WO2011109854A1

WO2011109854A1 - Multipart billiards-cue

Info

Publication number: WO2011109854A1
Application number: PCT/AU2010/000276
Authority: WO
Inventors: Joachim Kühl; Stan Mullin
Original assignee: Palko1Klik Pty Ltd
Priority date: 2010-03-10
Filing date: 2010-03-10
Publication date: 2011-09-15

Abstract

In order to simplify and speed-up the fastening and the release of an extension piece (4) at the rear end of a billiards-cue (1), or between the parts of an assembled billiards-cue (2) and (3), it is proposed to carry out the fastening with a shaft/hub connection (5,6) having a circumferential form deviating from a pure circular form and which can be brought into a firm friction lock by rotation. Preferably, the design is such that the shaft part (5) and the hub part (6) on their outer and inner circumferences respectively have three cams (12, 14), being offset by 120° and complementary to each other, that rise gradually and then abruptly descend again, and which can be brought into a firm friction lock by rotating the parts (2, 3) or (3, 4) respectively of the billiards-cue (1).

Description

MULTIPART BILLIARDS-CUE

FIELD OF THE INVENTION

The invention relates to a multipart billiards-cue with a shaft/hub connection to separate and join multiple parts of the billiards-cue. The invention also relates to a shaft part of the shaft/hub connection and to a hub part of the shaft hub connection.

BACKGROUND

It is often necessary to extend the length of a billiards-cue so that the ball to be hit can be reached. This is especially so for large snooker or billiards tables. To that end, an extension piece is added to the lower part of the billiards-cue using a joint. It is most common for the joint between the pieces to be a threaded joint.

In order to save time, extension of the billiards-cue should take place quickly and it should also be capable of being reversed quickly. A threaded joint requires some time to be screwed in and out again. A quick connection and removal of an extension piece would allow the player to attach not only an extension of the billiards-cue, but also a hand piece of greater mass if this were to appear useful for a forceful hit. Due to the time taken to connect parts using the threaded joint, this option is rarely exercised.

US patent 4,231 ,573 discloses a two-part billiards-cue where the connection of lower and upper part is achieved by circular pins and holes being offset across the longitudinal axis of the billiards-cue, which are pushed into each other and rotated. This leads to a wedging of the offset pins in the holes and they join the two parts with a^' small rotation of less than 90°. But this solution has the disadvantage that the two parts are not fully in line, a lateral offset remains between them.

From GB 2 226 251 , a two-part billiards-cue has become known where the lower and upper part of a billiards-cue are coupled together with a type of bayonet connection. Here, too, a rotation of about 90° is required to join or to separate the two parts.

Screwed connections between lower and upper part of a billiards- cue in the form of a tapered thread as per GB 2 246 302 also enable a quick connection and separation of upper and lower parts.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a connection with which the attachment of an extension to a billiards-cue or pool-cue, which may become necessary during the course of the game, can be achieved, which takes place quickly and by which coaxiality between the lower part and the extension piece is obtained. The invention solves this object in that a shaft/hub connection is used where, preferably, a shaft with a circumferential surface deviating from the pure circular form, is fixed to the extension piece, where the shaft can be inserted into a hub, in the lower part of the billiards-cue, where the hub has an internal circumferential surface adapted to the circumferential surface of the shaft. With a rotation of just a few angular degrees, the shaft and hub become wedged and they join the lower part and the extension piece immovably together by friction locking.

Such a circumferential form of the shaft and hub, deviating from a pure circular form, is obtained with ellipses of small differences in diameter.

It is particularly advantageous that, on the shaft, cams rise gradually from a small diameter and then abruptly decrease to the original diameter again while the complementary cams in the hub are placed on a slightly smaller circumference. Thus, a joining gap occurs between shaft and hub, which allows an easy insertion of the shaft into the hub. This joining gap is eliminated by rotating extension piece and lower part in the direction of the shallow rises of the billiards-cue, whereby the shaft and hub become wedged. The shaft/hub connection may comprise one or several cams. Particularly advantageous are three of the cams offset by 120° each around the circumference because, in this case, a very accurate centering is achieved when rotating the two parts against each other. The taper of the cams can be selected at 1 :20 to 1 :50 with such a low level that, even with a minor rotation of about 15°, a secure wedging of the circumferential surfaces is achieved.

Such a shaft/hub connection is taught in WO 9216763 and known in the machinery industry as a 3K connection. The disclosure of the shaft/hub connection of WO 9216763 is incorporated herein by reference.

By having the option to quickly attach an additional component to a billiards-cue, a player will more readily opt for connecting an extension for the purpose of increasing the mass of the billiards-cue. Such extensions may be made of heavy material such as steel or similar in order to increase the impact of a forceful hit.

