[Code of Federal Regulations]
[Title 49, Volume 6]
[Revised as of October 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR571.202a]
[Page 531-546]
TITLE 49--TRANSPORTATION
OF TRANSPORTATION
PART 571_FEDERAL MOTOR VEHICLE SAFETY STANDARDS--Table of Contents
Subpart B_Federal Motor Vehicle Safety Standards
Sec. 571.202a Standard No. 202a; Head restraints; Mandatory applicability begins on September 1, 2009.
S1. Purpose and scope. This standard specifies requirements for head
restraints to reduce the frequency and severity of neck injury in rear-
end and other collisions.
S2. Application & incorporation by reference.
S2.1 Application. This standard applies to passenger cars, and to
multipurpose passenger vehicles, trucks and buses with a GVWR of 4,536
kg or less, manufactured on or after September 1, 2009. However, the
standard's requirements for rear head restraints do not apply to
vehicles manufactured before September 1, 2010, and, for vehicles
manufactured between September 1, 2010 and August 31, 2011, the
requirements for rear head restraints apply only to the extent provided
in S7. Until September 1, 2009, manufacturers may comply with the
standard in this
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Sec. 571.202a, with the standard in Sec. 571.202, or with the European
regulations referenced in S4.3(a) of Sec. 571.202. For vehicles
manufactured on or after September 1, 2009 and before September 1, 2010,
manufacturers may comply with the standard in Sec. 571.202 or with the
European regulations referenced in S4.3(a) of Sec. 571.202, instead of
the standard in this Sec. 571.202a, only to the extent consistent with
the phase-in specified in this Sec. 571.202a.
S2.2 Incorporation by reference.
(a) Society of Automotive Engineers (SAE) Recommended Practice J211/
1 rev. Mar 95, ``Instrumentation for Impact Test--Part 1--Electronic
Instrumentation,'' SAE J211/1 (rev. Mar 95) is incorporated by reference
in S5.2.5(b), S5.3.8, S5.3.9, and 5.3.10 of this section. The Director
of the Federal Register has approved the incorporation by reference of
this material in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. A
copy of SAE J211/1 (rev. Mar 95) may be obtained from SAE at the Society
of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA
15096. A copy of SAE J211/1 (rev. Mar 95) may be inspected at NHTSA's
Technical Information Services, 400 Seventh Street, SW., Plaza Level,
Room 403, Washington, DC, or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/
federal--register/code--of--federal--regulations/ibr--locations.html.
(b) Society of Automotive Engineers (SAE) Standard J826 ``Devices
for Use in Defining and Measuring Vehicle Seating Accommodation,'' SAE
J826 (rev. Jul 95) is incorporated by reference in S3, S5, S5.1, S5.1.1,
S5.2, S5.2.1, S5.2.2, and S5.2.7 of this section. The Director of the
Federal Register has approved the incorporation by reference of this
material in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. A copy of
SAE J826 (rev. Jul 95) may be obtained from SAE at the Society of
Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA
15096. A copy of SAE J826 (rev. Jul 95) may be inspected at NHTSA's
Technical Information Services, 400 Seventh Street, SW., Plaza Level,
Room 403, Washington, DC or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/
federal--register/code--of--federal--regulations/ibr--locations.html.
S3. Definitions.
Backset means the minimum horizontal distance between the rear of a
representation of the head of a seated 50th percentile male occupant and
the head restraint, as measured by the head restraint measurement
device.
Head restraint means a device that limits rearward displacement of a
seated occupant's head relative to the occupant's torso.
Head restraint measurement device (HRMD) means the Society of
Automotive Engineers (SAE) (July 1995) J826 three-dimensional manikin
with a head form attached, representing the head position of a seated
50th percentile male, with sliding scale at the back of the head for the
purpose of measuring backset. The head form is designed by and available
from the ICBC, 151 West Esplanade, North Vancouver, BC V7M 3H9, Canada
(www.icbc.com).
Height means, when used in reference to a head restraint, the
distance from the H-point, measured parallel to the torso reference line
defined by the three dimensional SAE J826 (July 1995) manikin, to a
plane normal to the torso reference line.
Intended for occupant use means, when used in reference to the
adjustment of a seat, positions other than that intended solely for the
purpose of allowing ease of ingress and egress of occupants and access
to cargo storage areas of a vehicle.
Rear head restraint means, at any rear outboard designated seating
position, a rear seat back, or any independently adjustable seat
component attached to or adjacent to a seat back, that has a height
equal to or greater than 700 mm, in any position of backset and height
adjustment, as measured in accordance with S5.1.1.
Top of the head restraint means the point on the head restraint with
the greatest height.
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S4. Requirements. Except as provided in S4.4, S4.2.1(a)(2) and
S4.2.1(b)(2) of this section, each vehicle must comply with S4.1 of this
section with the seat adjusted as intended for occupant use. Whenever a
range of measurements is specified, the head restraint must meet the
requirement at any position of adjustment within the specified range.
