ES2552697T3 - Crane lifting mechanism - Google Patents

Abstract

Crane lifting mechanism (10, 30, 40, 140) with at least one cable drive (12, 42, 142) and load collection means (52) suspended therein, whose cable drive (12, 42, 142) comprises several cable branches (14, 16, 34; 44, 46, 48, 50), namely, at least: - two outer cable branches (14, 16), which are wound on sections of a cable drum (20, 22), offset with respect to each other along a drum shaft (A) of a common cable drum (18) or of two cable drums connected in actuation with each other, - and a third cable branch (34), which is wound on a central cable drum section (36) approximately in a middle plane (E) perpendicular to the drum axis (A) between the two cable drum sections (20, 22) of the two outer cable branches (14, 16), whose three cable branches (14, 16, 34; 44, 46, 48, 50) extend down to the load collection means (52) of such a way The two outer cable branches (14, 16) and the third cable branch (34) form the edges of a three-sided pyramid resting on the vertex, characterized in that the two outer cable branches (14, 16) they are unwound directly from the cable drum (18) downwards and are respectively inclined at an oblique angle of inclination (α) with respect to the median plane (E) and are helically wound on their cable drum sections (20, 22 ) in such a way that the angles of inclination of its windings correspond to its angles of oblique inclination (6ALPHA;), and the third cable branch (34) extends downwards to the means for collecting cargo (52) through a unwinding roller (38) separated from the cable drum (18).

Description

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DESCRIPTION

Crane lifting mechanism.

The present invention relates to a crane lifting mechanism according to the preamble of claim 1.

The crane lifting mechanisms are used in the industry for the transport of items with stabilized cargo. They comprise one or several cable transmissions, whose cable branches are wound on a common cable drum or on several drums connected in drive. Usually, the cables extend downwards on deflection rollers to suspension points in the load collection means, that is, to a crane hook or a load lifting magnet. The cables are tensioned in such a way that a lateral deviation of the load is possible only by applying relatively large lateral forces. Therefore, the stabilized load thus does not perform pendular movements even under lateral movements of the cable drive.

To keep the wear of the cable branches as small as possible, the guide of these cable branches must comprise the smallest possible number of changes by bending. Therefore, it is intended to keep the number of deflection rollers used as small as possible. Therefore, in some constructions at least one of the cable branches is guided directly from the cable drum down to the load collection means. For example, European patent EP 0 941 959 B1 shows a cable drive with three cable branches that are wound on a common cable drum and whose unwinding places form a substantially equilateral triangle. While the outer cable branches are guided over the deflection rollers, the central cable branch runs directly from the cable drum down to the load collection means.

Here, the circumstance that the central cable branch is in the plane of symmetry of the pyramid covered by the three cable branches is used. This leads to the angle of lateral oblique inclination that forms this cable branch with a plane perpendicular to the axis of the cable drum is almost equal to zero. Therefore, in this case it is possible without problems a winding and a winding of the central cable branch. On the contrary, the two outer cable branches are guided through a deflection roller mounted articulately to keep the oblique angle of inclination in the cable drum as small as possible. Without these measures, the oblique inclination angle with an increasing elevation height will increase here until an impeccable operation of the crane lifting mechanism is no longer guaranteed.

Therefore, until now it was not possible to allow the cable branches of the cable drive to be unwound directly from the cable drum which are relatively fairly outer and have a clear oblique angle of inclination. Until now, limits have been placed on a simplification of such crane lifting mechanisms with stabilized load in the sense of minimizing the number of cable guide means.

Therefore, it is a problem of the present invention to create a new possibility to simplify the crane lifting mechanisms with stabilized load, described above, which is arranged with a smaller reduction of deflection rollers and, thus, reduces the wear of the cable branches.

This problem is solved according to the invention by means of a crane lifting mechanism with the characteristics of claim 1.

