U.S. patent application number 10/478933 was filed with the patent office on 2004-09-30 for safety belt winder comprising a power limitation system which can be actuated according to the strip of belt pulled out.
Invention is credited to Clute, Gunter.
Application Number | 20040188995 10/478933 |
Document ID | / |
Family ID | 7957571 |
Filed Date | 2004-09-30 |
United States Patent
Application |
20040188995 |
Kind Code |
A1 |
Clute, Gunter |
September 30, 2004 |
Safety belt winder comprising a power limitation system which can
be actuated according to the strip of belt pulled out
Abstract
A safety belt roll-up mechanism is provided, and includes a
force limitation device that operates in a multi-stage manner and
has a two-stage torque rod and a pyrotechnically operating
switching device that couples the torque rod, in various clamping
lengths, with a belt shaft. The extent of the belt strap unwound
from the belt shaft is utilized for actuation of the force
limitation device. A ratchet wheel is connected to the belt shaft
via a reduction gear mechanism. A portion of the periphery of the
ratchet wheel has a toothing for engaging the reduction gear
mechanism. A further portion of the periphery of the ratchet wheel
has a switching contour that rests against a contact pin of an
electric switch. The switching contour has a profile that effects
the connection or disconnection of the switching device for the
torque rod.
Inventors: |
Clute, Gunter; (Elmshorn,
DE) |
Correspondence
Address: |
Robert W. Becker & Associates
Suite B
707 Highway 66 East
Tijeras
NM
87059
US
|
Family ID: |
7957571 |
Appl. No.: |
10/478933 |
Filed: |
December 22, 2003 |
PCT Filed: |
May 25, 2002 |
PCT NO: |
PCT/EP02/05765 |
Current U.S.
Class: |
280/806 |
Current CPC
Class: |
B60R 21/0152 20141001;
B60R 2022/287 20130101; B60R 22/341 20130101; B60R 2022/288
20130101; B60R 21/01548 20141001; B60R 22/415 20130101; B60R
22/3413 20130101 |
Class at
Publication: |
280/806 |
International
Class: |
B60R 022/36 |
Foreign Application Data
Date |
Code |
Application Number |
May 31, 2001 |
DE |
201 09 114.3 |
Claims
1 and 2: Cancelled
3. A safety belt roll-up mechanism comprising: a housing; a belt
shaft that is mounted in said housing and serves as a carrier for a
belt strap that can be wound onto and unwound from said belt shaft;
a force limitation device that operates in a multi-stage manner and
has a 2-stage torque rod and a pyrotechnically operating switching
device that couples the torque rod, in various clamping lengths,
with said belt shaft, wherein an extent of belt strap unwound from
said belt shaft is utilized for an actuation of said force
limitation device; a reduction gear mechanism; a ratchet wheel that
is connected to said belt shaft via said reduction gear mechanism,
wherein said ratchet wheel is provided over a portion of a
periphery thereof with a toothing for engagement with said
reduction gear mechanism; and an electric switch that is connected
to said switching device for said torque rod, and that has a
contact pin, wherein said ratchet wheel is provided over a further
portion of its periphery with a switching contour that rests
against said contact pin of said electric switch, and wherein said
switching contour has a profile that effects a connection or
disconnection of said switching device for said torque rod.
4. A safety belt roll-up mechanism according to claim 3, wherein
said switching contour, proceeding from a position of said ratchet
wheel that is provided when said belt strap is essentially entirely
wound up, has a first portion for a contact of said contact pin,
which in this position effects a deactivation of a triggering of
said pyrotechnical switching device, has a second portion that
adjoins said first portion and that, upon rotation of said belt
shaft, is traveled over by said contact pin, whereby in a position
of said contact pin where it rests against said second portion of
said switching contour, said pyrotechnical switching device can be
triggered, and has a third portion that adjoins said second portion
and serves for contacting said contact pin, wherein said contact
pin, when it is in its position where it rests against said third
portion of said switching contour, deactivates the triggering of
said pyrotechnical switching device.
Description
[0001] The invention relates to a safety belt roll-up mechanism
having a belt shaft that is mounted in a housing and serves as a
carrier for a belt strap that can be wound onto and unwound from
the belt shaft, whereby the belt roll-up mechanism is provided with
a force limitation device that operates in a multi-stage manner and
has a torque rod and a switching device that couples the torque
rod, in various clamping lengths, with the belt shaft, and whereby
the extent of the belt strap unwound from the belt shaft is
utilized for the actuation of the force limitation device.
