An interesting form of two-point bearing is the Lake, made by the C. S. Caffrey Company of Camden, N. J. It makes the coned faces of cone and cup parallel and flat, inclined at an angle of 45 degrees to the axle. Here it is evident that the ball will run without twisting or skewing, and in order to keep the balls in place the old device of putting them in a perforated loose ring is employed. The holes in this ring for the balls are made oval instead of round, in what does not seem a very well grounded expectation of thus removing the slight friction between ball and ring. The holes are also “staggered,” so that the balls do not run on exactly the same tracks. It is claimed that, on a test, a front wheel with this bearing, being whirled by the hand, ran an hour and five minutes. This must be admitted to be a remarkable performance, even if the adjustment were loose.

Far the commonest construction, however, has been the three-point, partly because, by a confusion of ideas, a three-point bearing has seemed as if it must be firmer than a two-point, and partly because the former can be turned out at a very moderate cost. As in almost universal use during several years past, and as produced by the parts-makers almost without exception, the form of this is as shown in the cut. ([See page 86].) Turn the page so as to bring the surface C on the cone horizontal, and if you then imagine this surface C in the same plane as line CD, it is easy to see that the ball will roll upon the case at A and B both; and as the diameters of the ball at A and B are equal, it will roll around the circle easily and without skewing. As the inter-action of the parts is not changed thereby, we for the moment, as a matter of convenience, assume that the cup is stationary and the axle turns, which is the reverse of the fact. In actual position and working it is evident that under the weight of the load the ball will slip down the slope at C and be pressed hard against the side B as well as against the bottom A. The relative pressure on these two points will depend on the flatness or steepness of the surface C, but ordinarily the pressure on the two will be nearly equal. The action at C tries to roll the ball on a horizontal axis, parallel with the wheel axle; the action of B upon the ball tries to roll it on a vertical axis, parallel with CC. Moved by C, the ball may roll on A and slide on B, or it may stick fast to C and slide on A and B both, or it may stick fast to both A and B and slide on C. Certainly it cannot have more than one of these movements at any time, and hence the ball cannot possibly roll in two directions at once.

To make this more clear, imagine the ball and the two surfaces to be toothed where they come in contact, thus being visibly gear wheels; if these teeth are spur-teeth, the cone will impel the ball in its own plane of motion, namely, line CC, and the ball will then roll on side A and rub on side B; if the teeth are bevel, the ball will roll on B and rub on A.

“FOUR-POINT” BEARING—
TWO POSSIBLE FORMS.		ACTUAL
“FOUR-POINT” BEARING—
“E AND D” PATTERN.

HEEDLESS CONSTRUCTION.

For this reason—that this “jammed in a corner” pattern of bearing requires the ball to perform a physical impossibility—it must be unsparingly condemned. Indeed, if there is one form of polite and parliamentary phrase more decisive than another, we wish to be understood as using such form in condemning this particular construction. It does not violate any statute law, but it does violate laws of mechanics and good sense. What the ball actually does under such conditions is to “get around” as best it can, rolling somewhat, sliding somewhat, and slipping and skewing between times. The balls rub a little on each other and their contacting surfaces are moving in opposite directions; hence it is not to be supposed that they invariably roll, under even the best conditions, the only certainty being that they always follow the line of least resistance. Here we might say that exhibitions of a transparent bearing on a large scale, such as were at the recent shows, amuse visitors but prove little, and yet a close scrutiny of them will show that the balls have an irregular action; moreover, such a device as the “dynagraph,” professing to show graphically on an indicator card the frictional resistance of bearings, is a waste of ingenuity and construction, because it cannot be worked under actual practical conditions as when the wheel is in use. The difficulty with bearings as generally made hitherto has been that notwithstanding much talk in catalogues about “tool steel” and smooth grinding the common way has been to press the cups into the hubs, screw cones on the axle, drop in balls, turn up to place, and let it go so. Even in 1898, many catalogues furnish no information, either by text or by cuts, as to construction of bearings, and when we have had no other means of knowledge it has been in not a few cases impossible to find out certainly even such a distinct and practical matter as whether the adjustment is “cup” or “cone,” in such a heedless way has this part of the bicycle been passed over. Makers have been too prone to count anything with balls and a cone as a ball bearing, and they have had a good degree of liberty allowed them to so consider by these two facts: the rider does not know and the repairman does not care, and if a bearing is not screwed up too hard and run entirely dry it will move with a fair degree of ease even though the balls can not roll much. And yet in all such cases the defect makes its own witness by the “flats” made on cone and balls and by the ball track cut into the cup.

BALL-MAKING.

About eighteen years ago Col. Pope said to the writer, referring to the first [Columbia], then in market and the first American product, that it would cost $25 to put ball bearings on the back wheel (or possibly it was on both wheels). The usual extra on English makes at that time for balls to back-wheel was one pound sterling; the first ball pedals were also expensive, but for some years past any bearing without balls, even on the lowest-priced wheels, would have been rejected by every buyer. The difference has come largely by cheapened processes of ball-making, and, as in other things, reduction in cost and betterment in quality have come together. There are several ways of producing balls. According to one of the best, the Simonds Rolling Machine Co. of Fitchburg use forging machines, which are substantially two uprights, a half-die on each upright, and work automatically. Heated rods of tool steel are inserted in this machine, which forges a ball rough and at the same moment bites off the bit from the rod with the die. Next follow grinding and polishing automatically between horizontal disks about three feet in diameter in conjunction with emery wheels; finally come tempering, the last polishing and gauging automatically. Ordinarily a maximum variation of 1⁄1000 of an inch has been considered close enough, but this Company are able to guarantee a variation not over 4⁄10,000, the highest accuracy and uniformity being naturally considered somewhat in the price. The machines used are patented, and this bare outline is all we are permitted to publish.

There remains to be considered the four-point bearing, and no better example of this can be given than in the cut of one as used on the used on the “[E. & D].” as made by the Canadian Typograph Company of Windsor, Ontario. It is proper to say here that only minor details on this are patentable, for the principle is old and was in the old Bown Eolus bearing as long ago as 1877. Reference to the cut shows clearly that the ball rests on two points on cone and cup each, that its diameters are equal at these places of contact, and (most important of all) that the direction of pressure on the ball is at right angles to the axle, and hence that the ball will roll on an axis parallel to the axle; therefore there can be no sliding or skewing.