S4.1 Performance levels. In each vehicle other than a school bus, a
head restraint that conforms to either S4.2 or S4.3 of this section must
be provided at each front outboard designated seating position. In each
equipped with rear outboard head restraints, the rear head restraint
must conform to either S4.2 or S4.3 of this section. In each school bus,
a head restraint that conforms to either S4.2 or S4.3 of this section
must be provided for the driver's seating position. At each designated
seating position incapable of seating a 50th percentile male Hybrid III
test dummy specified in 49 CFR part 572, subpart E, the applicable head
restraint must conform to S4.2 of this section.
S4.2 Dimensional and static performance. Each head restraint located
in the front outboard designated seating position and each head
restraint located in the rear outboard designated seating position must
conform to paragraphs S4.2.1 through S4.2.7 of this section. Compliance
is determined for the height requirements of S4.2.1 and the backset
requirements of S4.2.3 of this section by taking the arithmetic average
of three measurements.
S4.2.1 Minimum height.
(a) Front outboard designated seating positions. (1) Except as
provided in S4.2.1(a)(2) of this section, when measured in accordance
with S5.2.1(a)(1) of this section, the top of a head restraint located
in a front outboard designated seating position must have a height not
less than 800 mm in at least one position of adjustment.
(2) Exception. The requirements of S4.2.1(a)(1) do not apply if the
interior surface of the vehicle at the roofline physically prevents a
head restraint, located in the front outboard designated seating
position, from attaining the required height. In those instances in
which this head restraint cannot attain the required height, when
measured in accordance with S5.2.1(a)(2), the maximum vertical distance
between the top of the head restraint and the interior surface of the
vehicle at the roofline must not exceed 50 mm for convertibles and 25 mm
for all other vehicles. Notwithstanding this exception, when measured in
accordance with S5.2.1(a)(2), the top of a head restraint located in a
front outboard designated seating position must have a height not less
than 700 mm in the lowest position of adjustment.
(b) All outboard designated seating positions equipped with head
restraints.
(1) Except as provided in S4.2.1(b)(2) of this section, when
measured in accordance with S5.2.1(b)(1) of this section, the top of a
head restraint located in an outboard designated seating position must
have a height not less than 750 mm in any position of adjustment.
(2) Exception. The requirements of S4.2.1(b)(1) do not apply if the
interior surface of the vehicle at the roofline or the interior surface
of the backlight physically prevent a head restraint, located in the
rear outboard designated seating position, from attaining the required
height. In those instances in which this head restraint cannot attain
the required height, when measured in accordance with S5.2.1(b)(2), the
maximum vertical distance between the top of the head restraint and the
interior surface of the vehicle at the roofline or the interior surface
of the backlight must not exceed 50 mm for convertibles and 25 mm for
all other vehicles.
S4.2.2 Width. When measured in accordance with S5.2.2 of this
section, 65 3 mm below the top of the head
restraint, the lateral width of a head restraint must be not less than
170 mm, except the lateral width of the head restraint for front
outboard designated seating positions in a vehicle with a front center
designated seating position, must be not less than 254 mm.
S4.2.3 Front Outboard Designated Seating Position Backset. When
measured in accordance with S5.2.3 of this section, the backset must not
be more than 55 mm, when the seat is adjusted in accordance with S5.1.
For adjustable restraints, the requirements of this section must be met
with the top of the head restraint in any height position of adjustment
between 750 mm and 800
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mm, inclusive. If the top of the head restraint, in its lowest position
of adjustment, is above 800 mm, the requirements of this section must be
met at that position. If the head restraint position is independent of
the seat back inclination position, the head restraint must not be
adjusted such that backset is more than 55 mm when the seat back
inclination is positioned closer to vertical than the position specified
in S5.1.
S4.2.4 Gaps.
All head restraints must meet limits for gaps in the head restraint
specified in S4.2.4.1. For gaps between the seat and head restraint,
adjustable head restraints must meet either the limits specified in
S4.2.4.1 or S4.2.4.2.
S4.2.4.1 Gaps within the head restraint and between the head
restraint and seat using a 165 mm sphere. When measured in accordance
with S5.2.4.1 of this section using the head form specified in that
paragraph, there must not be any gap greater than 60 mm within or
between the anterior surface of the head restraint and anterior surface
of the seat, with the head restraint adjusted to its lowest height
position and any backset position, except as allowed by S4.4.
S4.2.4.2 Gaps between the adjustable head restraint and seat using a
25 mm cylinder. When measured in accordance with S5.2.4.2 of this
section using the 25 mm cylinder specified in that paragraph, there must
not be any gap greater than 25 mm between the anterior surface of the
head restraint and anterior surface of the seat, with the head restraint
adjusted to its lowest height position and any backset position, except
as allowed by S4.4.
S4.2.5 Energy absorption. When the anterior surface of the head
restraint is impacted in accordance with S5.2.5 of this section by the
head form specified in that paragraph at any velocity up to and
including 24.1 km/h, the deceleration of the head form must not exceed
785 m/s\2\ (80 g) continuously for more than 3 milliseconds.
