A sofa bed

Abstract

The utility model discloses a sofa bed, including backrest frame, bottom frame, bottom frame sets up in the front side of backrest frame, and can move along the predetermined track relative to backrest frame, back frame, back frame sets up between bottom frame and backrest frame, and one end of back frame is articulated in backrest frame, back frame, back frame sets up between back frame and bottom frame, and one end of back frame is articulated in the other end of back frame, and the other end of back frame is articulated in bottom frame. When bottom frame moves relative to backrest frame, back frame and back frame will be linked and spread or close. In the process of unfolding into bed, the back frame and back frame that originally constitute sofa backrest will change from folding state to flat state, and its own length is effectively added to the bed surface length formed by bottom frame pulling out. The design of converting sofa backrest part into bed surface extension part makes the total length of unfolded bed body increase.

Description

Technical Field

[0001] This utility model relates to the field of furniture technology, and in particular to a sofa bed. Background Technology

[0002] With the accelerating pace of modern life and the increasing intensification of living spaces, the market demand for furniture that combines portability, space utilization, and multifunctionality is growing. Sofa beds, as a common type of multifunctional furniture, have certain advantages in saving space.

[0003] However, existing sofa bed products still have some shortcomings. For example, many sofa beds use a relatively simple pull-out structure, and when unfolded into bed form, their total length is often limited, making it difficult to meet users' needs for comfortable lying down and sleeping, resulting in a poor customer experience.

[0004] Therefore, how to design a sofa bed that provides sufficient length for lying flat when unfolded into a bed is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] The main purpose of this utility model is to provide a sofa bed to solve the above-mentioned technical problems.

[0006] This utility model provides a sofa bed, comprising: a backrest frame; a bottom frame, the bottom frame being disposed on the front side of the backrest frame and capable of moving relative to the backrest frame along a predetermined trajectory; a rear back frame, the rear back frame being disposed between the bottom frame and the backrest frame, one end of the rear back frame being hinged to the backrest frame; and an inner back frame, the inner back frame being disposed between the rear back frame and the bottom frame, one end of the inner back frame being hinged to the other end of the rear back frame, and the other end of the inner back frame being hinged to the bottom frame; wherein, when the bottom frame moves relative to the backrest frame along the predetermined trajectory, the rear back frame and the inner back frame unfold or close in conjunction.

[0007] The sofa leg is provided between the back frame and the inner back frame. The sofa leg includes at least one support rod and a linkage assembly connecting the support rod to the back frame and the inner back frame. The linkage assembly allows the support rod to rotate downward to a support position when the back frame and the inner back frame are unfolded, and to rotate upward to a folded position when the back frame and the inner back frame are closed.

[0008] The linkage assembly includes: a first fixing structure disposed on the inner back frame; a second fixing structure disposed on the rear back frame; a first connecting rod, one end of which is pivotally connected to the first fixing structure along with one end of the support rod; a second connecting rod, one end of which is pivotally connected to the second fixing structure; and a third connecting rod, one end of which is pivotally connected to the support rod. The other ends of the first connecting rod, the second connecting rod, and the third connecting rod are pivotally connected at a single point, forming a movable pivot joint.

[0009] Both the first fixing structure and the second fixing structure have opposing arms; the first fixing structure has a first pivot hole on its arm, which is pivotally connected to one end of the first connecting rod and one end of the support rod via a pivot shaft; the second fixing structure has a second pivot hole on its arm, which is pivotally connected to one end of the second connecting rod via another pivot shaft.

[0010] The system also includes a telescopic limiting mechanism disposed between the base frame and the backrest frame, used to lock the base frame relative to the backrest frame when it moves to a preset position. The telescopic limiting mechanism includes: a first rod having multiple limiting portions along its length and fixed to the backrest frame; a second rod telescopically cooperating with the first rod and fixed to the base frame; and a locking pin assembly fixed to the second rod and capable of cooperating with any of the limiting portions to lock the base frame at different preset positions.

[0011] Wherein, the first rod is an outer tube, the second rod is an inner tube passing through the outer tube; the plurality of limiting parts are plurality of limiting holes provided on the wall of the outer tube.

[0012] The locking pin assembly includes: a snap-fit ​​member capable of engaging or disengaging with the limiting portion; and a biasing member for applying a biasing force to drive the snap-fit ​​member toward engaging with the limiting portion.

[0013] The locking pin assembly further includes an actuation assembly, which includes a pressing member and a pressing member connected to the pressing member; the pressing member is configured to abut against the latching member in response to a pressing operation of the pressing member, such that the latching member overcomes the biasing force of the biasing member to disengage from the limiting portion.

[0014] The latching member includes a movable block body and a latching part connected to the movable block body. The latching part is used to latch with the limiting part. The movable block body is provided with a first guide surface that cooperates with the pressing member. The pressing member is provided with a second guide surface that slides with the first guide surface, so that when the pressing member is pressed, the latching part is disengaged from the limiting part by the cooperation of the first guide surface and the second guide surface.

[0015] The locking pin assembly further includes a housing, in which the snap-fit ​​member and the offset member are both disposed; the housing is fixed to the second rod, and through holes corresponding to the number and position of the snap-fit ​​members are provided on the side wall of the housing.

[0016] The actuation component further includes a reset elastic element, which is disposed between the pressing member and the second rod member, and is used to drive the pressing member and the abutment member to reset after the operation of the pressing member is released.

[0017] The backrest frame is provided with armrests at opposite ends, the bottom frame is located between the armrests, and a slide rail is provided between the bottom frame and the armrests.

