The present invention relates to tables which may be extended.

In certain environments there may be occasional demand for a large table surface, the home being one example of such an environment. The infrequency of such demand, however, particularly when coupled with limited accommodating space, may make the acquisition of a large table impractical. It is therefore desirable to have available a table which, whilst occupying a minimum of space when not in use, may be adapted to provide an extended table top when such is required. While various extendable tables with sliding or drop leaves are well known, there is a need for a table, especially for example a circular table, which can be outwardly extended about its entire periphery.

There is now provided, in accordance with the -present invention, an extendable table comprising a supporting trunk and a table top, wherein the table top comprises a central core and a plurality of adjacent flaps movable from a depending substantially vertical position to a horizontal position in which they form a continuous surface when the table is extended, and wherein at least some of the flaps are tapered and comprise two portions hinged together about a longitudinal axis such that the

flaps may be folded about the axis along their length when lowered to their depending position.

Preferably, each of the flaps is tapered and comprises two tapered portions hinged together. This arrangement allows the flaps to be folded together in substantially concertina-fashion when in the vertical position about a circular central core, each flap itself being hingedly connected to the immediately adjacent flaps.

The flaps are pivotally supported at one end to the central core, about which they pivot through 90° from a horizontal position where they extend radially outwards from ^" the core, combining with the core to provide a substantially planar continuous table surface, to the folded substantially vertical position in which they lie adjacent to the table trunk. When the flaps lie folded in the vertical position a table top of reduced surface area is constituted by the central core alone.

The central core of the table may typically be -circular, although other shapes could be adopted. The flaps are generally individually flared along their length, increasing in width from the end hinged to the central core towards the end which is remote from the core.

Each tapered flat is typically provided on its underside with a bracket, which forms a basis for a three- way attachment, by means of hinges, between the two portions of the flap and the periphery of the table.

The trunk of the table suitably may be a hollow column, for example constructed from aluminium, which is optionally fixed into a base. The trunk preferably houses a mechanism for effecting elevation of the table flaps.

Struts provided underneath the table top support the flaps, each strut being pivotally connected at opposite ends to a flap and member, for example, a collar about the trunk, which is movable vertically of the table trunk to control the raising and lowering of the flaps. The struts radiate outwardly from the trunk and may be operated either manually or by a motor to elevate and lower the table flaps in the manner of an umbrella.

The mechanism housed in the table trunk, for raising and lowering the table flaps, may be adapted for manual or motor driven operation. A mechanism suitable for motor driven operation comprises a vertical screw-threaded shaft driven by a motor and engaged by a nut connected to the collar. The table base suitably may house the motor, -rotation of the shaft causing vertical movement of the collar and, via the struts, elevation of the table flaps. The motor in the table base may conveniently be controlled by a switch on the outside of the base.

An example of a mechanism for manual operation involves the collar being connected, via a system of flexible members and pulleys or wheels housed in the trunk, to a piston which is manually operable to displace the

- A - collar and hence raise or lower the flaps.

The invention will be further described with reference to the accompanying drawings, in which:

Figure 1 is a side elevation of a circular table embodying the invention in extended form;

Figure 2 is a schematic view of the table of Figure 1 when folded;

Figure 3 is a schematic cross-sectional side view of the upper part of the trunk of the table;

Figure 4 is a cross-sectional view of the centre of the table trunk of Figure 3 viewed from underneath;

Figure 5 is a schematic diagram of the arrangement a cantilevered table flaps, and the manner of attachment to the central table core;

Figure 6 is a diagram of the manner of attachment of a table flap to an underlying bracket, a strut and to the central core;

Figure 7 is a side elevation of a second embodiment of table provided with a mechanism for manual operation; and

Figure 8 is a schematic plan sketch of the table illustrated in Figure 7.

Figures 9 and 10 show folded and open views of adjacent flap portions;

Figure 11 shows a universal hinge for use in the hinge arrangement of Figures 9 and 10;

Figure 12 shows the radially outward ends of the adjacent flap portions of a table according to the invention;

Figure 13 shows inducement springs for use with the invention;

Figure 14 is a plan view of a third embodiment of the invention;

Figure 15 is a sectional view taken on X-X in Figure 14; and.

Figure 16 is a side elevation of the seating element shown in Figure 15.

Referring to Figure l, the table consists of a trunk 10 which is a hollow column supported by a base 12 and surmounted by a substantially planar table top 16. The table top comprises adjacently positioned tapered flaps , or leaves, 18 pivoted by hinges to a central core (not shown) and supported on their undersides by struts 14 which radiate from a collar 20 encircling the trunk 10. The -edges of adjacent flaps 18 are hinged together so as to allow the flaps to collapse together during folding of the table. The manner of hinging will be described below. In one embodiment of the invention the base 12 houses a motor (not visible in Figure 1) for extending and lowering the table. The base may comprise further motors for giving the table mobility.

