CA2596726A1

CA2596726A1 - Lift support means for a lift system, lift system with such a lift support means and method for assembling such a lift system

Info

Publication number: CA2596726A1
Application number: CA002596726A
Authority: CA
Inventors: Ernst Ach; Luc Bonnard
Original assignee: Inventio AG
Current assignee: Inventio AG
Priority date: 2006-08-11
Filing date: 2007-08-09
Publication date: 2008-02-11
Also published as: AR062351A1; MX2007009682A; NO20074151L; BRPI0703336A; RU2007130684A; AU2007205744A1; TW200829503A; EP1886959A1; ES2347288T3; EP1886959B1; DE502007004052D1; SG139721A1; JP2008044791A; HK1117810A1; KR20080014704A; ATE470644T1

Abstract

A lift support means (1) for a lift system comprises a base body (2), a drive side with at least one drive rib (3), a deflecting side, which is opposite the drive side, with at least one guide rib (4), and a tensile carrier arrangement (5) arranged in the base body. The guide rib (4) has a greater flank height (h4) and/or a greater flank width (t4) than the drive rib (3).
The ratio (h4/w) of the flank height (h4) of the guide rib (4) to the width (w) of the lift support means (1) is at least 0.4. A respective guide rib (4) is associated with at most three drive ribs (3).

Description

Description Lift support means for a lift system, lift system with such a lift support means and method for assembling such a lift system The present invention relates to a lift support means for a lift system, to a lift system with such a lift support means and to a method for assembling such a lift system.

In a lift system, one or more lift support means transmit forces from a drive to a cage movable in a lift shaft or along free-standing guide rails. A cage can be coupled by way of the same or further support lift support means to a compensating weight or counterweight which travels in opposite sense to the cage.

Such a lift system with a lift support means according to the introductory part of claim 1 is known from EP 1 446 348 B1. In an example of embodiment the lift support means has on a drive side five drive ribs of wedge-ribbed shape for engagement with a drive wheel and on a deflecting side opposite the drive side a guide rib similarly of wedge-ribbed shape for engagement with a deflecting wheel. Guide ribs and drive ribs engage in corresponding wedge-shaped grooves which are formed on deflecting and drive wheels.

A rib generally has two mutually opposite flanks which include a flank angle a as schematically indicated in Fig. 2. In a wedge rib these flanks are generally inclined relative to one another and in a rectangular rib they are parallel to one another with a flank angle a = 0 . In the present case the projection of the flank onto the plane spanned by the longitudinal and transverse direction of the lift support means is termed flank width t. In a rectangular rib, for example, it is equal to zero and in a wedge rib with a flank length f the inclined flanks are generally t = f x sin(a/2). Correspondingly, the projection of the flank onto the median or longitudinal plane of the base body is termed flank height h. it corresponds, for example, in a rectangular rib with the flank length f and in a wedge rib is generally h = f x cos(a/2).

Due to the wedge effect the drive ribs of wedge-ribbed shape increase, for the same tension force in the lift support means, the normal forces acting on the flanks of the drive ribs and thus the drive capability of the drive. In addition, they advantageously guide the lift support means in transverse direction on the drive wheel.

The guide rib at the rear side guides the lift support means in transverse direction on deflecting wheels over which the lift support means is deflected so as to co-operate with, for example, the cage or the counterweight.

It has proved advantageous to arrange the tensile carrier arrangement at not too wide a distance and at a spacing from the drive side or the flanks of the drive ribs which is as uniform as possible so as to provide a more homogenous distribution of force in the drive ribs. This results in drive ribs with smaller flank height and flank width as well as a flatter flank angle.

The lift support means usually rests from above on a drive wheel of the lift system so that it is redisposed by its own weight in the grooves in the drive wheel circumference.
Conversely, it frequently loops around deflecting wheels laterally or from below so that its own weight does not redispose it or even urge it out of the grooves in the deflecting wheel circumference. If slackening of the lift support means occurs due to, for example, inertias of the cage or the counterweight or oscillations in the lift support means this can have the consequence that a guide rib slides completely out of the associated groove in the deflecting wheel. Without the then absent transverse guidance on the deflecting wheel a diagonal tension, which is usually present in the lift system due to assembly tolerances, twistings of the load run and the like, has the effect that the lift support means then migrates in transverse direction from its desired position and the guide rib also no longer finds its way back into the groove in the deflecting wheel when the lift support means tightens again.

The lift support means usually loops around a drive wheel of the lift system with a greater angle of wrap than deflecting wheels so as to prevent, at the drive wheel, slipping of the lift support means in correspondence with the Euler-Eytelwein formula. Accordingly, a drive rib frequently engages over a greater angular range in a drive wheel than a guide rib in a deflecting wheel. In addition, in a deflecting wheel with a smaller angle of wrap the forces in radial direction, which constrain the rib in the groove at the wheel circumference, are less than in the drive wheel with greater angle of wrap. If, for example, the lift support means loops around a drive wheel by 1800, but a deflecting wheel by only 900, the resultant radial force on the lift support means is then greater at the drive wheel by the factor ~2 than at the deflecting wheel.

In addition, the stronger diagonal running, which is caused by, for example, assembly tolerances, of the lift support means frequently occurs between adjacent deflecting wheels.
Moreover, compensation for this by deformation of the lift support means also cannot be sufficiently provided due to the frequently smaller spacings between adjacent deflecting wheels. The diagonal tension resulting therefrom seeks to displace the lift support means on the deflecting wheels in transverse direction.

It is therefore the object of the present invention to improve the guidance of a lift support means at its deflection side.

This object is fulfilled by lift support means according to at least one alternative of claim 1.
Claim 18 protects a lift system with such a lift support means and claim 22 a mounting method for such a lift system.

