CHAIR ASSEMBLY, IN PARTICULAR A CHAIR ASSEMBLY FOR USE IN VIRTUAL REALITY DEVICES

Abstract: Chair assembly (1) for use in virtual reality devices, comprising a sub-structure (6) which comprises a stationary bottom frame (7) and situated above it a top frame (8) bearing a chair (2-5), movement means being present between the bottom frame (7) and the top frame (8), in order to make the top frame move relative to the bottom frame, which movement means comprise drive means (11) and a connecting arm (9) of fixed length which interacts hingedly by way of a top hinge axis (10) with the top frame (8) and hingedly by way of a bottom hinge axis (10) with the bottom frame (7), the top hinge axis and the bottom hinge axis extending substantially parallel to each other. The chair (2-5) is tiltably connected to the top frame (8).

Description: Chair assembly, in particular a chair assembly for use in virtual reality devices The invention relates to a chair assembly, in particular a chair assembly for use in virtual reality devices, comprising a substructure which comprises a stationary bottom frame and situated above it a top frame bearing a chair, movement means being present between the bottom frame and the top frame, in order to make the top frame move relative to the bottom frame, which movement means comprise drive means and a connecting arm of fixed length which interacts hingedly by way of a top hinge axis with the top frame and hingedly by way of a bottom hinge axis with the bottom frame. Such a chair assembly is known from US Patent No. 3,628,829. In the case of this chair assembly the two hinge axes are placed perpendicular to each other, so that only tilting movements of the chair are possible. Moreover, these tilting movements are always jolting movements, since the tilting movements occur about a fixed tilting point situated in the centre underneath the chair. A chair placed on the assembly is therefore also provided with spring elements in the top frame, in order to be able to absorb these jolts. The object of the invention is to improve the known chair in such a way that several natural movements to be expected in a virtual reality environment can be imitated therewith substantially without jolts. This object is achieved according to the invention in the case of a chair assembly of the type mentioned in the preamble, by the fact that the top and bottom hinge axes extend substantially parallel to each other. In the case of the chair assembly according to the invention, the top frame can perform not only an upward and downward movement, but also a lateral movement and a tilting movement relative to the bottom frame. Moreover, the movements performed by the top frame relative to the bottom frame will always be smooth, jolt- free movements, and a very uniform rolling motion, for example, can be imitated. It will be clear, however, that jolting movements can also be produced, if necessary. In a practical embodiment, the movement means comprise two connecting arms, the distance between the top hinge axes of the connecting arms differing from the distance between the bottom hinge axes of the connecting arms . With the chair assembly according to this embodi- ment, by choosing the distance between the top hinge axes to be different from that between the bottom hinge axes, a more stable assembly, which can perform movements of a chair present on the assembly in a very reproducible way, can be obtained. The distance between the top hinge axes is preferably less than the distance between the bottom hinge axes. In this embodiment, the substructure of the chair assembly is more stable. The use of two connecting arms of fixed length has the major advantage that the top frame with the chair thereon can undergo a tilting movement and also an upward and downward movement with very accurate control . Although, as will be clear to an expert, the drive means can be selected from many different known drive means, they preferably comprise a linear actuator. In a special embodiment, the top and bottom hinge axes are situated substantially perpendicular to the transverse direction of the chair. In this embodiment, the top frame with the chair can perform a combined lateral and tilting movement relative to the bottom frame. Moreover, the lateral tilting movement and upward and downward movement can be fairly great, since in a to and fro movement it is not easy for the person seated in such a chair to fall out of the chair. In a preferred embodiment, the chair is tiltably connected to the top frame, the tilting movement most preferably occurring in a plane extending substantially parallel to the top and bottom hinge axes. As a result of the combination of the tilting facility of the chair and the movement possibilities of the substructure, a person seated in the chair can be subjected to substantially all movements, varying from tilting, both forwards and backwards and from left to right, but also combined, in combination with upward and downward movements. A major advantage here is that all these movements can occur in a rolling and smooth manner, but jolting movements are possible if necessary. In a practical embodiment, the chair is tiltably supported in two opposite upright parts of the top frame. In this embodiment the tilting axes of the chair can be placed at abdomen level of a user, which counters motion sickness. For performing the tilting movement of the chair relative to the top frame, the chair assembly preferably comprises a linear actuator which is connected between the chair and the substructure . The invention also provides a substructure obviously intended for use with a chair assembly according to the invention. Finally, the invention provides a virtual reality device comprising a chair assembly according to the invention. The invention will be explained in greater detail with reference to figures shown in a drawing, in which: figure 1 shows diagrammatically a perspective view of a chair assembly according to the invention; figure 2 and Figure 3 show a diagrammatic front and side view respectively of the chair assembly of Figure 1; figure 4 corresponds to Figure 3, except that the chair assembly is shown in various positions; figures 5 and 6 correspond to Figure 2, wherein various tilting positions of the chair assembly being shown; and figure 7 relates to an embodiment of the chair assembly according to the invention which differs from that shown in figure 1. Figure 1 shows a preferred variant of an embodiment of a chair assembly 1 according to the invention, comprising a chair with a seat 2, a backrest 3, armrests 4, a leg support 5 and a substructure 6. Said substructure 6 is composed of a stationary, i.e. immobile, bottom frame 7 resting on the ground, and a top frame 8 situated above it. The two frames 7, 8 are fixed to each other by means of four connecting arms 9, which are hingedly supported by means of hinge axes 10 in the corresponding frame 7, 8. The substructure 6 has the shape of a trapezium, so that tilting movements, which will be explained in greater detail below with reference to figures 5 and 6, can be performed by means of a piston/cylinder unit 11 fixed between the two frames 7, 8. The piston/cylinder unit 11 is in particular pneumatically or hydraulically driven. In order to produce an additional tilting movement of the chair in a plane parallel to the hinge axes 10, the chair comprising seat 2, backrest 3, armrests 4 and leg support 5 is swivellably supported in upright parts 12 of the chair frame 8. For this purpose, hinge axes 13 of the parts 12 extend into corresponding holes in the armrest 4. The abovementioned swivelling movement, which is achieved by the same type of piston/cylinder unit 14 as the unit 11, will be explained in greater detail below with reference to figure 4. The abovementioned swivelling or tilting movement in a plane parallel to the hinge axes 10 can be achieved not only by the construction of figure 1, but also by a construction shown in figure 7, which will be described later. Figure 2 and figure 3 show a diagrammatic front and side view respectively of the chair assembly 1 of figure 1, in which parts which correspond to those of figure 1 are indicated by the same reference numbers . Figure 4 corresponds to figure 3, except that tilting or swivelling movements of the chair comprising seat 2, backrest 3, armrests 4 and leg support 5 are also shown by dotted lines. As shown clearly, said swivelling movement is made possible by the piston/cylinder unit 14, i.e. by the piston sliding into and out of the cylinder. Figures 5 and 6 correspond to figure 2 , but in figure 5 the action of the piston/cylinder unit 11 causes a cn necting arms 9 in the bottom frame 7 is greater than that in the intermediate frame 17. In the constructions according to figures 1 and 7 it is important that the mass centre is situated at abdomen level of a user during use of the unit, which counters motion sickness and ensures that the motion envelope relative to the ground is as small as possible. The invention is not limited to the embodiments shown in the figures, but also extends to other variants.

