Back part for a seat and seat

Abstract

The invention relates to a backrest (6) for a piece of seating furniture (2), comprising a base frame (10) and at least one headrest (8) arranged on the base frame (10), wherein the respective headrest (8) is held on the base frame (10) by means of a headrest adjustment device (12) of the base frame (10) and can be automatically moved back and forth between a lower height position of the headrest (8) and an upper height position of the headrest (8), and wherein the headrest adjustment device (12) has two guide rods (14, 16) movable along a vertical axis of the base frame (10) and spaced apart from each other for holding the headrest (8) and a lower crossbar (18) extending perpendicular to the guide rods (14, 16) and mechanically connected to the guide rods (14, 16), wherein the lower crossbar (18) is connected at both end faces of the lower crossbar (18) by a bearing extending along the vertical axis of the drive section (20) running along the base frame (10)22) a drive comprising an electric motor (24) of the headrest adjustment device (12) is connected in a force-transmitting manner, wherein the drive comprises only a single electric motor (24), the electric motor (24) being arranged in a fixed position substantially centrally between the two guide rods (14, 16) on an upper crossbeam (26) of the headrest adjustment device (12). The invention further relates to a piece of seating furniture (2).

Description

[0001] The invention relates to a backrest for a piece of seating furniture for providing posterior support to a user of the seating furniture, comprising a base frame and at least one headrest arranged on the base frame for providing headrest support to the user, wherein the respective headrest is held on the base frame by means of a headrest adjustment device of the base frame and can be automatically moved back and forth between a lower height position of the headrest and an upper height position of the headrest, and wherein the headrest adjustment device has two guide rods, each movable along a vertical axis of the base frame and spaced apart from each other, for holding the headrest and a lower crossbar extending perpendicular to the guide rods and mechanically connected to the guide rods.wherein the lower crossbeam is connected at both end faces of the lower crossbeam to a drive element extending along the vertical axis of the base frame, of a drive for the headboard adjustment device which includes an electric motor, transmitting force.

[0002] Furthermore, the invention relates to a piece of seating furniture with such a backrest.

[0003] Such backrests for seating furniture and seating furniture equipped with them are already known in the prior art in a multitude of different embodiments. The known backrests for seating furniture are designed to provide posterior support to a user of the seating furniture and comprise a base frame and at least one headrest arranged on the base frame for headrest support of the user, wherein the respective headrest is held on the base frame by means of a headrest adjustment device and can be automatically moved back and forth between a lower and an upper height position of the headrest.and wherein the headboard adjustment device has two guide rods, each movable along a vertical axis of the base frame and spaced apart from each other, for supporting the headboard, and a lower crossbeam extending perpendicular to the guide rods and mechanically connected to the guide rods, wherein the lower crossbeam is connected at both end faces of the lower crossbeam to a drive element extending along the vertical axis of the base frame of a drive of the headboard adjustment device comprising an electric motor, transmitting force.

[0004] The object of the present invention is to improve a backrest for a piece of seating furniture and a piece of seating furniture.

[0005] To solve this problem, the invention, in conjunction with the preamble of claim 1, is characterized in that the drive comprises only a single electric motor, wherein the electric motor is fixedly arranged essentially centrally between the two guide rods on an upper crossbar of the headrest adjustment device. Furthermore, this problem is solved by a piece of seating furniture with the features of claim 10.

[0006] The particular advantage of the invention lies in improving both the backrest and the seat itself. Due to the inventive design of the backrest and the seat, it is possible to ensure excellent synchronization of the two guide rods for supporting and adjusting the height of the respective headrest relative to the base frame of the backrest. Accordingly, tilting, and thus stiffness, blockage, or even damage to the headrest adjustment mechanism during height adjustment of the aforementioned headrest—i.e., when moving it from the lower to the upper position or vice versa—is effectively prevented. The inventive backrest with the headrest adjustment mechanism is therefore functionally reliable and durable.The single electric motor driving the headrest adjustment mechanism does not need to move along with the headrest height adjustment, as is usually the case, due to its stationary position. This allows for either greater stability of the backrest according to the invention compared to the prior art, or, with comparable stability, a less material-intensive and / or more space-saving design. Furthermore, the essentially central positioning of the single electric motor ensures that unwanted torque input into the backrest according to the invention is easily avoided. The aforementioned advantages apply particularly to backrests according to the invention that have large headrests, for example, with a large extension perpendicular to the vertical axis of the base frame, i.e., very wide headrests.Furthermore, the aforementioned advantages can be realized in a very simple and robust manner in terms of design and manufacturing technology using the invention.

