Patent Description:
Intelligent warehousing is a link in the logistics chain. The use of intelligent warehousing ensures the speed and accuracy of data input in all steps of warehouse management, so as to ensure that enterprises can grasp the real data of the inventory timely and accurately, and properly maintain and control the enterprise's inventory. Batches and shelf life of warehouse goods can be conveniently managed by means of scientific coding. By using the storage location management function of the SNHGES system, current locations of all warehouse goods can be grasped more timely, which is conducive to improving the efficiency of warehouse management.

The carrying robot plays an important role in the intelligent warehousing. The carrying robot replaces the manual carrying of goods, but when the existing carrying robot is carrying containers, the containers are unstable and easy to fall off.

Document <CIT> discloses an Automated Guided Robot (AGV) system designed for carrying, storing and retrieving inventory items. The AGV is equipped with a material handling device comprising a lateral device that is configured to move in a lateral direction and a retractable device that retracts or extends in a direction perpendicular to the lateral direction. The movement of the lateral device can be either rotational or translational. The retractable device allows the material handling device to extend into a storage shelf to fetch or place an inventory item.

Based on this, it is necessary to provide a fork and a carrying robot to resolve the problem of instability of a container when the conventional carrying robot carries the container.

In a first aspect, there is provided a carrying robot, as in claim <NUM>, comprising:.

In a second aspect, there is provided a method as in claim <NUM>, performed by a carrying robot, wherein
the carrying robot comprises:.

According to the carrying robot provided in this application, the sliding assembly is capable of pushing the temporary storage tray to make the temporary storage tray extend relative to the fixed arm, and the extending direction of the temporary storage tray is consistent with the extending direction of the movable arm. Therefore, when the fork pulls in or pushes out the goods, the container can be stably transferred between a stationary rack and the temporary storage tray and will not fall off during the transfer.

Robot body <NUM>, Movable chassis <NUM>, Shelving unit <NUM>, Shelf board <NUM>; Handling device <NUM>, Rotary assembly <NUM>, Fork bracket <NUM>, Symmetry axis S1, Fork <NUM>, Fixed arm <NUM>, Underframe <NUM>, Side wall <NUM>, Movable arm <NUM>, First arm section <NUM>, Connecting plate <NUM>, Second arm section <NUM>, Top end <NUM>, Temporary storage tray <NUM>, Free end <NUM>, Rib <NUM>, Sliding assembly <NUM>, Spring <NUM>, Guide rod <NUM>, Sliding block <NUM>, Stopper <NUM>, Pusher assembly <NUM>, Movable pusher <NUM>, Fixed pusher <NUM>, Pusher driving member <NUM>, First driving assembly <NUM>, Chain wheel mechanism <NUM>, Driving member <NUM>, Second driving assembly <NUM>, Movable pulley <NUM>, Strop <NUM>; and Stationary rack <NUM>.

For ease of understanding this application, this application is described more comprehensively below with reference to the accompanying drawings. Exemplary embodiments of this application are provided in the accompanying drawings. However, this application may be implemented in many different forms, and is not limited to the embodiments described in this specification. On the contrary, an objective of providing the embodiments is to make the understanding of the invention of this application more clearly and comprehensively.

It should be noted that, when a component is referred to as "being fixed to" another component, the component may be directly on the another component, or there may be an intermediate component between them. When a component is considered to be "connected to" another component, the component may be directly connected to the another component, or there may be an intermediate component between them. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this specification are merely for purposes of illustration but not indicate a unique way for implementation.

Unless otherwise defined, meanings of all technical and scientific terms used in this specification are the same as those usually understood by a person skilled in the art to which this application belongs. In this application, terms used herein are merely intended to describe the specific embodiments, but are not intended to limit this application. The term "and/or" used in this specification includes any and all combinations of one or more related listed items.

