HEIGHT ADJUSTABLE HEADREST FOR SEAT BACKRESTS

Abstract

A height-adjustable headrest for seat backrests, of the type comprising a support body (1) configured to provide support to the cervical or occipital region of a user, characterized in that it comprises a support rod (2) describing a closed or substantially closed contour of generally rectangular geometry with an upper section (6), a lower section (7), and two lateral sections (8) connecting the upper section (6) and the lower section (7), said rectangular contour being shaped so as to adopt a convex configuration in which the plane defined by the upper section (6) is offset with respect to the plane defined by the lower section (7), such that the support rod (2) is configured to embrace the upper edge (10) of a backrest (9) with the upper section (6) located on the front face of the backrest (9) and the lower section (7) located on the rear face of the backrest (9), the support body (1) further comprising guiding means (5) configured to receive the support rod (2) and allow relative sliding between the body of {2.} Headrest according to claim 1, characterized in that the support rod (2) has an asymmetric configuration in which the lateral sections (8) have different lengths, such that the upper section (6) and the lower section (7) are vertically offset from each other. {3.} Headrest according to claim 2, characterized in that the asymmetric configuration of the support rod (2) allows different positioning geometries of the support body (1) to be obtained by reversing the orientation of the support rod (2) by rotating it 180 degrees about a horizontal axis. 4. Headrest according to any of the preceding claims, characterized in that the guiding means (5) consist of a plurality of loops (5) arranged on the rear face of the support body (1), said loops (5) defining respective pins through which the support rod (2) slides. 5. Headrest according to claim 4, characterized in that the loops (5) are made of textile material forming loops or fabric pins fixed to the support body (1). 6. Headrest according to claim 4, characterized in that the loops (5) are made of plastic material obtained by injection molding and fixed to the support body (1) by sewing, adhesive, or riveting. 7. Headrest according to any of claims 4 to 6, characterized in that the configuration and dimensions of the clips (5) provide sufficient friction with the support rod (2) to maintain the selected position of the support body (1) without unintentional slippage during normal use. 8. Headrest according to any of the preceding claims, characterized in that the support body (1) comprises an outer cover (3) and an inner filling (4) of deformable material with elastic recovery. 9. Headrest according to claim 8, characterized in that the outer cover (3) is made of textile material, natural leather, or synthetic leather. 10. Headrest according to any of claims 8 or 9, characterized in that the inner filling (4) is made of textile fibers, foamed materials of the foam rubber type, or combinations of both. 11. Headrest according to any of the preceding claims, characterized in that the support body (1) has a geometric configuration selected from square, rectangular, circular, or oval. 12. Headrest according to any of the preceding claims, characterized in that the support rod (2) is made of metallic material, preferably steel or metallic alloys. 13. Headrest according to any of the preceding claims, characterized in that the support rod (2) has a circular cross-section. 14. Headrest according to any of the preceding claims, characterized in that the convex configuration of the support rod (2) is dimensioned to position the support body (1) forward of the plane of the front face of the backrest (9), so that the support body (1) is configured to provide support to the back of the user's neck. 15. Headrest according to any of the preceding claims, characterized in that the enveloping geometry of the support rod (2) is configured to retain the headrest on the backrest (9) regardless of the tilt angle of said backrest (9).

