DE2118614A1 - Chair for dental purposes - Google Patents

Description

The invention relates to chairs for by one Dentist to be treated.

The previously known chairs for dental Purposes usually include a stationary base, a height-adjustable seat and an angle-adjustable The backrest is supported, the latter being articulated with the rear end of the seat. With these well-known Chairs, which are hereinafter referred to as "chairs of the known type", are those which form the seat and the backrest Structures connected by joints so that they can perform angular movements about a horizontal axis.

There is a disadvantage of such a known arrangement in that the angular movements of the gap backrest with respect to the seat, which take place around the axis of the joints, do not lead to corresponding movements of the patient's body, whose hump is opposite the pelvis and the lower Limbs resting on the seat rotates about an axis which does not coincide with the axis of rotation of the back of the chair. If the backrest is lowered, it therefore moves

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the patient's torso opposite the backrest, d. H. it moves in relation to the support surface of the backrest. At the same time, the patient's head moves in relation to the headrest, which is usually an integral part forms the backrest, so that it is usually necessary after the backrest has lowered, the headrest and certain auxiliary equipment, e.g. "lighting devices, reset.

Furthermore, the aforementioned movement of the backrest leads to that the patient's body takes up a different position on the backrest and "the seat, to tell the difference between the relative position of the seat and the backrest on the one hand and the relative position of the pelvis and the trunk of the patient on the other hand.

In practice, when lowering the headrest moves the head of the patient along an arc from its original position to another position opposite stationary Tools and other devices that the doctor may need; this applies in particular in the event that the dentist works in a sitting position.

. Another disadvantage is that dental Treatment chairs of the current type usually with hydraulic devices for lifting the moving parts are equipped, so that the setting up and the correct adjustment of the chair is gymnastic and time consuming.

The invention is based on the object of avoiding the above-mentioned disadvantages} for this purpose the invention proposes a chair of the type mentioned for dental purposes, which is simpler, more robust and more economical Is an instruction that is easy to set up and in which the relative movements between the seat and the backrest when the backrest is pivoted is automatically

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be like. Furthermore, the invention provides a chair of the type mentioned, in which the relative movement between the Support surfaces of the seat and the backrest as well as the parts of the patient's body resting on these surfaces a relative angular movement between the seat and the Backrest is avoided or at least largely reduced. Furthermore, the invention provides according to a preferred one Embodiment a chair of the type mentioned for dental purposes Purposes before, which is designed so that the position of the head of the patient relative to a passing through the head vertical line when pivoting the seat back remains essentially unchanged, so that it is no longer necessary is to readjust the distance between the patient's head and the dentist's seat and his instruments. Finally, the invention provides a chair of the type mentioned, which can be used easily and comfortably and is easily adjustable.

To achieve the object on which it is based, the invention provides a chair of the type mentioned for dental practitioners Purposes before, in which the seat comprises a support structure on which a frame is mounted longitudinally displaceable, in which this frame carries a seat cushion, in which the backrest comprises a frame carrying a backrest cushion, which along two parallel tubular supports articulated to the rear end of the seat support structure is displaceable, and in which a device is provided that it is opposite when pivoting the backrest allows the seat to slide longitudinal movements of the backrest frame and the seat frame in opposite directions Directions and to bring about different amounts so that the two took jointly in proportion to the downward movement the swiveling backrest can be moved relative to the seat support structure, with the two frames at love the backrest compared to the seat structure

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apart from each other proportionally to this upward movement.

The invention and advantageous details of the invention are explained in more detail below on the basis of schematic drawings of exemplary embodiments.

Pig. 1 shows in perspective an embodiment of a chair according to the invention for dental purposes.

FIG. 2 shows, in an enlarged perspective view, the chair according to FIG. 1 with the omission of the P coatings.

Fig. 3 shows schematically in plan the lower part of the Chair.

FIG. 4 is an enlarged section taken along the line IY-IV in FIG. 3.

FIG. 5 is a cross section taken along line V-V in FIG. 4.

