Abstract: Apparatus for controlling the position and location of a stationary device extending across the transverse dimension of a web in a paper machine for acting on the web during operation of the paper machine and by which the distance of the device from the web and/or its angular position is adjusted. The control apparatus is provided at both transverse ends of the frame of the stationary device and comprises a slide member assembly including a first slide member which supports the frame portion of the stationary device, a second slide member supported on the frame of the paper machine and an intermediate slide member situated between the first and second slide members and slidably engaging the same at respective engaging pairs of sliding surfaces thereof. The intermediate slide member and one of the first and second slide members have opposed engaging curved sliding surfaces, the center axis of such curvature substantially coinciding with a straight line defining the tip edge of the stationary device.