According to the present invention, at least one cable branch that is unwound directly downward from the cable drum and which is inclined at an oblique angle of inclination, is helically wound on the cable drum so that the slope angle of the winding corresponds to its angle of oblique inclination. This kind of winding causes the angle of oblique inclination to remain constant throughout the entire lifting height of the load and also does not increase with a large lifting height. Due to the relatively large slope or step height of the windings, the cable is relatively relatively wound, with increasing elevation height, in the direction of the load, that is, the windings move towards the load, while in the winding geometry known so far the unwinding point in the drum remains substantially unchanged, except for insignificant displacement movements.

With a cable drum diameter D, a constant slope P and a slope angle a the relationship known by the thread gauge is fulfilled

P = tan a * d * n (1)

The angle of slope a is in this relation (1) according to the invention equal to the angle of oblique inclination.

Therefore, a deflection roller for the guided cable branch can be renounced without problems in this way, even if it is a cable branch arranged quite outside on the cable drive, which does not unwind directly on the load, but is strongly decanted with respect to this in the axial direction

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of the drum

According to a preferred embodiment of the present invention, the winding of this cable branch is guided in a corresponding helical crane on the envelope of the cable drum. Therefore, the cable branch does not wind freely over the drum envelope, but runs in a groove in the manner of a screw thread, that is, for example, in a groove groove that prefers a defined winding path. and prevents lateral slipping of the curls. Additionally, other means for fastening the cable branch in the wire may be present, such as, for example, pinch rollers applied to the cable drum or the like.

According to the invention, the cable drive comprises at least two cable branches of this type that are unwound directly from the cable drum to the load collection means and are wound on sections, stripped with respect to one another. along the drum shaft, a common cable drum or two cable drums which, connected in drive with each other, are arranged on a common drum shaft. These two cable branches are each inclined at an angle of oblique inclination with respect to the mid-vertical plane between their two drum sections, the angles of inclination of their windings corresponding to their angles of oblique inclination in the manner already described above. . The principle of the cable winding according to the invention has been extended to two cable branches that are symmetrically wound with respect to the vertical vertical plane that cuts the axis of the drum, and are inclined at the angle of oblique inclination, on both sides, with respect to to this middle plane.

According to the invention, the cable drive comprises a third cable branch which is wound on a central drum section approximately in the middle plane between the two drum sections of the two outer cable branches that are unwound directly from the cable drum. This third cable branch runs downwards on a winding roller separated from the drum sections to the load collection means, so that the two outer cable branches and the third cable branch form the edges of a pyramid of three faces resting on the vertex. Therefore, the load is also stabilized in an additional direction, so that pendular movements can be suppressed. Since the third cable branch is in the middle plane, it can be narrowly wound over the central drum section in a conventional manner because its oblique angle of inclination is approximately equal to zero.

Preferably, in this case the central drum section may have a diameter slightly smaller than that of the two outer drum sections. This serves to compensate for different winding lengths in windings of different slopes.

According to an embodiment not belonging to the invention, but known according to the state of the art, the cable drive comprises at least two cable branches that are unwound directly from the cable drum, which are double-wound as a pair. of cables on a section of common cable drum and extending diverging from its unwinding point in the cable drum to different suspension points in the load collection means, which are separated from each other transversely to the axis of the drum, corresponding the angle of slope of the double-pass winding to the angles of oblique inclination of the cables of the cable pair. Therefore, in this embodiment the principle of adapting the slope angle to the angle of oblique inclination has been extended to a double-pass winding in the manner of a double-pass screw thread. The two cables of the pair of cables can be closely juxtaposed in this winding, but the slope must be of a sufficiently large magnitude to be able to compensate for the oblique inclination angle even at higher elevations. That is, the individual double curls can have a relatively large distance from one to another.

According to an embodiment not belonging to the invention, but known according to the state of the art, the cable drive comprises two pairs of cables with respective cable branches that are unwound directly from the cable drum and are wound with double pass, which are wound on sections - bent with respect to each other along the drum axis - of a common cable drum or two cable drums arranged on a common axis and connected in actuation with one another and are arranged specularly symmetric with respect to a medium plane between the two drum sections. Therefore, in this embodiment two pairs of double-wound coiled cables are present, which are symmetrically arranged on both sides of the middle plane and can form with said plane, on both sides of this, the same oblique inclination angles.

