Bsi bs en 01728 2012 (2013)

19 c Seating without a back/stools Key A Seat loading point – seating with backs B Back loading point C Seat loading point – seating without backs Figure 9 — Determination of seat and b

Preliminary preparation

Furniture must be tested upon delivery, with knock-down pieces assembled according to the provided instructions In cases where multiple assembly options are permitted, the least favorable configuration should be utilized for testing Prior to testing, all knock-down fittings must be securely tightened, and any additional tightening should only occur if explicitly instructed by the manufacturer.

Seating intended for permanent installation must be securely mounted in accordance with the manufacturer's guidelines to a structure that accurately represents the service installation This structure must possess adequate strength and rigidity to ensure that it does not influence the test outcomes.

Unless otherwise specified by the manufacturer, the sample for test shall be stored in indoor ambient conditions for at least 24 h immediately prior to testing

Tests will be conducted under controlled indoor conditions If the temperature during testing falls outside the range of 15°C to 25°C, the highest and lowest temperatures must be documented in the test report.

Application of forces

In durability and static load tests, it is essential to apply test forces slowly to minimize dynamic load effects Additionally, during durability tests, the forces must be applied at a controlled pace to prevent kinetic heating.

Unless otherwise stated, static forces shall be maintained for (10 ± 2) s Unless otherwise stated, durability forces shall be maintained for (2 ± 1) s

The forces may be replaced by masses The relationship 10 N = 1 kg shall be used.

Tolerances

Unless otherwise stated, the following tolerances are applicable to the test equipment:

 Forces: ± 5 % of the nominal force;

 Velocities: ± 5 % of the nominal velocity;

 Masses: ± 1 % of the nominal mass;

 Dimensions: ± 1 mm of the nominal dimension;

 Angles: ± 2 o of the nominal angle

The accuracy for the positioning of loading pads and impact plates shall be 5 mm

NOTE For the purposes of uncertainty measurement, test results are not considered to be adversely affected when the above tolerances are met

The equipment must allow for natural movement without restricting deformation of the unit or component, ensuring it can adapt to any changes during testing.

All loading pads must be designed to pivot according to the direction of the applied force, with the pivot point positioned as near as feasible to the load surface.

If a loading pad tends to slide, use a slip resistant material between the loading pad and the foam for loading pads (5.8)

The tests can be conducted on any appropriate device, as the outcomes rely solely on the accurate application of forces rather than the specific apparatus used However, exceptions exist for impact tests, which must utilize the apparatus specified in sections 5.9 and 5.10, and for the arm rest durability test, which requires the apparatus outlined in section 5.11.

5.1 Loading point template, consisting of two shaped members (see Figure 1) fastened together by a pivot at one end

The designed contours of the shaped surfaces are intended to integrate seamlessly with the upholstery To achieve this, the loading point template requires an additional mass of 20 kg, with a tolerance of +1 kg and -0 kg, applied at the seat loading point The apparatus is illustrated in Figure 2.

Figure 1 — Loading surface curves for seat and back loading point template

3 Straight edge for the determination of seat or back inclination

So that the template can be positioned easily with the two members at 90° to each other, a line is drawn on the back portion

5.2 Floor, which is horizontal, flat and rigid with a smooth surface

For the back and arm rest impact tests (6.25 and 6.26), as well as the drop test (6.27) and backwards fall test (6.28), the floor must be covered with a 2 mm thick rubber layer, exhibiting a hardness of (85 ± 10) IRHD in accordance with ISO 7619-2:2010.

Stops are essential for preventing items from sliding while allowing a tilt of no more than 12 mm However, if the item's design requires higher stops, the minimum height necessary to prevent movement should be utilized.

5.4 Seat loading pad, which is anaturalistically shaped rigid indenter with a hard, smooth surface having overall dimensions within the limits shown in Figure 3

For details of design, see Annex A

Figure 3 — Seat loading pad – Overall dimensions

The smaller seat loading pad is a rigid circular object with a diameter of 200 mm Its loading surface features a convex spherical curvature with a radius of 300 mm and a front edge radius of 12 mm.

Figure 4 — Smaller seat loading pad

The back loading pad is a rigid rectangular structure measuring 200 mm in height and 250 mm in width Its loading surface features a curved design across the width, characterized by a convex cylindrical curvature with a radius of 450 mm, and all front edges are rounded with a 12 mm radius.

Figure 5 — Back loading pad 5.7 Local loading pad, which is a rigid cylindrical object 100 mm in diameter, with a flat face and a

5.8 Foam for use with loading pads

A flexible foam layer with a bulk density of (120 ± 25) kg/m³ and thickness options of 25 mm or 10 mm is to be affixed to the loading pads or placed between the loading pad and the test structure.

The seat impactor is shown in Figure 6 The impactor is comprised of the following elements

The circular body, measuring 200 mm in diameter, is positioned above the striking surface and is supported by helical compression springs, allowing it to move freely along a line perpendicular to the central area of the striking surface The mass of the body and its components, excluding the springs, is (17 ± 0.1) kg, while the total mass of the entire apparatus, including the mass, springs, and striking surface, is (25 ± 0.1) kg.

The springs shall be such that the nominal spring rate of the combined spring system is (7 ± 2) N/mm and the total friction resistance of the moving parts is less than 1 N

The spring system must be compressed to an initial static force of (1 040 ± 5) N, with a minimum compression movement of 60 mm from the initial compression point to the fully closed position of the springs.

