Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
A BREAKED CASTOR WHEEL MEANS AND AN OFFICE CHAIR OR A WORK CHAIR
Document Type and Number:
WIPO Patent Application WO/2004/043713
Kind Code:
A1
Abstract:
The present invention relates to a braked castor wheel means (10) comprising a wheel (14) being rotatable around a first shaft member (12), which wheel is provided with a braking member (16) for rotational braking of the wheel (14). Furthermore, the castor wheel means (10) comprises a swivel-braking member (18) arranged at a second shaft member (20), which second shaft member (20) is arranged perpendicular in relation to the first shaft member (12). The wheel (14) is, by means of a bearing member arranged around the second shaft member (20), furthermore swivelly rotatable around the second shaft member (20). The swivel-braking member (18) comprises a first swivel-braking part (18’) arranged in connection with the wheel (14) and a second swivel-braking part (18”) arranged around the second shaft member (20). The first and second swivel-braking parts (18’, 18”) face each other and have a design so that they are locked by means of self-braking on applying a predetermined force by means of a force transmission member (22).

Inventors:
ENGSTROEM BENGT AAKE (SE)
Application Number:
PCT/SE2003/001744
Publication Date:
May 27, 2004
Filing Date:
November 11, 2003
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
RVS EUROFLEX AB (SE)
ENGSTROEM BENGT AAKE (SE)
International Classes:
A47C7/00; B60B33/00; B60B33/02; (IPC1-7): B60B33/02
Foreign References:
US4658466A1987-04-21
US4205413A1980-06-03
US4998320A1991-03-12
DE20016429U12000-12-21
Attorney, Agent or Firm:
Karlsson, Leif (Box 6107, Stockholm, SE)
Download PDF:
Claims:
CLAIMS
1. A braked castor wheel means (10; 70) comprising a wheel (14) being ro tatable around a first shaft member (12), which wheel is provided with a braking member (16) for rotational braking of the wheel (14), which castor wheel means (10; 70) furthermore comprises a swivelbraking member (18; 72) arranged at a second shaft member (20), which second shaft member (20) is arranged perpen dicularly in relation to the first shaft member (12), the wheel (14) by means of a bearing member arranged around the second shaft member (20) furthermore be ing swivelly rotatable around the second shaft member (20), characterized in that the swivelbraking member (18; 72) comprises a first swivelbraking part (18' ; 72') arranged in connection with the wheel (14) and a second swivelbraking part (18" ; 72") arranged around the second shaft member (20), the first and second swivel braking parts (18', 18" ; 72', 72") facing each other and having a design so that they are locked by means of selfbraking on applying a predetermined force by means of a force transmission member (22).
2. A braked castor wheel means (10; 70) according to claim 1, character ized in that the force transmission member (22) consists of a spring (22).
3. A braked castor wheel means (10; 70) according to claim 1 or 2, charac terized in that the first swivelbraking part (18' ; 72') is provided with first teeth (24; 74) and the second swivelbraking part (18" ; 72") is provided with second teeth (26; 76), the first and second teeth (24,26 ; 74,76) at least facing each other on applying the predetermined force.
4. A braked castor wheel means (10) according to claim 3, characterized in that the second swivelbraking part (18") is discshaped and in that the second teeth (26) have a radial extension and are arranged on the second swivelbraking part (18") in a plane substantially perpendicular in relation to the longitudinal direc tion of the second shaft member (20), and in that the first swivelbraking part (18') is disc segmentshaped and in that the first teeth (24) have a radial extension and are arranged on the first swivelbraking part (18') in a plane substantially perpen dicular in relation to the longitudinal direction of the second shaft member (20).
5. A braked castor wheel means (70) according to claim 3, characterized in that the second swivelbraking part (72") is a cogwheel (72") arranged around the second shaft member (20) and in that the second teeth (76) are arranged at the periphery of the second swivelbraking part (72"), and in that the first swivelbrak ing part (72') is discshaped having an extension substantially perpendicular in re lation to the second shaft member (20) and in that the first teeth (74) are arranged at a periphery of an essentially circular recess in the first swivelbraking part (72').
