Abstract
A zoned vacuum gripping tool comprising one tool-change interface, two suction cups, one plant vacuum connection, one manifold, two zone branches, one pressure sensor and one blow-off valve. When the suction cups reach the workpiece, the suction cups are evacuated by the plant vacuum connection. Before the workpiece reaches the set-down position, the workpiece is blown off by the blow-off 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: two suction cups carried on a tool-change interface, fed by a plant vacuum connection. It is arranged for handling workpieces that do not cover the whole gripping face, verifying that the workpiece is held before the arm moves, clearing the face at release and exchanging the tool without rewiring the cell. 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 tool-change interface. The tool-change interface splits the tool into a robot side and a tool side, so the tool can be exchanged without dismantling it. The tool-change interface has a pneumatic lock.
[0003]Two suction cups. Each suction cup presents a sealing lip to the workpiece and is evacuated through its own connection. The count of two follows from the arrangement: one gripping element per zone branch. The suction cups are of the oval form.
[0004]One plant vacuum connection. The plant vacuum connection takes vacuum from the plant line, so the tool carries no generator of its own.
[0005]One manifold. The manifold receives the vacuum at one inlet and distributes it to its outlets. The manifold has three outlets.
[0006]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.
[0007]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.
[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 sustained blast. The blow-off pulse is given before set-down.
[0009]The suction cups are carried on the tool side of the tool-change interface.
[0010]The manifold is fixed to the tool side of the tool-change interface.
[0011]The manifold inlet is connected to the plant vacuum connection, which supplies every outlet of the manifold.
[0012]Each of the two zone branches is taken from its own manifold outlet, so that the branch carries the vacuum of its own zone only.
[0013]Each suction cup is connected to its own zone line, one suction cup per zone, and is evacuated through that line.
[0014]The pressure sensor is tapped into the line between the plant vacuum connection and the distribution and reads the pressure of the whole circuit.
[0015]The blow-off valve is connected to the circuit at the plant vacuum connection, so that compressed air can be driven back through the circuit to the face.
[0016]The robot side of the tool-change interface is bolted to the robot flange.
[0017]The remaining one manifold outlet is plugged and carries no line.
[0018]The blow-off valve is fed from the compressed air supply of the cell.
[0019]The locking piston of the tool-change interface is fed from the compressed air supply of the cell.
[0020]The blow-off valve and the lock of the tool-change interface are switched by the cell controller; the pressure sensor reports to the cell controller.
3. Operating sequence and conditions
[0021]
- When the suction cups reach the workpiece, the suction cups are evacuated by the plant vacuum connection.
[0022]
- When the vacuum level exceeds the gripping threshold, a secure grip is signalled by the pressure sensor.
[0023]
- The workpiece may not be lifted unless the pressure sensor signals a secure grip.
[0024]
- Before the workpiece reaches the set-down position, the workpiece is blown off by the blow-off valve while the workpiece is above the receiving surface.
[0025]
- The workpiece is held until the blow-off valve has opened the circuit.
[0026]The cell controller reads the pressure sensor (the common supply line) and commands the blow-off valve, the tool-change interface; no sensor drives an actuator directly.
4. Parameters and operating assumptions
[0027]Parameter values of this embodiment: locking of the tool-change interface: pneumatic (sets what has to be present at the interface for the tool to stay attached); form of the suction cups: oval (sets the shape of the contact area and the behaviour of the lip on a curved workpiece); material of the suction cups: polyurethane (sets the friction at the lip and the tolerance of the lip to oil and heat); outlets of the manifold: three (sets how many lines can be fed from one inlet); 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); duration of the blow-off valve: a sustained blast (sets how quickly the face clears and how much air each release costs); timing of the blow-off valve: before set-down (sets whether the pulse assists a drop release or clears the face after set-down).
[0028]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.
[0029]The blow-off is a sustained blast: the valve stays open for the whole release so that the face is cleared of dust and the workpiece is pushed positively away.
[0030]The tool carries no valve between the plant line and the face, so the plant vacuum is applied to the face whenever the plant line is live; release relies on the release element alone.
[0031]The lock is engaged by compressed air acting on the locking piston and is held only while that air pressure is applied; what the lock does on loss of air pressure is not fixed by this arrangement.
[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 US-10259123-B2, US-11427405-B1, US-11858125-B2, US-2016214812-A1, US-8006968-B2, US-8132312-B2, WO-2026020244-A1; their text is not reproduced, and the description above is generated from the structure of the combination.