DE2322409A1 - EXTENDABLE AND RETRACTABLE LIFTING MASTER FOR USE IN CONNECTION WITH A PALLET TRUCK - Google Patents

Description

2322403

Extendable and retractable lifting mast for use in conjunction with a lift truck

The invention relates generally to lift trucks which can be used for industrial purposes and / or in the open and particularly relates to extendable and retractable lifting masts to be mounted on a lift truck.

The invention is based on the object of an improved load lifting device for industrial purposes To create serving and / or manoeuvrable pallet trucks in open terrain with an extendable and retractable lifting mast is present, assigned to the Lasthebeketven or other flexible tension members, which by a hydraulic Plungers can be operated to either of the

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at least to lift a load supported by a sled, and an improved load lifting and locking device suitable for use in connection with such a lifting mast to create such that firstly an economical construction of low weight for Is available, which proves to be expedient in operation and works reliably, that secondly with the help of a inevitably working locking mechanism an inevitable pole control of the extension movement of the slide and the Mastes causes thirdly, a significantly improved view through the mast for the driver of the lift truck results through it, while the parts of the Iviastes run through the last section of their movement path when being pushed out, that fourth, the height adjustability of a mast of the usual three-stage extendable design on one Such V.'eise is achieved that at the same time a full free lifting movement of the carriage on the upper inner i ^ astteil achieved before pushing out any load part is that fifth, given the lowest height of the mast in the retracted state, a "comparison." Increased lifting height compared to known boxes can be achieved while increasing the load to be lifted at the same time, that the above improvements can be achieved using a single simple plunger with a Cylinder and a piston can be achieved, resulting in an increase in the stroke speed, a decrease the pressure oil requirement of the ram, a constant stroke ratio of 4: 1 and a constant load lifting speed

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shows that seventh the improvements mentioned are achieved without it being necessary to increase the width of the To enlarge the mast, so that the mast can be mounted on most of the existing lift trucks without it it is necessary to provide drive axles with a particularly large track width, and that eighth an improved, inevitably working locking mechanism or a locking device is available that is more robust, simple and reliable construction.

The invention and advantageous details of the invention are described below with reference to schematic drawings explained in more detail using exemplary embodiments. It shows:

Pig. 1 is a perspective bar position of a known type of lift truck in the form of a forklift truck, which with an improved extendable mast is equipped according to the invention, which loos its retracted Assumes position while the carriage has been raised to the upper end of its full free stroke;

Fig. 2 shows a pig. 1 similar perspective view, but in which the mast is extended to its full height has been;

Pig. 3 an enlarged perspective illustration; from which only the East can be seen, which is in the inserted state, with the slide is located at the lower end of its full free stroke, and with the forks of the carriage of clarity are omitted for the sake of

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Pig. 4 one drawn on an even larger scale Top view of the bast according to Fig. 3, the mast at _ * Viewing it from the line 4-4 in FIG shows;

Pig. 5 shows a horizontal section along the line 5-5 in FIG. 3;

Pig. 6 part of the rear of the upper end of the innermost part of the mast when viewed from line 6-6 in Pig. 4, with part of a locking device can be seen according to the invention;

Pig. Figure 7 is a vertical section along line 7-7 in Pig. 5;

Figure 8 is an exploded perspective view of the outermost lower barrel and associated parts Plunger, chain and locking parts;

Fig. 9 "is an exploded perspective view of the central part of the ^ branch and the associated Chain, auxiliary slide and guide construction;

10 is an exploded perspective view of the innermost upper mast part and the associated one Slide, lift rod and locking parts;

11 shows an exploded perspective partial representation of the slide with an actuating member for a locking device and with a lateral guide role;

Fig. 12 is a side view of a part of the carriage and lifting rod construction;

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Pig. 13 »14 and 15 partly as vertical sections side views shown along line 13-13 in Pig, Figure 6 the ^ illustration of the mode of action of the locking mechanism according to the invention, Pig. 13 the locking of the inner mast opposite the outer mast can be seen, with Pig. 14 the working of one on the sled Existing actuator with the lock to unlock the inner mast from the outer mast reveals, and where Pig. Figure 15 shows the manner in which the carriage has been locked to the inner mast and carried by the inner mast, which in turn has been unlocked from the outer mast;

Pig. 16, 17 and 18 vertical sections through the branch according to FIGS. 1 to 14, Pig. 16 the burden in his fully inserted state can be seen in which the carriage is at the lower end of its free stroke located while Pig. 17 shows the sledge in case it is at the top of its free Lifting distance is located while the load is still pushed in, and Fig. 16 the mast in ^ fully extended Shows state; and

19 and 20 each in a compressed longitudinal section a second and a third embodiment of a load that can be pushed in and out according to the invention.

The basic ideas of the invention can be applied to lifting devices that can be pushed in and out itframe construction that usually

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is referred to as a mast and is composed of "several parts, whereby according to the herei ^^ e ^ reTfenrUBxfe ^ B ^ lTing preferably three mast parts are present. The term" mast part "denotes in the following" -eahe ^ aTi-ziLge ^ai s4ruTe " of the mast, to which usually a ^r t ^v e "h% fe € ^fc3.ge-: belongs SahmBnkonstruktion resulting from two ^ dSrch ^ ei in ^7" separate horizontal distance, stehefcd ^a äEgeordnöf; s "tracks" and connecting them, horizontally disposed transverse struts composed, said-visual £ enes ^s so ^e exhj | are erichtet that they each turn of another mast member with entspfeefienain ^ rails and aTässehieb rails "refers to the arranged upright lateral structural members ^5" 6ar-züsammenarbeiten the term. " one-Sästteiis, "which are rolled profiles atfsg-eb-iftSe-fe" Seppel "-IT profiles or other profiles ^r T £ aiSn, ^u iSfid ^G die ^ & ucim- ■ borrowed in the standing mast parts- used in pairs. In the following, the term "ram" denotes the hydraulically actuatable -Zytincfef "-" lind "ίϊσΓ -ben arrangement, which serves to move the BestKebevox direction vertically, and which is preferably designed as a simple two-part ram», "to tfern% in" Zyi "£ nö" he belongs, which forms the outer lower skin egg-1 -des "ßirassels and is firmly connected at its lower end to the lowest outer mast part, as well as a stamp or a push rod that carries a pressure-actuated" piston protrudes from the cylinder and is guided so that it can slide in and out with respect to the upper end

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also possible to use other multi-part plunger designs use. The term "carriage" denotes a skirt part which is perpendicular to the uppermost inner mast part is movable and usually carries fork tines or other cantilevered members that serve to lift the, Pick up the load to be lowered and / or transported directly. The term "chain" denotes the common ones flexible load bearing elements, which serve to transmit tensile forces, and the connections between the Make the ram, the load parts and the slide. These chains are preferably roller chains known type, because such chains operate with minimal friction and are only to a minimal extent one Subject to stretching, but other types of chains such as ropes, straps or the like could be used, if one takes their extensibility into account in the construction.

