Safety system and lifting equipment comprising such a safety system

Abstract

The invention relates to a safety system for at least one person (P) positioned on a platform (9) of a lifting equipment (1), comprising a lanyard (14) attaching the person (P) to the platform. According to the invention, the length of the lanyard (14) is variable, and the safety system comprises: a sensor for measuring the distance between one end of the lanyard (14) attached to the person (P) and one end of the lanyard (14) attached to the platform (9), and a unit for processing the measurement from the sensor, suitable for transmitting information and / or warning signals (15).

Description

[0001] The invention relates to a lifting machine comprising a safety system for a person working on a platform of the lifting machine.

[0002] Operators working on lifting equipment such as aerial work platforms are usually equipped with personal protective equipment (PPE) by which they are attached to the platform of the lifting equipment. Either a short lanyard is used to reduce the risk of ejection from the platform, especially when moving at high speeds, or a longer lanyard with a shock absorber is used to limit injuries in the event of a fall from a height.

[0003] KR20140079069 describes personal protective equipment comprising a harness, a lanyard, a shock absorber, a carabiner, sensors, and a speaker. A first sensor detects whether the carabiner is detached from a receptacle attached to the harness and emits an audible message if it is not. A second sensor detects whether the shock absorber is slack. This device does not detect whether the carabiner is attached to an external anchor point. The use of separate sensors for each function makes it a complex and expensive device.

[0004] US6265983 describes a safety device that detects whether an electrically conductive lanyard loop, connecting the operator to the platform, is attached and informs the operator if he is not attached. The controls are blocked if the operator is not attached. Detection is achieved by an electrical current passing through the lanyard. This safety device can easily be deactivated by an operator by substituting a short metal cable for the lanyard.

[0005] US2015284231 describes a lifting platform equipped to detect the presence of harnesses in the platform using RFID techniques. This device does not detect whether the harnesses are mechanically attached to the platform.

[0006] US 2013 / 200196 describes a lanyard reel equipped with a centrifugal brake allowing the lanyard to be stopped in the event of a fall.

[0007] EP 3 475 894 and EP 3 582 860, which are European patent applications falling under Article 54(3) EPC, each describe fall protection equipment for persons working at height. This equipment comprises a position sensor for monitoring the distance by which a safety line extends outside a housing of the equipment. US2015 / 027808A1 discloses a lifting device according to the preamble of claim 1.

[0008] The invention aims to remedy these drawbacks by proposing a new lifting device that improves the detection of risks for people on the platform of the lifting device.

[0009] For this purpose, the invention relates to a lifting device, as defined in claim 1.

[0010] Thanks to the invention, the position of the operator in the platform of the lifting machine can be observed and the safety system can trigger treatments taking into account the risks involved.

[0011] Advantageous but not mandatory aspects of the invention are specified in the other claims.

[0012] The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of a lifting device in accordance with its principle, given by way of non-limiting example with reference to the appended drawings, in which: there figure 1 is a perspective view of a lifting platform according to the invention, comprising a platform on which stands a person connected to the platform by a safety system, the lifting platform being in the folded configuration; figure 2 is a view similar to the figure 1 , in a deployed configuration of the lifting platform; the figure 3 is a view of a person equipped with a harness and a lanyard belonging to the safety system of the lifting device according to the invention; figure 4 is a perspective view of the loin of the figure 3 ; there figure 5 is a top view of the platform of the aerial work platform of the figure 1 , in which a person stands.

[0013] There figure 1 represents a lifting platform 1 comprising a lower part including a chassis 3 equipped with ground connection members, such as wheels or tracks. The lower part also comprises a turret 5 movable in rotation relative to the chassis 3 along an axis perpendicular to the axes of rotation of the wheels, a lifting structure 7 and a platform 9 supported by the lifting structure 7. The platform 9 comprises a mesh floor 90 surrounded by a guardrail 92. The platform 9 is equipped with a control console 94 allowing a person P present on the platform 9 to control the lifting platform 1, that is to say the movement of the chassis 3 relative to the ground, the movements of the platform 9 relative to the chassis, the starts / stops, etc.

