U.S. patent application number 10/886424 was filed with the patent office on 2005-01-13 for headrest for vehicles.
Invention is credited to Park, Ji-Whan.
Application Number | 20050006941 10/886424 |
Document ID | / |
Family ID | 33455698 |
Filed Date | 2005-01-13 |
United States Patent
Application |
20050006941 |
Kind Code |
A1 |
Park, Ji-Whan |
January 13, 2005 |
Headrest for vehicles
Abstract
Disclosed herein is a headrest for vehicles, which can fixedly
support the passenger's head including the mandible in an
automobile crash, thereby preventing hyper-flexion of the neck. The
headrest comprises a pair of support rods fitted at the top of a
backrest of an automotive vehicle seat, first and second cushion
units rotatably fitted at the top of the respective support rods,
respectively, at least one elastic member for elastically
connecting the first and second cushion units, jaw-restraint
portions formed at opposite sides of the first and second cushion
units, respectively, and stoppers for keeping the support rods in
an immobilized state after the first and second cushion units are
rotated to a predetermined degree. By using the headrest of the
present invention, it is possible to minimize injury to the neck of
the passenger. Especially, the present invention can effectively
protect the passenger's neck, which is further endangered when the
passenger wears a safety belt, and thus can secure the greatest
safety of the passenger.
Inventors: |
Park, Ji-Whan; (Daejeon,
KR) |
Correspondence
Address: |
CANTOR COLBURN LLP
55 Griffin Road South
Bloomfield
CT
06002
US
|
Family ID: |
33455698 |
Appl. No.: |
10/886424 |
Filed: |
July 7, 2004 |
Current U.S.
Class: |
297/406 |
Current CPC
Class: |
B60N 2/885 20180201;
B60N 2/888 20180201; B60N 2002/022 20130101; B60N 2/856 20180201;
B60N 2/853 20180201 |
Class at
Publication: |
297/406 |
International
Class: |
A47C 001/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 8, 2003 |
KR |
2003-46196 |
Jun 15, 2004 |
KR |
2004-44149 |
Claims
1. A headrest for a vehicle comprising: a pair of support rods
fitted at the top of a backrest of an automotive vehicle seat;
first and second cushion units rotatably fitted at the top of the
respective support rods, respectively; at least one elastic member
for elastically connecting the first and second cushion units;
jaw-restraint portions formed at opposite sides of the first and
second cushion units, respectively; and stoppers for keeping the
support rods in an immobilized state after the first and second
cushion units are rotated to a predetermined degree.
2. The headrest as set forth in claim 1, wherein the first and
second cushion units include: a pair of symmetrical seating
portions, respectively, formed at positions corresponding to the
passenger's occipital bone; and a pair of auxiliary cushion members
located below the respective seating portions for supporting the
bottom of the occipital bone.
3. The headrest as set forth in claim 1, wherein each of the
stoppers includes: a case provided inside one of the first and
second cushion units; a latch protruding at one end thereof out of
the case so as to come into contact with the outer periphery of an
associated one of the support rods; a spring disposed inside the
case so as to elastically support the other end of the latch; a
fixing groove defined at the outer periphery of the support rod for
allowing the latch to be lockably engaged therein as a result of
rotation of the corresponding cushion unit; and a pulling member
for pulling out the latch inserted in the fixing groove.
4. The headrest as set forth in claim 3, wherein the pulling member
has: a wire connected at one end thereof to the other end of the
latch, the other end of the wire protruding out of the
corresponding cushion unit; and a pull grip provided at the
outwardly-protruded end of the wire.
5. A headrest for a vehicle comprising: first and second cushion
units rotatably fitted at the top of a pair of support rods,
respectively, the support rods being fitted at the top of a
backrest of an automotive vehicle seat, the first and second
cushion units having jaw-restraint portions formed at opposite
sides thereof, respectively; impact sensors for detecting shock
applied to the vehicle in an automobile crash, and outputting
signals; pressure sensors for detecting shock caused as the
passenger's head collides against the first and second cushion
units, and outputting signals; a control unit for receiving the
signals from the impact sensor and the pressure sensors, and
outputting a control signal for causing rotation of the first and
second cushion units; driving units for rotating the first and
second cushion units according to the control signal; and stoppers
for keeping the first and second cushion units in an immobilized
state after they are rotated by a predetermined degree.