S4.2.6 Height retention. When tested in accordance with S5.2.6 of
this section, the cylindrical test device specified in S5.2.6(b) must
return to within 13 mm of its initial reference position after
application of at least a 500 N load and subsequent reduction of the
load to 50 N 1 N. During application of the
initial 50 N reference load, as specified in S5.2.6(b)(2) of this
section, the cylindrical test device must not move downward more than 25
mm.
S4.2.7 Backset retention, displacement, and strength.
(a) Backset retention and displacement. When tested in accordance
with S5.2.7 of this section, the described head form must:
(1) Not be displaced more than 25 mm during the application of the
initial reference moment of 37 0.7 Nm;
(2) Not be displaced more than 102 mm perpendicularly and posterior
of the displaced extended torso reference line during the application of
a 373 7.5 Nm moment about the H-point; and
(3) Return to within 13 mm of its initial reference position after
the application of a 373 7.5 Nm moment about the
H-point and reduction of the moment to 37 0.7 Nm.
(b) Strength. When the head restraint is tested in accordance with
S5.2.7(b) of this section with the test device specified in that
paragraph, the load applied to the head restraint must reach 890 N and
remain at 890 N for a period of 5 seconds.
S4.3 Dynamic performance and width. At each forward-facing outboard
designated seating position equipped with a head restraint, the head
restraint adjusted midway between the lowest and the highest position of
adjustment must conform to the following:
S4.3.1 Injury criteria. When tested in accordance with S5.3 of this
section, during a forward acceleration of the dynamic test platform
described in S5.3.1, the head restraint must:
(a) Angular rotation. Limit posterior angular rotation between the
head and torso of the 50th percentile male Hybrid III test dummy
specified in 49 CFR part 572, subpart E, fitted with sensors to measure
rotation between the head and torso, to 12 degrees for the dummy in all
outboard designated seating positions;
(b) Head injury criteria. Limit the maximum HIC15 value
to 500. HIC15 is calculated as follows--
For any two points in time, t1 and t2, during
the event which are separated by not more than a 15 millisecond time
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interval and where t1 is less than t2, the head
injury criterion (HIC15) is determined using the resultant
head acceleration at the center of gravity of the dummy head, a
r, expressed as a multiple of g (the acceleration of gravity)
and is calculated using the expression:
[GRAPHIC] [TIFF OMITTED] TR04MY07.164
4.3.2 Width. The head restraint must have the lateral width
specified in S4.2.2 of this section.
S4.4 Folding or retracting rear head restraints non-use positions. A
rear head restraint may be adjusted to a position at which its height
does not comply with the requirements of S4.2.1 of this section.
However, in any such position, the head restraint must meet either
S4.4(a), (b) or (c) of this section.
(a) The head restraint must automatically return to a position in
which its minimum height is not less than that specified in S4.2.1(b) of
this section when a test dummy representing a 5th percentile female
Hybrid III test dummy specified in 49 CFR part 572, subpart O is
positioned according to S5.4(a); or
(b) The head restraint must, when tested in accordance with S5.4(b)
of this section, be capable of manually rotating forward or rearward by
not less than 60 degrees from any position of adjustment in which its
minimum height is not less than that specified in S4.2.1(b) of this
section.
(c) The head restraint must, when tested in accordance with S5.4(b)
of this section, cause the torso reference line angle to be at least 10
degrees closer to vertical than when the head restraint is in any
position of adjustment in which its height is not less than that
specified in S4.2.1(b)(1) of this section.
S4.5 Removability of head restraints. The head restraint must not be
removable without a deliberate action distinct from any act necessary
for upward adjustment.
S4.6 Compliance option selection. Where manufacturer options are
specified in this section, the manufacturer must select an option by the
time it certifies the vehicle and may not thereafter select a different
option for that vehicle. The manufacturer may select different
compliance options for different designated seating positions to which
the requirements of this section are applicable. Each manufacturer must,
upon request from the National Highway Traffic Safety Administration,
provide information regarding which of the compliance options it has
selected for a particular vehicle or make/model.
S4.7 Information in owner's manual.
S4.7.1 The owner's manual for each vehicle must emphasize that all
occupants, including the driver, should not operate a vehicle or sit in
a vehicle's seat until the head restraints are placed in their proper
positions in order to minimize the risk of neck injury in the event of a
crash.
S4.7.2 The owner's manual for each vehicle must--
(a) Include an accurate description of the vehicle's head restraint
system in an easily understandable format. The owner's manual must
clearly identify which seats are equipped with head restraints;
(b) If the head restraints are removable, the owner's manual must
provide instructions on how to remove the head restraint by a deliberate
action distinct from any act necessary for upward adjustment, and how to
reinstall head restraints;
(c) Warn that all head restraints must be reinstalled to properly
protect vehicle occupants.
(d) Describe in an easily understandable format the adjustment of
the head restraints and/or seat back to achieve appropriate head
restraint position relative to the occupant's head. This discussion must
include, at a minimum, accurate information on the following topics:
(1) A presentation and explanation of the main components of the
vehicle's head restraints.
(2) The basic requirements for proper head restraint operation,
including an explanation of the actions that may affect the proper
functioning of the head restraints.
