Convertible sitting/reclining furniture article

A convertible sitting/reclining furniture article comprises a main frame and a seat element which is supported at a predetermined elevation above ground. A bed frame can be pulled out of and pushed into the main frame in a drawer-like manner and includes a front side, a rear side and two lateral sides. An extension element is mounted on the bed frame for displacement between a retracted position and an extended position in which the extension element is disposed at the predetermined elevation to form an extension of the seat element by a five-bar kinematic linkage at each of the lateral sides of the bed frame. Each of the kinematic linkages includes a steering lever pivotally mounted at a first region of the extension element and at a first portion of the bed frame, and two steering links more remote from the front side of the bed frame than the steering lever and adjacent to the steering lever. The steering links are articulately connected to one another at a connection region and one of them is pivotally connected to a second region of the extension element while the other is pivotally connected to a second portion of the bed frame which is spaced from said first portion by a distance exceeding the distance between the first and second regions of the extension element. The steering links assume a straight-line orientation with respect to one another in the extended position of the extension element to block the connection region against pivoting in at least one of its pivoting directions.

BACKGROUND OF THE INVENTION 
The present invention relates to articles of furniture in general, and more 
particularly to a convertible sitting/reclining furniture article. 
There are already known various constructions of convertible 
sitting/reclining furniture articles, such as sofa beds, recliners or the 
like, among them such which include a main frame and a bed frame which can 
be pulled out of and pushed back into the main frame, as well as an 
extension element which is mounted on the bed frame for pivoting between 
its retracted position in the main frame and its extended position in 
which it is situated at the same elevation as a seat element of the 
furniture article to form an extension thereof. In such known 
constructions, pivotal mounting arrangements are usually arranged at the 
two lateral sides of the bed frame and mount the extension element on the 
bed frame for its pivotal movements between the retracted and extended 
positions. However, experience with the known furniture articles of this 
type has shown that they are usually very complex, cumbersome to handle, 
and expensive to manufacture and therefore costly, and yet in many 
instances it is not assured that the extension element will remain in its 
extended position for as long as needed. 
SUMMARY OF THE INVENTION 
Accordingly, it is a general object of the present invention to avoid the 
disadvantages of the prior art. 
More particularly, it is an object of the present invention to provide a 
convertible sitting/reclining furniture article in which the extension 
element is positively guided during its pivotal movement by the pivotal 
mounting arrangements. 
Still another object of the present invention is to construct the furniture 
article of the type here under consideration in such a manner that the 
extension element is arrested in its extended position by the pivotal 
mounting arrangements. 
In keeping with these objects and others which will become apparent 
hereafter, one feature of the present invention resides in a sitting 
furniture article convertible into a reclining furniture article, this 
furniture article comprising a main frame; a seat element; means for 
supporting the seat element at a predetermined elevation above ground; a 
bed frame which can be pulled out of and pushed into the main frame in a 
drawer-like manner and includes a front side, a rear side and two lateral 
sides; an extension element; and means for mounting the extension element 
on the bed frame for displacement between a retracted position and an 
extended position in which the extension element is disposed at the 
predetermined elevation to form an extension of the seat element. The key 
features are that such mounting means includes a five-bar kinematic 
linkage at each of the lateral sides of the bed frame, that each of the 
kinematic linkages includes a steering lever pivotally mounted at a first 
region of the extension element and at a first portion of the bed frame 
and arranged closer to the front side of the bed frame, and two steering 
links arranged more remotely from the front side of the bed frame and 
adjacent to the steering lever and articulately connected to one another 
at a connection region, that one of the steering links is pivotally 
connected to a second region of the extension element at a predetermined 
distance from the first region while the other of the steering links is 
pivotally connected to a second portion of the bed frame which is spaced 
from the first portion by a distance exceeding the predetermined distance, 
and that the steering links assume a straight-line orientation with 
respect to one another in the extended position of the extension element 
to block the connection region against pivoting in at least one pivoting 
direction thereof. 
