FR2757980A1 - Electro-sensitive device for controlling access of operator in protected zone - Google Patents

Abstract

The access control system has two terminals (1,2) opposite each other. The first terminal (1) includes at least two pairs (3) of transmitters/receivers (4) of a luminous beam, which are aligned along a first line (1) and separated from each other by a predetermined gap (p). The second terminal (2) includes at least two pairs (5) of mirrors (6) which are inclined about 45 degrees. The mirrors (6) of a pair (5) are opposite each other. Each mirror (6) is arranged with respect to a transmitter/receiver (4) and the mirrors of the same pair (5) are aligned along a line (L,L') sensibly parallel to the first line (1), so that the luminous beam (Fe) emitted by the transmitters and the beam (Fr) reflected by the mirrors onto the receivers are sensibly parallel to each other. The system is characterised in that the distance separating the mirrors (6) of the same pair, with respect to a first pair of transmitters/receivers, is different from the distance separating the mirrors of a second pair, with respect to a second pair of transmitters/receivers, next to the first pair of transmitters/receivers. This is done so that the emitted beam is shifted in respect to the step (p) between two emitted or reflected neighbouring parallel beams so that for an assembly of beams emitted by a transmitter of a pair, a single beam is not reflected onto the receiver of the same pair.

Description

 The invention relates to a device for controlling the access of an operator in a protected area.

 The invention is more particularly intended to protect people - operators and / or visitors - from the risks that may arise from the proximity of dangerous machines such as machine tools, mobile machines, packaging machines, robots, etc.

 It is understood that the invention can receive other types of application.

 Systems of the aforementioned type are already known implementing manual and mechanical procedures such as doors or gates.

 Another device consists in providing two mechanical controls which have to be successively actuated, which prevents the operator from placing himself in a dangerous situation.

 Currently, these safety devices are less and less used due in particular to their maneuverability and their reduced ergonomics.

 This is why a multi-beam light barrier is generally used today to, on the one hand, stop the operation of the dangerous machine when the operator cuts the first beam and, on the other hand, prohibit any restarting. untimely as long as an operator is in this zone.

 To comply with the standards in force, there are safety grids on both sides of the light barrier intended to prevent the dangerous parts of the machine from being reached from the side.

 Generally, we add to this security system a reset console for the light column and a button to restart the machine.

 The advantage of such a system is its reliability if a follow-up of the assembly has been correctly done and if, in particular, the light barriers or their support do not serve as "steps" to reach the dangerous zones.

 However, this system has two major drawbacks apart from its cost: on the one hand, a significant loss of space and on the other hand, a long and tedious assembly on site, involving different trades.

 There is also known an electro-sensitive device of the aforementioned type, described in French patent application No. FR-A-2733849, comprising two terminals facing each other, one containing all the electronic and electromechanical part of the device, and the other does not require an electrical connection with the first.

 More specifically, the first terminal comprises at least two pairs of light beam transceivers, substantially aligned along a first line and spaced from each other by an identical predetermined pitch; the second terminal comprises at least two pairs of inclined mirrors of approximately 450, the mirrors of the same pair being facing one another, each mirror being arranged facing a transceiver and the mirrors d the same pair being aligned along a line substantially parallel to the first line, so that the light beams emitted by the emitters and the light beams reflected by the mirrors on the receivers are substantially parallel to each other.

 This device has in particular the advantage of saving space, speed and simplicity of the installation.

 However, since the mirrors are spaced by the same distance and aligned on the same line, respectively facing the transceivers, there is a risk that several beams emitted by a transmitter of a pair, and reflected on different mirrors arrive on the associated receiver of said pair. This risk is all the more important if the angle of the light spot emitted is large.

 The invention therefore aims to overcome the drawbacks of the prior art.

 To this end, the invention proposes a device of the aforementioned type characterized in that the distance separating the mirrors from a first pair, respectively opposite a first pair of transceivers, is different from the distance separating the mirrors of a second pair, respectively opposite a second pair of transceivers, adjacent to the first pair of transceivers, so that the emitted light beams are offset while respecting the predetermined pitch between two neighboring parallel emitted or reflected beams , so that for a set of beams emitted by a transmitter of a pair, only one beam is reflected on the receiver of the same pair.

 According to one embodiment of the invention, the mirrors are arranged on at least two parallel lines, the space between two neighboring mirrors being constant.

 In addition, the pairs of mirrors of the same line are distinct and successive and each pair of mirrors of a line is interposed or straddled between a pair of mirrors of the other line.

