--- publication_id: "OT-2026-000008558" title: "Three cup vacuum gripper, three zone face, two stage ejector, vented before set-down" published_at: "2026-09-17T08:10:36.030441Z" canonical_url: "https://opentechnical.org/p/OT-2026-000008558" categories: - "robotics-automation/end-effectors/vacuum-grippers" - "industrial-motion-power-transmission/fluid-power/valves-and-manifolds" - "industrial-motion-power-transmission/fluid-power/vacuum-generation" - "lifting-positioning-manipulation/vacuum-lifting/vacuum-safety-systems" keywords: - "zoned vacuum tool" - "mounting flange" - "suction cup" - "ejector" - "zone branch" - "vent valve" - "compressed air supply" - "drop release" - "release control" - "vacuum" --- # Three cup vacuum gripper, three zone face, two stage ejector, vented before set-down ## Abstract A zoned vacuum gripping tool comprising one mounting flange, three suction cups, one ejector, three zone branches and one vent valve. When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. Before the workpiece reaches the set-down position, the vacuum circuit is vented by the vent valve while the workpiece is above the receiving surface. 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: three suction cups carried on a mounting flange, fed by an ejector. It is arranged for handling workpieces that do not cover the whole gripping face and controlling the moment of release. 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 mounting flange.** The mounting flange carries the whole assembly and presents the bolt pattern that meets the robot. [0003] **Three suction cups.** Each suction cup presents a sealing lip to the workpiece and is evacuated through its own connection. The count of three follows from the arrangement: one gripping element per zone branch. The suction cups are of the oval form. [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] **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. [0006] **One vent valve.** The vent valve opens the circuit it is connected to towards atmosphere, which ends the grip. The circuit is vented before set-down. [0007] The suction cups are carried on the tool side of the mounting flange. [0008] The ejector is fixed to the tool side of the mounting flange. [0009] The three zone branches are taken from a branch junction on the ejector outlet, so that each branch carries the vacuum of its own zone only. [0010] Each suction cup is connected to its own zone line, one suction cup per zone, and is evacuated through that line. [0011] The vent valve is connected to the circuit at the ejector outlet and opens that circuit to atmosphere when it is actuated. [0012] The robot side of the mounting flange is bolted to the robot flange. [0013] The ejector is fed from the compressed air supply of the cell. [0014] The vent valve is switched by the cell controller. ## 3. Operating sequence and conditions - When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. - Before the workpiece reaches the set-down position, the vacuum circuit is vented by the vent valve while the workpiece is above the receiving surface. - The workpiece is held until the vent valve has opened the circuit. [0018] The cell controller commands the vent valve; no sensor drives an actuator directly. ## 4. Parameters and operating assumptions [0019] Parameter values of this embodiment: form of the suction cups: oval (sets the shape of the contact area and the behaviour of the lip on a curved workpiece); material of the suction cups: polyurethane (sets the friction at the lip and the tolerance of the lip to oil and heat); stages of the ejector: two (sets the flow drawn at low vacuum and the compressed air consumed while a sealed face is held); material of the zone branches: plastic; zones of the zone branches: three (sets how much of the face can be treated separately); timing of the vent valve: before set-down (sets whether the workpiece is released before or after it is supported by the set-down surface). [0020] The workpiece is released while it is still above the receiving surface and falls the remaining distance onto it. This sequence is for a workpiece and a receiving surface that tolerate that drop, for example a part released into a container or onto a conveyor; the drop height is set by the application and is not fixed here. ## 5. Provenance and status [0021] 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 US-10549431-B2, US-2016214812-A1, 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 [0022] This publication supersedes OT-2026-000004237, 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: suction_cup material 'silicone' is not offered by the library; the source-stated value 'polyurethane' is used.