Abstract
A zoned vacuum gripping tool comprising one tool-change interface, three suction cups, one ejector, three isolation valves, three zone branches and one vent valve. When the suction cups reach the workpiece, the suction cups are 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: three suction cups carried on a tool-change interface, fed by an ejector. It is arranged for handling workpieces that do not cover the whole gripping face, cutting part of the circuit while the rest holds vacuum, controlling the moment of 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 mechanical lock.
[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 three stages.
[0005]Three isolation valves. Each isolation valve sits in the line it controls; closing it cuts that line without disturbing the rest of the circuit. The count of three follows from the arrangement: one valve per zone branch. Isolation is per zone.
[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]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.
[0008]The suction cups are carried on the tool side of the tool-change interface.
[0009]The ejector is fixed to the tool side of the tool-change interface.
[0010]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.
[0011]One isolation valve is placed in each zone branch, so that closing that valve cuts its zone from the circuit and leaves the other zones under vacuum.
[0012]Each suction cup is connected to its own zone line, one suction cup per zone, and is evacuated through that line.
[0013]The vent valve is connected to the circuit at the ejector outlet and opens that circuit to atmosphere when it is actuated.
[0014]The robot side of the tool-change interface is bolted to the robot flange.
[0015]The ejector is fed from the compressed air supply of the cell.
[0016]The isolation valves and the vent valve are switched by the cell controller.
3. Operating sequence and conditions
[0017]
- When the suction cups reach the workpiece, the suction cups are evacuated by the ejector.
[0018]
- When a zone is not covered by the workpiece, the isolation valve of that zone is closed by the cell controller.
[0019]
- While the isolation valve of that zone is in the open state, the vacuum of a covered zone is maintained by the ejector.
[0020]
- After the workpiece has reached the set-down position, the vacuum circuit is vented by the vent valve.
[0021]
- The workpiece is held until the vent valve has opened the circuit.
[0022]The cell controller commands the isolation valves, the vent valve; no sensor drives an actuator directly.
4. Parameters and operating assumptions
[0023]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); 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: three (sets the flow drawn at low vacuum and the compressed air consumed while a sealed face is held); control of the isolation valves: per zone (sets which part of the circuit the valve cuts: one branch line on its own or the whole circuit); material of the isolation valves: steel; 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: after set-down (sets whether the workpiece is released before or after it is supported by the set-down surface).
[0024]Which zones the workpiece covers is known to the controller from the workpiece programme; the arrangement provides the valve per zone and the controller decides which valves to close.
[0025]A zone whose isolation valve is closed is cut from the common line and does not vent or blow off until its valve opens.
[0026]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.
5. Provenance and status
[0027]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-10163334-B1, US-11858125-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
[0028]This publication supersedes OT-2026-000007290, 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: release element added: a vent valve after set-down (the legacy assembly had no way to let go); suction_cup material 'silicone' is not offered by the library; the source-stated value 'polyurethane' is used.