DE102022129460A1 - Rope length sensor with sensor - Google Patents

Abstract

The invention relates to a cable length sensor (10) which comprises a housing (18) and/or frame. The cable length sensor (10) contains a cable drum (42) which is rotatably mounted in the housing (18) and/or frame and on which a measuring cable (31) can be wound up and unwound. A drive (12) is provided for the cable drum (42) of the measuring cable (31), wherein the drive (12) for the cable drum (42) for winding up and unwinding the measuring cable (31) is formed by an electric motor (14). A measuring sensor (20) detects the rotation of the drive (12) and/or the cable drum (42) and outputs the output values to a cable drum brake (35).

Description

1. a) ein Gehäuse und/oder Rahmen,
2. b) eine in dem Gehäuse und/oder Rahmen drehbar gelagerte Seiltrommel, auf welcher ein Messseil auf- und abwickelbar vorgesehen ist,
3. c) einen Antrieb für die Seiltrommel des Messeils, wobei der Antrieb für die Seiltrommel zum Auf- bzw. Abwickeln des Messseils von einem elektrischen Motor gebildet wird,
4. d) einen Messwertaufnehmer zur Erfassung und Ausgabe der Messwerte der Rotation des Antriebs und/oder der Seiltrommel,
5. e) eine Seiltrommelbremse.

The invention relates to a cable length sensor according to the preamble of claim 1 comprising

1. (a) a housing and/or frame,
2. b) a cable drum rotatably mounted in the housing and/or frame, on which a measuring cable is provided for winding and unwinding,
3. c) a drive for the cable drum of the measuring cable, whereby the drive for the cable drum for winding or unwinding the measuring cable is formed by an electric motor,
4. d) a sensor for recording and outputting the measured values of the rotation of the drive and/or the cable drum,
5. e) a cable drum brake.

Description

Such cable length sensors are used, for example, to measure the distance by which the boom of a crane has been extended. The cable length sensor contains a measuring cable that is wound onto a cable drum. The cable drum is rotatably mounted in a housing and/or frame of the cable length sensor. When the measuring cable is pulled off the cable drum, the cable drum rotates. This rotation is measured by a sensor of a measuring transducer. It provides a measure of the length of cable pulled off the cable drum. The cable length sensor is attached to a reference point and the free end of the measuring cable is attached to a part that is moving relative to the reference point. The length of cable pulled off then provides the movement of the moving part. For example, the cable length sensor can be attached to a stationary part of a crane and the end of the measuring cable can be attached to the end of a crane boom. The extension length of the crane boom can then be monitored using the signal from the cable length sensor. The cable drum is under the influence of a restoring torque that can be applied by a spring motor, for example. The measuring cable is pulled against this restoring moment. The measuring cable is guided out of the housing of the cable length sensor via a cable guide with little friction. This cable guide can be designed so that the cable can also be pulled out of the housing at an angle. Such cable guides can have a roller guide with two pairs of guide rollers arranged crossed to one another around the measuring cable. The cable guide can also be formed by a body with a guide hole that is pivotally mounted on all sides in a spherical bearing surface.

State of the art

The DE 295 198 09 U1 relates to a cable drum arrangement in a cable length sensor with a housing and a cable drum arranged in the housing, mounted so as to rotate against the action of a return drive and guided so as to be longitudinally movable, with a measuring cable wound onto the cable drum. The cable is led out of the housing via a cable outlet fixed to the housing. Using an adjusting gear, the cable drum is adjusted in the axial direction in the housing according to its revolutions in such a way that the windings of the measuring cable unwound or wound up from the cable drum are essentially in the plane of the cable outlet. When the cable is wound onto the cable drum, one cable winding lies next to the other, with the cable being wound neatly onto the cable drum in one layer. The cable runs through a cable outlet fixed to the housing and therefore has a defined position in relation to the housing. To achieve this, the cable drum is axially displaced by the adjusting gear according to the revolutions of the cable drum when the cable is wound up or unwound, by one cable diameter with each revolution. The end plate has a threaded hole with which the end plate is mounted on a threaded spindle. The threaded spindle is fixedly attached to an end plate of the cylindrical housing. When the cable drum rotates, the end plate screws along the threaded spindle so that the end plate also moves axially with the rotation. The rotary movement of the cable drum is transmitted via off-center/axial guide rods/which extend through openings in the end plate of the cable drum to an input gear of a reduction gear, which in turn is connected to the input shaft of an angle encoder.

