GB1425694A - Recorder checking device - Google Patents

Abstract

1425694 Recording apparatus KIENZLE APPARATE GmbH 10 July 1974 [21 July 1973] 30602/74 Heading G1J A vehicle tachograph with one or more record medium carriers 13 driven by a clock mechanism, and a spring-mounted stylus 8 or 20 movable perpendicularly of the carrier 13, has a switch associated with the record carrier 13 and/or the stylus to control an impulse transmitter 4 to produce a visual or audible warning when the tachograph is not functional, e.g. if there is no record medium 12 present, or the stylus has jammed clear of the record medium, or the lid of the tachograph is not properly closed, or the power supply to a motor 45 which oscillates the stylus to produce a bar diagram is interrupted. In Fig. 1, a switch 3 is closed when a pre-set vehicle speed is exceeded, to light a warning lamp 2. The impulse transmitter 4 causes this lamp 2 to flash when the tachograph is not functional. A normally open switch 5 closes if the stylus 8 drops into a recess 14 in the carrier 13 due to the absence of a record medium (disc) 12, or if the stylus is jammed in a retracted position, or if the lid of the tachograph is not properly closed so that the stylus support arm 9 is too far from the carrier 13. A support plate 18 for a second record medium 18 carries a conducting bridge 19 which is contacted by spring contacts 17, 16 of a switch 6 in the carrier 13 if the second record medium 18 is absent. In Fig. 2, an arm 25 on the stylus 20 actuates the contacts of a switch 27 if the record medium 12 is absent. In Fig. 3 (not shown), the stylus carries an insulated bridge contact (32) engageable with contact strips (30, 31) along the sides of the recess (14) if the stylus drops into the recess. A modification Fig. 4 (not shown) uses two wires (34, 35) in the recess (14) instead of the strips. In a further form Fig. 5 (not shown) the stylus has an insulated support, and can engage a contact brush (37) in the bottom of the recess (14). In Fig. 6, the pulse transmitter 4 is energized if the motor 45 for oscillating the stylus is deenergized, via a sensing circuit having a capacitor 44, resistor 42, diode 43, resistor 40, capacitor 41, and transistors 38, 39. Capacitive, inductive, or photo-electric switching may be used.