DE3347255C2 - Dental patient chair with headrest - Google Patents

Abstract

A dental chair has a headrest (4) which, together with the tilting movement, performs an additional movement. A four-bar linkage (7) has two swivel levers (11, 12) which are connected to a support at one end via a joint (8, 8a) and at the other end via a joint (9, 10) with a strut ( 13) are connected. The pivot levers (11, 12) are of different lengths. One of them can be pivoted by a motor (19). The headrest (4) is connected to a slide (20) which can be displaced on the strut (13) designed as a slide track (22). A longitudinal displacement linkage (23), which has two linkage levers (24, 25), engages the slide (20). One is articulated to the slide (20), the other to a part (11) of the quadrangle. Another part (12) of the four-bar linkage, which is movable relative to this, is provided with a guide track (29) for the intermediate joint (26) of the linkage. This results in a combined movement of the headrest without high surface pressures occurring between parts which can be displaced on one another.

Description

The invention relates to a dental patient chair with a headrest according to the preamble of claim 1.

A similar patient chair is known from DE-OS 25 41 506. There the headrest is firmly attached to an intermediate piece attached, which is with a curved track on a guide attached to the backrest is supported and articulated with an axial actuator. The cam track is like a wave oppositely curved sections so that the patient's head contact point on the headrest in their Adjustment of the natural inclination trajectory of the patient's head follows. This leads to small structural ones Dimensions for a combined headrest movement that involves a tilting movement, a movement superimpose in the direction of the backrest and a movement perpendicular to it. In particular moves the headrest, when its upper end swivels forwards, upwards and forwards at the same time. if the headrest is loaded by the patient, there is a large torque, which is supported by the contact point between the cam track and the guide roller must become. This creates a considerable surface pressure that adversely affects the curved path, what leads to a shortening of the service life.

There is also an adjusting device known (DE-GM 16 84 541), in which the headrest is fixed to the Strut of a four-bar linkage is attached, which has a front longer pivot lever and a shorter one rear pivot lever are connected to a height-adjustable base element. A control lever acts on two cams, with the help of which the base element is adjusted in height and at the same time the rear shorter pivot lever is pivoted. This construction is very space-consuming.

A dental treatment chair is also known (DE-AS 12 13 955) in which the backrest, which is formed in one piece with the seat surface, is articulated to a frame which is height-adjustable in a vertical guide with the aid of a hydraulic jack. The treatment chair can be tilted with the aid of a second lifter, which engages on the one hand on the frame and on the other hand on a joint connected to the backrest. An additional adjustment of the angle of inclination can be made with the aid of a third lifter.
The invention is based on the object at a

A patient chair of the type described above to achieve a combined headrest movement without that excessive surface pressures, which shorten the service life, occur.

This object is achieved by the features of claim 1.

When the four-bar linkage is adjusted, its strut assumes different positions, which both the inclination as well as the offset of the headrest determine the front opposite the backrest. In the plane defined in this way, the headrest can by means of the The height of the slide can be adjusted. This is done with the help of the longitudinal displacement linkage, its movement is coupled with that of the four-bar linkage In this construction, the headrest is at one Load by the patient over a large area on the slide track of the strut. The occurring Forces can be transferred to the carrier or the motor without difficulty via the pivoting lever of the four-bar linkage Actuator are transmitted.

In the embodiment according to claim 2, by changing the angle of the two-armed angle lever all three movements of the headrest, i.e. the tilting movement, the forward movement and the vertical movement, forcibly controlled.

In the embodiment according to claim 3, the front, shorter pivot lever performs within the adjustment range the headrest has a greater swivel angle than the rear, longer swivel lever. aside from that the second arm can also be made relatively long when the axial actuator located inside the backrest.

The embodiment according to claim 4 simplifies the guidance of the slide on the slide track, since the center of gravity of the headrest is below the pivot point of the linkage lever on the slide.

In particular, the slide needs to rest freely on the slide track.

The development according to claim 6 results in a particularly simple construction.

In the embodiment according to claim 7, there is no need for an additional joint between the longitudinal displacement linkage and articulated square to be provided.

In the further development according to claim 8 there is a compact embodiment in which the linkage lever are largely arranged in the projection area of the pivot lever.

With the Maßnahire of claim 9, the transverse to Force components directed towards the guideway are small.

Due to the additional tilting option according to claim 10, special positions can be achieved, such as they are useful, for example, for taking teeth.

In the embodiment according to claim 11 is a free The headrest can be tilted in relation to the slide.

Claim 12 indicates preferred adjustment options.

The invention is explained below with reference to an embodiment shown in the drawing. It shows

F i g. 1 a schematic representation of a patient chair,

F i g. 2 shows a headrest according to the invention in one end position with an associated carrier and FIG

Fig.3 the headrest in its other end position, wherein the carrier is omitted.

In Fig. 1 illustrates a dental patient chair 1 which has a seat 2, a backrest 3 and a headrest 4. The seat 2 is mounted on a base 5 and can be adjusted in height in relation to this in the direction of the arrow A by means of a motor. The backrest 3 is motorized tiltable in the direction of arrow B , optionally together with the seat 2. The headrest 4 is held by a carrier 6, which is height-adjustable in the direction of the arrow C with respect to the backrest 3. The headrest 4 is in the direction of the arrow D tiltable relative to the carrier 6, with a change in height and a displacement in the direction of the center plane of the patient chair 1 taking place at the same time.

For this purpose, a four-bar linkage 7 is provided which has the two articulation points attached to the support 6 8 and 8a as well as the two further articulation points 9 and 10. It has a shorter front Pivoting lever 11 and a longer rear pivoting lever 12, which are articulated by a strut 13 are connected to each other. The carrier 6 forms the fourth part of the four-bar linkage 7.

