Patent Application
20070017749
The present invention relates to an elevator installation with a support means end connection and a support means and to a method of fastening an end of a support means in an elevator installation.
An elevator installation usually consists of a car and a counterweight, which are moved in opposite sense in an elevator shaft. The car and the counterweight are connected together and supported by way of support means. An end of the support means is fastened by a support means end connection to the car or to the counterweight or in the elevator shaft. The location of the fastening is oriented towards the mode of construction of the elevator installation. The support means end connection accordingly has to transmit the force, which acts in the support means, to the car or the counterweight or to the elevator shaft. It has to be designed in such a manner that it can transmit a required supporting force of the support means.
Currently, use is made of multiple support means in which several cables or cable strands are combined to form a support means. The support means consists of two cables or cable strands extending at a spacing from one another and consists of a common cable casing. The cables or cable strands then substantially serve for transmission of supporting and movement forces and the cable casing protects the cables or cable strands from external influences and it improves the transmission capability of drive forces which are introduced by drive motors into the support means.
In the case of known constructions the support means is fixed in a wedge pocket by means of a wedge. A first wedge pocket surface of the wedge pocket is, in this connection, formed in correspondence with a tension direction of the support means. This first wedge pocket surface is arranged in the departure direction of the support means. A second wedge pocket surface of the wedge pocket is formed to be displaced in correspondence with a wedge angle of the wedge relative to the first wedge pocket surface. The support means is now arranged between wedge pocket surfaces and wedge and draws the wedge into the wedge pocket by virtue of the friction conditions, whereby the support means is fixed. Obviously, a supporting run of the support means thus slides, during build-up of the supporting force, along the first wedge pocket surface, whereagainst a loose run of the support means experiences only a slight stretching movement in its position relative to the second wedge pocket surface. In the following description the first wedge pocket surface is termed a wedge pocket sliding surface and the second wedge pocket surface is termed a wedge pocket adhesion surface.
A support means end connection for a support means provided with an elastomeric sheathing is shown in patent application publication WO 00/40497, in which a wedge pocket angle is formed in such a manner that the pressure loading, which is produced by the wedge in the case of a given length and width, of the support means produces lower values than the permissible pressure loading of the elastomeric sheathing.
A disadvantage of this construction is that on the one hand the force introduction from the support means end connection to the cable casing of the support means is released solely by the geometry of the wedge, but that the transmission of force from the casing to the actual, supporting cable or cable strands is not released. The coefficients of friction within a cable strand or a cable are, in many cases, less than from the cable casing to the connecting parts. This has the consequence that a cable strand or cable is held only insufficiently within the cable casing, whereby the permissible supporting force of the support means is limited.
An object of the present invention is to provide an optimized support means end connection which maximizes the supporting force of the support means and securely transmits as well as fulfils the following points:
The present invention relates to an elevator installation with a support means end connection and a support means and to a method of fastening a support means in an elevator installation.
The elevator installation consists of a car and a counterweight, which are moved in opposite sense in an elevator shaft. The car and the counterweight are connected together and supported by way of support means. The support means consists of at least one cable or a cable strand and a cable casing which surrounds the cable or the cable strand. The cables or cable strands are made of synthetic fibers or of metallic material, preferably steel wires. Several of these support means together form a support means strand.
An end of the support means is fastened by a support means end connection to the car or the counterweight or in the elevator shaft. The location of the fastening is oriented towards the mode of construction of the elevator installation. The support means is held in the support means end connection by means of a wedge which fixes the support means in a wedge pocket. The part of the support means end connection containing the wedge pocket is formed by a wedge housing. The support means has a loose run at its unloaded end. This loose run runs on a wedge pocket adhesion surface, which is inclined relative to the vertical direction, and is there pressed onto the wedge pocket adhesion surface by the wedge by means of its wedge adhesion surface. The support means is further led around a wedge curve and extends between an opposite wedge sliding surface and the wedge pocket sliding surface, which is oriented substantially vertically or in the tension direction of the support means, to the supporting run of the support means. The tensile force of the support means is thus transmitted by the pressing along the wedge surface and wedge pocket surface and the looping around of the wedge. The support means is held in the wedge pocket by means of the wedge and the support means extends between wedge and wedge pocket.
