Such "Stempelbremsen" (stamp brakes or plunger brakes?) are not particularly effective.
For one thing, you don't get very much power through the linkage and the power only acts on one point and not on two as with a u-brake or v-brake, for example. In addition, rubber meets rubber, and when the tire is wet, nothing happens anymore. With this kind of brake you can slow down your ride a little, that's it.
I remember that my first children's bicycle was fitted with such a brake. The brake pad was constantly coming off and flying around.....