Item loading by chamber bounded by synchronized conveying surfaces

An inventory loading system comprising an insertion system, the insertion system comprising:

• a chassis having at least a front face, a first lateral face, a second lateral face, and a bottom face;
• a bottom conveying surface fastened to the bottom face of the chassis;
• a first side conveying surface fastened to the first lateral face of the chassis;
• a second side conveying surface fastened to the second lateral face of the chassis;
• a chamber having bounds defined by the bottom conveying surface, the first side conveying surface, and the second side conveying surface, wherein the first side conveying surface and the second side conveying surface are spaced apart from one another to define a top opening of the chamber through which one or more items are loadable into the chamber, and wherein a rear wall of the chamber is defined at least in part by the front face of the chassis;
• and
• a linear actuator coupled with the chassis to move the chassis from a home position and toward an extended position so as to advance the bottom conveying surface, the first side conveying surface, and the second side conveying surface along with the rear wall of the chamber to decrease a size of the chamber and advance contents of the chamber in a depth direction toward a receiving zone.