Assembly system for chair components

Abstract

 The present invention concerns a system of assembly of the components of a chair of the type made up of a load bearing frame (10), in metal, a backrest (11) and a seat (12).
The backrest (11) has two tubular housings (17) formed in the rear, extending upwards and suitable for accepting two tubular support struts (16). Each of the housings has an aperture at the top for the inserting of a securing plug (19) which engages under pressure with the upper part of the respective struts so preventing the sliding and detaching of the backrest upwards.

Description

[0001] The present invention concerns chairs of the type which have a load bearing frame, normally in metal, and having a backrest and a seat, both consisting of panels moulded in a plastic material and secured to the said frame.

[0002] In one well known product, of the type of chair where the backrest and the seat are fixed to the load bearing frame, each are fixed by means of at least a pair of screw clamping methods. In particular, the backrest is made with two vertical blind housings in the rear, into which are inserted support struts which form part of the load bearing frame. The backrest remains hung in this way and is prevented from becoming separated by the inserting of screws which pass through the housings and the struts themselves.

[0003] However, an assembly of this type requires the parts to be fixed to be drilled, the use of screws and in general specific machining which tends to have a negative impact on production times and costs. Furthermore, the means of fixing remain visible on both the backrest and the seat, interrupting the uniformity of the surfaces and therefore the line of these elements.

[0004] The aim of this invention is to propose a new system of chair component assembly, in particular for the assembly of the backrest with the support struts, achieved by means of an original configuration and a combination of elements such as to exclude the use of screw fixings. The result is an easier and more rapid assembly, with the advantage of a reduction in manufacturing costs and not being able to see the mentioned elements at least with regard to the backrest.

[0005] This aim and the inherent advantages are achieved with a component assembly system in accordance with claim 1.

[0006] Further details of the assembly will however be evident from the following description which is made with reference to the attached drawings, in which:

Fig. 1 shows an exploded view of the chair components;

Fig. 2 shows, in section, the clamping of the backrest to a support strut;

Fig. 3 shows one method of fixing the seat to the frame; and

Fig. 4 shows another method of fixing the seat.

[0007] As shown in Fig. 1 the chair is essentially made up of a load carrying frame 10, in metal, a backrest 11 and a seat 12 both made of moulded plastic.

[0008] The frame 10, in addition to having two pairs of legs 13 connected by means of transverse pieces 14 and, where required, arms 13¹, also has two tubular substantially L shaped elements each with a horizontal portion 15 that is fixed to the transverse pieces 14, and a vertical portion 16.

[0009] The horizontal portions 15 of the L shaped elements act as the seating for the seat 12; the vertical portions 16 constitute the two struts for applying and supporting the backrest 11.

[0010] For the application of the backrest 11 onto the struts 16, the backrest 11 has formed in its rear two tubular housing 17, which run vertically and have at their upper ends stop rims 18 formed internally.

[0011] The tubular housings 17 are designed to accept, entering from the bottom, the vertical portions or struts 16 up to the point where they contact the stop rims 18, as shown in Fig. 2. The backrest 11 is in this way mated to and is supported by the struts 16 without the possibility of slipping downwards. Into the top of each housing 17 there is then fitted a securing plug 19 with a stem 20 which passes through the stop rim 18 and engages with pressure in the upper portions of the respective struts 16 (Fig. 2) and with the head 20¹ abutting onto the housing.

[0012] In this way the backrest 11 is secured to the struts 16, ensuring that the backrest 11 cannot slide upwards, with the advantage of not having used any means of screw fixings.

[0013] The seat 12 in its turn can be fixed to the horizontal portions 15 of each L shaped element by at least one self-tapping screw 21 which is screwed in from the bottom into an insert 22 inserted, without rotating, into a hole formed in the seat, as shown in Fig. 3.

[0014] Alternatively, the seat 12 can have integral moulded projections 23 that locate in the holes in the portions 15 and into which are screwed the securing screws 24. This is as is shown in Fig. 4 and has the advantage of not having any inserts or parts projecting above the upper surface of the seat.

Claims

1. A system of assembly of the components of seats of the type having a load bearing frame (10), in metal, a backrest (11) and a seat (12) each produced from plastic moulded panels and where the said frame presents two portions (16) that extend upwards constituting struts for the application of the backrest (11) and two horizontal portions (15) which constitute the seating for the seat, characterised by the fact that the backrest (11) has two tubular inserts (17) formed in the rear, extending upwards and suitable for accepting the said tubular struts (16), and by the fact that each of the said housings has an upper aperture suitable for accepting a securing plug (19) which engages by pressure to the tops of the respective struts to prevent the backrest sliding upwards and becoming detached.

2. A system of assembly in accordance with claim 1, in which the housing (17) has at its upper aperture a stop rim (18) formed by a reduction of the internal diameter, where the top of the strut inserted into the said housing will butt up against the said stop rim (18) preventing the sliding of the backrest downwards, and in which each securing plug (19) has a stem (20) passing through the said stop rim and which engages under pressure with the respective struts and a head (20¹) abutting on the top of the housing preventing the detachment of the backrest upwards.

3. A system of assembly in accordance with the previous claims, in which the seat has integral moulded projections (23) into which are inserted screws for the fixing of the seat to the horizontal portions (15) of the L shaped elements of the frame.

Drawing