The invention relates to a piece of seating furniture, in particular of the armchair or sofa type, having a seat surface and a legrest which is displaceable between a stowed position in which the legrest is arranged beneath the seat surface in the vertical direction of the furniture, and a use position in which the legrest is arranged in front of the seat surface in the longitudinal direction of the furniture. In this case, the legrest is configured with a variable length by two mutually displaceable fitting portions of the legrest. A force is able to be applied to these two fitting portions of the legrest by a spring portion of a spring device, said spring portion acting between a first force application point at a first of the two fitting portions and a second force application point at a second of the two fitting portions. This spring portion is stretched depending on the relative positions of the fitting portions with respect to one another and exerts a force on the fitting portions.
The invention furthermore relates to a fitting for such a generic piece of seating furniture.
Generic pieces of seating furniture are distinguished by their leg unit that forms a legrest. The legrest, when it is not used, is moved into said stowed position, in which it is arranged in a manner concealed beneath the seat surface. If the legrest is required, in order that a more comfortable sitting position with raised legs can be taken up, the legrest is to this end moved into the use position, in particular by way of a pivoting movement, in which it is located in front of the seat surface and as it were lengthens the latter.
In the case of pieces of seating furniture having such a variable-position legrest, one problem is that the stowage space beneath the seat surface is limited and the pivoting range through which the leg unit is displaced, starting from the use position, on being transferred in the direction of the stowed position, is likewise limited. A legrest which has a sufficient size in the use position to allow comfortable sitting with raised legs is difficult to accommodate under the seat surface on account of its length and risks colliding with the floor or the base of the piece of seating furniture during the pivoting movement.
In generic pieces of seating furniture, this problem is solved in that the legrest is configured with a variable length. Length-variability is understood to mean the variability of the legrest with respect to the use position in the longitudinal direction of the furniture, that is to say in the direction of extent of the legs resting on the legrest.
The length-variability of the legrest is realized in that the latter comprises at least two fitting portions which are movable with respect to one another in a relative displacement direction moved by the legrest and as a result can have different spacings from one another in the stowed position and the use position of the legrest. Usually, a linear guide is provided between these two fitting portions of the legrest.
In order to couple the desired variation in length to the position of the legrest, in particular to the pivoted position of the legrest, various designs are known. The starting point of the invention is in this case a design in which provision is made of a spring means which comprises a spring portion that acts indirectly or directly between the two fitting portions. Said spring portion results in permanent force activation of the two fitting portions with respect to one another, such that these permanently tend to move toward or away from one another and as a result to increase or decrease the size of the legrest. This tendency brought about by the spring means is limited by a control member which is directed counter to the application of force by the spring and is provided at a different fitting portion of the piece of seating furniture and the relative position of which with respect to the legrest varies during the movement of the legrest such that it brings about a decrease or increase in size of the legrest counter to the force of the spring means during pivoting in a first pivoting direction, while in the opposite direction of movement it continuously enables the movement of the fitting portions of the legrest such that the spring means, depending on its mounting, can bring about the increase or decrease in size of the legrest.
The solutions known at least from the internal prior art include the provision of a metal helical spring, which extends in the longitudinal direction of the furniture, between the fitting portions of the legrest. However, this has been found to be problematic, since the mutual displaceability, desired to be quite large in practice, of the fitting portions by for example 20 cm cannot be provided by conventional space-saving springs. A helical spring, which is relaxed in the stowed state of the legrest and is shortened for example to a length of 5 cm, would have to be stretched by 20 cm in order to reach the use state. However, in common helical springs, this results in overstretching and thus in permanent damage to the helical spring. An alternative to such extensive stretching as described is the use of a lever system which acts between the fitting portions and which allows the use of a shorter spring and less extensive stretching of this spring. However, such a spring system results in comparatively high costs and a number of mechanical difficulties.
The problem addressed by the invention is therefore that of developing a generic piece of seating furniture such that the latter at least partially overcomes the described problems of the prior art in a structurally simple manner.
According to the invention, this is achieved by two measures, which are preferably realized together, but which can in principle also be realized individually and may also be individually suitable for solving the problem addressed.
According to a first measure proposed according to the invention, provision is made for the two force application points at the two fitting portions of the legrest to be arranged in a manner offset with respect to one another in a transverse direction of the furniture, such that the spring portion takes up a diagonal direction of extent more or less in a plane defined by the transverse direction of the furniture and the relative displacement direction. According to this aspect of the invention, the spring portion thus acts between two points, of the fastening-point or deflection-point type, at the two fitting portions, which are arranged in an offset manner in the transverse direction of the furniture. Thus, the force application point at the first fitting portion of the legrest could for example be arranged on the left-hand side of the piece of furniture or of the legrest, while the second force application point at the second fitting portion is arranged on the right-hand side of the piece of furniture or of the legrest.
