Patent Publication Number: US-5154474-A

Title: Stackable line chair

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a stackable line chair with four legs which stand on the floor and which support a seating plate, the legs being arranged in pairs in respective planes on both sides of the chair and diverging obliquely in the downward direction. 
     Different embodiments of stackable chairs having lateral pairs of legs arranged in one plane which are obliquely diverging downwards to the front and the rear are well known. When stacked, the lateral pairs of legs can be pushed more or less far over the corresponding pairs of legs of the next chair below. This leads to a relatively low stacking hight, even if a great number of chairs are stacked. Apart therefrom, also stackable line chairs are known providing the additional object to obtain a possible close compound arrangement in the lateral direction or in the direction of the line to be formed, so that it is common also here to form the lateral pairs of legs such that the lateral leg pairs of two adjacent chairs can be pushed one into the other. Examples of these known solutions may be found in German Auslegeschrift (examined, published patent application) 1,285,137 and U.S. Pat. No. 3,827,749. 
     The legs on both sides of the chair according to German Auslegeschrift 1,285,137 are positioned at different distances, so that the left pair of legs can be pushed between the right pair of legs of the adjacent chair, respectively, and vice versa. Since the distance between the lateral legs of one side is about two leg diameters greater than on the other side, the result is a clearly visible asymmetry of the chair and thus, an appearance which is undesirable at least if the chair is used singly. 
     The chair of U.S. Pat. No. 3,828,749 does not only have the difference in respect of the distance between the lateral legs, which is two leg diameters also here, but both lateral leg pairs each are part of an U-shaped shackle positioned laterally of the seating plate, which is significantly higher on one side than on the other, so that the shackles may be stacked one upon another when forming a line of chairs, so that, as a result, the assymetry is even more visible here. 
     SUMMARY OF THE INVENTION 
     It is therefore the object of the invention to produce a stackeable line chair allowing a lateral joining of the lateral leg pairs of adjacent chairs without the necessity of having to accept a significant asymmetry in respect of the vertical center plane of the chair determined by the user&#39;s line of vision. 
     According to the invention this object is achieved by a chair of the above kind in that the legs of one side of the chair are offset by one leg thickness relative to the seating plate as compared with the legs on the other side. 
     Thus, both legs of one side are standing either more to the rear or more to the front by one leg thickness than the legs of the other leg pair, with the leg pairs however giving a totally identical appearance. This kind of asymmetry of the chair is optically hardly visible. Thus, this chair may also readily be used as an individual chair or a normal stacking chair. 
     In the case of traditional chairs of this kind either the lateral leg pairs are legs of U-shaped shackle, the center part of which is arranged along the side of the chair, as it is the case with U.S. Pat. No. 3,827,749, or the front and rear leg pairs form a corresponding U-shaped shackle, the center part of which is running in a transverse direction below the seating plate from one side to the other (German Auslegeschrift 1,285,137). This means that both shackles have to be connected sufficiently stable by two connecting rods. According to the U.S. Patent, these connecting rods are running in a transverse direction of the chair, and according to the German Auslegeschrift on both sides of the seating plate in the longitudinal direction thereof. The use of these connecting rods not only means increased material and labour consumption, but also leads to a statically relatively unfavourable more or less point-like connection between shackles and connecting rods. 
     According to a preferred embodiment of the invention, the front legs are running obliquely below the seating plate and join on the rear side until they are connected behind the seating plate to a raised up holder for a backrest, whereas both rear leg pairs are parts of a continuous shackle positioned below the seating plate and arched as a bow to the front, thus crossing both front legs which are running to the rear side. Thereby, a triangular compound arrangement is formed between both front legs obliquely running to the rear side and meeting in the middle and the center part of the shackle of the rear legs. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective general representation of the chair according to the invention; 
     FIG. 2 is a plane view of the frame of the chair; 
     FIG. 3 shows an elevation of the frame. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The chair shown in FIG. 1 comprises a seating plate 10 and a backrest 12. The chair also comprises front and rear legs 14 and 16 (which are in the present connection also defined as the left leg pair) and right front and rear legs 18 and 20 (the right leg pair). 
     FIG. 2 shows a plane view of the frame of the chair without the seating plate and backrest. FIG. 3 shows the corresponding elevation, and it will be seen from FIG. 3 that the leg pairs are obliquely diverging downwards, that is, the front legs 14 and 18 are directed obliquely to the front and the rear legs 16 and 20 are directed obliquely to the rear. According to FIG. 3, the rear legs form a greater angle relative to the normal than the front legs. 
     Apart from the frame, FIG. 2 shows several auxiliary lines, illustrating the geometry of the chair. Firstly, A designates the longitudinal center line of the seating plate, that is, the forward-backward direction of a person sitting on the chair. Lines B and C run parallel to line A on both sides and respectively designate the planes of the lateral leg pairs 18, 20 and 14, 16. In this connection, from FIG. 2 it will be apparent that the legs of both leg pairs stand directly one before the other or one behind the other, thus defining vertical planes on both sides of the chair. 
     Further, in FIG. 2 two lines D and E are shown running perpendicularly relatively to lines A, B and C, and thus extending horizontally transversely with respect to the seating direction. Lines D and E directly show that the legs 14 and 16 of the--for the user of the chair--left leg pair of FIG. 2 are offset to the rear or the top as compared with the legs 18 and 20 of the right leg pair. This offsetting a is about one leg thickness. As a result, laterally adjacent chairs can be joined such that the adjacent leg pairs are in one plane. In most cases from this follows a close compound arrangement in the lateral direction. 
     According to FIGS. 2 and 3 the front legs 14 and 18 run obliquely below the seating plate to the rear and to the middle or the longitudinal center line A of the seating plate. Here they are connected, for example, welded, to form a holder 22 which rises up. The holder 22 accommodates the backrest 12. On the other hand, according to FIG. 2, the rear legs 16 and 20 are part of a continuous, generally U-shaped shackle 24 which is arched below the seating plate to the front (that is, down in FIG. 2) the center section 26 the shackle 24 crosses both extensions--designated by 28 and 30--of the front legs 14 and 18 obliquely running below the seating plate to the rear and to the center. 
     In this manner the shackle 24 or the center section 26 thereof together with the extensions 28 and 30 of the front legs 14 and 18 forms a triangle, which is statically very stable. In particular, this triangular compound arrangement is significantly more stable than the common, T-shaped connections between legs and connecting rods connecting the legs. At the same time, the holder 22 for the backrest, starting from the rear top of the triangle, is directly connected to the frame of the chair. 
     The legs, the extensions thereof and the shackles may be made of tube material which is flatly compressed in the area of the crossing points between the extensions 28 and 30 of the front legs and the rear shackle 24 in order, to form relatively large contact areas behind the crossing points. 
     The drawing does not show armrests, which may be fixed to the front or rear legs, if necessary, or connecting elements for laterally connecting a line of chairs, since these parts may be made in the usual manner.