DE29517897U1 - Hanging device for a load - Google Patents

Description

Description Tiipke Gerard Klionstra, Martensweq 33, NL-8071 Nunspeet Hanging device for a load

The invention relates to a hanging device with a frame and a cable connected to it, which has a vertical cable section for hanging a load, wherein a lever is mounted on the frame so as to be pivotable about a horizontal axis, which carries a counterweight on a first lever arm and whose second lever arm is connected to the cable arm in such a way that a lifting force is exerted on the counterweight when a tensile force is applied to the cable.

Hanging devices of this type can be used in different ways. A simple hanging device is used, for example, to lift loads for storage in a warehouse or for removal from storage. Another application of the hanging device is to carry out work on building facades if the hanging device has a bridge-like elevator car or a gondola that is used to carry people. Such a hanging device often has a counterweight to prevent the frame from tilting in the direction of the load. The frame of such a hanging device is usually arranged on the roof of a building along the edge of the roof, with two pairs of hanging cables attached to an end of the frame that projects over the edge of the roof, one pair of which is hooked onto the end of the bridge-like elevator car. One cable from each pair serves as a lift cable or suspension cable and is therefore provided with a lifting device, while the other cable serves as a safety device and is therefore called a safety cable. The lift cable and the safety cable of each pair are

usually attached to one end of the bridge-like elevator car and allow the cable in question to pass further downwards after it has been guided lengthways or over internal organs. If the elevator cable breaks, the safety devices come into action, causing the bridge-like elevator car to come to a stop and remain suspended on the safety cable even after covering a certain braking distance, fall distance or safety distance.

In each of the cables mentioned and in each of the suspension devices mentioned, including those with a bridge-type car, such large fluctuations in the cable's tensile force can occur as a result of the movement of the load that it is desirable to dampen the dynamic tensile force and in particular the significant shocks in the cable. In suspension devices with bridge-type cars, shock absorber devices are used for the safety cables. Such shock absorbers are arranged at the end of the frame that protrudes over the edge of the roof and consist of a fixed compression spring, via which the cable is attached, for example, to the end of a support of the frame, or of a plastically deformable end of a support of the frame to absorb the shock energy in the relevant safety cable. In this suspension device, the counterweight is not connected to one of the cables.

Such a spring damper has the disadvantage that the construction consists of a large number of parts, the spring is designed as a heavy and expensive compression spring, assembly is difficult because the spring must be assembled under a high preload (on the order of the weight of the elevator car), and the costs of the spring damper are relatively high. The design with the plastically deformable element has the disadvantage that a precise determination of the properties of the material is required and that after absorbing a shock, a replacement must be made after plastic deformation of the element, which results in high costs.

None of the suspension devices mentioned are equipped with damping devices in the elevator cable to dampen the fluctuations in the traction force. This can cause damage to the cable or other parts of the suspension devices and, in the case of a suspension device with a lift car, it can be unpleasant for the people in the lift car if the shocks occurring in the suspension cable are so strong that they are clearly noticeable, but not yet so great as to lead to a cable break.

From the French patent FR-A-I 413 966 a crane is known whose construction is essentially the same as the construction of the suspension device described above. The crane consists of a column on which a support beam with a vertical pivot axis can be hinged through the column with a first arm (boom or jib) on one side of the axis and a second arm on the other side of the axis. A winding device for a hoist cable is attached to the base of the column. At the free end of the second arm there is a lever arm which can be pivoted about an axis which is attached above the support beam and which consists of a third arm between the latter axis and the column of the lifting device and a fourth arm on the other side of the latter axis. A counterweight is attached to the free end of the fourth arm. A cable is passed over a pulley attached to the second arm, a pulley attached to the free end of the third arm, a pulley attached to the first arm a short distance from the column of the lifting device and a pulley attached to the free end of the first arm. At the end of the cable, which hangs down from the last-mentioned pulley, a load is attached or can be coupled to it.

