Sealing device for telescopic draw hook

Abstract

The present disclosure relates to a sealing device (1) for closing and protecting an interface between a first element (10) and a second element (20) of a retractable tow hook assembly (500). The sealing device (1) comprises a first housing part (100) fixedly attachable to a first element (10) and a second housing part (200) fixedly attachable to a second element (20). The first housing part (100) and the second housing part (200) are arranged to telescopically mate. The first housing part (100) and the second housing part (200) enclose a variable volume (V) fluidly connectable to the ambient air via a channel (P) between the first housing part (100) and the second housing part (200), and the channel (P) is arranged to be fluidly closed when the first housing part (100) is in sealing contact with the second housing part (200). The disclosure also relates to a towing hook arrangement comprising the sealing arrangement and a vehicle comprising the towing hook arrangement.

Description

Technical Field

[0001] The present disclosure relates to a sealing device for a retractable towing hook. In particular, the present disclosure relates to a sealing device for sealing and protecting an interface between a first element and a second element of a retractable towing hook. The present disclosure also relates to a towing hook device including the sealing device, and a vehicle including the towing hook device. Background Art

[0002] A retractable tow hook includes multiple components that move relative to each other during the transition of the tow hook from the stowed position to the deployed position when the tow hook is mounted on the vehicle. The retractable tow hook is typically mounted on a cross member at the rear of the vehicle. Due to the harsh environment of hot, cold or wet weather, as well as exposure to dust and salt, it is important to protect the moving parts, especially the interfaces between the moving parts, to maintain the operability of the tow hook.

[0003] Different solutions have been developed to protect retractable towing hooks. Some solutions include seals with a bellows-type design, which are fixedly attached between two parts that move relative to each other to protect the interface between the parts. Bellows seals are mainly used in retractable systems when complex movements are performed on multiple axes of rotation and / or translation. This is due to the great flexibility of this type of sealing system.

[0004] An example of such a seal is the subject of EP2711210, which discloses a seal in the form of a bellows adapted to tilting movements. The bellows is rotatably connected to a ball pivot at the upper end of the seal via a track. The bellows also engages below the housing and completely surrounds the lateral periphery of the housing. When the system has complex movements (multiple axes of rotation / translation), bellows are the only feasible way to design a sealing system. A major disadvantage is that bellows are expensive and complex to develop due to their complex shape.

[0005] According to its abstract, DE102018124518 A1 relates to a trailer coupling, comprising a pivot bearing unit having a pivot bearing body which is pivotably mounted about a pivot axis between a working position and a rest position on a bearing base fixed to the vehicle, on which bearing base a ball neck is held by a first end and supports a coupling ball on a second end, wherein an extension of a passage extending through the bearing base is arranged on the pivot bearing body coaxially with the pivot axis, wherein the pivot bearing body comprises a form-fitting body which can be moved back and forth in the working position by moving the pivot bearing body parallel to the pivot axis between a fixed position and a release position, wherein the pivot bearing body has a guide body with a receiving portion in which a locking body is movably arranged. The locking body can be moved from the release position to an axial blocking position, in which the locking body abuts against a support surface of the bearing base, thereby holding the support surface in the fixed position.

[0006] However, for towing hooks with more complex movement patterns, bellows seals are not always the right solution. Summary of the invention

[0007] Therefore, one object of the present disclosure is to provide an improved sealing device for a retractable towing hook. More specifically, one object of the present disclosure is to provide a sealing device for a retractable towing hook that can handle both axial and rotational movements of the towing hook. Another object of the present disclosure is to provide a towing hook device including such a sealing device, and to provide a vehicle including such a towing hook device.

[0008] According to a first aspect of the present disclosure, this object is at least partially achieved by a sealing device according to claim 1 .

[0009] Therefore, a sealing device for sealing and protecting an interface between a first element and a second element of a retractable towing hook assembly is provided, the second element being movable relative to the first element along a longitudinal axis and rotatable relative to the first element about the longitudinal axis, wherein the sealing device comprises a first housing portion that is fixedly attached to the first element, wherein the sealing device comprises a second housing portion that is fixedly attached to the second element, wherein the first housing portion and the second housing portion are arranged to telescopically cooperate during relative movement of the first housing portion and the second housing portion between a first position and a second position, and wherein the first housing portion is arranged to be in sealing contact with the second housing portion at least in the first position and the second position. The first housing portion and the second housing portion enclose a variable volume. The variable volume can be fluidically connected to the surrounding air via a channel between the first housing portion and the second housing portion. When the first housing portion is in sealing contact with the second housing portion, the channel is fluidically closed.

