Seat calf rest mechanism

A vehicle seat assembly with a release mechanism for a leg support member, a release mechanism, and a method of installing a release mechanism for a leg support connected to a seat assembly are provided. The release mechanism has a support member to connect to one of a seat base and a leg support member. An arm has a proximal end region rotatably connected to the support member and a distal end region, The arm defines a cam surface. A biasing member is connected to the support member, and is in contact with the distal end region of the arm. A follower is provided to connect to the other of the seat base and the leg support member, and is engageable with the cam surface of the arm when the leg support member is rotated between a deployed position and a stowed position.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims foreign priority benefits under 35 U.S.C. § 119(a)-(d) to DE 10 2020 205 480.0, Filed Apr. 30, 2020, the disclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The disclosure relates to a mechanism for a vehicle seat assembly having a deployable calf rest.

BACKGROUND

A vehicle seat assembly may be provided with a deployable calf or leg rest. Examples of such vehicle seat assemblies are disclosed in German Pat. No. DE 102016215741 B4, Chinese Pat. No. CN 109228987 B, U.S. Pat. No. 10,293,717, and Korean Pat. Pub. No. KR 20190041631 A.

SUMMARY

In an embodiment, a vehicle seat assembly is provided with a seat base, and a leg support rotatably connected to the seat base and movable between a stowed position and a deployed position. An arm has a proximal end region rotatably supported by one of the seat base and the leg support, with the arm defining a cam surface. A spring is supported by the one of the seat base and the leg support, and the spring is in contact with a distal end region of the arm. A follower is connected to the other of the seat base and the leg support. The follower is engageable with the cam surface of the arm when the leg support is rotated between the deployed position and the stowed position.

In a further embodiment, from the deployed position, the follower biases the arm to rotate the leg support relative to the seat base using only a force imparted on the leg support.

In another further embodiment, the arm defines a planar surface opposite to the cam surface. The spring is engageable with the planar surface of the arm to translate therealong when the leg support is rotated between the deployed position and the stowed position.

In a further embodiment, the spring is preloaded to bias the arm in a first direction. The cam surface defines a recess and a convex transition region positioned between the distal end region and the proximal end region of the arm. In response to engagement of the follower with the transition region, the spring is further loaded, and the arm is rotated in a second direction opposite to the first direction.

In another further embodiment, a mounting bracket defines first and second guide slots spaced apart from one another, with the follower received within the first and second guide slots. The arm is positioned between the first and second guide slots and is rotatably connected to the mounting bracket.

In a yet further embodiment, the spring is a cantilever spring member having an intermediate region positioned between a first end and a second end. The first and second ends are supported by the mounting bracket, and the intermediate region is in contact with the arm.

In an even yet further embodiment, the spring is a first spring. A second cantilever spring is provided and has an intermediate region positioned between a first end and a second end, with the first and second ends of the second spring supported by the mounting bracket. The intermediate region of the second spring in contact with the arm and adjacent to the intermediate region of the first spring.

In another even yet further embodiment, a proximal end region of the arm defines an aperture. A fastener extends through the mounting bracket and the aperture of the arm to connect the arm to the mounting bracket.

In a yet even yet further embodiment, a first eccentric bushing and a second eccentric bushing are connected to the mounting bracket via the fastener. The arm is positioned between the first and second eccentric bushings. An outer surface of the first eccentric bushing contacts the spring adjacent to the first end, and an outer surface of the second eccentric bushing contacts the spring adjacent to the second end. Rotation of the first and second eccentric bushings varies a preload force of the spring on the arm.

In an even yet even yet further embodiment, the fastener has a shank defining a first non-circular cross-sectional shape. Each eccentric bushing defines an aperture therethrough with a second non-circular cross-sectional shape. The first and second non-circular cross-sectional shapes form fit with one another such that rotation of the fastener relative to the mounting bracket rotates the first and second eccentric bushings.

In a yet even yet even yet further embodiment, a third bushing and a fourth bushing are connected to the mounting bracket via the fastener. The third and fourth bushings are positioned between the first and second eccentric bushings, and the arm is positioned between the third and fourth bushings. Each of the third and fourth bushings defines an aperture therethrough with the second non-circular cross-sectional shape. Each of the third and fourth bushings defines a cylindrical outer surface sized to be received by and in contact with the aperture of the arm such that the arm rotates about the third and fourth bushings.

