FR2699559A1 - Raschel knitter for medical application materials - Google Patents

Abstract

The fabric take-in rollers (1-3) for a Raschel knitter, where some have an angular shift, have at least one barrier (5) inserted into the roller angular shift zone. The operative is prevented (5) from inserting hands between the rollers when the barrier (5) is in place.The barrier (5) is pref. fitted in combination with sensors (6) to stop the machine if a barrier is displaced. The barriers have pref. tubes (5a, 5b) of a smaller dia., to be fitted between the displaced rollers (1, 2), end to end along the roller lines. The tubes (5a, 5b) are of a lightweight material, especially PVC.The sensors (6) form a photo-electric screen.

Description

Safety device for the knitting loom of the type
RACHEL.

 The invention relates more particularly to the technical sector of automatic knitting looms, in particular for the manufacture of special fabrics for medical use for example.

 In particular, the invention applies to knitting looms of the RACHEL single needle type, such as those known in the trade under the reference RS3 / 4 / N2K. These trades are perfectly known to a person skilled in the art and are characterized by very high working speeds.

 Essentially, these trades include a set of attracting rollers driven in rotation and between which passes the fabric to be manufactured. Some of these rollers are arranged angularly, being directly accessible by the user.

Given the very high speed of these rollers, we
l understands that there are very significant risks of accidents, given that the user, when he must for example work on the fabric, may inadvertently put his hands between the rollers. These risks of jamming are unfortunately facilitated by the angular offset of the rollers.

 In an attempt to remedy these drawbacks and prevent such accidents, it has been proposed to equip this type of trade with a protective casing preventing access to the attractor rollers. This casing is pivotally mounted to tilt forward to give free access to the needle bed. However, this casing, in the working position, prevents visual monitoring of the proper progress of the weaving.

 In addition, when the operator must intervene in this area, for example for the breaking of a wire, it turns out to be necessary to tilt the casing towards him, which distances him considerably from his area of intervention. Furthermore, when the casing is tilted, it rests on the fabric previously knitted and wound on rolls. This results in the risk of dirt and deposits of particles on the fabric thus wound.

It is understood that this is not acceptable, having regard to certain medical applications envisaged.

 The object of the invention is to remedy these drawbacks in a simple, safe, effective and rational manner.

 The problem which the invention proposes to solve is to ensure the protection of the operator, by preventing him from accidentally sliding his fingers between the attracting rollers, while allowing him to visualize the good progress of the fabric manufacture.

 To solve such a problem, a safety device has been designed and developed which is particularly applicable to a knitting machine of the RACHEL single needle type comprising a set of attracting rollers driven in rotation and between which passes the fabric to be produced, some of the said rollers being angularly offset. According to the invention, the device comprises at least one insert element inserted in the zone of angular offset of the rollers, the said element or elements being shaped to prevent the introduction of hands between said rollers.

 Another problem which the invention proposes to solve is to ensure double security by stopping the trade in the event that the operator passes, despite everything, his hands at the level of the protective element or elements.

 Such a problem is solved in that the protective element or elements are mounted in combination with detector members capable of stopping the loom when at least one of the protective elements is raised.

 To solve the problem of lifting at any place in the loom, the protective elements consist of tubes of reduced diameter, to be fitted between the rollers offset angularly, said tubes being arranged end to end according to the generatrices of said rollers.

 The tubes are made of light material, in particular PVC.

 To solve the problem posed of stopping the loom when at least one of the protective elements is raised, the detector members are cells creating a photoelectric barrier.

The invention is set out below in more detail using the appended drawings, in which:
Figure 1 is a schematic perspective view of a loom equipped with the device according to the invention.

 Figure 2 is a longitudinal sectional view of the device.

 Figure 3 is a cross-sectional view taken along line 3.3 of Figure 2.

We recall for a better understanding of the sequence of
the description, that the loom comprises a set of attracting rollers (1) (2) (3) (4) driven in rotation. Between these rollers passes the fabric (T) woven downstream by any known and appropriate means. The rollers (1) (2) and (3) are angularly offset. Such arrangements are not described in detail since they do not form part of the specific object of the invention and are perfectly known to a person skilled in the art.

 According to the invention, the device comprises at least one insert (5) inserted in the angular offset zone of the rollers (1) (2) and (3). More particularly, these protective elements (5) consist of several sections of tubes (5a) (5b) (5c) arranged end to end according to the generatrices of the attracting rollers (1) (2) (3) (4). These tube sections are arranged between the rollers (1) and (2) and bear against the angularly offset upper roller (3), so as to prevent access to the zone resulting from the angular offset of the superimposed rollers (2) and (3).

These tubes are of reduced diameter and are executed in a
..

lightweight material, especially PVC. They are therefore driven in rotation simultaneously with the attractor rollers, given their entirely free mounting on the latter.

 Advantageously, these protective elements in the form of tubular sections (5a) (5b) (5c), are mounted in combination with detector members (6) when at least one of the elements is lifted.

For this purpose, these detector members (6) are constituted by cells arranged opposite one another, constituting respectively a transmitter and a receiver. These cells are positioned at each end of the set of tube sections (5a) (5b) (5c) creating a
photoelectric barrier, the light beam of which passes through the tubes,
taking into account their hollow section.

The operation of the device is particularly simple and
effective.

After placing the tubes (5a) (5b) (5c) between the
rollers (1) (2) (3), under the conditions indicated above,
The operator no longer has access to the attractor rollers (2) and (.3), avoiding all of them
risk of trapping his hands.

 Furthermore, in the event that, despite everything, the operator came to introduce his hands between the tubes (5a) (5b) (5c) and the attracting rollers, the tube concerned (5a) (5b) (5c) would be immediately raised, which would have the effect of intercepting the light beam and, consequently, causing the craft to stop simultaneously.

The advantages clearly emerge from the description, in particular it is emphasized and recalled:
- the simplicity of implementation,
- the effectiveness of the result obtained by the double security of the tubular sections and of the phoelectric cells,
- the possibility of adapting the system to all types of trades.

Claims (5)

-1- Safety device for knitting loom of the RACHEL single needle type comprising a set of attracting rollers (1) (2) (3) (4) driven in rotation and between which passes the fabric to be produced, some of said rollers (1 ) (2) (3) being angularly offset, characterized in that it comprises at least one insert (5) inserted in the angular offset zone of the rollers (1) (2) (3), the said element (s) ( 5) being shaped to avoid the introduction of hands between said rollers. -2- Device according to claim 1, characterized in that the protective element (s) (5) are mounted in combination with detector members (6) capable of stopping the loom when at least one of the protective elements is raised . -3- Device according to claim 1, characterized in that the protective elements (5) consist of tubes of reduced diameter (5a) (5b) (5c), to be fitted between the rollers (2) (3) , angularly offset, said tubes being arranged end to end according to the generatrices of said rollers. -4- Device according to claim 1, characterized in that the tubes (5a) (5b) (5c) are made of light material, in particular PVC.  -5- Device according to claim 1, characterized in that the detector members (6) are cells creating a photoelectric barrier.