Switching mechanism and rescue speed difference automatic control system

Abstract

The invention discloses a switching mechanism and a rescue speed difference automatic control system. The switching mechanism used for enabling the rescue speed difference automatic control system to be switched between the speed difference self-locking mode and the rescue mode comprises a mounting shaft capable of moving along the axis of the mounting shaft; the trigger shaft sleeve and the mounting shaft are respectively provided with a bulge and a chute, and the bulge is inserted into the chute and can slide in the chute, so that the trigger shaft sleeve can axially and circumferentially move relative to the mounting shaft; the chuck is fixedly arranged in the direction of the axis of the chuck and is circumferentially fixed relative to the mounting shaft, the chuck can be clamped with or not clamped with the trigger shaft sleeve, and the chuck and the trigger shaft sleeve have relative displacement in the axial direction and the circumferential direction of the mounting shaft between the clamped state and the non-clamped state; the elastic piece can enable the trigger shaft sleeve and the chuck to be kept in a clamping state and a non-clamping state; and the first transmission part can move along with the reciprocating motion of the mounting shaft and can be engaged with and disengaged from a second transmission part of the rope winding device. The switching mechanism is simple in structure, low in cost, convenient to operate, safe and stable.

Description

Technical Field

[0001] This document relates to the technical field of safety protection equipment, especially a switching mechanism and a rescue inertia reel system. Background Art

[0002] Rescue inertia reel systems are widely used by high-altitude workers during work. When a fall occurs, the rescue inertia reel system locks itself, and the person will suspend in mid-air. At this time, it is necessary to quickly rescue the person from mid-air to the ground. Rescue inertia reel systems that combine the functions of speed difference self-locking and rescue have emerged. The rescue inertia reel system needs to be able to switch between the two functional modes of speed difference self-locking and rescue as needed at any time, which requires a switching mechanism. The switching mechanisms on the current market have complex structures, inconvenient operations, and high costs. Summary of the Invention

[0003] The embodiments of the present application provide a switching mechanism that can achieve the switching between the speed difference self-locking mode and the rescue mode of the rescue inertia reel system through a simple structure, with convenient operation and fast switching, solving the problems of the complex structure and inconvenient operation of the switching mechanisms in the prior art.

[0004] In the switching mechanism of the embodiments of the present application, the trigger bushing and the mounting shaft are slidably matched through an inclined groove and a protrusion, so that only by pushing and pulling the mounting shaft, a relative axial displacement and a circumferential displacement can occur between the trigger bushing and the chuck, so that the trigger bushing can be engaged and disengaged with the chuck. The engagement and disengagement realized through the cooperation of this structure and the elastic member enable the mounting shaft to be respectively maintained at two specific axial positions after being pushed and pulled, so as to realize the switching between the speed difference self-locking mode and the rescue mode of the rescue inertia reel system.

[0005] The improvement of the embodiments of the present application further includes the engagement structure between the trigger bushing and the chuck, with a simple structure and smooth switching. In particular, when both of them have the design of protrusions and grooves, a constant axial relative displacement is provided when the trigger bushing and the chuck switch between the engaged and disengaged states, which enables the mounting shaft to be respectively maintained at two specific axial positions before and after the switching.

[0006] At the same time, elastic members are provided, including a first elastic member and a second elastic member, so that the mounting shaft can quickly return to its position under normal small external force disturbances, and will not accidentally change the state between the trigger bushing and the chuck, that is, it will not change the mode of the rescue inertia reel system due to accidental touch disturbances, and only when the external force reaches a specific threshold can the state between the trigger bushing and the chuck be switched, so as to achieve the mode switching of the rescue inertia reel system.

[0007] A further improvement of the embodiment of the present application further includes applying an elastic force to the first transmission member through the provided second elastic member, so that the first transmission member can move with the axial movement of the mounting shaft, so that the first transmission member can engage and disengage with the second transmission member of the rope winding device of the rescue speed differential self-locking system. The second elastic member is installed with one end abutted against the first transmission member and thus abutted against the mounting shaft, which is convenient for the first transmission member to be automatically engaged with the second transmission member under the elastic force of the second elastic member after the first transmission member and the second transmission member are aligned by rotating and finely adjusting the first transmission member during the process of switching from the speed differential self-locking mode to the rescue mode.

[0008] A further improvement of the embodiment of the present application further includes circumferentially fixing the first transmission member and the mounting shaft, so that in the rescue mode, the mounting shaft, as well as the engaged first transmission member and second transmission member, can be driven to rotate by rotating the hand crank, so as to rescue the person hanging in mid-air to the ground.

[0009] A further improvement of the embodiment of the present application further includes designing the chuck and the friction seat of the lifting and lowering assembly of the rescue speed differential self-locking system as an integral structure, so as to simplify the structure of the rescue speed differential self-locking system.

[0010] The present application provides a switching mechanism for switching a rescue speed differential self-locking system between a speed differential self-locking mode and a rescue mode, and the switching mechanism includes:

[0011] A mounting shaft configured to be reciprocally movable along its axis;

[0012] A trigger bushing sleeved on the mounting shaft, and one of the mounting shaft and the trigger bushing is provided with a protrusion, and the other is provided with an inclined groove inclined relative to the axis of the mounting shaft, and the protrusion is configured to be inserted into the inclined groove and can slide in the inclined groove, so that the trigger bushing can perform axial and circumferential displacements relative to the mounting shaft;

[0013] A chuck fixedly arranged in the direction along its axis and circumferentially fixedly sleeved on the mounting shaft relative to the mounting shaft, the chuck is configured to be capable of being clamped and unclamped with the trigger bushing, and between the two states of clamping and unclamping, the chuck and the trigger bushing have relative displacements in the axial direction and the circumferential direction of the mounting shaft;

[0014] An elastic member sleeved on the mounting shaft and configured to enable the trigger bushing and the chuck to be kept in the clamped and unclamped states; and

[0015] A first transmission member circumferentially fixedly sleeved on the mounting shaft and capable of moving with the reciprocating movement of the mounting shaft, the first transmission member is configured to be capable of engaging and disengaging with the second transmission member of the rope winding device of the rescue speed differential self-locking system.

[0016] In some exemplary embodiments, the elastic member includes:

[0017] A first elastic member, which is installed such that both ends thereof abut against the trigger bushing and the mounting shaft respectively, and is configured to apply a force towards the chuck to the trigger bushing; and

[0018] A second elastic member, which is installed such that one end thereof abuts against the first transmission member and thus abuts against the mounting shaft, and the other end abuts against the housing of the rescue inertia reel system.

[0019] In some exemplary embodiments, the first elastic member is located on a side of the trigger bushing away from the chuck, and the second elastic member is located on a side of the first elastic member away from the chuck.

[0020] In some exemplary embodiments, during the process that the trigger bushing and the chuck are in a clamped state, a non-clamped state, and switching between the two states of clamped and non-clamped, the first elastic member and the second elastic member are always in a compressed state.

[0021] In some exemplary embodiments, the mounting shaft is provided with a retaining ring, the first elastic member is sleeved on the mounting shaft, and the first elastic member is installed such that one end thereof abuts against the mounting shaft by abutting against the retaining ring.

[0022] In some exemplary embodiments, the mounting shaft includes a first mounting section, an end face of the first mounting section forms an axial stop surface, and the first transmission member is sleeved on the first mounting section adjacent to the axial stop surface;

[0023] The second elastic member is sleeved on the mounting shaft, and the second elastic member is installed such that one end thereof abuts against the first transmission member to make the first transmission member abut against the axial stop surface.

[0024] In some exemplary embodiments, the first mounting section is provided with a circumferential fixing portion, the first transmission member is provided with a circumferential fixing and cooperating portion, and the circumferential fixing portion cooperates with the circumferential fixing and cooperating portion to circumferentially fix the first transmission member to the first mounting section.

[0025] In some exemplary embodiments, when the mounting shaft moves along a first direction, the first transmission member moves along the first direction with the mounting shaft to approach the second transmission member, so as to be able to engage with the second transmission member; when the mounting shaft moves along a second direction opposite to the first direction, the first transmission member moves along the second direction with the mounting shaft to move away from the second transmission member, so as to be able to disengage from the second transmission member.

[0026] In some exemplary embodiments, the switching mechanism further includes:

[0027] A switching handle, fixed to one end of the mounting shaft and configured to drive the mounting shaft to reciprocate.

[0028] In some exemplary embodiments, the trigger shaft is provided with the inclined groove, and the protrusion includes a connecting pin mounted to the mounting shaft and protruding from the outer peripheral surface of the mounting shaft.

[0029] In some exemplary embodiments, the inclined groove penetrates the wall of the trigger shaft in the wall thickness direction of the trigger shaft.

[0030] In some exemplary embodiments, the mounting shaft is provided with a mounting hole, the connecting pin is mounted to the mounting hole, and the end of the connecting pin protrudes from the mounting hole.

[0031] In some exemplary embodiments, the connecting pin is in a tight fit with the mounting hole.

[0032] In some exemplary embodiments, the connecting pin and the mounting shaft are fixed by screws.