In another yet further embodiment, the spring is a torsion spring with an intermediate region positioned between first and second end regions. The first and second end regions are supported by the mounting bracket, and the intermediate region in contact with the arm.

In an even yet further embodiment, at least one of the first and second end regions of the torsion spring are formed as a coil.

In another even yet further embodiment, a first fastener extends through the mounting bracket and the proximal end region of the arm to rotatably connect the arm to the mounting bracket. A second fastener extends through the mounting bracket and is spaced apart from the first fastener. The second fastener supports the torsion spring adjacent to the distal end region of the arm.

In another embodiment, a release mechanism for a leg support member of a seat assembly is provided with a support member to connect to one of a seat base and a leg support member. An arm has a proximal end region rotatably connected to the support member and a distal end region, The arm defines a cam surface. A biasing member is connected to the support member, and is in contact with the distal end region of the arm. A follower is provided to connect to the other of the seat base and the leg support member, and is engageable with the cam surface of the arm when the leg support member is rotated between a deployed position and a stowed position.

In a further embodiment, the biasing member biases the arm in a first direction. The cam surface defines a recess and a convex transition region positioned between the distal end region and the proximal end region of the arm. In response to engagement of the follower with the transition region, the biasing member is further loaded and the arm is rotated in a second direction opposite to the first direction with the biasing member translating along a surface of the arm.

In a yet further embodiment, the follower sequentially engages the recess and the transition region as the leg support member is rotated from the deployed position towards the stowed position.

In an embodiment, a method of installing a release mechanism for a leg support member connected to a seat assembly is provided. A support member is connected to one of a seat base and a leg support member, and defines at least one guide slot therethrough. A proximal end region of an arm is rotatably connected to the support member, and the arm extends from the proximal end region to a distal end region. The arm defines a cam surface. A follower is connected to the other of the seat base and the leg support member such that the follower extends through the at least one guide slot. The follower is engageable with the cam surface of the arm when the leg support member is rotated between a deployed position and a stowed position. A biasing member is connected to the support member. The biasing member is preloaded such that the biasing member is in contact with the distal end region of the arm to bias the arm in a first direction towards the follower.

In a further embodiment, the arm is connected to the support member using a fastener. An eccentric bushing is supported about the fastener for rotation therewith, and is in contact with the biasing member. A preload force on the biasing member is adjusted by rotating the fastener and the eccentric bushing.

In another further embodiment, the leg support member is moved from a deployed position to a stowed position using only a force imparted on the leg support member. In response to the force imparted on the leg support member, the follower engages a convex region of the cam surface to further load the biasing member and rotate the arm in a second direction opposite to the first direction and the biasing member translates along the arm.

DETAILED DESCRIPTION

FIG. 1illustrates a vehicle seat assembly10having a seat back12, a seat base14, and a leg support16. The seat base may be formed from or include a portion of a vehicle frame20, or may be a separate component that is connected to a vehicle frame. In one example, the vehicle seat assembly10may be provided in a second row of seats.

The leg support16or leg support member is rotatably connected to the seat base14such that the leg support16can fold, pivot, or rotate between a first position and a second position. In the example shown inFIG. 1, the first position is a stowed position allowing a seat occupant to place their feet on an underlying floor. The second position is a deployed position and is shown in broken lines. In the deployed position, the leg support member supports the lower leg region, e.g. calves, of a seat occupant.

The leg support member is rotatably connected to the seat base using a mechanism22. In the non-limiting example shown, the mechanism22is provided by a four bar linkage, and other mechanisms are also contemplated for use with the leg support member.

The mechanism22is also provided with an electric motor. The electric motor may be operated or controlled by the seat occupant to selectively deploy the leg support from the stowed position to the deployed position.

The vehicle seat assembly10has a release mechanism24. The release mechanism24is connected the seat base14and the leg support16and acts to release the leg support member16from the deployed position towards the stowed position solely in response to a force or load being applied to the leg support when the leg support is in the deployed position. Therefore a seat occupant can release the leg support member from the deployed position merely by using their legs to impart a force on the leg support member. The force required to release the release mechanism24may have an associated threshold value to prevent inadvertent release of the leg support. The release mechanism24acts to release the leg support without actuation of the electric motor and operates independently of the electric motor.