[0018] The beneficial technical effects of this utility model are as follows:

[0019] This invention achieves optimized space utilization during the transformation from sofa to bed through its linked structure design. The core of the design lies in the fact that when the base frame moves relative to the backrest frame, the backrest frame and inner backrest frame unfold or fold in tandem. During the unfolding process into a bed, the backrest frame and inner backrest frame, which originally constituted the sofa backrest, transform from a folded state to a flat state, effectively adding their length to the length of the bed surface formed by the extension of the base frame. This design, which transforms the sofa backrest components into an extension of the bed surface, increases the total length of the unfolded bed, directly overcoming the problem of insufficient bed length and inadequate comfort for lying down in the prior art due to simple pull-out mechanisms, thus providing users with a more spacious and comfortable sleeping experience. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A three-dimensional schematic diagram of a sofa bed provided for an embodiment of this utility model;

[0022] Figure 2 for Figure 1 Enlarged diagram of C in the middle;

[0023] Figure 3 for Figure 1 An enlarged schematic diagram of D in the diagram.

[0024] Figure 4 This is a three-dimensional schematic diagram of the telescopic limiting structure in a sofa bed provided in an embodiment of the present utility model;

[0025] Figure 5 This is a schematic cross-sectional view of the telescopic limiting structure in the sofa bed provided in an embodiment of the present utility model;

[0026] Figure 6 for Figure 5 Enlarged diagram of A in the middle;

[0027] Figure 7 for Figure 5 Enlarged diagram of B in the diagram;

[0028] Figure 8 A schematic diagram of the mating of the pressing part and the moving block body in the sofa bed provided in this embodiment of the utility model;

[0029] Explanation of reference numerals in the attached figures:

[0030] In the diagram: 10-First rod, 11-Limiting part, 20-Second rod, 32-Offset part, 33-Moving block body, 34-Snap-fit ​​part, 35-First guide surface, 41-Pressing part, 42-Push rod, 43-Abutting part, 44-Second guide surface, 45-Reset elastic part, 70-Box body, 71-Through hole, 80-Support rod, 90-Bottom frame, 100-Backrest frame, 110-Backrest frame, 120-Inner backrest frame, 140-First fixing structure, 150-Second fixing structure, 160-First connecting rod, 170-Second connecting rod, 180-Third connecting rod, 190-Armrest, 200-Slide rail. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0032] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0033] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0034] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0035] Please also refer to Figures 1-8 This utility model provides a sofa bed, which is mainly used to convert between sofa and bed modes to save space and provide multi-functionality.

[0036] The sofa bed includes: a backrest frame 100; a bottom frame 90, which is located at the front of the backrest frame 100 and is movable relative to the backrest frame 100 along a predetermined trajectory; a backrest frame 110, which is located between the bottom frame 90 and the backrest frame 100, with one end of the backrest frame 110 hinged to the backrest frame 100; and an inner backrest frame 120, which is located between the backrest frame 110 and the bottom frame 90, with one end of the inner backrest frame 120 hinged to the other end of the backrest frame 110 and the other end of the inner backrest frame 120 hinged to the bottom frame 90; wherein, when the bottom frame 90 moves relative to the backrest frame 100 along the predetermined trajectory, the backrest frame 110 and the inner backrest frame 120 unfold or close in conjunction.

[0037] In this embodiment, the backrest frame 100 constitutes the main backrest portion of the sofa bed in its sofa form, providing rear support for the entire sofa bed. The backrest frame 100 can be a frame structure on which upholstery or similar materials can be installed.

[0038] The bottom frame 90 is positioned at the front of the backrest frame 100. That is, when the observer is facing the sofa bed, the bottom frame 90 is located on the side of the backrest frame 100 closer to the observer. The bottom frame 90 is capable of moving relative to the backrest frame 100 along a predetermined trajectory. This predetermined trajectory is a horizontal straight line, allowing the bottom frame 90 to be pulled forward from a position close to the backrest frame 100 (sofa mode) to a position away from the backrest frame 100 (partial or complete movement in bed mode).

[0039] The backrest frame 110 is positioned between the base frame 90 and the backrest frame 100. More specifically, one end of the backrest frame 110, for example, the end near the lower rear of the sofa bed, is hinged to the backrest frame 100. This hinged connection allows the backrest frame 110 to rotate relative to the backrest frame 100. In sofa mode, the backrest frame 110 can be part of the backrest frame 100 or together with the backrest frame 100 to form the backrest of the sofa; when unfolded into bed mode, the backrest frame 110 flips downwards.

[0040] The inner backrest frame 120 is disposed between the backrest frame 110 and the bottom frame 90. More specifically, one end of the inner backrest frame 120 is hinged to the other end of the backrest frame 110, that is, the end of the backrest frame 110 away from its hinge point with the backrest frame 100, for example, the upper edge of the backrest frame 110. And, the other end of the inner backrest frame 120, that is, the lower edge of the inner backrest frame 120, is hinged to the rear edge of the bottom frame 90.

[0041] Through the aforementioned structure and hinged connections, a linkage mechanism is formed. When the bottom frame 90 moves relative to the backrest frame 100 along a predetermined trajectory, since one end of the inner backrest frame 120 is hinged to the bottom frame 90 and the other end is hinged to the backrest frame 110, and the backrest frame 110 is hinged to the fixed backrest frame 100, this movement forces the backrest frame 110 and the inner backrest frame 120 to unfold in tandem. Specifically, when the bottom frame 90 moves forward, the backrest frame 110 will flip downward and forward around its hinge point with the backrest frame 100, and the inner backrest frame 120 will also move accordingly. Ultimately, the backrest frame 110 and the inner backrest frame 120 will unfold to form a relatively flat plane, which, together with the bottom frame 90, constitutes the bed surface. Conversely, when the bottom frame 90 moves backward relative to the backrest frame 100 along a predetermined trajectory, the backrest frame 110 and the inner backrest frame 120 will close in tandem, restoring from the unfolded bed form to the folded sofa form.

[0042] In this embodiment, in addition to the movement (forward extension) of the base frame 90, two components, the backrest frame 110 and the inner backrest frame 120, are introduced. These two components fold to form the backrest in sofa mode, but unfold in tandem during the bed-like process. Compared to a simple pull-out structure, the addition and unfolding of the backrest frame 110 and the inner backrest frame 120 effectively extends the bed surface further forward beyond the extended base frame 90. They transform the vertical or inclined space originally occupied by the sofa backrest into a horizontal bed surface length during unfolding.

