Patent Description:
In present days, the assembling of automotive side mirrors is mostly done manually by human beings within a manufacturing unit. This leads to high costs and is time consuming. Therefore there is the need for an automated robotic assembly line.

A gripping device for articles like motor vehicle headlights is known e.g. from <CIT>. The known device has gripping units which exert gripping forces perpendicular to individual points of surfaces of such articles. Each gripping unit grips an article at one gripping point such that the article can be hold by the device. This allows for gripping of geometrically different articles of similar upper surface topology with the same device; but the gripping device is rather complicated and not suited for different surface topologies.

As mirror parts of an automotive side mirror like a housing part, a lighting module or a circuit board can have a large variety of geometries and/or topologies, even differing from model to model, presently most of the mirror parts are gripped in different manners with specific gripper designs. This requires time consuming and cost intensive gripper changes.

In order to provide a high degree of freedom, flexible circuit boards are used in automotive mirrors, see for example <CIT>. Such flexible circuit boards or wire harnesses provide terminals to be connected to different kinds of modules, like a blind spotter module, a ground light module and a turn signal module. The respective connection between the terminals and the modules and the subsequent attachment of the modules might even require assembling steps with gripper movements in different directions.

<CIT> refers to the assembly of e.g. <NUM> reaction vessels to a tray with <NUM> seats. Each vessel is provided with a standard gripping collar to be gripped by a gripper via a snap connection. The collar can have different cross-sections. The gripper can be attached to a robotic arm which comprises sensors/detectors.

<CIT> teaches a gripping device to be attached to a robot at a top with a plurality of arms and being controlled via sensor signals. Each arm comprises an upper and a lower part connected via a joint and gripping fingers providing a plurality of degrees of freedom for moving the fingers.

<CIT> discloses a gripping device to be attached to a robot with <NUM> arms. Each arm can be controlled for a rotational and a translational motion and functions as a suction gripper for food items.

<CIT> refers to a robot hand capable of gripping a plurality of gripping objects. This robot hand comprises gripping mechanisms capable of opening and closing a pair of fingers and gripping a gripping object with fingers, and a relative position changing drive mechanism for changing a relative position between the gripping mechanism.

<CIT> discloses a gripping device to be attached to a robot with grippers. Each gripper can be controlled for a rotational and a translational motion:
<CIT> claims a. a manipulator for manipulating an item of crockery. A robot arm having at least two degrees of freedom; a gripper unit provided at an end of the robot arm; and a controller for controlling an operation of the robot arm and the gripper unit are comprised of the manipulator. The gripper unit comprises at least one gripper member, the gripper member comprising a gripper body; and a pair of fingers extending from the gripper body, the fingers being movable towards one another and away from one another, and each finger having an end carrying a clamping member for contacting the item of crockery. The gripper member is configured to be driven for rotating the clamping members around an axis parallel to a line connecting the ends of the fingers.

<CIT> refers to a chuck device with chuck portions.

<CIT> teaches a manipulator for transporting food products. For example a food product arranged on a conveyor belt can be slided on two blades which can be moved relative to each other.

A clamp mechanism known from <CIT> includes a base defining two first sliding grooves, a sliding member slidable relative to the base and two second sliding grooves corresponding to the first sliding grooves respectively, a pair of first connecting members slidably received in the first sliding grooves respectively, a pair of second connecting members slidably received in the second sliding grooves respectively, a first clamp member connected to one first connecting member and one second connecting member, a second clamp member connected to the other first connecting member and the other second connecting member, an impelling member fixed to the sliding member; and a driver capable of driving the sliding member along with the first and second clamp members to move toward or away from each other in order to clamp or release an object, and the impelling member capable of removing the object when the object is released.

A plurality of gripper modules positioned in space apart relationship along a frame member provide an end-of-arm tool are described in <CIT>. A pair of gripper modules disposed on opposite sides of the end-of-arm tool each support a Hall effect sensor which is coupled through a signal processing circuit to control the heads of the gripper modules.

It is the object of the present invention to further develop the known device for automating the assembly of in particular automotive mirrors, to overcome the drawbacks of the prior art.

This object is solved by the characterizing portion of claim <NUM>. Preferred embodiments of the device according to the invention are described in the sub-claims <NUM> to <NUM>.