[0033] In some exemplary embodiments, one end of the trigger shaft close to the chuck is provided with a plurality of first clamping protrusions protruding towards the chuck, and a first clamping groove is formed between adjacent first clamping protrusions;

[0034] One end of the chuck close to the trigger shaft is provided with a plurality of second clamping protrusions protruding towards the trigger shaft, and a second clamping groove is formed between adjacent second clamping protrusions;

[0035] Wherein, when each of the plurality of first clamping protrusions is inserted into a corresponding one of the second clamping grooves and each of the plurality of second clamping protrusions is inserted into a corresponding one of the first clamping grooves, the trigger shaft and the chuck are clamped; and when each of the plurality of first clamping protrusions is separated from the corresponding second clamping groove, each of the plurality of second clamping protrusions is separated from the corresponding first clamping groove, and the plurality of first clamping protrusions and the plurality of second clamping protrusions are in contact, the trigger shaft and the chuck are not clamped.

[0036] In some exemplary embodiments, the side wall surfaces of the first clamping groove and the second clamping groove are inclined with respect to the axis of the mounting shaft, and the inclination direction of the side wall surfaces is the same as the inclination direction of the inclined groove.

[0037] In some exemplary embodiments, the chuck is configured to be an integral structure with the friction seat of the lifting and lowering assembly of the rescue speed differential self-locking system.

[0038] In some exemplary embodiments, the first transmission member includes a first transmission gear, and the second transmission member includes a second transmission gear.

[0039] The present application also provides a rescue speed differential self-locking system, including:

[0040] A rope winding device, including a second transmission member; and

[0041] The switching mechanism provided in any of the foregoing embodiments, the switching mechanism being configured to enable the first transmission member to engage and disengage with the second transmission member through reciprocating movement of the mounting shaft.

[0042] In some exemplary embodiments, the rescue speed differential self-locking system further includes:

[0043] A lifting and lowering assembly mounted to the mounting shaft; and

[0044] A hand crank connected to the lifting and lowering assembly and configured to drive the mounting shaft to rotate through the lifting and lowering assembly.

[0045] The switching structure of the embodiment of the present application, by providing a slidingly engaged inclined groove and a connecting pin, and combining the ingenious clamping structure of the trigger bushing and the chuck and the elastic member, enables the rescue speed differential self-locking system to be switched between the speed differential self-locking mode and the rescue mode by simply pulling and pushing the mounting shaft. The structure is simple, the design is ingenious, the cost is low, the operation is convenient, and the switching is fast, so it is easy to be widely applied.

[0046] Other features and advantages of the present application will be described in the subsequent specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings are used to provide an understanding of the technical solutions of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solutions of the present application and do not constitute a limitation to the technical solutions of the present application.

[0048] Figure 1 FIG. is a three-dimensional structural schematic diagram of the rescue speed differential self-locking system of the embodiment of the present application without a housing, wherein the rescue speed differential self-locking system is in the rescue mode;

[0049] Figure 2 is Figure 1 an exploded schematic diagram of the structure shown;

[0050] Figure 3 is Figure 1 a front view schematic diagram of the structure shown, wherein the rescue speed differential self-locking system is in the rescue mode;

[0051] Figure 3a is Figure 3 an enlarged schematic diagram of the structure of part A of

[0052] Figure 4 is Figure 1 a schematic cross-sectional view of the structure shown, where the rescue speed differential self-locking system is in the rescue mode;

[0053] Figure 5 is Figure 1 a schematic front view of the structure shown, where the rescue speed differential self-locking system is in the process of switching between the rescue mode and the speed differential self-locking mode;

[0054] Figure 6 is Figure 1 a schematic front view of the structure shown, where the rescue speed differential self-locking system is in the speed differential self-locking mode;

[0055] Figure 6a is Figure 6 an enlarged schematic view of the structure of part B of

[0056] Figure 7 a schematic structural view of the assembly of the trigger bushing and the chuck of the switching mechanism according to the embodiment of the present application;

[0057] Figure 8 is Figure 7 a three-dimensional structural schematic view of the trigger bushing in

[0058] Figure 9 is Figure 7 a three-dimensional structural schematic view of the chuck in

[0059] Figure 10 a schematic assembly structure view of the installation shaft and the connecting pin of the switching mechanism according to the embodiment of the present application;

[0060] Figure 11 a three-dimensional structural schematic view of the lifting and lowering assembly of the rescue speed differential self-locking system according to the embodiment of the present application;

[0061] Figure 12 a three-dimensional structural schematic view of the rescue speed differential self-locking system according to the embodiment of the present application;

[0062] Figure 13 is Figure 12 a schematic side view of the rescue speed differential self-locking system shown after removing the housing;

[0063] Figure 14 is Figure 12 a schematic cross-sectional view of the rescue speed differential self-locking system shown, where the rescue speed differential self-locking system is in the rescue mode.

[0064] Reference numerals:

[0065] 100 - switching mechanism, 200 - rope winding device, 300 - rescue speed differential self-locking system;

[0066] 10 - Mounting shaft, 101 - Mounting hole, 102 - Connecting pin, 103 - Retaining ring, 104 - First mounting section, 1041 - Axial stop surface, 105 - Second mounting section, 106 - Threaded hole, 107 - Screw, 11 - Trigger bushing, 111 - Oblique groove, 112 - First clamping projection, 113 - First clamping groove, 12 - Chuck, 121 - Second clamping projection, 122 - Second clamping groove, 123 - Friction seat, 124 - Flange flange, 126 - External thread, 13 - First elastic member, 14 - Second elastic member, 15 - First transmission member, 16 - Second transmission member, 17 - Switching handle, 18 - Lifting and lowering assembly, 181 - Friction plate, 182 - First ratchet wheel, 183 - First ratchet pawl, 184 - Adjusting nut, 19 - Hand crank, 20 - Housing, 21 - Second ratchet wheel, 22 - Second ratchet pawl, 23 - Rotating member. Detailed implementation manners

[0067] As Figure 1-11 shown, an exemplary embodiment of the present application provides a switching mechanism for switching a rescue inertia reel self - locking system between a speed - difference self - locking mode and a rescue mode. The switching mechanism includes a mounting shaft 10, a trigger bushing 11, a chuck 12, elastic members 13, 14 and a first transmission member 15.

[0068] The mounting shaft 10 is arranged to be reciprocally movable along its axis.

[0069] The trigger bushing 11 is sleeved on the mounting shaft 10, and one of the mounting shaft 10 and the trigger bushing 11 is provided with a projection, and the other of the mounting shaft 10 and the trigger bushing 11 is provided with an oblique groove 111 inclined with respect to the axis of the mounting shaft 10. The projection is arranged to be inserted into the oblique groove 111 and can slide in the oblique groove 111 so that the trigger bushing 11 can displace axially (in the extending direction of the axis of the mounting shaft 10) and circumferentially relative to the mounting shaft 10.

[0070] The chuck 12 is fixedly arranged in the direction along its axis and is sleeved on the mounting shaft 10 in a circumferentially fixed manner relative to the mounting shaft 10. The chuck 12 is arranged to be capable of being clamped and unclamped with the trigger sleeve 11. Among them, the chuck 12 can be installed in the housing of the rescue speed differential self-locking system. The chuck 12 is fixedly arranged in the direction along its axis (coinciding with the axis direction of the mounting shaft 10), so that the chuck 12 cannot axially move relative to the housing in the direction along its axis. Therefore, it cannot reciprocate with the mounting shaft 10. Thus, the mounting shaft 10 can axially move relative to the chuck 12. The chuck 12 is sleeved on the mounting shaft 10 in a circumferentially fixed manner, so that the chuck 12 cannot have a circumferential displacement relative to the mounting shaft 10, and the two can rotate together. The chuck 12 can be provided with a first clamping structure, and the trigger sleeve 11 can be provided with a second clamping structure. The first clamping structure can be clamped and unclamped with the second clamping structure to realize the clamping and unclamping of the trigger sleeve 11 and the chuck 12. Among them, between the two states of clamping and unclamping, there are relative displacements between the chuck 12 and the trigger sleeve 11 in the axial direction and the circumferential direction of the mounting shaft 10.

[0071] The first transmission member 15 is sleeved on the mounting shaft 10 in a circumferentially fixed manner and can move with the reciprocating movement of the mounting shaft 10. The first transmission member 15 is arranged to be capable of meshing and disengaging with the second transmission member 16 of the rope winding device 200 of the rescue speed differential self-locking system. Among them, the first transmission member 15 can be axially fixed to the mounting shaft 10, so that the first transmission member 15 cannot have an axial displacement relative to the mounting shaft 10, and the two can reciprocate along the axis of the mounting shaft 10 together.

[0072] The elastic member is sleeved on the mounting shaft 10 and is configured to enable the trigger sleeve 11 and the chuck 12 to stably maintain the engaged and disengaged states. Among them, the elastic member may include a first elastic member 13 and a second elastic member 14. The first elastic member 13 is mounted with both ends abutted against the trigger sleeve 11 and the mounting shaft 10 respectively, and the first elastic member 13 is configured to apply a force towards the chuck 12 to the trigger sleeve 11; the second elastic member 14 is mounted with one end abutted against the first transmission member 15 to thereby abut against the mounting shaft 10, and the other end abutted against the housing 20 of the rescue inertia reel self-locking system. When the rescue inertia reel self-locking system is switched from the speed difference self-locking mode to the rescue mode, if the first transmission member 15 and the second transmission member 16 are misaligned (for example: the teeth of the first transmission member 15 and the tooth grooves of the second transmission member 16 are not aligned, or the tooth grooves of the first transmission member 15 and the teeth of the second transmission member 16 are not aligned) and cannot be engaged, the first transmission member 15 will be blocked by the second transmission member 16 and cannot be directly engaged with the second transmission member 16. At this time, the mounting shaft 10 can be slightly rotated to drive the first transmission member 15 to rotate, so that the first transmission member 15 and the second transmission member 16 are aligned (for example: the teeth of the first transmission member 15 and the tooth grooves of the second transmission member 16 are aligned, or the tooth grooves of the first transmission member 15 and the teeth of the second transmission member 16 are aligned), and then the first transmission member 15 can move axially along the mounting shaft 10 under the elastic force of the second elastic member 14 to be engaged with the second transmission member 16. Therefore, the setting of the second elastic member 14 facilitates that during the process of switching from the speed difference self-locking mode to the rescue mode, after the first transmission member 15 and the second transmission member 16 are aligned by rotating and finely adjusting the first transmission member 15, the first transmission member 15 can be automatically engaged with the second transmission member 16 under the elastic force of the second elastic member 14.

