CA2631250A1 - Log rolling apparatus - Google Patents

Description

This invention relates to log rolling or birling apparatus and more particularly to the structure of a cylinder for use in the sport of log rolling or birling.

In my U.S. patent no. 5,334,100 issued on August 2, 1994 I describe an apparatus for carrying out the sport of log rolling in a swimming pool. The apparatus comprises a rotating central cylinder and two stationary outer cylinders at opposite ends of the rotating cylinder. The outer cylinders are adjacent to the deck of the pool and have flattened tops.
The outer cylinders serve not only to provide access to the rotating cylinder from the deck but also to minimize sideways and rocking movement of the rotating cylinder when the rotating cylinder is floating in water. The outer cylinders do not however interfere with rotation of the rotating cylinder.

The outer surface of the rotating cylinder as it rolls into and out of the water in the pool becomes quite slippery. If a person slips when he is attempting to remain standing on the cylinder as it rolls, he is apt to lose his balance and fall. The more the person falls, the less likely he is to enjoy himself and the more likely that he and persons like him will lose interest in the log rolling apparatus.

The obvious means for reducing slippage is to overlay the outer surface of the rotating cylinder with an abrasive, non-slip coating of material such as sand or grit embedded in plastic or roughened plastic. The problem with such a coating is that it my injure the feet of a person on the rolling cylinder because the person, to remain on the cylinder as it rolls, must constantly shift his position. As he does so, his feet will inevitably slide on the coating and be injured by it.

Another means of reducing slippage is to provide the person on the rolling cylinder with shoes having spikes on their soles and heels. However the spikes damage the soft coating which overlies the outer wall of the cylinder. The coating is soft so that a person on the rolling cylinder is not injured if he falls on it. The coating is easily torn by spikes and once torn, the metal be-neath the coating is exposed. The metal is of necessity considerably harder than the coating to provide strength to the cylinder. If the person falls on the metal, he will be bruised and possibly injured.

I have found that an effective way of minimizing sliding on the rotating cylinder is to form a number of grooves in its outer surface. To be most effective, the grooves must be longitudinally extending and spaced apart on the circumference of the cylinder. Preferably the grooves are straight, parallel to one another and spaced an equal distance apart.

The direction in which the grooves extend on the cylinder is important. If, for example, the grooves encircle the rotating cylinder, they are not effective to prevent a person from slipping. Somewhat effective are grooves which spiral along the length of the cylinder but they are not as effective as straight longitudinally extending grooves for preventing slippage.

Grooves on the outer surface of the cylinder are preferable to a non-slip coating because grooves do not injure the feet of a person who shifts his position on the outer surface. They do not, for example, bruise or injure the feet of a person who shift his position in contrast to a cylinder having an abrasive outer surface which do.

2 Briefly, the log rolling apparatus of my invention includes a cylinder which floats on water and which has an outer layer of material soft enough to substantially prevent injury by a person who falls on the cylinder from an upright position. The outer layer has a number of longitudinally extending grooves therein spaced apart sufficiently to resist slipping by the person when log rolling on the cylinder. The apparatus includes fastening means adapted to hold the cylinder when floating on water such that its axis of rotation is substantially horizontal and such that sideways and rocking movement of the cylinder is minimized..

The log rolling apparatus of the invention is described with reference to the accom-panying drawings in which:

Figure 1 is an elevation of the log rolling apparatus described in my U.S.
patent no.
5,334,100 issued on August 2, 1994;

Figure 2 is a side elevation of the rolling cylinder Figure 3 is a section on line A-A of Figure 2;

Figure 4 is a section, in larger scale, of a portion of the section illustrated in Figure 3; and Figure 5 is a side elevation, in larger scale, of a portion of the rolling cylinder.

Like reference characters refer to like parts throughout the description of the drawings.
With reference to Figure 1, a cylinder, generally 10 is mounted on an axle 12 for rotation about its longitudinal axis or axis of rotation. The axle is mounted in bearings 16 at either end of the cylinder. The bearings are affixed to a separate stationary non-rotating cylinder 18, 20 and the

3 latter cylinders are attached to the walls 22 of a swimming pool or other like stationary object by means of brackets 26. The stationary cylinders have flattened tops and provide access to the rotating cylinder from the deck 28 of the swimming pool. The foregoing components are known and are described in detail in my U.S. patent no. 5,334,100.

With reference to Figures 2 and 3, grooves 30 are formed in the outer wall of the central rotating cylinder 32 and in the two stationary cylinders 34, 36 on either side of the central cylinder. The grooves extend parallel to the longitudinal axis 40-40 of the central cylinder and the like axes of the stationary cylinders.

With reference to Figure 4 and 5, the outer layer 42 of the central cylinder is composed of an inner thickness 44 of low density polymeric foam and an outer thickness 46 of high density polymeric foam. The latter surface is relatively soft so that a person who falls on it does not injure himself and yet is sufficiently strong to last a reasonable length of time. Polyethylene foam is the preferred polymeric material.

Grooves 30 are equally spaced about the circumference of the outer layer. Each groove has a lower wall 30a in the shape of a portion of a circumference, the centre of which lies on the longitudinal axis of the cylinder. The side walls 30b of each groove are radially outwardly opening and extend from the lower wall to the outer wal146a of the cylinder.
The outer wall, like the lower wall, is in the shape of the portion of a circumference, the centre of which lies on the longitudinal axis 40-40 of the cylinder.

4 It will be understood, of course, that modifications can be made in the structure of the log rolling apparatus of the invention from that described herein without departing from the scope and purview of the invention as defined in the appended claims.

Claims (4)

I claim:

1. A birling apparatus including: a cylinder which floats on water and which has an axis of rotation and an outer layer of material soft enough to substantially prevent injury by a person who falls on said cylinder from an upright position thereon, said outer layer having a plurality of longitudinally extending grooves therein spaced apart sufficiently to resist slipping by said person when log rolling on said cylinder; and fastening means adapted to hold said cylinder when floating on water such that said axis of rotation is substantially horizontal and such that sideways and rocking movement of said cylinder is minimized.

2. The log rolling apparatus of claim 1 wherein said grooves are parallel to one another and are radially outwardly opening.

3. The log rolling apparatus of claim 2 wherein each said groove is defined by a circumfer-entially extending lower wall and a pair of radially extending side walls.

4. The log rolling apparatus of claim 1 wherein said outer layer is composed of an inner thickness of low density polyethylene foam and an outer thickness which overlies said inner thickness and which is composed of high density polyethylene foam.