The present application claims priority under 35 U.S.C. §119 of German Patent Application No. 10 2006 048 069.4, filed on Oct. 11, 2006, the disclosure of which is expressly incorporated by reference herein in its entirety.
1. Field of the Invention
The invention relates to a suction gripper for handling workpieces, in particular, to a suction gripper having a suction plate with a plurality of suction openings connected to a vacuum source.
2. Discussion of Background Information
Suction grippers of this type are used in aircraft construction, e.g., for handling flexible carbon fiber-reinforced plastic (CFRP) plies and are typically arranged on a robot arm. However, they can also be operated manually.
For example, a fabric gripper by Brötje Automation GmbH is known, having active suction face of the gripper adaptable to the contour of the workpiece to be transported. Suctioning is intended to occur only at the suction openings that bear against the workpiece in particular to prevent further objects (waste, offcuts) from being suctioned. The active suction face thus essentially corresponds to the contour of the workpiece itself. To this end, the suction openings on the suction plate can be individually controlled, i.e., each of the suction openings (or alternatively individual groups of suction openings) is equipped with a hose connection to the vacuum source and can be activated or deactivated individually via on-off valves. This complex structure makes this a very heavy and awkward device, which in particular cannot be used manually. The central vacuum source, e.g., a fan, is arranged in a stationary manner and is separate from the movable gripper. The power dissipation of the fan is high because of the great length of the suction lines required.
Suction grippers are known in the field of handling circuit boards. The perforated suction plate of a suction gripper can be optionally covered with different templates in order to establish areas of the suction plate with suction action (EP 0 267 874 A1, DE 196 46 186 A1, DE 43 35 735 A1).
In unpublished German application number DE 10 2005 023 487 A1, templates of this type are present in roll form and can be moved past the suction plate by rollers.
A suction gripper with suction box and a hood arranged thereon is known from DE 100 09 108 A1, which includes several vacuum blowers arranged inside a hood. An elastic suction pad is arranged on the suction plate, the openings of the suction pad correspond to the openings of the suction plate.
According to the invention, a suction gripper includes a controllable active suction face. The suction gripper is very flexible in case of changing a template and is suitable for manual use.
In accordance with an aspect of the invention, a suction gripper for handling work pieces is provided. The suction gripper includes several templates and a device for positioning the templates on the suction plate to adjust the active area of the suction plate to suction by selecting a specific template. The templates can be in a strip form such that the individual templates are arranged sequentially, and the strip can be rolled up on rollers and can be moved past the suction plate by a roller drive. The vacuum sources include one or more pairs of fans, in which the fans of the pair are contrarotating and have parallel drive axles.
According to an embodiment of the invention, the active area of suction can be adjusted on the suction plate by several templates being present on the suction gripper. The templates can be applied to the suction plate of the suction gripper. A template may include permeable and impermeable areas, and a permeable area can correspond essentially to the workpiece contour. By selecting one of these templates, individual suction openings can be blocked out in a targeted manner, whereas other active suction openings all lie inside the workpiece contour.
In an embodiment of the invention, a light, manageable, suction gripper with controllable suction face is created, which can be used manually as well as non-manually. No complicated pipe connections, on-off valves, or complex electronic controls are required. Workpieces can be grasped and transported very precisely therewith, which is very important in particular with CFRP plies with very high susceptibility to distortion.
According to a further embodiment, the templates are made of a flexible, rollable film material, e.g., a plastic film or a fabric. The individual templates are lined up next to one another to form a strip that is rolled up on at least two separately driven rollers. The templates can be guided sequentially, in either direction, along the suction plate by using a reel drive (e.g., manually by way of a crank or electrically) in order to transport the desired template to the suction plate.