Claims: Claims 1. Chair assembly, in particular a chair assembly for use in virtual reality devices, comprising a substructure which comprises a stationary bottom frame and situated above it a top frame bearing a chair, movement means being present between the bottom frame and the top frame, in order to make the top frame move relative to the bottom frame, which movement means comprise drive means and a connecting arm of fixed length which interacts hingedly by way of a top hinge axis with the top frame and hingedly by way of a bottom hinge axis with the bottom frame, characterized in that the top hinge axis and the bottom hinge axis extend substantially parallel to each other. " 2. Chair assembly according to claim 1, characterized in that the movement means comprise two connecting arms, the distance between the top hinge axes of the connecting arms differing from the distance between the bottom hinge axes of the connecting arms. 3. Chair assembly according to claim 2, characterized in that the distance between the top hinge axes is less than that between the bottom hinge axes. 4. Chair assembly according to one or more of claims 1-3, characterized in that the drive means comprise a linear actuator. 5. Chair assembly according to one or more of claims 1-4, characterized in that the top and bottom hinge axes are situated substantially perpendicular to the transverse direction of the chair. 6. Chair assembly according to one or more of claims 1-5, characterized in that the chair is tiltably connected to the top frame. 7. Chair assembly according to claim 6, characterized in that the chair is tiltable in a direction extending substantially parallel to the top and bottom hinge axes. 8. Chair assembly according to claim 6 or 7, charac- terized in that the chair is tiltably supported in two opposite upright parts of the top frame. 9. Chair assembly according to claim 6, 7 or 8 , characterized in that said chair assembly preferably comprises a linear actuator which is connected between the chair and the substructure. 10. Substructure obviously intended for use in a chair assembly according to one or more of claims 1-9. 11. Virtual reality device comprising a chair assembly according to one or more of claims 1-9.

Inventors: DE LA HAYE FRANS, DE LA HAYE, FRANS
Applicants: HAYE FRANS DE, RPI ADVANCED TECHNOLOGY GROUP, DE LA HAYE, FRANS, RPI ADVANCED TECHNOLOGY GROUP EUROPE B.V.
Application year: 1997
Main classification: A47C3
IPC codes: A47C3, A47C9, A47C15, G09B9