An elastic weaved belt to sustain the human body

Description

[0001] The present invention relates to woven elastic belts used to support the human body in applications for articles of indoor or outdoor furniture, such as chairs, seats, settees, beds or other similar items, as well as for seats of motor vehicles and similar applications. These belts are placed in tension between opposite sides of a frame of the article of furniture or the like and support, as stated, the weight and the thrust of the human body in place of more traditional springs.

[0002] Every belt is obtained from webbing with elastic warp threads in tension and substantially anelastic weft threads.

[0003] Every warp thread is in fact formed from a rubber thread, either natural latex or synthetic rubber, that it is covered with a substantially anelastic thread, for example a polypropylene thread. The covering can be carried out by various methodologies, in themselves known, called respectively " chain stitch", "monospiral" or "bispiral". In particular, the chain stitch covering forms a plurality of knots, substantially equidistant, that limit the maximum elastic excursion of the complex formed by the elastic thread and the substantially anelastic covering thread. For example, the distance between two consecutive knots on the rubber thread, in conditions of maximum traction, is usually comprised between some tenths of a millimeter and some millimeters.

[0004] These elastic belts have found very many applications in the fields cited, but however it has also been found that they can have some disadvantages, both in relation to particular uses, and in relation to their durability and the retention of their characteristics over time

[0005] In effect, the elastic belts with rubber threads have, exactly due to such rubber threads, an insufficient resistance to heat, ozone and to chemical agents in general. They tend to age and the rubber threads, with use, tend to tear and break, especially as a result of the tightening action exerted on them by the knots or the threads of the covering.

[0006] The object of the present invention is to propose an elastic belt of the type used for the cited applications which, while maintaining at least the same performance as the current elastic belts, avoids the disadvantages cited above.

[0007] This object is achieved, according to the invention, by replacing one or more of the rubber threads - preferably all the rubber threads - each with a thread or bundle of two or more polyurethane threads, especially threads in spandex.

[0008] These threads or bundles of threads in spandex remain unaltered under all conditions in which rubber threads degrade, and the spandex threads are not in danger of breaking or being cut by the knots or the threads of the covering. Considering that the threads of spandex that are commercially available are in general thinner than the rubber threads necessarily employed in the belts cited, it can be suitable to replace every rubber thread with a bundle of two or more threads in spandex, up to an overall value of 1000 to 11000 dtex.

[0009] Moreover, the covering can be advantageously carried out with a covering having chain stitch knots that are closer to each other than those used in the covering on the rubber threads (up to + 80%) and this without danger of ruining the spandex threads. For example, the knots of the covering applied on the spandex are located with a gap thereof, under conditions of maximum traction, comprised between 1 mm and 9 mm.

[0010] The covered spandex threads are then arranged as the warp for the webbing of the belt according to classic methods. The warp can also be placed under tension in this case, but it is possible in this way to exercise a tension close to the maximum that can be applied to the covered elastic threads of spandex, unlike what happens in the case of the rubber threads, where the tension must be limited in order not to excessively wear out the rubber.

[0011] Under these conditions, the spandex works better than the rubber, which shows the maximum wears under tension.

Claims

1. A woven elastic belt, destined to support the human body in indoor and outdoor articles of furniture, seats for motor vehicles or the like, of the type comprising a plurality of elastic threads covered by substantially anelastic threads, which forms the warp of the belt woven with substantially anelastic weft threads, characterized in that at least some of the elastic threads are in the form of polyurethane threads.

2. An elastic belt according to Claim 1, characterized in that the elastic threads are of spandex.

3. An elastic belt according to Claim 1 or 2, characterized in that the elastic threads are each formed by one, two or more polyurethane threads bundled and covered with a single substantially anelastic thread.

4. An elastic belt according to Claim 3, characterized in that every thread or group of threads covered together by a single substantially anelastic thread, has a total value of 1000 to 11000 dtex.

5. An elastic belt according to one or more of the previous Claims, characterized in that every elastic thread or every group of elastic threads is covered with a substantially anelastic thread applied as a "monospiral" or "bispiral" chain stitch.

6. An elastic belt according to Claim 5, in which every elastic thread or every group of elastic threads is covered with a substantially anelastic thread applied as a chain stitch, characterized in that the knots of the covering chain stitch are located at a mutual distance of between 1 mm and 9 mm under conditions of maximum tension.

7. An elastic belt according to any of the previous Claims, characterized in that it is woven with the warp threads stretched close of the their maximum allowed tension.