Seatback rod and chassis assembly structure

Abstract

The present invention relates to a seatback rod and chassis assembly structure, comprising a chassis, a seatback rod, an elastic device, and a connecting rod set. The chassis has a top surface and a bottom surface, along with a set of connecting slot holes. Additionally, the bottom surface is provided with grooves extending in the left and right directions. The front end of the bottom portion of the seatback rod is provided with a coupling base, which has two laterally opposed side walls. An engaging post, which can be embedded into the grooves, is arranged on the upper front side of the side walls. Furthermore, a first through hole is provided at a position corresponding to the set of connecting slot holes. The elastic device possesses elasticity and is positioned to abut against the bottom surface of the coupling base. The connecting rod set includes an end portion with a diameter larger than the width of the connecting slot holes. The lower part of this end portion passes through the set of connecting slot holes, the first through hole, and the elastic device for assembly. By this configuration, the present invention provides improved operational stability and enhanced reclining comfort.

Description

Technical Field

[0001] This invention relates to a seat backrest and chassis combination structure, mainly referring to a structure that can provide better reclining comfort. Prior Technology

[0002] Conventional chairs typically have an elastic device attached to the backrest frame to enhance backrest comfort. This elastic device can be compressed when the chair back is reclined, thus providing elastic comfort.

[0003] Figures 8-10 show the conventional backrest and chassis assembly structure of a chair, with Figure 8 being an inverted view. It includes a chassis 1', a backrest 2', a spring mechanism 3', and a pivot 4'. The chassis 1' is fixed below the seat (not shown) and has two downward-protruding pivot pieces 11'. Each pivot piece 11' has a pivot hole 111', and a connecting rod 12' is positioned downwards from the rear. The backrest 2' connects to the backrest cushion (not shown), and its bottom end, corresponding to the pivot piece 11', has a pivot portion 21' that can be positioned between the two pivot pieces 11'. This pivot portion 21' has a pivot hole 211'. This allows the pivot portion 21' to be positioned between the two pivot pieces 11' and pivotally connected by the pivot rod 4' through the pivot holes 111' and 211'. A long slot 22' is provided in the backrest 2' for inserting the combined rod 12'. The elastic device 3' includes a spring 31', a sleeve 32', and a pressing seat 33', with the spring 31' located within the sleeve 32' and the pressing seat 33'. The sleeve 32' has a connection hole 321' for combining with the combined rod 12', allowing the combined rod 12' to be inserted into the slot 22' of the backrest 2', the pressing seat 33', the spring 31', the sleeve 32', and the connection hole 321'. When reclining in the chair, the backrest 2' can pivot backward relative to the chassis 1' via the pivot 4', and the bottom surface A of the front end of the backrest 2' can press against the pressing seat 33' and compress the spring 31' to generate a restoring elastic force.

[0004] As shown in Figure 9, when the backrest 2' is not reclined, the distance between position A of the backrest 2' and the pivot 4' is D1. As shown in Figure 10, when the backrest 2' is reclined, its front end can be offset downward by the pivot 4' as the rotating axis, so that position A of the backrest 2' and the pivot 4' have a horizontal distance D2, which is greater than D1, and have an inclination angle Ɵ corresponding to the bottom wall 1' to compress the spring 31'.

[0005] However, because the backrest 2' rotates from the pivot 4' with the pivot at a fixed position, the greater the downward movement of the front end A of the backrest 2', the greater the tilt angle between position A and the chassis 1'. This makes it difficult for the tilted position to press against the pressure seat 33' at an angle, requiring more force to compress the spring 31'. At the same time, the pivot 4' will also bear more pressure. Therefore, the compression force of the spring 31' varies as the backrest 2' tilts backward, resulting in discomfort when lying down and difficulty in compressing the spring 31' when the tilt angle is large.

[0006] Furthermore, when assembling the back rod 2', the slot 22' of the back rod 2' must be inserted through the combined rod 12' and the elastic device 3'. Also, the pivot hole 211' of the pivot part 21' must be aligned with the pivot hole 111' of the two pivot pieces 11' before inserting the pivot rod 4'. This makes assembly inconvenient and lacking. Summary of the Invention

[0007] The purpose of this invention is to provide a structure that can improve reclining comfort, movement stability, and ease of assembly.

