DE8804040U1 - Rocking mechanism - Google Patents

Description

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Description

The invention relates to a rocking mechanism for connecting a seat to a base frame according to the preamble of claim 1.

Such rocking mechanisms are used in particular in swivel chairs and desk chairs, seats in planetariums and panoramic cinemas, conference chairs, seats for airplanes, trains and buses. They allow the seat height to be adjusted, the seat to be rotated vertically and the seat to be tilted around a swivel axis located at the front end of the seat. Such rocking mechanisms have so far required a relatively large amount of space and, because they are unsightly, are hidden from the viewer's view under bulky covers.

These rocking mechanisms are also relatively expensive, as they represent only a small percentage of the total number of rocking mechanisms produced, since a large proportion of the Preh.3 chairs used in offices are still only available with a reduced number of adjustment options.
25

The present invention is intended to develop a rocking mechanism according to the preamble of claim 1 in such a way that its basic component can be used equally for single versions with only limited adjustment options as for sophisticated versions with the full spectrum of adjustment options, and that the mechanism is compact and thus its mechanically supporting housing can also represent the lightweight housing at the same time.

This object is achieved according to the invention by a rocking mechanism according to claim 1.

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In the rocker mechanism according to the invention, the two

The coil springs arranged next to each other together with the transmission rod running between them form a very flat unit. There is still a free space under the transmission rod, which can accommodate a large part of a seat tilt locking cylinder used in more expensive versions with stepless tilt lock. This also means that the overall arrangement of coil springs, transmission rod and locking cylinder is reduced in the vertical direction; the

Housing fails. Even in the horizontal direction, the rocking mechanism according to the invention requires only little space, so that

the housing as a whole appears as a radially projecting arm of the base supporting the gas spring. This creates an optically light overall impression that is appealing without additional cladding.

- The two coil springs can provide a high level of pre—

Apply tension to the seat, whereby the symmetrical arrangement of the transmission rod between the two coil springs ensures that no tilting moments have to be absorbed in the force transmission path between the movable spring element and the seat.

-i 25 Advantageous further developments of the invention are specified in the subclaims.

With the rocker mechanism according to claim 2, a hydraulic locking cylinder can also be used to save space, which is longer than the shortest length of the coil springs that can occur in operation. Nevertheless, the sea office arrangement of coil springs, transmission rod and hydraulic locking cylinder is very low in the vertical direction.

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widely spaced parts of the housing ensure that the tipping moments exerted on the seat can be well absorbed.

The further development of the invention according to claim 4 is again advantageous with regard to a symmetrical force transmission, balanced with regard to tilting moments, from the movable spring seat part to the bit fastening part.

The further development of the invention according to claim 5 is advantageous in terms of low friction in the power transmission between the transmission rod and the seat fastening part, as well as in terms of avoiding tipping moments on the spring arrangement.

In a rocking mechanism according to claim 6, the force with which the seat fastening part is pre-tensioned upwards can be continuously adjusted. This adjustment is carried out from the front end of the rocking mechanism, so it can be carried out comfortably by the user even when sitting, if the adjusting nut can be operated by a rotary handle placed on it, also pointing forwards.

The further development of the invention according to claim 7 is advantageous in terms of adjusting the preload force with low friction.

With the development of the invention according to claim 8, very precise and cleanly functioning guides are obtained for the two adjusting shafts for operating the head valve of a vertical adjustment, the locking mechanism and the oil tilt adjustment. This solid and play-free operation of the height and tilt adjustment is perceived by the user as particularly pleasant.

In known tilt mechanisms, the unbalanced steering is carried out by the handles for height and tilt adjustment.

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The valve has a seed spring or the tilt locking device using multi-cranked levers mounted in the housing and two swivel levers. These levers require a relatively large amount of space and are not remotely accessible. The OS Aneprueh 9 can very easily carry out the movement redirection using cables and pulleys, whereby the cables only require very little space, which favors compact housing dimensions.

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Cost-effective, simple and reliable locking mechanism of the Sri-ff it for locking or releasing the tilt adjustment.

With the further development of the invention according to claim 11, it is possible to adjust the inclination of the backrest by an angle that is proportional to the inclination of the seat surface but different from it (synchronous backrest adjustment) with only a small amount of additional material.

