57 force exerted by the operator in rotation of the document holder h easily overcomes the force holding the damper arm 23 and actuator tab 9 together leaving the damper arm 23 resting against the underside of stop 56 in position for the next copying cycle also shown in fig7 are portions of base member 1 elements 16 18 19 20 21 26 38 39 are as described in fig5 and 6 fig8 depicts a top plan view of the inventive device in its second position i e rotated to the right as viewed herein with the document holder h at rest and with panel 3 visible actuator tabs 9 are shown engaged with lever arms 23 of dampers 25 two dampers 25 are shown for balancing the forces although one may suffice in other embodiments base plate 1 has a window zone 27 serving to expose obverse or front side 22 not visible of document 50 to scanning head 41 moving in direction c the reverse side 45 of the document to be copied is visible here hinge leaf 18 is attached to lower plate 3 of the document holder shown also is the second leg 49 of spring 15 pressing against the outer surface of plate 3 elements 4 5 6 8 14 15 16 17 20 21 26 38 39 42 43 and 47.