Abstract
A bellows-cup vacuum gripping tool comprising one mounting flange, two bellows cups, one ejector, one manifold, one pressure sensor 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 verifying that the workpiece is held before the arm moves, 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 manifold. The manifold receives the vacuum at one inlet and distributes it to its outlets. The manifold has two outlets.
[0006]One pressure sensor. The pressure sensor taps the line it is placed in and reports the vacuum level in that line. The pressure is measured in the supply line.
[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 mounting flange.
[0009]The manifold is fixed to the tool side of the mounting flange.
[0010]The ejector is fixed to the tool side of the mounting flange.
[0011]The manifold inlet is connected to the ejector outlet, which supplies every outlet of the manifold.
[0012]Each manifold outlet feeds one bellows cup by its own vacuum line, so that the two outlets feed two bellows cups.
[0013]The pressure sensor is tapped into the line between the ejector and the distribution and reads the pressure of the whole circuit.
[0014]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.
[0015]The robot side of the mounting flange is bolted to the robot flange.
[0016]The ejector is fed from the compressed air supply of the cell.
[0017]The blow-off valve is fed from the compressed air supply of the cell.
[0018]The blow-off valve is switched by the cell controller; the pressure sensor reports to the cell controller.
3. Operating sequence and conditions
[0019]
- When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector.
[0020]
- When the vacuum level exceeds the gripping threshold, a secure grip is signalled by the pressure sensor.
[0021]
- The workpiece may not be lifted unless the pressure sensor signals a secure grip.
[0022]
- After the workpiece has reached the set-down position, the workpiece is blown off by the blow-off valve.
[0023]
- The workpiece is held until the blow-off valve has opened the circuit.
[0024]The cell controller reads the pressure sensor (the common supply line) and commands the blow-off valve; no sensor drives an actuator directly.
4. Parameters and operating assumptions
[0025]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); outlets of the manifold: two (sets how many lines can be fed from one inlet); placement of the pressure sensor: in the supply line (sets where in the circuit the reading is taken and what it describes); 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).
[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]Vacuum levels are stated as gauge pressure below atmosphere. A stronger vacuum is a larger pressure difference below atmosphere, and the vacuum level 'exceeds the gripping threshold' when that difference is at least the threshold difference.
5. Provenance and status
[0028]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-10549431-B2, US-11427405-B1, 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.