Description

HEIGHT ADJUSTABLE HEADREST FOR SEAT BACKRESTS Technical field of the invention The present invention relates to a height-adjustable headrest for seat backs, of the type comprising a padded body and means for attaching it to the backrest. More specifically, the invention falls within the technical field of comfort accessories for seating furniture, such as sofas, armchairs, and similar seats, and specifically in the field of detachable and adjustable headrests intended to provide cervical support to users of different heights. Background of the invention It is well known that a significant portion of seating furniture intended for domestic use, particularly sofas and armchairs, has backrests whose height is insufficient to provide adequate support for the cervical and cranial areas of users. This has led to the development of various types of auxiliary headrests which, placed at the top of the backrest, increase its effective height and allow the user to rest their head, thus improving comfort while using the seat. Among the solutions known in the prior art, the most common auxiliary headrests are those that incorporate a support structure made of a metal rod. Within this general category, several types can be distinguished, differentiated by their construction and their method of attachment to the backrest. One type of headrest consists of relatively robust metal rods inserted into the structural frame of the backrest, where they are housed in receptacles or sheaths designed for this purpose. These headrests generally incorporate a height adjustment system based on horizontal slots in the rods. These slots work in conjunction with locking mechanisms located in the frame's receptacles, allowing the headrest to be positioned at different heights by vertically moving the rods and locking them into the selected slot.While this type of headrest offers reasonably effective height adjustment, it has the drawback of requiring a specific configuration of the backrest frame with receptacles sized to accommodate the rods, which limits its applicability to those seats whose original design provides for this coupling system, excluding its installation in conventional sofas and armchairs not equipped with such receptacles. A second type of headrest uses thinner metal rods positioned between the backrest cushion and the base of the seat frame. These rods, due to their smaller cross-section, can be inserted into the space between these two elements without requiring modifications to the seat structure. This type of headrest allows for some horizontal movement, enabling adjustment of the lateral position of the head support. However, this design does not allow for height adjustment of the headrest; the vertical position of the support is determined by the fixed geometry of the rod.Additionally, this second type of headrest has a significant limitation in its application, as it is incompatible with backrests whose cushion or pad is attached to the frame base using zipper-type fasteners. In such cases, the perimeter zipper prevents the rod from being inserted between the cushion and the frame, making headrest installation impossible. A third type of headrest, which has achieved considerable commercial use in various markets, comprises a padded support body and a band or strip of textile material with a counterweight at its rear end. This headrest is positioned on the upper edge of the backrest so that the padded body is located on the front of the backrest, facing the user, while the textile band runs down the back of the backrest. The counterweight exerts a gravitational force that keeps the headrest in position. Height adjustment is achieved by relative sliding between the padded body and the textile band, allowing modification of the band's length on the front of the backrest and, consequently, the vertical position of the support body.This type of headrest offers significant advantages in terms of ease of installation, versatility of use, and the level of comfort provided. However, it presents a significant functional drawback when used on sofas or armchairs equipped with reclining mechanisms of the type commonly known as "relax." In these seats, the backrest can pivot backward, adopting positions inclined relative to the vertical. When the backrest tilts backward, the counterweight headrest loses its stable equilibrium, since the component of gravitational force acting on the counterweight is no longer sufficient to keep the assembly in position on the inclined backrest, causing the headrest to slide and fall toward the back of the seat. From an ergonomic standpoint, it should be noted that most headrests are designed to sit on the upper edge of the backrest, with the support element positioned above this edge and providing support to the occipital region of the skull, that is, the back of the head. However, ergonomic studies on postural comfort while seated indicate that optimal cervical support is achieved when the support element supports the entire back of the user's neck, not just the occipital area. To achieve this ergonomically favorable arrangement, the headrest's support element should not be positioned exclusively above the upper edge of the backrest, but rather partially forward of the backrest's front surface, in a position that allows it to make contact with the user's cervical spine while seated in a natural position.Of the types of headrests described, the third one is the one that best allows approximating this optimal configuration, but it is affected by the aforementioned instability problem when the backrest is tilted. In view of the state of the art described above, the technical problems that arise and which the present invention intends to solve are the following: Firstly, there is a need for a headrest that