EP2237841A1

EP2237841A1 - Crash safety device having a rope drive mechanism

Info

Publication number: EP2237841A1
Application number: EP08708073A
Authority: EP
Inventors: Jean-Luc Born; Sebastien Close; Frédéric ARENS; Richard Grossmann; Armin Kreuzer; Jean-Claude Dahner
Original assignee: CTI Systems SARL
Current assignee: Amova Sarl
Priority date: 2008-01-22
Filing date: 2008-01-22
Publication date: 2010-10-13
Anticipated expiration: 2028-01-22
Also published as: US8579086B2; US20110127112A1; BRPI0822197A2; CN101977657B; US20140124296A1; CN101977657A; EP2237841B1; WO2009092438A1

Abstract

The invention relates to a crash safety device having a safety rope (105) wound onto a drum, a recuperating spring tensioned by the drum during the winding of the rope, and a locking device for blocking the drum from rotation in the rope unwinding direction during the crash of a person secured by the rope. A rope drive mechanism is provided in order to unwind the rope (105) from the drum and to slowly move the rope end having a hook (290) attached thereto toward such that a person can hook onto the safety rope (105). The drive mechanism has a motor (140) driving a rope drive wheel (210) via a freewheel (200) for lowering the rope end having the hook (290). In order to rewind the rope, the motor (140) is operated in a reverse direction of rotation at a controlled rotational speed in order to limit the speed at which the rope (105) is pulled up by the tensioned recuperating spring.

Description

Fall arrester with cable drive mechanism

The invention relates to a fall protection device with a safety rope that can be blocked in the event of a crash of a secured person. Furthermore, the invention relates to a drive mechanism for a safety rope of a fall protection device.

Such fall arrest devices are known in the art, see e.g. GB patent 1552667 and also EP patent application 0 247 818. These devices have a rotatably mounted in a housing drum for up and

Unwind the safety rope. When unwinding becomes a

Tensioning return spring, which rewinds the rope when the person has released the rope. In the drum there is a blocking device, which further unwinding the

Rope prevents a person who has connected to the rope, suddenly crashes. The rope to the

Person can connect protrudes through an opening at the bottom of the fall protection device and is equipped with a hook.

The known fall arrest device, sometimes referred to as fall arrester, usually hangs on the ceiling of a factory floor or the like, and the connection hook of the device is normally in the uppermost position due to the internal return spring of the device. To reach the connection hook usually hangs a leash on the connection hook, by means of which the rope to pull down and unwind the safety rope, so that the person to be secured can connect to the device. The traditional leash permanently impedes work in the factory floor. The connection hook could also be achieved by means of a Hubsteigers, but this option would be particularly expensive. The object of the invention is therefore a

Fall arrest device to create that without a leash to

Pull down the connection hook can get along and to a person to secure can easily connect.

To achieve this object, the invention provides a fall arrest device with a wound on a drum safety rope, a return spring to tension the unwinding of the rope from the drum, and a locking device for blocking the drum against rotation in Seilabwicklungsrichtung in the crash of a secured by the rope Person, characterized by a cable drive mechanism to unwind the rope from the drum and to move downwards from the device, wherein the drive mechanism comprises a drive motor, a Seilantriebsrad and a freewheel, and the drive wheel from the engine via the freewheel in a direction of unwinding and To move down the rope is to drive.

With the device according to the invention, the connection hook can be lowered by pressing a button.

To improve the drive force transmission from the drive wheel to the cable, the cable drive mechanism preferably has a pressure wheel and the cable is passed through a gap between the drive wheel and the pressure wheel and is in frictional engagement with both wheels in the gap. Preferably, the contact pressure of the Anpressrades is adjustable. The drive wheel may be rotatably mounted on a pivotable lever, and the lever may be biased by spring force to press the Anpressrad to the rope.

According to an advantageous embodiment of the

Motor provided with a device for switching the

Motor rotation direction between the one direction of rotation and an opposite direction of rotation and for setting a predetermined engine speed at least in the opposite direction of rotation to limit the winding speed of the rope by the set engine speed in the opposite direction of motor rotation. Preferably, the motor is a three-phase motor having a control circuit for switching the motor rotation direction and setting a predetermined motor speed in both directions of rotation. The set engine speed in reverse operation (opposite direction of rotation) prevents or limits the rocking of the rope and only raises the rope as fast as it corresponds to the set engine speed. Preferably, the motor is a three-phase asynchronous three-phase motor whose speed is adjustable in both directions of rotation via a frequency converter.

