Office Chair Tip-Over Test

The office chair tip-over test mainly includes various standards and procedures to evaluate the anti-tipping capability of office chairs in different usage scenarios, ensuring their safety and stability.

1. BS 5459 - 2 Standard
   This standard evaluates the anti-tipping capability of office chairs by simulating scenarios where users lean forward or backward while seated. The test is divided into two parts: forward and backward stability. In the forward test, the loading force is applied to the front edge of the seat or the front side of the backrest, directed forward and downward, with the force value gradually increased to the standard specified value or until the chair tips over or component damage occurs. In the backward test, a force is applied downward and backward to the upper edge of the backrest, also gradually loaded and results recorded.

2. EN 12520 Standard
   This standard includes a tipping test, lateral load test, and anti-rocking test, with the tipping test being the core part. The tipping test involves gradually applying an external force to tip the seat, observing the tipping angle and required load, such as applying a vertical downward force at the edge of the seat while applying a horizontal thrust, and recording the critical force value when the seat begins to tip over. The lateral load test simulates the performance of the seat when subjected to lateral impact forces, applying a gradually increasing lateral load at the edge of the seat until tipping occurs or the ultimate load (e.g., 500N) is reached, allowing for the evaluation of factors such as the friction between the chair legs and the ground and structural stability.

3. Calculation Method Test
   This method is suitable for lateral tipping tests of armless chairs, calculating the tipping force by measuring key parameters. Measure the horizontal distance (a) between the vertical projection line of the load application point on the seat and the constraint point of the constrained leg, the horizontal distance (b) between the load application point on the armrest and the constraint point of the constrained leg, and the vertical distance (h) between the externally applied horizontal tipping force and the horizontal plane on which the chair is placed. When the seat load W is 600N, calculate the force F required to tip the chair using a formula. This method requires precise measurement of parameters to avoid calculation errors due to dimensional inaccuracies.

4. Forward Tipping Test
   A stop block is placed against the front side of the chair legs to fix the position. A loading pad applies a vertical force of 600N at a point 50mm from the front edge and side edge of the seat centerline, and then a standard-specified force F is applied horizontally outward. Record whether the chair tips over and the actual force applied, allowing for the evaluation of the tipping risk caused by forward leaning actions during normal use.

5. Lateral Stability Test in EN 1335 Certification for Office Chairs
   This test simulates the lateral tilting actions that may occur when a user is seated, applying a force in a specific direction to inspect the chair's ability to resist sideways tipping. During the test, the chair is placed on a horizontal test platform, the backrest angle adjustment device is locked, the seat height is adjusted to the middle position, and all movable parts are in normal use condition. The test device applies a gradually increasing force horizontally on one side of the front edge of the seat, with the force application point at a certain height above the seat surface to simulate the moment generated by the user's center of gravity. The applied force value must reach the standard-specified value and be maintained for a certain period of time, measuring the critical force value that causes the chair to start tilting and whether the chair can remain stable without continuing to tip over under this force.