A lift support means according to the invention comprises a base body, a drive side, which is provided for friction-coupling engagement with the drive wheel of a lift system and has at least one drive rib, and a deflecting side, which is disposed opposite the drive side and which is provided for contact with a deflecting wheel of the lift system and has at least one guide rib. A tensile carrier arrangement is arranged in the base body for transmission of the tension forces.

When in the following reference is made to at least one drive rib or at least one guide rib in that case always several drive ribs or guide ribs can equally well be comprehended, wherein a feature defined for at least drive rib or guide rib then applies to at least one of these several drive or guide ribs, preferably for several drive and/or guide ribs, particularly preferably for all drive and/or guide ribs, of the support means.

According to a first embodiment of the present invention at least one, preferably each, guide rib now has a greater flank height than at least one, preferably each, drive rib. This ensures better guidance of the lift support means in transverse direction.

The flank height determines the radial displacement which the lift support means experiences relative to a drive or deflecting wheel before the rib exits entirely from an associated groove in the outer circumference of the drive or deflecting wheel and can no longer guide the lift support means in transverse direction.

Through the extension of the flank height of the guide ribs relative to the drive ribs partial compensation can be provided for the effects illustrated in the introduction and at the same time a more homogenous forced distribution between the drive side and the tensile carrier arrangement can be realised.

The higher guide rib can, in the case of a microscopic or macroscopic slackening of the lift support means, move radially further away from a deflecting wheel without the transverse guidance being completely lost. If the lift support means tightens again, the guide rib, which always still enters partly into the groove of the deflecting wheel due to its greater flank angle, advantageously centres the lift support means again on the deflecting roller.
In addition, the flank area, which engages in the groove in the deflecting wheel circumference, of the guide rib increases and can thus ensure a sufficient transverse guidance even with smaller deflecting angles. A greater diagonal tension up to 4% can therefore preferably also be realised by a lift support means according to the first embodiment of the present invention.

Through the drive rib, which is lower by comparison, the change in spacing and/or the maximum spacing of the tensile carriers from the drive side can at the same time be reduced so that a more homogenous distribution of force in the drive rib is achieved.

Preferably the ratio of the flank height of at least one, preferably each, guide rib to the flank height of at least one, preferably each, drive rib is at least 1.5, preferably at least 2.0 and particularly preferably at least 2.5. A ratio of at least 1.5 can, for example, be sufficient in order to provide compensation for the deterioration in guidance on a deflecting wheel due to a smaller angle of wrap. A ratio of at least 2.0 can, for example, be advantageous in order to provide compensation for the deterioration in the guidance on a deflecting wheel due to the intrinsic weight which does not return the lift support means to its position on the deflecting wheel or even sets it away from this. A ratio of at least 2.5 can, for example, be advantageous in order to make possible a greater diagonal tension.
Additionally or alternatively to the greater flank height at least one, preferably each, guide rib can have a greater flank width than at least one, preferably each, drive rib. This, too, guarantees better guidance of the lift support means in transverse direction.

The flank width determines the offset in transverse direction by which a rib can run into a groove or run out of this and yet is automatically guided back into the groove, in other words the 'capture range' within which a rib is still captured by a groove of a drive or deflecting wheel. Due to the fact that in accordance with the invention the flank width of the guide rib is greater than the flank width of the drive rib, thus the guide rib is wider in transverse direction, a more homogenous distribution of force in the drive rib can be provided in the narrower drive rib due to the resulting smaller spacing of the tensile carriers from the drive side, whilst the lift support means when deflected over a deflecting wheel at the same time has better guidance due to the wider guide rib.

This can similarly provide partial compensation for the above-explained effects of poorer guidance and/or stronger diagonal tension due to its intrinsic weight or a smaller angle of wrap at the deflecting side. In the event of microscopic or macroscopic slackening of the lift support means the wider guide rib can displace more strongly in transverse direction on a deflecting wheel without completely losing transverse guidance. When the lift support means tightens again the guide rib, which due to its greater flank width always still lies partly over the groove of the deflecting wheel, advantageously centres the lift support means on the deflecting roller again. In addition, the flank area, which engages in the groove in the deflecting wheel circumference, of the guide rib increases and can thus ensure sufficient transverse guidance even in the case of smaller angles of wrap. Thus, a greater diagonal tension can equally be realised with a lift support means in which the guide rib has a greater flank width than the drive rib.

The ratio of the flank width of at least one, preferably each, guide rib to the flank width of at least one, preferably each, drive rib is preferably at least 1.5, preferably at least 1.75 and particularly preferably at least 2Ø A ratio of at least 1.5, for example, can be sufficient in order to provide compensation for deterioration in the guidance on a deflecting wheel due to a smaller angle of wrap. A ratio of at least 1.75, for example, can be advantageous to provide compensation for deterioration in the guidance on a deflecting wheel due to the intrinsic weight which does not return the lift support means to its position on the deflecting wheel or even sets it away from this. A ratio of at least 2.0, for example, can be advantageous to make possible a greater diagonal tension.

The above-explained advantages of a greater flank height or flank width of the guide rib by comparison with the drive rib are already self-evident. For preference, however, the two features are combined together so that the higher and wider guide rib can further displace not only in radial direction, but also in axial direction and nevertheless is guided, especially centred, by the guide rib on the deflecting wheel. A greater diagonal tension can thereby be realised at the deflecting wheel, whilst at the same time the more homogenous distribution of force arises due to the lower, narrower drive ribs.

According to a second embodiment of the present invention, additionally or alternatively to the ratio of the flank height and/or flank width of at least one guide rib to at least one drive rib it is provided that the ratio of the flank height of at least one, preferably each, guide rib to the width of the lift support means is at least 0.4, preferably at least 0.45 and particularly preferably at least 0.5.