As a result of this particular construction of the pivotal mounting 
arrangement, it is feasible for the user to effectively and easily move 
the mattress element of such a convertible sitting furniture article into 
a position where he or she can easily move the mattress element into its 
extended position of use without having to resort to any deliberations or, 
worse yet, having to consult the operation manual for helpful operating 
instructions. 
On the basis of the construction of the pivotal mounting arrangement in 
accordance with the present invention, it is even possible to accomplish 
the pivotal movement of the mattress element without having to exert any 
substantial force. 
A further advantage of the construction according to the present invention 
results from the fact that, for all intents and purposes, the pivotal 
movement range of the mattress element does not extend beyond the area 
which is predetermined by the outline of the bed frame so that such a 
furniture article can be used even under circumstances where the available 
space is limited. 
It is further advantageous in this context that the corresponding pivotal 
mounting arrangement assumes its arrested condition when the mattress 
element reaches its extended position, so that there is no need for 
providing any additional support, for instance a covering element, on 
which the mattress element would rest in its extended position. This means 
that the configuration of the bed frame, especially the shape and 
arrangement of a front covering plate thereof, can be determined 
exclusively on the basis of optical and esthetic appeal considerations, 
without regard for any stability-determined dimensioning. 
According to another advantageous facet of the present invention, the 
sitting furniture article further comprises two abutment pins mounted on 
the extension element in a stationary manner and on the bed frame, 
respectively, at the regions of the respective steering links and in 
directions away from the steering links and towards the steering lever. It 
is also advantageous when the steering links include respective abutment 
noses at their regions facing the respective abutment pins. Last but not 
least, it is advantageous when the sitting furniture articles further 
comprises, at each of the kinematic linkages, a tension spring which is 
connected with one end thereof at the first region of the extension 
element and with the other end thereof at the connecting region of the 
steering links.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawing in detail, and first to FIGS. 1 to 5 thereof 
taken in conjunction with one another, it may be seen that the reference 
numeral 10 has been used therein to identify a main frame, while the 
reference numeral 11 designates a seat frame which can be pulled out of 
the main frame 10. 
A mattress element 12 is pivotally mounted on the seat frame 11 by means of 
two laterally arranged kinematic linkages 20 in such a manner that the 
mattress or extension element element 12 can be pivoted up from a non-use 
or collapsed position which is depicted in FIG. 1 of the drawing into a 
use or extended position which is shown in FIGS. 4 and 5 of the drawing 
and in which the mattress element 12 is situated at the same elevation as 
a seat cushion or seat element 14 which is supported on the seat frame 11. 
Herein, the kinematic linkages 20 are mounted, on the one hand, on the 
mattress element 12 and, on the other hand, on a bed frame 13. A free 
front side of the bed frame 13 is provided with a front frame covering 
element 15. The bed frame 13 is provided with rollers or casters by means 
of which it is movably supported on a floor. The bed frame 13 can be 
pulled out of the seat frame 11 until it abuts against a non-illustrated 
end abutment. 
It will, of source, be understood from the title and from the drawing that 
a user can initiate actuation of a return movement of the extension 
element from an extended position thereof to its retracted position. 
FIG. 2 illustrates a beginning of a pivoting of the mattress element 12 out 
of its collapsed position. In FIG. 2, as well as in FIG. 3, it can be very 
clearly seen that at first the free front side of the mattress element 12 
is lifted while the oppositely located rear side remains situated 
underneath a projecting edge region of the seat cushion 14. Herein, the 
kinematic linkages 20 provide the pivoting axis for such pivoting 
movement. 
FIG. 4 illustrates the conversion of the original sitting furniture article 
into a reclining furniture article in which the seat cushion 14 and the 
mattress element 12 are situated at the same elevation, while a head rest 
16 is so pivoted in a known manner that it bridges an intermediate space 
which has come into being between the seat cushion 14 and a back rest 17 
as a result of the conversion of the sitting furniture article into the 
reclining furniture article. 