(3) The basic requirements for proper positioning of a head
restraint in relation to an occupant's head position, including
information regarding the
[[Page 536]]
proper positioning of the center of gravity of an occupant's head or
some other anatomical landmark in relation to the head restraint.
S5. Procedures. Demonstrate compliance with S4.2 through S4.4 of
this section with any adjustable lumbar support adjusted to its most
posterior nominal design position. If the seat cushion adjusts
independently of the seat back, position the seat cushion such that the
highest H-point position is achieved with respect to the seat back, as
measured by SAE J826 (July 1995) manikin, with leg length specified in
S10.4.2.1 of Sec. 571.208 of this part. If the specified position of
the H-point can be achieved with a range of seat cushion inclination
angles, adjust the seat inclination such that the most forward part of
the seat cushion is at its lowest position with respect to the most
rearward part. All tests specified by this standard are conducted with
the ambient temperature between 18 degrees C. and 28 degrees C.
S5.1 Except as specified in S5.2.3 and S5.3 of this section, if the
seat back is adjustable, it is set at an initial inclination position
closest to the manufacturer's design seat back angle, as measured by SAE
J826 manikin. If there is more than one inclination position closest to
the design angle, set the seat back inclination to the position closest
to and rearward of the design angle.
S5.1.1 Procedure for determining presence of head restraints in rear
outboard seats. Measure the height of the top of a rear seat back or the
top of any independently adjustable seat component attached to or
adjacent to the rear seat back in its highest position of adjustment
using the scale incorporated into the SAE J826 (July 1995) manikin or an
equivalent scale, which is positioned laterally within 15 mm of the
centerline of the rear seat back or any independently adjustable seat
component attached to or adjacent to the rear seat back.
S5.2 Dimensional and static performance procedures. Demonstrate
compliance with S4.2 of this section in accordance with S5.2.1 through
S5.2.7 of this section. Position the SAE J826 (July 1995) manikin
according to the seating procedure found in SAE J826 (July 1995).
S5.2.1 Procedure for height measurement. Demonstrate compliance with
S4.2.1 of this section in accordance with S5.2.1 (a) and (b) of this
section, using the headroom probe scale incorporated into the SAE J826
(July 1995) manikin with the appropriate offset for the H-point position
or an equivalent scale, which is positioned laterally within 15 mm of
the head restraint centerline. If the head restraint position is
independent of the seat back inclination position, compliance is
determined at a seat back inclination position closest to the design
seat back angle, and each seat back inclination position less than the
design seat back angle.
(a)(1) For head restraints in front outboard designated seating
positions, adjust the top of the head restraint to the highest position
and measure the height.
(2) For head restraints located in the front outboard designated
seating positions that are prevented by the interior surface of the
vehicle at the roofline from meeting the required height as specified in
S4.2.1(a)(1), measure the clearance between the top of the head
restraint and the interior surface of the vehicle at the roofline, with
the seat adjusted to its lowest vertical position intended for occupant
use, by attempting to pass a 25 mm sphere between them. Adjust the top
of the head restraint to the lowest position and measure the height.
(b)(1) For head restraints in all outboard designated seating
positions equipped with head restraints, adjust the top of the head
restraint to the lowest position other than allowed by S4.4 and measure
the height.
(2) For head restraints located in rear outboard designated seating
positions that are prevented by the interior surface of the vehicle at
the roofline or the interior surface of the rear backlight from meeting
the required height as specified in S4.2.1(b)(1), measure the clearance
between the top of the head restraint or the seat back and the interior
surface of the vehicle at the roofline or the interior surface of the
rear backlight, with the seat adjusted to its lowest vertical position
[[Page 537]]
intended for occupant use, by attempting to pass a 25 mm sphere between
them.
S5.2.2 Procedure for width measurement. Demonstrate compliance with
S4.2.2 of this section using calipers to measure the maximum dimension
perpendicular to the vehicle vertical longitudinal plane of the
intersection of the head restraint with a plane that is normal to the
torso reference line of SAE J826 (July 1995) manikin and 65 3 mm below the top of the head restraint.
S5.2.3 Procedure for backset measurement. Demonstrate compliance
with S4.2.3 of this section using the HRMD positioned laterally within
15 mm of the head restraint centerline. Adjust the front head restraint
so that its top is at any height between and inclusive of 750 mm and 800
mm and its backset is in the maximum position other than allowed by
S4.4. If the lowest position of adjustment is above 800 mm, adjust the
head restraint to that position. If the head restraint position is
independent of the seat back inclination position, compliance is
determined at each seat back inclination position closest to and less
than the design seat back angle.
S5.2.4 Procedures for gap measurement.
S5.2.4.1 Procedure using a 165 mm sphere.
Demonstrate compliance with S4.2.4.1 of this section in accordance
with the procedures of S5.2.4.1 (a) through (c) of this section, with
the head restraint adjusted to its lowest height position and any
backset position, except as allowed by S4.4.
(a) The area of measurement is anywhere on the anterior surface of
the head restraint or seat with a height greater than 540 mm and within
the following distances from the centerline of the seat--
(1) 127 mm for seats required to have 254 mm minimum head restraint
width; and
(2) 85 mm for seats required to have a 170 mm head restraint width.