[0010] The sealing device described herein has an operating movement with only one rotational and translational axis, namely a helical movement; making it possible to have a sealing design that is less flexible than, for example, a bellows sealing system.

[0011] When the first shell part and the second shell part are moved from the other of the two positions, the first position and the second position each define an end position. The first position and the second position may correspond to the deployed position and the stowed position of the towing hook device including the sealing device. This movement is achieved by a combination of axial movement and rotational movement. Axial movement is movement along the axis or in the direction of the axis, and rotational movement is movement around the axis. Due to the axial movement and rotational movement involved, the retractable design of the seal is particularly advantageous because the first shell part of the sealing device can rotate and axially move relative to the second shell part. At the same time, the first shell part is in sealing contact with the second shell part, preventing water, dust, etc. from contacting the interface between the first element and the second element. The first position can be defined as the retracted position of the retractable design of the first shell part of the sealing device relative to the second shell part. The second position can be defined as the extended position of the retractable design of the first shell part of the sealing device relative to the second shell part.

[0012] The first element or the second element is an element of the retractable towing hook, which element is fixed relative to the vehicle on which the towing hook is arranged. The other of the first element and the second element is fixed relative to the towing hook itself. Since the first housing part is fixedly attached to the first element and the second housing part is fixedly attached to the second element, the movement of the first element relative to the second element will be a relative movement of the first housing part and the second housing part relative to the axis. The relative movement may be a rotational movement around the axis and / or an axial movement along the axis.

[0013] The terms "seal" and "sealing" are to be understood herein as a barrier that prevents water, dust and gas from passing through the barrier. However, in practice, gas (e.g. air) may pass through the seal defined herein at a slow speed over a long period of time. Therefore, the first shell part and the second shell part are in sealed contact, and water and dust do not pass between the first shell part and the second shell part in the area where the shell parts are in sealed contact with each other. It should be further understood that the first shell part and the second shell part are in sealed contact with each other at least in a first position and a second position corresponding to the end positions of their relative movement. In other words, the first shell part and the second shell part are in sealed contact with each other at least in the end position. As described above, the end position can correspond to the deployed position and the stowed position of the towing hook device including the sealing device. Therefore, the sealing function of the sealing device works at least in the end position.

[0014] The variable volume is configured to change volume upon relative movement of the first housing portion and the second housing portion. The interface of the retractable towing hook may be enclosed in the variable volume. The sealing contact between the first housing portion and the second housing portion prevents dust and moisture from entering the variable volume. In practice, the sealing device is usually in the first position or the second position. Therefore, when the sealing device is assembled with the retractable towing hook, the channel is fluidly closed most of the time, thereby protecting the variable volume and the interface from dust and moisture.

[0015] Optionally, the passage is fluidly open, thereby fluidly connecting the variable volume to ambient air via the passage during relative movement of the first housing portion and the second housing portion between the first position and the second position.

[0016] It can be understood that according to this alternative embodiment, the first housing portion is in sealing contact with the second housing portion only in the first position and the second position. During movement between the first position and the second position, i.e. when the variable volume changes and the first housing portion and the second housing portion are not in sealing contact, when the sealing device is assembled with the retractable towing hook assembly, the variable volume is fluidly connected to the surrounding air via the passage so as to equalize the gas pressure inside the variable volume when the variable volume changes during movement.

[0017] Optionally, the sealing device further comprises at least one sealing member arranged in the passage between the first shell part and the second shell part, and wherein the sealing member is arranged to be in sealing contact with the first shell part and the second shell part at least in the first position and the second position, thereby fluidly closing the passage.

[0018] The sealing member performs a sealing function, i.e. closes the passage, because it is in sealing contact with the first housing part and the second housing part in the first position and the second position, thereby closing the passage between the first housing part and the second housing part.

[0019] Optionally, during relative movement between the first housing portion and the second housing portion, the sealing member is in sealing contact with only one of the first housing portion and the second housing portion such that the passage is fluidly open between the first position and the second position.

[0020] When the sealing member is in sealing contact with only one of the first and second housing portions, the passage is open for fluid communication between the sealing member and the first or second housing portion with which the sealing member is not in sealing contact.

