at least one pair of twist-locks is lowered in WTP mode onto respective lifting castings provided with top openings having a transversal center-to-center distance corresponding to the standard position.
2. The spreader according to claim 1, wherein the first distance is about 2258 mm and the second distance is about 2448 mm.
3. The spreader according to claim 1, wherein each twist-lock comprises an abutment face flanking the male locking insert, the abutment face being configured to rest on a top surface of the respective lifting casting when the spreader has been lowered onto the container such that the male locking insert has been inserted into the top opening, and wherein the indicator comprises an actuator movable between a lower position, in which it protrudes below said abutment face, and an upper position, in which it is flush with said abutment face.
4. The spreader according to claim 3, wherein the actuator comprises a U-shaped loop comprising a first loop leg and a second loop leg, said loop legs extending upwards from an intermediate portion interconnecting the loop legs, wherein each loop leg is guided in the vertical direction by a respective loop leg guide.
5. The spreader according to claim 4, wherein said first loop leg is connected to a sensor configured to detect whether the loop is in its lower position or in its upper position, said first loop leg being located outside a vertical projection of the abutment face.
6. The spreader according to claim 3, wherein at least one of said twist-locks within at least one of said pairs of twist-locks comprises a landing indicator configured to indicate, when the abutment face is lowered onto the respective lifting casting top surface, the presence of a portion of the lifting casting top surface transversally inside a transversally outer edge of the top opening of the respective lifting casting.
7. The spreader according to claim 3, said indicator being configured to generate an electronic landing confirmation signal, wherein each twist-lock within said at least one of said pairs of twist-locks further comprises an auxiliary landing indicator comprising an auxiliary actuator movable between a lower position, in which it protrudes below said abutment face, and an upper position, in which it is flush with said abutment face, wherein said auxiliary actuator is shaped to, when in the lower position, mechanically block the male locking insert end portion from turning to the lock position, and to, when in the upper position, provide clearance to allow the male locking insert end portion to turn to the lock position.
8. A top-lift spreader for lifting an intermodal transport container, the top-lift spreader comprising: a first pair of twist-locks and a second pair of twist-locks, wherein each pair of twist-locks comprises a first twist-lock and a second twist-lock, said first and second pairs of twist-locks being arranged in a rectangular pattern, a long side of which defines a longitudinal direction and a short side of which defines a transversal direction, the twist-locks being configured to engage with lifting castings arranged in a mating rectangular pattern on a top face of the container, wherein each pair of twist-locks is telescopically suspended to allow changing a longitudinal distance between the first pair of twist-locks and the second pair of twist-locks, and the twist-locks within each pair of twist-locks are telescopically suspended to allow changing a transversal distance between the first twist-lock and the second twist-lock, each twist-lock comprising a male locking insert configured to be inserted into a top opening of the respective lifting casting, the male locking insert comprising an insert end portion which is twistable about a vertical axis to a lock position; and an abutment face, flanking the male locking insert, the abutment face being configured to rest on a top surface of the respective lifting casting when the spreader has been lowered onto the container such that the male locking insert has been inserted into the top opening, wherein at least one of said twist-locks within at least one of said pairs of twist-locks comprises a respective landing indicator configured to detect when the abutment face is lowered onto the respective lifting casting top surface, wherein the landing indicator is configured to detect a portion of the lifting casting top surface transversally outside a transversally inner edge of the top opening of the respective lifting casting.
9. The spreader according to claim 8, wherein the landing indicator comprises an actuator movable between a lower position, in which it protrudes below said abutment face, and an upper position, in which it is flush with said abutment face.
10. The spreader according to claim 9, wherein the actuator comprises a U-shaped loop comprising a first loop leg and a second loop leg, said loop legs extending upwards from an intermediate portion interconnecting the loop legs, wherein each loop leg is guided in the vertical direction by a respective loop leg guide.
11. The spreader according to claim 10, wherein said first loop leg is connected to a sensor configured to detect whether the loop is in its lower position or in its upper position, said first loop leg being located outside a vertical projection of the abutment face.
12. The spreader according to claim 8, wherein said at least one of said twist-locks within at least one of said pairs of twist-locks comprises a landing indicator configured to indicate, when the abutment face is lowered onto the respective lifting casting top surface, the presence of a portion of the lifting casting top surface transversally inside a transversally outer edge of the top opening of the respective lifting casting.
13. The spreader according to claim 8, said landing indicator being configured to generate an electronic landing confirmation signal, wherein each twist-lock within said at least one of said pairs of twist-locks further comprises an auxiliary landing indicator comprising an auxiliary actuator movable between a lower position, in which it protrudes below said abutment face, and an upper position, in which it is flush with said abutment face, wherein said auxiliary actuator is shaped to, when in the lower position, mechanically block the male locking insert end portion from turning to the lock position, and to, when in the upper position, provide clearance to allow the male locking insert end portion to turn to the lock position.
14. The spreader according to claim 8, wherein said transversal distance between the first twist-lock and the second twist-lock is changeable between a predefined standard-body distance between center axes of the respective male locking inserts, and a predefined wide twist-lock position distance between center axes of the respective male locking inserts, wherein the standard body distance is less than the wide twist-lock position distance.
15. The spreader according to claim 14, wherein the first distance is about 2258 mm and the second distance is about 2448 mm.