(b) Applying a load of no more than 5 N against the area of
measurement specified in subparagraph (a), place a 165 2 mm diameter spherical head form against any gap such
that at least two points of contact are made within the area. The
surface roughness of the head form is less than 1.6 [micro]m, root mean
square.
(c) Determine the gap dimension by measuring the vertical straight
line distance between the inner edges of the two furthest contact
points, as shown in Figures 2, 3 and 4.
S5.2.4.2 Procedure using a 25 mm cylinder.
Demonstrate compliance with S4.2.4.2 of this section in accordance
with the procedures of S5.2.4.2 (a) through (c) of this section, with
the head restraint adjusted to its lowest height position and any
backset position, except as allowed by S4.4.
(a) The area of measurement is between the anterior surface of the
head restraint and seat with a height greater than 540 mm and within the
following distances from the centerline of the seat--
(1) 127 mm for seats required to have 254 mm minimum head restraint
width; and
(2) 85 mm for seats required to have a 170 mm head restraint width.
(b) Orient a 25 1 mm diameter cylinder such
that its long axis is perpendicular to the seat back angle and in a
vertical longitudinal vehicle plane. Applying a load of no more than 5 N
along the axis of the cylinder, place the cylinder against any gap
within the area of measurement specified in subparagraph (a). The
surface roughness of the cylinder is less than 1.6 [micro]m, root mean
square.
(c) Determine if at least 125 mm of the cylinder can completely pass
through the gap.
S5.2.5 Procedures for energy absorption. Demonstrate compliance with
S4.2.5 of this section in accordance with S5.2.5 (a) through (e) of this
section, with adjustable head restraints in any height and backset
position of adjustment.
(a) Use an impactor with a semispherical head form with a 165 2 mm diameter and a surface roughness of less than 1.6
[micro]m, root mean square. The head form and associated base have a
combined mass of 6.8 0.05 kg.
(b) Instrument the impactor with an acceleration sensing device
whose output is recorded in a data channel that
[[Page 538]]
conforms to the requirements for a 600 Hz channel class as specified in
SAE Recommended Practice J211/1 (March 1995). The axis of the
acceleration-sensing device coincides with the geometric center of the
head form and the direction of impact.
(c) Propel the impactor toward the head restraint. At the time of
launch, the longitudinal axis of the impactor is within 2 degrees of
being horizontal and parallel to the vehicle longitudinal axis. The
direction of travel is posteriorly.
(d) Constrain the movement of the head form so that it travels
linearly along the path described in S5.2.5(c) of this section for not
less than 25 mm before making contact with the head restraint.
(e) Impact the anterior surface of the seat or head restraint at any
point with a height greater than 635 mm and within a distance of the
head restraint vertical centerline of 70 mm.
S5.2.6 Procedures for height retention. Demonstrate compliance with
S4.2.6 of this section in accordance with S5.2.6(a) through (e) of this
section. For head restraints that move with respect to the seat when
occupant loading is applied to the seat back, S5.2.6(a) through (e) may
be performed with the head restraint fixed in a position corresponding
to the position when the seat is unoccupied.
(a) Adjust the adjustable head restraint so that its top is at any
of the following height positions at any backset position--
(1) For front outboard designated seating positions--
(i) The highest position; and
(ii) Not less than, but closest to 800 mm; and
(2) For rear outboard designated seating positions equipped with
head restraints--
(i) The highest position; and
(ii) Not less than, but closest to 750 mm.
(b)(1) Orient a cylindrical test device having a 165 2 mm diameter in plan view (perpendicular to the axis
of revolution), and a 152 mm length in profile (through the axis of
revolution) with a surface roughness of less than 1.6 [micro]m, root
mean square, such that the axis of the revolution is horizontal and in
the longitudinal vertical plane through the longitudinal centerline of
the head restraint. Position the midpoint of the bottom surface of the
cylinder in contact with the head restraint.
(2) Establish initial reference position by applying a vertical
downward load of 50 1 N at the rate of 250 50 N/minute. Determine the reference position after 5.5
0.5 seconds at this load.
(c) Increase the load at the rate of 250 50
N/minute to at least 500 N and maintain this load for 5.5 0.5 seconds.
(d) Reduce the load at the rate of 250 50 N/
minute until the load is completely removed. Maintain this condition for
not more than two minutes.
(e) Increase the load at the rate of 250 50
N/minute to 50 1 N and, after 5.5 0.5 seconds at this load, determine the position of the
cylindrical device with respect to its initial reference position.
S5.2.7 Procedures for backset retention, displacement, and strength.
Demonstrate compliance with S4.2.7 of this section in accordance with
S5.2.7(a) and (b) of this section. The load vectors that generate moment
on the head restraint are initially contained in a vertical plane
parallel to the vehicle longitudinal centerline.
(a) Backset retention and displacement. For head restraints that
move with respect to the seat when occupant loading is applied to the
seat back, S5.2.7(a)(1) through (8) may be performed with the head
restraint fixed in a position corresponding to the position when the
seat is unoccupied.