<FIG> is a schematic structural diagram of a carrying robot in an initial state according to an embodiment of this application. As shown in <FIG>, in an embodiment, the carrying robot includes a robot body <NUM> and a handling device <NUM>. The robot body <NUM> includes a movable chassis <NUM>, a shelving unit <NUM>, and a lifting assembly (not shown in the figure). The shelving unit <NUM> is mounted to the movable chassis <NUM>, and the shelving unit <NUM> includes more than two shelf board assemblies distributed at different height. Each shelf board assembly includes a shelf board <NUM> for placing goods. The lifting assembly is configured to drive the handling device <NUM> to rise or fall relative to the shelving unit <NUM>, so that the handling device <NUM> is at the same height as the shelf board <NUM> or a stationary rack <NUM>. <FIG> is a schematic diagram of an exploded structure of a handling device according to an embodiment of this application. As shown in <FIG>, the handling device <NUM> includes a rotary assembly <NUM>, a fork bracket <NUM>, and a fork <NUM>. The fork bracket <NUM> is mounted to the shelving unit <NUM> and can be lifted or lowered relative to the shelving unit <NUM> with an action of a lifting assembly. The fork <NUM> and the rotary assembly <NUM> are both mounted to the fork bracket <NUM>. The fork <NUM> is rotatable relative to the fork bracket <NUM> in a vertical direction with an action of the rotary assembly <NUM>. The fork <NUM> is used for carrying goods to the shelf board <NUM> at the same height as the fork <NUM> or used for moving out the goods from the shelf board <NUM> at the same height as the fork <NUM>.

<FIG> is a schematic structural diagram of a movable arm of a handling device in an extended state according to an embodiment of this application. As shown in <FIG> and <FIG>, the fork <NUM> is provided with a symmetry axis S1 and includes a telescopic arm, a temporary storage tray <NUM>, and a sliding assembly <NUM>. The telescopic arm includes a fixed arm <NUM>, a movable arm <NUM>, a pusher assembly <NUM>, and a driving assembly. The fixed arm <NUM> includes an underframe <NUM> and two side walls <NUM> that are fixedly connected to the underframe <NUM>. The underframe <NUM> is mounted to the rotary assembly <NUM>. One end of the movable arm <NUM> is connected to the side wall <NUM> of the fixed arm <NUM>, and an other end thereof is connected to the pusher assembly <NUM>. The movable arm <NUM> is telescopically movable relative to the fixed arm <NUM> along the symmetry axis S1 with an action of the driving assembly. The pusher assembly <NUM> is configured to pull in or push out goods during the telescopic movement of the movable arm <NUM>, and the temporary storage tray <NUM> is mounted to the underframe <NUM> of the fixed arm <NUM> and is used for temporarily storing the goods pulled by the pusher assembly <NUM>. The sliding assembly <NUM> is mounted between the underframe <NUM> of the fixed arm <NUM> and the temporary storage tray <NUM>, and is capable of pushing the temporary storage tray <NUM> to make the temporary storage tray <NUM> extend relative to the fixed arm <NUM> along the symmetry axis S1. An extending direction of the temporary storage tray <NUM> is consistent with an extending direction of the movable arm <NUM>.

Further, in an embodiment, as shown in <FIG> and <FIG>, quantities of the side walls <NUM> of the fixed arm <NUM> and the movable arms <NUM> are both two. The two side walls <NUM> and the two movable arms <NUM> are symmetrically disposed on two opposite sides of the symmetry axis S1. Each movable arm <NUM> includes a first arm section <NUM> and a second arm section <NUM>. The first arm section <NUM> is mounted to the fixed arm <NUM>, and the second arm section <NUM> is mounted to the first arm section <NUM>. <FIG> is a schematic structural diagram of a first arm section according to an embodiment of this application, and <FIG> is a schematic structural diagram of a handling device when facing to a stationary rack according to an embodiment of this application. As shown in <FIG>, the driving assembly includes a first driving assembly <NUM> and a second driving assembly <NUM>. The first arm section <NUM> is telescopically movable relative to the fixed arm <NUM> with an action of the first driving assembly <NUM>, and the second arm section <NUM> is telescopically movable relative to the first arm section <NUM> with an action of the second driving assembly <NUM>. In a specific embodiment, as shown in <FIG>, the fixed arm <NUM> is an outer arm, the first arm section <NUM> is a middle arm, and the second arm section <NUM> is an inner arm. The middle arm is mounted to an inner side of a side wall of the outer arm, and the inner arm is mounted to an inner side of the middle arm. The middle arm is telescopically movable relative to the outer arm with the action of the first driving assembly <NUM>, and the inner arm is telescopically movable relative to the middle arm with the action of the second driving assembly <NUM>. It may be understood that, in another specific embodiment, the fixed arm <NUM> may further be an inner arm, the first arm section <NUM> is a middle arm, and the second arm section <NUM> is an outer arm. The middle arm is mounted to an outer side of a side wall of the inner arm, and the outer arm is mounted to an outer side of the middle arm. In addition, according to an actual condition, the number of movable arms <NUM> is not limited to two, and in other embodiments, the number of movable arms <NUM> may be one. In addition, it may be understood that, in another embodiment, the movable arm <NUM> may include only the inner arm, but not the middle arm. The inner arm is mounted to the inner side of the side wall of the outer arm, and the inner arm is telescopically movable relative to the outer arm along the symmetry axis S1 with the action of the driving assembly. In still another embodiment, the movable arm <NUM> may include an inner arm and more than two middle arms. The movable arm <NUM> is telescopically movable relative to the outer arm along the symmetry axis S1 with the action of the driving assembly.

