Patent Description:
In the field of (metal, plastic, wood, composite,. ) sheet working, in particular in automatic cutting and sorting stations, the need to assist a cutting machine with automatic sheet handling equipment (also called handlers or sorting machines) exists, capable of drawing the raw sheets from respective warehouses, transfer them onto the introduction table in the cutting centre and then retrieve the cut pieces and the scraps to distribute them to the subsequent collection stations. A particularly effective and advantageous sorting machine is the one described for example in <CIT> in the name of the same Applicant.

Typically, these machines are equipped with handlers provided with gripping heads which can operate with a plurality of workpieces having different materials, thickness and size. For such purpose, in this sector it is common practice for different interchangeable collecting tools to be apt to be engaged with handler gripping heads.

Normally, a universal fastening member is hence provided at the end of each gripping head, which can be engaged with a plurality of different operating tools, controlled with a suitable control line or energy line (pneumatic fluid, hydraulic fluid, electric current,.

The different tools are tidily stored in a tool carrier area located outside of the operating area, where the gripping heads can be led to from the sorting machine, to collect them, use them in respective operating steps and then release them at the end of a specific working step. Evidently, the step of the operating cycle wherein the gripping head is caused to interact with the tool carrier, called 'tool changing step', represents an idle time in the machine operation time and it would be desirable to be able to eliminate it.

Other fields of the art exist, for example in the field of tool machines, wherein a plurality of tools is mounted directly onboard of the same operating head. However, the technical approach used on tool machines is not immediately applicable to the sector of handlers for a series of reasons, among which mainly the bulk of the multi-tool head. As a matter of fact, operation of sorting machines requires that multiple gripping heads are allowed to interact and operate at a close mutual distance, handling also workpieces stacked at different heights each other: therefore, it is necessary that the footprint of gripping heads, for a significant height, to be as small as possible. The presence of multiple tools mounted on a multi-tool head determines a plan bulk which would be incompatible with the operation of a handler for sorting machines.

<CIT> discloses changing tool machine having a selecting support cooperating with a mandrel.

<CIT> discloses a machine to change end effectors stored on a linear storage, where a picking up head shall be displaced.

The need is therefore felt to provide an improved sorting apparatus, which is arranged so as to dispense of a separate tool carrier where the gripping head shall be displaced for the tool changing operations. In particular it is desired to provide a gripping head for a sorting machine which can use various types of tools, maintaining the versatility of known gripping heads, however, without suffering time and space consuming tool-changing operations.

The above-reported objects, according to the present invention are achieved by means of a gripping head of a sorting apparatus and operating method thereof having the features defined in the attached main claims. Other preferred features of the invention are defined in the dependent claims.

Further features and advantages of the invention will in any case be more evident from the following detailed description of a preferred embodiment of the same, provided purely as a non-limiting example and illustrated in the attached drawings, wherein:.

A sorting machine is normally arranged in cooperation with a cutting centre, for example a laser cutting apparatus for metal sheets (not shown). The sorting machine has the task of picking up individual raw metal sheets from a storage area, normally arranged horizontally in a stack, and to transfer them to the entry of the cutting apparatus. Once the cutting of a number of shaped workpieces from the metal sheet has been completed, the sorting machine has the further task of picking up the individual workpieces and to transfer them in a sorted manner, possibly stacking them, to appropriate sorting positions. At the end of the workpiece transfer, even the remaining metal sheet scraps are removed by the sorting machine to a disposal location.

As can be guessed, since in the various manufacturing batches the raw sheets, the individual workpieces and the scraps can be of a very different nature, size, shape and weight, the sorting machine must employ a variety of gripping tools. For such gripping operation, the sorting machine makes use, in a manner known per se, of one or more gripping heads provided with gripping tools, mounted at the lower end of a handling arm belonging to a system with displacement axles, at least along two orthogonal axes on the horizontal plane and a vertical axis.

According to the invention, a gripping head T for a sorting machine consists of a housing frame which houses a plurality of tools. In <FIG> gripping head T is shown in a compact home condition; the internal structure is not visible due to the presence of a cover body C; in the upper part, gripping head T ends with a flange F fastening to a moving arm of the sorting machine; through fastening flange F the control or energy transfer lines L are caused to pass - for example a vacuum pipe, a compressed air pipe, one or more electric cables and so on - for suitably controlling the members of the gripping head and the tools; in the lower part, gripping head T houses a plurality of gripping tools which will be better described further on.

In particular, as illustrated in <FIG>, gripping head T consists of a support frame <NUM>, integral with fastening flange F, whereon a series of operating components is mounted. The operating components comprise a revolver-shaped tool carrier <NUM>, with a relative rotation actuator <NUM> for driving rotation about an axis H, and a vertical transfer platform <NUM> with relative linear actuator <NUM>. On the head T a pneumatic distribution unit <NUM> is furthermore preferably provided, which puts a single pneumatic line, which runs across flange F, in communication with a plurality of lines to the various control members onboard the head.

