AN ARRANGEMENT IN A CHAIR, PARTICULARLY A CHAIR HAVING AN ADJUSTABLE BACK AND HEADREST
Background of the invention The present invention relates to an arrangement in a chair, particularly a chair having an adjustable back and headrest, a pulling element, e.g. a rod, being arranged between a portion of the headrest and an attachment portion on the chair structure, which, upon movement of the adjustable back, is arranged to influence the angular position of the headrest with respect to the back, the angular position of the headrest being changeable, at least in the reclining position of the back, by changing the effective length of the pulling element .
Prior art
From NO 176384 (Ekornes) there is known an arrangement in a chair, particularly a chair having adjustable back and headrest, where the headrest may be adjusted with respect to the inclined position of the chair back, and where it is suggested that a telescopic rod which extends between the headrest and a suitable place on the chair, is made with relatively complicated and expensive adjusting means and locking means for adjusting the length of the rod and thereby the angular position of the headrest with respect to the back.
These means had to be operated through the upholstery of the chair and were difficult to make function satisfactorily.
Objects of the invention The object of the present invention is to provide an arrangement in a chair which has a pulling element which is designed so that the adjustment between the positions of the back and headrest can be performed in a very simple manner.
A further object of the invention is to provide a pulling element which comprises simple parts, which are robust, and which may be operated automatically or manually as desired.
Another object of the present invention is to provide a pulling element which has manual or automatic adjustment and can be adapted to any chair having a headrest, also chairs having curved guides and further such chairs that have an adjustable lumbar support.
Summary of the invention
Said objects are obtained by an arrangement of the type recited in the introductory paragraph above, which according to the invention is characterised by the features recited in the appending claim 1.
Further features and advantages of the present invention will be apparent from the following description taken in conjunction with the appended drawings and from the further claims .
Short description of the drawings
Fig. 1 is a perspective view of the frame of a chair accord- ing to the invention, where the chair back is in the upper
"sitting" position and with a maximum angle between the back and headrest .
Fig. 2 is a lateral view of a similar chair and shows the back in a reclining position, where the steepest position between the headrest and back is shown in full lines, while the same position of the headrest as in Fig. 1 is shown in broken lines.
Figs. 3-5 show various positions of the headrest with respect to the chair back in a first embodiment of the present invention.
Fig. 6 is a schematic perspective view of a modification of the embodiment shown in Figs. 3-5, where the embodiment may be used in connection with an adjustable lumbar support.
Fig. 7 is a perspective view showing a further embodiment of
the invention, especially a solution suitable for automatic activation and deactivation of the headrest.
Fig. 8 is a schematic perspective view showing an embodiment which is a modification of the one shown in Fig. 7.
Fig. 9 is a perspective view showing yet another embodiment of the invention, especially where the headrest may be activated in the reclining position of the back.
Description of embodiments
Figs. 1 and 2 show generally the frame of two chairs 1 of the type described in O 176384, said chair 1 comprising an adjustable back 2 having an adjustable headrest.
It is to be understood that the chair shown in Figs. 1 and 2 has a particular adjustment of the headrest 3. The present invention may be viewed as a further development that may find application in the general type of chair shown in said figures. However, it is to be understood that the present invention is not limited to use in that type of adjustable chairs, but may also find use in any chair comprising an adjustable back and headrest.
In Figs. 1 and 2 the chair back 2 is journalled about a pivot axis 9, permitting the back 2 to assume various angular positions, while the back concurrently at its lower end has a connecting link 9A to a chair seat 5 made with a movement mechanism 8 known per se .
In Figs. 1 and 2 is also shown a pulling rod 17, which at the top is attached to a pin connection 19 and at the bottom is attached to an articulation 18. The pulling rod 17 may be arranged such that when the chair back 2 is in its upper po- sition, as shown in fig. 1, the headrest 3 will almost be an extension of the back 2 and form its largest angle (close to 180°) to the back. When the back 2 is reclined, as is shown in fig. 2, the relative movement between the back 2 and the
pulling rod 17 will entail that the headrest 3 is pulled forward into a steeper angle with respect to the back 2. By means of a mechanism, the headrest may be lowered to the position 3' shown in broken lines.
