Abstract
A zoned vacuum gripping tool comprising one mounting flange, one foam pad, one vacuum pump, one isolation valve, four zone branches, four pressure sensors and one blow-off valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the vacuum pump. 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: one foam pad carried on a mounting flange, fed by a vacuum pump. It is arranged for handling workpieces that do not cover the whole gripping face, cutting part of the circuit while the rest holds vacuum, verifying that the workpiece is held before the arm moves, clearing the face at release and holding a workpiece that a rigid lip cannot seal against. 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]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 open cell foam.
[0004]One vacuum pump. The pump draws the circuit down mechanically and adds its own mass to the moving assembly.
[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]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]Four pressure sensors. Each pressure sensor taps the line it is placed in and reports the vacuum level in that line. The count of four follows from the arrangement: one sensor per zone branch. The pressure is measured at each zone.
[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 foam pad is carried on the tool side of the mounting flange.
[0010]The vacuum pump is fixed to the tool side of the mounting flange.
[0011]The isolation valve is placed in the line from the vacuum pump, so that closing the valve cuts the whole circuit from the supply.
[0012]The four 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.
[0013]Each zone line opens into its own section of the distribution chamber behind the porous face of the foam pad, so that the pad is evacuated zone by zone.
[0014]One pressure sensor is tapped into each zone line, so that each of the four sensors reads its own zone and no other.
[0015]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.
[0016]The robot side of the mounting flange is bolted to the robot flange.
[0017]The pump motor is supplied from the electrical supply of the cell.
[0018]The blow-off valve is fed from the compressed air supply of the cell.
[0019]The isolation valve and the blow-off valve are switched by the cell controller; the pressure sensors reports to the cell controller.
3. Operating sequence and conditions
[0020]
- When the foam pad reaches the workpiece, the foam pad is evacuated by the vacuum pump.
[0021]
- When the vacuum level exceeds the gripping threshold, a secure grip is signalled by the pressure sensor of each zone in use.
[0022]
- The workpiece may not be lifted unless the pressure sensor of each zone in use signals a secure grip.
[0023]
- After the vacuum level has exceeded the gripping threshold, the isolation valve is closed by the cell controller.
[0024]
- While the isolation valve is in the closed state, the vacuum downstream of the valve is maintained by the sealed gripping face.
[0025]
- After the workpiece has reached the set-down position, the workpiece is blown off by the blow-off valve.
[0026]
- The workpiece is held until the blow-off valve has opened the circuit.
[0027]The cell controller reads the pressure sensor (each zone line) 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: material of the foam pad: sponge (sets the compliance of the sealing face); porosity of the foam pad: open cell (sets whether air passes through the pad body or only through openings cut through it); drive medium of the vacuum pump: electric (sets the supply the pump motor needs from the cell); 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: four (sets how much of the face can be treated separately); placement of the pressure sensors: at each zone (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).
[0029]A zone is in use when the workpiece covers it. Which zones are in use is decided by the controller from the workpiece programme; this arrangement fixes where each zone is measured, not how the programme is written.
[0030]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.
[0031]The open-cell foam passes air through its whole face, so an uncovered part of the face draws air through the pad itself; the supply is sized for that continuous flow and the pad relies on flow restriction through the foam, not on a seal, to hold vacuum behind a covered area.
[0032]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
[0033]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-10549431-B2, US-11427405-B1, US-8132312-B2, WO-2026020244-A1; their text is not reproduced, and the description above is generated from the structure of the combination.
6. Correction notice
[0034]This publication supersedes OT-2026-000004490, whose text described this arrangement with defects recorded in the quality register at https://opentechnical.org/qa/. The earlier publication is unchanged and remains public. Changes made to reach a consistent configuration: foam_pad material 'foam' is not offered by the library; the source-stated value 'sponge' is used.