[0008] This invention includes a chassis, a back rod, an elastic device, and a set of connecting rods. The chassis has a top surface and a bottom surface, and is provided with a set of connecting slots. The bottom surface has a groove running left and right in front of the connecting slots. The back rod has a connecting seat at its bottom front end, the connecting seat having two opposing side walls. A connecting post running left and right in the grooves is provided above the front side of each side wall, and a first through hole penetrating the connecting seat vertically in front of the connecting slots is provided. The elastic device is elastic and abuts against the bottom surface of the connecting seat. The connecting rod has an end with a diameter larger than the width of the connecting slots. The lower part of this end can be inserted into the connecting slots, the first through hole, and the elastic device. When the back rod is not under force, the elastic force of the elastic element can cause the connecting post to be embedded in the groove for positioning. When the back rod moves backward, it can compress the elastic device, and the connecting post can be displaced to partially or completely disengage from the groove.

[0009] In one embodiment of the present invention, the groove is approximately semi-circular, the insert post is approximately cylindrical, and a portion of the volume of the insert post can be embedded in the groove.

[0010] In one embodiment of the present invention, a sleeve is fitted around the outer edge of the insert post, which can rotate corresponding to the insert post and can contact the surface of the groove.

[0011] In one embodiment of the present invention, a limiting block is further included. The limiting block has a restoring elasticity and is disposed on the top surface of the chassis. An elastic part is disposed corresponding to the position of the assembly slot hole, and a hook part is disposed behind the elastic part that can abut against the rear of the end of the assembly rod.

[0012] In one embodiment of the present invention, the top surface of the chassis is provided with curved flanges on both sides of the assembly slot hole, which can abut against the bottom surface of the end of the assembly rod.

[0013] In one embodiment of the present invention, two baffles are provided protruding downward on the bottom surface of the chassis, and the side wall of the connecting seat is assembled on the outside of the two baffles.

[0014] In one embodiment of the present invention, a post is provided at the rear end of the top of the side wall that can abut against the rear end of the chassis and simultaneously position the insert post at the groove position and abut against the edge.

[0015] In one embodiment of the present invention, the connecting slot extends from the rear end of the chassis toward the front, has two side walls, and has an opening at the rear. Furthermore, a contact part is provided below the end of the connecting rod to abut against the side wall of the connecting slot to prevent the connecting rod from rotating.

[0016] In one embodiment of the present invention, the elastic device includes a spring, a pressing seat, and a sleeve seat. The spring is disposed in the pressing seat and the sleeve seat, and the pressing seat abuts against the bottom surface of the sleeve seat. The abutting part of the connecting rod has a assembly part below it. The pressing seat has a top wall and an annular wall, and a first fitting groove in the center that can fit the top of the spring. A second through hole is provided at the position of the first through hole of the back rod that can be inserted into the connecting rod. The sleeve seat has a bottom wall and an annular wall, and a second fitting groove in the center that can fit the bottom of the spring and the annular wall of the pressing seat. An assembly hole is provided in the center of the bottom wall that can be combined with the assembly part of the connecting rod.

[0017] After assembly, the insert post and sleeve of this invention can be partially embedded in the groove for stable positioning. When the back rod moves backward, the bottom surface of the connecting seat can press against the downward pressure seat of the elastic device and compress the spring to generate compression elasticity. At this time, the bottom surface of the end of the connecting rod can be offset along the curved flange, and the insert post can be offset downward accordingly. The insert post and sleeve can be displaced to partially or completely disengage from the groove. Therefore, the insert post of this invention is not a fixed pivot, and when the back rod tilts backward, the bottom surface of the connecting seat can be offset to stably abut against the top wall of the pressure seat, making it easy for the pressure seat to compress the spring. This allows the backward tilting process of the back rod to compress the spring linearly and smoothly for better comfort.

[0018] When not lying down against the backrest, the elastic force of the spring can cause the bottom of the backrest to shift upwards. At this time, the insert post and the sleeve can shift accordingly, so that part of the sleeve volume engages with the surface of the groove, which can stabilize the backrest shifting operation and reduce the operating noise. Simple Explanation of the Diagram

[0019] Figure 1 is a top-view exploded view of the backrest and chassis assembly structure of the seat of the present invention.