In order to prevent that the cable end is pulled out of the gap between the drive wheel and the Anpressrad when winding up a stop is preferably arranged below the drive wheel and the rope is a spacer attached to the stop on the stop when the rope reaches an upper end position , The stop can also serve as limit switch actuator.

The motor can be controlled by radio or via a busbar.

According to another aspect, the invention relates to a drive mechanism for the safety rope of a fall protection device (claims 17 to 31).

In the following the invention will be described in more detail with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of the inventive fall protection device with cable drive mechanism. Figure 2 is a front view of the device of Figure 1 with the housing open of the drive mechanism to show the internal components thereof.

Figures 3A, 3B, 3C and 3D are schematic representations of the freewheel for explaining the operation of the device.

Figure 4 is a schematic representation of a sleeve freewheel, and

Figure 5 is the block diagram of the electronic control of the drive motor.

As shown in Figures 1 and 2, the fall protection device 100 has a housing 110, 120, in which a cable drum (not shown) is rotatably mounted, for winding and unwinding a safety rope 105. The safety rope 105 protrudes through a rope opening (not shown ) at the lower end of the housing 110, 120 addition.

In the housing 110, 120 a drum (not shown) is rotatably mounted. If a person wishing to attach himself to the safety rope 105 pulls the rope down and unwinds from the drum, a return spring (not shown) is tensioned, which later releases the safety rope as the person releases the rope and releases it; pull back up and wind up on the drum. The fall arrest device 100 also has a locking mechanism (not shown) which permits rotation of the reel to unwind the rope when the rope is slowly pulled down at low speed, but blocks rotation in the direction of unwinding of the safety rope 105 when the rope pulled down at high speed, as in the crash of a person connected to the safety rope 105 person. At the top of the housing 110, 120 is a hanger 115.

A fall protection device with these features is known in the art from the aforementioned Publications and will therefore not be described in more detail here.

Under the Tromraelgehäuse 110, 120 a cable drive mechanism according to the invention is attached. The cable drive mechanism has a housing 170, 180 which may be secured to the drum housing 110, 120 via an intermediate frame or plate 130. The cable drive mechanism has a drive wheel 210 and a counterpressure or pressure wheel 220, which are mounted in a housing 180, 170. The safety cable 105 extends from the drum housing 110, 120 vertically down through the housing 170, 180 and is passed through the gap between the drive wheel 210 and the counter-pressure 220 and is in the gap in frictional or frictional contact with the wheels 210, 220th for driving force transmission. The safety cable 105 extends under the wheels 210, 220 through a guide ring 260 which is secured to the underside of the housing 170, 180. At the free end of the cable 105, a hook 290 is attached. Above the hook 290 is a spacer 270, which is supported on the hook 290.

In the upper end position of the spacer 270 is received in the guide ring 260 and is located at its upper end to a stop 280, through which the cable is passed, and which is located in the housing between the guide ring 260 and the pair of wheels 210, 220. In this way it is prevented that during winding of the rope 105 this can be pulled up out of the gap between the wheels 210 and 220. Preferably, the stopper 280 is simultaneously a limit switch operation and consists of a rotatably mounted at its right end lever which actuates a limit switch 190 when the spacer 270 comes into contact with the stopper 280. In the housing 170, 180 is also another lever or a pivotally mounted L-shaped rocker 230, on which the counter-pressure wheel 220 is rotatably mounted. A compression spring 240 pushes the back pressure 220 against the drive wheel 210 for clamping or clamping the safety cable 105 between these two wheels. An Anpressdruckeinstellmechanismus 250 is provided at the free end of the spring 240 and consists of a set screw with nut, the screw protrudes through an opening in an angle piece which is fixed to the housing 170, 180. The counter-pressure wheel 220 preferably has a rubber or plastic body.

The drive wheel 210 is driven by a motor 140, which is shown in Figure 1 and flanged on the back of the housing 170, 180. On the front side of the housing 170, 180 is a terminal box 160 to which a radio receiver 150 for controlling the motor is attached. The radio control is not essential to the invention but the engine can also be controlled via a busbar.

According to the invention, the motor driven drive wheel 210 is driven via a freewheel 200, which transmits the drive force for slowly unwinding the cable 105 from the drive motor 140 to the drive wheel.