[0073] The switching mechanism of the exemplary embodiment of the present application works, enabling the rescue inertia reel self-locking system to be in the speed difference self-locking mode (such as Figure 6 and 6a shown) and the rescue mode (such as Figure 1 and Figures 3-4switch between the states shown). The rescue inertia reel system typically operates in the inertia self-locking mode. In the inertia self-locking mode, the first transmission member 15 disengages from the second transmission member 16 of the rope winding device 200 of the rescue inertia reel system. At this time, the rescue inertia reel system functions the same as a common rescue inertia reel system. If the user accidentally falls, the rescue inertia reel system can lock itself to prevent the user from descending further, thus protecting the safety of the user. After the fall occurs, it is necessary to switch the rescue inertia reel system from the inertia self-locking mode to the rescue mode. In the rescue mode, the first transmission member 15 engages with the second transmission member 16 of the rope winding device 200 of the rescue inertia reel system. At this time, the first transmission member 15 can be rotated, and the first transmission member 15 further drives the second transmission member 16 to rotate, so that the rope winding device 200 rotates to unwind the rope, in order to rescue the user from mid-air to the ground. Among them, the first transmission member 15 can be circumferentially fixed to the mounting shaft 10, and the first transmission member 15 is driven to rotate by rotating the mounting shaft 10.

[0074] When the rescue inertia reel system switches from Figure 6 and 6a the inertia self-locking mode shown to Figure 1 and Figures 3-4 the rescue mode shown, the mounting shaft 10 can be pulled in the first direction ( Figure 6 the right direction in ). As a result, the protrusion located in the inclined groove 111 can push the inner wall surface of the inclined groove 111 in the first direction (for example, when the mounting shaft 10 is provided with a protrusion and the trigger sleeve 11 is provided with an inclined groove 111), or the inclined groove 111 can push the outer wall surface of the protrusion located in the inclined groove 111 in the first direction (for example, when the mounting shaft 10 is provided with an inclined groove 111 and the trigger sleeve 11 is provided with a protrusion), so that relative sliding can occur between the protrusion and the inclined groove 111. Since the inclined groove 111 is inclined relative to the axis of the mounting shaft 10, the sliding of the protrusion in the inclined groove 111 can cause the trigger sleeve 11 to generate an axial displacement along the axis of the mounting shaft 10 and a circumferential displacement around the axis of the mounting shaft 10 relative to the mounting shaft 10. When the mounting shaft 10 is pulled, the chuck 12 can remain stationary axially along the mounting shaft 10, but due to the axial movement of the mounting shaft 10, the chuck 12 can undergo an axial displacement relative to the mounting shaft 10. In addition, since the chuck 12 is circumferentially fixed to the mounting shaft 10, the chuck 12 will not rotate relative to the mounting shaft 10. As a result, during the process of pulling the mounting shaft 10 in the first direction, the trigger sleeve 11 can undergo an axial movement and a rotation around the axis of the mounting shaft 10 relative to the chuck 12, so that the trigger sleeve 11 can be engaged with the chuck 12.

[0075] During the process of pulling the mounting shaft 10 in the first direction, the first elastic member 13 always applies a force towards the chuck 12 to the trigger bushing 11, which helps the trigger bushing 11 to undergo an axial displacement along the axis of the mounting shaft 10 and a circumferential displacement of rotating around the axis of the mounting shaft 10. Moreover, the first elastic member 13 helps to push the trigger bushing 11 into engagement with the chuck 12, as Figure 1 and Figures 3-4 shown. After the trigger bushing 11 and the chuck 12 are in the engaged state, the first elastic member 13 can keep the trigger bushing 11 in the engaged position, and thus remain in the engaged state with the chuck 12, preventing the trigger bushing 11 and the chuck 12 from being accidentally disengaged.

[0076] When pulling the mounting shaft 10 in the first direction, the first transmission member 15 also moves along the first direction with the mounting shaft 10 to approach the second transmission member 16. When the trigger bushing 11 and the chuck 12 are in the engaged state, the first transmission member 15 meshes with the second transmission member 16. At this time, the rescue inertia reel self-locking system is in the rescue mode, as Figure 1 and Figures 3-4 shown. In this rescue mode, the first transmission member 15 rotates controllably using the existing device, so as to drive the second transmission member 16 to rotate, and further drive the rope winding device 200 to release the rope controllably, so that the user hanging in mid-air can be rescued to the ground.

[0077] When the rescue inertia reel self-locking system switches from the Figure 1 and Figures 3-4 shown rescue mode to the speed difference self-locking mode for normal use of the rescue inertia reel self-locking system, in the second direction opposite to the first direction ( Figure 1 and Figures 3-4Push the installation shaft 10 in the leftward direction (in the middle), so that the protrusion located in the inclined groove 111 can push the inner wall surface of the inclined groove 111 in the second direction (for example, when the installation shaft 10 is provided with a protrusion and the trigger bushing 11 is provided with an inclined groove 111), or the inclined groove 111 can push the outer wall surface of the protrusion located in the inclined groove 111 in the second direction (for example, when the installation shaft 10 is provided with an inclined groove 111 and the trigger bushing 11 is provided with a protrusion), thereby causing relative sliding between the protrusion and the inclined groove 111. Since the inclined groove 111 is inclined relative to the axis of the installation shaft 10, the sliding of the protrusion in the inclined groove 111 can cause the trigger bushing 11 to generate an axial displacement along the axis of the installation shaft 10 and a circumferential displacement around the axis of the installation shaft 10 relative to the installation shaft 10. The process of the axial displacement and circumferential displacement of the trigger bushing 11 is opposite to the process of the axial displacement and circumferential displacement of the trigger bushing 11 when the rescue speed differential self-locking system switches from the speed differential self-locking mode to the rescue mode. As a result, during the process of pushing the installation shaft 10 in the second direction, the trigger bushing 11 can move axially relative to the chuck 12 and rotate around the axis of the installation shaft 10. The process of this movement and rotation is opposite to the process of the trigger bushing 11 moving and rotating relative to the chuck 12 during the process of pulling the installation shaft 10 in the first direction as described above, so that non-engagement between the trigger bushing 11 and the chuck 12 can be achieved, as Figure 6 and 6a shown. In addition, during the process of pushing the installation shaft 10 in the second direction, the first elastic member 13 always applies a force towards the chuck 12 to the trigger bushing 11. The first elastic member 13 pushes the trigger bushing 11 to abut against the chuck 12 at the non-engagement position, so that the trigger bushing 11 is in a non-engaged state with the chuck 12. After the trigger bushing 11 and the chuck 12 are in a non-engaged state, the first elastic member 13 can keep the trigger bushing 11 at the non-engagement position and remain in a non-engaged state with the chuck 12, thereby keeping the installation shaft 10 fixed.

[0078] When the installation shaft 10 is pushed in the second direction, the first transmission member 15 also moves along with the installation shaft 10 away from the second transmission member 16 in the second direction. When the trigger bushing 11 and the chuck 12 are in a non-engaged state, the first transmission member 15 disengages from the second transmission member 16. At this time, the rescue speed differential self-locking system is in the speed differential self-locking mode, as Figure 6 and 6a shown. In the speed differential self-locking mode, since the first transmission member 15 disengages from the second transmission member 16 and the first transmission member 15 does not affect the second transmission member 16, the rescue speed differential self-locking system can operate like an ordinary rescue speed differential self-locking system, allowing the rope of the rope winding device 200 to continuously descend within a certain speed range. When the user falls and descends rapidly, when the descending speed reaches the threshold, the rescue speed differential self-locking system will self-lock, causing the rope to stop further descending.

[0079] Therefore, in the switching mechanism of the present application, a protrusion and an inclined groove 111 that extends obliquely with respect to the axis of the mounting shaft 10 are respectively provided on the trigger bushing 11 and the mounting shaft 10. By using the sliding fit between the protrusion and the inclined groove 111, the engagement or non-engagement of the trigger bushing 11 and the chuck 12 can be achieved only by pulling or pushing the mounting shaft 10. Furthermore, the engagement or disengagement of the first transmission member 15 and the second transmission member 16 is realized, and the stable and rapid switching of the rescue differential self-locking system between the differential self-locking mode and the rescue mode is completed. The switching mechanism has a simple structure, low cost, simple and convenient operation, and fast switching speed. Only by pulling or pushing the mounting shaft 10 can rapid switching be achieved. Therefore, the switching mechanism has high practicability and is conducive to wide application.

[0080] In some exemplary embodiments, as Figures 1-6a shown, the trigger bushing 11 is provided with an inclined groove 111, and the protrusion includes a connecting pin 102 that is mounted to the mounting shaft 10 and protrudes from the outer peripheral surface of the mounting shaft 10.

