Leg rest assembly for vehicle seat and vehicle seat

Abstract

The utility model relates to a leg support assembly for a vehicle seat and the vehicle seat. The leg rest assembly includes a bracket assembly to be secured to a seat floor of the vehicle seat; the leg supporting part is connected to the bracket assembly on the front side of the bracket assembly in a pivoting manner; a link mechanism; the driving mechanism drives the leg supporting part to conduct pivoting movement through the connecting rod mechanism, and the support assembly comprises an upper support and a lower support which are separated from each other so as to be fixed to the upper side and the lower side of the seat bottom plate respectively. The vehicle seat comprises a seat bottom plate and the leg support assembly. The leg supporting assembly is simple in structure, easy to install and capable of being directly and additionally installed on the vehicle seat without changing the structure of an existing vehicle seat, the leg supporting part can move relative to the support assembly under the condition that overload is caused by misoperation, overload force is prevented from being transmitted to a driving mechanism, and the driving mechanism is prevented from being damaged. And the leg supporting part can be automatically reset after the overload force is eliminated.

Description

TECHNICAL FIELD

[0001] The present utility model relates to the field of vehicles. Specifically, in a first aspect, the present utility model relates to a leg rest assembly for a vehicle seat. In a second aspect, the present utility model relates to a vehicle seat comprising the leg rest assembly BACKGROUND

[0002] In order to maximize the comfort of the vehicle occupants, many vehicles are provided with a leg rest on the vehicle seat, the position of which is adjusted by a motor in order to better support the legs of the occupants. The current conventional design is to connect the leg rest to the seat bottom via a linkage mechanism, which requires changes to the structure of the seat bottom.

[0003] In addition, in order to avoid overloading the motor due to incorrect use of the leg rest and thus damaging it and possibly also causing injury to the occupants, an overload protection device is currently provided on the leg rest.

[0004] DE102010002897A1 discloses an overload clutch for a leg rest, having a clutch assembly with two clutch legs pivotable about a predetermined pivot point and a guide channel formed between the clutch legs for the clutch assembly to be transferred from a receiving position to a release position, wherein a coupling element is in a firm operative connection with a frame of the clutch assembly in the receiving position, and in the event of an overload, the coupling element is moved along the guide channel, thereby causing the clutch assembly to be transferred to the release position.

[0005] DE102015000841A1 discloses a leg rest for a vehicle seat, having a fixing part for fixing the leg rest to a seat bottom; and a carrying part which is pivotally mounted on the fixing part and can assume at least one use position in which the carrying part is loaded, wherein a holding device is provided which holds the carrying part in the use position, wherein the holding device has an overload protection device with a coupling part and a fixing element and a spring, which, when a predetermined force acting on the carrying part is reached or exceeded, causes the carrying part to pivot beyond the use position in the direction of gravity.

[0006] DE102016215741A1 discloses a leg rest for a vehicle seat, having a base and a carrying part which is pivotally mounted relative to the base about a pivot axis, wherein the angle position of the carrying part relative to the base can be adjusted between a non-use position and at least one use position, and has an overload protection device which, in the event of an overload, enables the carrying part to be pivoted in the direction of the non-use position.

[0007] US2005173948A1 discloses a leg rest for a vehicle seat, which is movable between a stowed position and a use position and can be fixed in a freely selectable position. In order to prevent malfunctions, the leg rest comprises an overload protection device with a ratchet mechanism, which releases the fixation of the leg rest upon overload.

[0008] Figures 1A-1B Shown is a leg rest 11 for a vehicle seat 10, which was previously designed by the applicant, whose overload protection device employs a torsion bar spring 12, which is arranged below the seat pan 13 of the vehicle seat 10. As shown, the adjustment of the leg rest 11 is realized by a spindle motor 14 and a screw 15, and a connecting rod 16 is provided, which is fixed at one end to the motor 14, and the torsion bar spring 12 is arranged at one end against the other end of the connecting rod 16, and the other end of the torsion bar spring 12 is arranged from below against the seat pan 13. In Figure 1B , the connecting rod 16 is composed of two rods, which are fixed together at the end against which the torsion bar spring 12 is arranged, and are separated at the other end in order to avoid interference with the movement of the screw 15. In case of overload, the overload force (see arrow F in Figure 1A ) acting on the leg rest 11 is transmitted via the motor 14 to the connecting rod 16, which overcomes the spring force of the torsion bar spring 12 and forces the connecting rod 16 to rotate backwards (see arrow R in Figure 1A ), which in turn moves the motor 14 backwards in order to avoid damage to the motor 14.