[0014] The lifting structure 7 comprises, in this example, a lower deploying arm 70, an upper arm 72 and a pendulum arm 74. The movements permitted by the arms 70, 72 and 74 are known per se and will not be described further below.

[0015] To secure the operations of the person P standing in the platform 9, the lifting platform 1 comprises a safety system 12 comprising a lanyard 14 by which the person P is attached to the platform 9. The lanyard 14 comprises a ribbon 141 forming the physical link between the person P and the platform 9. This ribbon 141 comprises an end 140, forming a first end of the lanyard 14, attached to a fixing point 96 of the platform 9. The lanyard 14 comprises a second end 142, which is attached to a harness 16 equipping the person P. The lanyard 14 makes it possible to prevent the person P from falling in different configurations of use of the lifting platform 1.

[0016] The lanyard 14 has a variable length, and the safety system 12 is equipped with a sensor 18 for measuring the distance L between the two ends of the lanyard 14, and a processing unit 20 for the measurement of the sensor 18, adapted to emit information and / or alert signals 15. This makes it possible to correlate the length of the lanyard 14, and consequently the positioning of the person P in the platform 9, with different safety situations which may arise during the use of the lifting platform 1, to alert or inform the person P wearing the safety system 12 of potential dangers or particular situations. Since people working at height are not necessarily familiar with the operation and safety limitations of a lifting platform, their work and safety are therefore improved.

[0017] The lanyard 14 preferably comprises a self-locking reel 144 with automatic return, according to a principle similar to that of motor vehicle seat belts. The reel 144 is formed by a cover in which the ribbon 141 is wound thanks to a return mechanism not shown. The sensor 18 therefore measures the length of ribbon 141 unwound to know the distance L between the two ends of the lanyard 14.

[0018] The measuring sensor 18 may be, for example, a multi-turn potentiometer, or an optical or magnetic sensor detecting optical distance marks or metal strips on the tape 141, or a roller in contact with the winder 144 and whose rotations are measured, among other things.

[0019] Preferably, the measuring sensor 18 and the processing unit 20 for the sensor measurement are provided on the tether 14. For example, the sensor 18 is mounted in the reel 144.

[0020] The processing unit 20 is formed by a housing containing electrical components connected to the sensor 18. The processing unit 20 can advantageously be fixed to the reel 144.

[0021] By way of example, the lanyard 14 can be removably attached to the harness 16 equipping the person P, for example by means of a quick link forming the end 142. This quick link can be connected to the reel 144 and to the processing unit 20 by a rigid element 146. Alternatively, the lanyard 14 can be fixed in a non-removable manner to the harness 16, and form an integral part of this harness 16 as shown in FIG. figure 3 .

[0022] The tether 14 is equipped with an autonomous battery power supply, and an electronic card which incorporates the components of the processing unit 20. The housing containing the processing unit 20 comprises the battery, the housing of which is closed by a cover 21. The battery electrically supplies the sensor 18, the processing unit 20, and the communication device.

[0023] The safety system 12 may include a memory for recording the measurements taken by the sensor and events involving use of the lanyard 14. This memory dates the variations in length of the lanyard 14, dates the attachments or detachments of the lanyard 14 on the platform 9, any defects, etc., in order to use the data for statistical purposes, to improve the consideration of the values ​​recorded by the sensor 18, to define new safety procedures, etc. The processing unit 20 may advantageously incorporate this memory.

[0024] The lanyard 14, and more generally the safety system 12, can operate autonomously, that is to say without connection with the lifting platform 1. In this case, the safety system 12 provides an alert and information function for the person P who is wearing it, or for the surrounding people, without modifying the operating parameters of the lifting platform 1.

[0025] The safety system 12 can emit, to the person P, a signal indicating failure of the distance measuring sensor 15 in the event of detection of a distance L less than a minimum value corresponding to the length of the lanyard 14 fully wound, or in the event of detection of a distance greater than a maximum value Lmax, corresponding to the maximum length of the lanyard 14. In a first embodiment, the maximum length of the lanyard 14 is its length when it is fully unwound. In a second embodiment, the lanyard 14 is equipped with a fall indicator or a shock absorber - not shown - and the maximum length of the lanyard 14 is the addition of the length of the lanyard fully unwound and the additional length created by the activation of the fall indicator or the shock absorber.

