Patent Application
20070034454
The present invention relates to a support means end connection for fastening an end of a support means in an elevator installation, an elevator installation with support means end connection and method for 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 means of a support means. An end of the support means is in that case fastened by a support means end connection to the car or the counterweight or in the elevator shaft. 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 securely transmit a required supporting force of the support means. Currently, increasing use is made of support means in which several cables or cable strands are combined to form a support means. The support means in that case consists of at least two cables or cable strands extending at a spacing from one another and 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 improves the transmission capability of drive forces introduced into the support means by drive engines.
In known embodiments of support means end connections the support means is fixed in a wedge pocket by means of a wedge.
A support means end connection for a support means provided with an elastomeric sheathing is known from patent publication WO 00/40497. The elastomeric sheathing sheaths and/or separates the individual cables or cable strands and it defines a force transmission surface relative to the drive engine. In this support means end connection a wedge angle shall be selected in such a manner that the pressure loading, which is produced by the wedge for a given length and width, on the support means produces lower values than the permissible pressure loading of the elastomeric sheathing.
In this construction a proposal is indeed made for force introduction from the support means end connection to the cable casing of the support means, but the transmission of the force from the casing to the actual supporting cable or cable strands is not solved. The coefficients of friction within a cable strand or a cable are in many cases smaller than from the cable casing to the connecting parts. This has the consequence that a cable strand or a cable is held only insufficiently within the cable casing, whereby the permissible load-bearing force of the support means is limited.
An object of the present invention is to provide an optimized support means end connection which maximally and reliably transmits the load-bearing force of the support means. This has the advantage that an economic elevator installation can be provided. The force introduction as far as to the supporting cables or cable strands can be ensured, the overall stresses in the support means can be optimized and a long service life of the support means can be achieved. Moreover, the support means can be constructed to be resistant to increased environmental temperatures and it can be mounted in simple manner.
The present invention relates to a support means end connection for fastening a support means end in an elevator installation 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 the support means. The support means consists of at least one cable or cable strand and a cable casing which encloses the cable or the cable strand. The cable or cable strand is produced from synthetic fibers, which can be impregnated, or from metallic material, preferably steel wires. Several of these support means together form a support means stretch.
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 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 up on a wedge pocket adhesion surface inclined relative to the vertical direction and is there pressed by the wedge, by means of its wedge adhesion surface, onto the wedge pocket adhesion surface. The support means is further guided around a wedge curve and runs between an opposite wedge slide surface and the wedge pocket slide surface, which is oriented substantially vertically or in tension direction of the support means, to the supporting run of the support means. The support means loops around the wedge. The tension force of the support means is thus applied by pressing along the wedge and the wedge-pocket surfaces and the looping around of the wedge. The support means is held by means of the wedge in the wedge pocket and the support means extends between wedge and wedge pocket.
A tolerable tension force of the support means is in that case decisively influenced by the form of the mutually contacting surfaces and the kind of the force flow from the support means end connection to the casing and the cables or cable strands.
According to the present invention the cable or the cable strand is glued to, fused together with or mechanically connected with the cable casing in the region of the support means end connection. The gluing, fusing together or mechanical connection of the cable or 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 friction force which is transmitted from the surfaces of the wedge pocket or the wedge to the cable casing is passed on directly in the load-bearing core of the support means to the cables or the cable strands. The tolerable tension force in the support means is increased.
A gluing takes place, for example, in that a predefined quantity of low-viscosity liquid adhesive is dripped or cast into the individual cables or cable strands at the end of the support means. The adhesive soaks in, due to gravitational force and capillary action, between cable or cable strand and casing and permanently connects these parts. In the case of impregnated cables or cable strands the adhesive also bonds with, in particular, the impregnating medium, for example polyurethane. This gluing forms an economic method for producing a cable means end fastening.
A fusing together can be carried out in that a punctiform fusing together of the casing material with the cables or the cable strands is effected by way of a heat source from outside or by way of an ultrasound source. Particularly advantageous is fusing together with use of like materials, such as, for example, polyurethane, for the cable strand impregnation and for the casing.
A mechanical connection is carried out in that, for example, a pin is introduced into the end of the cable or the cable strand, whereby the local pressing forces increase. The use of a wood screw or a screw-in pin, which runs out to a point, screwed into an end of the support means or the cable or cable strands thereof is particularly advantageous.
This embodiment is particularly optimal in costs and the wood screw produces an increase in the tolerable take-off force in a double respect. On the one hand the local pressing force is increased and on the other hand the wood screw head is exposed at the housing or the wedge in the case of possible slipping. This increases the tolerable take-off force.
A further mechanical connection can also be achieved by knotting or braiding the ends of the cable strands or cables of the support means. This connection it is preferably used for cables or cable strand ends which are thin and correspondingly soft in bending.
The illustrated solutions are particularly advantageous in the case of cables or cable strands of synthetic fibers. Synthetic fibers usually have more favorable adhesion characteristics. A tolerable take-off force can be increased with use of the illustrated invention. The cable casing preferably substantially consists of thermoplastic synthetic material or elastomer.
