GB2417023A - Lifting frame having hose tensioning means for an industrial truck - Google Patents

Abstract

A lifting frame for an industrial truck having a stationary mast <B>1</B> that cannot be raised, at least one extending mast <B>2,3</B> that can be raised relative to the stationary mast <B>1</B> and at least one flexible line <B>8</B> connecting the stationary mast <B>1</B> to the at least one extending mast <B>2, 3</B>. The line <B>8</B> is fixed to a fixing point <B>10</B> arranged in the upper region of the stationary mast <B>1</B>, led downwards from this fixing point <B>10</B> to a tensioning roller <B>9</B> and is led upwards from the tensioning roller <B>9</B> to the at least one extending mast <B>2, 3</B>, the tensioning roller <B>9</B> being able to move freely in the vertical direction. The tensioning roller <B>9</B> may be connected to a weight. The lifting frame may have apparatus for determining the vertical position of the or each extending mast <B>2, 3</B>, the apparatus comprising at least one endless flexible pulling means <B>13</B>.

Description

Lifting frame for an Industrial truck The invention relates to a lifting

frame for an ndustnal truck, having a stationary mast that cannot be raised, at least one extending mast that can be raised relative tc the stationary mast, and at least one flexible line that connects the stationary mast to the extending mast.

Lifting frames of Industrial trucks are generally of telescopic design, a stationary mast of the lifting frame being fixed to a frame of the industrial truck such that it cannot be adjusted vertically, and a first extending mast being guided on the stationary mast. As a rule, there is a second extending mast, which is In turn guided on the first extending mast such that it can be moved In the vertical direction. On the extending mast which can be extended furthest - in the case of two extending masts this Is the second extending mast - a lifting carriage Is guided such that it can be moved In the vertical direction, to which a load-lftng means is fixed, for example designed as a load fork Frequently, the lifting carriage also has handling devices for a load that has been picked up, for example a clamping apparatus for the load, a lateral reach apparatus or a forward reach apparatus. Furthermore, the handling device can comprise an eiectucally driven hydraulic valve In addition, venous electrical sensors can be arranged In the region of the lifting carnage, for example for detecting the presence of a load or for registering the weight of a load The handling devices and/or sensors arranged in the region of the extending mast, in particular on the lifting camage, are connected via flexible hydraulic and/or electric lines to the hydraulic system and, respectively, to the electrical system of the Industrial truck. These flexible lines have to be formed in such a way that they can compensate for the vertical movements of the extending mast and of the lifting carnage In the case of lifting frames from the prior art, it is known, for exampie7 to arrange the flexible lines on line drums. The line drums need a considerable amount of space and require a free line guide In order to make it possible to wind up and unwind the flexible line Viewed from a first aspect, the present Invention relates to a lifting frame for an industrial truck' having a stationary mast that cannot be raised, at least one extending mast that can be raised relative to the stationary mast, and at least one flexible line c:;',iectng +ric statioila-y 'mast xi? the c,t.nrlii:g idlest Chew. TV, 'art,_ fi.6 t.; > fixing point arranged in the upper region of the stationary mast, is led downwards From this fixing point to a tensioning roller and is led upwards from the tensioning roller to the extending mast or one of said extending masts, the tensioning roller being able to move freely In the vertical direction Viewed from a further aspect, the present Invention relates to a lifting frame for an industrial truck, having a stationary mast that cannot be raised, at least one extending mast that can be raised relative to the stationary mast, and at least one fiexble line connecting the stationary mast to the extending mast, wherein the line Is fixed to a fixing point on the stationary mast, is led from this fixing point to a tensioning roller and Is led from the tensioning roller to the extending mast or one of said extending masts, the tensioning roller being able to move freely In the vertical direction.

