Chatelain etal tachograph

Claim 1

IN A TECHOGRAPH, A CUP-SHAPED CASING, A COVER PIVOTALLY MOUNTED ON SAID CASING AND COMPRISING A RIM, A CRYSTAL MOUNTED IN SAID RIM, A DIAL MOUNTED IN SAID RIM AND SPACED BACK OF SAID CRYSTAL, A PLATE SPACED BACK OF SAID DIAL AND FIXED RELATIVE THERETO, A SPEED-INDICATING HAND BETWEEN SAID DIAL AND CRYSTAL, A CENTRAL SPINDLE CARRYING SAID HAND AND EXTENDING REARWARDLY THROUGH SAID DIAL AND PLATE AND INTO THE INTERIOR OF SAID CASING, DRIVING MEANS IN SAID CASING COUPLING WITH SAID SPINDLE TO DRIVE IT, A TIME-INDICATING HAND BETWEEN SAID DIAL AND CRYSTAL, A SHAFT COAXIAL WITH SAID SPINDLE AND CARRYING SAID TIMEINDICATING HAND, A SELF-CONTAINED CLOCKWORK UNIT DISPOSED IN SAID CASING ON THE REAR OF SAID PLATE WHOLLY AT ONE SIDE OF SAID SPINDLE, MEANS REMOVABLY SECURING SAID CLOCKWORK UNIT TO THE REAR OF SAID PLATE FOR EASY REMOVAL AS A COMPLETE UNIT, SAID CLOCKWORK UNIT HAVING A ROTARY OUTPUT MEMBER ALIGNED WITH AN OPENING IN SAID PLATE, MEANS INCLUDING GEAR MEANS BETWEEN SAID DIAL AND PLATE DRIVINGLY CONNECTING SAID SHAFT OF SAID TIME-INDICATING HAND WITH SAID OUTPUT MEMBER OF SAID CLOCKWORK UNIT TO BE DRIVEN THEREBY, A CHART-HOLDING MEMBER ROTATABLY MOUNTED COAXIAL WITH SAID SPINDLE AND HAVING A CHART-SUPPORTING SURFACE IN A PLANE IMMEDIATELY BACK OF SAID CLOCKWORK UNIT, MEANS INCLUDING SAID GEAR MEANS DRIVINGLY CONNECTING SAID CHART-CARRYING MEMBER WITH SAID OUTPUT MEMBER OF SAID CLOCKWORK UNIT AND SAID TIME-INDICATING HAND SHAFT, AND A STYLUS IN SAID CASING IN POSITION FOR ENGAGEMENT WITH A CHART ON SAID CHART-HOLDING MEMBER, SAID COVER BEING SWINGABLE BY SAID PIVOTAL MOUNTING TO AN OPEN POSITION AFFORDING ACCESS TO SAID COMPLETE REMOVABLE CLOCKWORK UNIT.