--- publication_id: "OT-2026-000070670" title: "Single bellows cup vacuum gripper, pump fed, vented before set-down, on a tool changer" published_at: "2026-09-17T08:52:49.344646Z" canonical_url: "https://opentechnical.org/p/OT-2026-000070670" 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: - "bellows compliant vacuum tool" - "tool-change interface" - "bellows cup" - "vacuum pump" - "contact detector" - "vent valve" - "compressed air supply" - "contact sensing" - "drop release" - "electric actuation" --- # Single bellows cup vacuum gripper, pump fed, vented before set-down, on a tool changer ## Abstract A bellows-cup vacuum gripping tool comprising one tool-change interface, one bellows cup, one vacuum pump, one contact detector and one vent valve. When the bellows cup reaches the workpiece, the bellows cup is evacuated by the vacuum pump. 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 bellows-cup vacuum gripping tool: one bellows cup carried on a tool-change interface, fed by a vacuum pump. It is arranged for starting the cycle at the moment of contact, 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 pneumatic lock. [0003] **One bellows cup.** Each bellows cup is folded so that it shortens under vacuum and takes up a height difference between the face and the workpiece. Each bellows cup has two folds. [0004] **One vacuum pump.** The pump draws the circuit down mechanically and adds its own mass to the moving assembly. [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 gripping face. [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 bellows cup is carried on the tool side of the tool-change interface. [0008] The vacuum pump is fixed to the tool side of the tool-change interface. [0009] The bellows cup is connected to the pump inlet line by a single vacuum line, so that the face is evacuated through that line. [0010] The contact detector is mounted on the gripping face and reports the moment a workpiece is present against the gripping face. [0011] The vent valve is connected to the circuit at the pump inlet line and opens that circuit to atmosphere when it is actuated. [0012] The robot side of the tool-change interface is bolted to the robot flange. [0013] The pump motor is supplied from the electrical supply of the cell. [0014] The locking piston of the tool-change interface is fed from the compressed air supply of the cell. [0015] The vent 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 bellows cup reaches the workpiece, the bellows cup is evacuated by the vacuum pump. - 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. [0020] The cell controller reads the contact detector (on the gripping face) and commands the tool-change interface, the vent valve; no sensor drives an actuator directly. ## 4. Parameters and operating assumptions [0021] 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); folds of the bellows cup: 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 cup: plastic (sets the friction at the lip and the resistance of the folds to fatigue); drive medium of the vacuum pump: electric (sets the supply the pump motor needs from the cell); placement of the contact detector: on the gripping face (sets where the presence of the workpiece is detected); 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). [0022] 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. [0023] 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 [0024] 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-11427405-B1, US-11858125-B2, US-2022339798-A1, WO-2008134339-A4; their text is not reproduced, and the description above is generated from the structure of the combination.