1 and 2 show, as an exemplary embodiment, a preferred embodiment of a load lifting device of the invention with a three-stage or three-part mast 20, the lifting height of which is slightly greater than that a three-stage load of a known type, or which is at the same maximum lifting height compared to a Push in a known type to a lower height leaves. In Fig. 1, the load 20 is completely pushed in, but the sled is 22: to the upper end of its free one Boy stretch rehoben v / orden. ^ he mast 20 is in the usual V: ei se mounted on the front axle of the lift truck 24, at

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which, according to FIGS. 1 and 2, is one with hard beeps provided pallet truck for industrial purposes or an all-terrain pallet truck. The mast can be in a firm upright position by at the front End of the lift truck fastened screws 26 are held, or it can be pivoted on the front axle of the lift truck be stored and connected to the lift truck by tilt ram, not shown, so that it is known Way in sighting the longitudinal axis of the lift truck can pivot forwards and backwards.

According to I ¹ Xg. 2 belong to the trunk 20 three hasty parts, namely a lower mast part 28 provided with two rails, which has a fastening structure so that it can be detachably connected to the front end or the front axle of the lift truck 24 at its lower end or in its cage , also a middle mast part 30 provided with two rails and an uppermost inner load part 32 provided with two rails. The middle load part 30 can be pushed into the lower box part 28 and the upper mast part 32 can be pushed into the middle mast part 30. It is true that slide rails of a known type could be provided in order to enable the load parts to work together, but it is preferred to use an EoI guide structure in the IvIa st 20, as described in detail in US Pat. No. 3,213,96? is described. - "■ erner the .. branch 20 has a load lifting carriage 22 , which carries two removable fork prongs 24 and 24 'on its horizontally arranged upper rail 23, and the

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opposite the rails 36 and 36 'of the upper mast part 32 through front guide rollers 52 »rear guide rollers 52 "and lateral guide rollers 25. Furthermore, the mast 20 includes a two-part plunger 34- and two sets of lifting chains 33 »33 'and 35>, respectively 35 '

Further details regarding the construction and mode of operation of the mast 20 emerge from the following Description of the carriage and the boom construction with reference to FIGS. 3 to 15 and the overall representations in Figures 16 through 18. In certain figures, certain components are forward of their actual locations or shown offset to the rear to show the arrangement of the chains more clearly. In addition, Fig. to 18 of each pair of components present, only one of the components concerned. Since the i> * est construction for the is symmetrical for the most part, form those in the direction of view of the driver sitting on the pallet truck on the Components lying on the left side are in most cases mirror-inverted counterparts of those on the right side lying components, and with this in mind, the relevant reference numerals are appended with an identifier.

According to FIGS. 16, 17 and 18 as well as those based on further Figures yet to be given explanations can be the individual ftiastteile 28, 30 and 32 of the multi-part Mast 2C from its retracted position according to FIG. 16 bring it into its fully extended position according to FIG. 18, with at least the same vertical lifting height

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.. is reached, as in a three-part ^ ast known type Referring to Figure 16 and 7, the innermost ^L:. branch portion 32 lifted in the position shown in FIG 18 is the uppermost mast part, the middle mast part 30 and forms by v / ie before the middle box part, and the outermost mast part 28 maintains its position, so that it is the lowest part of the mast.

2, 8, 9 and 10 belong to each of the load parts 28, 30 and 32 two standing parallel Rails 40, 40 'and 38, 38' and 36, 36 ', respectively, passing through Cross struts 122, 209 or 31, 69, 224 or 100, 101, 103 are connected to one another. As best seen in Fig. 5, in the preferred embodiment, rails 36 and 36 'of inner box portion 32 are as well the rails 38 and 38 'of the middle load part 30 as Double-T-profiles formed. In contrast, the Rails 40 and 40 'of the outer load part 28 are designed as U-profiles, but they could also have a double-T-shape Have cross-section. The load 20 is preferably formed as a roller guide mast, i.e. the various Rails are guided relative to one another by rollers mounted on the rails, instead of in direct contact with one another Perform sliding movements, but the invention can also with such a load with sliding guided Apply splints. 4 and 7, the rails 40 and 40 'of the outer link 26 are near their upper ends Stub axles 41 and 41 'installed, on which rollers 42

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and 42 'are rotatably mounted, which cooperate with outer grooves, which are formed by the adjacent rails 38 "and 38 'of the central mast part 30. Each the rails 38 and 38 'is arranged in pairs with Stub axles 4-3, 4-3 'and 45, 45' provided, on which inner Bollen 44, 44 'or outer rollers 46, 46' are rotatably mounted are. The inner rollers are adjacent the upper ends of rails 38 and 38 'while the outer rollers are adjacent to the lower ends Ends of these rails are adjacent; the rollers run in the adjacent rails 36 and 36 ' formed outer grooves or in the inner grooves formed by the rails and 40 'of the outer east part 28. The rails 36 and 36 'of the inner mast part 32 are with Stub axles 47, 47 'provided on which rollers 48, 48' are rotatably mounted near the lower ends of these rails, these rollers with the inner grooves of the rails 38 and 38 'work together. Ler load lifting carriage 22 is vertically movable along the inner load part 32 and has, according to FIG. 3, two struts 50 arranged upright and 50 ', each of which has an associated 1 aar of upper and lower rollers 52, 54-, 52 ', 54' carries, wherein the rollers of each laars cooperate with the inner groove of the associated rail 36 and 36 '.

2'u the main features of the invention include the • use of a sliding, channel-shaped or U-shaped lifting carriage 6C, the two tubular guides and 62 ', each of which is slidably movable

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Guide rod 64 or 64 'receives. These guide bars are at their upper ends with the help of with openings provided blocks 66 and 66 'attached, the cantilevered Arms 140 and 140 'are connected, which with the rails 38 and 38' of the central mast part 30 near the upper ends are welded, while the lower ends of the guide rods according to Pig. 9 through apertured Blocks 68 and 68 'are held in place, which are welded to a lower cross brace 69, which is in turn attached to the rails 3S and 38 '. Thus, the auxiliary slide 60 can be along the middle load part 30 slide up and down, and this is where the Movement path of the auxiliary slide according to FIG. 9 through the blocks 66, 66 'and 68, 68' limited, thus as Attacks come into effect. According to FIG. 9, the guide rods are 64 64 'against an upward movement in relation to the central mast part 30 by means of dowel pins 64a and 64a' secured, which are built into the lower ends of the guide rods below the blocks 68 and 68 'and Downward movement of the guide rods is prevented by nuts 64b and 64b 'on the threaded ones upper ends of the guide rods above the Kietze 66 and 66 'are screwed on.

Another "feature of the invented load is achieved by a lifting rod visible in FIGS. 2, 5, 7 and 1C 70 formed, which serves to increase the lifting effect of the Auxiliary slide 6C with respect to the slide 22 and the inner i. branch 32 and reverse it at the same time

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~ ¹³ "21-22409

enables the plunger 34 to be secured against tilting movements.

Another feature of the invention consists in the "use of a locking mechanism to which, according to FIGS. 13 to 15 a locking device 72, 72 'belongs to which serves, the inner mast part 32 during the free lifting movement of the carriage 22 to connect to the outer box part 28, this being produced between the two mast parts Connection by the upward movement of the slide 22 is released as soon as the slide according to Fig. 14 reaches the top of rails 36 and 36 ', whereupon the carriage according to FIG. 15 compared to the upper one Ends of rails 36 and 36 'is then locked to Help of the rails 36 and 36 'during the further extension of the bast to be moved upwards.

