Shelf system

Abstract

The shelf system includes an outer frame and an internal unit. The internal unit is connected to the frame using one or more link mechanism assemblies. The link mechanism assembly includes a bracket attached to the frame, and the first and second arms are pivotally connected to the bracket. The first and second arms are pivotally connected to a multi-bar link mechanism connected to the internal unit. The guide arm is pivotally connected to the multi-bar link mechanism and can also move within the curved opening of the bracket. One or more actuators shift the shelf system from an upper configuration to a lower configuration and vice versa. In the upper arrangement, the internal unit is substantially within the frame, and in the lower arrangement, the internal unit is substantially away from the frame and is lowered from the frame.

Description

Technical Field

[0001] The present invention relates to a shelf system, and more particularly to an articulated shelf system.

Background Art

[0002] Shelf systems are commonly used for storage. They can be found in various locations, including, for example, kitchens, living rooms, garages, factories, and the like. One typical form of a shelf system is a cabinet. A cabinet generally takes the form of a rectangular box with one or more doors on the front to hide the contents of the cabinet from view. The doors may be opened to allow access to the interior of the cabinet, and the interior may be partitioned by one or more shelves.

[0003] The cabinet may be placed on the ground, and such a cabinet may sometimes be called a base cabinet. Alternatively, the cabinet may be attached to a wall so as to be suspended above the ground (usually called a wall cabinet). Such a wall cabinet has the advantage of providing some usable space below the cabinet, such as providing space for a countertop or table.

[0004] However, wall cabinets suspended above the ground may be difficult for some people to access. If the wall cabinet is mounted relatively high along the wall, it may be difficult for a short person to access the interior of the cabinet, especially the upper part of the cabinet.

[0005] Therefore, there is a need for a shelf system that allows the cabinet to be attached to a wall while still enabling easy access to the interior of the cabinet. These and other objects will be better understood by reference to the entire present application. Note that not all of the objects are necessarily met by all embodiments of the present invention described below.

Summary of the Invention

Means for Solving the Problem

[0006] In one aspect of the present invention, the shelf system includes an outer frame and an internal unit. The internal unit is connected to the frame using one or more link mechanism assemblies. The link mechanism assembly includes a bracket attached to the frame and has first and second arms pivotally connected to the bracket. The first and second arms are pivotally connected to a multi-bar link mechanism connected to the internal unit. The guide arm is pivotally connected to the multi-bar link mechanism and can also move within the curved opening of the bracket. One or more actuators shift the shelf system from an upper configuration to a lower configuration and vice versa. In the upper configuration, the internal unit is substantially within the frame, and in the lower configuration, the internal unit is substantially away from the frame and is lowered from the frame.

[0007] In another embodiment, the shelf system includes an outer frame, an internal unit, and one or more link mechanism assemblies. The link mechanism assembly is configured to connect the internal unit to the frame and cause a transition between an upper configuration and a lower configuration of the shelf system. In the upper configuration, the internal unit is disposed within the frame, and in the lower configuration, the internal unit is disposed offset both horizontally and vertically from the frame. Each of the link mechanism assemblies includes a bracket, a multi-bar link mechanism, first and second bracket arms, a guide assembly, and an actuator. The bracket is attached to the frame and the bracket includes an elongated curved bracket opening. The multi-bar link mechanism is attached to the internal unit. The first and second bracket arms are pivotally connected to the bracket and the multi-bar link mechanism. The guide assembly is pivotally connected to the multi-bar link mechanism and is configured to engage the bracket opening. The actuator includes an actuator body and an actuator arm configured to move longitudinally relative to the actuator body. The actuator body is attached to the frame and the actuator arm is pivotally connected to one of the first and second bracket arms. Movement of the actuator arm relative to the actuator body causes movement of the internal unit relative to the frame for the transition and includes movement of the guide assembly along the bracket opening during at least a portion of the transition.

[0008] In yet another embodiment, the bracket further includes a bushing.