The EP 2 653 428 A1 describes a cable length sensor which comprises a housing and/or frame. A cable drum is rotatably mounted in the housing and/or frame, on which a measuring cable can be wound up and unwound. A measuring sensor records the number of rotations of the cable drum. The cable length sensor also has a reset drive for the cable drum, which winds the unwound measuring cable back onto the cable drum.

The known reset drives work with a spring motor. The springs of the spring motors can lose the necessary elasticity over the course of their service life. In particular, applications with a high number of cycles and simultaneously long measuring lengths, such as applications for a high-bay warehouse, for an elevator or for an automation system, lead to high load changes in the spring motor or a drive spring. shortened service life. This means that this type of drive requires a lot of maintenance. In the worst case, constant stress can even lead to the spring breaking.

The EP 1 014 031 B1 relates to a measuring cable displacement sensor. The measuring cable displacement sensor has a housing in which a cable drum is arranged so that it can rotate and be moved longitudinally relative to the axis of rotation. A cable feedthrough fixed to the housing is provided for the measuring cable. A longitudinal drive for the cable drum with a spindle drive comprises a threaded spindle that can be screwed relative to a spindle nut. The longitudinal drive has an additional gear so that the rotation of the cable drum is transferred to the spindle drive. A flat spring cascade is used as the reset drive. Instead of the flat spring cascade, an electric motor with appropriate control can be used, which - analogous to the spring cascade - sits coaxially on the right-hand end of the shaft. A limit on the rotational speed when winding up the cable drum is achieved by using a contactless, magnetic brake. The components involved must be made of an electrically conductive material. Since the winding is carried out on the radially outer surface using a measuring cable, the magnets are preferably aligned in the longitudinal direction, i.e. parallel to the rotation axis of the cable drum, between two components that are adjacent in this axial direction. Due to the rotation of the cable drum, an eddy current is initially generated in the component that carries the brake magnet, regardless of the distance of the brake magnet from the component to be influenced. This eddy current results in a magnetic field that closes over the part not in the magnetic field and causes a braking torque. The braking effect is - in addition to the strength of the magnet used - very strongly determined by the distance between the magnet and the component to be influenced, which is why this distance can be adjustable. One disadvantage is that the eddy current brake works in both directions. It therefore also slows down the extension. This is why it is suitable for moderate adjustment speeds. Another disadvantage is that the braking power only works in a fixed ratio to the speed. The ratio is determined by the selection of magnets, air gap and materials. This means that the braking power cannot be changed during operation. With the current state of the art, the braking power and resulting speed reduction are effective at all times. In the design shown, an electric motor must therefore also overcome the braking torque of the eddy current brake. This has a negative effect on the dynamics and electrical effective power or efficiency. Furthermore, the reduction in the retraction speed with increased adjustment speed of the system in the elevator direction can lead to slack rope and thus to the measuring rope jumping off the measuring drum.

The disadvantage of the known rope length sensors is that if the rope breaks, an uncontrollable situation arises which can lead to the destruction of the rope length sensor. In the worst case, the user can injure themselves when the rope snaps back.

Disclosure of the invention

The object of the invention is therefore to avoid the disadvantages of the prior art and to create a functionally reliable rope length sensor that can be safely controlled even in the event of a rope break.

• f) einen Sensor zur Erfassung der Seileinzugs- bzw. der Seilauszugsgeschwindigkeit und/oder der Seileinzugs- bzw. der Seilauszugsbeschleunigung aufweist.