When the load rests on the ground, the lever arm is rotated so that the counterweight is in the lowest position. When the lifting device is then activated, the cable is first wound on a part of a drum of the winding device.

tension and the counterweight is rotated up in a direction away from the column of the hoist before the load is released from the ground and moved further upwards. In this situation the moments (force x displacement) exerted in a vertical plane by the crane's support beam on either side of the vertical axis of rotation are essentially equal, so that the resulting bending moment exerted on the column is minimised. Depending on the heaviness of the load to be hoisted, the counterweight is raised before the load is released from the ground. When the load is raised, changes in the tensile force occurring in the cable section between the end of the first arm and the load result in the counterweight being rotated to a higher or lower position accordingly.

In some situations, such dynamic behavior of the device can be undesirable, e.g. if the load is designed as a bridge-like elevator car in which people are working on the facade of a building, for example. In this case, unwanted lifting movements should be limited as much as possible. Furthermore, for some applications, especially for elevator cars, it is undesirable for the counterweight to be displaced horizontally during the lifting movement. This can cause space problems when used on a building.

The invention is based on the object of avoiding the disadvantages mentioned above.

This object is achieved according to the invention in that blocking means are provided which limit the sinking of the counterweight to a minimum height.

This design creates a shock-absorbing effect with a simple and inexpensive, yet reliable construction that is suitable for every type of suspension device and for every cable.

belart can be used. Changes in the tensile force in the cable will only result in significant vertical movements of the load if the tensile force exceeds a certain value. This is convenient for the comfort of the staff if the load hanging on the suspension device is designed as a bridge-like car.

In contrast to the previously described known lifting device, the hanging device according to the invention is not intended to compensate the moment (force x path) exerted by the load and the counterweight, so that with the hanging device according to the invention it is not necessary to move the counterweight absolutely horizontally. In this way, the construction can be designed in such a way that the horizontal mobility of the counterweight is limited, whereby the hanging device takes up essentially the same space regardless of the state it is in. This is generally advantageous when using the hanging device on roofs and/or when people are near the counterweight.

By choosing the right dimensions and points of application, it is possible to influence the properties of the damping means. This also allows the length of the path where the damping takes place to be influenced. The size of the damping force can be influenced by choosing the ratios of the lever arms. By designing the lever structures appropriately, the characteristics of the shock absorption can be set in advance as progressive or degressive as required.

If the counterweight of the suspension device is designed to counteract the tilting of the frame in the direction of the load, as in the case of a suspension device with a bridge-type lift cage, the counterweight suspended from the lever is at least one part of the prevention of tilting. In this way, the counterweight has a double function, because it counteracts the tilting

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and allows a dampening of the tensile force in the cable. The invention is explained in the drawing. It shows:

Figure 1 a hanging device according to the invention

tion in schematic side view;

Figure 2 is an enlarged view of a

Part of the hanging device according to Figure 1 in side view with a lever;

Figure 3 is a plan view of the device shown in Figure 2.

th part of the hanging device according to Figure 1;

Figure 4 is a front view of the device shown in Figures 2

and 3 shown part of the hanging device according to Ij

Figure 5 is an enlarged view of the figure in Fig.

gur 2 shown part of the device with two positions of the lever.

The hanging device shown in Figure 1 has a frame 1 with a horizontal support 2 that rests on footrests 3 that are supported on wheels 4. The wheels 4 run on rails 5 that are placed on a roof 6 of a building 7. At an end of the support 2 located above the roof 6 (Figure 1 left) a lever 8 is mounted so that it can rotate about a horizontal axis 9. A counterweight 12 is suspended from a first lever arm 10 of the lever 9 via a suspension means 11. A horizontal cable section 14 of a cable 15 is attached to a second lever arm 13 of the lever 8. A cable deflection in the form of a deflection roller 17 is attached to the end of the support 2 that protrudes over the roof edge 16 of the building 7. The cable 15 is guided over the deflection roller 17.

wherein a vertical cable section 18 of the cable 15 hangs downwards in front of a facade 19 of the building 7. The vertical cable section 18 of the cable 15 is connected to a bridge-like elevator car 21 via coupling means 20.

The invention can be used for an elevator cable (also called a suspension cable) or for a safety cable or for both cables of a suspension device. If the cable 15 is an elevator cable, the coupling means 20 are designed as lifting means, in particular as a pulley. If the cable 15 is a safety cable, the coupling means 20 are safety means that generally react to an excessively high descent speed in order to then clamp the safety cable in place if the lifting cable should break. The cable 15 can leave the coupling means 20 with a strap section 22 hanging downwards.

