Holding head for a vacuum holding device for handling a plate-shaped workpiece and corresponding vacuum holding device

A holding head is provided for a vacuum holding device for handling a plate-shaped workpiece about an axis. An arrangement of operating elements on a base body of the holding head includes at least three operating elements connected as actuating elements in a double actuation circuit for releasing the plate-shaped workpiece. Two of the actuating elements are arranged on sides of the arrangement opposite to one another with respect to the position of the axis and the third actuating element is designed ring-shaped and surrounds the axis circumferentially.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit and priority of German patent application number DE 10 2019 104 590.8, filed on Feb. 22, 2019. The entire disclosure of the above application is incorporated herein by reference.

FIELD

The invention relates to a holding head for a vacuum holding device for handling a plate-shaped workpiece, in particular a glass plate, wherein the holding head is rotatably mounted with respect to an axis and comprises a base body with an arrangement of operating elements of a control system for controlling a vacuum system of the vacuum holding device, wherein the arrangement surrounds the axis, and at least one vacuum holding element mounted directly or indirectly on the base body for holding the plate-shaped workpiece.

The invention further relates to a corresponding vacuum holding device for handling a plate-shaped workpiece and an arrangement of operating elements on the base body of a holding head.

BACKGROUND

Vacuum holding devices for handling a plate-shaped workpiece are known as vacuum lifting devices (in short: vacuum lifters). They are suitable for handling large and flat, largely suction-tight workpieces, such as, for example: for handling and positioning glass plates and windows during the production, framing and assembly, for loading and unloading CNC laser cutting machines with metal sheets or for loading and unloading CNC processing machines with wooden or plastic plates.

There are various safety requirements for such vacuum lifting devices. These result, for example, from the European standard EN 13155:2003 (cranes—safety—loose load bearing center). Chapter 5 lists the safety requirements and safety measures. Point 5.2.2 in the standard lists “special requirements for vacuum lifting devices”. Sub-item 5.2.2.9 describes the following requirement: “The release of the load has to be implemented by use of a control with double actuation. This is not necessary if a release of the load is not possible before the load is set down or in secure areas.”

When handling plate-shaped workpieces, for example in handling and positioning of glass plates and windows during assembly, as many degrees of freedom of motion as possible are desired. However, the double actuation should be easy to perform in each position.

Document EP 1314836 A2 shows a holding head of a vacuum holding device for handling a glass plate, wherein the holding head is rotatably mounted with respect to an axis of rotation and comprises a base body with an arrangement of operating elements of a control system for controlling a vacuum system of the vacuum holding device, wherein the arrangement surrounds the axis of rotation, and a plurality of vacuum holding elements mounted directly or indirectly on the base body for holding the glass plate. The rotatable mounting is implemented by means of bearing means, which is arranged outside the axis of rotation and the arrangement of the operating elements. This rotatable bearing is quite complex and allows an expansion by additional degrees of freedom only with increased effort.

SUMMARY

It is an object of the invention to provide measures that enable a convenient operation of the prescribed control with double actuation with rotatably mounted holding heads.

According to the invention, the object is achieved by the features of the independent claims. Advantageous embodiments of the invention are specified in the dependent claims.

In the holding head according to the invention for a vacuum holding device for handling a plate-shaped workpiece which is rotatably mounted with respect to an axis and comprises a base body with an arrangement of operating elements of a control system for controlling a vacuum system of the vacuum holding device, wherein the arrangement surrounds the axis, and at least one vacuum holding element mounted directly or indirectly on the base body for holding the plate-shaped workpiece, it is provided that at least three of the operating elements are connected as actuating elements in a double actuation circuit for releasing the plate-shaped workpiece, wherein the first two of the actuating elements are disposed on sides of the arrangement opposite to one another with respect to the position of the axis and the third actuating element is formed ring-shaped and surrounds the axis circumferentially. This configuration and arrangement of the actuating elements enables to operate the double actuation circuit without problems at any angular position of the holding head, because even if the holding head is mounted close to the axis, at least one of the first two actuating elements and at least one segment of the third actuating element should always be accessible.

Said mounting close to the axis, that is to say a rotatable mounting which is in the region of the axis of rotation, can be expanded relative easily by further degrees of freedom of motion.

In the holding head the actuating elements are in particular connected in such a way that the actuation of the first and/or the second actuating element releases a locking of the third actuating element and releases this third actuating element for actuation. Normally, a locking mechanism is provided for the releasable locking of the third actuating element. The third actuating element, if actuated, then triggers the “release of the load”.

According to an advantageous embodiment of the invention, it is provided that the ring-shaped third actuating element can be actuated by rotating. The rotation takes place in particular with a rotational movement along the ring-shaped structure.

According to a further advantageous embodiment of the invention, it is provided that the first actuating element, the axis and the second actuating element are arranged on an imaginary straight line. Here, each of the first two actuating elements, that is to say the first and the second actuating element, has in particular the same distance from the axis. In other words, the first two actuating elements have point symmetry with respect to the axis.

In the holding head, it is in particular provided that the first and/or the second actuating element is/are designed as a push switch, in particular as a push button. Such switches/buttons are proven standard actuators.

According to an advantageous embodiment of the holding head according to the invention it is provided that the first two actuating elements are arranged outside the ring-shaped third actuating element. This arrangement of the actuating elements is favoured by many operators/users in a double actuation circuit.

In the vacuum holding device according to the invention for handling a plate-shaped workpiece, in particular a glass plate, comprising a vacuum system, a control system for controlling the vacuum system and a holding head rotatably mounted with respect to an axis it is provided that the holding head is designed as the holding head mentioned above.

