The present invention relates to a table with a table bed provided at its periphery with an upright strike edge with a height adapted for rebound of balls of a predetermined diameter which roll over the table bed. Such tables are hereby adapted for the purpose of playing ball games on the table bed. Examples of such tables are snooker tables, pool tables and billiard tables.

It is known in the case of such tables to heat the table bed. The table bed is typically heated over its whole surface area to a temperature between 25° and 30°C. A table is alternatively heated to a temperature X degrees above the ambient temperature, wherein X typically lies between 2 and 15 degrees. This is done mainly for professional and semi-professional players. The reason for this is that players are under the impression that the uniformity of play is considerably higher when the table bed is heated. Uniformity of play relates here to the way in which balls roll and collide on the table. Moisture content of the table bed, more particularly of the textile which forms part of the table bed, has a particularly noticeable influence on the deceleration which the ball undergoes as the ball rolls over the table bed. A more uniform moisture content of the table bed is obtained by heating the table bed.

A drawback of such tables with heated table bed is that these tables considerably heat the space in which the table is located. This heating is unpleasant for the players and these spaces are then provided in practice with air conditioning which cools the ambient temperature in the space. Energy is thus expended at the table position to heat the table bed in order to achieve a greater uniformity of play, and the air conditioning is simultaneously used to cool the space. These two systems counteract each other, which is unnecessarily wasteful of energy.

It is an object of the invention to provide a table which allows a great uniformity of play and which generates less heat.

The invention provides for this purpose a table with a table bed provided at its periphery with an upright strike edge with a height adapted for rebound of balls of a predetermined diameter which roll over the table bed, wherein the strike edge is provided with heating means for heating the upright strike edge, which heating means are positioned in the table at a height above the table bed.

Tests have shown that heating the strike edges has an unexpectedly positive effect on the uniformity of play. In the table according to the invention heating means are therefore provided in the strike edge, i.e. at a height above the table bed. The table according to the invention is hereby distinguished from known billiard tables and snooker tables with heating elements mounted under the table bed. Because the heating means are mounted in the strike edge at a height above the table bed, these heating means will heat only the strike edge and no longer the whole table bed. The overall volume of material which is heated in order to achieve a greater uniformity of play is hereby appreciably smaller than if the whole table bed were heated. Great uniformity of play can hereby be obtained in a considerably more energy-efficient manner with the table according to the invention. The moisture content of the textile at the position of the strike edge is controlled by heating the strike edge. The moisture content of the textile at the position of the strike edge has a great influence on the coefficient of friction between ball and strike edge when the ball collides with the strike edge. The moisture content of the textile at the position of the strike edge hereby determines the angle at which the ball rebounds.

The upright strike edge preferably further has a temperature sensor for measuring the temperature of the strike edge. By measuring the temperature of the strike edge with a temperature sensor the heating means can be controlled in an intelligent manner to keep the strike edge at a predetermined temperature. For this purpose the temperature sensor is preferably operatively connected to the heating means and provided with a controller to keep the strike edge at a substantially constant and predetermined temperature. Because the temperature can be set and is controlled via the temperature sensor and the controller, the game experience can be made more uniform in energy-efficient manner.

The upright strike edge preferably has a plurality of segments, each provided with heating means. Each segment is preferably also provided here with a separate temperature sensor. The temperature sensor of each segment is more preferably operatively connected to the heating means of the respective segment via the controller in order to keep each segment of the strike edge at a predetermined temperature. Tests have shown that the temperature of a strike edge can depend greatly on the position of the table in the surrounding area. A table placed adjacently of a window through which the sun shines has a strike edge lying close to the window which is typically warmer than the strike edge lying furthest removed from the window. In another situation a table can be placed in a space where there is a draught, wherein the segment of the strike edge in the draught has a considerably lower temperature than another segment not in the draught. By providing different segments with different heating means and respective temperature sensors the temperature of each segment can be controlled such that the strike edge has substantially the same temperature over the whole periphery of the table irrespective of external influences. Great uniformity of play is hereby improved considerably for tables which are not placed in a uniformly conditioned environment.