A hanging device with a car 21 is generally provided with a counterweight to counteract tilting of the frame 1 in the direction of the vertical cable section 18. Instead of the counterweight 12 described above, a weight can be used that corresponds to a counterweight or a part of the counterweight that is required to counteract tilting. This allows the existing means in the known hanging device to be used to the maximum. Instead of the means for hanging the counterweight, which is intended to prevent tilting of the frame 1, the lever 8 and the hanging means 11 are then used. In this way, when using the present invention, no or only a few more parts are required.

When a high tensile force occurs in the cable 15, the counterweight 12 is raised via the lever 8. This dampens the changed tensile force, especially shocks. This not only makes working more comfortable for the people in the car 21, but above all serves stability and the shape and strength of the entire system.

position, including frame 1 and car 21.

As will be explained later, the damping characteristics can be determined in advance by a suitable choice of the lengths of the lever arms 10, 13 and the position of the axes 9 of the lever 8. This can ensure that if the cable 15 is a safety cable of a suspension device with a car and an associated hoist cable of the suspension device breaks, the shock energy released when the invention is used during the fall is quickly dampened or absorbed and the height of fall of the car 21 is reduced. Although the cable 15 is attached directly to the lever 8, the cable 15 could also be attached to a lever at the point where the deflection roller 17 is present, and a rod could be provided between this lever and the lever 8. It can be seen from this that according to the invention a construction is also possible in which the lever 8 (or a functionally equivalent lever) and the deflection roller 17 swap places. The principle of the invention is then retained. This also applies if a simple load is hanging on the cable 15 instead of the car 21, and also if existing lifting equipment is located at a location other than the load or the car 21.

Figure 2 shows the lever 8, namely a lever disk 30 of the lever 8 in a preferred embodiment. The part of the lever disk 30 between the axis 9 and an axis 31, to which the suspension means 11 with the counterweight 12 is attached, is to be regarded as the first lever arm 10 shown in Figure 1. The part of the disk 30 between the axis 9 and an axis 32, to which the horizontal cable section 14 of the cable 15 is attached, is to be regarded as the second lever arm 13 shown in Figure 1. The lever arms 10, 13 are indicated in Figure 2 by a dot-dash line.

Figures 3 and 4 show a top view and a side view from the left of the part of the hanging device shown in Figure 2.

As can be seen from Figures 3 and 4, a disk 30 is provided on each side of the carrier, whereby the disks 30 are connected to one another via the axes 9, 31, 32. A blocking means in the form of a rod 35 is attached to and between the two disks 30.

A suspension device for a bridge-shaped elevator car 21 will generally comprise two supports 3 with the configurations shown in Figures 2 to 4 for each end of the elevator car 21 and possibly be provided with a double version of the construction shown in Figures 2 to 4 for each support 2 for both a hoist cable and a safety cable of the elevator car 21.

In the position of the suspension device shown in Figure 2, the blocking rod 35 rests on the support 2, which prevents the counterweight 12 from sinking further. Below a certain weight of the elevator car 21, fluctuations in the tensile force in the cable 15 will not be sufficient to pivot the lever 8 or the lever discs 30 and thereby raise the counterweight 12. This creates a threshold below which changes in the tensile force are not dampened. This threshold can be determined during the design of the device by selecting the appropriate distances between the axes 9, 31, 32 and the blocking rod 35.

Figure 5 shows, on a further enlarged scale, the section of the suspension device shown in Figure 2, whereby the horizontal cable section 14, the coupling means for attaching the cable section 14 to the axle 32 and the suspension means 11 for the counterweight 12 are omitted for reasons of clarity. The solid lines show the lever disc 30 in its rest position, which is identical to the position shown in Figure 2, while the dashed lines show the lever disc 30 in a raised position, which is called the working position here. ·"

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In the working position, the tensile force in the cable 15 has exceeded the above-mentioned threshold so that the counterweight 12 has been raised. In Figure 5, a vertical displacement amount of the axis 31 is indicated by SVl, while a horizontal displacement amount of the axis 31 is indicated by SHl. A vertical displacement amount of the axis 32 is indicated by SV2, while a horizontal displacement amount of the axis 32 is indicated by SH2. As can be seen, the axis 31 in the working position has been displaced horizontally relative to the axis 9 by the amount SHl compared to the rest position.

