Apparatus for and method of stacking articles

A stacking apparatus comprising:

• a stacking table for receiving a plurality of articles, the stacking table including separately movable first and second portions;
• means for moving the stacking table through a range of motion;
• and
• means for displacing the second portion of the stacking table relative to the first portion of the stacking table in response to movement of the stacking table through the range of motion by the moving means.

A stacking apparatus comprising:

• a stacking table including separately movable first and second support surfaces;
• a selectively stationary cam plate having a cam surface;
• an actuator for moving the stacking table through a range of motion relative to the cam plate;
• and
• a cam follower mechanically coupled to the second support surface and located to engage the cam surface when the stacking table is moved through at least part of the range of motion, so that when the actuator moves the stacking table and the cam follower engages the cam surface, the second support surface is displaced relative to the first support surface.

A stacking method comprising the steps of:

• delivering a plurality of articles sequentially to a stacking table at a delivery height, the stacking table including a first support surface and a second support surface;
• lowering the stacking table relative to the delivery height so that each subsequent article delivered to the stacking table is stacked on top of a previous article at substantially the delivery height;
• and
• simultaneously with the lowering step and responsive to the lowering of the stacking table, downwardly displacing the second support surface relative to the first support surface.

An apparatus for stacking sequentially a plurality of articles, the articles each having a relatively thin portion and a relatively thick portion, the apparatus comprising:

• a stacking table for receiving the plurality of articles, the stacking table including a first support surface for supporting the relatively thin portion of the articles and a second support surface for supporting the relatively thick portion of the articles;
• a cam plate having a cam surface;
• an actuator coupled to the stacking table for moving the stacking table through a range of motion relative to the cam plate;
• and
• a lever pivotally mounted relative to the stacking table and linked to the second support surface, the lever having a cam follower connected thereto so that as the stacking table is moved through at least part of the range of motion, the cam follower engages the cam surface, thereby pivoting the lever to displace the second support surface relative to the first support surface.

A bag stacking method comprising the steps of:

• delivering a continuous stream of articles sequentially to a stacking table at a delivery height, the articles each having a relatively thin portion and a relatively thick portion, the stacking table including a first support surface for supporting the relatively thin portion of the articles and a second support surface for supporting the relatively thick portion of the articles, wherein a spring biases the second support surface upward into horizontal alignment with the first support surface;
• lowering the stacking table relative to the delivery height, so that each subsequent article is stacked on top of a previous article at substantially the delivery height;
• and
• downwardly displacing the second support surface a vertical distance relative to the first support surface against the upward biasing of the spring, such that the uppermost article in the stack is maintained in a substantially horizontal orientation, wherein the lowering of the stacking table drives the downward displacement of the second support surface relative to the first support surface.

A stacking apparatus comprising:

• a stacking table for receiving a plurality of flexible articles, each article having a non-uniform thickness, the stacking table including separately movable first and second support surfaces;
• a frame on which the first support surface is mounted;
• an elongated reciprocating member coupled to the second support surface;
• a spring for biasing the second support surface upward relative to the frame;
• a lever comprising two arms disposed at an angle relative to one another, the lever being pivotally coupled to the frame near an intersection of the two arms of the lever, the lever having a cam follower mounted on one arm thereof, and the lever being pivotally coupled to the reciprocating member at the other arm thereof;
• a selectively stationary cam plate having a cam surface for engagement with the cam follower;
• and
• an actuator coupled to the stacking table for moving the stacking table downward relative to the cam plate, wherein as the actuator moves the stacking table downward, the cam follower engages the cam surface, causing the lever to pivot so as to displace the second support surface downward relative to the first support surface against the upward biasing of the spring.

A bag stacking apparatus comprising:

• a stacking table for receiving a plurality of articles, the stacking table including separately movable first and second portions;
• means for moving the stacking table through a range of motion;
• means for displacing the second portion of the stacking table relative to the first portion of the stacking table as the stacking table is moved through the range of motion;
• and
• means for adjusting a relative distance by which the displacing means displaces the second portion of the stacking table relative to the first portion of the stacking table,
• wherein the displacement of the second portion of the stacking table relative to the first portion is independent of the weight of the articles stacked on the stacking table.

A bag stacking method comprising the steps of:

• delivering a continuous stream of articles sequentially to a stacking table at a delivery height, the articles each having a relatively thin portion and a relatively thick portion, the stacking table including a first support surface for supporting the relatively thin portion of the articles and a second support surface for supporting the relatively thick portion of the articles, wherein a spring biases the second support surface upward into horizontal alignment with the first support surface;
• lowering the stacking table relative to the delivery height, so that each subsequent article is stacked on top of a previous article at substantially the delivery height;
• and
• downwardly displacing the second support surface a vertical distance relative to the first support surface against the upward biasing of the spring, such that the uppermost article in the stack is maintained in a substantially horizontal orientation,
• wherein the vertical distance that the second support surface is displaced relative to the first support surface is independent of the weight of the articles stacked on the stacking table.