EP1879825B1 - Device for stretching compensation in lift cables - Google Patents

Abstract

The invention relates to a device for stretching compensation in lift cables, arranged within a lift unit, with a lift shaft, a cabin (1) (FIGS. 1 and 2), a counter-weight (7) (FIGS. 1 and 2), at least one lift cable (3) (image 1), said cabin and said counter-weight on the pulley (4) (image 1 and 2) and a cable (9) (FIGS. 1 and 2) connected to the underside of the cabin and the counter-weight (FIG. 2) running around the freely-rotating pulley (10) (FIGS. 1 and 2) in the lift shaft. According to the invention, the device comprises a drive, mechanically connected to the end of at least one cable rod (27) (FIG. 4) on the underside of the cabin (11) (FIG. 2) and passing through pressure springs applied to the cabin cable section and a sensor (34) on the spring (12) (FIGS. 1 and 2), which serves to trigger the drive (16) (FIGS. 1, 2, 3 and 4). Two solutions to achieve automatic load compensation on a lift into which a load is charged are given.

Description

The present invention relates to an elevator system with a device for the extension compensation of elevator cables according to the preamble of claim 1. Such an elevator system is eg off US-A-6223862 known.

The aim of the invention is to realize an elevator system, which is always balanced when changing the load in the cabin. This problem is solved by an elevator installation according to the subject-matter of independent claim 1.

In the patent application, a rope was considered. However, the elevator has several ropes with a total load - (F ₁ -F ₂ -F ₃ -F ₄ ), which is evenly distributed on the different ropes (F on a rope - applies to 5 ropes $$\mathrm{F}=\frac{{\mathrm{<figure-callout\; id="1"\; label="F"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">F</figure-callout>}}_1}{5}O\frac{{\mathrm{<figure-callout\; id="2"\; label="F"\; filenames="imgf0001.png"\; state="\{\{state\}\}">F</figure-callout>}}_2}{5}O\frac{{\mathrm{<figure-callout\; id="3"\; label="F"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">F</figure-callout>}}_3}{5}O\frac{F_4}{5}$$

• Figur 1, schematisch, eine Aufzugsanlage in einer ersten Lösung der Realisierung,
• Figur 2, schematisch, eine Aufzugsanlage in einer zweiten Lösung der Realisierung,
• Figur 3, eine Vorrichtung für den Ausgleich von Seilverlängerüngen,
• Figur 4, einen Querschnitt Ebenen III-III aus Figur 3
• Figur 5 eine Aufzugsanlage in einer dritten Lösung der Realisierung und
• Figur 6 die Einzelheit C aus Figur 5.

F ₁ refers to the force on the spring 12 - F ₂ refers to the force on the spring 13 - F ₃ refers to the force on the spring 14 - F ₄ refers to the force on the plate 15 (FIG. Figure 4 ).
The features and the details of the device according to the invention will become apparent from the following description of a preferred embodiment, which is illustrated in the accompanying drawings. Show it

• FIG. 1 , schematically, an elevator installation in a first solution of the realization,
• FIG. 2 , schematically, an elevator installation in a second solution of the realization,
• FIG. 3 , a device for the compensation of rope extensions,
• FIG. 4 , a cross-section levels III-III FIG. 3
• FIG. 5 an elevator installation in a third solution of the realization and
• FIG. 6 the detail C off FIG. 5 ,

In FIG. 1 1, the entirety of an elevator installation is shown which, according to a known manner, comprises a car 1 suspended in position 2 on at least one cable 3, which is wound around a traction sheave 4 in order to move inwards Position 6 to be connected to a counterweight 7, whose other end is connected in position 8 with at least one cable 9, which is deflected by a disc 10 to be connected in position 11 at the bottom of the car 1.

According to the invention, a spring 12 is inserted in position 2, a spring 13 in position 6 and a spring 14 in position 8, while in position 11 a device 15 for the adjustment of the cable length is provided, which will be explained in more detail here.
Is according to the invention F ₁ as a force on the ropes 3 to the cabin, F ₂ as a force on the ropes on the counterweight, F ₃ as a force on the cable section between the lower disc and the counterweight and F ₄ as a force on the cable section between disc and floor of the cabin, according to the invention the following relationships apply:

The first solution ( FIG. 1 ) of the implementation does not give the load balance of the load that loads the cabin, but is exemplary to have the first solution.