[0009] In yet another embodiment, the guide assembly comprises a first guide end, a second guide end, a guide arm, a guide wheel, and an engagement member. The guide arm extends between the first guide end and the second guide end, and the guide arm is pivotally connected to the multi-bar link mechanism in the vicinity of the second guide end. The guide wheel is attached to the guide arm in the vicinity of the first guide end, and the guide wheel is configured to engage with the bracket opening. The engagement member extends from the guide arm, and the engagement member and the guide arm at least partially define a slot. The engagement member is configured to engage with the bushing by engaging the bushing within the slot during at least a portion of the transition.

[0010] In a further embodiment, the multi-bar link mechanism comprises at least three bars.

[0011] In yet another further embodiment, the multi-bar link mechanism comprises four bars.

[0012] In another embodiment, each of the first and second bracket arms is pivotally connected to two of the four bars.

[0013] In yet another further embodiment, each of the four bars is pivotally connected to two other of the four bars.

[0014] In yet another further embodiment, one of the four bars is fixedly connected to the internal unit.

[0015] In another embodiment, one of the first and second bracket arms comprises a bend.

[0016] In yet another further embodiment, the angle of the bend is greater than 90°.

[0017] In yet another further embodiment, the bracket opening comprises a first opening end and a second opening end. In the upper arrangement, the guide assembly engages with the bracket opening in the vicinity of the first opening end.

[0018] In a further embodiment, during the transition, the guide assembly moves along the bracket opening towards the second end of the opening.

[0019] In yet another embodiment, the slot has an open end and a closed end. In the upper arrangement, the slot engages the bushing near the closed end.

[0020] In still a further embodiment, during the transition, the guide assembly moves relative to the bushing such that the engagement member slides along the bushing towards the open end.

[0021] In another embodiment, the frame includes an upper panel and two outer side panels extending from the upper panel. The link mechanism assembly is connected to the outer side panels.

[0022] In yet another embodiment, the inner unit includes a lower panel and two inner side panels extending from the lower panel. The link mechanism assembly is connected to the inner side panels.

[0023] In yet another embodiment, the actuator is electric.

[0024] In another embodiment, the inner unit includes one or more wheels attached to the lower panel. The bracket includes protrusions configured to engage the one or more wheels in the upper arrangement.

[0025] In a further embodiment, the bracket further includes a flat portion and one or more flanges. The flat portion includes the bracket opening. The flanges extend from the flat portion. The flanges separate the flat portion from the outer side panel.

[0026] In a further embodiment, the bracket further includes one or more attachment portions extending from the one or more flanges. The attachment portions engage the outer side panel.

[0027] The above is intended only as an overview of some aspects of the present invention. It is not intended to define the limits or requirements of the present invention. Other aspects of the present invention will be understood by referring to the detailed description of the embodiments.

[0028] Preferred embodiments of the present invention will be described with reference to the drawings.

Brief Description of the Drawings

[0029]

Figure 1

[0030]

Figure 2

[0031]

Figure 3

[0032]

Figure 4

[0033]

Figure 5

[0034]

Figure 6

[0035]

Figure 7

[0036]

Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0037] Referring to FIGS. 1 and 2, according to an embodiment of the present invention, a shelf system 10 includes an outer frame 12 and an internal unit 14. The frame 12 preferably includes an upper panel 16 and two external side panels 18 extending substantially downward from the upper panel 16. In FIGS. 1 and 2, one of the external side panels 18 is removed to show the internal mechanism of the shelf system 10. One or more doors 20 may be attached to the external side panel 18 and / or the upper panel 16. The door 20 is preferably hingedly connected to the external side panel 18 and / or the upper panel 16. In the embodiment shown in FIGS. 1 and 2, the door 20 is hingedly connected to the external side panel 18. However, it will be understood that in other embodiments, the door 20 may be connected using other types of connection means, or the door 20 may be completely omitted.