[0002] A safety belt roll-up mechanism having the aforementioned
features is known from DE 27 27 470 A1. The known safety belt
roll-up mechanism has a torque rod as a force limitation device
that at its one end is fixedly connected to the shaft blocking
mechanism, and at its other end is coupled to the belt shaft in
such a way that even when the shaft blocking mechanism is
triggered, the belt shaft, upon torsion of the torque rod, can
still rotate further by a certain amount. Since the adjustment of
the force limitation level should be effected as a function of, in
particular, the size of a vehicle occupant, the known belt roll-up
mechanism has a device for the continuous alteration of the
clamping length of the torque rod, which clamping length, in one
embodiment of the known belt roll-up mechanism, is to be
controllable as a function of the length of the belt strap
withdrawn by connecting a sliding sleeve, which fixes the clamping
length, with the belt shaft via a gear mechanism.
[0003] The known safety belt roll-up mechanism has the drawback
that the sliding sleeve does not represent an adequate reliability
for the fixing of the clamping length of the torque rod, and in
addition, the mechanics for a continuous adaptation of the clamping
length of the torque rod to the rotational speed of the belt shaft,
and hence to the respectively existing belt strap withdrawal, is
complicated.
[0004] It is therefore an object of the invention to simplify the
construction of a safety belt roll-up mechanism having the
aforementioned features, while providing a high operational
reliability.
[0005] The realization of this object, including advantageous
embodiments and further developments of the invention, are provided
in the content of the patent claims, which follow this
description.
[0006] In detail, the invention provides for a two-stage torque rod
having a pyrotechnically operating switching device, and a ratchet
wheel that is connected to the belt shaft via a reduction gear
mechanism, whereby the ratchet wheel is provided over a portion of
its periphery with a toothing for engagement with the reduction
gear mechanism, and over a further portion of its periphery is
provided with a switching contour that rests against a contact pin
of an electric switch that is connected to the switching device for
the torque rod, and the switching device is formed with a profile
that effects a connection or disconnection of the switching device
for the torque rod.
[0007] The invention is, above all, advantageously characterized in
that merely one two-stage torque rod is proposed as a force
limitation device, because therewith the various body sizes of
large occupants or of small women, teenagers and children are
adequately taken into consideration in the respectively fixed
response range. With the reduction to one two-stage torque rod,
one, known pyrotechnical switching device for the two applicable
clamping lengths of the torque rod is also usable, by means of
which, in a very operationally reliable manner, the respective
clamping lengths of the torque rod can be fixed, whereby when an
accident is sensed, the pyrotechnical switching device is triggered
or not depending upon the extent of the belt strap that is unwound
from the belt shaft. If the pyrotechnical switching device is not
triggered, the load level, which is set appropriately high as is
expedient for large vehicle occupants, is effective, whereas when
the switching device is triggered, the clamping length of the
torque rod is altered, and an appropriately low force limitation
level is set. With reference to this, the control of the triggering
readiness of the pyrotechnical switching device is inventively
effected in that the ratchet wheel, which is brought into a
position in conformity with the prevailing belt strap withdrawal,
acts via a switching contour formed thereon upon the contact pin of
an electric switch, whereby the electric switch fixes the
triggering readiness of the pyrotechnical switching device in the
sense previously described. In so doing, a straightforward
construction and a reliable operation of the inventively equipped
belt roll-up mechanism is ensured.
[0008] In detail, to fix the response readiness, one embodiment of
the invention provides that, proceeding from the position of the
ratchet wheel that is provided when the belt strap is fully wound
up, the switching contour has a first portion for the contact of
the contact pin, which in this position effects the deactivation of
the triggering of the pyrotechnical switching device, and a second
portion that adjoins the first portion and that, upon rotation of
the belt shaft, is traveled over by the contact pin, whereby in the
position of the contact pin where it rests against the second
portion of the switching contour, the pyrotechnical switching
device can be triggered, and has a third portion of the switching
contour that adjoins the second portion for contacting the contact
pin, and the contact pin, in its position where it rests against
the third portion of the switching contour, deactivates the
triggering of the pyrotechnical switching device. By dividing the
switching contour into three portions, consideration is given to
the circumstance that where the belt strap is entirely removed or
withdrawn only slightly, no triggering of the pyrotechnical
switching device is to be effected. If the belt strap is withdrawn
to an extent that is customary for smaller vehicle occupants, then,
via the appropriate position of the contact pin that rests against
the switching contour, the triggering readiness of the
pyrotechnical switching device is brought about, so that when an
accident is sensed, the switching device becomes operative. If the
belt strap is withdrawn further by large vehicle occupants, the
contact pin moves along the third portion of the switching contour,
and in this position the triggering readiness of the pyrotechnical
switching device is again deactivated, so that the force limitation
level, which is set high, becomes effective.