Billiards-cues, being about one and a half metres long, are most commonly detachable at their mid-point into an upper and lower part in order to facilitate transport. Therefore, the proposed shaft/hub connection can also be used advantageously between the upper part and lower part of the billiards-cue. In this case, the upper part and lower part can be separated or connected quickly and easily. The use of a 3K connection in particular guarantees absolute coaxiality of the parts.

Further advantageous of the invention will be apparent from the description of the embodiment of the invention.

In one form, the invention resides in a multipart billiards-cue with a shaft/hub connection for connecting at least two of the multiple parts of the billiards-cue, wherein the shaft/hub connection includes a circumferential surface on a shaft part of the shaft/hub connection and a complementary circumferential surface on a hub part of the shaft/hub connection, the circumferential surface and complementary circumferential surface each deviating from a pure circular form to provide friction locking between the shaft part and the hub part. In another form, the invention resides in a shaft part of a shaft/hub connection for connecting parts of multipart billiards-cue, the shaft part including:

a shaft having cams rising gradually from an imagined cylinder surface and then abruptly descending again to the imagined cylinder surface; and

a pin having a surface structure configured for fixing the pin in one of the multiple parts of the billiards-cue.

In yet another form the invention resides in a hub part of a shaft/hub connection for connecting parts of multipart billiards-cue, the hub part including:

a hub comprising cams inside the hub, the cams rising gradually from an imagined cylinder surface towards the centre of the hub and then abruptly descend to the imagined cylinder surface again; and

a surface structure on the outside the hub which is configured for fixing the hub in one of the multiple parts of the billiards-cue

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be readily understood and put into practical effect, reference will now be made to a preferred embodiment of the invention as illustrated with reference to the accompanying drawings, wherein like reference numbers refer to like elements, in which:

Fig. 1 is a schematic diagram illustrating a longitudinally sectioned view of the shaft part of a billiard-cue in accordance with the invention;

Fig. 2 is a schematic diagram illustrating a longitudinally sectioned view of the hub part of the billiard-cue;

Fig. 3 is a schematic diagram illustrating a cross section of a shaft/hub connection in an insertion position;

Fig. 4 is a schematic diagram illustrating a cross section of the shaft/hub connection in a friction lock position; and

Fig. 5 is a schematic diagram illustrating the whole of the multipart billiards-cue. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Fig.5, a multipart billiards-cue, in accordance with one embodiment of the invention, is designated generally by reference numeral 1. The billiards-cue 1 consists of an upper part 2, a lower part 3, and an extension piece 4 to be attached to the lower end of the lower part 3.

A shaft/hub connection (5,6) releasably connects the lower part 3 with the extension piece 4. Another shaft/hub connection (5,6) also releasably connects the upper part 2 with the lower part 3. The shaft/hub connection (5,6) for connecting the lower part 3 with the extension piece 4 is shown more particularly with reference to Fig's 1 and 2.

Fig 1 shows a shaft part 5 of the shaft/hub connection (5,6) and Fig 2 shows a hub part 6 of the shaft/hub connection (5,6). The shaft part 5 is preferably fixed in the extension piece 4, and the hub part 6 is preferably fixed in the lower part 3. The shaft part 5 and the hub part 6 are preferably of metal material such as steel or brass, or may be suitable plastics material.

The shaft part 5 comprises a projecting shaft 7 and a pin 8 by which it is fixed into the lower part 3. Between the shaft 7 and pin 8, a washer 9 is placed being arranged perpendicular to a longitudinal axis 19 of the shaft part 5. The washer 9 may be integrally formed with the shaft part 5.

The hub part 6 consists of a hub 10 which is closed off at a blind end. The hub 10 also has a washer 11 , at its open end. The washer 11 is integrally formed with the hub 10.

As can be seen from Fig. 3, the shaft 7 has three cams 12 on its circumference being radially offset by 120° from each other. The cams 12 define a circumferential surface of the shaft 7 which deviates from a pure circular form. The cams 12 rise gradually from an imagined cylinder surface 13 and then abruptly descend again to the cylinder surface 13. The hub 10 also has three cams 14 being complementary to the cams 12, which rise gradually from an imagined cylinder surface 15 towards the centre and then abruptly descend onto it again. The cams 14 define a complementary circumferential surface of the hub 10 which deviates from a pure circular form. The inclines of cams 12, 14 are opposed to each other and, along their gradual rise, have a taper between about at 1 :20 to 1 :50 relative to the imagined cylinder surfaces 13,15. The taper is indicated by an exaggerated angle a in Fig 3.

A surrounding curve over the highest rises of the cams 12 has a larger diameter than a surrounding curve over the highest rises of the cams 14 in the hub 10. At the same time, the surrounding curves have a smaller diameter than the imagined cylinder surfaces 13, 15 of the mating component. Thus, as referred to in Fig. 3, a narrow joining gap 16 results between the shaft 7 and hub 10, which makes it possible to slide the shaft 7 into the hub 10 when one part into the other.

