CLAMP FOR CABLE

Abstract: The invention relates to a clamp device for fixing cables (12) on a crossbar (11). The device comprises a U-shaped stirrup (1) which encloses the cables (12), and a thrust washer (4) for distributing the clamping pressure. According to the invention, a spring device applies an adapted compressive force on the thrust washer (4). In one embodiment, the clamp device comprises a control lever (6) which permits locking of the spring device in the compressed position for fitting of the clamp.

Description: TITLE OF THE INVENTION: CLAMP FOR CABLE FIELD OF THE INVENTION The present invention relates to a clamp for fixing cables, principally on masts where the cables are exposed to the effects of the wind and weather. PRIOR ART It is already known to use clamps for this purpose. The clamps according to the prior art comprised a U-shaped stirrup which enclose the cables, and a thrust washer which was pressed against the cables with the aid of a screw. The screw was tightened with a defined torque using a torque wrench, and the screw was locked fast with the aid of a locking nut and locking washer. A number of problems were associated with the prior art. The fitting of the clamp was complicated, since a special tool was required, and screwing by hand is a relatively time-consuming operation. Since the screws also tended to come loose despite the locking, a follow-up inspection and maintenance were required at regular intervals in order to check that the screws had not come loose. In this case, the screws were once again fixed using the torque wrench. If the fitter chose hot to use the torque wrench, there was additionally a risk of damaging the cable if the screw was tightened too hard. There was also a risk of the fitter injuring himself on the screws which stuck relatively far out. It was not uncommon for the fitters to strike their elbows and legs when climbing the masts. The clamp according to the prior art was also expensive to manufacture on account of the fact that the hole in the stirrup had to be threaded, and on account of the screws and the nuts. The present invention solves the abovementioned problems by replacing the previously used screw with a spring which is arranged to provide an appropriate compressive force. In this way the fitting of the clamp is facilitated, the need for follow-up inspection and maintenance is eliminated, the risks of damage and injury are reduced, and the manufacture is less expensive. SUMMARY OF THE INVENTION The present invention thus makes available a clamp device for fixing at least one cable on a crossbar, the device comprising a U-shaped stirrup which encloses the cable, and a thrust washer for distributing a clamping pressure on the cable. According to the invention, a spring device applies an adapted compressive force on the thrust washer. In one embodiment, the device has a control lever which permits locking of the spring device in the compressed position for fitting of the clamp. Further embodiments of the invention are specified in the attached patent claims. BRIEF DESCRIPTION OF THE DRAWINGS The invention is described in detail below, with reference to the attached drawings in which: Figure 1 is a perspective view of a first embodiment of the invention, Figure 2 is a perspective view of a second embodiment of the invention, Figure 3 is a top view of an intermediate washer, Figure 4 is a side view of the intermediate washer, Figure 5 is a perspective view of the intermediate washer, and Figure 6 is a side view of a clamp according to the present invention mounted on a crossbar. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The invention relates to a clamp for fitting cables, for example on masts. According to the invention, a spring device is arranged to generate an appropriate clamping force under all circumstances. The spring device consists expediently of a helical spring of acidresistant steel, which is dimensioned so as to generate the appropriate force. Figure 1 shows a first embodiment of the invention. The clamp consists of a U-shaped stirrup 1 which encloses the cables (see Figure 6). The clamp is hooked securely, via hooks 2 at a recess 3 in the legs of the stirrup, about a crossbar on, for example, a radio mast. A thrust washer 4 distributes the force from a spring 5 against the cables. Figure 2 shows a second embodiment of the clamp according to the invention. The second embodiment is similar to the first, except that a control lever 6 is mounted on the thrust washer 4. The control lever consists of a rod which runs through a hole 8 in the stirrup. In the rod there is a recessed part 7 which can be made secure in the hole 8, which is similar in shape to a key hole. Round the rod, between the stirrup 1 and the thrust washer 4, there is also a spring, but the latter is not represented in Figure 2 so as to show the control lever 6 more clearly. By pulling on the control lever 6, the spring can be compressed and can be locked with the aid of the recessed part 7 and the hole 8 in order to facilitate the fitting of the clamp, as is described below. Figures 3,4 and 5 show an intermediate washer 9 in different views. The intermediate washer 9 is intended to be placed between cables and between the cable and the crossbar in the mast in order to distribute the binding pressure and in this way to avoid damage to the cables. The clamp also functions per se without metal washers. The intermediate washer 9 has recesses 10 which are open at the bottom so that the intermediate washer 9 can be placed on the stirrup 1 from above. Figure 6 shows the clamp according to the invention being used to secure three cables 12 on a crossbar 11 of a mast, for example a radio mast. Fitting of the first embodiment (Figure 1) of the invention proceeds as follows. The legs of the stirrup are placed on both sides of the cables, the spring 5 is compressed, and the hooks 2 are placed over the crossbar 11 in a single operation. The intermediate washers 9 are then passed, from above, in between the cables and between the crossbar 11 and the nearest cable 12. The fitting is then complete and does not require any maintenance, since the spring cannot be shaken loose by the effects of the wind and weather. Disassembly is carried out in a corresponding manner. The advantage of this embodiment is also that it does not have the protruding control lever 6, which is shown by a broken line in Figure 6. Fitting of the second embodiment (Figure 2) of the invention proceeds as follows. The spring is tensioned with the aid of the control lever 6 and is locked in the tensioned position with the aid of the recessed part 7 and the hole 8. The fitter thus carries a number of clamps which have been tensioned in advance. The legs 1 of the stirrup are slipped over the cables and are hooked securely about the crossbar 11 without the spring having to be compressed. The intermediate washers 9 are then put into place without it being necessary to work against the force of the spring. The spring is then released by pushing on the control lever 6 so that the locking action is disengaged. Fitting is then complete. Disassembly is carried out in reverse order. The advantage of the second embodiment is that the spring does not need to be compressed during the actual fitting of the clamp. The present invention thus makes available a clamp for cables, which clamp affords a number of advantages compared with the prior art: Since the spring is adapted to the application, a correct binding force is always obtained without any risk of the clamp damaging the cable. Fitting is quicker and simpler compared with the prior art. It does not require any special tools, and the time-consuming screwing operation is obviated. The clamp requires neither follow-up inspection nor maintenance, since the spring cannot be shaken loose in the same way as a screw. The clamp is less expensive to manufacture, since it is not necessary to form a threaded hole in the stirrup. The clamp according to the invention also comprises fewer components. The clamp is also without any sharp protruding components such as a screw, particularly in embodiment 1. The knob on the control lever 6 in the second embodiment can also be made round and less sharp than a screw head. It will be clear that a person skilled in this field will be able to make many modifications to the present embodiments without departing from the concept and from the scope of the invention. For example, spring devices other than helical springs can be used, and the spring can be locked in the compressed position in many different ways. The scope of the invention is limited only by the patent claims attached.