[0009] One embodiment of the invention is shown in the drawing, and
will be described subsequently. In the drawing:
[0010] FIG. 1 shows in a side view the system side of a safety belt
roll-up mechanism with control of the force limitation device,
[0011] FIG. 2, in an enlarged view, shows the ratchet wheel as a
component of the control.
[0012] A known belt winder or roll-up mechanism is provided with a
U-shaped housing, in the lateral housing plates of which, of which
one housing plate 10 can be seen in FIG. 1, there is mounted a belt
shaft 11. As can be seen from FIG. 1, the belt shaft 11 is provided
with a shaft gear wheel 13 that is fixedly connected therewith.
Disposed on the lateral housing plate 10 is a sensor 12 that reacts
to the vehicle, and the function of which, for self-blocking belt
roll-up mechanisms, is adequately known from the state of the
art.
[0013] Connected to the externally toothed shaft gear wheel 13 is a
gear mechanism 14 that is comprised of a plurality of gears and by
means of which the ALR-ELR changeover of a belt roll-up mechanism
can be controlled, whereby this function also is not of importance
for the explanation of the present invention, and can be
selectively realized or not on an inventively embodied,
self-blocking, roll-up mechanism.
[0014] Important for the realization of the invention is that a
reduction gear mechanism 15, that comprises two further gears, be
connected to the shaft gear wheel 13; the reduction gear mechanism
acts upon a ratchet wheel 16 that is rotatably mounted on the
housing plate 10. For this purpose, the ratchet wheel 16 is
provided with an external toothing 20 over a portion of its outer
periphery. Associated with the ratchet wheel 16 is an electric
switch 17, out of which projects a switching pin 25 that is
illustrated in FIG. 2 and is guided on a switching contour 21
formed on the ratchet wheel 16, whereby the electric switch 17 is
coupled with a switch housing 18 for the pyrotechnically operated
switching device for adjusting the clamping length of the torque
rod, which forms the force limitation device and is not illustrated
in detail. The belt roll-up mechanism is furthermore provided with
a connector 19 for an energy supply line coming from the
vehicle.
[0015] As can be seen in the detailed view of FIG. 2, the switching
contour 21, which is formed over a portion of the periphery of the
ratchet wheel 16, has three zones, namely a first zone 22, a second
zone 23 and a third zone 24, whereby when the ratchet wheel 16 is
pivoted, the stationary switching or contact pin 25 that rests
against the ratchet wheel travels over these zones 22, 23, 24. In
this connection, the arrangement of the ratchet wheel 16 is such
that in the first zone 22, a position of the switching pin 25 is
effected in which the electric switch 17 establishes a deactivation
of the pyrotechnical switching device, so that if an accident is
sensed, the pyrotechnical switching device is not triggered. This
first zone 22 corresponds to a position of the belt shaft 11 where
the belt strap is entirely or nearly entirely wound up, in other
words, where the safety belt is not being worn or where the belt
strap is withdrawn only slightly, and in this belt withdrawal
position a triggering of the switching device is not required or
not desired.
[0016] If the belt strap is unwound from the belt shaft 11 to an
extent that corresponds to the strapped-in length of belt strap for
smaller persons, the switching pin, with a belt strap unwound in
such a manner, rests against the second zone 23 of the switching
contour 21 of the ratchet wheel 16, and in this position the
position of the switching pin 25 effects an activation of the
triggering readiness or operation in such a manner that when an
accident is sensed, the pyrotechnical switching device is now
triggered and thereby the clamping situation of the torque rod is
altered in such a way that a lower force limitation level
results.
[0017] Finally, if so much belt strap is unwound from the belt
shaft 11 that corresponds to the strapped-in length of larger
vehicle occupants, the third portion or zone 24 comes to rest
against the switching pin, and as a result the switching pin is
brought into a position corresponding to that when it rests against
the first portion 22, in which the triggering of the pyrotechnical
device is deactivated, so that in the absence of actuation of the
pyrotechnical switching device, the high force limitation level is
maintained.
[0018] The features of the subject matter of these documents
disclosed in the preceding description, the patent claims, the
abstract and the drawing can be important not only individually but
also in any desired combination with one another for the
realization of the various embodiments of the invention.
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