In the following reference is made to Figures 3A, 3B, 3C and 3D to explain the principle of operation of the freewheel 200. These figures do not show the actual construction of a freewheel but only serve to explain the freewheeling principle. According to these figures, the freewheel 200 has a middle shaft 201 which is connected to the rotor of the motor 140, or the motor shaft itself. On the shaft 201, an outer ring 202 is rotatably mounted. The shaft 201 has two diametrically opposed, radially outwardly projecting driver 203, with diametrically opposed, inwardly projecting projections 204 of the outer ring 202 cooperate. FIG. 3A shows the freewheel 200 during slow unwinding or downward movement of the cable. At this time, the motor 140 drives the middle shaft 201 clockwise. The radial catches 203 of the shaft 201 detect the radial surfaces of the projections 204 of the outer ring 202 and take the outer ring 202 in a clockwise direction. If the rope is sufficiently unwound, a person can connect to the safety rope 105.

FIG. 3B shows the freewheel 200 in the event of a crash of a secured person. In this case, the outer ring 202 is suddenly driven by the rope 105 at high speed in a clockwise direction. The inner shaft 201 is now stationary (motor does not rotate) and the projections 204 of the outer ring 202 move over the drivers 203 of the inner shaft 201 away. The locking device in the drum housing 110, 120 responds and prevents the further unwinding of the rope, i. the crash of the secured person.

FIG. 3C shows the freewheel 200 with the outer ring 202 stationary and the rotation of the motor 140 (the shaft 201) in the counterclockwise direction, i.e., in the counterclockwise direction. the lower end of the cable 105 is connected to a person to be secured and can not move upwards, the inner shaft 201 rotates freely in the counterclockwise direction, without driving the outer ring 202, the driver 203 slide over the tangential surfaces of the projections 204 away.

FIG. 3D shows the freewheel 200 with the lower end of the securing cable 105 released. The outer ring 202 is now driven counterclockwise by the securing cable 105, which is pulled up and wound up by the tensioned return spring (not shown). The outer ring 202 now has the tendency to take the inner shaft 201 in the counterclockwise direction over the freewheel 200 by conditioning the radial surfaces of the projections 204 of the Outer ring 202 at the radial catches 203 of the inner shaft 201. However, since the spring force of the return spring of the Hδhensicherungungsgerätes is less than the force applied to the motor 140 on the drive wheel 210, the rate of rise of the cable 105 adapts to the rotational speed of the drive wheel 210 at.

As already mentioned, Figures 3A, 3B, 3C, 3D show only the principle of a freewheel and not the actual construction of the freewheel. Freewheels are well known in the art, see e.g. DE 200 09 895 Ul, DE 42 16 055 C2, DE 42 10 560 C2, DE 196 44 045 C2, DE 44 42 404 C2 and DE 196 14 512 C2. Such a freewheel consists, as shown in Figure 4, of a sleeve 200a having on its inner surface axial recesses 200b with clamping surfaces. Clamping body 200c, such as Rollers or needles are guided in a cage 20Oe and are located in the recesses 200b. The cage 20Oe has spring elements 20Od (shown schematically as helical springs) for pressing the clamping bodies 200c against the clamping surfaces and also against the shaft 201. A plurality of recesses 200b (with clamping surfaces), clamping bodies 200c and pressing springs 20Od are of course over the inner circumference of the free-running sleeve 200a or the cage 20Oe arranged distributed. The freewheel 200 may be a component of the drive wheel 210 and the drive wheel 210 may be mounted on the shaft 201 via the freewheel 200 or the freewheel sleeve. For this purpose there are sliding or roller bearings on both sides of the clamp body. The drive wheel 210 has a rubber or KunstStoffkδrper or outer ring which is disposed on the freewheel 200.

According to the preferred embodiment to prevent the rope is wound at maximum speed by the return spring when the secured person has released the safety rope 105, otherwise the rope 105 is not properly wound on the cable drum (not shown) and the Spacer 270 would drive unrestrained in the end position, and the return spring (not shown) could be damaged.

Preferably, this is achieved by using an asynchronous three-phase motor 140 whose speed is adjustable in both directions of rotation. The reversal of the direction of rotation is done by a frequency converter. Such a motor with inverter and speed control is well known in the art and can be obtained from the company Lenze (engine type MDERRAXX 071-12). In forward run mode, the cable 105 is moved down according to the set engine speed. In reverse run mode, the speed-locked motor prevents the cable 105 from being pulled up too quickly by the return spring and striking hard against the end stop. The winding speed of the rope in the reverse operation of the motor 140 is thus limited by the predetermined speed of the motor 140.