[0021] Optionally, the sealing member is attached to the first housing portion or the second housing portion and includes a first flexible sealing lip sealably connectable to the other of the first housing portion and the second housing portion in at least a first position and a second position.

[0022] When the sealing member (e.g. in the form of a first flexible sealing lip) is attached to the first housing part or the second housing part, the sealing member also moves with the attached housing part relative to the other housing part. Therefore, the sealing member can move in the first position and the second position to make sealing contact with the other housing part.

[0023] Optionally, a first flexible sealing lip can be connected radially and sealably between the first housing part and the second housing part.

[0024] The first housing part can be arranged coaxially with the second housing part on the axis.Thus, the first flexible sealing lip can have an annular shape and be arranged coaxially between the first housing part and the second housing part so that it is radially connected between the housing parts in the first position and the second position.

[0025] Optionally, the sealing member comprises a second flexible sealing lip sealably connected to the other of the first housing portion and the second housing portion in the first position or the second position.

[0026] Thus, the second flexible sealing lip is configured to seal the channel only in the first position or the second position of the housing part.

[0027] Optionally, the second flexible sealing lip may be axially sealably connected to the other of the first housing part and the second housing part.

[0028] Since the first housing part and the second housing part are axially movable relative to each other, the second flexible sealing lip can have an annular shape and be arranged coaxially with the first housing part and the second housing part. When the first housing part and the second housing part are axially close to the first position or the second position, the second flexible sealing lip can seal the channel.

[0029] Optionally, the sealing member comprises a third flexible sealing lip connected to the other of the first housing portion and the second housing portion in the first position, the second position and during movement between the first position and the second position.

[0030] Thus, the third flexible sealing lip continuously blocks the passage between the first housing part and the second housing part. However, the third flexible sealing lip may include a vent. The vent may be small enough to prevent a large amount of dust or moisture from entering the passage, but may also be large enough to allow equalization of pressure within the variable volume when the housing parts move relative to each other. Thus, the third flexible sealing lip is not considered to fluidically seal the passage.

[0031] Optionally, a third flexible sealing lip is connected radially between the first housing part and the second housing part.

[0032] Thus, the third flexible sealing lip can be arranged coaxially between the first housing part and the second housing part, so that it always connects radially between the housing parts regardless of the relative position of the housing parts.

[0033] Optionally, the first shell portion and the second shell portion are both rigid shell portions.

[0034] Thus, when the towing hook device moves between the end positions, personnel close to the towing hook device cannot reach or contact any moving parts of the interface, thereby preventing injuries. The bellows seal of the prior art is soft and elastic and cannot provide such protection.

[0035] According to a second aspect of the present disclosure, this object is at least partially achieved by a towing hook device according to claim 13 .

[0036] Therefore, a towing hook device is provided, comprising a retractable towing hook assembly and a sealing device according to any one embodiment of the first aspect of the present disclosure. The retractable towing hook assembly comprises a first element and a second element, and has an interface between the first element and the second element. The first element of the retractable towing hook assembly comprises a fixed portion that can be fixedly attached to a vehicle, wherein the second element of the retractable towing hook assembly comprises a towing hook, and wherein the first position of the first housing portion and the second housing portion corresponds to the deployed position of the towing hook assembly, and the second position of the first housing portion and the second housing portion corresponds to the stowed position of the towing hook assembly.

[0037] A towing hook assembly is defined herein as a retractable towing hook comprising an actuator mechanism for actuating movement between a deployed position and a stowed position. The actuator mechanism is not described in detail in this disclosure, but may include a motor for actuating movement, mechanical mating components for guiding axial and rotational movement between the deployed position and the stowed position. Thus, the actuator mechanism comprises an interface between a first element and a second element. The sealing device is particularly advantageous for protecting the interface of the actuator mechanism for actuating axial and rotational movement of the retractable towing hook.

[0038] The interface may include a plurality of mechanically mating components movable relative to each other and relative to the first and second elements, as described below. Thus, the sealing arrangement protects the interface between the first and second elements of the retractable towing hook from dust and water at least in the deployed and stowed positions.

[0039] The second element may include a plurality of components that are fixed relative to each other and move together relative to the first element when the retractable towing hook moves between the stowed position and the deployed position. Thus, the second element may include a towing hook, a towing ball, a sealing member attachment portion for attachment to the second housing portion of the sealing device, etc.

[0040] According to a third aspect of the present disclosure, this object is at least partly achieved by a vehicle according to claim 14 .