The invention is based on the object of at least in preferred embodrnents providing a l'ffing frame whose flexible line takes up little space and which Is arranged in the region of the masts of the lifting frame in such a way that it does not restrict the field of view of an operator of the industrial truck, or restricts it only slightly According to the invention, at least in preferred embodiments this object is achieved In that the line Is fixed to a fixing point arranged In the upper region of the stationary mast.

is led downwards from this fixing point to a tensioning roller and Is led upwards from the tensioning roller to the extending mast, the tensioning roller being able to move freely in the vertical direction The flexible line Is therefore firstly fixed at the top to the stationary mast and secondly to the extending mast or to a component arranged on the extending mast. The length compensation required when extending the extending mast is provided by the ability of the tensioning roller to move vertically When the extending mast is lowered, the tensioning roller Is in its lowest position. During the raising of the extending mast, the tensioning roller is then moved, pulled upwards by the flexible line A first and a second extending mast may expediently be provided, the first extending mast being guided on the stationary mast such that it can be moved In the vertical direction, and the second extending mast being guided on the first extending mast such that it can be moved in the vertical direction, and the flexible line connecting the stationary mast to the second extending mast This arrangement with two extending riasts,> rieSp,rtIs its lo,o,iia dey,i,,, '',l.'ry arr,<-., i;jr =ip,''-ur.ecJ. trucks or reach fork-lift trucks. In this case, the flexible line is preferably fixed directly by one end to the second extending mast or to a component arranged on the second extending mast. fixing or guidance of the flexible line on the first extending mast is not provided.

According to a generally conventional arrangement, a lifting carriage may be guided In the vertical direction on the extending mast that can be extended furthest, and a luffing movement of the lifting carriage relative to the extending mast may be produced by means of an actuator that can be extended In the vertical direction and of a lifting chain, the lifting chain being fixed to the extending mast at a first fixing pointy being led upwards from this fixing point to a chain roller fixed on the extending actuator, and being led downwards from the chain roller to the lifting carriage. With this arrangement, the lifting carriage can be moved over the entire height of the extending mast having the guide for the lifting carriage. The actuator can be formed, for example, by a hydraulic cylinder or by an electrically driven threaded spindle The chain roller Is preferably mounted on the movable part of the actuator, which means that a movement of the movable part of the actuator Is transmitted to the lifting chain and from the latter to the lifting carriage. In the arrangement described, the movement of the extending part of the actuator Is transmitted to the lifting carriage with a step- up ratio of 2 1.

Particular advantages result if the flexible line Is led upwards from the tensioning roller to the chain roller arranged on the actuator of the extending mast and is led downwards from the chain roller to the lifting carnage The flexible line in this case ends not on the extending mast itself but on the lifting carnage guided on the extending mast In addition to the guide for the lifting chain, the chain roller preferably has a further guide for the flexible line. The length compensation of the flexbie line, required during the relative movement of the lifting carnage in relation to the extending mast, is preferabl achieved completely by the deflection of the flexible line on the chain roller If, therefore, with the extending mast at a standstill, only a vertical rnoven,ent of the lifting carriage is carried out' the vertical position of the tenscnng roller of the flexible line nnay rernan unchanged in order to ensure an adequate tension of the flexible line at any time the tensioning roller is preferably connected to a weight The force due to the weight In this case pulls the ter,sonng roller downwards.

The tensioning roller Is preferably guided on the stationary mast such that it can move freely and the vertical direction. At least in preferred embodiments, the Guide reliably prevents, for example, swinging of the tensioning roller and collision between the tensioning roller and other parts of the lifting frame. The guide may define the position of the tensioning roller in the horizontal direction, while the vertical position of the tensioning roller may be set automatically as a function of the Instantaneous lifting height. In the case of an arrangement with two extending masts, the guide preferably extends over the entire height of the stationary mast.

In one advantageous embodiment, on one side of the lifting frame, the flexible line may be formed by an electric line and, on the other side of the lifting frame, the flexible line may be formed by a hydraulic line In this case, virtually identical arrangements may be provided on the righthand and the left-hand side of the lifting frame, in which arrangements the hydraulic and the electric line, respectively, may each be guided over a tensioning roller and a chain roller According to an expedient development of the Invention, the lifting frame may further comprise an apparatus for determining the vertical position of the extending mast, the apparatus preferably comprising at least one endless flexible pulling means The endless pulling means may be arranged in such a way that it is moved In the direction of circulation during the vertical movement of the extending mast The endless pulling means is preferably formed by a belt In this case, the pulling means can reliably be prevented from slipping If the belt used is a toothed belt.