Claims: PATENT CLAIMS 1. Clamp device for fixing at least one cable (12) on a crossbar (11), the device comprising a U-shaped stirrup (1) which encloses the cable (12), and a thrust washer (4) for distributing a clamping pressure on the cable (12), characterized in that a spring device (5) applies an adapted compressive force on the thrust washer (4). 2. Clamp device according to Claim 1, characterized by a control lever (6) which permits locking of the spring device in the compressed position for fitting of the clamp and permits disengagement of the locking action so that the spring device exerts its force against the thrust washer. 3. Clamp device according to Claim 2, characterized in that the control lever comprises a rod with a blocking recessed part (7) which can be locked in a hole (8) in the stirrup (1), through which hole (8) the rod runs. 4. Clamp device according to any one of the preceding claims, characterized in that the spring device (5) is a helical spring. 5. Clamp device according to any one of the preceding claims, characterized in that intermediate washers (9) are placed between the cable (12) and the crossbar (11) and, where appropriate, between cables (12). 6. Clamp device according to Claim 5, characterized in that each intermediate washer (9) has recesses (10) which are open at the bottom so as to be placed on the stirrup (1) from above.

Inventors: ANDERSSON KENNETH, HJORT BO, NYRELL CARL-GOERAN, ANDERSSON, KENNETH, HJORT, BO, NYRELL, CARL-GOERAN
Applicants: ANDERSSON KENNETH, HJORT BO, NYRELL CARL GOERAN, TELIA AB, ANDERSSON, KENNETH, HJORT, BO, NYRELL, CARL-GOERAN
Application year: 1995
Main classification: F16L3
IPC codes: F16L3