An acceptable tensile force of the support means is in that case decisively influenced by the design of the contacting surfaces in the form of the force flow from the support means end connection to the casing and the cables or the cable strands.
According to the present invention the cable casing substantially consists of thermoplastic plastics material or elastomer and a region of the wedge or a region of the wedge pocket is provided with a longitudinal wedge groove and/or a region of the wedge or the wedge pocket or of the cable casing is provided in the region of the support means end connection with measures reducing the coefficient of friction.
The longitudinal wedge groove is arranged substantially in a region of the wedge or the wedge pocket, which in the assembled state of the support means end connection stands in direct contact with the support means. The longitudinal wedge groove provided in the corresponding wedge region or in the wedge pocket region increases the normal force, which acts on the support means, in such a manner that the cable or the cable strand is pressed by the longitudinal wedge groove together with the cable casing and sliding of the cables or the cable strands within the cable casing is prevented. The size of the longitudinal wedge groove can in that case be formed in correspondence with the requirements. The shape of the longitudinal wedge groove follows substantially analogously to the design of wedge grooves of a drive pulley. In particular, a longitudinal wedge groove angle can be selected in conformity with the support means construction.
The use of measures, which reduce the coefficient of friction, in the region of the wedge or the wedge pocket or of the cable casing have the effect in the region of the support means end connection that a retightening or further sliding of the support means in the support means end connection can take place selectively. Measures reducing-the coefficient of friction can be slide means which are coated on regions of the wedge, the wedge pocket and/or the support means or can be coatings such as, for example, “Teflon” (a trademark of E. I. du Pont de Nemours and Company) coatings. In addition, production of the entire wedge from a material capable of sliding is possible.
Overall, the solutions according to the present invention make it possible that the introduction of force from the cable casing into the supporting cables or cable strands is ensured, the overall stress in the support means is optimized and a long service life of the support means can be guaranteed.
An advantageous embodiment proposes that a wedge adhesion surface or wedge pocket adhesion surface closer to the loose run of the support means is provided with a longitudinal wedge groove. This is particularly advantageous, since in the case of loading of the support means the pressing force, which arises through drawing-in of the wedge, of the wedge onto the wedge pocket increases to a particular extent the possible restraining force in the support means on the side of the wedge pocket adhesion surface and presses together the cable or the cable strand amongst one another and together with the cable casing, since this surface has longitudinal wedge grooves, whereby the maximum possible support means force is increased as a consequence of a deflection around the wedge curve. The force is in that case continuously increased, since the force increase on the side of the loose run is built up further. In addition, the wedge groove can be formed over the curve of the wedge.
In a further embodiment the wedge pocket adhesion surface and/or wedge adhesion surface disposed closer to the loose run of the support means is or are provided with a surface roughness increased relative to the rest of the surface of the wedge pocket or the wedge, or these surfaces are provided with transverse flutes or transverse grooves. This is an advantage, since in the case of loading of the support means the pressing force, which arises through drawing-in of the wedge, of the wedge on the wedge pocket increases to particular extent the possible supporting force in the support means on the side of the wedge pocket adhesion surface or wedge adhesion surface, since this surface has an increased roughness or has transverse flutes or transverse grooves, whereby the maximum possible support means force increases as a consequence of the deflection around the wedge. The force is in that case continuously increased, since the initial force on the side of the loose run is built up. The loose run of the support cable is securely held and a high supporting force can be transmitted. Moreover, the wedge pocket sliding surface on which the support means slides mainly during the loading process is formed with an appropriately lesser degree of roughness, which counteracts damage of the support means, since the surface thereof is not harmed. An economic support means end connection with a high load-bearing capability can be provided by means of this invention.
