The present invention relates to a braking system for braking the movement of a first element relative to a second element, and to a vehicle seat including such a braking system.
More particularly, the invention relates to a braking system for braking a first element pivotally mounted on a pivot pin that is secured to a stationary second element, while the first element is pivoting from a first position towards a second position in a first pivot direction.
In this type of braking system for braking a first element relative to a stationary second element, the braking means are generally formed by pneumatic or hydraulic actuators that make it possible to brake the pivoting of the first element in the first pivot direction relative to the stationary second element. Unfortunately, use of pneumatic and/or hydraulic actuators increases quite considerably the cost of manufacturing such braking systems, and such actuators are also relatively voluminous, which makes it difficult to install them in known braking systems. In addition, such pneumatic and/or hydraulic actuators are of limited use or are even impossible to use when the angular pivot stroke of the first element relative to the second element, during braking, is greater than or equal to 900.
An object of the invention is, in particular, to mitigate those drawbacks.
To this end, according to the invention a braking system for braking a first element relative to a second element comprises:
In preferred embodiments of the invention, it is optionally possible to use one or more of the following provisions:
In addition, the invention also provides a motor vehicle seat comprising a seat back pivotally mounted on a seat proper, the seat back and the seat proper being connected together via a second spring member designed to urge the seat back to pivot in the first pivot direction, said motor vehicle seat being characterized in that the seat back and the seat proper are further connected together via a braking system as defined above.
Other characteristics and advantages of the invention appear from the following description of one of the embodiments thereof, given by way of non-limiting example and with reference to the accompanying drawings.
In the drawings:
In the various figures, like references designate elements that are identical or similar.
The seat 1 includes a seat back 2 which is mounted to pivot on a seat proper 3 about a pivot axis X that is substantially horizontal and transverse, so as to adjust the inclination of the seat back 2, in particular in comfort positions (
In a comfort position, the seat back 2 can, for example, be angularly adjusted over a first angular range α1 as shown in
For example, the angular adjustment system formed by the hinge 4 can comprise a first cheek plate (not shown) mounted on the seat proper 3 or on the structure of the seat proper, and a second cheek plate mounted on the seat back 2, and a hinge mechanism adapted to enable either the second cheek plate to turn relative to the first cheek plate about the pivot axis X, or the second cheek plate to be locked angularly relative to the first cheek plate.
Within the first angular range α1 through which the seat back 2 can turn about the pivot axis X, the hinge 4 is adapted to enable the pivoting of the second cheek plate on the seat back 2 relative to the first cheek plate on the seat proper 3 to be either locked or unlocked.
The seat proper 3 is carried by a base which can, for example, be formed by two mutually parallel runners which connect the seat proper 3 directly to the floor of the vehicle.
As can be seen in
Thus, when a user whishes to bring the back 2 into a folded-down tabletop-forming position (
The hinge can be adapted so that, while the back 2 is pivoting through the second angular range α2, said hinge does not lock the pivoting of said back 2 relative to the seat proper 3 even when the hinge mechanism tends to return to its locking position. Examples of such a hinge are given, for example, in Document FR-A-2 673 519.
As can be seen in
In addition, as can be seen in
The seat 1 is also provided with a brake system 7 serving to brake the pivoting of the back 2 when said back is within the second angular range α2, said system braking the back against the force exerted by the spiral spring 5.
The braking system 7 is described in detail below with reference to FIGS. 4 to 7.
The braking system 7 comprises a drive member 10 which is pivotally mounted directly on the pivot pin 6, and which serves to be driven in the first pivot direction R1 by the rigid structure 2a of the back 2. The drive member 10 has a first portion in the form of a dish-shaped washer 10a that extends perpendicularly to the pivot pin 6 and that is extended by a rim 10b parallel to the pivot axis 6 and extending towards the rigid structure 2a of the seat back 2. In addition, the drive member 10 also has a cylindrical portion 10c that extends away from the rigid structure 2a of the seat back 2, which cylindrical portion 10c has an inside wall mounted to move in rotation on the pivot pin 6. The cylindrical portion 10c of the drive member 10 also bears against a second shoulder 6b provided on the pivot pin 6. The drive member 10 is also connected to the pivot pin 6 by means of a spring member 11 which has a first end secured to the pivot pin 6 and a second end secured to the projecting rim 10b of the drive member 10 so as to urge said drive member 10 in a second pivot direction R2 opposite from the first pivot direction R1. For example, the spring member 11 can be formed by a spiral spring.