The total weight of the empty car is taken into account equal to Q (nominal capacity of the car) and according to the weight of the counterweight

Solution 2 - Figure 2 from the realization

The springs M ₁₂ and M _13, which will be the same and with constant rigidity, are arranged as shown in the drawing ( FIG. 2 ) and with a load equal to zero, until a load 3Q (see deflection) is reached. The spring M ₁₄ will also be of constant rigidity, which will be equal to half of the springs M ₁₂ and M ₁₃ . $${\mathrm{K}}_{\mathrm{M}\mathrm{14}}\mathrm{=}{\mathrm{½\; K}}_{\mathrm{M}\mathrm{12}}\mathrm{=}{\mathrm{½\; K}}_{\mathrm{M}\mathrm{13}}\mathrm{,}$$

For the positioning and the load on the springs M ₁₂ and M ₁₃ , the cables are tensioned by acting on the nuts of their tension rods until the deflection of the springs themselves corresponds to the size corresponding to the load (3Q with δ = 0)
(3Q is the load on springs M ₁₂ and M ₁₃ )

For the adjustment of the spring M ₁₄ , the procedure is such that with (8 = 0) (empty cabin without load), the deflection of the spring M _{14 is} equal to 0 (zero) (but must rest on the nuts and locknuts).

Solution 3 - Figure 5 and Figure 6 of the realization

• In die Kabine wird die Last Q geladen und unter Einwirkung auf die Muttern der Zugstäbe der Seile wird an der Feder M₁₂ die Last 4Q (siehe Durchbiegung) und an der Feder M₁₃ die Last 3Q (siehe die Durchbiegung). Dies kann erzielt werden, indem auf die Feder M₁₄ über Mutter und Gegenmutter 37 und den Anschlag 36 (Figur 6) gewirkt wird, die einstellbar sind.

The spring M ₁₂ must always have the same stiffness of the spring M ₁₃ and the spring M ₁₄ will have a rigidity equal to half of the springs M ₁₂ and M ₁₃ . Hence K _M14 = ½ K _M12 = ½ K _M13 .
Everything was in place for the positioning FIG. 5 and FIG. 6 and for their adjustment we proceeded as follows:

• The load Q is loaded into the cab and, acting on the nuts of the tension rods of the ropes, the load 4Q (see deflection) on the spring M ₁₂ and the load 3Q on the spring M ₁₃ (see the deflection). This can be achieved by acting on the spring M ₁₄ via nut and lock nut 37 and the stopper 36 (FIG. FIG. 6 ), which are adjustable.

unterscheiden werden (Die Durchbiegung von M₁₂ wird größer als jene von M₁₃ sein).

• p= Leergewicht der Kabine und Gewicht des Gegengewichts (sind gleich) - Newton
• δ = variable Berechnungstragkraft (von 0 bis 1, 5 Q) - Newton
• Δ = Kraftunterschied und Durchbiegungsdifferenz - Newton und mm
• F = Kräfte - Newton
• f= Durchbiegungen - mm
• K = Steifheit der Feder - Newton/mm
• Q = Nenntragkraft des Aufzugs (in der Regel = p) - Newton

With a cabin load equal to the nominal load capacity of the system, it is achieved that the deflection of the springs M ₁₂ and M ₁₃ is around the value $\frac{Q}{K_{M12}}$

(The deflection of M ₁₂ will be greater than that of M ₁₃ ).

• p = empty weight of the car and weight of the counterweight (are the same) - Newton
• δ = variable calculation power (from 0 to 1, 5 Q) - Newton
• Δ = force difference and deflection difference - Newton and mm
• F = forces - Newton
• f = deflections - mm
• K = spring stiffness - Newton / mm
• Q = nominal load capacity of the lift (usually = p) - Newton

1st realization

The device under the cabin comprises a base plate 15 fixedly fixed to the floor of the cabin 1. On the bottom of the car 1 opposite side, the plate carries a gear 16 which is fixed to the plate 15. The output shaft of the gear 16 is parallel to the ropes 9, carries a pinion 17, on which a link chain 18 is wound, wound on sprockets 19, 20, 21, 22 and 23, of the corresponding tie rods of the rope 9 (Fig. FIG. 1 ) or 25 ( FIG. 4 ), for example welded in position 38.