6. A braked castor wheel means (10; 70) according to claim 4 or 5, charac terized in that the first teeth (24; 74) in a plane perpendicular in relation to the ra dial extension thereof have a first crosssection, and in that the second teeth (26; 76) in a plane perpendicular in relation to the radial extension thereof have a sec ond crosssection, the first and the second crosssection being different.
7. A braked castor wheel means (10; 70) according to claim 6, character ized in that the first and the second crosssection are complementary.
8. A braked castor wheel means (10; 70) according to claim 6, character ized in that the first and the second crosssection are essentially complementary.
9. A braked castor wheel means (10; 70) according to claim 8, character ized in that the first and second teeth (24,26 ; 74,76) are selfseeking.
10. A braked castor wheel means (10; 70) according to claim 9, character ized in that at least the first and second teeth (24,26 ; 74,76) have a continuously changing crosssection in a plane perpendicular in relation to the radial extension.
11. A braked castor wheel means (10; 70) according to any one of claims 6 10, characterized in that the first and second teeth (24,26 ; 74,76) alternatingly comprise radial projections and radial recesses.
12. A braked castor wheel means (10; 70) according to claim 7, character ized in that the radial projections of the teeth (24,26 ; 74,76) of the first or second swivel brake part (18', 18" ; 72', 72") have a substantially semicircular crosssec tion having a radius r, and in that the radial recesses comprise a planar surface having a distance d between said projections having a substantially semicircular crosssection.
13. A braked castor wheel means (10; 70) according to claim 11, character ized in that the radial projections of the teeth (24,26 ; 74,76) of the first or second swivelbraking part (18', 18" ; 72', 72") have a substantially semielliptic crosssec tion, and in that the radial recesses comprise a planar surface having a distance d between said projections having a substantially semielliptic crosssection.
14. A braked castor wheel means (10; 70) according to any one of claims 3 13, characterized in that the braking member (16) is arranged at the first swivel brake part (18' ; 72'), and in that the force transmission member (22) furthermore transmits force for braking the braking member (16).
15. A braked castor wheel means (10; 70) according to any one of claims 1 14, characterized in that the braking member (16) for rotational braking of the wheel (14) consists of a brake shoe (16).
16. A braked castor wheel means (10; 70) according to any one of claims 1 15, characterized in that the braked castor wheel means (10; 70) in a unactuated state is braked and locked.
17. An office chair or work chair comprising at least four castor wheel means, characterized in that at least two of said castor wheel means consist of the braked castor wheel means (10; 70) according to any one of claims 116.
18. An office chair or work chair according to claim 17, characterized in that the chair furthermore comprises a regulator connected to a force transmission de vice for actuating the braking member (16) and the swivelbraking member (18; 72) of said at least two braked castor wheel means (10; 70).
19. An office chair or work chair according to claim 18, characterized in that the regulator furthermore comprises a cam curve which holds the castor wheel means (10; 70) in an unbraked state.
20. An office chair or work chair according to claim 19, characterized in that if the regulator is manoeuvred from the unbraked state to the braked state, force is transmitted from the regulator via the force transmission device for energising the spring (22), the swivelbraking parts (18', 18" ; 72', 72") being spaced apart with a predetermined distance.
21. An office chair or work chair according to any one of claims 1820, char acterized in that the force transmission device consists of wires.
Description:
A BREAKED CASTOR WHEEL MEANS AND AN OFFICE CHAIR OR A WORK CHAIR Field of the Invention The present invention relates, according to a first aspect, to a braked cas- tor wheel means.

