Rope pull emergency stop switch

Abstract

Rope pull emergency stop switch (100) for coupling with a rope (32) so that an emergency switching signal can be triggered when the rope (32) moves along a movement path (41), comprising a coupling element (31) and a housing (29) with an emergency switching release means (20) and an emergency switching element (22) arranged therein, wherein the coupling element (31) is operatively connected to the emergency release device (20) so that the emergency release element (22) can be switched by means of the movement of the emergency release device (20) to trigger the emergency switch signal, furthermore, a warning switch release means (10) and a warning switch element (12) are provided, wherein the warning switch release means (10) is operatively connected to the warning switch element (12), and wherein a warning signal relating to the movement of the rope (32) can be triggered with the warning switch element (12) before the emergency switch signal is triggered, characterized by that, starting from a central position (M) of the coupling element (31), a switching distance to an emergency switching point (44) of the emergency switching release device (20) is greater than a switching distance to a warning switching point (43) of the warning switching release device (10).

Description

[0001] The invention relates to a cable-operated emergency stop switch for coupling with a cable, such that an emergency stop signal can be triggered when the cable moves along a path of travel. The switch comprises a coupling element and a housing with an emergency stop release mechanism and an emergency stop element, wherein the coupling element is operatively connected to the emergency stop release mechanism, such that the emergency stop element can be switched to trigger the emergency stop signal by means of the movement of the emergency stop release mechanism. Furthermore, a warning switch release mechanism and a warning switch element are provided, wherein the warning switch release mechanism is operatively connected to the warning switch element, and wherein a warning signal relating to the movement of the cable prior to triggering the emergency stop signal can be triggered by the warning switch element. The invention further relates to a safety device with such a cable-operated emergency stop switch for a conveyor belt system.

[0002] Emergency stop switches are installed at specific intervals along long conveyor belt systems, for example, and serve to shut down the system in an emergency. A bidirectional cable is generally attached to the coupling element, running along the conveyor system and allowing the system to be shut down from any point along the conveyor by pulling the cable.

[0003] DIN EN 620 specifies guidelines for emergency stop switches with breakaway cord systems for inclined conveyors and system, safety, and ENV requirements for stationary belt conveyors for bulk materials. According to this standard, emergency stop switches with breakaway cord systems must be arranged so that the associated switching devices are actuated when the breakaway cord is either pulled in any direction or breaks. Furthermore, breakaway cord switches must be designed so that the failure of a single spring holding the breakaway cord under tension triggers the connected switching devices.

[0004] The breakaway switch must be triggered by applying a horizontal force of less than 125 Newtons to the pull cord, positioned midway between two guide rings and perpendicular to the rope. The lateral movement of the rope must be less than 300 mm. STATE OF THE ART

[0005] From DE 696 19 128 T2, a cable-operated switching device is known with which the power supply to machines can be interrupted by means of a switch. It is disclosed that horizontal displacement of a coupling element causes a rotation of a switching release element, which in turn actuates a switching element. A lever arrangement between the coupling element and a structure supporting the switching release elements ensures that a relatively small movement of the coupling element results in a relatively large angular movement of the switching release element.

[0006] Another cable-operated emergency stop switch is known from DE 11 59 074 A. Pulling a cable actuates a switching element controlled by a switching release mechanism, thereby stopping a conveyor belt. Furthermore, it is described that a locking element latches the switching elements in an emergency switching position, and that, in addition to an emergency switching signal, a switching contact is provided for outputting an optical and acoustic signal. This allows it to be determined whether the switching element has been activated.

[0007] EP 2 043 117 A2 describes a quick-release device for a rope pull switch according to the preamble of claim 1, with which the extension and tension of a rope can be detected. A signal can be generated if the tension deviates from a setpoint range. This allows deviations in rope tension to be detected and corrected at an early stage.

[0008] From EP 3 176 799 A2, a quick-release device for a rope pull switch is known, which is designed similarly to EP 2 043 117 A. In a rope pull emergency stop switch, the rope tension is monitored and a warning signal is emitted when a certain threshold is reached.

[0009] German patent DE 72 19 326 U describes a device for the visible indication of an irregular operating condition. This device comprises a housing containing a release mechanism equipped with a spring. The spring is tensioned by means of a lever, the end of which is connected to a tensioned wire.

[0010] If the mechanical tension of the wire is changed, either by an operator or unintentionally, the spring is no longer under load, the release device is activated, and a corresponding signal is given.