[0020] Figure 2 is an exploded view from below of the backrest and chassis assembly structure of the seat of the present invention.

[0021] Figure 3 is a schematic diagram of the backrest, elastic device, connecting rod assembly, and chassis assembly of the seat of the present invention from a top view.

[0022] Figure 4 is a schematic diagram of the backrest, elastic device, connecting rod assembly, and chassis assembly of the seat of the present invention from the upward viewing direction.

[0023] Figure 5 is a diagram showing the backrest and chassis assembly of the seat of the present invention.

[0024] Figure 6 is a cross-sectional view of the backrest and chassis assembly of the seat of the present invention.

[0025] Figure 7 is a schematic diagram of the backrest of the seat of the present invention being offset backward.

[0026] Figure 8 is an exploded view of the backrest and chassis of a conventional seat.

[0027] Figure 9 is a cross-sectional view of the backrest and chassis assembly of a conventional seat.

[0028] Figure 10 is a schematic diagram of the backrest compression spring of a conventional seat. Implementation

[0029] Please refer to Figures 1-6. This invention includes a chassis 1, a backrest 2, an elastic device 3, a set of connecting rods 4, and a limiting block 5. The chassis 1 is located below the seat of the chair (not shown) and has a top surface 11, a bottom surface 12, and a connecting slot 13 extending from the center of the rear end towards the front. The connecting slot 13 has two parallel sidewalls 131 and an opening 132 at the rear. Engaging holes 14 are provided on the left and right sides of the connecting slot 13. A groove 15, approximately semi-circular in shape, is provided on the bottom surface 12 in the left and right directions in front of the connecting slot 13. Two baffles 16 protrude downwards from the bottom surface 12 in front of the groove 15. Curved flanges 17 are provided on the top surface 11 on both sides of the connecting slot 13.

[0030] A connecting seat 21 is provided at the bottom front end of the back rod 2. The connecting seat 21 has two side walls 22 that are opposite each other and can be assembled on the outer side of the two baffles 16. A cylindrical insert post 23 that can be partially embedded in the groove 15 in the left and right direction is provided on the upper front side of the side wall 22. A sleeve 231 that can rotate around the insert post 23 and contact the surface of the groove 15 is sleeved on the outer edge of the insert post 23. A rear abutment 24 that can abut against the rear end of the chassis 1 is provided at the top rear end of the two side walls 22. A rear abutment 25 that can abut against the bottom surface 12 of the chassis 1 is also provided on the side walls 22. A first through hole 26 that penetrates the connecting seat 21 from top to bottom is provided at the position corresponding to the assembly slot 13.

[0031] The elastic device 3 includes a spring 31, a pressing seat 32, and a fitting seat 33. The spring 31 is a compression spring. The pressing seat 32 has a top wall 321, an annular wall 322, and a first fitting groove 323 in the center that can fit the top of the spring 31. A second through hole 324 is provided at the position of the first through hole 26 of the back rod 2. The periphery of the second through hole 324 has a protruding abutment edge 325 that can be inserted into the first through hole 26 and abut against the side wall of the first through hole 26.

[0032] The socket 33 has a bottom wall 331 and an annular wall 332. It has a second fitting groove 333 in the center that can fit the bottom of the spring 31 and the annular wall 322 of the pressing seat 32. A set of connecting holes 334 are provided in the center of the bottom wall 331.

[0033] The connecting rod 4 has an end 41 with a diameter larger than the width of the connecting slot 13. The bottom surface 411 of the end 41 abuts against the curved flange 17 of the base 1. Furthermore, a square abutment part 42 is provided below the end 41, which can abut against the side wall 131 of the connecting slot 13 to prevent the connecting rod 4 from rotating. Below the abutment part 42, there is a combination part 43 that can be combined with the first through hole 26, the second through hole 324, the spring 31 and the connecting hole 334 of the sleeve seat 33.

[0034] The limiting block 5 has a restoring elasticity and is provided on the top surface 11 of the chassis 1. An elastic part 51 is provided at the position corresponding to the assembly slot 13. A hook part 52 is provided behind the elastic part 51, a guide slope 521 is provided behind the hook part 52, and a stop surface 522 is provided in front of it. The limiting block 5 is provided with a fitting groove 53 at the position of the curved flange 17 of the top surface 11 of the chassis 1, and a fitting hole 54 is provided at the position of the assembly hole 14 of the chassis 1. The fitting element 55 is inserted through the fitting holes 54 and 14 to fix the limiting block 5 to the chassis 1. The fitting groove 53 fits the curved flange 17 to improve the stability of the combination of the limiting block 5 and the chassis 1.