[0043] Therefore, the structure described in this embodiment, comprising a backrest frame 100, a base frame 90, a backrest frame 110, and an inner backrest frame 120, and which achieves the coordinated unfolding of the backrest frame 110 and the inner backrest frame 120 when the base frame 90 moves through a specific hinge relationship, allows the sofa bed to significantly increase its total length when unfolded into a bed form through the unfolding of the backrest frame 110 and the inner backrest frame 120. This overcomes the problem mentioned in the background art that "the total length after stretching is often limited," thereby providing sufficient lying-flat length to meet the user's need for comfortable lying-flat sleep and improve the customer experience.

[0044] Simply put, by adding two interconnected and extendable "backrest" components, the bed surface is no longer just the length of the "seat pulled out", but the length of the "seat pulled out" + "two backrests laid flat", thus achieving a longer sleeping space.

[0045] In one embodiment, a connecting sofa leg is provided between the back frame 110 and the inner back frame 120. The connecting sofa leg includes at least one support rod 80 and a connecting rod assembly connecting the support rod 80 with the back frame 110 and the inner back frame 120. The connecting rod assembly causes the support rod 80 to rotate downward to a support position when the back frame 110 and the inner back frame 120 are unfolded, and to rotate upward to a stowed position when the back frame 110 and the inner back frame 120 are closed.

[0046] In this embodiment, in order to provide more stable support when the backrest frame 110 and the inner backrest frame 120 are unfolded to form a bed surface, especially in the middle area of ​​the bed surface, a connecting sofa leg is also provided between the backrest frame 110 and the inner backrest frame 120.

[0047] The linkage sofa leg includes at least one support rod 80 and a linkage assembly connecting the support rod 80 to the backrest frame 110 and the inner backrest frame 120. In this embodiment, one or more support rods 80 can be provided, for example, symmetrically arranged on the left and right sides of the sofa bed.

[0048] The support rod 80 is the component that ultimately contacts the ground and provides support. Its material can be metal, wood, etc., to ensure sufficient load-bearing capacity.

[0049] The linkage assembly is key to enabling the automatic deployment and retraction of the support rod 80. This linkage assembly converts the relative motion between the rear frame 110 and the inner frame 120 during deployment or retraction into the rotational motion of the support rod 80. Specifically:

[0050] When the backrest frame 110 and inner backrest frame 120 unfold in tandem, transforming the sofa bed from sofa mode to bed mode, the backrest frame 110 flips downwards, and the inner backrest frame 120 unfolds accordingly. The linkage assembly drives the support rod 80 to rotate downwards, eventually reaching a preset support position. In this support position, the lower end of the support rod 80 can contact the ground, providing stable support for the unfolded bed surface.

[0051] When the backrest frame 110 and the inner backrest frame 120 are closed in tandem, the sofa bed transforms from a bed mode to a sofa mode. The backrest frame 110 folds upwards, and the inner backrest frame 120 folds down accordingly. The linkage assembly drives the support rod 80 to rotate upwards, eventually reaching a preset folded position. In this folded position, the support rod 80 is folded and hidden between or near the backrest frame 110 and the inner backrest frame 120, without affecting the sofa bed's appearance and use.

[0052] By incorporating such linkage sofa legs, the sofa bed is designed to provide support not only at both ends but also in the middle when fully unfolded, thus improving its stability and load-bearing capacity and enhancing the user experience. Furthermore, due to its interconnected design, the unfolding and retraction of the support legs are automatic, requiring no additional user intervention and offering exceptional convenience.

[0053] In one embodiment, the linkage assembly includes: a first fixing structure 140 disposed on the inner back frame 120; a second fixing structure 150 disposed on the rear back frame 110; a first connecting rod 160, one end of which is pivotally connected to the first fixing structure 140 together with one end of the support rod 80; a second connecting rod 170, one end of which is pivotally connected to the second fixing structure 150; and a third connecting rod 180, one end of which is pivotally connected to the support rod 80; wherein the other ends of the first connecting rod 160, the second connecting rod 170, and the third connecting rod 180 are pivotally connected at a common point, forming a movable pivot portion.

[0054] In this embodiment, the linkage assembly specifically includes: a first fixing structure 140, a second fixing structure 150, a first link 160, a second link 170, and a third link 180.

[0055] The first fixing structure 140 is fixedly mounted on the inner frame 120. The first fixing structure 140 provides a fixed connection point on the inner frame 120 for the linkage assembly.

[0056] The second fixing structure 150 is fixedly mounted on the rear frame 110. This second fixing structure 150 provides a fixed connection point on the rear frame 110 for the linkage assembly. When the rear frame 110 and the inner frame 120 move relative to each other, the relative position and angle between the first fixing structure 140 and the second fixing structure 150 will change, which is the basis for driving the linkage assembly.

[0057] The first connecting rod 160 has one end pivotally connected to the first fixed structure 140 along with one end of the support rod 80. This means that a pivot point is formed at the first fixed structure 140, around which both the support rod 80 and the first connecting rod 160 rotate relative to the first fixed structure 140 (i.e., relative to the inner frame 120).

[0058] The second link 170 is pivotally connected at one end to the second fixed structure 150. This means that the second link 170 is able to rotate relative to the back frame 110 about its pivot point with the second fixed structure 150.

[0059] The third link 180 is pivotally connected at one end to a certain intermediate position along the length of the support rod 80, rather than at the end of the first fixed structure 140 that is pivotally connected together with the first link 160.

[0060] The key point is that the other ends of the first link 160 (away from its pivot point with the first fixed structure 140), the other ends of the second link 170 (away from its pivot point with the second fixed structure 150), and the other ends of the third link 180 (away from its pivot point with the support rod 80) are all pivotally connected to a single point. This point forms a movable pivot. This movable pivot is the intersection of the three links, and its position in space changes with the relative movement of the rear frame 110 and the inner frame 120.