16. A method for lifting an intermodal transport container with a top-lift spreader, the method comprising: providing a top-lift spreader comprising a first pair of twist-locks and a second pair of twist-locks, wherein each pair of twist-locks comprises a first twist-lock and a second twist-lock, said first and second pairs of twist-locks being arranged in a rectangular pattern, a long side of which defines a longitudinal direction and a short side of which defines a transversal direction, the twist-locks being configured to engage with lifting castings arranged in a mating rectangular pattern on a top face of the container, wherein each of said twist-locks comprises a male locking insert configured to be inserted into a top opening of the respective lifting casting, the male locking insert comprising an insert end portion which is twistable about a respective vertical rotation axis to a lock position for engaging with the respective lifting casting, wherein each pair of twist-locks is reconfigurable between a standard position mode, in which a distance between the rotation axis of the male locking insert end portion of the first twist-lock and the rotation axis of the male locking insert end portion of the second twist-lock is a first distance, and a wide twist-lock position (WTP) mode, in which the distance between the rotation axis of the male locking insert end portion of the first twist-lock and the rotation axis of the male locking insert end portion of the second twist-lock is a second distance that is greater than the first distance; and the top-lift spreader providing an indication, via an indicator on the spreader, that at least one pair of twist-locks is lowered in WTP mode onto respective lifting castings provided with top openings having a transversal center-to-center distance corresponding to the standard position.
17. The method according to claim 16, wherein each twist-lock comprises an abutment face flanking the male locking insert, the abutment face being configured to rest on a top surface of the respective lifting casting when the spreader has been lowered onto the container such that the male locking insert has been inserted into the top opening, and wherein the indicator comprises an actuator movable between a lower position, in which it protrudes below said abutment face, and an upper position, in which it is flush with said abutment face.
18. The method according to claim 17, wherein the actuator comprises a U-shaped loop comprising a first loop leg and a second loop leg, said loop legs extending upwards from an intermediate portion interconnecting the loop legs, wherein each loop leg is guided in the vertical direction by a respective loop leg guide.
19. The method according to claim 18, wherein said first loop leg is connected to a sensor configured to detect whether the loop is in its lower position or in its upper position, said first loop leg being located outside a vertical projection of the abutment face.
20. The method according to claim 16, wherein the first distance is about 2258 mm and the second distance is about 2448 mm.
21. The method according to claim 16, further comprising: suspending, based on the indication, at least one of operation of the twist-locks or lifting of the container.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the appended drawings, where the same reference numerals will be used for similar elements, wherein:
(2) FIG. 1 is a diagrammatic view in perspective of a top-lift spreader for handling intermodal containers;
(3) FIG. 2a is a diagrammatic view of the spreader of FIG. 1 as seen from below, wherein the spreader is in a first, contracted position;
(4) FIG. 2b is a diagrammatic view of the spreader of FIG. 1 as seen from below, wherein the spreader is in a second, extended position;
(5) FIG. 3a is a diagrammatic view in perspective of a first embodiment of a main beam for a top-lift spreader;
(6) FIG. 3b is a cross-section of the main beam of FIG. 3a, taken along the plane illustrated with a dashed rectangle and as seen along the arrows
(7) FIG. 4a is a diagrammatic view in perspective of a second embodiment of a main beam for a top-lift spreader;
(8) FIG. 4b is a cross-section of the main beam of FIG. 4a, taken along the plane illustrated with a dashed rectangle and as seen along the arrows IV-IV;
(9) FIG. 5 is a schematic view in perspective, and in cross-section, of a travelling beam for a spreader;
(10) FIG. 6 is a cross-section of a third embodiment of a main beam for a spreader;
(11) FIGS. 7-12b are schematic side views of the top-lift spreader of FIG. 1, as seen along the spreader's longitudinal direction, in different scenarios in which the spreader is lowered onto containers of different types;
(12) FIG. 13 is a diagrammatic view in perspective of a twist-lock of the top-lift spreader of FIG. 1, the twist-lock being provided with two separate landing indicator arrangements;
(13) FIG. 14 is a schematic side view of the twist-lock of FIG. 13, as seen along the spreader's longitudinal direction, in a position aligned with the top opening of a lifting casting;
(14) FIG. 15 is a schematic view in perspective of a corner casting of an intermodal container;
(15) FIG. 16 is a diagrammatic detail view in perspective illustrating one of the landing indicator arrangements of FIG. 13;
(16) FIG. 17a is a diagrammatic view in section illustrating the other of the landing indicator arrangements of FIG. 13 when in a lower position;
(17) FIG. 17b is a diagrammatic view corresponding to the view of FIG. 17a, in which said other of the landing indicator arrangements has been pushed to an upper position by the top surface of a lifting casting;
(18) FIG. 18 is a schematic view in perspective of a hydraulic cylinder assembly for operating a travelling beam of the spreader of FIG. 1;
(19) FIG. 19a is a schematic view in perspective of an alternative embodiment of a transversal beam attached to a longitudinal beam;
(20) FIG. 19b is an exploded view of the transversal and longitudinal beams of FIG. 19a;
(21) FIG. 19c is a schematic side view of the transversal beam of FIG. 19a, as seen along the spreader's longitudinal direction;
(22) FIG. 19d is a schematic side view of the transversal and longitudinal beams of FIG. 19a as seen along the spreader's transversal direction; and
(23) FIG. 19e is a schematic view of the transversal and longitudinal beams of FIG. 19a as seen vertically from below.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
(24) FIG. 1 illustrates a top-lift spreader 10 for lifting an intermodal transport container. The spreader 10 comprises a main frame 12, which is suspended in a suspension arrangement 14 in a manner allowing the main frame 12 to slide relative to the suspension arrangement 14 along a longitudinal direction L of the main frame 12. The spreader 10 is configured to be carried, via a rotator 16, by a spreader carrier (not illustrated), such as a container crane or a truck. Four twist-locks 18, three of which are visible in FIG. 1, are arranged in a rectangular pattern. The twist-locks 18 are configured to releasably attach, in a manner known in the art, to respective lifting castings 20 of a container 22 to be lifted by the spreader 10. The lifting casting 20 of FIG. 1 is a corner casting arranged at a corner of the container 22, which is typical of a 20-foot or 40-foot container. The lifting casting 20 has a short-side opening 23, a long-side opening 25, and a top opening 50 allowing the container 22 to be lifted from any direction. The spreader 10 is configured to telescopically translate the twist-locks 18 along the longitudinal direction L, as well as along a transversal direction T perpendicular to the longitudinal direction L, in a manner that will be elucidated with reference to FIGS. 2a-b.