[0038] The internal unit 14 preferably includes a lower panel 22 and two internal side panels 24 extending substantially upward from the lower panel 22. One or more shelves 26 may extend between the internal side panels 24. The internal unit 14 is connected to the frame 12 using one or more link mechanism assemblies 30 as described below.

[0039] When the shelf system 10 is in the fully upper position (e.g., the position shown in FIG. 3), the internal unit 14 is substantially below and within the frame 12. Preferably, the distance between the internal side panels 24 is less than the distance between the external side panels 18 so that the internal side panels 24 can fit between the external side panels 18. Further, each of the external side panels 18 includes a lower edge 28 (shown explicitly in FIG. 3). When the shelf system 10 is in the fully upper position, the lower panel 22 preferably is substantially flush with or abuts the lower edge 28 of the external panel 18. Thus, the lower panel 22 preferably extends beyond the internal side panels 24 (i.e., the width of the lower panel 22 is greater than the distance between the internal side panels 24). When the shelf system 10 is in the fully upper position, the upper panel 16, the external side panels 18, and the lower panel 22 form a substantially continuous outer perimeter.

[0040] Preferably, the shelf system 10 includes two link mechanism assemblies 30, and one of the link mechanism assemblies 30 connects one of the external side panels 18 to one of the internal side panels 24. FIGS. 3 - 8 are cross-sectional views of the shelf system 10 (seen from A in FIG. 2) showing one of the link mechanism assemblies 30 as the shelf system 10 transitions from the fully upper position to the fully lower position. It will be understood that the other of the link mechanism assemblies 30 may be provided on the other side of the shelf system 10 (as best shown in FIG. 2).

[0041] Each of the outer side panels 18 has an inner surface 34. Each of the link mechanism assemblies 30 has a bracket 32. Referring to FIGS. 3-8, each of the link mechanism assemblies 30 has a bracket 32 fixedly attached to one of the inner surfaces 34. The bracket 32 has a flat portion 36 that is substantially parallel to the inner surface 34 and rises away from the inner surface. The bracket 32 preferably further has one or more flanges 38 extending away from the flat portion 36 to raise the flat portion 36 from the inner surface. Preferably, the flange 38 extends substantially perpendicular to the flat portion 36. The bracket 32 preferably further has one or more attachment portions 35 extending from the flange 38. The attachment portion 35 preferably extends substantially perpendicular to the flange 38 and is configured to engage the inner surface 34. Preferably, the attachment portion 35 has one or more connector openings 37 configured to receive a connector for fixedly attaching the bracket 32 to the inner surface 34.

[0042] The flat portion 36 has an elongated curved bracket opening 40 configured to assist (as described below) in moving the shelf system 10 between an upper position and a lower position. The bracket opening 40 has an opening first end 80 and an opening second end 82. As best shown in FIG. 3, the bracket opening 40 preferably is not completely arcuate and instead includes two small curved portions between the opening first end 80 and the opening second end 82.

[0043] Each of the link mechanism assemblies 30 further has first and second bracket arms 42, 44. In the embodiment shown in FIGS. 3-8, the first bracket arm 42 may have a bend such that the first bracket arm 42 has first and second bent portions 92, 94. The angle B (shown in FIG. 6) formed by the first bent portion 92 and the second bent portion 94 is preferably greater than 90°.

[0044] Each of the first and second bracket arms 42, 44 is pivotally connected to the flat portion 36 and is also pivotally connected to the multi-link mechanism 46. The multi-link mechanism 46 is connected to the internal unit 14. Preferably, the first bracket arm 42 is pivotally connected to the flat portion 36 near one end of the first bracket arm 42, and the first bracket arm 42 is pivotally connected to the multi-link mechanism 46 near the other end of the first bracket arm 42. Similarly, the second bracket arm 44 is preferably pivotally connected to the flat portion 36 near one end of the second bracket arm 44, and the second bracket arm 44 is preferably pivotally connected to the multi-link mechanism 46 near the other end of the second bracket arm 44. However, it will be understood that the pivot connection portions are not necessarily limited to the ends of the first and second bracket arms 42, 44 and may be arranged at other locations along the first and second bracket arms 42, 44.