[0081] By pulling and pushing the mounting shaft 10 to reciprocate along its axis, the connecting pin 102 of the mounting shaft 10 pushes the inner wall surface of the inclined groove 111 of the trigger bushing 11 within the inclined groove 111 of the trigger bushing 11, forcing the trigger bushing 11 to perform axial movement along the axis of the mounting shaft 10 and rotation around the axis of the mounting shaft 10, so that the trigger bushing 11 can perform axial movement and rotation relative to the chuck 12 to achieve the engagement and non-engagement of the trigger bushing 11 and the chuck 12, thereby enabling the first transmission member 15 to engage and disengage with the second transmission member 16, and realizing the switching of the rescue differential self-locking system between the differential self-locking mode and the rescue mode.

[0082] In some exemplary embodiments, as Figures 7-8 shown, the inclined groove 111 extends obliquely with respect to the axis direction of the mounting shaft 10, and the inclined groove 111 penetrates the wall of the trigger bushing 11 in the wall thickness direction of the trigger bushing 11. One inclined groove 111 may be provided, or two or more inclined grooves 111 may be provided. As Figure 8 shown, the wall of the trigger bushing 11 is provided with two penetrating inclined grooves 111. The two inclined grooves 111 have the same size and shape, and are arranged symmetrically with each other in the circumferential direction around the axis of the mounting shaft 10.

[0083] In some exemplary embodiments, as Figure 10 shown, the mounting shaft 10 is provided with a mounting hole 101, and the connecting pin 102 is mounted to the mounting hole 101. Further, the connecting pin 102 and the mounting shaft 10 can be fixed by a screw 107.

[0084] The end of the connecting pin 102 protrudes from the mounting hole 101 and is inserted into the inclined groove 111 (as Figure 3a and 6a shown). As Figure 10As shown, the mounting hole 101 can penetrate the mounting shaft 10 radially. A connecting pin 102 passes through the mounting hole 101 of the mounting shaft 10, and both ends of the connecting pin 102 protrude from both ends of the mounting hole 101 respectively. Both ends of the connecting pin 102 can be inserted into the corresponding two inclined slots 111 of the trigger bushing 11 respectively, making the relative sliding between the connecting pin 102 and the inclined slots 111 more balanced and stable, and thus facilitating the axial and circumferential displacement of the trigger bushing 11 relative to the mounting shaft 10.

[0085] The mounting shaft 10 is provided with a threaded hole 106, and the threaded hole 106 can communicate with the mounting hole 101. A screw 107 can be screwed into the threaded hole 106 and abutted against the connecting pin 102 mounted in the mounting hole 101 to press and fix the connecting pin 102.

[0086] It should be understood that the connecting pin 102 can also be arranged in other ways, and the number of the connecting pins 102 can also be multiple. For example, a protruding connecting pin 102 can be provided on each of the opposite sides of the mounting shaft 10.

[0087] In some exemplary embodiments, the connecting pin 102 and the mounting hole 101 can be in a tight fit. For example, the connecting pin 102 and the mounting hole 101 can be in an interference fit, and the connecting pin 102 can directly achieve a fastening connection with the mounting hole 101 without the need for a screw. Or, when the connecting pin 102 and the mounting hole 101 are in a tight fit, they are also fixed by a screw 107 to further enhance the fixing effect between the connecting pin 102 and the mounting shaft 10.

[0088] In some exemplary embodiments, as Figures 1-6a shown, the first elastic member 13 is located on the side of the trigger bushing 11 away from the chuck 12, and the first elastic member 13 is installed so that both ends thereof abut against the trigger bushing 11 and the mounting shaft 10 respectively. Among them, the first elastic member 13 can be a first compression spring.

[0089] When the mounting shaft 10 reciprocates along its axis, the first compression spring is always in a compressed state between the mounting shaft 10 and the trigger bushing 11, thereby always applying an elastic compression force towards the chuck 12 to the end of the trigger bushing 11 away from the chuck 12, so that the trigger bushing 11 always has a tendency to move towards the chuck 12, and makes the connecting pin 102 of the mounting shaft 10 and the inclined slots 111 of the trigger bushing 11 always remain in an abutting state, and helps the relative sliding between the connecting pin 102 and the inclined slots 111, so as to realize the clamping between the trigger bushing 11 and the chuck 12. In addition, the first compression spring keeps the trigger bushing 11 in abutment with the chuck 12, so that the trigger bushing 11 and the chuck 12 are stably maintained in the clamped state or the unclamped state.

[0090] Due to the elastic compressive force exerted by the first elastic member 13 towards the chuck 12, even if there is an accidental touch on the mounting shaft 10 that generates a disturbing tensile force, an accidental switch will not occur. Specifically, when the trigger sleeve 11 and the chuck 12 are in a non-engaged state, as Figure 6 shown, since the first elastic member 13 always exerts a force towards the chuck 12 on the trigger sleeve 11, causing the trigger sleeve 11 to abut against the chuck 12. Therefore, even if there is an accidental touch on the mounting shaft 10 that generates an instantaneous disturbing tensile force, it will not cause the trigger sleeve 11 and the chuck 12 to become engaged. Only when, during the switching operation, the tensile force applied to the mounting shaft 10 reaches a specific threshold and persists, will the trigger sleeve 11 and the chuck 12 turn into an engaged state and finally switch. Therefore, the first elastic member 13 helps to maintain the dynamic stability of the non-engaged state after switching.

[0091] In some exemplary embodiments, as Figure 3a , 4 and as shown in 6a, the mounting shaft 10 is provided with a retaining ring 103. The first elastic member 13 is sleeved on the mounting shaft 10, and the first elastic member 13 is mounted such that one end abuts against the mounting shaft 10 by abutting against the retaining ring 103, and the first elastic member 13 is mounted such that the other end abuts against the end of the trigger sleeve 11 remote from the chuck 12, so that the first elastic member 13 is always in a compressed state between the retaining ring 103 of the mounting shaft 10 and the end of the trigger sleeve 11 remote from the chuck 12. It should be understood that a shoulder may also be provided on the mounting shaft 10 to abut against one end of the first elastic member 13 instead of the retaining ring 103.

[0092] In some exemplary embodiments, as Figure 3a , 6a and Figures 7-9 shown, the end of the trigger sleeve 11 close to the chuck 12 is provided with a plurality of first engaging protrusions 112 protruding towards the chuck 12, and a first engaging groove 113 is formed between adjacent first engaging protrusions 112. The end of the chuck 12 close to the trigger sleeve 11 is provided with a plurality of second engaging protrusions 121 protruding towards the trigger sleeve 11, and a second engaging groove 122 is formed between adjacent second engaging protrusions 121. The first engaging structure of the trigger sleeve 11 may include the first engaging protrusions 112 and the first engaging groove 113, and the first engaging structure of the chuck 12 may include the second engaging protrusions 121 and the second engaging groove 122.

[0093] The switching mechanism is arranged such that: as Figure 3a and Figure 7 shown, when each of the plurality of first engaging protrusions 112 snaps into a corresponding one of the second engaging grooves 122, and each of the plurality of second engaging protrusions 121 snaps into a corresponding one of the first engaging grooves 113, the trigger sleeve 11 and the chuck 12 are engaged; and as Figure 6aAs shown, when each of the multiple first latching protrusions 112 is separated from the corresponding second latching groove 122, each of the multiple second latching protrusions 121 is separated from the corresponding first latching groove 113, and the multiple first latching protrusions 112 are in contact with the multiple second latching protrusions 121, the trigger bushing 11 and the chuck 12 are disengaged.

[0094] Figure 8 As shown in , the trigger bushing 11 is provided with two spaced-apart first latching protrusions 112 and two first latching grooves 113. The two first latching protrusions 112 have the same shape and size, and are arranged symmetrically with respect to each other along the circumferential direction of the trigger bushing 11. Similarly, the two first latching grooves 113 have the same shape and size, and are arranged symmetrically with respect to each other along the circumferential direction of the trigger bushing 11.

[0095] Figure 9 As shown in

[0094] , the chuck 12 is provided with two spaced-apart second latching protrusions 121 and two second latching grooves 122. The two second latching protrusions 121 have the same shape and size, and are arranged symmetrically with respect to each other along the circumferential direction of the chuck 12. Similarly, the two second latching grooves 122 have the same shape and size, and are arranged symmetrically with respect to each other along the circumferential direction of the chuck 12.

[0096] The first latching protrusion 112 and the second latching groove 122 have similar shapes and sizes so that the first latching protrusion 112 and the second latching groove 122 generally match, but the second latching groove 122 is slightly wider than the first latching protrusion 112, such that one side of the first latching protrusion 112 abuts against one side of the second latching groove 122, and there is a gap between the other side of the first latching protrusion 112 and the other side of the second latching groove 122 to facilitate their relative movement and prevent the first latching protrusion 112 from being stuck in the second latching groove 122. Similarly, the second latching protrusion 121 and the first latching groove 113 have similar shapes and sizes so that the second latching protrusion 121 and the first latching groove 113 generally match, but the first latching groove 113 is slightly wider than the second latching protrusion 121, such that the second latching protrusion 121 is prevented from being stuck in the first latching groove 113.