The wider the lift support means is formed, the more inertial mass pushes away from the deflecting wheel when microscopic or macroscopic slackening occurs. Wider lift support means also permit, due to the geometrical moment of inertia thereof, stronger transverse forces or a stronger diagonal tension, which equally requires better guidance on a deflecting wheel. It has now proved in tests that with the above-mentioned ratios between guide rib height and lift support means width it is possible to achieve a very good guidance of the lift support means on a deflecting wheel. In that case a ratio of at least 0.4, for example, can be sufficient to provide compensation for deterioration in the guidance on a deflecting wheel due to a smaller angle of wrap. A ratio of at least 0.45, for example, can be advantageous in order to provide compensation for deterioration in the guidance on a deflecting wheel due to the intrinsic weight which does not return the lift support means to its position on the deflecting wheel or sets it away from this. A ratio of at least 0.5, for example, can be advantageous in order to make possible a greater diagonal tension.

The ratio of the flank height of at least one guide rib to the width of the lift support means according to the second embodiment of the present invention can be realised independently of the ratio of the flank height or flank width of the guide rib by comparison with a drive rib in accordance with the first embodiment. For example, the above-explained advantages can result even with high and wide drive ribs in which flank height and/or flank width of drive and guide ribs are substantially the same.
However, the two embodiments are preferably combined together so that not only the more homogenous distribution of force in the shorter and/or narrower drive ribs, but also the better guidance characteristics of the high and/or wide guide ribs are achieved, wherein the guide ribs are adapted to the width of the lift support means.

According to a third embodiment of the present invention, additionally or alternatively to the ratio of the flank height and/or flank width of a guide rib to a drive rib according to the first embodiment and/or additionally or alternatively to the ratio of the flank height of a guide rib to the width of the lift support means according to the second embodiment at least one, preferably each, drive rib and at least one, preferably each, guide rib is constructed as a wedge rib with a flank angle, wherein the flank angle of at least one, preferably each, drive rib is greater than the flank angle of at least one, preferably each, guide rib.

More acute guide ribs improve the transverse guidance of the lift support means at the deflecting side thereof and can thus better provide compensation for, for example, the above-explained effects due to the intrinsic weight, a smaller angle of wrap and/or the greater diagonal tension. In particular, greater penetration depths are thus provided by comparison with rib base area without having to widen the lift support means overall. On the other hand, more obtuse drive ribs lead to a more homogenous distribution of force in the lift support means, since the spacing of the individual tensile carriers from the drive side is more uniform and also the maximum spacing reduces.

The ratio of the flank angle according to a third embodiment of the present invention can be realised independently of the features of the first or second embodiment.
For example, the above-explained advantages can result even with shorter or narrower guide ribs in which the penetration depth is, nevertheless, increased relative to its base area by the more acute flank angle. The third embodiment is, however, preferably combined with the first and/or second embodiment so that the advantageous greater flank height of the guide rib results due to the more acute flank angle.

A flank angle between 600 and 120 , preferably between 80 and 100 and particularly preferably substantially equal to 90 has proved advantageous for a drive rib constructed as a wedge rib so as to on the one hand achieve a sufficient wedge effect and thus increase in the normal force and on the other hand prevent excessive area pressure, material loading and noise output connected therewith and a jamming of the lift support means.

A flank angle between 60 and 100 , preferably between 70 and 90 and particularly preferably substantially equal to 80 has proved advantageous for a guide rib constructed as a wedge rib so as on the one hand to ensure a sufficient guidance in a groove of a deflecting wheel and on the other hand to avoid excessive area pressures and the loading of the lift support means connected therewith as well as output of noise which occurs.

According to a fourth embodiment of the present invention it is provided, additionally or alternatively to the flank height and/or flank width of the guide rib according to the first and/or second embodiment and/or additionally or alternatively to the flank angle of the guide rib according to the third embodiment that a respective guide rib is associated with one, two or three guide ribs.

The transverse guidance on a deflecting wheel is particularly advantageous in order to prevent migration of the lift support means due to diagonal tension, which can result, for example, due to diagonal running of the lift support means between a drive wheel and a deflecting wheel. The diagonal tension possible between a drive wheel and a deflecting wheel is limited, inter alia, by the number of drive ribs guiding the lift support means on the drive wheel. It has proved in tests that with one guide rib for at most three, preferably at most two, drive ribs and particularly preferably one drive rib a particularly reliable guidance of the lift support means can be ensured. In addition, the lever arm between outer drive ribs and the associated guide rib advantageously reduces and thus the torque which acts on the lift support means and which results from the components of the forces, which act on the inclined flanks, perpendicularly to the flank width.

Advantageously the fourth embodiment is combined with the first, second and/or third embodiment of the present invention. In particular, if in accordance with the first or second embodiment a guide rib is constructed which is high and/or wide by comparison with the drive rib or the lift support means width and in accordance with the third embodiment a guide rib is constructed which is acute, advantageous guidance and lever conditions occur with a drive-to-guide rib ratio of at most 3:1.

A guide rib is preferably centred between two adjacent drive ribs. The resultant of the area load on a flank of the guide rib is then applied in statically stable manner between the two points of action of the resultant of the area loads on the flanks of the drive ribs. In addition, the lift support means can in this manner be constructed to be particularly slender.
According to an embodiment of the present invention the ratio of the width of the lift support means to the height of the lift support means is at most 0.95, preferably at most 0.93 and particularly preferably at most 0.91.

Thus, in particular, relatively acute and/or high guide ribs can be provided, which due to their flank height ensure good transverse guidance of the lift support means.
Advantageously, such a slender lift support means also has a greater geometrical moment of inertia in transverse direction and thus is stiffer than flat belts with respect to bending about the transverse axis. Such a lift support means therefore experiences a higher degree of biasing back into the straight, underformed position when deflected around a drive or deflecting wheel. This biasing counteracts jamming of drive or guide ribs of the lift support means in associated grooves on a drive or deflecting wheel and thus advantageously reduces the risk of jamming.