Each cable 9 extends in tie rods 27 which pass through openings in the platen 15, each traversing a ball and a thrust bearing and screwed into a nut and a lock nut 28 and 29, wherein the free end protrudes from the nut and the lock nut and accordingly equipped with a split pin 30.

Conveniently, the gear is adjustable, for example, by a slot attached to the plate 15, so that the voltage of the link chain 18th can be adjusted. On the spring 12, a sensor 34 is advantageously provided for measuring the change in length of the spring 12, the transmission 16 ( FIG. 3 and 4 ) sends a signal for its commissioning, so that the pinion 17 a rotation of the cables 9 rotates accordingly to compensate for the change in length of the spring 12.

Each pull rod 27 can be firmly fixed to the underside of the plate 15 by a thrust bearing 31, to maintain the alignment of the chain.

All of the above explanations are based on some considerations given here:

The calculation of the number of ropes (s) shall be carried out in accordance with the applicable legislation, taking into account that the load F ₁ applied at position 2 is evenly distributed over several ropes. The load on a rope therefore corresponds to the load on each of the other ropes. The load F _{1 / n} is thus present on each rope.

The value Δ f ₁ (deflection of springs 1) must not exceed 15 mm. For a load in the cabin, equal to Q (Q = rated capacity of the cabin).

The value Δ F ₁ or δ max. (maximum calculation load in the cabin) must never be less than 1.5. - In these versions 8 max. = 1.5 Q.

The ropes connecting the lower part of the cabin (with the pulley in the shaft) to the lower part of the counterweight 8 and its springs 14 correspond in number, size and technical characteristics to the suspension ropes (upper part of the cabin - upper part of the counterweight) This is not required; - They must weigh like the upper ropes.

Appropriate measures must be taken to prevent the tie rods of the ropes from rotating on their axles (with the exception of drawbars that are moved by the gearbox).

The gearbox (16) must be absolutely irreversible.

The sensor (34) that controls the movement of the gearbox must also function when the car is empty (δ = 0) and when the highest stop approaches (when the compensator is below the cab).

These designs were written taking into account a stiffness of the ropes corresponding to ∞ infinity.

With regard to the second and the third solution of the realization, an opinion of the "Consiglio Nazionale delle Ricerche" should be obtained on the question of whether "F ₄ in idle mode" must be greater than ≥ 2 Q or 3 Q or other ("F ₄ in idle mode "means that there is no weight in the cabin = δ = 0).

The balancing of the elevator can be achieved by using 2-3-4-5-6-7-8-9-10 and also more springs arranged on each rope.

Elevators using this principle (second and third solutions of the second implementation) must use textile core steel cables, all of which must have "same elevator" strands with the same torsion (all torsion right or all torsion left).

If cables with shortened extension are used, the compensation of the elevator by balancing the lengths of the cables can be done only with an under the car device (40) - at considerable rope lengths two devices (39, 40) should be used; one (39) for the cables above the car and the counterweight and one (40) for the cables connecting the car and the counterweight on the underside (see third solution of the realization, Fig. 5 )

Experience has shown that Seale ropes with 6 strands, 114 wires and textile core are best suited. These have the least extension.

K _3n is the stiffness of the springs 14 or K _M14 .

K _2n is the stiffness of the springs 13 or K _M13 .

K _1n is the stiffness of the springs 12 or K _M12 .

"n" will be the number of pull ropes.

The second and third solution of the realization were found taking into account that the cab is loaded with the upper sheave clamped by the engine's brake.

In FIG. 6 "36" indicates the adjustable stop of the spring M ₁₄ .

