FR2716821A1 - Protective chamber for laser appts. - Google Patents

Abstract

The chamber e.g. for protecting laser cutting or welding appts., has \- one observation port which is covered by a filter screen (5) which lets through visible light but stops the laser light. The filter screen (5) is associated with a mirror which is able to reflect light between the laser appts. and the filter screen and is situated in a lateral recess (3) formed by a projection (11) on the chamber's wall. The mirror is a normal one, with a reflective layer behind the glass, which is transparent in the visible light waveband and opaque in the infrared band. The body of the chamber is made from a material which is able to absorb and contain light.

Description

 The present invention relates to a protective enclosure for a laser machine equipped with at least one observation sight provided with a filter screen made of a material allowing visible light to pass through and stopping the light from the laser.

 It provides protection for personnel or operators from high-power laser machines (cutting, welding, etc.) working in the infrared by enclosing these machines in protective enclosures. Operators can observe the machine through observation windows or viewfinders provided on the enclosure and provided with transparent materials in the visible and opaque in the infrared. These materials only resist for a few seconds when they are struck, during an incident, by a beam of high-power laser light.

 The object of the present invention is to provide a protective enclosure provided with observation sights ensuring, in the event of an incident, effective protection of operators or observers with respect to beams of high power laser light.

 The enclosure according to the invention is characterized in that the filter screen is associated with a rear-view mirror capable of reflecting light between the machine and the filter screen and housed in a side window projecting from the wall of the 'pregnant.

The invention will now be described in more detail with reference to an embodiment given by way of example and represented by the appended drawings in which:
- Figure 1 is a top view of the protective enclosure according to
the invention;
- Figure 2 is an elevational view of the enclosure.

- Figure 3 is a detail view of an observation sight
formed on the enclosure of FIGS. 1 and 2.

 Referring to the drawings, the protective enclosure is constituted by a wall or a wall 1 having a closed contour so as to form a space in which is housed a laser machine 2 of great power working in the infrared (machine with solder or cut). The height of the wall is sufficient to protect the operators. The enclosure is open at the top.

 The enclosure has one or more observation sights 3 shown in detail in FIG. 3.

 Each observation sight 3 is provided on the operator's or observer's side with a filter screen 5 made of a material allowing visible light to pass and stopping laser light. The filter screen 5 is associated with a rear-view mirror 4 capable of reflecting visible light, between the laser machine 2 and said filter screen 5. The rear-view mirror 4 is housed in a side window 3 arranged projecting from the wall 1 of the 'pregnant.

 The body 11 of the telescope is integral with the wall 1 of the enclosure. The filter screen 5 closes the lens body, on the operator's side. The lens body 11 is made of a material capable of absorbing and collecting laser light.

 The filter screen 5 and the rear-view mirror 4 are arranged vertically and make an acute angle with respect to each other. Preferably the filter screen 5 is perpendicular to the wall 1 of the enclosure.

 The rear-view mirror 4 is an ordinary mirror having the reflecting part behind the glass slide which is transparent in the visible and opaque in the infrared.

 The operator or observer looks at the laser machine behind the filter screen 5, through the rear-view mirror 4.

 In the event of an incident, if an incident (infrared) laser beam 7 arrives on the rear-view mirror 4, the latter reflects a very small part of the light towards the filter screen 5 and absorbs the rest, that is to say the most much of the light. The filter screen 5 is capable of filtering the small part of laser light which has been reflected. If the power of the laser beam is low, the reflected part of the beam is therefore stopped by the filter screen 5 and cannot pierce it. On the other hand, if the power of the laser beam is large to the point that the absorbed part melts or breaks the rear-view mirror 4, the latter does not return laser light to the filter screen 5 and to the operator. The absorbent and heat-resistant material of the spectacle body 11 absorbs the beam of laser light.

 Due to its nature, the rear-view mirror 4 never reflects towards the filter screen 5 a beam likely to endanger this screen.

 It is understood that it is possible without departing from the scope of the invention to imagine variants and improvements in detail and even to envisage the use of equivalent means.

Claims (4)

 1. Protective enclosure for laser machine (2), comprising at least one observation sight provided with a filtering screen (5) made of a material allowing visible light to pass and stopping the laser light, characterized in that the filter screen (5) is associated with a rear-view mirror (4) capable of reflecting the light between the machine and the filter screen (5) and housed in a side window (3) projecting from the wall (1) of the 'pregnant.  2. Protective enclosure according to claim 1, characterized in that the rear-view mirror (4) is an ordinary mirror having the reflecting part behind the glass slide which is transparent in the visible and opaque in the infrared.  3. Protective enclosure according to any one of the preceding claims, characterized in that the filter screen (5) closes the telescope (3) on the side of the observer.  4. Protective enclosure according to any one of the preceding claims, characterized in that the body (11) of the lens is capable of absorbing and collecting laser light.