[0045] The multi-link mechanism 46 preferably includes first, second, third, and fourth bars 48, 50, 52, 54 arranged generally in a quadrilateral shape. The first bar 48 is preferably pivotally connected to the third bar 52 and the fourth bar 54, and the second bar 50 is preferably pivotally connected to the third bar 52 and the fourth bar 54. Preferably, the first bracket arm 42, the first bar 48, and the third bar 52 are pivotally connected to each other at a first connection point 100, and the second bracket arm 44, the second bar 50, and the third bar 52 are pivotally connected to each other at a second connection point 102. The first connection point 100 may be arranged near the ends of the first bracket arm 42, the first bar 48, and the third bar 52. The second connection point 102 may be arranged near the ends of the second bracket arm 44, the second bar 50, and the third bar 52.

[0046] The movement of the first and second bracket arms 42, 44 results in the movement of the multi-link mechanism 46 to and from the frame 12, as will be described later.

[0047] Preferably, the fourth bar 54 is fixedly attached to the inner side panel 24 (i.e., the fourth bar 54 cannot pivot or otherwise operate with respect to the inner side panel 24).

[0048] The first bar 48 is preferably pivotally connected to the fourth bar 54 at a third connection point 104. The third connection point 104 may be disposed near the ends of the first bar 48 and the fourth bar 54. In one embodiment, the fourth bar 54 may be fixedly attached to the inner side panel 24 at the third connection point 104, while the first bar 48 is pivotable with respect to the fourth bar 54 (and the inner side panel 24).

[0049] The second bar 50 is preferably pivotally connected to the fourth bar 54. In the embodiments shown in FIGS. 3-8, the link mechanism assembly 30 further includes a bar tab 55 extending from the fourth bar 54. The second bar 50 is pivotally connected to the bar tab 55 at a fourth connection point 106. The bar tab 55 may extend from the fourth bar 54 at a point along the length of the fourth bar 54 (not necessarily near the end of the fourth bar 54).

[0050] The fourth bar 54 may also be fixedly attached to the inner side panel 24 at an attachment point 108.

[0051] In another embodiment, the fourth bar 54 may be omitted from the multi-bar link mechanism 46. In this embodiment, the second bar 50 is pivotally connected to the inner side panel 24, and the first bar 48 is pivotally connected to the inner side panel 24.

[0052] Returning to FIGS. 3-8, the link mechanism assembly 30 further includes a guide assembly 56 that is pivotally connected to the second bar 50 and configured to engage the bracket opening 40. In the embodiment shown in FIGS. 3-8, the guide assembly 56 includes a guide first end 60 and a guide second end 62, and the guide arm 58 extends between the guide first end 60 and the guide second end 62. The guide wheel 64 is connected to the guide arm 58 in the vicinity of the guide first end 60, and the guide wheel 64 is configured to move within the bracket opening 40. The movement of the guide wheel 64 within the bracket opening 40 results in a corresponding movement of the guide assembly 56. The guide arm 58 is preferably pivotally connected to the second bar 50 in the vicinity of the guide second end 62 at a fifth connection point 110. The fifth connection point 110 is preferably disposed along the length of the second arm 50.

[0053] The guide assembly 56 further includes an engagement member 66 that extends from the guide arm 58. Preferably, the engagement member 66 includes one or more bends such that a portion of the engagement member 66 and the guide arm 58 at least partially define a slot 67. The slot 67 preferably extends substantially parallel to the guide arm 58 and includes an open end 96 and a closed end 98.

[0054] The bracket 32 further includes a bushing 68 configured to engage within the slot 67 during the transition of the shelf system 10 between an upper configuration and a lower configuration (as described below). For example, the bracket 32 may include a flap 69 that extends from the flat portion 36, and the bushing 68 is attached to the flap 69. Other methods for attaching the bushing 68 to the bracket 32 may be used. Preferably, the dimensions of the bushing 68 and the slot 67 are such that the bushing 68 can fit snugly within the slot 67.