[0061] When the sofa bed unfolds or folds, the backrest frame 110 and the inner backrest frame 120 rotate relative to each other, causing a change in the relative position between the first fixed structure 140 and the second fixed structure 150. This change is transmitted to the movable pivot part through the first connecting rod 160 and the second connecting rod 170, causing the movable pivot part to displace. The displacement of the movable pivot part then acts on the support rod 80 through the third connecting rod 180. Since one end of the support rod 80 is pivotally connected to the first fixed structure 140, the pushing or pulling action of the third connecting rod 180 causes the support rod 80 to rotate around its pivot point on the first fixed structure 140, thereby enabling the support rod 80 to unfold downwards or fold upwards.

[0062] This multi-link structure design can effectively convert the unfolding / closing motion of the rear frame 110 and inner frame 120 into the automatic synchronous support or retraction action of the support rod 80, reliably realizing the automatic deployment and retraction of the support rod 80.

[0063] In one embodiment, both the first fixing structure 140 and the second fixing structure 150 have opposing arms; the first fixing structure 140 has a first pivot hole on its arm, which is pivotally connected to one end of the first connecting rod 160 and one end of the support rod 80 via a pivot shaft; the second fixing structure 150 has a second pivot hole on its arm, which is pivotally connected to one end of the second connecting rod 170 via another pivot shaft.

[0064] In this embodiment, to achieve a stable yet flexible pivoting connection, both the first fixing structure 140 and the second fixing structure 150 have opposing arms. Specifically, these two fixing structures can be designed as, for example, U-shaped brackets or components with two parallel protruding arms, which are arranged opposite each other to provide installation space for the pivoting connection.

[0065] For the first fixed structure 140: first pivot holes are aligned on its opposing arms. This means that there is one hole on each arm of the first fixed structure 140, and the axes of the two holes are coaxial. The first pivot holes are pivotally connected to one end of the first connecting rod 160 and one end of the support rod 80 via a pivot. More specifically, the pivot passes through the first pivot hole on one arm of the first fixed structure 140, then sequentially through one end of the first connecting rod 160 (e.g., the hole at its end) and one end of the support rod 80 (e.g., the hole at its end), and finally through the first pivot hole on the other arm of the first fixed structure 140. In this way, the first connecting rod 160 and the support rod 80 can rotate freely together about the pivot relative to the first fixed structure 140, i.e., relative to the inner frame 120.

[0066] For the second fixed structure 150, a second pivot hole is also provided on its opposite arm. The second pivot hole is pivotally connected to one end of the second link 170 via another pivot. Similar to the connection of the first fixed structure 140, this other pivot passes through the second pivot hole on one arm of the second fixed structure 150, then through one end of the second link 170 (e.g., the hole at its end), and finally through the second pivot hole on the other arm of the second fixed structure 150. In this way, the second link 170 can rotate freely about this other pivot relative to the second fixed structure 150, that is, relative to the back frame 110.

[0067] This method of using a fixed structure with opposing arms and a pivot connection is simple, reliable, easy to process and assemble, and can ensure that the connecting rod and support rod 80 rotate smoothly in a predetermined plane.

[0068] In one embodiment, the sofa bed further includes a telescopic limiting mechanism disposed between the bottom frame 90 and the backrest frame 100, used to lock the bottom frame 90 relative to the backrest frame 100 when it moves to a preset position. The telescopic limiting mechanism includes: a first rod 10, on which a plurality of limiting parts 11 are provided along the length direction, and the first rod 10 is fixed to the backrest frame 100; a second rod 20, which telescopically cooperates with the first rod 10 and is fixed to the bottom frame 90; and a locking pin assembly, which is fixed to the second rod 20 and can cooperate with any of the limiting parts 11 to lock the bottom frame 90 in different preset positions.

[0069] In this embodiment, in order to facilitate users to stably fix the sofa bed in different usage states such as sofa mode, partially unfolded reclining mode or fully unfolded bed mode, the sofa bed also includes a telescopic limiting mechanism.

[0070] The telescopic limiting mechanism is located between the bottom frame 90 and the backrest frame 100. It is used to lock the bottom frame 90 and the backrest frame 100 to any one of a number of preset positions when the bottom frame 90 moves relative to the backrest frame 100 along a predetermined trajectory, so as to prevent the bottom frame 90 from sliding unexpectedly.

[0071] The telescopic limit mechanism includes:

[0072] First member 10: The first member 10 is fixed to the backrest frame 100 or a fixed structure connected to the backrest frame 100. The first member 10 has a plurality of limiting parts 11 along its length. These limiting parts 11 are the basis for realizing segmented locking, and each limiting part 11 corresponds to a lockable preset pull-out position of the bottom frame 90.

[0073] Second link 20: The second link 20 is fixed to the base frame 90. The second link 20 is telescopically compatible with the first link 10. This means that when the base frame 90 is pulled forward or pushed back relative to the backrest frame 100, the second link 20 will slide relative to the first link 10, thereby changing the overall length of the telescopic limiting mechanism.

[0074] Locking pin assembly: The locking pin assembly is fixed to the second member 20. This locking pin assembly is designed to selectively engage with any limiting part 11 on the first member 10. When the bottom frame 90 moves to a preset position, aligning the locking pin assembly with a limiting part 11 on the first member 10, the locking pin assembly can engage with that limiting part 11, thereby fixing the first member 10 and the second member 20 relative to each other, and locking the bottom frame 90 at that specific preset position. When it is necessary to adjust the position of the bottom frame 90, the locking pin assembly can be operated to disengage it from the current limiting part 11. At this time, the bottom frame 90 can move freely relative to the backrest frame 100 again until it moves to the next desired preset position and is locked again by engaging with the corresponding limiting part 11 through the locking pin assembly.