combines height adjustment with a construction configuration that guarantees its stability and permanence in position when the seat back tilts backwards, as occurs in sofas and armchairs equipped with relax-type reclining mechanisms, preventing the slippage and falling of the headrest that occurs with known counterweight solutions. Secondly, there is a need for a headrest whose installation does not require specific receptacles in the backrest frame or depend on the possibility of inserting elements between the backrest cushion and its structural base, so that it is compatible with a wide variety of backrest configurations, including those whose cushions are attached to the base by means of a zipper or other perimeter closure systems. Thirdly, there is a need for a headrest whose structural configuration allows it to be positioned forward of the backrest, so that the supporting body can provide effective support to the user's posterior cervical area and not only to the occipital region, thus improving the overall ergonomic performance. Fourth, the need is raised for the height adjustment system to be simple and intuitive to operate, allowing the user to adapt the vertical position of the support body to their particular height and the height of their cervical area without requiring tools or complex adjustment operations. Fifth, it is desirable that the headrest configuration allows for different positioning geometries, both in height and in the angle of inclination of the supporting body, using the same support structure, thus increasing the versatility of the product and its ability to adapt to different users and comfort preferences. Explanation of the invention The present invention relates to a height-adjustable headrest for seat backs that solves the technical problems described in the preceding section by means of a novel construction that combines a padded support body with a support structure consisting of a metal rod with a geometry specifically designed to guarantee the stability of the assembly in any backrest position. This objective is achieved with the headrest of claim 1. Other objects and embodiments are described in the dependent claims. The headrest of the invention comprises two main constituent elements: a support body and a support rod. The support body is configured to receive the user's head or cervical region, providing padded support that adapts to the user's anatomy. The support rod, on the other hand, constitutes the fundamental characteristic element of the invention and is configured to solve the technical problems identified in the prior art. The rod is made of metallic material, preferably steel or metal alloys of suitable rigidity, and has a circular cross-section or other geometries suitable for sliding through the loops of the support body. The described configuration resolves the technical problems raised in the background of the invention. First, regarding the need for a headrest that maintains its stability when the backrest reclines in reclining mechanisms, this is resolved by the enveloping configuration of the support rod. Unlike known counterweight headrests, where retention depends exclusively on the gravitational force exerted by a weight on the back of the backrest, the headrest of the invention is mechanically retained because the rod surrounds the upper edge of the backrest, preventing its backward movement regardless of the backrest's angle.When the backrest pivots backward, the front section of the rod tends to move upward due to gravity, but this movement is prevented by the rear section of the rod, which abuts the back of the backrest. The closed geometry of the rod's rectangular shape thus ensures positive retention of the headrest in any backrest tilt position, eliminating the risk of it falling, a problem with traditional counterweight solutions. The second technical issue, concerning compatibility with different backrest configurations, is resolved by the headrest's installation method, which requires neither specific receptacles in the backrest frame nor the insertion of any elements between the cushion and the structural base. The headrest is installed simply by placing the rod over the upper edge of the backrest, making it compatible with any backrest configuration regardless of its internal construction. Specifically, the headrest can be installed on backrests whose cushions are attached to the base with a zipper, since the rod does not need to be inserted inside the backrest but rests on it from the outside. The third technical problem, relating to the ergonomic arrangement of the support body to provide support to the cervical area, is resolved by the convex configuration of the support rod. The rod's curvature places the front section, to which the support body is attached, in a forward position relative to the backrest. This forward position allows the support body to make contact with the back of the user's neck when they are seated in a natural position, providing the optimal ergonomic cervical support that is not achieved with headrests positioned solely above the upper edge of the backrest. The fourth technical problem, related to the simplicity of the height adjustment system, is solved by the sliding clip system described. The user can adjust the height of the support body with a simple manual sliding action, without the need for tools, disassembly of any components, or operation of locking or releasing mechanisms. The adjustment is intuitive and can be performed with the headrest attached to the backrest, allowing the user to quickly and comfortably find the optimal position. The fifth technical problem, relating to the versatility of positioning configurations, is solved by the preferred asymmetrical configuration of the support rod. As mentioned, the asymmetry of