Embodiments according to the invention
The purpose of the present invention is to provide a new arrangement in an adjustable chair, particularly a chair having an adjustable back and headrest.
In Figs. 3-5 there is shown a first embodiment for an arrangement according to the present invention. Thus, the present invention is an arrangement in a chair 101, especially a chair having an adjustable back 102 and headrest 103. Be- tween a portion 119 on the headrest 103 and an attachment portion 109 on the chair structure there is arranged a pulling element 118, e.g. designed as a rod 117, which by movement of the adjustable back 102 is arranged to influence the angular position of the headrest 103 with respect to the back 102.
As shown in said figures, the pulling element 108 comprises first coupling means 120 co-operating with second coupling means 123, permitting the headrest 103 to be influenced in various ways.
In the embodiment shown in Figs. 3-5 and Fig. 9 the following headrest functions may be obtained:
Form a raised back (Fig. 3) to a lowered back (Fig. 4) one may have the headrest function activated so that the headrest will assume a progressively steeper position with respect to the back (Fig. 4) , whereupon the headrest 103 in the lowered position of the back may be pulled somewhat for- ward for uncoupling of the headrest function and deactivating to lowered position (Fig. 5) . This position can be maintained until the back once more is moved to its upright position, where the headrest again is coupled in, which en-
tails that one is back to the initial position (Fig. 3) .
In the embodiment described in Figs. 3-5, the pulling element 118 comprises coupling means in the form of a side track 121 and a free track 121, which co-operate with a coupling pin 123 arranged on the headrest 103.
In this case the side track 122 and free track 121 are connected to each other through a transition portion 124 there- between.
In the raised position of the back 102, as this appears from Fig. 3 and Fig. 6, the coupling pin 123 is located in the side track 122 to perform the headrest function when the chair back 102 is lowered, see Fig. 4, whereupon a small
(manual) pulling forward of the headrest 103, in the lowered position of the back 102, will force the coupling pin 123 out of the side track 122 and into the free track 122, thereby to enable uncoupling of the headrest, see Fig. 5 and Fig. 6. This entails that the coupling pin 123 will move in the free track 121 ard only when the back 102 once more is in a raised position, will it come back to the transition area 124 between the free track 121 and the side track 122. In this new raised position of the back 102 the coupling pin 123 will once more be pressed into the side track 122 and resume its headrest function in conjunction with the pulling element 118.
In the example of Figs. 3-5 the pulling element 118 with its pulling rod 117 is arranged to co-operate with a cam 124 or the like, which especially in the raised position of the back forces the rod in a direction which brings the pin 123 from the end of the free track 121 into the side track 122, e.g. activating the headrest function in the raised posi- tion, see particularly Fig. 5. A wire spring 125 is arranged to bring the pulling element 118 closer to the back frame 102 when the back is lowered in order to ensure that the pin 123 slides over into the free track 121 when the headrest is
moved forward. The cam 124 will be received in a recess 126 in the pulling element 118.
Furthermore, it is to be understood that the pulling element 118 with its pulling rod 117 alternatively may be arranged to co-operate with a suitable bias, e.g. a spring, rubber band, upholstery elasticity etc., which particularly in the raised position of the back forces the pulling rod in a direction to bring said pin from the end of the free track into the side track.
In Fig. 6 there is shown an alternative for moving the pulling element 118 so that the coupling pin 123 is guided into the appropriate part of the track 120. For this purpose, a guide 128 for the pulling rod 117 is arranged on the back frame 102. A possible embodiment of this guide is schematically shown in the detailed view A-A in the figure.
In Fig. 6 the chair back 102 is shown in the upper position. When the chair back is pivoted down, the chair back will form a larger angle with the arm 129 on which the lower pivot point 119 of the rod 117 is located. This results in that this end of the rod is moved away from the back frame 102. Concurrently, the pin 123 is pulled up along the curved track of the pipe hinge connecting the back frame and headrest frame 103 so that also this pivoted point moves further away from the extension of the back frame 102. In turn this results in that the rod 117, which is held laterally in the guide 128 and is supposed to have a certain resilience, is strained, so that when the pin 123 is moved out of the track 122, the resilience will cause the pulling element 118 to move closer to the chair track frame and thereby bring the pin over into the free back 121.