If the guide track is formed as specified in claim 12, the associated costs are very low. All housings can thus be provided with such a guide track as a preventative measure, regardless of whether the option of synchronous backrest adjustment is ultimately desired in the rocking mechanism built with the housing in question or not.

With the further development of the invention according to claim 13, a further improvement was achieved and again with regard to the inclusion of capacitance values, the seat fixing device was changed.

When establishing the force connection between the drive arm of the 3B seat fastening rod and the tilt locking device in a special position 14, a mechanical locking lever (excluding

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Use a hydraulic weighing device (step setting) or a locking device (step setting).

The further developments of the invention according to claims 15A and 16 are advantageous with regard to a simple and robust construction of a mechanical tilt locking device.

The invention is explained in more detail below using exemplary embodiments with reference to the drawing. In this

Figure II is a side view of a height and tilt adjustable swivel chair 15

Figure 2i is a top view of the seat tilt mechanism of the swivel chair shown in Figure 1)

Figure 3: a longitudinal section through the rocking mechanism shown in Figure 2

Figure 4 shows a longitudinal section through a slightly modified rocking mechanism, similar to Figure 3, but seen in the opposite direction{ 25

Figure 5: a transverse section through a sub-unit of the rocking mechanism according to Figures 2 and 3 or 4, which comprises pre-tensioning springs and a hydraulic locking cylinder for the inclination adjustment 3d of the seat surface; and

Figure 6i is a perspective view of a simplified rocker mechanism, which consists of the same basic components as the rocker mechanisms according to Figures 1 to 5.

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running foot cross 12. The latter carries an inner standpipe 14, not shown in detail in Figure 1. Its upper end engages with a rocking mechanism, designated 16 overall, from which a cover tube 18 hangs downwards. The latter overlaps the standpipe 14 .

The rocking mechanism 16 has a seat fastening part 20 which can be pivoted about an axis ZZ located at the front end of the seat. A seat part 24 is attached to the seat fastening part ZO.

Furthermore, a backrest fastening part, designated as a whole by 26, is mounted on the seat fastening part 20 so as to be pivotable about an axis 28. The backrest fastening part 26 has a follower roller 30 at a front end, which cooperates with a guide track (not shown in detail in Figure 1) on the top of a housing 32 of the rocking mechanism 16, such that the backrest fastening part 26 is pivoted more than the seat fastening part 20 when the inclination of the seat fastening part 20 is adjusted. Accordingly, a backrest 34 attached to the backrest fastening part 26 is pivoted more than the seat part 24 when the inclination of the seat part 24 is adjusted, as indicated by dashed lines in Figure 1.

As can be seen from Figures 1 and 2, the rocking mechanism 16 has a rotary handle 36 at the front for adjusting the strength of the spring force with which the seat part 24 is pre-tensioned into the raised position.

The seat fastening part 20 comprises two lateral fastening profiles 38 with a cross-section of 1 with fastening holes 40 ₉ to which the seat part 24 is screwed. The two fastening profiles 38 are connected by a cross member 42.

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The housing 32 is closed at the bottom by a snap-in cover 44 and has side walls 46, 48 and an upper wall 50. In practice, the housing 32 can be made from deep-drawn stamped parts and welded together, OS as indicated in Figure 3 by corresponding hatching.

At the front end of the upper wall 50, there are

Two bearing sleeves 52, 54 are welded to the side walls 46, 48.

In these a hollow bearing axis 56 is fixed, e.g.

screwed tight. Outer bearing sleeves 58, 60 and an inner bearing sleeve 62 are almost welded to the seat fastening part 20, which are opposite the end faces of the bearing sleeves 52, 54 with a small amount of play and thus position the seat fastening part 20 axially with respect to the housing 32.

The fastening profiles 38 are welded onto the bearing sleeves 58, 60.

Adjusting shafts 64, 66 are inserted into the bearing axis 56 from both sides, which in turn carry handles 68, 70 for locking the height adjustment or the inclination adjustment. As shown in Figure 2, the right-hand end of the bearing axis 96 is provided with two locking grooves 72 that are offset in the circumferential direction. The handle 70 carries a locking lug 74 that can optionally engage in one of the locking grooves 72.

