U.S. patent application number 09/754764 was filed with the patent office on 2001-05-17 for pivot mechanism for a vehicle seat and seat fitted with said mechanism.
This patent application is currently assigned to Bertrand Faure Equipements SA. Invention is credited to Cillierre, Francois, Rohee, Rene.
Application Number | 20010001220 09/754764 |
Document ID | / |
Family ID | 9542520 |
Filed Date | 2001-05-17 |
United States Patent
Application |
20010001220 |
Kind Code |
A1 |
Rohee, Rene ; et
al. |
May 17, 2001 |
Pivot mechanism for a vehicle seat and seat fitted with said
mechanism
Abstract
A pivot mechanism comprising first and second frames linked so
as to pivot, in which locking members may co-operate with teeth on
one of the frames in order to lock the mechanism, and at least one
stop member which is joined to the second frame and which is
arranged so that the locking member abuts at an angle against said
stop member if the pivot mechanism is subjected to a pivot torque
in a first direction of rotation whilst the locking member is in
its locked position: if this torque exceeds a threshold value, the
stop member is displaced towards the over-locking member and pushes
it against the teeth of the frame in order to lock it.
Inventors: |
Rohee, Rene; (La chapelle
Biche, FR) ; Cillierre, Francois; (La Selle La Forge,
FR) |
Correspondence
Address: |
MARSHALL, O'TOOLE, GERSTEIN, MURRAY & BORUN
6300 SEARS TOWER
233 SOUTH WACKER DRIVE
CHICAGO
IL
60606-6402
US
|
Assignee: |
Bertrand Faure Equipements
SA
|
Family ID: |
9542520 |
Appl. No.: |
09/754764 |
Filed: |
January 4, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09754764 |
Jan 4, 2001 |
|
|
|
09501248 |
Feb 10, 2000 |
|
|
|
Current U.S.
Class: |
297/367R |
Current CPC
Class: |
B60N 2/236 20150401;
B60N 2/235 20130101 |
Class at
Publication: |
297/367 |
International
Class: |
B60N 002/22 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 25, 1999 |
FR |
99 02349 |
Feb 25, 1999 |
FR |
PCT/FR99/02349 |
Claims
We claim:
1. A pivot mechanism comprising: first and second rigid frames
mounted so as to pivot relative to one another about an axis of
rotation, teeth joined to the first frame and forming at least one
circular arc centred on the axis of rotation, at least one rigid
locking member which is movable relative to the second frame
between a locking position on the one hand, in which it co-operates
with the teeth of the first frame in order to immobilise the first
and second frames relative to one another, and a retracted position
on the other hand, in which said locking member does not mesh with
the teeth of the first frame, control means designed to place the
locking member selectively either in its locked position or in its
retracted position, and at least one rigid stop member which is
joined to the second frame and which is arranged so that the
locking member abuts at an angle against said stop member if the
pivot mechanism is subjected to a pivot torque in a first direction
of rotation whilst the locking member is in its locked position,
said pivot mechanism also having at least one rigid over-locking
member which is movable relative to the second frame between an
active position on the one hand, in which it co-operates with the
teeth of the first frame to immobilise the first and second frames
relative to one another, and a retracted position on the other
hand, in which said over-locking member does not mesh with the
teeth of the first frame, this over-locking member normally being
retained in its retracted position by retaining means designed to
give way if the over-locking member is pushed towards its active
position with sufficient force, and wherein the stop member is
designed to be displaced towards the over-locking member and to
push said over-locking member into its active position by camming
action if the pivot mechanism is subjected to a torque greater than
a first predetermined value in the first direction of rotation.
2. A pivot mechanism as claimed in claim 1, in which the stop
member is designed to undergo plastic deformation if the pivot
mechanism is subjected to a rotation torque greater than said first
predetermined value.
