831,612. Feeding sheets; sheet-delivery apparatus. MIEHLE-GOSS-DEXTER Inc. May 22, 1956 [Aug. 18, 1955], No. 15749/56. Class 100(1) A signature guiding machine comprises a plurality of pile supports, means for separating the bottom sheet of each pile, and a carriage reciprocable beneath the supports and provided with grippers for taking the separated sheets when the carriage is at one end of its travel and depositing them when the carriage is at the other end of its travel. Pile tables and supports. The machine comprises a main frame 15 (Fig. 1) which supports a plurality of stacks of signatures 27 in pile tables 19. Each pile table comprises a pair of side plates 21, cross bars 22, 23, 24, bars 25 and 26 supported on the cross bars 22 and 23, a base plate 28, a front abutment plate 29, an adjustable rear strip 30 and two angle type adjustable front carrier guides 31. The base plate 28 terminates short of the front plate 29 to allow separation from the bottom of the stack of a signature 27. Sheet separators. Each pile support is provided' with a suction separator comprising a lever 32 disposed between bars 25 and 26 and pivoted thereon at 33. The lever 36 carries suction cups 34 and is 128 urged away from the signatures 27 by a spring 35. The levers 32 are rocked in unison by a linearly reciprocal, ladder type carriage 38 composed of bars 39, 40 (Fig. 4) mounted in bearing blocks 42, 43 attached to the plates 21, and a plurality of cross-brackets or rungs 41. The rungs 41 carry projecting abutments 44 which, as the carriage 38 moves to the left, as viewed in Fig. 1, contact and rock the levers 32 so as to cause the cups 34 to pivot upwardly to contact the lowermost signature of each stack. Sheet carriers and forwarders; receivers; signature gatherers. Also mounted on the rungs 41 are gripper units 57 comprising a main body 58 carrying a fixed jaw 59 and a movable jaw 60 biased into open and closed position by a toggle spring mechanism pivoted to the jaw 60 at 65 and controlled by the action of fixed cams 71 and 72 on an arm 70 of the movable jaw 60. As the carriage 38 moves to the right as viewed in Fig. 1, the lowermost signatures are separated from the piles by reason of the action of the springs 35 and presented to the advancing open grippers which are closed on the signatures at the end of reciprocation of the carriage 38 by the action of the cams 72 on the arms 70. As the carriage again moves to the left, the lowermost signatures are withdrawn from each stack and forwarded to receivers 74 mounted on the cross bars 22. When the arms 70 of the movable jaws 60 engage the cams 71 the grippers are opened to release the signatures which are stripped therefrom by fingers 73 so that the signatures fall into the receiver 74. Below the receiver 74 tables 75 are provided on endless chains 76 which also carry punches 78. The arrangement is such that on each reciprocation of the carriage 38 the chains 76 move a distance equal to the distance between successive stacks so that signatures from successive receivers 74 are removed by each pusher 78, thus collecting the signatures on each table 75. Faulty sheet feed detectors. Mounted on bars 25, 26 of each pile support is a U- shaped bracket 93 between the legs of which a second U-shaped bracket 94 having a cross-piece 96 and legs 95 is mounted for vertical adjustment by means of a wing-nut 110 and stud 109, and screws 105 and slots 104 interconnecting the two brackets. The movable jaw 80 of each gripper unit is provided with a dog 81 (Fig. 7) adapted to contact a screw in a lever 83 pivotally mounted in a rung 41 of the carriage and which is connected to a finger 88 slidably mounted in the gripper unit 58. The lever 83 is biased towards the dog 81 so that the top of the finger 88 is elevated to a height depending on the thickness of the signature gripped between the jaws. The lever 83 is adjusted by means of the screw 82 so that if the jaws fail to grip a signature the finger 88 is at a height just sufficient, on reciprocation of the unit 58, to contact a blade 126 whereas if two signatures are gripped, the finger 88 is raised to a height sufficient to contact a blade 113. Normally, with one signature, the finger is raised to a height intermediate these positions. The blade 113 is mounted in a block 112 pivoted in the bracket 94 and at its upper end contacts a shoulder 115 of a lever 114 which is also pivoted within the bracket 94 and which carries, in clips 121, a mercury switch 122 connected in series with the motor driving the machine. The blade 126 is connected at 125 to a bell-crank 123 to which a link 129 is pivotally connected as at 128. The link 129 is connected to the cross-bar of a pendulum 132 having a pair of vertical legs wide enough apart to avoid contact with the gripper unit 58 but in the line of movement of a gripped signature. The pendulum is pivoted to the cross bar 23. During normal operation, the edge of a gripped signature contacts the pendulum 132 and rocks it so that the blade 126 is withdrawn from the line of movement of the finger 88 which latter is at a height insufficient to contact the blade 113. If two signatures have been gripped, however, the finger 88 will be raised to a greater height, such that it will contact the blade 113 thus rocking it away from the shoulder 115 of the arm 114 so that the latter pivots about its pivot 100 under the action of a spring 118 and the mercury switch 122 is tilted to stop the motor driving the machine. Similarly, if no signature is gripped, then the pendulum is not actuated and the blade 128 remains in the line of movement of the finger 88. The finger 88 thus contacts the blade 126 which pushes the blade 113, again stopping the machine. Warning lights 153 are connected in parallel with each of the switches 122 so that when the latter are actuated, a visual indication is given as to the feeder which is at fault. To prevent the finger 88 rising to its highest level, when the gripper is opened by cam 71 to release a signature on to a receiver 74, a latch finger 156 is provided in the unit 58 one end of which is acted upon by the dog 81 when the jaw 60 is fully open so as to bring the other end of 'the latch to bear against the lever 83 and thus hold the finger 88 in its lowest position. Contact of the finger 88 with the blades 113 and 126 during the return movement of the carriage 38 is thus avoided.