CN107028386A - Slide rail assembly and operation method thereof - Google Patents

Abstract

The invention relates to a slide rail assembly, which comprises a first rail, a second rail, a third rail and a clamping mechanism. The second rail can move relative to the first rail; the third rail can move relative to the second rail; the clamping mechanism is movably arranged on the second rail; when the second rail moves from a first position to a second position in a first direction relative to the first rail and the third rail moves to a third position in the first direction relative to the second rail and exceeds the second rail, the first rail, the second rail and the third rail define a first length; when the second rail moves from the second position to a fourth position in a second direction, the first length can be shortened to a second length, and the second rail is located at the fourth position relative to the first rail by the clamping mechanism. The invention also provides an operation method of the slide rail assembly.

Description

Slide rail assembly and method of operation

technical field

The invention relates to a slide rail assembly, in particular to a rail member capable of shortening the extension length of the slide rail assembly to facilitate loading and unloading of the slide rail assembly in a limited environmental space.

Background technique

Generally speaking, the slide rail assembly usually includes at least two or more rail members, and these rail members can move and displace relative to each other, so that the slide rail assembly has an extended or retracted state. Among them, taking a three-section slide rail assembly with a first rail, a second rail, and a third rail as an example, usually when the second rail and the third rail are displaced in one direction relative to the first rail, they are completely In the extended state, the slide rail assembly has a fully extended length. At the fully extended length, the second rail is generally capable of maintaining a fully extended position relative to the first rail in the prior art.

However, if the operator wishes to temporarily hold the second rail of the slide rail assembly in the not yet fully extended position relative to the first rail, this type of slide rail assembly cannot meet this particular need.

Contents of the invention

The object of the present invention is to provide a slide rail assembly to shorten the extension length of the slide rail assembly, so as to allow operators to maintain the slide rail assembly in a limited environment.

Another object of the present invention relates to a method for operating the slide rail assembly, which can operate to shorten the extension length of the slide rail assembly, so as to facilitate the application in a limited environmental space.

According to a viewpoint of the present invention, a slide rail assembly includes a first rail, a second rail, a third rail, and a first locking mechanism, and is characterized in that: the first rail has a front end and a rear end; the second rail can be displaced relative to the first rail; the third rail can be displaced relative to the second rail and has a front end and a rear end; the first locking mechanism is movably installed on the second rail; Wherein, when the second rail is displaced relative to the first rail from a first position to a first direction to a second position, and the third rail is displaced to a third position relative to the second rail in the first direction When exceeding the second rail, a first length is defined between the rear end of the first rail and the front end of the third rail; wherein, when the second rail is displaced from the second position to a second direction to a In the fourth position, the first length between the rear end of the first rail and the front end of the third rail can be shortened to a second length, and by means of the first locking mechanism, the second rail is relatively The first rail is in this fourth position.

Preferably, the slide rail assembly further includes a first working part and a stopper, the first working part is installed on the third rail, and is operatively positioned between a first working position and a second working position Between, the blocking seat is arranged on the second rail and has a blocking portion, when the third rail is displaced to a position in the first direction, the first working part can be used to abut against the blocking in the first working position One side of the blocking part of the seat; when the first working part is operated from the first working position to the second working position, the first working part is no longer against the blocking part of the blocking seat, so that the The third rail is detachable relative to the second rail.

Preferably, the slide rail assembly further includes a second work piece elastically installed on the third rail, when the third rail is displaced to the position in the first direction, the second work piece moves along the When the stop part of the stop seat is displaced, when the second working part passes over the stop part of the stop seat, the second work part abuts against the other side of the stop part of the stop seat.

Preferably, the slide rail assembly also includes a switching member installed on the third rail, the switching member can be operated at a first switching position or a second switching position, and at the first switching position, the switching The part is staggered with the blocking portion of the blocking seat, and in the second switching position, the switching element is not staggered with the blocking portion of the blocking seat.