In Figure 5, the lengths of the lever arms 10, 13 are indicated by Rl and R2 respectively. However, the leverage of the lever disc 30 is dependent on the actual arm lengths perpendicular to the forces exerted on the axes 31 and 32 respectively, whereby these actual arm lengths and the associated forces form moments which determine the pivoting of the lever 8 and the lever discs 30 respectively. In Figure 5, these actual arm lengths for the rest state of the lever discs 30 are indicated by Rl' for the axis 31 and R2' for the axis 32. In the working position, the effective arm length for the moment generated by the counterweight 12 has increased from Rl' to Rl' + SHl, while the effective arm length of the moment generated by the tensile force in the cable 15 has increased from R2' to R2' + SV2.

For the rest position of the lever plates 30 of the hanging device, which is shown in solid lines in Figures 2 and 5, an angle A is formed between the first lever arm 10 and the horizontal, while an angle B is formed between the second lever arm 13 and the horizontal. The changes in the actual arm lengths Rl' and R2' during the pivoting of the lever plates 30 can be determined in advance, in terms of size and sign, by a skilful choice of the angles A and B and the lengths Rl and R2 of the lever arms 10 and 13, respectively.

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If the angle A - as shown - is below the horizontal, the actual arm length Rl' increases when the lever plates 30 are pivoted from the rest position. If the angle A is above the horizontal, the actual arm length Rl' decreases when the lever plates 30 are pivoted up. If the angle B - as shown - is less than 90°, the actual arm length R2' increases when the lever plates 30 are pivoted up. If the angle B is greater than 90°, the actual arm length R2' decreases when the lever plates 30 are pivoted up.

The options mentioned for selecting the angles A and B and the arm lengths Rl and R2 make it possible to determine in advance whether and with what course the damping forces increase or decrease during the travel of the damping path. This means that the damping characteristics can be set in advance as desired, either progressively or degressively.

Various modifications are possible within the scope of the invention. A number of alternatives to the construction shown have already been explained above. In addition, for example, the suspension means 11 can be connected by a rigid coupling to the counterweight 12 and the lever 8 or the lever disc 30, so that the counterweight 12 can swing in relation to the axis 9. Furthermore, as an alternative to the blocking rod 35, which limits the downward lifting movement of the counterweight 12 to a minimum height, the frame 1 could have means, e.g. a plateau under the counterweight 12, on which the counterweight 12 comes to rest when the minimum height is reached.

Claims (7)

Claims Tijpke Gerard Klionstra, Martensweq 33, NL-8071 Kj Nunspeet Suspension device for a load 1. Hanging device with a frame (1) and a cable (15) connected to it, which has a vertical cable section (18) for suspending a load (21), wherein a lever (8) is mounted on the frame (1) so as to be pivotable about a horizontal axis (9), which lever carries a counterweight (12) on a first lever arm (10) and whose second lever arm (13) is connected to the cable (15) in such a way that a lifting force is exerted on the counterweight (12) when a tensile force is applied to the cable (15), characterized in that blocking means (35) are provided which limit the sinking of the counterweight (12) to a minimum height. 2. Hanging device according to claim 1, characterized in that the blocking means consist of a stop (32) fastened to the lever (8) which rests on the frame (1) at the minimum height of the counterweight (12). 3. Hanging device according to claim 2, characterized in that the lever (8) consists of two identical plate parts (30) which are at a certain distance from one another and have the axis (9) as a common axis, the plate parts (30) being attached to both sides of a support (2) of the frame (1) and the stop being designed as a rod member (35) attached between the plates (30). 4. Hanging device according to claim 1, characterized in that the frame (1) has means on which the counterweight (12) rests when the minimum height is reached. 5. Hanging device according to one of the above claims, characterized in that the cable (15) is a hoist rope. 6. Hanging device according to one of the preceding claims, characterized in that the cable (15) is a Pang cable. 7. Hanging device according to one of the preceding claims, characterized in that the hanging device has a car (21) or a gondola.