(25) FIGS. 2a-2b schematically illustrate the spreader 10 in two different positions, as seen from below. For clarity of illustration, components of the spreader 10 unnecessary for illustrating the telescopic function are omitted in FIGS. 2a-b. The main frame comprises a main beam 24, which is hollow and defines a first travelling beam guide 26 and a second travelling beam guide 28. The travelling beam guides 26, 28 are mutually parallel, and parallel to the longitudinal direction of the main frame. The first travelling beam guide 26 guides a first travelling beam 30, which is movable along a first travelling beam guide axis A1. The second travelling beam guide 28 guides a second travelling beam 32, which is movable along a second travelling beam guide axis A2. In FIG. 2a, the spreader 10 is illustrated with the travelling beams 30, 32 fully retracted into the respective travelling beam guides 26, 28, whereas when in the position of FIG. 2b, only the proximal ends 34, 36 of the respective travelling beams 30, 32 remain in the respective travelling beam guides 26, 28. The first travelling beam 30 is operated by a first hydraulic cylinder 29 (FIG. 1), which has a first end attached to the main beam 24 and a second end attached to the first travelling beam 32. The second travelling beam 32 is operated by a second hydraulic cylinder 35 (FIG. 1) in a similar manner, mutatis mutandis. The hydraulic cylinders 29, 35 are arranged on the top face of the main beam 24, and extend along the length of the main beam 24. Distal ends 38, 40 of the travelling beams 30, 32 are connected to the twist locks 18 (FIG. 1) in such a manner that the distal end 38 of the first travelling beam 30 carries a first twist-lock arrangement 42 comprising a first pair 18a-b of said twist-locks 18, and the distal end 40 of the second travelling beam 32 carries a second twist-lock arrangement 44 comprising a second pair 18c-d of twist-locks 18. By varying the extent to which the travelling beams 30, 32 extend in opposite directions from the main beam 24, it is possible to adjust the longitudinal distance DL between the twist-lock arrangements 42, 44 to accommodate for containers of different axial lengths.
(26) The first pair of twist-locks consists of a first twist-lock 18a and a second twist-lock 18b. Similarly, the second pair of twist-locks consists of a first twist-lock 18c and a second twist-lock 18d. The first and second pairs of twist-locks are arranged in a rectangular pattern, a long side of which extends along the longitudinal direction L and a short side of which extends along the transversal direction T, allowing the twist-locks 18a-d to engage with lifting castings 20 (FIG. 1) arranged in a mating rectangular pattern on a top face of a container to be lifted. The first and second twist-locks 18a-b of the first pair of twist-locks are telescopically suspended in a first transversal beam 46, which interconnects the twist-locks 18a-b and the distal end 38 of the first travelling beam 30. The transversal distance D.sub.T between the first and second twist-locks 18a and 18b of the first pair of twist-locks can thereby be varied by moving the twist-locks 18a-b towards or away from each other along the transversal direction T. The first and second twist-locks 18c, 18d of the second pair are suspended in a second transversal beam 48 in a similar manner, mutatis mutandis, allowing also the transversal distance between the first and second twist-locks 18c, 18d of the second pair to be varied. The transversal movement of the twist-locks 18a-b of the first pair is coordinated with the transversal movement of the twist-locks 18c-d of the second pair, such that the length of the short side of the rectangular pattern can thereby be varied.
(27) In the view of FIG. 2a, the spreader 10 is contracted in the longitudinal and transversal directions L, T such that the rectangular pattern defined by the twist-locks 18a-d corresponds to the rectangular pattern defined by top openings 50 (FIG. 1) of the lifting castings 20 of an ISO-standard 20-foot by 8-foot intermodal container.
(28) FIG. 2b illustrates the same spreader 10 extended in the longitudinal and transversal directions L, T such that the rectangular pattern defined by the twist-locks 18a-d corresponds to the rectangular pattern defined by the top openings of the lifting castings of a 40-foot “pallet-wide” intermodal container, which has a typical width in the transversal direction of about 8 feet 6 inches. Clearly, even though only two positions are illustrated in FIGS. 2a-b, the spreader can also be longitudinally extended to 40 feet while simultaneously remaining transversally contracted to eight feet, and vice versa.