These features enable the use of a simple two-part hydraulic tappet 34, which, as shown in FIG. 8, consists of a single outer cylinder 74 and a single piston 76 working therein and according to FIGS. 3, 7 and 16 in the retracted state is less than the height of the various parts of the load; further

«Enable the mentioned features to connect the cylinder 74 in a stationary manner to the rails 4C and 4C ^{f of} the lowermost and the outer load part 28, respectively. Furthermore, the mentioned features make it possible to lift the carriage 22 according to FIG. 16 out of the floor: height to the upper end of the rails 56 and 36 ', while the rails are still fully inserted, as shown in FIGS *

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23224Ü9

16 and 17 is shown, so that a so-called free upward movement can be achieved such that the maximum vertical lifting height of the three-part masts known up to now is at least reached or even exceeded.

For a more detailed explanation, it should be noted that the piston 76 has two chain wheels at its upper end as shown in FIGS or carrying pulleys 80 and 80 'over which two chains 33 and 33' run. As shown in Figs. 16 to 18, The back strands of chains 33 and 33 'are on theirs lower ends with the cylinder 74- of the plunger 34- through a holding part 82 connected. In FIGS. 16 to 18, the auxiliary slide 60 is in front of the plunger for the sake of clarity 34- shown, but according to Fig. 3 to 5 and according to 9 shows the guide tubes 62 and 62 * for the auxiliary slide 60 actually behind.dem Stöeßl 34- arranged, the side Flatten 61 and 61 'of the auxiliary slide extend with a margin on both sides of the stöilel past forward, and according to FIGS. 7 and 9, a cross strut 63 of the auxiliary slide is arranged in front of the ram. The front burrs of the strands 33 and 33 'are according to FIG 4-, 9 and 16 to 18 with their lower ends 84 and 84- 'attached to horizontally arranged gusset plates, with which the auxiliary slide 60 is provided at its lower front corners. With this arrangement of the chains 33 and 33 'causes the piston 76 to move vertically, that the auxiliary slide 60 with a transmission ratio is raised or lowered by 2: 1.

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According to Fig. 4, 7, 9 and 16 to 18, the auxiliary " carriage 60 at its upper end two pulleys 86 and 86 'for the two chains 35 and 35' · the rear ones Strands of chains 35 and 35 'are at their lower ends 4 and 10 attached to holding parts 88 and 88 ', which are connected to the lower ends of the inner flanges of rails 36 and 36 '. The front strands of the Chains 35 and 35 'are shown with their lower ends Fig. 10 attached to the lifting rod VO, which is opposite the rails 40 and 40 'of the outer mast part 28 upwards and can move down and is thereby guided, that it comes to rest on the carriage 22 and supports him when the carriage moves, during the Mast 20 is still fully inserted, as shown in FIG and 17 can be seen. According to FIGS. 5, 7 and 12, the Struts 50 and 50 'of the carriage 22 at their lower End cutouts which receive the lifting rod 70 can so that the carriage is supported on the lifting rod so that the carriage supports in the vertical direction as it moves between its positions shown in Figs. The fact that the Chains 35 and 35 'the inner surfaces of struts 50 and 50' are closely adjacent, helps to ensure that the lifting rod is guided into the cutouts of the struts of the slide while the slide approaches the lifting rod from above. At the upper end of the cylinder 74 is shown in FIG. 8 a stop 90 attached, which according to rip ;. 4 a vertical central I-ohrunf 91, which serves to provide a

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Pick up mandrel 71 from the middle part of the lifting rod 70 protrudes from upwards; the lifting rod 70 moves to ' above, it finally comes to rest against the stop 90, like it in Pig. 17 and 18, i.e. the stop limits the outward movement of the lift rod. According to FIG. 7, the mandrel 71 has an annular groove 71 'with which according to FIG Fig. 4- a spring-loaded hurry ball 93 works together, which is built into the stop 90, so that the lifting rod 70 while the load parts are being pushed out is held resiliently in engagement with the stop 90.

The locking device or the locking mechanism is made up of two similar, automatically actuatable assemblies together, of which, according to FIG. 10, each of the rails 36 and 36 * of the inner mast part 32 is adjacent; the two Assemblies are on an upper cross brace 1GO of the inner Mast part 32 arranged on the rear sides of the rails 36 and 36 'is attached. In the following only the Reference numbers are given which apply to the lock located on the right, but it should be noted that the locking mechanism on the left-hand side is made up of corresponding components, the reference numbers of which are marked with a line Attached is; Each locking mechanism includes two upright plates 1C2, separated by a distance between them and 104, which are welded to the underside of the cross brace 1CC, also have one between these flats an axis 1C-8 rotatably mounted Kolle 1C6 as well as an all-

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common triangular locking member 71 · This locking member has a central slot 110, which serves to accommodate a transverse bolt 112 with a clearance, which protrudes above the axis 108 and parallel to it through the plates 1C2 and 104, so that the locking member 72 between the two plates is loosely supported. The separate or convex lower side surfaces 114 and 116 of the locking member ^ 2 can cooperate with a stop 118 on the carriage 22 or a stop 120 on the upper cross strut 124 of the outer mast part 28 when the locking member 72 according to FIG. 15 or according to 13 reaches one or the other limit position with respect to a dead center position. The locking member 72 has two semicircular cutouts 124 and 126 facing away from one another, which work together with actuating members 128 and 130 which are arranged on the upper end of the slide 22 and on the cross strut 122 of the outer load part 28.

If the locking member 72 is located in its from Fig. 13, brings the lifting force exerted by the chains 35 and 35 'on the inner load part 34- is, on the roller 106 and the actuating member a haltemoir.ent on the locking member 72, through which the locking member is held in its position according to FIG. Therefore, the inner box part becomes 3 ^ · opposite to the outer mast part reliably locked by the two locking mechanisms, so that. every upward movement of the inner i-branch part 32 is prevented while the carriage 22

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between its lowest position according to FIG. 16 and its uppermost freely raised position according to FIG. 17 is moved that the chains 35 and 35 'on the lifting rod works. Since the inner mast part 32 up to this point by its locking relative to the outer box part Has been held, the carriage 22 is compared to the upward movement of the auxiliary carriage 60 in one Ratio of 2: 1 and therefore in a ratio of 4: 1 compared to the upward movement of piston 76 moved up.

If the - ^ actuating member 128 from its 13 moved upwards, it can pass a shoulder 132 at the entrance of the cutout 124 move, since the locking member 72 assumes an inclined position, and therefore actuator 128 moves past shoulder 132 and then against the other shoulder 134 of the cutout 124 as soon as the carriage reached a position shortly below that shown in FIG. 14 during its downward movement. As soon as the actuating member 128 with the locking member 72 during the upward movement of the carriage 22 cooperates, causes the 'force that is through the - ^ actuating member 128 upwards and in the Is applied clockwise to the locking member 72, because of the larger lever arm of the actuating member compared to the locking member, that the locking member is rotated clockwise and as a whole relative to the bolt 112 is moved so that the curved surface 114 moves over the roller 106 away, while the carriage continues after

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is moved above. The actuating member 128 thus overcomes the locking forces that act on the locking member 72 exerted by roller 106 in actuator 130 so that during the further upward movement of the carriage 22 the actuating member 128 the locking member 72 rotates clockwise, the locking member successively those in Tig. 13, 14 and 15 positions shown, to the apex 136 of the locking surfaces 114 and 166 a line connecting the axes of the roller 106 and the actuating member 130 passes, whereupon the convex Surface 116 is supported on the roller 106, at the same time the shoulder 138 of the locking member 72 from the path of the Actuator 13O is removed. Through the one just described Operations, the carriage 22 is locked to the inner mast part 32, and thereafter, i.e. while the Slide 22 and the locking member 72 above the actuating member 130 are located, the weight of the load carried by the carriage 22 holds the locking mechanism in place according to FIG. 15. At the same time is the inner mast part 32 has been unlocked with respect to the outer mast part 28, so that it can be lifted unhindered. Should the locking member 72 perform too large an angular movement endeavor, as a result of brief reversals of the direction of action of forces or during exercise of the locking member, these movements are limited by the fact that the convex surface 116 on the stop 120 is applied, or that in the other stable position of the locking member, the convex surface 114 on the stop 118

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is present.