A further advantage resides in the additional volume of the lift support means in the direction of its height. This additional volume advantageously damps vibrations and diminishes shocks, which makes the running of such a belt more consistent.

The transmission of the circumferential force between tensile carriers and drive wheel takes place with transient deformation of the lift support means in shear. The thus-occurring alternating deformations lead, over the long term, to destruction of the lift support means and thus limit the service life thereof. Here, too, the additional volume of the lift support means in the direction of its height can advantageously on the one hand reduce the deformations in shear and on the other hand better dissipate the then-created heat over the greater volume and, in particular, over the greater surface area.

The drive side of the lift support means according to the invention preferably has at most three, preferably exactly two, drive ribs and the deflecting side exactly one guide rib. Such a lift support means can be of slender construction and thus realise the advantages explained in the foregoing.

As explained above, it is advantageous to associate one or two flanks of a drive rib with each tensile carrier so as to achieve a more homogenous distribution of force.
For this purpose it is thus advantageous to associate one or two tensile carriers with a drive rib. If the drive side has only two or three drive ribs, then a tensile carrier arrangement of two (two drive ribs each with an associated tensile carrier) up to a maximum of six (three drive ribs each with two associated tensile carriers) tensile carriers thus results.
If now for fulfilment of different tensile force requirements several lift support means are connected in parallel, then lift support means with only two or three drive ribs therefore significantly increase the modularity, because the tensile force transmissible by the combination of parallel lift support means can thus be graduated significantly more finely and be adapted to the respective requirements.

The flanks of at least one, preferably each, drive rib and/or at least one, preferably each, guide rib can be formed to be planar. This facilitates production and advantageously produces a self-centring of the rib in an associated groove due to the inclination. Equally, the flanks of, for example, at least one, preferably each, guide rib can also be formed to be concave so as to save material and at the same time achieve a large flank height and/or flank width. The flanks of, for example, at least one, preferably each, guide rib can just as well be formed to be convex so as to make available sacrificial material and thus increase the service life of the lift support means.

According to an embodiment of the present invention the minimum width of one or more drive ribs is greater than the minimum width of the associated grooves of a drive wheel. It can thereby be ensured that the distal flank regions of the drive ribs always completely rest on corresponding counter-flanks of the associated grooves, which still further taper below the completely penetrated drive rib. These counter-flanks thus do not exert, in their groove base, any notch effect on the drive ribs.

A groove with a radius is preferably formed between two adjacent drive ribs, wherein the ratio of this radius to a radius formed at the tip of an associated rib of the drive wheel of the lift system is less than one, preferably less than 0.75 and particularly preferably less than 0.5. It can thereby be ensured that the rib, which engages between the two adjacent drive ribs, of the drive wheel exerts no or only a small notch effect on the proximal flank regions of the drive ribs.

The base body, one or more drive ribs and/or one or more guide ribs can be of unitary or multi-part construction from an elastomer, particularly polyurethane (PU), polychloroprene (CR), natural rubber and/or ethelene-propylene-diene rubber (EPDM). These materials are particularly suitable for conversion of the friction forces acting on the drive side into tension forces in the tensile carriers and in addition advantageously damp vibrations of the lift support means. The drive and/or deflecting side can have one or more casings, for example of textile fabric, for protection against abrasion and dynamic destruction.

A unitary construction gives a particularly compact and homogenous lift support means. If, conversely, a group of one or more drive ribs is of multi-part construction with a group of one or more guide ribs, in that the lift support means, for example, is of two-part construction from a part comprising the drive ribs and a part connected therewith and comprising the guide ribs, different material characteristics can be provided on the drive side and deflecting side. For example, the drive side can have a lesser hardness, particularly a lesser Shore hardness, and/or a greater coefficient of friction than the deflecting side so as to achieve better drive capability, whereas conversely the lower coefficient of friction of the deflecting side reduces the energy loss during deflection.

For this purpose, in particular, the drive side and/or the deflecting side can additionally or alternatively have a coating of which the coefficient of friction, hardness and/or abrasion resistance differs or differ from the base body. Alternatively to the coating, a vapour deposition or a flocking can also be provided.

Through the multi-part construction of drive and guide rib and/or the coating of drive and/or deflecting side a lift support means according to the present invention can preferably have coefficients of friction of = 0.2 to 0.6 on the drive side and/or less than or equal to 0.3 on the deflecting side.

As explained in the foregoing, it can be advantageous for the spacing of the tensile carrier arrangement from the drive side to be less than from the deflecting side. A
more homogenous distribution of force in the drive rib and at the same time a better guidance of the lift support means at the deflecting side can thereby be combined. In that case, for example, there can be defined as spacing the maximum spacing of a tensile carrier from a flank, the mean spacing thereof and/or the spacing of the tensile carrier from the point of force action of the resultant of the area load on the flank.

The diameter of the tensile carriers is preferably in the region of 1.5 to 4 millimetres. Such tensile carriers have a sufficient capability of bending around drive and deflecting wheels and on the other hand have a sufficient strength and can be readily embedded in the base body.

According to an embodiment of the present invention each tensile carrier of the tensile carrier arrangement comprises a double-ply core strand with a core wire and two wire layers wrapped about this, and single-ply outer strands, which are arranged around the core strand, with a core wire, and a wire layer wrapped around this. Such a tensile carrier construction, which can have, for example, one core strand with 1+ 6 + 12 steel wires and eight outer strands with 1+ 6 steel wires, has in tests proved advantageous with respect to strength, ease of production and capability of bending.

