--- publication_id: "OT-2026-000006817" title: "Porous face vacuum gripper, three outlet manifold, two stage ejector, vented after set down" published_at: "2026-09-16T08:49:46.681000Z" canonical_url: "https://opentechnical.org/p/OT-2026-000006817" categories: - "robotics-automation/end-effectors/vacuum-grippers" - "industrial-motion-power-transmission/fluid-power/vacuum-generation" - "lifting-positioning-manipulation/vacuum-lifting/sealing-and-suction-pads" - "industrial-motion-power-transmission/fluid-power/valves-and-manifolds" keywords: - "ejector" - "foam pad" - "manifold" - "mounting flange" - "vent valve" - "release timing" - "end of arm tooling" - "sponge" - "open cell" --- # Porous face vacuum gripper, three outlet manifold, two stage ejector, vented after set down ## Abstract An end effector for porous-face vacuum end-of-arm tooling is described. The tool comprises a mounting flange (10), a foam pad (12), a ejector (14), a manifold (16), a vent valve (18). The arrangement addresses controlling the moment the workpiece is let go, where releasing before the workpiece is supported drops it, and releasing late drags it across the set-down surface as the tool lifts away. The description covers which valve opens the circuit, the position the workpiece must reach first, and what the tool does between those two moments. Every connection is stated with the medium it carries, and the operating sequence is given as conditions on named operations. ## 1. Technical Field [0001] This disclosure relates to porous-face vacuum end-of-arm tooling. It concerns the arrangement of a gripping interface, the supply that feeds it, the distribution and control between them, and the sequence in which those parts act on a workpiece. FIG. 1 shows the arrangement as a block diagram with the reference numerals used throughout this description. ## 2. Technical Context [0002] The arrangement addresses controlling the moment the workpiece is let go. The difficulty is that releasing before the workpiece is supported drops it, and releasing late drags it across the set-down surface as the tool lifts away. A tool that does not address it is still usable on a narrow range of workpieces, and the cost appears as cycle time, dropped parts or air consumption rather than as an outright failure. What follows covers which valve opens the circuit, the position the workpiece must reach first, and what the tool does between those two moments. ## 3. System Overview [0003] The tool comprises the mounting flange (10), the foam pad (12), the ejector (14), the manifold (16), the vent valve (18). FIG. 1 shows how these blocks are connected and which medium each connection carries. The blocks are not interchangeable by name: a connection is made only where one block offers a medium that another needs, and each connection below is stated together with the medium it carries. [0004] FIG. 2 shows elevation of the gripping face on its mounting. - The mounting flange is bolted to the robot flange (10). - The foam pad is connected to the ejector by a vacuum line that opens into the distribution chamber behind the porous face (12). - The foam pad is mounted on the mounting flange (12). - Compressed air is fed to the ejector from the compressed air supply of the cell (14). - The manifold inlet is connected to the ejector, which supplies every outlet of the manifold (16). - The vent valve is connected to the circuit at the ejector and opens that circuit to atmosphere when it is actuated (18). - The vent valve is switched by the controller of the cell (18). ## 4. Components [0012] **Mounting Flange (10).** The mounting flange (10) is provided once in this arrangement. The flange carries the whole assembly and presents the bolt pattern that meets the robot. [0013] **Foam Pad (12).** The foam pad (12) is provided once in this arrangement. The pad presents a porous face, so the holding force is spread over the contact area rather than concentrated at a lip. The pad is made of sponge. The pad is of open cell foam. [0014] **Ejector (14).** The ejector (14) is provided once in this arrangement. The ejector draws the circuit down by passing compressed air through a nozzle, so it needs no moving part at the tool. The ejector is built with 2 stages. [0015] **Manifold (16).** The manifold (16) is provided once in this arrangement. The manifold receives the vacuum and distributes it to the outlets that feed the face. The manifold has 3 outlets. [0016] **Vent Valve (18).