Scaffold provided with a fall protection device

Abstract

 The invention relates to a safety system for people working on a building or the like, in particular to a safety system for use with a scaffold. When erecting and dismantling scaffolding, the people working on the scaffold have a poor degree of protection, if any. The invention proposes providing the people working on the scaffold with a fall protection device, whilst ensuring that they still have sufficient freedom of movement to continue their erecting/dismantling work. A preferably horizontal scaffold tube is proposed for this purpose, such as a part of a platform, which is provided with a cable which extends along substantially the entire length of the outside of said tube. The person working on the scaffold can attach himself to the cable by means of a belt and move backwards and forwards along said cable over the length of the scaffold tube.

Description

[0001] The present invention relates to a building structure comprising a horizontal tube. When working at relatively great heights, safety measures must increasingly be taken to limit the risk of falling and/or limit the consequences thereof. An example thereof is found with scaffolding, where strict requirements are placed on guardrails and other protective measures, so that the people working on the scaffold, for example on a building, are not exposed to the risk of falling from the scaffold.

[0002] However, these safety measures are not yet in place during the erection of the scaffold or they are removed during the dismantling thereof. As a result, people erecting the scaffold are exposed to a risk of falling. Furthermore, this risk is great because such people have to perform all kinds of unusual operations in order to manoeuvre the pipes or tubes to be used into the correct position. Moreover, the structure is often not optimally stable during the erection/dismantling, which further increases the risk of falling.

[0003] On the other hand, there is the problem that if a fall protection device is provided, this needs to have considerable strength in order to be able to withstand the weight plus the speed of the falling person.

[0004] It is the object of the present invention to provide a relatively lightweight fall protection device which can be produced in a simple manner and may be used for building structures where work is carried out with tubes.

[0005] This object is achieved in respect of a building structure described above by virtue of the fact that said building structure comprises a horizontal tube provided with a fall protection device, wherein said fall protection device comprises a cable which extends along said tube for attaching a belt or the like thereto, one end of which tube is provided with an opening, wherein said cable extends through said opening into the interior of said tube, and wherein a free end of said cable which is located in said tube is secured via a damper arranged in said tube.

[0006] According to the present invention, use is made of a cable which extends parallel to the tube and to which the person working on the scaffold may be attached by means of a belt with an eyelet. He therefore has freedom of movement over the entire length of the tube.

[0007] The presence of the spring which is connected to a cable end means that in the event of a fall the shock loading which arises on the cable will be damped and converted into a load on the tube. As a result, on the one hand the fall is damped and on the other hand it is possible to place less stringent demands on the strength of the tube. In practice, a load on the tube will involve a bending load and/or in particular a crushing load. The resistance of the tube to bending depends on the material and the cross section of the tube. In the case of an aluminium tube, for example, the resistance to crushing will be significant. Furthermore, since one or preferably both openings for the cable are situated near the ends of the tube, the moment caused by the force of the fall will be relatively small and is able to be transmitted directly into the rest of the structure, such as a scaffold, via the coupling of a horizontal tube, for example.

[0008] The damper may comprise a structure which increases the length of the cable outside the tube in a damped manner, for example a friction damper and/or a spring.

[0009] As described above, it is possible in each case to provide an opening at opposite ends of the tube through which opening a cable end extends in each case. Each cable end is preferably connected to one single spring. The spring load is preferably such that, in the position of use, that is to say without the exertion of any load, the cable extends as far as possible taut along the tube. The spring used may be a tension spring or a compression spring. In the case of a tension spring, the cable ends are always attached at the end of the spring. In the case of a compression spring, and more particularly a coil spring, the cable ends extend through the interior of such a coil spring and are supported on the coil spring at opposite ends. When a compression spring is used, the deflection of the spring may be limited to the touching of the turns of the spring.

[0010] The openings in the tube may be of a relatively simple design. However, according to an advantageous embodiment of the invention, cable guides are present in order to as far as possible prevent the cable from being restrained due to friction at the opening. These cable guides may comprises plastic parts, for example, as a result of which a pulling movement on the outside of the tube is converted directly into a pulling movement on the cable on the inside of the tube. According to a particular embodiment, such a guide comprises a wheel.

[0011] Although the invention has been described above with reference to a scaffold tube, it will be understood that the tube may also be designed in another manner depending on the structure in which the fall protection device according to the invention is arranged. In the case of a scaffold tube, said tube is preferably provided with a coupling at both ends.

[0012] In a preferred embodiment of the present invention, a scaffold tube of this type forms part of a platform which is arranged between two uprights of a scaffold structure and on which the worker is able to walk. However, it is readily possible to also provide the present invention in other types of scaffold tube.

[0013] Instead of the scaffold described above, it is also possible to provide any other type of construction of the tube described above with a fall protection device.

[0014] The present invention also relates to a method for erecting a scaffold, comprising providing a number of vertical and horizontal scaffold tubes and connecting said tubes to one another, wherein one of the higher tubes of said horizontal scaffold tubes is provided with a cable which is connected thereto and extends parallel thereto, attaching a belt which is connected to the builder of said scaffold to said cable, wherein the builder can move along said cable by means of said belt.

