U.S. patent application number 11/695947 was filed with the patent office on 2007-10-04 for harness tension sensor and crash occurrence sensor.
Invention is credited to Said Nakhla.
Application Number | 20070228802 11/695947 |
Document ID | / |
Family ID | 38557743 |
Filed Date | 2007-10-04 |
United States Patent
Application |
20070228802 |
Kind Code |
A1 |
Nakhla; Said |
October 4, 2007 |
HARNESS TENSION SENSOR AND CRASH OCCURRENCE SENSOR
Abstract
A child safety device for a vehicle including a seat including a
shell, a harness including at least one strap for retaining an
occupant in the seat, and a sensor between a device on the strap
and the seat shell indicating a tension status of the harness.
Inventors: |
Nakhla; Said; (Clarkston,
MI) |
Correspondence
Address: |
ADAMS EVANS P.A.
Suite 2350 Charlotte Plaza, 201 South College Street
CHARLOTTE
NC
28244
US
|
Family ID: |
38557743 |
Appl. No.: |
11/695947 |
Filed: |
April 3, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60744239 |
Apr 4, 2006 |
|
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|
Current U.S.
Class: |
297/469 ;
297/217.3; 297/250.1 |
Current CPC
Class: |
B60R 2022/4841 20130101;
B60N 2/2812 20130101; B60N 2002/2815 20130101; B60R 22/48
20130101 |
Class at
Publication: |
297/469 ;
297/217.3; 297/250.1 |
International
Class: |
A47C 31/00 20060101
A47C031/00 |
Claims
1. A child safety device for a vehicle, comprising: (a) a seat
comprising a shell; (b) a harness comprising at least one strap for
retaining an occupant in the seat; and (c) a sensor between a
device on the strap and the seat shell for indicating whether the
harness is sufficiently tensioned.
2. A child safety device according to claim 1 wherein the harness
comprises shoulder straps and a crotch strap.
3. A child safety device according to claim 1 wherein the device on
the strap comprises a strap buckle or slide.
4. A child safety device according to claim 1 wherein the sensor is
positioned on a shell bottom.
5. A child safety device for a vehicle, comprising: (a) a seat
comprising a shell; (b) a harness comprising at least one strap for
retaining an occupant in the seat; and (c) a sensor including
crushable members between a device on the strap and the seat shell
for indicating whether the harness has been severely tensioned.
6. A child safety device according to claim 5 wherein the crushable
members are calibrated to crush at 500-700 pounds of load.
7. A child safety device according to claim 5 wherein the crushable
members comprise ribs or thin walls.
8. A child safety device according to claim 5 wherein the sensor is
a one use, one way type.
9. A child safety device for a vehicle, comprising: (a) a seat
comprising a shell; (b) a harness comprising at least one strap for
retaining an occupant in the seat; (c) a sensor between a device on
the strap and the seat shell for indicating whether the harness is
sufficiently tensioned; and (d) a sensor including crushable
members between the device on the strap and the seat shell for
indicating whether the harness has been severely tensioned.
10. A child safety device according to claim 9 wherein both sensors
are positioned under the seat shell.
Description
TECHNICAL FIELD AND BACKGROUND OF THE INVENTION
[0001] This invention relates to a harness tension sensor and
related apparatus for a child safety seat. Child safety seats have
a harness that includes a pair of shoulder straps that extend from
the back rest of the seat across the shoulders of the seat occupant
and a crotch strap that extends upwardly from the seat bottom to a
point between the legs of the seat occupant. The shoulder straps
extend downwardly and have latch members that interconnect with a
latch affixed to the crotch strap that extends upwardly through a
slot from below the seating surface. A tensioning strap extends
through an opening in the front of the seating surface. When the
shoulder straps are latched into the latch, the tensioning strap is
pulled to place the shoulder straps in tension so that they fit
securely against the anterior aspect of the upper torso of the seat
occupant. Any significant slack in the shoulder straps can increase
the risk of injury by subjecting the seat occupant to an initial
rapid, unrestrained acceleration before the shoulder straps are
tensioned by the forward movement of the seat occupant and bring
the seat occupant to an almost instantaneous stop.
[0002] At present, child safety seats do not incorporate a reliable
means to determine whether the shoulder straps have been properly
tensioned. Some proposals for placing tension sensors in the latch
or elsewhere require wiring in the crotch strap or in other
locations in the seating area. This wiring may be subject to wear
or exposure to moisture during use or cleaning, and thus may be
less than fully desirable for use in situations, such as child
safety seats, that should be cleaned periodically, or are subject
to wetting from spilled drinks or other liquids.
