NO342754B1

NO342754B1 - System for motorized adjustment of headrest

Info

Publication number: NO342754B1
Application number: NO20161813A
Authority: NO
Inventors: Rune Jonsen; Lars Inge Jakobsen
Original assignee: Img Group As
Priority date: 2016-11-17
Filing date: 2016-11-17
Publication date: 2018-08-06
Also published as: NO20161813A1

Abstract

The invention relate to a motorized adjustable headrest for a recliner chair comprising a back frame 1 with a pivotable headrest frame 5 mounted on top. The adjustable headrest further com prises a motor 7, a movement transfer line from the motor 7 to the headrest frame 5, wherein the movement transfer line comprises a bar (8) extending from the lower part of the back frame (1) to a first pivot unit (9) attached to the headrest frame (5), According to the invention the bar (8) is rotationally attached to the first pivot unit (9) and a release mechanism is located at a location along the length of the movement transfer line between the motor (7) and the headrest frame (5), wherein the release mechanism comprises means for movement of a first part of the transfer line relative to a second part of the transfer line corresponding to a predetermined movement of the headrest frame (5) and is provided with a pretensjon with a predetermined load to counteractthis movement. Furthermore a hinged connection (10) is attached to the side parts (2, 3) and each side of the headrest frame (5), each comprisingan angular restrictor, restricting the angular rotation of the headrest frame to a common predetermined sector. The release mechanism is moveable corresponding to the same or a langer angular sector as the hinged connection (10).The invention relates to a motorized adjustable headrest for a recliner chair comprising a back frame 1 with a pivotable headrest frame 5 mounted on top. The adjustable headrest further com prises a motor 7, a movement transfer line from the motor 7 to the headrest frame 5, while the movement transfer line comprises a bar (8) extending from the lower portion of the back frame (1) to a first pivot unit (9) attached to the headrest frame (5), according to the invention the bar (8) is rotationally attached to the first pivot unit (9) and a release mechanism is located at a location along the length of the movement transfer line between the motor (7) and the headrest frame (5), the release mechanism comprising means for movement of a first part of the transfer line relative to a second part of the transfer line corresponding to a predetermined movement of the headrest frame ( 5) and is provided with a pretension with a predetermined load to counteract this movement. Furthermore, a hinged connection (10) is attached to the side parts (2, 3) and each side of the headrest frame (5), each comprising an angular restrictor, restricting the angular rotation of the headrest frame to a common predetermined sector. The release mechanism is movable corresponding to the same or a longer angular sector than the hinged connection (10).

Description

Field of invention

The present invention relates to furniture in general and to a motorized adjustable head rest for a reclining chair in particular.

Background

In the following we will describe a so called "recliner", a chair which can be moved between a sitting position and a reclining position. In the reclining position the user has a semi lying position, and an in-build, foldable foot rest projecting horizontally as an elongation of the seat. To further enhance the comfort an adjustable backrest and headrest is provided.

The recliner has become a popular furniture in the average home in the industrialized world and several different versions have emerged. The 'stressless' of Ekornes is well known as a category of chairs and in the US a bulkier and bigger version is popular. The applicant aims at constructing a slim and light weight recliner with the same comfort as the big versions. There is also a growing demand for motorized remote control of head rest, foot rest and back support. This put restrictions on the framework of the chair and how the motorized adjustment mechanisms are built. This invention solves some of the problems related to the motorized adjustment mechanisms. In particular it solves a problem with the headrest adjustment mechanism concerning bending of a bar which is transferring movement from a motor at the base of the recliner to a movement of the headrest. Numerous damages on said bar have been registered during transport and use, because of unexpected forces pushing the headrest forward and downward. The invention solves the problem of the most common damage because the forces is absorbed and also allows for a slimmer more lightweight construction.

The motorized adjustable headrest will normally be positioned in the back frame of a recliner together with a mechanism for a motorized adjustable back support. The presence of two mechanisms in the back frame also gives some restrictions to the construction. The mechanism for a motorized adjustable back support is applied for in a parallel application.