[0015] More particularly, the invention relates to a method for erecting a scaffold, comprising:

• providing a number of vertical and horizontal scaffold tubes and connecting said tubes to one another, wherein one of the higher tubes of said horizontal scaffold tubes is provided with a fall protection device, wherein said fall protection device comprises a cable 6 which extends along said tube and is connected thereto, one end of which higher tube is provided with an opening, wherein said cable 6 extends through said opening into the interior of said tube, and wherein a free end of said cable which is located in said tube is secured via a damper arranged in said tube,
• attaching a belt which is connected to the builder of said scaffold to said cable, wherein the builder can move along said cable by means of said belt.

[0016] In one embodiment, the method comprises:

• arranging a number of higher horizontal tubes provided with a fall protection device along an imaginary line for increasing the freedom of movement of people who use the fall protection device.

[0017] The present invention also relates to a further method for erecting a scaffold, comprising:

• providing a number of vertical and horizontal scaffold tubes and connecting said tubes to one another in order to form a scaffold layer,
• providing at least one scaffold tube provided with a fall protection device, wherein said fall protection device comprises a cable 6 which is connected to said tube, one end of which tube is provided with an opening, wherein said cable extends through said opening into the interior of said tube, and wherein a free end of said cable which is located in said tube is secured via a damper arranged in said tube,
• arranging the tube provided with the fall protection device with respect to the scaffold layer in such a way that the tube end provided with the opening extends above the scaffold layer so that the cable is able to extend above the scaffold layer in order to provide people working on the scaffold layer with protection from falling during the fitting of the next scaffold layer.

[0018] The invention will be explained in greater detail below with reference to an exemplary embodiment illustrated in the drawing, in which:

Fig. 1 diagrammatically shows a scaffold with a person working thereon;

Fig. 2 diagrammatically shows the further erection of the scaffold.

Fig. 3 shows a partly cut-away detail view of the scaffold tube according to the invention; and

Fig. 4 shows the scaffold tube according to Fig. 2 while a force is being exerted. In Fig. 1, a scaffold is designated in its entirety by reference numeral 1. Said scaffold 1 comprises uprights 2. These may, for example, form a single entity with transverse parts 3, as a result of which it is possible to realize (part of) a scaffold structure with the aid of longitudinal parts, such as a tube 27 (as illustrated in Fig. 2), and cross braces 5. A platform 4 may be placed onto the transverse parts 3, on which platform 4 it is possible for a person 9 to work. The platform 4 comprises two tubes 7 which extend parallel to one another and between which cross pieces may be provided and wherein the end of each of the tubes 7 is provided with a coupling 8. In the example illustrated the scaffold 1 is being erected. The person is connected by means of a harness 10 and a belt 11 provided at the free end with a ring or hook 12 to a line or cable 6 which extends parallel to tube 7 of the platform illustrated in Fig. 1. Fig. 2 illustrates the situation after the next layer, including a further platform 24, has been positioned. In addition to said platform 24, the tube 27 is provided and serves as a guardrail which ensures that the situation on the platform 4 is safe. In this position, the person on the lower platform moves his ring or hook attachment from the lower platform 4 to the cable 6 of the upper platform 24. The person 9 is then able to move onto the upper platform 24 and continue working on the further erection of the scaffold there. The person is safely secured under all circumstances and has the maximum freedom of movement.

[0019] Fig. 3 shows an example of the tube 7 of a platform 4 or 24 in a cut-away illustration. It can be seen that the ends of the tube are provided with couplings 8. It will be understood that said couplings may have a different configuration or that, depending on the use, such couplings may be present only on one side, or not at all.

[0020] The tube 7 is provided with openings 15 close to the ends thereof. Cable guides such as wheels 14 are arranged in said openings 15. The cable 6 extends horizontally through said openings 15 along the wheels 14 on either side of the interior of the tube. In this case, a coil spring 16 is arranged in the interior of the tube. The cable ends extend through the interior of the coil spring so that cable end 17 is connected to the left-hand end (in Fig. 3) of the coil spring and cable end 18 is connected to the right-hand end. The coil spring may be supported in any way or be arranged loosely in the tube.

[0021] The prestress of the coil spring or the shortening of the cable or line 6 is configured in such a way that in the unloaded state cable 6 runs relatively taut along the outside of the tube. In this case, the free movement of a ring or hook 12 to which the belt 11 of the person 9 is attached is always readily possible. Free movement is possible predominantly along the cable, i.e. in the longitudinal direction of the cable. The tension on the cable means that the freedom of movement is limited in the direction transverse to the cable, which increases safety.

[0022] Fig. 4 diagrammatically shows the position in the event of an unforeseen fall. The fall generates a force F in the part of the cable 6 which is located outside the tube, as a result of which the cable is pulled to the outside. This occurs counter to the effect of the spring force of the coil spring 16 which is compressed as shown in Figure 3. As a result, the fall is damped with the aid of the coil spring and the load caused by the fall is transmitted into the tube 7 and then diverted into the rest of the structure 1 more gradually and with fewer peaks. In this way, a relatively lightweight construction of the tube 7 is sufficient, and said tube 7 can therefore be fitted in a simple manner and without an excessive amount of effort.