[0097] As Figure 7As shown, the two side walls of the first clamping protrusion 112 of the trigger bushing 11 (or the two side walls of the first clamping groove 113) and the two side walls of the second clamping protrusion 121 of the chuck 12 (or the two side walls of the second clamping groove 122) are inclined to one side relative to the axis of the mounting shaft 10, and are inclined to the same side as the inclined groove 111 of the trigger bushing 11 relative to the axis of the mounting shaft 10. That is, the inclination directions of the two side walls of the first clamping protrusion 112 (or the two side walls of the first clamping groove 113) and the two side walls of the second clamping protrusion 121 (or the two side walls of the second clamping groove 122) are the same as the inclination direction of the inclined groove 111. With this setting, when the mounting shaft 10 is pulled, the first clamping protrusion 112 can be more smoothly clamped into the second clamping groove 122, and the second clamping protrusion 121 can be more smoothly clamped into the first clamping groove 113, and it is not easy to get stuck, so as to realize the clamping of the trigger bushing 11 and the chuck 12; when the mounting shaft 10 is pushed, the first clamping protrusion 112 can be more smoothly disengaged from the second clamping groove 122, and the second clamping protrusion 121 can be more smoothly disengaged from the first clamping groove 113, so as to realize the non-clamping of the trigger bushing 11 and the chuck 12.

[0098] The corners where the two side walls of the first clamping protrusion 112 of the trigger bushing 11 intersect with the end wall are rounded, and the corners where the two side walls of the first clamping groove 113 intersect with the end wall are rounded; and the corners where the two side walls of the second clamping protrusion 121 of the chuck 12 intersect with the end wall are rounded, and the corners where the two side walls of the second clamping groove 122 intersect with the end wall are rounded, so that a smooth transition is achieved between the side wall and the end wall of the first clamping protrusion 112 of the trigger bushing 11, between the side wall and the end wall of the first clamping groove 113, between the side wall and the end wall of the second clamping protrusion 121 of the chuck 12, and between the side wall and the end wall of the second clamping groove 122, without sharp corners. With this setting, it is beneficial for the first clamping protrusion 112 to smoothly slide into and out of the second clamping groove 122 and for the second clamping protrusion 121 to smoothly slide into and out of the first clamping groove 113.

[0099] As Figure 1 and Figures 3-3a shown, when the trigger bushing 11 is clamped with the chuck 12, the trigger bushing 11 is in the clamping position relative to the chuck 12. At this time, the end wall of the first clamping protrusion 112 abuts against the end wall of the second clamping groove 122, and the end wall of the second clamping protrusion 121 abuts against the end wall of the first clamping groove 113.

[0100] As Figures 6-6aAs shown, when the trigger bushing 11 and the chuck 12 are in a non-engaged state, the trigger bushing 11 is in a non-engaged position relative to the chuck 12, and the trigger bushing 11 is farther from the chuck 12 in the non-engaged position than in the engaged position. At this time, the end wall of the first engaging protrusion 112 is separated from the end wall of the second engaging groove 122, and the end wall of the second engaging protrusion 121 is separated from the end wall of the first engaging groove 113. Meanwhile, since the first elastic member 13 always applies a force towards the chuck 12 to the trigger bushing 11, the end wall of the first engaging protrusion 112 abuts against the end wall of the second engaging protrusion 121.

[0101] When the rescue speed differential self-locking system switches from Figures 6-6a the speed differential self-locking mode shown to Figures 3-3a the rescue mode shown, pulling the mounting shaft 10 in the first direction causes the trigger bushing 11 and the chuck 12 to switch from Figures 6-6a the non-engaged state shown to Figures 3-3a the engaged state shown. Specifically, when pulling the mounting shaft 10 in the first direction, since initially the end wall of the first engaging protrusion 112 abuts against the end wall of the second engaging protrusion 121, which prevents the trigger bushing 11 from moving in the axial direction, the trigger bushing 11 only rotates relative to the chuck 12 under the action of the connecting pin 102 of the mounting shaft 10 and the first elastic member 13. When the relative circumferential displacement generated by the rotation of the trigger bushing 11 relative to the chuck 12 aligns the first engaging protrusion 112 with the second engaging groove 122 and aligns the second engaging protrusion 121 with the first engaging groove 113 (as shown in Figure 5As shown, under the action of the first elastic member 13, the trigger bushing 11 also generates a displacement in the axial direction relative to the chuck 12. This displacement causes the first engaging protrusion 112 to snap into the second engaging groove 122, and at the same time, the second engaging protrusion 121 snaps into the first engaging groove 113. During the snapping-in process, one of the two inclined sidewalls of the first engaging protrusion 112 abuts against the corresponding sidewall of the second engaging protrusion 121 and gradually slides into the second engaging groove 122. When the end wall of the first engaging protrusion 112 abuts against the end wall of the second engaging groove 122 and the end wall of the second engaging protrusion 121 abuts against the end wall of the first engaging groove 113, the trigger bushing 11 and the chuck 12 are snapped together in place. One end of the trigger bushing 11 away from the chuck 12 is subjected to an elastic compressive force towards the chuck 12 by the first elastic member 13, i.e., the first compression spring, to prevent the trigger bushing 11 from being disengaged from the chuck 12 and keep the trigger bushing 11 and the chuck 12 in the snapped-together state. At this time, the mounting shaft 10 has moved into place and can no longer move in the first direction. And due to the blocking effect of the inclined groove 111 on the connecting pin 102, unless an external force is applied, the mounting shaft 10 will not move in the second direction either. Thus, the mounting shaft 10 remains stationary (i.e., stays in the snapped-together position). The first transmission member 15 moves in the first direction under the drive of the mounting shaft 10 to engage with the second transmission member 16, and the rescue differential self-locking system is converted into the rescue mode. The designed structure of the above-mentioned engaging protrusions and engaging grooves can cooperate with the inclined groove 111 and the connecting pin 102, so that between the two states of being snapped together and not being snapped together, the trigger bushing 11 and the chuck 12 have a relative displacement with a predetermined distance in the circumferential direction of the mounting shaft 10. This also helps to maintain dynamic stability. This is because only after an external force causes a relative displacement with a predetermined distance in the circumferential direction between the trigger bushing 11 and the chuck 12 (for example, after the engaging protrusions and the corresponding engaging grooves are aligned), can the trigger bushing 11 and the chuck 12 start to change to the snapped-together state. Otherwise, if it is only an external force of touching and disturbing (for example, when the engaging protrusions and the corresponding engaging grooves are not yet aligned), under the action of the first elastic member 13, the two will still return to the non-snapped-together position, which realizes dynamic stability.

[0102] When the rescue differential self-locking system switches from Figures 3-3a the rescue mode shown in Figures 6-6a to the differential self-locking mode shown in Figures 3-3a by pushing the mounting shaft 10 in the second direction, the trigger bushing 11 and the chuck 12 switch from the Figures 6-6aThe non-latching state shown. Specifically, when the mounting shaft 10 is pushed in the second direction, since the side wall of the first latching protrusion 112 initially abuts against the side wall of the second latching protrusion 121, the side wall of the first latching protrusion 112 gradually slides out of the second latching groove 122 when abutting against the side wall of the second latching protrusion 121. Therefore, the trigger sleeve 11 can have a displacement in the axial direction relative to the chuck 12. When the displacement of the trigger sleeve 11 in the axial direction relative to the chuck 12 reaches a state where the first latching protrusion 112 completely exits the second latching groove 122 and the second latching protrusion 121 completely exits the first latching groove 113 (as shown in Figure 5 ), the trigger sleeve 11 can continue to rotate relative to the chuck 12 under the action of the connecting pin 102 of the mounting shaft 10 and the first elastic member 13, so that the first latching protrusion 112 is no longer aligned with the second latching groove 122 and the second latching protrusion 121 is no longer aligned with the first latching groove 113. Since an elastic compression force towards the chuck 12 is applied to the end of the trigger sleeve 11 away from the chuck 12 by the first elastic member 13, that is, the first compression spring, the trigger sleeve 11 can rotate and abut against the chuck 12 under the thrust of the first compression spring, that is, the end face of the first latching protrusion 112 abuts against the end face of the second latching protrusion 121. At this time, the trigger sleeve 11 and the chuck 12 are not latched. The first compression spring can keep the trigger sleeve 11 and the chuck 12 in the non-latching state. At this time, the mounting shaft 10 has moved in place and can no longer move in the second direction. And due to the blocking effect of the inclined groove 111 on the connecting pin 102, the mounting shaft 10 will not move in the first direction either. Thus, the mounting shaft 10 remains fixed (i.e., remains in the non-latching position). The first transmission member 15 moves in the second direction under the drive of the mounting shaft 10 and disengages from the second transmission member 16, and the rescue speed differential self-locking system is converted into the speed differential self-locking mode. This design structure of the latching protrusion and the latching groove can cooperate with the inclined groove 111 and the connecting pin 102, so that between the latching and non-latching states, the trigger sleeve 11 and the chuck 12 have a relative displacement with a predetermined distance in the axial direction of the mounting shaft 10, which also helps to maintain dynamic stability. This is because, in the latching state, only after an external force causes the trigger sleeve 11 and the chuck 12 to have a relative displacement of this predetermined distance in the axial direction (for example, after the latching protrusion completely exits the corresponding latching groove), can the trigger sleeve 11 and the chuck 12 start to change to the non-latching state. Otherwise, if it is only an external force of touch and disturbance (for example, when the latching protrusion has not completely exited the corresponding latching groove), under the action of the second elastic member 14, the two will still return to the latching position, which realizes dynamic stability.