[0026] When the length L of the lanyard 14 is less than a low value Lshort, corresponding to an attached state of the person P but not far from the attachment point 96, indicating that the person has probably not attached the lanyard 14 to the platform 9, an audible signal, for example an alarm, can be emitted by the lanyard 14 with a recorded message, possibly accompanied by light signals, to encourage the person P to hang on to the platform 9. The low value Lshort can be equivalent to a few centimeters.

[0027] The safety system 12 can also emit an alert signal to the outside when the length L of the lanyard 14 is substantially equal to the maximum value Lmax, indicating a probable fall of the person P.

[0028] The safety system 12 can also emit an alert signal in the event of detection of a period of non-variation of the distance L between the two ends of the tether 14 greater than a threshold duration. This threshold duration can be, for example, thirty seconds. This makes it possible to detect a physical problem of the person P. When the length L of the tether 14 does not vary for a period greater than the threshold duration, the tether 14 can trigger a pre-alarm emitting a recorded message addressed to the person P, ordering them to move to stop the alarm. If after a second delay the length of the tether 14 has still not varied, an alert is sent to the outside. An image capture and image display system (not shown) provided on the chassis 3 can then be implemented to provide assistance to the person P who is in a potentially dangerous situation. A system of this type is described in application FR1654415.

[0029] The light and / or sound signals can be emitted on the lanyard 14, or on the harness 16 equipping the person P. The box containing the processing unit 20 can in particular comprise indicator lights 24 displaying light signals, and a sound transmitter 26. The indicator lights 24 and the sound transmitter 26 are electrically powered by the battery of the lanyard 14.

[0030] Certain alert or information signals 15 may also be sent to a remote electronic device 17 such as a mobile phone, a computer, a server to relay this information to a supervisor, a centralized security system of a construction site, maintenance or medical intervention teams, etc.

[0031] The lanyard 14 is preferably attached to the person P behind the latter's back. In certain cases, in particular if the person P is in front of the control console 94 and attached to the attachment point 96, the lanyard 14 may partially surround the body of the person P. The processing unit 20 is adapted to weight the value measured by the sensor 18 to take into account a particular orientation of the person P, for example by taking into account a margin of error of 20% on the measured value.

[0032] The lifting platform 1 comprises a control unit 22, which includes sensors, processors and software processing all the operating data of the lifting platform 1 to control the means of movement of the lifting structure 7 and the lifting platform 1 relative to the ground.

[0033] According to an advantageous optional embodiment of the invention, the security system 12 comprises a communication device not shown, for example wired or wireless, allowing communication with the control unit 22. This communication device can advantageously be incorporated into the processing unit 20.

[0034] The control unit 22 can implement certain processing operations based on the information / alerts 15 received from the safety system 12. In particular, the control unit 22 is adapted to control the functionalities of the lifting platform 1 based on the information signals received from the safety system 12. This can consist of emitting a visual or audible signal, and limiting the possibility of movement on the ground of the lifting platform 1 and / or the movements of the platform 9 by the lifting structure 7 based on the value of the distance L between the two ends of the tether 14.

[0035] The signal 15 emitted by the safety system 12 may include information that the distance L between the two ends of the lanyard 14 is less than the low value Lshort, indicating that the person has probably not attached the lanyard 14 to the platform 9. The control unit 22 receiving this information then emits a visual or audible signal to encourage the person to attach the lanyard 14 when they are in the platform 9. Advantageously, this alert transmitted via the signal 15 is combined with the sending, via the signal 15, of an instruction to prohibit or limit the movement on the ground of the lifting platform 1 and / or the movement of the lifting structure 7.

[0036] The movement of the lifting platform 1 on the ground generates strong jolts of the platform 9, due to the presence of the lifting structure 7 and the significant lever arm between the chassis 3 and the platform 9. As a result, when a person P stands on the platform 9, he is subject to strong instabilities when the ground speed of the lifting platform 1 increases. To avoid being ejected, the person P must be connected to the platform 9 by a short lanyard 14, which only allows him limited movements relative to the attachment point and prevents him from passing over the guardrail 92 in the event of violent impacts.

