Slide rail assembly

1. A slide rail assembly, comprising:

a first rail;

a second rail longitudinally displaceable with respect to the first rail;

a first stop disposed on the first rail;

a blocking structure disposed on the first rail, the blocking structure including a guiding section and a blocking section;

an engaging member movably mounted on the second rail;

a working member movably mounted on the second rail;

a working portion coupled to the working member, the working portion having a columnar configuration; and

a third rail longitudinally displaceable with respect to the second rail;

wherein the second rail, responsive to reaching an extended position after displacement with respect to the first rail in an opening direction and the engaging member being cammingly displaced by the guiding section is blocked by the blocking section via the engaging member, the second rail being thereby prevented from displacing from the extended position in a retracting direction opposite to the opening direction, the third rail being configured to be extended beyond the extended position and retracted from the extended position;

wherein the second rail, when reaching a predetermined position after displacement with respect to the first rail from the extended position in the retracting direction following termination of a blocking relationship between the engaging member and the blocking section, is blocked by the first stop via the working portion, the working member not being in contact directly with the first stop, the second rail being thereby prevented from displacing from the predetermined position in the opening direction;

wherein the slide rail assembly has a first length when the second rail is at the extended position; and

wherein the slide rail assembly has a second length shorter than the first length when the second rail is at the predetermined position.

2. The slide rail assembly of claim 1 , wherein the second rail includes a first wall, a second wall, and a longitudinal wall connected between the first wall and the second wall of the second rail, and the slide rail assembly further comprises a shaft for pivotally connecting the working member to the longitudinal wall of the second rail in a transverse direction.

3. The slide rail assembly of claim 1 , wherein the longitudinal wall of the second rail has a first position-limiting wall section, a second position-limiting wall section, and an extension hole defined between the first position-limiting wall section and the second position-limiting wall section, and the extension hole is configured to allow passage of the working portion therethrough.

4. The slide rail assembly of claim 1 , further comprising an elastic structure for applying an elastic force to bias the working member to be blocked by the first stop.

5. The slide rail assembly of claim 1 , further comprising a second stop disposed on the first rail such that when the second rail is at the predetermined position with respect to the first rail, the working member is blocked by the second stop via the working portion and thereby prevents the second rail from displacing from the predetermined position in the retracting direction.

6. The slide rail assembly of claim 1 , wherein the second rail is movably mounted between the first rail and the third rail.

7. The slide rail assembly of claim 1 , further comprising a pivotal connection member for pivotally connecting the engaging member to the longitudinal wall of the second rail in a height direction, wherein the height direction is substantially perpendicular to the transverse direction.

8. The slide rail assembly of claim 7 , further comprising an elastic feature for applying an elastic force to bias the engaging member to be blocked by the blocking structure.

9. The slide rail assembly of claim 1 , further comprising an operating member disposed on one of the first rail and the second rail, wherein the operating member is configured to be operated in order to drive the engaging member and thereby free the engaging member from blockage by the blocking structure.

10. A slide rail assembly, comprising:

a first rail;

a second rail displaceable with respect to the first rail;

a third rail displaceable with respect to the second rail;

a first stop disposed on the first rail;

a blocking structure disposed on the first rail, the blocking structure including a guiding section and a blocking section;

an engaging member movably mounted on the second rail; and

a working member movably mounted on the second rail;

a working portion coupled to the working member, the working portion having a columnar configuration; and

a third rail longitudinally displaceable with respect to the second rail;

wherein the second rail, responsive to reaching an extended position after displacement with respect to the first rail in an opening direction and the engaging member being cammingly displaced by the guiding section, is blocked by the blocking section via the engaging member, the second rail being thereby prevented from displacing from the extended position in a retracting direction opposite to the opening direction, the third rail being configured to be extended beyond the extended position and retracted from the extended position;

wherein the second rail, when reaching a predetermined position after displacement with respect to the first rail from the extended position in the retracting direction following termination of a blocking relationship between the engaging member and the blocking section, is blocked by the first stop via the working portion, the working member not being in contact directly with the first stop, the second rail being thereby prevented from displacing from the predetermined position in the opening direction.

11. The slide rail assembly of claim 10 , wherein the second rail includes a first wall, a second wall, and a longitudinal wall connected between the first wall and the second wall of the second rail, and the slide rail assembly further comprises a shaft for pivotally connecting the working member to the longitudinal wall of the second rail.

12. The slide rail assembly of claim 10 , wherein the longitudinal wall of the second rail has a first position-limiting wall section, a second position-limiting wall section, and an extension hole defined between the first position-limiting wall section and the second position-limiting wall section, and the extension hole is configured to allow passage of the working portion therethrough.

13. The slide rail assembly of claim 10 , further comprising an elastic structure for applying an elastic force to bias the working member to be blocked by the first stop.

14. The slide rail assembly of claim 10 , further comprising a second stop disposed on the first rail such that when the second rail is at the predetermined position with respect to the first rail, the working member is blocked by the second stop via the working portion and thereby prevents the second rail from displacing from the predetermined position in the retracting direction.

15. The slide rail assembly of claim 11 , further comprising a pivotal connection member for pivotally connecting the engaging member to the longitudinal wall of the second rail.

16. The slide rail assembly of claim 15 , further comprising:

an elastic feature for applying an elastic force to bias the engaging member to be blocked by the blocking structure; and

an operating member disposed on one of the first rail and the second rail, wherein the operating member is configured to be operated in order to drive the engaging member and thereby free the engaging member from blockage by the blocking structure.