[0009] The overload protection device used in the above prior art example is relatively complex in structure, and is mostly arranged below the seat pan, which not only makes the installation inconvenient, but also requires a larger space below the seat pan for installing the overload protection device, which is undesirable. Figures 1A-1B The arrangement of the torsion bar spring in the leg rest shown also results in a large torque, which further increases the difficulty of installation. In addition, the leg rest in DE102010002897A1 cannot automatically return to the original position in case of elimination of overload. SUMMARY

[0010] The utility model discloses a leg support assembly for a vehicle seat. The leg support assembly comprises a bracket assembly to be fixed to a seat bottom plate of a vehicle seat; a leg support part pivotably connected to the bracket assembly at a front side of the bracket assembly; a link mechanism; and a drive mechanism to drive the leg support part to pivot via the link mechanism. According to the utility model, the bracket assembly comprises upper and lower brackets, for example in the form of a plate or a combination of tubes and plates, which are spaced apart from each other to be fixed to an upper side and a lower side of the seat bottom plate, respectively. With this arrangement, the leg support assembly can be directly retrofitted to an existing vehicle seat without any changes to the construction of the existing vehicle seat.

[0011] According to an embodiment, the link mechanism comprises a crossbar pivotably connected to the bracket assembly (for example the upper bracket) at both ends and fixed to the leg support part. Preferably, the upper bracket is provided with connecting tabs at both sides for this purpose. The link mechanism further comprises a drive link, one end of which is fixed to the crossbar and the other end of which is pivotably connected to the drive mechanism.

[0012] According to an embodiment, the drive mechanism comprises a spindle motor fixed to the bracket assembly (for example the lower bracket, for which a mounting seat is provided on the lower bracket) and a lead screw engaged with an output end of the spindle motor, the lead screw extending in a front-rear direction, one end of which is pivotably connected to the drive link and the other end of which is a free end, such that rotation of the output end of the spindle motor causes the lead screw to move forward and backward relative to the spindle motor. With this arrangement, as the output end of the spindle motor rotates, the lead screw moves forward and backward relative to the spindle motor, which in turn drives the drive link to rotate about the point at which it is fixed to the crossbar. Since the drive link is fixed to the crossbar, the crossbar rotates about the point at which it is pivotally connected to the bracket assembly, which in turn causes the leg support part fixed to the crossbar to rotate simultaneously. By using a spindle motor, direct transmission is achieved, which makes the transmission mechanism occupy a smaller volume and reduces manufacturing costs. In addition, by adjusting the length of the lead screw, the range of the rotation angle of the leg support part can be adjusted.

[0013] According to an embodiment, the leg support part comprises a support frame pivotably connected to the bracket assembly (for example the upper bracket) and a support plate linearly movable relative to the support frame. With this arrangement, the extension distance of the leg support part can be adjusted to accommodate passengers of different heights.

[0014] Preferably, the leg rest part is provided with a guide slot on the rest plate, and the rest frame is correspondingly provided with a slider extending out of the guide slot and capable of moving along the guide slot. In particular, two guide slots are provided on each side of the rest plate, extending in the front-rear direction and arranged side by side but staggered in the front-rear direction. With this arrangement, it is beneficial to guide the linear movement of the rest plate of the leg rest part relative to the rest frame. In addition, by the cooperation of the guide slot and the slider, the stroke of the linear movement can be defined. In particular, in the case of two guide slots on each side, the end points of the linear movement stroke are defined by the cooperation of one guide slot and the corresponding slider on each side, which allows the use of a longer rest plate to improve the support of the passenger's legs compared to a single guide slot on each side.