A number of light weight, slim constructions of chairs using wires has been developed. The life expectancy of such mechanisms is however considerably shorter than the lifetime of a recliner; the wires tend to break in their fastenings or jump out of their paths. Another option is to install the motor near the headrest, but this prohibits a slim construction of the backrest. This is why movement transfer through rigid structures is preferable and why the problem of slim chair structures should be solved with this in mind.

NO 20075182 B1 describes a device for a chair håving an adjustable backrest and an adjustable head rest, where the device, upon movement of the backrest, is constructed to influence the angle of the head rest in relation to the backrest so that the head rest is inclined forwardly as the backrest is tilted backwards. The device also provides a pronounced lumbar support as the backrest is in an upright position, whereas the lumbar support is decreased when the backrest is in a horizontal position.

WO 2004/058010 Al relates to loungers or beds consisting of pivoting elements and comprising a motor drive for adjusting their position. To prevent injury to users caused by improper adjustment, the pivoting movements are restricted.

JP 2005124796 A describes a headrest device equipped with a rod protruding and extending from a backrest, a pin attached to the protruding end of the rod, and a guide plate with an are shaped guide groove. The guide plate has one end fixed on the back side of a headrest and the other end rotatably mounted on a cylindrical support. The support extends along the rod and has one end fixed on an electric motor. When the support is mo ved in the longitudinal direction of the backrest by the electric motor, the pin moves in the guide groove. Consequently, the headrest turns around a connecting part P2 between the cranial bone and the cervical vertebrae of the user.

DE 20206250 Ul describes a computerWorkstation comprising a chair and holding means for an input device and a monitor in which at least one backrest of the chair is pivotable in the direction of a lying position, wherein at least one pivotable armrest is mounted on the chair, whose pivoting movement is coupled to the pivoting movement of the backrest (4) such that when pivoting the backrest (4) in the direction of a lying position, the armrest (18) is pivoted upwards.

US 6517156 Bl describes a chair comprising a base, a backrest, a seat including a rear end pivotally connected to a lower end of the backrest, two armrests securely mounted to the base, each armrest including a front end pivotally connected to the seat and a rear end pivotally connected to the backrest, and a waist rest including a waist rest body, two connecting pieces, and two linkages. The waist rest body includes an arcuate resting portion on an upper end thereof and a lower arcuate resting portion on a lower end thereof. Each connecting piece includes a first peg for pivotal connection with the rear end of an associated armrest. Each connecting piece further includes a second peg for pivotal connection with an end of an associated linkage. The other end of each linkage is pivotally connected to the seat.

Summary of the invention

The invention relate to a motorized adjustable headrest for a recliner chair comprising a back frame with two side parts, a lower part and a pivotable headrest frame mounted between the top ends of the two side parts. The back frame is covered by a backrest shaped to support a human back and head. The adjustable headrest further comprises a motor, a movement transfer line from the motor to the headrest frame, wherein the movement transfer line comprises a bar extending from the lower part of the back frame to a first pivot unit attached to the headrest frame,

According to the invention the bar is rotationally attached to the first pivot unit and a release mechanism is located at a location along the length of the movement transfer line between the motor and the headrest frame, wherein the release mechanism comprises means for movement of a first part of the transfer line relative to a second part of the transfer line corresponding to a predetermined movement of the headrest frame and is provided with a pretension with a predetermined load to counteract this movement. Furthermore a hinged connection is attached to the side parts and each side of the headrest frame, each comprising an angular restrictor, restricting the angular rotation of the headrest frame to a common predetermined sector. The release mechanism is moveable corresponding to the same or a larger angular sector as the hinged connection.

Brief description of the drawings

To improve the understanding of the invention a number of figures showing actual embodiments is provided. Like numerals in different figures are linked to the same part.

Fig. 1 shows a complete frame of a recliner chair.

Fig. 2 shows a front view of the back frame with one motor for adjusting the head rest.

Fig 3A and B shows the back frame with the headrest in two positions.