To preload the handle 70 against the bearing axis 58, a helical spring 71 is provided inside, the outer end of which is supported on the head of a screw 73. The latter is screwed into the adjusting shaft 66. To transmit torque, the cooperating ends of the handle 70 and the partial shaft 66 are connected in an axially movable manner via a spring/groove arrangement.

On this corn IAIt the tilt adjustment permanently

block or permanently released. For the purposes of the aforementioned &eegr;

Then tie the seat part 24 and the backrest 34 together |

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movable against spring force, as described in more detail below.

As can be seen in particular from Figure 3, a drive arm 78 is welded to the bearing sleeve 62 in the area between the two bearing sleeves 52, 54, which drive arm has a large through-opening 80 for a transmission rod 82. The end of the transmission rod 82 on the right in Figure 3 is firmly connected to a bridge-shaped spring seat part 84, which carries spring seats 86 for the movable ends of two helical compression springs 88, 90. The second ends of the latter are supported on another bridge-shaped spring seat part 92, which is welded to the housing 32 and has a through-opening 94 for the transmission rod 82.

As can be seen from Figure 3, the drive arm 78 forms a cutting edge 79 in the area of the through opening 80 that projects to the left, and a pressure disk 96 engages this, which is connected to another pressure disk 100 via an axial bearing 98. The pressure disk 100 is supported on the rear face of a nut 102, which can be adjusted on an end section 104 of the transmission rod 82 that is provided with a fine thread. For this purpose, the rotary handle 36 is placed on the nut 102 in a form-fitting manner, which passes through an opening 106 in the front end wall of the housing with play.

As can also be seen from Figure 3, the axes of the transmission rod 82 and the helical compression springs 86, 90 run at an angle of about 5 rad to the horizontal, and the upper wall 90 of the housing 32 also runs in Figure 3, sloping to the right, in order to enable the rear end of the bit fastening part 20 to be lowered. 33

A retaining bracket 110 is welded to the side walls 46, 48 of the housing 32 and has in the neighborhood

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its lower end» a fastening opening 112. The piston rod 118 of a hydraulic locking cylinder, designated as a whole by 120, is fixed to this by means of nuts 114, 116. The piston rod 118

O5 a plunger 122 is passed through, which serves to set the control valve of the locking cylinder (not shown in detail), via which the two working chambers of the locking cylinder can be optionally short-circuited or isolated.

The locking cylinder 120 has its largest part broken away in Figure 3 and is only indicated by dashed lines. The locking cylinder 120 extends at a short distance parallel below the transmission rod

92. The spring seat part 84 has a recess 124 at the bottom so that it can move over the outer surface of the locking cylinder 120 when the rotary handle 36 is moved in the sense of tensioning the helical compression springs 88, 90 or when the seat part 24 is pivoted downwards by the user using his weight when the inclination adjustment is released.

Two coupling pins 126, which are supported by molded-on lateral arms of the drive arm 78, engage rotatably on the outer surface of the left end of the locking cylinder 120 in Figure 3. The arms 128 are bent in the manner shown in Figure 3 and engage around the left end of the locking cylinder 120.

To operate the plunger IZ?, a V-shaped operating lever 130 is used, seen in plan view, which is mounted on a pivot pin 132 carried by the housing 32. The end of the operating lever 130 lying above the plane of the drawing in Figure 3 is coupled to the actuating shaft 66 via a cable eye (not shown in detail), in a similar way to that described below for an operating lever 134, which works on a plunger 13, with which the

23.03.1988

Valve of the seat height adjustment spring indicated at 138 in Figure 3 is actuated.

The operating lever 134 is cranked and is mounted on the side wall 46 of the housing 32 by means of a pivot pin 140 so that it can rotate about a horizontal axis. A cable 142 engages its operating end and is deflected from the vertical lever actuation direction into a horizontal direction by a deflection roller 144, which is also mounted on the side wall 46. The end of the cable 142 on the left in Figure 1 is attached to a steep arm 146 which is guided through windows of the bearing axis 56 and the bearing sleeve 66 running in the circumferential direction and engages the adjusting shaft 64. By lifting the handle 68, the lever arm 146 is pivoted clockwise, which leads to a pivoting of the operating lever 134 in the same direction. This releases the gas spring 138 for height adjustment.