The endless pulling means is preferably tensioned over two deflection rollers, which are mounted in the upper and In the lower region of the stationary mast, respectively The endless pulling means Is preferably connected to the tensioning roller of the flexible line in such a way that the endless pulling means Is set Into a circulating movement during a vertical movement of the tensioning rolled The vertical position of the tensioning roller preferably depends drectiv on the extended height of the extending mast and is transmitted directly to the pulling means, so that the extended height of the extending mast can be:ierve:4 dre.ctly fr. crn {he po:,tior. nit tin? :2i''.,ulatirig pulling means.

In this case, it Is particularly expedient If at least one deflection roller is connected to a signal generator registering a rotational movement of the deflection roller The signal generator preferably determines the position of the lifting carriage from the rotational movement of the deflection roller and passes on the corresponding signal to an electronic evaluation unit. The signal generator can be formed, for example, by an incremental encoder.

Viewed from a further aspect, the present invention provides a lifting frame for an industrial truck, having a stationary mast that cannot be raised, at least one extending mast that can be raised relative to the stationary mast, and at least one flexible line connecting the stationary mast to the extending mast. According to the invention, the line Is Fixed to a fixing point arranged in the upper region of the stationary mast, Is led downwards from this fixing point to a tensioning roller and is led upwards from the tensioning roller to the extending mast, the tensioning rollerbeng able to move freely In the vertical direction. According to a development of the Invention, the lifting frame has an apparatus for determining the vertical position of the extending mast, the apparatus comprising at least one endless flexible pulling means.

Further advantages and details of the invention Will be explained In more detail using the exemplary embodiment Illustrated in the schematic figures, in which: Figure 1 shows a lifting frame according to the invention, illustrated schematically, figure 2 shows a lifting frame according to the invention In side view, figure 3 shows a detail view from the side in the region of a tensioning roller, Figure 4 shows a detail view from above In the region of a tensioning roller, Figure 5 shows a schematic view of a duplex-lfting frame according to the invention, and figure 6 shows a schematic view of a trplex-iifting frame according to the invention The lifting frame illustrated In Figure 1' of an ndustnal truck has a stationary mast l, a first extending mast 2 guided on the stationary mast 1 and a second extending mast 3 guided or brie filet exte,d,ii; recast Gi; tars sc-;] exei'diig Breast >, a i,'iS'y carnage 4 to which, in the present exemplary embodiment, a load fork 5 Is fine:i' is guided such that it can be moved vertically Raising the two extending masts 2, 3 relative to the stationary mast 1 Is done by means of actuators, not illustrated, for example hydraulic lifting cylinders, and lifting chains In this case, the extending movement of the first and of the second extending mast 2, 3 can always be Gamed out at the same time, so that the extending masts 2, 3 in each case reach their respective upper or lower end position at the same time. It is likewise possible to drive the extending movements of the extending masts 2, 3 sequentially, so that, for example, first of all the first extending mast 2 Is raised together with the second extending mast 3 relative to the stationary mast 1, and only then Is the second extending mast 3 raised relative to the first extending mast 2 However, the Invention can be used as well with other mast sequences, e.g. the second extending mast 3 raising first, followed by a raising movement of the first extending mast 2 and the second extending mast together.

The vertical movement of the lifting camage 4 on the second extending mast 3 Is carried out ndependentiy of the movements of the extending masts 2, 3 themselves In order to move the lifting carriage 4, the second extending mast 3 has an actuator 6 designed as a hydraulic cylinder in the present exemplary embodrnent, a chain roller 7 being arranged at the upper end of the extending part 6a of the actuator 6 According to the invention, a flexible line 8 is provided, for example an electric line or a hydraulic line, which connects the stationary mast 1 to the second extending mast 3.

The flexible line 8 is used to attach the electrical andlor hydraulic assemblies arranged on the lifting carnage 4 to the components arranged In the region of the vehicle frame of the industrial truck. In order to guide the line, a tensioning roller 9 Is provided, guided on the stationary mast 1 such that it can be moved freely in the vertical direction A further deflection point for the flexible line 8 Is represented by the chain roller 7. The lower end of the flexible line 8 is fixed to the stationary mast 1, while the upper end of the flexible line 8 Is fixed to the lifting carnage 4 Dunng a displacement of the lifting carriage 4 relative to the second extending mast 3, the length compensation of the flexible line 8 is carried out by means of the vertical position change of the tensioning roller 7 arranged on the actuator 6. During the extension of the two exteriding masts 2, ;;, tint; length;,ongensatiu,- o, the flexible lice;', Is rn=j out by means of a position change of the tensioning roller 9 In the vertical direction.