the side sections allows the same rod to offer different installation geometries depending on its orientation, multiplying the adjustment possibilities available to the user without increasing the product's construction complexity. In light of the foregoing, the invention offers the following advantages over the prior art. First, it provides positive mechanical retention of the headrest that is independent of the backrest's tilt position, allowing the headrest to be used on sofas and armchairs with a reclining mechanism without risk of falling. This is a substantial improvement over known counterweight headrests, which are unsuitable for this type of seating. Furthermore, the invention offers universal compatibility with different backrest configurations, including those with cushions attached by zippers, overcoming the installation limitations of known headrests that require specific receptacles or insertion spaces between the cushion and the frame. The invention provides an improved ergonomic design that effectively supports the cervical spine, not just the occipital region, enhancing the user's postural comfort during prolonged use of the seat. Additionally, the headrest features a simple, intuitive, and tool-free height adjustment system, allowing for quick adaptation to users of varying heights. Furthermore, it offers multiple positioning configurations with a single support element, thanks to the ability to reverse the orientation of the asymmetrical rod, increasing the product's versatility and adaptability to different comfort preferences. The aforementioned advantages are achieved through a simple construction with a reduced number of components, which promotes manufacturing cost savings and product reliability by minimizing elements susceptible to wear or failure. Finally, the invention allows for the independent replacement of the padded support body and the support rod, facilitating maintenance, cleaning of the textile cover, and potential product customization through support bodies of different materials, colors, or configurations. Brief description of the drawings To complement the description being made and in order to facilitate the understanding of the characteristics of the invention, a set of figures is included with this descriptive report in which, for illustrative and non-limiting purposes, the following has been represented: Figure 1 shows a perspective view of the headrest of the invention, in which the padded support body with clips, the support rod with its convex rectangular configuration, and the backrest of a seat can be seen. The arrows shown indicate the direction of movement of the rod during the installation of the headrest onto the upper edge of the backrest. Figure 2 shows a front-side perspective view of the headrest installed on the back of a seat, with the backrest in its upright position for conventional use. This figure shows the arrangement of the padded support on the front of the backrest and the portion of the support rod that runs above the upper edge of the backrest. Figure 3 shows a side view of the headrest installed on a backrest that is tilted backward, corresponding to the configuration adopted by seats equipped with a reclining mechanism. The arrow indicates the direction of the backrest's tilt. This figure shows how the headrest remains stably positioned on the backrest despite its tilt, thanks to the wrap-around design of the support rod. Figure 4 shows a perspective view of the headrest installed on a backrest in a reclined position. This figure clearly illustrates the three-dimensional geometry of the support rod, showing its convex and asymmetrical shape, as well as how the rod hugs the upper edge of the backrest, ensuring the assembly remains securely in place. Figure 5 shows a perspective view from a top-rear angle of the headrest installed on the back of a seat. This figure illustrates the asymmetrical configuration of the support rod, showing the different lengths of its side sections, as well as the rear portion of the rod that extends down the back of the seat. Figure 6 shows a general perspective view of the headrest of the invention installed on the back of a seat. This figure depicts the complete assembly consisting of the padded support body, the guide clips located on the rear face of the support body, and the support rod with its convex and asymmetrical rectangular geometry, illustrating the relative arrangement of all the constituent elements of the invention. List of numerical references: (1) Support body (2) Support rod (3) Outer cover (4) Inner filling (5) Guiding means / Clamps (6) Upper section of the support rod (7) Lower section of the support rod (8) Lateral sections of the support rod (9) Backup (10) Upper edge of the backrest Preferred embodiment of the invention A preferred embodiment of the invention is described in detail below with reference to the accompanying figures, in which the various constituent elements of the headrest are represented with numerical reference symbols that will be used consistently throughout this description. The headrest of the invention comprises two main constituent elements: a support body (1) and a support rod (2), as can be seen in Figures 1 and 6. The support body (1) consists of a volumetric element that can adopt various geometric configurations in plan view, such as square, rectangular, circular, or oval, according to aesthetic preferences and desired comfort requirements. In the embodiment shown in the figures, the support body (1) has a substantially rectangular configuration with rounded corners. This support body (1) comprises an outer cover (3) made of textile material, natural leather, synthetic leather, or other suitable upholstery materials, and an inner filling (4) of material that provides the deformability