DE2259010A1 - ADJUSTABLE CHAIR - Google Patents

Description

Desmond Gogarty, Lamlash, Mornington, Drogheda, County Louth,

Ireland.

Adjustable chair

The invention relates to the construction of an adjustable Chair. .

Dentists, doctors, hairdressers and other professions often require the use of a chair that can be adjusted so that the person concerned is seated in each. position can be adjusted from the stretched position to sitting upright.

The chairs used by dentists are usually with one Motor, a control device and a locking device are provided to keep them inclined and fixed in any desired position can be. Such a chair construction is relatively expensive and not only complex and difficult to use, but it also requires frequent and expensive maintenance.

The different positions that such a chair moves into usually require a change in the angle between the seat and the backrest. The invention is based in part on realizing that changing this angle was sensational

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Inconveniences and the occasional alarm seated person triggers when the axes around which the chair parts pivot a considerable distance from the pivot axis of the Have hip joint of the person concerned.

The invention relates to an adjustable chair and it is the object of the invention to make the previous constructions more adjustable To avoid disadvantages inherent in chairs by eliminating the need for expensive control and actuation means and in part by the fact that the geometric adaptation between the articulation of the chair and the anatomy of the Chair occupying people is adapted.

The invention provides an adjustable chair which can be continuously transferred between an essentially upright position and a stretched position via intermediate positions and which can be fixed in any position as desired. According to the invention, the chair has a stand which supports as a unit around a single main pivot axis, a backrest, a seat and preferably a footrest, the main body contacting surfaces of the backrest and the seat being offset dorsally from the axis relative to a person , which normally occupies the chair and at such a distance that the center of mass of the person is approximately on the main pivot axis. This basic feature of the invention ensures that the body of the person resting on the seat exerts a negligible torque around the main axis of the chair, so that the chair together with the Perlon resting on it can be manually moved into any conceivable position with the least amount of force by the operator and this force can turn arbitrarily either on the backrest or the dita or, tall .; present, on the footrest auu ^ e exercises wt-rd-m oiUn ' also aiii "Ιιγ · ί-η <1 which extensions, eg adjusting lever.

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The invention also provides an adjustable chair of the type mentioned Type before, in which the 'backrest and the seat are pivotally connected via a secondary joint, the axis of which is parallel to the mentioned main pivot axis offset to this in one direction which runs anatomically below a normal one that occupies the chair Person lies with the main body meeting surface of the seat further offset in the same direction and the offset distances are chosen so that the hip joint of a normal person occupying the chair and the secondary joint are coaxial '. Seat hinge assemblies are also provided to adjust the angle between the main body contact surfaces of the backrest; and the seat in a predetermined dependence on the inclination of any selected part of the back, seat or footrest relative to one Guide axis of the stand. '·' ... -.;.

In the body of an average adult, the hip joint axis is about 5 cm below the center of mass and accordingly this is the preferred offset distance between the main joint and the secondary joint in the chair designed according to the invention. ^;

If a footrest is provided, then a footrest hinge can also be provided and this can be adapted to one or more parts of the seat joints are pivotably mounted and are coupled to the backrest and the seat by means of separate handlebars. This guide lever can be 'additionally coupled to the footrest via an additional handlebar.' ^:

The lengths of these handlebars and their attachment points with the 'guide lever, the backrest, the seat and the footrest are of course like that chosen that in each case not only the necessary connection but also the desired mechanical advantage is achieved, so that

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the relative swivel rates of the backrest, seat and footrest can be predetermined. In this way, it becomes an allowable area determined by positions for the adjustable chair which can be converted from the upright position to the lying position, wherein The backrest, seat and footrest are essentially in one plane. The handlebars preferably consist of rigid connecting rods, which are pivotably articulated at both ends.

The adjustable chair designed according to the invention is, as mentioned above, optionally lockable in any position and to this A locking device of suitable design can be provided for this purpose will. The common feature of such a locking device is that they have at least one pivotable Defines component of the adjustable chair with respect to another part that has a different range of motion, or it takes place a fix to the frame. For example, a clutch can be provided which, when actuated, reduces the friction in any swivel joint of the chair so far that a safe shutdown is guaranteed. Instead, a Piston-cylinder drive are provided, which has stops to set the piston within the cylinder. The piston is connected to a swivel member of the chair and the cylinder to another. This arrangement has the additional advantage that Piston and cylinder can be constructed as a hydraulic unit, with an incompressible fluid duroh a small one Opening is pressed as a result of the movement of the piston, so that a Damping effect is exerted on the chair during its pivoting movement, so that the adjustment is smooth and easy by the operator controllable and can be carried out comfortably for the person lying on it.