Next, examples of preferred embodiments of the present invention are explained in more detail with the aid of the drawing.

Figure 1 is a schematic representation of the guide geometry of two cable branches as part

of a preferred embodiment of the crane lifting mechanism according to the invention;

Figure 2 shows a further embodiment of the crane lifting mechanism according to the invention with

three cable branches in total, in a view from the front;

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Figure 3 is a side view of the crane lifting mechanism of Figure 2; Figure 4 is a plan view of the crane lifting mechanism of Figure 2;

Figure 5 is a perspective view of an embodiment - which does not belong to the invention and known according to the state of the art - of the crane lifting mechanism according to the invention with four cable branches in total; Y

Figure 6 is a perspective view of a loading crane comprising the crane lifting mechanism of Figure 5 and a crane lifting mechanism comparable to this.

Figure 1 shows a schematically simplified crane lifting mechanism 10 with a cable drive 12 comprising several cable branches converging at a common suspension point L in the load, not shown in detail. The cable drive may comprise additional cable branches that are not shown in detail, in particular an additional central cable branch for load stabilization in the direction transverse to the drum axis, as shown in more detail in the following way. of embodiment in Figures 2 to 4. With the aid of the embodiment shown here, it is intended to explain only the principle of the invention, which can be used in different ways of carrying out cable transmissions.

The two cable branches shown 14 and 16 are wound on a common cable drum 18 that can rotate around a horizontal drum shaft A. Each of the cable branches 14, 16 is wound on a section 20, 22 of the cable drum 18 and runs obliquely down to the suspension point L. The cable branches 14, 16 converge in a V-shape at the point L and form a respective angle of oblique inclination with respect to the vertical median plane E that passes through the suspension point L and cuts perpendicularly the axis A of the cable drum. Therefore, the angle formed between the two cable branches 14, 16 amounts to twice the angle of oblique inclination, namely 2 a.

Each of the cable branches 14, 16 is helically wound on its cable drum section 20, 22, specifically such that the slope angle of this winding corresponds to the oblique inclination angle a. Thus, the individual windings 24 are separated along the axis A of the cable drum to the extent of the slope or pitch height P. The slope P is calculated with a diameter D of the cable drum 18 according to the relationship

P = tan a * d * n (1)

which is known for thread size.

This type of winding with a constant slope angle ensures that the oblique inclination angle remains constant throughout the height of elevation. In figure 1 this is represented with the help of different suspension points L at four different heights. It can be seen that in the lowest position the angle of oblique inclination a is exactly the same as in the remaining positions in height of the suspension point L. Due to the angle of oblique inclination to which it remains constant even at higher elevations, the branches of Cable 14, 16 can be unwound directly from the cable drum 18, without adversely affecting the operation of the crane lifting mechanism 10. Therefore, additional bypass rollers can be dispensed with and the wear of the cable branches 14 is reduced , 16.

The geometry shown here of the cable branches 14, 16 stabilizes a load, which is suspended at the suspension point L, only with respect to deflection forces acting approximately in the direction of the drum shaft A. For additional stabilization in the direction perpendicular to this, additional cable branches may be present that are not shown in Figure 1, but are shown in the embodiment of Figures 2, 3 and 4 below. The same components are designated in the following figures with the same reference numbers as in Figure 1.

The crane lifting mechanism 30 in Figure 2 also comprises a cable drum 18 that can be rotated about a horizontal cable drum shaft A. At one end of the cable drum 18, an actuation 32 is provided. The cable drum 18 comprises two cable drum sections 20, 22 offset with respect to each other along the axis A, on which the branches of winding are wound. cable 14, 16 as outer cable branches. The type of winding corresponds to that described in relation to Figure 1, that is, the angles of inclination a of the windings 24 correspond to the angle of oblique inclination a between the cable branch 14, 16 and the vertical median plane E between the two cable drum sections 20, 22. In figure 2 two different lifting positions of the suspension point L. are represented. Likewise, it can be seen here that the oblique inclination angle a in the lowest lifting position is equal to the highest elevation position.