In the prior art, to return the leg support from the deployed position to the stowed position, the seat occupant would need to activate one or more mechanisms. For example, in various prior art, the seat occupant may need to operate the electric motor to retract the leg support, or may need to actuate a lever or other input to the mechanism22.

FIGS. 2-4illustrate a release mechanism100according to an embodiment. The release mechanism100may be used as release mechanism24with the vehicle seat assembly10as shown inFIG. 1. The release mechanism100is connected to or supported by both the leg support16and the seat base14.

The release mechanism100has a mounting bracket102. The mounting bracket102may be connected to an end region of an actuator rod104that is connected to the motor of the mechanism22, and is connected to or supported by the seat base14. The actuator rod104may be moved by the motor via a lead screw or the like to move the leg support from the stowed position to the deployed position. In other examples, the mounting bracket102may be connected to or supported by the leg support16.

In one example, and as shown, the mounting bracket102has first and second guide slots106. The guide slots106may be aligned with one another, and are spaced apart from one another. The guide slots106may be formed from opposite side regions of the mounting bracket102, e.g. for a U-shaped mounting bracket102.

An arm110is rotatably connected to the mounting bracket102. The arm110has a proximal end region112and a distal end region114. The proximal end region112is rotatably connected to the mounting bracket102and associated seat base. The proximal end region112of the arm defines an aperture116. A fastener118extends through the mounting bracket102and the aperture116of the arm to connect the arm110to the mounting bracket102.

As shown inFIG. 4, the arm110is positioned within the mounting bracket102, and between the first and second guide slots106.

The arm defines a cam surface120or first surface120. The arm also defines a second surface122opposite to the cam surface120. The cam surface120defines a recess124and a convex transition region126positioned between the distal end region114and the proximal end region112of the arm. In various examples, the cam surface120may include one or more linear, concave arcuate, convex arcuate, or another profile shapes as are known in the art. The second surface122may be a planar surface as shown, or may be formed with another shape.

A follower130or pin130is provided with the release mechanism100. The follower130may be connected to or supported by the leg support16when the mounting bracket102is supported by the seat base14. Alternatively, the follower130may be connected to or supported by the seat base when the mounting bracket is supported by the leg support.

The follower130or pin is received by the first and second guide slots106, and moves within the guide slots106as the leg support16moves between the stowed and deployed positions. The follower130engages with or contacts the cam surface120of the arm110when the leg support16is rotated between the deployed position and the stowed position.

One or more springs140or biasing members140are provided. In the example shown inFIGS. 2-4, the release mechanism100has a pair of springs140. In other examples, the release mechanism may have a single spring, or may have three or more springs.

Each spring140is supported by or connected to the mounting bracket102and seat base14. The spring140is in contact with the second surface122and distal end region114of the arm110.

Each spring140may be a cantilever spring as shown. Each spring140has a first end142and a second end144. The first and second ends142,144are supported by or connected to the mounting bracket102. The first and second ends142,144may be received by apertures in the mounting bracket102as shown. As can be seen inFIGS. 2-4, the springs140may be bent or otherwise shaped such that each spring140extends from the aperture in the mounting bracket towards the second surface122, and then alongside the second surface122of the arm. The springs140may also be arranged as shown inFIG. 4, with one spring nested inside the other spring.

An intermediate region146of the spring is positioned between the first and second ends142,144of the spring. The intermediate region146of each spring is in contact with the arm110. For a release mechanism100with multiple springs140, the intermediate regions146of the springs may be positioned adjacent to one another as shown inFIG. 4. The intermediate region146of the spring is in contact with the second surface122or planar surface of the arm110and translates or slides along the second surface122as the leg support16rotates between the deployed position and stowed position.

The spring140is preloaded upon installation of the spring140into the release mechanism100such that the arm110is biased in a first direction. In the example shown inFIGS. 2-3, the first direction is clockwise. Multiple springs140may be needed for the release mechanism in order to provide the desired preload force from the spring(s)140onto the arm110.

For operation of the release mechanism such that the leg support is being released from the deployed position towards the stowed position, a force is exerted on the leg support16by a seat occupant. The force on the leg support causes the follower130to impart a force onto the cam surface120of the arm110such that the follower130engages the cam surface120and biases the arm110to rotate the leg support16relative to the seat base14using only the force imparted on the leg support.