** The vent valve (18) is provided once in this arrangement. The vent valve opens the circuit to atmosphere, which is what ends the grip. The circuit is vented after set-down. ## 5. Operation [0017] The operating sequence is given as conditions on named operations. Each condition names the event it depends on and the operation it governs, so the order of events is explicit rather than implied by the order of the sentences. FIG. 2 shows the gripping face referred to in these steps. The tool is presented to the workpiece square to the face, and the numbered operations below are what the arrangement does from that point. - When the foam pad seals 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 workpiece is held until the vent valve has opened the circuit. [0021] An operation whose condition is not met does not run. A condition that is stated with UNLESS holds except while its event is true, and one stated with UNTIL ends the operation at the moment its event becomes true. With the workpiece released, the tool returns to the pick position and the cycle repeats. ## 6. Example Embodiments [0022] In one embodiment the gripping face carries 1 foam pads on a common mounting, fed as shown in FIG. 1, and the tool is presented to the workpiece square to the face. In a second embodiment the same face is arranged in two rows so that a long workpiece is supported at both ends, with the connections of FIG. 1 unchanged. In a third embodiment the face is built at half the pitch and the number of foam pads is doubled for the same envelope, which suits a workpiece that is lighter but less rigid. ## 7. Alternative Configurations [0023] The gripping face may instead use a folded bellows cup, which takes up height differences at the cost of lateral stiffness. The gripping face may instead use a flat cup, which is stiffer laterally but needs the face and the workpiece to meet squarely. A gripping face of this kind may also be replaced by fingers closing on the workpiece, which removes the air circuit entirely and requires access to two opposed surfaces of the workpiece. The ejector may be replaced by a pump at the tool, which stops the continuous air draw and adds mass to the moving assembly, or by a connection to a plant vacuum line, which removes the generator from the tool and couples the tool to the rest of the site. An isolation valve may be added in the line to each zone, which allows one part of the face to be cut from the circuit while the rest holds its vacuum. The vent may be supplemented by a blow-off pulse, which clears the face rather than waiting for it to refill. ## 8. Parameter Variations [0024] Each parameter below is stated with what it changes in the arrangement. The porosity of the foam pad is open cell in the arrangement described; varying it changes the flow drawn through the face and the vacuum level that can be held behind it. The stages of the ejector is 2 in the arrangement described; varying it changes the flow drawn at low vacuum and the air consumed to hold a sealed face. The outlets of the manifold is 3 in the arrangement described; varying it changes how many connections can be fed from one inlet without dividing the face. The timing of the vent valve is after set-down in the arrangement described; varying it changes whether the workpiece is released before or after it is supported. ## 9. Additional Implementations [0025] A pressure sensor may be tapped into the circuit so that the state of the grip is observable, and the motion that follows the grip may be made conditional on the level it reports. A contact detector may be placed at the face so that evacuation starts only once the workpiece is present, which keeps the circuit closed during the approach. The whole assembly may be carried on a tool-change interface so that it can be exchanged between jobs without dismantling the tool. A separating element may be added so that a workpiece which follows the face upwards after release is pushed off positively. The face may be divided into zones, each fed by its own branch, so that a workpiece covering part of the face is handled without the uncovered part being held under vacuum. The arrangement may be duplicated on one mounting so that two workpieces are handled in one cycle, with the distribution fed from a common inlet and each face controlled on its own. ## 10. Provenance and method [0026] This document is an original combination composed from a typed library of mechanism blocks. Each block was derived from the published patent literature and carries typed connection points, the parameters its source states, and its own construction and operating description. The combination described here is proposed rather than taken from any one source, and it is not asserted to have been constructed. The published documents behind the blocks used in this arrangement are EP-4385681-B1, US-10549431-B2, US-8006968-B2, WO-2008134339-A4. Their text is not reproduced here; the description above is generated from the structure of the combination. ## 11. Figures ![FIG. 1](figures/fig-001.svg) Block diagram of the tool, with the medium carried by each connection. ![FIG. 2](figures/fig-002.svg) Elevation of the gripping face on its mounting.