Detailed description

In the following the terms up, down, left, right forward, backward will be defined by a person sitting in the chair in an upright position. Fig. 1 shows an entire frame of a recliner chair with a back frame 1 and the contour of a backrest 6 covering the frame 1 and shaped to support a human back and head. In order to achieve a light weight, slimmer and cheaper frame, the frame is preferably made of a tubular metal such as steel, but other materials like wood, fibers or a plastic might be used. In this description we will not describe the seat and foot rest and related mechanisms, but focus on the back frame 1, headrest frame 5 and related mechanisms. Furthermore we will not describe the remote control system needed to operate the adjustable headrest, because different versions of remote control systems are readily available. Fig 2 shows the back frame 1 of a recliner seen from the front. The recliner with a motorized adjustable headrest comprises a back frame 1 with two side parts 2, 3, a lower part 4, and a pivotable headrest frame 5 mounted between the top ends of the two side parts 2, 3. The frame 1 is covered by a backrest 6 which is shaped to support a human back and head. The motorized adjustable headrest further comprises a motor 7, and a movement transfer line from the motor to the headrest frame. The movement transfer line comprises a bar 8 extending from the lower part of the back frame 1 to a first pivot unit 9 attached to or integrated with the headrest frame 5. The first part of the transfer line can take many forms, two of which is described later.

The bar 8 is rotationally attached to the first pivot unit 9, and a release mechanism is located somewhere along the length of the movement transfer line between the motor 7 and the headrest frame 5. The release mechanism comprises means for movement of a first part of the transfer line relative to a second part of the transfer line corresponding to a predetermined movement of the headrest frame 5, and is provided with a pretension with a predetermined load to counteract this movement. The purpose of the release mechanism is to prevent mechanical overload on the motor 7 and the movement transfer line.

In one embodiment the pretension is provided by at least one spring 19 attached in one end to the side parts 2, 3 and in the other end to the head rest frame 5 and / or the first pivot unit 9, thus pretensioning the headrest frame 5 towards an upright position. Furthermore movement between the two parts of the transmission line is provided by a slot 15 in the first pivot unit 9, to which slot the bar 8 is rotationally and glidingly attached. Advantageously the slot 15 is a radial slot 15 describing a part of a circle with center in the rotational axis of the headrest frame 5. The advantage of a radial slot is that it gives the least friction and sideways movement of the bar 8. It is also conceivable that sufficient pretension towards an upright position of the headrest frame 5 is provided in the material used in the upper section of the backrest, thus removing the need for a spring.

As can be seen in figures 3a and b the headrest frame is attached to the back frame 1 by means of hinged connections 10. A hinged connection 10 is connected to a side part 2, 3 and a side of the

headrest frame 5 and comprises an angular restrictor, restricting the angular rotation of the headrest frame 5 to a predetermined sector, preferably corresponding to the desired adjustable movement of the headrest. Figure 3 a and b also shows two typical extreme positions of the headrest frame 5. The release mechanism is moveable corresponding to the same or a larger angular sector as the hinged connection 10.

In one embodiment the hinged connection 10 comprise an upper restriction plate 11 attached to the headrest frame 5, a lower restriction plate 12 attached to a side part 2, 3, and a center bolt 16 connecting the two plates. Each restriction plate 11,12 has a radial restriction slot 13a, b describing a part of a circle centered in the rotational axis of the headrest frame, and a restriction lug 14a, b extending at a right angle from the restriction plate in a position such that the slot 13 a mates with the lug 14 b and visa versa,

The two restriction plates 11, 12, slots 13a, b and lugs 14a, b are configured in a way that the headrest only is free to rotate over a desired angular sector, and the movement of the release mechanism must be the same as or bigger than the movement corresponding to this rotation. Preferably the two hinged connections on each side of the headrest frame 5 are able to move over common angular sectors. The effect of this is that when a force is applied to the headrest bending the headrest forward, this will not cause the bar (8) to bend or cause damage to the motor 7, because the release mechanism will allow the headrest to move at least to the point where the hinged connections 10 reaches the end of their common angular sector and the movement stops.