Preferably, the third rail has a front stop, and the front stop and the switching member are separated from each other.

Preferably, the slide rail assembly further includes a first stopper disposed on the first rail, when the second rail is at the fourth position, the second rail is locked on the first latch mechanism by means of the first locking mechanism. One piece.

Preferably, the first latching mechanism includes a first latching member and a first elastic member providing elastic force to the first latching member. When the second rail is in the fourth position, the first latching The element is locked against the first blocking element by virtue of the elastic force of the first elastic element.

Preferably, the slide rail assembly further includes a second stopper and a second locking mechanism, the second stopper is arranged on the first rail and includes a release part, and the second locking mechanism is movable Installed on the second rail, the third rail has a back stop, wherein, the third rail can push the second latch mechanism with the back stop to synchronously drive the second rail from the first position to the The first direction is displaced until the release portion of the second blocking member is used to disengage the second locking mechanism from the rear blocking.

Preferably, the second latching mechanism includes a second latching member and a second elastic member to provide elastic force to the second latching member, and the third rail can push against the second latching member by means of the backstop .

Preferably, the second stopper also includes a limiting portion, and the slide rail assembly also includes a third locking mechanism movably installed on the second rail, when the second rail is displaced to the second position , the third locking mechanism is located adjacent to the limiting portion of the second blocking member.

Preferably, the third latching mechanism includes a third latching member and a third elastic member providing elastic force to the third latching member, when the second rail is displaced to the second position, the third latching In response to the elastic force of the third elastic member, the latch is located adjacent to the limiting portion of the second blocking member.

According to another aspect of the present invention, a slide rail assembly is suitable for installing a load on a rack, the slide rail assembly includes a first rail, a second rail, a third rail, a first The stopper, a first locking mechanism, and a first work piece are characterized in that: the first rail is mounted to the frame and has a front end and a rear end; the second rail can be displaced relative to the first rail ; the third rail can be displaced relative to the second rail, the third rail is used to carry the load and has a front end and a rear end; the first stopper is configured on the first rail; the first locking mechanism movably mounted on the second rail; the first working part is mounted on the third rail, and the first working part is operable between a first working position and a second working position; wherein, when the second The rail is displaced relative to the first rail from a first position in a first direction to a second position, and the third rail is displaced in the first direction relative to the second rail to a third position beyond the second rail , a first length is defined between the rear end of the first rail and the front end of the third rail; wherein, when the second rail is displaced from the second position to a second direction to a fourth position, the The first length between the rear end of the first rail and the front end of the third rail can be shortened to a second length, and by means of the first locking mechanism, the first stopper is locked, so that the second rail is relatively The first rail is located at the fourth position; wherein, when the first work piece is operated to be displaced from the first working position to the second working position, the third rail can be removed relative to the second rail.

According to yet another aspect of the present invention, a method for operating a slide rail assembly is characterized in that it includes providing a first rail; providing a second rail that can move from a first position to a first direction relative to the first rail Displacement to a second position; providing a third rail that is displaceable relative to the second rail beyond the second position to a third position; providing a first working member operable between a first working position and a second Between working positions, wherein, in the first working position, the third rail is at the third position relative to the second rail such that the first rail, the second rail and the third rail define a first length ; Provide a first latching mechanism, so that when the second rail is displaced from the second position to a second direction to a fourth position relative to the first rail, the second rail is relative to the second rail by means of the first latching mechanism The first rail is located at the fourth position, shortening the first length to a second length; and, in the state of the second length, the first working member is operable to displace from the first working position to the The second working position enables the third rail to be unloaded relative to the second rail.

Description of drawings

To further illustrate and confirm the above-mentioned purpose, structural features and effects of the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

FIG. 1 shows a schematic perspective view of a pair of slide rail assemblies installing a load to a rack according to an embodiment of the present invention.

FIG. 2 is an exploded schematic diagram of a slide rail assembly according to an embodiment of the present invention.