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For mechanical reasons, the greater part of the described Mechanism can be duplicated, with a group of components placed on each side of the chair, so that a given Pivoting is carried out by two swivel members, each of which lies on one side of the chair, but with both one have a common swivel axis in space. The reference in the present description to a swivel joint is to be understood in this way be that in this sense, several joints can be arranged on one axis. In the drawings, an embodiment is shown in which a pivot mechanism 'on one side of the adjustable chair is arranged and an identical mechanism is a mirror image on the other side, with the two mechanisms work together in the swivel bearing of the chair. All essential swivel joints are arranged in pairs and coaxially to one another each joint of a pair is assigned to one of the two mechanisms. These remarks apply to all components shown in the drawing except ...

a) for the stand 1 and port sets thereof and.

b) the locking device 25,26,27 etc.

An exemplary embodiment of the invention is described below with reference to the drawing. In the drawing show:

Pig. Figure 1 is a side view of the mechanism of an adjustable chair according to the invention in an inclined position,

Fig. 2 is a side view of the mechanism of the chair in a further upright position,

Fig. 3 is a side view of the chair according to Fig.l in an even steeper Position,

4 shows a view of the stand of the chair, FIG. 5 shows a side view of the guide lever of the chair according to FIG.

Fig. 6 is a side view of a second embodiment of an adjustable Chair.

The chair according to the embodiment naoh Fig.l to 5 has a

Stand 1, which is adapted to an upper support frame 2, which carries a seat frame 3, a backrest 4 and a footrest 5-The The seat frame 3, the backrest 4 and the footrest 5 carry the conventional upholstery and springs, which are not shown in the drawing are.

The upper support frame 2 has upwardly projecting legs 2a which carry an inclined handlebar 6. The upper support frame 2 is also provided with an arm extension 7. The backrest frame 4 is connected to the inclined rod 6 by means of a pin 8 and an arm 9 articulated to it. A four-armed guide lever 10 is pivotably articulated on the inclined rod 6 by means of a pin 11. One leg of the four-armed lever 10 is connected to a link 14 and the backrest frame 4 via pins 13 and 13. This frame 4 and the seat frame 3 are connected by means of a pin 15 and rigid connecting arms 4a and Ja . The seat frame 3 is connected to one leg of the four-armed guide lever 10 by means of a link 16 and by means of pins 17 and 18. The footrest frame 5 is pivotably connected to the seat frame 3 via a pin 19 and by means of a link 20 and pins 21 and 22 to one leg of the four-armed guide lever 10.

A rod 23 is articulated to the arm extension 7 by means of a pin 24 and hereby engages in a hole 25 of a carrier plate 26. This carrier plate 26 is divided by a slot 29 which extends up to the hole 25 extends. A threaded rod 27 with a handle 27 a cooperates with the carrier plate 26 in the vicinity of the slot 29. By rotating the handle 27a is effected that the not-shown slot surfaces are moved relative to each other, whereby the Seat of the steel rod 23 in the hole 25 is tightened or loosened. This forms the locking device. she can be replaced by a ratchet wheel with two pawls.

When a person is sitting in the chair, that person's center of gravity is roughly on the imaginary line between the pegs ¹ 8.

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When the handle 27a is rotated so that the rod 23 is free in the hole 2 £> can slide, then the seated on the chair can Person can be easily moved to any other position. The movement of the parts 4a and 3a around the pin 15 simulates the effect of the hip joint the person. When it is necessary to lock the chair in any position, the handle 27a is rotated around the Seat of the rod 23 in the hole 25 to tighten. It is only necessary to tighten the handle 27 to the rod 23 in the hole 25 if e.g. a dentist has a rigid seat for treatment of a patient needed.