(1) Adjust the head restraint so that its top is at a height closest
to and not less than:
(i) 800 mm for front outboard designated seating positions (or the
highest position of adjustment for head restraints subject to
S4.2.1(a)(2)); and
(ii) 750 mm for rear outboard designated seating positions equipped
with head restraints (or the highest position of adjustment for rear
head restraints subject to S4.2.1(b)(2)).
(2) Adjust the head restraint to any backset position.
(3) In the seat, place a test device having the back pan dimensions
and torso reference line (vertical center line), when viewed laterally,
with the
[[Page 539]]
head room probe in the full back position, of the three dimensional SAE
J826 (July 1995) manikin;
(4) Establish the displaced torso reference line by creating a
posterior moment of 373 7.5 Nm about the H-point
by applying a force to the seat back through the back pan at the rate of
187 37 Nm/minute. The initial location on the
back pan of the moment generating force vector has a height of 290 mm
13 mm. Apply the force vector normal to the torso
reference line and maintain it within 2 degrees of a vertical plane
parallel to the vehicle longitudinal centerline. Constrain the back pan
to rotate about the H-point. Rotate the force vector direction with the
back pan.
(5) Maintain the position of the back pan as established in
S5.2.7(a)(4) of this section. Using a 165 2 mm
diameter spherical head form with a surface roughness of less than 1.6
[micro]m, root mean square, establish the head form initial reference
position by applying, perpendicular to the displaced torso reference
line, a posterior initial load at the seat centerline at a height 65
3 mm below the top of the head restraint that
will produce a 37 0.7 Nm moment about the H-
point. After maintaining this moment for 5.5 0.5
seconds, measure the posterior displacement of the head form during the
application of the load.
(6) Increase the initial load at the rate of 187 37 Nm/minute until a 373 7.5 Nm
moment about the H-point is produced. Maintain the load level producing
that moment for 5.5 0.5 seconds and then measure
the posterior displacement of the head form relative to the displaced
torso reference line.
(7) Reduce the load at the rate of 187 37 Nm/
minute until it is completely removed. Maintain this condition for not
more than two minutes.
(8) Increase the load at the rate of 187 37
Nm/minute until a 37 0.7 Nm moment about the H-
point is produced. After maintaining the load level producing that
moment for 5.5 0.5 seconds, measure the posterior
displacement of the head form position with respect to its initial
reference position; and
(b) Strength. Increase the load specified in S5.2.7(a)(7) of this
section at the rate of 250 50 N/minute to at
least 890 N and maintain this load level for 5.5
0.5 seconds.
S5.3 Procedures for dynamic performance. Demonstrate compliance with
S4.3 of this section in accordance with S5.3.1 though S5.3.9 of this
section with a 50th percentile male Hybrid III test dummy specified in
49 CFR part 572 subpart E, fitted with sensors to measure head to torso
rotation. The dummy with all sensors is to continue to meet all
specifications in 49 CFR part 572 subpart E. The restraint is positioned
midway between the lowest and the highest position of adjustment.
S5.3.1 Mount the vehicle on a dynamic test platform at the vehicle
altitude set forth in S13.3 of Sec. 571.208 of this part, so that the
longitudinal centerline of the vehicle is parallel to the direction of
the test platform travel and so that movement between the base of the
vehicle and the test platform is prevented. Instrument the platform with
an accelerometer and data processing system. Position the accelerometer
sensitive axis parallel to the direction of test platform travel.
S5.3.2 Remove the tires, wheels, fluids, and all unsecured
components. Remove or rigidly secure the engine, transmission, axles,
exhaust, vehicle frame and any other vehicle component necessary to
assure that all points on the acceleration vs. time plot measured by an
accelerometer on the dynamic test platform fall within the corridor
described in Figure 1 and Table 1.
S5.3.3 Place any moveable windows in the fully open position.
S5.3.4 Seat Adjustment. At each outboard designated seating
position, if the seat back is adjustable, it is set at an initial
inclination position closest to 25 degrees from the vertical, as
measured by SAE J826 (July 1995) manikin. If there is more than one
inclination position closest to 25 degrees from the vertical, set the
seat back inclination to the position closest to and rearward of 25
degrees. Using any control that primarily moves the entire seat
vertically, place the seat in the lowest position. Using any control
that primarily moves the entire seat in the fore and aft directions,
place the seat midway between the forwardmost and rearmost position. If
an adjustment position does not exist midway between
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the forwardmost and rearmost positions, the closest adjustment position
to the rear of the midpoint is used. Adjust the seat cushion and seat
back as required by S5 and S5.1 of this section. If the head restraint
is adjustable, adjust the top of the head restraint to a position midway
between the lowest position of adjustment and the highest position of
adjustment. If an adjustment position midway between the lowest and the
highest position does not exist, adjust the head restraint to a position
below and nearest to midway between the lowest position of adjustment
and the highest position of adjustment.
S5.3.5 Seat Belt Adjustment. Prior to placing the Type 2 seat belt
around the test dummy, fully extend the webbing from the seat belt
retractor(s) and release it three times to remove slack. If an
adjustable seat belt D-ring anchorage exists, place it in the adjustment
position closest to the mid-position. If an adjustment position does not
exist midway between the highest and lowest position, the closest
adjustment position above the midpoint is used.