[0035] As shown in Figures 3 and 4, the present invention can be assembled into a single unit by the back rod 2, the elastic device 3, and the connecting rod 4 before being packaged at the factory. When the consumer unpacks and assembles the assembly, as shown in Figures 3 to 6, the connecting rod 4 can be aligned with the direction of the connecting slot 13, and the connecting seat 21 of the back rod 2 can be moved toward the chassis 1. When the end 41 of the connecting rod 4 presses against the guide slope 521 of the hook 52 of the limiting block 5, the hook 52 can be shifted upward so that the connecting rod 4 can continue to move forward. When the connecting rod 4 moves to below the elastic part 51, the hook 52 can rebound so that the stop surface 522 can be located behind the end 41 of the connecting rod 4 to ensure that the connecting rod 4, the elastic device 3, and the back rod 2 do not detach from the chassis 1.

[0036] Meanwhile, the rear edge 24 of the coupling seat 21 can abut against the rear end of the chassis 1 to prevent the coupling seat 21 from moving forward. The insert post 23 and the sleeve 231 can also be partially embedded in the groove 15 of the chassis 1 for positioning, which can facilitate assembly and alignment and provide better combination stability. Furthermore, the user can rotate the sleeve 33 to adjust the compression force of the spring 31, and make the end 41 of the connecting rod 4 and the top wall 321 of the coupling seat 21 more firmly clamp the chassis 1 and the pressing seat 32 to improve the combination stability.

[0037] After assembly, the side wall 22 of the connecting seat 21 can be abutted against the baffle 16 of the chassis 1. This prevents the backrest 2 from shifting left or right relative to the chassis 1, thus improving reclining stability. Furthermore, the upper edge 25 of the connecting seat 21 can abut against the bottom surface 12 of the chassis 1, further enhancing assembly stability. Therefore, this invention allows consumers to complete assembly simply by moving the backrest 2 towards the chassis 1, making the assembly process far simpler and faster than traditional methods.

[0038] Please refer to Figures 6 and 7. When the backrest 2 moves backward, the bottom surface of the connecting seat 21 can press against the downward movement of the pressing seat 32 of the elastic device 3, compressing the spring 31 and generating compression elasticity. At this time, the connecting rod 4 can be offset accordingly, and the inserting post 23 can be offset downward accordingly. The inserting post 23 and the sleeve 231 can be displaced to partially or completely disengage from the groove 15. Therefore, the inserting post 23 of this invention is not a fixed pivot, and when the backrest 2 tilts backward, the bottom surface of the connecting seat 21 can be offset to stably abut against the top wall 321 of the pressing seat 32. This allows the pressing seat 32 to easily compress the spring 31, and provides a linear and smooth compression of the spring 31 during the backward tilting process of the backrest 2, greatly improving the comfort of lying down.

[0039] When not lying down against the backrest 2, the elastic force of the spring 31 can cause the bottom of the backrest 2 to shift upward. At this time, as shown in Figure 6, the insert post 23 and the sleeve 231 can shift accordingly, so that part of the volume returns to engage and position with the surface of the groove 15. This can stabilize the shifting action of the backrest 2. In addition, the contact between the rotatable sleeve 231 and the surface of the groove 15 can reduce friction and reduce collision noise.

[0040] Therefore, as described above, the present invention can provide better reclining comfort and convenient assembly. The foregoing embodiments are illustrative of the present invention and are not intended to limit the present invention. All equivalent modifications made in accordance with the spirit of the present invention should also fall within the scope of the present invention.