Advantageously, in that case the two wire layers of the core strand have the same angle of wrap, whilst the one wire layer of the outer strands is wrapped against the wrap direction of the core strand, and the outer strands are wrapped around the core strand opposite to the wrap direction of their own wire layer. The tensile carrier thus has the order SSZS or ZZSZ. This reduces stretching of the strands.

As mentioned in the foregoing, a modular construction of a lift support means composite of several lift support means according to the present invention is advantageous in order to provide different tensile force requirements. In that case the lift support means are guided parallel to the drive wheel and deflecting wheel.

In this connection, two lift support means can be spaced apart by a gap. This simplifies mounting and allows slight deformations of the individual lift support means without these rubbing against one another or mutually working out of the grooves of the drive wheel or deflecting wheel. Advantageously for this purpose the gap is at least 3%, preferably at least 4% and particularly preferably at least 5% of the width of the lift support means.

For mounting, the lift support means can be produced from a pre-product, wherein the pre-product consists of two or more lift support means with a one-piece base body.
The pre-product is partly divided between drive ribs and guide ribs so that lift support means substantially separated in that manner remain connected by way of at least one thin base body web before they are mounted in the lift system. This facilitates handling thereof and positionally correct arrangement on drive wheel and deflecting wheel.
Alternatively, it is possible for mounting to permanently or detachably connect two or more lift support means with an assembly band before they are mounted in the lift system.

A drive wheel and/or a deflecting wheel of a lift system according to an embodiment of the present invention has or have for each drive or guide rib an associated groove in such a manner that when the lift support means is laid in place the flanks of the drive or guide rib contact corresponding counter-flanks of the associated groove. In this connection the grooves are preferably formed in correspondence with the ribs of the lift support means: if the guide rib or drive rib has a specific flank height, flank width and/or a specific flank angle, then advantageously the counter-flanks of the associated groove have substantially the same flank height and/or flank width and/or substantially the same flank angle. In particular it is preferred for the penetration depth by which at least one, preferably each, guide rib of a lift support means according to the present invention penetrates into a groove in a deflecting wheel to be greater than the penetration depth by which the at least one, preferably each, drive rib penetrates into a groove in a drive wheel. In other words, preferably at least one, preferably each, groove in a deflecting wheel is so formed that the projection of the contact surface between a flank of a guide rib arranged in this groove and the corresponding counter-flank of this groove is greater in axial and/or radial direction than the corresponding projection of the contact surface between a flank of at least one, preferably each, drive rib and the corresponding counter-flank of a groove, which is associated with this drive rib, in the drive wheel.

The drive wheel or the drive wheels can have several drive zones which are looped around at least partly by the or each lift support means. Advantageously, a lift support means loops around a drive wheel with an angle of wrap of 180 , preferably less than 180 , preferably less than 1500, particularly preferably less than 1200 and especially 90 .
Due to the small bending radii, which are possible, of the lift support means it is possible to connect the drive with a separate drive pulley or, however, to integrate drive zones in a drive output shaft with a drive. Drive pulleys and drive shafts provided with drive zones are therefore uniformly referred to as drive wheel. Advantageously, the diameter of a drive wheel is less than or equal to 220 millimetres, preferably less than 180 millimetres, preferably less than 140 millimetres, preferably less than 100 millimetres, preferably less than 90 millimetres and preferably less than 80 millimetres. The tension forces are introduced into the belts by the drive wheel in friction-coupling and/or shape-coupling manner.

A lift support means can be constructed as an endless belt, the ends of which are fastened to beft locks. The belt can, particularly in the case of difficult deflecting conditions, for example be led through openings or placed on belt wheels mounted so as to be non-aligned.

Further objects, features and advantages are evident from the subclaims and the examples of embodiment described in the following. For this purpose, with partly schematic illustrations:

Fig. 1 shows a section through a lift system according to an embodiment of the present invention;

Fig. 2 shows a lift support means according to an embodiment of the present invention for explanation of mentioned specifications;

Fig. 3 shows a part section through a lift support means of the lift system of Fig. 1, along the line III-III;

Fig. 4 shows a part section through a lift support means of the lift system of Fig. 1, along the line IV-IV;

Fig. 5 shows a pre-product of the lift support means of Fig. 2;

Fig. 6 shows an embodiment of a combination of lift support means of Fig. 2, produced from the pre-product of Fig. 5; and Fig. 7 shows a further embodiment of the combination of lift support means of Fig. 2.

Fig. 1 shows a section through a lift installation, which is installed in a lift shaft 12 according to an embodiment of the present invention. This comprises a drive, which is fixed in the lift shaft 12, with a drive wheel 20, a lift cage 10, which is guided at cage guide rails 11, with two deflecting wheels, which are mounted below the cage floor, in the form of cage support rollers 21.2, 21.3, a counterweight 13 with a further deflecting wheel in the form of a counterweight support roller 21.1 and several lift support means, which are constructed as wedge-ribbed belts 1, for the lift cage 10 and the counterweight 13, which transmit the drive force from the drive wheel 20 of the drive unit to the lift cage and the counterweight.

Each wedge-ribbed belt 1 is fastened at one of its ends below the drive wheel 20 at a first belt fixing point 14.1. From this it extends downwardly to the counterweight support roller 21.1, loops around this and extends out from this to the drive wheel 20, loops around this and runs downwardly along the cage wall of the counterweight side, loops on either side of the lift cage around cage support rollers 21.2 and 21.3 - which are respectively mounted below the lift cage 10 - each time through approximately 90 and run upwardly along the cage wall remote from the counterweight 13 to a second belt fixing point 14.2.