Figures 6 and 7 each show a schematic view Side view of two different positions of use, certain parts of a further development of the chair according to FIGS. 1 to 5-

Fig. 8 shows in a perspective front view the middle part of a further embodiment of an inventive Chairs for dental purposes.

Fig. 9 is a side perspective view of the chair of Fig. 8 in which the seat back is upright Takes position.

Fig. 10 is similar to Fig. 9 but shows the seat back. in a lowered position.

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Pig. 11 and 12 schematically show two different positions of use of the in each case in a side view Pig's chair. 8 to 10.

In all figures are the same or corresponding to one another Parts are each denoted by the same reference numerals. To the following is first of all Pig. 1 to 5 shown Chair described.

The one in Pig. 1 to 5 shown Chair for dental Zwdke has a fixed base 1, which can be anchored to the ground on one side of the base 1 are parallel with the horizontal axes 2 and 2 ¹ two lower lever mounted 3 and 3 'by pivot axes 4 and 4 ^{1 are} connected to two upper levers 5 and 5 'so that the levers form a pantograph rod lying in a vertical plane. A similar pantograph linkage is arranged symmetrically to the linkage just described on the opposite side of the substructure 1, and the levers 3, 3 ¹ and 5 »5 ^{1 of} this second linkage are arranged parallel to the corresponding levers of the first linkage.

The upper levers 5 and 5 ^{1 of} each pantograph rod are connected by hinge axes 6 and 6 ¹ to a supporting cross member 7 which supports the seat part of the chair.

The adjacent ends of the P: ntograpgenhebel 3, 3 ^f and 5 '5' are provided with gear segments 3a, 3k · ¹ and 5a, 5a ^1, which interlock iden be-about the stability of Pant ο graph close to enhance rod.

The joint axes 4 of the two pantograph rods carry a first horizontally arranged U-shaped ironing piece 8, which supports an electrically drivable reduction gear 9. The other joint axes 4 'of the two P; ntograph rods carry a second horizontally arranged U-shaped bracket part 11, with which a nut is connected

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is, which cooperates with a threaded spindle 10, which is coupled to the reduction gear 9 according to FIG. 4 and can be driven by this gear.

If the threaded spindle 10 is rotated in one direction or the other, the hinge axes 4 and 4 ^{1 of} the two pantograph rods are moved towards or away from one another, so that the seat of the chair is raised or lowered relative to the substructure 1. The use of the U-shaped bracket parts 8 and 11 makes it possible to keep the overall length of the threaded spindle 10 used for actuation small.

Two parallel longitudinal members 12 are attached to the load-bearing cross member 7, which are secured by two cross pieces 13 and 14 and a front plate 15 are connected to each other. At the U underside of each of the two cross pieces 15 and 14 is

• n

a nut 16 or 17 attached. Lit the two nuts 16 and 17, a threaded spindle 18 works together, which is in the one or the other Eichtung can be rotated by an electrically drivable reduction gear 19, which is supported by the front plate 15.

On the outer surfaces of the longitudinal members 12 are two tubular iührungsbuchseji 20 attached. In these guide bushes two horizontally arranged parallel rods 21 are slidably mounted. At the ends of the two Rods 21 are each attached to two blocks 22 and 25 of a certain shape, and these blocks are movable with a Seat frame 24 connected, which, according to FIG. 1, carries the seat cushion A and is movable in the direction of its longitudinal axis.

At the rear ends of the two longitudinal members 12 are two parallel blocks 12a attached, which together with the longitudinal members form two G bein, in each of which one is horizontal arranged hinge pin or an axis 26 is mounted. Zv, egg flattened eyes 27a at the ends of two parallel tubular supports 27 are through the axles 26

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articulated to the longitudinal members 12. Furthermore are two tubular parts 28 (FIG. 2) are provided, which on the tubular U supports 27 are slidably guided. According to FIG. 2, the tubular bag parts 28 carry a Backrest frame 29 as a support for the backrest cushion B.