6. The headrest as set forth in claim 5, wherein each of the
stoppers includes: a first detector positioned just inside the
outer periphery of one of the support rods; a second detector
positioned just inside the inner periphery of a sleeve, which
surrounds the support rod, so as to correspond to the first
detector; and a locking member adapted to support the lateral
surface of the support rod according to a signal generated when
positions of the first and second detectors coincide with each
other as a result of rotation of the first and second cushion
units.
7. The headrest as set forth in claim 5, wherein each of the
driving units includes: a servo-motor fixed inside one of the first
and second cushion units, and adapted to be driven by the control
signal; and a power-transmission member for transmitting a rotating
force of the servo-motor to the support rod.
8. A headrest for a vehicle comprising: first and second cushion
units rotatably fitted at the top of a pair of support rods,
respectively, the support rods being fitted at the top of a
backrest of an automotive vehicle seat, the first and second
cushion units having jaw-restraint portions formed at opposite
sides thereof, respectively; impact sensors for detecting shock
applied to the vehicle in an automobile crash, and outputting
signals; a distance adjustment unit for maintaining a constant
distance between the passenger's head and the first and second
cushion units; a control unit for receiving the signals from the
impact sensor, and outputting a control signal for causing pivotal
rotation of the first and second cushion units; driving units for
pivotably rotating the first and second cushion units according to
the control signal; and stoppers for keeping the first and second
cushion units in an immobilized state after they are pivotably
rotated by a predetermined degree.
9. The headrest as set forth in claim 8, wherein the distance
adjustment unit includes: a distance sensor for detecting a
distance between the passenger's occipital bone and the first and
second cushion units, and outputting a signal; the control unit for
detecting the signal from the distance sensor, and outputting a
control signal if the detected distance exceeds a predetermined
value, thereby allowing the first and second cushion units to be
spaced apart from the passenger's head by a distance within a range
of the predetermined value; and a position adjustor for adjusting
positions of the first and second cushion units according to the
control signal from the control unit.
10. The headrest as set forth in claim 8, wherein the vehicle
comprises: a seat sensor for detecting the presence of the
passenger on the seat, and outputting a signal; and a switch for
turning on/off a power source of the distance adjustment unit
according to the signal from the seat sensor.
11. The headrest as set forth in claim 2, wherein each of the
stoppers includes: a case provided inside one of the first and
second cushion units; a latch protruding at one end thereof out of
the case so as to come into contact with the outer periphery of an
associated one of the support rods; a spring disposed inside the
case so as to elastically support the other end of the latch; a
fixing groove defined at the outer periphery of the support rod for
allowing the latch to be lockably engaged therein as a result of
rotation of the corresponding cushion unit; and a pulling member
for pulling out the latch inserted in the fixing groove.
12. The headrest as set forth in claim 6, wherein each of the
driving units includes: a servo-motor fixed inside one of the first
and second cushion units, and adapted to be driven by the control
signal; and a power-transmission member for transmitting a rotating
force of the servo-motor to the support rod.
13. The headrest as set forth in claim 9, wherein the vehicle
comprises: a seat sensor for detecting the presence of the
passenger on the seat, and outputting a signal; and a switch for
turning on/off a power source of the distance adjustment unit
according to the signal from the seat sensor.
Description
BACKGROUND OF THE INVENTION
[0001] 1Field of the Invention
[0002] The present invention relates to a headrest for vehicles,
and more particularly to a headrest for vehicles, which can fixedly
support the passenger's head including the mandible in an
automobile crash, thereby preventing sprain due to hyper-flexion of
the neck.
[0003] 2. Description of the Related Art
[0004] In general, an automotive vehicle seat is provided at the
top of a backrest with a headrest for supporting the passenger's
occiput. Such a headrest serves to relieve shock applied to the
occiput in an automobile crash, thereby minimizing injury to the
passenger.