(29) FIGS. 3a-b illustrates a container spreader main beam 124 similar to a general type known in the art. The main beam 124, which may replace the main beam 24 and hence be integrated within a spreader 10 as described hereinbefore with reference to FIGS. 1 and 2a-b, is formed by a pair of rectangular HSS (Hollow Structural Section) steel beams 101, 102 of uniform material thickness. A typical material thickness of the HSS beams of a main beam 124 capable to withstand the weight of a laden 40-foot container may be about 12 mm. Each HSS beam 101, 102 defines a respective travelling beam guide 126, 128. The HSS beams 101, 102 are welded together along an upper longitudinal line 103 and a lower longitudinal line 104, to form the main beam 124. Top reinforcement bands 105 of steel plate are welded transversally across the outer top face of the main beam 124 at the predetermined, longitudinal positions along the main beam 124 where the proximal ends 34, 36 of the travelling beams 30, 32 will be located when the spreader is set in the 20- and 40-foot positions (c.f. FIGS. 2a-b), respectively. A typical material thickness of the top reinforcement bands 105 may be about 30 mm for spreaders capable of handling laden 40-foot containers. Similar bottom reinforcement bands 106 are welded transversally across the outer bottom face of the main beam 124, and reinforce the bottom at the same longitudinal positions. A pair of side shift rails 152, 154 extend in the longitudinal direction along opposite outer side wall faces 156, 158 of the main beam 124. The side shift rails 152, 154 allow the main beam 124 to be slidably suspended in a suspension arrangement 114 functionally corresponding to the suspension arrangement 14 of FIG. 1. Slide pads 109, attached to the suspension arrangement 114, reduce the friction in such sliding engagement, and steel plate side reinforcements 107, 108 are welded along the side wall faces 156, 158 in order to reinforce the main beam 124 against transversal loads from the suspension arrangement 114.
(30) FIGS. 4a-b illustrate in greater detail the main beam 24 of FIGS. 1 and 2a-b, wherein FIG. 4b illustrates a cross-section of the main beam 24 as seen in a plane IV-IV perpendicular to the main beam's longitudinal direction L. The main beam 24 of FIGS. 4a-b is of a lighter and stronger design than the main beam 124 of FIGS. 3a-b for reasons that will be elucidated in the following. The main beam 24 is formed of a first, upper C-beam, or channel beam, 60 of a relatively thicker material thickness MT.sub.U1, the upper C-beam 60 being oriented with its channel facing downwards; and a second, lower C-beam 62 of a relatively thinner material thickness, MT.sub.L1, wherein relatively thicker in this context should be construed as thicker than the relatively thinner material thickness. The lower C-beam 62 is oriented with its channel facing upwards, towards the channel of the upper C-beam 60, such that the channels of the upper and lower C-beams 60, 62 face each other. The lower C-beam 62 may have a material thickness MT.sub.L1 of less than ⅔ of the material thickness MT.sub.U1 of the upper C-beam 60. In the particular example illustrated, the lower C-beam 62 has a material thickness MT.sub.L1 of about half the material thickness MT.sub.U1 of the upper C-beam 60. By way of example, the upper C-beam 60 may be made of steel plate having a thickness MT.sub.U1 of about 20 mm, whereas the lower C-beam 62 may be made of steel plate having a thickness MT.sub.L1 of about 10 mm.
(31) As seen in the section plane IV-IV, the lower C-beam 62 has a vertical height HL which is higher than the vertical height Hu of the upper C-beam 60. The upper and lower C-beams 60, 62 are welded directly together along a pair of longitudinal welds 64, 66, to form a main beam 24 of a generally rectangular cross-section. A vertical separation wall 37 extends between the upper and lower C-beams 60, 62, and divides the inner space defined by the upper and lower C-beams 60, 62 into said first and second travelling beam guides 26, 28, thereby making also the travelling beam guides 26, 28 substantially rectangular in cross-section. The separation wall 37 may be provided with a plurality of lightening holes (not shown). A pair of L-shaped side shift rails 52, 54 are welded to the lower C-beam 62 and extend in the longitudinal direction along opposite outer side wall faces 56, 58 of the main beam 24, thereby allowing the main beam 24 to be slidably suspended in the suspension arrangement 14. The thinner material thickness of the lower C-beam 62 allows the side shift rails 52, 54 to be countersunk laterally inside the outer side wall faces of the upper C-beam 60, and attached directly below the same, so as to vertically bear against the lower longitudinal edges of the upper C-beam 60. Thereby, the vertical load of the main beam 24 will be vertically applied directly onto the side shift rails 52, 54, reducing the strain on the welds connecting the side shift rails 52, 54 to the main beam 24. Each side shift rail 52, 54 rests in the suspension arrangement 14 on a set of slide pads 68, of which one on each side of the main beam 24 is illustrated in the cross-section of FIG. 4b. A set of side support pads 70 face the outer side wall faces 56, 58 above the welds 64, 66, and guide the main beam 24 along the longitudinal direction L. Inner bottom slide pads 72 are arranged on inner bottom faces of the respective travelling beam guides 26, 28 adjacent to their respective guide apertures 86, 88. The inner bottom slide pads 72 are configured to support the travelling beams 30, 32, and provide a distribution of the weight of the travelling beams 30, 32 across said inner bottom faces. Similar slide pads (not illustrated) are attached to outer top and bottom faces of the proximal end 34, 36 of each travelling beam 30, 32. The slide pads 72 each have a length, in the longitudinal direction L, of about 400 mm, i.e. the total slide pad length carrying each travelling beam 30, 32 is about 800 mm.