A circular-arch-shaped material flap is formed on the fixed spring seat part 92, which forms a guide 150, and a material flap forming a guide 148 is pressed out of the upper wall 50 opposite this and is bent in a circular shape so that together with the guide 150 it forms a circular guide path for the follower roller 30 of the backrest fastening part 26. The center of this guide path is at the point marked M in Figure 3, i.e. is away from the axis 28 about which the backrest fastening part 26 can be pivoted. Lowering the seat fastening part 20 thus leads to an additional pivoting of the backrest fastening part 26 with respect to the seat fastening part 20, which results in the synchronous backrest adjustment already mentioned above.

■&bull;1 the» modified embodiment according to WiQur 4, with reference to Figure 3, already explained parts are shown again

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Instead of the continuously adjustable locking cylinder 120, a locking lever 184 is now provided which is operated by an actuating arm 182 connected to the actuating shaft 64. The actuating arm 182 passes through windows running in the circumferential direction in the bearing sleeve 62 and the bearing shaft 36. The locking lever 154 has a bearing sleeve 156, the bore diameter of which corresponds to the clear width of the bearing recesses of the locking cylinder 120 and the corresponding dimension corresponds to the distance between these bearing recesses. The locking lever 154 can thus be connected in an articulated manner to the articulated arch 126 of the drive arm 7B instead of the locking cylinder 120.

An actuating arm 13Θ of the locking lever 154, welded to the bearing sleeve 156, is fork-shaped and engages around the actuating arm 152 for direct torque transmission. A locking arm 160, also welded to the bearing sleeve, has several recesses 162, each of which can accommodate a latch section 164 that is molded onto the fixed spring seat part 92. By operating the handle 70, the seat surface can thus be locked at different inclinations.

The trap section 164 is also provided in the embodiment example according to Figure 3, where it has no function.

It can be seen that the rocking mechanisms in Figures 3 and 4 are largely identical despite different levels of comfort and are therefore manufactured in exactly the same way except for the insertion of the locking cylinder or the locking lever, which reduces the manufacturing costs due to the maximum

3S reduces the quality of larger series.

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Tilting mechanism 16, which allows the synchronous adjustment of the seat inclination and backrest inclination
ale also offers the possibility of adjusting the spring preload for the seat inclination and backrest inclination,

OS you can also use simpler Wfpp mechanics with less

Comfort. Such a simpler rocking mechanism is shown in Figure 5. This rocking mechanism contains
no adjusting shafts 64, 66 and no sriffes 68, 70. The
Preload of the helical compression springs 88, 90 is set once with an Allen key on the appropriately designed head 166 of the transmission rod 82 and then remains
unchanged.

In a further modified embodiment,
IS the synchronous adjustment of the backrest can be omitted and a rigid seat shell can be attached to the bit fastening part 20. For this purpose, the rocking mechanism 16 can be used unchanged.

From the examples given above it is clear that the round elements of the rocker mechanism 16 can be used equally for very simple rocker mechanisms as well as for rocker mechanisms that offer all adjustment options.

To provide additional resistance for adjusting the
In order to obtain the desired inclination of the backrest, a Bummi block fader 168 can be inserted between the slat fastening part 26 and the seat part 24, which is gauzed in the unloaded state in Figures 3 and 4.

Claims (16)