Another position of the sitting furniture article is shown in FIG. 5 of the 
drawing. It may be seen here that the seat frame 11 with the associated 
seat cushion 14 is now situated at the region of the main frame 10, while 
the mattress element 12 is pivoted up in the above-described manner to the 
elevation of the seat cushion 14, so that there is obtained in this manner 
a possibility, which may be preferred by the user of the sitting furniture 
article, of sitting on the sitting furniture article with outstretched 
legs. 
FIGS. 6 to 9 of the drawing show one of the kinematic linkages 20 in 
various positions thereof. The kinematic linkage 20 is shown to include a 
steering lever 21. The steering lever 21 is mounted, on the one hand, on 
the bed frame 13 and, on the other hand, on the mattress element 12, in 
each instance in a pivotable manner. In the illustrated construction, the 
steering lever 21 is arranged in the direction toward the free front side 
of the mattress element 12. 
Two steering links 22 and 23, which are articulated to one another by a 
common pivot 24, are arranged adjacent to the steering lever 21. One of 
such steering links 22 and 23 is connected to the mattress element 12 
while the other is connected to the bed frame 13, also in a pivotable 
manner. 
FIG. 6 of the drawing shows the kinematic linkage 20 in a position 
corresponding to the non-use or collapsed position of the mattress element 
12, this particular position being also illustrated in FIG. 1 of the 
drawing. In this position, the kinematic linkage 20 corresponds to a 
five-bar linkage, that is, it is inherently unstable by itself. 
This instability condition changes at the commencement of the pivotal 
movement of the mattress element 12 towards its extended position, 
inasmuch as the steering links 22 and 23 come into abutment at the region 
of their common pivot 24 with the bottom side of the mattress element 12, 
which means that the link region between the steering link 23 and the 
mattress element 12 is blocked and, as a result of this blocking, the 
kinematic linkage 20 becomes a four-bar linkage. In this manner, there is 
obtained, of necessity, a stable condition of the kinematic linkage 20. 
The same reasoning also applies to the pivoted position of the mattress 
element 12 which is illustrated in FIG. 8 of the drawing. In this 
position, however, an abutment nose 28 which is provided on the steering 
link 22 at the connection region with the bed frame 13 and which points in 
a direction toward the steering lever 21 additionally engages an abutment 
pin 25 which is secured in position on the bed frame 13. 
In FIG. 9, the kinematic linkage 20 is illustrated in a position which it 
assumes when the mattress element 12 is in its extended or use position 
corresponding to that depicted in FIGS. 4 and 5 of the drawing. In this 
particular position, the steering links 22 and 23 are disposed in a 
straight position with respect to one another, that is, they extend along 
a common straight line. The abutment nose 28 which has been mentioned 
before in connection with the description of FIG. 8 remains in engagement 
with the abutment pin 25. Another abutment nose 29 is provided on the 
other steering link 23 and also points in a direction toward the steering 
lever 21. The abutment nose 29 engages an additional abutment pin 26 which 
is secured in position to the mattress element 12, so that the kinematic 
linkage 20 is held in a stable position and keeps the mattress element 12 
in its position illustrated in FIG. 9. For aiding the pivoting of the 
steering links 22 and 23 and for stabilizing the kinematic linkage 20, 
there is provided a tension spring 27 which is secured, on the one hand, 
to the common pivot 24 and, on the other hand, to a connecting region of 
the steering lever 21 with the mattress element 12. 
An important feature of the present invention is that, as can be easily 
ascertained from FIGS. 7 to 9 of the drawing, the distance between the 
connection region of the steering link 23 and the connection region of the 
steering lever 21 to the mattress element 12 is smaller than the distance 
between the connection region of the steering link 22 and the connection 
region of the steering lever 21 to the bed frame 13.