FIG. 3 is a partially enlarged schematic view of the second rail of the slide rail assembly in FIG. 2 , showing that the stopper seat has a stopper portion.

FIG. 4 shows an exploded schematic view of the third rail, a first working part, a second working part, a switching part and an auxiliary elastic part of the slide rail assembly according to an embodiment of the present invention.

FIG. 5 shows a schematic diagram of a third rail according to an embodiment of the present invention.

FIG. 6 shows a schematic view of the slide rail assembly in a folded state according to an embodiment of the present invention, wherein a first locking mechanism, a second locking mechanism and a third locking mechanism are in a predetermined state.

FIG. 7 shows a partial perspective view of the front stop of the third rail in FIG. 6 abutting against the stop seat.

Fig. 8 shows that the third rail of the slide rail assembly according to an embodiment of the present invention pushes against the second latching member of the second latching mechanism by means of the backstop, so that the second rail follows the third rail to be displaced in a first direction schematic diagram.

Fig. 9 shows a schematic diagram of the displacement of the third rail in Fig. 8 relative to the second rail in the first direction, wherein the second latching member of the second latching mechanism is deflected by the guide of the release part of the second blocking member. At an angle, the third locking member of the third locking mechanism is located at the limiting portion adjacent to the second blocking member.

FIG. 10 is a partial perspective view of the first work piece and the second work piece in FIG. 9 abutting against the two sides of the stop portion of the stop seat.

FIG. 11 shows a schematic diagram of the second working part in FIG. 9 that can be operated without abutting against the blocking portion of the blocking seat.

FIG. 12 shows a partial perspective view of the stop portion of the second work piece in FIG. 11 that does not abut against the stop seat.

FIG. 13 shows a schematic diagram of a switching member in a first switching position when the third rail of the slide rail assembly is in an extended position relative to the second rail according to an embodiment of the present invention.

FIG. 14 shows a schematic diagram of the switching member in a second switching position when the third rail of the slide rail assembly is in the extended position relative to the second rail according to an embodiment of the present invention.

FIG. 15 is a schematic diagram showing that when the third rail of FIG. 14 is displaced in a second direction, the second rail can be driven to a position by means of a switching member.

FIG. 16 shows a partial perspective view of the blocking portion of the switching element in FIG. 15 abutting against the blocking seat.

FIG. 17 is a schematic diagram showing that the second rail in FIG. 15 is located at this position relative to the first rail, and the third rail is displaced in the first direction relative to the second rail until the first work piece abuts against the stop portion of the stop seat.

FIG. 18 shows a schematic diagram of the first working part in FIG. 17 disengaging from the stop portion of the stop seat.

Fig. 19 shows a schematic diagram of the third rail of Fig. 18 being detachable relative to the second rail.

FIG. 20 is a schematic diagram showing a first space between a slide rail assembly in a first extended state and an environmental object according to an embodiment of the present invention.

FIG. 21 is a schematic diagram showing a second space between the slide rail assembly of FIG. 20 in a second extended state and the environmental object.

detailed description

FIG. 1 shows that a pair of slide rail assemblies 20 according to an embodiment of the present invention can be used to mount a load 22 to a rack 24 . Specifically, each slide rail assembly 20 can be mounted on a first column 28a and a second column 28b of the frame 24 by means of a first bracket 26a and a second bracket 26b. Since this part is a technical category that can be understood by those who are familiar with the field, for the sake of brevity, details are not repeated here.

As shown in FIG. 2 , the slide rail assembly 20 includes a first rail 30 , a second rail 32 and a third rail 34 . The first rail 30 is provided with the above-mentioned first bracket 26a and second bracket 26b. The first rail 30 has a front end 36a, a rear end 36b, and a first channel 38 located between the front end 36a and the rear end 36b. Preferably, the first rail 30 has at least one contact portion 40, such as two protrusions, located adjacent to the rear end 36b. In this embodiment, the slide rail assembly 20 further includes a first stopper 42 and a second stopper 44 , wherein the first stopper 42 can be disposed adjacent to the rear end 36b of the first rail 30 ; The second stopper 44 can be disposed away from the rear end 36b of the first rail 30 .

