Patent Application
20170313211
This application is related to and claims the benefit of European Patent Application No. 16382185, filed on Apr. 27, 2016, the contents of which are herein incorporated by reference in their entirety.
The disclosure is related to locking mechanisms for vehicle seats, especially for locking the backrest of a rear seat to a vehicle structure.
Conventional locking mechanisms for locking vehicle seats comprise a rotary latch for engaging over a striker fixed to the vehicle structure and a detent pawl for locking the movement of the rotary latch establishing a locking position for the seat. The rotary latch and the detent pawl are coupled by a spring such that the spring pushes the rotary latch to the locking position. Due to manufacturing/assembly tolerances, in the locking position there can be a gap between the rotary latch and the locking striker that produces noises (squeak and rattle). This gap can also be produced due to different sizes of the striker. To solve this problem the locking mechanisms usually comprise a noise preventing device such as springs, metal bands, rubber parts, wedges or pivoting parts for pushing the striker against the mechanism.
Locking mechanisms are disclosed for example in DE-3825594-A1, DE-3743558-A1, EP-1619329-A1, DE-102006030732-A1, DE-102004021516-A1 and DE-10058044-A1.
The problem is that all of these mechanisms require the use of additional parts (springs, metal bands, rubber parts, wedges or pivoting parts) which make the mechanism more complex. That also means that the weight of the mechanism increases and also the space required for its mounting in the backseat of the vehicle.
The disclosure relates to a locking mechanism for a backrest of a vehicle seat (mountable on the backrest of the seat) comprising:
a rotary latch engageable over a locking striker fixed to the vehicle; and
a detent pawl comprising a first contact surface or locking surface for contacting against the rotary latch when the rotary latch rotates with a first pivoting movement, to establish a first locking position wherein the rotary latch is in engagement over the locking striker. The first locking position is a position in which the rotary latch is engaged over the striker and blocked by the detent pawl such that the rotary latch cannot return back to an unlock position unless the user pushes an unblocking button. In this position, due to manufacturing/assembly tolerances, a distance or gap can be established between the rotary latch and the striker. In the locking position the backrest is placed substantially vertical and the locking mechanism is engaged over the striker such that the backrest cannot be folded onwards.
According to the disclosure, the detent pawl comprises a second contact surface for contacting against the rotary latch, when the rotary latch rotates with an additional pivoting movement further form the first locking position, to establish a second locking position wherein the detent pawl pushes the rotary latch to contact against the striker, preventing any relative movement between the locking mechanism and the striker. In that second locking position the rotary latch is pressed against the striker to keep permanent contact such that no noises are generated.
In preferred embodiments of the disclosure, the first contact surface is a radial surface of the detent pawl (all the points of the first contact surface are at the same radial distance from the pivoting axis of the detent pawl) whilst the second contact surface comprises a cam profile at a radial distance from the pivoting axis greater that the radial distance of the first contact surface and preferably the radial distance increases gradually in the pivoting direction. Thus the detent pawl pushes against the striker in a different point of its cam profile depending on the relative position of the striker and rotary latch. The amplitude of the additional pivoting movement will depend on the relative position of the striker and rotary latch, i.e. the more distance gap between the rotary latch and the striker the greater the amplitude of the additional pivoting movement is. Thus the mechanism adapts automatically to every different position or different diameter of the striker due to manufacturing/assembly tolerances.
The disclosure also relates to a seat of a vehicle with a locking mechanism as previously described.
To complete the description and in order to provide for a better understanding of the disclosure, a set of drawings is provided. Said drawings form an integral part of the description and illustrate embodiments of the disclosure, which should not be interpreted as restricting the scope of the disclosure, but just as examples of how the disclosure can be carried out. The drawings comprise the following figures:
A locking striker 2 attachable to the vehicle structure is also represented although the vehicle structure is nor illustrated.
As explain previously, due to manufacturing/assembly tolerances, there can be a gap 5 between the rotary latch 1 and the locking striker 2 which produces noises. This gap 5 can be seen in
The detent pawl 3 comprises a first contact surface 6 for contacting against the rotary latch 1 to establish the first locking position, when the detent pawl 3 rotates from the unlocked position of
In a preferred embodiment, the second contact surface 7 is a cam as illustrated in
For smaller diameters of the striker 2, the pivoting of the detent pawl 3 is larger such that the rotary pawl 1 moves further and contacts against the striker 2. For greater diameters of the striker 2 the pivoting of the detent pawl 3 is small because the rotary pawl 1 needs a smaller movement to contact against the striker 2.
In this text, the term “comprises” and its derivations (such as “comprising”, etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc.
Unless otherwise indicated, any ranges referred to in this document include the indicated end points.
The disclosure is obviously not limited to the specific embodiment(s) described herein, but also encompasses any variations that may be considered by any person skilled in the art (for example, as regards the choice of materials, dimensions, components, configuration, etc.), within the general scope of the disclosure as defined in the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16382185 | Apr 2016 | EP | regional |
