--- publication_id: "OT-2026-000032989" title: "Single cup vacuum gripper, single stage ejector, pulsed blow-off after set-down, on a tool changer" published_at: "2026-09-17T08:21:57.065765Z" canonical_url: "https://opentechnical.org/p/OT-2026-000032989" categories: - "robotics-automation/end-effectors/vacuum-grippers" - "sensors-controls-machine-vision/position-and-presence-sensing" - "robotics-automation/end-effectors/tool-changers" - "industrial-motion-power-transmission/fluid-power/vacuum-generation" keywords: - "discrete suction cup tool" - "tool-change interface" - "suction cup" - "ejector" - "contact detector" - "blow-off valve" - "blow off release" - "compressed air supply" - "contact sensing" - "release control" --- # Single cup vacuum gripper, single stage ejector, pulsed blow-off after set-down, on a tool changer ## Abstract A suction-cup vacuum gripping tool comprising one tool-change interface, one suction cup, one ejector, one contact detector and one blow-off valve. When the suction cup reaches the workpiece, the suction cup is evacuated by the ejector. After the workpiece has reached the set-down position, the workpiece is blown off by the blow-off 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 suction-cup vacuum gripping tool: one suction cup carried on a tool-change interface, fed by an ejector. It is arranged for starting the cycle at the moment of contact, clearing the face at release 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 pneumatic lock. [0003] **One suction cup.** Each suction cup presents a sealing lip to the workpiece and is evacuated through its own connection. The suction cups are of the flat 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 one stage. [0005] **One contact detector.** The contact detector reports the moment a workpiece is present at the gripping face; its sensing technology is not fixed by this arrangement. The contact detector is mounted on the frame. [0006] **One blow-off valve.** The blow-off valve drives compressed air back through the circuit to the face, which clears the face instead of waiting for the circuit to refill. The blow-off is a short pulse. The blow-off pulse is given after set-down. [0007] The suction cup is carried on the tool side of the tool-change interface. [0008] The ejector is fixed to the tool side of the tool-change interface. [0009] The suction cup is connected to the ejector outlet by a single vacuum line, so that the face is evacuated through that line. [0010] The contact detector is mounted on the frame and reports the moment a workpiece is present against the gripping face. [0011] The blow-off valve is connected to the circuit at the ejector outlet, so that compressed air can be driven back through the circuit to the face. [0012] The robot side of the tool-change interface is bolted to the robot flange. [0013] The ejector is fed from the compressed air supply of the cell. [0014] The blow-off valve is fed from the compressed air supply of the cell. [0015] The locking piston of the tool-change interface is fed from the compressed air supply of the cell. [0016] The blow-off valve and the lock of the tool-change interface are switched by the cell controller; the contact detector reports to the cell controller. ## 3. Operating sequence and conditions - After the contact detector has detected the workpiece, the vacuum supply is actuated by the cell controller. - When the suction cup reaches the workpiece, the suction cup is evacuated by the ejector. - After the workpiece has reached the set-down position, the workpiece is blown off by the blow-off valve. - The workpiece is held until the blow-off valve has opened the circuit. [0021] The cell controller reads the contact detector (on the frame) and commands the blow-off valve, the tool-change interface; no sensor drives an actuator directly. ## 4. Parameters and operating assumptions [0022] Parameter values of this embodiment: locking of the tool-change interface: pneumatic (sets what has to be present at the interface for the tool to stay attached); form of the suction cup: flat (sets the shape of the contact area and the behaviour of the lip on a curved workpiece); material of the suction cup: polyurethane (sets the friction at the lip and the tolerance of the lip to oil and heat); stages of the ejector: one (sets the flow drawn at low vacuum and the compressed air consumed while a sealed face is held); placement of the contact detector: on the frame (sets where the presence of the workpiece is detected); duration of the blow-off valve: a short pulse (sets how quickly the face clears and how much air each release costs); timing of the blow-off valve: after set-down (sets whether the pulse assists a drop release or clears the face after set-down). [0023] The blow-off is a short pulse: the valve opens for a fraction of a second, long enough to break the seal and clear the face, and closes again. [0024] The lock is engaged by compressed air acting on the locking piston and is held only while that air pressure is applied; what the lock does on loss of air pressure is not fixed by this arrangement. ## 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 US-11858125-B2, US-2016214812-A1, US-2022339798-A1, US-8132312-B2, WO-2008134339-A4; their text is not reproduced, and the description above is generated from the structure of the combination.