OPENTECHNICAL PUBLICATION
OT-2026-000078780

Single bellows cup vacuum gripper, three stage ejector, vented after set-down

Published: 2026-09-17T08:57:28.017032Z
Permanent URL: https://opentechnical.org/p/OT-2026-000078780
Categories: Robotics & Automation > End Effectors > Vacuum Grippers

------------------------------------------------------------------------

ABSTRACT

A bellows-cup vacuum gripping tool comprising one mounting flange, one bellows
cup, one ejector, one contact detector and one vent valve. When the bellows
cup reaches the workpiece, the bellows cup is evacuated by the ejector. After
the workpiece has reached the set-down position, the vacuum circuit is vented
by the vent 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 bellows-cup vacuum gripping tool: one
bellows cup carried on a mounting flange, fed by an ejector. It is arranged
for 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] One bellows cup. Each bellows cup is folded so that it shortens under
vacuum and takes up a height difference between the face and the workpiece.
Each bellows cup has two folds.

[0004] One ejector. The ejector draws the circuit down by passing compressed
air through a nozzle; it has no moving part at the tool and consumes air for
as long as it runs. The ejector has three stages.

[0005] 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.

[0006] One vent valve. The vent valve opens the circuit it is connected to
towards atmosphere, which ends the grip. The circuit is vented after set-down.

[0007] The bellows cup is carried on the tool side of the mounting flange.

[0008] The ejector is fixed to the tool side of the mounting flange.

[0009] The bellows cup is connected to the ejector outlet by a single vacuum
line, so that the face is evacuated through that line.

[0010] The contact detector is mounted on the frame and reports the moment a
workpiece is present against the gripping face.

[0011] The vent valve is connected to the circuit at the ejector outlet and
opens that circuit to atmosphere when it is actuated.

[0012] The robot side of the mounting flange is bolted to the robot flange.

[0013] The ejector is fed from the compressed air supply of the cell.

[0014] The vent valve is switched by the cell controller; the contact detector
reports to the cell controller.

3. Operating sequence and conditions

[0015]
  - After the contact detector has detected the workpiece, the vacuum supply is actuated by the cell controller.

[0016]
  - When the bellows cup reaches the workpiece, the bellows cup is evacuated by the ejector.

[0017]
  - After the workpiece has reached the set-down position, the vacuum circuit is vented by the vent valve.

[0018]
  - The workpiece is held until the vent valve has opened the circuit.

[0019] The cell controller reads the contact detector (on the frame) and
commands the vent valve; no sensor drives an actuator directly.

4. Parameters and operating assumptions

[0020] Parameter values of this embodiment: folds of the bellows cup: two
(sets the travel taken up between the face and the workpiece, and the lateral
stiffness of the cup under load); material of the bellows cup: plastic (sets
the friction at the lip and the resistance of the folds to fatigue); stages of
the ejector: three (sets the flow drawn at low vacuum and the compressed air
consumed while a sealed face is held); placement of the contact detector: on
the frame (sets where the presence of the workpiece is detected); timing of
the vent valve: after set-down (sets whether the workpiece is released before
or after it is supported by the set-down surface).

5. Provenance and status

[0021] 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-2022339798-A1, WO-2008134339-A4; their text is not reproduced, and the
description above is generated from the structure of the combination.

------------------------------------------------------------------------

OpenTechnical publication OT-2026-000078780
Published 2026-09-17T08:57:28.017032Z
https://opentechnical.org/p/OT-2026-000078780