GB2111592A - Chair with hydraulic elevator and pump - Google Patents

Abstract

The chair has a seat supporting cylinder (2), a hydraulic elevator (1) and a stop device when the base (4) of the chair is provided with wheels or rollers. The hydraulic elevator includes a vertical axis hydraulic cylinder (10) provided with piston (8) connected to the seat support (3) and a foot-lever operated pump (12) connected to said hydraulic cylinder (10) and communicating with a tank (13), containing the hydraulic fluid, through a valve and a conduit, in which said hydraulic cylinder (10), pump (12) and tank (13) with the associated valves are arranged along the vertical axis (A) of a container cylinder (7) slidably inserted in the seat supporting cylinder (2). <IMAGE>

Description

SPECIFICATION Chairs or arm-chairs This invention relates to a chair or arm-chair.

More particularly, this invention relates to a chair or arm-chair provided with a hydraulic elevator and, in the case where the chair base is provided with wheels or rollers, a stop device for fixing the position of the chair or arm-chair base relative to the ground.

Already known are chairs and/or arm-chairs provided with hydraulic mechanisms for seat elevation, as well as devices for maintaining the bases thereof stationary relative to the ground.

All of the known hydraulic seat elevation mechanisms operate on the principle of conventional hydraulic lifting jacks enabling the multiplication of the involved muscular strength.

Generally, such devices comprise a vertical axis cylinder provided with a piston or ram which is raised and lowered by introduction and ejection of a liquid and by a pump, normally connected to the cylinder and having the pumping member(s) arranged along a horizontal axis. Arrangement of the pump and cylinder along intersecting axes normally perpendicular to one another results in discomfort since the pump, which should be placed close to the chair base, would project from one side or from both sides of the cylinder.

Moreover, the above arrangement for the cylinder and pump, which has been hitherto compulsory, make it impossible to use normal or standard bases, thus causing the manufacturers to provide for special bases, which are unaesthetic and cumbersome.

Also the known stop devices for chair and/or arm-chair bases are cumbersome and assembling thereof requires a modification to the chair and/or arm-chair base having said devices secured thereto.

It is the object of the present invention to provide a chair and/or arm-chair fitted with a hydraulic seat elevating mechanism (and in the case where this is provided, a stop device) free of the above mentioned disadvantages.

More particuarly, it is the object of the present invention to provide a hydraulic mechanism for elevating the seat of chairs or arm-chairs, in which the various parts comprising said mechanism are of such dimensions and structure as to be contained within the vertical seat or arm-chair supporting cylinder.

It is a further object of the present device to provide a hydraulic mechanism for elevating the seat of a chair or arm-chair not requiring any particular base, supporting cylinders or other expensive and rather irrational elements for assembling and use thereof.

It is still a further object of the present invention at least in its preformed form to provide a stop device for fixing the position of the chair or armchair relative to the ground, particularly for chairs or arm-chairs fitted with wheels or rollers, which is not cumbersome, does not require any modification to the aesthetics of the chair or armchair base to which it is secured, and which is effective, sturdy and reliable in operation.

The invention provides a chair or arm-chair, comprising a seat supporting member or cylinder and a hydraulic elevator in which said hydraulic elevator includes a hydraulic cylinder with a vertical axis and fitted with a piston connected to the seat supporting member, and a pump connected to said hydraulic cylinder and communicating with a hydraulic fluid containing tank through a valve and conduit, wherein said hydraulic cylinder, pump and tank with associated valves are arranged along the vertical axis of a container shell or cylinder slidably inserted in said seat supporting member or cylinder. Preferably the container cylinder is attached to the chair base by a frustoconical connecting member.

Preferably the liquid tank is formed within the space defined by the outer surface of the hydraulic cylinder and internal surface of the container cylinder.

The pump piston may be actuated by the end of a lever, pivoted to the chair or arm-chair base at the opposite end of the user's foot.

In operation, the pump piston, as actuated by the user through the lever, draws the liquid from the tank and forces it into the hydraulic cylinder, thus raising the piston of said cylinder, and accordingly the chair or arm-chair seat to which it is connected, to the top of its stroke.

By fully pushing the pump piston, when at the position of top of stroke, a valve is actuated and causes the liquid to return to the tank and accordingly causes the downward movement of the shaft of the hydraulic cylinder and seat to a position of bottom of stroke.

Where the chair or arm-chair according to the present invention is provided with wheels or rollers fixed to the base, it may be fitted with a stop device for maintaining the base stationary to the ground. Said stop device is preferably secured within the cavity of the base or a spoke of the chair or arm-chair, and comprises:: a a fixed hollow body; - a pin coaxially arranged within the cavity of said fixed body and provided at the end with a pushbutton and stop stalk, respectively; - a small block secured to said pin, movable in the vertical guideway formed between the walls of the hollow body and coaxial pin, and provided with a groove comprising parallel and inclined sections, with respect to the vertical axis of the pin, and a basin-like portion; - a spring which is effective on said small block holding the latter constantly upward urged; and - a U-shaped rod, one end of which slides in the small block groove, and the other end of which is secured to the base of the fixed hollow body, said rod setting the positions of top end of stroke and bottom end of stroke for said small block and pin secured to the latter. Said movable small block can take two extreme positions: of which one is at the top of stroke through the spring thrust, in which the stop stalk is remote from the ground, and thus the chair or arm-chair is free to move, and the other of which is an intermediate position caused by the uses pressure on the pushbutton and maintained by the connection of the rod end at the basin-like position of the small block groove.