According to a second aspect, the present invention relates to an office chair or work chair.

Background of the Invention For people having different degrees of a functional disorder, also called "users", so-called work chairs are manufactured. In order for these work chairs to be classified as aids, and thereby be exempted from costs for the user, the work chairs have to, among other things, be equipped with lockable/braked wheels.

Most users only have a limited functional disorder, and therefore the work chairs are normally equipped with two lockable wheels, the'rear ones. However, a smaller group of users need, for different reasons, that all four wheels of the work chair are braked. These reasons may, for instance, be functional disorder, the sur- rounding environment, the nature of the floor and so on.

The brakes on a braked castor wheel act in two ways: - Braking of the rotation of the wheel to such an extent that it exceeds the friction of the stationary wheel against the substrate (at a load of approx.: 25 kg/wheel) - Locking/braking of the so-called"swivel rotation"of the castor wheel.

A braked castor wheel is normally unbraked in an unactuated state and is braked when the mechanism is actuated with force and motion.

The braked castor wheels on the market are fairly equivalent in the con- struction thereof and have a number of built-in problems.

The technical principle that in general is used in braked castor wheels (compare the figures 1-4) requires that a very large force is applied in order to safely lock the so-called swivel brake on the castor wheel.

The large required force implies that in general brake levers are used which act as long levers for bringing down the required force from the user. This means a lever on approx. 400 mm and approx. 45° way.

When the user for some reason needs four braked wheels on the work chair, the required force becomes so large that regulation of the brake is frequently needed by means of an electric motor.

Another disadvantage is that the mounting height on existing wheels is very large. This involves that the chassis of a product where the braked castor wheel should be mounted in many cases becomes unreasonably high, which cre- ates problem, both aesthetically and functionally.

In an urgent situation, the need to brake the castor wheel may arise very fast. The promptness in this activity is made more difficult when either a large force or a long control travel has to be applied to a regulator in this situation.

One of the technical basic problems with existing braked castor wheels is in the design of the teeth in the swivel brake. The used design does not provide any so-called"self-braking", which means that the larger locking effect that is de- sired on the swivel brake, the larger force has to be applied.

Summary of the Invention The present invention aims at solving the above mentioned problems.

This is provided, according to a first aspect, with a braked castor wheel means according to claim 1. The castor wheel means comprises a wheel being ro- tatable around a first shaft member, which wheel is provided with a braking mem- ber for rotational braking of the wheel. The castor wheel means furthermore com- prises a swivel-braking member arranged at a second shaft member, which sec- ond shaft member is arranged perpendicularly in relation to the first shaft member.

The wheel, which by means of a bearing member is arranged around the second shaft member, is furthermore swivelly rotatable around the second shaft member.

The swivel-braking member comprises a first swivel-braking part arranged in con- nection with the wheel and a second swivel-braking part arranged around the sec- ond shaft member, the first and second swivel-braking parts facing each other and having a design so that the same are locked by means of self-braking on applying a predetermined force by means of a force transmission member. With said braked castor wheel means, the advantage is obtained that a lower and controlled force than conventionally is required for simply and efficiently locking the swivel ro- tation of the castor wheel.

In this connection, an advantage is obtained if the force transmission member consists of a spring.

An advantage in this connection is obtained if the first swivel-braking part is provided with first teeth and the second swivel-braking part is provided with sec- ond teeth, the first and second teeth at least facing each other on applying the predetermined force.

In this connection, an advantage is obtained if the second swivel-braking part is disc-shaped and in that the second teeth have a radial extension and are arranged on the second swivel-braking part in a plane substantially perpendicular in relation to the longitudinal direction of the second shaft member, and in that the first swivel-braking part is disc segment-shaped and in that the first teeth have a radial extension and are arranged on the first swivel-braking part in a plane sub- stantially perpendicular in relation to the longitudinal direction of the second shaft member.

According to another embodiment, an advantage is obtained if the second swivel-braking part is a cogwheel arranged around the second shaft member and in that the second teeth are arranged at the periphery of the second swivel-braking part, and in that the first swivel-braking part is disc-shaped having an extension substantially perpendicular in relation to the second shaft member and in that the first teeth are arranged at a periphery of an essentially circular recess in the first swivel-braking part.

An advantage in this connection is obtained if the first teeth in a plane per- pendicular in relation to the radial extension thereof have a first cross-section, and in that the second teeth in a plane perpendicular in relation to the radial extension thereof have a second cross-section, the first and the second cross-section being different.

In this connection, an advantage is obtained if the first and the second cross-section are complementary.

According to another embodiment, an advantage is obtained if the first and the second cross-section are essentially complementary An advantage in this connection is obtained if the first and second teeth are self-seeking.

In this connection, an advantage is obtained if at least the first and second teeth (24,26 ; 74,76) have a continuously changing cross-section in a plane per- pendicular in relation to the radial extension.

An advantage in this connection is obtained if the first and second teeth al- ternatingly comprise radial projections and radial recesses.

In this connection an advantage is obtained if the radial projections of the teeth (24,26 ; 74,76) of the first or second swivel brake part (18', 18" ; 72', 72") have a substantially semi-circular cross-section with a radius r, and in that the ra- dial recesses comprise a planar surface having a distance d between said projec- tions having a substantially semi-circular cross-section.