According to the invention, the object is achieved in that, in a cable length sensor of the type mentioned at the beginning, the

• f) has a sensor for detecting the cable retraction or extension speed and/or the cable retraction or extension acceleration.

The invention is based on the principle that the speed or acceleration of the measuring cable is recorded directly. The speed or acceleration of the measuring cable could in principle be determined indirectly, for example, via the electric motor, the shaft or the cable drum. The measuring sensor could also be used for such a measurement. In principle, values for the speed or acceleration would be provided even if there is no longer a measuring cable due to a measuring cable break. However, the sensor of the cable length sensor according to the invention records the speed or acceleration directly on the measuring cable, which means that a measuring cable break can also be detected immediately. This means that the necessary safety measures can be initiated to protect the cable length sensor and possibly also people nearby.

A further advantageous embodiment of the cable length sensor according to the invention is that the sensor is optical, electrical and/or mechanical. The optical sensor can work, for example, by means of reflection from a laser diode and light receiver, whereby the phase shift of the emitted and received light is compared with each other and converted into a speed or acceleration. Another variant of an optical sensor is, for example, that the measuring cable is provided with markings which are in at the same distance. A photosensitive sensor detects these markings when the measuring cable is pulled in or out. This can also be used to determine the speed or acceleration. A mechanical alternative would be a roller at the measuring cable outlet as a sensor, over which the measuring cable runs. The rotation of the roller can be detected here

A further advantageous embodiment of the cable length sensor according to the invention is achieved by a control system which evaluates and processes the speed or acceleration measurement values of the sensor. The sensor's measurement values are forwarded to the control system. The control system uses these to create the corresponding speed or acceleration values and, if necessary, controls the cable length sensor with these values. However, these values can be transmitted to another, even external, evaluation unit via a suitable interface. It also serves to log how the cable length sensor is used. It can also be used to estimate the wear of the measuring cable or the entire cable length sensor.

A preferred variant of the cable length sensor according to the invention further consists in that a braking system is provided for braking the cable retraction or cable extension. This measure serves to ensure that the normal extension and retraction of the measuring cable are not carried out too abruptly in order not to place too much strain on the cable length sensor as such. The braking system is able to reduce the cable extension or cable retraction speed. This in particular prevents the measuring cable from hanging slackly.

In a preferred embodiment of the cable length sensor according to the invention, at least one control line is provided, via which the control system controls the braking system. This measure serves to link the directly recorded speed or acceleration with the braking system. If a threshold value is exceeded, the control system can, for example, activate the braking system. This is particularly necessary if an undesirable measuring cable breakage occurs in the cable length sensor.

A special design of the cable length sensor according to the invention is also achieved by the fact that the braking system contains the electric motor. The electric motor of the cable length sensor can also function as a brake. An EMF brake (short circuit of the motor windings) switched on in the de-energized state prevents the cable drum from twisting or running too quickly, e.g. when the measuring cable is manually pulled out by a user. The same applies, of course, to systems that are in motion and the supply voltage is suddenly interrupted. This is intended in particular to ensure that the measuring cable does not jump off the cable drum.

As an alternative to the electric motor as a brake or in combination with the electric motor, the braking system of the cable length sensor according to the invention can preferably have at least one brake lever arrangement for the cable. The brake lever arrangement presses the measuring cable, for example with a brake lever, against the cable drum, a brake shoe or the housing. The measuring cable is thereby prevented from moving further.

As a preferred embodiment of the cable length sensor according to the invention with such a brake lever arrangement, a brake drive is provided which can be actuated mechanically, hydraulically, pneumatically and/or electrically. The brake lever is activated by the different variants for braking the measuring cable.

Preferably, the cable length sensor according to the invention is provided with control means (95) for the braking system, which dynamically brakes the measuring cable. This prevents, for example, the measuring cable from hanging slackly and yet still being able to be pulled out or retracted.

