Ball unit

Ball transfer unit, in particular for conveying devices such as for example ball mats, and having a load ball which by a part of its surface can bear against a first body, in particular against a load object to be displaced by way of the conveying device;

• said ball unit comprising:
• a bearing unit which bears the load ball to be freely rotatable and to a large extent so encloses it that a free part of the surface of the load ball projects out of the bearing unit through a circular passage opening to bear against the first body,
• a holder which, for the fastening of the ball unit at a second body, in particular at the carrying frame of a conveying device, has a fastening portion which in the assembled state bears against the second body, wherein the bearing unit is so movable to and fro linearly relative to the holder between an advanced and a withdrawn end position that the free surface of the load ball in the advanced end position projects further beyond a surface of the second body than in the withdrawn end position, and
• spring means including a spring which is stressed between the bearing unit and holder, is arranged concentrically with the passage opening of the bearing unit as seen in the direction of the linear movement of the bearing unit and which biases the bearing unit into the advanced end position, said spring (18) being constructed as a flatly bowed annular disk and being supported at the holder (20) in immediate proximity of said fastening portion (31), said disk being bowed to conform generally to a sphere or truncated cone.