and elastic recovery necessary for user comfort. This inner filling (4) can be made of textile fibers, foam materials such as foam rubber, or combinations of both.The support body (1) is configured to receive the user's head or cervical area, providing padded support that adapts to the user's anatomy. The support body (1) is provided with guiding means (5) configured to receive the support rod (2) and allow relative sliding between the two elements. These guiding means (5) preferably consist of a plurality of loops (5) arranged on the rear face of the support body (1), i.e., on the face intended to face the seat back (9), as shown in Figures 1 and 6. The loops (5) may be made of textile material, forming loops or fabric fasteners sewn or attached to the outer cover (3) of the support body (1), or alternatively, they may be made of plastic elements obtained by injection molding and attached to the support body (1) by sewing, adhesive, riveting, or other suitable fastening means.The clips (5) define two pins through which the support rod (2) passes, sliding securely within these pins. The configuration and dimensions of the clips (5) allow the smooth longitudinal sliding of the support rod (2), enabling relative movement between the support body (1) and the support rod (2), while simultaneously providing sufficient retention to maintain the user's selected position without unintentional slippage during normal use of the headrest. The support rod (2) is the fundamental characteristic element of the invention and is configured to solve the technical problems identified in the prior art. The support rod (2) is made of metallic material, preferably steel or metallic alloys of suitable rigidity, and has a circular cross-section or other geometries suitable for sliding through the clamps (5) of the support body (1). The defining characteristic of the support rod (2) lies in its three-dimensional geometric configuration, clearly visible in Figures 4, 5, and 6. The support rod (2) describes a closed or substantially closed contour with a generally rectangular geometry, defining a perimeter frame with four main sections: an upper section (6), a lower section (7), and two lateral sections (8) that connect the former. This rectangular contour is shaped in such a way that it adopts a convex configuration as a whole; that is, the support rod (2) does not describe a flat rectangle, but rather presents a curvature that causes the plane defined by the upper section (6) to be displaced forward with respect to the plane defined by the lower section (7), or vice versa, generating an enveloping three-dimensional configuration. In particular, the support rod (2) has an asymmetrical configuration in which the side sections (8) are of different lengths, such that the upper section (6) and the lower section (7) are vertically offset from each other, as shown in Figure 6. This asymmetry, combined with the convex shape of the contour, allows the same support rod (2) to provide different positioning geometries for the support body (1) depending on its installation orientation. By reversing the orientation of the support rod (2), i.e., by rotating it 180 degrees about a horizontal axis, both the relative height of the support body (1) with respect to the upper edge (10) of the backrest (9) and the angle of inclination of the support plane with respect to the vertical are modified, thus offering multiple usage configurations with a single support element. The headrest is installed on the seat backrest (9) as illustrated by the arrows in Figure 1. The support rod (2) is positioned so that its rectangular outline partially surrounds the backrest (9) along its upper edge (10). The upper section (6) of the support rod (2) is located on the front face of the backrest (9), facing the user, while the lower section (7) is located on the rear face of the backrest (9). The side sections (8) of the support rod (2) run over the upper edge (10) of the backrest (9), connecting the front and rear portions. In this way, the support rod (2) embraces the upper edge (10) of the backrest (9), being held in place by its own enveloping geometry.The support body (1), linked to the support rod (2) by means of the clips (5), is positioned on the front face of the backrest (9), in order to provide support to the cervical or occipital area of ​​the user, as shown in Figures 2 and 3. The height adjustment of the support body (1) is achieved by sliding it along the support rod (2). The user can manually move the support body (1) up or down by sliding the clips (5) along the portion of the support rod (2) that passes through them. This sliding action allows the vertical position of the support body (1) to be modified relative to the upper edge (10) of the backrest (9), adapting the height of the cervical support point to the user's height. Once the desired position is selected, the friction between the clips (5) and the support rod (2) holds the support body (1) in that position during normal use, without the need for additional locking mechanisms. Figure 3 illustrates the behavior of the headrest when the backrest (9) is tilted backward, as occurs in seats equipped with a reclining mechanism. In this configuration, the headrest remains stably positioned on the backrest (9) because the lower section (7) of the support rod (2) is held against the rear face of the backrest (9), preventing the assembly from sliding and falling regardless of the tilt angle of the backrest (9). Figures 4 and 5 show in greater detail the three-dimensional configuration of the support rod (2) when the backrest (9) is in an inclined position, clearly showing the convex and asymmetrical geometry that characterizes said support rod (2) and which constitutes the essential technical element of the present invention.