S5.3.6 Dress and adjust each test dummy as specified in S8.1.8.2
through S8.1.8.3 of Sec. 571.208 of this Part. The stabilized test
temperature of the test dummy is at any temperature level between 69
degrees F and 72 degrees F, inclusive.
S5.3.7 Test dummy positioning procedure. Place a test dummy at each
outboard designated seating position equipped with a head restraint.
S5.3.7.1 Head. The transverse instrumentation platform of the head
is level within \1/2\ degree. To level the head of the test dummy, the
following sequence is followed. First, adjust the position of the H-
point within the limits set forth in S10.4.2.1 of Sec. 571.208 to level
the transverse instrumentation platform of the head of the test dummy.
If the transverse instrumentation platform of the head is still not
level, then adjust the pelvic angle of the test dummy. If the transverse
instrumentation platform of the head is still not level, then adjust the
neck bracket of the dummy the minimum amount necessary from the non-
adjusted ``0'' setting to ensure that the transverse instrumentation
platform of the head is horizontal within \1/2\ degree. The test dummy
remains within the limits specified in S10.4.2.1 of Sec. 571.208 after
any adjustment of the neck bracket.
S5.3.7.2 Upper arms and hands. Position each test dummy as specified
in S10.2 and S10.3 of Sec. 571.208 of this Part.
S5.3.7.3 Torso. Position each test dummy as specified in S10.4.1.1,
S10.4.1.2, and S10.4.2.1 of Sec. 571.208 of this Part, except that the
midsagittal plane of the dummy is aligned within 15 mm of the head
restraint centerline. If the midsagittal plane of the dummy cannot be
aligned within 15 mm of the head restraint centerline then align the
midsagittal plane of the dummy as close as possible to the head
restraint centerline.
S5.3.7.4 Legs. Position each test dummy as specified in S10.5 of
Sec. 571.208 of this part, except that final adjustment to accommodate
placement of the feet in accordance with S5.3.7.5 of this section is
permitted.
S5.3.7.5 Feet. Position each test dummy as specified in S10.6 of
Sec. 571.208 of this part, except that for rear outboard designated
seating positions the feet of the test dummy are placed flat on the
floorpan and beneath the front seat as far forward as possible without
front seat interference. For rear outboard designated seating positions,
if necessary, the distance between the knees can be changed in order to
place the feet beneath the seat.
S5.3.8 Accelerate the dynamic test platform to 17.3 0.6 km/h. All of the points on the acceleration vs.
time curve fall within the corridor described in Figure 1 and Table 1
when filtered to channel class 60, as specified in the SAE Recommended
Practice J211/1 (March 1995). Measure the maximum posterior angular
displacement.
S5.3.9 Calculate the angular displacement from the output of
instrumentation placed in the torso and head of the test dummy and an
algorithm capable of determining the relative angular displacement to
within one degree and conforming to the requirements of a 600 Hz channel
class, as specified in SAE Recommended Practice J211/1, March 1995. No
data generated after 200 ms from the beginning of the forward
acceleration are used in
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determining angular displacement of the head with respect to the torso.
S5.3.10 Calculate the HIC15 from the output of
instrumentation placed in the head of the test dummy, using the equation
in S4.3.1(b) of this section and conforming to the requirements for a
1000 Hz channel class as specified in SAE Recommended Practice J211/1
(March 1995). No data generated after 200 ms from the beginning of the
forward acceleration are used in determining HIC.
S5.4 Procedures for folding or retracting head restraints for
unoccupied rear outboard designated seating positions.
(a) Demonstrate compliance with S4.4 (a) of this section, using a
5th percentile female Hybrid III test dummy specified in 49 CFR part
572, subpart O, in accordance with the following procedure--
(1) Position the test dummy in the seat such that the dummy's
midsaggital plane is aligned within the 15 mm of the head restraint
centerline and is parallel to a vertical plane parallel to the vehicle
longitudinal centerline.
(2) Hold the dummy's thighs down and push rearward on the upper
torso to maximize the dummy's pelvic angle.
(3) Place the legs as close as possible to 90 degrees to the thighs.
Push rearward on the dummy's knees to force the pelvis into the seat so
there is no gap between the pelvis and the seat back or until contact
occurs between the back of the dummy's calves and the front of the seat
cushion such that the angle between the dummy's thighs and legs begins
to change.
(4) Note the position of the head restraint. Remove the dummy from
the seat. If the head restraint returns to a retracted position upon
removal of the dummy, manually place it in the noted position. Determine
compliance with the height requirements of S4.2.1 of this section by
using the test procedures of S5.2.1 of this section.