The table bed is preferably rectangular and a segment of the strike edge is formed by a straight side or a portion of a straight side of the table. The table hereby has at least four segments, each with a temperature sensor and a heating means, such that the four segments can be set to the same temperature. The temperature of each straight side of the table is individually controllable here. When the table is in the form of a snooker or pool table, each longitudinal side is typically provided with a hole in the strike edge. In such a table each straight longitudinal side will comprise two segments, one on either side of the hole, so that the table comprises a total of six segments.

The heating means are preferably formed by an electrical resistor. An electrical resistor can be monitored and controlled in simple manner by a controller. An electrical resistor is also easily built into a strike edge of the table.

The upright strike edge preferably comprises a main frame provided with a finishing layer, wherein a cushion directed toward a centre of the table is further attached to the main frame. The cushion is preferably formed here from a resilient material. The heating means are preferably positioned between the main frame and the cushion. Tests have shown that the temperature of the cushion has a great influence on the resilience of the cushion, and consequently on the way in which a ball rebounds from the cushion after colliding therewith. By mounting the heating means between the main frame and the cushion the heating means lie close to the cushion, whereby the effect of the heating by means of the heating means has a direct influence on the temperature of the cushion. The uniformity of play can hereby be enhanced in a highly energy-efficient manner.

The table bed is preferably provided with table bed heating means positioned under the table bed and controllable independently of the heating means. Table bed and strike edges can be heated to different temperatures by providing table bed heating means under the table bed in addition to the heating means in the cushion and by making the table bed heating means controllable independently of the heating means. The temperature of the cushion can be considerably higher here than the temperature of the table bed. A uniform moisture content of the table bed is obtained by heating the table bed. Tests here have surprisingly shown that it is in many situations unnecessary to heat the table bed greatly. A temperature of the table bed several degrees above the ambient temperature will be sufficient to control the moisture content of the table bed and thereby increase the uniformity of play. The strike edges can then be heated to a higher temperature, for instance a temperature several degrees higher than the temperature of the table bed. These strike edges have a relatively low mass and relatively small surface area however, at least compared to the table bed, whereby the influence of this heating on the surrounding area is minimal.

The table bed is preferably formed as a stone slab and a textile is stretched over the table bed and at least a portion of the strike edge. The table is more preferably chosen from a billiard table, a snooker table and a pool table, the table is more preferably a billiard table. It is important in billiard tables that the ball collides with the strike edges in a predictable and uniform manner. The invention is therefore highly suitable for billiard tables.

The invention will now be further described on the basis of an exemplary embodiment shown in the drawing.

In the drawing:

figure 1 shows a table suitable for application of the invention; figure 2 shows a cross-section of an edge of the table in which an embodiment of the invention is applied;

figure 3 shows a schematic top view of a table in which the invention according to a further embodiment is applied.

The same or similar elements are designated in the drawing with the same reference numerals.

Figure 1 shows a table 1 with a table bed 2. Table bed 2 is provided at its peripheral edges with an upright strike edge 3. This strike edge 3 is provided so that balls with predetermined properties, which roll over table bed 2, rebound when the balls collide with strike edge 3. Strike edge 3 is optionally provided here with openings at the corners of table 1 and at the centre of the longitudinal sides of table 2, which openings are provided to allow passage of the balls with predetermined properties. Such tables are generally billiard tables, pool tables, carom tables and snooker tables.

Figure 2 shows a schematic section of table 1 at the position of an upright edge 3 of table 1, wherein several elements of a preferred embodiment of table 1 are illustrated. Figure 2 thus shows how strike edge 3 comprises a base body 5 which is provided on an inner side of a strike edge 3 with a cushion 4. The inner side of strike edge 3 is defined here as the side of the strike edge situated to the side of table bed 2. Cushion 4 is preferably manufactured from an elastic material such as rubber such that cushion 4 displays predetermined elastic properties. A ball which collides with cushion 4 will hereby rebound from cushion 4 in a predictable manner. This behaviour of cushion 4 forms the basis for playing ball games on table 1. A finishing layer 16 which determines the visual impression of strike edge 3 can further be provided on base body 5. A further aspect which influences the rebound of the ball which collides with a cushion 4 is the moisture content of the textile 9 typically stretched over cushion 4. This moisture content influences the coefficient of friction between ball and cushion 4.