[0055] Preferably, the link mechanism assembly 30 further comprises one or more actuators 70 configured to operate the shelf system 10 between an upper position and a lower position. For example, one actuator 70 may be provided for each of the link mechanism assemblies 30. Each of the actuators 70 may be configured to enable linear movement and may include an actuator body 72 and an actuator arm 74 configured to move longitudinally within the actuator body 72. The actuator 70 includes an actuator first end 76 and an actuator second end 78, the actuator body 72 extends from the actuator first end 76, and the actuator arm 74 extends from the actuator second end 78. The actuator body 72 is preferably pivotally connected to the inner surface 34 or the top panel 16 in the vicinity of the actuator first end 76, and the actuator arm 74 is preferably pivotally connected to the second bracket arm 44 in the vicinity of the actuator second end 78 at a sixth connection point 112. The sixth connection point 112 may be arranged along the length of the second bracket arm 44 (not necessarily near the end of the second bracket arm 44). For example, in the embodiments shown in FIGS. 3-8, an arm tab 79 extends from the second bracket arm 44, and the sixth connection point 112 is arranged on the arm tab 79. In other embodiments, the sixth connection point 112 may be arranged directly on the second bracket arm 44.

[0056] The actuator 70 can use one of many commonly known operating mechanisms such as a hydraulic actuator, a linear motor, etc. The actuator 70 may be electric. Thus, the actuator 70 may be battery-powered or connected to some other power source (e.g., a commercial power source). Preferably, the actuator 70 is electrically connected to a switch 11 configured to control the operation of the shelf system 10. For example, the switch 11 may be used to switch the shelf system 10 from an upper position to a lower position (or vice versa).

[0057] Figures 3 to 8 are cross-sectional views of the shelf system 10 showing the shelf system as it transitions from the upper arrangement (the arrangement shown in Figure 3) to the lower arrangement (the arrangement shown in Figure 8). Only one side of the shelf system 10 is shown, but it will be understood that the other side of the shelf system 10 functions similarly.

[0058] Figure 3 shows the posture of the shelf system 10 in the upper arrangement. In this posture, the actuator arm 74 is substantially fully retracted within the actuator body 72. Further, the guide wheel 64 is disposed within the bracket opening 40, near the first end portion 80 of the opening, and the bushing 68 is engaged within the slot 67 and disposed near the closed end portion 98 of the slot 67. As can be seen in Figure 3, when the shelf system 10 is in the upper arrangement, the internal unit 14 is substantially below and within the frame 12.

[0059] Figure 4 shows the posture of the shelf system when the shelf system 10 begins to transition from the upper arrangement to the lower arrangement. In this posture, the actuator arm 74 is partially extended from within the actuator body 72, moving the internal unit 14 outward relative to the frame 12. In particular, as the actuator arm 74 extends from within the actuator body 72, the actuator arm 74 pushes the second bracket arm 44, which biases the internal unit 14 to move outward from the frame 12. The guide wheel 64 is biased to move within the bracket opening 40 from the first end portion 80 of the opening toward the second end portion 82 of the opening. Further, the engagement member 66 is biased to slide along the bushing 68 from the closed end portion 98 toward the open end portion 96. During this stage of the transition, the movement of the internal unit 14 is substantially horizontal, and this horizontal movement is determined at least in part by the curvature of the bracket opening 40 near the first end portion 80 of the opening and the movement of the guide wheel 64 within it.

[0060] Furthermore, the internal unit 14 preferably comprises one or more lower wheels 84 configured to be attached to the lower panel 22 and to abut against the brackets 32. In particular, each of the brackets 32 may comprise a substantially L-shaped protrusion 86 attached to one of the flanges 38. The protrusion 86 preferably extends inwardly. The lower wheel 84 is configured to abut against the protrusion 86, thereby facilitating the horizontal movement of the internal unit 14 during the initial stage of the transition from the upper position to the lower position. Also, one or more connector openings 37 may be provided in the protrusion 86.