In an embodiment, as shown in <FIG> and <FIG>, the sliding assembly <NUM> includes a spring <NUM>. One end of the spring <NUM> is connected to the underframe <NUM> of the fixed arm <NUM>, and an other end thereof is connected to the temporary storage tray <NUM>. The temporary storage tray <NUM> extends out relative to the fixed arm <NUM> with the push of an elastic force of the spring <NUM>. <FIG> is a schematic structural diagram of a handling device when pulling goods according to an embodiment of this application. As shown in <FIG>, when the temporary storage tray <NUM> extends relative to the fixed arm <NUM>, a free end <NUM> of the temporary storage tray <NUM> may protrude from the fixed arm <NUM>. <FIG> is a schematic structural diagram of a movable arm of a handling device in a retracted state according to an embodiment of this application. In another embodiment, as shown in <FIG> and <FIG>, the sliding assembly <NUM> includes a spring <NUM>, a guide rod <NUM>, and a sliding block <NUM>. The guide rod <NUM> is fixed to the fixed arm <NUM>, and the spring <NUM> and the sliding block <NUM> are both sleeved on the guide rod <NUM>. The temporary storage tray <NUM> is connected to the sliding block <NUM>, and the temporary storage tray <NUM> and the sliding block <NUM> are slidable along the guide rod <NUM> with the elastic action of the spring <NUM>. Further, a stopper <NUM> is disposed on the guide rod <NUM> to prevent the temporary storage tray <NUM> and the sliding block <NUM> from slipping off the guide rod <NUM>.

It should be noted that this application does not limit the number of guide rods <NUM>, sliding blocks <NUM>, and springs <NUM> in the sliding assembly <NUM>. In the embodiment shown in <FIG> and <FIG>, two guide rods <NUM> are disposed, four sliding blocks <NUM> are disposed, and two springs <NUM> are disposed. It may be understood that, in other embodiments, one guide rod or other number of guide rods <NUM> may be disposed, one sliding block or other number of sliding blocks <NUM> may be disposed, and one spring or other number of springs <NUM> may be disposed.

In an embodiment, as shown in <FIG>, the pusher assembly <NUM> is mounted to the second arm section <NUM>. The pusher assembly <NUM> includes a fixed pusher <NUM>, a movable pusher <NUM>, and a pusher driving member <NUM>. The movable pusher <NUM> is mounted to a top end <NUM> of the second arm section <NUM>. It may be understood that the top end <NUM> mentioned herein refers to an end farthest from the fixed arm <NUM> when the movable arm <NUM> extends relative to the fixed arm <NUM> along the symmetry axis S1. The fixed pusher <NUM> is mounted to an end of the second arm section <NUM> facing away from the movable pusher <NUM>, and the pusher driving member <NUM> is connected to the movable pusher <NUM> for driving the movable pusher <NUM> to be folded or unfolded relative to the second arm section <NUM>. When the movable pusher <NUM> is unfolded relative to the second arm section <NUM>, the movable pusher <NUM> protrudes from the second arm section <NUM> in a direction close to the symmetry axis S1, as shown in <FIG>. When the movable pusher <NUM> is folded relative to the second arm section <NUM>, the movable pusher <NUM> and the second arm section <NUM> substantially overlap, as shown in <FIG>. In a specific embodiment, the pusher driving member <NUM> is a pusher motor. The movable pusher <NUM> is directly driven by the pusher motor. The pusher motor is configured to drive the movable pusher <NUM> to rotate relative to the second arm section <NUM>, so that the movable pusher <NUM> is unfolded or folded relative to the second arm section <NUM>. It may be understood that, according to the actual condition, in other embodiments, the movement manner of the movable pusher <NUM> is not limited to rotation. For example, the movable pusher <NUM> may extend out of the second arm section <NUM> or retract into the second arm section <NUM>.