The second rail 32 is mounted to the first channel 38 of the first rail 30 . The second rail 32 has a front end 46a, a rear end 46b, and a second channel 48 located between the front end 46a and the rear end 46b. Preferably, the slide rail assembly 20 further includes a first locking mechanism 50 , a second locking mechanism 52 , a third locking mechanism 54 and a blocking seat 56 . Wherein, the first engaging mechanism 50 , the second engaging mechanism 52 and the third engaging mechanism 54 are installed on the second rail 32 and are located at different positions. For example, the second locking mechanism 52 is located between the first locking mechanism 50 and the third locking mechanism 54, wherein the first locking mechanism 50 is adjacent to the rear end of the second rail 32 46b. The first latching mechanism 50 includes a first latching member 58 and a first elastic member 60 to provide elastic force to the first latching member 58; the second latching mechanism 52 includes a second latching member 62 and a The second elastic member 64 provides elastic force to the second engaging member 62 ; the third engaging mechanism 54 includes a third engaging member 66 and a third elastic member 68 provides elastic force to the third engaging member 66 . Preferably, it also includes a first pivotal member 70, a second pivotal member 72 and a third pivotal member 74 to connect the first latching member 58, the second latching member 62 and the third latching member respectively. The locking member 66 is pivotally connected to the second rail 32 . On the other hand, the blocking seat 56 (this part can be further referred to FIG. 3 ) is disposed on the second rail 32 , for example adjacent to the front end 46 a of the second rail 32 , and the blocking seat 56 has a blocking portion 76 .

The third rail 34 is installed to the second channel 48 of the second rail 32, and the third rail 34 can be used to carry the above-mentioned load 22 (not shown), because this part can be understood by those who are familiar with this field For the sake of brevity, the technical category will not be repeated here.

As shown in FIGS. 4 and 5 , the third rail 34 has a front end 78 a and a rear end 78 b. The third rail 34 includes an upper wall 80a, a lower wall 80b, and a longitudinal wall 82 connected between the upper wall 80a and the lower wall 80b (wherein, since the third rail 34 shown in FIGS. 4 and 5 is are reversed, so all related components shown in the two figures, such as the upper wall 80a and the lower wall 80b are also reversed). The third rail 34 has a rear stop 84 and a front stop 86 . The rear stopper 84 is located adjacent to the rear end 78b of the third rail 34 ; the front stopper 86 is located adjacent to the front end 78a of the third rail 34 . In this embodiment, both the rear stopper 84 and the front stopper 86 are a protrusion as an example.

Preferably, a first work piece 88 and a second work piece 90 are installed on the longitudinal wall 82 of the third rail 34 . In this embodiment, a fourth pivot member 92 and a fifth pivot member 94 are further included to pivotally connect the first work piece 88 and the second work piece 90 to the longitudinal wall 82 of the third rail 34 respectively .

In this embodiment, it further includes an elastic seat 96 , a first operating member 98 , a second operating member 100 , a first auxiliary elastic member 102 and a second auxiliary elastic member 104 . The elastic seat 96 is connected to the longitudinal wall 82 of the third rail 34 to elastically support at least a part of the first working part 88 and the second working part 90; the first operating part 98 and the second operating part 100 It can be used to operate the first working member 88 and the second working member 90 respectively; the first auxiliary elastic member 102 and the second auxiliary elastic member 104 can be used to provide elastic force to the first operating member 98 and the second operating member 98 respectively. Two operating elements 100 . Preferably, a switching member 106 is installed on the third rail 34 , and the switching member 106 and the front stopper 86 are separated by a longitudinal distance from each other. Specifically, the switch member 106 is movably connected, for example, pivotally connected to the longitudinal wall 82 of the third rail 34 via a sixth pivot member 108 . Preferably, the third rail 34 also has a supporting feature 110 , and the switching member 106 has two switching features 112 . When the switch member 106 is in different positions, each switch feature 112 can be supported by the support feature 110 correspondingly. Wherein, the supporting feature 110 and the two switching features 112 can be, for example, corresponding structures of concave and convex, convex and concave, or convex and convex.