[0011] The cable pull switch described in DE 35 08 302 A1 for the emergency shutdown of drive units in underground operations comprises a housing with switching contacts featuring roller levers and a switching device that acts on the roller levers. The switching device includes a switching drum. The switching contacts are arranged on both sides of the switching drum, with roller levers bearing against the drum. A switching mechanism is associated with the switching drum for the forced locking of the drum in the on or off position. The drum surface has positioning contours on it corresponding to the on and off positions for the roller levers that engage in them. This results in a simplified and compact design, which significantly facilitates the mounting of the switching contacts and optimizes the switching sequences.

[0012] From DE 197 25 491 C1, a pull-cord emergency stop switch is known, comprising an actuating lever by which a cam roller can be moved into a lockable end position for actuating at least one control switch, and a release lever by which the cam roller can be released from its end position. For enhanced safety, a switching device is available that includes a translationally displaceable element coupled to the cam roller, which can be moved translationally into an end position by a sliding element connected to the actuating lever and locked by a locking mechanism. The translation of the displaceable element causes the cam roller to rotate about its axis into its end position. The translationally displaceable element is in engagement with the sliding element in this position. Further actuation of the actuating lever does not cause the cam roller to rotate.

[0013] DE 29 35 420 C2 discloses an electrical disconnect device, in particular a cable-operated emergency disconnect device. The cable-operated emergency disconnect device is designed to be coupled to a cable so that an emergency switching signal can be triggered when the cable moves along a defined path. The device comprises a coupling element and a housing containing an emergency release mechanism and an emergency switching element. The coupling element is operatively connected to the emergency release mechanism, allowing the emergency switching element to be switched by the movement of the emergency release mechanism to trigger the emergency switching signal. It is further disclosed that switching elements are arranged in the housing and are actuated by a roller. The switching elements can also be distributed around the circumference of the roller at various angular positions.

[0014] The previously described cable-operated emergency stop device is designed to ensure increased safety through its redundant design with multiple switches and decoupling between the coupling element and the roller. However, its complex design with numerous components makes the cable-operated emergency stop device expensive to manufacture and prone to malfunctions during operation. REVELATION OF THE INVENTION

[0015] It is therefore the object of the present invention to provide a cable pull emergency stop switch and a safety device designed with a cable pull emergency stop switch, which respectively ensures, in a cost-effective and reliable manner, trouble-free, in particular continuous operation of a conveyor belt system without unnecessary emergency shutdowns.

[0016] This problem is solved starting from a rope-operated emergency stop switch according to the preamble of claim 1 in conjunction with the characterizing features and with a safety device according to claim 12. Further embodiments of the invention are specified in the dependent claims.

[0017] According to the invention, starting from a central position of the coupling element, the switching distance to an emergency switching point of the emergency release device is greater than the switching distance to a warning switching point of the warning release device. The direct coupling provides a simple and reliable solution with few components. Deviations or malfunctions due to transmission, leverage, or play between components are avoided.

[0018] By issuing a warning signal, adjustments can be made to the rope or, for example, foreign objects such as falling debris, which puts the rope under additional tension, can be removed before an emergency stop signal is triggered and the conveyor system is halted. This results in a higher conveying rate and improved efficiency of the conveyor system.

[0019] In an advantageous embodiment of the cable-operated emergency stop switch, the emergency release mechanism and / or the warning release mechanism are arranged on at least one roller. This provides a particularly reliable and cost-effective switching device for actuating the emergency release element and / or warning element with a precisely defined switching point. Advantageously, the emergency release mechanism is designed as an emergency release cam and / or the warning release mechanism as a warning release cam, wherein the warning release cam and / or the emergency release cam are formed within the at least one roller. This enables a particularly space-saving and compact design of the cable-operated emergency stop switch.

[0020] Advantageously, the emergency stop gate is longer than the warning stop gate and / or the warning stop gate is deeper than the emergency stop gate. Both the warning stop gate and the emergency stop gate are designed as recesses in the roller. The length of each is determined by the length of the recess along the circumference of the roller. The depth of both is determined by how far the recess extends from the circumference of the roller towards an axis of rotation, i.e., how close the recess is to the roller's axis of rotation. Due to the different lengths of the gates, a simple design without additional complex mechanisms for switching the emergency stop or warning stop element is necessary.Alternatively, by providing a single backdrop with different depths, a particularly compact design is possible, in which the warning switching element and the emergency switching element are implemented in a single unit in a so-called two-stage switch, which can be switched depending on different depths in the recess of the roller.