[0005] However, since headrests are designed to only to support the
passenger's occiput, they have a problem in that they cannot
provide protection to the neck, in spite of the fact that the neck
is an extremely fragile region of the human body, in an automobile
crash.
[0006] In an automobile crash, such as a broadside, a head-on or
rear-end collision, passengers are mostly injured at their neck.
The following table represents percentages of injured passengers
according to body regions. As can be seen from the table, in years
1998 and 2000, the percentage of passengers, which suffered neck
injuries, is the highest, and waist and head injuries follow in
order.
1 Year 1998 Year 2000 Note Neck (%) 62.3% 69.9% 7.3% increase Waist
(%) 33.7% 32.9% 0.8% reduce Head (%) 31.0% 28.0% 3% reduce
[0007] In order to solve the above problem, there have been
conventionally developed neck protecting devices, which are
designed to elastically support the scruff of the passenger's neck
so as to absorb shock generated in an automobile crash. One example
of the conventional neck protecting devices is shown in FIGS. 9a
and 9b, which are, respectively, a plan view and a side view. The
device shown is disclosed in Korean Registration Patent Publication
No. 302153, titled in "AUXILIARY SUPPORT DEVICE OF HEADREST FOR
VEHICLES".
[0008] Referring to FIGS. 9a and 9b, a headrest 200, installed at
the top of a backrest 101 of a conventional automotive vehicle seat
100, comprises a pair of support rods 220 fitted at the top of the
backrest 101, and a head cushion 210 fitted at the top of the
support rods 220 for supporting the passenger's occipital bone.
[0009] Between the head cushion 210 and the backrest 101 an
auxiliary support device 300 is provided for supporting the scruff
of the neck. The auxiliary support device 300 comprises an air bag
310, and a plurality of springs 320 for elastically supporting the
rear surface of the air bag 310.
[0010] Although the above described conventional headrest, provided
with the auxiliary support device, can relieve shock generated at
the moment of an automobile crash by supporting the passenger's
occiput as well as the scruff of the neck at the rear side thereof,
it cannot prevent hyperflexion of the neck caused as the
passenger's head rebounds forward, thereby potentially causing
sprain to the passenger' neck. Now explanation is made in detail to
such sprain to the neck according to kinds of traffic
accidents.
[0011] First, in case of a sudden acceleration or rear-end
collision of an automotive vehicle, the body of the passenger is
moved forward along with the vehicle, but the passenger's head is
pushed rearward due to inertia. This results in a successive
hyperextension-hyperflexion injury, and consequently sprains the
neck. Even in case of a sudden stop or head-on collision of an
automotive vehicle in motion, the passenger's head is pushed
forward by inertia as the vehicle is momentarily stopped. This
similarly results in a successive hyperflexion-hyperextension
injury, and consequently sprains the neck.
[0012] Such sprain is caused due to the fact that the passenger's
head is not stably immobilized so as not to move in an automobile
crash. When the passenger wears a safety belt and thus his/her body
is stably immobilized, especially, a larger moment is applied to
the passenger's neck, resulting in a risk of whiplash due to
hyperflexion. Such a risk has awakened us to the urgent need for
appropriate measures to safeguard passengers.
SUMMARY OF THE INVENTION
[0013] Therefore, the present invention has been made in view of
the above problems, and it is an object of the present invention to
provide a headrest for vehicles, which can fixedly support the
passenger's head including the mandible in an automobile crash,
thereby preventing sprain due to hyperflexion of the neck.
[0014] It is another object of the present invention to provide a
headrest for vehicles, which is designed to closely support the
passenger's occipital bone, thereby allowing shock applied to the
occipital bone in an automobile crash to be rapidly distributed,
and allowing lessen load of the passenger's head to be transmitted
to the backbone.
[0015] It is a further object of the present invention to provide a
headrest for vehicles, which can automatically immobilize the
passenger's head in an automobile crash, such as a broadside,
head-on or rear-end collision.
[0016] It is yet another object of the present invention to provide
a headrest for vehicles, which automatically keeps a constant
distance relative to the passenger's head according to the position
of the head, and thus enables rapid and accurate support of the
passenger's head in an automobile crash.