In a preferable embodiment, the movement between the two restriction plates 11,12 of the hinged connection 10 is provided with extra friction. Due to the movement allowed by the release mechanism, some degree of play in the movement transfer line is likely to occur and the extra friction prevents the play to be felt in the headrest.

In one embodiment the release mechanism is a radial slot 15 in the pivot unit 9 describing a part of a circle with center in the rotational axis of the headrest frame 5, to which slot the bar 8 is rotationally and glidingly attached and wherein a spring 16 is attached to the side part and the pivot unit 9 pretensioning the headrest frame 5 towards an upright position.

In one embodiment the movement transfer line comprises an extendable rod 17 moveable in a direction parallel to the lower part 4 and attached to the motor 7, which is fastened to the lower part 4. The movement transfer line further comprises a second pivot unit 18 rotationally attached to the lower part 4, wherein the extendable rod 17 and second pivot unit 18 is configured to move the bar 8 up and down. In an alternative embodiment the motor might be located just below the bar 8 and the extendable rod 17 could then be directly connected to the bar 8.

Claims

1. Motorized adjustable headrest for recliner chair comprising: a back frame (1) with two side parts (2, 3), a lower part (4) and a pivotable headrest frame (5) mounted between the top ends of the two side parts (2, 3), a backrest (6) covering the frame (1) and shaped to support a human back and head, a motor (7), a movement transfer line from the motor to the headrest frame (5), wherein the movement transfer line comprises a bar (8) extending from the lower part of the back frame (1) to a first pivot unit (9) attached to the headrest frame (5), characterized in thatthe bar (8) is rotationally attached to the first pivot unit (9), a release mechanism is located at a location along the length of the movement transfer line between the motor and the headrest frame (5), wherein the release mechanism comprises means for movement of a first part of the transfer line relative to a second part of the transfer line corresponding to a predetermined movement of the headrest frame (5) and is provided with a pretension with a predetermined load to counteract this movement, a hinged connection (10) attached to a side part (2, 3) and a side of the headrest frame (5) comprises an angular restrictor, restricting the angular rotation of the headrest frame (5) to a predetermined sector, and wherein the release mechanism is moveable corresponding to the same or a larger angular sector as the hinged connection (10).

2. Adjustable headrest according to claim 1 wherein the release mechanism is a slot (15) in the first pivot unit (9), to which slot the bar (8) is rotationally and glidingly attached and wherein at least one spring (19) is attached in one end to the side parts 2, 3 and in the other end to the head rest frame (5) and / or the pivot unit (9) pretensioning the headrest frame (5) towards an upright position.

3. Adjustable headrest according to claim 1 and 2, wherein the slot (15) is a radial slot describing a part of a circle with center in the rotational axis of the headrest frame (5).

4. Adjustable headrest according to claim 1 wherein the movement transfer line comprises: an extendable rod (17) moveable in a direction parallel to the lower part (4) and attached to the motor (7) fastened to the lower part (4), and a second pivot unit (18) rotationally attached to the lower part (4), the extendable rod (17) and the bar (8), being configured to move the bar (8) up and down.

5. Adjustable headrest according to claim 1 wherein the movement transfer line comprises: an extendable rod (17) moveable in a direction parallel to the side parts (2, 3) and attached to the motor (7), wherein the rod (17) is directly connected to the bar (8).

6. Adjustable headrest according to claim 1 wherein the hinged connection comprises: an upper restriction plate (11) attached to the headrest frame (5), a lower restriction plate (12) attached to a side part (2, 3), a center bolt (16) rotationally connecting the two plates, wherein each restriction plate (11, 12) comprise a radial restriction slot (13a, b) describing a part of a circle centered in the rotational axis of the headrest frame, and a restriction lug (14a, b) extending at a right angle from the restriction plate in a position such that the slot (13 a) mates with the lug (14 b) and visa versa, wherein the two restriction plates (11, 12), slots (13a, b) and lugs (14a, b) are configured in a way that the headrest frame (5) is free to rotate over a predetermined angular sector.

7. Adjustable headrest according to claim 1 wherein the movement between the two restriction plates 11, 12 of the hinged connection 10 is provided with extra friction.