As soon as the carriage 22 according to FIG. 17 reaches its highest position according to FIG. 17 during its free lifting movement reached, locking with the inner mast part 32 is, the lifting rod 70 arrives at the same time to the plant the stop 90 at the upper end of the cylinder 74 ·· As a result any further upward movement of the lifting rod 70 is prevented, and the further lifting movement of the carriage 22 is then effected by the inner mast part. aside from that the auxiliary slide 60 is at the same time along its full movement distance compared to the central mast part JO corresponding to half the free cubic height of the carriage 22 have moved, and the upper ends of the guide tubes 62 and 62 'v / earth to rest against the stops 66 and 66' have come to, so every further downward movement of the auxiliary To prevent carriage 60 relative to the central mast part 30 and to cause the auxiliary carriage 60 a Eubkraft exerts on the middle load part 30. As soon as the piston 76 about its position according to Pig. 17 moved upwards, the chains 33 and 33 * come over the auxiliary slide 60, which rests against the stops 66 and 66 ', to the effect to directly route the middle load part 30 compared to the stroke of the piston 76 in a ratio to be raised by 2: 1. When the auxiliary slide 60 after moved above and thereby lifts the middle load part 30, the inner load part 32 is supported by the laths 35 and 35 ' compared to the movement of the auxiliary slide 60 and the middle load part 30 raised in a ratio of 2: 1.

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Thus, the inner Iviastteil 32 moves compared to Stroke of the piston 76 in the ratio of 4: 1 upwards, and it takes the slide 22 together with the inner mast part 32 at the same speed until the mast is its completely extended position according to FIG. 16 is reached. Thus, the movement of the carriage 22 plays out of his lowest position on the floor according to FIG. 16 to its highest position according to FIG. 18 while maintaining a constant ratio of 4: 1 compared to the stroke of the piston 76, so that a brisk upward and downward movement of the slide is guaranteed over its entire vertical cubic distance. When inserting the luastes and when the slide is lowered, the work cycle described above runs in the opposite direction, but it does run all movements in a brisk manner and in compliance with the stated ratios between the movement speeds of the parts concerned.

The actuating members 128 for the locking assemblies are preferably formed in accordance with FIG. 11 in the form of two extension pieces 160 and 16C, which are connected to the associated struts 50 and ^ C of the carriage 22 by a screw 162 and 162 ', respectively; Each of these screws is screwed into a threaded hole which opens out on the underside of a rearwardly projecting plate 164 or 164, which is welded to the associated screw 50 or 5 '. as only in Iig. 15, one or more spacers 166 and 166 'respectively can be placed between each of the extensions 1 & G, 16C and the associated

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Arrange plate 164 or 164 'to adjust the height of the extension pieces. The free end of each extension piece has a surface 168 extending over an angular range of 270 and forming part of a cylindrical surface, the radius of which is essentially the same as the radius of the associated cutout 124 or 124 ^{1 of} the relevant locking member 72 or 72 '.

According to FIG. 6, the actuating member 130 preferably includes a pivotable plate 170 with a central bore 172 for receiving a bearing pin 174. The pivoting plate is secured against axial movement along the bearing pin 174 by a snap ring 176 which is inserted into an annular groove in the bearing pin 174 is installed, the inner end of which is welded to the ^ orseite of the cross strut 122 and an associated Yerstärkungsstück 178. On the ends of the plate 170, two movement take-off rollers 180 and 180 'are rotatably mounted, the radius of which essentially corresponds to the radius of the cutouts 126 and 126' of the blocking lilacs 72 and 72 '. I; 'it the top of the plate 170 two stops 182 and 182' ver _{T are} welded, which protrude down over the top of the cross brace 122 so that there is a sufficient vertical distance between the stops on the one hand and the cross brace on the other hand, so that the Plate 17Ο can carry out limited pivoting movements on the axis of the bearing pin 174, »so that the plate T / C of the lever actuator I30 can act as a compensating arm,

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2322A0S

the simultaneous cooperation of the roles 180 and 180 'with the associated locking members 72 and 72' ensured when the inner mast part 52 is lowered and one after the other the positions according to Pig. 15 »14 · and 13 achieved. The action of the actuator 130 as a balance arm also ensures an even distribution of the load on the two locking members 72 and 72 ', so that the locking members come simultaneously and smoothly to the mark, although slight deviations with respect to the arrangement of the locking members and other parts of the locking mechanism may be present.

The locking mechanism of the wastes 20 is preferably provided with devices for orienting and holding the locking members 72 and 72 'as shown in FIG. These devices include two pressure pieces 184 and 184 ', which are arranged in associated spring housings 166 and 186', which are screwed into the ^ uerstrebe 100 so that each pressure piece protrudes downward from the spring housing under the action of an associated biasing spring and is in Direction of the upper surface 188 or 18S ^{1 of} the relevant locking member extends when the locking members are in their locking position according to FIG. 13 and 15; However, the upper surfaces 188 and 188 'only come into contact with the pressure pieces 184 and 184' when the apex 136 of the relevant locking member according to FIG L _o is associated lzen rentihert 112 and 112 '. Thus, each of the under

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Spring-loaded pressure pieces exert a resilient resistance to the associated locking member in order to prevent the locking member from executing a sudden movement from one working position to the other working position. The resistance applied by the pressure pieces is adjusted so that the locking members 72 and 72 'maintain their position according to FIG. 13 when the mast 20 is shipped from the manufacturer to the customer. When the customer has mounted the mast on a lift truck, ie when the mast is ready to lift the carriage 22 for the first time, the locking members 72 and 72 'are properly synchronized so that they operate in the normal manner described above. However, the resilient resistance exerted by the pressure pieces 184 and 184- ^{f is} insufficient to impede the normal operation of the lock when the normal lifting and lowering forces are applied to the box.

It has been shown that the plunger 34 when actuated of the mast 20 tends to tilt forward carry out, and especially when, with the load still pushed in, the carriage 22 along its free Lifting distance is raised or lowered. To remedy this too create, according to another aspect of the invention, the load 2C is provided with devices preventing the shock from tipping over where for the most part use is made of the existing components. According to 8, in addition to the components already described, the tappet 34 includes a piston rod wiper 190

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known type, a socket 192, an externally threaded one Cylinder end cap 194-, a cup-shaped Spacer 196, two O-rings 198 and 200 built into the annular grooves of the piston 152, a support ring 202 Gland ring 204 and a retaining ring 206 that holds the components 202 and 204 on the lower end of the piston 152 holds on. The lower end of the cylinder 74- is on any 'neise attached to a saddle part 207, the rear flank of which by screws with the lower cross strut 209 are connected by the outer box part 28. Of the A bearing 208 is assigned to the chain deflection roller 80 ', which is placed on an axle 210, which in turn comes with the head 212 of the piston, which is beveled on both sides, or of the piston rod 76 is connected; are also on the Axis 210, a thrust washer 214 and a cold part 216 arranged, the latter being held in place by a fastening screw 218; for lubricating the pulley 80 'is a grease nipple 220. The cap 194 is screwed into the upper end of the cylinder 74, and the piston rod 76, which is coaxial with the cylinder is, protrudes through the cap and is connected to the actual piston 152 by the retaining ring 206.

