GB2252904A

GB2252904A - Chair apparatus

Info

Publication number: GB2252904A
Application number: GB9122043A
Authority: GB
Inventors: Gianpietro Zappa
Original assignee: NORMALIEN Srl
Current assignee: NORMALIEN Srl
Priority date: 1991-02-21
Filing date: 1991-10-17
Publication date: 1992-08-26
Anticipated expiration: 2011-10-17
Also published as: ITBS910020A1; ITBS910020A0; FR2673087A1; IT1249167B; GB9122043D0; ES2046096A2; GB2252904B; ES2046096B1; ES2046096R; DE4122028A1

Abstract

Figure 1 shows a seat support 6 pivotally mounted on a housing 7. The inclination and height of the seat support 6 is determined by the fluid cylinders 3 and 4. A lever controlled member 2 operates both of the fluid cylinders 3 and 4. Pushing the lever 1 in one direction enables the height of the seat support 6 to be adjusted, and pushing the lever 1 in the opposite direction enables the inclination of the seat support 6 to be adjusted. There is at least one spring 5 urging the support into a level position and there is means 8 for adjusting the force exerted by the spring on the support. <IMAGE>

Description

22 5 2 9t14 TITLE Chair Apparatus DESSCRIPTION

Technical Field

The invention relates to chair apparatus particularly for seat adjusting. Chairs having adjustable seats are commonly used in offices, for example by typists.

Background Art

Chairs are know to have apparatus for adjusting, for instance, the height and inclination of a seat. The apparatus is generally between a chair base, possibly provided with wheels, and the seat, which is attached to a seat support of the apparatus. The apparatus has an individual mechanism dedicated to controlling each of the height and inclination of the seat. The mechanisms are usually lever operated, and each mechanism requires an individual lever. Apparatus for adjusting both the height and inclination of a seat is therefore awkward to house, because there are two mechanisms, and adjusting involves the separate operation of each of the individual levers. In practical terms, this means that a person seated in the chair has to use both hands to make adjustments.

The Invention The invention provides chair apparatus comprising a seat support pivotally mounted on a housing which contains a lever controlled member operating a plurality of fluid cylinders for maintaining a selected height and inclination of the support, at least one spring urging the support into a level position and means for adjusting the force exerted by the spring on the.,-upport. The one member is used for both height and inclination adjustments, so only one member has to be housed.

The member is preferably controlled by a single lever, enabling height and inclination adjustments to be made with only one hand.

The Drawings Figure 1 is a side view of a chair including apparatus according to the invention; Figure 2 is a partial top view of apparatus according to the invention; Figure 3 is a side sectional view taken along the line A-A shown in Figure 2; Figure 4 is a partial side sectional view of apparatus according to the invention, the section taken along the line-B-B shown in Figure 2.

Figure 5 is a series of magnified views of the three ringed areas in Figure 3, illustrating the operation of apparatus according to the invention; and Figure 6 is a top view of the chair shown in Figure the seat being shown as though transparent.

Best Mode With reference to f igures 1 and 6, a chair has a seat 10 attached to a seat support 6. The seat support 6 is pivotally mounted at one end on a housing 7 by a mounting 21. Just visible in the f igure is a spring 5 that acts to rotate the seat support 6 anticlockwise as viewed in figure 1, so as to force the seat support 6 into a substantially level position. A control wheel 8 is used to adjust the force exerted by the spring 5. At an end of the seat support 6 remote from the pivotal mounting 21, the seat support 6 is pivotally attached by a mounting 23 to a fluid cylinder 3 which is used to adjust and maintain the inclination of the seat support 6. The fluid cylinder 3 extends through a cover 17 into the housing 7. The housing 7 is mounted on top of a piston rod 20 of a second fluid cylinder 4 fixed to the chair 1 base. The f 1 u i d c y 1 i n d e r 4 i S used to adjust and maintain the height of the seat support 6. The height and inclination of the seat support 6 is adjusted by operating the lever With reference also to Figures 2 and 3, fluid cylinders 3 and 4 are well known in this technical field for adjusting seat supports. The fluid cylinders 3 and 4 have valves 9 and 12 respectively, and when the valves 9 and 12 are actuated, the piston rods 31 and 20 are freed and can reciprocate within the fluid cylinders.3 and 4 respectively. However, when the valves 9 and 12 are not actuated, the piston rods 3' and 20 are held and maintained at the positions where the valves 9 and 12 were last actuated.