Further embodiments and advantages emerge from the subject matter of the subclaims and the drawings with the associated descriptions. Exemplary embodiments are explained in more detail below with reference to the attached drawings. The invention is not intended to be limited to these exemplary embodiments alone. They merely serve to explain the invention in more detail. The present invention is intended to relate to all objects that the person skilled in the art would now and in the future consider obvious for the implementation of the invention.

Short description of the drawing

• 1 shows schematically an overall view of a cable length sensor according to the invention with electromotive retraction.
• 2 shows a longitudinal section of the cable length sensor according to 1 .
• 3 shows a cross-section of the rope length sensor according to the invention at the level of the rope exit and with the rope drum brake deactivated.
• 4 shows a cross-section of the rope length sensor according to the invention at the level of the rope exit and with the rope drum brake activated.
• 5 shows a sectioned motor housing of the cable length sensor according to the invention with a view of the driver (transport lock), freewheel and motor.

Preferred embodiment

1 shows a schematic overall view of a cable length sensor 10 according to the invention with a drive 12, which is designed as an electric motor 14. In the present embodiment, a brushless servo motor with encoder is used as the electric motor 14. The cable length sensor 10 also comprises a base body 16 with a housing 18. The reference number 20 designates a measuring sensor, which is arranged on a first end face 22 of the housing 18 in a measuring sensor housing 24. It should be noted that a separate measuring sensor 20 is not absolutely necessary. Alternatively, the measuring sensor 20 can also be formed by the electric motor 14 itself. In principle, both variants for the measuring sensor 20 can also be used simultaneously for additional safety.

On a second end face 26 of the housing 18, the electric motor 14 is flanged to a motor housing 28.

A measuring cable 31 is guided from a cable nozzle fixed to the housing or a cable outlet 30 of the housing 18. In the area of the cable outlet 30, a sensor 32 is provided for detecting the speed or acceleration of the measuring cable 31 as it passes through the cable outlet 30. The sensor 32 can be electrical, optical and/or mechanical. In the present embodiment, the sensor 32 is optical. The measured values of the sensor 32 are transmitted to a controller 33 for further processing. The sensor 32 directly detects the speed or acceleration of the measuring cable 31.

In critical situations in which the sensor 32 delivers measured values for speed or acceleration that are above a predetermined threshold value, a cable drum brake 35 is activated by the control 33. The cable drum brake 35 is provided in the upper area of the housing 18. The measuring cable 31 is unwound or wound up when the electric motor 14 is actuated.

The 2 shows a longitudinal section of the cable length sensor 10 as shown in 1 is shown. Where the figures correspond, the same reference numerals are used. The cable length sensor 10 comprises the base body 16. A shaft 34 is axially mounted in a bearing 37 in the end faces 22, 26 of the housing 18 of the base body 16. A splined hub 36 and a guide spindle 38 as a guide 40 for a cable drum 42 are pushed onto the shaft 34. The guide spindle 38 is mounted on the shaft 34 with bearings 44, 46. The cable drum 42 sits on the guide spindle 38. For this purpose, the cable drum 42 has a measuring drum flange 48, 50 on each of its front sides 47. The measuring drum flange 48 sits on the guide spindle 38 with a driver 51 and a guide bush 52. Accordingly, the other measuring drum flange 50 sits with a driver 53 on the spline hub 36.

The measuring cable 31 is provided so that it can be wound up or unwound around the circumference of the cable drum 42, with one end of the measuring cable 31 located in the housing 18 being fastened to the cable drum 42 in a cable suspension 54. Due to its strength, the measuring cable 31 is designed as a wire cable 56 in the present embodiment. Other materials with sufficient strength, such as plastic fibers, are of course also conceivable as the measuring cable 31.

The speed or acceleration of the measuring cable 31 could in principle be determined indirectly, for example, via the electric motor 14, the shaft 34 or the cable drum 42. The measuring sensor 20 could also be used for such a measurement. In principle, values for the speed or acceleration would be provided even if there is no longer any measuring cable 31 due to a measuring cable break. In the present embodiment, however, the sensor 32 records the speed or acceleration directly on the measuring cable 31, which means that a measuring cable break can also be detected immediately.

