Abseiling device with torque limiter
Patent Information
- Application Number
- EP2023712790
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-03-21
- Filing Date
- 2023-03-08
- Publication Date
- 2025-01-29
AI Technical Summary
Abseiling devices used for rescue operations risk damage to the device and potential injury due to excessive torque introduced by handwheels or external drive means, which can lead to mechanical failure and harm during rescue operations.
A descending device with a torque limiter featuring a first and second coupling body that decouples when a torque threshold is exceeded, utilizing a biasing device like a plate spring for precise torque control and featuring locking elements that disengage to prevent further torque transmission, accompanied by mechanical and acoustic signals to indicate decoupling.
The solution effectively prevents damage to the device and reduces the risk of injury by decoupling the drive means from the guide arrangement at high torque levels, extending the device's service life and ensuring safe operation by signaling torque limits to the user.
Smart Images
Figure 1.1
Abstract
Description
[0001] Descender with torque limiter
[0002] The invention relates to a descender device comprising a guide arrangement rotatable in both directions for guiding a traction means, a braking device coupled to the guide arrangement, wherein a drive means is connectable to the guide arrangement for actuating the guide arrangement, and a torque limiter with a first coupling body and a second coupling body, wherein the torque limiter decouples the drive means and the guide arrangement when a threshold value of the torque is exceeded.
[0003] In practice, abseil devices are used as rescue hoisting devices, for example, to rescue people who have fallen. These devices not only require the ability to lower a person at a limited speed using a traction device such as a rope, but also require a drive mechanism for the traction device guided on a guide device, such as a guide pulley, such as a handwheel, with which the load can be lifted in the opposite direction of lowering - for example, to unlock a locking device or to rescue a person from a crevasse. The problem here, however, is that the torque introduced by the handwheel into the gear system or a locking device of the abseil device can cause damage to these components.To avoid such damage, it is known to use a torque limiter in a descender device, which allows decoupling if the applied torque is too high.
[0004] DE 20 2015 001 685 LI1 describes a descender comprising a housing, a guide assembly arranged in the housing, rotatable in both directions, and a braking device coupled to the guide assembly and designed as a centrifugal brake. Furthermore, the descender comprises a torque limiter for decoupling a motor drive means that can be coupled to the descender for the purpose of actuating the guide assembly. In a first embodiment, the torque limiter is formed by a plug-in part and a sleeve part, which are inserted in the region of a handwheel. Torque limitation is effected by the plug-in part slipping relative to the sleeve part when a torque acting on the plug-in part by a motor drive means exceeds a predetermined threshold.
[0005] DE 10 2006 050 995 B4 discloses a torque limiter for decoupling a drive shaft rotatable about a drive axis from an output shaft. The torque limiter comprises a first coupling body and a second coupling body coupled to one another via a plurality of locking elements. When a predetermined torque threshold is exceeded, the first coupling body is axially displaced relative to the second coupling body, so that the locking elements disengage and the first coupling body slips relative to the second coupling body.
[0006] It is the object of the invention to provide a descender device which, during the rescue of persons in particular, reliably prevents damage to the person to be rescued or to parts of the descender device.
[0007] This object is achieved according to the invention by a descender device having the features of independent claim 1.
[0008] According to one aspect of the invention, a descender device is provided, comprising a bidirectionally rotatable guide assembly for guiding a traction device, a braking device coupled to the guide assembly, and a drive means connectable to the guide assembly for actuating the guide assembly. Furthermore, the descender device comprises a torque limiter with a first coupling body and a second coupling body, wherein the torque limiter decouples the drive means and the guide assembly when a torque threshold is exceeded. The descender device according to the invention is characterized in that the first coupling body is translationally displaceable relative to the second coupling body between a coupling position and a decoupling position.Advantageously, the decoupling of the drive and the guide arrangement can be designed in such a way that the mechanical vibrations or acoustically perceptible noises caused by the translational displacement of the first coupling body clearly indicate to a user of the abseiling device according to the invention that the torque threshold has been exceeded and that a torque reduction is therefore necessary. This further advantageously reduces the stress on the torque limiter, thus extending the service life and / or maintenance interval of the torque limiter.The abseil device according to the invention advantageously allows for the direct or indirect connection of external drive means to the guide assembly, whose torque often exceeds that required for a person's rescue and which, due to the associated risk of injury, are generally not permitted for operating the guide assembly. This allows the abseil device to be coupled to an external drive means without risk of injury to the person or load being lifted, thus allowing forces other than manual force to be transmitted to the traction device. The abseil device thus becomes a versatile and reliable rescue hoisting device.