[0021] In a further embodiment of the cable-operated emergency stop switch, the emergency release mechanism and the warning release mechanism are arranged side by side, interlocked, or nested within each other on at least one roller. This embodiment simplifies the construction. Furthermore, production costs can be reduced through synergies and a reduction in manufacturing steps in the production of the roller.

[0022] In a further embodiment of the cable-operated emergency stop switch, the roller is directly connected to the coupling element and can be rotated around a common axis of rotation depending on the movement path of the cable.

[0023] Advantageously, the coupling element of the cable-operated emergency stop switch is held in the neutral position by a spring. In particular, the roller can be operatively connected to the spring, thus keeping the coupling element in the neutral position. This allows the roller to perform multiple functions and eliminates the need for additional components. The use of a spring also allows for easy readjustment and adjustment of the force that counteracts cable tension or deflection in relation to cable movement. This prevents false shutdowns caused by cable tension or movement below a certain threshold.

[0024] In a further preferred embodiment of the cable-operated emergency stop switch, a detent element is provided for engaging and holding the emergency release mechanism in an emergency position when the emergency signal is triggered. A reset element is also provided for disengaging the detent and returning the device to its neutral position. The detent element ensures that unintentional reactivation is prevented after the emergency signal has been triggered and the conveyor system has stopped. Advantageously, the reset element ensures that the conveyor system can only be operated by deliberately returning the device to its neutral position.

[0025] Alternatively, the warning switch release device, the emergency switch release device and the locking element can be designed in other functionally fulfilling forms and designs, such as cams, pins, cams, hooks, etc.

[0026] Furthermore, the invention relates to a safety device for a conveyor belt system comprising a rope and a rope-operated emergency stop switch for coupling to the rope, such that an emergency stop signal and a warning signal can be triggered when the rope moves along a path of travel, and to a control module configured to issue a warning message when the warning signal is triggered and to stop the conveyor belt system when the emergency stop signal is triggered. The warning signal allows for adjustments to the rope or the removal of foreign objects, such as falling debris that puts the rope under additional tension, before an emergency stop signal is triggered and the conveyor belt system is stopped. This results in a higher conveying rate and greater efficiency of the conveyor system.Alternatively, the use of a control module can be omitted, and a drive can be stopped directly or the conveyor belt system halted using the emergency stop switch. Additionally, a warning signal can be emitted directly via the warning switch.

[0027] Advantageously, the safety device is provided as part of the safety device with a rope pull emergency stop switch in the design according to the features described above. List of characters

[0028] Further measures improving the invention are described in more detail below, together with a description of a preferred embodiment of the invention, with reference to the figures. The figures show: Fig. 1. A rope pull emergency stop switch without a housing cover in perspective view; Fig. 2 a top view of the opened cable pull emergency stop switch; Fig. 3 side views of the section along the cutting line AA of the rope pull emergency stop switch according to Fig. 2 with an emergency switching backdrop and warning switching backdrop arranged on a roller, as well as an emergency switching element; Fig. 4 side views of the section along the section line BB of the cable pull emergency stop switch according to Fig. 2 with a warning switching backdrop and a warning switching element arranged on the roller; Fig. 5 the cable pull emergency stop switch in a middle position, an emergency switching position and a warning switching position; Fig. 6 a section of the emergency switch backdrop with the emergency switch element in the center position and the emergency switch position; Fig. 7 the roller in side view with nested emergency stop and warning stop; Fig. Figure 8 shows a schematic representation of a conveyor belt system with safety device, comprising the cable pull emergency stop switch, a cable and a control module.

[0029] Fig. 1 and Fig. Figure 2 shows a perspective view and a top view of a cable-operated emergency stop switch 100 with a roller 30 arranged in a housing 29. A warning release element 10, configured as a warning switch cam 11, and an emergency release element 20, configured as an emergency switch cam 21, are mounted on the roller 30. A warning switch element 12 and an emergency switch element 22 are operatively connected to the warning switch cam 11 and the emergency switch cam 21, respectively. A coupling element 31 for receiving a cable 32 is directly connected to the roller 30. The roller 30 and the coupling element 31 are movable about a rotational axis 34. A detent element 35 with a return element 36 coupled to it is also installed in the housing 29.