The entire backrest is thus hinged to the seat frame so that it can pivot about the horizontal Axis of the hinge pin 26 can run; In addition, the backrest can be in the direction of its longitudinal axis with respect to the Supports 27 move to their hinge axis approach or move away from her.

Accordingly, the movable seat frame 24 can move in the longitudinal direction with respect to the stationary support structure of the chair and move closer to or further away from the hinge axis of the backrest.

The flattened eyes 27a of the rods 27 each have a crank arm 50, and these crank arms extend downward relative to the seat frame 24 according to FIGS. The free ends of the crank arms 50 are articulated to two rods 52 by bolts 51, the other ends of which are articulated to a cross member 54 by bolts 55. The cross member 54 carries a nut 55 screwed onto the threaded spindle 18 in the middle between its ends.

The rods 52 carry pivot pins near the cross member 54 56, by means of which in each case one of two curved support rods 57 is articulated to the associated rod 52 is. The support rods 57 are at their other ends by means of bolts 58 on the movable frame 29 of the Rotatable backrest.

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21186H

If the threaded spindle 18 in one way or another Rotated direction, the support rods 27 of the backrest pivoted, while at the same time a gliding movement of the "movable boasting 29 of the backrest so caused is that the backrest approaches the hinge axis of the hinge pins 26 in proportion to the extent to which the Backrest is lowered; on the other hand, if the backrest is raised, the movable backrest frame 29 moves away from the pivot axis of the bolts 26.

The thread spindle 18 comprises a front section ψ 18a of the opposite thread direction, which compared to the rear section 18b has a smaller pitch. This front threaded spindle section 18a cooperates with a nut §9, which is supported by a fire member 40 attached to the movable seat frame 24. Therefore, when the lead screw 18 is rotated, the moveable seat frame 24 is also caused to move towards the pivot pins 26 as the backrest is lowered to accommodate the movement of the patient's body, and accordingly the seat frame 24 moves from the pivot pins 26 away as soon as the backrest is lifted.

Thus, the seat frame 24 and the backrest ™ frame 29 opposite movements of different Extent to allow the patient's body to shift in relation to the seat and backrest when raising or lowering the backrest.

In a modified embodiment shown in Figs. 6 and 7 The rods 21 only extend over part of the length of the longitudinal members 12, and they are in guide bushings 20 slidably guided, which are rotatably mounted on the longitudinal members 12. The rods 21 are with the help of Intermediate links 41 and hinge pins 42 and 43 are articulated to two front rod sections 21 '. the

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front rod sections 21 'are inclined in associated Guide bushes 20 'stored which are attached to the longitudinal members 12 so that the movable seat frame 24 at each axial movement is raised and lowered depending on the pivoting movement of the backrest.

Thus, the seat is raised or lowered in accordance with the pivoting movement of the seat back so that the lower The patient's limbs are raised when the backrest is lowered, and vice versa, to accommodate movement of the body of the patient to counteract the backrest.

8 to 10 show a chair according to the invention, which is a modification of the embodiment according to Fig. 1 to 7, and in which the entire structure relative to the stationary substructure 1 is movable

is. The base 1 and the device for regulating the vertical movement of the seat structure are also designed as in the embodiment according to FIGS. 1 to 5

The supporting cross member 7 is provided with two parallel longitudinal members 44 extending along both sides of the Cross member extend. The ends of the two longitudinal members 44 protrude beyond the cross member 7 and carry four rollers 45 with transverse horizontal axes, of which only one is indicated with dashed lines in FIG. 8, and these Shells engage in corresponding parallel longitudinal grooves according to FIG. 9 46 a, which are formed in two movable longitudinal members 12 ', which on both longitudinal sides on the outside the stationary Stuhl Konstruktign are arranged.

The longitudinal movable members 12 'are divided by three upper cross members 15% 13 and 14 and / or one a reduction gear 19 supporting front plate 15 connected. That reduction gear 19 is used to have a threaded spindle 18 of the type described to rotate, which with nuts 16 ·, 16

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and cooperates 17 which are 'attached to 15 »15 and 14 on the underside _n U of the various cross-members.