[0009] The torque limiter preferably comprises a pretensioning device with at least one pretensioning means, which pretensions the first coupling body toward the second coupling body into the coupling position. Particularly preferably, the pretensioning device is adjustable, so that the torque threshold value, above which decoupling of the first coupling body and the second coupling body occurs through translational displacement, can be precisely defined. In an advantageous development, the pretensioning means is designed as a spring element, in particular as a disc spring. This advantageously makes the pretensioning means particularly cost-effective and compact.
[0010] In a particularly preferred embodiment, first locking elements are arranged on the first coupling body and second locking elements are arranged on the second coupling body, which engage with one another in a positive and frictional manner in a coupling position. Particularly preferably, the first locking elements and the second locking elements are designed as locking balls. Expediently, the first locking elements and the second locking elements are in frictional engagement with one another in the uncoupling position of the first coupling body and the second coupling body. Advantageously, if the threshold value of the torque is exceeded, the translational displacement of the first coupling body from a coupling position to the uncoupling position is automatically effected, since the spherical shape of the locking elements ensures that a force component acts in the direction of the translational displacement when a torque is present between the coupling bodies.
[0011] In a practical development, the first coupling body has first recesses for receiving the first locking elements, and the second coupling body has second recesses for receiving the second locking elements. Advantageously, the locking elements are fixed relative to the respective coupling body and cannot be displaced translationally relative to their respective coupling body. Advantageously, the first locking elements protrude from the first recesses, and the second locking elements protrude from the second recesses, so that the first locking elements engage with the second locking elements. Advantageously, the coupling between the first coupling body and the second coupling body takes place exclusively via their locking elements.
[0012] Particularly preferably, the first locking elements are arranged concentrically on an end face of the first coupling body facing the second coupling body, and the second locking elements are arranged concentrically on an end face of the second coupling body facing the first coupling body. In an advantageous development, the adjacent first locking elements and the adjacent second locking elements are each arranged equidistant from one another. Particularly preferably, the distance between adjacent first locking elements is equal to the distance between adjacent second locking elements.
[0013] Particularly preferably, the first coupling body is axially displaceable relative to the second coupling body along a common axis of rotation. The decoupling is advantageously particularly reliable, particularly when the locking elements are designed as locking balls, and also with correspondingly easily perceptible mechanical vibrations and the generation of audible noises.
[0014] Further advantages, features and characteristics of the invention will become apparent from the following description of a preferred embodiment and from the appended claims.
[0015] The invention is explained in more detail below with reference to the accompanying drawings using preferred embodiments.
[0016] Fig. 1 shows a front view of a first embodiment of a descender device according to the invention.
[0017] Fig. 2 shows a section along the line AA through the abseiling device from Fig. 1 .
[0018] Fig. 3 shows a detailed view of the torque limiter area.
[0019] Fig. 1 shows a preferred embodiment of a descender device 1 in a front view. The descender device 1 comprises a housing 2, wherein the housing 2 comprises a first housing part 3 and a second housing part 4, which are connected to one another. The first housing part 3 is closed on a side facing away from the second housing part 4 with a first housing cover 5, wherein the first housing cover 5 is fastened to the first housing part 3 with two screws 6, 7. A snap hook 8 is fastened to an upper side of the first housing part 3 via a pin 9, so that the descender device 1 can advantageously be suspended from a fixed point. At the opposite ends of the pin 9, two hooks 10, 11 are fixedly arranged, over which a traction means designed as a rope can be placed.
[0020] The abseiling device 1 further comprises a locking device 12 designed as a ratchet, which allows the rotation of a guide arrangement provided in the abseiling device 1 for guiding a traction device to be locked in at least one direction of rotation. The locking device 12 comprises a switching arrangement 13, which can switch the locking by means of an externally accessible switching element 14.
