--- publication_id: "OT-2026-000008215" title: "Foam pad vacuum gripper, three zone face, six outlet manifold, three stage ejector, pressure sensor per zone, vented after set-down, on a tool changer" published_at: "2026-09-17T08:10:14.564317Z" canonical_url: "https://opentechnical.org/p/OT-2026-000008215" categories: - "robotics-automation/end-effectors/vacuum-grippers" - "sensors-controls-machine-vision/force-and-pressure-sensing/vacuum-sensors" - "industrial-motion-power-transmission/fluid-power/valves-and-manifolds" - "robotics-automation/end-effectors/tool-changers" keywords: - "zoned vacuum tool" - "tool-change interface" - "foam pad" - "ejector" - "manifold" - "zone branch" - "pressure sensor" - "vent valve" - "compressed air supply" - "per zone measurement" --- # Foam pad vacuum gripper, three zone face, six outlet manifold, three stage ejector, pressure sensor per zone, vented after set-down, on a tool changer ## Abstract A zoned vacuum gripping tool comprising one tool-change interface, one foam pad, one ejector, one manifold, three zone branches, three pressure sensors and one vent valve. When the foam pad reaches the workpiece, the foam pad is 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: one foam pad carried on a tool-change interface, fed by an ejector. It is arranged for handling workpieces that do not cover the whole gripping face, verifying that the workpiece is held before the arm moves, controlling the moment of release, holding a workpiece that a rigid lip cannot seal against 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] **One foam pad.** The foam pad presents a compliant face to the workpiece; the holding force is spread over the contact area rather than concentrated at a lip. The pad is of open cell foam. [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 three stages. [0005] **One manifold.** The manifold receives the vacuum at one inlet and distributes it to its outlets. The manifold has six outlets. [0006] **Three zone branches.** Each zone branch carries the vacuum of one zone of the face and no other. The count of three follows from the arrangement: one branch per zone. The distribution is divided into three zones, each fed by its own branch. [0007] **Three pressure sensors.** Each pressure sensor taps the line it is placed in and reports the vacuum level in that line. The count of three follows from the arrangement: one sensor per zone branch. The pressure is measured at each zone. [0008] **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. [0009] The foam pad is carried on the tool side of the tool-change interface. [0010] The manifold is fixed to the tool side of the tool-change interface. [0011] The ejector is fixed to the tool side of the tool-change interface. [0012] The manifold inlet is connected to the ejector outlet, which supplies every outlet of the manifold. [0013] Each of the three zone branches is taken from its own manifold outlet, so that the branch carries the vacuum of its own zone only. [0014] Each zone line opens into its own section of the distribution chamber behind the porous face of the foam pad, so that the pad is evacuated zone by zone. [0015] One pressure sensor is tapped into each zone line, so that each of the three sensors reads its own zone and no other. [0016] The vent valve is connected to the circuit at the ejector outlet and opens that circuit to atmosphere when it is actuated. [0017] The robot side of the tool-change interface is bolted to the robot flange. [0018] The ejector is fed from the compressed air supply of the cell. [0019] The remaining three manifold outlets are plugged and carry no line. [0020] The vent valve is switched by the cell controller; the pressure sensors reports to the cell controller. ## 3. Operating sequence and conditions - When the foam pad reaches the workpiece, the foam pad is evacuated by the ejector. - When the vacuum level exceeds the gripping threshold, a secure grip is signalled by the pressure sensor of each zone in use. - The workpiece may not be lifted unless the pressure sensor of each zone in use signals a secure grip. - After the workpiece has reached the set-down position, the vacuum circuit is vented by the vent valve. - The workpiece is held until the vent valve has opened the circuit. [0026] The cell controller reads the pressure sensor (each zone line) and commands the vent valve; no sensor drives an actuator directly. ## 4. Parameters and operating assumptions [0027] 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); material of the foam pad: sponge (sets the compliance of the sealing face); porosity of the foam pad: open cell (sets whether air passes through the pad body or only through openings cut through it); stages of the ejector: three (sets the flow drawn at low vacuum and the compressed air consumed while a sealed face is held); outlets of the manifold: six (sets how many lines can be fed from one inlet); material of the zone branches: plastic; zones of the zone branches: three (sets how much of the face can be treated separately); placement of the pressure sensors: at each zone (sets where in the circuit the reading is taken and what it describes); 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). [0028] A zone is in use when the workpiece covers it. Which zones are in use is decided by the controller from the workpiece programme; this arrangement fixes where each zone is measured, not how the programme is written. [0029] The open-cell foam passes air through its whole face, so an uncovered part of the face draws air through the pad itself; the supply is sized for that continuous flow and the pad relies on flow restriction through the foam, not on a seal, to hold vacuum behind a covered area. [0030] 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. [0031] Vacuum levels are stated as gauge pressure below atmosphere. A stronger vacuum is a larger pressure difference below atmosphere, and the vacuum level 'exceeds the gripping threshold' when that difference is at least the threshold difference. ## 5. Provenance and status [0032] 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-4385681-B1, US-11427405-B1, US-11858125-B2, US-8006968-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 [0033] This publication supersedes OT-2026-000003893, 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.