US372387A - Alfeed eix - Google Patents

Description

(ModeL) A. RIX.

BALL GASTER. No. 372,387. Patented Nov. 1, 1887.

NlTED STATES PATENT rice.

ALFRED RlX, OF SAN FRANCISCO, CALIFORNIA.

BALL-CASTER.

SPECIFICATION forming part of Letters Patent No. 372,387, dated November 1, 188?.

Application filed November 30, 1886. Serial X0. 220,32. (ModeL) To all whom, it may concern.-

Be it known that I, ALFRED RIX, of the city and county of San Francisco and State of California, have made an Improvement in Ball-Casters, of which the following is a specification.

The object of the invention is a caster having its point of support upon the floor directly beneath the leg supported, and at the same time movable in any direction with no hitch and but little friction.

It consists of a ball within a socket considerably larger than the ball, with the space between filled not quite full of small balls, like shot, which I call pellets, loosely disposed in a single layer or bed, and acting as rollers,

and kept in place by a stop at the lower edge of the socket.

The accompanying drawing is an enlarged vertical central section view, (substantially,) and constitutes a part hereof.

A is the ball; 13, the upper part of the socket; O, the lower part; I), the pellets; E, the stop, and E a modification of the same. This stop is placed high enough to clear the floor and low enough to allow a return-channel for the pellets not under pressure. The drawing shows a good example. The stop is so made and placed that the point at which the pellets come in contact with it shall be near enough to the ball to prevent the pellets from wedging between the stop and the ball. The drawing shows two kinds-cach properly constructed-so as to allow the pellets to rest and move upon it without wedging, the one at E having its upper face a trough with a curve a little greater than that of the pellets, and the one at E with its face plain and in line with the center of the ball.

As to the absolute size of the pellets, they should not be so small as to drop out on little wear, and as to their size relatively to the ball they should not be so large as to clog in the returnrhannel or prevent the ball from protruding sufficiently.

Pellets one-eighth of an inch in diameter work well with a ball one inch and a quarter in diameter. The fit of the pellets between the ball and socket should not be tight nor very loose, but fairly free, so that when the upper part of the socket rests upon the pellets the lower partof the socket will fall away from the ball slightly. The action will not prove satisfactory if the pellet-chamberis full. The amount of vacancy for the best action is about one-tenth of the chamber. A few tests for any particular construction will determine how much the vacancy should be. This vacancy, when the caster is in action, is more or less distributed among'thc pellets under pressure, whereby their rubbing againstcaeh other is almost wholly prevented. The socket is shown divided at the center, with the lower part spun upon the upper. This allows the upper part to be conveniently formed and finished, and the lower part to be made together with the stop; but the socket can be a single piece and the stop spun or otherwise fastened to it.

A convenient way of filling the pellctchanr her when the socket is divided at the center, as shown, is to turn the upper part of the socket upside down and arrange a few pellets in a single layer at the (then) bottom with the ball upon them. Then place over them a form precisely like the lower part of the socket with the stop omitted. Finally, fill and remove the form and put on the lower part of the socket.

The operation is obvious. All the pellets not under pressure between the upper hemispheres go to the lower part of the chamber, where they rest upon the stop and are free to be moved. As the caster moves forward in any direction the rear pellets roll on the ball upward, over, and downward in front and drive the loose ones backward through the lower part of the chamber--the return-cha11- nel-a part turning to the right and a part to the left. This backward movement is also aided by the action of the ball. As the ball always presses to the rear, it does not rub against the pellets resting on the stop in front, and as the pellets under pressure run substantially clear of each other the action is almost wholly the rolling one.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is I In and constituting a ball-caster, the combination of the following parts, to wit: the 1), each part constructed and all united in the ball A, the socket B, being enough more than manner and for the purposes substantially as a hemisphere to affordthe return-channel deset forth.

scribed, the stop E, presenting its upper side ALFRED RIX. 5 to the pellets, as described, so as to avoid Witnesses:

wedging, and the chamber formed by the ball, WV. W. WATSON,

socket, and stop not quite filled with pellets M. T. MOPHERSON.

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