When rotating the shaft 7 clockwise, the joining gap 16 is reduced until the cams 12, 14 slide against each other and form a firm friction lock as shown in Fig. 4. The joining gap 16 and taper of the cams 12,14 are adapted to each other such that the friction lock starts occurring after the shaft 7 is rotated by only about 15°.

The friction lock joins the extension piece 4 firmly to the lower part 3 for resisting the torsional and linear forces occurring when the billiards-cue 1 is in use. The friction lock is released by turning the extension piece 4 anti-clockwise, thereby reinstating the joining gap 16 so that the extension piece 4 can be pulled from the lower part 3 again.

For fixing the pin 8 and the hub 10 into the lower part 3 and the extension piece 4 respectively, their outer surfaces have a surface structure 17 applied to it which is configure so the pin 8 and the hub 10 can be fixed in their locations. The surface structure 17 may consist of a thread that can be screwed into the respective parts 2 and 3 of the billiards-cue 1. Alternatively, but not detailed here, this surface structure 17 may also consist of a knurl, grooves around the circumference, or barbed grooves around the circumference.

The tensile load on the shaft/hub connection (5,6) is low and compression is absorbed and transmitted by the washers 9, 11. To prevent loosening of the shaft part 5 and/or the hub part 6 in the parts 3,4 of the billiards-cue 1 , the surface structure 17 of the pin 8 or hub 10 may also consist of grooves parallel to the axis 19. The grooves resist rotation of the shaft part 5 and/or the hub part 6 in the parts 3,4 of the billiards-cue 1 when torque is applied between the parts 3,4 to release or lock the shaft/hub connection (5,6).

The cams 12,14 run parallel along the axis 19.

The pin 8 and hub 10 are screwed or pressed into the parts 3, 4. The connection between the pin 8, hub 10 and the parts 3, 4 can be further enhanced by applying glue at the surface structure 17.

If, for ease of transport, the billiards-cue is divided into a separable upper part 2 and lower part 3, the described shaft/hub connection (5,6) can also be placed advantageously between the upper part 2 and lower part 3 of the billiards-cue 1.

A taper of between 1 :20 to 1 :50 includes tapers of 1 :20, 21 , 22, 23,

24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49,or 50.

Claims

1. A multipart billiards-cue with a shaft/hub connection for connecting at least two of the multiple parts of the billiards-cue, wherein the shaft/hub connection includes a circumferential surface on a shaft part of the shaft hub connection and a complementary circumferential surface on a hub part of the shaft/hub connection, the circumferential surface and complementary circumferential surface each deviating from a pure circular form to provide friction locking between the shaft part and the hub part.

2. The billiards-cue according to claim 1 , wherein the shaft part includes a shaft comprising cams defining the circumferential surface, the cams rising gradually from an imagined cylinder surface and then abruptly descend again to the imagined cylinder surface.

3. The billiards-cue according to claim 2, wherein the hub part includes a hub comprising internal cams defining the complementary circumferential surface inside the hub, the internal cams of the hub are complementary to the cams of the shaft and also rise gradually from an imagined cylinder surface towards the centre of the hub and then abruptly descend to the imagined cylinder surface again.

4. The billiards-cue according to claim 3, wherein the shaft and the hub each comprise three cams being radially offset from each other by 120°.

5. The billiards-cue according to claim 2 or claim 3, wherein the gradual rise of the cams is provided by the cams having an incline with a taper of about 1 :20 to 1 :50.

6. The billiards-cue according to claim 3, wherein the shaft/hub connection in an insertion position has a joining gap which allows the shaft to be inserted into the hub.

7. The billiards-cue according to any one of the preceding claims, wherein the shaft part includes a pin having a surface structure configured for fixing the pin to one of the multiple parts of the billiards-cue.

8. The billiards-cue according to any one of the preceding claims, wherein the hub part has a surface structure for fixing the hub part in one of the multiple parts of the billiards-cue.

9. The billiards-cue according to any one of the preceding claims, wherein the shaft/hub connection is arranged between a lower part and an extension piece of the billiards-cue.

10. The billiards-cue according to any one of the preceding claims, wherein the shaft/hub connection is arranged between an upper part and a lower part of the billiards-cue.

11. A shaft part of a shaft/hub connection for connecting parts of multipart billiards-cue, the shaft part including:

12. The shaft part according to claim 11 , wherein the shaft comprise three cams being radially offset from each other by 120°.

13. The shaft part according to claim 11 or claim 12, wherein the gradual rise of the cams is provided by the cams having an incline with a taper of about 1 :20 to 1 :50.

14. A hub part of a shaft/hub connection for connecting parts of multipart billiards-cue, the hub part including:

a surface structure on the outside the hub which is configured for fixing the hub in one of the multiple parts of the billiards-cue.

15. The hub part according to claim 14, wherein the hub comprise three cams being radially offset from each other by 120°.

16. The hub part according to claim 14 or claim 15, wherein the gradual rise of the cams is provided by the cams having an incline with a taper of about 1 :20 to 1:50.