The striking surface shall be a rigid circular object, 200 mm in diameter, the face of which has a convex spherical curvature of 300 mm radius with a 12 mm front edge radius

1 Joint of lifting device not inhibiting free fall

5.10 Impact hammer, with a cylindrical pendulum head having a mass of 6,5 kg, supported from a pivot by a steel tube of 38 mm in diameter and with a wall thickness of 2 mm

The pendulum arm shall be pivoted by a low friction bearing (see Figure 7)

1 Pendulum head, steel mass 6,4 kg

3 Rubber (50 ± 10) IRHD according to ISO 7619-2:2010

4 Pendulum arm, length 950; steel tube ∅ 38 x 2; mass 2 kg ± 0,2 kg

Figure 7 — Impact hammer 5.11 Arm rest durability test apparatus, capable of applying a cyclic force simultaneously to both arm rests of a seat

The forces shall be applied through an arm rest loading device in principle operating as shown in Figure 8

The apparatus must apply forces at different angles to the vertical and be adjustable both vertically and horizontally, as outlined in section 6.20 It should also be able to accommodate the deformation of the arm rests during testing Additionally, the loading pad must measure 100 mm in length, with the force applied through its center.

Figure 8 — Arm rest durability test – Arm rest loading device 5.12 Test surface for castor testing, which is a horizontal, flat smooth and rigid steel surface

5.13 Test weights drop test , which are discs with a mass of 10 kg each, diameter 350 mm and a thickness of 48 mm

6 Test procedures - Chairs other than Work Chairs

General

Unless otherwise specified, the tests shall be carried out in the configuration most likely to cause failure

If a test cannot be conducted according to the specified standard, such as when a loading pad is unsuitable for force application due to product design, the test should be performed to the greatest extent possible as outlined.

Except in the case of test 6.13, a layer of foam (5.8) shall be positioned between the loading pads and the test structure.

Determination of seat and back loading points

General

The seat and back loading points shall be determined using the template as specified in 5.1 in the manner specified in 6.2.2 or 6.2.3

In some cases, it may not be possible to determine the loading points by means of the template

The seat loading point must be positioned 175 mm forward of the seat/back junction, or at the nearest point that permits the application of the seat force.

When the seat geometry prevents the back force from being applied at the specified point, it should instead be applied at the nearest available point, either above or below the back The bending moment, calculated as the back force multiplied by the distance from the seat to the back loading point, will remain unchanged.

To determine the number of seats when the total seat length is not clearly defined, divide the total length (in mm) by 600 mm and round to the nearest whole number This calculation will yield the number of seats, which can then be divided into equal lengths.

Seating with a back rest

For seating with adjustable back rests, set the back rest to its most upright position

Adjust the template such that the angle between the seat and back portions is 90º

Position the loaded template (5.1) on the centreline of the seat as far towards the rear as possible

To ensure proper alignment for upholstered and flexible seating, adjust the template by pushing the back loading section against the backrest until it makes full contact This allows the shape of the seat portion of the template to match the contours of the seat (refer to Figure 9 a)).

To properly adjust rigid seating, ensure the template's back loading portion is pushed fully against the back rest, while confirming that point A on the template makes contact with the seating surface (refer to Figure 9 b)).

When a template can be positioned in multiple ways, select the position that creates the smallest angle between the seat and back portions, ensuring this angle is never less than 90° Mark the necessary loading positions based on the template, and if applicable, repeat these steps for any additional seat(s).

Seating without a back rest

Position the template (5.1) at a 90° angle using mark C, as illustrated in Figure 2 Place it at each seating position indicated in Figure 9 c) and mark the necessary loading point from the template.

18 a) Upholstered/flexible seating with a back b) Rigid seating with a back

19 c) Seating without a back/stools Key

A Seat loading point – seating with backs

C Seat loading point – seating without backs

Determination of Back Angle

The angle of inclination of the backrest from the horizontal (∅) is determined by measuring the slope of the straight edge of the seat loading point template when it is properly aligned.

Seat static load and back static load test

Only the vertical seat static force shall be applied to items without a back rest

The test will be conducted in specific positions: a) on the seat of a single-seat item; b) simultaneously on both seats for a two-seat item; and c) simultaneously on two adjacent seats in the most adverse configuration for items with three or more seats If the most adverse position is indeterminate, testing will occur at a maximum of two locations.

When conducting the test, ensure that the untested seat(s) are loaded with the specified weight, applying the load at the designated seat loading position for parts not undergoing testing.

Seating with a fixed back position, and seating with reclining mechanisms that cannot be locked into a fixed position, shall be tested for the number of cycles specified

Seating fitted with a spring rocking action base or tilting mechanism that has a tension adjustment, shall be tested with the tension adjusted to its maximum value

Seating with adjustable reclining mechanisms must undergo testing for half the specified number of cycles in the most upright position and half in the most extreme reclined position.

The most unfavorable seating position is typically regarded as 10° above the fully reclined angle for fully adjustable mechanisms, or one position higher than the fully reclined setting for seats equipped with multi-position backrests.

Prevent the item from moving rearwards by placing stops (5.3) behind the rear legs, feet or castors (see Figure 11)

Position the seat loading pad(s) (5.4) at the seat loading position(s) determined by the loading point template (5.1)

For items with a back, align the centers of the back loading pad(s) (5.6) either at the designated back loading position from the loading point template or 100 mm below the top of the back, choosing the lower option Ensure that all adjustable backs are positioned in the most unfavorable setting.

