For the isolation of building elements isolating fibrous material is used, which with todays common methods is injected into the building element (s) to be isolated either at the workshop producing the element (s) or at the existing building sites.

Such an isolating material are e. g. environmental fibres, produced by means of waste paper and have excellent isolating properties and are at the same time environmentally acceptable.

Various devices might be used for the injection, normally, however, an isolating material is supplied to the injection device from bales packed into bags delivered to the workshop or the site. To provide an effective isolation of the building element in question the bale of isolating material must be split up and finally be dissolved to expose the individual fibres.

Such a method uses a device fluffing the material, e. g. a shaft with wings to break up the packaged isolating material, whereafter it is, after an eventual further beating, led to a flash conduct to be supplied to filling aggregate with an injection device, with which the building element is filled with the isolating fibres.

When the material is transported packaged together in bales in bags it has however become apparent that the handling known in the art of the material is not sufficient to dissolve the fibres without the remaining problem that the fibres are not sufficiently exposed before they are led to the spraying device, but create lumps and knots decreasing the isolating characteristics during spraying and can moreover result in an unnecessarily high isolating material consumption.

Examples of known machines for tearing or dissolving coherent bales of fibrous material are found in the Swedish publications 395733,464880,464881 and 466501. In these machines various kinds of the above described fluffing means with wings for dissolving the coherent material, possibly in combination with further tearing means and lock feeding means, before the material is led to a blowoff pipe feeding the fibres to means to inject them into building elements to be isolated.

However, it has become apparent in practice, that none of the machines known in the art was able to solve the problems mentioned above so that a complete dissolving or tearing of the fibrous material to separate fibres could be achieved.

The main purpose of the invention is to propose a method and a device, with which a complete dissolving can be achieved of the isolating fibrous material into separate components, preferably separate fibres, before an injection into the building element or any other item to be isolated.

This and other purposes of the invention are achieved in that the method and the device are provided with the characteristics specified in the claims to follow.

The invention will in the following be described with an embodiment of a device for accomplishing the method, with the device illustrated in the attached drawings.

Figure 1 shows a side view of the device for accomplishing the method, Figure 2 shows a top view of the device shown in figure 1, Figure 3 is a cross section along the line III-III in figure 1 through the device shown in figure 1.

The device shown in figure 1 comprises a feeding shaft 10 with vertical walls 12. The shaft 10 provides the feeding tank for isolating material supplied to the shaft as a coherent mass, e. g. in form of bales (here not shown). The shaft 10 is connected to a casing 14 with an opening 15, as shown in figure 2, and the opening forces the bales to fall down into the casing and to be supplied to a feed worm 16, the shaft of which is suspended in a bearing box 22 arranged at one end of the shaft at the end wall 20 in the casing 14 and in a bearing 26 situated outside said end wall on a bracket 24. On top of each turn of the worm thread a tear edge 25 is placed, shown in section in figure 3, the tear edge 25 possibly approaching the inner wall of the casing 14 or being arranged in an intermediate space of it. Several edges 25 might of course be arranged for each turn of the worm thread 16 if so needed for a sufficient dissolving of the coherent fibrous material, or the worm thread might have a more or less regular edge on its circumference.

On the far-off end of the shaft 18 outside the bearing 26 a pulley 28 is arranged, which by means of a belt 30 is driven by a driving motor 32. The worm 16 passes at its side facing the drive a partition wall 34 in a chamber 36 cylindrically and totally surrounding the worm gear. The portion of the worm gear 16 situated in the chamber 36 has no tear edges on its circumference.

Next to the chamber 36 a cylinder cutter 40 is arranged in a cylindrical casing 38 at a short distance from the end of the worm 16 situated in the casing 36 and is driven by a here schematically shown driving motor 41. When the material hits the cylinder cutter 40 possibly remaining lumps or mats of fibres are dissolved and torn apart so that separate fibres are achieved. Between the worm end and the cutter 40 a free zone is formed, in which a pressure is created by the material transported there by the worm. This pressure pushes the material with a desired force against the cutter cylinder 40.

In the bottom of the cutter casing 38 an opening is made, followed by a pipe channel 42, from which the fibres, exposed by the cutter and falling down into the pipe channel 42 are blown by means of a ventilator and a blow pipe (here not shown) to the filling device used to fill e. g. a building element to be isolated. For adjusting the supply of exposed fibres to the channel 42 and thus a forming of a pressure in the described free zone, the size of the opening in the bottom of the cutter casing 38 is adjustable by means of a displaceable throttle 44.

The casing 14 with the worm 16 and the cutter casing 38 are placed on a socket 46 with legs 48 with such a length that the pipe channel 42 is housed below the socket 46.

The shown and described embodiment operates in the following way. In the shaft 10 a number of bales is inserted, of which the lowest by means of the weight of the bales on top is pressed against the worm 16 in the casing 14. In rotating the worm 16 the bales of fibrous material are loosened by the tear edges 25 on the worm threads and the released fibrous material will by the worm 16 be transported towards the cutter cylinder 40 in the casing 38. When the material arrives in the packed casing 36 completely surrounding the worm thread the worm 16 will build up a pressure in the material in the free zone between the worm end and the cylinder cutter 40, as mentioned previously, the pressure being used to push the material against the cutter cylinder 40 and the final dissolving of the isolating material into separate fibres thus being achieved. By means of the opening or the throttle 44 the supply of the dissolved fibres to the pipe channel 42 is then controlled so that the desired filling in the element to be isolated is accomplished.

It can be seen that the invention has achieved a method and a device, with which the problems described in the beginning for dissolving isolating material in form of bales have been eliminated. The combination of a feed worm and a cutter device and especially the adaptation of a zone in front of the cutter device has shown to provide an excellent exposure of the fibres for a further use, in which zone a pressure is build up achieving a more effective cutting of the material.