At this position of bottom end of stroke for the movable small block, said stop stalk is pressed by a spring against the ground, thus blocking the chair or arm-chair position. An embodiment of hydraulic elevator and stop device for chairs or arm-chairs, in accordance with the present invention, will now be described by way of example only, with reference to the figures of the accompanying drawings in which:: Fig. 1 is a schematic vertical sectional view of a hydraulic elevator with the operating lever at the position of bottom end of stroke; Fig. 2 is a same schematic sectional view as that of Fig. 1 with the operating lever at the position of top end of stroke; Fig. 3 is a schematic view showing the stop device secured within the cavity of the base of a chair or arm-chair at stop position; Fig. 4 is a schematic view of the stop device shown in Fig. 3 at the release position as raised from the ground; Fig. 5 is a schematic side view for the side A of a cross-section provided by a plane passing along the line B--B of the stop device shown in Fig. 3; Fig. 6 is a schematic view of the cross-section according to Fig. 5 when the device is at not stop or release position; and Fig. 7 is a schematic sectional view of the device shown in Fig. 6 as provided by a plane passing along the line C-C.

Referring to Figs. 1 and 2, and elevator 1 is housed along the vertical axis A of a sleeve 2 supporting the rest or mounting 3 to which the seat of a chair or arm-chair (not shown) is coupled. Said elevator 1 comprises an outer shell or container cylinder 7 sliding within said sleeve 2 and is secured to the chair or arm-chair base 4 by a frustoconical attachment member 5 and a threaded ring 6. A multiplier cylinder 10 is placed within said shell 7, the piston 8 of which acts upon said rest or mounting 3 by means of a ball 9. The rectilinear and vertical movements of said piston 8 are controlled by a lever or pedal 11 pivoted at 22 to the chair base 4 and operated at one end by a user's foot.These movements are carried out by a pump 12, the piston 18 of which, sliding in the cylindrical seat 1 9, is actuated by the lever 11 or pedal through its other end provided with a roller 17, while spring 20 maintains said piston 18 in a compressed state against said roller 1 7. The cylindrical seat 1 9 of pump 1 2 is connected through a conduit and valve 14 to a tank 13 containing the oil or liquid and through a valve 15 with the chamber 16 of said multiplier cylinder 10.

Said tank 13 is defined by the inner walls of shell 7 and by the outer walls of cylinder 10 and closed at the two ends. During intake, piston 1 8 draws oil from tank 13 in seat 21 and pumps it into the chamber 1 6 of the multiplier cylinder 10 during compression, thus causing rise of piston 8.

Continued movement of piston 18, as provided by lever 11, accomplishes full rise of the piston 8 and accordingly of the chair seat.

After completion of rise of piston 8, further downward pushing on said pedal 11, causes a higher rise for piston 1 8 which then operates the valve 15, causing oil to return to tank 13 and thus causing downward movement of the seat.

It is the novel feature of said elevator 1 that cylinder 7 with tank 13, cylinder 10 with shaft 8 and pump 12 are all aligned on the same vertical axis A and housed within said sleeve 2.

Thus, the hydraulic elevator for chairs and armchairs according to the present invention can be contained within the same space as occupied by a conventional empty sleeve, central support or mounting 2 connecting the seat to the base 4.

Where the chair or arm-chair is provided with wheels or rollers secured to the base, it may be provided with a stop device for fixing the position of the chair or arm-chair with respect to the ground.

Referring to Figs. 3 to 7, a stop device comprises a hollow body 31 secured in the spoke 23 of a chair or arm-chair base by screws 33. A pin 28 is placed within the cavity of said hollow body 31 and projects from the latter and from the chair base, and at the upper end is provided with a pushbutton 26, and at the lower end with a stalk 24 bearing on the ground or floor 25. This stalk 24 is coated with rubber or felt material 27 for gripping on the ground. Said pin 28 connects said various elements, holding the same in guides and transmits thereto the user's controls by moving along the axis D. By means of a dowel 34, said pin 28 has secured thereto a small block 29 moving within the cavity or vertical rectilinear guide 32, the latter being formed between the inner surface of the hollow body 31 and the outer surface of pin 28.

A spring 35, spirally would along pin 28, urges said small block 29 upwards, as well as pin 28, pushbutton 26 and stalk 24 secured thereto.

A pressure exerted by the user on pushbutton 26 will drive all of the above mentioned elements and also provides for compression of a small spring 36 located within said stalk 24. The action of this small spring 36 exerts the thrust for holding the chair to the ground or floor through said stalk 24.