In response to engagement of the follower130with the transition region126of the cam surface of the spring, the spring(s)140are further loaded, and the arm110is rotated in a second direction opposite to the first direction. As the follower130moves along the cam surface120, the intermediate region146of the springs may translate or move along the second surface122of the arm. With respect to the example shown inFIGS. 2-3, the second direction is counterclockwise.

As the release mechanism releases the leg support16from the deployed position, the follower130sequentially engages the recess124and the transition region126and moves towards the proximal end of the arm110and within the guide slots106, as shown inFIGS. 1-2. The leg support member16is released by the mechanism100and rotates from the deployed position towards the stowed position.

In one or more examples, it may be desirable to adjust the preload force of the springs140on the arm110. By increasing the preload force provided by the springs140onto the arm110, the force on the leg support16that is needed to release the release mechanism100is also increased. Similarly, by decreasing the preload force provided by the springs140onto the arm110, the force on the leg support16that is needed to release the release mechanism100is also decreased.

The fastener118has a shank150defining a first non-circular cross-sectional shape. In the example shown, the non-circular shape is square; however, other non-circular shapes are also contemplated.

A first eccentric bushing152and a second eccentric bushing154are connected to the mounting bracket102via the fastener118. The arm110is positioned between the first and second eccentric bushings152,154. The mounting bracket102is also positioned between the first and second eccentric bushings152,154.

Each eccentric bushing152,154defining an aperture156therethrough with a second non-circular cross-sectional shape. The second non-circular shape may be the same as or similar to the first non-circular shape. The first and second non-circular cross-sectional shapes form fit with one another such that rotation of the fastener118relative to the mounting bracket102rotates the first and second eccentric bushings152,154.

An outer surface158of the first eccentric bushing152contacts the springs140adjacent to the first ends142of the spring(s), and wherein an outer surface158of the second eccentric bushing154contacts the springs140adjacent to the second end144of the spring(s). The outer surface158of each of the eccentric bushings152,154is eccentric relative to the central or longitudinal axis of the fastener118and apertures of the mounting bracket102and arm110.

As the fastener118is rotated relative to the mounting bracket102, the form fit provided by the first and second non-circular shapes rotates the first and second eccentric bushings152,154with the rotation of the fastener118. Therefore the position of the first and second eccentric bushings152,154may be adjusted relative to the mounting bracket102, arm110, and springs140. The first and second non-circular shapes also maintain the position of the first and second eccentric bushings152,154relative to one another such that their respective outer surfaces158remain aligned.

As the fastener118and eccentric bushings152,154are rotated, the outer surface158of the eccentric bushings contacts the springs(s)140, and imparts a force on the springs140that moves the intermediate region146of the spring towards or away from the distal end114of the arm, which in turn causes an adjustment in the location that the intermediate region146of the spring140contacts the arm110, and varies the location of the preload force of the spring on the arm. Rotation of the first and second eccentric bushings152,154therefore varies a preload force of the spring on the arm, with the preload force increasing as the intermediate region146of the spring moves towards the distal end114of the arm.FIGS. 2-3illustrate the eccentric bushings152,154interacting with the spring to provide a lower preload force on the arm, as noted by the location of the eccentricity of the bushing152,154relative to the spring140. If the eccentric bushing inFIGS. 2-3were rotated 180 degrees, the eccentric bushings152,154interacting with the spring140would provide a higher preload force on the arm110.

The release mechanism100also has third and fourth bushings160,162that are connected to the mounting bracket102via the fastener118. The bushings160,162allow for rotation of the arm110relative to the fastener118, as the shank of the fastener has the first non-circular shape.

The third and fourth bushings160,162are positioned between the first and second eccentric bushings152,154, and the arm110is positioned between the third and fourth bushings160,162. Each of the third and fourth bushings160,162defines an aperture therethrough with the second non-circular cross-sectional shape. Each of the third and fourth bushings160,162also defines a cylindrical outer surface164sized to be received by and in contact with the cylindrical aperture of the arm110such that the arm110rotates about the third and fourth bushings160,162and the arm rotates relative to the fastener118and first and second bushings152,154.

In order to install the release mechanism100onto a seat assembly with a leg support member16, such as the vehicle seat assembly10ofFIG. 1, a support member such as a mounting bracket is connected to either the seat base or the leg support member. The proximal end region of the arm is rotatably connected to the mounting bracket using a fastener. Eccentric bushings are supported by the fastener for rotation with the fastener.