(32) The main beam 24 is, at each of a first end 74 and a second end 76, provided with a respective steel plate end collar 78, 80 extending outwards from the hollow structure defined by the upper and lower C-beams along a respective plane perpendicular to the longitudinal direction L. As is illustrated in FIGS. 4a-b, the first end collar 78 encloses a beam guide aperture 82 of the first travelling beam guide 26 and partly closes a rear end opening 84 of the second travelling beam guide 28. In a similar manner, the second end collar 80 encloses a beam guide aperture 88 of the second travelling beam guide 28 and partly closes a rear end opening 86 of the first travelling beam guide 26. Each of said end collars 78, 80 also forms a diagonal truss element 87 across the respective rear end opening 84, 86.
(33) FIG. 5 illustrates a cross-section of an exemplary embodiment of the first travelling beam 30. Needless to say, the second travelling beam 32 (FIG. 2) may be constructed in a similar manner. The first travelling beam 30 is formed of a first, upper C-beam, or channel beam, 31 of a relatively thinner material thickness MT.sub.U2, the upper C-beam 31 being oriented with its channel facing downwards; and a second, lower C-beam 33 of a relatively thicker material thickness, MT.sub.L2, wherein relatively thicker in this context should be construed as thicker than the relatively thinner material thickness. The lower C-beam 33 is oriented with its channel facing upwards, towards the channel of the upper C-beam 31, such that the channels of the upper and lower C-beams 31, 33 face each other. The upper C-beam 31 may, for example, have a material thickness MT.sub.U2 of less than ⅔ of the material thickness MT.sub.L2 of the lower C-beam 33. In the particular example illustrated, the upper C-beam 31 has a material thickness MT.sub.U2 of about half the material thickness MT.sub.L2 of the lower C-beam 33. By way of example, the upper C-beam 31 may be made of steel plate having a thickness MT.sub.U2 of about 10 mm, whereas the lower C-beam 33 may be made of steel plate having a thickness MT.sub.L2 of about 20 mm. Similar to the main beam 24, the upper and lower C-beams 31, 33 of the travelling beam 30 are welded together along a pair of welds extending in the longitudinal direction L.
(34) Optionally, the proximal end 34 of the upper C-beam 31 may be provided with a reinforcement (not illustrated), which may reinforce the travelling beam 30 at its location where the proximal end 34 applies its load onto the upper, inner surface of the travelling beam guide 26 (FIG. 4b). By way of example, the reinforcement may be configured as steel plate end cover at least partly closing the hollow structure defined by the upper and lower C-beams 31, 33 at the proximal end 34, similar to the collar 78, 80 of the main beam 24, or as a transversal reinforcement band, similar to the bands 105 of FIG. 3a, welded to the inside or outside surface of the upper C-beam 31 at the proximal end 34.
(35) FIG. 6 schematically illustrates a cross-section of yet an embodiment of a main beam 224 for a spreader, such as a side-lift spreader or the top-lift spreader 10 of FIG. 1. The main beam 224 comprises an upper C-beam 260 of relatively thicker material thickness, and a lower C-beam 62 of relatively thinner material thickness. The upper and lower C-beams 60, 62 are rigidly attached to each other via a pair of intermediate elements 261. A pair of travelling beams 230, 232 are guided inside the inner space enclosed by the upper and lower C-beams 260, 262; in this respect, the main beam 224 forms a pair of parallel guides 226, 228 for the respective travelling beams 230, 232. The intermediate elements 261 extend inwards into the main beam 224 to form guide rails, which form-fittingly keep the travelling beams 230, 232 apart. FIGS. 7-12b illustrate a number of different lifting scenarios that the spreader 10 (FIG. 1) may encounter when lifting a container 22. Each figure schematically illustrates the spreader from the side, as seen along the longitudinal direction, and hence illustrates a transversal beam 46 provided with a respective pair of telescopically arranged twist-locks 18a-b.
(36) FIG. 7 illustrates the spreader when set in an ISO standard position mode, i.e. its transversal center-to-center distance D.sub.T between the male locking inserts 19a-b of the twist-locks 18a-b is adjusted for lifting an ISO standard container having a width of 8 feet. The container 22a to be lifted is an ISO standard container having a width in the transversal direction T of 8 feet.
(37) FIG. 8 illustrates the spreader 10 when set in a “wide twist-lock position”, WTP, mode, i.e. its transversal center-to-center distance D.sub.T between the male locking inserts 19a-b of the twist-locks 18a-b is adjusted for lifting a so-called “pallet-wide container” or “wide-body container”. The pallet-wide container 22b to be lifted has a width in the transversal direction T adapted for accommodating two standardized pallets next to each other, and therefore is slightly wider than an ISO container. It has a width in the transversal direction T of about 8 feet and 6 inches. The pallet-wide container 22b has its lifting castings separated by 6 inches more than an ISO standard container, and may therefore be termed a WTP pallet-wide container.