The guide 128 may conveniently be dimensioned in such a manner that when the chair back is brought back to the raised position, the rod 117 is subjected to an opposite bending which serves to bring the pin 123 back into the track 122.
A further embodiment of an arrangement according to the invention is shown in Fig. 7.
It will appear from these figures that the pulling element 218 is provided with a side track 222 having a larger width Bl, and a free track 221 having a smaller width B2. The wider track 222 and narrower track 221 co-operate with a coupling pin 223 having a stepped diameter, a first portion 223A1 thereof having a larger diameter Dl fitting into the wider track with a certain clearance, and a second portion 223B1 of the pin 223 having a smaller diameter D2 fitting into the narrower track with a certain clearance.
Here, the pulling element 218 may co-operate with a ramp 250 (hidden) on the headrest 203, said ramp 250 in the lowered position of the back 202 pushing the pulling element 218 sideways so that it slides from the wider portion Dl of the pin 223 to the narrower portion D2 of the pin, and such that the narrower portion D2 slide into the narrower free track 221, thereby to uncouple the headrest. This entails that not until the back is anew in the raised position will the coupling pin be forced back into the side track 222 and resume its headrest function in co-operation with the pulling ele- ment 218.
The function described in connection with Fig. 7 is particularly suited for cases where the headrest in the lowered position of the back will have its headrest function automati- cally uncoupled for automatic free-coupling of the headrest to the lowered position.
A variant of the embodiment of Fig. 7 is shown in Fig. 8. The difference lies primarily in that the side track 222 having the enlarged diameter does not lie to the side of the free track 221, but forms an enlargement of the free track at one end thereof. Furthermore, a cam arrangement 230 is arranged on the back frame 202 in order to push the rod 217
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laterally when it is moved towards and away from the back frame 202 under the pivoting movement of the latter. Further details of this cam arrangement is not shown, but would be easy for the skilled person to design to produce the desired lateral movement of the pulling element 218. Also in this case the resilient properties of the rod 217 are utilised.
In Fig. 9 is schematically shown a further embodiment of an arrangement according to the invention which provides a fur- ther variant of the headrest function.
In the embodiment according to Fig. 9 the headrest function will be uncoupled from raised back to lowered back, i.e. the headrest will have a substantially constant position with respect to the back, whereupon the headrest in the lowered position can be pulled somewhat forwards (manually) for activating the headrest function and maintaining a steeper position of the headrest with respect to the back. This activated function is maintained until the back once more is moved to the raised position with a progressively larger angle between the headrest and back, where the headrest once more is uncoupled.
More particularly, the embodiment according to Fig. 9 is such that when the back 302 is in the upright position, the coupling pin 323 is located in a free track 321, the result being that the pulling element 318 does not perform any headrest function until the back is completely lowered.
When the back has reached the completely lowered position, one may by means of a small (manual) forward movement of the headrest 303 force the coupling pin out of the end of the free track 321 and into a first side track 327, or move the headrest further and thereby force the pin out of the track 327 and over into side track 322. This activates the headrest function in co-operation with the pulling element 318, whereupon the coupling pin 323 will be forced once more into the free track 321 for uncoupling the headrest function when
the back 302 is again moved to the upright position.
Uncoupling of the headrest function in the new upright position may also here be performed by a suitable ramp forcing the pulling element in a direction which brings the pin from the side track to the free track, i.e. uncoupling of the headrest function in the upright position.
Alternatively one may use a suitable bias, spring, rubber band, upholstery resillience etc. to perform the necessary activating and uncoupling functions.
It will be understood that the coupling means described may co-operate with a headrest comprising, as known per se, curved portions which may be moved with respect to other curved portions or guides on top of the back.
Furthermore, it will be understood that in such a case, said coupling pin may be arranged on one of said curved portions of the headrest for co-operating in a suitable manner with said pulling element.
At its lower end the pulling element may be shaped like a rod which is attached to a suitable location on the chair structure. It should also be understood that the pulling element may comprise a rod portion having a thickness giving a suitable elastic resilience.
Furthermore, it will be understood that the present arrange- ment may comprise adjustment means and locking means for pre-setting or post-setting of a progressive angular position between the back and headrest .