[0021] Fig. 2 shows a cross-sectional view of a section along the dashed line AA in Fig. 1 . In this view it can be seen that the housing 2 of the descender 1 is formed by the first housing part 3 and the second housing part 4, wherein the first housing part 3 and the second housing part 4 are screwed together by means of a plurality of screws, of which a screw 17 is shown here. The first housing part 3 is closed by the first housing cover 5, which is detachably fastened to the first housing part 3 by means of the screws 6, 7 and the second housing part 4 is closed by a second housing cover 15, which is fastened to the second housing part 4 by means of a plurality of screws, of which a screw 16 is shown here.
[0022] As can be seen in the cross-sectional view, the abseiling device 1 comprises a guide arrangement 18 which can be rotated in both directions for guiding a traction means 19 in the form of a rope, the guide arrangement 18 comprising a first shaft 20. The guide arrangement 18 is arranged for the most part in the first housing part 3. A cable pulley 21 is connected in a rotationally fixed manner to the first shaft 20, the cable pulley 21 having a radially circumferential V-shaped profile 22 in which the traction means 19 is guided. The first shaft 20 projects into the locking device 12 designed as a ratchet and is rotationally coupled to it, such that the rotation of the first shaft 20 or of the cable pulley 21 rotationally coupled to the first shaft 20 can be locked in at least one direction of rotation.
[0023] The abseiling device 1 further comprises a second shaft 23, which is coupled to the first shaft 20 via a gear 24. The second shaft 23 projects axially beyond the second housing cover 15 and is circumferentially rotatably mounted in the second housing cover 15 and in the first housing part 3. The second shaft 23 has a circumferentially toothed section 23a, which meshes with a gear 25 formed integrally with the first shaft 20 to form the gear 24.
[0024] The ratio of the circumferences of the circumferentially toothed section 23a and the gear 25 is approximately 1 to 9, so that the gear 24 is designed as a reduction gear. The first shaft 20 with the gear 25 is rotatably mounted with a first end in the first housing part 3 and with a second end in the second housing part 4. Furthermore, the first shaft 20 is centrally supported in an opening of a partition 3a of the first housing part 3, which at the same time spatially separates the cable pulley 21 from the gear 25. As a result, the cable pulley 21 is arranged in a separate sub-chamber within the housing 2, wherein this sub-chamber is open at the bottom so that the two ends of the traction means 19 designed as a cable are guided downwards out of the housing 2.
[0025] A brake arrangement 26 designed as a centrifugal brake is connected to the second shaft 23, which causes a braking force when a certain rotational speed of the second shaft 23 is exceeded and brakes the rotational movement of the gear 24 and thus the rotational speed of the first shaft 20 or the cable pulley 21 as a whole.
[0026] Furthermore, the abseiling device 1 comprises a mechanical torque limiter
[0027] 27, which serves to limit a torque acting from the outside on the second shaft 23 or on the gear 24 and the first shaft 20. The abseiling device 1 according to the invention can thus be used flexibly as a rescue hoist, wherein a force on the traction means 19 is limited and thus, in addition to preventing damage to the gear 24 or the first shaft 20 or the second shaft 23, also the risk of serious injury to the person being lifted by means of the traction means 19 is prevented. In particular, the torque limiter 27 prevents the traction means 19, designed as a rope, with a load attached to it, in particular the load of a person to be rescued, from being subjected to a high torque, which can lead to serious injuries in the event of entrapment or the like.
[0028] In the embodiment shown here, the torque limiter 27 is arranged between the second shaft 23 and a handwheel 28. The torque limiter 27 comprises a first coupling body 29 and a second coupling body 30, wherein the first coupling body 29 is preloaded toward the second coupling body 30 via a preloading device 31.
[0029] Fig. 3 shows a detailed view in the area of the torque limiter 27. The first coupling body 29 is coupled to the second shaft 23 in a rotationally fixed manner, so that when the first coupling body 29 rotates about an axis of rotation D, shown here in dash-dotted lines, the second shaft 23 also rotates about the same axis of rotation D. The second coupling body 30 is arranged concentrically to the axis of rotation D and, on an end face facing away from the first coupling body 29, has a connecting section 30b which partially protrudes from the handwheel 28 and is provided for connecting the second coupling body 30 to an external drive means, for example a cordless screwdriver or other motor drive means. The connecting section 30b has a central recess 32 for a rotationally positive connection to such a drive means.In the present embodiment, the central recess 32 has a polygonal profile, which is designed to fit a drive shaft of a drive means. Advantageously, the second coupling body 30 can thus be driven into rotation by the drive means, and thus, as long as a predetermined torque threshold is not exceeded, rotation of the cable pulley 21 can be driven due to the existing coupling with the second shaft 23. However, if the predetermined torque threshold is exceeded, the drive means is decoupled from the second shaft 23 or the cable pulley 21.
