Furniture structure with sectional elements assembled with fixity and by hinges with final stiffening by thrust action on the hinges

The present invention relates to a furniture structure such as, for example, a chair, table, bed, cupboard or the like, usually furnished with legs, side members, flat surfaces or the like, which structure is composed of single sectional elements capable of being assembled together, some of which are connected by hinges, in such a manner that by the use of a spider or brace or the like adapted for exerting thrust forces upon the hinges, the final stiffening of the structure is obtained as required for its intended use.

Normal items of furniture possess structures, frames or the like, composed of single elements which are then connected together to form parts or the entire structure by the use of glues, adhesives, screws, nails or the like adapted for connecting the elements in a rigid manner so as to exert the support of load-bearing action for which the furniture item is intended.

The necessity, in known items of furniture, for using said connecting means, in particular glues or the like, obliges the constructor to have appropriate equipment, suitable rooms and the like, with appreciable cost and the use of labour.

Furthermore, furniture items constructed in this manner require considerable space for storage and transportation due to the appreciable bulk, which is largely empty.

According to the present invention, the aforementioned disadvantages are overcome and furthermore it is possible to carry out the assembly at the destination by simple operations, even on the part of the user himself, with notable advantages in respect of cost, reduction of dimensions, elimination of the need for special working areas and the possibility of producing all the component pieces by simple operations on ordinary machines.

Said advantages are achieved by the furniture structure according to this invention, composed of single elements equipped with bearing fixings and hinges for connecting them together, said elements being assembled in the intended bearing position and the structure being stiffened for use by means of a spider comprising pairs of opposed arches having wedge-shaped ends, which ends exert a thrust action upon shaped supports, these supports in turn acting against said hinges and thrusting them outwards, under the action of a tension member or the like which tends to bring the arches of the spider towards each other and consequently to force the end wedges into their respective seatings.

Said spider is composed of pairs of opposed arches, which arches, in addition to having wedge-shaped ends, are shaped to be partly elastic, thereby producing not only a translatory movement of the end wedge but also a strut action towards the end itself.

Said spider of opposed arches may possess, at the ends, hinge bearings or the like for exerting the strut action only when the centre of the spider is compressed by the associated tension member.

The closure plane cooperates in the stiffening of the structure by fitting into the seatings provided when in the position of use and by a force fit in said position, produced by the tension member of the spider.

The stiffening elements may be composed of spiders having screw tension members, acting by tension upon the hinges or the like connecting the various components of the furniture together, thereby creating an inward thrust on them.

These are other characteristics will become apparent from the following description of an example of embodiment of a chair according to the present invention, prepared with reference to the attached drawings, which show:

• in Fig. 1, an exploded view of the chair structure according to this invention,
• in Fig. 2, a perspective view of the chair of Fig. 1 when assembled,
• in Fig. 3, a section through the chair structure on the plane III-III of Fig. 4,
• in Fig. 4, a plan view of the structure of Fig. 1 partly in section on the plane IV-IV of Fig. 3 and
• in Fig. 5, the assembled chair, complete with the seat plate.

With reference to the attached Figures, the chair structure illus­trated in Fig. 1 is composed of a series of separate pieces, constituted of two front legs 1-2, two back legs 3-4 continued upwards for the chair back, a series of four lateral members F₁, F₂, F₃, F₄, a central spider C composed of two pairs of opposed arches C₁₋₂ and C₃₋₄, equipped at their ends with shaped supports 5, of a seat plate 6 and of one or more back boards 7.

As can be seen from Figure 1, the separate pieces, in the case of a chair structure as given by way of example, may be the same as one another, such as for instance the front legs, the lateral members, the pairs of spiders with their supports and other elements, as will be described below, it being possible in this manner to mass produce the individual components and to carry out assembly when required, even at the point of use, thereby reducing the dimensions for storage and transportation which, as is known, are always appreciable in the case of fully assembled furniture.

According to this invention, the construction and form of the individual elements enables the structure to the assembled with complete final stiffening, as required in the conditions of use, simply by placing the elements against one another under determined thrusts, without the use of glues or other holding means.

For this purpose, each front leg 1-2 is shaped at its upper end with a recess 1A-2A in such a manner as to receive towards the outside the ends of the adjacent side members F₁-F₂ and F₂-F₃, coupled to one another by means of tongue-and-groove joints 8, adapted for forming a hinge, the hinge pin 9 of which is introduced into the respective aligned holes of the joints 8.

Analogously, each rear leg 3-4 possesses a recess 3A-4A, in such a manner as to receive on the outside the ends of the adjacent side members F₁-F₄ and F₃-F₄, coupled together by the tongue-and-groove joints 10, adapted for forming a hinge, the pin 11 of which is introduced into the respective aligned holes of the joints 10.