[0061] FIG. 5 shows the posture of the shelf system 10 as it continues to transition from the upper position to the lower position. In this posture, the internal unit 14 is no longer under the frame 12 and is substantially separated from the frame 12. As the actuator arm 74 extends further outward from the actuator body 72, the guide wheel 64 is fully biased here to the second end portion 82 of the opening. The engagement member 66 is also biased to slide further along the bushing 68 (towards the open end 96) until the engagement member 66 is almost separated from the bushing 68. Furthermore, the movement of the internal unit 14 is no longer substantially horizontal but vertical.

[0062] FIG. 6 shows the posture of the shelf system when the shelf system 10 continues to transition from the upper position to the lower position. In this posture, as the actuator arm 74 continues to extend further outward from the actuator body 72, the guide arm 58 is biased to pivot substantially downward with respect to the first end portion 60 of the guide (i.e., since the guide wheel 64 is already at the second end portion 82 of the opening, the guide arm 58 can no longer move along the bracket opening 40). Thereby, as the internal unit 14 moves downward with respect to the frame 12, the internal unit 14 moves substantially vertically. Furthermore, the engagement member 66 is now free from the bushing 68 (i.e., the bushing 68 is no longer engaged with the slot 67).

[0063] FIG. 7 shows the posture of the shelf system 10 when it continues to shift from the upper arrangement to the lower arrangement. In this posture, when the actuator arm 74 continues to extend further outward from the actuator body 72, the guide arm 58 is further biased so as to pivot substantially downward with respect to the first guide end 60. Thereby, as the actuator arm 74 extends further, the internal unit 14 moves further substantially vertically.

[0064] FIG. 8 shows the posture of the shelf system 10 in the (complete) lower arrangement. In this posture, the actuator arm 74 extends substantially completely from the actuator body 72. At this time, the internal unit 14 is at the lowest position with respect to the frame 12.

[0065] In order for the shelf system 10 to shift back from the lower arrangement to the upper arrangement, the actuator arm 74 is configured to retract into the actuator body 72, and the shelf system 10 generally follows the progression shown in FIGS. 3 to 8, but in the reverse direction.

[0066] In another embodiment, the shelf system 10 may also include one or more springs (not shown) for assisting the movement of the internal unit 14 along its path. The spring may include a gas spring or a conventional steel spring.

[0067] In yet another embodiment, instead of the actuator 70, the shelf system 10 may be manually shifted from the upper arrangement to the lower arrangement (and vice versa) while being assisted by a counterweight.

[0068] In another embodiment, the actuator 70 may be remotely controlled to enable movement between (and vice versa) an upper and a lower placement of the shelf system 10. Further, the actuators 70 may preferably be synchronized to act in unison, thereby eliminating the need for one or more torque bars extending between the link mechanism assemblies 30. In yet another embodiment, only one actuator 70 may be used. In this embodiment, the actuator 70 may be centrally located within the shelf system 10 or may be located on only one side of the shelf system 10.

[0069] The exact positions of the pivot points (e.g., the first, second, third, fourth, fifth and / or sixth connection points 100, 102, 104, 106, 110, 112) and the curvature of the bracket openings 40 can be adjusted to effect various movements of the inner unit 14.

[0070] Referring to FIG. 2, the frame 12 may also include a rear frame panel 88 extending between the outer side panels 18. Further, the inner unit 14 may also include a rear inner panel 90 extending between the inner side panels 24.

[0071] In yet another embodiment, the shelf system 10 may be configured such that the actuation mechanism is reversed. In other words, the shelf system 10 may be configured such that the inner unit 14 can be lifted from a lower position to a higher position.

[0072] While the preferred embodiments have been described in detail, it will be understood by those skilled in the art that certain modifications can be made without departing from the principles of the invention.