The embodiment according to FIG. 6 is intended to illustrate that certain details of the invention can be modified within wide limits. Most of the components are in corresponding Numbered manner as in Figures 1-5. However, it can be seen that the guide lever 10 is no longer four-armed, but Is designed C-shaped. The body-contacting surface 60 of the backrest 4 is by the amount X of about 10 cm along the vertical offset to this surface uiö the pivot pin 8 and this is the average depth of the center of gravity of a human body, calculated from the back surface of the body. In In the same way, the seat surface 61 is about 10 cm in the amount Y offset from joint 15 and that is the average height of the hip joint axis above the lower surface of the thighs in an upright position. It's a lockable hydraulic piston and cylinder provided, which is only indicated by dashed lines at 62 and is articulated via pins 63 and 64, the points of Linkage can be chosen within wide limits. If a latch has occurred against a reciprocating movement, the piston-cylinder drive 62 blocks the entire chair opposite another shot.

People differ widely in terms of their size dimensions. The inventive arrangement leads to a

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Construction of an adjustable chair that is very comfortable, can only approximate the ideal conditions «because the ideal Condition is the relationship described above between the pivot pin 8 and the center of mass of the person and between the joint 15 and the hip joint axis of the person sitting on the chair Person.

The fact that a length graduation, e.g. of the links ^ a and 9 in 6 is made, the chair according to the invention can be used on people whose hip joint or center of gravity deviate from the average value with regard to the anatomical position. These further refinement is contemplated and implemented by the invention.

The invention is not restricted to the exemplary embodiment described, but can deviate from the exemplary embodiment within wide limits.

Claims

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Claims (12)

Claims: ' 1.) Adjustable chair that can be steplessly switched between a sitting position - ^ and a lying position movable and lockable in any position is provided, with a stand that is mounted on a single, Main pivot axis carries a backrest and a seat, characterized, that the main body contact surfaces of the backrest and seat , dorsally offset from the main axis in relation to a person are, who sits in the normal position on the chair, and that the extent of the offset is chosen such that the center of gravity of the Person roughly through the main pivot axis. 2. Chair according to claim 1, characterized, that the backrest and the seat can be pivoted via a secondary joint are interconnected, the axis of the swivel joint runs parallel to the axis of the main joint and opposite this is offset in a direction that is anatomically inward with respect to a person sitting in the normal position on the chair, and that the main body contact surface of the seat further offset in the same direction and the offset distances are chosen so that the hip joint of a normal person resting on the chair and the secondary joint are coaxial and that seat hinge assemblies are provided to adjust the angle between the main body contact surfaces of the seat back and seat in a predetermined depending on the inclination of any one To guide part of the backrest-seat combination opposite an axis of the stand » 3. Chair according to claim 2, characterized, that the seat hinge comprises a guide lever to a fixed point of the stand can be rotated and that the lever 1st connected to the backrest and to the seat via separate handlebar. '■■ -. ■ - .: 'ti BATH ORIGINAL 225901Q 4. Chair according to one of claims l to 3, characterized in that a footrest is pivotably hinged to the front end of the seat 5. Chair according to claim 4, <characterized by that a footrest hinge arrangement is provided to adjust the angle between the body contact surface of the seat and the footrest according to claim 2 for the respective surfaces of Control the backrest and seat. 6. Chair according to claim 5 * characterized in that the seat hinge assembly and the footrest hinge assembly have one or more common components. 7. Chair according to claim 6, characterized in that the guide lever is also connected to the footrest via a handlebar is coupled. 8. Chair according to claims 3 to 7, characterized in that that the handlebars are formed by rigid connecting rods which are pivotably articulated at both ends. 9. Chair according to claims 1 to 8, characterized in that that the offset distance between the surface of the backrest and the main pivot axle is adjustable. P '■' ■ BATH ORIGINAL 259010 10 * chair according to claims 2 to 9, characterized, that the offset distance between the seat surface and the secondary pivot joint is adjustable according to Figure 2. 11. Chair according to claims 1 to 10,
characterized, that a locking device is provided to arbitrarily the unit consisting of the backrest, seat and footrest is relative to lock the stand by placing between this unit and the Stand a rigid connection is created. 12. Chair according to claims 2 to Ϊ0,
characterized, that a locking device is provided to arbitrarily to lock the moving parts of the chair relative to each other and to the stand by placing between the bejrien parts and the Chair that are moved relative to each other during adjustment, one Connection is switched on, which can be made rigid. 309826/0292 lee rs e