[0103] It can be seen that when the mounting shaft 10 is pulled in the first direction, the trigger sleeve 11 first rotates relative to the chuck 12, and then has an axial movement relative to the chuck 12 until the trigger sleeve 11 is fully engaged and clamped with the chuck 12, and at the same time, the first transmission member 15 is engaged with the second transmission member 16; when the mounting shaft 10 is pushed in the second direction, the trigger sleeve 11 has a relative displacement in the axial direction relative to the chuck 12, and then continues to rotate relative to the chuck 12 until the trigger sleeve 11 and the chuck 12 are in a non-clamped state, and at the same time, the first transmission member 15 and the second transmission member 16 are disengaged. Therefore, the engagement and disengagement of the first transmission member 15 and the second transmission member 16 can be achieved only by pulling and pushing the mounting shaft 10, so that the rescue differential self-locking system can be quickly switched between the differential self-locking mode and the rescue mode, and this switching structure enables the switched state to maintain dynamic stability.

[0104] In some exemplary embodiments, such as Figures 3-6a and Figure 10 shown, the mounting shaft 10 includes a first mounting section 104. An axial stop surface 1041 is formed on one end surface of the first mounting section 104. The first transmission member 15 is sleeved on the first mounting section 104 adjacent to the axial stop surface 1041, and the first transmission member 15 abuts against the axial stop surface 1041 under the elastic force of the second elastic member 14.

[0105] The axial stop surface 1041 of the mounting shaft 10 and the second elastic member 14 respectively block the first transmission member 15 on both sides of the first transmission member 15, so that the first transmission member 15 is axially fixed relative to the mounting shaft 10 and can move along with the reciprocating movement of the mounting shaft 10 in the axial direction thereof. Fixing the first transmission member 15 axially in this way has a simple structure and is convenient for the installation and disassembly of the first transmission member 15. Of course, the axial stop surface 1041 of the first mounting section 104 can also be replaced by a snap ring.

[0106] In some exemplary embodiments, such as Figures 1-6aAs shown, the first transmission member 15 is located on the side of the first elastic member 13 away from the chuck 12. The second elastic member 14 is sleeved on the mounting shaft 10 and is located on the side of the first transmission member 15 away from the chuck 12. One end of the second elastic member 14 is mounted to abut against the first transmission member 15, thereby abutting against the mounting shaft 10, and the other end abuts against the housing 20 of the rescue inertia reel system. Therefore, on the mounting shaft 10, along the axial direction of the mounting shaft 10, the second elastic member 14, the first transmission member 15, the first elastic member 13, the trigger sleeve 11, and the chuck 12 are arranged in sequence. The first elastic member 13 is located on the side of the trigger sleeve 11 away from the chuck 12, and the second elastic member 14 is located on the side of the first elastic member 13 away from the chuck 12. The end of the second elastic member 14 away from the first transmission member 15 can directly abut against the housing 20 of the rescue inertia reel system, or the second elastic member 14 can abut against other fixing members fixed to the housing 20, so as to realize the abutment between the second elastic member 14 and the housing 20.

[0107] The second elastic member 14 can be a second compression spring. During the process of the trigger sleeve 11 and the chuck 12 being in the engaged state, the disengaged state, and switching between the two states, the first elastic member 13 and the second elastic member 14 can always be in a compressed state.

[0108] The second compression spring is compressed between the housing 20 of the rescue inertia reel system and the first transmission member 15, thereby applying an elastic compression force to the first transmission member 15 to prevent the first transmission member 15 from axially moving away from the axial stop surface 1041, so that the first transmission member 15 remains axially fixed to the mounting shaft 10, so that the first transmission member 15 can move to engage and disengage with the second transmission member 16 under the drive of the mounting shaft 10.

[0109] Since the second elastic member 14 applies an elastic compression force to the first transmission member 15 and can apply a force to the mounting shaft 10 through the first transmission member 15, even if there is an accidental touch on the mounting shaft 10 that generates an instantaneous disturbing thrust, it will not cause the accidental disengagement of the trigger sleeve 11 and the chuck 12. Only when the thrust applied to the mounting shaft 10 reaches a specific threshold and persists during the switching operation, will it cause disengagement and finally switch to the disengaged state. Therefore, the second elastic member 14 helps to maintain the dynamic stability of the disengaged state after switching.

[0110] The switching mechanism of the embodiment of the present application, through the cooperation of the first elastic member 13 and the second elastic member 14, enables the trigger sleeve 11 and the chuck 12 to maintain the original clamped and unclamped states even when there is an accidental touch on the mounting shaft 10 resulting in an instantaneous disturbance, and also helps the mounting shaft 10 to return to its original position, so that the first transmission member 15 and the second transmission member 16 can maintain the meshed and disengaged states, and enables the rescue differential self-locking control system 300 to maintain in the rescue mode and the differential self-locking mode.

[0111] As Figure 3a shown, when the trigger sleeve 11 and the chuck 12 are in the clamped state, when an accidental touch on the mounting shaft 10 causes an instantaneous disturbance that makes the mounting shaft 10 displace leftward, the second elastic member 14 can cause the mounting shaft 10 to displace rightward to return to its original position, and the first elastic member 13 can keep the trigger sleeve 11 and the chuck 12 in the clamped state, so that the first transmission member 15 and the second transmission member 16 remain in the meshed state, and enables the rescue differential self-locking control system 300 to dynamically and stably maintain in the rescue mode.

[0112] As Figure 6a shown, when the trigger sleeve 11 and the chuck 12 are in the unclamped state, when an accidental touch on the mounting shaft 10 causes an instantaneous disturbance that makes the mounting shaft 10 displace leftward, the second elastic member 14 can cause the mounting shaft 10 to displace rightward to return to its original position, and the first elastic member 13 can keep the trigger sleeve 11 and the chuck 12 in the unclamped state, so that the first transmission member 15 and the second transmission member 16 remain in the disengaged state, and enables the rescue differential self-locking control system 300 to maintain in the differential self-locking mode; and when the trigger sleeve 11 and the chuck 12 are in the unclamped state, when an accidental touch on the mounting shaft 10 causes an instantaneous disturbance that makes the mounting shaft 10 displace rightward, the first elastic member 14 can cause the mounting shaft 10 to displace leftward to return to its original position, and the first elastic member 13 can keep the trigger sleeve 11 and the chuck 12 in the unclamped state, so that the first transmission member 15 and the second transmission member 16 remain in the disengaged state, and enables the rescue differential self-locking control system 300 to dynamically and stably maintain in the differential self-locking mode.

[0113] In some exemplary embodiments, as Figure 10 shown, the first mounting section 104 is provided with a circumferential fixing portion, and the first transmission member 15 is provided with a circumferential fixing and cooperating portion, and the circumferential fixing portion cooperates with the circumferential fixing and cooperating portion to circumferentially fix the first transmission member 15 to the first mounting section 104. Among them, the cross-section of the first mounting section 104 can be in a kidney shape, and correspondingly, the shaft hole of the first transmission member 15 is also in a kidney shape to cooperate with the first mounting section 104. The kidney shape can circumferentially fix the first transmission member 15 to the first mounting section 104, preventing the first transmission member 15 from rotating relative to the first mounting section 104 of the mounting shaft 10, that is, enabling the first transmission member 15 and the first mounting section 104 of the mounting shaft 10 to rotate synchronously.

[0114] It should be understood that the first mounting section 104 of the mounting shaft 10 and the first transmission member 15 can also be fixed in the circumferential direction by structures such as splines.

[0115] In some exemplary embodiments, as Figures 1-6a shown, the first transmission member 15 includes a first transmission gear. Correspondingly, the second transmission member 16 may include a second transmission gear, and the mounting shaft 10 is arranged to be able to rotate about its axis.

[0116] When the mounting shaft 10 rotates about its axis, it can drive the first transmission gear fixed to it in the circumferential direction to rotate; when the first transmission gear meshes with the second transmission gear, the first transmission gear can drive the second transmission gear to rotate, so as to drive the first transmission gear and the second transmission gear to rotate by rotating the mounting shaft 10.

[0117] In some exemplary embodiments, as Figures 1-6 shown, the switching mechanism further includes a switching handle 17. The switching handle 17 is fixed to one end of the mounting shaft 10 and is arranged to be able to drive the mounting shaft 10 to move reciprocally.

[0118] The switching handle 17 can be fixed to the right end of the mounting shaft 10 and is arranged outside the housing 20 of the rescue speed differential self-locking system, so that it can be easily touched and manipulated by the user. By pulling and pushing the switching handle 17, the mounting shaft 10 is driven to move reciprocally, thereby realizing the switching between the rescue mode and the speed differential self-locking mode of the rescue speed differential self-locking system.

[0119] In some exemplary embodiments, as Figures 1-6 , Figure 9 and Figure 11 shown, the chuck 12 is arranged to be an integral structure with the friction seat 123 of the lifting and lowering assembly 18 of the rescue speed differential self-locking system.

[0120] As Figure 9 shown, the chuck 12 and the friction seat 123 are of an integral structure. The left side of this integral structure is provided with a second clamping protrusion 121 and a second clamping groove 122 for cooperating with the trigger sleeve 11; the right side part of this integral structure can cooperate with other components of the lifting and lowering assembly 18 except the friction seat 123 to form the lifting and lowering assembly 18.

[0121] The chuck 12 and the friction seat 123 of the lifting and lowering assembly 18 are arranged as one body, which can reduce the number of components, simplify the structure, and reduce the assembly steps. It should be understood that the chuck 12 and the friction seat 123 of the lifting and lowering assembly 18 can also be of a split structure. For example, the two can be connected together by fasteners such as screws.