[0003] Also, it may not be fully apparent in all cases that the
shoulder straps have not been fully latched. Thus, inadequate
tension on the shoulder straps may be the result of simple failure
to sufficiently tighten the shoulder straps, or because the
shoulder straps have not been properly latched. In the case of
improper latching, the seat occupant is essentially unprotected in
the event of an impact, since the latch members will exit the latch
and prevent any significant tension at all on the straps during the
initial phase of the impact.
[0004] In addition, present child safety seats to not provide a
positive means of indicating that the seat has been subjected to a
load of sufficient severity to require that the seat not be further
used. A severe impact may stretch the shoulder straps beyond their
elastic limit, warp or damage plastic seat parts, or otherwise
render the seat unsafe for further use. In many cases the damage
will not be readily visible and, in any event, it may not be
apparent to the user that the damage is severe enough to require
seat replacement.
SUMMARY OF THE INVENTION
[0005] Therefore, it is an object of the invention to provide a
harness tension sensor and related apparatus for a child safety
seat.
[0006] It is another object to provide a child safety seat that has
a sensor that detects both that the seat is properly latched and
that the shoulder straps have been properly tensioned.
[0007] It is another object to provide a child safety seat that has
a sensor that detects that the seat is properly latched and that
the shoulder straps have been properly tensioned, wherein the
operative elements of the sensor and related parts are under the
seat and away from wear and liquids.
[0008] It is another object to provide a child safety seat that has
a sensor that detects that the seat has been subjected to a load of
sufficient severity that further use of the seat should not be
permitted.
[0009] These and other objects of the present invention are
achieved in the preferred embodiments disclosed below by providing
a child safety device for a vehicle including a seat including a
shell, a harness including at least one strap for retaining an
occupant in the seat, and a sensor between a device on the strap
and the seat shell for indicating whether the harness is
sufficiently tensioned.
[0010] According to another preferred embodiment of the invention,
the harness includes shoulder straps and a crotch strap.
[0011] According to another preferred embodiment of the invention,
the device on the strap includes a strap buckle or slide.
[0012] According to another preferred embodiment of the invention,
the sensor is positioned on a shell bottom.
[0013] According to another preferred embodiment of the invention,
a child safety device for a vehicle includes a seat including a
shell, a harness including at least one strap for retaining an
occupant in the seat, and a sensor including crushable members
between a device on the strap and the seat shell for indicating
whether the harness has been severely tensioned.
[0014] According to another preferred embodiment of the invention,
the crushable members are calibrated to crush at 500-700 pounds of
load.
[0015] According to another preferred embodiment of the invention,
the crushable members comprise ribs or thin walls.
[0016] According to another preferred embodiment of the invention,
the sensor is a one use, one way type.
[0017] According to another preferred embodiment of the invention,
a child safety device for a vehicle includes a seat including a
shell and a harness including a strap for retaining an occupant in
the seat. The device further includes a sensor between a device on
the strap and the seat shell for indicating whether the harness is
sufficiently tensioned, and a sensor including crushable members
between the device on the strap and the seat shell for indicating
whether the harness has been severely tensioned.
[0018] According to another preferred embodiment of the invention,
both sensors are positioned under the seat shell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Embodiments of the invention may be best understood by
reference to the following description in conjunction with the
accompanying drawing figures in which:
[0020] FIG. 1 is front perspective view of an embodiment of a child
safety seat;
[0021] FIG. 2 is side view of the embodiment of the child safety
seat;
[0022] FIG. 3 is an enlarged view of an embodiment of a crash
occurrence assembly for the child safety seat;
[0023] FIG. 4 is a top view of an embodiment of a sensor
housing;
[0024] FIG. 5 is a side view of the sensor housing of FIG. 4
showing crash occurrence and belt tension sensors;
[0025] FIG. 6 is an enlarged side view of an embodiment of a belt
tension sensor in a closed state;
[0026] FIG. 7 is an enlarged side view of an embodiment of a crash
occurrence sensor in an open state;
[0027] FIG. 8 is a side view of the crash occurrence sensor of FIG.
