Abstract
A zoned vacuum gripping tool comprising one mounting flange, one foam pad, one vacuum pump, two zone branches, one pressure sensor and one vent valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the vacuum pump. Before the workpiece reaches the set-down position, the vacuum circuit is vented by the vent valve while the workpiece is above the receiving surface. 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, verifying that the workpiece is held before the arm moves, controlling the moment of 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]Two zone branches. Each zone branch carries the vacuum of one zone of the face and no other. The count of two follows from the arrangement: one branch per zone. The distribution is divided into two zones, each fed by its own branch.
[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 vent valve. The vent valve opens the circuit it is connected to towards atmosphere, which ends the grip. The circuit is vented before set-down.
[0008]The foam pad is carried on the tool side of the mounting flange.
[0009]The vacuum pump is fixed to the tool side of the mounting flange.
[0010]The two zone branches are taken from a branch junction on the pump inlet line, so that each branch carries the vacuum of its own zone only.
[0011]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.
[0012]The pressure sensor is tapped into the line between the vacuum pump and the distribution and reads the pressure of the whole circuit.
[0013]The vent valve is connected to the circuit at the pump inlet line and opens that circuit to atmosphere when it is actuated.
[0014]The robot side of the mounting flange is bolted to the robot flange.
[0015]The pump motor is supplied from the electrical supply of the cell.
[0016]The vent valve is switched by the cell controller; the pressure sensor reports to the cell controller.
3. Operating sequence and conditions
[0017]
- When the foam pad reaches the workpiece, the foam pad is evacuated by the vacuum pump.
[0018]
- When the vacuum level exceeds the gripping threshold, a secure grip is signalled by the pressure sensor.
[0019]
- The workpiece may not be lifted unless the pressure sensor signals a secure grip.
[0020]
- Before the workpiece reaches the set-down position, the vacuum circuit is vented by the vent valve while the workpiece is above the receiving surface.
[0021]
- The workpiece is held until the vent valve has opened the circuit.
[0022]The cell controller reads the pressure sensor (the common supply line) and commands the vent valve; no sensor drives an actuator directly.
4. Parameters and operating assumptions
[0023]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); material of the zone branches: plastic; zones of the zone branches: two (sets how much of the face can be treated separately); placement of the pressure sensor: in the supply line (sets where in the circuit the reading is taken and what it describes); timing of the vent valve: before set-down (sets whether the workpiece is released before or after it is supported by the set-down surface).
[0024]The workpiece is released while it is still above the receiving surface and falls the remaining distance onto it. This sequence is for a workpiece and a receiving surface that tolerate that drop, for example a part released into a container or onto a conveyor; the drop height is set by the application and is not fixed here.
[0025]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.
[0026]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
[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-10549431-B2, US-11427405-B1, WO-2008134339-A4, WO-2026020244-A1; their text is not reproduced, and the description above is generated from the structure of the combination.
6. Correction notice
[0028]This publication supersedes OT-2026-000008200, 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: isolation valve removed.