In another embodiment of the invention, vacuum sources, e.g., fans, are located in a housing having one limiting face which is formed by a suction plate. This produces a very structurally compact device. The fans are located directly behind the suction plate, i.e., in close proximity to the suction openings. Therefore, no hose or pipe connection is required between the suction plate and fan, however, some embodiments may include a hose or pipe connection to remove the outlet air. This short distance between the fan and active area of the suction device that hardly any pressure losses occur, such as are inevitable with longer lines. The power dissipation is thus very low. Because the fan is arranged proximally to the gripper head, the operator can control the function of the gripper very effectively and with low engineering effort. In particular the operator can adjust the power directly on the gripper, e.g., via a rotary handle, and switch the gripper on and off according to current requirements. Continuous operation of the fan, and the associated disadvantages such as noise pollution and/or inefficient use of energy, can be avoided by the operator's control actions.
The number of fans in any particular embodiment depends on the suction power required. According to one embodiment, exactly two contrarotating fans are used, and the drive axles of these fans are selected to be parallel to one another. A torque balance is achieved through this type of arrangement so that, consequently, no resulting torque acts on the suction gripper. The manageability of the suction gripper is thus greatly improved for the operator. The same effect may be achieved by using an even number of fans, if in each case the fans are contrarotating and have parallel drive axles.
The fans to be used can thereby include axial-flow fans as well as centrifugal fans (roller fans).
The described suction gripper is particularly suitable for handling dry, flexible fiber webs in the production of components of fiber-reinforced plastic. In aircraft construction these are often large-size components with dimensions in the range of several meters.
The invention is directed to a suction apparatus. The suction apparatus includes at least one vacuum source, a suction plate having a plurality of openings, and at least one movable template positionable on the suction plate. The at least one movable template defines an active area, and the at least one vacuum source includes at least one pair of fans, and at least one of the pairs of fans are arranged to be contrarotating.
According to an aspect of the invention, the at least one movable template can be composed of a flexible material. The flexible material can be a plastic film or a fabric.
In accordance with another aspect of the instant invention, the at least one moveable template can be arranged in a strip form.
According to still another feature of the invention, the at least one movable template may be advanced sequentially. Further, the at least one movable template can be advanced electronically or manually.
In accordance with another feature of the invention, the suction apparatus may include a roller device structured and arranged to move at least one movable template past at least two separately driven rollers.
Another feature of the invention includes the at least one vacuum source, which may be located proximally to the suction plate. The vacuum source may also be arranged in a housing having a face formed by the suction plate. The at least one vacuum source may be comprised of an even number of contrarotating fans.
According to yet another aspect of the invention, the at least one pair of fans can have parallel drive axles.
Further aspects of the invention may include an air distribution layer structured and arranged to provide a uniform flow distribution, the air distribution layer may be positionably adjacent to the suction plate. The air distribution layer may further be composed of at least an open-pore foam, a three-dimensional honeycomb or lattice structure, and made of at least one of a metal or plastic.
The invention is directed to a method for gripping workpieces. The method includes selecting a template, positioning the template on a suction plate, creating suction through the suction plate with at least one pair of fans arranged in contrarotation, and suctioning a workpiece corresponding in size and shape to openings in the template.
In accordance with an aspect of the present invention, the template may be composed from a flexible material such as a plastic film or a fabric.
According to another aspect of the invention, the template can be sequentially selected. The template can be arranged in strip form. The template can also be positioned electronically or manually. Furthermore, the template may include at least one permeable and at least one impermeable area, whereby a vacuum can suction the workpiece located proximate to the permeable area. The at least one permeable area may be shaped to a contour of the workpiece.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.
The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.
The top of the housing 11 has two protuberances 12, 13, within which respectively a fan 4 is arranged to generate a vacuum (see
Two winding or unwinding devices, which are illustrated as rollers 3, are arranged at the side of the housing 11 of the suction gripper 10. While rollers are illustrated in this embodiment, it should be understood that alternative mechanisms for winding or unwinding may be used instead of rollers. The rollers 3 are configured to have one or more templates 1 (see
Of course, templates are also possible that have only one perforation (for transporting just one workpiece) or with any desired number of perforations for the transport of a corresponding number of workpieces.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
Number | Date | Country | Kind |
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10 2006 048 069.4 | Oct 2006 | DE | national |