[0030] Fig. 3 and Fig. Figure 4 shows a cross-sectional view of the cable-operated emergency stop switch 100 in a central position M. A roller 37 of a switching arm 38 of the emergency switching element 22 is positioned centrally in the emergency switching cam 21 or the warning switching cam 11. Starting from the central position M, the switching distance is the distance between the roller 37 and the warning switching point 43 or the distance between the roller 37 and the emergency switching point 44. A detent hook 39 of the detent element 35, which is acted upon by a spring force of a detent spring 47, rests under tension against a detent cam 40 of the roller 30. With the movement of the cable 32 along a path of movement 41, the coupling element 31 and the roller 30 rotate about the axis of rotation 34. As shown in Fig. As shown in Figure 4, the warning switching element 12 with roller 37 and switching arm 38 is arranged centrally in the warning switching gate 11. The roller 37 with switching arm 38 can be pivoted out of the warning switching gate 11 by a rotational movement clockwise or counterclockwise. When a warning switching position W is reached (according to Figure 4), the warning switching element 12 is activated. Fig. 5d) The roller 37 is at a warning switching point 43 and the warning switching element 12 activates a warning signal. In this case, the locking hook 39 remains on the locking cam 40, so no locking occurs and the roller 30 with the coupling element 31 can move freely back to the central position M. Thus, it is possible to detect any movement of the cable 32 that indicates a misalignment or a potentially imminent emergency shutdown. Measures can be taken to prevent this emergency shutdown without having to stop operation. A support 45 arranged on the housing 29 holds the ends of the spring 33. The roller 30 and the coupling element 31 are movable about the axis of rotation 34, whereby the spring force of the spring 33 holds the roller 30 and the coupling element 31 in the central position M.When the coupling element 31 is deflected and the roller 30 rotates away from the central position M, the spring 33 causes a restoring force acting in the direction of the central position M.

[0031] Fig. Figure 5 shows a schematic representation of the cable-operated emergency stop switch 100 and the cable 32, which is connected at both ends to a cable spring 42 and thus kept under tension. According to Fig. 5a The coupling element 31 is in the central position M. The force of the tension springs 42 on the coupling element 31 is equal in opposite directions. A warning switch position W according to Fig. 5d is caused by a short deflection of the coupling element 31 by movement of the rope 32. The rope pull emergency stop switch 100 is also shown in an emergency switching position N. In a first case according to Fig. In 5b, the cable 32 is broken on one side. The resulting one-sided tension on the cable spring 42 pulls the coupling element 31 into the emergency switching position N. In a second case with a completely intact cable 32 according to Fig. 5c is the emergency switching position N, which is caused by unloading on the one hand and / or loading of the rope 32 on the other hand of the rope pull emergency switch 100. For example, by falling material from a conveyor belt onto the rope or temperature fluctuations and the associated expansion or contraction of the rope 32.

[0032] Fig. 6a and Fig. Figure 6b shows a section of the roller 30 in the direction of view along the axis of rotation 34 with the emergency switching cam 21 in the center position M according to Fig. 6a, as well as in the emergency switching position N according to Fig. 6b. The switching arm 38 with roller 37 is pivoted out of the emergency switching cam 21 and positioned at the emergency switching point 44 on the roller 30. The pivoting of the switching arm 38 activates the emergency switching element 22 (not shown) and emits an emergency switching signal. In this position, the locking hook 39 has jumped in front of or behind a cam flank 46 of the locking cam 40 and engaged, thus preventing a return movement to the neutral position M. The locking hook 39 rests on the roller 30 under the spring force exerted by the locking spring 47. The emergency switching position N described here is reached by a clockwise or counterclockwise rotation. An advantage of this arrangement with emergency switching cam 21 and locking cam 40 is that even if the roller 30 is turned further or over-turned, the switching arm 38 remains in its position and the locking hook 39 catches the roller 30 again on the cam flank 46 when turning backwards.This prevents damage to components and ensures that the emergency signal is continuously emitted.

[0033] Fig. Figure 7 shows a roller 30 with a warning switching cam 11 and an emergency switching cam 21 nested within it. By rotating the switching arm 38 with the roller 37, it is pivoted from the warning switching cam 11 into the emergency switching cam 21, thereby emitting the warning signal when the warning switching point 43 is reached. With further rotating movement, the emergency switching signal is emitted when the emergency switching point 44 is reached.

