Three bellows cup vacuum gripper, three outlet manifold, pump fed, supply line pressure sensor, vented before set-down

Abstract

A bellows-cup vacuum gripping tool comprising one mounting flange, three bellows cups, one vacuum pump, one manifold, one pressure sensor, one contact detector and one vent valve. When the bellows cups reach the workpiece, the bellows cups are 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 bellows-cup vacuum gripping tool: three bellows cups 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 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]Three 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 three follows from the arrangement: one gripping element per manifold outlet. Each bellows cup has three folds.

[0004]One vacuum pump. The pump draws the circuit down mechanically and adds its own mass to the moving assembly.

[0005]One manifold. The manifold receives the vacuum at one inlet and distributes it to its outlets. The manifold has three 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 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.

[0008]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.

[0009]The bellows cups are carried on the tool side of the mounting flange.

[0010]The manifold is fixed to the tool side of the mounting flange.

[0011]The vacuum pump is fixed to the tool side of the mounting flange.

[0012]The manifold inlet is connected to the pump inlet line, which supplies every outlet of the manifold.

[0013]Each manifold outlet feeds one bellows cup by its own vacuum line, so that the three outlets feed three bellows cups.

[0014]The pressure sensor is tapped into the line between the vacuum pump and the distribution and reads the pressure of the whole circuit.

[0015]The contact detector is mounted on the frame and reports the moment a workpiece is present against the gripping face.

[0016]The vent valve is connected to the circuit at the pump inlet line and opens that circuit to atmosphere when it is actuated.

[0017]The robot side of the mounting flange is bolted to the robot flange.

[0018]The pump motor is supplied from the electrical supply of the cell.

[0019]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

[0026]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

[0027]Parameter values of this embodiment: folds of the bellows cups: three (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); drive medium of the vacuum pump: electric (sets the supply the pump motor needs from the cell); outlets of the manifold: three (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); 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).

[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]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

[0030]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-2022339798-A1, US-8006968-B2, WO-2008134339-A4; their text is not reproduced, and the description above is generated from the structure of the combination.