[0041] Therefore, a vehicle is provided comprising a towing hook device according to the second aspect of the present disclosure, the towing hook device comprising a sealing device according to any one embodiment of the first aspect of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Other objects, advantages and features of the present disclosure will become apparent from the following description of one or more embodiments with reference to the accompanying drawings, in which:

[0043] Figure 1 and Figure 2 is a perspective view of a towing hook device according to a second aspect of the present disclosure, the towing hook device comprising a sealing device according to the first aspect of the present disclosure;

[0044] Figure 3 is an exploded view of a towing hook device according to a second aspect of the present disclosure, the towing hook device comprising a sealing device according to the first aspect of the present disclosure;

[0045] Figure 4 is a cross-sectional view of a sealing device according to the first aspect of the present disclosure in a first position;

[0046] Figure 5 is a cross-sectional view of a sealing device according to the first aspect of the present disclosure in a first position;

[0047] Figure 6 is a cross-sectional view of a towing hook device according to the second aspect of the present disclosure in a deployed position, the towing hook device comprising a sealing device according to the first aspect of the present disclosure;

[0048] Figure 7 is a cross-sectional view of a towing hook device according to the second aspect of the present disclosure in a stowed position, the towing hook device comprising a sealing device according to the first aspect of the present disclosure, and

[0049] Figure 8 A vehicle according to a third aspect of the present disclosure is shown, comprising a towing hook device according to the second aspect of the present disclosure. DETAILED DESCRIPTION

[0050] The present disclosure is described in more detail below with reference to the accompanying drawings showing examples of embodiments. The present disclosure should not be considered to be limited to the examples of embodiments described. Throughout the description, the same numerals represent the same elements.

[0051] Figure 1 A towing hook device 2 according to the second aspect of the present disclosure is shown. The towing hook device 2 comprises a sealing device 1 according to the first aspect of the present disclosure and a retractable towing hook assembly 500. Figure 1 The towing hook device 2 is shown in the deployed position. When arranged on a vehicle 3 ( Figure 8 ), the retractable towing hook 20 is deployed and ready to tow or haul an object such as a trailer or bicycle rack (not shown).

[0052] Figure 2 The same towing hook device 2 is shown in a stowed position, wherein the towing hook 20 is stowed and cannot tow or tow an object. Figure 8 ), the towing hook device 2 in the retracted position is usually not visible, for example, hidden behind the bumper of the vehicle 3.

[0053] The sealing device 1 is configured to seal and protect the interface between the first element 10 and the second element 20 of the retractable towing hook assembly 500. Figure 1 and Figure 2 In the example embodiment shown, the first element 10 may include a fixed portion 10 that can be attached to the vehicle 3. The second element 20 may include a towing hook 20. The second element 20 is movable relative to the first element 10 along the longitudinal axis A and is rotatable relative to the first element 10 about the longitudinal axis A. In the example shown or for example Figure 6 In the embodiment, the interface includes the main shaft 60, the guide shaft 40, the guide rail 42 and / or the guide pin 44. Different retractable towing hook assemblies 500 may have interfaces 70 of different configurations without departing from the present disclosure.

[0054] The sealing device 1 comprises a first housing part 100 which can be fixedly attached to the first element 10. The sealing device 1 also comprises a second housing part 200 which can be fixedly attached to the second element 20.

[0055] During the relative movement between the first and second positions of the first and second housing parts 100 and 200, the first and second housing parts 100 and 200 can be telescopically matched. When the sealing device 1 is assembled with the towing hook device 2, the first position of the first and second housing parts 100 and 200 can correspond to the deployed position, and the second position of the first and second housing parts 100 and 200 can correspond to the stowed position of the towing hook 20. The first housing part 100 is in sealing contact with the second housing part 200 at least in the first and second positions. When installed on the vehicle, the towing hook device 2 is usually in the deployed position or the stowed position, corresponding to the first and second positions of the first and second housing parts 100 and 200, respectively. Thus, the sealing contact between the first and second housing parts 100 and 200 ensures that the sealing device 1 protects the interface most, if not all, of the time.

[0056] Figure 31 shows an exploded view of an exemplary sealing device 1 and a towing hook assembly 500 according to the present disclosure. A towing hook device 2 according to the second aspect of the present disclosure is also shown as comprising a combination of the sealing device 1 and the retractable towing hook assembly 500. The sealing device 1 is Figure 3 However, this illustration only indicates that the sealing device 1 is manufactured as a separate component before being assembled into the first housing part 100 and the second housing part 200 .