 In a particular embodiment, the first terminal comprises several lines of transceivers and the second terminal also includes, opposite, several lines of mirrors.

 In many areas of production, it is necessary to control both access to and presence in the protected area, and therefore to combine perimeter protection with surface protection.

 To this end, the first terminal and the second terminal each comprise at least one vertical line and at least one horizontal line so that the emitted and reflected light beams extend in two planes forming a barrier, one vertical, the other horizontal.

 It can also be provided that at least one of the beams is common to the plane forming a vertical barrier and to the plane forming a horizontal barrier.

 In general, the vertical barrier plan is intended for controlling operator access to the protected area and is located towards an extreme part of the terminals, determining the entrance to the protected area.

 The device of the invention may further comprise an integrated system for assisting in the optical alignment of all the mirrors, constituted by a laser.

 Other characteristics and advantages of the invention will appear on reading the description which follows, with reference to the appended figures, given by way of nonlimiting examples.

 Figure 1 is a perspective view of an electro-sensitive device according to an embodiment of the invention.

 Figure 2 is a top view of the second terminal having the mirrors.

 FIG. 3 represents a front view of the first terminal comprising the light beam transceivers.

 Finally, FIGS. 4a and 4b are two schematic views from above of a device according to the invention, operating partially.

 As indicated above, the device of the invention is intended, in the embodiment which will be described, to control the access of a person to an area comprising for example a dangerous machine.

 This machine, not shown, is surrounded by protective grids (not shown).

 More specifically, the machine is surrounded by two first substantially parallel protective grids and a third protective grid, substantially perpendicular to the first two grids, and fixed towards their end part.

 On the side opposite the third grid, the first two protective grids are extended respectively by a terminal 1, 2.

 These two terminals 1, 2 are arranged opposite one another, and extend, substantially vertically, as shown in FIG. 1.

 They are intended to be fixed, for example, directly to the ground.

 The first terminal 1 includes an electronic and electromechanical part necessary to generate light beams.

 This first terminal 1 is connected, for example, to the electrical control system of the power unit of the machine according to the standards in force.

 The connection is made on an industrial terminal block.

 With reference to FIG. 3, the first terminal 1 comprises five pairs 3 of transceivers 4 of light beams.

 The transceivers 4 are aligned along a first line 1 and spaced from each other by the same predetermined pitch.

 This first line 1 extends substantially parallel to the ground, as can be seen in FIG. 1.

 Still with reference to FIG. 3, the first terminal 1 comprises a second line 1 ′ comprising a pair 4a of transceivers 4.

 The second line 1 'is located towards the free end of the terminal 1 determining the entry of the protected area, on the side opposite the machine.

 The first line 1 extends substantially perpendicular to the second line 1 ', at its middle part. Lines 1 and 1 'thus form substantially a coated T.

 It is understood that FIG. 3 is only one embodiment, not exclusive of others. Consequently, the arrangement, indicated in this figure, of lines 1 and 1 ′ with respect to the edges of the first terminal 1 is not exclusive. It will depend on needs, even standards.

 It could also be envisaged that the lines 1 and 1 ′ are arranged so as to form an L as shown in FIG. 1.

 In addition, one of the transceivers 4 of the first line 1 is also located on the second line 1 '. In Figure 3, it is placed between the two transceivers 4 of the pair 4a.

 It is understood that the number of transceivers 4 is not limited to the number which has just been indicated.

 The transceivers 4 include testable photoelectric sensors.

 Indeed, it is possible at any time to cut off the light emission via a specific input.

 This possibility makes it possible to check that the sensor is operating correctly and to multiplex the sensors.

 These sensors are self-checking, that is to say that any failure of an internal component of the unit or of a sensor results in the safety of the system.

 With reference to FIG. 2, the second terminal 2 comprises five pairs 5 of mirrors 6.

These mirrors 6 are arranged along two lines L,
The substantially parallel to each other and to the ground.

 Each line L, L ′ comprises at least one pair of mirrors 6.

 More specifically, as shown in the embodiment of Figure 2, the line L has three pairs 5a, 5b, 5c of mirrors, while the line L 'has two pairs 5', 5 "of mirrors.

 Each mirror 6 is inclined at an angle a of approximately 450 relative to the line L, L '.

 In addition, the mirrors 6 of the same pair 5 are arranged opposite one another.

 The mirrors 6 are fixed on a part 7 having in cross-section a generally rectangular shape.

 The mirrors 6 are thus fixed on one of the long sides of the rectangle forming the part 7.