[0017] In accordance with one aspect the present invention, the
above and other objects can be accomplished by the provision of a
headrest for a vehicle comprising: a pair of support rods fitted at
the top of a backrest of an automotive vehicle seat; first and
second cushion units rotatably fitted at the top of the respective
support rods, respectively; at least one elastic member for
elastically connecting the first and second cushion units;
jaw-restraint portions formed at opposite sides of the first and
second cushion units, respectively; and stoppers for keeping the
support rods in an immobilized state after the first and second
cushion units are rotated to a predetermined degree.
[0018] Preferably, the first and second cushion units include: a
pair of symmetrical seating portions, respectively, formed at
positions corresponding to the passenger's occipital bone; and a
pair of auxiliary cushion members located below the respective
seating portions for supporting the bottom of the occipital
bone.
[0019] In accordance with another aspect the present invention, the
above and other objects can be accomplished by the provision of a
headrest for a vehicle comprising: first and second cushion units
rotatably fitted at the top of a pair of support rods,
respectively, the support rods being fitted at the top of a
backrest of an automotive vehicle seat, the first and second
cushion units having jaw-restraint portions formed at opposite
sides thereof, respectively; impact sensors for detecting shock
applied to the vehicle in an automobile crash, and outputting
signals; pressure sensors for detecting shock caused as the
passenger's head collides against the first and second cushion
units, and outputting signals; a control unit for receiving the
signals from the impact sensor and the pressure sensors, and
outputting a control signal for causing rotation of the first and
second cushion units; driving units for rotating the first and
second cushion units according to the control signal; and stoppers
for keeping the first and second cushion units in an immobilized
state after they are rotated by a predetermined degree.
[0020] In accordance with yet another aspect the present invention,
the above and other objects can be accomplished by the provision of
a headrest for a vehicle comprising: first and second cushion units
rotatably fitted at the top of a pair of support rods,
respectively, the support rods being fitted at the top of a
backrest of an automotive vehicle seat, the first and second
cushion units having jaw-restraint portions formed at opposite
sides thereof, respectively; impact sensors for detecting shock
applied to the vehicle in an automobile crash, and outputting
signals; a distance adjustment unit for maintaining a constant
distance between the passenger's head and the first and second
cushion units; a control unit for receiving the signals from the
impact sensor, and outputting a control signal for causing rotation
of the first and second cushion units; driving units for rotating
the first and second cushion units according to the control signal;
and stoppers for keeping the first and second cushion units in an
immobilized state after they are rotated by a predetermined
degree.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The above and other objects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0022] FIG. 1 is a perspective view illustrating an automotive
vehicle seat provided with a headrest in accordance with a first
embodiment of the present invention;
[0023] FIGS. 2a and 2b are a front view and a plan view,
respectively, illustrating the headrest shown in FIG. 1;
[0024] FIG. 3 is a plan view illustrating the operation of the
headrest shown in FIG. 2b;
[0025] FIG. 4 is a cross-sectional view illustrating a stopper
shown in FIG. 2b;
[0026] FIG. 5 is a cross-sectional view illustrating another
example of the stopper shown in FIG. 2b;
[0027] FIG. 6 is a cross-sectional view illustrating a headrest in
accordance with a second embodiment of the present invention;
[0028] FIG. 7 is a front sectional view illustrating a driving unit
for use in the headrest shown in FIG. 6;
[0029] FIG. 8 is a side sectional view illustrating a headrest in
accordance with a third embodiment of the present invention;
and
[0030] FIGS. 9a and 9b are a plan view and a side view,
respectively, illustrating a headrest of the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] Reference will now be made in greater detail to preferred
embodiments of the invention, examples of which are illustrated in
the accompanying drawings.
[0032] FIG. 1 is a perspective view illustrating an automotive
vehicle seat provided with a headrest in accordance with a first
embodiment of the present invention. FIGS. 2a and 2b are a front
view and a plan view, respectively, illustrating the headrest shown
in FIG. 1.