The angle of back rest inclination ỉ (6.3), in degrees shall be measured

Table 1 — Determination of seat and back force Angle of back rest inclination ỉ Seat force F 1 (N) Back force F 2 (N)

Back rest set to an angle 70º or more to the horizontal Specified force Specified force

Back rest set to an angle of less than

70º, but not less than 55º to the horizontal

Specified force x Sin (ỉ) ((ỉ/60°) – 0,1666) Specified force x

55º to the horizontal 0,75 x Specified force 0,75 x Specified force x Cos ỉ

Apply the downward force F1 (determined in Table 1) per seat loading pad (5.4) to the seats (see a), b) and c) above)

To ensure proper loading, apply the back force F2, as specified in Table 1, to each back loading pad (5.6) while maintaining the seat force When fully loaded, the back force should be directed at an angle of (90 ± 10)º relative to the back rest plane.

To prevent rearward overturning of the item, reduce the force F2 to a level that maintains stability without falling below the minimum required force If the item still shows a tendency to overturn at this adjusted force, increase F1 until the overturning tendency is eliminated.

Remove the F2 and then the F1 This constitutes one cycle

F1 shall be maintained as long as necessary for the F2 to be applied (4.2)

In cases where the standard testing procedure cannot be implemented, the seat and back tests can be conducted sequentially This involves performing the seat test first, followed by the back test while applying a static load on the seat.

The most unfavorable seating position is typically regarded as 10° above the fully reclined angle for fully adjustable mechanisms, or one position higher than the fully reclined setting for seats with multi-position backrests.

For items with a back, align the centers of the back loading pad(s) (5.6) either at the designated back loading position from the loading point template or 100 mm below the top of the back, choosing the lower option Additionally, all adjustable backs must be positioned in the most unfavorable setting.

70º, but not less than 55º to the horizontal

Specified force x Sin (ỉ) ((ỉ/60°) – 0,1666) Specified force x

55º to the horizontal 0,75 x Specified force 0,75 x Specified force x Cos ỉ

Apply the downward force F1 (determined in Table 1) per seat loading pad (5.4) to the seats (see a), b) and c) above)

To ensure proper loading, apply the back force F2, as specified in Table 1, to each back loading pad (5.6) while maintaining the seat force When fully loaded, the back force should be directed at an angle of (90 ± 10)º relative to the back rest plane.

To prevent rearwards overturning of the item, reduce the force F2 to a level that maintains stability without falling below the minimum required force If the item still shows a tendency to overturn at this adjusted force, increase F1 until the overturning tendency is eliminated.

In cases where the standard testing procedure cannot be implemented, the seat and back tests can be conducted sequentially This involves performing the seat test first, followed by the back test, while applying a static load on the seat.

Replace the existing Table 1 by the following:

Table 1 — Determination of seat and back force Angle of backrest inclination ỉ Seat force F 1 (N) Back force F 2 (N)

Back rest set to an angle 70º or more to the horizontal Specified seat force Specified back force

Back rest set to an angle of less than 70º, but not less than 55º to the horizontal

Specified seat force x Sin (ỉ) ((ỉ/60°) – 0,166 6) Specified seat force x Cos ỉ

Back rest set to an angle of less than 55º to the horizontal 0,75 x Specified seat force 0,75 x Specified seat force x

22 a) Example for chairs b) Example for stools

Seat Front Edge Static Load

Apply the specified force using the seat loading pad (5.4) at a point on the seat centre line 100 mm inwards from the front edge of the structure

For multiple seating units, the static load test on the front edge of the seats must be conducted concurrently with the seat and back static load test During this procedure, the seats not under test should be loaded with the specified weight at the designated loading position.

If the seating tends to overturn, reduce the force(s) to a magnitude that just prevents overturning

Record the actual force(s) used.

Vertical load on back rests

Apply the specified seat load to the seat loading point and maintain for the duration of the test

To apply the designated downward static force, position it at the center line of the back rest, utilizing the seat loading pad (5.4) If the seat loading pad is unavailable, use the smaller seat loading pad (5.5) to exert the force.

When testing multiple seating units, the downward static force must be applied simultaneously at the same positions used for the seat and back static load test Additionally, during the testing process, the seats that are not being tested should be loaded with the specified seat load at the designated loading position.

If the seating tends to overturn, reduce the downwards static force(s) on the back rest to a magnitude that just prevents overturning

Record the actual force(s) used

Horizontal forward static load test on back rests

This test is only applicable to seating fixed to the floor

To conduct the test, apply a horizontal static force on the backrest, positioning it 50 mm below the center of the top This force should be exerted through the smaller seat loading pad (5.5), as illustrated in Figure 12.

For multiple seating units, the horizontal static force test shall be applied simultaneously to the same positions as used for the seat static load test (6.4).

Foot rest static load test

Apply the specified downward force to the seat at the seat loading point

To assess potential failure points, apply a vertical force using the local loading pad (5.7) positioned 80 mm from the front edge of the load-bearing structure of the footrest For footrests with a round cross-section, ensure the force is directed through the center of the ring's cross-section.

If the seating tends to overturn, increase the load on seat to a magnitude that just prevents overturning and record the load used.

Leg rest static load test

This test is only applicable to leg rests designed to support the full weight of the user

Using the seat loading pad (5.4), apply the specified force 100 mm in from the outer edge of the leg rest at the point most likely to cause failure

If the seating tends to overturn, increase the load on seat to a magnitude that just prevents overturning and record the load used

Arm rest sideways static load test

To test seating with a single armrest, exert an outward force at the point along the armrest that is most susceptible to failure, ensuring it is at least 100 mm from the end of the armrest structure This force should be applied using the local loading pad as specified in section 5.7.

If the item tends to overturn, apply a load on the side of the seat opposite to the arm rest under test large enough to prevent the item from overturning

To test seating with two arm rests, simultaneously apply an outward force to each arm rest at the point most susceptible to failure, ensuring the application is at least 100 mm from either end of the arm rest structure (refer to Figure 13) Use the local loading pad (5.7) for this force application.