The plane of the drive wheel 20 can be arranged at right angles to the cage wall at the counterweight side and its vertical projection can lie outside the vertical projection of the lift cage 10. It is therefore preferred that the drive wheel has a small diameter of less than or equal to 220 millimetres, preferably less than 180 millimetres, preferably less than 140 millimetres, preferably less than 100 millimetres, preferably less than 90 millimetres, and preferably less than 80 millimetres, so that the spacing between the cage wall at the counterweight side and the wall of the lift shaft 12 opposite thereto can be as small as possible. Moreover, a small diameter of the drive wheel 20 enables use of a gearless drive motor with a relatively low drive torque as drive unit. The belt fixing points 14 are devices which are known to the expert and in which the wedge-ribbed belt 1 is clamped between a wedge and a housing.

Figures 3 and 4 show a section through a lift support means in the form of a wedge-ribbed belt 1 of Fig. 1 according to an embodiment of the present invention. This comprises a base body 2 in which a tensile carrier arrangement 5 of four tensile carriers is arranged.
As indicated in the figures, each tensile carrier is constructed as a steel wire cable which comprises a double-ply core strand with a core wire with 0.19 millimetres diameter, a wire layer, which is wrapped therearound in S wrap, of six wires with 0.17 millimetres diameter and a wire layer, which is wrapped therearound similarly in S wrap, of twelve wires with 0.17 millimetres diameter, as well as eight single-ply outer strands with a core wire with 0.17 millimetres diameter and a wire layer, which is wrapped therearound in Z
wrap, of six wires with 0.155 millimetres diameter, which are wrapped in S wrap around the core layer.
A drive side (at the bottom in Fig. 3) of the lift support means 1 is intended for contact with the drive wheel 20 and the counterweight support roller 21.1. It has for this purpose two drive ribs in the form of wedge ribs 3, which, as shown in Fig. 3, engage in associated grooves 20.1 of the drive wheel 20 and are laterally guided by these. The pressing pressure thereby advantageously increases and therewith the traction capability of the drive.

A deflecting side (at the top in Fig. 4) of the lift support means 1 is intended for contact with the cage support rollers 21.2, 21.3 and has for this purpose a guide rib in the form of a wedge rib 4 which, as shown in Fig. 4, engages in an associated groove 21.5 of the deflecting wheel 21.3 and is laterally guided by this.

The dimensional sizes of the lift support means 1 are schematically shown in Fig. 2. In that case the flank height h3 or h4 of a drive rib 3 or of the guide rib 4 is the projection of the rib onto the median plane of the lift support means 1, which is spanned by the length axis and height axis (vertical in Fig. 2). The overall height h1 of the lift support means is thus composed of the flank heights h3, h4 of the drive and guide ribs 3, 4 and the height h2 of the base body 2. Due to this large flank height t4, this total height h1 is greater than the width w of the lift support means, which advantageously increases the bending stiffness thereof about its transverse axis and thus counteracts jamming in grooves 20.1 or 21.5. In the example of embodiment the ratio w/h 1= 0.906.

The flank width t3 or t4 of a drive rib 3 or of the guide rib 4 corresponds with the projection of the rib on the base body 2 of the lift support means 1, i.e.
perpendicularly to the flank height (horizontal in Fig. 2). The overall width is denoted by w. The width of a rib resufts from its two flank widths t as well as the width of a(flattened) tip. Thus, the width of a drive rib 3 is, for example, 2 x t3 + d3 (cf. Figures 2, 3).

The flank angle a4 of the guide rib 4 is the internal angle between the two flanks of the guide rib 4 and in the example of embodiment is 80 . The correspondingly defined flank angle 0 of the drive ribs 3 is, in the example of embodiment, 900.

As recognisable in Fig. 2, the flank height h4 of the one guide rib 4 is greater than the flank height h3 of the two drive ribs 3. The guide rib 4 can thereby, as comparison of Figures 3 and 4 shows, penetrate deeper into an associated groove 21.5 in the deflecting wheel 21.3 than is the case with the drive ribs 3 and the associated grooves 20.1 of the drive wheel 20. The guide rib 4 therefore remains, in the case of radial lifting off (downwardly in Fig. 4) which can set in, for example, due to the intrinsic weight of the lift support means 1 in the case of support means slackness, longer in the groove 21.5 and automatically centres the lift support means 1, after tightening thereof, again on the deflecting wheel 21.3. On the other hand, the maximum spacing of the tensile carriers 5 from the drive side is smaller, so that a more homogenous distribution of force in the drive ribs 3 occurs.

As similarly recognisable in Fig. 2 the flank width t4 of the guide rib 4 is also greater than the flank width t3 of the two drive ribs 3. If the lift support means on a wheel 20, 21 migrates outwardly by its maximum flank width t then it is returned to its position by the inclined flanks. Due to the greater flank width t4 the lift support means 1 is thus guided at its deflecting side over a wider region in transverse direction. This allows, in particular, also a more pronounced diagonal tension, since even a lift support means entering at greater inclination is still 'captured', due to its greater flank width, by the corresponding groove 21.5 of the deflecting wheel.

This is particularly advantageous, since, due to mounting tolerances with the deflecting wheels 21.2, 21.3 as well as the small spacing thereof from one another, a more pronounced diagonal tension can occur, which opposes the improved guidance at the deflecting side. In addition, greater tolerances can be accepted between the deflecting wheel 21.3 and the belt fixing point 14.2, since the wider and higher guide rib 4 allows a greater diagonal tension.

Partial compensation can be provided between drive wheel 20 and deflecting wheel 21.2 for such diagonal tension by deformation of the lift support means, so that the shorter and narrower drive ribs 3 run into the drive wheel 20 with smaller diagonal tension.

A guide rib 4 which extends over substantially the entire width w of the lift support means 1 and is thus approximately twice as wide as the two drive ribs 3 is associated with the two drive ribs 3. In order to further increase the depth of penetration the flank angle a4 of the guide rib 4 is formed, at a 80 , to be more acute than the flank angle a3 of the drive ribs 3.

