Anti-skid brake control system

An anti-skid brake control system comprising brake pressure control means for producing a release signal to trigger the release of brake pressure and a subsequent re-apply signal to trigger the re-application of brake pressure in successive brake pressure release/re-apply cycles;

• and change-over control means for producing during a brake re-apply period a change-over signal to trigger a change from a first, rapid re-apply stage of said re-apply period, in which brake pressure is re-applied rapidly, to a second, slow re-apply stage of said re-apply period in which brake pressure is re-applied slowly;
• the change-over control means comprising storing means responsive to the duration of the re-apply period in successive cycles so that the change-over point in each cycle is controlled in a manner dependent on the duration of the re-apply period in the preceding cycle, whereby the duration of the re-apply period is dynamically adjusted to assume a preset value;
• said change-over control means comprising a first signal generator that is triggered at the beginning of the re-apply period and produces a first signal that varies progressively in a predetermined manner, a second signal generator including said storing means that produces a second signal that varies progressively in a predetermined manner in one sense during each release period and in the opposite sense during each re-apply period, and comparator means that compares said first and second signals and produces a change-over signal to trigger said change-over when the two signals are coincident.