For seating with three or more arm rests, carry out the test on one pair of adjacent arm rests All different arm rest designs shall be tested.

Arm rest downwards static load test

When dealing with seating that features a single armrest or two armrests spaced more than 1000 mm apart, it is essential to apply the specified vertical force at the points along the armrest that are most susceptible to failure, as illustrated in Figure 14 This force should be applied at least 100 mm from the end of the armrest structure.

If the chair tends to overturn, apply a load on the side of the seat opposite to the arm rest under test large enough to prevent the chair from overturning

For seating with two armrests, when the distance between the centers of the armrests is 1,000 mm or less, it is essential to apply the specified vertical force simultaneously to both armrests This force should be applied at the points along the armrests that are most likely to cause failure, ensuring that the application occurs no less than 100 mm from either end of the armrest structure.

For seating with three or more arm rests, carry out the test on one pair of adjacent arm rests All different arm rest designs shall be tested

Apply the force through the smaller seat loading pad (5.5) or the local loading pad (5.7)

Headrest static load test

Prevent the item from moving rearwards by placing stops behind the rear legs, feet or castors

Seating with reclining mechanisms that can be set or locked in a number of positions shall be set to the most upright position

Adjustable headrests shall be set to their highest position

To ensure proper testing, apply the designated rearwards force at the center of the headrest using the local loading pad (5.7) The force must be directed at an angle of (90 ± 10)º relative to the headrest plane when fully loaded.

If the seating tends to overturn, place a load on seat with a magnitude that just prevents overturning and record the load used

Vertical upwards static load on arm rests

Seating which may be moved when occupied

This test is only applicable to seating where it is expected that it may be moved when occupied by lifting by the arm rests

Place the seat load specified at the seat loading point

Apply an upwards force simultaneously to both arms, at the balance point, sufficient to lift the seating Lower the chair so that it rests on the floor.

Stacking seating

This test is specifically designed for stacking seating units that are lifted by the armrests It typically does not apply when manufacturers provide devices for moving the seating or when usage instructions indicate methods for moving the stack of chairs without lifting by the armrests.

Load the chair with the specified load at the seat loading point

Apply an upwards force sufficient to lift the seating simultaneously to both arms at the balance point Lower the seating unit so that it rests on the floor.

Vertical static load on auxiliary writing surfaces

Load the chair with the specified load at the seat loading point

To apply the required downward force, use the local loading pad (5.7) on the writing surface at the point farthest from any support, ensuring it is at least 100 mm away from any edge.

Leg forward static load test

Prevent the unit from movement by stops (5.3) against the front legs

Apply the specified seat load at the seat loading position determined by the loading point template (4.3) to all seat positions

To test a single seat, apply a horizontal force centrally to the rear of the seat at seat level in a forward direction using the local loading pad (5.7) as shown in Figure 15 a).

When applying horizontal force to seating with multiple positions, direct the force centrally to the rear of the least favorable seat position at seat level, using the local loading pad (5.7) For seating supported by three legs, ensure that one leg is positioned on the fore and aft centerline, while the other leg is secured by stops (refer to Figure 15 b)).

To prevent an item from overturning before reaching the specified force, reduce the force to a level that effectively stops forward tipping, ensuring it remains above the minimum required force Be sure to document the actual force applied.

27 a) Example – four leg chair b) Example – three leg stool

Leg sideways static load test

Prevent the unit from movement by stops (5.3) placed against one pair of front and rear feet

Apply the vertical seat load specified at a suitable position across the seat but not more than 150 mm from the unloaded edge of the seat

Apply a horizontal force centrally to the unrestrained side of the seat, at seat level, in a direction towards the restrained feet (see Figure 16)

For seating with only three legs, one foot on the fore and aft centre line of the item of seating and one other foot shall be restrained by stops

To prevent an item from overturning when subjected to a vertical seat load at its furthest position from the unloaded edge, it is essential to reduce the horizontal force to a level that effectively prevents sideways tipping, while ensuring it does not fall below the minimum required force Additionally, it is important to document the actual force applied.

Combined seat and back durability test

Only the vertical seat durability force shall be applied to items without a back rest

The test shall be carried out on the same positions as used for the seat static load test (6.4)

When conducting the test, ensure that the seats not being tested are loaded with the specified weight at the designated seat loading position.

Seating with a fixed back position, and seating with reclining mechanisms that cannot be locked into a fixed position, shall be tested for the number of cycles specified

Seating fitted with a spring rocking action base or tilting mechanism that has a tension adjustment, shall be tested with the tension adjusted to its maximum value

Seating with adjustable reclining mechanisms must undergo testing for half the specified cycle count in the most upright position and half in the most extreme reclined position.

The most unfavorable seating position is typically regarded as 10° above the fully reclined angle for fully adjustable mechanisms, or one position higher than the fully reclined setting for seats with multi-position backrests.

Position the centers of the back loading pad(s) (5.6) at the designated back loading position according to the loading point template, or 100 mm below the top of the back, whichever is lower.

All adjustable backs shall be set in the most adverse position

Back rest set to an angle of less than 70º, but not less than 55º to the horizontal Specified force x Sin

Back rest set to an angle of less than 55º to the horizontal 0,75 x Specified force 0,75 x Specified force x Cos ỉ

Apply the downward force F3 (determined in Table 2) per pad to the seats (see a), b) and c) defined in 6.4)

With the seat force maintained, apply the back force F4 (determined in Table 2) per pad When fully loaded, the back force shall act at (90 ± 10)º to the back rest plane

To prevent rearwards overturning, reduce the force F4 to a level that maintains stability without falling below the minimum required force If the item still shows a tendency to overturn at this adjusted force, increase F3 until the overturning tendency is eliminated.