(38) FIG. 9 illustrates the spreader 10 set in the ISO standard position mode. The container 22c to be lifted is of a first type of pallet-wide container with lifting castings 20 in ISO position. Thanks to having its lifting castings 20 in the more common ISO position, the intermodal container 22c can, as it is moved by different trucks and cranes along its route of transport, be lifted by spreaders capable of handling ISO containers only. The container 22c has a wider body of about 8 feet and 6 inches, but the transversal distance between its top corner castings 20 is the same as that of ISO containers.
(39) FIG. 10 again illustrates the spreader 10 set in the ISO standard position mode.
(40) The container 22d to be lifted is of a second type of pallet-wide container with lifting castings 20 in ISO position. The container 22d differs from the container 22c of FIG. 9 in that the lifting castings 20 extend outwards to the full width of the pallet-wide container body, allowing the lifting castings 20 to be accessed also from the side by e.g. a side-lift spreader (not illustrated), whereas the top openings 50 (illustrated schematically with dashed lines) are separated by a center-to-center distance D.sub.T corresponding to the center-to-center distance between the male locking inserts 19a-b when the spreader 10 is in ISO position. This allows the container 22d to be lifted by the spreader 10 in ISO position, even though the container 22d has a wider body of about 8 feet and 6 inches.
(41) FIG. 11a illustrates a first potentially dangerous situation. The container 22d is again of the second type of pallet-wide container with lifting castings 20 in ISO position, which is described with reference to FIG. 10. However, the spreader 10 is erroneously set in WTP mode; this may, by way of example, happen due to human mistake. In particular, the locations of the top openings 50 are not visible from below. It is very difficult, and in some situations impossible, to see the difference between a WTP wide-body container 22b (FIG. 8), and said second type of pallet-wide container 22d (FIG. 10) with lifting castings 20 in ISO position, from e.g. a reach stacker below a stack of containers. Therefore, a reach stacker truck driver will generally have to read, and rely on, container type codes written on the containers for their type identification. Container type codes may also be worn or otherwise difficult to read. The interpretation of container type codes requires knowledge and skill, and also requires the reach stacker driver to be attentive and focused. When lowered onto the container 22d to the position illustrated in FIG. 11b, the male part 19a of the first twist-lock 18a is inserted into the respective lifting casting 20, whereas the male part 19b of the second twist-lock 18b is lowered just outside the container 22d. Twisting the twist-locks to their lock positions, and thereafter lifting the spreader 10, will damage the container 22d, and may also result in dropping the container 22d to the ground. In particular, the latter may occur if the second male part 19b engages with a long-side opening 25 (FIG. 1) of the lifting casting 20, allowing the container 22d to follow the spreader 10 up as it is lifted.
(42) FIG. 12a illustrates a second potentially dangerous situation. The containers 22a, 22a′ are standard ISO dimension containers of the type described with reference to FIG. 7. However, the spreader 10 is erroneously set in WTP mode; this may, by way of example, happen due to human mistake. When lowered onto the container 22a to the position illustrated in FIG. 12b, the male part 19a of the first twist-lock 18a is inserted into the respective lifting casting 20, whereas the second twist-lock 18b is lowered onto the lifting casting 20′ of an adjacent container 22a′, with its male locking insert 19b just outside the adjacent container 22a′. Locking and lifting the spreader 10 from this position may damage the containers 22a, 22a′, and could potentially also result in dropping the container 22a to the ground.
(43) FIG. 13 illustrates a twist-lock 18 capable of avoiding the dangerous situations of FIGS. 11a-b and 12a-b. The twist-lock 18 comprises a male locking insert 19 configured to be inserted into a top opening 50 (FIG. 1) of a respective lifting casting 20. Once inside the lifting casting 20, an end portion 89 of the male locking insert 19 is configured to be twisted 90° about a vertical axis R to a lock position, in which it engages with the lifting casting 20. An abutment face 90 (hatched), flanking the male locking insert 19, corresponds to the size and shape of the top surface 27 (FIG. 1) of the lifting casting 20, and is configured to rest thereupon once the spreader 10 (FIG. 1) has been lowered onto the container 22. A first landing indicator 91 has a vertically movable indicator body 92, a portion of which protrudes downwards from the abutment face 90. The indicator body 92 is located on a distal side 90a of the male locking insert 19, i.e. outside the male locking insert 19 along the transversal direction T. The first landing indicator 91 is configured to indicate when the upper surface 27 of the lifting casting 20 presses the vertically movable indicator body 92 vertically into the abutment face 90 of the twist-lock 18, as the abutment face 90 is lowered into abutment on the respective lifting casting top surface 27. Thereby, the first landing indicator 91 allows verifying that a transversally distal portion 90a of the abutment face 90 rests upon a lifting casting 20, before the twist-lock 18 is locked. This facilitates avoiding the potentially dangerous situation of FIGS. 11a-b. A second landing indicator 93 has a vertically movable indicator body 94, a portion of which protrudes downwards from the abutment face 90. The indicator body 94 is located on a proximal side 90b of the male locking insert 19, i.e. inside the male locking insert 19 along the transversal direction T. The second landing indicator 93 is configured to indicate when the upper surface 27 of the lifting casting 20 presses the vertically movable indicator body 94 vertically into the abutment face 90 of the twist-lock, as the abutment face 90 is lowered onto the lifting casting top surface 27. Thereby, the second landing indicator 93 allows verifying that a transversally proximal portion 90b of the abutment face 90 rests upon a lifting casting 20, before the twist-lock 18 is locked. This facilitates avoiding the potentially dangerous situation of FIGS. 12a-b.