[0034] In Fig.Figure 8 shows a safety device 110 of a conveyor belt system 120, comprising a conveyor belt 121, conveyor belt rollers 122, and a conveyor belt drive 123. The safety device 110 includes the cable-operated emergency stop switch 100 with a cable 32 connected to it, and a control module 111, which is connected to the cable-operated emergency stop switch 100 via a signal cable 112 for receiving the warning signal and emergency stop signal. The control module 111 is also connected to the drive 123 and to signaling devices 113. Upon receiving the emergency stop signal, the control module 111 shuts down the drive 123 and transmits the emergency stop signal via the signaling devices 113. Upon receiving a warning signal, the control module 111 sends a warning message to a control room (not shown). Reference symbol list 10 warning switch trigger devices 11 Warning switch panel 12 Warning switch element 20 emergency release devices 21 Emergency switch panel 22 Emergency switching element 29 cases 30 rollers 31 Coupling element 32 rope 33 spring 34 Rotation axis 35 locking element 36 Return element 37 rolls 38 Shift arm 39 locking hooks 40 locking cams 41 Movement path 42 Cable spring 43 Warning switching point 44 Emergency switching point 45 carriers 46 Cam flank 47 Detent spring M middle position Emergency switching position W Warning switch position 100 cable pull emergency stop switches 110 Safety device 111 Control module 112 signal cables 113 Signaling devices 120 conveyor belt system 121 Conveyor belt 122 conveyor belt rollers 123 Conveyor belt drive

Claims

A cable-operated emergency stop switch (100) for coupling with a cable (32) such that an emergency stop signal can be triggered when the cable (32) moves along a path of movement (41), comprising a coupling element (31) and a housing (29) with an emergency release device (20) and an emergency stop element (22) arranged therein, wherein the coupling element (31) is operatively connected to the emergency release device (20) so that the emergency stop element (22) can be switched to trigger the emergency stop signal by means of the movement of the emergency release device (20), wherein a warning release device (10) and a warning switch element (12) are further provided, wherein the warning release device (10) is operatively connected to the warning switch element (12), and wherein a warning signal relating to the movement of the cable (32) before the emergency stop signal is triggered can be triggered by the warning switch element (12). is characterized bythat, starting from a central position (M) of the coupling element (31), a switching distance to an emergency switching point (44) of the emergency switching release device (20) is greater than a switching distance to a warning switching point (43) of the warning switching release device (10). Rope pull emergency stop switch (100) according to claim 1, characterized in that the emergency stop release means (20) and / or the warning stop release means (10) are arranged on at least one roller (30). Rope pull emergency stop switch (100) according to claim 1 or 2, characterized in that the emergency stop release means (20) is designed as an emergency stop cam (21) and / or the warning stop release means (10) is designed as a warning stop cam (11). Cable pull emergency stop switch (100) according to claim 3 in its reference to claim 2, characterized in that the warning switch cam (11) and / or the emergency switch cam (21) is formed as recesses in the at least one roller (30). Rope pull emergency stop switch (100) according to claim 3 or 4, characterized in that the emergency stop cam (21) is longer than the warning stop cam (11) and / or that the warning stop cam (11) is deeper than the emergency stop cam (21). Rope pull emergency stop switch (100) according to one of claims 2 or 4 or according to claim 3 in its reference to claim 2 or according to claim 5 in its reference to claim 4, characterized in that the emergency stop release means (20) and the warning stop release means (10) are arranged next to each other, together or nested inside each other on the at least one roller (30). Rope pull emergency stop switch (100) according to one of claims 2 or 6, characterized in that the at least one roller (30) is directly connected to the coupling element (31) and is movable about a common axis of rotation (34) depending on the movement path (41) of the rope (32). Cable pull emergency stop switch (100) according to one of the preceding claims, characterized in that the coupling element (31) can be held in the central position (M) by means of a spring (33). Cable pull emergency stop switch (100) according to claim 8 in its reference to claim 2, characterized in that the at least one roller (30) is operatively connected to the spring (33) so that the coupling element (31) is held in the central position (M). Rope pull emergency stop switch (100) according to one of the preceding claims, characterized in that a locking element (35) is provided for locking and holding the emergency stop release means (20) in an emergency stop position when the emergency stop signal is issued. Cable pull emergency stop switch (100) according to claim 10, characterized in that a reset element (36) is provided for disengaging and returning to the central position (M). Safety device (100) for a conveyor belt system (120) with a rope (32) and with a rope pull emergency stop switch (100) for coupling with the rope (32) according to one of claims 1 to 11, such that when the rope (32) moves along a movement path (41) a warning signal can be triggered first and, if the movement continues, an emergency stop signal can be triggered, and with a control module (111) which is configured to issue a warning message when the warning signal is triggered and to stop the conveyor belt system (120) when an emergency stop signal is triggered.

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