In cases where the standard testing procedure cannot be applied, the seat and back tests can be conducted sequentially by first performing the seat test, followed by the back test while a static load is applied to the seat This method is applicable for both chairs and stools.

Figure 17 — Seat and back durability test

In cases where the standard testing procedure cannot be applied, the seat and back tests can be conducted sequentially by first performing the seat test, followed by the back test while a static load is applied to the seat This method is applicable for both chairs and stools.

In cases where the standard testing procedure cannot be applied, the seat and back tests can be conducted sequentially First, perform the seat test, followed by the back test while applying a static load on the seat This method is applicable for both chairs and stools.

Seat front edge durability test

Restrain the item by use of stops (5.3)

To test the vertical seat durability, apply the specified force using the smaller seat loading pad (5.5) alternately at two points, each located 100 mm from the front edge of the seat structure and as close as possible to either side, ensuring they are at least 100 mm from the edges Each cycle consists of one application of the specified force at each load position.

NOTE In some instances it might be appropriate to apply the force through the local loading pad (5.7)

When seating cannot accommodate force application at two points, the force must be applied at a single location along the longitudinal axis, specifically 100 mm from the front edge of the seat structure Each testing cycle consists of two applications of the specified force.

An example of an item of seating requiring one application point is shown in Figure 18

Figure 18 — Example of seating where a single force is required

The durability test for the front edge of multiple seating units will be conducted on one end seat Additionally, the test will be repeated by applying a single vertical durability force to one intermediate seat, similar to the procedure used in the seat static load test.

If the item tends to overturn, reduce the force to a magnitude that just prevents overturning Report the actual force used.

Durability test on seating with a multi-position back rest

This test is only applicable to seating with three or more manually adjustable reclined positions of the back rest

Position the seating in its standard use configuration, ensuring the backrest is set to the most unfavorable angle If the optimal adverse position is unclear, conduct the test with the backrest adjusted to the midpoint To prevent the seating from shifting backward, secure it by placing stops behind the rear feet, legs, or castors.

Apply the specified load to the seat loading point

The height of the back rest loading points shall be 100 mm above the back loading point (6.2) They shall be

50 mm from the right and left outer edges of the back rest

Apply rearwards alternating forces perpendicularly to the back rest, as specified

Carry out the test for the number of cycles specified

1 cycle = 1 application of force on the right side and 1 application of force on the left side

NOTE This test is often used for testing outdoor reclining seating.

Arm rest durability test

Position the chair on the testing surface with the stops aligned against the outer legs, feet, or castors Apply test forces simultaneously on each armrest at the most vulnerable point, ensuring the application is at least 100 mm from both the front and rear edges of the armrest length (3.6) and centered across the width, but not exceeding 100 mm from the inner edge of the armrest.

To conduct the arm rest durability test, adjust the apparatus so that the load application arms are positioned at an angle of (10 ± 1)° to the vertical, with the distance from the low friction pivots to the horizontal surface of the arm loading devices set at (600 ± 10) mm Once the apparatus is correctly configured, apply the specified load for the required number of cycles to both arm rests simultaneously for single seating positions, and to one arm rest only for multiple seating positions.

Foot rest durability test

To assess the load-bearing capacity of footrests, a vertical force should be applied using the local loading pad (5.7), positioned 80 mm from the front edge of the load-bearing structure at critical failure points For footrests with a round cross-section, the force must be directed through the center of the ring's cross-section.

If the seating tends to overturn, increase the load on seat to a magnitude that just prevents overturning and record the load used

Auxiliary writing surfaces durability test

Apply a downwards vertical force at the same position as specified in 6.14 using the local loading pad (5.7) for the number of cycles specified

Tipping seat operation

If the seating unit features tip-up seats, one seat shall be operated for the specified number of cycles

A complete cycle involves moving the seat from the fully closed position to the fully open position and then returning it to the fully closed position The maximum allowable rate for this operation is ten cycles per minute.

During each cycle, the seat shall be allowed to open or close freely under gravity if that is its correct mode of operation.

Seat impact test

To begin, place a 25 mm thick layer of foam (5.8) on the seat Next, measure the height of the fall from the position of the impactor when it is resting on the surface of the foam layer (5.8).

For the test, position a second layer of 25 mm thick foam between the striking surface and the chair seat Allow the seat impactor to drop freely from the specified height onto the designated seat loading position.

Conduct the test at an additional location that is expected to lead to failure, ensuring it is at least 100 mm away from any edge of the seat, as outlined in the loading point template (5.1).

For multiple seating units, apply the test to one end seat and an intermediate seating position

2 Seat loading point according to template

Back impact test

This test is intended to be used for chairs that are not tested in accordance with 6.28

To properly test the item, ensure its front legs, feet, or castors are secured by stops to prevent forward movement Use an impact hammer to strike the center of the top outside back structure, following the specified drop height or angle for different seating configurations: a) for single-seat items, strike the center; b) for two-seat items, strike both positions; c) for three or more seat items, strike one end position and the center.

If the item has no back, strike the centre of the seat rear edge

If a stool or bench has no easily determined rear edge, apply the test in the direction most likely to cause failure (see Figure 20b))

The item of seating shall not be prevented from overturning during the test, and shall be allowed to strike the rubber faced test floor (5.2)

Arm rest impact test

Position the item with one pair of front and rear legs, ensuring that the feet or castors are secured by stops to prevent lateral movement Use an impact hammer to strike the outer side of one armrest, targeting the area most susceptible to failure, but at least 50 mm from the end During the test, the seating item must not be restrained from overturning and should be permitted to make contact with the rubber-faced test floor.