[0057] In this example, the first housing portion 100 may be fixedly attached to the first element 10 of the towing hook assembly 500, and the second housing portion 200 may be fixedly attached to the second element 20 of the towing hook assembly 500. As illustrated above, the first element 10 of the retractable towing hook assembly 500 may include a fixed portion 10 that may be fixedly attached to the vehicle 3, and the second element 20 of the retractable towing hook assembly 500 may include a towing hook 20. However, the first element may also be exemplified by the towing hook 20, and the second element may be exemplified by the fixed portion 10, so that the sealing device 1 has an opposite orientation on the axis A.

[0058] In the example shown, the components of the retractable towing hook assembly 500 and the sealing device 1 are shown aligned on the axis A. The first element 10 is here exemplified by a fixing portion 10 which can be fixedly attached to the vehicle 3 ( Figure 8 ). In this example, the first element 10 can be regarded as a fixed point, relative to which other components of the retractable towing hook device 2 can move.

[0059] A component being close to another component is defined herein as the component being closer to the first element 10 relative to the other component. A component being far from another component is defined herein as the component being farther from the first element 10 relative to the other component. A proximal movement direction is defined herein as a movement toward the first element 10. A distal movement direction is defined herein as a movement away from the first element 10.

[0060] Furthermore, movement in the axial direction is movement along the axis A, ie, movement parallel to the axis A. As shown in FIG.

[0061] Radial position is a position about axis A. A component being radially outside of another component is defined herein as the component being further from axis A relative to the other component. A component being radially inside of another component is defined herein as the component being closer to axis A relative to the other component. Movement in a radial direction is movement away from axis A or towards axis A.

[0062] refer to Figure 4 and Figure 5, the first housing portion 100 is shown as an annular housing portion, which includes an outer peripheral wall 110 located radially outside the inner peripheral wall 120, and an annular transverse wall 130, which is connected to the proximal end of the outer peripheral wall 100 and the proximal end of the inner peripheral wall 120, thereby closing the annular housing portion in the proximal direction. In other words, the first housing portion includes an annular housing portion that is open in the distal direction.

[0063] The second housing part 200 is shown as an intermediate peripheral wall 210 coaxially aligned with the first housing part 100 on the axis A. The term "intermediate" means that when the sealing device 1 is assembled, the intermediate peripheral wall 210 is configured to be radially received between the outer peripheral wall 110 and the inner peripheral wall 120 of the first housing part 100, such as Figure 4 and Figure 5 shown.

[0064] The first housing portion 100 includes a first annular gasket 140, and the second housing portion 200 includes a second annular gasket 240. The first annular gasket 140 and the second annular gasket are sealably contacted with the first element 10 and the second element 20 of the retractable towing hook assembly 500, respectively. The first housing portion 100 and the second housing portion 200 enclose a variable volume V. The variable volume V is variable in the axial direction when the first housing portion 100 and the second housing portion 200 are telescopically matched during the relative movement between the first position and the second position. The variable volume V can be fluidly connected to the surrounding air via a passage P between the first housing portion 100 and the second housing portion 200, and the passage P is fluidly closed when the first housing portion 100 is in sealing contact with the second housing portion 200, that is, in the first position and the second position.

[0065] During the relative movement of the first housing portion 100 and the second housing portion 200 between the first position and the second position, the passage P may be fluidly opened, thereby fluidly connecting the variable volume V to the surrounding air via the passage P. According to this exemplary embodiment, the first housing portion 100 is in sealing contact with the second housing portion 200 only in the first position and the second position. During the movement between the first position and the second position, i.e., when the variable volume V changes, the variable volume V is fluidly connected to the surrounding air via the passage P, so that when the sealing device 1 is assembled with the retractable towing hook assembly 500, the gas (e.g., air) pressure inside the variable volume V is equalized as the variable volume V changes during the movement between the first position and the second position.

[0066] The sealing device 1 shown may include at least one sealing member 310 disposed in the passage P between the first housing portion 100 and the second housing portion 200. The sealing member 310 is in sealing contact with the first housing portion 100 and the second housing portion 200 at least in a first position and a second position, thereby fluidically closing the passage P.

[0067] The sealing member 310 performs a sealing function because it is in sealing contact with the first and second housing portions 100, 200 in the first and second positions, thereby closing the passage P between the first and second housing portions 100, 200. The variable volume V is defined by the diameter of the sealing member 310 and the stroke length of the actuator mechanism.

