Foam pad vacuum gripper, common isolation valve, plant vacuum fed, sustained blow-off after set-down, on a tool changer

Abstract

A foam-pad vacuum gripping tool comprising one tool-change interface, one foam pad, one plant vacuum connection, one isolation valve, one contact detector and one blow-off valve. When the foam pad reaches the workpiece, the foam pad is 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 foam-pad vacuum gripping tool: one foam pad carried on a tool-change interface, fed by a plant vacuum connection. It is arranged for cutting part of the circuit while the rest holds vacuum, starting the cycle at the moment of contact, clearing the face at release, holding a workpiece that a rigid lip cannot seal against 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]One foam pad. The foam pad presents a compliant face to the workpiece; the holding force is spread over the contact area rather than concentrated at a lip. The pad is of closed cell foam.

[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]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.

[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 sustained blast. The blow-off pulse is given after set-down.

[0008]The foam pad is 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 foam pad is connected to the isolation valve outlet by a single vacuum line, so that the face is evacuated through that line.

[0011]The contact detector is mounted on the frame and reports the moment a workpiece is present against the gripping face.

[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 isolation valve and the blow-off valve are switched by the cell controller; the contact detector reports to the cell controller.

3. Operating sequence and conditions

[0022]The cell controller reads the contact detector (on the frame) and commands the blow-off valve, the isolation 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); material of the foam pad: sponge (sets the compliance of the sealing face); porosity of the foam pad: closed cell (sets whether air passes through the pad body or only through openings cut through it); 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; placement of the contact detector: on the frame (sets where the presence of the workpiece is detected); duration of the blow-off valve: a sustained blast (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 sustained blast: the valve stays open for the whole release so that the face is cleared of dust and the workpiece is pushed positively away.

[0025]The closed-cell foam does not pass air through its body; the face is evacuated through openings cut through the pad into the distribution chamber, and the foam around each opening forms the seal against the workpiece.

[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 EP-4385681-B1, US-10163334-B1, US-10259123-B2, US-11858125-B2, US-2022339798-A1, US-8132312-B2; their text is not reproduced, and the description above is generated from the structure of the combination.