An advantage in this connection is obtained if the radial projections of the teeth of the first or second swivel-braking part have a substantially semi-elliptic cross-section, and in that the radial recesses comprise a planar surface having a distance d between said projections having a substantially semi-elliptic cross-sec- tion.

In this connection, an advantage is obtained if the braking member is ar- ranged at the first swivel brake part, and in that the force transmission member fur- thermore transmits force for braking the braking member.

An advantage in this connection is obtained if the braking member (16) for rotational braking of the wheel (14) consists of a brake shoe (16).

In this connection, an advantage is obtained if the braked castor wheel means (10; 70) in an unactuated state is braked and locked.

According to a second aspect of the present invention, an office chair or work chair is provided. The office chair or work chair comprises at least four castor wheel means, at least two of said castor wheel means consisting of the braked castor wheel means according to the present invention. With said chair, the advan- tage is obtained that a lower and controlled force than conventionally is required for simply and efficiently locking the swivel rotation of the castor wheel. Another advantage is that the height of the chair is decreased by the mounting height being decreased.

In this connection, an advantage is obtained if the chair furthermore com- prises a regulator connected to a force transmission device for actuating the brak- ing member and the swivel-braking member of said at least two braked castor wheel means.

An advantage in this connection is obtained if the regulator furthermore comprises a cam curve that holds the castor wheel means in an unbraked state.

In this connection, an advantage is obtained if the regulator is manoeuvred from the unbraked state to the braked state, force is transmitted from the regulator via the force transmission device for energising the spring, the swivel-braking parts being spaced apart a predetermined distance.

An advantage in this connection is obtained if the force transmission de- vice consists of wires.

The invention will now be explained closer by the subsequent description of preferred embodiments of the same, reference being made to the accompa- nying drawings.

Brief Description of the Drawings Figure 1 shows a perspective view, partly in cross-section, on a castor wheel means according to prior art; Figure 2 shows an exploded view of the castor wheel means shown in figure 1; Figure 3 shows a perspective view of a first swivel-braking part 58'included in the castor wheel means shown in figure 1; Figure 4 shows a perspective view of the second swivel-braking parts 18" ; 58" included in the castor wheel means shown in figure 1 as well as in the castor wheel means shown in figure 5; Figure 5 shows a perspective view, partly in cross-section, of a first embodi- ment of a castor wheel means according to the present invention; Figure 6 shows an exploded view of the castor wheel means shown in figure 5; Figure 7 shows a perspective view of a first embodiment of a swivel-braking member 18 included in the castor wheel means shown in figure 5; Figure 8 shows a perspective view of a first swivel-braking part 18'included in the swivel-braking member 18 shown in figure 7; Figure 9 shows a perspective view, partly in cross-section, of a second em- bodiment of a castor wheel means according to the present inven- tion;

Figure 10 shows an exploded view of the castor wheel means shown in figure 9; and Figure 11 shows a perspective view of a second embodiment of a swivel-brak- ing member included in the castor wheel means shown in figure 9.

Detailed Description of Embodiments In figure 1, a perspective view, partly in cross-section, is shown of a castor wheel means 50 according to prior art. In figure 2, an exploded view is shown of the castor wheel means 50 shown in figure 1. The castor wheel means 50 accord- ing to prior art comprises a wheel 54 which is rotatable around a first shaft mem- ber 52. Furthermore, the castor wheel means 50 comprises a braking member 56 arranged at the wheel 54 for rotational braking of the wheel 54. The castor wheel means 50 comprises, furthermore, a swivel-braking member 58 arranged at a second shaft member 60. The second shaft member 60 is arranged perpen- dicularly in relation to the first shaft member 52. The wheel 54 may also, by means of a bearing member (not shown) arranged around the second shaft member 60, be swivelly rotatable around the second shaft member 60. The bearing member is arranged under the arrow 51 in figure 1. Furthermore, the castor wheel means 50 comprises a return spring 62 arranged above the bearing member. The castor wheel means 50 furthermore comprises an eccentric 64 for braking force as well as an attachment for brake lever. As is seen in figure 1, the castor wheel means 50 has a mounting height h1.

