Soft-start electromagnetic coupling

DETAILED DESCRIPTION The general aim of the present invention is to provide a new and improved electromagnetic coupling in which opposing disc-like members (e.
g.
, the driving and driven members) are uniquely constructed in such a manner as to enable the members to engage gradually and then to reach high torque without need of a specialized electrical control for regulating the degree of engagement of the members.
A more detailed object of the invention is to achieve the foregoing by providing disc-like members in which the opposing high reluctance regions are arranged to move from less nearly radially matched positions to more nearly radially matched positions and then back to less nearly radially matched positions as the relative angular positions of the members change through 360 degrees.
As a result of the changing radial relationship between the high reluctance regions of the two members, the strength of the flux field varies during start-up so as to reduce the average torque which is initially transmitted between the members and thereby enable the members to engage gradually.
Still another object of the invention is to provide an electromagnetic coupling in which the high reluctance regions are shaped and located so as to permit high torque to be transmitted between the disc-like members once the members have engaged gradually.
The invention also resides in varying the specific shape and location of the high reluctance regions in accordance with the type of load associated with the coupling.
These and other objects and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.