As shown in FIG. 6, the first latching member 58, the second latching member 62 and the third latching member 66 may respectively have a first extension 113, a second extension 115 and a third extension The portion 117 protrudes from the second rail 32 to correspond to the first rail 30 . The second blocking member 44 includes a release portion 114 and a limiting portion 116 extending from the release portion 114 and bent at an angle. Wherein, the release portion 114 can be a slope or a curved surface. When the slide rail assembly 20 is in a retracted state, the second rail 32 is retracted relative to the first rail 30 , and the rear end 46b of the second rail 32 can be against at least one contact of the first rail 30 part 40 and is in a first position P1; the third rail 34 is retracted relative to the second rail 32, and the front stop 86 of the third rail 34 can be against the stop portion 76 of the stop seat 56 of the second rail 32 ( This part can further refer to Figure 7). Wherein, the two opposite parts of the first locking member 58 can be respectively supported by the first elastic member 60 and the third rail 34 (such as the lower wall 80b of the third rail 34) to maintain a predetermined state; On the other hand, the second latching member 62 and the third latching member 66 are respectively maintained in a predetermined state by providing elastic forces provided by the second elastic member 64 and the third elastic member 68 . Wherein, when the second engaging member 62 is in the predetermined state, the position of the second engaging member 62 corresponds to the rear stop 84 of the third rail 34, in this embodiment, the rear stop 84 and the second There is a distance between the catch pieces 62, and the position of the second extension 115 of the second catch piece 62 corresponds to the release portion 114 of the second stopper 44; on the other hand, in the third catch piece When 66 is in the predetermined state, the position of the third extension portion 117 of the third locking member 66 corresponds to the release portion 114 of the second locking member 44 .

As shown in FIG. 8 , when the third rail 34 is displaced in a first direction D1 relative to the second rail 32 , the third rail 34 can be pushed against the second engaging member 62 by the backstop 84 to synchronously Drive the second rail 32 to move from the first position P1 to the first direction D1, and when it is displaced to a position, the third extension 117 of the third engaging member 66 can be moved by the second stopper 44 The release part 114 guides and abuts against the second blocking member 44, so that the third elastic member 68 stores an elastic force, and the second extending portion 115 of the second locking member 62 contacts the second blocking member 44 The release part 114.

As shown in FIG. 9 , when the third rail 34 is further displaced to a predetermined position in the first direction D1, the second locking member 62 can be guided to swing by the release portion 114 of the second blocking member 44 An angle, so that the second catch 62 can be disengaged from the backstop 84 of the third rail 34, so as to release the synchronous displacement relationship between the second rail 32 and the third rail 34, and the second rail 32 is relatively The first rail 30 has reached a second position P2; on the other hand, after passing the second blocking member 44, the third locking member 66 can respond to the elastic force of the third elastic member 68 to deflect at an angle And it is located adjacent to the limiting portion 116 of the second blocking member 44 , so that the second rail 32 can stay at the second position P2 temporarily. In addition, since the third rail 34 can continue to displace in the first direction D1 relative to the second rail 32, the first engaging member 58 is no longer held by the third rail 34 (such as the lower wall 80b of the third rail 34). ) support, and the first locking member 58 can respond to the elastic force of the first elastic member 60 to deflect at an angle to correspond to the first blocking member 42 .

Further, the third rail 34 is displaced relative to the second rail 32 in the first direction D1 to reach a third position P3 (for example, an extended position), and the front end 78a of the third rail 34 exceeds the second In the state of the front end 46a of the rail 32, the first rail 30, the second rail 32 and the third rail 34 define a first length L1. In other words, the first length L1 is defined between the rear end 36 b of the first rail 30 and the front end 78 a of the third rail 34 .