The stop 90 for the lifting rod 70 is with the front upper hand of a neck of the cylinder cap 194 welded, and the holding part 62 for attaching the Chains is at the rear ΐεϋ of a splash at the top Welded to the end of the cylinder cap. The components 90 and

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82 not only fulfill the tasks discussed above, but they also form parts of a device for preventing tilting movements of the plunger 34. Is located the mast 20 in the fully retracted state, overlap two hooks 222 and 222 ', which can be seen in FIG are, and which are welded to the front of the central cross brace 224 of the central box part JC, the Holding part 82, and here the downwardly angled free ends of the two hooks are by a distance separate cutouts 226 and 226 'of the holding part of FIG. 8 added. Thus, the sharks capture 222 and 222 'the holding part 82 to the plunger 34 against the action to be held by forces tending to tilt the plunger away from the central load part 30 forwards.

If the middle load part 30 is initially lifted in the described manner in order to start pushing up the mast, the lifting rod 70 has already come to rest against the stop 9C, and it is thereby releasably locked to the stop in the manner described be that the F.ast member 93 has come into engagement with the recess 71 'of the mandrel 71. ^T änn the hooks are lifted 222 and 222 'and disengaged with the .Halteteil 82, v / ith the plunger 34 thereafter against forward tilting by liräfte noted that on the upper end of Zylinders- 74 through the lifting rod 70 and the associated Chains 35 and 35 'are applied. It is true that the Ealtewirk occurs, which is caused by the lifting rod on the plunger while the middle one is being pushed out

. , 3 09848/0418

• 2322403

Mast part 30 and the inner fcast part 32 is exercised, in a less inevitable way to effect than the holding effect the hooks 222 and 222 'with the mast fully retracted, but the one by the chains on the Lift rod 70 applied holding force is greatest when it is needed most, i.e. during the initial Pushing out the load parts, as the forces who strive to tilt the ram forwards, progressively reduce it until the load is completely pushed out has been. The forces that strive to tilt the plunger forward are greatest when the It is completely pushed in, but if this is the If so, the hooks 222 and 222 'cause a shape conclusive anchoring of the mast with the aid of the holding part 62.

From the above description it can be seen that the load loving device described is a solution of the Finding task forms, and that it is in the form of the mast 20 are equipped as a three-part box with a carriage freely movable over part of the lifting height, in which however, only a single two-part plunger 34- required whose cylinder 74- its position relative to the outer iiastteil 28 not changed, and in which the haste against a Forward tilting is automatically secured by a multi-tasking device. In this way it is possible, the manufacturing costs of the plunger and ■ the associated supporting structure compared to a

. , 309848/0418

Lower ram, which moves vertically to operate the mast, and / or compared to known rams with three or four main parts. Furthermore, the hydraulic line connections can be simplified guide the plunger; in other words, the invention makes it possible according to FIG. 2, a short, permanently laid or immovable pressure medium line 142 of known type to connect to the lower end of the cylinder 74 to the hydraulic Pressure medium of the working chamber of the cylinder from the usual pump and a container (not shown) from which are arranged on the Kubwagen 24. It also enables the use of a stationary one Cylinder 74, according to FIG. 2, only a single fixedly laid Provide drainage line 150 extending from the room in the cylinder above the piston 152 to the container on the pallet truck instead of venting it directly to the atmosphere. Thus the difficulties which would result from venting to atmosphere, i.e., pressurized oil, which is up along piston 152 escapes when the piston has worn out, is not released from the plunger to the outside, but the Entleerungsbzw. Vent line 150 directs the escaping oil back to the container.

In addition to the advantages already mentioned, the achievable transmission ratio of 4i1 delivers a plentiful supply dimensioned multiplication of the stroke length of the ram, so that the plunger can have an overall length that is less

309848/0418

than the length of a single mast section. This in turn makes it possible to ^{arrange the two pulleys 80 and 80 f} close to one another on the upper end of the piston rod 76 so that the chains 33 and 33 'are close to the cylinder 74 of the ram. As a result, there is more open barely in the lateral direction between the chains 33 »33 'on the one hand and the rails of the mast parts on the other hand, so that the driver has a better view through the mast.

In the mast 20 only two sets of chains 33 »33 'and 35> 35 'is required, i.e. the complexity of the chains is no greater than with the three-part chains known up to now Masts. Furthermore, the locking mechanisms with components 72, 128 and 130 are of a relatively simple construction, however very durable and reliable, and they do not lead to a significant increase in the manufacturing costs of the Mast. The same applies to the auxiliary slide 60 and the components that work with it. Finally will the ratio between the fully retracted and fully extended height of the mast by the Lifting construction according to the invention brought to a maximum value; this is due to the route multiplication effect the arrangement according to the invention of the chains and the auxiliary slide 6C and the lifting rod? C, which cooperate with it, attributed. '

309848/0418

Second embodiment

19 shows in a vertical section a second embodiment, designated as a whole by 300, of an extendable and retractable mast in the fully extended position, in which the mast reaches the same vertical lifting height as a normal four-stage mast. The mast 300 can have essentially all of the components of the mast 20 described above, and in FIG. 1 the relevant components are each denoted by the same reference numerals as in the mast 20 described, so that a renewed description is unnecessary. The hydraulic ram 34-0 of the mast 300 includes an outer cylinder 74- and a piston rod 76 protruding upwardly therefrom, so that the ram 34-0 is similar to the ram 34- described. However, the plunger 34-0 differs from the plunger 34- in that it is designed in a known manner as a three-part plunger and therefore has an additional piston rod 302 which can be pushed into the piston rod 76 and down from the lower one The end of the cylinder 74- protrudes. One such three-piece ram that can be used with mast 300 is described in U.S. Patent 2,518,251. On the lower piston rod 302, two chain deflection rollers 304 and 304 ′, separated by a transverse distance, are rotatably mounted at its lower end, with which two chains 306 and 306 ^{1 work} together; In Fig. 19, however, only one of the guide pulleys and one of the two chains can be seen. One end of each of the nice 3C6's

309848/0418

and 306 'is attached to component 310 at 308, by means of of which the lower end of the cylinder 74- with the lower End of the outer mast part 28 is fixedly connected. The other end of each of chains 306 and 306 is on one Chain anchoring part 312 attached, which in turn a fourth mast part 314 is attached to the two belong upright arranged rails, which is designed similarly to the box part 28, and the opposite of the latter is felt in the usual way with the help of roller guides can be pushed out and in, so that after insertion of the Ivlastes 300 all four load parts 32, 30, 28 and 314-so are pushed together so that their upper and lower ends are in alignment with one another, as it is with regard to branch 20 in Fig. 16 is shown. Between the ram 34-0 and the pallet truck on which the The plunger is mounted, lines, not shown, are laid in a known manner for the hydraulic pressure medium.