The diagonal extent of the spring portion results in a reduction in the required stretching. Since the force application points are moved with respect to one another only in the relative displacement direction of the fitting portions, but not in the transverse direction, orthogonal thereto, of the furniture during the shortening or lengthening of the legrest, a spring which exhibits much less extensive stretching can be used, without the external dimensions of the legrest having to be changed as a result. Thus, metal helical springs can be used in such a diagonal orientation, said helical springs as a result having to be stretched by no more than 20% to 30% compared with their relaxed state with the legrest retracted, in order for example to allow lengthening or shortening of the legrest by 20 to 30 cm.
The diagonal orientation is provided preferably both in the use position of the legrest and in the stowed position of the legrest. However, it is also conceivable in principle for the force application points to be at the same height with respect to the relative displacement direction in one of these positions, such that the spring portion could also be oriented virtually in the transverse direction of the furniture in such an extreme position.
According to the mentioned second measure of the invention, which is preferably realized together with the first measure of the diagonal spring-portion arrangement, it is proposed to configure the spring portion as an elastomer spring portion. Accordingly, in contrast to hitherto conventional spring means, it is proposed that a spring means made of an elastomer material be used. It has been found that this is capable of comparatively extensive stretching and is therefore highly suitable for the mentioned purpose. Within the meaning of the invention, an elastomer material is understood to be an elastically stretchable, plastics-based and/or natural-rubber-based material. A combination in which a number of natural-rubber strands are arranged within a plastics cover is particularly advantageous. As a result, high external chemical and mechanical stability at the same time as a particularly good stretching behaviour is achievable. Said cover can consist for example of polyester. The internal strands are preferably braided together or interlaced in some other way in order to increase the stability. Preferably, the stretching behaviour of the spring portion made of elastomer material is such that an elongation of 100% at an applied force of between 20 newtons and 50 newtons is achieved.
It is particularly advantageous for the elastomer spring portion to be configured in the manner of a strand of constant cross section, which may be formed for example in a round, square or rectangular manner. This allows a simple type of deflection, the advantages of which are explained further below.
As already mentioned, it is considered to be particularly advantageous for the two above-described measures to be realized together, that is to say a spring portion which consists of an elastomer material is used in a diagonal direction of extent.
Even if a single spring portion, one end of which is fastened to the first fitting portion and the other end of which is fastened to the second fitting portion, can in principle make available the desired spring-force activation of the fitting portions of the legrest with respect to one another, it is considered to be advantageous for at least two force application points to be provided at least at one of the two fitting portions and for the spring device to have at least two spring portions which extend, in particular diagonally, between the two fitting portions.
The distribution of the spring force to be applied over more than one spring portion makes it possible to use spring portions having a lower spring coefficient, with the result that relaxation of the spring portions can be reduced again.
If use is made of such two or more spring portions extending preferably in each case diagonally, it is particularly advantageous for these to be connected integrally together and in particular to be preferably deflected by a common one of the force application points. Thus, for example two force application points at one of the two fitting portions can each act as fastening points for the two ends of said double spring portion, while these are placed around the force application point at the other fitting portion between these two ends. Here, use can be made for example of a rotatable roller or a simple peg. Of course, it is also possible to use more than two spring portions. Depending on the configuration of the piece of sitting furniture, the required spring forces and in particular also the width of the legrest, it may be advantageous to arrange at least three preferably diagonally extending spring portions, which in particular are preferably connected integrally together, in a zigzag arrangement between force application points at the two fitting portions.
As already mentioned, the spring portions, if a number of spring portions are provided between force application points at the two fitting portions, are preferably part of an integral spring means, in particular a common elastomer band. As a result, the costs for the individual parts of the piece of sitting furniture and in particular also the outlay for assembly are reduced.
When such an elastomer band is used, provision is preferably made, as already mentioned, for this to be deflected by rollers .or pegs. Such deflection is in particular advantageous when the elastomer band is arranged regionally between force application points at the same fitting portion. Such a portion, which can be oriented in particular preferably in the transverse direction of the furniture, provides further lengthening of the spring means and therefore, as long as an appropriate deflection is provided, allows even further reduced stretching while the legrest is being transferred between the stowed state and the use state. It may be particularly advantageous, in particular in this connection, for the elastomer band to be configured as a closed elastomer band and thus to be configured as it were in an annular manner. As a result, it is possible to dispense completely with the complicated fastening of ends of the elastomer band to one of the two fitting portions. Instead, the force application points at the fitting portions are designed in such a case as deflection points about which the elastomer band is placed. Preferably, here too, subregions of this elastomer band are provided between force application points at the same fitting portion, which extend in particular in the transverse direction of the furniture. In addition to the abovementioned advantages when use is made of more than one spring portion, a particular advantage also results in the case of legrests having an uncommon width. While most legrests do not exceed a width of 60 cm, in less common pieces of seating furniture it may also be expedient to provide wider legrests, for example having a width of at least 80 cm. Thus, for example a common legrest for a number of persons sitting on a sofa is conceivable. The hitherto customary systems having only one spring means which is usually arranged on one of the two sides are not very appropriate precisely in the case of such legrests, since problems arise with regard to tilting of the fitting portions with respect to one another. The design with at least two spring portions allows equal force activation of the fitting portions in an eccentric manner on both sides, in particular at their ends located opposite one another in the transverse direction of the furniture, with the result that harmonious and tilt-free lengthening and shortening of the legrest can be realized.
