STATE OF THE ART Such a bushing is known from US-A-3 880 453. In the case of that bushing, the filling means comprises a polymer compound. A problem with that bushing is that when the polymer compound has solidified the bushing becomes permanent, which means that it cannot thereafter easily be taken apart for replacement, removal or addition of cables.

Such taking apart has therefore to entail first laboriously removing the solidified polymer compound from the cables and then replacing it with fresh polymer compound when the bushing has been put together again.

SUMMARY OF THE INVENTION One object of the invention is to provide a bushing/cable lead-through of the kind indicated in the introduction which solves the abovementioned problem and which can in a simple, flexible, sealing and dismantlable manner accommodate a varying number of cables.

This is achieved by features indicated in the claims set out below.

According to the invention, the filling means comprises a filling element made of flexible material and provided with slitting to accommodate and sealingly enclose said one or more cables continuously through the casing.

Using instead of a filling compound a slit filling element made of a flexible material makes it possible by varying compression of the flexible material in a single casing to provide a noise-damping, water-tight and at the same time dismantlable bushing for a varying number of cables.

The slitting comprises two or more slits which may extend radially with respect to a central axis of the filling element. This makes it possible to ensure that cables varying in number and size are suitably distributed in both radial and angular directions in the filling element.

Whereas the filling element is preferably made of foam plastic material, the casing may be a rubber bellows with a rotationally symmetrical shape which narrows with increasing distance from the wall aperture. The casing also advantageously has peripheral stages at which it can be cut off as appropriate to the combined thickness of the cluster of cables to be accommodated in the bushing.

Other features and advantages of the invention are indicated by the claims and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 depicts partly in longitudinal section a bushing according to the invention, when fitted in a wall aperture so as to be ready for use; Fig. 2 depicts a bushing according to the invention corresponding to Fig. 1, in use; Fig. 3 is a cross-sectional view of a filling element according to the invention, when ready for use; and Fig. 4 is a view corresponding to Fig. 3 of a filling element according to the invention, in use.

DESCRIPTION OF AN EMBODIMENT The bushing denoted generally by ref. 10 in Figs. 1 and 2 incorporates an elastic casing or a bellows 12 made of rubber or similar material and, accommodated in it, a filling element 22 made of a flexible material such as waterproof foam plastic with closed pores.

The bushing 10 is shown fitted in a circular aperture 28 in a wall 26, e. g. a dividing wall between an engine compartment and a cab or passenger compartment of a motor vehicle.

The rotationally symmetrical casing 16 narrows stage by stage with increasing distance from the wall 26. At its broader end the bushing 12 is provided with a peripherally situated recess 14 which engages with the edge of the wall aperture 28 and holds the bushing firmly in the wall 26.

In the embodiment depicted, the filling element 22 has an external shape which substantially corresponds to the shape of the inside of the bushing 12 and has at its broader end a radial ledge 23 which engages behind the recess 14 of the bushing 12 in order to retain the filling element 22 within the bushing 12. If the bushing element 22 is made of a soft foam plastic, however, it may possibly have a simple conical shape.

As most clearly indicated in Figs. 3 and 4, the filling element 22 is provided with slitting in the form of a multiplicity of radial slits 24 which extend radially inwards from the outside of the filling element 22 and along the whole length of the filling element 22. As illustrated by Figs. 2 and 4, each slit 24 can accommodate one or more cables or the like 30 sealingly enclosed by flexible material of the filling element 22 when the latter is inserted in the casing 12.

If two or more cables 30 to be led through have a larger combined thickness than the diameter of the opening 19 at the free end of the casing 12, the casing and the filling element 22 may be cut off at a larger diameter such as defined in more detail by a section 20 (Fig. 1) just before a stop flange 18 on a peripherally situated portion 16 of the casing 12. As may be seen in Fig. 2, the cluster of cables 30 may thereafter be secured in the

casing 12 by a collar band 34 held in position by the stop flange 18 at the free end of the casing 12.

The bushing 10 is fitted as follows: The casing 12 and the filling element 22 are first cut as necessary to create a suitable diameter of the opening 19 at the narrow end of the casing 12 to allow all the desired cables, including any contact devices 32, to be led through. Thereafter the filling element 22 is taken out and the cables are threaded one by one through the casing 12. Outside the casing 12, the cables 30 are then pressed radially into radial slits 24 in the filling element 22. This is followed by pushing the filling element 22, with the cables 30, into position in the casing 12. Where necessary, a collar band 34 is also tightened round the portion 16 to hold the cables 30 securely at the narrow end of the casing 12. Finally, the casing 12 is fixed in the wall 26 by squeezing it together somewhat and introducing it into the wall aperture 28 so that the recess 14 is caused to engage about the edge region of the wall aperture 28 when the casing 12 is allowed to expand again.

When the bushing 10 is not in use, as in Fig. 1, it serves to seal the wall aperture 28 and is ready for future laying of cables, e. g. on the occasion of retrofitting of extra equipment in a vehicle cab.