[0075] With this telescopic limiting mechanism, users can easily pull out the base frame 90 of the sofa bed to different lengths as needed and lock it reliably, thereby achieving smooth switching and stable support for various usage modes such as sofa, recliner, and bed.

[0076] In one embodiment, the first rod 10 is an outer tube, and the second rod 20 is an inner tube inserted into the outer tube; the plurality of limiting parts 11 are plurality of limiting holes provided on the wall of the outer tube.

[0077] In this embodiment, the first rod 10 is specifically an outer tube. The outer tube may have a circular, square, rectangular, or other suitable cross-sectional shape. As a part fixed to the backrest frame 100, the interior of the outer tube is hollow, providing a channel for the insertion and movement of the second rod 20.

[0078] The second member 20 is specifically an inner tube that can be inserted into the outer tube. The outer contour dimensions of the inner tube match the inner cavity shape of the outer tube and are slightly smaller than the inner cavity dimensions of the outer tube, so as to ensure that the inner tube can smoothly slide and extend axially within the outer tube, thereby realizing the relative movement of the base frame 90 relative to the backrest frame 100. The inner tube is fixed to the base frame 90.

[0079] The multiple limiting parts 11 are specifically in the form of multiple limiting holes opened along the wall of the outer tube. These limiting holes are arranged at preset intervals along the length of the outer tube. Each limiting hole corresponds to a preset position where the bottom frame 90 can be locked. When the inner tube slides inside the outer tube, the locking pin assembly fixed on the inner tube can align and engage with the limiting holes at different positions on the outer tube, thereby locking the inner tube relative to the outer tube at different extension lengths.

[0080] The structure employing an outer tube, an inner tube, and limiting holes on the outer tube wall offers the following advantages: a simple and compact structure, easy to manufacture and assemble; good guiding properties, ensuring smooth extension and retraction of the inner tube; and accurate and reliable positioning via the limiting holes. For example, when the sofa bed is extended from its sofa state to its bed state, the inner tube gradually withdraws from the outer tube, and the locking pin assembly's snap-fit ​​portion 34 can sequentially engage with the limiting holes at different positions on the outer tube, achieving multi-level length adjustment and locking.

[0081] In one specific embodiment, the outer tube has a rectangular cross-sectional shape, and correspondingly, the inner tube also has a rectangular cross-sectional shape to match it. By using rectangular (or other non-circular, such as square, elliptical, or other directional cross-sectional shapes) inner and outer tubes, compared to inner and outer tubes with circular cross-sections, unpredictable circumferential rotation of the inner tube inside the outer tube can be effectively avoided.

[0082] This design improves the motion stability and positioning accuracy of the telescopic limit structure, ensuring its reliability and durability in various application scenarios, such as the repeated pulling and adjusting of sofa beds.

[0083] In one embodiment, the locking pin assembly includes: a snap-fit ​​member capable of engaging or disengaging from the limiting portion 11; and a biasing member 32 for applying a biasing force to drive the snap-fit ​​member toward engaging with the limiting portion 11.

[0084] In this embodiment, the latching member is an actuator that directly performs the locking and unlocking functions. The latching member is designed to be movable, allowing it to mechanically engage with or disengage from the limiting portion 11 on the first rod 10.

[0085] Specifically, when the base frame 90 moves to a preset position, if the locking member aligns with the limiting part 11 corresponding to that position, the locking member can engage with the limiting part 11, thereby locking the second rod 20 (fixed to the base frame 90) relative to the first rod 10 (fixed to the backrest frame 100) and preventing relative movement. When it is necessary to adjust the position of the base frame 90, the locking member can be operated to disengage from the current limiting part 11, thereby allowing the second rod 20 to move freely relative to the first rod 10 again.

[0086] The biasing element 32 can be one or more springs, such as compression springs, disposed inside the locking pin assembly. Its main function is to apply a biasing force to the latching element. The direction of this biasing force is set to drive the latching element towards engaging with the limiting part 11. This means that under normal circumstances, i.e., when no external force actively operates the locking pin assembly to unlock, the biasing element 32 will continuously push the latching element, causing the latching part 34 on the latching element to automatically and inclinedly engage with the limiting part 11 aligned on the first rod 10, thereby enabling the sofa bed's base frame 90 to be stably held in the user-selected preset position and preventing accidental slippage. When the user needs to move the base frame 90, an external force capable of overcoming the biasing force generated by the biasing element 32 must be applied to disengage the latching element from the limiting part 11.

[0087] This locking pin assembly design, which includes a snap-fit ​​connector and a biasing element 32, ensures automatic and reliable locking, and enhances the convenience and security of user operation.

[0088] In one embodiment, the locking pin assembly further includes an actuation assembly comprising a pressing member 41 and a pressing member connected to the pressing member 41; the pressing member is configured such that, in response to a pressing operation of the pressing member 41, the pressing member abuts against the latching member, such that the latching member overcomes the biasing force of the biasing member 32 to disengage from the limiting portion 11.

[0089] In this embodiment, in order to facilitate the user to actively release the latching state between the latching member and the limiting part 11 so as to adjust the position of the bottom frame 90, the locking pin assembly also includes an actuation component.

[0090] The actuation assembly includes a user-operable push button 41 and a stop button 43 mechanically connected to the push button 41. The push button 41 is a button located in an easily accessible position at the front end of the base frame 90.

[0091] The pressing member 43 is configured such that when the user presses down on the pressing member 41, the pressing member 43 moves accordingly and abuts against the latching member. When the pressing member 43 abuts against and applies force to the latching member, the force overcomes the biasing force applied to the latching member by the biasing member 32, thereby causing the latching member to disengage from its currently engaged limiting portion 11.

[0092] Once the latching member disengages from the limiting part 11, the locking state between the first rod 10 and the second rod 20 is released, allowing the user to freely pull forward or push back the bottom frame 90 to adjust the unfolding degree of the sofa bed. When the user releases the pressing part 41, the force exerted by the pressing part 43 on the latching member disappears, and the offset part 32 will again drive the latching member to engage with the next aligned limiting part 11.