[0037] The signal 15 emitted by the safety system 12 therefore comprises an authorization for the movements on the ground of the lifting platform 1 without speed limit when the distance L between the two ends of the tether 14 is between the low value Lshort and an intermediate value Llong, greater than the low value Lshort, corresponding to an anti-ejection configuration of the person P. By anti-ejection configuration, we mean a length value of the tether 14 sufficiently short to retain the person P in the platform 9 and prevent him from passing over the guardrail 92 in the event of ejection. The length Llong may be less than 1 meter, for example 50 centimeters. In this case, the person P can direct, via the control panel 94, the lifting platform 1 relative to the ground at the maximum speed provided by the characteristics of the machine.

[0038] The signal 15 may also comprise an instruction to limit the ground movement speed of the lifting platform 1 when the distance L between the two ends of the tether 14 is between the intermediate value Llong and an edge value Lbord, corresponding to the distance of the person P from an edge of the platform 9, for example in a work situation in which the person P must pass his arms over the guardrail 92. The value Lbord may be, for example, 1.5 meters. In this configuration, the signal 15 may also command a limitation of the possibilities of movement of the platform 9 by the lifting structure 7, in particular in the case of lifting platforms not comprising ground movement means.

[0039] The signal 15 may also include an instruction prohibiting the movement on the ground of the lifting platform 1 when the distance L between the two ends of the tether 14 is between the edge value Lbord and the maximum value Lmax, because the person P may have left the platform 9 to carry out work outside the platform 9, for example on a roof. This may also be a case of a fall if the distance L is substantially equal to the maximum value Lmax. This value Lmax may be, for example, 2 meters.

[0040] In both cases, an alert signaling the presence of a person outside the platform 9 is issued. In this configuration, the signal 15 can also command a prohibition of the possibilities of movement of the platform 9 by the lifting structure 7, in particular in the case of lifting cradles not comprising means of movement on the ground, or an authorization only via a dedicated device, for example to rescue the person P who has fallen, by setting up a specific movement of return to the ground.

[0041] When the distance L measured between the two ends of the lanyard 14 is greater than the maximum length Lmax of the lanyard 14 or less than the minimum value corresponding to the length of the lanyard 14 fully wound, a failure or fault alert is issued and in this case, the signal 15 is sent to the control unit 22. It signifies a failure of the distance measuring sensor 18 and includes a limitation or prohibition of the movements of the lifting platform 1. Possibly, only certain movements such as emergency movements, in particular returning to the ground, can be carried out.

[0042] It may be envisaged that the aforementioned limitations and authorizations are implemented jointly or independently depending on the programming of the control unit 22. Furthermore, these limitations may be implemented in addition to the other limitations theoretically provided by the control system 22, in particular to limit the speed of movement on the ground when the lifting structure 7 is deployed and the platform 9 is at height.

[0043] According to an embodiment not shown, the sensor for measuring the length between the ends of the lanyard 14 can measure the length of a cable separate from the lanyard 14 and stretched parallel to it.

[0044] It may be envisaged that several safety systems 12 such as those mentioned above are used with the lifting platform 1, to secure several people P present in the platform 9.

[0045] The invention is not limited to a lifting platform with a turret and articulated arm as shown in this example, and also applies to all types of personnel lifting platforms, in particular lifting structures of the telescopic arm, scissor and vertical mast type and non-self-propelled platforms, mounted on a truck chassis, a trailer chassis or a handling trolley.

[0046] The technical features of the embodiments and variants described above may be combined with each other to form new embodiments of the invention, which is defined by the following claims.

Claims

1. A lifting equipment (1), comprising: - a lower portion (3, 5), - a lift structure (7); - a platform (9) carried by the lift structure, and - at least one safety system (12) for at least one person (P) located on the platform (9), characterized in that the safety system comprises : - a lanyard (14) having a variable length, the lanyard having a first end (140), attached to the platform (9), and a second end (142), by which the person (P) is attached to the platform, - a sensor (18) for measuring the distance (L) between the first and second ends (140, 142) of the lanyard (14) , and - a processing unit (20) for the measurement from the sensor (18), suitable for sending information and / or warning signals (15).

2. The lifting equipment according to claim 1, wherein the safety system (12) comprises a winder (144) with automatic return of the lanyard (14), and wherein the sensor (18) measures the length unwound between the first and second ends (140, 142) of the lanyard (14).