3. A pivot mechanism as claimed in claim 1, additionally
comprising: at least one additional rigid over-locking member which
is movable relative to the second frame between an active position
on the one hand, in which said additional over-locking member
co-operates with the teeth of the first frame in order to
immobilise the first and second frames relative to one another, and
a retracted position on the other hand, in which said additional
over-locking member does not mesh with the teeth of the first
frame, this addition over-locking mechanism normally being retained
in its retracted position by retaining means designed to give way
if the additional over-locking member is pushed to its active
position with sufficient force, and at least one additional rigid
stop member which is joined to the second frame and which is
arranged so that the locking member abuts at an angle against said
additional stop member if the pivot mechanism is subjected to a
pivot torque in a second direction of rotation opposite the first
direction whilst the locking member is in its locked position, the
additional stop member being designed to be displaced towards the
additional over-locking member and to push said additional
over-locking member into its active by camming action if the pivot
mechanism is subjected to a pivot torque greater than a second
predetermined value in the second direction of rotation.
4. A pivot mechanism as claimed in claim 3, in which the additional
stop member is designed to be practically deformed if the pivot
mechanism is subjected to a rotation torque greater than said
second predetermined value.
5. A pivot mechanism as claimed in claim 3, in which the first and
second predetermined values of the rotation torque are between 50
and 200 mdaN.
6. A pivot mechanism as claimed in claim 1, in which the teeth of
the first frame form a full circle and the pivot mechanism
comprises: a number n, ranging between 3 and 6, of locking members
operated by control means, n over-locking members, distributed at
an angle between the locking members, and 2n stop members
distributed at an angle between the locking members and the
over-locking members, the locking members being mounted so as to
slide radially between the stop members, and the over-locking
members having pointed ends with an acute angle which are delimited
between a front face on the one hand, provided with teeth designed
to mesh with the teeth of the first frame, and a side face on the
other hand, arranged in contact with one of the stop members.
7. A pivot mechanism as claimed in claim 6, in which the teeth of
the first frame are directed radially towards the interior, the
locking members, one over-locking members and the stop members
being arranged to the interior of said teeth.
8. A pivot mechanism as claimed in claim 1, in which the retaining
means have matching bosses and indentations some of which belong to
each side face of each locking member and the others of which
belong to the corresponding stop members, these bosses and
indentations co-operating by a reciprocal nesting action so that
the over-locking member is normally retained in its retracted
position.
9. A vehicle seat comprising a backrest mounted so as to pivot on a
seat part by means of at last one pivot mechanism as claimed in
claim 1.
Description
FIELD OF THE INVENTION
1. The present invention relates to the pivot mechanisms used with
vehicle seats and seats fitted with these mechanisms.
2. More specifically, the invention relates to a pivot mechanism
comprising: p1 first and second rigid frames mounted so as to pivot
relative to one another about an axis of rotation,
3. teeth joined to the first frame and forming at least one
circular arc centred on the axis of rotation,
4. at least one rigid locking member which is movable relative to
the second frame between a locking position on the one hand, in
which it co-operates with the teeth of the first frame in order to
immobilise the first and second frames relative to one another,
and, on the other hand, a retracted position in which said locking
member does not mesh with the teeth of the first frame,
5. control means designed to place the locking member selectively
either in its locked position or in its retracted position,
6. and at least one rigid stop member which is joined to the second
frame and positioned so that the locking member abuts at an angle
against said stop member if the pivot mechanism is subjected to a
pivot torque in a first direction of rotation whilst the locking
member is in its locked position.
BACKGROUND OF THE INVENTION
7. Document EP-A-0 720 930 describes an example of a pivot
mechanism of this type, which is totally satisfactory.
OBJECTS AND SUMMARY OF THE INVENTION
8. However, in view of the way in which safety standards are
changing, it would be of interest to make the type of pivot
mechanisms described above stronger in order to prevent these
mechanisms from breaking in the event of an accident, in which case
the pivot mechanisms would be subjected to a particularly high
rotation torque.
9. To this end, the invention proposes a pivot mechanism of the
type in question, which also has at least one rigid over-locking
member which is movable relative to the second frame between an
active position on the one hand, in which it co-operates with the
teeth of the first frame so as to immobilise the first and second
frames relative to one another, and a retracted position on the
other hand, in which said over-locking member does not mesh with
the teeth of the first frame, this over-locking member normally
being maintained in its retracted position by retaining means
designed to give way if the over-locking member is pushed with
sufficient force into its active position, and wherein the stop
member is designed to be displaced towards the over-locking member
and to push said member into its active position by camming action
if the pivot mechanism is subjected to a torque higher than a
predetermined value in the first direction of rotation.
10. As a result of these features, the pivot mechanism is
considerably stronger in the event of impact without at the same
time requiring more complicated control means since the normal
control of the locking member does not act on the over-locking
member.