When using the branch 300, the feeding causes of the pressure medium to the plunger 34-0 that initially the Piston rod 76 pushed out of the cylinder 74- upwards is to utilize the full free stroke of the carriage 22 relative to the mast part 32, while all IJastteile in the same way their inserted position retained as described in relation to branch 2C became. Wepen his larger work surface and / or one lower load, the piston 76 sets its upward

309848/0418

Movement relative to the cylinder 74- after the carriage 22 has been locked to the mast part 32 until it reaches the end of its upward stroke before the lower piston rod 302 is extended. The mast part 28 therefore retains its retracted position with respect to the lowermost mast part 314, and the mast parts 30 and 32 are extended to a height that corresponds to the fully extended position of the branch 20 according to Pig. 18 corresponds, so that the lifting movement of the carriage 22 is continued while maintaining a ratio of 4: 1 to the movement of the piston rod 76 with respect to the cylinder 74-. As soon as this extended position is reached, the further supply of the pressure medium to the plunger 34-0 causes the piston rod 302 to begin to be extended out of the lower end of the cylinder 74 so that it moves downward relative to the cylinder, or that for an observer standing on the floor there is an upward movement of the cylinder 74 relative to the piston rod 302, while the piston rod 76 is hydraulically held in its fully extended position and therefore moves together with the cylinder 74-. This has the result that the chains 306 and 3C6 ¹ move the load part 28 and all parts supported by it while maintaining a ratio of 2: 1 with respect to the movement of the piston rod 302 relative to the cylinder 74- upwards . When the piston rod 302 is in Big. 19 reached the fully extended position shown, the ft. Branch part 28 will have been raised to a height that is slightly lower * than

309848/0418

the height of the lowermost mast part 314, and therefore the carriage 22 will also have been raised to a correspondingly greater height, which is greater than the height which is reached with the iaast 20 when this according to Pig. 18 is fully extended. If the iilast 300 is to be pushed in, the pressure medium is allowed to escape gradually in the usual way; this first causes the piston rod 302 to be pushed into the cylinder 74, whereupon the upper piston rod 76 is pushed in. Therefore, the slide 22 is first lowered while maintaining a speed ratio of 2: 1, while the branch part 28 is pushed in completely with respect to the box part 314, and. then the slide is moved down the remaining distance to the ground in the same way as with the mast 20 at the speed ratio of 4: 1.

From the description of the load 3C0 it can be seen that that the load 20 can also be used as a sub-assembly in a four-part hurry can use if a greater lifting height is to be achieved, and that in this case only a relatively simple three-part plunger and an additional Pair of chains needed. With this arrangement, the vertical movement speed of the Carriage 22 is halved when it is lifted along a distance that corresponds approximately to the height of a right-hand part, during the last part of its upward movement and during the first part of its downward movement;

309843/0418

_ 34 -

in view of the improvement achieved in this way Stability and operational safety, this is to be regarded as a desirable feature. It should be noted, however, that it is possibly possible to adjust the ratio zv / ischen the working surfaces of the piston rods 76 and 302 of the To change plunger 340 to change the sequence of operations of the two piston rods so that when lifting and Lowering the carriage 22 results in a more uniform speed; the measures required for this result for any person skilled in the art from the above description.

Third embodiment

FIG. 20 shows, in a vertical section, a third embodiment, designated as a whole by 400 extendable and retractable mast according to the invention. The mast 400 is just like the! Mast 300 19 to a four-part! .load, in which as Sub-assembly for the three upper box parts, the components of the mast 20 are used. However, the box is similar the mast 20 to the extent that it is even stronger than the same two-part plunger 34 in conjunction with the rest of the mast already described components of the Iv-branch 20 are used will. The mast 400 also has an outer lower one fourth Iviastteil 402, the load portion 314 of the mast 300 is similar. In order to convert the box 20 into a four-step mast, it is only necessary to "add two more Chain pulleys 404 and 404 'and two additional chains. 406 and 406 'to be provided, of which in Fig. 20 only in each case one can be seen; chains 406 and 406 'overflow

309848/0418

the underside of the associated pulleys 404 and 404 '. One end of each of the chains 406 and 406 'is on a chain anchor member 408 attached, which is connected to the mast part 30 near its lower end, and the other ends of the two chains are connected to a chain anchoring part 410, which is close to the mast part 402 its upper end is attached.

When using the mast 400, the carriage 22 along its entire free stroke length along the innermost Masttßil 32 moved before any mast sections extended i.e. the carriage moves in the same manner as with the mast 20 and in a ratio of 4: 1 for moving the piston rod 76 relative to the cylinder 7 ^ ·. However, as soon as the carriage 22 with the innermost Mast part 32 has been locked and the mast parts 32 and 30 begin to slide apart and become compared to the outer mast part 28 in the with respect to the Bastes 20 described way to move causes the Movement of the middle mast part 30 relative to the lowermost mast part 402, that the chains 406 and 406 * the mast part 28 together with all parts supported by it in a ratio of 2: 1 compared to the fcast part 402 move. As soon as the extension of the mast is initiated, the carriage 22 therefore moves in a ratio of 8: 1 to move the piston rod 76 relative to the Cylinder 74 upwards. In other words, the cube speed of the carriage 22 is being pushed in and out

309848/0418

of the mast twice as high as during the free lifting movement when the speed of the extending and retracting of the ram remains constant. The mast 400 thus forms a simpler and more economical one compared to the mast 300 Construction. However, if a constant movement speed of the carriage is to be achieved, can to provide automatic control devices of a known type that monitor the work steps when extending the mast and regulate the speed of the supply of the hydraulic pressure medium to the ram so that it is possible establish a relationship between the extension of the plunger and the stroke ratio of the chain assembly in such a way that that the carriage 22 during its entire Eew movement from the ground to the maximum lifting height with a constant Speed is moved $ such measures should be familiar to every person skilled in the art.

Expectations 309848/0418

Claims (1)