Drop tests

Drop test for multiple seat units

To measure the vertical force needed to lift either side of the item, identify the minimum upward force required to raise at least one end or a pair of legs by (10 ± 5) mm off the ground Additionally, calculate the drop height as a percentage of the specified drop height using the appropriate formula.

Mass of one end of multiple seating unit Percentage of Specified Nominal Drop Height

10 – 65 kg 100 – [90 x [Mass of one end of unit – 10]/55]

Lift the item at one end/side and allow it to fall freely from the specified height so that the feet or castors strike the floor (5.2) (see Figure 22)

Repeat the test on the other end of the item

Drop test for stacking seating

To conduct the test, stack one chair on top of another and position a 10 kg loading disc on the rear of the upper chair's seat If the total weight of the stacked chairs exceeds 20 kg, substitute the disc with bag weights and adjust the load until the combined mass is 20 kg.

The weight will be secured using straps around the upper seating unit or both seating units if space is limited Other acceptable methods for restraining the loading disc are also permitted.

To ensure stability, elevate one leg of the bottom seating unit to the designated drop height, ensuring that the line connecting this leg to the diagonally opposite leg is inclined at an angle of 10 degrees to the horizontal (refer to Figure 23) The other two legs must remain at a consistent level.

Drop it on the rubber faced test floor (5.2) for the number of times specified The test shall be carried out on one front leg and one rear leg

The test may be carried out by lifting the seating by means of three cords, which are adjusted in length so that the 10° angle is obtained

Drop test from the height of a table

This test applies exclusively to seating intended for high-level placement, such as on a tabletop during cleaning To conduct the test, support the seating so that one leg is elevated to the specified drop height, ensuring that the line connecting this leg to the diagonally opposite leg is inclined at 10° to the horizontal Meanwhile, the other two legs must remain at the same level.

Drop it on to the rubber faced test floor (5.2) The test shall be carried out on one front leg and on one rear leg

The test may be carried out by lifting the seating by means of three cords, which are adjusted in length so that the 10° angle is obtained

Backward fall test

Place the unloaded seating on the drop test floor (5.2) in normal use position

To determine the force needed to lift the front legs off the floor, apply a rearward horizontal load at the center of the back rest, positioned 50 mm below the top Measure the force exerted during this process.

If the measured force is below 30N, push the top of the backrest backward until it reaches the equilibrium point Then, let it fall freely onto the rubber-faced test floor without applying any initial force or velocity.

Repeat for the number of cycles specified.

Castor and chair base durability

This test only applies to seating which is designed to be moved while occupied by the user

This test does not apply to chairs with castors which are braked when the chair is loaded

The chair must be positioned on a rotating table, aligning the chair's rotating axis with that of the table Apply the specified load at the designated seat loading point, ensuring the item is loosely secured to allow for natural caster movement during testing The casters should remain free to swivel while the table rotates at a speed of six cycles per minute, with each cycle consisting of a forward rotation from 0° to 180° and a backward rotation back to 0°.

To conduct the test, attach the chair to a device that allows for linear movement of (1,000 ± 25) mm and a designated test surface Apply the specified load at the seat loading point, ensuring the item is loosely secured to prevent rotation while allowing the natural movement of the castors The castors must remain free to swivel, and the device should operate at a rate of six cycles per minute.

One movement forward and one movement backward constitutes one cycle

For both alternatives it is recommended to perform the test with a speed as slow as possible with a short break when the device changes direction.

Rolling resistance of the unloaded chair

The chair shall be placed on the test floor (see 5.12) and shall be pushed or pulled over a distance of at least

550 mm A speed of (50 ± 5) mm/s shall be maintained over the measuring distance The force shall be applied at a height of (200 ± 50) mm above the test surface

Record the force used to push or to pull the chair over the distance from 250 mm to 500 mm as the rolling resistance

NOTE This test is normally intended for seating for non-domestic single seating units

General

The chair and its components shall be configured as specified in Table 3

If a test cannot be conducted according to the specified Standard, such as when a loading pad is unsuitable for force application due to product design, the test should be performed to the greatest extent possible as outlined.

Position the chair and its components as specified in Table 3 on the test surface (5.2)

Table 3 — Positioning of chair components

Clause Test Seat height Seat Back rest in height Back rest in depth Tilt tension adjustment Castors and base Arm rest Foot rest

7.3 Seat front edge static load test highest position foremost position - - - least likely to cause overturning

7.4 Combined seat and back static load highest position most adverse position highest position rearmost position mid range least likely to cause overturning

7.5 Arm rest downward static load test – central lowest position Horizontal - - - - most likely to cause failure

7.6 Arm rest downward static load test – front lowest position Horizontal - - - - highest, widest, foremost position

7.7 Arm rest sideways static load test lowest position Horizontal - - - - highest, widest position

7.8 Foot rest static load test - - - - - least likely to cause overturning

7.9 Seat and back durability highest position Horizontal, foremost position highest position most likely to cause failure mid range least likely to cause overturning

7.10 Arm rest durability lowest position Horizontal - - maximum tension - highest, widest position

7.11 Swivel test highest position horizontal, foremost position highest position rearmost position - - - -

7.12 Footrest durability - - - - - least likely to cause overturning

7.13 Castor durability lowest position Horizontal - - - - - -

Loading points

General

The loading points for work chairs are graphically shown in Figure 27.

