Three cup vacuum gripper, three zone face, common isolation valve, plant vacuum fed, pulsed blow-off after set-down, on a tool changer

Abstract

A zoned vacuum gripping tool comprising one tool-change interface, three suction cups, one plant vacuum connection, one isolation valve, three zone branches and one blow-off valve. When the suction cups reach the workpiece, the suction cups are evacuated by the plant vacuum connection. 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: three suction cups carried on a tool-change interface, fed by a plant vacuum connection. 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 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]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 plant vacuum connection. The plant vacuum connection takes vacuum from the plant line, so the tool carries no generator of its own.

[0005]One isolation valve. The isolation valve sits in the line it controls; closing it cuts that line without disturbing the rest of the circuit. Isolation is common.

[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 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 suction cups are carried on the tool side of the tool-change interface.

[0009]The isolation valve is placed in the line from the plant vacuum connection, so that closing the valve cuts the whole circuit from the supply.

[0010]The three zone branches are taken from a branch junction on the isolation valve outlet, so that each branch carries the vacuum of its own zone only.

[0011]Each suction cup is connected to its own zone line, one suction cup per zone, and is evacuated through that line.

[0012]The blow-off valve is connected to the circuit at the line downstream of the isolation valve, so that compressed air can be driven back through the circuit to the face.

[0013]The robot side of the tool-change interface is bolted to the robot flange.

[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 isolation valve, the blow-off valve and the lock of the tool-change interface are switched by the cell controller.

3. Operating sequence and conditions

[0022]The cell controller commands the blow-off valve, the isolation valve, the tool-change interface; no sensor drives an actuator directly.

4. Parameters and operating assumptions

[0023]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 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); control of the isolation valve: common (sets which part of the circuit the valve cuts: one branch line on its own or the whole circuit); material of the isolation valve: steel; material of the zone branches: plastic; zones of the zone branches: three (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).

[0024]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.

[0025]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

[0026]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-10259123-B2, US-11858125-B2, US-2016214812-A1, US-8132312-B2, WO-2026020244-A1; their text is not reproduced, and the description above is generated from the structure of the combination.