Abstract: Apparatus for delivering singularized stacks of paper sheets to a packing machine has a first conveyor which intermittently receives groups of several abutting stacks and is intermittently driven by a variable-speed electric motor to advance the groups onto the individual endless bands of a gathering conveyor which serves to accumulate the groups into a row of abutting stacks ready to be singularized and delivered to the packing machine. The bands of the gathering conveyor are normally driven at a constant speed by a prime mover which further drives a first encoder serving to transmit a first signal whenever the bands cover a unit distance. A second encoder generates second signals whenever the motor is on and the first conveyor covers the same unit distance. The motor can also drive the bands at a speed higher than that at which the bands can be driven by the prime mover whenever the speed of the first conveyor exceeds the speed of the bands.

Abstract: Successive watermarks on a running web of coherent paper sheets are monitored by a scanner which generates defect signals in response to detection of watermarks outside of selected portions of the respective sheets, and the cross cutter which severs the web to form discrete sheets is then adjusted to separate the respective sheets from the next-following sheets with a delay or prematurely so that the sheets bearing the improperly positioned watermarks are too short or too long. Such defective sheets are segregated from satisfactory sheets downstream of the cross cutter in properly delayed response to generation of defect signals by the scanner.

Abstract: Apparatus for delivering singularized stacks of paper sheets to a packing machine has a first conveyor which intermittently receives groups of several abutting stacks and is intermittently driven by a variable-speed electric motor to advance the groups onto the individual endless bands of a gathering conveyor which serves to accumulate the groups into a row of abutting stacks ready to be singularized and delivered to the packing machine. The bands of the gathering conveyor are normally driven at a constant speed by a prime mover which further drives a first encoder serving to transmit a first signal whenever the bands cover a unit distance. A second encoder generates second signals whenever the motor is on and the first conveyor covers the same unit distance. The motor can also drive the bands at a speed higher than that at which the bands can be driven by the prime mover whenever the speed of the first conveyor exceeds the speed of the bands.

Abstract: Stacks of superimposed paper sheets are formed from a succession of layers each of which contains a given number of groups of sheets. One or more layers which contain a first number of groups can be followed by one or more layers containing a different second number of groups so that a stack can contain layers which, in turn, contain different numbers of groups and hence different numbers of sheets. The number of sheets in each stack and in each layer is a whole multiple of the number of sheets in a group. If the average number of sheets in a series of successive stacks is to deviate from a whole multiple of the number of sheets in a group, successive stacks contain different numbers of sheets; each such number is a whole multiple of the number of sheets in a group but the total number of sheets in the series of stacks divided by the number of stacks which form the series can deviate from such whole multiple.

Abstract: Stacks of superimposed paper sheets are formed from a succession of layers each of which contains a given number of groups of sheets. One or more layers which contain a first number of groups can be followed by one or more layers containing a different second number of groups so that a stack can contain layers which, in turn, contain different numbers of groups and hence different numbers of sheets. The number of sheets in each stack and in each layer is a whole multiple of the number of sheets in a group. If the average number of sheets in a series of successive stacks is to deviate from a whole multiple of the number of sheets in a group, successive stacks contain different numbers of sheets; each such number is a whole multiple of the number of sheets in a group but the total number of sheets in the series of stacks divided by the number of stacks which form the series can deviate from such whole multiple.