Loading point A

The point in which the chair's axis of rotation intersects with the seat surface with the seat in a position as close as possible to the horizontal.

Loading point B

The point on the centreline of the back rest, 300 mm above loading point A (7.2.2) measured when the seat is loaded with 640 N through the seat loading pad

Loading point C

A point in front of loading point A (7.2.2) along the centre line of the seat, 100 mm from the edge of the load bearing structure of the seat.

Loading point D

The point 150 mm to the right of loading point A (7.2.2), but not less than 100 mm from the edge of the seat structure.

Loading point E

The point 50 mm to the right of loading point B (7.2.3).

Loading point F

A point in front of loading point D (7.2.5) on a line parallel to the centre line, 100 mm from the edge of the load bearing structure of the seat on that line

If the distance from any edge of the structure is less than 100 mm, adjust the point inward along a line parallel to the one connecting points A, D, and G, ensuring that the distance from the edge is exactly 100 mm.

Dimensions in millimetres a) Example of loading points F & J b) Example of loading points F & J

Figure 26 — Determination of loading points F & J

Loading point G

The point 150 mm to the left of loading point A (7.2.2), but not less than 100 mm from the edge of the seat structure.

Loading point H

The point 50 mm to the left of loading point B (7.2.3).

Loading point J

A point in front of loading point G (7.2.8) on a line parallel to the centre line, 100 mm from the structure of the seat edge on that line

If the distance from any edge of the structure is under 100 mm, adjust the point inward along a line parallel to the one connecting points A, D, and G, ensuring the distance from the edge is exactly 100 mm.

A loading point A D loading point D G loading point G

B loading point B E loading point E H loading point H

C loading point C F loading point F J loading point J

Combined seat and back static load test

Prevent the chair from moving rearwards by placing stops (5.3) behind two adjacent supporting points at the rear of the chair

Chairs equipped with locking mechanisms for adjusting the seat and backrest angles must undergo testing in two phases: the first half of the cycles with the locking device engaged and the second half with it disengaged During the initial phase, the backrest should be positioned upright.

To test the chair's stability, apply a vertical force F1 at point A through the seat loading pad and maintain this load Next, apply a force F2 at point B through the center of the back loading pad Ensure that the force acts at an angle of (90 ± 10)° to the backrest plane when fully loaded If the chair shows signs of overturning, decrease the backrest force and document the actual force applied Finally, remove the back force followed by the seat force.

Arm rest downward static load test – central

load test – central lowest position Horizontal - - - - most likely to cause failure

Arm rest downward static load test – front

load test – front lowest position Horizontal - - - - highest, widest, foremost position

Arm rest sideways static load test

load test lowest position Horizontal - - - - highest, widest position

Foot rest static load test

Seat and back durability

foremost position highest position most likely to cause failure mid range least likely to cause overturning

Arm rest durability

Swivel test

foremost position highest position rearmost position - - - -

Foot rest durability

7.13 Castor durability lowest position Horizontal - - - - - -

The loading points for work chairs are graphically shown in Figure 27

The point in which the chair's axis of rotation intersects with the seat surface with the seat in a position as close as possible to the horizontal

The point on the centreline of the back rest, 300 mm above loading point A (7.2.2) measured when the seat is loaded with 640 N through the seat loading pad

A point in front of loading point A (7.2.2) along the centre line of the seat, 100 mm from the edge of the load bearing structure of the seat

The point 150 mm to the right of loading point A (7.2.2), but not less than 100 mm from the edge of the seat structure

The point 50 mm to the right of loading point B (7.2.3)

A point in front of loading point D (7.2.5) on a line parallel to the centre line, 100 mm from the edge of the load bearing structure of the seat on that line

To ensure compliance with structural guidelines, if any edge of the structure is within 100 mm, adjust the point inward along a line parallel to the one connecting points A, D, and G, maintaining a distance of 100 mm from the edge (refer to Figure 26).

Dimensions in millimetres a) Example of loading points F & J b) Example of loading points F & J

Figure 26 — Determination of loading points F & J

The point 150 mm to the left of loading point A (7.2.2), but not less than 100 mm from the edge of the seat structure

The point 50 mm to the left of loading point B (7.2.3)

A point in front of loading point G (7.2.8) on a line parallel to the centre line, 100 mm from the structure of the seat edge on that line

To ensure compliance with structural guidelines, if any edge of the structure is within 100 mm, adjust the point inward along a line parallel to the one connecting points A, D, and G, maintaining a distance of 100 mm from the edge (refer to Figure 26).

A loading point A D loading point D G loading point G

B loading point B E loading point E H loading point H

C loading point C F loading point F J loading point J

Figure 27 — Loading points 7.3 Combined seat and back static load test

Prevent the chair from moving rearwards by placing stops (5.3) behind two adjacent supporting points at the rear of the chair

Chairs equipped with locking mechanisms for seat and backrest angle adjustments must undergo testing in two phases: the first half of the cycles with the locking device engaged and the second half with it disengaged During the initial phase, the backrest should be positioned upright.

To test the chair's stability, apply a vertical force F1 at point A through the seat loading pad and maintain this load Next, apply a force F2 at point B through the center of the back loading pad Ensure that the total force is directed at an angle of (90 ± 10)° to the backrest plane If the chair shows signs of overturning, decrease the backrest force and document the actual force applied Finally, remove the back force followed by the seat force.