EXPECTATIONS 1. Extendable and retractable, vertically arranged, multi-level lifting mast for mounting on a pallet truck, characterized geken.η is that to the mast a first, a second and a third extendable and retractable Mast part (28, 30, 32) include that on the third "'branch part (32) a carriage (22) is guided so that a free vertical stroke movement of the slide is possible because there is a ram (34-) to which a cylinder (74-) and a piston or piston rod (76) that includes one of the two components of the plunger operatively the first box part (28) is connected that on the second mast part (30) an Eilfsschlxtten (60) opposite this tfiastteil between these associated upper stops (66, 66 ') and lower stops (68, 68') vertically is movable that a locking mechanism is present, the third when lifting a load with the help of the carriage Mast part locked to the first load part to an upward s movement of the third mast part during the free lifting movement to prevent the slide on the third box part, and that the slide when reaching the top The end of its free stroke is locked with the third load part and dependent on the upward movement of the second and third box parts the lock between the third part and the first load part 309848/0418 solves that the locking "when lowering the load in action joins the third mast section with the first & branch section * to lock again as soon as these ^ branches are completely again are inserted, and to release the lock between the carriage and the first mast part, that first flexible elements (33 »33 ') are present, which are connected to the other component of the plunger and to the first load part and the auxiliary slide are connected that a lifting rod (70) is present, which is vertically movable with respect to the first box part, that second flexible elements (35 »35 ') with the auxiliary carriage, the third mast part and the Eub pole are connected, that a device is available, which enables the carriage to be releasably supported on the lifting rod along the free stroke path of the carriage, and that a hub st ange nans chi ag (90) is available, which enables a releasable connection between the lifting rod and the first load part depending on the Upward movement of the slide to the upper end of its free kub path and in the opposite direction to manufacture. 2. Lifting mast according to claim 1, characterized in that one component of the plunger (34-) is a cylinder (74-), and that the piston rod (76) can be pushed into the cylinder, 3. Lifting mast according to claim 2, characterized in that the piston rod (76) the , plunger (3 * 0 is only movable piston rod and 303848/0418 protrudes from the upper end of the cylinder (74), and that the lower end of the cylinder is attached to the first mast part (28). 4. Lifting mast according to claim 3j, characterized in that the first mast part (28) directly can be supported by a lift truck (24) to form the lowest part of the mast, and that it is against any vertical movement relative to the pallet truck can be determined. 5. Lifting mast according to claim 1, characterized in that the box parts (28, 3C, 34) with bulbs (42, 42 ^!, 46, 46 «, 44, 44 ¹ , 48, 48 ¹ ) are provided, by means of which the mast parts are guided relative to each other. 6. Lifting mast according to claim 1, characterized in that the locking mechanism includes locking members (72i 72 ') which are movably mounted on the third load part (32) near its upper end, that first actuating members (128) on the carriage (24) that second actuating members (13C, 13C) are present on the first contact part (28) near its upper end, that inhibiting devices (184, 1.84 ') cooperating with the locking members are present on the third load part (32) near the locking members, that the Heinmeinrichtungen are arranged opposite the locking members so that they have a first and a second stable position of the locking members 309848/0418 the one or the other side of a central position determine that the locking mechanism is in its first position it is stated that the second actuating members, the locking members and the locking devices cooperate, and that the locking mechanism in its second position thereby it is noted that the first actuators, the locking members and the inhibiting device work together. 7. Lifting mast according to claim 6, characterized in that a locking member (? 2j 72 ') belongs to the locking mechanism, which at one end has convex surfaces (114, 114', 116, 116 ¹ ) which are attached to a switch (136, I36 ¹ ) coincide that the locking member is provided with a slot (110, 11O ¹ ), the longitudinal axis of which is aligned with the apex, that the locking member furthermore has lateral surfaces which are adjacent to the slot and a cutout ( 124, 124 ¹ , 126, 126 ') that a retaining bolt (112, 112') protrudes through the slot, loosely around the locking member. to store, so that it is movable as a whole with respect to the Ealtebolt to a limited extent, that the locking device includes a roller (106, 106 '), which is mounted so that its axis is parallel to the retaining bolt, and that a Rolling contact between the roller and the curved surfaces of the locking member is possible that the roller is arranged below the retaining bolt and aligned with it in the direction of movement of the carriage (22) and the pushing out of the bast (20) that the first actuating members (128 , 128 ') and the second 309848/0418 Actuators (150, 130 ') have rounded sections, that these sections are suitable to work together with the associated cutouts of the locking member, and that they are rotatable to a limited extent in the manner of trunnions in the cutouts. 8. Lifting mast according to claim 7 »characterized in that the second actuating device a compensating member (170) belongs, which is rotatably mounted on the second mast part (28) about an axis which is at right angles to the direction of movement of the carriage (22) and to the direction of extension of the mast (20) as well as at right angles to the transverse dimension of the mast that the compensating member has one at its ends first and second, cooperating with a locking member portion (180, 18O ') carries that to the Locking mechanism includes two plate-shaped locking members (72, 72 '), which are assigned to the third mast part (32) and run through a transverse section are separated that the first cooperating with the locking members sections suitable are to engage in the associated cutout of one of the locking members, and that the second cooperating with the locking members Section is suitable to engage in the associated section of the other locking member. 9. Lifting mast according to claim 1, characterized in that the auxiliary slide (60) includes a generally U-shaped frame structure that a first and a second vertically arranged socket (62, 62 ') that a first and a second 309848/0418 Guide rod (64, 64 ') on the second mast part (30) are arranged separated by a transverse distance on both sides of the center line of this mast part that the guide rods opposite the sockets of the auxiliary chute are slidably guided that the auxiliary slide lateral Plates (61, 61 ') on opposite Sides of the plunger (34 ·) and are arranged at a distance from it that pulleys on the Kilfsschlitten (86, 86 ') are rotatably mounted that the second flexible Elements (35, 35 ') around the pulleys of the auxiliary slide are laid around and extend downward from them that one end of each flexible element is attached to the lower end of the third east part (32), and that the other end of every other flexible Element is connected to the lifting rod (70). 10. Lifting mast according to claim 9 *, characterized in that the -t-piston rod (76) protrudes upwards from the cylinder (74) and at its upper end ^{carries pulleys (80, 80 1} ) that the first flexible elements (33 » 33 ') run over the pulleys of the piston rod and extend downward from there so that one end of each first flexible element is connected to the cylinder and that the other end of each first flexible element is attached to the auxiliary slide (60) . - '' · 11. Lifting mast according to claim 1, characterized in that the lifting rod is a rod (70) 309848/0418 is, which is transverse to the longitudinal axis of the bast (20) near the The plunger (34) extends that the second flexible elements are two chains (35i 35 ') that each of these chains with one end at the corresponding end of the lifting rod is attached that the carriage (22) has two upright struts separated by a transverse distance (50, 50 '), each with a cutout is provided for receiving the associated end of the lifting rod, and that the chains through the carriage extend between the upright struts and in their vicinity, so that they contribute to the Eubstange to guide so that it comes releasably into engagement with the cutouts of the carriage to raise the carriage to enable. 12. Lifting mast according to claim 1, characterized in that the lifting rod (70) and the lifting rod stop (90) are associated with each other which can be brought into engagement with each other ^xv asteinrichtungen (711 93) which are suitable for keeping the lifting rod resiliently in contact with the lifting rod stop, when the mast sections are extended. 13 · Loose lifting mast according to claim 1, characterized in that the lifting rod stop (90) attached to the plunger (34) and arranged opposite it so that the lifting rod (70) and the second flexible Elements (35 * 35 ') when the mast is extended (20) exert an effective force on the plunger, which opposes forces which are aimed at the 309848/0418 Tilt ram. 14. Lifting mast according to claim 13 _}, characterized in that the second box part (JO) holding members (222, 222 ¹ ) which come into engagement with the plunger (34) when the mast is pushed in, in order to support the plunger against tilting forces when the Lifting rod (70) is out of engagement with lifting rod stop (90) and supports the carriage (22). 