In an embodiment, as shown in <FIG> and <FIG>, the first driving assembly <NUM> is disposed on the fixed arm <NUM> and includes a chain wheel mechanism <NUM> and a driving member <NUM>. An output end of the driving member <NUM> is connected to a driving chain wheel of the chain wheel mechanism <NUM>. A connecting plate <NUM> is disposed on the first arm section <NUM>, and the connecting plate <NUM> is fixedly connected to a link chain of the chain wheel mechanism <NUM>. The first driving assembly <NUM> is configured to drive the driving chain wheel to rotate. Since the first arm section <NUM> is fixedly connected to the link chain of the chain wheel mechanism <NUM> by using the connecting plate <NUM>, the chain wheel mechanism <NUM> can drive, by using the connecting plate <NUM>, the first arm section <NUM> to move relative to the fixed arm <NUM> along the symmetry axis S1. As shown in <FIG>, a rib <NUM> is disposed on the temporary storage tray <NUM>. <FIG> is a schematic structural diagram of a movable arm when retracting after a handling device pulls goods according to an embodiment of this application. As shown in <FIG>, when the first arm section <NUM> retracts relative to the fixed arm <NUM> with the action of the first driving assembly <NUM>, the connecting plate <NUM> abuts against the rib <NUM>. Therefore, the temporary storage tray <NUM> can be pushed to retract relative to the fixed arm <NUM>, and the temporary storage tray <NUM> is pushed back to the original position. When the temporary storage tray <NUM> is pushed back to the original position, as shown in <FIG>, the spring <NUM> is in a compressed state, and the temporary storage tray <NUM> is blocked by the connecting plate <NUM> and is located on the underframe <NUM> of the fixed arm <NUM>. Once the connecting plate <NUM> extends relative to the fixed arm <NUM> along with the first arm section <NUM> with the action of the first driving assembly <NUM>, as shown in <FIG>, the temporary storage tray <NUM> loses obstruction and is pushed out with an elastic restoring force of the spring <NUM>, so that the free end <NUM> of the temporary storage tray <NUM> protrudes from the fixed arm <NUM>. It should be noted that a direction in which the temporary storage tray <NUM> is pushed out by the spring <NUM> is consistent with a direction in which the movable arm <NUM> extends relative to the fixed arm <NUM>. It may be understood that, according to the actual condition, the chain wheel mechanism <NUM> of the first driving assembly <NUM> may be replaced with a pulley mechanism or the like.

In addition, it should be noted that in the embodiment shown in <FIG>, the spring <NUM> is a compression spring. It may be understood that in other embodiments, the spring <NUM> may be a tension spring. When the temporary storage tray <NUM> is pushed back to the original position, the spring <NUM> is in a stretched state, and the connecting plate <NUM> blocks the temporary storage tray <NUM>, and the temporary storage tray <NUM> is located on the underframe <NUM> of the fixed arm <NUM>. Once the connecting plate <NUM> extends relative to the fixed arm <NUM> along with the first arm section <NUM> with the action of the first driving assembly <NUM>, the temporary storage tray <NUM> loses obstruction and is pulled out with the elastic restoring force of the spring <NUM>.

In an embodiment, as shown in <FIG>, the second driving assembly <NUM> includes a movable pulley <NUM> and a strop <NUM>. The movable pulley <NUM> is mounted to the first arm section <NUM>, and a middle part of the strop <NUM> is bent, so that two ends of the strop <NUM> are disposed opposite to each other. The middle part of the strop <NUM> is sleeved on the movable pulley <NUM>, one end of the strop <NUM> is fixedly connected to the fixed arm <NUM>, and an other end thereof is fixedly connected to the second arm section <NUM>. The movable pulley <NUM> and the strop <NUM> form a movable pulley structure. When the first arm section <NUM> moves at a first speed relative to the fixed arm <NUM>, the second arm section <NUM> moves at a second speed relative to the fixed arm <NUM>. The second speed is twice the first speed. By disposing a movable pulley mechanism, the extension or retraction speed of the second arm section <NUM> can be faster, and the efficiency of picking and placing goods of the fork is improved. In a specific embodiment, the movable pulley <NUM> is a flat pulley, and the strop <NUM> is an open-loop flat belt. It may be understood that, in other embodiments, the movable pulley <NUM> may be a chain wheel, and the strop <NUM> may be a link chain.