[0093] With this design, users can easily unlock the locking mechanism with a simple press operation. The operation process is simple and clear, requiring no complicated learning cost and conforming to the usage habits of general users. The actuation component acts directly on the latching component through the pressing component, which can stably and effectively transmit the user's operating force, ensuring that the latching component can reliably overcome the bias force and disengage from the limiting part 11, avoiding jamming or operation difficulties caused by poor unlocking.

[0094] In this embodiment, the first rod 10 and the second rod 20 are arranged such that their length direction, i.e., the direction of their relative extension and retraction axis, is the same as or parallel to the direction of movement of the base frame 90 relative to the backrest frame 100, for example, the direction in which the base frame 90 is pulled out when the sofa bed unfolds from sofa mode to bed mode. This unidirectional arrangement ensures that the extension and retraction stroke of the telescopic limiting structure can accurately correspond to and control the displacement of the base frame 90.

[0095] For ease of user operation, the pressing element 41 is located on the front side of the base frame 90. Here, "front side" refers to the area of ​​the base frame 90 that is first contacted or most easily operated when the user stands in front of the sofa bed to operate it. For example, the pressing element 41 could be a button mounted on the outer surface of the front panel of the base frame 90. By pressing the pressing element 41, the user can actuate the actuator inside the telescopic limiting structure, thereby releasing the locking pin assembly from the limiting part 11, allowing the base frame 90 to move freely. When the base frame 90 moves to the desired position, the user releases the pressing element 41, and the locking pin assembly, under the action of the biasing member 32, automatically engages the latching member into the new limiting part 11, thus reliably locking the base frame 90.

[0096] This design, which places the pressing component 41 on the front side of the bottom frame 90, allows users to naturally and smoothly complete the unlocking and locking operations while extending or retracting the bottom frame 90, improving the ease of use and user experience of the sofa bed.

[0097] In one embodiment, the latching member includes a movable block body 33 and a latching part 34 connected to the movable block body 33. The latching part 34 is used to latch with the limiting part 11. The movable block body 33 is provided with a first guide surface 35 that cooperates with the pressing member, and the pressing member is provided with a second guide surface 44 that slides with the first guide surface 35, so that when the pressing member 41 is pressed, the latching part 34 is disengaged from the limiting part 11 by the cooperation of the first guide surface 35 and the second guide surface 44.

[0098] In this embodiment, the locking part 34 is the part of the locking member that actually engages mechanically with the limiting part 11 on the first rod 10 to achieve locking. The locking part 34 can be a pin-shaped, wedge-shaped, or boss-shaped structure, which is fixedly connected to the moving block body 33.

[0099] The movable block body 33 is provided with a first guide surface 35. At the same time, the pressing member 43 is provided with a corresponding second guide surface 44. These two guide surfaces are designed to slide and engage with each other.

[0100] This sliding guide mask has a powerful conversion function. The specific working principle is as follows:

[0101] When the user presses the pressing member 41, the pressing member 41 drives the pressing member 43 to move axially. During the movement of the pressing member 43, the second guide surface 44 on it contacts and acts on the first guide surface 35 on the moving block body 33. The axial thrust of the pressing member 43 is decomposed into a component force perpendicular to the locking direction of the locking part 34, i.e., the component force that causes the locking part 34 to disengage from the limiting part 11, through the sliding engagement of the two guide surfaces.

[0102] It is this component force that drives the moving block body 33 and the latching part 34 connected thereto to overcome the biasing force of the biasing member 32 and retract inward, thereby causing the latching part 34 to disengage from its currently engaged limiting part 11.

[0103] By setting up this mating structure of the first guide surface 35 and the second guide surface 44, the principle of inclined plane force is utilized to effectively convert the small axial thrust applied by the user to the pressing part 41 into a force sufficient to overcome the bias force and drive the latching part to move. This makes the unlocking operation more effortless and provides a better user experience. This guide surface mating structure design is relatively simple, easy to process and assemble, occupies little space, and at the same time provides reliable force conversion and guiding functions.

[0104] In one embodiment, the locking pin assembly includes two latching members arranged symmetrically; a biasing member 32 is disposed between the moving block bodies 33 of the two latching members, for simultaneously applying a biasing force to the moving block bodies 33 of each of the two latching members.

[0105] In this embodiment, each of the two snap-fit ​​components includes a movable block body 33 and a snap-fit ​​portion 34 fixed to the movable block body 33.

[0106] The key is that these two locking components are symmetrically arranged. "Symmetrically arranged" here can be understood as symmetrical with respect to a central axis or central plane. For example, if the second member 20 is an inner tube, these two locking components can be symmetrically arranged on opposite sides of one end of the inner tube. When they move outward simultaneously, they can engage with the two corresponding limiting parts 11 on the first member 10. Using two symmetrical locking components allows for a more even distribution of locking force, avoiding the shaking or deflection that may occur with single-point locking, thereby improving the overall locking stability of the mechanism.

[0107] Accordingly, the biasing member 32 is disposed between the moving block bodies 33 of the two snap-fit ​​members. A compression spring may be used here. The two ends of the spring abut against the two opposing moving block bodies 33.

[0108] Because the spring is located between the two moving block bodies 33, it applies a biasing force to both moving block bodies 33 simultaneously. This biasing force pushes the two moving block bodies 33 outwards, causing their respective locking parts 34 to engage with the corresponding limiting parts 11. This design uses a single biasing element 32 to simultaneously drive two symmetrical locking parts to achieve the locking action, simplifying the structure, reducing the number of parts, and ensuring the synchronicity of the action and consistency of the force on the two locking parts.

[0109] In one embodiment, the pressing member includes a push rod 42 and two pressing portions 43 connected to one end of the push rod 42, and a pressing member 41 is disposed at the other end of the push rod 42; the two pressing portions 43 each have a second guide surface 44.

