GB2142547A

GB2142547A - Simulated slate bed for a billiard table

Info

Publication number: GB2142547A
Application number: GB08311644A
Authority: GB
Inventors: William Henry Burrell
Original assignee: Goodyear Tire and Rubber Co
Current assignee: Goodyear Tire and Rubber Co
Priority date: 1983-04-28
Filing date: 1983-04-28
Publication date: 1985-01-23
Also published as: GB8311644D0; GB2142547B

Abstract

The table includes a bed composed of a compression moulded cured blend of a thermoset resin and a silicious aggregate having particles of .01 to 5 millimeters in size. The aggregate is sand and/or pumice and the resin examples are phenol aldehydes, resorcinol-urea, and resorcinol-formaldehyde. A curative such as hexamethylenetetramine can be used and methods of manufacture are disclosed.

Description

SPECIFICATION A simulated slate and like material for a playing or gaming table and method of manufacture This invention relates to improvements in the manufacture of snooker tables, billiard tables and pool tables and the like playing or gaming tables or boards and particuiarly to the construction of the bed or bed plate.

More particularly, this invention relates to a synthetic compressed thermostat resin filled silicious aggregate or simulated slate plate and to the method of making the same, viz a simulated slate like product.

Playing or gaming tables such as snooker, billiard and pool tables, used privately or commercially, are well known and used in the sport and business field. Usually the playing surface plate or bed upon which the game is executed is taught to be made of metal, laminated wood, reinforced concrete to mention only a few of the materials taught, but the preferred playing surface material is made of natural slate with Italian slate being considered to be the most preferred. Natural slate is relatively expensive and its weight is a disadvantage. Also slate requires extensive sanding and polishing to give the desired and required smooth surface to be covered with the table cloth or felt to yield the desired playing surface.

The nature of this invention and its advantages are best understood by reference to the drawing where the Figure is a vertical longitudinal section through a table such as a billiard table without the legs being shown.

In the construction shown in the Figure, the bed plate 1 is mounted in a frame 2 which may be of wood or a metal and a support 4, preferably of a metal may be fastened to the bed plate 1 by screws 3 or other means.

The frame 6, carrying the cushion means 9, is secured to the support by suitable means, for instance screws 5. Further a frame 7 preferably of wood is fixed to the frame 2 and serves for securing the cloth. The structure just described is enclosed by an outer frame 8. The nature of this invention is still better understood and illustrated by the following description of the bed plate 1 where the plate may be a uniform structure or a laminate of at least two or more layers with two layers being preferred. The bed plate 1 preferably is a single molded sheet of from 0.6 centimeters to 2.0 centimeters thickness and of sufficient width and length to fill the frame.The bed plate is made by molding under pressure a silicious aggregate, preferably .01 to 5 millimeters in a diameter such as fine sand and/or pumice mixed with a thermosetting resin, such as phenol aldehyde resins and preferably phenol-formaldehyde resin to give a simulated plate like material compacted to a specific gravity of 1.2 to 1.8. Chopped fibers having lengths 3 to 30 mm may optionally be added to the mixture at levels up to 15 parts by weight based on 100 parts of aggregate. The chopped fibers may be made from fiber glass, aramid, carbon, synthetic textile fibers or yarns. In the following examples all the parts and percentages are by weight unless otherwise stated.

Example 1 A series of mixtures may be made by dry blending a hundred parts of very fine sand, preferably 80% passes a 200 mesh screen, with 10, 15, 20 and 40 parts of thermosetting resins. Examples of these resins are phenol aldehyde resins, such as phenol-formaldehyde resin available as SG-3110 with a melting point of 90"C from Schenectady Strode-Midland, Limited or resorcinol-urea resins or resorcinol-formaldehyde resins, especially the well-known novolak resins. These dry blends may be compacted between the plates of a platten press at a pressure of 100 to 700 pounds per square inch and a temperature of 140 to 220"C for several minutes, usually 3 to 45 minutes to yield a simulated slate.It is desirable that the pressure be sufficient to compress the thickness of the dry blend by at least 5% and up to 60% to get the simulated slate of the desired thickness and strength, with preferred thickness of .5 to 5.0 cm for plate 1. Particularly desired are the phenol-formaldehyde or resorcinol-formaldehyde resins which have incorporated in the blend 8 to 14% of hexamethylenetetramine paraformaldehyde or other well known curatives based on the resin.

Example 2 A blend of 100 parts of parts of fine sand and 15 parts of resin, SG 3110 melting point 90"C and 8-14% hexamethylenetetramine was placed in a platten press 100 mm x 150 mm to give a layer 0.1 to 0.6 cm thick and then covered with a layer of a blend of a 100 parts of pumice ground to 0.5 to 5 mm in diameter and 15 parts of resin SG 3110 melting point 90"C and 8-14% hexamethylenetetramine which was applied to give a thickness of 1.3 cm. The press was closed and the layers were pressed and cured for 7 minutes at 160"C and 400 pounds per square inch pressure to give a simulated slate approximately 1.3 cm thick having a satisfactory hardness and moisture resistance.This simulated slate was tested by the ASTM D 790 method from 1979 Edition, part 35, section PH325, as shown in Table I which compares it with natural slate. It should be noted that the natural slate test sheet had a thickness of 19 mm while the simulated slate test sheet thickness was only 13 mm. The flexural strength value in the table for natural slate has been converted to show the prorated value for a 13 mm sheet in accordance with the flexural strength equation of the test method as set forth in the footnote to the table.

TABLE I Tests Simulated Slate Natural Slate Compression strength, Newtons 1320 2774 Deflection at break, mm 0.56 0.56 Flexural strength, megapascals 18.3 38.6 *This Figure represents the calculated value for a 13 mm thickness (d) sheet of natural slate by using the actual test value from the 19 mm sheet and substituting into the ASTM D-790 test method equation: Flexural strength=3 P.U2Bd3.

While certain representative embodiments of the invention have been set forth in the examples, Figures and description, it will be readily apparent to one skilled in this art various that changes and modifications may be made therein and may be described in differing language without departing from the scope of this invention.

Claims

1. A playing or gaming table including a bed plate composed of compression molded cured mixture of a thermoset resin and a silicious aggregate having a particle size of 0.01 to 5 millimeters in diameter.

2. The table of claim 1 wherein the thermoset resin is a phenol-aldehyde resin which is composed of 10 to 40 parts per hundered of the silicious aggregate.

3. The table of claim 2 wherein the phenol aldehyde resin is a phenol-formaldehyde resin.

4. The table of claim 1 wherein the plate is composed of a molded cured mixture of a phenol-aldehyde and a silicious aggregate, said aggregate being pumice.

5. The table of claim 1 wherein the plate is composed of a molded cured mixture of a phenol-aldehyde and a silicious aggregate, said aggregate being fine sand.

6. A laminate composed of a layer of phenol-aldehyde resin mixed with sand and a layer of phenol-aldehyde resin mixed with pumice.

7. The laminate of claim 6 composed of a layer of phenol-formaldehyde resin and sand and a layer of phenol-formaldehyde resin and a layer of phenol-formaldehyde resin and pumice.

8. The laminate of claim 1 wherein the thickness of the layers of the laminate has been reduced during the compression to yield a laminate compacted at least 5% during the compression to effect cure.

9. The laminate of claim 8 wherein the thickness of layers has been reduced at least 50% during the compression and cure.

10. A laminate of claim 6 wherein said laminate contains chopped fibers of from 3 to 30 millimeters in length.

11. A table of claim 1 wherein said cured mixture contains chopped fibers of from 3 to 30 millimeters in length.