Abstract: Apparatus for controlling the frequency of vibrations imparted by the vibrating element of a compacting machine to the ground which comprises a vibration pick-up responsive to the amplitude of vibrations of a mass composed of the vibrating element and the ground being vibrated which produces a vibration signal; a position sensor sensing the angular position of an eccentrically loaded rotary shaft on which the vibrating element is mounted, which produces a position signal; and a phasemeter which receives the vibration and position signals and provides an output signal related to the phase difference therebetween. This phase difference may be displayed in which case the motor for the rotary shaft can be controlled manually in accordance therewith or it may be fed to an automatic control system in which it is compared with a set signal to produce an error signal for automatically regulating the speed of motor turning the rotary shaft.

Abstract: A direction and speed control system for a steerable locomotive having independent speed controls for two driving rollers, in which, where C.sub.D and C.sub.G are speed control signals for the two rollers, .alpha. is a steering angle of a steerable support, which may be a mere skid or a driving roller and C.sub.max is a maximum speed control value, there are three operational networks which generate signals F.sub.1, F.sub.2 and F.sub.3 given by C(1-K.sub.1 tan .alpha.), C(1+K.sub.1 tan .alpha.) and C.sub.max (1-K.sub.1 .vertline. tan .alpha..vertline.)/(1+K.sub.1 .vertline. tan .alpha..vertline.), comparators which receive C.sub.max and F.sub.1 and C.sub.max and F.sub.2 respectively and output terminals fed in parallel, through gating circuits controlled by the comparators, by the first and third networks and by the second and third networks respectively.

Abstract: Apparatus for compacting or consolidating a strip of road surfacing material essentially comprises a self-propelled compacting machine and a guide vehicle. The guide vehicle has a steerable wheel and a set of drive wheels. The compacting machine is guided for orbital movement around the guide vehicle at a preset turning radius. The guide vehicle may be self-propelled in which case it carries its own motor for driving its driving shaft. Preferably the guide vehicle is driven for progressive displacement along the strip of surfacing material in response to the turning of a coupling bar, connecting the compacting machine with the guide vehicle about its end for determining the turning radius of the former. The coupling bar in turn rotatably drives the driving shaft of the guide vehicle which in turn drives the drive wheels of the guide vehicle through a power transmission.

Abstract: A control lever assembly for controlled reciprocation of an operating member which may be a Bowden cable for regulating the flow rate of a pump supplying a hydraulic motor in a hydrostatic transmission. In addition to the usual pivotally mounted control lever, an intermediate lever is pivotally connected between the control lever and the operating member. The intermediate lever is received in a sleeve member which is pivotally mounted about a fixed axis spaced from the fixed axis about which the control lever pivots. The sensitivity of the control lever assembly is thus made smoother and more gradual proximate to the neutral or dead center position of the assembly.

Abstract: A hydrostatic transmission vehicle which is direction controlled by a speed controlled running assembly known as a motor-director running assembly and which has at least one further speed controlled driving running assembly. The motor-director running assembly is pivotable by means of a direction control system and its speed control system is coupled with that of each driving running assembly so that a speed which is coordinated with each driving running assembly is automatically applied to the motor-director running assembly when the vehicle is travelling in a straight line or turning.

Abstract: Apparatus for effecting passes of a self-propelled compacting machine following a spreading machine after the latter has laid a strip of surfacing composition. A guide vehicle is hitched to the spreading machine and is towed therewith, and has a guide member which may either have the contour of a closed geometrical figure such as a circle or be simply a pivot. The compacting machine turns about the guide vehicle along an epicycloidal path of travel. A sensing device on the compacting machine which may be a feeler or a flexible member is responsive to the variations of the radial distance between the compacting machine and guide member. The sensing device operates a limit switch when the variations exceed a predetermined amount which in turn controls an electrically operable hydraulic valve which communicates with a double-action cylinder and piston unit controlling in turn the direction of the front wheel of the compacting machine for increasing or decreasing the turning radius thereof.