As shown in FIG. 10 , when the third rail 34 reaches the third position P3, the first work piece 88 can abut against one side S1 of the stop portion 76 of the stop seat 56 at a first work position X1; On the one hand, when the third rail 34 reaches the third position P3, the second work piece 90 is displaced along the stop portion 76 of the stop seat 56 and generates an elastic force, when the second work piece 90 passes over the The blocking portion 76 of the blocking seat 56 releases the elastic force immediately, so that the second working member 90 can abut against the other side S2 of the blocking portion 76 of the blocking seat 56 in a first working position Y1. That is to say, in this state, the third rail 34 cannot extend or retract relative to the second rail 32 .

As shown in FIG. 11 and FIG. 12 , an operator can apply a force F1 to displace the second operating member 100, so as to operate the second working member 90 to swing an angle from the first working position Y1 to a second working position. Y2, so that the second work piece 90 cannot touch the other side S2. That is, in this state, the third rail 34 can be folded in a second direction D2 relative to the second rail 32 .

As shown in FIGS. 13 and 14 , the operator can operate the switching member 106 from a first switching position W1 to a second switching position W2 . Wherein, at the first switching position W1, the switching member 106 is staggered from the stop portion 76 of the stop seat 56; at the second switching position W2, the switching member 106 is not staggered from the stop portion 76 of the stop seat 56 .

As shown in FIG. 14, when the third rail 34 is displaced from an extended position to the second direction D2 to a position relative to the second rail 32, the third rail 34 (for example, the lower wall 80b of the third rail 34 ) will push against the third latching member 66, so that the third latching member 66 can be deflected at an angle and disengage from the limiting portion 116 of the second blocking member 44.

As shown in FIGS. 14 and 15 , the first blocking member 42 has a guiding portion 118 and a locking portion 120 extending from the guiding portion 118 and bent at an angle. Wherein, the guiding portion 118 can be a slope or a curved surface. When the third rail 34 is further displaced in the second direction D2, the third rail 34 can be pushed against the other side S2 of the blocking portion 76 of the blocking seat 56 at the second switching position W2 by the switching member 106 (This part can cooperate with referring to Fig. 16), so that the second rail 32 follows the third rail 34 from the second position P2 to the second direction D2 displacement, and in the process of displacement to the second direction D2, by means of Guided by the guide portion 118, the first latching member 58 can deflect at an angle and respond to the elastic force of the first elastic member 60 against the latching portion 120 of the first stopper 42, so that the second rail 32 is kept at a fourth position P4, such as a retracted position. In this state, the second rail 32 cannot be displaced relative to the first rail 30 in the second direction D2 or the first direction D1 (a direction opposite to the second direction D2).

It is worth mentioning that since the switching member 106 replaces the front stop 86 of the third rail 34 and is adjacent to the other side S2 of the stop portion 76 of the stop seat 56, the third rail 34 is opposite to the second rail. When the third rail 32 is folded, the backstop 84 of the third rail 34 will keep a certain distance from the second locking member 62, so that the second rail 32 cannot be driven synchronously when the third rail 34 is displaced.

As shown in FIG. 17 , when the second rail 32 is at the fourth position P4, the third rail 34 can be displaced in the first direction D1 relative to the second rail 32 until the first work piece 88 touches On one side S1 of the blocking portion 76 of the blocking seat 56, a second length L2 is defined between the rear end 36b of the first rail 30 and the front end 78a of the third rail 34 at this time, and the second length L2 is relatively short. In the above-mentioned first length L1 (as shown in FIG. 9 ). That is to say, the first length L1 can be shortened to the second length L2 by virtue of the second rail 32 being retracted to the fourth position P4 relative to the first rail 30 .

As shown in Figures 18 and 19, in the state of the second length L2, the operator can apply a force F2 to displace the first operating member 98, so as to operate the first working member 88 to move from the first working position X1 To a second working position X2 , the first work piece 88 is disengaged from the side S1 of the blocking portion 76 of the blocking seat 56 , so that the third rail 34 can be dismounted relative to the second rail 32 .