[0033] As shown in the above drawings, a headrest for vehicles in
accordance with a first embodiment of the present invention, which
is designated as reference numeral 1, comprises: a pair of support
rods 10 fitted at the top of the backrest 101 of the automotive
vehicle seat 100; first and second cushion units 20a and 20b
rotatably installed at the top of the respective support rods 10;
an elastic member 30 for elastically connecting the first and
second cushion units 20a and 20b; a jaw-restraint portions 21a and
21b formed at opposite sides of the first and second cushion units
20a and 20b, respectively; and a pair of stoppers 40a and 40b for
stopping rotation of the first and second cushion units 20a and 20b
after they completely surround the passenger's head.
[0034] Within the first and second cushion units 20a and 20b are
disposed cylindrical sleeves 24a and 24b, respectively, for use in
the insertion of the respective support rods 10. These sleeves 24a
and 24b enable the first and second cushion units 20a and 20b to
freely rotate about the respective support rods 10.
[0035] The jaw-restraint portions 21a and 21b, formed at the
opposite sides of the first and second cushion units 20a and 20b,
protrude forward so that they can surround the passenger's head
including the mandible as the first and second cushion units 20a
and 20b rotate about the support rods 10.
[0036] The stoppers 40a and 40b are disposed within the first and
second cushion units 20a and 20b. At the moment when the
jaw-restraint portions 21a and 21b completely surround the
passenger's head, the stoppers 40a and 40b serve to stop rotation
of the first and second cushion units 20a and 20b in order to
immobilize the passenger's head. Detailed description related to
the operation of the stoppers 40a and 40b will follow with
reference to FIG. 3.
[0037] Meanwhile, at front surfaces of the first and second cushion
units 20a and 20b are symmetrically formed concave seating portions
22a and 22b. These concave seating portions 22a and 22b are
positioned in correspondence to the passenger's occipital bone, so
as to closely support the occipital bone, thereby serving to
allowing shock applied to the occipital bone in an automobile crash
to be rapidly distributed and thus providing protection to the
brain.
[0038] Attached at the front surfaces of the first and second
cushion units 20a and 20b below the concave seating portions 22a
and 22b are auxiliary cushion members 23a and 23b for supporting
the bottom of the occipital bone. These auxiliary cushion members
23a and 23b serve to lessen load of the head to be transmitted to
the backbone, resulting in a comfortable ride for the
passenger.
[0039] Preferably, the auxiliary cushion members 23a and 23b are
made of memory foam so that they come into close contact with the
occipital bone regardless of different occipital bone's shapes in
order to multiply the comfort of the ride.
[0040] FIG. 3 is a plan view illustrating the operation of the
headrest 1 shown in FIG. 2b. FIG. 4 is a cross-sectional view
illustrating the stopper 40b shown in FIG. 2b.
[0041] As shown in FIGS. 3 and 4, when the occiput of the passenger
is rapidly moved back in an automobile crash, and collides against
the first and second cushion units 20a and 20b, by collision shock
applied thereto, the first and second cushion units 20a and 20b are
rotated about the support rods 10 so as to surround the passenger's
occiput.
[0042] Considering the configuration of the stoppers in relation to
the second cushion unit 20b as shown in FIG. 4, the stopper 40b
comprises: a case 41 provided inside the second cushion unit 20b;
the latch 42 protruding at one end thereof out of the case 41 so as
to come into contact with the outer periphery of the support rod 10
within the second cushion unit 20b; the spring 43 disposed inside
the case 41 so as to elastically support the other end of the latch
42; the fixing groove 44 defined at the outer periphery of the
support rod 10 for allowing the latch 42 to be lockably engaged
therein as a result of rotation of the second cushion unit 20b; and
a pulling member 45 for pulling out the latch 42 inserted in the
fixing groove 44.
[0043] Therefore, at the moment that the jaw-restraint portions 21a
and 21b surround the mandible as a result of rotation of the first
and second cushion units 20a and 20b, latches 42 formed at the
stoppers 40a and 40b are coincided with fixing grooves 44 defined
at the outer periphery of the respective support rods 10, and
lockably engaged in the fixing grooves 44 by the elasticity of
springs 43, thereby allowing the first and second cushion units 20a
and 20b to be fixedly maintained at such a rotated position.
