FIELD OF THE INVENTION

The present invention relates to a suction head, in particular a suction head or gripper for a waste sorting/processing system, such as a robotic waste sorting/processing system.

BACKGROUND ART

European patent application EP0706838A1 discloses a machine and method for fully automated sorting of various heterogeneous objects with at least one robotic arm. The machine utilises a robotic arm with a gripper formed by a pneumatic device operated by suction to grip an object and by blowing to release the object.

SUMMARY OF THE INVENTION

The present invention seeks to provide an improved suction head or gripper for waste sorting systems, wherein the suction head provides reliable and robust suction based gripping of waste items to be removed from a waste stream. The suction head further provides improved conformal engagement with waste items to increase the variety of waste items that can be gripped. Furthermore, the suction head is designed to greatly simplify the assembly and disassembly of the suction head to improve serviceability thereof.

According to the present invention, the suction head comprises a main tubular body having a connecting end for connection to a suction system and a suction end for engagement with a waste item;

an upper sleeve member and a lower sleeve member arranged around the suction end, wherein the upper sleeve member is longitudinally movable with respect to the main tubular body and wherein the lower sleeve member is removable from the suction end. An annular gripper sheet of flexible material is arranged between the upper and lower sleeve member. The suction head further comprises a biasing member in longitudinal biasing engagement with the upper sleeve member for biasing the upper sleeve member toward the lower sleeve member, clamping the annular gripper sheet between the upper and lower sleeve member.

According to the present invention, the clamped arrangement of the movable upper sleeve member, the removable lower sleeve member and the annular gripper sheet clamped there between provides for an extremely simple to assemble and dissemble suction head. For example, replacing the annular gripper sheet is readily achieved by moving the upper sleeve member in upward fashion against a biasing force imposed by the biasing member. Doing so loosens the annular gripper sheet and allows the lower sleeve member to be removed followed by the removal of the annular gripper sheet. The assembly process of the suction head is simply the reverse, i.e. moving the upper sleeve member in upward direction against the biasing member, placing the annular gripper sheet followed by attaching the lower sleeve member to the suction end. Letting go of the upper sleeve member will then allow the biasing member to move, in downward fashion, the upper sleeve member toward the lower sleeve member as a result of which the annular gripper sheet is firmly clamped there between.

Furthermore, another advantage of the suction head is that the above exemplified assembly and disassembly process can be performed manually without tools and without having to loosen or tighten bolts, nuts, or having to deal with any other conventional fasteners, clip rings, washers etc. So in case the suction head is e.g. clogged with a waste item and/or the annular gripper sheet requires repair or replacement, then servicing the suction head can be performed very quickly and in manual fashion. This ensures that a waste sorting and/or processing system is productive with minimal interruption and downtime.

In an advantageous embodiment, the annular gripper sheet comprises elastomeric material, e.g. rubber, silicone, EPDM or a combination thereof, thereby providing durability and flexibility to the annular gripper sheet.

In embodiment, the lower sleeve member comprises a circumferential upward facing bevelled edge for clamping engagement with the annular gripper sheet, allowing the annular gripper sheet to attain a substantially conic shape such that a circumferential edge of the annular gripper sheet has a much higher chance of properly and adequately engaging a waste item with minimum air leakage during strong suction.

In an advantageous embodiment, the lower sleeve member is formed by two semi-circular sleeve parts/shells, each semi-circular sleeve part comprising a circumferential upward facing bevelled edge portion of the circumferential upward facing bevelled edge. This embodiment simplifies assembly and removability of the lower sleeve member, which is achieved through the two semi-circular sleeve parts or shells each of which wrap in part around the suction end in removable fashion. Each of the semi-circular sleeve parts can be placed and removed in lateral direction with respect to the suction end.

In a further advantageous embodiment, the suction end of the main tubular body comprises an outer surface provided with a circumferential groove, wherein each semi-circular sleeve part mentioned above comprises an inwardly extending circumferential ridge receivable in the groove of the suction end. The groove and the inwardly extending circumferential ridges are so configured to engage and interlock in conformal fashion such that longitudinal movement of each semi-circular sleeve part is prevented.

Note that in a further embodiment, each of the semi-circular sleeve parts comprises a lower sleeve portion comprising the circumferential upward facing bevelled edge portion mentioned earlier and an upper sleeve portion being receivable in the upper sleeve member. The upper sleeve portion of each semi-circular sleeve part/shell can be inserted into the upper sleeve member so that the upper sleeve member encloses and encircles in part the lower sleeve member, encloses and encircles the upper sleeve portions, allowing the upper sleeve member to act as a retainer preventing separation of each of the semi-circular sleeve parts from the suction end.

To ensure that the annular gripper sheet is able to firmly engage the circumferential upward facing bevelled edge, an embodiment is provided wherein the annular gripper sheet comprises an aperture in which the upper sleeve portion of each semi-circular sleeve part is receivable. This embodiment is also advantageous for centering the annular gripper sheet in lateral/sideways fashion with respect to the suction head.

In an exemplary embodiment, the biasing member is a coil or spiral spring member arranged around the main tubular body in longitudinal biasing engagement with the upper sleeve member. Having the coil spring member arranged around the main tubular body prevents buckling of the coil spring member yet enables reliable biasing engagement. In a further embodiment, the coil spring member is in biasing engagement with a circumferential upper edge portion of the upper sleeve member, allowing a circumferentially distributed biasing force to be provided on the upper sleeve member which minimizes tilting/rotation of the upper sleeve member.

In an embodiment, the suction head further comprises a connector sleeve member for connection to a robot manipulator and wherein the connector sleeve member is arranged around the connecting end of the main tubular body and longitudinally moveable with respect thereto. The biasing member is in longitudinal biasing engagement with the connector sleeve member.

In a further embodiment, an inner connector sleeve member comprising an upper inner sleeve portion is receivable in the connector sleeve member and a lower inner sleeve portion provided with a circumferential outward protruding collar for engagement with the biasing member. The inner connecter sleeve member improves longitudinal movement of the connector sleeve member through reduced friction offered by the upper inner sleeve portion whilst the outward protruding collar provides an abutment/contact area for the biasing member.

To provide a removable backstop for the connector sleeve member as the biasing member is in upward biasing engagement with the connector sleeve member, an embodiment is provided wherein a locking sleeve member is arranged around the connecting end of the main tubular body and releasably, e.g., removably, connected to the connecting end. The connector sleeve member is then longitudinally arranged between the upper sleeve member and the locking sleeve member. Note that the removable locking sleeve member further simplifies the assembly and disassembly of the suction head should servicing and/or maintenance be required.