11. In preferred embodiments of the invention, one and/or the other
of the following features may be incorporated:
12. the stop member is designed to be plastically deformed if the
pivot mechanism is subjected to a rotation torque greater than said
first predetermined value: this plastic deformation allows some of
the mechanical energy of the impact to be absorbed in the event of
an accident, which attenuates the effects of the impact felt by the
passenger occupying the seat;
13. The locking mechanism also has:
14. at least one additional over-locking member which is able to
move relative to the second frame between an active position on the
one hand, in which said additional over-locking member co-operates
with the teeth of the first frame in order to immobilise the first
and second frames relative to one another, and a retracted position
on the other hand, in which said additional over-locking member
does not mesh with the teeth of the first frame, this additional
over-locking member normally being maintained in its retracted
position by retaining means designed to give way if the additional
over-locking member is pushed into its active position with
sufficient force,
15. and at least one additional rigid stop member joined to the
second frame which is positioned so that the locking member abuts
at an angle against said additional stop member if the pivot
mechanism is subjected to a pivot torque in a second direction of
rotation opposite the first direction whilst the locking member is
in its locked position, the additional stop member being designed
to be displaced towards the additional over-locking member and to
push this additional over-locking member into its active position
by camming action if the pivot mechanism is subjected to a pivot
torque greater than a second predetermined value in the second
direction of rotation;
16. the additional stop member is designed so that it is
plastically deformed if the pivot mechanism is subjected to a
rotation torque greater than said second predetermined value;
17. the first and second predetermined values for the rotation
torque range between 50 and 200 mdaN;
18. the teeth of the first frame form a full circle and the pivot
mechanism has:
19. a number n, ranging between 3 and 6, of locking members
activated by the control means,
20. n over-locking members, distributed at an angle between the
locking members and the over-locking members,
21. and 2n stop members distributed at an angle between each
locking member and an over-locking member, the locking members
being mounted so as to slide radially between the stop members and
the over-locking members having pointed ends with an acute angle
which are delimited between a front face on the one hand, having
teeth designed to mesh in the teeth of the first frame, and a side
face on the other hand, arranged in contact with one of the stop
members;
22. the teeth of the first frame are directed radially towards the
interior, the locking members, the over-locking members and the
stop members being arranged to the interior of said teeth;
23. the retaining means have bosses and matching indentations, some
of which belong to each side face of each locking member whilst the
others belong to the corresponding stop members, these bosses and
indentations co-operating normally in a reciprocal nesting action
so that the over-locking member is normally retained in its
retracted position.
24. The invention also relates to a vehicle seat comprising a
backrest which is pivotally mounted on a seat by means of a pivot
mechanism of the type defined above.
BRIEF DESCRIPTION OF THE DRAWINGS
25. Other features and advantages of the invention will become
clear from the description below of two embodiments, given by way
of example and not restrictive in any respect, and with reference
to the appended drawings.
26. Of the drawings:
27. FIG. 1 is a schematic view of a vehicle seat comprising a pivot
mechanism as proposed by the invention,
28. FIG. 2 is a view in axial section of a first embodiment of the
pivot mechanism fitted to the seat illustrated in FIG. 1,
29. FIG. 3 is a view in section along the broken line III-III of
FIG. 2,
30. FIG. 4 shows a detail, in section along the line IV-IV of FIG.
3,
31. FIG. 5 is a view similar to that of FIG. 3, showing the pivot
mechanism after the vehicle in which the seat is fitted has been
involved in an accident, and
32. FIG. 6 is a view similar to that of FIG. 3, showing a second
embodiment of the pivot mechanism proposed by the invention.
MORE DETAILED DESCRIPTION
33. The same references are used in the different drawings to
denote the same or similar components.
34. As schematically illustrated in FIG. 1, the invention relates
to a vehicle seat 1, in particular a front seat of a motor vehicle,
which comprises:
35. on the one hand a seat part 2 mounted on the floor 3 of the
vehicle,
36. and, on the other hand, a backrest 4 mounted on the seat 2 so
as to pivot about a horizontal transverse axis X by means of a
pivot mechanism 5 controlled by a control lever 6 or similar.