3. The lifting equipment according to claim 2, wherein the lanyard (14) is kept tensed by the winder (144) with automatic return.

4. The lifting equipment according to any one of claims 2 and 3, wherein the measuring sensor (20) is chosen from among a multi-turn potentiometer, an optical or magnetic sensor, or a roller.

5. The lifting equipment according to one of the preceding claims, wherein the measuring sensor (18) and the processing unit (20) of the measurement from the sensor are provided on the lanyard (14).

6. The lifting equipment according to one of the preceding claims, wherein the second end (142) of the lanyard (14) is suitable to be fastened permanently to a safety harness (16) equipping the person (P) located on the platform (9).

7. The lifting equipment according to one of the preceding claims, wherein the lifting equipment (1) comprises a remote electronic device (17) suitable for receiving and relaying the information and / or warning signals (15) emitted by the processing unit (20).

8. The lifting equipment according to one of the preceding claims, wherein the safety system (12) comprises a temporal recording memory (20) for the measurements done by the sensor (18) and usage events of the lanyard (14).

9. The lifting equipment according to one of the preceding claims, wherein the lifting equipment (1) comprises a control unit (22), which is in communication with the processing unit (20) and which is suitable for controlling the functionalities of the lifting equipment as a function of the information and / or warning signals (15) sent by the processing unit (20),10. The lifting equipment according to claim 9, wherein the information and / or warning signals (15) comprise an instruction to limit the possibility of movement on the ground of the lifting equipment (1) and / or the movements of the lifting structure (7) as a function of the value of the distance (L) between the first and second ends (140, 142) of the lanyard (14).

11. The lifting equipment according to one of the claims 9 and 10, wherein the information and / or warning signals (15) comprise an authorization for movements on the ground of the lifting equipment (1) without speed limit when the distance (L) between the first and second ends of the lanyard (14) is between a low value (Lcourt), corresponding to an attached state of the person (P) but not separated from an attachment point (96), and an intermediate value (Llong) above the low value, corresponding to an anti-ejection configuration of the person (P).

12. The lifting equipment according to one of the claims 9 to 11, wherein the information and / or warning signals (15) comprise an instruction to limit the ground movement speed of the lifting equipment (1) when the distance (L) between the first and second ends of the lanyard (14) is between an intermediate value (Llong) corresponding to an anti-ejection configuration of the person (P) and an edge value (Lbord), corresponding to the separation of the person (P) on an edge of the platform (9).

13. The lifting equipment according to one of the claims 9 to 12, wherein the information and / or warning signals (15) comprise an instruction prohibiting the ground movement of the lifting equipment (1) and / or movements of the lifting structure (7) of the lifting equipment (1) when the distance (L) between the first and second ends of the lanyard (14) is between an edge value (Lbord) corresponding to the separation of the person (P) on an edge of the platform (9) and a maximum value (Lmax), corresponding to the maximum length of the lanyard (14).

14. The lifting equipment according to one of the preceding claims, wherein the information and / or warning signals (15) comprise a warning signal (15) in case the distance (L) between the first and second ends of the lanyard (14) is below a low value (Lcourt) corresponding to an attached state of the person (P) but not separated from the attachment point (96).

15. The lifting equipment according to one of the preceding claims, wherein the information and / or warning signals (15) comprise a warning signal (15) ) in case the distance (L) between the first and second ends of the lanyard (14) is substantially equal to a maximum value (Lmax) corresponding to a maximum length of the lanyard (14), indicating a likely fall of the person (P).

16. The lifting equipment according to one of the preceding claims, wherein the information and / or warning signals (15) comprise a warning signal (15) in case of detection of a distance (L) greater than a maximum value (Lmax) corresponding to the maximum length of the lanyard (14), or in case of detection of a distance (L) between the first and second ends of the lanyard (14) smaller than a minimum value corresponding to the length of the lanyard (14) fully wound.

17. The lifting equipment according to one of the preceding claims, wherein the information and / or warning signals (15) comprise a warning signal (15) in case of detection of a non-variation period of the distance (L) between the first and second ends of the lanyard (14) greater than a threshold duration.

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