According to a first aspect of the invention the same is based on a modification of individual mirror parts in order to make them suitable for handling during an automated assembling of an automotive mirror within a manufacturing unit, namely such that any type of common basic gripper instead of several different grippers for handling mirror parts with different designs and thus different geometries and/or topologies can be used. The modification is to provide standard gripping points. Such standard gripping points can be provided by slots, cut outs, recesses, clips, straps and/or projections and can be introduced at any available area within the individual mirror parts with a shape (like square, rectangular, triangular, circular, hexagonal, octagonal or pentagonal) and dimension adapted to the gripper design or vice versa. As soon as a common gripper design has been selected, pre-defined gripping points can be introduced on the mirror parts such that they can be assembled by a robot or automated. This reduces the overall costs involved in setting up a production line. In long term it also helps reducing the overall maintenance costs of the production line and also reduces the overall production cycle time and assembling time involved. Using standard gripping points on individual automotive mirror part also enables a handling of these parts in any orientation or method by a robotic gripping device.

The slots, cut outs, recesses, clips, straps and/or projections providing the standard gripping points can fulfill an additional function like enabling a snap connection or can be provided by a functional member like a snap-in clips or even two terminals serving an electrical connection between a circuit board and an electric module like a lightning module.

According to a second aspect of the invention a robotic gripping device is provided which is in particular suited for handling mirror parts during the assembly of an automotive mirror, even in form of a flexible circuit board with e.g. n branches for connecting n electric modules to a power source, n being a member of the natural numbers above <NUM>. Such a gripping device is provided with n gripping units each having one arm arranged around a central spine, each arm having a pair of <NUM> fingers, with the spine, the arms as well as the fingers being operated pneumatically, hydraulically and/or electrically for handling e.g. the n branches of a flexible circuit board, wire harnesses, mirror parts or any other applicable objects. Thus the gripping device can be operated by supplying for example air, oil, water or electrical current.

In case the spine has <NUM> degrees of freedom, namely for <NUM> translatory and <NUM> rotary movement, each arm is provided with <NUM> parts providing at least <NUM> further degree of freedom and each pair of fingers is provided with at least <NUM> additional degree of freedom, the gripping device is suited for ample assembly steps, even in different production directions. Thus, the gripping device is a multi operational gripper which can be used for different applications. By varying the features of the gripping units and by adjusting the position of the arms or fingers thereof, even more applications become possible.

The gripping device is designed based on the idea to benefit from a combination of the advantages of spider legs and a human palm with fingers and, therefore, is called spider gripper in the following.

The spider gripper can be directly integrated as an end effector tool to an industrial robot or to any type of machinery, but can also be used with an industrial robot or machinery via an automatic tool changer system where the tool side of the respective automatic tool changer module will be connected to the spider gripper top.

The preferred spider gripper has <NUM> arms and <NUM> pairs of fingers which are in particular designed for each holding a branch of a flexible circuit board. Each free end of an arm of the spider gripper has a small pneumatic or hydraulic cylinder or electrically operated motor based system for gripping one branch, inserting the terminals or connectors of said branch in corresponding sockets provided by an electric module and ejecting the branch at the end.

The number of arms and/or fingers of the spider gripper can be increased or decreased based on the design of the article to be handled, like the design of wire harnesses, and depending on the number of branches of involved flexible circuit boards. The position of the arms and fingers of the spider gripper relative to the central spine and/or relative to each other can be manually or pneumatically, hydraulically and/or electrically adjusted based on the handled articles.

The spider gripper spine, arms and fingers can be controlled individually. Sensors and mechanical stoppers can be used in the spider gripper for controlling the movement in particular of the individual arms and/or fingers.

The invention, together with further objects and advantages, may be best understood, by example, with reference to the following description of embodiments taken together with the accompanying schematic drawings:.

An automotive side mirror comprises a plurality of parts like a housing ring as shown in <FIG>, a top cap as shown in <FIG>, a mirror foot as shown in <FIG> and a flexible circuit board as shown in <FIG>. In order to assemble said parts in an automated production line with a standard or rather common gripper each part is provided with standard gripping points as described in the following in more detail.

The housing ring <NUM> shown in <FIG> comprises a plurality of straps <NUM> each providing first standard gripping points. This is further illustrated by <FIG> showing a standard gripping unit <NUM> with two gripping fingers <NUM> each having an inner surface <NUM> with a recess <NUM> and an outer surface <NUM> with a recess <NUM>. Each strap <NUM> can be gripped between the inner surfaces <NUM> of the gripping fingers <NUM> of the gripping unit <NUM> in a standard manner.

