Abstract
A foam-pad vacuum gripping tool comprising one mounting flange, one foam pad, one vacuum pump, one pressure sensor, one contact detector 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 foam-pad vacuum gripping tool: one foam pad carried on a mounting flange, fed by a vacuum pump. It is arranged for verifying that the workpiece is held before the arm moves, starting the cycle at the moment of contact, 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 closed cell foam.
[0004]One vacuum pump. The pump draws the circuit down mechanically and adds its own mass to the moving assembly.
[0005]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.
[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 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 foam pad is connected to the pump inlet line by a single vacuum line, so that the face is evacuated through that line.
[0011]The pressure sensor is tapped into the line between the vacuum pump and the foam pad and reads the pressure of the whole circuit.
[0012]The contact detector is mounted on the frame and reports the moment a workpiece is present against the gripping face.
[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 and the contact detector report to the cell controller.
3. Operating sequence and conditions
[0017]
- After the contact detector has detected the workpiece, the vacuum supply is actuated by the cell controller.
[0018]
- When the foam pad reaches the workpiece, the foam pad is evacuated by the vacuum pump.
[0019]
- When the vacuum level exceeds the gripping threshold, a secure grip is signalled by the pressure sensor.
[0020]
- The workpiece may not be lifted unless the pressure sensor signals a secure grip.
[0021]
- 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.
[0022]
- The workpiece is held until the vent valve has opened the circuit.
[0023]The cell controller reads the pressure sensor (the common supply line) and the contact detector (on the frame) and commands the vent valve; no sensor drives an actuator directly.
4. Parameters and operating assumptions
[0024]Parameter values of this embodiment: 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); drive medium of the vacuum pump: electric (sets the supply the pump motor needs from the cell); placement of the pressure sensor: in the supply line (sets where in the circuit the reading is taken and what it describes); placement of the contact detector: on the frame (sets where the presence of the workpiece is detected); 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).
[0025]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.
[0026]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.
[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-4385681-B1, US-10549431-B2, US-11427405-B1, US-2022339798-A1, WO-2008134339-A4; their text is not reproduced, and the description above is generated from the structure of the combination.
6. Correction notice
[0029]This publication supersedes OT-2026-000006020, 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: sensor placement moved from an absent manifold to the supply line; foam_pad material 'foam' is not offered by the library; the source-stated value 'sponge' is used.