[0007] In principle, the backrest according to the invention and the seating furniture according to the invention equipped with it can be freely selected within wide suitable limits with regard to type, function, material and dimensions.

[0008] An advantageous embodiment of the backrest according to the invention provides that the electric motor is connected to a portion of the drive unit via at least one drive rod in a torque-transmitting manner. Preferably, the drive rod is designed as a polygonal rod, and particularly preferably, as a hexagonal rod. This allows for a structurally reduced yet robust implementation of the headrest adjustment device and thus of the backrest according to the invention. This applies particularly to the preferred and especially to the particularly preferred embodiment of this embodiment. In this context, it is very advantageous if the at least one drive rod is designed as a single drive rod.

[0009] A further advantageous embodiment of the back section according to the invention provides that the aforementioned remaining part of the drive has two bevel gear units, wherein each bevel gear unit is connected to the electric motor on the drive side in a torque-transmitting manner and to one of the drive components, each designed as a spindle, on the output side in a torque-transmitting manner, and wherein each spindle interacts with a spindle nut corresponding to this spindle and mechanically connected to one of the two end faces of the lower crossbeam in a force-transmitting manner. This provides, on the one hand, a very reliable gear technology for redirecting a torque by 90°, which is available in many embodiments on the market. For example, bevel gear units designed as bevel gear units are mentioned here.On the other hand, the combination of the respective angle gear on one side and the corresponding spindle with the respective spindle nut on the other side provides a very simple implementation of this torque redirection, both in terms of design and manufacturing technology.

[0010] An advantageous further development of the aforementioned embodiment of the backrest according to the invention provides that the respective spindle is arranged in a U-profile of the headrest adjustment device extending along the vertical axis of the base frame, and the respective spindle nut is guided in the corresponding U-profile perpendicular to the vertical axis of the base frame with essentially no play. In this way, the stability of the headrest adjustment device, and thus of the backrest according to the invention, is significantly improved by means of the U-profiles, while simultaneously resulting in only a minimal increase in material and therefore weight. Furthermore, the combination of the U-profiles with the respective spindle nut provides a simple yet highly reliable and robust transverse guidance of the spindle nut along the vertical axis during height adjustment of the respective headrest.

[0011] An advantageous embodiment of the backrest according to claim 3 or 4 provides that the respective spindle is arranged in a U-profile of the headrest adjustment device extending along the vertical axis of the base frame, and the respective spindle nut is guided in the corresponding U-profile along the vertical axis of the base frame with essentially no play. Analogous to the aforementioned embodiment, this again significantly improves the stability of the headrest adjustment device and thus of the backrest according to the invention by means of the U-profiles, while simultaneously resulting in only a slight increase in material and therefore weight. Furthermore, the combination of the U-profiles with the respective spindle nut provides a simple yet very reliable and robust longitudinal guidance of the spindle nut along the vertical axis during height adjustment of the respective headrest.

[0012] Accordingly, an advantageous embodiment of one of the two aforementioned embodiments of the back section according to the invention provides that the respective spindle nut is designed to compensate for tolerances perpendicular to the vertical axis of the base frame and / or along the vertical axis of the base frame, preferably that the respective spindle nut is biconvex along the vertical axis of the base frame. This ensures that the respective spindle nut is reliably guided in the corresponding U-profile, i.e., without tilting or the like, despite unavoidable component and assembly tolerances perpendicular to the vertical axis of the base frame and / or along the vertical axis of the base frame. This applies in particular to the preferred embodiment of this embodiment.Due to the aforementioned biconvex design of the respective spindle nut, i.e., a spindle nut with a convex shape along its vertical axis, a close, force-transmitting contact is achieved between the spindle nut and the corresponding U-profile, thus compensating for any play between the spindle on one side and the spindle nut on the other. This also applies in particular to a reversal of the spindle nut's movement, i.e., when switching from a movement of the respective head section towards the lower height position to a movement towards the upper height position and vice versa.

