Storage system for products using supporting units

A storage system for product-containing crates or the like of substantially identical dimensions, comprising, in combination:

• (a) a staging having a plurality of storeys extending between entry and exit sides of said staging,
• (b) at least one crate supply conveyor at said entry side and at least one crate removal conveyor at said exit side,
• (c) at least one entry elevating device at said entry side for receiving crates from a supply conveyor, and at least one exit elevating device at said exit side for delivering crates to a removal conveyor, said elevating devices being longitudinally movable along said entry and exit sides respectively,
• (d) operating means on each entry and exit elevating device which means are vertically movable along said elevating devices into alignment with selected storeys, and are adapted respectively to receive crates from an entry elevating device and insert them into a selected storey, and to extract crates from a selected story and insert them into an exit elevating device, and
• (e) one or more step conveyors for the crates, mounted in each storey and extending from the entry to exit sides of the staging, and adapted for operative interconnection with an operating means on an elevating device when said operating means is aligned with a selected storey, each step conveyor comprising a channel member provided with shoulder means along the length thereof for supporting crates and a channel therebetween having reciprocating means in said channel with forward and return strokes, said reciprocating means being adapted to move upwardly to engage the bottom of a crate supported on said shoulder means on a forward stroke towards said exit side, and to move downwardly to disengage the bottom of said crate on the return stroke toward said entry side, thus leaving the crate in a forwardly moved position resting on said shoulder means, said reciprocating means being activated when an operating means on an elevating device is in interconnected position with a corresponding step conveyor,
• whereby crates are successively received at said entry side, inserted into the step conveyor of a selected storey, advanced step-wise along said shoulder means, and then successively extracted from the exit side as desired
• and wherein said reciprocating means comprises at least one oscillating beam in the channel of the step conveyor, each beam having segments on the underside thereof hinged on shafts mounted crosswise in the channel, said segments having spiral tread surfaces engaging the bottom of the channel and shaped so that on the forward stroke of the beam a portion of a segment moves around its hinge to urge the beam upwardly to engage the bottom of an overlying crate to move it forwardly, and on the return stroke of beam, another portion of said segment urges the beam downwardly to disengage from the bottom of the crate, and leave the crate in a forwardly advanced position on said shoulder means of the channel.