[0110] In this embodiment, the pressing member includes a push rod 42 and two pressing portions 43 connected to one end of the push rod 42. The push rod 42 is an elongated component that transmits the operation of the pressing member 41. The two pressing portions 43 are the working parts of the push rod 42, and they correspond to two symmetrically arranged snap-fit ​​members, respectively. These two pressing portions 43 can be designed to extend from one end of the push rod 42 in a forked manner, or connected to the push rod 42 in other ways, ensuring that they can act on both snap-fit ​​members simultaneously.

[0111] The pressing element 41 is located at the other end of the push rod 42. The user operates this pressing element 41 to drive the push rod 42. When the pressing element 41 is pressed, the push rod 42 moves accordingly. The movement of the push rod 42 causes the two abutting parts 43 at one end to move as well. During the movement, the second guide surfaces 44 of the two abutting parts 43 respectively make sliding contact and engage with the first guide surfaces 35 of the corresponding moving block body 33.

[0112] Through the cooperation of the push rod 42, the pressing part 43 and the moving block body 33, this embodiment realizes an actuation mechanism that can operate the two symmetrical latching parts synchronously, smoothly and effectively to achieve unlocking, thereby improving the convenience and reliability of operation.

[0113] In this embodiment, the push rod 42 is slidably inserted inside the second rod 20. Specifically, the second rod 20 has a pre-reserved channel that matches the outer diameter of the push rod 42, within which the push rod 42 performs axial reciprocating motion. This arrangement guides the movement of the push rod 42, ensuring that when the user presses the pressing member 41, the push rod 42 can move forward stably in a straight line, thereby effectively transmitting the operating force to the pressing part 43.

[0114] In one embodiment, the locking pin assembly further includes a housing 70, and both the snap-fit ​​member and the offset member 32 are disposed inside the housing 70; the housing 70 is fixed to the second rod 20, and the side wall of the housing 70 is provided with through holes 71 corresponding to the number and position of the snap-fit ​​members 34.

[0115] In this embodiment, the locking pin assembly also includes a housing 70. This housing 70 is a shell structure with an internal space, such as a small box made of plastic or metal.

[0116] Both the snap-fit ​​component and the offset component 32 are housed within the housing 70. Containing these moving parts within the housing 70 provides an efficient path of movement and also makes the entire locking pin assembly a relatively independent module, facilitating production and assembly.

[0117] The box 70 is fixed to the second rod 20, and it moves relative to the first rod 10 together with the second rod 20.

[0118] The side of the box body 70 is provided with through holes 71 corresponding to the number and position of the snap-fit ​​parts 34. These through holes 71 are channels reserved for the snap-fit ​​parts 34 to extend out of the box body 70 and engage with the limiting part 11 on the first rod 10.

[0119] If there is only one snap-fit ​​component in the locking pin assembly, a through hole 71 will be opened on the corresponding side of the housing 70.

[0120] If there are two symmetrically arranged snap-fit ​​parts in the locking pin assembly, a through hole 71 will be opened on each of the opposite sides of the housing 70. The positions of these two through holes 71 correspond to the positions of the two snap-fit ​​parts 34 inside.

[0121] The through holes 71 on these housings 70 ensure that the extension path of the latching part 34 is unobstructed when the biasing member 32 drives the latching member to move outward. At the same time, the walls of the housings 70 can also provide guidance and limit for the reciprocating motion of the moving block body 33.

[0122] By adding a housing 70 to accommodate the snap-fit ​​component and the offset component 32, and by opening corresponding through holes 71, this embodiment not only improves the integration of the locking pin assembly, but also optimizes its installation and operational reliability.

[0123] In one embodiment, the actuation assembly further includes a reset elastic element 45, which is disposed between the pressing element 41 and the second rod 20, and is used to drive the pressing element 41 and the pressing element to reset after the operation of the pressing element 41 is released.

[0124] In this embodiment, in order to ensure that the pressing element 41 can automatically and reliably return to its initial unpressed state after the user's pressing operation is released, the actuation component further includes a reset elastic element 45.

[0125] The reset elastic element 45 can be a compression spring disposed between the pressing element 41 and the second rod 20.

[0126] When the user presses the pressing element 41, the reset elastic element 45 is compressed and stores elastic potential energy. Once the user releases the pressing force on the pressing element 41, the previously stored elastic potential energy is released, generating a reverse driving force.

[0127] This driving force acts directly on the pressing member 41, driving it and the push rod 42 mechanically connected to it to reset together, that is, return to their initial positions before the pressing operation. Specifically, the pressing part 43 will retract from the position where it previously abutted and acted on the first guide surface 35 of the moving block body 33.

[0128] When the pressing part 43 retracts, the force it exerted on the moving block body 33 for unlocking disappears. At this time, the biasing member 32 can drive the locking part 34 to re-engage with the limiting part 11, preparing the bottom frame 90 to lock in the next preset position.

[0129] By adding this reset elastic element 45, the automatic and reliable reset of the pressing element 41 and the abutting element is ensured. After the user completes the unlocking operation and releases the pressing element 41, there is no need to perform any additional actions to return the pressing element 41 to its original position. This makes the entire adjustment process smoother and more natural, improving the convenience and intuitiveness of the operation.

[0130] In one embodiment, the backrest frame 100 is provided with armrests 190 at opposite ends, the bottom frame 90 is disposed between the armrests 190, and a slide rail 200 is provided between the bottom frame 90 and the armrests 190.

