Abstract
A zoned vacuum gripping tool comprising one tool-change interface, four bellows cups, one ejector, four isolation valves, four zone branches and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are 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 zoned vacuum gripping tool: four bellows 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, clearing the face at 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 mechanical lock.
[0003]Four bellows cups. Each bellows cup is folded so that it shortens under vacuum and takes up a height difference between the face and the workpiece. The count of four follows from the arrangement: one gripping element per zone branch. Each bellows cup has two folds.
[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]Four 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 four follows from the arrangement: one valve per zone branch. Isolation is per zone.
[0006]Four zone branches. Each zone branch carries the vacuum of one zone of the face and no other. The count of four follows from the arrangement: one branch per zone. The distribution is divided into four zones, each fed by its own branch.
[0007]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.
[0008]The bellows 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 four 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 bellows cup is connected to its own zone line, one bellows cup per zone, and is evacuated through that line.
[0013]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.
[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 blow-off valve is fed from the compressed air supply of the cell.
[0017]The isolation valves and the blow-off valve are switched by the cell controller.
3. Operating sequence and conditions
[0018]
- When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector.
[0019]
- When a zone is not covered by the workpiece, the isolation valve of that zone is closed by the cell controller.
[0020]
- While the isolation valve of that zone is in the open state, the vacuum of a covered zone is maintained by the ejector.
[0021]
- After the workpiece has reached the set-down position, the workpiece is blown off by the blow-off valve.
[0022]
- The workpiece is held until the blow-off valve has opened the circuit.
[0023]The cell controller commands the blow-off valve, the isolation valves; no sensor drives an actuator directly.
4. Parameters and operating assumptions
[0024]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); folds of the bellows cups: 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 cups: plastic (sets the friction at the lip and the resistance of the folds to fatigue); stages of the ejector: two (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: four (sets how much of the face can be treated separately); 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).
[0025]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.
[0026]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.
[0027]A zone whose isolation valve is closed is cut from the common line and does not vent or blow off until its valve opens.
[0028]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
[0029]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-10163334-B1, US-11858125-B2, US-8132312-B2, WO-2008134339-A4, WO-2026020244-A1; their text is not reproduced, and the description above is generated from the structure of the combination.