Overall, the guide rib 4 thus has a significantly larger flank area f4 =4(t42 + h4Z) than the drive ribs 3 at f3 =4(t3Z + h3 2), which significantly improves the guidance at the deflecting side. On the other hand, the tensile carriers 5 are arranged near the drive side, wherein due to the flatter flank angle 0 the spacing from the drive side varies only a little. Since, in addition, two tensile carriers 5 are associated with each drive rib 3, friction forces can be transferred from the drive wheel 20 substantially by way of each flank drive of a drive rib 3 to an associated tensile carrier 5, which has the effect of a particularly homogenous distribution of force in the drive ribs.

As schematically indicated in Fig. 3, the flattened tip of the drive rib 3 has a width d3, which width d3 is the same width as or wider than the minimum spacing d20 of the two counter-flanks of the groove 20.1 in the drive wheel 20. The edges which are formed in these counter-flanks and at which the inclined counter-flanks go over into a rectangular groove in the groove base thereby do not contact the flanks of the drive ribs 3, so that this is protected against a corresponding notch effect. The same applies to the guide rib 4 and to the groove 21.5 associated therewith as is recognisable in Fig. 4.

On the other hand, the counter-flanks of adjacent grooves 20.1 of the drive wheel go over into one another by a radius R20 which is greater than a radius R3 by which mutually facing flanks of the adjacent drive ribs 3 go over into one another. The contact between the flanks of the drive ribs 3 and the counter-flanks of the grooves 20.1 thus takes place smoothly and without large notch effects.

The drive side can have at least in the regions of its wedge ribs 3, which come into friction couple with the flanks of the drive wheel 20, a coating (not illustrated) with a PA film.
Advantageously the entire drive side is coated in a continuous or discontinuous process, which simplifies manufacture. Alternatively to the coating, a vapour deposition and/or flocking can also be provided. The vapour deposition is, for example, a metal vapour deposition. The flocking is, for example, a flocking with short synthetic or natural fibres.
This vapour deposition or flocking can also extend over the entire drive side and be carried out in a continuous or discontinuous process. In principle, in the case of pairings of wedge ribs and grooves in which only the flanks of the wedge ribs bear against the grooves with friction coupling it is possible to provide only these flanks of the wedge ribs with a coating or vapour deposition and/or flocking, so that those regions between the rib flanks which are not in contact with the drive wheel 20 are uncoated. In addition, the possibility exists of providing the rib 4 with a coating reducing the coefficient of friction and/or noise.

As indicated in Figures 3, 4 by dashed lines, apart from the lift support means one or several further, preferably constructionally identical, lift support means are arranged and spaced from one another by a gap 23 which is sufficient to prevent mutual contact of the lift support means on the drive or deflecting wheels even when the lift support means deform. Through such a lift support means combination a desired width of narrow individual lift support means which are easy to handle can be mounted on site in simple and quick manner, which significantly simplifies production and stock-keeping, transport and mounting and demounting. Due to the construction with two drive ribs 3, with which four tensile carriers are associated, the total load-bearing force of the lift support means combination can be adapted in fine steps by addition of individual lift support means.
Through the narrow individual lift support means it can be avoided that a lift support means combination with n lift support means has to be reinforced by a further wide lift support means (n + 1) by a correspondingly large load-bearing force step and thus significantly over-dimensioned when the load-bearing force, which is made available by n lift support means, is only slightly less than the required total load-bearing force.

For mounting such a lift support means combination the lift support means 1 can be made, as shown in Figs. 5 and 6, from a pre-product 7. The pre-product 7 consists of two or more lift support means 1 with a one-piece base body 2. The pre-product 7 is partly divided between drive ribs 3 and/or guide ribs 4 so that lift support means remain connected by way of at least one thin base body web 17 before they are mounted in the lift system. According to the embodiment of Fig. 6, three lift support means 1 are connected together by way of two base body webs 17. The base body webs 17 can, as shown in Fig.
6, be mounted on the deflecting side of the lift support means 1 so that the drive side of the individual lift support means I is freely accessible even in the composite. In particular, the individual lift support means 1 in the composite can lie by their drive side in corresponding grooves of the drive wheel 20. In that case the base body webs 17 can also guarantee correct lateral spacing 23 of the lift support means 1 from one another on the drive wheel 20. For this purpose the lift support means 1 are connected, at lateral assembly spacings from one another, by way of the base body webs 17, which spacings substantially correspond with the lateral spacings 23 of the individual lift support means 1 on the drive wheel 20. After mounting has taken place the base body webs 17 can be torn, for example in that the base body webs 17 are slightly shorter than the lateral spacings 23 of the lift support means 1 on the drive wheel 20 and the base body webs 17 tear in controlled manner under the stress which arises. It is obviously also possible to provide the base body webs 17 on the drive side of the lift support means 1.

Alternatively, for mounting such a lift support means composite it is also possible, as shown in Fig. 7, for several lift support means 1 to be connected together by way of an assembly band 30. The assembly band 30 surrounds the lift support means 1 at least partly. For example two, three, four, six or eight lift support means form a composite which is partly surrounded by assembly band 30 and which, rolled up as a loop, can be transported in simple manner and without problems into the lift shaft 12. The assembly band 30 is, for example, fixed reversibly or irreversibly by material locking to the lift support means 1. Advantageously, it is a thin plastics material band with an adhesive layer at one side. The plastics material band is connected with the lift support means 1 by way of the adhesive layer. In the case of reversible material locking the adhesive band can be pulled off the lift support means 1 and the detached lift support means thus separated.
Advantageously, the assembly band 30 is mounted on the deflecting side of the lift support means so that the drive side of the individual lift support means 1 is freely accessible even in the composite. In particular, the individual lift support means 1 in the combination can lie by way of their drive side in corresponding grooves of the drive wheel 20.
In that case the assembly band 30 can also guarantee the correct lateral spacing 23 of the lift support means from one another on the drive wheel 20. For this purpose, the lift support means 1 are connected at lateral assembly spacings from one another with the assembly band 30, which spacings substantially correspond with the lateral spacings 23 of the individual lift support means 1 on the drive wheel 20. It is obviously also possible to mount the assembly band 30 on the drive side of the lift support means 1.