[0013] According to a particularly preferred embodiment of the back section according to claim 6, the respective spindle nut is designed to be reversibly deformable perpendicular to and / or along the vertical axis of the base frame. Preferably, the respective spindle nut has a slot on both sides, and most preferably, the slot extends along the vertical axis of the base frame. This makes the respective spindle nut particularly suitable for the present application. This is especially true for the preferred embodiment of this development, by means of which the respective spindle nut can be implemented in a particularly simple manner from a design and manufacturing perspective.The particularly preferred embodiment of this further development is especially suitable for the application because it enables the very important compensation of the play between the respective spindle and the corresponding spindle nut along the vertical axis of the base frame in a simple and reliable manner.

[0014] Further advantages, features, and details of the invention can be found in the dependent claims and the following description. Features mentioned therein can be essential to the invention individually or in any combination. The drawings serve only as examples to clarify the invention and are not limiting in nature. They show: Fig. 1 shows an embodiment of the seating furniture according to the invention with two backrests according to the invention in a perspective view; Fig. 2 shows the embodiment in a partial view in analogous representation to the Fig. 1 , with regard to the base frames of the two back sections, Fig. 3 shows the left base frame from the Fig. 2 in a perspective view, with the head section at the lower height, Fig. 3b the left base frame from the Fig. 2 in a perspective single view, with the head section in the upper height position, Fig. 3c, detail "A" from the Fig. 3a in an enlarged view, Fig. 3d, detail "B" from the Fig. 3b In an enlarged view, Fig. 4, the basic frame in a partial, perspective sectional view, with the left angle gear from the Fig. 3a and the corresponding spindle with the spindle nut, Fig. 5, the basic frame from the Fig. 4 in a frontal view, but without U-profile and lower crossbeam, Fig. 5b section "CC" from the Fig. 5a and Fig. 5c the section according to the Fig. 5b in a perspective view.

[0015] In the Fig. 1 bis 5c An embodiment of a seating furniture according to the invention, comprising a total of two backrests according to the invention, is shown purely by way of example.

[0016] The seating furniture 2 is designed as a two-seater sofa and comprises two seat sections 4 for each of the two users (not shown) and two back sections 6 assigned to the two seat sections 4 for posterior support of the user. In the present embodiment, each back section 6 has a headrest 8 for head support of the user. See the Fig. 1 The two back sections 6 and the two head sections 8 are identical in design, so that in the following sections only a single back section 6 with its corresponding head section 8 is sometimes shown or explained. The explanations provided apply accordingly to the back section 6 and its head section 8 that are not shown or explained.

[0017] In the present embodiment, the respective backrest 6 for the seating furniture 2 comprises a base frame 10 and the headrest 8 arranged on the base frame 10 for head-side support of the user, wherein the respective headrest 8 is held on the base frame 10 by means of a headrest adjustment device 12 and is positioned between a [missing information] in the image planes of the Fig. 1 and 2 The lower height position of the head section 8, shown on the left, and one in the image planes of the Fig. 1 and 2The upper height position of the headboard 8, shown on the right, can be automatically moved back and forth. See also the Fig. 3a with the head section 8 of the left back section 6 according to the Fig. 1 and 2 at the lower altitude and the Fig. 3b with the head section 8 of the left back section 6 according to the Fig. 1 and 2in the upper height position. The headboard adjustment device 12 further comprises two guide rods 14, 16, each movable along a vertical axis of the base frame 10 and spaced apart from one another, for supporting the headboard 8, and a lower crossbeam 18 extending perpendicular to the guide rods 14, 16 and mechanically connected to them, wherein the lower crossbeam 18 is connected at both end faces of the lower crossbeam 18 to a drive element 20, 22 of a drive for the headboard adjustment device 12, which includes an electric motor 24 and extends along the vertical axis of the base frame 10. See in particular the Fig. 3a bis 3d in a summary.

[0018] According to the invention, the drive comprises only a single electric motor 24, wherein the electric motor 24 is arranged in a fixed position essentially centrally between the two guide rods 14, 16 on an upper crossbeam 26 of the headrest adjustment device 12. See the Fig. 2 bis 3b .

[0019] The electric motor 24 is connected to a portion of the drive unit by means of at least one drive rod 28, which transmits torque. The drive rod 28 is designed as a polygonal rod, specifically a hexagonal rod. With a suitable selection of the electric motor, the drive rod can be designed as a single drive rod.