FIG. 5 shows a block diagram of the electrical control of the fall protection device according to the invention

Cable drive mechanism. It consists of the busbars /

Feed cable 10 or the alternative control via a radio remote control 20, from the Hubendschalter 30 (190 in Figure 2), the relay switching logic 10, a single-phase frequency converter 50, and an asynchronous three-phase motor (40 in Figure 1).

The busbars / supply cable 10 form the electrical interface to the power supply and the

Control of fall protection. As the main current, a 1-phase network with 230 VAC and protective conductor is fed (Ll + N

+ PE).

To lower the safety rope 105 is a

Control signal to the relay logic 40 transmitted. This can be done via the busbars / supply cable 10. Alternatively, this can be done via a radio remote control 20 be transmitted. The controller 20 is a commercially available radio remote control according to the prior art.

As feedback, a control signal is transmitted when the limit switch 30 (190 in Fig. 2) is operated in the upper position. This is transmitted to the power rail / feed cable 10 and is available for further processing in a higher-level controller.

The relay control 40 consists of two commercially available relays. One relay is responsible for the transmission of the control signal "sink", the other for the transmission of the control signal "lifting" to the frequency converter 50. The frequency converter is a device or a control circuit for switching between clockwise or anti-clockwise rotation and for setting a desired speed in both directions. Input signals of the relay controller 40 are the signal "not up" of the hump switch 30 and the control signal "sink" of 10 and 20, respectively. Table 1 shows the states of the relay controller.

Table 1; Logic of relay control

X = state is correct

50, a commercially available single-phase frequency converter is shown. As power supply is the power rails / feed cable 10, the energy transmitted. Internally, the AC voltage is converted via a rectifier into a DC voltage, which feeds the DC intermediate circuit. From the DC intermediate circuit, a variable three-phase rotating field is generated. The rotating field is dependent on the control command raising or lowering a right- or a left-rotating field. The frequency and the voltage are dependent on the preselected speed. The speed preselection is set in the frequency inverter. At the digital inputs is dependent on the control of the relay control 40, the control signal raising or lowering on. The control signals can be assigned different values. In order to minimize the mechanical wear when the rope is completely unwound, the current-limiting drive torque is limited by means of the current limitation. If the limit value of the set current limit is exceeded, no lowering rotary field will be output by the frequency inverter, despite the presence of a lowering control command.

The asynchronous three-phase motor 60 is a commercially available three-phase three-phase motor with temperature monitoring sensor. The temperature monitoring sensor is monitored in the frequency converter 50 and switches off the drive in the event of an error.

Claims

FRW-13771PATENTIAL CLAIMS:

1. fall protection device with a wound on a drum safety rope, a return spring to be tensioned when unwinding the rope from the drum, and a locking device for locking the drum against rotation in Seilabwicklungsrichtung in the fall of a person secured by the rope, characterized by a cable drive mechanism to unwind the rope from the drum and to move downwardly from the device, the drive mechanism having a drive motor, a cable drive wheel and a freewheel, and drive the drive wheel from the motor via the freewheel in a direction of unwinding and moving down the cable is.

2. Fall arrest device according to claim 1, characterized in that the cable drive mechanism further comprises a pressure wheel, and the cable is passed through a gap between the drive wheel and the Anpressrad and in the gap in frictional contact with the wheels.

3. fall protection device according to claim 2, characterized in that the pressure wheel is pressed by means of spring pressure, wherein the spring pressure is preferably adjustable.

4. Fall arrest device according to claim 2 or 3, characterized in that the pressure wheel is rotatably mounted on a pivotable lever, and the lever is biased by spring force to press the Anpressrad to the rope.

5. Fall arrest device according to claim 1, characterized in that the motor is provided with a device for switching the direction of motor rotation between the one direction of rotation and an opposite direction of rotation and to Setting a predetermined engine speed at least in the opposite direction of rotation to limit the winding speed of the cable through the adjusted engine speed in the opposite direction of engine rotation.

6. fall arrest device according to claim 5, characterized in that the motor is a three-phase motor with a control circuit for switching the direction of motor rotation and for setting a predetermined engine speed in both directions.

7. fall protection device according to claim 6, characterized by a frequency converter for adjusting the engine speed in both directions of rotation.