In the middle plane E runs a third cable branch 34 over a narrow central drum section 36. This is guided down to the suspension point L on a non-tiltable deflection roller 38 that can be seen

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in the side view of Fig. 3. This deflection roller 38 is at the same height as the cable drum 18 and is laterally offset with respect to it, so that the third cable branch 34 forms an angle with the plane in which the two cable branches 14, 16 run. However, the central cable branch 34 always runs approximately in the middle plane E, disregarding insignificant lateral movement movements during winding and unwinding which, however, lack importance for the operation of the crane lifting mechanism 30. Therefore, the cable branch 34 has at most a very small oblique angle of inclination approximately equal to zero. Consequently, for this central cable branch 34, measures that keep the oblique angle of inclination small must not be taken. The central cable branch 34 is thus closely wound on its central drum section 36 in a conventional manner, whereby the turns can be directly juxtaposed. For compensation of the different slopes of the outer cable branches 14, 16 in conjunction with the inward displacement with respect to the central cable branch 34, the central drum section 36 has a somewhat smaller diameter than that of the two sections of External drum 20 and 22.

The sections of the two outer cable branches 14, 16 and the third cable branch 34 that extend downward from their unwinding points are on the edges of a three-sided pyramid, whose vertex is formed by the suspension point L. In the plan view of Figure 4 it can be seen that, in the lowest elevation position, this pyramid consists of a regular pyramid with the same lengths as its sides. However, as the elevation height increases, the windings and also the unwinding points of the outer cable branches 14, 16 along the axis A of the cable drum move towards each other in the direction of the middle plane E, with What the pyramid gets narrower.

Figure 5 shows an embodiment of a crane lifting mechanism 40 not belonging to the invention and known according to the state of the art, which comprises a cable drive 42 with four cable branches 44, 46, 48, 50 which they are unwound from a common cable drum 18 directly down to a load collection means 52. These load collection means 52 comprise four different suspension points 56, 58, 60, 62 which, separated from each other, are arranged in a load carrier 64 forming a rectangle. In particular, the suspension points 60 and 62 of the cable branches 48 and 50 are separated from each other in the direction transverse to the drum axis A, and also the suspension points 56 and 58, into which the cable branches enter 44 and 46, are also separated from each other in the same distance in the transverse direction. The suspension points 56 and 60 on the left side of the cable drum 18 in Figure 5 are separated from each other in axial direction at a distance significantly smaller than in the transverse direction, and the same occurs with the suspension points 58 and 62 on the opposite right side of the cargo collection means 52.

The cable branches 44 and 46 form a pair of cables 66 which is double-wound on a common cable drum section 20, that is, the two cable branches 44, 46 of the cable pair 66 are directly juxtaposed from one very tight way, but they present in their double-pass winding the same angle of slope. This angle of slope corresponds according to the invention to the angle of oblique inclination of the two cable branches 44, 46 with respect to an average vertical plane E perpendicular to the axis A of the cable drum.

The two cable branches 44 and 46 of the cable pair 66 extend diverging from the cable drum 18 to its different suspension points 56 and 58 on opposite sides of the load collection means 52. Since these suspension points 56, 58 are separated from each other in the transverse direction, the cable branches 44, 46 form an angle p with each other.

Between two double windings of the cable branches 44, 46 there is an axial distance corresponding to the slope of the double-pass winding. Likewise, in this embodiment of the crane lifting mechanism 40, the angle of inclination forms, which forms each of the cable branches 44, 46 with the middle plane E, remains the same throughout the lifting height of the collection means of load 52, since the double winding of the cable pair 66 follows the same laws as the winding of the individual cables 14, 16 in the previous embodiments. Thus, the windings move relatively fairly inwardly over the cable drum section 20 as the elevation height increases, but the oblique inclination angle a remains constantly equal to the slope angle of the winding.

