Method of and apparatus for the localizing of security line faults for ski lifts and the like

Claim 1

A process for locating a fault along a security line for a cable railway which comprises the steps of: applying to said security line a voltage pulse capable of generating a response in the form of an electrical echo signal from an end of the line; detecting the response of the line in the form of an echo signal to the voltage pulse; and comparing the detected response to the normal response of the same line in the absence of a fault, thereby producing a signal representing a sense of deviation from the normal response and a time of deviation of said signal, whereby the sense of deviation of said signal represents the nature of the fault and the time of said deviation represents the location of the fault along the line, the response of the line being compared to two predetermined values flanking the normal response, the results of these comparisons being expressed as logic levels "0" and "1", registering the logic levels at successive instants over an interval corresponding to a predetermined frequency, and collecting the registered results and displaying same at the end of a period of time sufficient to permit analysis of the line over its entire length, the period defined by said frequency being small by comparison to the time for reflection of said echo signal.

Claim 5

A system for localizing faults in a security line for a cable railway, comprising in combination: a first clock having a frequency corresponding to successive instants in which results are to be displayed; a second clock operatively connected to said first clock and defining a frequency of analysis of said line which is less than the frequency of the first clock; a step-signal generator triggered at each pulse of the second clock and applying a voltage step to said line inducing an electrical echo response in said line; means for delivering two electrical levels representing values flanking a normal echo response of said line in the absence of a fault; two comparators adapted to compare the echo response of said line with respective ones of said values whereby the comparator outputs indicate the locale of a fault represented by an echo response deviating from said normal echo response; and means for registering and displaying the outputs of said comparators, said comparators being operatively connected to said first clock for triggering thereby at each pulse thereof.

Claim 6

A system for localizing faults in a security line for a cable railway, comprising in combination: a first clock having a frequency corresponding to successive instants in which results are to be displayed; a second clock operatively connected to said first clock and defining a frequency of analysis of said line which is less than the frequency of the first clock; a step-signal generator triggered at each pulse of the second clock and applying a voltage step to said line inducing an electrical echo response in said line; means for delivering two electrical levels representing values flanking a normal echo response of said line in the absence of a fault; two comparators adapted to compare the echo response of said line with respective ones of said values whereby the comparator outputs indicate the locale of a fault represented by an echo response deviating from said normal echo response; and means for registering and displaying the outputs of said comparators, said comparators being operatively connected to said first clock for triggering thereby at each pulse thereof.