[0020] The aforementioned remainder of the drive comprises two bevel gear units 30, 32, wherein the bevel gear units 30, 32 are each connected on the input side to the electric motor 24 in a torque-transmitting manner and on the output side to one of the drive components 20, 22, each designed as a spindle, in a torque-transmitting manner, and wherein each spindle 20, 22 interacts in a force-transmitting manner with a spindle nut 34, 36 corresponding to this spindle 20, 22 and mechanically connected to one of the two end faces of the lower crossbeam 18. See in particular the Fig. 3c and 3d as well as the Fig. 5a bis 5c in a summary. As can be seen from the Fig. 3d As can be seen by way of example, the respective guide rod 14, 16 is mechanically fastened to the lower crossbeam 18 by means of a screw connection 38 and is longitudinally guided by means of a spherical bearing 40 of the upper crossbeam 26. The two bevel gears 30, 32 are largely made of plastic parts and are each designed as a bevel gear bearing. See the Fig. 5a bis 5c in a summary in which only the angle gear 30 is shown as an example.

[0021] In the present embodiment, the respective spindle 20, 22 is arranged in a U-profile 42, 44 of the headboard adjustment device 12 extending along the vertical axis of the base frame 10, and the respective spindle nut 34, 36 is guided in the corresponding U-profile 42, 44 at least along the vertical axis of the base frame 10 with essentially no play.

[0022] For this purpose, the respective spindle nut 34, 36 is designed to compensate for tolerances at least along the vertical axis of the base frame 10, wherein the respective spindle nut 34, 36 is biconvex along the vertical axis of the base frame 10. See in particular the Fig. 5b and 5c Furthermore, the respective spindle nut 34, 36, designed as a plastic nut, is designed to be reversibly deformable perpendicular to and along the vertical axis of the base frame 10, wherein the respective spindle nut 34, 36 has a slot 46, 48 on both sides, namely such that the respective slot 46, 48 runs along the vertical axis of the base frame 10.

[0023] Furthermore, the respective spindle nut 34, 36 is designed to match the corresponding U-profile 42, 44 in such a way that the play between the spindle nut 34, 36 on one side and the corresponding spindle 20, 22 on the other side along the vertical axis of the base frame 10 can be compensated in such a way that when the head section 8 is moved between the two height positions of the head section 8, the two guide rods 14, 16 move in a substantially synchronous manner.

[0024] The following describes the functioning of the seating furniture according to the invention with the backrest according to the invention, as illustrated in the present exemplary embodiment. Fig. 1 bis 5c explained in more detail.

[0025] As explained above, the seating furniture 2 is a two-seater sofa with a total of two seat sections 4 and corresponding back sections 6. Since the two seat-back section pairs 4, 6 are identical in design, it is sufficient to explain only one of the two pairs 4, 6 in more detail. The explanations provided apply accordingly to the seat-back section pair 4, 6 that is not shown and / or not explained. The same applies if the application text only describes one of the two sides of the base frame 6.

[0026] Initially, the image is located on the left side of the image plane. Fig. 2 The illustrated headrest adjustment device 12 is positioned in a way that corresponds to the lower height position of the headrest in the plane of the image. Fig. 2 Head section shown on the left 8. As can be seen from the Fig. 3c As can be seen, the spindle nut 34, which is firmly screwed to the lower crossbeam 18, is in a first end position at the lower end of the U-profile 42. If the user (not shown) now wishes to move the head section 8 from the lower height position to the upper height position, the user can initiate control of the electric motor 24 in a manner known to those skilled in the art, for example by actuating an actuating element (not shown).A rotor of the electric motor 24 (not shown) is rotated in a predetermined direction according to this control, so that the drive rod 28, which is coupled to this rotor in a torque-transmitting manner, rotates such that the torque, deflected by 90° by means of the bevel gear 30, moves the spindle nut 34, which is guided on the spindle 20 in a force-transmitting manner, from the aforementioned first end position to a second end position at the upper end of the U-profile 42, corresponding to the upper height position of the head section 8. See the [reference to be added]. Fig. 3d The same applies to the angle gear 32 in conjunction with the spindle 22 arranged in the U-profile 44 and the spindle nut 36. Due to the design of the two spindle nuts 34, 36 described above, namely their essentially backlash-free guidance at least along the vertical axis of the base frame 10, the two spindle nuts 34, 36 move essentially synchronously along the vertical axis of the base frame 10. This is because, due to their specific design, each spindle nut 34, 36 must first be reversibly deformed with a predetermined force before the actual movement of the spindle nut 34, 36 from the first end position towards the second end position begins.By means of this deformation, the existing play on both sides of the headboard adjustment device 12 is compensated in such a way that the two spindle nuts 34, 36 move essentially synchronously to each other from the first end position to the second end position.