As shown in FIG. 20, in a limited space environment, when the slide rail assembly 20 is in an extended state, there is a first A space S1. However, the first space S1 may be quite narrow for operators to maintain the slide rail assembly 20 , such as removing the aforementioned third rail 34 .

As shown in FIG. 21 , the operator can use the above-mentioned operation method to make the second rail 32 retract relative to the first rail 30 and temporarily lock it on the first rail 30, so that the entire slide rail assembly 20 The length is shortened. In this state, there is a second space S2 between the slide rail assembly 20 and the environmental object 122. The second space S2 can be larger than the first space S1, so that the operator has more space. The space can be used to facilitate the related maintenance work of the slide rail assembly 20; or to facilitate the unloading of the third rail 34 from the second rail 32.

In addition, the present invention also provides a method for operating the slide rail assembly, which has been disclosed in the above-mentioned embodiments, and will not be repeated here for the sake of brevity.

According to the above description, it can be seen that the enhanced efficacy and advantages of the present invention lie in that the extension length of the slide rail assembly can be shortened to facilitate application in a limited environmental space.

Although the present invention has been described with reference to the current specific embodiments, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present invention, and other modifications can be made without departing from the spirit of the present invention. Various equivalent changes and modifications, therefore, as long as the changes and modifications to the above embodiments are within the true spirit of the present invention, they will all fall within the scope of the claims of the present application.

Claims (15)