[0122] As Figures 12-14As shown, an exemplary embodiment of the present application further provides a rescue inertia reel system 300, including: a rope winding device 200 and the switching mechanism provided in any of the foregoing embodiments. The rope winding device 200 includes a second transmission member 16. The switching mechanism is configured to enable the first transmission member 15 to engage and disengage from the second transmission member 16 through the reciprocating movement of the mounting shaft 10, so that the rescue inertia reel system 300 can switch between the inertia self-locking mode and the rescue mode.

[0123] In some exemplary embodiments, as Figure 12 shown, the rescue inertia reel system further includes a housing 20. A hanging point is provided on the outside of the housing 20 to hang the rescue inertia reel system 300. The rope winding device 200 is wound with a rope, and the end of the rope is connected to a tie on the user's body.

[0124] In some exemplary embodiments, as Figures 1-6a and Figure 11 、 Figure 14 shown, the rescue inertia reel system 300 further includes a lifting and lowering assembly 18 and a hand crank 19. The lifting and lowering assembly 18 is mounted to the mounting shaft 10, and the hand crank 19 is connected to the lifting and lowering assembly 18 and is configured to drive the mounting shaft 10 to rotate through the lifting and lowering assembly 18.

[0125] The lifting and lowering assembly 18 may include two friction plates 181, a first ratchet wheel 182 disposed between the two friction plates 181, and a first pawl 183. The first pawl 183 is swingably mounted to the housing 20, and a torsion spring (not shown) is provided between the first pawl 183 and the housing 20. Under the action of the first pawl 183, the first ratchet wheel 182 can only rotate in one direction.

[0126] The lifting and lowering assembly 18 further includes an adjusting nut 184. The adjusting nut 184 can be threadedly connected to the friction seat 123. An external thread 126 is provided on a side of the friction seat 123 away from the second clamping protrusion 121, and the adjusting nut 184 is provided with an internal thread (not shown) matching the external thread 126 to achieve the threaded connection between the adjusting nut 184 and the friction seat 123. The two friction plates 181 and the first ratchet wheel 182 are clamped between the flange 124 of the friction seat 123 and the adjusting nut 184. The hand crank 19 is fixedly connected to the adjusting nut 184.

[0127] When in one direction (e.g., the clockwise direction when viewed from the direction facing the hand crank 19, i.e., from Figures 1-6 and Figure 14When turning the hand crank 19 clockwise (in the clockwise direction of looking from right to left in the figure), the adjusting nut 184 is driven to rotate clockwise. The rotation of the adjusting nut 184 causes the adjusting nut 184 to axially move in the second direction (leftward direction). The adjusting nut 184 approaches the flange 124 of the friction seat 123 in the axial direction of the mounting shaft 10, causing the two friction plates 181 and the first ratchet 182 to be pressed between the flange 124 of the friction seat 123 and the adjusting nut 126. The greater the pressure, the greater the frictional force, and thus the greater the torque transmitted by the frictional force. The first ratchet 182 is locked by the first pawl 183 and can only rotate in the clockwise direction. Therefore, the clockwise rotation of the hand crank 19 (i.e., the rotation of the adjusting nut) is transmitted to the integral structure of the chuck 12 and the friction seat 123 through the two friction plates 181 and the first ratchet 182, causing the two friction plates 181, the first ratchet 182, and the integral structure of the chuck 12 and the friction seat 123 to rotate together.

[0128] The mounting shaft 10 is provided with a second mounting section 105, and the cross-section of the second mounting section 105 is an incomplete circle with a part cut off. The chuck 12 or the friction seat 123 is provided with a shaft hole matching the second mounting section 105, so that the chuck 12, the friction seat 123 and the mounting shaft 10 rotate synchronously. The chuck 12 or the friction seat 123 and the mounting shaft 10 can also be connected by splines to achieve synchronous rotation. When the hand crank 19 is rotated clockwise, the chuck 12 and the friction seat 123 also rotate clockwise and drive the mounting shaft 10 to rotate together. The mounting shaft 10 then drives the first transmission member 15 to rotate clockwise, and the first transmission member 15 drives the second transmission member 16 meshing with it to rotate counterclockwise, causing the rope to wind upward and lift the fallen person upward.

[0129] When in the opposite direction (e.g., the counterclockwise direction when looking from the direction facing the hand crank 19, i.e., from Figures 1-6 and Figure 14When turning the hand crank 19 counterclockwise (in the counterclockwise direction when viewed from the right side in the figure), the adjusting nut 184 is driven to rotate counterclockwise. The rotation of the adjusting nut 184 causes the adjusting nut 184 to axially move in the first direction (rightward direction). The adjusting nut moves away from the flange 124 of the friction seat 123 in the axial direction of the mounting shaft 10, resulting in the two friction plates 181 and the first ratchet 182 not being pressed but loosened between the flange 124 of the friction seat 123 and the adjusting nut 184. The two friction plates 181 and the first ratchet 182 cannot transmit torque, so the rotation of the hand crank 19 cannot be transmitted to the chuck 12 through friction. At this time, the user moves downward under gravity, driving the second transmission member 16 to rotate clockwise. The second transmission member 16 in turn drives the first transmission member 15 to rotate counterclockwise. The first transmission member 15 drives the mounting shaft 10 to rotate counterclockwise. The mounting shaft 10 further drives the chuck 12 and the friction seat 123 to rotate counterclockwise. The counterclockwise rotation of the chuck 12 and the friction seat 123 causes the chuck 12 to move toward the adjusting nut 184 in the axial direction of the mounting shaft 10. Thus, the two friction plates 181 and the first ratchet 182 are pressed again between the flange 124 of the friction seat 123 and the adjusting nut 184. Therefore, due to the increase in the frictional force acting on the flange 124 and the side surface of the first ratchet 182 after pressing, the rotation of the chuck 12 is braked by the first pawl 183 and the first ratchet 182, preventing the chuck 12 from rotating counterclockwise, thereby preventing the mounting shaft 10 from rotating counterclockwise. So the user temporarily stops descending. Then, turn the hand crank 19 counterclockwise again and repeat the above process. Thus, the user descends a certain distance, then pauses, then descends another certain distance, then pauses again, repeating such a process. Eventually, the user is lowered to the ground.

[0130] In some exemplary embodiments, such as Figure 13 shown, the rope winding device 200 includes a differential self-locking mechanism such that when the rescue differential self-locking control system 300 operates in the differential self-locking mode, if the user accidentally falls, the rope winding device 200 can self-lock.

[0131] The speed difference self-locking mechanism can be arranged on one side of the rope winding device 200. The speed difference self-locking mechanism includes a second ratchet wheel 21 fixedly arranged (for example, the second ratchet wheel 21 can be fixedly installed on the housing 20), a rotating member 23 that rotates together with the reel of the rope winding device 200, and a second pawl 22 pivotally connected to the rotating member. A compression spring (not shown) is installed with one end abutting against the rotating member 23 and the other end abutting against the second pawl 22, so that in the normal operation state, the second pawl 22 is biased by the compression spring and does not engage with the second ratchet wheel 21, and the rope winding device 200 can rotate slowly. When the user accidentally falls, the reel of the rope winding device 200 rotates at a high speed, causing the second pawl 22 to have a large enough centrifugal force to pivot outwardly to overcome the elastic force of the compression spring, thereby engaging with the teeth of the second ratchet wheel 21 to lock the rope winding device 200 and prevent the reel of the rope winding device 200 from continuing to rotate.

[0132] When the user accidentally falls, the rope winding device 200 is self-locked, and the user is suspended in mid-air. Therefore, it is necessary to rescue the user to the ground. At this time, the switching handle 17 can be first pulled to the right in the first direction to engage the first transmission member 15 with the second transmission member 16, and the rescue speed difference automatic control system 300 is changed from the speed difference self-locking mode to the rescue mode. Rotate the hand crank 19 clockwise (clockwise as viewed from the direction facing the hand crank 19) to move the user upward a small distance so that the second pawl 22 leaves the teeth of the second ratchet wheel 21 and returns to the normal use state under the biasing of the compression spring, that is, the second pawl 22 remains separated from the second ratchet wheel 21. Then, rotate the hand crank 19 counterclockwise to move the user downward a distance, and then due to the braking action of the lifting and lowering assembly 18, the rope winding device 200 is temporarily stopped from rotating. Then, rotate the hand crank 19 counterclockwise again to repeat the above process. In this controllable manner, the user can be gradually lowered to the ground. Then, push the switching handle 17 to the left in the second direction to change the rescue speed difference automatic control system 300 from the rescue mode to the speed difference self-locking mode, so that the rescue speed difference automatic control system 300 can continue to operate normally.

[0133] In the rescue speed differential self-locking system according to the embodiment of the present application, when the user slowly pulls down the rope normally, the rope can be smoothly pulled out, and the rescue speed differential self-locking system does not lock itself, so that the user can work normally. If the pulling speed of the rope reaches a threshold value (for example, the user falls and the falling speed reaches the threshold value), the rescue speed differential self-locking system locks itself to achieve the speed differential self-control function. It can be seen that the rescue speed differential self-locking system allows the continuous pulling out of the rope when the rope moving speed is appropriate, and only locks itself when the rope moving speed is relatively large. That is to say, the condition for locking is that the rope moving speed is significantly greater than the rope moving speed during normal use, and there is an obvious speed difference. Therefore, this system is called a "speed differential self-control" system. When a fall occurs and the rescue speed differential self-locking system locks itself to suspend the user in mid-air, it is necessary to rescue the user from mid-air to the ground. Therefore, this system has a rescue function. This system combines the speed differential self-locking function and the rescue function, and can rescue people to a safe position after the speed differential self-locking occurs. Through the switching mechanism, it can be switched between the speed differential self-locking function and the rescue function, that is, between the speed differential self-locking mode and the rescue mode.