 Each part 7 comprises at least one lug 8 on at least one of its faces, in particular on the lower and upper faces, the whole being for example then mounted in a profile machined in the second terminal 2, so as to avoid any tedious adjustment of alignment of mirrors 6.

 Each pair 5 of mirrors 6 of line L is interposed or astride a pair 5 of mirrors 6 of line L '.

 Thus, as shown in Figure 2, starting from the left in the figure, the two mirrors 6 of the first pair Sa of the line L are located between the two mirrors, 6 ', 6' 'of the first pair 5' of the second line L '.

 In addition, the first mirror 6 of the second pair 5b of the line L is disposed near the first pair 5a of the first line L and between the mirrors 6 ', 6 "of the first pair 5' of the line L ' , while the second mirror 6 of this same pair 5b is disposed between the two pairs 5 'and 5 "of mirrors 6 of the line L'.

 Furthermore, the third pair 5c of line L is arranged between the two mirrors 6 of the second pair 5 "of line L '.

 In the assembled position of terminals 1 and 2, the lines L and L 'of the second terminal 2 are arranged so as to be opposite line 1 of the first terminal 1.

 The second terminal 2 also includes mirrors 6 arranged along one or two lines, not shown, substantially perpendicular to the lines L and L ', and parallel to and opposite the line 1' of the first terminal 1.

 These mirrors 6 can be arranged in the same arrangement as on the lines L and L '.

 They are also the same number as the transceivers 4 of line 1 '.

 In addition, each mirror 6 of the second terminal 2 is arranged opposite a transceiver 4 in a direction D perpendicular to the lines 1, L and L '.

 Thus, two neighboring mirrors 6, whether or not belonging to the same line L or L ′ or to the same pair 5, are spaced apart by the pitch p, separating two neighboring transceivers 4.

 In addition, the distance between the two mirrors 6 of a pair 5 is different from the distance between the two mirrors 6 of the neighboring pair 5.

 We therefore understand that the first mirror 6 'of the pair 5' of line L 'receives at least one light beam emitted by the first transceiver 4' of line 1 to send it back to the second mirror 6 '' of the same pair 5 ', which returns a light beam to the receiver 4' 'arranged facing in the direction D.

 In this way, the beams emitted and reflected between a transceiver 4 ', 4 "and a mirror 6', 6" are mutually parallel and extend in the direction D.

 As before, the transceiver 4 "', which is close to the transceiver 4', emits at least one light beam towards the first mirror 6 of the first pair Sa, arranged opposite.

 The light beam is then reflected towards the second mirror of the pair Sa to be returned to the receiver 4 opposite, that is to say the one which is adjacent to the transmitter 4 '' 'in this case. And so on.

 Thus, as for the mirrors 6, the distance separating the two transceivers 4 from a pair 3 is different from that separating the two transceivers 4 from the neighboring pair 3, while the distance separating two transceivers 4 neighbors, whether or not belonging to the same pair, is always equal to the step p.

 From the above, it is understood that each pair 3 of transceivers 4 associated with a pair 5 of mirrors 6 makes it possible to generate two parallel light beams, and this in particular due to the inclination and the arrangement of the mirrors 6.

 In addition, the distance between neighboring beams is always equal to the step p.

 Furthermore, it is understood that the second terminal 2 does not require any electrical connection with the first terminal 1 and has the sole function of reflecting the beams emitted by the transceivers 4 of the first terminal 1.

The beams emitted and reflected by and on the transceivers 4 of line 1 extend in a plane forming a substantially horizontal barrier
Likewise, the light beams reflected by and on the transceivers 4 of the line 1 'extend in a plane forming a substantially vertical barrier
The planes Pv and PH are substantially perpendicular to each other.

 The plan forming a vertical barrier PV is intended for the access control of an operator in the protected zone and is situated towards the extreme part 1a of the first terminal 1, which determines the entrance to the protected zone, that is to say - say the front part of the first terminal 1.

 In addition, the horizontal dam plan is intended to control the presence of an operator in this same danger zone.

 The plane forming a vertical barrier Pv is placed at a minimum distance from the machine, increased by a distance corresponding to the movement of a person in the direction of the machine, traveled during the braking time necessary for stopping the machine.

 For this purpose, it is possible to arrange the transceivers 4 and the mirrors 6 so that the first beam of the line 1 ′ and closest to the ground is located approximately 300 mm from the ground.

 Furthermore, terminals 1 and 2 can be arranged in such a way that it is impossible to enter the protected area without at least one of the beams being cut.