In figure 3, a perspective view is shown of a first swivel-braking part 58'in- cluded in the castor wheel means 50 according to prior art shown in figure 1. In figure 4 a perspective view is, among other things, shown of the second swivel- braking part 58"included in the castor wheel means 50 according to prior art shown in figure 1. The first swivel-braking part 58'is provided with radially ar- ranged teeth 66. Furthermore, in figure 3 the braking member 56 is seen, in this case a brake shoe 56. At the top of figure 4, the second swivel-braking part 58"is shown provided with radially arranged teeth 66. In this case, the teeth 66 are simi- lar and the angles of action that generally are used (approx.: 45°) do not provide any so-called"self-braking", which means that the greater locking effect that is de- sired on the swivel brake 58, the greater force has to be applied.

In order to decrease the large force required from the user, brake levers that act as long levers are used. A usual dimension is a lever of approx.: 400 mm and approx.: 45° way.

The use of smooth, hidden brake devices, such as for instance wires, and short brake regulators is made impossible by the large required force.

When the user for some reason needs four braked castor wheel means 50 on the work chair, the required force becomes so large that regulation of the brakes by means of an electric motor is frequently required.

The castor wheel means 50 shown in the figures 1 and 2 is normally un- braked in an unactuated state and is braked when the mechanism is actuated with force and motion.

By the use of clumsy brake devices and the location of the return spring 62, the mounting height h1 becomes very large. This means that the chassis of a product where the braked castor wheel means 50 should be mounted becomes unreasonably high. This entails problems, both of an aesthetic and a functional character.

In figure 5, a perspective view, partly in cross-section, is shown of a first embodiment of a castor wheel means 10 according to the present invention. In fig- ure 6, an exploded view is shown of the castor wheel means 10 shown in figure 5.

The castor wheel means 10 comprises a wheel 14 rotatable around a first shaft member 12. The wheel 14 is provided with a braking member 16 for rotational braking of the wheel 14. Furthermore, the castor wheel means 10 comprises a swivel-braking member 18 arranged at a second shaft member 20. As is seen in figure 5, the second shaft member 20 is arranged perpendicularly in relation to the first shaft member 12. By means of a bearing member (not shown) arranged around the second shaft member 20 the wheel 14 is furthermore swivelly rotatable around the second shaft member 20. The bearing member is arranged on a level with the reference designation 8 in figure 5. The castor wheel means 10 comprises furthermore a force transmission member 22 arranged between the wheel 14 and the bearing member. In this case, the force transmission member 22 is a spring 22 and the braking member 16 consists of a brake shoe 16. Furthermore, the castor wheel means 10 comprises an attachment 21 for arrangement for transfer of force and motion, for instance a wire. As is seen in the figures 5 and 6, the swivel-brak- ing member 18 comprises a first swivel-braking part 18'arranged in connection

with the wheel 14 and a second swivel-braking part 18"arranged around the sec- ond shaft member 20.

In figure 7, a perspective view is shown of a first embodiment of a swivel- braking member 18 included in the castor wheel means 10 shown in figure 5. In figure 8, a perspective view is shown of a first swivel-braking part 18'included in the swivel-braking member 18 shown in figure 7. In figure 4, a perspective view is shown of, among other things, a second swivel-braking part 18"included in the swivel-braking member 18 shown in figure 7. As is seen in figure 7, the swivel- braking member 18 comprises a first swivel-braking part 18'provided with first teeth 24 and a second swivel-braking part 18"provided with second teeth 26 ar- ranged around the second shaft member 20 (compare the figures 5 and 6). The first and second teeth 24,26 face each other and have a design so that they be- come self-locking when a predetermined force is applied. The second swivel- braking part 18"is disc-shaped and the second teeth 26 are arranged at the pe- riphery thereof and have a radial extension. In a plane perpendicular in relation to the radial extension of the teeth 24,26, the teeth 24,26 have different cross- sections which are complementary. In figure 4 is seen that the second swivel- braking part 18"comprises teeth 26 which alternatingly comprise radial projections 26 and radial recesses 26'. In the embodiment illustrated, the projections 26 have a substantially semi-circular cross-section with a radius r. The radial recesses 26' comprise a planar surface having a distance d between said projections 26. In fig- ure 8 is seen that the first swivel-braking part 18'comprises teeth 24 which alter- natingly comprise radial projections 24 and radial recesses 24'. The radial projec- tion 24 has a design that is complementary to the radial recess 26'. The radial re- cess 24'has a design that is complementary to the radial projection 26.