[0044] Since the support rods 10 are surrounded by the sleeves 24a
and 24b inside the first and second cushion units 20a and 20b, the
sleeves 24a and 24b have through-bores (not designated),
respectively, for allowing the end of the respective latches 42 to
come into contact with the outer periphery of the respective
support rods 10 therethrough.
[0045] With such a configuration as stated above, shock, which is
generated in the course of the collision of the passenger's head
against the first and second cushion units 20a and 20b, is
exhausted largely by virtue of the elasticity of the elastic member
30, resulting in effective reduction of the shock transmitted to
the brain of the passenger.
[0046] Further, since the jaw-restraint portions 21a and 21b are
immobilized in a state that they completely surround the
passenger's head including the mandible, thereby serving to
effectively restrict further movement of the head, sprain due to
hyperflexion of the neck can be completely prevented.
[0047] After the automobile crash, with reference to FIG. 4, the
latches 42 are removed from the fixing grooves 44 by means of the
pulling members 45, thereby serving to release an immobilized state
of the first and second cushion units 20a and 20b. Each of the
pulling members 45 has a wire 450, which is connected at one end
thereof to the other end of the corresponding latch 42. The other
end of the wire 450 protrudes out of the cushion unit. The pulling
member 45 further has a pull grip 451 provided at the
outwardly-protruded end of the wire 450.
[0048] As both the pull grips 451 are simultaneously pulled, the
latches 42 are drawn from the fixing grooves 44 by means of the
wires 450, thereby allowing the first and second cushion units 20a
and 20b to be released from their immobilized state. The released
first and second cushion units 20a and 20b are automatically
returned to their original positions by the elasticity of the
elastic member 30.
[0049] FIG. 5 is a cross-sectional view illustrating another
example of the stopper shown in FIG. 2b. The shown example is
different from the above embodiment in that springs 43', used to
elastically support the other end of the respective latches 42 are
plate springs rather than coil springs.
[0050] FIG. 6 is a cross-sectional view illustrating a headrest in
accordance with a second embodiment of the present invention. FIG.
7 is a front sectional view illustrating a driving unit for use in
the headrest shown in FIG. 6.
[0051] In an automobile crash, signals from impact sensors (not
shown) mounted in an automotive vehicle are inputted into a control
unit (not shown). In succession, as the passenger's occiput is
rapidly moved back due to such an automobile crash, and collides
against the first and second cushion units 20a and 20b, pressure
sensors (not shown) disposed inside the first and second cushion
units 20a and 20b detect shock applied thereto by the passenger's
head, thereby sending signals to the control unit. Upon receiving
the above described signals, the control unit outputs a control
signal to driving units, so that the first and second cushion units
20a and 20b, and the sleeves 24a and 24b disposed therein are
rotated about the support rods 10 according to the operation of the
driving units. In this way, the first and second cushion units 20a
and 20b are adapted to surround the passenger's head.
[0052] The second embodiment employs a pair of stoppers, which are
different from those of the first embodiment. Considering now the
configuration of the stoppers with reference to FIG. 6, the stopper
comprises: a first detector 46 positioned just inside the outer
periphery of the support rod 10; a second detector 47 positioned
just inside the inner periphery of the sleeve 24b, which surrounds
the support rod 10, so as to correspond to the first detector 46;
and a locking member 48 adapted to support the lateral surface of
the support rod 10 when positions of the first and second detectors
46 and 47 coincide with each other as a result of rotation of the
second cushion unit 20b, thereby serving to stop rotation of the
second cushion unit 20b and maintaining it in an immobilized state.
It will be noted that the above configuration is also applicable to
the stopper of the first cushion unit 20a.
[0053] Considering the locking members 48 of the stoppers in more
detail, they serve to immobilize the first and second cushion units
20a and 20b by making use of a frictional force. Each of the
locking members 48 comprises: a hydraulic or pneumatic cylinder
480; a clamp 481 which comes into close contact with the support
rod 10 under operation of the cylinder 480 so as to generate a
frictional force; and the control unit (not shown) for receiving a
signal generated when positions of the first and second detectors
46 and 47 coincide with each other, and sending a driving signal to
the cylinder 480.