(44) FIGS. 14-15 illustrate the geometry, as the twist-lock 18 lands on the lifting casting 20, in greater detail. In the illustrated example, the indicator body 92 of the first landing indicator 91 is located transversally outside a transversally outer edge of the male locking insert 19, so as to detect the presence of a portion of the upper surface 27 of the lifting casting 20 transversally outside a transversally outer edge 85b of the top opening 50. However, in order to avoid the potentially dangerous situation of FIG. 11b, it is sufficient that the first landing indicator 91 be configured to detect the presence of a portion of the upper surface 27 of the lifting casting 20 transversally outside a transversally inner edge 85a of the top opening 50. Hence, even though it may, for space considerations, be preferred to have the indicator body 92 located at the illustrated position transversally outside the male locking insert 19, it may, as an alternative, be located transversally aligned with the male locking insert 19. Similarly, in the illustrated example, the indicator body 94 of the second landing indicator 93 is located transversally inside a transversally inner edge of the male locking insert 19, so as to detect the presence of a portion of the upper surface 27 of the lifting casting 20 transversally inside a transversally inner edge 85a of the top opening 50. However, in order to avoid the potentially dangerous situation of FIG. 12b, it is sufficient that the second landing indicator 93 be configured to detect the presence of a portion of the upper surface 27 of the lifting casting 20 transversally inside a transversally outer edge 85a of the top opening 50. Hence, even though it may, for space considerations, be preferred to have the indicator body 94 located at the illustrated position transversally inside the male locking insert 19, it may, as an alternative, be located transversally aligned with the male locking insert 19. A single indicator body transversally aligned with the male locking insert may, in fact, assist in avoiding both potentially dangerous situations of FIGS. 11b and 12b.
(45) FIG. 16 illustrates the second landing indicator 93 in greater detail. The rotatable male locking insert end portion 89 is provided with a blocking pin 96 extending radially from an upper portion of the male locking insert end portion 89. The vertically movable indicator body 94 comprises a blocking element 95 shaped to, when in the lower position as illustrated in FIG. 16, mechanically block the blocking pin 96 from swinging past the blocking element 95, and thereby mechanically block the male locking insert end portion 89 from turning to the lock position. When in the upper position (not illustrated), clearance is provided below the blocking element 95 to allow the blocking pin 96 to swing below the blocking element 95. Preferably, the indicator body 94 is resiliently biased towards a lower position in which it protrudes from the abutment face 90.
(46) The cross-sections of FIGS. 17a-b illustrate the first landing indicator 91 in greater detail. In FIG. 17a, the indicator body 92 is in a lower position, in which it protrudes below the abutment face 90, whereas FIG. 17b illustrates the indicator body 92 in an upper position, in which it is flush with the abutment face 90. A spring 97 applies a bias, pressing the indicator body 92 towards its lower position. The indicator body 92 is shaped as a U-shaped loop, comprising a first loop leg 98a and a second loop leg 98b, said legs 98a-b extending upwards from an intermediate portion 99 interconnecting the loop legs 98a-b, wherein each loop leg 98a-b is guided in the vertical direction by a respective loop leg guide 100. An elongate track 41 in the abutment face 90 allows the intermediate portion 99 of the indicator body 92 to be received therein in its entirety. The first loop leg 98a, which is located outside the vertical projection (dotted area) of the abutment face 90, is provided with a washer 43. An inductive sensor 45 is configured to detect the presence of the washer 43 when the loop 92 is in its upper position. The inductive sensor 45 is connected to an electronic control system 39 of the spreader 10, which may in turn be connected to the control system of any truck or crane carrying the spreader. Thereby, the control systems may be provided with an electronic landing indication indicating whether the transversally outer portion of the abutment face 90 abuts the upper surface 27 of a lifting casting 20. The second loop leg 98b is a simple stub, serving for preventing the indicator body 92 from turning about the first loop leg 98a. The electronic landing signal, or the absence of an electronic landing signal, may be used for allowing or prohibiting the operation of the twist-locks. Alternatively, the electronic landing signal may be indicated to an operator, such as a reach stacker driver. FIG. 18 illustrates the second hydraulic cylinder 35 (FIG. 1), for operating the second travelling beam 32 (FIG. 2b), in greater detail. The hydraulic cylinder 35 is incorporated in a hydraulic cylinder assembly 1001, and has a first end 1003 attached to a top face of the main beam 24 (FIG. 1), and a second end 1005 attached to a top face of the second twist-lock arrangement 44 (FIG. 2b) at the distal end 40 of the second travelling beam 32. The hydraulic cylinder assembly 1001 comprises a hydraulic connection assembly 1007 comprising a plurality of hydraulic hoses 1009. In the illustrated example, the hydraulic connection assembly 1007 comprises seven hydraulic hoses 1009a-g, two of which 1009a-b are hydraulically connected to the hydraulic cylinder 35 adjacent to the respective ends 1003, 1005, to control the hydraulic cylinder 35 in both directions. The remaining five hydraulic hoses 1009c-g are configured to forward respective hydraulic control signals to hydraulic actuators other than the hydraulic cylinder 35, such as the first hydraulic cylinder 29 (FIG. 1), any hydraulic cylinders (not shown) for moving the twist-locks 18 between standard position mode (FIG. 7) and wide twist-lock position mode (FIG. 8), and hydraulic actuators for turning the insert end portions 89 of the twist-locks 18 (FIG. 13). In this respect, the hydraulic cylinder 35 doubles as a carrier for hydraulic connections 1009c-g unrelated to the function of the hydraulic cylinder 35.
