OPENTECHNICAL PUBLICATION OT-2026-000011057 Two bellows cup vacuum gripper, two zone face, common isolation valve, two stage ejector, vented after set-down, on a tool changer Published: 2026-09-17T08:12:10.156048Z Permanent URL: https://opentechnical.org/p/OT-2026-000011057 Categories: Robotics & Automation > End Effectors > Vacuum Grippers ------------------------------------------------------------------------ ABSTRACT A zoned vacuum gripping tool comprising one tool-change interface, two bellows cups, one ejector, one isolation valve, two zone branches and one vent valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. After the workpiece has reached the set-down position, the vacuum circuit is vented by the vent valve. The arrangement is a proposed configuration composed from a typed library of mechanism blocks derived from published patents; it has not been constructed. 1. Purpose and arrangement [0001] This disclosure describes a zoned vacuum gripping tool: two bellows cups carried on a tool-change interface, fed by an ejector. It is arranged for handling workpieces that do not cover the whole gripping face, cutting part of the circuit while the rest holds vacuum, controlling the moment of release, taking up height differences at the face and exchanging the tool without rewiring the cell. One concrete embodiment is described; every connection is stated with the medium it carries, and the operating sequence is given as conditions on named operations. 2. Components, construction and connections [0002] One tool-change interface. The tool-change interface splits the tool into a robot side and a tool side, so the tool can be exchanged without dismantling it. The tool-change interface has a mechanical lock. [0003] Two bellows cups. Each bellows cup is folded so that it shortens under vacuum and takes up a height difference between the face and the workpiece. The count of two follows from the arrangement: one gripping element per zone branch. Each bellows cup has two folds. [0004] One ejector. The ejector draws the circuit down by passing compressed air through a nozzle; it has no moving part at the tool and consumes air for as long as it runs. The ejector has two stages. [0005] One isolation valve. The isolation valve sits in the line it controls; closing it cuts that line without disturbing the rest of the circuit. Isolation is common. [0006] Two zone branches. Each zone branch carries the vacuum of one zone of the face and no other. The count of two follows from the arrangement: one branch per zone. The distribution is divided into two zones, each fed by its own branch. [0007] One vent valve. The vent valve opens the circuit it is connected to towards atmosphere, which ends the grip. The circuit is vented after set-down. [0008] The bellows cups are carried on the tool side of the tool-change interface. [0009] The ejector is fixed to the tool side of the tool-change interface. [0010] The isolation valve is placed in the line from the ejector, so that closing the valve cuts the whole circuit from the supply. [0011] The two zone branches are taken from a branch junction on the isolation valve outlet, so that each branch carries the vacuum of its own zone only. [0012] Each bellows cup is connected to its own zone line, one bellows cup per zone, and is evacuated through that line. [0013] The vent valve is connected to the circuit at the line downstream of the isolation valve and opens that circuit to atmosphere when it is actuated. [0014] The robot side of the tool-change interface is bolted to the robot flange. [0015] The ejector is fed from the compressed air supply of the cell. [0016] The isolation valve and the vent valve are switched by the cell controller. 3. Operating sequence and conditions [0017] - When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. [0018] - After the bellows cups have reached the workpiece, the isolation valve is closed by the cell controller. [0019] - While the isolation valve is in the closed state, the vacuum downstream of the valve is maintained by the sealed gripping face. [0020] - After the workpiece has reached the set-down position, the vacuum circuit is vented by the vent valve. [0021] - The workpiece is held until the vent valve has opened the circuit. [0022] The cell controller commands the isolation valve, the vent valve; no sensor drives an actuator directly. 4. Parameters and operating assumptions [0023] Parameter values of this embodiment: locking of the tool-change interface: mechanical (sets what has to be present at the interface for the tool to stay attached); folds of the bellows cups: two (sets the travel taken up between the face and the workpiece, and the lateral stiffness of the cup under load); material of the bellows cups: plastic (sets the friction at the lip and the resistance of the folds to fatigue); stages of the ejector: two (sets the flow drawn at low vacuum and the compressed air consumed while a sealed face is held); control of the isolation valve: common (sets which part of the circuit the valve cuts: one branch line on its own or the whole circuit); material of the isolation valve: steel; material of the zone branches: plastic; zones of the zone branches: two (sets how much of the face can be treated separately); timing of the vent valve: after set-down (sets whether the workpiece is released before or after it is supported by the set-down surface). [0024] The lock is engaged by a manually operated lever on the interface; no supply crosses the interface for the lock, and tool exchange needs an operator at the tool. 5. Provenance and status [0025] This document is an original combination composed from a typed library of mechanism blocks. Each block was derived from a published patent and carries typed connection points, the parameters its source states, and its own construction and operating description. The combination described here is proposed and has not been constructed. The published documents behind the blocks used in this arrangement are EP-4489564-B1, US-10163334-B1, US-11858125-B2, WO-2008134339-A4, WO-2026020244-A1; their text is not reproduced, and the description above is generated from the structure of the combination. 6. Correction notice [0026] This publication supersedes OT-2026-000006845, whose text described this arrangement with defects recorded in the quality register at https://opentechnical.org/qa/. The earlier publication is unchanged and remains public. Changes made to reach a consistent configuration: release element added: a vent valve after set-down (the legacy assembly had no way to let go). ------------------------------------------------------------------------ OpenTechnical publication OT-2026-000011057 Published 2026-09-17T08:12:10.156048Z https://opentechnical.org/p/OT-2026-000011057