In Figure 27 the lifting frame according to the Invention Is illustrated In a detailed representation in a side view in the lowered position. It Is possible to see the stationary mast 1, the first extending mast 2 and the second extending mast 3 The lifting cylinder 1G and lifting chains for raising the extending masts 2, 3 relative to the stationary mast ar not illustrated, for better clarity Not Illustrated either are the actuator (Fig. 1, item 6) for the vertical movement of the chain roller 7 and the lifting carriage (Fig. 1, item 4) The flexible line 8 is fixed to the stationary mast 1 at the fixing point 10, runs downwards from this fixing point 10 to the tensioning roller 9 and is deflected upwards at the tensioning roller 5 The flexible line then runs upwards to the chain roller 7 and is deflected downwards again at the chain roller 7. At the point 11, the flexible line 8 is then fixed to the lifting carnage (pig. 1, item 4). It is also possible to see a weight 12, on which the tensioning roller 9 is rotatably mounted and which, because of its weight, pulls the tensioning roller 9 downwards, so that the flexible line 8 Is tensioned. The weight 12 is guided on the stationary mast 1 by means of guide elements such that it can be moved in the vertical direction. Likewise illustrated is an apparatus for determining the vertical position of the extending mast, which has an endless pulling means 13 designed as a circulating belt which Is tensioned over an upper deflection roller 14 and a lower deflection roller 15.

figure 3 shows a detail view In the region of the tensioning roller 9, viewed from the side It Is possible to see, further, the flexible line 8 deflected and tensioned by the tensioning roller 9, and the weight 12 which pulls the tensioning roller 9 downwards.

I\Aounted on the weight 12 are guide rollers 16, which guide the weight 12 and therefore the tensioning roller on a guide rail 17 fixed to the stationary mast 1. At the upper and at the lower end of the guide rail 17, the deflection rollers 14 (see Fig. 2) and 15 for the circulating pulling means 13 are mounted, the lower deflection roller 15 having a signal generator 18 registering a rotational movement of the deflection roller 15. The right hand section of the pulling means 13 in the drawing is connected to the weight 12 by a clamping apparatus 19, so that a vertical movement of the weight 1 Q effects a circulating movement of the pulling means 13 and therefore leads to a rotation of the deflection roller 15.

f inure 1 'fus'.rates a petal view i.,'above all I:= ,goi o1 rte,er,so,, r' ,ui'-, it shows in particular the stationary mast 1, the first extending mast 2 and the guide rail 17 which Is fixed to the stationary mast 1 and In which the guide rollers 16 of the weight 12 engage. The circulating pulling means 13 is arranged along the guide rail 17 The clamping apparatus 19 produces a force-ftting connection between the weight 12 and one side of the circulating pulling means 13 The tensioning rollers 39, 41 have different diameters, such that they always have the same rotational speed figure 5 shows a schematic view of a duplex-lftng frame with a stationary mast 21 and one single extending mast 22. The actuator 6 and the chain roller 7 serve only for lifting the lifting carriage 4, but not for the guidance of flexible lines. The flexible line 28 Is fixed to the top of the stationary mast 21, is deflected at the tensioning roller 29 and Is lead upwards from the tensioning roller 2g to the lifting carnage 4 A tensioning roller 29 and a device for measuring the lifting height can be used according to the arrangements shown In l:'g. 3 and 4 With this embodiment the lifting height of the lifting carnage can be measured directly Figure 6 shows a triplex-liffing frame with two extendible masts 32, 33, which enables as well a direct measurement of the lifting height of the lift carriage 4. The flexible Line 38 Is fixed to the top of the stationary mast 31 an is guided as follows starting from the fixing point downwards to a First tensioning roller 39, from the first tensioning roller upwards to a deflection roller 40, from the deflection roller 40 downwards to a second tensioning roller 41 and from the second tensioning roller upwards to the lift carnage 4.

