Site News  |   Monitor Keywords  |   Monitor Archive  |   Organizer  |   Account Info  |

Fibre for an acoustic insulating material, especially for sound dampers compressed air devices

The present invention relates to a new acoustic insulating material, especially for sound dampers in compressed air devices.

From DE 10248183 A1, for example, it is known that insulating materials can be used in the form of a knitted fabric roll in sound dampers of compressed air devices. Such a knitted fabric roll is made from a tubular knitted fabric produced on a circular knitting machine from warp knit thermoplastic fibres having, for example, rectangular cross section, by cutting a knitted fabric tube to a predetermined length and heat sealing it at its cut faces in such a way that a rectangular tubular portion is obtained. This rectangular tubular portion is then rolled up to obtain a knitted fabric roll. The knitted fabric roll is then pushed into a connecting tube leading to the atmosphere. Aside from the fact that it is necessary to use an additional connecting tube, which requires a large amount of installation space, and that it is necessary to take additional measures to ensure that the knitted fabric roll is held sufficiently in place in the connecting tube, the resulting sound damping is not satisfactory.

DE 42 37 630 A1 describes a compressed air venting device that has a primary air path routed from an inlet of a housing via noise damping means to an outlet, and a secondary air path provided parallel thereto and comprising a first sub-channel extending from the inlet and a second sub-channel formed by the outlet or leading to the outlet. The two sub-channels are not filled with the noise damping means. The two sub-channels are in communication with one another via the noise damping means. The two sub-channels and that part of the noise damping means which places the two sub-channels in communication are arranged in such a way that such part of the noise damping means opens up a direct communication path between the two sub-channels when a dynamic pressure is admitted. The noise damping means are formed by a filtering knitted fabric, which comprises a stocking-like woven part of plastic flat wire, which is wound in the form of a roll. The housing is composed of one housing part resembling a pot and another housing part formed as a cover to be snapped thereon. A disadvantage of this compressed air venting device used as a sound damper is that the danger of leaks causing a loud noise level exists at the joints of the housing parts. Moreover, the known device is relatively bulky, and therefore requires considerable installation space.

Generally speaking, in accordance with the present invention, a new acoustic insulating material, especially for sound dampers of compressed air devices, is provided. The inventive material overcomes disadvantages associated with conventional acoustic insulating material and enables the construction of a sound damper in the form of a kitted fabric roll for compressed air devices which offers improved noise or sound damping.

The present invention embodies an insulating material comprising a knitted fabric tube made from fibres and rolled up to form a knitted fabric roll. According to the present invention, plastic fibres having a larger surface area than conventional fibre structures are used because the outer cross-sectional contour of the fibres has a geometric shape differing from that of the round outer form.

According to advantageous embodiments of the present invention, the enlargement of the surface area of the fibre is achieved by regularly or irregularly profiled fibre cross-sectional contours, especially by a cruciform or stellate fibre cross section.

According to one embodiment of the present invention, an enlargement of the surface area can also be achieved by an embossed, regular or irregular structure or profiling of the surface of the fibre in longitudinal direction of the fibre.

The foregoing approaches for increasing the surface area according to embodiments of the present invention can also be combined.

Still other objects and advantages of the present invention will in part be obvious and will in part be apparent from the specification.

The present invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

The present invention will be described in greater detail hereinafter on the basis of the accompanying drawings, wherein:

FIG. 1 shows a fibre with cruciform cross section in accordance with one embodiment of the present invention,

FIG. 2 shows a fibre with stellate cross section in accordance with another embodiment of the present invention,

FIG. 3 shows a fibre with an irregular stellate cross section in accordance with yet another embodiment of the present invention,

FIG. 4 shows a fibre with surface profiling in the longitudinal direction in the form of alternating thick and thin cross-sectional regions in accordance with a further embodiment of the present invention,

FIG. 5 shows a fibre having a cross-sectional profile similar to the fibre depicted in FIG. 1 with additional longitudinal profiling in accordance with a still further embodiment of the present invention, and

FIG. 6 shows a fibre having a cross-sectional profile similar to the fibre depicted FIG. 2 with additional longitudinal profiling in accordance with another embodiment of the present invention.