The shaft 34 is driven by the electric motor 14. A rotor 57 of the electric motor 14 is also visible here. 58 denotes a motor flange. The electric motor 14 is flanged with its motor housing 28 to the housing 18 via a motor support 61. A motor shaft 60 connected to the rotor is coupled to the shaft 34, which rotates with the cable drum 42. When the measuring cable 31 is wound up or unwound, the cable drum 42 is guided axially with the guide spindle 38 over the splined hub 36, so that the measuring cable 31 is always wound up or unwound in a fixed position relative to the cable outlet 30.

The motor housing 28 contains a removable cover 62 with a sealing plug 64. The reference numeral 66 designates a freewheel and 53 the A pressure disk 70 holds the freewheel 66 in position in the motor housing 28. The motor shaft 60 is fixed with a clamping ring 72.

Control elements, such as a processor-controlled control unit, for the electric motor 14 are provided on a circuit board 74. The controller 33 acts on the control elements and triggers an abrupt braking process if necessary.

The cable length sensor 10 is supplied with the required electrical voltage via a plug connection 76, which is arranged in a plug housing 78. Voltage is applied to the electric motor 14, the circuit board 74, the sensor 32, the control 33 and the cable drum brake 35 in particular via this. The plug connection 76 can also contain data lines, in particular for parameterization and/or communication with a higher-level control system.

The cable drum brake 35 comprises a brake housing 82 in which a lifting magnet 84 is arranged. The lifting magnet 84 contains a movable plunger 86 or piston and coils 88 with an iron core. The plunger 86 is guided by a compression spring 90 at the upper end in a pressure bushing 92, which is vertical here. The lifting magnets 84 form a brake lever arrangement 93 with the plunger 86, the compression spring 90 and a brake lever 94. The brake lever 94 is located at the lower end of the plunger 86. The compression spring 90 presses the plunger 86 against the brake lever 94. When voltage is applied to the coils 88, the plunger 86 is pulled away from the brake lever 94. The brake lever 94 then releases the measuring cable 31. Depending on the voltage applied to the coils 88, the brake pressure can be varied dynamically. In combination with the control 33, they also form control means 95 for a dynamic braking process of the measuring cable 31.

The shaft 34 is led out through the front side 22 of the housing 18 and connected to a sensor shaft 96 of the sensor 20 via a coupling 98. An adapter flange 100 is provided as a spacer element between the sensor 20 and the front side 22 of the housing 18, so that the coupling 98 in particular is protected. Instead of the coupling 98, a gear (not shown) can be used under the adapter flange 100 if necessary. The adapter flange 100 can be designed differently if required and can be designed depending on the sensor 20 used.

The 3 shows a cross section of the cable length sensor 10 according to the invention according to the previous 1 and 2 at the level of the rope exit 30 and with the rope drum brake 35 deactivated. As far as the 3 corresponds to the previous figures, the same reference numerals are used.

In order to prevent the measuring cable 31 from jumping off or coming loose from the cable drum 42, the measuring cable 31 and the cable drum 42 are fixed by means of the cable drum brake 35. The brake lever 94 is pressed against the measuring cable 31 using the spring force of the compression spring 90. Only when the coils 88 are subjected to voltage is the lifting magnet 84 actuated and the cable drum brake 35 released by pulling the brake lever 94 away from the measuring cable 31 on the cable drum 42. The speed or acceleration of the measuring cable 31 is recorded by the sensor 32 and forwarded to the control 33 for processing.

The cable drum 42 can thus be driven by the electric motor 14. During the operating phase, the cable drum brake 42 is thus released. An EMF brake (short circuit of the motor windings), which is also switched in the de-energized state, prevents the cable drum 42 from twisting quickly or running on when the measuring cable is manually pulled out by a user. The same applies to systems that are in motion and the supply voltage is suddenly interrupted. This ensures that the measuring cable 31 cannot jump off the cable drum 42.