The stiffness of the springs applied to the ropes is always calculated by starting from the reference base of the "n" springs M ₁₂ ; it will always be: ${\mathrm{K}}_{\mathrm{M}\mathrm{12}}=\frac{Q}{n\cdot 15}\frac{N}{\mathit{mm}}$

The size 15 of the above formula can also be changed, but never exceed the actual value "25" [(which are the values allowed by European legislation]); (Level which forms the car threshold with the floor threshold when the car itself is loaded with the rated load "Q")]

The reference numerals 2-5-6 are identical to the reference numerals FIG. 1 ,

The second and third solution of the realization are presented taking into account that the elevator system has only a single rope (not realistic case).

The two solutions that can achieve the balancing of the plant, ie the second and the third solution of realization, are to be adjusted with cabin at the same height of the counterweight and provided that the weight of the cabin (along with all its accessories) plus the weight of the ropes is equal to the load capacity "Q".

Claims (14)

1. Lift installation which comprises a lift shaft, a cabin (1), a counterweight (7), at least one suspension cable (3) for the above-mentioned cabin and the above-mentioned counterweight on a pulley (4) and a cable (9) connected to the underside of the cabin and the counterweight which is wound round a freely rotating pulley (10) in the lift shaft, and a device for the extension compensation of the suspension cables, thus characterised in that

   • the device for the extension compensation contains a drive (16) which is mechanically connected to the end of at least one cable pull rod (27) at the lower part of the cabin (11)

   • it contains one spring (12) which is attached to the upper section of the cabin's (1) cable (3)

   • it contains a sensor (34) which serves to release the drive (16).
2. Lift installation according to Claim 1, thus characterised in that the extension compensation device can operate one to five cables.
3. Lift installation according to Claim 1, thus characterised in that the extension compensation device comprises a base plate which is rigidly fixed to the chassis of the cabin (1); whereby the plate carries a drive (16) with a pinion (17), the gear unit is attached to the plate (15), whereby the output shaft of the drive (16) is parallel to the cable pull rods (27); a link-chain (18) which is wound round the pinion and the gear wheels, the cable pull rods being splined or welded to the corresponding cable pull rods, whereby the above-mentioned gear wheels (19, 20, 21,22 and 23) are on the same plane as the pinion (17).
4. Lift installation according to Claim 3, thus characterised in that at least one spring moves the sensor (34) which controls the drive (16).
5. Lift installation according to Claims 2 to 4, thus characterised in that the gear (16) is absolutely irreversible.
6. Lift installation according to Claims 2 to 5, thus characterised in that the cable pull rods (35) which are not moved by the drive unit must not rotate about their axes.
7. Lift installation according to Claims 2 to 6, thus characterised in that a system is provided to increase the pitch of the strands of five cables.
8. Lift installation according to Claims 2 to 7, thus characterised in that the whole system for compensating the cable extension is attached to the plate (15), with the exception of the sensor which is attached to a spring and takes up the cable slack.
9. Lift installation according to Claims 2 to 8, thus characterised in that thrust bearings (26 and 31) as well as nuts and lock nuts (28, 29, 32 and 33) are bolted to the pull rods (27) in such a way that the pull rod can rotate freely about its own axis before the installation of the link-chain (18) and before the cables are attached to the corresponding pull rods.
10. Lift installation according to Claims 2 to 9, thus characterised in that the cable pull rods (27) are splined or welded to the various gear wheels (19, 20, 21,22 and 23).
11. Lift installation according to Claims 2 to 10, thus characterised in that a connection (24) is provided between the cable (9) and pull rod (27), which is valid for all pull rods and cables.
12. Lift installation according to Claims 2 to 11, thus characterised in that one or more sensors (34) are provided.
13. Lift installation according to Claims 2 to 12, thus characterised in that the sensor (34) initiates operation of the drive (16), is only operational with an empty cabin stopped at the highest position of lift travel, when the counterweight is at minimal distance to its end stop.
14. Lift installation according to Claims 2 to 13, thus characterised in that with two cable extension compensation devices (39, 40) - one at the bottom of the cabin (40) and one at the top of the counterweight (39) - their mode of operation is controlled by the same sensor, however they must operate in turn, and the cabin must always be at the highest point it can achieve.

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