[0068] The sealing member 310 may also be in sealing contact with only one of the first housing portion 100 and the second housing portion 200 during relative movement of the first housing portion 100 and the second housing portion 200 so that the passage P is fluidly open between the first position and the second position.

[0069] When the sealing member 310 is disposed in the passage P and is in sealing contact with only one of the first housing portion 100 and the second housing portion 200, the passage P is opened for achieving fluid communication between the sealing member 310 and the first housing portion 100 or the second housing portion 200 with which the sealing member 310 is not in sealing contact. Therefore, when the first housing portion 100 moves axially relative to the second housing portion 200, that is, when the sealing device 1 is in a state between the first position and the second position, the passage P is opened.

[0070] As previously mentioned, the transition between the first position and the second position occurs in a relatively short time compared to the rest time (during which the sealing device 1 is in the first position or the second position in use). Therefore, equalizing the pressure in the variable volume V by fluidly opening the passage during the transition between the first position and the second position is preferred to continuously sealing the variable volume V (e.g. by always keeping the passage P fluidly closed).

[0071] There are various methods to achieve the sealing function of the sealing device 1 by changing the design of the channel P, the first housing part 100, the second housing part 200, the sealing member 310, etc., without detracting from the concept of the present disclosure. The detailed construction disclosed herein should not be regarded as limiting the scope of the claimed invention. Instead, it is only used as an example of how to put the present disclosure into practice.

[0072] like Figure 4 and Figure 5As shown, the second housing portion 200 may include a sealing member 310. The sealing member 310 may be an annular member coaxially disposed on the second housing portion 200 and fixedly attached to the outer circumferential surface of the second housing portion 200.

[0073] It should be understood that the sealing member 310 can be attached to the first housing portion 100 or the second housing portion 200 and includes a first flexible sealing lip 310a that can be sealingly connected to the other of the first housing portion 100 and the second housing portion 200 at least in the first position and the second position. The sealing lip 310a can be an annular, radially inwardly directed first flexible sealing lip 310a. The first flexible sealing lip is elastically flexible.

[0074] As shown, the inner peripheral wall 120 of the first housing portion 100 includes an outer peripheral surface 122 that changes along the axis A in a manner described below. The radius of the outer peripheral surface 122 of the inner peripheral wall 120 is greater at the distal and proximal ends of the inner peripheral wall (adjacent to the annular transverse wall 130) than the radius of the middle section of the outer peripheral surface 122, which is located between the distal and proximal ends of the inner peripheral wall 120. Thus, the first flexible sealing lip 310a of the sealing member 310 (the sealing member 310 is attached to the outer peripheral surface of the second housing portion 200) can be radially sealed and connected between the first housing portion 100 and the second housing portion 200 at a first position and a second position.

[0075] The smaller radius of the outer peripheral surface 122 of the inner peripheral wall 120 between the distal end and the proximal end of the inner peripheral wall 120 can be configured so that the sealing lip 310a is not in sealing contact with the first housing portion between the first position and the second position. Thus, the passage P can be fluidly opened between the first position and the second position.

[0076] like Figures 3 to 5 As shown, the sealing member 310 may include a second flexible sealing lip 310b that is sealably connected to the first housing portion 100 in the first position. It is also conceivable that the flexible sealing lip 310b is provided on the first housing portion 100 to be sealably connected to the second housing portion 200 in the first position. The second flexible sealing lip 310b is illustrated as being provided on the proximal end of the sealing member 310. Therefore, the second flexible sealing lip 310b is proximally directed from the proximal end of the intermediate peripheral wall 210 of the second housing portion 200. In the first position, the sealing lip 310b is sealingly connected to the annular peripheral wall 130 of the first housing portion 100, thereby fluidically closing the passage P.

[0077] The second flexible sealing lip 310b may include a biasing element (not shown), such as a spring, which is configured to apply an additional axial force, ie in the proximal direction in the shown example, to increase the contact pressure between the second flexible sealing lip 310b and the first housing part 100.