[0030] The first coupling body 29 has a plurality of first recesses 29a on an end face facing the second coupling body 30, and the second coupling body 30 has a plurality of second recesses 30a on an end face facing the first coupling body 29. First locking elements 33 designed as locking balls are received in the first recesses 29a, and second locking elements 34 designed as locking balls are received in the second recesses 30a, wherein the first locking elements 33 and the second locking elements 34 protrude axially from their respective recesses 29a, 30a, so that the first locking elements 33 and the second locking elements 34 touch each other under the pretension of the pretensioning device 31.
[0031] The pretensioning device 31 comprises a pretensioning means 35 designed as a disc spring, wherein the pretensioning means 35 is arranged or clamped between an adjusting element 36 designed as an adjusting nut and the first coupling body 29. The adjusting element 36 has a radially inwardly directed abutment 36a, against which the pretensioning means 35 is axially supported. The adjusting element 36 further has an internal thread 36b, which meshes with an external thread 30c provided on the second coupling body 30. Advantageously, the pretensioning force of the first coupling body 29 in the direction of the second coupling body 30 and thus also the threshold value of the torque at which the decoupling between the first coupling body 29 and the second coupling body 30 occurs can be set.For this purpose, the adjusting element 36 is screwed onto the second coupling body 30 and, when the desired preload force, which determines the threshold value of the torque, is reached, is secured axially relative to the second coupling body 30, preferably by means of a pin.
[0032] The preloading means 35 is axially supported on the other side by a first ball bearing 37, which is arranged on the first coupling body 29 on an end face facing away from the first locking elements 33, so that the first coupling body 29 can rotate relative to the preloading means 35. The first ball bearing 37 is arranged in a groove 38 which is concentric with the axis of rotation D and has a U-shaped cross-section, such that the bearing balls present in the first ball bearing 37 protrude axially beyond an upper U-leg, so that the preloading means 35 is supported on the bearing balls.
[0033] Furthermore, a second ball bearing 40 is arranged in a further circumferential U-shaped groove 39 of the second coupling body 30, wherein the bearing balls protrude downwards from the U-shaped groove 39 in the direction of the first coupling body 29, so that the first coupling body 29 can rotate relative to the second coupling body 30 when the first locking elements 33 and the second locking elements 34 become disengaged when a threshold value of the torque is exceeded, thus resulting in decoupling between the first coupling body 29 and the second coupling body 30. The second coupling body 30 is injection-molded into the handwheel 28 in a rotationally fixed manner. In Fig. 2 and in Fig. , the first coupling body 29 is in a decoupling position relative to the first coupling body.
[0034] When a predetermined threshold value of a torque is exceeded, the first locking elements 33 slip relative to the second locking elements 34, wherein at the same time an axial displacement of the first coupling body 29 relative to the second coupling body 30 takes place against the pretension of the pretensioning device 31 or the pretensioning means 35 into a decoupling position.If the torque threshold is exceeded, a continuous engagement and disengagement movement of the first locking elements 33 and second locking elements 34 occurs, which is clearly perceptible both mechanically and acoustically from the outside by a user of the abseiling device 1, so that the user is automatically signaled during a rescue hoist process that the drive means connected to the abseiling device 1 via the central recess 32 has an excessive torque and that a corresponding reduction in the load on the drive means is necessary, since a higher torque is not possible for the rescue hoist process anyway. This advantageously prevents a user from introducing excessive torque into the abseiling device 1 over a prolonged period.
[0035] The invention has been explained above using an exemplary embodiment in which an adjusting element with a screw thread is shown. It is understood that the adjusting element can also be used, for example, as a locking element with discrete locking positions. Furthermore, the use of adjusting elements that can be integrally connected to the second coupling body 30 is also possible, so that the setting of the torque threshold value is fixed by the manufacturer and cannot be easily adjusted by the user. However, the adjusting element is particularly preferably designed such that it can be axially adjusted and releasably fixed at specific positions, thus enabling readjustment.