7 in the closed state;
[0028] FIG. 9 is an enlarged side view of an embodiment of a belt
tension sensor in an open state;
[0029] FIG. 10 is a side view of the belt tension sensor of FIG. 9
in the closed state;
[0030] FIG. 11 is an enlarged side view of an embodiment of a
combined belt tension and crash occurrence sensor showing the belt
tension sensor in a closed state; and
[0031] FIG. 12 is a side view of the embodiment of FIG. 11 showing
the crash occurrence sensor in a closed state.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] FIGS. 1-3 show a child safety seat 12 and harness 20
including a pair of shoulder straps 23 and 25 for insertion into a
buckle 22 fixed to a crotch strap 26 that passes through a slot 29
in a seat shell 14 and is fixed at a distal end to a three bar
slide 27. A sensor housing 18 is positioned between the seat shell
14 and the three bar slide 24.
Tension Sensor
[0033] As shown in FIGS. 1-6 and 9-11, the tension sensor 10 is
designed to insure that sufficient tension is present in a harness
20 for a child safety seat 12. The sensor 10 may be associated with
a buckle 22 or three bar slide 24 that captures one end of the
crotch strap 26. The buckle 22 or three bar slide 24 is
sufficiently large to retain the crotch strap 26 in the correct
position between the legs of the seat occupant by bearing against
the underside or bottom of the plastic seat bottom shell 14 with
the strap 26 itself extending through the slot 29 and into the
crotch area of the seat occupant.
[0034] In one embodiment shown in FIGS. 1-3, the sensor 10 sits
between the crotch strap buckle 22, or, a three-bar slide 24, and
the plastic seat bottom shell 14. When sufficient tension is on the
harness 20, the crotch strap 26 or three bar slide 24 is pulled
upwardly thorough the slot 29 in the seat 12 bottom, and the buckle
22 or three bar slide 24 presses the sensor 10 against the seat
bottom shell 14.
[0035] In one embodiment, a plunger 42 or other mechanism urges the
sensor 10 from a normally open position to a closed position when
there is too little tension on the harness 20. Closing the circuit
allows a current to flow to a device such as a microprocessor that
can activate any conventional alert means, such as a bell, buzzer,
light, etc. that the harness needs to be further tightened.
Latching the harness correctly and/or further tightening the
harness 20 opens the circuit and deactivates the alert.
[0036] Conversely, the circuit can be designed so that the circuit
is normally closed when the tension is correct, as shown in FIGS. 6
and 10, and in the open condition when the tension must be
increased, as shown in FIGS. 5 and 9. The open circuit is sensed
and a microprocessor generates the alert, as described above.
[0037] The sensor may be any suitable pressure-sensitive on-off
type switch, for example, spring-loaded contacts 13 that engage a
complementary contact 15 in order to close the circuit, as shown in
FIGS. 5 and 9-12.
Crash Occurrence Sensor
[0038] As shown in FIGS. 1-5, 7-8 and 11-12, in another aspect of
the invention, the child safety seat 12 has a sensor 11 that
detects that the seat 12 has been subjected to a load of sufficient
severity that further use of the seat 12 should not be permitted.
This crash occurrence sensor 11 may be used together with or
separate from the tension sensor 10 described above. FIG. 11 shows
an embodiment of the invention wherein a plunger 42 indicates first
that belt tension is sufficient and also indicates when the harness
20 has been subjected to a more severe load.
[0039] In general, the crash occurrence sensor 11 is a "one use,
one way" sensor. When it detects a severe load on a single
occasion, it closes a circuit that provides an alert that the seat
12 has potentially been subjected to sufficient damage that the
seat 12 should be discarded and not further used. The circuit is
designed not to return to a normal state.
[0040] More specifically, the crash occurrence sensor 110 includes
crushable members 77 that are calibrated to crush at, for example,
500-700 lbs. of load. Crushing of the crushable members 77, as
shown in FIGS. 8 and 12, closes a circuit. The crushable members 77
may be ribs, thin walls, foam or honeycomb materials, or any other
suitable material that has the ability to resist crushing up to a
predetermined point, and then reliably crush to a degree sufficient
to close a circuit.
[0041] As also shown in the attached drawings, the crushable
members 77 may be positioned on an upper surface of the crotch
strap buckle 22, or a three-bar slide 24, so that in the event of a
severe load, the buckle 22 or slide 24 is pulled upwardly against
the plastic shell 14 of the seat by the crotch strap 26 so severely
that the crushable members 77 are crushed against the plastic shell
14, engaging the contact 17 and 19 to close a circuit. With less
severe loads, the crushable members 77 do not crush to any
appreciable degree.
[0042] As is apparent from the foregoing, all of the electronic
features of both the tension sensor 10 and the crash occurrence
sensor 11 may be placed under the seat shell 14 away from the seat
occupant and possible wear and damage.
* * * * *