[0027] Here, the lower crossbeam 18, which is firmly screwed together with the two spindle nuts 34, 36, is shown in the respective image plane of the Fig. 1 bis 3d also moved from bottom to top, so that the guide rods 14, 16, which are firmly screwed to the lower traverse 18, with the attached head section 8, are guided longitudinally by means of the upper traverse 26, also in the respective image plane of the Fig. 1 bis 3d move upwards. See in particular the Fig. 3a and 3b .

[0028] If the user wishes to lower the headrest 8 from its upper position back to its lower position, this is done in the same manner as described above for the transition from the lower to the upper position. The electric motor 24 can be activated accordingly, for example, by re-actuating the operating element. Alternatively, it is also conceivable that different operating elements are provided for each direction of movement. Furthermore, other methods of operating such a piece of seating furniture that are generally known to those skilled in the art are also applicable.

[0029] Of course, embodiments of the invention are also possible in which the headrest can be moved from the lower to the upper position and vice versa by means of intermediate positions, either in steps or continuously. The intermediate positions are each positioned at different heights between the lower and upper positions of the headrest 8. Accordingly, the user can move the respective headrest 8 not only to the two extreme positions, but also to at least one desired intermediate position, in which the respective headrest 8 is then held to support the user's head. This holding of the respective headrest 8 in the lower and upper positions, as well as, if present, in the at least one intermediate position, is achieved solely by means of the mechanism described above.Approaching one of the aforementioned positions can be achieved, for example, by means of a number of actuations of the actuating element corresponding to the respective position, by means of different actuating elements, or by means of other suitable operating concepts.

[0030] Due to the inventive design of the backrest 6 and the seat 2, it is possible to ensure very good synchronization of the two guide rods 14, 16 for supporting and adjusting the height of the headrest 8 of the backrest 6 relative to the base frame 10 of the backrest 6. Accordingly, tilting and thus stiffness, blockage, or even damage to the headrest adjustment device 12 during height adjustment of the aforementioned headrest 8, i.e., when moving it from the lower to the upper position and vice versa, is effectively prevented. The inventive backrest 6 with the headrest adjustment device 12 is therefore designed to be functionally reliable and durable.The single electric motor 24 of the headrest adjustment device 12, due to its stationary position, does not need to move along with the respective headrest 8 during height adjustment, as is usually the case. This allows for either greater stability of the backrest 6 compared to the prior art, or, with comparable stability of the backrest 6, a less material-intensive and / or more space-saving design. Furthermore, the essentially central positioning of the single electric motor 24 ensures that unwanted torque input into the backrest 6 due to this motor 24 is easily avoided. The aforementioned advantages apply particularly to the described backrests 6 with large headrests 8, for example, with a large extension perpendicular to the vertical axis of the base frame 10, i.e., very wide headrests 8.Furthermore, the aforementioned advantages can be realized in a very simple and robust manner in terms of design and manufacturing using the back parts 6.

[0031] The invention is not limited to the present embodiment. See, for example, the relevant explanations in the introductory section of the description and the optional and alternative features in the specific description section. Bezugszeichenliste

[0032] 2 Seating furniture 4 Seat sections 6 Back sections 8 Head section 10 Base frame 12 Head section adjustment device 14 Guide rod 16 Guide rod 18 Lower cross member 20 Drive part (spindle) 22 Drive part (spindle) 24 Electric motor 26 Upper cross member 28 Drive rod 30 Angle gear 32 Angle gear 34 Spindle nut 36 Spindle nut 38 Screw connection 40 Spherical bearing 42 U-profile 44 U-profile 46 Slot 48 Slot