[0015] Preferably, the leg rest assembly further comprises an overload protection mechanism, which includes a linkage link fixed at one end to the crossbar; a cross tube pivotally connected at the other end of the linkage link; a guide arm fixedly connected at one end to the cross tube and movably connected at the other end to the rest frame, so that the leg rest part can move relative to the guide arm between a first position and a second position, the leg rest part being pivoted downward relative to the bracket assembly in the first position compared to the second position; and a torsion spring fixedly sleeved on the cross tube, and one of the spring legs abutting against the linkage link from below. Preferably, one overload protection mechanism is provided on each side of the leg rest assembly. Alternatively, an overload protection mechanism is provided in the middle of the leg rest assembly, or only one overload protection mechanism is provided on one side of the leg rest assembly. With this arrangement, in the case of overload caused by incorrect use, the overload force acting on the leg rest part will overcome the elastic force of the torsion spring, forcing the torsion spring and thus the cross tube to rotate, in turn driving the guide arm to move relative to the rest frame, thereby causing the leg rest part to pivot downward from the second position to the first position relative to the bracket assembly, to prevent the overload from being transmitted to the drive mechanism and other components to cause damage. In addition, by using a torsion spring, it can avoid that a lower force triggers the overload protection mechanism, and the leg rest part can automatically return to the initial position when the overload force is removed. According to the calculation, when a force of 350N acts vertically on the leg rest part at the midpoint between the two sides of the leg rest part, the threshold torque of the torsion spring should be set to 43.4N*the length of the guide arm (in millimeters). For example, the length of the guide arm is 36.3mm, then the torque is about 1575 newton millimeters.

[0016] Preferably, the rest frame of the leg rest part is provided with a guide slot, in particular a guide slot extending in the front-rear direction and arranged perpendicularly to the rest plate on each side, the two ends of the guide slot defining the first position and the second position respectively. Correspondingly, the other end of the guide arm is provided with a slider extending out of the guide slot, which is capable of moving along the guide slot. With this arrangement, it is beneficial to guide the pivoting of the leg rest part relative to the bracket assembly and thus the seat bottom plate (not rotatable relative to the bracket assembly) in the case of overload caused by incorrect use, to avoid damage to the main shaft motor. In addition, by adjusting the length of the guide slot, the angle range of the downward pivoting movement of the leg rest part can be defined.

[0017] According to an embodiment, the leg rest further comprises a rest plate driving mechanism, which comprises a spindle motor fixed to the rest frame and a lead screw engaged with the output end of the spindle motor, the lead screw extending in the front-rear direction, one end of the lead screw being fixed to the rest plate of the leg rest and the other end being a free end. With this arrangement, as the output end of the spindle motor rotates, the lead screw moves forward and backward relative to the spindle motor, which in turn drives the rest plate to move linearly relative to the rest frame. By using a spindle motor, direct transmission is achieved, so that the transmission mechanism occupies a smaller volume and reduces manufacturing costs. In addition, by adjusting the length of the lead screw, the extension distance of the leg rest can be adjusted.

[0018] In another aspect, the utility model provides a vehicle seat, it includes seat bottom and above -mentioned leg rest subassembly, the upper and lower support of leg rest subassembly is fixed on the upper side and the lower side of seat bottom respectively, for example by means of screw, thereby form sandwich structure.

[0019] The leg rest subassembly of the utility model has the following advantages. First, compared with the leg rest subassembly of the prior art, it can be directly installed on the seat bottom without changing the structure of the seat bottom. Second, since the overload protection mechanism is arranged in the front, it is easy to install and place, and the required space below the seat bottom is smaller. Third, compared with the scheme of DE102010002897A1, when the overload force is removed, the leg rest can automatically return to its initial position. Fourth, compared with the scheme of using a torsion spring in the prior art, the torque required for using a torsion spring is smaller, and it is easy to install. BRIEF DESCRIPTION OF DRAWINGS

[0020] Embodiments of the utility model will be explained in more detail in the drawings, in which:

[0021] Figure 1A is a schematic perspective view of a vehicle seat with a leg rest subassembly of a prior art example;

[0022] Figure 1B is a schematic perspective view from below of a vehicle seat with a leg rest subassembly of a prior art example;

[0023] Figure 2A is a schematic perspective view from above of a vehicle seat with a leg rest subassembly according to an embodiment of the utility model, wherein the leg rest subassembly is in the extended position;

[0024] Figure 2B is a schematic perspective view from below of Figure 2A ;

[0025] Figure 3 is a schematic exploded perspective view of a leg rest subassembly according to an embodiment of the utility model;

[0026] Figure 4 is a schematic side view of a vehicle seat with a leg rest assembly according to an embodiment of the present application.

[0027] The drawings are not necessarily to scale. Like reference numerals in different drawings denote like parts. DETAILED DESCRIPTION

[0028] Reference will now be made, by way of example, to the embodiments of the present application. Figures 2A-4 Embodiments of the present application are described below. For the sake of convenience, the following directional terms are used with reference to the vehicle seat when installed in a vehicle.

