To guarantee the same angular velocity of the two axles, independent of the angle formed by their centerlines, a ball cage is mounted between the outer and inner transmiis sion members in such a way that the plane formed by the cen- ters of the six balls always divides the angle formed by the axles in two equal parts.

The theoretical arrangement is shown on figure A , with the following meanings: 1: The bell-shaped outer transmission member, fixed to one of the axles;

2: The ball-shaped inner transmission member, fixed to the other axle; 3: The ball cage; 4: The torque transmitting balls.

Figure B represents the theoretical arrangement of one of the six balls, shown on an enlarged scale. The arrows PI are representing the forces acting between the inner

transmission member (2) and the balls; the arrows P2,the cor responding forces acting between the balls and the outer transmission member (1). Figure B also shows that the lenght of the circular arcs, represented with heavy lines, are par- ticipating in transmitting those forces, due to the fact that in this theoretical arrangement the radius of the ball and the ball races of inner and. outer transmission members are exactly the same.

In real conditions, all transmitting member suffer elastic deformations, as is demonstrated in exaggerated form in Figure C.

It can be seen in this figure that the elastic de¬ formation (5) and (6) interferes with the ball cage (3), blocking the movement and leading to fast destruction of the cage.

Besides the elastic deformation, it is necessary to consider that the balls rotate during the transmission of forces in the direction indicated by (S) in Figure B.

At the parts of the races which transmit forces (shown in heavy lines), this movement is almost perfectly a rolling movement.

At the parts of the ball races located at right an gle to the direction of (S) (demonstrated with broken lines) substancial differences exists between direction and veloci- ty of balls and races,causing strong frictions not tolerable for normal working conditions.

The known solution, normally used to avoid the con ditions above described,consists in machining the ball races of the inner and the outer transmission members slightly el- liptical, as shown in Figure D.

This solution effectively separates the surface of

the balls and the ball races near the cage and forms grease pockets near the regions of high friction, creating in this way good working conditions, as has been demonstrated by inumerable quantities of ball joints manufactured with el- liptical ball races during the last tens of years.

The most important incovenience of elliptically formed ball races is the fact that the forces between races and balls are transmited by point contact only, as can be seen in Figure D and not by line contact as shown in Figure B, reducing for this reason substantially the forces and the torques that can be transmited by the system.

This invention presents a new and improved design for the form of the ball races, solving at the same time the problems due to elastic deformation and also the friction problem caused by the elevated speed and direction differen¬ ces and eliminating the reduction of transmitting capacity due to the point contact between balls and elliptical races.

The new design of the transverse section of the ball races is represented at Figure E, where the system is shown as it appears without transmitting forces.

Shown again are the bell-shaped outer member (1) , the ball-shaped inner member (2), the ball cage (3) and one of the balls (4) .

The radius of the balls equal to (r). The ball races of the outer member (1) and the in¬ ner one (2) are also formed as arcs of a circle with the cor responding lenght (tl) and (t2) and with the radius (r) exac tly the same as the radius of the balls, but their centers are displaced to the right and to the left of the center of the ball to a distance (S) .

It is important to mention that the distance (S)

is in reality very small in relation to the radius (r), and that it is represented for better clarity much enlarged in Figure E. The design of the ball races is completed with two recesses (8) and the breaking of the edges (9) at member (l) and (10) at member (2).

Finally, in Figure F the new design of the ball ra ces is represented in working conditions, transmitting tor¬ que in the direction of arrow (11).

The advantages obtained with the new design of the ball races are immediately visible in this figure.

The balls are in perfect contact with the ball ra¬ ces of the outer and the inner transmission member within the lenght (b) , making this contact along the lines of cir¬ cular arcs instead of points, as it is in the case with el- liptical races.

The rotation of the ball in direction the arrow (12) does not give rise to any friction with the rest of the outline of the ball races, not even at one single point, as in the case with elliptical races, eliminating in this way completely the loss of transmission efficiency and the des¬ truction of the balls and races by friction.

The broken edges (9) and (10) avoid the ball cage gets stuck because of the elastic deformation of the ball ra ces.