The follower is connected to the other of the seat base and the leg support member such that the follower extends through the guide slots of the mounting bracket, and such that the follower engages the cam surface of the arm when the leg support member is rotated between a deployed position and a stowed position.

One or more biasing members or springs are then connected to the mounting bracket. The springs are preloaded such that they are in contact with the distal end region of the arm to bias the arm in the first direction towards the follower. The springs are in contact with the eccentric bushings. The preload force on the biasing member is adjusted if needed by rotating the fastener and the eccentric bushing.

The leg support member is moved from a deployed position to a stowed position using only a force imparted on the leg support member. In response to the force imparted on the leg support member, the follower engages a convex region of the cam surface to further load the springs and rotate the arm in the second direction such that the springs translate or move along the arm.

FIG. 5illustrates a release mechanism200according to another embodiment. The release mechanism200may be used as release mechanism24with the vehicle seat assembly10as shown inFIG. 1. Elements that are the same as or similar to those described with respect toFIGS. 1-4are given the same reference numbers, and are generally described above with respect toFIGS. 1-4. The mechanism200operates similarly to that described above for mechanism100.

The arm110has a proximal end112that is rotatably connected to the mounting bracket102and seat base14via a first fastener202. The pin130is connected to the leg support16. The follower130engages the cam surface of the arm.

The mechanism200has a spring140. The spring140is a torsion spring204and has an intermediate region206positioned between first and second end regions208,210. The first and second end regions208and210are supported by respective plates212on a second fastener214on the mounting bracket102. The second fastener214extends through the mounting bracket102adjacent to the distal end region114of the arm110, and is spaced apart from the first fastener202. The second fastener214supports the torsion spring204adjacent to the distal end region114of the arm.

The intermediate region206is in contact with the second surface of the arm110. As shown inFIG. 5, the torsion spring204has first and second coiled sections216or coils, with each coiled section216positioned between the intermediate region206and an associated end region208,210.

The position of the plates212may be adjusted to adjust the tension in the spring204and vary the preload that the spring204applies to the arm110.

Generally, and referring toFIGS. 1-5, the follower130is engageable with the cam surface120of the arm110when the leg support16is moved from the deployed position towards the stowed position based on a force on the leg support member16exceeding a threshold value. In one example, this threshold value is 400 Newtons, although other values are also contemplated, and may be based on the geometry of the seat assembly10and the maximum load to be applied to the motor. The follower follows the cam surface120as the leg support16rotates with respect to the seat base14. The springs140are compressed in response to the follower130engaging the cam surface120such that the arm110is rotated in a second direction opposite to the first direction.

As the profile of the cam surface120changes, the follower130moves the arm110and the spring is elastically deformed. As the arm moves, the amount of force exerted by the spring140on the arm110changes as the follower130moves relative to the cam surface120. For example, the follower130moving over the transition region126involves a large amount of deformation of the spring140over a short distance of the cam surface120, since it is a steep profile and a convex shape.

The springs140maintain the arm110in contact with the follower130. In response to a force applied on the leg support16, the follower130exerts a force on the arm110. If the force applied by the follower130onto the arm110is greater than the preload force exerted by the springs140onto the arm110, the follower130moves along the cam surface120, the springs140are elastically deformed such that the arm110rotates in the second direction, and the intermediate region146of the springs may move along the second surface122of the arm110. Note that the preload force applied the springs140may be set or tuned to correspond to the desired threshold force on the leg support to release the mechanism. Also note that the preload force may or may not be equivalent in value to the threshold force based on the geometry of the seat assembly10and where the forces are respectively applied to the assembly10.

The move the leg support16from the deployed position to the stowed position, the user exerts a force on the leg support that will overcome the preload force applied by the springs140, without operating a lever or other user input associated with the mechanism22, and also without operating the motor of the mechanism22. This simplifies operation for the seat occupant, and also provides load protection for the motor as the leg support is released based on the preload force. The eccentric bushings152,154or plates212provide a fine tune or control over the preload force applied by the springs140onto the arm110. In one example, the preload force may be varied by twenty percent or more using the eccentric bushings or plates.

Additionally, the type and location of the springs140according to the present disclosure provide a release mechanism with smaller packaging size, especially in the vertical direction, which allows for use with reduced clearances below the seat assembly, for lowering the seat assembly within a vehicle, and the like.