Chairs and seats – Movable bottom – Tiltable
Reexamination Certificate
1999-08-11
2001-07-17
Cuomo, Peter M. (Department: 3624)
Chairs and seats
Movable bottom
Tiltable
C248S424000, C248S429000
Reexamination Certificate
active
06260922
ABSTRACT:
The invention relates to a vehicle seat with an adjusting device provided with a first adjusting element and with a second adjusting element, particularly with a length-adjustment device for an underframe relative to a seat part. The adjusting device has a spindle and an auxiliary spindle nut encompassing the spindle. The spindle is associated to the first adjusting element of the adjusting device and the spindle nut is motion-linked with the second adjusting element.
Such adjusting devices for vehicle seats are well known. They are particularly suitable for being used with a multi-turn actuation designed as an electromotor. According to the state of the art, the spindle is multi-turn actuated. Several solutions are known to reduce or abolish the end play of the spindle nut relative to the spindle.
The adjusting devices of the type mentioned above have proved effective. The invention criticizes the pre-cited adjusting devices for being made of lots of component parts. The multi-turn actuation of the spindle by means of an electromotor entails that said electromotor has to be topped by a step-down gear with a high step-down ratio. The bearing of the spindle is not easy to realize, whereas the arrangement of the spindle nut in the second element is easy and does not make any problem.
On the basis thereof, the object of the present invention is to develop the adjusting device of a vehicle seat of the type mentioned above so that its constructive design is as easy as possible, that the adjusting device may be manufactured at low costs with simple means, that installing and servicing it is easy, that a complicated step-down gear may be omitted and that the multi-turn connection between the multi-turn actuation and the actual adjusting device may be designed in the easiest possible way.
The solution of this object is to give a vehicle seat an adjusting device having a first adjusting element and a second adjusting element, particularly a length-adjustment device for an underframe relative to a seat part, whereas the adjusting device has a spindle and an associated spindle nut encompassing the spindle and whereas the spindle is fastened onto the first adjusting element of the adjusting device so as to rotate in unison with it and the spindle nut a) is rotatably borne in the second adjusting element which is motion-linked with the first adjusting element and b) is forming on its outer case a worm wheel that is engaged with a worm which may be connected to a multi-turn actuation.
In the vehicle seat with an adjusting device according to the invention, the combination of worm and worm wheel on one side and of spindle nut and spindle on the other is forming the complete transmission. Thanks particularly to the worm and the worm wheel, a high stepping down is achieved. The multi-turn actuation may thus directly occur by means of an electromotor typically turning with 3000 revolutions per minute. Measures for a complicated step-down gear may thus be saved. The shaft connecting the multi-turn actuation with the worm wheel may be very simple since it turns with a relatively high number of revolutions, the torque to be transmitted being thus small. Accordingly, the shaft may have a small section and may be made of synthetic material for example. It preferably is a flexible shaft.
The firm arrangement of the spindle in the first adjusting element allows a very simple constructional design. Although the spindle nut has to be rotatably borne in the second adjusting element, easy solutions are available therefor. The whole arrangement may particularly be installed with relatively small measurements.
The invention makes it possible to install an adjusting device with very easy means so that it is light in weight, highly reliable, easy to design for locking in case of acceleration due to an accident and relatively easy to install and to service.
In a preferred embodiment of the invention, the spindle nut is arranged in a holder connected with the second adjusting part and provided with an opening for the spindle. The connection of this holder with the second adjusting part provides a radial spacing from the spindle. In case of an acceleration occurring between the first and the second adjusting element due to an accident, the spacing generates a force on the holder that strives to tilt it.
Thanks to the adequate size of the opening for the spindle, the edge of the holder's opening gets in touch with the thread of the spindle when the holder is bending due to an accident. The holder and the spindle are thus getting interlocked. The misplacement induced between the two adjusting elements by the forces generated by the accident is thus at least slowed down, normally it is hindered so much that it comes to a standstill.
In a preferred embodiment, the holder mentioned above has a base and two flanges projecting from said base. The opening for the free passage of the spindle is located in each flange. The two flanges are particularly parallel to one another. Such a holder allows the spindle nut to be received and borne in an easy way. It also has the above-mentioned advantages of interlocking in case of acceleration forces generated by an accident and acting upon the area between the first and the second adjusting element.
The holder is constructed so that, in case of an accident, it loses its shape under stress and occasions an additional interlocking. When not under stress due to an accident, the holder essentially keeps its shape and—if at all—is at least resilient. Thanks to the additional safety imparted by the holder, the spindle nut as well as the worm wheel may be made of synthetic material.
REFERENCES:
patent: 4645159 (1987-02-01), Terada et al.
patent: 4802374 (1989-02-01), Hamelin et al.
patent: 4805866 (1989-02-01), Aihara et al.
patent: 4838511 (1989-06-01), Terada et al.
patent: 5150872 (1992-09-01), Isomura
patent: 5222402 (1993-06-01), White et al.
patent: 5259257 (1993-11-01), Mouri
patent: 5273242 (1993-12-01), Mouri et al.
patent: 5292164 (1994-03-01), Rees
patent: 5314158 (1994-05-01), Mouri
patent: 5342013 (1994-08-01), Ito et al.
patent: 5349878 (1994-09-01), White et al.
patent: 5823499 (1998-10-01), Ito et al.
Becker Burckhard
Frohnhaus Ernst-Reiner
Cornaby K. S.
Cuomo Peter M.
White Rodney B.
LandOfFree
Vehicle seat with an adjusting device provided with a... 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 with an adjusting device provided with a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vehicle seat with an adjusting device provided with a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2527366