In Figure 2, the table is shown in folded position. The flaps 10 are folded down about hinges 22 (shown in Figure 1) such that they extend substantially vertically

downwardly with the ends of the flaps which are remote from the central core 24 of the table being adjacent to the base 12. A drive shaft 26 with a two start helical thread 28, is positioned inside the trunk 10 which, when rotatably driven by a reversible motor housed in the base 12, provides the vertical drive necessary to elevate or lower the table flaps 18.

While a reversible motor is preferred, as providing the simpler structure, instead a single direction motor could be utilised with a reversible drive mechanism coupling it with the shaft. Preferably, power means are provided for moving the table and these could comprise two reversible motors driving respective ground engaging wheels with the table itself being supported by the two ground engaging wheels and a castor, the wheels and the castor being approximately equiangularly spaced adjacent the periphery of the base of the table. Conveniently, a remote control device, for example infrared operated, can be -utilised to control all three motors with the direction of movement of the table being controlled by the relative directions of rotation of the two wheel drive motors. By incorporating a variable speed control also, the table can readily be moved from a position of storage, for example adjacent a wall, to the position of use and then be extended, without requiring any physical exertion by the user. Suitably, the motors will be powered by a self-

contained power system, including rechargeable batteries.

The construction of the drive shaft 26 is shown in more detail in Figure 3. The shaft 26 is housed inside the table trunk 10 and mounted in bearings at its opposite ends. Its upper end is shown carried by a bearing 31 secured to the table top 16. A nut 40 is threaded at 42 to the shaft 26 and has three radially outwardly extending cantilevered arms 44, which are secured by bolts 46 to an inner collar 34 which is itself assembled with an outer collar 36 by bolts 38. The outer collar is attached to a plurality of flap raising struts 14 by a means 15 which will be described in connection with Figure 4.

Preferably, means are provided for counter¬ balancing, raising and lowering of the table and such means are illustrated in Figure 3 as comprising an adjustable spring tape sash balance 60 recessed into the table top 16 and secured by screws 70 to the upper end of the column and also by bolts and collars 62 to the underside of the -central portion of the table top. The inner collar ,34 is provided with hooks 64 which engage a member 66 attached to the lower end of sash tape 68 so that when the flaps are lowered downward movement of the collar is resisted by the spring action of the spring tape sash balance with the action of the balance assisting to lift the collar against the weight of the table flaps during raising of the table flaps. Suitably, a pair of such spring tape sash balances

may be provided, mounted on diametrically opposite sides of the column, although more preferably three sash balances are provided equiangularly spaced about the table axis.

Referring to Figure 4, the three cantilevered journal arms 44 are drilled for six detent units with bullet or ball catches, which are spring loaded to engage detent recesses and the'reby locate the collar at a height corresponding w.ith the table being properly extended. Similar detent recesses may be provided to locate the collar when the flaps are fully collapsed. Six bolts 38 couple the inner collar 34 with the outer collar 36. The hollow column of the table trunk 10 is provided with slots 11 through which the cantilevered arms 44 project.

T-section units 35, typically of aluminum, provide the means (denoted 15 in Figure 3) of attaching the flap raising table struts 14 to the outer collar 36 by means of suitable pivot pins or bolts.

Referring now to Figure 5, a flap 18 is attached to -the central core 24 of the table top by means of a hinge 23. Two hingedly connected adjacent flaps 17 and 19 are included in the Figure, which shows the division of a single flap into two portions 54 and 55 which are hinged along the length of the flap by a hinge 56. A bracket 50 runs beneath the hinge 56 and is shown more clearly in Figure 6. The bracket 50 is hinged to the same hinge pin as the hinge 56 connecting the flap portions.

Figure 6 shows the radially inward end of a flap 18 supported by the underlying bracket 50 due to the common hinge pin connecting the bracket and the two flap portions. The bracket 50 is connected by a hinge 22 to the central core 24. The strut 14 extending from a collar 36 encircling the trunk has its outer end pivotally attached to the bracket 50. As 'can be seen from Figures 5 and 6, the inner end of the bracket 50 is received between flanges of two angle brackets 23, the other flanges of which are secured to the part 53 of the hinge 22.

The bracket 50 thus lies beneath a line dividing the two portions of the flap 18, the bracket being hinged to both portions as shown in Figure 5 as well as to the central core 24. Also shown are seating elements 25a-d which, when the table is extended, support the inward corners of the flap portions which are not supported directly by the underlying bracket 50.