2334.7 - 1 - 23.03.198© Claims 1. Rocking mechanism for connecting a seat to a footrest frame via a vertical column, with a housing which is provided at the rear end with a receptacle for the upper end of the vertical column, with a seat fastening part which is connected to the housing via a pivot bearing located at the front end of the housing; with a spring arrangement housed in the housing, by means of which the seat fastening part is pre-tensioned into a raised position) and with a locking device for locking the seat fastening part at different inclinations, characterized in that the spring arrangement IS comprises two adjacent coil springs (88, 90), one end of which is supported together on a spring seat part (92) fixed to the housing and the other end of which jointly engages a movable spring seat part (84) coupled to the seat fastening part (20), which works on the seat fastening part (20) via a transmission rod (82) running between the two coil springs (88, 90) and attached to the movable spring seat part (84). 2. Rocking mechanism according to claim 1, characterized in that the spring seat parts (84, 92) are provided with recesses (124, 128) located underneath and the locking device has a hydraulic locking cylinder (120) which can engage in the recesses (124, 128). 30 3. Rocker mechanism according to claim 1 or 2, characterized in that the housing (32) is supported up to its two side walls. (46, 48) each carries an eleventh bearing sleeve (52, 54), ^vrc which has a bearing axis (§6) fixed on which a bearing sleeve (62) is rotatably mounted axially positioned between the bearing sleeves (52, 54), which is connected to the seat fastening part (20) and carries a radial drive arm (7S), 2334.7 .:.r.Ä ^# - ·..*·..· *..'·.,· 33.03.1989 which works together with the transmission rod (82). 4. Rocker mechanism according to claim 3, characterized in that the transmission rod (82) is guided through the drive arm (78) with radial play (80) and the transmission rod (82) has a force transmission device (96 to 104) acting on the drive arm (78) on-UCriSt. 5. Rocking mechanism according to claim 4, characterized in that the section of the drive arm (78) which cooperates with the force transmission device (96 to 104) is designed as a cutting edge (79). IS 6. Rocker mechanism according to claim 4 or 5, characterized in that the force transmission device has a nut (102) running on a threaded end section (104) of the transmission rod (82). 7. Rocker mechanism according to claim 6, characterized in that the nut (102) engages the drive arm (78) via an axial bearing (98). 8. Rocker mechanism according to one of claims 3 to 7, characterized in that the bearing axis (56) is a hollow axis and from both of its ends adjusting shafts (64, 66) carrying springs (68, 70) are rotatably inserted, which extend into the interior of the housing (32) and there carry adjusting arms (146, 152) which are guided through windows running in the circumferential direction in the bearing axis (56) and the bearing sleeve (62) of the rod fastening part (20). 9. Rocker mechanism according to claim 5, characterized in that the rocker arms (146, 142) operate via cable eyes (142) and swivel rollers (144) on the head (32) pivotally mounted release levers (130, 134), via which the head valve of the rocker spring (13·) is connected to the control valve of the hydraulic - 3 2334.7 mechanical locking cylinder (120). 10. Rocker mechanism according to claim 8 or 9, characterized in that one end of the hollow bearing shaft (56) has one or more locking grooves offset in the circumferential direction (72) which cooperate with a locking lug (74?) of the associated actuating shaft (66) or of the screw (70) carried by the latter. 11. Rocker mechanism according to one of claims 1 to 10, characterized characterized in that the upper wall (50) of the seat housing (32) has a guide track (148, 150) with a curvature parallel to the axis of the bearing axis (56) and that a backrest fastening part (26) on the seat fastening part (20) is pivotably mounted about an axis (28) which is away from the center of curvature (M) of the guide track, and that a follower part (30) is arranged at the front end of the backrest fastening part (26), which cooperates with the guide track (148, 150). 12. Rocker mechanism according to claim 11, characterized in that the guide track is formed by a bent-out material tab (148) of the upper housing wall (SO) and by a material tab (150) parallel thereto, which is molded onto the spring seat part (92) fixed to the housing. 13. Rocking mechanism according to one of claims 3 to 12, characterized in that further bearing sleeves (58, 56) of the seat mounting point (20) run on the bearing axis (56) axially outside the fixed bearing sleeves (52, 54), the outer diameter of which is preferably equal to the outer diameter of the bearing sleeves (52, 54). 14· Rocker mechanism according to «Inem dar claims 4 to 13, characterized characterized in that the drive arm (78) has at its free end one, preferably two «aligned HHHl ti« I» mt /L m &bull;&bull;&bull;&bull;III I)III ^ &Ggr;&igr;&ogr;! 11* j IM·! S 2334.7 ·.·· *·- 23.03*1988 opposite pivot bolts (126) which can be inserted in an articulated manner either in bearing recesses of a locking cylinder (120) or in a bearing sleeve (156) of a locking lever (154) working together with a latch (164) fixed to the housing. 15. Rocking mechanism according to claim 14, characterized in that the locking lever (154) has an actuating arm (158) which works directly with the associated actuating arm (15S). 16. Rocker mechanism according to claim 14 or 15, characterized in that the latch (164) is formed by a folded-on section of the fixed spring seat part (92). * * 44 II* llf (I I It t\ ', "I'"l· i
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