The two movable longitudinal members 12 'each carry two pairs of laterally outwardly protruding profiled lumps 20a with transverse axes, which serve as guides for two longitudinal guide rods 21 act, which two pairs of profiled, separated by a longitudinal distance support blocks 25 and 25 'support on which the not shown movable upholstered seat frame is arranged movably in the longitudinal direction.

At the front ends of the guide rods 21 two further small blocks 22 'are attached by a lower cross member 40 are connected, which carries a nut 59, which with a having a small pitch front section 18a of the threaded spindle 18 cooperates.

A transverse member 47 (FIG. 8) is arranged between the two longitudinal members 44 and is connected to the longitudinal members. To the cross member 47, a nut 48 is fixed, which cooperates with a central portion 18b of the threaded spindle 18, whose thread has a large pitch and the same ψ Gcngrichtung as having the front portion 18a.

The lead screw 18 further includes a rear portion 18tr with a mean pitch between the Pitches of sections 18a and 18b; the thread of the rear section 18c has compared to the two sections 18a and 18b have an opposite direction. The rear section 18c cooperates with a nut 54, which is supported by a movable cross member 55 to which two rods 52 are articulated, whose other ends each articulated with an associated crank arm 50 are connected; the crank arms 50 are on the associated tubular supports 27 for the backrest attached.

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-11- 21186U

The tubular supports 27 are connected to the rear ends 12'a of the movable length members 12 'by hinge pins 26 connected, which determine a common horizontal joint axis.

Feners are two curved support poles W? provided, which are hinged to the movable cross member 35 and connected at their upper feet, not shown, to the movable backrest frame 29, which carries the backrest cushion, also not shown.

The following is the mode of action of the chair 8 to 10 described.

Eb it is assumed that the backrest initially assumes an upright position, as it is in lig. 9 shown and that the threaded spindle 18 is rotated in such a direction that the backrest is lowered. This turning movement the threaded spindle 18, in conjunction therewith, causes its central portion 18b to be connected to the stationary nut 4-8 cooperates that the threaded spindle 18 and the two movable longitudinal members 12 'in the axial direction move forward so that the entire chair according to j? ig. 10 in is adjusted lengthways relative to the substructure »At the same time, the front nut $ 9 moves along the a small pitch front portion 18a of the threaded spindle, whereby the rods 21 moves rearward so that the seat frame in the longitudinal direction opposite the movable longitudinal members 12 'in the direction of the hinge pin 26 of the backrest is moved. In addition, the rear ivutter $ 4- moves along the die at the same time middle Ga): the rear section 18c of the height having the Threaded spindle, whereby the backrest is lowered, so that the movable liückenlehnenrahmen 29 in the described Way through the support rods 37 in the direction of the axis the hinge pin 26 is displaced.

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These combined, schematized in Figs. 11 and 12, The movements shown ensure that the subject's head C is essentially in the same vertical transverse plane remains while the seatback is swiveled. The vertical projection of the head 0 lies in FIG. 11 of the patient on the horizontal surface supporting the chair initially at point C, and this point of projection would move to point 0 "if the only movement was to lower the backrest B, as indicated in Fig. 11 with dashed lines. ^ Ensure the iiinx * seals described above However, that the downward movement of the backrest B from a compensating horizontal longitudinal movement of the entire Chair construction including seat A, which in this case is a forward movement is the distance D, so that the backward movement of the vertical projection of the head C is so balanced the patient's head remains in the same vertical plane as shown in FIG.