The measuring cable 31 is guided from the cable drum 42 through a tube 102 to the cable outlet 30 fixed to the housing. A brush 104 with a brush holder 106 is provided in the tube 102 for cleaning the extended or retracted measuring cable 31. A guide bushing 108 is provided on the tube 102 at the tube inlet. The tube 102 is closed off to the outside by a guide ball 110. A rubber buffer 112 dampens the stop of the measuring cable 31 on the cable outlet 30 on the housing 18. At the end of the measuring cable 31 that leads out of the housing 18 there is a cable suspension 113.

A tension spring 114 is attached to the brake housing 82 with one side by a pin 116 and to the brake lever 94 with the other side by a pin 118. The brake lever 94 is pivotally mounted about an axis 120. The tension spring 114 pulls the brake lever 94 against the plunger 86.

A circuit board 122 with a proximity sensor 124 is provided in the brake housing 82 opposite the brake lever 94. An adjusting screw 126 is adjustably attached to the brake lever 94. By pivoting the brake lever 94 the adjusting screw 126 approaches or moves away from the proximity sensor 124. If the distance of the brake lever 94 changes in an unusual way, e.g. due to the measuring cable 31 jumping off or lying undesirably on top of one another, an emergency switching system can trigger an emergency stop via the proximity sensor 124. The cable drum 42 is then braked immediately. This can be necessary, for example, if the measuring cable 31 breaks during winding. The proximity sensor 124 also monitors the switching states of the cable drum brake 35, whereby the cable drum brake 35 is activated when the brake lever 98 is down or deactivated when the brake lever 98 is up.

The 4 shows a cross section of the cable length sensor 10 according to the invention according to the 3 at the level of the rope exit 30 and with the rope drum brake 35 activated.

As far as the 3 corresponds to the previous figures, the same reference numerals are used here.

From the cable drum 42, the measuring cable 31 is guided through the tube 102 to the cable outlet 30 fixed to the housing. The brush holder 106 with the brush 104 is arranged in the tube 102 for cleaning the moving measuring cable 31. A guide bushing 108 is provided on the tube 102 at the tube inlet. To prevent the ingress of dirt or water, the tube 102 is closed off to the outside with the guide ball 110. The rubber buffer 112 dampens the stop that is caused by the cable suspension 113 of the measuring cable 31 on the cable outlet 30 when it is wound up. Here, too, the speed or acceleration of the measuring cable 31 is optically determined via the sensor 32 and forwarded to the control 33 for processing.

In this 4 the coils 88 are not subjected to electrical voltage. The plunger 86 presses the brake lever 94 onto the measuring cable 31 with the spring force of the compression spring 90. The tension spring 114 and the compression spring 90 act against each other. The compression spring 90 has the greater spring force.

The circuit board 122 is arranged opposite the brake lever 94. The proximity sensor 124 is provided on the circuit board 122. The proximity sensor 124 reacts to an adjustment screw 126, which is adjustably attached to the brake lever 94. By pivoting the brake lever 94, the adjustment screw 126 approaches or moves away from the proximity sensor 124. The proximity sensor 124 can detect different heights of the brake lever 94 and thus different states. If the cable drum brake 35 is deactivated, the adjustment screw 126 is closest to the proximity sensor 124. If the cable drum brake 35 is activated, the adjustment screw 126 moves away from the proximity sensor 124. As an example, the distance between the proximity sensor 124 and the adjustment screw 126 is greatest when the brake lever 94 rests on the cable drum 42 and can therefore detect a cable break.