Claims

1. Height-adjustable headrest for seat backrests, of the type comprising a support body (1) configured to provide support to the cervical or occipital area of ​​a user, characterized in that it comprises a support rod (2) describing a closed or substantially closed contour of generally rectangular geometry with an upper section (6), a lower section (7) and two lateral sections (8) connecting the upper section (6) and the lower section (7), said rectangular contour being shaped so as to adopt a convex configuration in which the plane defined by the upper section (6) is displaced with respect to the plane defined by the lower section (7), so that the support rod (2) is configured to embrace the upper edge (10) of a backrest (9) with the upper section (6) located on the front face of the backrest (9) and the lower section (7) located on the rear face of the backrest (9),further comprising the support body (1) and guiding means (5) configured to receive the support rod (2) and allow relative sliding between the support body (1) and the support rod (2) for height adjustment of the support body (1).

2. Headrest according to claim 1, characterized in that the support rod (2) has an asymmetric configuration in which the lateral sections (8) have different lengths, such that the upper section (6) and the lower section (7) are vertically offset from each other.

3. Headrest according to claim 2, characterized in that the asymmetric configuration of the support rod (2) allows for different positioning geometries of the support body (1) to be obtained by reversing the orientation of the support rod (2) by rotating it 180 degrees about a horizontal axis.

4. Headrest according to any of the preceding claims,characterized in that the guiding means (5) consist of a plurality of loops (5) arranged on the rear face of the support body (1), said loops (5) defining respective pins through which the support rod (2) slides.

5. Headrest according to claim 4, characterized in that the loops (5) are made of textile material forming fabric loops or pins fixed to the support body (1).

6. Headrest according to claim 4, characterized in that the loops (5) are made of plastic material obtained by injection molding and fixed to the support body (1) by sewing, adhesive, or riveting.

7. Headrest according to any one of claims 4 to 6,characterized in that the configuration and dimensions of the clips (5) provide sufficient friction with the support rod (2) to maintain the selected position of the support body (1) without unintentional slippage during normal use.

8. Headrest according to any of the preceding claims, characterized in that the support body (1) comprises an outer cover (3) and an inner filling (4) of deformable material with elastic recovery.

9. Headrest according to claim 8, characterized in that the outer cover (3) is made of textile material, natural leather, or synthetic leather.

10. Headrest according to any of claims 8 or 9, characterized in that the inner filling (4) is made of textile fibers, foamed materials of the foam rubber type, or combinations of both.

11. Headrest according to any of the preceding claims,characterized in that the support body (1) has a geometric configuration selected from square, rectangular, circular, or oval.

12. Headrest according to any of the preceding claims, characterized in that the support rod (2) is made of metallic material, preferably steel or metallic alloys.

13. Headrest according to any of the preceding claims, characterized in that the support rod (2) has a circular cross-section.

14. Headrest according to any of the preceding claims, characterized in that the convex configuration of the support rod (2) is dimensioned to position the support body (1) forward of the plane of the front face of the backrest (9), so that the support body (1) is configured to provide support to the back of the user's neck.

15. Headrest according to any of the preceding claims,characterized in that the enveloping geometry of the support rod (2) is configured to retain the headrest on the backrest (9) regardless of the tilt angle of said backrest (9).