On the inner sides of all the legs there are disposed the shaped supports 5 which possess, on the side towards the leg, a recess 5A and, on the side towards the spider, two grooves with inclined base 5B with opposite inclinations, said grooves being adapted for receiving the wedge-shaped ends, having an equal slope, of the arches of the spiders C₁₋₂ and C₃₋₄.

This arrangement and form can be better seen in the cross-section of Fig. 3, where the relative and opposed positions of the wedge-­shaped inclined surfaces 5B can be seen.

On the upper part of the back legs 3-4 there are provided cavities 3B-4B, adapted for receiving the ends of the back boards 7 to form, as a whole, the back of the chair.

The structure is completed by the seat 6 composed of a seat plate of any desired appearance, for example comprising holes 12, recesses, designs or the like (Fig. 5) and having, at each of the back corners, a recess 13 which fits the internal form of the respective back leg.

For blocking the elements, as will be stated below, a screw tie 14 is provided, having a head 14A and nut or wing nut 15, operated by hand or by spanner.

Assembling of the chair structure according to this invention is carried out in the following manner, with particular reference to Figures 1 and 2.

A start is made with the insertion of the back boards 7 into the associated cavities 3B-4B of the upper part, forming the chair back, of the rear legs 3 and 4, then the side members F₁, F₄ and F₃, hinged to one another by means of the pins 11, are placed in the respective recesses 3A-4A and connection of the side members F₁, F₂ and F₃ is completed, the two front hinges being made by the pins 9.

The hinged ends of said side members are then inserted into the recesses 1A-2A of the front legs 1-2, which thus adopt their position in the complex of the structure.

At this point, the spider C is inserted between the four legs, in such a manner that the respective shaped bearings or supports 5 come into bearing, with the recesses 5A, against the internal face of the legs and, with the inclined surfaces 5B, with the respective wedge-shaped surfaces 5C of the ends of the spiders C₁₋₂ and C₃₋₄.

The chair structure, assembled in this manner, is shown in Fig. 2, with all the elements, excluding the seat 6 and the tie 14, in their positions, but the structure itself is not yet stiffened ready for use, unavoidable constructional clearances being present between the various parts and in the hinges, which permit limited relative movements.

In order to achieve stiffening of the complete structure according to this invention, the seat plate 6 is inserted at the top, which comes into bearing with the corners on the shaped bearing or supports 5, already in position, and then the tie member 14 is introduced, with its head resting on a depression 6A of the seat 6, into the central hole of the spider C and the nut 15 is fitted against the spider itself. By tightening of the nut or wing nut 15, the action of the tie 14 is developed, consisting of bringing nearer together the arches C₁₋₂ and C₃₋₄ of each pair, thereby producing a wedge action with the respective inclined ends 5C against the corresponding surfaces 5B of the shaped bearings 5.

One component of the loading causes an outward thrust, which blocks in position the end hinges of the side members against the asso­ciated legs, thus subjecting the side members themselves to tension.

If the arrangement of the arches of the spider C permits or is designed for this purpose, by continuing the tightening action on the nut 15, after the opposed surfaces of the end wedges are blocked against one another by friction, it is possible to add a still further additional lateral thrust, by stressing the pair of opposed arches in slight bending towards each other, in such a manner as to obtain small displacements of the ends by deflection of the arch itself, adapted for increasing the outward blocking thrust.

The final blocking position by effect of the wedge action of the ends of the spider C can be easily seen from Figure 3, where it can be noted how the tie 14 pulls the arches of the pair against each other, with a movement of the wedge ends tending to force the bearings 5 further apart and therefore to bear against the end hinges.

From Fig. 3 it may also be noted that if, as stated, a slightly elastic form is given to the arches of the pair, then by tightening up the nut 15 a slight outward movement is obtained of the bearing end 5, with addition of the stiffening thrust.

Said spider comprising opposed arches may also possess, at its ends, hinge bearings or the like, instead of the wedge planes 5C, 5B, to allow the arch-shaped spider elements to exert only the thrust action when the centre of the spider elements themselves is com­pressed by the tie member.

It is also possible for the user to operate on the nut 15 if, for example, play is detected in the entire assembly as a result of temperature changes, humidity changes or the like, and it is also evident that assembly of the structure may be carried out directly by the user, the assembly operations being very simple and within everyone's scope.

With this structure, appropriately adapted and dimensioned, other items of furniture may be constructed, such as for example tables, beds, cupboards and the like, and it is also possible to provide for the stiffening spider to produce a tension action, instead of thrust action, at its ends, thereby producing if appropriately intended, a compression on the side members (instead of tension). In such a case the spider, instead of being composed of struts, would be composed of tension members having ends with a screw and control nut.

It will be understood that other variants are possible for the construction, without adhesives, of items of furniture of all types, also achieving the inherent advantages of the structure according to this invention, of eliminating any application of glue or adhesive, with the elimination of the associated operations and equipment, and also the possibility of storing, transporting and assembling the individual components with a minimum of space and directly on the job.