Constant vacuum pneumatic sucking device in particular for application to spinning frames

Abstract

 There is disclosed a sucking pneumatic device, for application on spinning frames, which is so arranged and designed as to provide a substantially constant vacuum.
This device comprises a sucking assembly, such as a fan motor assembly, arranged in a suitable casing (1) therefrom a tubular chamber (2) extends longitudinally of the spinning frame and through the side walls of which there are provided a plurality of suitably spaced holes (3).
With these holes (3) there are associated sucking tubes (4) of different shapes to the sucking mouth portions (6) of which, coupled to the side wall of the longitudinal chamber, there are applied reducing elements (5).
These reducing elements (5), in particular, are provided with different diameter openings so as to provide, considered the usual pressure drop, the same sucking force or vacuum through each said sucking tube arranged on the overall extension of the longitudinal chamber.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a constant vacuum pneumatic sucking device in particular for application to spinning frames.

[0002] As is known, a spinning frame is usually provided with a sucking apparatus which comprises a motor and fan assembly arranged on the head of the spinning frame.

[0003] More specifically, the sucking assembly, held within a suitable casing, operates through a sucking or vacuum channel longitudinally arranged with respect to the spinning frame.

[0004] Also known is the fact that through the side walls of the mentioned vacuum channel there are formed a plurality of holes to which there are coupled specifically designed sucking or vacuum tubes, the so-called "flutes" which cooperate with the drawing assemblies of the spinning frame.

[0005] These sucking tubes are specifically designed to provide, for each table of the last drawing cylinder, a suitable sucking so that as the spinning operation is interrupted, for example because of a breakage of a thread, the broken thread is automatically sucked thereby being prevented from spreading through the apparatus.

[0006] Moreover, the mentioned sucking operation is adapted to remove from the made thread possible free fibres which are not bound to the thread and are susceptible to provide the thread with an undesired hairiness.

[0007] The mentioned sucking channel is provided for removing broken threads, powders and all of the waste which is produced during the cotton processing steps which precede the spinning operation proper.

[0008] In this connection it should be pointed out that the sucking channels, because of a comparatively great length thereof, are subjected to an unevitable negative pressure drop which increases as the distance from the fan-motor assembly casing increases.

[0009] This negative pressure or vacuum drop causes several drawbacks the main of which consists of undesirable thread breakages, mainly at the sucking control unit.

[0010] As a thread breakage occurs, an operator must recover the proper spinning conditions by joining the broken threads.

[0011] This operation, as it should be apparent, results in a comparatively great cost due to the use of labour, waste of thread and reduced yield of the machine.

[0012] Constructional remedial steps have been already taken in order to reduce the negative pressure drop along the several portions of the sucking channel, as disclosed, for example, in the DE 38 10 588 A1 document to Zinser Textilmaschinen.

[0013] These steps, however, lead to the construction of comparatively high cost systems both because inherent constructional complications and because of very great difficulties during the assembling of the several component parts of these systems.

SUMMARY OF THE INVENTION

[0014] Accordingly, the aim of the present invention is to overcome the above mentioned drawbacks, by providing a pneumatic sucking device for application to spinning frames which is adapted to provide a substantially constant negative pressure or vacuum through the overall longitudinal extension thereof.

[0015] Within the scope of the above mentioned aim, a main object of the present invention is to provide such a pneumatic sucking device, to be applied to spinning machines, which is very simple construction-wise and accordingly has a very reduced cost.

[0016] Another object of the present invention is to provide such a pneumatic sucking device for application to spinning frames which is very reliable in operation.

[0017] According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a pneumatic sucking device, to be applied to spinning frames, comprising a fan-motor assembly, arranged within a holding casing, therefrom a tubular chamber extends through the side walls of which there are formed a plurality of holes, to which there are coupled a corresponding plurality of sucking tubes, characterized in that on the outlet mouth portions of said sucking tubes there are arranged reducing elements having different diameter ports so as to provide, considered the usual operative pressure drop, the same sucking or negative pressure value through each of said sucking tubes extending all along said chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Further characteristics and advantages of the pneumatic sucking device according to the present invention will become more apparent from the following detailed description of a preferred, though not exclusive embodiment of the device which is illustrated, by way of a merely indicative but not limitative example, in the figures of the accompanying drawings, where :

Figures 1 and 2 show two sucking tubes or "flutes" provided with reducing elements including different diameters outlet ports;
and

Figure 3 schematically shows a sucking device according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0019] With reference to the figures of the accompanying drawings, the pneumatic sucking device, for application to spinning frames, according to the invention, comprises a fan-motor assembly arranged in a holding casing 1 therefrom a tubular chamber 2 extends through the side walls of which there are formed a plurality of holes 3 to which there are coupled specifically designed sucking tubes or "flutes" 4.

[0020] According to the invention, on the outlet sucking mouth portions of the mentioned sucking tubes there are applied reducing elements 5, provided with different diameter ports, and so designed as to provide the same sucking value through each of said flutes, depending on the vacuum or negative pressure which is present in the inside of the chamber, at the considered portion.

[0021] According to the preferred embodiment, if the chamber has a length of 40 metres, then on the sucking tubes or flutes there will be arranged reducing elements having a cross-section opening varying from 10 to 20 mm.

[0022] These sucking tubes or flutes can also be provided with a constant opening at the sucking chamber and the tubes can be partially throttled by means of reducing elements or dams arranged at the end mouth portions 6 for sucking in the environment air.

[0023] In particular, the above mentioned end mouth portions will be preferably provided with an ellipsoidal or ovoidal profile.

[0024] From the above disclosure it should be apparent that the invention fully achieves the intented aim and objects.

[0025] While the invention has been disclosed and illustrated with reference to a preferred embodiment thereof, if should be apparent that the disclosed embodiment is susceptible to several modifications and variations all of which will come within the spirit and scope of the appended claims.

Claims

1. A pneumatic sucking device, to be applied to spinning frames, comprising a fan-motor assembly, arranged within a holding casing, therefrom a tubular chamber extends through the side walls of which there are formed a plurality of holes, to which there are coupled a corresponding plurality of sucking tubes, chararterized in that on the outlet mouth portions of said sucking tubes there are arranged reducing elements haring different diameter ports so as to provide, considered the usual operative pressure drop, the same sucking or negative pressure value through each of said sucking tubes extending all along said chamber.

2. A pneumatic sucking device according to claim 1, characterized in that said sucking tubes are provided with a constant opening at said chamber and are partially throttled by reducing elements or dams arranged at end mouth portions thereof.

3. A pneumatic sucking device according to the preceding claims, characterized in that said end mouth portions have an ellipsoidal or ovoidal profile.

Drawing