Claims

1. Backrest (6) for a piece of seating furniture (2) for providing posterior support to a user of the seating furniture (2), comprising a base frame (10) and at least one headrest (8) arranged on the base frame (10) for providing headrest support to the user, wherein the respective headrest (8) is held on the base frame (10) by means of a headrest adjustment device (12) and can be automatically moved back and forth between a lower height position of the headrest (8) and an upper height position of the headrest (8), and wherein the headrest adjustment device (12) has two guide rods (14, 16) which are movable along a vertical axis of the base frame (10) and spaced apart from each other for holding the headrest (8) and a lower crossbar (18) which extends perpendicular to the guide rods (14, 16) and is mechanically connected to the guide rods (14, 16),wherein the lower crossbeam (18) is connected at both end faces of the lower crossbeam (18) to a drive element (20, 22) extending along the vertical axis of the base frame (10) of a drive for the headboard adjustment device (12) having an electric motor (24) in a force-transmitting manner, characterized by the fact that the drive has only a single electric motor (24), wherein the electric motor (24) is arranged in a fixed position essentially centrally between the two guide rods (14, 16) on an upper crossbeam (26) of the headboard adjustment device (12).

2. Back section (6) according to claim 1, characterized by the fact that the electric motor (24) is connected to a remainder of the drive by means of at least one drive rod (28) in a torque-transmitting manner, preferably that the drive rod (28) is designed as a polygonal rod, particularly preferably that the polygonal rod is designed as a hexagonal rod.

3. Back section (6) according to claim 1 or 2, characterized by the fact thatthe aforementioned remainder of the drive comprises two bevel gears (30, 32), wherein the bevel gears (30, 32) are each connected on the drive side to the electric motor (24) in a torque-transmitting manner and on the output side to each of the drive parts (20, 22) designed as spindles in a torque-transmitting manner, and wherein the respective spindle (20, 22) cooperates in a force-transmitting manner with a spindle nut (34, 36) corresponding to this spindle (20, 22) and mechanically connected to one of the two end faces of the lower traverse (18).

4. Back section according to claim 3, characterized by the fact that the respective spindle is arranged in a U-profile of the headboard adjustment device running along the vertical axis of the base frame and the respective spindle nut is guided in the corresponding U-profile perpendicular to the vertical axis of the base frame with essentially no play.

5. Back section (6) according to claim 3 or 4, characterized by the fact thatthe respective spindle (20, 22) is arranged in a U-profile (42, 44) of the headboard adjustment device (12) running along the vertical axis of the base frame (10) and the respective spindle nut (34, 36) is guided in the corresponding U-profile (42, 44) along the vertical axis of the base frame (10) essentially without play.

6. Back section (6) according to claim 4 or 5, characterized by the fact that the respective spindle nut (34, 36) is designed to compensate for tolerances perpendicular to the vertical axis of the base frame and / or along the vertical axis of the base frame (10), preferably that the respective spindle nut (34, 36) is biconvex along the vertical axis of the base frame (10).

7. Back section (6) according to claim 6, characterized by the fact thatthe respective spindle nut (34, 36) is designed to be reversibly deformable perpendicular to and / or along the vertical axis of the base frame (10), preferably that the respective spindle nut (34, 36) has a slot (46, 48) on both sides, particularly preferably that the slot (46, 48) runs along the vertical axis of the base frame (10).

8. Back section (6) according to one of claims 3 to 7, characterized by the fact that the respective spindle nut (34, 36) is designed to match the corresponding U-profile (42, 44) in such a way that the play between the spindle nut (34, 36) on one side and the corresponding spindle (20, 22) on the other side along the vertical axis of the base frame (10) can be compensated in such a way that when the head section (8) is moved between the two height positions of the head section (8) a substantially synchronous movement of the two guide rods (14, 16) takes place.

9. Back section (6) according to one of claims 3 to 8, characterized by the fact thatthe respective angle gear (30, 32) and / or the respective spindle nut (34, 36) are at least partially, preferably completely, made of a plastic.

10. Seating furniture (2), comprising at least one seat section (4) for a user of the seating furniture (2) to sit on and at least one back section (6) associated with the at least one seat section (4) for back support of the user, wherein at least one of the at least one back section (6) has at least one head section (8) for head support of the user, characterized by the fact that the back part (6) is designed according to one of claims 1 to 9.

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