8. fall protection device according to one of claims 1 to 7, characterized in that a stop is arranged below the drive wheel, and a spacer is attached to the rope, for abutment against the stop when the rope end reaches an upper end position.

9. fall protection device according to claim 8, characterized in that the stop is a limit switch actuator.

10. fall protection device according to one of claims 1 to 9, characterized in that the motor is controllable via radio or via a busbar.

11. Fall arrest device according to one of claims 1 to 10, characterized in that the freewheel is a component of the drive wheel and the drive wheel is mounted on the freewheel on the motor shaft or driven by a motor shaft.

12. Fall arrest device according to claim 1 or 11, characterized in that the drive wheel has a Gummioder the plastic body which is mounted on the freewheel.

13. fall protection device according to claim 2, characterized in that the pressure wheel has a rubber or plastic body,

14. Fall arrest device according to one of claims 1 to 13, characterized in that the drum in one

Drum housing is arranged and the cable drive device comprises a housing which is fixed to the drum housing under this.

15. fall protection device according to claim 14, characterized in that the safety rope through the housing of

Cable drive device is passed and the drive wheel and the freewheel are located in the housing.

16. Fall arrest device according to claim 8, characterized in that on a housing of

Cable drive device, a guide ring is provided for the spacer.

17. Drive mechanism for the safety rope of a fall arrest device with a drum to be wound on the safety rope, a return spring which is to be tensioned when unwinding the rope from the drum, and a locking device for blocking the drum against rotation in Seilabwicklungsrichtung in the crash of a through the rope secured person, characterized in that the drive mechanism comprises a drive motor, a Seilantriebsrad and a freewheel, and the drive wheel is to be driven in a rotational direction from the engine via the freewheel to drive the rope in one direction.

18. A drive mechanism for the safety rope of a fall arrest device according to claim 17, characterized in that the drive mechanism further comprises a pressure wheel, and the rope is passed through a gap between the drive wheel and the Anpressrad and in the gap in frictional contact with the wheels.

19. Drive mechanism for the safety rope of a fall protection device according to claim 18, characterized in that the pressure wheel is pressed by means of spring pressure, wherein the spring pressure is preferably adjustable.

20. Drive mechanism for the safety rope of a fall arrest device according to claim 18 or 19, characterized in that the pressure wheel is rotatably mounted on a pivotable lever, and the lever is biased by spring force to press the pressure wheel to the rope.

21. The safety mechanism for the safety rope of a fall arrest device according to claim 17, characterized in that the motor is provided with means for switching the engine speed between the one direction of rotation and an opposite direction of rotation and for setting a predetermined engine speed at least in the opposite direction of rotation, the movement speed to limit the rope in the opposite direction by the set engine speed.

22. A drive mechanism for the safety rope of a fall arrest device according to claim 21, characterized in that the motor is a three-phase motor with a control circuit for switching the motor rotation direction and for setting a predetermined engine speed in both directions.

23. Drive mechanism for the safety rope of a fall arrest device according to claim 22, characterized by a frequency converter for adjusting the engine speed in both directions of rotation.

24. Drive mechanism for the safety rope of a fall protection device according to one of claims 17 to 23, characterized in that a stop is arranged below the drive wheel, and the rope is a spacer attached to the stop at the stop when the rope end reaches an end position.

25. Drive mechanism for the safety rope of a fall protection device according to claim 24, characterized in that the stop is a limit switch actuator.

26 drive mechanism for the safety rope of a fall arrest device according to one of claims 17 to 25, characterized in that the motor via the radio or via a power rail is controllable.

27 drive mechanism for the safety rope of a fall arrest device according to one of claims 17 to 26, characterized in that the freewheel is a component of the drive wheel and the drive wheel is mounted on the freewheel on the motor shaft or driven by a motor shaft.

28 drive mechanism for the safety rope of a fall arrest device according to claim 17 or 27, characterized in that the drive wheel has a rubber or plastic body which is mounted on the freewheel.

29. Drive mechanism for the safety rope of a fall protection device according to claim 18, characterized in that the pressure wheel has a rubber or plastic body.

30 drive mechanism for the safety rope of a fall arrest device according to one of claims 17 to 29, characterized in that the drive mechanism a

Housing which is to be attached to a fall protection device under the same, that the rope is passed through the housing and the drive pulley and the freewheel are located in the housing.

31, drive mechanism for the safety rope of a fall arrest device according to claim 24, characterized in that on a housing of the drive mechanism, a guide ring is provided for the spacer.