Gathering machine for paper sheets or the like

In a machine for gathering sheets into stacks or similar accumulations, the combination of a conveyor having a plurality of spaced-apart entraining means arranged to move in a predetermined direction and along a predetermined path;

• a plurality of supports adjacent to said path and disposed one after the other, as considered in said direction;
• transfer means for delivering sheets to said supports so that the delivered sheets extend into said path;
• a plurality of mobile combined advancing and hold-down devices, one for each of said supports, for urging the delivered sheets against the respective supports;
• means for moving said devices into engagement with the sheets on said supports and thereupon at least substantially in said direction in synchronism with movements of said entraining means so that a sheet which is about to be engaged by the oncoming entraining means is urged against the respective support by the associated device and is accelerated by such device on the respective support only in said direction at least approximately to the speed of said entraining means before the accelerated sheet on its support is actually engaged by the oncoming entraining means;
• means for directing streams of a gaseous fluid against the sheets on said supports;
• and means for regulating the admission of a gaseous fluid against the sheets on said supports in synchronism with movements of said entraining means, including means for interrupting the discharge of a stream against a sheet on the respective support while said transfer means delivers a sheet to such support.