Two bellows cup vacuum gripper, two outlet manifold, common isolation valve, three stage ejector, pulsed blow-off after set-down

Abstract

A bellows-cup vacuum gripping tool comprising one mounting flange, two bellows cups, one ejector, one isolation valve, one manifold, one contact detector 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 bellows-cup vacuum gripping tool: two bellows cups carried on a mounting flange, fed by an ejector. 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 and taking up height differences at the face. 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 mounting flange. The mounting flange carries the whole assembly and presents the bolt pattern that meets the robot.

[0003]Two 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 two follows from the arrangement: one gripping element per manifold outlet. Each bellows cup has one fold.

[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]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 manifold. The manifold receives the vacuum at one inlet and distributes it to its outlets. The manifold has two outlets.

[0007]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.

[0008]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.

[0009]The bellows cups are carried on the tool side of the mounting flange.

[0010]The manifold is fixed to the tool side of the mounting flange.

[0011]The ejector is fixed to the tool side of the mounting flange.

[0012]The isolation valve is placed in the line from the ejector, so that closing the valve cuts the whole circuit from the supply.

[0013]The manifold inlet is connected to the isolation valve outlet, which supplies every outlet of the manifold.

[0014]Each manifold outlet feeds one bellows cup by its own vacuum line, so that the two outlets feed two bellows cups.

[0015]The contact detector is mounted on the frame and reports the moment a workpiece is present against the gripping face.

[0016]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.

[0017]The robot side of the mounting flange is bolted to the robot flange.

[0018]The ejector is fed from the compressed air supply of the cell.

[0019]The blow-off valve is fed from the compressed air supply of the cell.

[0020]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

[0027]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

[0028]Parameter values of this embodiment: folds of the bellows cups: one (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: three (sets the flow drawn at low vacuum and the compressed air consumed while a sealed face is held); 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; outlets of the manifold: two (sets how many lines can be fed from one inlet); placement of the contact detector: on the frame (sets where the presence of the workpiece is detected); 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).

[0029]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.

5. Provenance and status

[0030]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-10549431-B2, US-2022339798-A1, US-8006968-B2, US-8132312-B2, WO-2008134339-A4; their text is not reproduced, and the description above is generated from the structure of the combination.