 The device for resetting the first terminal 1, which will allow the machine to restart on power-up or after tripping, must be located outside the protected area and cannot be reached inside the area.

 Before resetting, the operator must check that no one is in the protected area.

 The machine will only be restarted after resetting and manual operator command, for example.

 It is also possible to install on the first terminal 1 a light column 9 with three colored cylinders.

 Finally, the device of the invention may comprise an integrated system for assisting in the optical alignment of all the mirrors 6.

 In a particular embodiment, this consists of a laser 10.

 In addition, the first terminal 1 may include control buttons 11.

 FIGS. 4a, 4b represent an example of transmission-reception of beams between transceivers of a terminal 1 and the mirrors of terminal 2.

 The mirrors 6 are not arranged in exactly the same pattern as that of FIG. 2, but respect the arrangement in two lines of the pairs 5 of mirrors 6, with different distances between two mirrors of a pair, as explained above.

 Thus in these figures, a transmitter E emits a light ray R, consisting of a plurality of light beams Fet the light ray R being directed in a different direction according to FIG. 4a or 4b.

 The light beams F e are sent to various mirrors 6 belonging to different pairs and which can be located on two different lines L, L '.

 These light beams F e are then reflected on the mirror 6 of the corresponding pair 5 to be returned to a receiver R, while respecting the laws of optics.

 These reflected beams are referenced Fr.

We then observe that the receivers R receive only a beam Fr
Of course, the invention is not limited to the embodiment which has just been described.

 Indeed, it is possible to envisage placing the mirrors 6 according to different patterns and for example to modify the pitch p.

 Furthermore, the number of transceivers 4, and therefore of mirrors 6, defined in the embodiment shown is not exclusive.

 Furthermore, it could be envisaged that the terminals 1 and 2 respectively only have a vertical or horizontal line.

 Finally, the number of lines L, L ′ comprising the mirrors 6 can be greater than 2.

Claims (9)

 1. Electrosensitive device for controlling operator access in a protected area comprising two terminals (1,2) facing each other  - the first terminal (1) comprising at least two pairs (3) of light beam transceivers (4), substantially aligned along a first line (1) and spaced from each other by a predetermined pitch (p) identical  the second terminal (2) comprising at least two pairs (5) of mirrors (6) inclined by about 45, the mirrors (6) of the same pair (5) being opposite one another,  each mirror (6) being arranged opposite a transceiver (4) and the mirrors (6) of the same pair (5) being aligned along a line (L, L ') substantially parallel to the first line ( 1),  so that the light beams emitted (Fe) by the emitters (4) and the light beams reflected (Fr) by the mirrors on the receivers (4) are substantially parallel to each other  characterized in that the distance separating the mirrors (6) from a first pair, respectively opposite a first pair of transceivers (4), is different from the distance separating the mirrors from a second pair, respectively opposite a second pair of transceivers, adjacent to the first pair of transceivers so that the emitted light beams are offset while respecting the predetermined pitch (p) between two neighboring parallel emitted or reflected beams, so that for a set of beams emitted by a transmitter of a pair, only one beam is reflected on the receiver of the same pair.  2. Device according to claim 1, characterized in that the mirrors (6) are arranged on at least two parallel lines (L, L '), the space between two neighboring mirrors being constant.  3. Device according to claim 2, characterized in that the pairs (5) of mirrors (6) of the same line (L, L ') are distinct and successive.  4. Device according to claim 3, characterized in that each pair (5a, 5b, 5c) of mirrors of a line (L) is interposed or straddled between a pair (5 ', 5 ") of mirrors of the other line (L ').  5. Device according to claims 1 to 4, characterized in that the first terminal (1) comprises several lines (1, 1 ') of transceivers (4) and the second terminal (2) also comprises opposite, several lines of mirrors (6).  6. Device according to claim 5, characterized in that the first terminal (1) and the second terminal (2) each comprise at least one vertical line and at least one horizontal line so that the emitted and reflected light beams extend in two planes forming a dam, one vertical (Pv), the other horizontal  7. Device according to claim 6, characterized in that at least one of the beams is common to the plane forming vertical barrier (Pv) and to the plane forming horizontal barrier  8. Device according to any one of claims 6 or 7, characterized in that the plane forming a vertical barrier (Pv) is intended for the access control of the operator in the protected area and is located towards an extreme part (the ) terminals, determining the entrance to the protected area.  9. Device according to any one of claims 1 to 8, characterized in that it comprises an integrated system for assisting in the optical alignment of all the mirrors, constituted by a laser (10).