The top cap <NUM> of <FIG> comprises two different kinds of second standard gripping points in form of clips <NUM> and <NUM>. The clips <NUM> correspond substantially to the straps <NUM> shown in <FIG> and can be gripped between the inner surfaces <NUM> of the gripping fingers <NUM> of the gripping unit <NUM>, whereas the clip <NUM> is gripped by the outer surfaces <NUM> of the gripping fingers <NUM> of the gripping unit <NUM> by entering the gripping fingers <NUM> into recesses 26a, 26b as best seen in <FIG>.

The clips <NUM> can also serve to enable a snap connection with another housing part of an automotive side mirror.

The mirror foot <NUM> of <FIG> is provided with two cut outs <NUM> forming standard gripping points with can be gripped between the inner surfaces <NUM> of the gripping fingers <NUM> of the gripping device <NUM> as shown in <FIG>.

Of particular interest for the present invention is the provision of standard gripping points by the flexible circuit board <NUM> of <FIG> having <NUM> branches each provided with terminals <NUM> to <NUM> to be connected to electrical modules as shown in <FIG> for one of the branches, whereas an additional branch is connected to cables <NUM> for connecting the electrical modules <NUM> to a not shown power supply.

Either the branches as such are provided with standard gripping points by selecting a standard width or providing cut outs or the terminals <NUM> to <NUM> as such provide gripping points such that gripping fingers <NUM> can grip the terminals in order to insert them into the respective electric module to achieve an electrical connection in line with <FIG>. The electrical modules <NUM> can be formed with recesses <NUM> providing said gripping points.

In order to handle a plurality of mirror parts, in particular in form of the flexible circuit board <NUM> with its plurality of branches, the invention also proposes a gripping device <NUM> shown in <FIG>. Such a gripping device <NUM> is provided with a center spine <NUM> which is connected at its upper end in <FIG> to a tool connection means <NUM> for the attachment to a not shown robot and at its lower end to six gripping units <NUM>. Via a center spine placing means <NUM> operated by supplying air to air nipples <NUM> the center spine <NUM> can be moved upwards and downwards whereas a rotation of the center spine <NUM> can be achieved manually.

Each gripping unit <NUM> comprises an arm having two parts, in form of an upper gripping arm <NUM> and a lower gripping arm <NUM>, which can be pivoted with respect to each other via an arm bending means <NUM> provided with an air nipple <NUM> pneumatically moving a piston <NUM>. At the free end of the arm of each gripping unit <NUM> a pair of gripping fingers <NUM> is provided, as best seen in <FIG>. The fingers <NUM> of each pair cooperate with ejecting means <NUM> each provided with an air nipple <NUM> in order to pneumatically move a piston <NUM> to eject an article gripped between the two gripping fingers <NUM>.

The gripping device <NUM> can be controlled to move its gripping units <NUM> like the legs of a spider with the additional advantage of fingers of a human palm. With this particular design it is possible to grip each of the <NUM> branches of the flexible circuit board <NUM> shown in <FIG> between a pair of gripping fingers <NUM> and move said branches in different directions relative to each other allowing a high degree of freedom with respect to the arrangement of the electrical modules <NUM> within the automotive side mirror and still have them all connected to the power supply via the electrical circuit board <NUM>.

Claim 1:
Device for automating the assembly of at least two parts (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) with a gripping device (<NUM>) comprising a plurality of gripping units (<NUM>) for gripping the parts (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) at gripping points, with
the gripping units (<NUM>) being moveable relative to each other and all together,
each gripping unit (<NUM>) comprising a pair of <NUM> fingers (<NUM>) for gripping one part (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and an arm for moving said pair of <NUM> fingers (<NUM>), and
the fingers (<NUM>) of each pair being moveable,
characterized in that
the parts (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) are mirror parts of automotive mirrors, are each provided with at least one standard gripping point and comprise an electrical module (<NUM>) and a flexible circuit board (<NUM>),
a control unit cooperates with the gripping device (<NUM>), wherein the control unit is configured to control the gripping units (<NUM>) for gripping the parts (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) at the standard gripping points and assembling the parts (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) by controlling the gripping device (<NUM>) and to control each pair of fingers (<NUM>) for gripping a branch of a flexible circuit board (<NUM>) having a plurality of branches to insert terminals (<NUM>-<NUM>) or wire harnesses carried by the branches into electrical modules (<NUM>), and
the gripping units (<NUM>) are designed to be moved in different directions during the assembling.