[0131] In this embodiment, armrests 190 are fixedly connected to opposite ends of the backrest frame 100, such as its left and right sides. These two armrests 190 not only provide arm support in the sofa form but also constitute the lateral enclosure structure of the sofa bed. The base frame 90 is disposed between the internal space defined by the two armrests 190. To ensure that the base frame 90 can move smoothly and maintain correct guidance relative to the backrest frame 100 and armrests 190 to unfold or retract, slide rails 200 are respectively provided between the left and right outer walls of the base frame 90 and the inner walls of the corresponding armrests 190. Specifically, the slide rail 200 on each side can be composed of a guide rail fixed to the inner wall of the armrest 190 and a slider or roller assembly fixed to the corresponding outer wall of the base frame 90 (not shown in the figure); or it can be a common telescopic metal slide rail 200 composed of an inner rail and an outer rail, with one part fixed to the inner side of the armrest 190 and the other part fixed to the outer side of the base frame 90.

[0132] When the user needs to convert the sofa bed from sofa mode to bed mode, they first operate the pressing component 41 to release the locking mechanism that restricts the relative position between the bottom frame 90 and the backrest frame 100. At this point, the user can pull the bottom frame 90, which, guided and supported by the side rails 200, slides forward stably between the two armrests 190. As the bottom frame 90 slides out, the backrest frame 110 and inner backrest frame 120 unfold in conjunction, ultimately forming the bed surface. Conversely, when folding the bed, the bottom frame 90 is pushed back along the rails 200, and the backrest frame 110 and inner backrest frame 120 fold in conjunction until the bottom frame 90 is locked in the sofa mode position by the telescopic limiting mechanism.

[0133] By setting armrests 190 at both ends of the backrest frame 100 and placing the bottom frame 90 between the armrests 190, and then connecting the bottom frame 90 and the armrests 190 through the slide rail 200, the overall structure of the sofa bed is not only more stable and complete, but also the smoothness and accuracy of the bottom frame 90 when moving are greatly improved, reducing the possibility of jamming or shaking, and improving the user experience and product durability.

[0134] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A sofa bed, characterized in that, include: Backrest frame; A base frame is disposed on the front side of the backrest frame and is capable of moving relative to the backrest frame along a predetermined trajectory; A backrest frame is disposed between the base frame and the backrest frame, and one end of the backrest frame is hinged to the backrest frame. An inner back frame is disposed between the rear back frame and the bottom frame, with one end of the inner back frame hinged to the other end of the rear back frame and the other end of the inner back frame hinged to the bottom frame. When the bottom frame moves relative to the backrest frame along the predetermined trajectory, the backrest frame and the inner backrest frame expand or close in conjunction.

2. The sofa bed according to claim 1, characterized in that, A connecting sofa leg is provided between the back frame and the inner back frame. The connecting sofa leg includes at least one support rod and a connecting rod assembly connecting the support rod to the back frame and the inner back frame. The connecting rod assembly allows the support rod to rotate downward to a support position when the back frame and the inner back frame are unfolded, and to rotate upward to a folded position when the back frame and the inner back frame are closed.

3. The sofa bed according to claim 2, characterized in that, The linkage assembly includes: A first fixing structure is disposed on the inner back frame; The second fixing structure is disposed on the rear frame; The first connecting rod, one end of which is pivotally connected to the first fixed structure together with one end of the support rod; The second link, one end of which is pivotally connected to the second fixed structure; The third link, one end of which is pivotally connected to the support rod; The other ends of the first link, the second link, and the third link are pivotally connected at a single point, forming a movable pivot joint.

4. The sofa bed according to claim 3, characterized in that, Both the first fixing structure and the second fixing structure have opposing arms; the first fixing structure has a first pivot hole on its arm, which is pivotally connected to one end of the first connecting rod and one end of the support rod via a pivot shaft; the second fixing structure has a second pivot hole on its arm, which is pivotally connected to one end of the second connecting rod via another pivot shaft.

5. The sofa bed according to claim 3, characterized in that, It also includes a telescopic limiting mechanism, which is disposed between the bottom frame and the backrest frame and is used to lock the bottom frame when it moves relative to the backrest frame to a preset position; The telescopic limiting mechanism includes: The first rod has multiple limiting parts along its length and is fixed to the backrest frame. The second member is telescopically coupled to the first member and is fixed to the bottom frame; A locking pin assembly is fixed to the second rod and can cooperate with any of the limiting parts to lock the bottom frame in different preset positions.

6. The sofa bed according to claim 5, characterized in that, The first rod is an outer tube, and the second rod is an inner tube that passes through the outer tube; the plurality of limiting parts are plurality of limiting holes provided on the wall of the outer tube.

7. The sofa bed according to claim 5, characterized in that, The locking pin assembly includes: A snap-fit ​​component, which can engage or disengage from the limiting portion; A biasing member is used to apply a biasing force to drive the snap-fit ​​member toward a snap-fit ​​state with the limiting portion.

8. The sofa bed according to claim 7, characterized in that, The locking pin assembly further includes an actuation assembly, which includes a pressing member and a pressing member connected to the pressing member; the pressing member is configured to abut against the latching member in response to a pressing operation of the pressing member, such that the latching member overcomes the biasing force of the biasing member to disengage from the limiting portion.

9. The sofa bed according to claim 8, characterized in that, The latching member includes a movable block body and a latching part connected to the movable block body. The latching part is used to latch with the limiting part. The movable block body is provided with a first guide surface that cooperates with the pressing member. The pressing member is provided with a second guide surface that slides with the first guide surface, so that when the pressing member is pressed, the latching part is disengaged from the limiting part by the cooperation of the first guide surface and the second guide surface.

10. The sofa bed according to claim 9, characterized in that, The locking pin assembly also includes a housing, in which the snap-fit ​​member and the offset member are both disposed; the housing is fixed to the second rod, and through holes corresponding to the number and position of the snap-fit ​​members are provided on the side wall of the housing.

11. The sofa bed according to claim 10, characterized in that, The actuation assembly further includes a reset elastic element disposed between the pressing member and the second rod member, which is used to drive the pressing member and the abutment member to reset after the operation of the pressing member is released.

12. The sofa bed according to any one of claims 1-11, characterized in that, The backrest frame is provided with armrests at opposite ends, the bottom frame is located between the armrests, and a slide rail is provided between the bottom frame and the armrests.

Images