The tow tensioning rollers 39, 41 both are mounted on the same weight and are guided at the stationary mast 31. The arrangements shown in Figs. 3 and 4 therefore have to be adapted for the use in this embodiment. Preferably the tensioning rollers 39, 41 have different diameters, such that they always have the same rotational speed. g

Claims (1)

1. Clalms: 1 Lifting frame for an industrial truck, having a stationary mast

   that cannot be rasecl, at least c,,.- exte,idriy ',-,as BITS. Bale be,=cl iatV; ? to i',e stat-ia,> i,,.St, ,,; at least one flexible line connecting the stationary mast to the extending mast, wherein the line is fixed to a fixing point arranged in the upper region of the stationary mast, is led downwards from this fixing point to a tensioning roller and Is fed upwards from the tensioning roller to the extending mast or one of said extending masts, the tensioning roller being able to move freely in the vertical direction.

   2. Lifting frame according to Claim 1, wherein a first and a second extending mast are provided, the first extending mast being guided on the stationary mast such that it can be moved in the vertical direction, and the second extending mast being guided on the first extending mast such that it can be moved In the vertical direction, and the flexible line connecting the stationary mast to the second extending mast.

   3 Lifting frame according to Claim 1 or 2, wherein a lifting carriage Is guided in the vertical direction on the extending mast that can be extended furthest, and a lifting movement of the lifting carriage relative to the extending mast can be produced by means of an actuator that can be extended in the vertical direction and of a lifting chain, the lifting chain being fixed at a first fixing point on the extending mast that can be extended furthest, being led upwards from this fixing point to a chain roller fixed on the extending actuator, and being led downwards from the chain roller to the lifting carriage 4 Lifting frame according to Claim 3, wherein the flexible line is led upwards from the tensioning roller to the chain roller arranged on tine actuator and Is led downwards from the chain roller to the lifting carriage Lifting frame according to Claim 4, wherein the actuator is provided On the extending mast that can be extended furthest 6 Lifting frame according to Claim 3, 4 or 5 comprising first and second masts, the first extending mast being guided on the stationary mast and the second extending mast being guided on the first extending mast, the lifting carnage being provided on the secono extending 'cast 7 Lifting France according to any one of the preceding Claims, wherein the tensioning rollems connected to a weight 8. Lifting frame according to any one of the preceding Claims, wherein the tensioning roller is guided on the stationary mast such that it can move freely in the vertical direction.

   9 Lifting frame according to any one of the preceding Claims, wherein on one side of the lifting frame, the flexible line is formed by an electric line and, on the other side of the lifting frame, the flexible line is formed by a hydraulic line 1() Lifting frame according to any one of the preceding Claims, wherein the lifting frame has an apparatus for determining the vertical position of the or each extending mast, the apparatus comprising at least one endless flexible pulling means.

   11. Lifting frame according to Clan-, 10'wherein the endless pulling means is formed by a belt.

   12 Lifting frame according to Claim 10 or 11, wherein the endless pulling means is tensioned over two deflection rollers which are mounted in the upper and in the lower region of the stationary mast, respectively.

   13 Lifting frame according to one of Claims 1 O. 1 1 or 12, wherein the endless pulling means Is connected to the tensioning roller of the flexible line In such a way that the endless:'uilng means is set into a crc,uiating movement during a vertcai movement of the tensioning roller. 1 1

   14 Lifting frame according to Claim 12 or Claim 13 when dependent on Claim 12' wherein at least one of said deflection rollers is connected Kit a signs! generator registering a rotational movement of the or each deflection roller 15 Lifting frame for an ndustnal truck, having a stationary mast that cannot be raised, at least one extending mast that can be raised relative to the stationary mast, and at least one flexible line connecting the stationary mast to the extending mast, wherein the line is fixed to a fixing point on the stationary mast, is led from this fixing point to a tensioning roller and is led from the tensioning roller to the extending mast or one of said extending masts the tensioning roller being able to move freely in the vertical direction.

   16 Lifting frame according to Claim 15, wherein the flexible line Is led downwards from the fixing point to the tensioning roller 17 Lifting frame according to Claim 15 or 16, \,vheren the flexible line Is led upwards from the tensioning roller to the extending mast or one of said extending masts.

   18. Lifting frame according to Claim 15, 16 or 17, wherein the fixing point Is arranged in the upper region of the stationary mast.

   19. Lifting frame substantially as herein described and with reference to figures 1 to 4; Figure 5; or Figure 6.