Therefore, the dentist does not need to change his working position or the position of his seat, and it is no need to move the stationary instruments to bring them close to the patient's head, after the backrest has been pivoted, because the horizontal distance between the instruments and the head of the Patient has remained practically unchanged »

Claims ;

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Claims (5)

EXPECTATIONS M.J chair for dental use with a fixed Underbody as a support for a height-adjustable Seat and one with the rear end of the seat articulated . Bound, vertically adjustable backrest, characterized in that the height-adjustable seat comprises a support structure (12) which is a frame (24), which carries the seat cushion (A), is mounted displaceably in the longitudinal direction that the backrest a frame (29) supporting a backrest cushion (B) comprises, which is displaceable along two parallel tubular supports (27), which at the rear end of the Seat support structure are articulated, and that a device (55 »57) is provided which when pivoting the backrest longitudinal movements of the backrest frame and the seat frame, sliding relative to the seat, in opposite directions uncnim causes different amounts, so that the two frames when lowering the pivoting backrest be moved at the same time proportionally to this pivoting movement with respect to the seat support structure. 2. Chair according to claim 1, characterized geke η η ze I η et that the means for controlling the movement of the movable seat frame (24 ·) and the movable backrest frame (29) comprises a threaded spindle (18) that this threaded spindle has a rear portion (18b) and a front section (18a) comprises that the front section of the threaded spindle compared to the rear ab- 109845/1282 21186H cut a smaller gingjöhe and an opposite one Gc-ngrichtung that the two threaded spindle sections each work together with a nut (35 or 39) so that the one nut (35) is supported by a rod (32, 30) with swiveling backrest supports (27) is connected, which determine the angle of inclination of the backrest that the other nut (39) with the movable Seat frame (24) is connected to control the longitudinal movement of the seat frame, and that supports (37) are present, which the first! lining (35) with the movable backrest frame (29) to control the longitudinal movements of the backrest frame on the supports (27) so that the seat back frame moves in the opposite direction to the seat frame, 3. Chair according to claim 1 or 2, characterized geke η η ζ ei ch η et that the height adjustment of the seat is determined by pairs of levers (3, 3'j 5j 5 ¹ ) which form a pantograph rod and a centrally located one Actuating threaded spindle (10) are connected, which can be driven by an electric motor (9), and that the adjacent ends of the levers of the p & ntograph linkage are provided with intermeshing gearwheel segments (3a >> 3a ¹ ,. 5a, 5a ¹ ) in order to increase the stability of the construction. 4. Chair according to one of claims 1 to 3, characterized in that the seat frame (24) is guided by at least one longitudinally extending Kihrungsstange (21) which is supported by the frame and supported by the seat support structure (12) Guide parts (20) cooperates that at least one of the guide parts (20 ¹ ) is inclined to the horizontal and cooperates with a hinged part (21 ') of the S ¹ clocking rod, so that each longitudinal movement of the seat frame in one direction or the other one 109845/1262 vertical movement of the seat frame accompanied is. 5. Chair after. To claim 1, characterized in that a fixedly arranged raisable and lowerable element (7) supports the seat a stationary cross member (47) containing ^N parallel a stationary nut (48) and two, is supported in the longitudinally extending Iragglieder (44) , on which two components of the seat support structure forming, longitudinally extending BiUglieder (12 ¹ ) are movably mounted in the longitudinal direction, that these structural members support a longitudinally extending threaded spindle (18) which has a central section (18b) of relative large aisle, with which the stationary cutter (48) cooperates so that the lengths (12 ') are guided during their movement by two bars (21) extending in the longitudinal direction, on which the movable seat frame ( 24) supports that the Mihrungsstangeη are connected by a lower cross member (49) which carries a further i..utter (39) which is connected to a front section (18a) of the Ge co-operating lead screw, which compared to the middle lead screw section (18b) has a relatively small pitch and the same G; ngrichtung that the threaded spindle further comprises a rear portion (18c) of middle pitch, the Gpngrichtung the G; direction; of the front and the middle section is opposite that this rear section cooperates with a third Lutter (34), which is supported by a movable cross member (35) on which two rod members (32) determining the inclination of the seat back frame (24) and two curved support (37) are articulated, which control the sliding longitudinal movement of the movable space back frame (29), so that a rotation of the threaded spindle at the same time a whirling movement of the backrest, a change in the distance 109845/1262 between the movable frames of the backrest and the The seat as well as a horizontal movement of the entire seat support structure is effected in such a way that the vertical Projection of the head (C) of a patient supported on the backrest in a horizontal direction practically not relocated. 109845/1262