Electrostatic chair

Abstract

 Concerns an electrostatic chair, suitable for being used in places where there is radiation or electromagnetic fields to which the operator working in front of a video terminal or in material research and testing laboratories is exposed. Such a chair is characterised in that it can absorb the electrostatic charge which deposits upon the body of the operator sitting down and then discharge it to earth (Fig. 1).

Description

[0001] The present finding regards an electrostatic chair suitable for discharging electrical charge, accumulated in the body of a person sitting down, into the ground.

[0002] The problem of the radiation and electrostatic charge to which the operator is exposed, working in front of a video terminal or in material research and testing laboratories, where there are radiation and electromagnetic fields, which can even have a substantial intensity, is well known to those responsible for safety in the workplace.

[0003] At the current state of the art the safety of such operators is taken care of by constructing apparatuses with low radiation emission or else by screening them, for example with the use of protective screens arranged on the video terminals of computers.

[0004] Despite this the operator, who, for example, remains seated for a long period of time, even for the whole day, in front of the video of a computer, always absorbs an amount of electrostatic discharge which exceeds the safety threshold, which is harmful for the operator himself.

[0005] The purpose of the present finding is that of foreseeing a device which is capable of discharging to the ground all electrostatic charge accumulated on the body of an operator who works sitting down in an area subjected to radiation like, for example, in front of a computer.

[0006] This is realised by foreseeing that a special fabric with electrostatic properties, thus capable of attracting the electrostatic charge present on the surface of the operator's body, be inserted on the seat of the chair and, possibly, also on the arms and on the backrest.

[0007] Such a fabric is placed connected to the metallic frame of the chair and this frame, through a flexible cable, is placed in contact with the ground, so as to allow the electrostatic charge to discharge to earth.

[0008] The electrostatic fabric, placed immediately below the cover fabric, to be as close as possible to the body of the operator, consists of a textile fibre layer in which a portion of the weft thread and warp end are made out of metal, preferably copper, from whence comes the name "copper fabric".

[0009] In particular, the finding foresees that in chairs equipped with adjustable height seats there be a continuous connection between the vertically sliding piston of the pump and the central cylinder of the base, usually prevented by the presence of the gaskets of the gas pump, placed between the aforementioned two metallic bodies.

[0010] As can easily be understood with the constructive solution according to the finding the electrostatic charge present on the fabric is discharged to ground through a single metallic conducting path, consisting of the cable which connects the fabric to the support plate for the seat, of the piston of the gas pump, which holds up the plate, of the device which ensures the continuous contact between the aforementioned piston and the central cylinder of the base and of the flexible cable which connects the end of said cylinder with a metallic body trailing along the ground.

[0011] The finding shall be better understood through the description of a possible embodiment thereof, given as a non-limiting example, with the help of the attached table of drawings, where:

• fig. 1 represents an elevated front view of a chair according to the finding;
• fig. 2 represents a detailed view of the copper fabric applied to the chair;
• fig. 3 represents a detailed view of the continuous connection between the piston and the cylinder of the base.

[0012] As can be seen in fig. 1, the finding foresees that a fabric 1 having special electrostatic characteristics is fitted onto the seat and is inserted between the covering fabric 11 and the cushioning sponge 12.

[0013] As can be seen in fig. 2 the fabric 1 is characterised in that it foresees that part of the threads 2, which form the weft thread and warp are made from metal, preferably copper.

[0014] The fabric 1, through the flexible cable 3, is placed in connection with the metallic plate 4 and, consequently, also with the piston 5 of the gas pump, both of said elements obviously being metallic.

[0015] The electrical connection between the piston 5 and column 6 of the base is realised through the sliding contact, wholly indicated with reference numeral 7.

[0016] Finally, the flexible cable 8, equipped with the ball 9, anchored, through a self-threading screw 10, at the lower end of the cylinder, takes care of closing the electric circuit, allowing the electrical charge to discharge into the ground.

[0017] In detail, the sliding contact 7 foresees a conventionally produced carbon piece 20, placed in sliding contact on the surface of the piston 5 through the pushing action of a spring 21 and connected, through the flexible lead 22, to an eyelet 23, in turn placed in contact with the surface of the cylinder 6, the whole thing closed inside a cover 24 and locked through the self-threading screw 25.

[0018] Obviously, different embodiments to the one described are possible; for example it is possible to use the copper fabric in different parts of the chair just as it is possible to use different types of connection between the various components without, for this reason, moving away from the scope of the claims defined hereafter.

Claims

1. ELECTROSTATIC CHAIR, suitable for being used in places where there is radiation or electromagnetic fields to which the operator working in front of a video terminal or in material research and testing laboratories is exposed, said chair being characterised in that
it can absorb the electrostatic charge which deposits on the body of the operator sitting down and discharges them to earth.

2. ELECTROSTATIC CHAIR, according to claim 1, characterised in that on the seat it foresees the insertion of an electrostatic fabric in which at least part of the threads which form the weft and warp are metallic.

3. ELECTROSTATIC CHAIR, according to claim 2, characterised in that the electrostatic fabric is placed immediately below the covering fabric.

4. ELECTROSTATIC CHAIR, according to claim 2, characterised in that the material of the metallic thread is pure copper or alloys thereof.

5. ELECTROSTATIC CHAIR, according to claim 2, characterised in that the metallic fabric is inserted into the backrest.

6. ELECTROSTATIC CHAIR, according to claim 2, characterised in that the metallic fabric is inserted into the arms.

7. ELECTROSTATIC CHAIR, according to one or more of the previous claims, characterised in that the electrostatic metallic fabric is connected to the metallic frame of the chair.

8. ELECTROSTATIC CHAIR, according to one or more of the previous claims, of the type equipped with a height adjustable seat, characterised in that it foresees a device for electrical connection between the piston of the gas pump and the cylinder of the base.

9. ELECTROSTATIC CHAIR, according to one or more of the previous claims, characterised in that an electrically conducting thread which discharges the electrostatic charge to the ground is applied to the frame.

10. ELECTROSTATIC CHAIR, according to one or more of the previous claims, characterised in that the electrostatic charge present on the fabric (1) is discharged to earth through a single conductive metallic line consisting of the cable (3) which connects the fabric to the plate (4) for supporting the seat, of the piston (5) of the gas pump, which holds up the plate, of the sliding contact (7) which ensures the continuous contact between the aforementioned piston and the cylinder (6) of the base and of the flexible cable (8) which connects the lower end of said cylinder with a metallic body (9) trailing on the ground.

11. ELECTROSTATIC CHAIR, according to claim 10,
characterised in that the sliding contact (7) is made up of a conventionally produced carbon piece (20), placed in sliding contact on the surface of the piston (5) through the pushing action of a spring (21) and connected, through the flexible lead (22), to an eyelet (23), in turn placed in contact with the surface of the cylinder (6), the whole thing closed inside a cover (24) and locked through the self-threading screw (25).

Drawing