37. As illustrated in FIGS. 2 and 3, the pivot mechanism 5
comprises:
38. a metal flange 7 which in this case is stationary and joined to
the rigid frame of the seat part,
39. a metal flange 8 which in this case is movable and joined to
the frame of the backrest,
40. a metal crown 9 which is crimped around the periphery of the
stationary and mobile flanges, delimiting therewith a closed
circular housing,
41. and a locking device 10 which is contained in this housing and
which is designed to immobilise the mobile flange 8 relative to the
stationary flange 7 provided the lever 6 is not operated.
42. In a manner known per se, this locking device may comprise, for
example:
43. at least one and preferably three metal plates or locking
members 11 (more generally, there might be a number n of plates 11,
where n is between 1 and 6 and preferably between 3 and 6), which
are arranged at 120.degree. relative to one another and each of
which has external teeth 12 designed to mesh with a ring of
internal teeth 13 provided in the mobile flange 8, each of these
plates being mounted so as to slide radially in a guide formed by
two stop members 14 which frame the plate 11 in the circumferential
direction and which are joined to the stationary flange 7, the
plates 11 thus being displaceable between a locking position on the
one hand, in which the teeth 12 of these plates mesh with the teeth
13 of the mobile flange so as to block the pivot mechanism, and a
retracted position on the other hand, in which the plates do not
co-operate with the teeth of the mobile flange, each plate also
having at least one pin 15 projecting out axially towards the
mobile flange 8,
44. a metal cam 16 which is joined to a control shaft 17 which is
in turn joined to the lever 6, this cam controlling the sliding
action of the plates 11,
45. a spring 18 which is mounted, for example, in a shaped
indentation 19 provided in the stationary flange 7 and which biases
the control shaft 17 and the cam 16 in the angular direction 20
towards a rest position in which said cam places the plates 11 in
their locking position, said cam being able to pivot in the
opposite angular direction 21 under the action of the control lever
6, enabling the plates to slide towards their retracted position,
thereby releasing the pivot mechanism,
46. and a rigid metal plate 22 which is joined to the cam 16 in
rotation and which extends radially between said cam and the mobile
flange 8 partially covering the plates 11, this plate having three
cut-out sections 23 in which the pin 15 of the plates engage, each
of these pins co-operating with a cam edge 24 delimiting the
corresponding cut-out section radially towards the exterior and
which is of a matching shape so as to displace the corresponding
plate radially towards the interior when the cam rotates in the
direction 21.
47. In addition, in accordance with the invention, the pivot
mechanism also has at least one and preferably three over-locking
members 25 (more generally, there is preferably the same number n
of over-locking members as there are plates 11), each of which is
provided in the form of a rigid metal plate, punched out from a
sheet, for example.
48. These over-locking members are distributed at an angle of 120
degrees relative to one another between the plates 11 and each is
housed between two successive stop members 14.
49. They each have a front face 26 of a circular arc shape, the two
ends thereof being provided with teeth 27 designed to mesh with the
teeth 13 of the mobile flange in order to strengthen the locking
action of the pivot mechanism.
50. In conjunction with the corresponding side face 28 of said
over-locking member, each of the two ends of the front face 26 of
the over-locking member 25 forms a point having an acute angle.
Each of the side faces 28 of the over-locking member is preferably
straight, as seen in a plan view, and is arranged abutting against
a matching surface 29 of the corresponding stop member 14.
51. Furthermore, in order to retain the over-locking member 25 in a
retracted position in which its teeth 27 do not co-operate with the
teeth 13 of the mobile flange, the side faces 28 of each
over-locking member 25 advantageously have at least one boss 30
which nests in a matching indentation 31 of the corresponding stop
member 14 (optionally, the boss 30 could be provided on the stop
member 14 and the indentation 31 in the side face 28 of the
over-locking member 25).
52. The pivot mechanism described above operates as follows.
53. If the passenger in the seat 1 wants to adjust the inclination
of the backrest 4, he operates the lever 6, causing it to rotate in
the angular direction 21, which releases the pivot mechanism 5
enabling the passenger to adjust the inclination of the backrest 4
by acting directly on this backrest, for example by pushing
backwards with his back or, vice versa, by letting it move forward
under the action of one or more springs inside this backrest (not
illustrated).
54. On the other hand, if the passenger is not operating the lever
6, the pivot mechanism will remain in a locked position.