Claims
REQUIREMENTS 1. Abseiling device comprising a guide arrangement (18) rotatable in both directions for guiding a traction element (19), a braking device (26) coupled to the guide arrangement (18), wherein a drive element is coupled to the guide arrangement (18) for actuation of the guide arrangement (18) is connectable, and a torque limiter (27) with a first coupling body (29) and a second coupling body (30), wherein the torque limiter (27) decouples the drive means and the guide arrangement (18) when a threshold value of the torque is exceeded, characterized in that the first coupling body (29) is translationally displaceable relative to the second coupling body (30) between a coupling position and a decoupling position.
2. Abseiling device according to claim 1, characterized in that the torque limiter (27) comprises a pretensioning device (31) with at least one pretensioning means (35) which pretensions the first coupling body (29) in the direction towards the second coupling body (30) into the coupling position.
3. Abseiling device according to claim 2, characterized in that the pretensioning device (31) is adjustable so that the threshold value of the torque, from which a decoupling of the first coupling body (29) and the second coupling body (30) takes place by translational displacement, can be determined.
4. Abseiling device according to claim 2 or 3, characterized in that the The preloading element (35) is designed as a spring element, in particular as a disc spring. A descender according to one of claims 2 to 4, characterized in that the preloading element (35) is arranged or clamped between an adjusting element (36) designed as an adjusting nut and the first coupling body (29). A descender according to claim 5, characterized in that the adjusting element (36) has a radially inwardly directed abutment (36a) against which the preloading element (35) is axially supported. A descender according to claim 6, characterized in that the adjusting element (36) has an internal thread (36b) which meshes with an external thread (30c) provided on the second coupling body (30).A descent device according to claim 7, characterized in that the pretensioning means (35) is axially supported on a first ball bearing (37) which is arranged on the first coupling body (29) on an end face facing away from the first locking elements (33), so that the first coupling body (29) can rotate relative to the pretensioning means (35). A descent device according to claim 8, characterized in that the first ball bearing (37) is arranged in a groove (38) concentrically circumferential to an axis of rotation (D) and having a U-shaped cross-section, such that the bearing balls in the first ball bearing (37) project axially beyond an upper leg of the U, so that the pretensioning means (35) is supported on the bearing balls. A descent device according to any one of the preceding claims, characterized in that the first coupling body (29) is arranged on the first coupling body (29). Locking elements (33) and a second locking element (34) are arranged on the second coupling body, which are in a coupling position in a form-locking and friction-locking engagement with each other. 1 1 . Abseiling device according to claim 10, characterized in that the first locking elements (33) and the second locking elements (34) are designed as locking balls.
12. Abseiling device according to claim 10 or 1 1 , characterized in that the first locking elements (33) and the second locking elements (34) are frictionally engaged with each other in the decoupling position of the first coupling body (29) and the second coupling body (30).
13. Abseiling device according to one of claims 1 to 13, characterized in that the first coupling body (29) has first recesses (29a) for receiving the first locking elements (33) and the second coupling body (30) has second recesses (30a) for receiving the second locking elements (34).
14. Abseiling device according to claim 13, characterized in that the first locking elements (33) protrude from the first recesses (29a) and the second locking elements (34) protrude from the second recesses (30a), so that the first locking elements (33) engage with the second locking elements (34).
15. Abseiling device according to one of claims 10 to 14, characterized in that the first locking elements (33) are arranged concentrically on an end face of the first coupling body (29) facing the second coupling body (30) and the second locking elements (34) are arranged concentrically around an axis of rotation (D) on an end face of the second coupling body (30) facing the first coupling body (29). A descender according to claim 15, characterized in that the adjacent first locking elements (33) and the adjacent second locking elements (34) are each arranged equidistantly from one another. A descender according to claim 16, characterized in that the distance between adjacent first locking elements (33) is equal to the distance between adjacent second locking elements (34). A descender according to any one of the preceding claims, characterized in that the first coupling body (29) is axially displaceable relative to the second coupling body (30). A descender according to claim 18, characterized in that the first coupling body (29) and the second coupling body (30) are rotatably mounted coaxially about an axis of rotation (D). A descender according to claim 19, characterized in that the first coupling body (29) is axially displaceable relative to the second coupling body (30) in the direction of the axis of rotation (D).