Both of the valves 9 and 12 are actuated by a cranked rod 2 pivotally mounted on one of two supports 14 (the left most support 14 as viewed in f igure 3). The second of the two supports 14 (the right most support 14 as viewed in figure 3) pivotally mounts a guide pin 18 aff ixed at the end of the piston rod 3 around the valve 9. The guide pin 18 can rotate within the support 14 so as to enable the fluid cylinder 3 to pivot about the longitudinal axis of the guide pin 18. One end of the rod 2 extends into a recess in the side of a valve actuating slider 19. The s I i d e r 19 has a f inger 11 extending from the region of the slider 19 that overlays the longitudinal axis of the fluid cylinder 4. The finger 11 actuates the valve 12 when the slider moves downwards. The slider 19 moves downwards as a result of the end of the rod 2 nearest the slider 19 pivotting downwards, that is clockwise as viewed in Figure 3, about the support 14. Adjacent the end of the rod 2 nearest the slider 19, the rod 2 is shaped for interaction with the valve 9 of fluid cylinder 3. The rod 2 contacts and 4 actuates the valve 9 as a result of the rod 2 pivotting upwards in the region of the valve 9, that is anticlockwise as viewed in Figure 3, about the support 14.

The end of the rod 2 nearest the lever 1 is enlarged and is provided with a cam track 100. Inside the housing 7, affixed to and operated by the lever 1, is a cam pin 110 which extends perpendicular to the plane of rotation of the lever 1 into the cam track 100. The cam pin 110 can run back and forth in the cam track 100. The cam track 100 is as wide as the diameter of the cam pin 110 for a proportion of the length of the cam track 100, but at the end "of cam track 100 furthest from the support 14, the cam track 100 widens out to be larger than the diameter of the cam pin, there effectively being a notch in the otherwise linear lower surface of the cam track 100.

The lever 1 is illustrated in Figure 3 in the neutral position, neither valve 9 nor valve 12 being actuated. Movement of the lever 1, and hence the cam pin 110 in the cam track 100, to the right causes the rod 2 to pivot anticlockwise about the support 14. Movement of the lever 1 to the left causes the rod 2 to pivot clockwise about the support 14.

Figure 5 shows the different modes of operation of the lever 1. Figures Saa to 5cc show the lever in the neutral position. In this position the rod actuates neither valve 9 nor valve 12 so that the fluid cylinders 3 and 4 maintain the selected positions of the seat support 6. Figures 5dd to 5ff show the effects of moving the lever 1 to the left as illustrated. The subsequent motion of the cam pin 110 (initially left) in the cam track 100 results in the enlarged end of the rod 2 being forced upwards and the opposite end of the rod 2 being forced downwards. This downwards movement actuates the valve 12, as explained earlier, and thereby frees the fluid cylinder 4, enabling the height of the seat support 6 to be adjusted. Once a suitable height for the seat support 6 has been selected, returning the lever 1 to the neutral position disengages the finger 11 from the valve 12 and so locks the cylinder 4 at the selected height. Figures 59g to 5ii show the effects of moving the lever 1 to the right as illustrated. The subsequent motion of the cam pin 110 (initially right) in the cam track 100 results in the enlarged end of the rod 2 being forced downwards and the opposite end of the rod 2 being forced upwards, so the portion of the rod 2 adjacent the valve 9 engages and actuates the valve 9, thereby freeing the cylinder 3. A seat support 6 inclination is selected, in the same manner as the seat support height is selected, and the lever 1 is returned to the neutral position to lock the seat support 6 at the selected inclination by disengaging the rod 2 from the valve 9.

Reverting back to Figures 2 and 3 and with additional reference to Figure 4, the seat support 6 is mounted on the supports 21 which are each able to rotate around tubular steel sections 22. In between each of the sections 22 is a nylon s h a f t 16. The tubular steel sections 22 act as extensions for the nylon shaft 16 which is received in the bores of both the tubular sections 22. The torsion spring 5 is coiled around the shaft 16, and the tension of the spring 5 can be adjusted by a lever 15 which is controlled by the wheel 8. Rotation of the wheel 8 moves the lever 15 either toward or away from wheel 8.

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Claims

1. Chair apparatus comprising a seat support pivotally mounted on a housing which contains a lever controlled member operating a plurality of fluid cylinders for maintaining a selected height and inclination of the support, at least one spring urging the support into a level position and means for adjusting the force exerted by the spring on the support.

2. Apparatus according to claim 1 wherein the member is controlled by a single lever.

3. Apparatus according to claim 1 or claim 2 wherein movement of the member in a first direction operates a first fluid cylinder and movement of the member in a second direction operates a second fluid cylinder.

4. Apparatus according to claim 3 wherein each of the first and second fluid cylinders has a valve operated by movement of the member in the appropriate direction.

5. Apparatus according to any of claims 1 to 4 wherein the member is a pivotally mounted cranked rod.

6. Apparatus according to any preceding claim wherein the support pivots about a shaft contained by the housing, and the at least one spring is coiled around the shaft.

7. Apparatus according to claim 6 wherein the shaft comprises a plurality of longitudinal sections.

8. Apparatus acording to any preceding claim comprising two springs.

9. Apparatus according to any preceding claim wherein the means for adjusting the force exerted by th spring is controlled by a wheel on the housing.

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10. A chair including apparatus according to any of claims 1 to 9.

11. Apparatus substantially as herein described with reference to figures 1 to 6 of the drawings.

12. A chair substantially as herein described with reference to figures 1 to 6 of the drawings.