Strike edge 3 is formed on the inner side such that strike edge 3 at least partially overhangs table bed 2. This is illustrated in figure 2, is generally known and is often applied in such tables 1. The point of strike edge 3 which projects furthest is always formed here by cushion 4, and is typically positioned at a height from table bed 2 which is substantially equal to the radius of the balls with predetermined properties. A ball which, rolling over table bed 2, collides with cushion 4 will thus rebound substantially parallel to the table bed. As a result the ball will not have any noticeable tendency to shoot upward or be pressed downward when rebounding.

Table bed 2 is typically formed by a stone or slate 11. Any material with a great hardness and a great stiffness, in other words with a hardness and a stiffness functionally similar to those of stone or slate, can theoretically be used as table bed 11. A cloth 9 is then typically stretched over this bed 11 , which cloth 9 is also stretched over at least a portion of the inner side of the strike edge. Figure 2 shows an embodiment wherein strike edge 3 is provided with a groove 8 in which cloth 9 can be fixed. The cloth can be secured at the position of connection 10 between strike edge 3 and table bed 2 by means of known techniques. Cloth 9 can for instance be clamped between bed 11 and base body 5 in order to thus stretch cloth 9. Cloth 9, which is shown as being integrally formed in the figure, alternatively consists of a plurality of pieces, wherein a first piece is stretched over bed 11 and wherein a second piece is stretched over at least a portion of strike edge 3. The skilled person will be familiar with techniques for stretching cloth 9, and this cloth 9 is therefore shown only schematically in the figure.

Figure 2 shows how strike edge 3 is provided with a heating element 6. Heating element 6 is positioned at a height above table bed 2 in table 1. The primary objective of the heating element here is to heat strike edge 3. Heating element 6 is preferably placed between cushion 4 and base body 5 of strike edge 3. When the heating element is active, heating element 6 will heat cushion 4 as well as at least a portion of base body 5 of strike edge 3. Tests have shown that the temperature of cushion 4 has a surprisingly great influence on the elastic properties of cushion 4. As a result the temperature of cushion 4 has a great influence on the rebound properties when a ball collides with cushion 4. In order to achieve a great uniformity of play the rebound properties are preferably as constant as possible. This means that the temperature of the cushion 4 in particular must be as constant as possible over the whole periphery of table 1. Heating element 6 is therefore preferably elongate and heating element 6 preferably extends over substantially the whole periphery of table 1. As a result the temperature of cushion 4 can be influenced over the whole periphery of table 1 by heating element 6. Strike edge 3 is preferably provided here with at least one temperature sensor 7 to measure the temperature of the strike edge. This temperature sensor 7 can be placed at multiple positions (also referred to as transverse position) as seen in cross-section of strike edge 3 and is preferably provided close to cushion 4. Placing a temperature sensor 7 enables heating element 6 to be controlled in intelligent manner by a controller (see figure 3) to a predetermined temperature. Strike edge 3 is for instance heated to a predetermined temperature which is defined in relation to an ambient temperature and is preferably more than 3°C higher, more preferably more than 5°C higher and most preferably more than 7°C higher, preferably less than 20°C higher, more preferably less than 15°C higher than the ambient temperature. The table is preferably provided with an ambient temperature sensor (not shown) which is operatively connected to controller 12 (see figure 3) such that the heating means can be controlled dynamically in relation to the ambient temperature.

The elongate heating element 6 is preferably provided in a plurality of segments. One temperature sensor 7 is most preferably provided here for each segment. By segmenting the heating elements and providing respective temperature sensors the strike edge 3 can be set to one predetermined temperature irrespective of external temperature influences. Examples have been described above of environments which have an influence on the temperature of strike edges 3, which influences can be compensated by the segmented heating element 6.