[0029] Figures 2A-2B A vehicle seat 100 is shown, which includes a seat bottom 110 and a leg rest assembly 120. The leg rest assembly includes a bracket assembly 1210 fixed to the seat bottom 110; a leg rest portion 1220 pivotally connected to the bracket assembly 1210 at a front side of the bracket assembly 1210; a linkage mechanism 1230; and a drive mechanism 1240 driving the leg rest portion 1220 to pivot movement via the linkage mechanism 1230.

[0030] Figure 3 Detailed configuration of the leg rest assembly is shown. As shown, the bracket assembly 1210 includes upper and lower brackets 1211 and 1212 in the form of plates, which are spaced apart from each other and fixed to the upper and lower sides of the seat bottom 110, respectively, by means of screws 1213, thereby forming a sandwich structure.

[0031] The leg rest portion 1220 includes a rest frame 1221 pivotally connected to the upper bracket 1211 of the bracket assembly 1210 and a rest plate 1222 linearly movable relative to the rest frame 1221. The rest plate 1222 of the leg rest portion 1220 is further provided with guide grooves 1223, and the rest frame 1221 is correspondingly provided with sliders 1224 extending out of the guide grooves 1223, which are fixed to the rest frame 1221 and movable along the guide grooves 1223 relative to the rest plate 1222. In this example, the rest plate 1222 is provided with two guide grooves 1223 on each side, which extend in the front-rear direction and are arranged side by side but staggered front to back.

[0032] The leg rest portion 1220 further includes a rest plate drive mechanism 1225, which includes a main shaft motor 1225a fixed to the rest frame 1221 and a lead screw 1225b engaged with the output end of the main shaft motor, the lead screw extending in the front-rear direction with one end fixed to the rest plate 1222 of the leg rest portion 1220 and the other end being a free end.

[0033] The link mechanism 1230 includes a crossbar 1231 pivotally connected to the upper bracket 1211 at both left and right ends and fixed to the leg rest portion 1220 of the rest frame 1221. To this end, the upper bracket 1211 is provided with a connecting tab 1214 at both left and right sides. The link mechanism 1230 further includes a drive link 1232, one end of which is fixed to the crossbar 1231 and the other end of which is pivotally connected to one end of a lead screw 1242 of the drive mechanism 1240.

[0034] The drive mechanism 1240 includes a main shaft motor 1241 fixed to a mounting seat 1215 provided on the lower bracket 1212 and a lead screw 1242 engaged with the output end of the main shaft motor 1241, the lead screw extending in the front-rear direction, one end of which is pivotally connected to one end of the drive link 1232, and the other end of which is a free end.

[0035] The leg rest assembly 120 is provided with an overload protection mechanism 1250 at both left and right sides, which includes a linkage link 1251 fixed to one end of the crossbar 1231; a cross tube 1252 pivotally connected to the other end of the linkage link 1251; a guide arm 1253 fixedly connected to one end of the cross tube 1252 and movably connected to the rest frame 1221 at the other end, so that the leg rest portion 1220 can move relative to the guide arm 1253 between a first position and a second position, the leg rest portion 1220 being pivoted downward relative to the bracket assembly 1210 in the first position compared to the second position; and a torsional spring 1254 fixedly sleeved on the cross tube 1252, and one of the spring legs 1254a abutting against the linkage link 1251 from below.

[0036] The rest frame 1221 of the leg rest portion 1220 is provided with a guide slot 1226 on each side, which extends in the front-rear direction and is perpendicular to the rest plate 1222, and the two ends of the guide slot define the first position and the second position respectively. Correspondingly, the other end of the guide arm 1253 is provided with a slider 1256 protruding into the guide slot 1226, which can move along the guide slot 1226.

[0037] Figure 4 A schematic view of the overload protection mechanism is shown. In the case of an overload caused by incorrect use, the overload force F acting on the leg rest portion will overcome the elastic force of the torsional spring 1254, forcing the torsional spring and thus the cross tube to rotate, in turn driving the guide arm 1253 to move relative to the rest frame 1221, thereby causing the leg rest portion 1220 to pivot downward relative to the bracket assembly 1210. According to the calculation, when the overload force F of 350 N acts perpendicularly on the leg rest portion at the midpoint between the two sides of the leg rest portion 1220, a force f of 43.4 N will be generated at the pivot point on each side, and therefore the threshold torque of the torsional spring should be set to 43.4 N*36.3 mm (the length of the guide arm 1253), i.e. about 1575 N*mm.

