Systems and methods for maintaining the density of grouped sheet articles

A density control system for maintaining desired density of sheet articles in a group, the density control system comprising:

• (a) a support for supporting a plurality of sheet articles in a group;
• (b) an air nozzle positioned proximate the support for blowing air toward the group of sheet articles on the support;
• (c) a pneumatic sensor for monitoring density of the group of sheet articles, the pneumatic sensor configured for measuring pressure of the air blown by the air nozzle and reflected back from the group of sheet articles
• (d) a movement and control system for moving sheet articles in the group in response to measurements from the pneumatic sensor, the movement and control system comprising a belt for contacting and moving the group of sheet articles along the support and a motor for moving the belt.

A method for controlling density of sheet articles in a group, the method comprising:

• (a) maintaining a plurality of sheet articles in a group;
• (b) monitoring density of the sheet articles in the group with a pneumatic sensor, the monitoring of the density including blowing air against at least a portion of the sheet articles in the group and measuring the blown air that is reflected back by the sheet articles;
• and
• (c) controlling the density of the sheet articles in the group in response to the density monitored by the pneumatic sensor.

A method for maintaining density of sheet articles in a group, the method comprising:

• (a) maintaining a plurality of sheet articles in an upright position in a group;
• (b) monitoring density of the sheet articles in the group using a pneumatic sensor to blow air against a portion of the sheet articles in the group wherein the blown air is reflected back by the sheet articles and measured by the pneumatic sensor;
• and
• (c) controlling the density of the sheet articles in the group in response to the density monitored by the pneumatic sensor by moving at least a portion of the group of sheet articles in a forward direction for increasing the density of the sheet articles in the group or moving the group of sheet articles in a reverse direction for decreasing the density of the sheet articles in the group.

An envelope system for feeding envelopes from or to a group of envelopes, the envelope feeding system comprising:

• (a) a support for supporting a plurality of envelopes in a group;
• (b) an envelope feeder for removing envelopes from the group or adding envelopes to the group;
• (c) an envelope density mechanism for maintaining density of envelopes in the group against each other;
• and
• (d) a pneumatic monitor and control system for monitoring density of envelopes against each other in the group and for causing the envelope density mechanism to maintain density of envelopes in the group against each other in response to the monitored density, the monitor and control system comprising:
• (i) an air source for blowing air against a portion of the group of envelopes;
• and
• (ii) a sensor for sensing air blown against and reflected back towards the air source by the group of envelopes.

An envelope feeding system for feeding envelopes from or to a group of envelopes, the envelope feeding system comprising:

• (a) a support for supporting a plurality of envelopes in a group where the envelopes are in a vertical orientation;
• (b) an envelope feeder for removing envelopes from or adding envelopes to the group;
• (c) an envelope density mechanism for maintaining density of envelopes in the group against each other;
• and
• (d) a pneumatic monitor and control system for monitoring density of envelopes against each other in the group and for causing the envelope density mechanism to maintain density of envelopes in the group against each other in response to the monitored density, the monitor and control system comprising:
• (i) an air source for blowing air against a portion of the group of envelopes;
• and
• (ii) a sensor for sensing air blown against and reflected back by the group of envelopes.

A method for maintaining pressure of envelopes against each other in a group for feeding of the envelopes from or to the group, the method comprising:

• (a) providing an envelope feeding system comprising:
• (i) a support for supporting a plurality of envelopes in a group;
• (ii) an envelope feeder for removing envelopes from the group or adding envelopes to the group;
• (iii) an envelope pressure mechanism for maintaining pressure of envelopes in the group against each other;
• and
• (iv) a pneumatic monitor and control system for monitoring pressure of envelopes against each other in the group and for causing the envelope pressure mechanism to maintain pressure of envelopes in the group against each other in response to the monitored density;
• (b) monitoring pressure of envelopes against each other in the group by blowing air against a portion of the group of envelopes and sensing air reflected back by the group of envelopes;
• and
• (c) controlling the pressure of the envelopes against each other in the group in response to the monitored density of the envelopes in the group.

A method for maintaining pressure of envelopes against each other in a group for feeding of the envelopes from or to the group, the method comprising:

• (a) providing an envelope feeding system comprising:
• (i) a support supporting a plurality of envelopes in a group in a vertical orientation;
• (ii) an envelope feeder for removing envelopes from the group or adding envelopes to the group;
• (iii) a pressure mechanism for maintaining density of envelopes in the group against each other;
• and
• (iv) a pneumatic monitor and control system for monitoring density of envelopes against each another in the group and for causing the envelope pressure mechanism to maintain density of envelopes in the group against each other in response to the monitored density;
• (b) feeding envelopes from or to the group of envelopes;
• (c) monitoring pressure of envelopes against each other in the group by blowing air against a portion of the group of envelopes and sensing air reflected back by the group of envelopes;
• and
• (d) controlling the density of the envelopes against each other in the group in response to monitoring the density of the envelopes in the group by controlling the envelope pressure mechanism to increase or decrease density of the envelopes against each other in the group.

A method for maintaining density of envelopes against each other in a group of envelopes, the method comprising:

• (a) pneumatically monitoring density of envelopes against each other in a group of envelopes, the density being monitored by blowing air against at least a portion of the group of envelopes and sensing air reflected back by the group of envelopes;
• (b) feeding envelopes from or to the group of envelopes;
• and
• (c) controlling the density of the envelopes against each other in the group of envelopes in response to pneumatically monitoring the density of the envelopes in the group.

A density control system for sheet articles in a group, the density control system comprising:

• (a) a support for supporting a plurality of sheet articles in a group;
• (b) a pneumatic sensor for monitoring density of the group of sheet articles, the pneumatic sensor configured to detect a pressure of air reflected back from a portion of the group of sheet articles;
• and
• (c) a control system for changing density of sheet articles in the group in response to measurements from the sensor, the control system including a belt and a motor for moving the belt, the belt configured to contact and move the sheet articles in the group along the support.

A method for controlling density of sheet articles in a group, the method comprising:

• (a) maintaining a plurality of sheet articles in a group;
• (b) monitoring density of the sheet articles in the group with a pneumatic sensor by blowing air against at least a portion of the sheet articles in the group wherein the blown air is reflected back by the sheet articles and the pressure of the reflected air is measured;
• and
• (c) controlling the density of the sheet articles in the group in response to the density monitored by the pneumatic sensor by rotating a belt in contact with sheet articles in at least one of a first direction or a second direction to move the sheet articles along a support in the direction of rotation of the belt.