(b) Demonstrate compliance with S4.4 (b) of this section in
accordance with the following procedure:
(1) Place the rear head restraint in any position meeting the
requirements of S4.2 of this section;
(2) Strike a line on the head restraint. Measure the angle or range
of angles of the head restraint reference line as projected onto a
vertical longitudinal vehicle plane. Alternatively, measure the torso
reference line angle with the SAE J826 (July 1995) manikin;
(3) Fold or retract the head restraint to a position in which its
minimum height is less than that specified in S4.2.1 (b) of this
section;
(4) Determine the minimum change in the head restraint reference
line angle as projected onto a vertical longitudinal vehicle plane from
the angle or range of angles measured in 5.4(b)(2). Alternatively,
determine the change in the torso reference line angle with the SAE J826
(July 1995) manikin.
S6 Vehicles manufactured on or after September 1, 2009, and before
September 1, 2010 (Phase-in of Sec. 571.202a).
(a) For vehicles manufactured for sale in the United States on or
after September 1, 2009, and before September 1, 2010, a percentage of
the manufacturer's production, as specified in S6.1, shall meet the
requirements specified in this Sec. 571.202a without regard to any
option to comply with the standard in Sec. 571.202 or with the European
regulations referenced in S4.3(a) of Sec. 571.202. So long as this
percentage requirement is met, a vehicle may comply with the standard in
this Sec. 571.202a, with the standard in Sec. 571.202, or with the
European regulations referenced in S4.3(a) of Sec. 571.202.
(b) Notwithstanding S6(a), vehicles that are manufactured in two or
more stages or that are altered (within the meaning of 49 CFR 567.7)
after having previously been certified in accordance with part 567 of
this chapter may comply with the standard in this Sec. 571.202a, with
the standard in Sec. 571.202, or with the European regulations
referenced in S4.3(a) of Sec. 571.202.
S6.1 Phase-in percentage. For vehicles manufactured by a
manufacturer on or after September 1, 2009, and before September 1,
2010, the amount of vehicles complying with S6(a) shall be not less than
80 percent of:
(a) If the manufacturer has manufactured vehicles for sale in the
United States during both of the two production years prior to September
1, 2009,
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the manufacturer's average annual production of vehicles manufactured on
or after September 1, 2007, and before September 1, 2010, or
(b) The manufacturer's production on or after September 1, 2009, and
before September 1, 2010.
S6.2 Vehicles produced by more than one manufacturer.
S6.2.1 For the purpose of calculating average annual production of
vehicles for each manufacturer and the number of vehicles manufactured
by each manufacturer under S6.1, a vehicle produced by more than one
manufacturer shall be attributed to a single manufacturer as follows,
subject to S6.2.2.
(a) A vehicle that is imported shall be attributed to the importer.
(b) A vehicle manufactured in the United States by more than one
manufacturer, one of which also markets the vehicle, shall be attributed
to the manufacturer that markets the vehicle.
S6.2.2 A vehicle produced by more than one manufacturer shall be
attributed to any one of the vehicle's manufacturers specified by an
express written contract, reported to the National Highway Traffic
Safety Administration under 49 CFR part 585, between the manufacturer so
specified and the manufacturer to which the vehicle would otherwise be
attributed under S6.2.1.
S7. Vehicles manufactured on or after September 1, 2010, and before
September 1, 2011 (Phase-in of rear seat requirements of Sec.
571.202a).
(a) For vehicles manufactured for sale in the United States on or
after September 1, 2010, and before September 1, 2011 a percentage of
the manufacturer's production of vehicles equipped with rear outboard
head restraints, as specified in S7.1, shall meet the requirements
specified in this Sec. 571.202a for rear head restraints.
(b) Vehicles that are manufactured in two or more stages or that are
altered (within the meaning of 49 CFR 567.7) after having previously
been certified in accordance with part 567 of this chapter are not
subject to the requirement specified in S7(a).
S7.1 Phase-in percentage. For vehicles manufactured by a
manufacturer on or after September 1, 2010, and before September 1,
2011, the amount of vehicles equipped with rear outboard head restraints
complying with S7(a) shall be not less than 80 percent of:
(a) If the manufacturer has manufactured vehicles for sale in the
United States during both of the two production years prior to September
1, 2010, the manufacturer's average annual production of vehicles
equipped with rear outboard head restraints manufactured on or after
September 1, 2008, and before September 1, 2011, or
(b) The manufacturer's production of vehicles equipped with rear
outboard head restraints on or after September 1, 2010, and before
September 1, 2011.
S7.2 Vehicles produced by more than one manufacturer.
S7.2.1 For the purpose of calculating average annual production of
vehicles for each manufacturer and the number of vehicles manufactured
by each manufacturer under S6.1, a vehicle produced by more than one
manufacturer shall be attributed to a single manufacturer as follows,
subject to S7.2.2.
(a) A vehicle that is imported shall be attributed to the importer.
(b) A vehicle manufactured in the United States by more than one
manufacturer, one of which also markets the vehicle, shall be attributed
to the manufacturer that markets the vehicle.
S7.2.2 A vehicle produced by more than one manufacturer shall be
attributed to any one of the vehicle's manufacturers specified by an
express written contract, reported to the National Highway Traffic
Safety Administration under 49 CFR part 585, between the manufacturer so
specified and the manufacturer to which the vehicle would otherwise be
attributed under S7.2.1.
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[72 FR 25514, May 4, 2007]