[0038] In some cases, features disclosed in the present application can be used independently of other features. On the other hand, where necessary, features disclosed in the present application can be combined to provide various combinations.

[0039] The expressions and statements used in the present application are all illustrative and not restrictive. Therefore, the present application is not limited to the above-mentioned embodiments. Moreover, it is obvious to those skilled in the art that the basic idea of the present application can be implemented in various ways. Therefore, various modifications, variations and alternatives can exist within the scope of the claims.

Claims

1. A leg rest assembly for a vehicle seat, the leg rest assembly comprising a bracket assembly to be fixed to a seat pan of a vehicle seat; a leg rest portion pivotably connected to the bracket assembly at a front side of the bracket assembly; a link mechanism; and a drive mechanism to drive a pivoting movement of the leg rest portion via the link mechanism, characterized in that, The bracket assembly includes upper and lower brackets, which are separated from each other to be fixed to the upper and lower sides of the seat base, respectively.

2. The leg rest assembly of claim 1, wherein, The upper and lower supports are in the form of plates or a combination of tubes and plates.

3. The leg rest assembly of claim 1 or 2, wherein, The linkage mechanism includes: a crossbar, which is pivotally connected to the support assembly at both ends and fixed to the leg support; and a drive link, which is fixed at one end to the crossbar and pivotally connected to the drive mechanism at the other end.

4. The leg rest assembly of claim 3, wherein, The upper support has connecting tabs on both the left and right sides to connect with the crossbar.

5. The leg rest assembly of claim 1 or 2, wherein, The drive mechanism includes a spindle motor fixed to the bracket assembly and a lead screw meshing with the output end of the spindle motor. The lead screw extends in the front-to-back direction, with one end pivotally connected to the drive linkage and the other end being a free end, so that rotation of the output end of the spindle motor causes the lead screw to move back and forth relative to the spindle motor.

6. The leg rest assembly of claim 5, wherein, A mounting base is provided on the lower bracket, and the spindle motor is fixed to the mounting base.

7. The leg rest assembly of claim 1 or 2, wherein, The leg support includes a support frame pivotally connected to the support assembly and a support plate linearly movable relative to the support frame.

8. The leg rest assembly of claim 7, wherein, The support plate of the leg support has a guide groove, and the support frame is correspondingly provided with a slider that extends out of the guide groove and can move along the guide groove.

9. The leg rest assembly of claim 8, wherein, Each side of the support plate has two guide slots that extend in the front-to-back direction and are arranged side by side but staggered.

10. The leg rest assembly of claim 7, wherein, The leg support assembly also includes an overload protection mechanism, which includes a linkage rod fixed at one end to a crossbar; a cross tube pivotally connected to the other end of the linkage rod; and a guide arm fixedly connected at one end to the cross tube and movably connected to the support frame at the other end, so that the leg support can move relative to the guide arm between a first position and a second position, wherein the leg support pivots downward relative to the support assembly in the first position compared to the second position. And a torsion spring, which is fixedly sleeved on the horizontal tube, and one of the spring legs abuts against the linkage from below.

11. The leg rest assembly of claim 10, wherein, An overload protection mechanism is provided on both the left and right sides of the leg support assembly, or an overload protection mechanism is provided in the middle of the leg support assembly, or an overload protection mechanism is provided only on one side of the leg support assembly.

12. The leg rest assembly of claim 10 or 11, wherein, The support frame of the leg support has a guide groove that extends in the front-to-back direction and is arranged perpendicular to the support plate. The two ends of the guide groove define a first position and a second position, respectively. The other end of the guide arm is provided with a slider that extends out of the guide groove and can move along the guide groove.

13. The leg rest assembly of claim 7, wherein, The leg support also includes a support plate drive mechanism, which includes a main spindle motor fixed to the support frame and a lead screw meshing with the output end of the main spindle motor. The lead screw extends in the front-back direction, with one end fixed to the support plate of the leg support and the other end being a free end.

14. A vehicle seat comprising a seat pan, characterized by The vehicle seat also includes a leg support assembly according to any one of claims 1-13, wherein the upper and lower supports of the leg support assembly are respectively fixed to the upper and lower sides of the seat base.

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