The winding of the remaining cables 48, 50 corresponds specularly symmetrically to that of the cable pair 66. The cable branches 48 and 50 also form a pair of cables 70 which is wound with a double passage over a cable drum section 22 which it is offset with respect to the first section of the cable drum 20 along the axis A of the cable drum, the slope angle of the double-pass winding of the cable pair 70 corresponding to the oblique inclination angle of the cable branches 48 and 50 with respect to the median plane E between the cable drum sections 20 and 22. The cable branches 48 and 50 extend diverging downward from the cable drum 18 to their suspension points 60 and 62, that is, they form An angle p with each other. Thus, the two pairs of cables 66, 70 run specularly symmetrically with respect to the middle plane E.

It is understood that the two drum sections 20 and 22 may be arranged here and also in the embodiments described above on two different cable drums that are on a common drum shaft of cable A and are connected in drive with each other.

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On the cable drum sections 20, 22, helical guides can be arranged in the manner of outer threads in which the individual twisted cable branches 14, 16 or the pairs of cable branches 66, 70 are guided in the desired manner. In this way, a defined winding can be preset. Additional means, such as tightening rollers, can keep the cable branches additionally in their guides.

The crane 160 of Figure 6, which does not represent an embodiment belonging to the invention, but known according to the state of the art, comprises two crane lifting mechanisms that are arranged at the same height and comprise a respective cable drum 18 The two cable drums 18 and 118 have parallel cable drum shafts A, A '. The crane lifting mechanism 40 corresponds to that of Figure 5. The other crane lifting mechanism 140 is similarly constituted to the crane lifting mechanism 40 and has an identical cable drive 142 which also comprises four cable branches that run as the cable branches 44, 46, 48, 50 in Figure 5. One difference is that the suspension points 56, 60 or 58, 62 separated from each other in the transverse direction are arranged on different load carriers 144, 146. The load collection means in this case comprise the load support 64 of the crane lifting mechanism 40, the load supports 144, 146 of the crane lifting mechanism 140 and a joint support, not shown in Figure 6, which is arranged transversely to the cable drum axes A, A 'and on which the load carriers 64, 144, 146 are fixedly mounted.

Through the two crane lifting mechanisms 40 and 140, which operate in synchronism with one another by means of corresponding drives 146, 148 and are coupled by the joint support, not shown, of the load collection means, the Load is stabilized in a pendular manner not only in the longitudinal direction of the cable drum axes A, A ', but also in the transverse direction to these.

In the cable drum 18, the tightening rollers 150 can be appreciated, which keep the double-pass windings of the cable branches in their guides.

Claims (3)

5 10 fifteen twenty 25 30 1. Crane lifting mechanism (10, 30, 40, 140) with at least one cable drive (12, 42, 142) and load collection means (52) suspended therein, whose cable drive ( 12, 42, 142) comprises several cable branches (14, 16, 34; 44, 46, 48, 50), namely at least: - two outer cable branches (14, 16), which are wound on cable drum sections (20, 22), stripped relative to each other along a drum shaft (A) of a cable drum common (18) or two cable drums connected in actuation with each other, - and a third cable branch (34), which is wound on a central cable drum section (36) approximately in a middle plane (E) perpendicular to the drum axis (A) between the two cable drum sections ( 20, 22) of the two outer cable branches (14, 16), whose three cable branches (14, 16, 34; 44, 46, 48, 50) extend down to the load collection means (52) such that the two outer cable branches (14, 16) and the third cable branch (34) forms the edges of a three-sided pyramid that rests on the vertex, characterized in that the two outer cable branches (14, 16) are unwound directly from the cable drum (18) downwards and are respectively inclined at an oblique angle of inclination (a) with respect to the median plane (E) and are wound helically on its cable drum sections (20, 22) such that the angles of inclination of its windings correspond to its angles of oblique inclination (a), and the third cable branch (34) extends down to the load collection means (52) through a unwinding roller (38) separated from the cable drum (18). 2. Crane lifting mechanism according to claim 1, characterized in that the windings of the two outer cable branches (14, 16) are guided in corresponding helical guides arranged on the envelope of the cable drum (18, 118). 3. Crane lifting mechanism according to claim 1 or 2, characterized in that the central cable drum section (36) has a diameter somewhat smaller than that of the two outer cable drum sections (20, 22).