Claims

1. Lift support means for a lift system, with a base body, a drive side with at least one drive rib, a deflecting side, which is opposite the drive side, with at least one guide rib and a tensile carrier arrangement arranged in the base body, characterised in that at least one, preferably each, guide rib has a larger flank height than at least one, preferably each, drive rib and/or that at least one, preferably each, guide rib has a greater flank width than at least one, preferably each, drive rib and/or that the ratio of the flank height of at least one, preferably each, guide rib to the width (w) of the lift support means is at least 0.4 and/or that the flank angle of at least one, preferably each, drive rib is greater than the flank angle of at least one, preferably each, guide rib and/or that a respective guide rib is associated with at most three drive ribs.

2. Lift support means according to claim 1, characterised in that the ratio of the flank height of at least one, preferably each, guide rib to the flank height of at least one, preferably each, drive rib is at least 1.5.

3. Lift support means according to either one of the preceding claims, characterised in that the ratio of the flank width of at least one, preferably each, guide rib to the flank width of at least one, preferably each, drive rib is at least 1.5.

4. Lift support means according to any one of the preceding claims, characterised in that the ratio of the width (w) of the lift support means to the height of the lift support means is at most 0.95.

5. Lift support means according to any one of the preceding claims, characterised in that the drive side has two or three drive ribs and the deflecting side has one guide rib.

6. Lift support means according to any one of the preceding claims, characterised in that at least one, preferably each, drive rib is formed as a wedge rib with a flank angle between 60° and 120°.

7. Lift support means according to any one of the preceding claims, characterised in that at least one, preferably each, guide rib is formed as a wedge rib with a flank angle (.alpha.) between 60° and 100°.

8. Lift support means according to any one of the preceding claims, characterised in that the minimum width of at least one, preferably each, drive rib is of the same size as or greater than the minimum width of an associated groove of a drive wheel of the lift system.

9. Lift support means according to any one of the preceding claims, characterised in that a groove with a radius is formed between at least two, preferably between all, adjacent drive ribs, wherein the ratio of this radius to a radius formed on an associated rib of a drive wheel of the lift system is less than 1.

10. Lift support means according to any one of the preceding claims, characterised in that the base body of at least one, preferably each, drive rib and/or at least one, preferably each, guide rib is or are of unitary or multi-part construction from an elastomer, particularly polyurethane (PU), polychloroprene (CR), natural rubber and/or ethylene-propylene-diene rubber (EPVM).

11. Lift support means according to any one of the preceding claims, characterised in that the drive side and/or the deflecting side has or have a covering or coating of which the coefficient of friction, hardness and/or abrasion resistance differs or differ from the base body.

12. Lift support means according to any one of the preceding claims, characterised in that a group with at least one, preferably all, drive ribs and a group with at least one, preferably all, guide ribs are of multi-part construction, wherein the group of drive ribs has a lesser hardness, particularly a lesser Shore hardness, and/or a greater coefficient of friction than the group of guide ribs.

13. Lift support means according to any one of the preceding claims, characterised in that at least one tensile carrier , preferably two tensile carriers, is or are associated with at least one, preferably each, drive rib.

14. Lift support means according to any one of the preceding claims, characterised in that the diameter of the tensile carriers is in the region of 1.5 to 4 millimetres.

15. Lift support means according to any one of the preceding claims, characterised in that the spacing of the tensile carrier arrangement from the drive side is less than from the deflecting side.

16. Lift support means according to any one of the preceding claims, characterised in that at least one, preferably each, tensile carrier of the tensile carrier arrangement comprises a double-ply core strand with a core wire and two wire layers wrapped around this and single-ply outer strands, which are arranged around the core strand, with a core wire and a wire layer wrapped around this.

17. Lift support means according to claim 16, characterised in that the two wire layers of the core strand have the same angle of wrap, the one wire layer of the outer strands is wrapped opposite to the wrap direction of the core strand, and the outer strands are wrapped opposite to the wrap direction of their own wire layer around the core strand.

18. Lift system with a cage, a lift support means connected therewith according to any one of the preceding claims and a drive wheel which co-operates in friction-coupling manner with the drive side of the lift support means in order to move the cage.

19. Lift system according to claim 18, characterised in that several lift support means according to any one of the preceding claims 1 to 17 are provided for moving the cage, wherein each lift support means at least partly loops around the drive wheel by its drive side and at least one deflecting wheel by its deflecting side, wherein at least one groove on the drive wheel circumference is associated with each drive rib of each lift support means and wherein at least one groove on the at least one deflecting wheel circumference is associated with each guide rib of each lift support means.

20. Lift system according to claim 19, characterised in that two lift support means are spaced apart by a gap.

21. Lift system according to claim 20, characterised in that the gap is at least 3% of the width of a lift support means.

22. Method of mounting a lift support means in a lift system according to any one of claims 18 to 20, characterised in that a pre-product consisting of two or more lift support means with integral base body is partly divided between drive ribs and/or guide ribs and that the lift support means remain connected by way of at least one thin base body web before they are mounted in the lift system.

23. Method of mounting a lift support means in a lift system according to any one of claims 18 to 20, characterised in that at least two lift support means are permanently or detachably connected with an assembly band before they are mounted in the lift system.