An advantageous embodiment proposes that a wedge adhesion surface or wedge pocket adhesion surface, which lies closer to the loose run of the support means, is provided with a longitudinal wedge flute or 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 on the wedge pocket increases to particular extent the possible retaining force in the support means on the side of the wedge pocket adhesion surface and presses the cable or the cable strand together and with the cable casing—since this surface has longitudinal wedge flutes—whereby the maximum possible support means force increases as a consequence of the deflection around the wedge curve. The force is in that case continuously increased, since the force increase is further built up on the side of the loose run. In addition, the wedge flute can be formed over the curve of the wedge.
In a further embodiment the wedge pocket adhesion surface and/or wedge adhesion surface, which lies closer to the loose run of the support means, is 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 advantageous, since in the case of loading of the support means the pressing force, which arises through the drawing-in of the wedge, of the wedge on the wedge pocket increases to particular extent the possible load-bearing 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 transverse flutes or transverse grooves—whereby the maximum possible support means force increases as a consequence of the deflection around the wedge curve. 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 means is securely held and a high load-bearing force can be transmitted. In addition, the wedge pocket slide surface on which the support means slides during the loading process is formed with a correspondingly lesser roughness, which counteracts damage of the support means, since the surface thereof is not harmed. An economic support means end connection with high support load can be provided by means of this invention.
Alternatively or additionally a wedge slide surface and/or wedge pocket slide surface, which lies closer to the supporting run of the support means, is provided with measures reducing the coefficient of friction. Measures reducing the coefficient of friction are, for example, a slide spray, an intermediate layer of synthetic material capable of sliding 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 this surface is not harmed and a loading in the casing and in the cable or cable strand takes place uniformly. An economic support means end connection with high support load can be provided by means of this embodiment.
In another form of embodiment a wedge slide surface or wedge pocket slide surface, which lies closer to the supporting run of the support means, has a first and a second surface region, wherein the first surface region is arranged in the zone of exit of the support means from the support means end fastening and this first surface region has a larger wedge angle than the second surface region, which adjoins the first surface 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. The first surface region is increasingly spaced from the corresponding counter surface in direction towards the wedge end at the exit side. 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 run continuously, i.e. in correspondence with a transition contour, wherein the nth surface region determines the main pressing region.
These solutions effect a continuous decrease in the pressing force of the support means over a definable exit stretch of the support means from the support means end connection. Advantageously, this surface region extends over less than 50% of the entire wedge slide surface or wedge pocket slide surface. The support means does not experience any abrupt load transitions. This increases the service life of the support system.
Moreover, the ends, which are at the tension cable side, of the wedge slide surface and the wedge pocket slide surface are advantageously provided with radii or formed to be curved. The use of a radius or curved transitions has the effect that a pressing force of the support means is built up gradually. No abrupt stress changes are forced and a 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 formed 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 load transitions. 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 slide 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 which are at both 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 deformation stresses in the support means itself. Conversely, at the same time the tension force acting in the support means reduces towards the loose run in correspondence with the looping law of Eytelwein, which causes decreasing tension stresses in the support means. Increasing deformation stresses thus oppose decreasing tension 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.
An advantageous support means end connection of the illustrated kind arises through use of a support means in the form of a multiple cable. The support means in that case 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 then has a longitudinal structure, preferably longitudinal flutes or grooves.
The longitudinal structure can be an image of an individual cable or cable strand or a group of cables or cable strands can be fitted into a longitudinal structure. The cable casing can in that case be specially profiled according to the respectively desired groove structure. A possible construction of the cable pocket or the cable is preferably oriented towards the kind of longitudinal structure. This enables provision of a particularly economic support means end connection.
Advantageously, each cable or cable strand run is clamped by means of an associated longitudinal wedge groove of the wedge or wedge pocket.
This allows a particularly good force introduction of the support means force into the support means end connection.
In addition, an end of the illustrated support means or the multiple cable is divided up into individual cable or cable strand runs and each cable or cable strand run is clamped by means of an associated longitudinal wedge flute of the wedge or wedge pocket. The separation of the support means into individual cable or cable strand runs can be carried out manually, for example by cutting or tearing, or it can be carried out forcibly by a center web which arises through the formation of the longitudinal grooves on the wedge surface or wedge pocket surface.
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 illustrates a gluing process. A defined quantity of liquid adhesive 26 is dripped into an end of the support means 6. The cable 6a or the cable strands 6c draws or draw in the liquid adhesive 26 substantially through capillary action. The dripping in is repeated until a predetermined quantity of the liquid adhesive is introduced. This quantity is usually determined experimentally in a model support means. Advantageously the adhesive quantity is determined in such a manner that a penetration length L results which embraces the region of the wedge adhesive surface 13.2, the region of the wedge curve 14 and a part of the wedge slide surface 13.3.
a,
8
c,
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 10b 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
Alternatively or additionally the wedge pocket slide surface 16 correspondingly has a first surface region 16.1 and a second surface region 16.2. In addition, in this connection the first surface region 16.1 is constructed in such a manner that it is spaced from the corresponding wedge slide surface in a direction towards the wedge end at the exit side.
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 |
|---|---|---|---|
| 05106754.4 | Jul 2005 | EP | regional |