[0078] The sealing member 310 may further include a third flexible sealing lip 310c, which is connected to the other of the first housing portion 100 and the second housing portion 200 in the first position, the second position, and during the movement between the first position and the second position. Thus, the third flexible sealing lip 310c continuously blocks the passage between the first housing portion 100 and the second housing portion 200. However, the third flexible sealing lip 310c may include a vent g( Figure 3 ). The vent g may be small enough to prevent substantial dust or moisture from entering the passage P, but large enough to equalize the pressure within the variable volume when the housing parts 100, 200 move relative to each other. Due to the vent g, the third flexible sealing lip 310c does not seal the passage according to the definition of the term "seal" as used herein.

[0079] exist Figures 3 to 5 In the example shown, the third flexible sealing lip 310c is an annular elastic flexible lip provided along the periphery of the sealing member 310, which is fixedly attached to the outer peripheral surface of the second housing portion 200. Thus, the third flexible sealing lip 310c is radially connected between the first housing portion 100 and the second housing portion 200. The third flexible sealing lip 310c can be referred to as a "scraping ring" which is configured to scrape dust and moisture from the inner peripheral surface of the outer peripheral wall 110 of the first housing portion 100 when the third flexible sealing lip 310c is assembled with the second housing portion 200. Therefore, the third flexible sealing lip 310c is configured to clean the surface with which it contacts when the first housing portion 100 and the second housing portion move relative to each other.

[0080] In one embodiment, the first housing portion 100 and the second housing portion 200 can be rigid housing portions 100, 200, so that when the towing hook device moves between the end positions, personnel near the towing hook device cannot touch or contact any moving parts of the interface, thereby preventing injuries. The bellows seal of the prior art is soft and flexible and cannot provide such protection.

[0081] Now refer to Figure 6 and Figure 7 The function of the sealing device 1 is briefly summarized. Figure 6 A cross-sectional view of the towing hook device 2 is shown in the deployed position, i.e. if the towing hook device 2 is attached to a vehicle 3 ( Figure 8), the towing hook 20 will be ready to tow or haul an object. The first flexible sealing lip 310a is assembled with the second housing portion 200 and radially closes the passage P by sealably connecting with the first housing portion 100 at the proximal end of the inner peripheral wall 120, wherein the radius of the outer peripheral surface 122 of the inner peripheral wall 120 is greater than the radius of the middle section between the proximal end and the distal end of the inner peripheral wall 120. The second flexible sealing member 310b closes the passage P by sealing contact with the annular transverse wall 130 of the first housing portion 100. The third flexible sealing member 310c closes the passage P between the second housing portion 200 and the outer peripheral wall 110 of the first housing portion 100.

[0082] Although not shown, at any position between the first position and the second position of the sealing device 1, that is, between the deployed position and the stowed position of the towing hook device 2, the first flexible sealing lip 310a does not contact the outer peripheral surface 122 of the inner peripheral wall 120, because the radius of the outer peripheral surface 122 of the middle section between the proximal end and the distal end of the inner peripheral wall 120 decreases. The second flexible sealing lip 310b does not contact the annular transverse wall 130. However, the third flexible sealing member 310c closes the passage P except for the vent g of the third flexible sealing lip 310c during the movement between the end positions.

[0083] The movement of the traction hook device 2 can be actuated in a variety of ways, which are only briefly described herein. An electric motor (not shown) can be mechanically connected to the threaded spindle 60. The motor rotates the spindle 60 about the axis A. The threads of the spindle 60 engage with the internal threads of the guide shaft 40. The guide shaft 40 also has a guide rail 42, which is engaged by at least one guide pin 44 included in the fixed part 10. Therefore, the rotation of the spindle 60 pushes the guide shaft 40 toward the distal end, but due to the interaction between the at least one guide pin 44 and the guide rail 42, the guide shaft 40 is forced to rotate about the axis A. Since the traction hook 20 is fixedly attached to the guide shaft by the screw 50, the traction hook 20 also moves toward the distal end along the axis A while rotating about the axis A.

[0084] Figure 7 A cross-sectional view of the towing hook device 2 is shown in the stowed position, i.e. when the towing hook device 2 is attached to the vehicle 3 ( Figure 8), the towing hook 20 can be hidden behind the bumper. The first flexible sealing lip 310a is assembled with the second housing portion 200 and radially closes the passage P by sealingly connecting with the first housing portion 100 at the distal end of the inner peripheral wall 120, wherein the radius of the outer peripheral surface 122 of the inner peripheral wall 120 is greater than the radius of the middle section between the proximal end and the distal end of the inner peripheral wall 120. The second flexible sealing lip 310b does not contact the annular transverse wall 130. The third flexible sealing member 310c closes the passage P between the second housing portion 200 and the outer peripheral wall 110 of the first housing portion 100, except for the vent g of the third flexible sealing lip 310c.