15 · Lifting mast according to claim 14, characterized in that the holding members as on the second hast part (30) attached hooks (222, 222 ') are formed, and that on the plunger ($ 4) "a chain anchoring part (82), which is adapted to releasably cooperate with the hooks, and that with the second flexible elements (35> 35 ') is connected. 16. Lifting mast according to claim 1, characterized in that a fourth Llestteil (314) is present, which is connected to the first load part (28) so that it can be pushed out and pushed in and when pushed out des Ibastes (300) one layer below the first, the second and the third load part (28, 30} 32) assumes that to the tappet (340) has a third element (302) which is opposite the two first-mentioned tappet elements (74, 76) is movable that with the third plunger element flexible Llemente (306, 306 ') are connected, which can be actuated are to the first looser part compared to the fourth load part depending on the fact that the third 309848/0418 Plunger element opposite at least one of the "first two Plunger elements is moved. 17. Lifting mast according to claim 1, characterized in that a fourth mast part (314) is present, which is connected to the first box part (28) and can be pushed in and when the bast is pushed out a layer under the first, the second and the third mast part assumes that deflection rollers (304, 3C4 ¹ ) are mounted on the first mast part (26), and that third flexible elements (306, 3O6 ¹ ) run over these deflection rollers, each of which is connected to one end with the second mast part (30) and are connected at the other end to the fourth box part, so that a relative movement of the second and the fourth load part brings about a movement of the first mast part with respect to the fourth load part. 18. Extendable and retractable, vertically arranged multi-level lifting mast for mounting on a pallet truck, characterized in that there are several extendable and retractable load parts that on one the East part of a slide (22) which can be moved vertically across from it is mounted that this box part is a .Stößel is connected (34), that an auxiliary carriage (60) is present, with respect to the! .Last between associated with it upper stops (66, 66 ') and lower stops (68, 68') is perpendicular BEV / egbar, that flexible elements (33 »33 ') are present, which are connected to the plunger, the and the auxiliary sc ^ suffered that opposite 309848/0418 the mast a lifting rod (70) is vertically movable that the flexible elements with the auxiliary slide, the mast and the Eubstange are connected that one device is present, which releasably supports the slide from the Eubstange, while the slide is opposite moves the associated mast part, and that a lifting rod connecting device is present, which is a releasable connection between the lifting rod and the plunger as a function from the upward movement of the carriage to a predetermined point of its stroke and vice versa manufactures. 19. Lifting mast according to claim 16, characterized in that the lifting rod (90) and the Lifting rod connection device (90) associated with detachable latching devices (7I, 93) that can be brought into engagement with one another which are capable of providing a compliant "connection between the lift rod and the lift rod connector when the box parts are pushed out. 20. Lifting mast according to claim 18, characterized in that the lifting rod connection device is connected to the ram and is arranged opposite it in such a way that the lifting rod and the flexible elements exert a striving holding force on the ram when the load is extended to oppose the tilting forces acting on the ram with a resistance. 309848/0418 21. Lifting mast according to claim 20, characterized in that another load part ($ 0) is provided with holding devices (222, 222 ') which work together with the ram (34-) when the mast is fully extended, to support the ram against tilting forces when the lifting rod (70) is out of engagement with the lifting rod connecting device has been brought and supports the carriage (22). 22. Load lifting arm according to claim 21, characterized in that to the ^ old facilities hooks (222, 222 ') attached to the other load part (30) and a chain anchoring part (82), which the latter attached to the plunger (34-), releasably engageable with the hooks and with the flexible elements connected is. 23 Extendable and retractable, vertically arranged, multi-level lifting mast for allocation to a Kubwagen, characterized in that there are several box parts, that opposite a! '. load part (32) a carriage (22) is vertically movable that a plunger is connected to another load part that on the * "ast an auxiliary slide (60) between attached to the load upper stops (66, 66 ') and lower stops (68, 66') is vertically movable that a locking mechanism is present is that when i, a load comes into action, in order to lock the one branch part with the other load part and ho an upward movement of the one load part 309848/0418 to prevent during the movement of the carriage on this ^ branch part, and to lock the carriage with the one mast part and ^{to unlock the one IJastteil against the other lki} branch part depending on the extension movement of the mast, that the locking mechanism when lowering the load and when Pushing in the mast comes into action to lock one load part again with the other load part as soon as these mast parts have returned to their pushed-in position, and to release the lock between the carriage and one load part, the flexible elements with the plunger are connected, which are operatively connected to the load and the auxiliary carriage, that a lifting rod (70) is present which is vertically movable with respect to the Iviast, that the flexible elements are connected to the carriage and operatively to the load and the lifting rod, that a device is available that releasably un .on the lifting rod during its movement supports, and that an Ilubstangenanschlag is present, which produces a releasable "connection between the lifting rod and the Iv.ast depending on the" locking of the slide with the one Iv.ast section and vice versa. ■ 24. Lifting mast according to Claim 23, characterized in that a cylinder for the ram (34) (74) belongs, and that a piston or a piston rod (76) can be extended and retracted in the cylinder is. 309848/0418 25 · Lifting mast according to claim 24, characterized in that the piston rod (76) from the upper end of the cylinder (74) protrudes and the cylinder is attached with its lower end to the one mast part is. 26. Lifting mast according to claim 25 »characterized in that the other mast part (28) is suitable to be supported directly by a pallet truck (24) in order to be the lowest part of the mast (20) to act, and that it is set up so that it is set against vertical movement with respect to the pallet truck leaves. 27 · Load lifting mast for a Kubwagen with load lifting devices that can be moved relative to one another and a locking mechanism for establishing a detachable connection between certain parts of the load lifting devices, characterized in that locking members (72, 72 ^f ) are movably mounted on a first of the load lifting devices of the load Actuating device (128, 128 ') are arranged on a second load lifting device, that a third load lifting device has a second operating member (150, 1JO ¹ ) that a device for inhibiting the locking member is arranged on the first load lifting device near the locking member, that the ^ emmeinrichtung is arranged opposite the locking member so that there is a first and a second stable position of the locking member on one or the other side of a 309848/0418 Central position defines that the locking member is held in its first position by the fact that the second actuating member, the locking member and the inhibiting device cooperate, and that the locking member in the second position is held by the fact that the first actuator, the locking member and the locking device cooperate. 28. Lifting mast according to claim 27, characterized in that the locking mechanism includes a plate-shaped locking member (72, 72 ') which at one end has convex surfaces (114, 116) which at an apex (136, 136') coincide that the locking member is provided with a slot (110), the longitudinal axis of which is aligned with the apex, that the locking member furthermore has lateral surfaces which are adjacent to the slot and each delimit a cutout (124, 126), that an Ealtebolzen ( 112) protrudes through the slot in order to mount the locking member so loosely that it can be moved as a whole relative to the iialte bolt within certain limits, that the locking device includes a roller (106, 106 ') whose axis runs parallel to the retaining bolt, and which cooperates with the convex surfaces of the locking member with a rolling movement that the roller is below the retaining bolt and in alignment with the retaining bolt in relation to the direction of movement of the carriage (22) and the extension movement of the mast is arranged, and that the first and the second actuating member each has a rounded portion which is in engagement with the 309848/0418 associated cutout of the locking member can be brought and therein in the manner of a bearing pin within certain limits is rotatable. 29. Lifting mast according to claim 28, characterized in that a compensating member (170) belongs to the second actuating member, which on the third load lifting device is rotatably mounted about an axis which is at right angles to the direction of movement of the Slide and the direction of the pushing-out movement of the ^ astes and extends at right angles to the transverse dimension of the mast that the compensating member at its ends first and a second member which can be brought into engagement with the locking member, that to the locking mechanism, two plate-shaped members Locking members belong, which are assigned to the one load lifting device and separated by a transverse distance are that the first cooperating with the locking member section is suitable in the associated section of a of the locking members to intervene, and that the second / side with the Locking member cooperating section is suitable to cooperate with the associated portion of the other locking member. 309848/0418 eerseite