[0134] The embodiment of the present application has the following beneficial effects:

[0135] 1. Through the sliding fit of the inclined groove 111 and the connecting pin 102, the clamping and non-clamping fit of the trigger sleeve 11 and the chuck 12, and the elastic force of the first elastic member 13 and the second elastic member 14, only by pushing and pulling the mounting shaft 10 can the switching between the speed differential self-locking mode and the rescue mode be realized. The switching mechanism has a simple structure, convenient operation and fast switching. In addition, the setting of this switching mechanism enables the mounting shaft 10 to quickly return to its position even under accidental touch and disturbance, and will not accidentally change the state between the trigger sleeve 11 and the chuck 12. Only when the external force reaches a specific threshold value can the state between the trigger sleeve 11 and the chuck 12 be switched, so as to realize the mode switching of the rescue speed differential self-locking system.

[0136] 2. The clamping structure of the trigger sleeve 11 and the chuck 12 is ingeniously designed, with a simple structure and smooth switching, which is beneficial to the stable maintenance of the state between the trigger sleeve 11 and the chuck 12.

[0137] 3. The rescue speed differential self-locking system 300 is added with a switching mechanism 100. After the switching mechanism 100 switches the rescue speed differential self-locking system 300 to the rescue mode, the person hanging in mid-air can be rescued to the ground by turning the hand crank 19; the switching mechanism 100 can also switch the rescue speed differential self-locking system 300 back to the speed differential self-locking mode for the normal use of the rescue speed differential self-locking system 300.

[0138] This application describes multiple embodiments, but the description is exemplary rather than restrictive, and it will be apparent to those of ordinary skill in the art that there can be more embodiments and implementation solutions within the scope encompassed by the embodiments described in this application. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically restricted, any feature or element of any embodiment can be used in combination with any other feature or element in any other embodiment, or can replace any other feature or element in any other embodiment.

[0139] This application includes and contemplates combinations with features and elements known to those of ordinary skill in the art. The embodiments, features, and elements disclosed in this application can also be combined with any conventional features or elements to form unique inventive solutions defined by the claims. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this application can be implemented alone or in any suitable combination. Thus, the embodiments are not limited except as defined by the appended claims and their equivalents. In addition, various modifications and changes can be made within the scope of the appended claims.

[0140] Furthermore, in describing representative embodiments, the specification may have presented the method and / or process as a particular sequence of steps. However, to the extent that the method or process does not depend on the particular order of the steps herein, the method or process should not be limited to the particular order of steps. As will be understood by those of ordinary skill in the art, other sequences of steps are possible. Therefore, the particular order of steps set forth in the specification should not be construed as a limitation on the claims. In addition, the claims directed to the method and / or process should not be limited to performing their steps in the order written, as those skilled in the art can readily understand that these orders can vary and still remain within the spirit and scope of the embodiments of this application.

Claims

1. A switching mechanism for switching a rescue inertia reel system between an inertia locking mode and a rescue mode, characterized in that, the switching mechanism comprises: a mounting shaft configured to reciprocate along its axis; a trigger sleeve sleeved on the mounting shaft, and one of the mounting shaft and the trigger sleeve is provided with a protrusion, and the other is provided with an inclined groove inclined with respect to the axis of the mounting shaft, and the protrusion is configured to be inserted into the inclined groove and slide therein, so that the trigger sleeve can axially and circumferentially displace relative to the mounting shaft; a chuck fixedly arranged in the direction along its axis and circumferentially fixedly sleeved on the mounting shaft, the chuck being configured to be engageable and disengageable with the trigger sleeve, and between the engaged and disengaged states, there is a relative displacement between the chuck and the trigger sleeve in the axial and circumferential directions of the mounting shaft; an elastic member sleeved on the mounting shaft and configured to keep the trigger sleeve and the chuck in an engaged or disengaged state; and a first transmission member circumferentially fixedly sleeved on the mounting shaft and movable with the reciprocating movement of the mounting shaft, the first transmission member being configured to engage and disengage with a second transmission member of a rope winding device of the rescue inertia reel system.

2. The switching mechanism according to claim 1, characterized in that, the elastic member comprises: a first elastic member mounted with both ends respectively abutted against the trigger sleeve and the mounting shaft and configured to apply a force towards the chuck to the trigger sleeve; and a second elastic member mounted with one end abutted against the first transmission member to thereby abut against the mounting shaft and the other end abutted against the housing of the rescue inertia reel system.

3. The switching mechanism according to claim 2, characterized in that, the first elastic member is located on a side of the trigger sleeve away from the chuck, and the second elastic member is located on a side of the first elastic member away from the chuck.

4. The switching mechanism according to claim 3, characterized in that, during the process of the trigger sleeve and the chuck being in an engaged state, a disengaged state, and switching between the engaged and disengaged states, the first elastic member and the second elastic member are always in a compressed state.

5. The switching mechanism according to claim 2, characterized in that, the mounting shaft is provided with a retaining ring, the first elastic member is sleeved on the mounting shaft, and the first elastic member is mounted with one end abutting against the retaining ring to thereby abut against the mounting shaft.

6. The switching mechanism according to claim 2, characterized in that, the mounting shaft includes a first mounting section, an end face of the first mounting section forms an axial stop surface, and the first transmission member is sleeved on the first mounting section adjacent to the axial stop surface; the second elastic member is sleeved on the mounting shaft, and the second elastic member is mounted with one end abutting against the first transmission member to make the first transmission member abut against the axial stop surface.

7. The switching mechanism according to claim 6, characterized in that, The first installation section is provided with a circumferential fixing portion, and the first transmission member is provided with a circumferential fixing and mating portion. The circumferential fixing portion and the circumferential fixing and mating portion are cooperated to circumferentially fix the first transmission member and the first installation section.

8. The switching mechanism according to any one of claims 1 to 7, wherein, when the installation shaft moves along the first direction, the first transmission member moves along the first direction with the installation shaft to approach the second transmission member, so as to be able to engage with the second transmission member; when the installation shaft moves along the second direction opposite to the first direction, the first transmission member moves along the second direction with the installation shaft to move away from the second transmission member, so as to be able to disengage from the second transmission member.

9. The switching mechanism according to any one of claims 1 to 7, wherein, further comprising: a switching handle, fixed to one end of the installation shaft and configured to drive the installation shaft to reciprocate.

10. The switching mechanism according to any one of claims 1 to 7, wherein, the trigger shaft sleeve is provided with the inclined groove, and the protrusion includes a connecting pin installed on the installation shaft and protruding from the outer peripheral surface of the installation shaft.

11. The switching mechanism according to claim 10, wherein, the inclined groove penetrates through the wall of the trigger shaft sleeve in the wall thickness direction of the trigger shaft sleeve.

12. The switching mechanism according to claim 10, wherein, the installation shaft is provided with an installation hole, the connecting pin is installed in the installation hole, and the end of the connecting pin protrudes from the installation hole.

13. The switching mechanism according to claim 12, wherein, the connecting pin is in a tight fit with the installation hole.

14. The switching mechanism according to claim 12, wherein, the connecting pin and the installation shaft are fixed by screws.

15. The switching mechanism according to any one of claims 1 to 7, wherein, one end of the trigger shaft sleeve close to the chuck is provided with a plurality of first clamping protrusions protruding towards the chuck, and a first clamping groove is formed between adjacent first clamping protrusions; one end of the chuck close to the trigger shaft sleeve is provided with a plurality of second clamping protrusions protruding towards the trigger shaft sleeve, and a second clamping groove is formed between adjacent second clamping protrusions; wherein, when each of the plurality of first clamping protrusions is clamped into a corresponding one of the second clamping grooves and each of the plurality of second clamping protrusions is clamped into a corresponding one of the first clamping grooves, the trigger shaft sleeve and the chuck are clamped; and when each of the plurality of first clamping protrusions is separated from the corresponding second clamping groove, each of the plurality of second clamping protrusions is separated from the corresponding first clamping groove, and the plurality of first clamping protrusions and the plurality of second clamping protrusions are in contact, the trigger shaft sleeve and the chuck are not clamped.

16. The switching mechanism according to claim 15, wherein, The side wall surfaces of the first clamping groove and the second clamping groove are both inclined relative to the axis of the mounting shaft, and the inclination direction of the side wall surface is the same as that of the inclined groove.

17. The switching mechanism according to any one of claims 1 to 7, characterized in that the chuck is provided as an integral structure with the friction seat of the lifting and lowering assembly of the rescue inertia reel system.

18. The switching mechanism according to any one of claims 1 to 7, characterized in that the first transmission member includes a first transmission gear, and the second transmission member includes a second transmission gear.

19. A rescue inertia reel system, characterized in that it includes: a rope winding device including a second transmission member; and the switching mechanism according to any one of claims 1 to 18, the switching mechanism being arranged to be able to engage and disengage the first transmission member and the second transmission member by reciprocating movement of the mounting shaft.

20. The rescue inertia reel system according to claim 19, characterized in that it further includes: a lifting and lowering assembly mounted to the mounting shaft; and a hand crank connected to the lifting and lowering assembly and arranged to drive the mounting shaft to rotate through the lifting and lowering assembly.

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