[0085] like Figure 8 As shown and as described above, the towing hook device 2 is intended to be mounted on a vehicle 3 .

Claims

1. A sealing device (1) for sealing and protecting an interface between a first element (10) and a second element (20) of a retractable towing hook assembly (500), wherein the second element (20) is movable relative to the first element (10) along a longitudinal axis (A) and is rotatable relative to the first element (10) about the longitudinal axis (A), in, The sealing device (1) comprises a first housing part (100) which can be fixedly attached to the first element (10), The sealing device comprises a second housing portion (200) which can be fixedly attached to the second element (20), wherein the first housing portion (100) and the second housing portion (200) are configured to telescopically fit together during relative movement of the first housing portion (100) and the second housing portion (200) between a first position and a second position, and wherein the first housing portion (100) is arranged to be in sealing contact with the second housing portion (200) at least in the first position and the second position, and The first shell part (100) and the second shell part (200) enclose a variable volume (V), and the variable volume (V) can be fluidically connected to the surrounding air via a channel (P) between the first shell part (100) and the second shell part (200), and the channel (P) is configured to be fluidically closed when the first shell part (100) is in sealing contact with the second shell part (200).

2. The sealing device (1) according to claim 1, wherein: The passage (P) is arranged to be fluidically opened so that the variable volume (V) is fluidically connected to the surrounding air via the passage (P) during the relative movement of the first housing part (100) and the second housing part (200) between the first position and the second position.

3. The sealing device (1) according to claim 1 or 2, further comprising at least one sealing member (310) arranged in a channel (P) between the first shell part (100) and the second shell part (200), and wherein the sealing member (310) is arranged to be in sealing contact with the first shell part (100) and the second shell part (200) at least in the first position and the second position, thereby fluidically closing the channel (P).

4. The sealing device (1) according to claim 3, wherein: The sealing member (310) is configured to be in sealing contact with only one of the first shell part (100) and the second shell part (200) during the relative movement of the first shell part (100) and the second shell part (200), so that the channel (P) is fluidically opened during the relative movement.

5. The sealing device (1) according to claim 4, wherein: The sealing member (310) is attached to the first shell part (100) or the second shell part (200) and includes a first flexible sealing lip (310a) which can be sealingly connected to the other of the first shell part (100) and the second shell part (200) at least in the first position and the second position.

6. The sealing device (1) according to claim 5, wherein: The first flexible sealing lip (310a) is radially sealably connected between the first housing part (100) and the second housing part (200).

7. The sealing device (1) according to claim 5 or 6, wherein: The sealing member (310) includes a second flexible sealing lip (310b) which is sealingly connectable to the other of the first housing portion (100) and the second housing portion (200) in the first position or the second position.

8. The sealing device (1) according to claim 7, wherein: The second flexible sealing lip (310b) is axially sealably connected to the other of the first housing portion (100) and the second housing portion (200).

9. The sealing device (1) according to any one of claims 5 to 8, wherein: The sealing member (310) includes a third flexible sealing lip (310c) connected to the other of the first housing portion (100) and the second housing portion (200) in the first position, the second position, and during movement between the first position and the second position.

10. The sealing device (1) according to claim 9, wherein: The third flexible sealing lip (310c) is radially connected between the first housing part (100) and the second housing part (200).

11. The sealing device (1) according to any one of the preceding claims, wherein: The first housing part (100) and the second housing part (200) are rigid housing parts.

12. A traction hook device (2), comprising a retractable traction hook assembly (500) and a sealing device (1) according to any one of claims 1 to 11, wherein: The retractable towing hook assembly (500) comprises a first element (10) and a second element (20), an interface (70) is provided between the first element (10) and the second element (20), and a first position of the first shell part (100) and the second shell part (200) corresponds to an extended position of the towing hook assembly (500), and a second position of the first shell part (100) and the second shell part (200) corresponds to a retracted position of the towing hook assembly (500).

13. The towing hook device (2) according to claim 12, wherein: The first element (10) of the retractable towing hook assembly (500) comprises a fixed portion (10) that can be fixedly attached to a vehicle (3), and the second element (20) of the retractable towing hook assembly (500) comprises a towing hook (20).

14. A vehicle (3) comprising a towing hook device (2) according to any one of claims 12 or 13.

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