The "disk" harrow and "spring tooth" both have wheels (but not always). A manual crank, or hydraulic cylinder adjust the height/depth of cut/penetration.

The "spike tooth" harrow is mounted on a frame and the angle of all the spikes can be pivited with one lever to adjust angle. These are generally of the drag type. Then there is the newer chain link drag type that is not adjustable.

Clover, rape, trefoil, chicoryseed is so small, it does not need to be burried by any mechanical means. If you have access to a cultipacker roller, use it before and after broadcasting seed, otherwise, don't worry about attempting to burry tiny seed. Rain will take care of it for you. JMHO