The pivot lever 11 is formed by one arm of a two-armed angle lever 14, the other Arm 15 protrudes approximately at right angles and with a threaded bushing that is rotatable and displaceable relative thereto 16 (an axial actuator) is connected. In this engages the threaded part 17 of the shaft 18 of a motor 19, which is in Carrier 6 is held.

The headrest 4 is mounted on a slide 20, which rests freely with a sliding surface 21 on a slide track 22 formed on the strut 13 and longitudinally this path is displaceable. A longitudinal displacement linkage 23 has two linkage levers 24 and 25 which are connected to one another via an intermediate joint 26. The longer lever 24 is on a joint 27 on the upper end of the carriage 20 is articulated. The shorter lever 25 is connected to the joint 9 of the four-bar linkage 7 tied together. A guide element 28 is attached to the intermediate joint 26, which with one from the plane of the drawing protruding wall rests on a guide track 29 which is formed on the pivot lever 12.

While F i g. 2 illustrates the rear end position of the headrest 4, FIG. 3 the front end position. Man recognizes that by pivoting the double-armed lever 14, the slide track 22 on the strut 11 is theirs Has decreased inclination to the axis of the motor 19 from about 30 ° to a value of about 16 °. At the same time is the headrest moved a little forward. In addition, the guide element 28 has along the guide track 29 shifted upwards, so that the carriage 20 is carried along by the linkage lever 24 upwards has been. Overall, there is therefore a movement of the composed of three components Headrest 4.

As Figure 3 shows, the headrest 4 is also around a pivot joint 30 pivotable with respect to the carriage 20 in two further positions. In position 4a it runs approximately parallel to the axis of the motor 19, but in the position 46 it takes an angle of 16 ° with the opposite inclination than in the normal working position of FIG. 3 a. In such positions you can keep the patient's head completely vertical, as is necessary for taking a denture.

In the illustrated construction, the individual parts of the four-bar linkage and the longitudinal displacement linkage lie in the rear end position so closely together that they largely into the interior of the Slide 20 fit. Nevertheless, as Fig.3 shows the headrest 4 tilt and pivot relatively far.

The joint of the linkage lever 25 does not have to be
the joint 9 match. Likewise, the guide track 29 for the intermediate joint 26 does not have to be attached to the rear pivot lever, but can instead
are at any part of the quadrangle that
relative to the articulation point of the linkage lever 25
emotional. The guideway on the swivel levers will
preferred because the linkage lever 24 approximately in the
The direction in which it is also intended to adjust the carriage 20 extends.

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Claims (12)

Patent claims: 1. Dental patient chair with a headrest which can be adjusted with respect to a backrest by means of a motor and which executes a translational movement together with the tilting movement, characterized in that a four-bar linkage (7) has a front shorter pivot lever (11) and a rear longer pivot lever (12), which are connected at one end via a joint (8, 8a) to a support (6) attached to the backrest (3) and at the other end via a joint (9.10) to a strut (13) and of which the one pivot lever can be pivoted by the motor (19), that the headrest (4) is connected to a slide (20) which rests on a slide track (22) formed on the strut and is displaceable on this, and that a longitudinal displacement linkage on the slide (23) attacks, which has two articulated linkage levers (24, 25), one of which is articulated to the slide and the other is articulated to a counter enover the carrier moving part (pivot lever 11) of the articulated square is connected, a relatively movable other part (pivot lever 12) of the articulated square is provided with a guide track (29) on which the intermediate joint (26) of the linkage when the articulated square is adjusted is displaceable in the sense of a height adjustment of the slide. 2. Patient chair according to claim 1, characterized in that the one pivot lever (11) through an arm of a two-armed angle lever (14) is formed, on the other arm (15) one of the Motor (19) driven axial actuator (16) engages. 3. Patient chair according to claim 1 or 2, characterized in that the motor (19) is the front shorter pivot lever (11) adjusted. 4. Patient chair according to one of claims 1 to 3, characterized in that the longitudinal displacement linkage (23) with the longer of the two Linkage lever (24) is hinged to the top of the slide (20). 5. Patient chair according to one of claims 1 to 4, characterized in that the slide (20) rests freely on the slide track (22). 6. Patient chair according to one of claims 1 to 5, characterized in that the guide track (29) runs along one of the pivot levers (12). 7. Patient chair according to one of claims 1 to 6, characterized in that the longitudinal displacement linkage (23) on the joint (9) between a the pivot lever (11) and the strut (13) are articulated. 8. Patient chair according to claim 6 or 7, characterized in that the longitudinal displacement linkage (23) hinged to the joint (9) between the front, shorter pivot lever (11) and the strut (13) and the guide track (29) runs along the rear pivot lever (12). 9. Patient chair according to one of claims 1 to 8, characterized in that the two linkage levers (24, 25) have an angle of less than 90 ° to enclose between them. 10. Patient chair according to one of claims 1 to 9, characterized in that the headrest (4) mounted on the slide (20) so as to be pivotable about a swivel joint (30) and can be tilted relative to the slide from the normal working position into at least one further position (4a, Ab). 11. Patient chair according to claim 10, characterized in that that the swivel joint (30) is at the lower end of the headrest (4) and slide (20) is located. 12. Patient chair according to claim 10 or 11, characterized characterized in that the inclination of the headrest (4) in the normal working position during the adjustment of the quadrangle (7) forward from a larger value, z. B. 30 °, to the course of Backrest (3) to a smaller value, e.g. B. 16 °, and by tilting around the swivel joint (30) in the other position can be changed up to 0 "or beyond.