[0054] At the moment when the jaw-restraint portions 21a and 21b
surround the passenger's head including the mandible as a result of
rotation of the first and second cushion units 20a and 20b,
positions of the first and second detectors 46 and 47 coincide with
each other, and thus the resultant signal is sent to the control
unit. Thereby, the control unit drives the cylinder 480 so that the
clamp 481 compresses the lateral surface of the support rod 10,
thereby generating a frictional force for immobilizing the first
and second cushion units 20a and 20b.
[0055] In order to release such an immobilized state of the first
and second cushion units 20a and 20b, the cylinder 480 must be
driven so as to remove a pressure applied to the clamp 481. Such a
pressure removal operation can be easily achieved by installing a
separate operator unit (not shown) for inputting a release signal
to the control unit.
[0056] Referring to FIG. 7 illustrating one of the driving units
adapted to be driven by a control signal from the control unit, in
relation with the second cushion unit 20b, the driving unit,
designated as reference numeral 50, has a servo-motor 51 fixed
inside the second cushion unit 20b, and a power-transmission member
52 for transmitting a rotating force of the servo-motor 51 to the
support rod 10 inside the second cushion unit 20b.
[0057] The power-transmission member 52 transmits the rotating
force of the servo-motor 51 to the second cushion unit 20b, thereby
allowing the second cushion unit 20b to rotate about the support
rod 10. Such a power-transmission member 52 consists of a driving
gear (not designated) provided at the servo-motor 51, and a driven
gear (not designated) fitted around the support rod 10 so as to
engage with the driving gear.
[0058] With such a configuration, if the impact sensors detect an
automobile crash, and successively, the pressure sensors inside the
first and second cushion units 20a and 20b detect shock generated
when the passenger's head collides against the first and second
cushion units 20a and 20b, the control unit drives the servo-motor
51 so as to rotate the driving gear. As the driving gears rotate
around the driven gears fitted to the respective support rods 10,
the first and second cushion units 20a and 20b are automatically
rotated so as to fixedly support the passenger's head.
[0059] In this case, in order to allow the first and second cushion
units 20a and 20b to be rapidly rotated, and be stopped in a state
wherein they fixedly support the passenger's head, data related to
the rotating speed of the servo-motors 51 is inputted to the
control unit.
[0060] Alternatively, a time required for the backward movement of
the passenger's head by inertia in an automobile crash may be
previously calculated and stored in the control unit. Thereby,
after the control unit detects an automobile crash, the first and
second cushion units 20a and 20b are rotated by a predetermined
time interval depending on the stored data.
[0061] FIG. 8 is a side sectional view illustrating a headrest in
accordance with a third embodiment of the present invention. The
present embodiment employs a distance adjustment unit for allowing
the first and second cushion units 20a and 20b at the top of the
backrest 101 to be equally moved toward the passenger's head
according to the position of the head. By such a distance
adjustment unit, therefore, the first and second cushion units 20a
and 20b can closely support the passenger's head.
[0062] Some passengers prefer to lean their head on the headrest,
whereas others prefer to space their head from the headrest. In the
latter case, when a broadside collision occurs, the passenger's
head is moved only laterally without colliding with the headrest.
This makes it impossible to obtain any protection by the
headrest.
[0063] In order to solve the above problem, the present embodiment
enables the first and second cushion units 20a and 20b to be
closely spaced from the passenger's head, thereby allowing the
first and second cushion units 20a and 20b to freely rotate
regardless of the collision direction of an automotive vehicle.
This secures accurate and stable supporting of the passenger's
head.
[0064] The distance adjustment unit comprises: a distance sensor
(S) for detecting a distance between the passenger's occipital bone
and the first and second cushion units 20a and 20b, and outputting
a corresponding signal; the control unit for detecting the signal
from the sensor (S), and outputting a control signal if the
detected distance exceeds a predetermined value; and a position
adjustor 60 for adjusting positions of the first and second cushion
units 20a and 20b according to the control signal. The distance
sensor (S) is selected from among conventional photo-sensors,
ultrasonic sensors, etc. Such a distance sensor (S) is installed
between the support rods 10, and is adapted to measure the distance
between the occiput or neck of the passenger and the support rods
10, thereby allowing the distance to be kept in a constant
value.