In 5 the cable length sensor 10 according to the invention is shown in perspective according to the previous figures with the electric motor 14, in which the motor housing 28 is shown in section. This illustration thus provides a view of the driver 53 as a transport lock, the freewheel 66 and the electric motor 14. The cover 62 protects the freewheel 66 of the electric motor 14. The cable drum 42 can be fixed by inserting the driver 53 as a transport lock into the cover 62. The driver 53 engages in the groove 128 on the motor through a clearance 130 in the freewheel 66. By fixing the cover 62 with screws, the motor 14 and thus also the cable drum 42, which is firmly connected via the coupling 98, are fixed. The measuring cable 31 can therefore be kept taut even during transport. If the screws on the cover 62 are removed, the cover can be turned using the recessed grips 132 to manually wind up the measuring cable 31. The freewheel 66 prevents twisting in the wrong direction and thus an unintentional jumping off of the measuring cable 31 from the cable drum 42.

List of reference symbols

10

Rope length sensor

12

drive

14

electric motor

16

Base body

18

Housing

20

Transducer

22

first front side

24

Sensor housing

26

second front side

28

Engine housing

30

Rope exit of the housing

31

Measuring rope

32

sensor

33

steering

34

Wave

35

Cable drum brake

36

Splined hub

37

camp

38

Guide spindle

40

guide

42

Rope drum

44

camp

46

camp

47

Front sides of the measuring drum

48

Measuring drum flange

50

Measuring drum flange

51

Driver

52

Guide bush

53

Driver

54

Rope suspension

56

Wire rope

57

rotor

58

Motor flange

60

Motor shaft

61

Engine mount

62

Lid

64

Sealing plug

66

Freewheel

70

Pressure disc

72

Clamp ring

74

Circuit board

76

Plug connection

78

Connector housing

82

Brake housing

84

Lifting magnet

86

Pestle

88

Wash

90

Compression spring

92

Pressure bushing

93

Brake lever arrangement

94

Brake lever

95

Control means

96

Transducer shaft

98

coupling

100

Adapter flange

102

Pipe

104

brush

106

Brush holder

108

Guide bush

110

Guide ball

112

Rubber buffer

113

Rope suspension (outside)

114

Tension spring

116

Pin (brake housing)

118

Pin (brake lever)

120

axis

122

Circuit board

124

Proximity sensor

126

Adjustment screw

128

Groove

130

Clearance

132

Grip recesses

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 29519809 U1 [0003]
• EP 2653428 A1 [0004]
• EP 1014031 B1 [0006]

Claims (9)

Rope length sensor (10) comprising a. a housing (18) and/or frame, b. a rope drum (42) which is rotatably mounted in the housing (18) and/or frame and on which a measuring rope (31) can be wound up and unwound, c. a drive (12) for the rope drum (42) of the measuring rope (31), the drive (12) for the rope drum (42) for winding up and unwinding the measuring rope (31) being formed by an electric motor (14), d. a measured value sensor (20) for detecting and outputting the output values of the rotation of the drive (12) and/or the rope drum (42), e. a rope drum brake (35), characterized by f. a sensor (32) for detecting the rope retraction or extraction speed and/or the rope retraction or extraction acceleration. Cable length sensor (10) after Claim 1 , characterized in that the sensor (32) is optical, electrical and/or mechanical. Rope length sensor (10) according to one of the Claims 1 or 2 , characterized in that a controller (32) is provided which evaluates and processes the speed or acceleration measured values of the sensor. Rope length sensor (10) according to one of the Claims 1 until 3 , characterized in that a braking system (35) is provided for braking the cable retraction or the cable extension. Rope length sensor (10) according to one of the Claims 1 until 4 , characterized in that at least one control line is provided, via which the controller (33) controls the braking system (35). Rope length sensor (10) according to one of the Claims 4 until 5 , characterized in that the braking system (35) contains the electric motor (14). Rope length sensor (10) according to one of the Claims 4 until 6 , characterized in that the braking system (35) has at least one brake lever arrangement (93) for the cable. Cable length sensor (10) after Claim 7 , characterized in that a brake drive is provided for the brake lever arrangement (93), which can be actuated mechanically, hydraulically, pneumatically and/or electrically. Rope length sensor (10) according to one of the Claims 4 until 8th , characterized in that control means (95) are provided for the braking system (35), which dynamically brakes the measuring cable.