Chairs and seats – Movable back – Tiltable
Reexamination Certificate
1999-04-05
2001-06-12
Barfield, Anthony D. (Department: 3636)
Chairs and seats
Movable back
Tiltable
C297S216130
Reexamination Certificate
active
06244661
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to vehicle seats fitted with locking mechanisms for inclining the seat back, and to safety devices for such seats.
More particularly, the invention concerns a vehicle seat including a seat part and a back hereafter called, the one first seat component and the other second seat component, the back being pivoting mounted relative to the seat part around a transverse horizontal axis of rotation, and the back being connected to the seat part by means of at least one locking mechanism controlled by an operating part able to be activated by a user, this operating part being assisted to a neutral position where said operating part places the locking mechanism into a locked position preventing the seat from pivoting, and the operating part being movable to an activating position where said operating part places the locking mechanism into an unlocked position which allows a free pivoting of the back, the seat comprising additionally at least one first inertia safety device adapted to drive the locking mechanism into its locked position in the event of the vehicle being subjected to sudden impact.
BACKGROUND OF THE INVENTION
The document U.S. Pat. No. 5,163,736 describes an example of such a seat, which allows the back of the seat to be locked automatically when the vehicle is subjected to a violent accidental impact, which stops the seat from then pivoting freely under the effect of the impact when there is a chance of serious injury to the seat user, if this user is in the process of adjusting the inclination of the seat at the time of the accident.
In this known seat, the inertia safety device includes a balance weight which is normally kept in a neutral position by resilient means, and which is moved into a position where said balance weight controls the locking of the back when the vehicle is subject to acceleration or deceleration above a certain threshold.
This prior art seat has however the drawback that the kinetic energy of the balance weight, used on impact to overcome the force of the resilient means acting upon this balance weight and to lock the seat, is relatively low, given the light weight of the balance weight.
Because of this, on the one hand, it is relatively difficult to calibrate the inertia safety device, and on the other hand, the acceleration or deceleration threshold which triggers the locking of the seat back is quite high, so that said locking is not triggered for relatively slight accidental impacts to which the vehicle is subjected, whereas such impacts can nonetheless cause injuries to the seat passenger if the latter is in the process of adjusting the inclination of his/her seat back at the time of the accident.
Moreover, the operation of this type of inertia safety device is influenced by the inclination of the vehicle or of the seat part of the seat, since this inclination modifies the acceleration or deceleration threshold prompting movement of the balance weight and causing the back to lock.
OBJECTS AND SUMMARY OF THE INVENTION
A particular object of this invention is to overcome these drawbacks.
To this end, according to the invention, a seat of the type in question is essentially characterised in that the first safety device includes an input part which is driven by the relative pivoting of the first and second seat components and which is connected, by means of an inertia clutch, to an output part adapted to control the locking mechanism, said clutch being adapted to be placed into an engaged state to drive the output part in a movement direction allowing this output part to place the locking mechanism into its locked position when the back of the seat pivots in a first angular direction with an angular acceleration above a pre-specified acceleration threshold, the inertia clutch being normally in a disengaged state where said clutch uncouples the output part relative to the input part of the first safety device.
By means of these arrangements, given the relatively heavy weight of the back, the variation in kinetic energy of this back, which occurs during acceleration or deceleration of the vehicle, is relatively high even at levels of acceleration or deceleration corresponding to relatively slight impacts to which the vehicle is subjected in its longitudinal direction, in the direction corresponding to the pivoting of the back in the first above-mentioned angular direction (in practice, the first angular direction generally corresponds to the forward pivoting of the back following a frontal impact to which the vehicle is subjected).
Thus, the safety device of the seat according to the invention can be made more sensitive than prior art safety devices, and its calibration is much less tricky.
Moreover, the seat safety device according to the invention is generally insensitive to the inclination of the vehicle or the seat.
In preferred versions of the invention, use may possibly be made additionally of one and/or the other of the following arrangements:
the operating part is pivoting mounted around a transverse horizontal axis of rotation, the input and output parts of the safety device being also rotary relative to transverse horizontal axes and the output part being adapted to control said operating part;
the input part of the safety device is an input toothed wheel which is rotary mounted around the pivoting axis of the seat back and which is fixed to rotate with the second seat component, this input toothed wheel driving (directly or not) an input gear which belongs to the inertia clutch and which is rotary mounted around a transverse horizontal axis relative to the first seat component, the inertia clutch comprising additionally an output gear which is also rotary mounted around a transverse horizontal axis and which is uncoupled from the input gear when the inertia clutch is in its disengaged state, the inertia clutch being adapted to drive said output gear when said clutch is in its engaged state, and the output gear itself driving (directly or not) an output toothed wheel which is fixed to rotate with the operating part of the locking mechanism and which constitutes the output part of the safety device;
the operating part is pivoting mounted relative to the first seat component, the neutral position and the activating position of this operating part being fixed relative to said first seat component;
the input and output gears of the inertia clutch are rotary mounted around a common axis of rotation, the input gear being fixed to rotate with a support part which carries a ratchet movable between, on the one hand, an active position where said ratchet engages with teeth integral with the output gear to drive said output gear in an angular direction corresponding to the movement of the operating part to its activating position, and the ratchet being assisted resiliently to a neutral position where said ratchet does not engage with said teeth integral with the output gear, the inertia clutch comprising additionally a flywheel which is freely rotary mounted around the common axis of rotation of the input and output gears and which comprises a stop part engaging with the ratchet to drive said flywheel to rotate when the seat back pivots in the first angular direction, this stop part being adapted to move the ratchet into its active position under the effect of the inertia of the flywheel when the seat back pivots in said first angular direction with an angular acceleration above said pre-specified acceleration threshold,
the safety device comprises a gear train adapted so that, when the seat back pivots with a certain angular speed and the inertia clutch is in its engaged state, said safety device makes the operating part pivot with an angular speed higher than the angular speed of the seat back;
the first angular direction corresponds to the forward pivoting of the seat back;
the seat back comprises an upper part in mechanical connection with a safety belt;
the first angular direction corresponds to the backward pivoting of the seat back;
the seat comprises a second safety device which include
Moradell Pierre
Timon Michel
Barfield Anthony D.
Bertrand Faure Equipements SA
Marshall O'Toole Gerstein Murray & Borun
LandOfFree
Vehicle seat fitted with a locking mechanism for inclining... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vehicle seat fitted with a locking mechanism for inclining..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vehicle seat fitted with a locking mechanism for inclining... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2485870