[0065] In the present embodiment, as can be seen from FIG. 8, such
a distance adjustment is achieved by adjusting an inclination angle
of the first and second cushion units 20a and 20b. For this, the
support rods 10 are hingedly fixed at their lower ends inside the
backrest 101, and the position adjustor 60, which is also fixed
inside the backrest 101, serves to allow the first and second
cushion units 20a and 20b to be pivotably rotated by a desired
angle. As the position adjustor 60 is used a conventional
cylinder.
[0066] In a state wherein a desired distance value between the
first and second cushion units and the passenger's head is
previously set in the control unit, only when the distance value
detected by the distance sensor (S) exceeds the desired preset
value, the control unit is adapted to output a control signal to
the position adjustor 60.
[0067] As stated above in relation with FIG. 7, the first and
second cushion units 20a and 20b are pivotably rotated in an
automobile crash so as to fixedly support the passenger's head. In
this case, the first and second cushion units 20a and 20b are
automatically pivoted corresponding to the position of the
passenger's occipital bone, thereby keeping a constant distance
relative to the passenger's head. This enables rapid and accurate
support of the passenger's head even if the head is moved laterally
in case of a broadside collision.
[0068] Meanwhile, the present embodiment employs a separate
manually-operated switch provided at an automotive vehicle for
selectively operating the distance adjustment unit as occasion
demands by controlling a power source of the distance adjustment
unit. Further, in order to allow positions of the first and second
cushion units to be selectively adjusted by the distance adjustment
unit only when a passenger rides in the vehicle, the vehicle is
provided with a seat sensor for detecting the presence of the
passenger on the vehicle seat.
[0069] In this case, through the use of the switch for turning
on/off the power source of the distance adjustment unit according
to a signal from the seat sensor, the first and second cushion
units are automatically pivoted in boarding, or automatically
stopped in alighting.
[0070] The seat sensor serves to confirm the presence of the
passenger, and is selectable from among various types of sensors,
for example, pressure-sensitive sensors, which are usually
installed on a vehicle seat for detecting the weight of the
passenger, and sensors, which are usually installed in the vehicle
for detecting ignition of the vehicle.
[0071] As apparent from the above description, the present
invention provides a headrest for vehicles, which can fixedly
support the passenger's head including the mandible in an
automobile crash, thereby preventing sprain due to hyperflexion of
the neck. This has an effect of minimizing injury to the neck of
the passenger. Especially, in spite of the fact that the
passenger's neck is further endangered when the passenger wears a
safety belt, the headrest of the present invention can effectively
protect the passenger's neck, and can secure the greatest safety of
the passenger.
[0072] Further, by forming seating portions at first and second
cushion units of the headrest for closely supporting the
passenger's occiput, shock applied to the occiput in an automobile
crash can be rapidly distributed, resulting in minimization in
transmission of the shock to the brain.
[0073] In addition to the seating portions, by providing auxiliary
cushion members therebelow for supporting the bottom of the
occiput, it is possible to allow lessen load of the passenger's
head to be transmitted to the backbone, resulting in a more
comfortable ride.
[0074] According to the present invention, the first and second
cushion units may be adapted to automatically support the
passenger's head in an automobile crash. This enables more rapid
and accurate support of the head and thus results in more
successful lifesaving.
[0075] Furthermore, according to the present invention, since the
first and second cushion units are adapted to automatically keep a
constant distance relative to the passenger's head according to
position of the head, and thus rapidly support the head, it is
possible to protect the passenger's head in an automobile crash
regardless of the posture of the passenger or the collision
direction of an automotive vehicle.
[0076] Finally, as a distance adjustment unit, for adjusting a
distance between the first and second cushion units and the
passenger's occipital bone, is constructed so as to be
automatically turned on/off according to the presence of the
passenger without requiring a separate switch manipulation,
resulting in simplified control in operation of the first and
second cushion units.
[0077] Although the preferred embodiments of the present invention
have been disclosed for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying
claims.
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