In order that the muscular strength exerted by the foot can be automatically maintained at a constant level in time and in order that, by doing so, spring 36 will continue its thrust action with respect to stalk 34, a small shaped rod 30 is operated, this rod performing the task of holding the small block 29 at an intermediate position, as always urged upward by spring 35.

One curved end 37 of this U-shaped rod 30 is inserted in a cavity formed in the base of the hollow body 31, and the other curved end 38 slides within a groove 40 formed on the surface of the small block 29. Said groove 40 comprises parallel sections relative to the vertical axis of pin 28, inclined sections relative to said axis, and a basin-like portion 39.

When the small block 29 is at the high position of top end of stroke, the stalk 24 is not in touch with the ground or floor 25. The small block 29 is retained at the position of top end of stroke by the thrust of spring 35.

On the other hand, when said small block 29 is retained at the intermediate position, said stalk 24 is in touch with the ground or floor 25 and is pressed thereagainst by the action of spring 36.

Therefore, the functions performed by said stalk 24 with respect to the ground or floor 25 are accomplished by said small block which, by being movable and guided in the cavity 32, can take two fixed and well defined positions. The first of these two positions, shown in Fig. 5, is due to the stop or check action carried out by the shaped small rod 30 with the turned over end 37 fixed and set in said body 31, as shown in Fig. 7. When the pushbutton 26 is downward pressed by the user, said small block 29 is lowered and the curved end 38 of said small rod 30 in groove 40 (from the left).When the thrust action terminates and the user's foot releases the pushbutton 26, the small block 29 tries to recover the upward position, but the curved end 38 of said small rod 30, still sliding in the groove 40, arrives at the basin-like portion 39, retaining said small block 29 which cannot move back to the top position. At this position, said stalk 24 is connected to the ground floor 25 and is urged thereagainst by the loaded spring 36.

The second position for the small block 29 with respect to the body 31 (see Fig. 6), is still provided by the user's foot, this time exerting a higher pressure on the pushbutton 26. This action causes the small block 29 to move in downward direction, disconnecting the curved end 38 of the small rod 30 from the basin-like portion 39. Thus, said curved end 38 is inserted in the right channel of groove 40 and, when the user's foot releases the pressure, the small block 29 is allowed to return upward free since the curved end 38 does not encounter any further obstacles. Thereby, said small block 29 comes in touch with the upper wall 41 of the vertical guideway 32.

Under the condition shown (see Figs, 6 and 7), small block 29 moves said stalk 24 away from the ground or floor 25. A small pin 42, movable within the slot 43 and secured to pin 28, guides the movement of said pin 28 and small block 29.

Claims (8)

1. A chair or arm-chair, comprising a seat supporting member or cylinder and a hydraulic elevator in which said hydraulic elevator includes a hydraulic cylinder with a vertical axis and fitted with a piston connected to the seat supporting member, and a pump connected to said hydraulic cylinder and communicating with a hydraulic fluid containing tank through a valve and conduit, wherein said hydraulic cylinder, pump and tank with associated valves are arranged along the vertical axis of a container shell or cylinder slidably inserted in said seat supporting member or cylinder.

2. A chair or arm-chair according to Claim 1, wherein the container cylinder or shell is secured to the base of the chair or arm-chair by means of a frustoconical attachment element and a threaded ring.

3. A chair or arm-chair according to Claim 1 or Claim 2, wherein the liquid tank is formed in the space defined by the outer surface of the hydraulic cylinder and the inner surface of the container cylinder and is closed at both ends.

4. A chair or arm-chair according to any of the preceding claims, wherein a lever pivoted to the base of the chair or arm-chair and arranged to be actuated at one end by a user, has its other end effectively connected to the pump piston, causing the movement thereof.

5. A chair or arm-chair according to any of Claims 1 to 4 having wheels or rollers and a stop device, wherein the stop device is secured in the base cavity or the cavity of a spoke for the chair or arm-chair and comprises a fixed hollow body; a pin coaxially arranged in the cavity of said fixed hollow body and provided at the ends with a pushbutton and a stop stalk, respectively; a small block attached to said pin and movable in the vertical guideway formed between the walls of the hollow body and pin, and provided with a groove comprising parallel and inclined sections relative to the vertical axis of the pin, and a basin-like portion; a spring acting upon the small block and maintaining the latter constantly upward urged, and a U-shaped rod having one end secured to the base of the fixed hollow body, said rod establishing the positions of top and bottom end of stroke for the small block and pin secured to the latter.

6. A chair or arm-chair according to Claim 5, wherein said movable small block takes two extreme positions; of which one at top end of stroke due to the action of the spring thrust or force, has said stop stalk remote from the ground or floor, and the other at intermediate position caused by the user's pressure on the pushbutton and retained by the connection of the rod end in the basin-like portion of the small block-groove has said stop stalk engaging the ground.

7. A chair or arm-chair according to Claim 5 or Claim 6, wherein a spring is placed within the stop stalk and urges said stalk towards said ground or floor.

8. A chair substantially as described herein with reference to or as illustrated in Figs. 1 to 3 and/or Figures 4 to 7 of the accompanying drawings.