1. A slide rail assembly comprising a first rail, a second rail, a third rail and a first locking mechanism, wherein the first rail has a front end and a rear end; the second rail It can be displaced relative to the first rail; the third rail can be displaced relative to the second rail, and the third rail has a front end and a rear end; it is characterized in that: The first locking mechanism is movably installed on the second rail; Wherein, when the second rail is displaced relative to the first rail from a first position to a first direction to a second position, and the third rail is displaced to a third position relative to the second rail in the first direction When exceeding the second rail, a first length is defined between the rear end of the first rail and the front end of the third rail; Wherein, when the second rail is displaced from the second position to a fourth position in a second direction, the first length between the rear end of the first rail and the front end of the third rail can be shortened to a the second length, and by means of the first locking mechanism, the second rail is located at the fourth position relative to the first rail. 2. The slide rail assembly according to claim 1, further comprising a first working part and a stop seat, the first working part is mounted on the third rail and is operatively positioned on a first Between the working position and a second working position, the blocking seat is arranged on the second rail and has a blocking portion, when the third rail is displaced to a position in the first direction, it can be moved by the first working part on the The first working position abuts against one side of the blocking portion of the blocking seat; when the first working part is operated from the first working position to the second working position, the first working part is no longer against the The blocking part of the blocking seat enables the third rail to be unloaded relative to the second rail. 3. The slide rail assembly according to claim 2, further comprising a second working part elastically mounted on the third rail, when the third rail is displaced to the position in the first direction wherein, the second work piece is displaced along the stop portion of the stop seat, and when the second work piece passes over the stop portion of the stop seat, the second work piece abuts against the other side of the stop portion of the stop seat. 4. The slide rail assembly according to claim 2, further comprising a switching member installed on the third rail, the switching member can be operated at a first switching position or a second switching position, and at In the first switching position, the switching member is staggered from the blocking portion of the blocking seat, and in the second switching position, the switching member is not staggered from the blocking portion of the blocking seat. 5 . The slide rail assembly according to claim 4 , wherein the third rail has a front stop, and the front stop and the switching member are separated from each other. 6. The slide rail assembly according to claim 1, further comprising a first stopper disposed on the first rail, when the second rail is in the fourth position, the second rail is The first locking mechanism is on the first blocking member. 7. The slide rail assembly according to claim 6, wherein the first engaging mechanism comprises a first engaging member and a first elastic member providing elastic force to the first engaging member, when the first engaging member When the second rail is at the fourth position, the first engaging member is locked against the first blocking member by virtue of the elastic force of the first elastic member. 8. The slide rail assembly according to claim 1, further comprising a second blocking member and a second locking mechanism, the second blocking member is arranged on the first rail and includes a release portion , the second locking mechanism is movably installed on the second rail, and the third rail has a rear stop, wherein the third rail can push against the second locking mechanism by means of the rear stop to synchronously drive the first The two rails are displaced from the first position to the first direction, and when they are displaced to a predetermined position, the second latching mechanism is disengaged from the backstop by means of the release portion of the second stopper. 9. The slide rail assembly according to claim 8, wherein the second latching mechanism comprises a second latching member and a second elastic member providing elastic force to the second latching member, the first latching member The three rails can be pushed against the second engaging member by means of the backstop. 10. The slide rail assembly according to claim 8, wherein the second stopper further includes a limiting portion, and the slide rail assembly further includes a third locking mechanism movably mounted on the first stopper. The second rail, when the second rail is displaced to the second position, the third engaging mechanism is located adjacent to the limiting portion of the second blocking member. 11. The slide rail assembly according to claim 10, wherein the third latching mechanism comprises a third latching member and a third elastic member providing elastic force to the third latching member, in which When the second rail is displaced to the second position, the third engaging member is located adjacent to the limiting portion of the second blocking member in response to the elastic force of the third elastic member. 12. A slide rail assembly, suitable for installing a load on a rack, the slide rail assembly includes a first rail, a second rail, a third rail, a first stopper, a first A locking mechanism and a first work piece, wherein the first rail is mounted to the frame, the first rail has a front end and a rear end; the second rail can be displaced relative to the first rail; the third The rail can be displaced relative to the second rail, and the third rail is used to carry the load. The third rail has a front end and a rear end, and is characterized in that: The first stopper is arranged on the first rail; The first locking mechanism is movably installed on the second rail; and the first working member is mounted on the third rail, the first working member is operatively between a first working position and a second working position; Wherein, when the second rail is displaced relative to the first rail from a first position to a first direction to a second position, and the third rail is displaced to a third position relative to the second rail in the first direction When exceeding the second rail, a first length is defined between the rear end of the first rail and the front end of the third rail; Wherein, when the second rail is displaced from the second position to a fourth position in a second direction, the first length between the rear end of the first rail and the front end of the third rail can be shortened to a the second length, and the second rail is located at the fourth position relative to the first rail by means of the first locking mechanism on the first stopper; Wherein, when the first work piece is operated to move from the first working position to the second working position, the third rail can be detached relative to the second rail. 13. A method for operating a slide rail assembly, comprising: provide a first track; providing a second rail displaceable from a first position in a first direction to a second position relative to the first rail; providing a third rail displaceable relative to the second rail beyond the second position to a third position; providing a first working member operatively between a first working position and a second working position, wherein, in the first working position, the third rail is in the third position relative to the second rail such that the first rail, the second rail and the third rail define a first length; A first latching mechanism is provided, so that when the second rail is displaced from the second position to a second direction to a fourth position relative to the first rail, the second rail is moved relative to the first rail by means of the first latching mechanism. the first rail is located in the fourth position, shortening the first length to a second length; and In the state of the second length, the first working member is operatively displaced from the first working position to the second working position, so that the third rail can be detached relative to the second rail. 14. The method for operating the slide rail assembly according to claim 13, characterized in that, in the step of providing the first work piece, further comprising providing a stop seat with a stop portion to the second rail, so that When the third rail is displaced in the first direction, the first work piece can be used to abut against one side of the stop portion of the stop seat by virtue of the first work piece being in the first work position. 15. The operation method of the slide rail assembly according to claim 13, further comprising providing a first stopper to the first rail, when the second rail is in the fourth position, the second The rail is locked against the first stopper by means of the first locking mechanism.