[0023] Fig. 5 illustrates a scaffold 1. The scaffold 1 comprises a number of horizontal tubes 7 provided with a fall protection device according to the present invention. The number of tubes 7 is arranged along an imaginary line 18 and thus offers workers a greater freedom of movement in the longitudinal direction of the cable, which guarantees safety. In this case, the cable 6 extends along one tube 7 as shown in Fig. 4. By coupling the tubes 7, the freedom of movement is extended still further, which may be desirable. It is conceivable that the cable 6 extends along one or more tubes 7. The number of tubes 7 provides workers with protection from falling while they are positioning the next layer onto the existing layer 23, or board, of the scaffold 1, or when working on a building against which the scaffold 1 has been erected.

[0024] Figures 6 and 7 show successive steps in a method for erecting a scaffold. In Figure 6, a number of vertical and horizontal scaffold tubes are provided which are connected to one another to form a scaffold layer 23 alongside a building 22. In this case, some of the tubes are provided in the form of a preformed frame 19, or gantry 19. Figure 6 also shows that two tubes 21a, 21b are connected to the scaffold 1 at a distance from one another. These two scaffold tubes 21a, 21b are each provided with a fall protection device. Said fall protection device comprises a cable 6 connected to the two tubes, which tubes are provided with an opening 15 at an end thereof (Fig. 3). The cable 6 extends through said openings into the interior of said tubes. A free end 17; 18 of said cable 6 which is located in said tubes is secured via a damper 16 arranged in said tubes. It is also conceivable for only one tube to be provided with an above-described fall protection device. The tubes 21 a, 21b are arranged with respect to the scaffold layer 23 in such a way that the tube end 24 provided with the opening extends above the scaffold layer 23 so that the cable 6 is able to extend above the scaffold layer 23 in order to provide people working on the scaffold layer 23 with protection from falling while they are positioning the next scaffold layer, as shown in Fig. 7. In this case, the scaffold tubes 2 1 a, b are pivotably connected to the scaffold 1 and assume a vertical position. In this case, the cable 6 extends horizontally and parallel to the scaffold layer 23.

[0025] With the aid of the present invention, it is possible to provide a fall protection device without making any further changes to the structure. It is possible to use a friction damper or the like as damper instead of the spring described above, in which case the peak load is damped in a corresponding manner.

Claims

1. Building structure (1) comprising a horizontal tube (7) provided with a fall protection device, wherein said fall protection device comprises a cable (6) which extends along said tube for attaching a belt (11) or the like thereto, one end of which tube is provided with an opening (15), wherein said cable (6) extends through said opening into the interior of said tube, and wherein a free end (17; 18) of said cable (6) which is located in said tube is secured via a damper (16) arranged in said tube.

2. Structure according to Claim 1, wherein said damper comprises a part which increases the length of the cable (6) which is located outside the tube in the event of loading.

3. Structure according to one of the preceding claims, wherein said damper comprises a spring.

4. Structure according to one of the preceding claims, wherein said tube is provided with an opening at opposite ends, wherein a cable end extends through each opening.

5. Structure according to Claim 3, wherein each cable end (17; 18) is connected to an end of said spring (16).

6. Structure according to one of the preceding claims, wherein said cable (6) is held taut by said spring (16) in the unloaded state.

7. Structure according to one of the preceding claims, wherein said spring (16) comprises a coil spring and wherein a free end (17; 18) of said cable (6) extends through the interior of said coil spring.

8. Structure according to one of the preceding claims, wherein said opening (15) in said tube comprises a cable guide (14).

9. Structure according to Claim 8, wherein said cable guide comprises a wheel.

10. Structure according to one of the preceding claims, wherein said tube is provided with a coupling (8) at its free ends.

11. Structure according to one of the preceding claims, wherein said tube comprises a scaffold tube.

12. Structure according to one of the preceding claims, wherein said tube is part of a platform.

13. Structure according to one of the preceding claims, comprising a scaffold having horizontal and vertical tubes which are coupled to one another.

14. Method for erecting a scaffold (1), comprising:

- providing a number of vertical and horizontal scaffold tubes and connecting said tubes to one another, wherein one of the higher tubes (7) of said horizontal scaffold tubes is provided with a fall protection device, wherein said fall protection device comprises a cable (6) which extends along said tube and is connected thereto, one end of which higher tube is provided with an opening (15), wherein said cable (6) extends through said opening into the interior of said tube, and wherein a free end (17; 18) of said cable (6) which is located in said tube is secured via a damper (16) arranged in said tube,

- attaching a belt (11) which is connected to the builder (9) of said scaffold (1) to said cable, wherein the builder can move along said cable (6) by means of said belt.

15. Method according to Claim 14, comprising:

- arranging a number of higher horizontal tubes (7) provided with a fall protection device along an imaginary line (18) for increasing the freedom of movement of people who use the fall protection device.

Drawing