Alternatively or additionally thereto a wedge sliding surface and/or wedge pocket sliding surface disposed closer to the supporting run of the support means is or are provided with measures reducing the coefficient of friction. Measures reducing the coefficient of friction are, for example, a slip spray, an intermediate layer of synthetic material with sliding capability or a surface coating. This enables sliding of the support means during the loading process, which counteracts damage of the support means on the side of the support means end connection loaded in tension, since the surface thereof is not harmed and loading in the casing and in the cable or cable strand takes place uniformly. An economic support means end connection with a high load-bearing capability can be provided by means of this construction.
In another embodiment a wedge sliding surface or wedge pocket sliding surface disposed closer to the supporting run of the support means has a first and a second surface region, wherein the first surface region is arranged at the zone of departure of the support means from the support means end fastening and this first surface region has a greater wedge angle than the second surface region, which adjoins the first region and which forms the transition to a further surface region or to the upper end of the wedge pocket surface or the wedge surface. Advantageously, the transitions between the individual surface regions are formed to be continuous. In an optimized embodiment the surface regions are formed in such a manner that a transition from the first to the nth surface region extends continuously, i.e. in correspondence with a transition contour, wherein the nth surface region determines the main pressing region.
The solutions produce a progressive decrease in the pressing of the support means over a definable outlet path of the support means from the support means end connection. Advantageously, this surface region extends over less than 50% of the entire wedge sliding surface or wedge pocket sliding surface. The support means does not experience any abrupt transitions in loading. This increases the service life of the support system.
In addition, the ends, which are at the traction cable side, of the wedge sliding surface and the wedge pocket sliding surface are advantageously provided with radii or formed to be curved. The use of a radius or of curved transitions has the effect that pressing of the support means is built up gradually. No abrupt stress changes are imposed, and sliding of the support means in the highly loaded tension zone of the support means is made possible without damage of the support means. Alternatively, the wedge is constructed to be resilient at its wedge-shaped end. This leads to a slow reduction in the pressing force of the support means. In addition, the support means thereby does not experience any abrupt transitions in loading. This increases the service life of the support system.
In a further embodiment the wedge adhesion surface of the loose run is connected with the wedge sliding surface of the supporting run at the upper end of the wedge by means of the wedge curve and this wedge curve tangentially adjoins the wedge surfaces at the two sides, wherein in the embodiment according to the invention the radius of curvature of the curve is smaller towards the wedge adhesion surface of the loose run. A smaller radius of curvature produces a greater curvature of the support means and thereby indicates greater deformations in the support means itself. In countermove, the tension force acting in the support means simultaneously reduces towards the loose run in correspondence with the looping law of Eytelwein, which produces decreasing tensile stresses in the support means. Increasing deforming stresses are thus opposed by decreasing tensile stresses and in the ideal case compensate for one another. This produces an optimization of the overall stress in the support means and prolongs the service life of the support means overall.
In a further embodiment the wedge consists of a material soft by comparison with steel—a material with a low modulus of elasticity—preferably aluminium, synthetic material or a composite of metal and synthetic material. The use of a soft material produces an evening out of pressure points and correspondingly preserves the support means. In the case of use of a metal and synthetic material composite the possibility is additionally offered of realizing special sliding characteristics. With use of materials with a low modulus of elasticity the jump in stiffness between the wedge or the housing and the support means can be reduced, which results in an enhanced supporting force.
Additionally, the wedge pocket surface can be formed by means of an insert plate. Thus, a basic construction of a support means end connection can be provided, which depending on a construction of the support means can be completed by an appropriate insert plate or the insert plate can be formed, in accordance with requirements, with wedge grooves, transverse flutes, transverse grooves or to be sliding.