When the handling device <NUM> is in an initial state, as shown in <FIG>, the free end <NUM> of the temporary storage tray <NUM> is provided towards the shelving unit <NUM>. The carrying robot carries a container on the stationary rack <NUM> to the shelf board <NUM> of the shelving unit <NUM> by performing the following steps. Step <NUM>: The handling device <NUM> is raised or lowered relative to the shelving unit <NUM> with an action of the lifting assembly, so that the symmetry axis S1 of the fork <NUM> is at a same height as the container on the stationary rack <NUM>. Step <NUM>: As shown in <FIG>, the fork <NUM> rotates with an action of the rotary assembly <NUM>, so that the container is located on the symmetry axis S1 of the fork <NUM>, and the free end <NUM> of the temporary storage tray <NUM> is oriented towards the container on the stationary rack <NUM>. It should be noted that, in the embodiments shown in <FIG> and <FIG>, the container on the stationary rack <NUM> is not shown in the figures. Step <NUM>: As shown in <FIG>, the movable arm <NUM> extends relative to the fixed arm <NUM> along the symmetry axis S1 with the action of the driving assembly. At the same time, the temporary storage tray <NUM> loses the blocking of the connecting plate <NUM> and is then pushed out with the action of the elastic restoring force of the spring <NUM>, so that the free end <NUM> of the temporary storage tray <NUM> protrudes from the fixed arm <NUM>, and the free end <NUM> of the temporary storage tray <NUM> is closer to the stationary rack <NUM>. In addition, in step <NUM>, the movable pusher <NUM> mounted to the top end <NUM> of the second arm section <NUM> is folded relative to the second arm section <NUM>, and the top end <NUM> of the second arm section <NUM> moves from a side of the container towards the temporary storage tray <NUM> to a side of the container away from the temporary storage tray <NUM>. Step <NUM>: The movable pusher <NUM> is unfolded relative to the second arm section <NUM> with an action of the pusher driving member <NUM>, and then the movable arm <NUM> retracts relative to the fixed arm <NUM> along the symmetry axis S1 with the action of the driving assembly, so that the movable pusher <NUM> can pull the container onto the temporary storage tray <NUM>. As shown in <FIG>, when the movable arm <NUM> retracts to a certain extent, the connecting plate <NUM> on the first arm section <NUM> abuts against the rib <NUM> on the temporary storage tray <NUM>, and the second arm section <NUM> continues to retract relative to the fixed arm <NUM> along the symmetry axis S1 with the action of the driving assembly, and pushes the temporary storage tray <NUM> to make the temporary storage tray retract relative to the fixed arm <NUM> along the symmetry axis S1, thereby pushing the temporary storage tray <NUM> back to the original position.

Step <NUM>: <FIG> is a schematic structural diagram of a handling device when orienting towards a shelving unit according to an embodiment of this application. As shown in <FIG>, the fork <NUM> rotates with an action of the rotary assembly <NUM>, so that the free end <NUM> of the temporary storage tray <NUM> orients towards the shelf board <NUM> on the shelving unit <NUM>. Step <NUM>: The handling device <NUM> is lifted or lowered relative to the shelving unit <NUM> with the action of the lifting assembly, so that the symmetry axis S1 of the fork <NUM> is at the same height as one empty shelf board <NUM> on the shelving unit <NUM>. Step <NUM>: <FIG> is a schematic structural diagram of a handling device when pushing goods on a temporary storage tray to a shelving unit according to an embodiment of this application. As shown in <FIG>, the movable arm <NUM> extends relative to the fixed arm <NUM> along the symmetry axis S1 with an action of the driving assembly. At the same time, the temporary storage tray <NUM> loses the blocking of the first arm section <NUM> and is then pushed out by the elastic restoring force of the spring <NUM>, so that the free end <NUM> of the temporary storage tray <NUM> protrudes from the fixed arm <NUM>, and the temporary storage tray <NUM> is closer to the shelf board <NUM> on the shelving unit <NUM>. During the extending of the movable arm <NUM>, the container is pushed onto the empty shelf board <NUM> of the shelving unit <NUM> by the fixed pusher <NUM>. In addition, in step <NUM>, the movable pusher <NUM> mounted to the top end <NUM> of the second arm section <NUM> may be folded relative to the second arm section <NUM> or may be unfolded relative to the second arm section <NUM>. In this embodiment, the movable pusher <NUM> is unfolded relative to the second arm section <NUM>, and the unfolded movable pusher <NUM> can prevent the container from falling from an other end of the shelf board <NUM>. Step <NUM>: The movable pusher <NUM> is folded relative to the second arm section <NUM> with the action of the pusher driving member <NUM> (in another embodiment, this step may also be performed in step <NUM>, step <NUM>, or step <NUM>. If the movable pusher <NUM> has been folded relative to the second arm section <NUM> in step <NUM>, then this step can be omitted in step <NUM>). The movable arm <NUM> retracts relative to the fixed arm <NUM> along the symmetry axis S1 with the action of the driving assembly. When the movable arm <NUM> retracts to a certain extent, the connecting plate <NUM> on the first arm section <NUM> abuts against the rib <NUM> on the temporary storage tray <NUM>. The movable arm <NUM> continues to retract relative to the fixed arm <NUM> along the symmetry axis S1 with the action of the driving assembly, and pushes the temporary storage tray <NUM> to make the temporary storage tray retract relative to the fixed arm <NUM> along the symmetry axis S1, thereby pushing the temporary storage tray <NUM> back to the original position.