Figure 3 shows an example of a table 1 provided with a heating element 6 in four segments 61, 62, 63 and 64. In the example each straight side of the table is provided with a segment. Each straight side of the table is further provided with a separate or unique temperature sensor 71, 72, 73 and 74. Each of the segments of heating element 6 and each of the temperature sensors is connected to a controller 12. The controller is provided for the purpose of controlling the heating element segments 61, 62, 63, 64 on the basis of the respective temperature measurements by temperature sensor 71, 72, 73 and 74. Controller 12 can be operatively connected to input means (not shown) which enable a user via the input means to set a predetermined temperature for strike edge 3, or to set a temperature defined in relation to the ambient temperature.

Further heating means 13 are preferably placed under table bed 2. These further heating means 13 are intended primarily to heat table bed 2. Further heating means 13 (table bed 2) are controllable here separately of heating means 6 (strike edge 3). Further temperature sensors (not shown) can be placed on table bed 2 in order to measure the temperature of the table bed. Further heating means 13 can thus be adjusted with controller 12 to a predetermined temperature or to a temperature defined in relation to the ambient temperature.

Controller 12 is preferably provided for the purpose of adjusting the temperature of strike edges 3 via heating element 6 to a first predetermined temperature which can be absolute or relative, and controller 12 is provided for the purpose of adjusting the temperature of table bed 2 via further heating means 13 to a second predetermined temperature, wherein the first

predetermined temperature is higher than the second predetermined temperature. The first predetermined temperature is preferably appreciably higher than the second predetermined temperature. Appreciably higher is defined here as a minimum of 2 degrees higher, preferably a minimum of 4 degrees higher, more preferably about 5 degrees higher.

Controller 12 is preferably provided for the purpose of setting the second predetermined temperature (temperature of table bed 2) to roughly the ambient temperature or to a maximum of several degrees above the ambient temperature. This generally does achieve the effect that the table bed has a uniform moisture content and is pleasant to play on, but that table bed 2 is prevented from heating the surrounding area to any appreciable extent. Because the first predetermined temperature, being the temperature of strike edges 3, preferably lies appreciably higher than table bed temperature 2, cushion 4 can be brought to a constant temperature along the periphery of table 1 in simple manner. A great uniformity of play is hereby obtained, this being greatly valued by professional and semi-professional players in particular. Strike edges 3 are then heated to a temperature which does lie appreciably above the ambient temperature, but the influence thereof on the surrounding area will be minimal because strike edges 3 have a small mass or surface area (at least compared to the table bed).

Figure 3 shows one temperature sensor per segment of heating element 6. Temperature sensor 71 is here placed substantially centrally in the longitudinal direction of strike edge 31, while temperature sensor 72 is placed substantially on a side in the longitudinal direction of strike edge 32. This is to illustrate that the temperature sensor can be placed at a plurality of lengthwise positions without departing from the principles of the invention. It is noted in this context that it is also possible to place a plurality of temperature sensors per heating element segment. A plurality of heating element segments can alternatively also be placed per temperature sensor. The temperature sensors are preferably chosen so as to perform an optimal temperature measurement within a temperature range of between 15°C and 50°C.

Heating element 6 can be technically implemented in different ways. Heating element 6 is preferably formed by an electrical resistor. An electrical resistor 6 is inexpensive and easily built into a strike edge 3. An electrical resistor 6 can further be controlled easily by a controller. The heating element can alternatively also be formed by liquid channels, wherein liquid at a predetermined temperature can flow through determined channels so as to thus influence the temperature of strike edge 3.

According to an alternative embodiment of the invention (not shown), heating element 6 is formed as a heat-conducting element, wherein the heat source is placed at a distance from heat- conducting element 6. It is theoretically possible here to position the heat source at a height below the table bed but, because the heat is conducted to cushion 4 by means of a heat-conducting material arranged specially for the purpose in strike edge 3, such a configuration will still be deemed a configuration wherein heating element 6 is placed above the table bed. This is because the definition of the position, above the table bed, relates to the location where the heat fulfills its function, i.e. close to cushion 4.

It will be apparent to the skilled person that the invention can be applied to billiard tables, snooker tables, carom tables or pool tables. The above description and accompanying figures serve only to illustrate several embodiments of the invention and are not intended to limit the invention. The scope of protection will therefore be defined solely in the claims.