Tunneling machine guidance by impingement of laser beam on pair of machine carried targets

Claim 1

IN A GUIDANCE SYSTEM FOR A MACHINE WHOSE WORK TRAVEL DIRECTION IS TO BE CONTROLLED, A PAIR OF TARGETS ARRANGED TO BE CARRIED BY THE MACHINE IN SPACED APART ALIGNMENT WITH ONE ANOTHER ON AN AXIS PARALLEL WITH THE LINE OF MACHINE WORKING TRAVEL, A SIGNAL DIRECTING DEVICE LOCATED REARWARDLY OF THE TARGETS AND ARRANGED TO PROJECT A TARGET IMPINGING SIGNAL BEAM ON A FORWARD LINE AND OF A TRANSVERSE DIMENSION WHICH IS SMALLER THAN THE TARGET AREA EXPOSED THERETO, PRESET ALIGNMENT MARKER MEANS FIXED IN REARWARDLY SPACED RELATION WITH SAID MACHINE AND A DIRECTION-SETTING MEMBER FIXEDLY SECURED WITH THE SIGNAL DIRECTING DEVICE AS A UNIT THEREWITH FOR ALIGNMENT CO-ACTION WITH THE ALIGNMENT MARKER MEANS SO AS TO AIM THE BEAM PROJECTION PATH OF SAID DEVICE IN SELECTED RELATION WITH THE ALIGNMENT MARKER MEANS FOR THE INDICATION BY COMPARATIVE LOCATIONS OF BEAM IMPINGEMENT ON THE TWO TARGETS OF MACHINE POSITION RELATIVE TO SAID ALIGNMENT MARKER MEANS.

Claim 3

THE METHOD FOR MAINTAINING A TUNNELLING MACHINE ON A PRESCRIBED COURSE COMPRISING PRESETTING THE LOCATION OF MARKER MEANS TO COINCIDE WITH A PRESCRIBED DIRECTION TRAINING THE TELESCOPE OF A COMBINED TELESCOPE AND BEAM PROJECTOR UNIT TOWARD THE MARKER MEANS, ADJUSTING THE POSITION OF THE UNIT INTO ALIGNMENT WITH THE MARKER MEANS AS THE LATTER IS VIEWED BY THE TELESCOPE, THEN OBSERVING ON A PAIR OF LONGITUDINALLY SPACED APART AND MACHINECARRIED TARGETS, THE BEAM IMAGES THEREON AS PROJECTED BY THE PROJECTOR, ADJUSTING MACHINE POSITION UNTIL BEAM IMAGES ARE CENTERED ON BOTH TARGETS, THEN OPERATING THE TUNNELLING MACHINE WHILE COMPARING BEAM IMAGES ON THE TARGETS FOR DETERMINING MACHINE POSITIONING READJUSTMENTS NEEDED TO STEER THE MACHINE IN THE PRESCRIBED DIRECTION.

Claim 4

THE METHOD FOR MAINTAINING A TUNNELLING MACHINE ON A PRESCRIBED COURSE COMPRISING PRESETTING THE LOCATION OF MARKER MEANS TO COINCIDE WITH A PRESCRIBED DIRECTION TRAINING THE TELESCOPE OF A COMBINED TELESCOPE AND BEAM PROJECTOR UNIT TOWARD THE MARKER MEANS, ADJUSTING THE POSITION OF THE UNIT INTO ALIGNMENT WITH THE MARKER MEANS AS THE LATTER IS VIEWED BY THE TELESCOPE, THEN OBSERVING ON A PAIR OF LONGITUDINALLY SPACED APART AND MACHINECARRIED TARGETS, THE BEAM IMAGES THEREON AS PROJECTED BY THE PROJECTOR, ADJUSTING MACHINE POSITION UNTIL BEAM IMAGES ARE CENTERED ON BOTH TARGETS, THEN OPERATING THE TUNNELLING MACHINE WHILE COMPARING BEAM IMAGES ON THE TARGETS FOR DETERMINING MACHINE POSITIONING READJUSTMENTS NEEDED TO STEER THE MACHINE IN THE PRESCRIBED DIRECTION.