It may be understood that the carrying robot of this application may further carry the container on the shelf board <NUM> of the shelving unit <NUM> to the stationary rack <NUM>. This process is contrary to the above process, and the details will not be described herein again.

According to the fork and the carrying robot of this application, the sliding assembly is disposed between the fixed arm of the handling device and the temporary storage tray. The sliding assembly is capable of pushing the temporary storage tray to make the temporary storage tray extend relative to the fixed arm, and the extending direction of the temporary storage tray is consistent with the extending direction of the movable arm. Therefore, when the fork of this application pulls in or pushes out the goods, the container can be stably transferred between the stationary rack and the temporary storage tray and will not fall off during the transfer.

The technical features in the foregoing embodiments may be randomly combined. For concise description, not all possible combinations of the technical features in the embodiments are described. However, provided that combinations of the technical features do not conflict with each other, the combinations of the technical features are considered as falling within the scope described in this specification.

Claim 1:
A carrying robot, comprising:
a robot body (<NUM>) comprising a movable chassis (<NUM>); and
a handling device (<NUM>) comprising a rotary assembly (<NUM>), a fork bracket (<NUM>), and a fork (<NUM>), the fork bracket (<NUM>) being mounted to the robot body (<NUM>), the fork (<NUM>) and the rotary assembly (<NUM>) being both mounted to the fork bracket (<NUM>), the fork (<NUM>) being rotatable relative to the fork bracket (<NUM>) around a vertical direction with an action of the rotary assembly (<NUM>);
wherein the fork (<NUM>) comprises a telescopic arm, a temporary storage tray (<NUM>), and a sliding assembly (<NUM>);
wherein the telescopic arm comprises:
a fixed arm (<NUM>);
a driving assembly;
a movable arm (<NUM>) connected to the fixed arm (<NUM>), the movable arm (<NUM>) being telescopically movable relative to the fixed arm (<NUM>) with an action of the driving assembly; and
a pusher assembly (<NUM>) mounted to the movable arm (<NUM>) and configured to pull or push goods during telescopic movement of the movable arm (<NUM>);
wherein the temporary storage tray (<NUM>) is mounted to the fixed arm (<NUM>) and is configured to temporarily store the goods, the temporary storage tray (<NUM>) being configured to extend or retract relative to the fixed arm (<NUM>), wherein an extending direction of the temporary storage tray (<NUM>) is consistent with an extending direction of the movable arm (<NUM>);
wherein the sliding assembly (<NUM>) is mounted between the fixed arm (<NUM>) and the temporary storage tray (<NUM>), the sliding assembly (<NUM>) being configured to push or pull the temporary storage tray (<NUM>) so as to enable the temporary storage tray (<NUM>) to extend relative to the fixed arm (<NUM>);
characterized in that
the sliding assembly (<NUM>) comprises a spring (<NUM>), a first end of the spring (<NUM>) being connected to the fixed arm (<NUM>), a second end of the spring (<NUM>) being connected to the temporary storage tray (<NUM>).