The embodiment of the invention shown schematically in Figure 7 has a trunk 10 having a piston 13 which is connected via flexible members in the form of thin steel cables 21 entrained around a pulley 25, mounted on the underside of the central core 24 of the table, to a sleeve 27. Journalled to the sleeve are the struts 14 attached to table flaps 18. The piston is operated from above by means of a removable push rod 29, which is pushed down through an aperture in the central part 24 of the table to raise the

table flaps. The weight of the piston itself may be used to counterbalance the weight of the flaps during opening and closing of the table. Locking means, for example a simple detent engaged by rotation of the push rod 29 or a releasable spring detent, are provided to retain the rod 29 in its inserted position to keep the table extended. The table of Figure 7 is shown in plan in Figure 8, which illustrates the relative positioning of three pulleys 25 mounted underneath the central core 24, from which the adjacent tapered flaps 18 radiate.

Figures 9 and 10 show a hinging arrangement between two adjacent flaps. Two hinges 60, 61 are shown, which define an axis 63 between them. The flap portions rotate about the axis as the table is folded down. This axis also rotates downwardly. In the extended portion of the table this axis is inclined downwardly and inwardly from the periphery of the flat table top.

Only one hinge is strictly necessary between two -adjacent flap portions, and this may preferably be a hinge 61 of the universal type i.e. a ball and socket hinge. It is preferable that this hinge is provided on or near the plane of the table, and disposed towards the radially outermost portion of the joint between adjacent flaps. With a single hinge between each pair of adjacent flap portions, these are constrained into regular lowered positions as well as their flat positions when the table is

extended. Inducement springs 70 are preferably provided between the two portions of one flap, so as to induce the flaps to fold about the axis of the underlying bracket so when they are lowered, as shown in Figures 12 and 13. As shown at Figure 12, dowel and socket arrangements 65 may be provided in adjacent edges of adjacent flap portions so as to locate them positively with respect to one another in the extended position of the table top. Alternatively, a tongue-and-groove arrangement may be used to locate adjacent flaps with respect to one another.

When two hinges are provided between a pair of flap portions, these define an axis 63 about which the flaps rotate during lowering or extension of the table. This axis itself is lowered or extended towards or away from the table centre at the same time as the flaps themselves rotate. At all times, the axis between two adjacent flap portions is positioned substantially at the intersection of two planes which are respectively perpendicular to the flap -portions and which pass through the adjacent edges of the flap portions. The second, inner hinge may thus be positioned once the position of the first, outer hinge is known.

For convenience, both inner and outer hinges may be in the form of universal hinges, as shown in Figures 9 and 10, so that they are tolerant of mis-alignments arising during manufacture. More than two universal hinges may be

provided on the axis 63. It is possible nevertheless for these to be plain axial hinges aligned along the axis previously defined.

Preferably, as shown in Figures 9 and 10, the hinges are ball and socket hinges. More preferably, the outer hinges-are let into recesses 66 in the underside of the flaps so that they 'are close to the surface of the table. Some chamfering of the adjacent underside edges of the flaps may be necessary to give the required clearance for the flaps to be able to rotate about the hinge or hinge axis. The bodies of the outer hinges may also be partially recessed into the under surface of the table.

The inner hinges are in the form of a ball and socket joint, mounted so that the centre of rotation defined by the joint falls substantially on the axis of hinging previously defined. They may be provided with stops 62a and 62b on their mountings to prevent over- rotation of the flap portions beyond their horizontal -position when extended. This stop is in addition to the support provided by the seating elements 25 (a-d) provided adjacent the inward end of each of the flap portions.

In an alternative embodiment of the invention, where only one hinge 61 is provided between each pair of flaps, further seating may be provided between the flap portions of each flap and the underlying bracket. This is in addition to the seating 25 (a,b,c) provided at the

central core.

As shown at Figures 14 to 16, the further seating 71 (a - d) is shown attached between respective flap portions 50, 55, 57. These are arranged so that as the flaps are extended towards their flat position, and rotate downwardly about the brackets, the seatings contact the underlying bracket 50 and support the flap portions in their correct, flat position. The seatings may also be mounted on the underlying bracket, so that the flap portions rotate down towards the upper surfaces of the seatings (71a, b) so as to be supported. Care has to be taken so that the seatings beneath adjacent flap portions of adjacent flaps do not obstruct each other when the table is in the folded position. This may be achieved either by making the size of the seatings sufficiently small for them not to interfere when the table is folded, or by positioning the seatings of opposing faces of adjacent flap portions or brackets at different radial distances from the centre of the table, so that they may overlap when the table is folded.

Figures 14, 15 also show the provision of sleeve inserts 75 in the flaps, the sleeve material being lubricious, so as to ease the rotation of the flap portions about their respective pins. A respective sleeve insert segment may be provided for each of the tabs of the flap portions and bracket which form the hinge. Suitable materials for the sleeve include PTFE, or impregnated fibre compacts.