[0041] 1: Chassis 11: Top surface 12: Bottom surface 13: Assembly slot hole 131: Sidewall 132: Opening 14: Connecting hole 15: Groove 16: Baffle 17: Curved flange 2: Back bar 21: Connecting seat 22: Sidewall 23:Embedded column 231: Sleeve 24: Backing Edge 25: Relying on fate 26: First through hole 3: Elastic device 31: Spring 32: Pressure seat 321: Top Wall 322: Circumferential Wall 323: First set of grooves 324: Second through hole 325: Reliance 33: Socket 331: Bottom wall 332: Circumferential Wall 333: Second set of grooves 334: Assembly hole 4: Assembly rod 41:End 411: Bottom 42: Abutment Part 43: Assembly Section 5: Limiting block 51: Elastic part 52: hook part 521: Guide sloping surface 522: Block 53: Fitting groove 54: Connecting hole 55: Connecting element 1': Chassis 11': Pivot plate 111': Pivot hole 12': Combination bar 2': Back pole 21': Pivot section 211': Pivot 22': Slot 3': Elastic device 31': Spring 32': Socket 321': Assembly hole 33': Pressure seat 4': Pivot

Claims

1. A seat backrest and chassis assembly structure, comprising: A chassis has a top surface and a bottom surface, and a set of connecting slots. The bottom surface has a groove in the left and right directions in front of the connecting slots. A back rod has a connecting seat at its bottom front end. The connecting seat has two opposing side walls. A connecting post in the left and right directions is provided on the upper front side of the side wall, which can be embedded in the groove. A first through hole is provided at the position corresponding to the connecting slot, penetrating the connecting seat from top to bottom. An elastic device is elastic and abuts against the bottom surface of the connecting seat. A connecting rod has an end with a diameter larger than the width of the connecting slot. The lower part of the end passes through the connecting slot, the first through hole, and the elastic device, and the connecting seat abuts against the bottom surface of the chassis. When the back rod is not under force, the elastic force of the elastic element can cause the connecting post to be embedded in the groove for positioning. When the back rod moves backward, it can compress the elastic device, and the connecting post can be displaced to partially or completely disengage from the groove.

2. The seat backrest and chassis assembly structure as described in claim 1, wherein the groove is approximately semi-circular, the insert post is approximately cylindrical, and a portion of the volume of the insert post can be embedded in the groove.

3. The seat backrest and chassis assembly structure as described in claim 2, wherein a sleeve is fitted around the outer edge of the insert post, which is rotatable relative to the insert post and can contact the surface of the groove.

4. The seat backrest and chassis assembly structure as described in claim 1, further comprising a limiting block having a restoring elasticity, disposed on the top surface of the chassis, with an elastic portion disposed corresponding to the assembly slot, and a hook portion disposed behind the elastic portion that can abut against the rear of the end of the assembly rod.

5. The seat backrest and chassis assembly structure as described in claim 4, wherein the hook has a guide ramp at the rear and a stop at the front that can abut against the end of the connecting rod.

6. The seat backrest and chassis assembly structure as described in claim 1, wherein the top surface of the chassis is provided with curved flanges on both sides of the assembly slot hole, which can abut against the bottom surface of the end of the assembly rod.

7. The seat backrest and chassis assembly structure as described in claim 1, wherein two baffles are provided downward on the bottom surface of the chassis, and the side wall of the connecting seat is assembled on the outside of the two baffles.

8. The seat backrest and chassis assembly structure as described in claim 1, wherein the top rear end of the side wall is provided with a flange that abuts against the rear end of the chassis and simultaneously positions the insert post at the rear edge of the recessed position.

9. The seat backrest and chassis assembly structure as described in claim 1, wherein the connecting slot extends from the rear end of the chassis toward the front, has two side walls, has an opening at the rear, and a contact part is provided below the end of the connecting rod that can abut against the side wall of the connecting slot to prevent the connecting rod from rotating.

10. The seat backrest and chassis assembly structure as described in claim 9, wherein the elastic device includes a spring, a pressing seat, and a sleeve seat, the spring being disposed within the pressing seat and the sleeve seat, the pressing seat abutting against the bottom surface of the sleeve seat, and the connecting rod having an assembly portion below its abutting portion; the pressing seat having a top wall and an annular wall, with a first fitting groove in the center for fitting the top of the spring, and a second through hole corresponding to the first through hole of the backrest for inserting the connecting rod; the sleeve seat having a bottom wall and an annular wall, with a second fitting groove in the center for fitting the bottom of the spring and the annular wall of the pressing seat, and an assembly hole in the center of the bottom wall for assembling with the assembly portion of the connecting rod.

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