(47) The hydraulic control connection assembly 1007 is attached to the hydraulic cylinder 35 at a plurality of attachment positions 1011 distributed along the length of the hydraulic cylinder 35, such that the hydraulic hoses 1009 require no or very few attachment points directly onto the main beam 24 (FIG. 1).
(48) Thanks to the modular design of the hydraulic cylinder assembly 1001 with the hydraulic connection assembly 1007, the hydraulic cylinder assembly 1001 can be assembled before attaching it to the main frame 12 (FIG. 1). This saves valuable time for assembling the spreader 10 (FIG. 10), as well as substantially reduces the amount of threaded attachment holes needed in the main beam 24 (FIG. 1).
(49) FIGS. 19a-e illustrate an alternative embodiment of a transversal beam 346, which may replace any of the transversal beams 46, 48 of the spreader 10 (FIG. 1). Similar to the transversal beam 46, the transversal beam 346 interconnects a pair of twist-locks 18a-b. For reasons of clarity of illustration, the transversal beam 346 is illustrated as non-telescopic, even though the transversal beam structure described hereinbelow may equally well be applied to a telescopic transversal beam such as the beam 46 described hereinbefore. The male locking inserts 19 (FIG. 13) of the twist-locks are, also for reasons of clarity of illustration, not illustrated in FIGS. 19a-f. The transversal beam 346 is connected to a longitudinal beam 330, which may be telescopically or fixedly attached to the main frame of the spreader 10 (FIG. 1). The transversal beam 346 comprises an outer side wall 2001, an inner side wall 2003, a bottom wall 2005, and a top wall 2007, which are welded together to define a hollow structural section, HSS, structure extending in the transversal direction T. The HSS structure has a cross-section which varies along the length of the transversal beam 346 in the transversal direction T in such a manner that its vertical height H.sub.T decreases towards the ends of the transversal beam 346. Assuming a total length L.sub.T of the transversal beam, the transversal beam portions exhibiting a gradual height decrease extend in each direction to respective positions P located about 1/10*L.sub.T from the transversal beam's 346 ends. The gradually decreasing height H.sub.T is defined by respective inclined upper edges 2013, 2015 of the outer and inner side walls 2001, 2003. The upper edges 2015, 2013 of the inner and outer side walls 2003, 2001 are interconnected by an upper top wall 2007 extending along the length of the upper edges 2013, 2015.
(50) The longitudinal beam 330 penetrates through the inner side wall 2003 and into abutment with the outer side wall 2001, and is attached to both side walls 2001, 2003 by means of respective welds extending about the circumference of the longitudinal beam 330. An inner edge 2009 of the bottom wall 2005 extends inwards, beyond the inner side wall, to define an inwardly extending flange 2011. The flange 2011 has a width W.sub.F, in the longitudinal direction, which gradually increases towards the location where the longitudinal beam 330 interfaces the transversal beam 346, and is welded to the longitudinal beam 330 via a pair of supports 2017.
(51) Each of the inner and outer side walls 2001, 2003 has a respective upper wall portion 2001a, 2003a which is inclined longitudinally inwards, so as to form an acute angle α with a plane defined by the four twist-locks 18 (FIG. 1). The inclined upper wall portions 2001a, 2003a are parallel to each other, and their top edges 2013, 2015 substantially coincide with each other as seen along the longitudinal direction L of the spreader 10. Each of the inner and outer side walls 2001, 2003 also has a respective lower wall portion 2001b, 2003b which extends along a respective substantially vertical plane, so as to form an obtuse angle θ with the respective upper side wall 2001a, 2003a. Also the lower wall portions 2001b, 2003b are parallel to each other. As is evident from FIGS. 19a-b, the longitudinal beam 330 engages with, and is welded to, upper and lower wall portions 2001a-b, 2003a-b of both side walls 2001, 2003, resulting in a very rigid structure.
(52) The present disclosure describes several different inventive concepts, each of which may be implemented independently of, or in combination with, the others. Each separate inventive concept described herein may also form the basis of a divisional application.
(53) The concepts herein have mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.
(54) For example, the present disclosure describes a spreader comprising only one single main beam. The teachings provided herein may be applied to other types of spreaders, such as spreaders of the type having a pair of parallel main beams spaced from each other, each main beam holding one single twist-lock at each end.
(55) The first landing indicator 91 has been described as an electronic landing indicator, connected to an electronic control system, whereas the second landing indicator has been described as a purely mechanical arrangement, indicating by blocking/unblocking the motion of the male locking insert end portion 89. Clearly, either of the landing indicators could be of electronic type, of a mechanically blocking type, or both. Landing indicators need not involve any movable parts; instead, the presence of a lifting casting top surface can be detected by e.g. resistive, capacitive, or inductive sensors. In fact, an indication of whether the spreader is set in WTP mode, when lowered onto respective lifting castings having top openings separated according to the ISO standard, can even be performed well before landing, using e.g. a camera mounted to the spreader, and digital image processing determining the distance between the lifting casting top openings.