In principle, the two directions of action of the spring devices, in which the spring device acts either in the direction of an increase in size or in the direction of a decrease in size of the legrest, are conceivable. The respectively opposite size change effect is brought about by the control member already mentioned at the beginning. A design in which the spring device acts on the fitting portions of the legrest in the direction of an increase in size of the legrest is particularly preferred. This means that the spring device is in a tensioned state when the legrest is in the stowed position and thus is reduced in size. Proceeding herefrom, the state of tension in the spring device decreases during the increase in size of the legrest while it is being transferred into its use position.
The abovementioned control member, which counteracts the spring force effected by the spring device and thus tensions the spring device while the legrest is being transferred into the stowed position or the use position, in particular into the stowed position, is preferably configured as a cable pull which acts on one of the fitting portions such that the latter is displaced with respect to the other fitting portion counter to the spring force of the spring device by a tractive force on this cable pull. A cable pull is understood to be any desired variable-shape control member which is configured merely to transfer tensile forces. Instead of a cable pull, it is also possible to use a rigid element, however. The displacement of the control member can take place by way of the direct or indirect connection thereof to other fitting portions of the piece of furniture, which are likewise displaceable relative to one another or with respect to the base. Thus, in the case of a piece of furniture according to the invention, provision is preferably made for the seat unit likewise to be displaceable with respect to the base.
The invention furthermore relates to a fitting for a piece of seating furniture, which is configured as a fitting of the above-described piece of seating furniture.
Further aspects and advantages of the invention can be gathered from the following description of exemplary embodiments of the invention which are explained with reference to the figures, in which:
a to 2b show a piece of seating furniture according to the invention with its legrest arranged in a stowed position and a use position, respectively,
a and 3b show a plan view of the legrest of the exemplary embodiment according to
a to 2b show a piece of seating furniture according to the invention, in particular the fitting components thereof, with cushion portions omitted. In this case,
First of all, the essential sub-components are intended to be explained with reference to
The piece of seating furniture 10 is configured in the manner of an armchair. It has a base 12, which is intended to be arranged on an underlying surface in a stationary manner or, equipped with rollers, in a displaceable manner. Provided above this base 12 is a seat unit 14 having a seat surface 14′. A backrest unit 16 adjoins the rear thereof. In the configuration illustrated in
In the region of the front termination edge of the seat unit 14, the leg unit 18 is pivotable about a pivot axis 8 oriented in the transverse direction of the furniture.
The arrows 2, 4 and 6 indicate the notions, used in the context of this invention, of the transverse direction 2 of the furniture, the longitudinal direction 4 of the furniture and the vertical direction 6 of the furniture.
As can be seen from a comparison of
As can likewise be seen from
As can be seen in particular from
In order to control this variation in length, provision is made of a flexible band 26 which is on the one hand fitted to the outer of the two fitting portions 40 and on the other hand is coupled to the seat unit 14 such that, during the movement thereof from the position in FUG. 1a into the position in
The band 26 acts as a control member for controlling the variation in length of the leg unit 18. The tensile force which is able to be brought about by this band 26 and which works towards shortening the leg unit 18 is counteracted by the force of a spring device 50. This spring device 50 acts between the two fitting portions 30, 40, wherein it is connected to the two fitting portions 30, 40 such that the spring force acts in the direction of the extended state of the leg unit, that is to say the state which the leg unit takes up in the use position.
In order to explain the spring device 50 in more detail, reference is made to
When the leg unit is arranged in its stowed position, the control band 26 compels this tensioned state of the spring device 50, as is illustrated in
If, in the context of the overall transfer of the piece of seating furniture into the comfort position, the seat unit 14 is now displaced towards the rear with respect to the base 12 and the leg unit 18 is pivoted out in the direction of its use position, the control band 26 is also continuously released, such that it allows an increase in size, brought about by the spring device 50, of the leg unit 18. In this case, the elastomer strand 53 contracts until it reaches its most relaxed state with the leg unit extended in a manner corresponding to the state illustrated in
On account of the fact that the portions 53a extend diagonally, and on account of the fact that the portion 53b forms as it were a compensation portion as a result of the deflection rollers 33, the stretching of the elastomer strand 53 in the state in
In the design according to
In a variant of
In the design according to
Number | Date | Country | Kind |
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10 2014 207 972.1 | Apr 2014 | DE | national |
This application claims the priority of German Application No. 10 2014 207 972.1, filed on Apr. 28, 2014, the disclosure of which is hereby incorporated by reference in its entirety into this application.