Abstract: In described examples, a cushioning unit assembler includes first, second, third, and fourth rows of welding heads, a transport, and a feed module. The welding heads have a welding position and a retracted position. A main axis of the welding heads is oriented in a first dimension while in the welding position. The transport is disposed above the rows of welding heads. The transport has a main axis oriented in a second dimension perpendicular to the first dimension. The feed module includes a pocketed spring intake and a pocketed spring outflow. The transport is mechanically coupled to enable the feed module to move in the second dimension along a scope of movement. An exit aperture of the outflow vertically aligns with welding heads of the first row that are in the welding position, and vertically aligns with welding heads of the second row that are in the welding position.