Figure 28 — Combined seat and back static load test 7.4 Seat front edge static load test

Position the smaller seat loading pad (5.5) at loading point F or J (7.2.7 or 7.2.10) Apply a vertical downward force through the centre of the loading pad

7.5 Arm rest downward static load test – central

The arm rests must be vertically loaded using the local loading pads (5.7), with loading points positioned at the midpoint of the arm rest's length and centered laterally For arm rests that are not horizontal or are curved, the length should be measured in a horizontal plane 20 mm below the highest point of the arm rest.

Apply the force to both arm rests simultaneously (see Figure 29)

Figure 29 — Arm rest downward static load test – central 7.6 Arm rest downward static load test – front

The arm rests shall be loaded vertically by means of the local loading pads (5.7) The loading points shall be

75 mm from the front edge and centred side to side

Apply the force to both arm rests simultaneously (see Figure 30)

Figure 30 — Arm rest downward static load test – front

7.7 Arm rest sideways static load test

This test shall be carried out as described in 6.10

7.8 Foot rest static load test

The upper section of the chair must be aligned so that the center of the backrest is positioned halfway between two adjacent supporting points of the base, with stops in place against these supporting points.

The seat load must be applied vertically with the seat loading pad (5.4) in positions A and C, while the smaller seat loading pad (5.5) is to be used in positions D, F, G, and J Additionally, the backrest force should be applied at a specified angle.

(90 ± 10)° to the back rest when fully loaded (see Figure 31) using the back loading pad (5.6)

Figure 31 — Back rest force application – principle

All chairs shall be tested to steps 1 to 5 (see Table 4)

Chairs equipped with locking devices for seat and backrest angle adjustments must undergo testing in two phases: first with the devices locked for half of the cycles, and then with them unlocked for the remaining cycles During the initial phase, the backrest should be positioned upright In subsequent steps, the mechanism will be allowed to move freely.

One cycle shall consist of the application and removal of the force(s) at the respective loading point(s)

Each step shall be completed before going to the next

First the seat force shall be applied and maintained while the back rest force is applied

When the backrest pad pivots around a horizontal axis positioned above the seat height and is allowed to move freely, the horizontal force must be applied at this axis If the backrest is height adjustable, the axis should be positioned as close to the seat as possible.

300 mm above point A (7.2.2) If the axis cannot be adjusted to 300 mm, adjust the force to produce the same bending moment

Table 4 — Seat and back durability test

The test shall be carried out as described in 6.20

The chair's base must be securely mounted on a rotating table, ensuring that the chair's rotating axis aligns with that of the table The upper section of the chair should be loosely attached to allow for free rotation of the base Load the seat at point A with the specified weight and at point C with the additional specified load, or an equivalent load that produces the same downward force and bending moment The rotation angle should be 360° at a specified rate.

(10 ± 5) cycles/minute Change direction after each rotation

This test shall be carried out as described in 6.21.

Castor and chair base durability

This test does not apply to chairs with castors which are braked when the chair is loaded

The chair must be positioned on a rotating table, ensuring that the chair's rotating axis aligns with that of the table Apply the specified load at point A on the seat, while the base is loosely fixed to prevent rotation but allow natural caster movement The casters should be free to swivel as the table rotates at a speed of six cycles per minute, with the rotation angle ranging from 0° to 180° and back.

One rotation forward and one rotation backward constitutes one cycle

To conduct the test, attach the chair to a device that allows for linear movement within the range of (1,000 ± 250) mm, ensuring a suitable test surface is provided Apply the specified load at point A on the seat, while loosely fixing the base to prevent rotation, allowing natural movement of the castors during testing The castors must remain free to swivel, and the device should operate at a rate of six cycles per minute.

One movement forward and one movement backward constitutes one cycle

For both alternatives it is recommended to perform the test with a speed as slow as possible with a short break when the device changes direction

Rolling resistance of the unloaded chair

General

The tests shall be carried out in the configuration most likely to cause failure

If a test cannot be conducted according to the specified Standard, such as when a loading pad is unsuitable for force application due to product design, the test should be performed to the fullest extent possible as outlined.

Seat and back static load test

Additional seat and leg rest static load test

Load the seat with the specified seat load at the seat loading point (6.2) and maintain the load for the duration of the test

Using the seat loading pad (5.4), apply the specified force at the most adverse position between point D and E specified in Figure 32

If the item tends to overturn, apply a load to the opposite side of to the most adverse load position, with a load just sufficient to prevent overturning

Dimensions in millimetres a) lounger with arm rest b) lounger without arm rest Key

F Location of static load application

Seat and back durability test

Seat and back durability test procedure

The test shall be carried out as described in 6.17

Additional seat durability test procedure

Apply the vertical seat durability load specified using the smaller seat loading pad (5.5) alternately at points G and H (see Figure 33)

Dimensions in millimetres a) Lounger with adjustment

Durability test on back rest mechanism

The test shall be carried out as described in 6.19.

Arm rest downwards static load test

Arm rest durability test

Impact test

With the exception of the application points specified below, the impact test procedure is performed in accordance in 6.24

The application points shall be:

 the most adverse point on the seat-leg rest section,

 150 mm in from the edge of the lounger, and,

 directly on the end support,150 mm from any edge of the lounger (see Figure 34) on the same side of the lounger as the first impact position

NOTE The most adverse point is normally over any adjustment mechanism, or the mid-point of the span between seat-leg rest section supports

Dimensions in millimetres a) Lounger with adjustment

1 Impact point – most adverse position

Tiêu đề	Furniture — Seating — Test Methods For The Determination Of Strength And Durability
Trường học	British Standards Institution
Chuyên ngành	Standards Publication
Thể loại	Standard
Năm xuất bản	2012
Thành phố	Brussels

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Số trang	62
Dung lượng	1,44 MB