55. If the vehicle is involved in an accident whilst the pivot
mechanism is in this locked position, the mobile flange 7 of the
pivot mechanism may, depending on the circumstances, be subjected
to a very high torque in one or other of the angular directions 20,
21, in this case direction 21 in the example illustrated in FIG.
5.
56. This torque may be due, for example, to:
57. the inertia of the passenger in the case of rear impact or if
the safety belt has a top anchoring point joined to the
backrest,
58. and/or the impact of luggage located to the rear of the seat in
the event of a frontal impact.
59. If the torque reaches a certain threshold value, for example
100 or 150 mdaN (decameters Newton) or more generally a threshold
value between 50 and 200 mdaN, the plates 11 are subjected to very
high forces in the circumferential direction so that each of these
plates causes the stop member 14 located downstream in the
direction in which the force is applied to be plastically deformed,
in this case direction 21: one stop member 25 in two is therefore
displaced in the direction 21 towards the corresponding
over-locking member 25.
60. Under the effect of this plastic deformation, most keenly felt
by the relatively narrow bridges of material 14a linking the stop
members 14 to the stationary flange 7 if these members 14 are made
by a stamping process with said flange 7 (see FIG. 4), each
over-locking member 25 is displaced radially towards the exterior
by the stop members 14, under the action of the cam or pointed
end.
61. As the over-locking members 25 move in this manner, the bosses
30 normally retaining the members 25 in the retracted position are
crushed and/or the corresponding indentations 31 become wider and
the over-locking members 25 shift into the active position
illustrated in FIG. 5 in which their teeth 27 co-operate with the
teeth 13 of the mobile flange 8 so as to assist in immobilising
this flange.
62. Once the over-locking members 25 are in the active position,
they form, in conjunction with the stop members 14 and the plates
11, a continuous circular chain of rigid members meshing with the
teeth 13 of the mobile flange over a major part of its periphery,
which therefore exhibits greater resistance to the torques acting
on the mobile flange.
63. The pivot mechanism is therefore able to withstand torques in
excess of 300 mdaN for a modest additional cost as compared with a
conventional mechanism of the prior art.
64. It should also be pointed out that the plastic deformation of
the stop members 14 enables a not inconsiderable amount of the
mechanical energy induced by the impact on the vehicle to be
absorbed, which helps to absorb the impact experienced by the
passenger occupying the seat.
65. The pivot mechanism would operate in the same way if the torque
were applied to the mobile flange 7 in the direction 20.
66. It should be pointed out that the over-locking plates 25 retain
their final position after the vehicle has been subjected to an
accident: if the impact were high, the over-locking plates 25 would
then hold the backrest locked in position. These plates 25 are
therefore evidence of the amount of damage sustained by the seat
and hence an indication to the user and/or service personnel that
the seat needs to be replaced in order to guarantee the safety of
the passenger.
67. Clearly, the invention is not limited to the example of an
embodiment described above; on the contrary, it includes all
possible variants, in particular those in which:
68. the pivot mechanism might be used to control an adjustment to
the seat other than the inclination of the backrest (for example
the height adjustment of the seat part or another adjustment),
69. those in which the spring 18 is arranged inside the housing
formed by the flanges 7, 8 and the crimped crown 9,
70. those in which the spring 18 is replaced by one or more springs
32 acting directly on the cam 16, it being possible for these
springs 32 to be housed in recesses 33, for example, provided to
the rear of the over-locking members 25, as illustrated in FIG. 6
(the other elements already described are exactly the same or
similar in the embodiment illustrated in FIG. 6, which will
therefore not be described in detail),
71. those in which each over-locking plate 25 has one side face 29
arranged as described above and one side face co-operating with a
stationary stop member, by meshing, belonging to the stationary
flange 7 so that the over-locking plate pivots when it shifts from
its retracted position to its active position,
72. those in which what is referred to as the mobile flange is
joined to circular teeth directed radially towards the exterior, in
which case the locking plates 11 and the over-locking plates 25
will be arranged around these teeth and will have teeth pointing
radially towards the interior,
73. and those in which the locking plates pivot between their
locking position and retracted position, these plates co-operating
as above with stop members by deforming them if the vehicle is
subjected to a violent impact so as to drive the over-locking
members into their active position.
* * * * *