An advantageous support means end connection of the illustrated kind results in the case of use of a support means in the form of a multiple cable. The support means then consists of at least two cables or cable strands extending at a spacing from one another and the cable casing encloses the cable or cable strand composite and separates the individual cables or cable strands from one another. The support means in that case has a longitudinal structuring, preferably longitudinal grooves. The longitudinal structuring can be an image of an individual cable or cable strand, or a group of cables or cable strands can be fitted in a longitudinal structure. The cable casing can in that case be specially profiled according to the respective desired groove structure. An applicable construction of the wedge pocket or of the wedge is preferably oriented to the kind of longitudinal structuring. This enables provision of a particularly economic support means end connection. With particular advantage an end of the illustrated support means or of the multiple cable is divided up into the individual cable runs or cable strand runs and each cable run or cable strand run is clamped by means of a respectively associated longitudinal wedge groove of the wedge or of the wedge pocket. This allows a particularly good force introduction of the support means force into the support means end connection. The division of the support means into individual cable runs or individual cable strand runs can be carried out manually, for example by cutting or tearing, or it can be constrainedly effected by means of a center web which arises through formation of the longitudinal grooves on the wedge surface or wedge pocket surface.
In a preferred support means end connection the cable or the cable strand is glued, fused or mechanically connected with the cable casing in the region of the support means end connection. The gluing, fusing or mechanical connection of the cable or the cable strands with one another and with the cable casing has the effect that no relative movement within the support means can take place. A gluing is carried out, for example, in that a predefined quantity of liquid adhesive is dripped or cast at the end of the support means in the individual cables or cable strands. The adhesive draws in between cable or cable strand and casing, due to gravitational force and capillary action, and permanently connects these parts.
The above, as well as other, advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:
a a fragmentary cross-sectional view of the support means end fastening with longitudinal wedge grooves, which are arranged at the wedge pocket, and the belt-shaped support means divided up into individual strands;
c is a fragmentary cross-sectional view of the support means end fastening with longitudinal wedge grooves, which are arranged at the wedge pocket, and the belt-shaped support means with a fused casing;
a is a fragmentary cross-sectional view of the support means end fastening with longitudinal wedge grooves, which are arranged at the wedge pocket, and the support means divided up into individual strands;
An elevator installation consists, as illustrated in
In
The cable 6a and the cable strand 6a′ run are one of glued, fused or mechanically connected with the cable casing 6b, 6b′ , respectively, in the region of the support means end connection 9.
A tolerable tensile force of the support means is in that case decisively influenced by the design of the contacting surfaces in the form of force flow from the support means end connection 9 to the casing of the cable 6 or of the cable strands.
In the illustrated example the wedge 12 is connected with an attachment point by means of a tie rod 17, 18. Moreover, the wedge 12 is secured, against slipping out, by way of means 19 securing against loss and a split-pin 20 and the loose run 7 is fixed to the supporting run 8 by means of plastic ties 23.
a, 8c, 9 and 9a show advantageous alternative embodiments of the wedge pocket surface and the wedge surface.
In
a shows a similar solution in which, however, the wedge pocket surface 15a, 16a of the housing 10a is provided with longitudinal wedge grooves and the wedge surface 13.2a, 13.3a is formed to be substantially smooth. The longitudinal wedge groove is advantageously arranged at the wedge pocket adhesion surface 15a. An optimum adhesion of the support means in the case of the loose run 7 of the support means 6′ thereby results. With particular advantage, in the case of this solution, as illustrated in
In
a shows a similar solution in which, however, the wedge pocket surface 15b, 16b of the housing 1Ob is provided with longitudinal wedge grooves and the wedge surface 13.2b, 13.3b is formed to be substantially smooth. The longitudinal wedge groove is advantageously arranged at the wedge pocket surface 15b. An optimum adhesion of the support means in the case of the loose run 7 of the support means 6 thereby results.
The wedge 12 used in
The illustrated examples are examples of various embodiments of the present invention. The different embodiments can be combined. Thus, the insert part or plate 25 illustrated in
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
| Number | Date | Country | Kind |
|---|---|---|---|
| 05106751.0 | Jul 2005 | EP | regional |