According to an advantageous embodiment of the vacuum holding device according to the invention it is provided that it has an arm at which the holding head is rotatably mounted. Here, it is in particular provided that the holding head at the arm is also pivotably mounted with respect to at least one further axis.

In the arrangement of operating elements according to the invention on the base body of a holding head for a vacuum holding device for handling a plate-shaped workpiece around an axis it is provided that at least three of the operating elements are connected as actuating elements in a double actuation circuit for releasing the plate-shaped workpiece, wherein the first two of the actuating elements are arranged on opposite sides of the arrangement with respect to the position of the axis, and the third actuating element is configured in a ring shape and surrounds the axis circumferentially. This configuration and arrangement of the actuating elements enables to operate the double actuation circuit without problems at any angular position of the holding head even if the holding head is mounted close to the axis.

The embodiments of the invention mentioned in connection with the holding head which relate to the operating elements arranged on the base body are also intended to apply in the same way to the arrangement of these operating elements on the base body of the holding head.

DETAILED DESCRIPTION

FIG. 1shows a vacuum holding device10for handling a plate-shaped workpiece (not shown) such as a glass plate. The vacuum holding device10comprises parts of a corresponding vacuum system and a control system for controlling the vacuum system, and as mechanical components: a holding head12and an arm14carrying the holding head12. The holding head12, which essentially extends in one plane, is mounted at the arm14so that it can be rotated about an axis16. The axis16passes in the middle through a central component of the holding head12—the base body18—and is oriented perpendicular to said plane. The arm14can be attached to a crane hook of a crane, for example.

In addition to this base body18the holding head12comprises a plurality (in the example, four) vacuum holding elements20for holding the plate-shaped workpiece which are indirectly mounted on the base body18. For this purpose, the holding head12comprises four support arms22projecting outwards from the base body18, on the free ends of which the vacuum holding elements20are arranged. The vacuum areas of these vacuum holding elements20are all arranged on one side of the plane. In the diagram ofFIG. 1this is the rear side. On the front side of the base body18there is an arrangement24of operating elements26,28,30of the control system for controlling said vacuum system, wherein the arrangement surrounds the axis16. In addition to the operating elements not further described here, these are the actuating elements26,28,30of a double actuation circuit for releasing the plate-shaped workpiece, that is to say actuating elements26,28,30connected in this circuit. The actuating elements26,28,30are arranged such that the first two actuating elements26,28are arranged on sides or half-planes of the arrangement24opposite to one another with respect to the position of the axis16, and such that the ring-shaped third actuating element30surrounds the axis16circumferentially.

By means of a corresponding double actuation of these actuating elements26,28,30a ventilation of the vacuum areas of the vacuum holding elements20is caused.

Due to a safety requirement for such vacuum holding devices10(and also other vacuum lifting devices) the release of the load, that is to say the plate-shaped workpiece, has to be effected by a control with double actuation. In the present case, this requirement/regulation is met by connecting the actuating elements26,28,30in such a way that the actuation of the first and/or the second actuating element26,28releases a locking of the third actuating element30and releases it for actuation. If subsequently the third actuating element30is actuated, there is certainly a double actuation and the vacuum system is controlled so that the vacuum areas of the vacuum holding elements20are vented, which results in the release of the plate-shaped workpiece, i.e. the load, from the holding head12.

The holding head12further comprises a plurality of railings on its front side, wherein a respective one of these railings surrounds the base body18and the support arms22. The operator/user can grip and move the holding head well via these railings.

FIG. 2shows the mounting of the holding head12at the arm14and the arrangement24of the operating elements26,28,30of the control system for controlling the vacuum system in more detail.

On the front side of the holding head12facing the operator it is mounted at the level of the axis16at the end of the arm14. The mounting is carried out in such a way that the holding head12is mounted rotatable with respect to the axis16(double arrow32) and also pivotable with respect to at least one further axis36(double arrow34). The two axes16,36are perpendicular to each other. With such a mounting it is therefore possible that individual operating elements, in particular also actuating elements26,28,30of the holding head12are completely or partially covered by the arm14when the holding head12is in a corresponding angular position.

In order to enable a comfortable actuation of the double actuation circuit in any angular position of the holding head12for the operator, the actuating elements26,28,30are arranged and designed as follows:

The first two of the three actuating elements26,28connected in the double actuation circuit for releasing the plate-shaped workpiece are arranged on half planes of the arrangement24opposite to one another with respect to the position of the axis16and are designed as push switches. The third actuating element30is configured in a ring shape, can be actuated by rotating it along its ring-shaped structure and is arranged around the axis16. Distributed circumferentially on the ring-shaped base structure of the third actuating element30this comprises handles38. The position of the axis16forms the center of the ring-shaped structure of the third actuating element30and the two first actuating elements26,28are arranged outside the ring-shaped third actuating element30such that the first actuating element26, the axis16and the second actuating element28are disposed on an imaginary straight line, wherein the first two actuating elements26,28are disposed at the same distance from the axis16.

In the holding head12, the three actuating elements26,28,30are connected such that the actuation of the first and/or the second actuating element26,28releases a locking of the third actuating element30and releases this third actuating element30for actuation. A locking mechanism is provided for the releasable locking of the third actuating element30, but is not visible in this illustration. A valve (not shown) can now be actuated with the third actuating element30, via which the vacuum areas of the vacuum holding element20are ventilated.

The actuating elements26,28,30can thus be described as follows:

The arrangement24of the actuating elements26,28,30is symmetrical, central and always visible or accessible. In no situation the actuating elements26,28,30can be covered by the arm14in such a way that a double actuation would not be possible.