In addition, as can be seen in
Thus, when the back 2 enters the second angular range α2, the projecting member 132 on the rigid structure 2a of the back 2 causes the drive member 10 to pivot via the drive abutment 12 thereon, against the force exerted by the spiral spring 11 disposed inside the dish-shaped washer 10a of said drive member 10.
In addition, the braking system 7 further comprises a sleeve 14 that is substantially bell-shaped and that has a wall 14a perpendicular to the pivot pin 6 and a cylindrical wall 14b which is parallel to the pivot pin 6 and which extends towards the drive member 10. The cylindrical wall 14b of the sleeve 14 has a cylindrical inside wall 15 which co-operates with the cylindrical portion 10c of the drive member 10 to form a housing 16. The sleeve 14 is mounted directly on the pivot pin 6 secured to the rigid structure 3a of the seat proper 3, and is stationary to said pivot pin 6, e.g. by means of a nut 17 which makes it possible for the wall 14a of the sleeve 14 to be brought into abutment and stationary against a third shoulder 6c provided on the pivot pin 6. The sleeve 14 is indexed angularly on the pivot pin 6 when it is stationary thereto, and the pivot pin 6 is itself indexed angularly on the rigid structure 3a of the seat proper 3.
In addition, the braking system 7 further comprises a helical spring 18 which has a diameter adapted so that, when said helical spring 18 is mounted inside the housing 16, said helical spring is in contact with the inside wall 15 of the sleeve 14. As can be seen in more detail in
The winding direction of the helical spring 18 from its first end 18a towards its second end 18b corresponds to the first pivot direction R1 in which the seat back pivots.
Thus, when a user wishes to bring the seat back 2 into its tabletop position as shown in
Under drive from said spring 5, the seat back 2 enters the second angular range α2 as shown in
It should also be noted that, while the seat back 2 is pivoting in the first pivot direction R1, the spiral spring 11 also tends to brake the pivoting of the seat back 2 slightly, even though the main function of said spiral spring 11 does not lie in braking the seat back 2 over the second angular range α2.
Conversely, when the user wishes to bring the seat back 2 into an in-use upstanding position, the user causes the seat back 2 to pivot against the drive exerted by the spiral spring 5 so that the projecting member 13 pivots in the second pivot direction R2, thereby enabling the spiral spring 11 to cause the drive member 10 to pivot in the second pivot direction R2. The drive member 10 pivoting in the second pivot direction R2 also causes the first end 18a of the helical spring 19 to pivot, thereby enabling the diameter of said helical spring 18 to be reduced. This reduction in the diameter of the helical spring makes it possible to reduce substantially the friction force between the turns of the helical spring 18 and the inside wall 15 of the sleeve 14, thereby allowing the seat back 2 to pivot towards an in-use upstanding position.
As can be seen in
Since the sleeve 14 is stationary with angular indexing on the pivot pin 6 which is itself secured to the rigid structure 3a of the seat proper 3, the stud 19 thus makes it possible for the drive member 10 always to be returned to a predetermined relative position relative to the seat proper 3, under drive from the spiral spring 11. Said predetermined angular position of the drive member 10 corresponds to a position in which the projecting member 13 on the rigid structure 2a of the seat back is designed to be in abutting contact with the drive abutment 12 of said drive member 10, when the seat back 2 enters the second angular range α2.
In the above description, the drive member 10 is caused to pivot when the seat back 2 enters the second angular range α2 so as to brake the pivoting of the seat back 2 by increasing the friction force between the helical spring 18 and the sleeve 14. However, it is also possible to arrange the projecting member 13 and the drive abutment 12 on the drive member 10 differently so that the seat back 2 drives the drive member 10 so that it pivots into a different position, e.g. lying within the angular range α2.
Similarly, the hinge 4 can be adapted to bring the seat back into an intermediate folded-down position so as, for example, to give access to the rear seats of a vehicle having only two side doors, the braking system 7 then being adapted to brake the pivoting of the seat back as soon as said seat back enters the second angular range α2.
Number | Date | Country | Kind |
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03 09142 | Jul 2003 | FR | national |