Claims

1. A shelf system comprising: an outer frame; an internal unit; one or more link mechanism assemblies configured to shift the shelf system between an upper arrangement in which the internal unit is connected to the outer frame and disposed within the outer frame, and a lower arrangement in which the internal unit is offset horizontally and vertically from the outer frame, each of the link mechanism assemblies comprising: a bracket attached to the outer frame, the bracket having an elongate curved bracket opening; a multi-bar link mechanism attached to the internal unit; a first bracket arm and a second bracket arm pivotally connected to the bracket and the multi-bar link mechanism; a guide assembly pivotally connected to the multi-bar link mechanism and configured to engage the bracket opening; an actuator comprising an actuator body and an actuator arm configured to move longitudinally relative to the actuator body, the actuator body being attached to the outer frame and the actuator arm being pivotally connected to one of the first bracket arm and the second bracket arm; a link mechanism assembly comprising; A shelf system comprising: movement of the actuator arm relative to the actuator body causes movement of the internal unit relative to the outer frame to effect the shift, and includes movement of the guide assembly along the bracket opening during at least a portion of the shift.

2. The shelf system according to claim 1, wherein the bracket further comprises a bushing.

3. The guide assembly comprises: a guide first end and a guide second end, and a guide arm extending between the guide first end and the guide second end, the guide arm being pivotally connected to the multi-bar link mechanism in the vicinity of the guide second end; a guide wheel attached to the guide arm in the vicinity of the guide first end, the guide wheel being configured to engage the bracket opening. An engaging member extending from the guide arm, wherein the engaging member and the guide arm at least partially define a slot, and the engaging member; comprising; The shelf system according to claim 2, wherein the engaging member is configured to engage the bushing by engaging the bushing in the slot during at least a portion of the transition.

4. The shelf system according to claim 1, wherein the multi-bar link mechanism comprises at least three bars.

5. The shelf system according to claim 4, wherein the multi-bar link mechanism comprises four bars.

6. The shelf system according to claim 5, wherein each of the first bracket arm and the second bracket arm is pivotally connected to two of the four bars.

7. The shelf system according to claim 6, wherein each of the four bars is pivotally connected to two other bars of the four bars.

8. The shelf system according to claim 7, wherein one of the four bars is fixedly connected to the internal unit.

9. The shelf system according to claim 1, wherein one of the first bracket arm and the second bracket arm comprises a bent portion.

10. The shelf system according to claim 9, wherein the angle of the bent portion is greater than 90°.

11. The bracket opening comprises an opening first end and an opening second end, and in the upper arrangement, the guide assembly engages the bracket opening in the vicinity of the opening first end. The shelf system according to claim 1.

12. The shelf system according to claim 11, wherein during the transition, the guide assembly moves along the bracket opening towards the opening second end.

13. The slot comprises an open end and a closed end, and in the upper arrangement, the slot engages the bushing in the vicinity of the closed end. The shelf system according to claim 3.

14. The shelf system according to claim 13, wherein during the transition, the guide assembly moves relative to the bushing such that the engaging member slides along the bushing towards the open end.

15. The outer frame includes an upper panel and two external side panels extending from the upper panel, and the link mechanism assembly is connected to the external side panels. The shelf system according to claim 1.

16. The inner unit includes a lower panel and two inner side panels extending from the lower panel, and the link mechanism assembly is connected to the inner side panels. The shelf system according to claim 15.

17. The actuator is electric. The shelf system according to claim 1.

18. The inner unit includes one or more wheels attached to the lower panel, and the bracket includes a protrusion configured to engage with the one or more wheels in the upper arrangement. The shelf system according to claim 16.

19. The bracket has a flat portion including the bracket opening, and one or more flanges extending from the flat portion and separating the flat portion from the external side panel. The shelf system according to claim 15, further comprising.

20. The bracket further includes one or more attachment portions extending from the one or more flanges, and the attachment portions are configured to engage with the external side panels. The shelf system according to claim 19.

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