According to another embodiment, the radial projections of the teeth of the first or second swivel-braking part 18' ; 18"have a substantially semi-elliptic cross- section. The radial recesses comprise a planar surface having a distance d be- tween said projections By the fact that the teeth 24,26 in the castor wheel means 10 according to the present invention become self-locking, it is possible to simply and efficiently lock the swivel rotation of the castor wheel 14 with a lower, calculated and con- trolled force. The same force is used also for braking the rotation of the wheel 14 in a sufficient degree. The braked castor wheel means 10 is in an unactuated state

braked and locked. When the user desires that the wheel 14 should be possible to rotate, the swivel-braking member 18 is spaced apart approx. 3 mm by means of transmission of force and regulator, the spring 22 being energised. In an urgent situation, a very small force and a very small motion is required in order to brake the wheel 14 again when the requisite braking force is included in the proper cas- tor wheel means 10.

In figure 9, a perspective view, partly in cross-section, is shown of a sec- ond embodiment of a castor wheel means (70) according to the present invention.

In figure 10, an exploded view is shown of the castor wheel means 70 shown in figure 9. The castor wheel means 70 comprises a wheel 14 rotatable around a first shaft member 12. The wheel 14 is provided with a braking member 16 for rota- tional braking of the wheel 14. Furthermore, the castor wheel means 70 comprises a swivel-braking member 72 arranged at a second shaft member 20. As is seen in figure 9, the second shaft member 20 is arranged perpendicularly in relation to the first shaft member 12. By means of a bearing member (not shown) arranged around the second shaft member 20 the wheel 14 is furthermore swivelly rotatable around the second shaft member 20. The bearing member is arranged on a level with the reference designation 8 in figure 9. Furthermore, the castor wheel means 70 comprises a force transmission member 22. In this case, the force transmission member 22 is a spring 22 and the braking member 16 consists of a brake shoe 16.

The castor wheel means 70 comprises furthermore an attachment 21 for arrange- ment for transfer of force and motion, for instance a wire. As is seen in the figures 9 and 10, the swivel-braking member 72 comprises a first swivel-braking part 72' arranged in connection with the wheel 14 and a second swivel-braking part 72"ar- ranged around the second shaft member 20.

In figure 11, a perspective view is shown of a second embodiment of a swivel-braking member 72 included in the castor wheel means 70 shown in figure 9. As is seen in figure 11, the swivel-braking member 72 comprises a first swivel- braking part 72'provided with first teeth 74 and a second swivel-braking part 72" provided with second teeth 76 arranged around the second shaft member 20 (compare the figures 9 and 10). As is seen in figure 11, the second swivel-braking part 72"is a cogwheel 72"and the second teeth 76 are arranged at the periphery of the cogwheel 72". The first swivel-braking part 72'is disc-shaped having an ex- tension substantially perpendicular in relation to the second shaft member 20

(compare the figures 9 and 10). The first teeth 74 are arranged at a periphery of an essentially circular recess in the first swivel-braking part 72'. The teeth 74,76 in the second embodiment of the swivel-braking member 72 may have same design, i. e. cross-section as the teeth 24,26 according to the first embodiment. This means that the teeth 74,76 also become self-locking.

Furthermore, at least the first or the second teeth 24,26 ; 74,76 may have a continuously changing cross-section in a plane perpendicular in relation to the radial extension of the teeth. This ensures that the teeth 24,26 ; 74,76 become self-seeking, i. e. the locking state of the swivel-braking member 18; 72 is attained easier.

According to a second aspect, the present invention relates to an office chair or work chair comprising at least four castor wheel means, at least two of which consist of the braked castor wheel means 10 according to the present in- vention. Furthermore, the chair comprises a regulator connected to a force trans- mission device for actuating the braking member 16 and the swivel-braking mem- ber 18 of said at least two castor wheel means 10. Furthermore, the regulator comprises a cam curve that holds the castor wheel means 10 in an unbraked state.

According to an embodiment of the office chair or work chair, the force transmission device consists of wires.

The decreased required force of the braked castor wheel means 10 also makes it possible to regulate, for instance, four braked wheels 14 from a single manual regulator within the capability of the user. This decreases the need to equip the work chairs with electric motors for this purpose.

It should be pointed out that the braked castor wheel means 10 may be mounted on other products than office chair or work chairs. Other products are, for instance, conveyor tables, operating tables, institutional beds and institutional laundry trolleys.

The invention is not limited to the shown embodiments, but a plurality of variations are feasible within the scope of the accompanying claims.