In <FIG> and <FIG> the revolver-shaped tool carrier <NUM> with the actuator thereof <NUM> are illustrated in detail.

The revolver-shaped tool carrier <NUM> substantially comprises an engaging body <NUM>, rotatably mounted around a selection axis H and driven into rotation by a pulley <NUM> actuated by an actuator <NUM> comprising a gear motor M1 and a toothed belt <NUM>. On engaging body <NUM> some tools U are coupled, as will be better described further on.

Selection axis H is preferably horizontal.

Coaxially to pulley <NUM> a rotary fluid distributor <NUM> is preferably provided, fluidly connected to the engaging body <NUM>. The distributor <NUM> has the purpose of giving continuity to a plurality of fluid pipes directed to the tools, connecting a plurality of input fluid connectors <NUM>, arranged in a fixed position on the distributor, with a corresponding plurality of tool sockets <NUM> provided on the movable gripping tools.

Fixed input connectors <NUM> on the distributor <NUM> are connected to pneumatic distribution unit <NUM>, so as to suitably fluidly connect the vacuum line coming from the handling arm (not shown), down to the tool sockets <NUM> which are movably mounted in rotation on engagement body <NUM>. For such reason, the vacuum suction creates a suction airflow from the tools to the top of the handling arm.

Preferably, between the tool sockets <NUM> and rotary fluid distributor <NUM>, respective flexible and extendable hoses <NUM>' are provided, for example spirally wound as shown in the drawings, to allow a continuity of the fluid pipe even when the tool is moved far away from rotary distributor <NUM> (as will be shown further on).

Rotary fluid distributor <NUM> preferably hosts in a central position a longitudinal through-hole <NUM>, parallel to axis H, apt to house also an electrical through-wire, to supply other electrical devices, for example electromagnets <NUM> integral with engagement body <NUM> or other electromagnets onboard tools U.

The rotation control of gear motor M1 is preferably alternate, so as to perform rotations smaller than <NUM>° in the two opposite directions. Thereby it is not necessary to provide a sliding contact to maintain the continuity of the electrical wire, but an alternate twist thereof in the two directions is tolerated.

In the embodiment shown, engagement body <NUM> is conceived to host four different tools U<NUM>-U<NUM>. For such purpose, body <NUM> takes up the shape of a square plate, with four orthogonal sides whereon an equal number of gripping tools U<NUM>-U<NUM> are coupled. On each side, pairs of adjustment holes <NUM> and an electromagnet <NUM> are provided. Each side is furthermore equipped with a fork having a pair of elastic arms 29a and 29b, one elastically pushed towards the other for defining a gripping action on gripping tools U<NUM>-U<NUM>.

Electromagnet <NUM> and forks with elastic arms 29a and 29b overall form releasable engagement means, which could even take on different embodiments. They keep tools U<NUM>-U<NUM> coupled with engagement body <NUM>, but allow controlled detachment thereof, in the manners and times which are illustrated in the following.

The various gripping tools U<NUM>-U<NUM> are all equipped with a universal fastening base <NUM> (<FIG>), whereto an active component is fastened which varies according to the type of tool. Base <NUM> is equipped with retaining means arranged so as to securely engage with the corresponding releasable engagement means present on the engaging body <NUM> of revolver-shaped carrier <NUM>. In particular, base <NUM> has a pair of centring pins <NUM> meant to engage with corresponding centring holes <NUM> of engaging body <NUM>, as well as a metal insert <NUM> meant to couple with electromagnets <NUM>. On the same base <NUM> a pair of retaining pins <NUM> is furthermore provided, meant to engage with engagement means provided on transfer platform <NUM>, as will be seen further on.

The lateral design of base <NUM> is conceived to cooperate with elastic arms 29a, 29b and to remain securely snap-engaged between them.

As shown in <FIG>, the engaging body <NUM> of revolver-shaped carrier <NUM> retains in a releasable manner four different tools, exploiting the engagement of centring pins <NUM> with centring holes <NUM> and the retaining snap force imparted by elastic arms 29a, 29b and by electromagnets <NUM>. In <FIG> revolver-shaped carrier <NUM> is attached to three exemplifying gripping tools with different active components:.

<FIG> shows a further preferred tool U<NUM> (for example mountable on the gripping head instead of tool U<NUM>), provided with two concentric electromagnets apt to be controlled independently. In particular, a first central electromagnet is of a circular shape and has a diameter ranging between <NUM>-<NUM>: this is meant to collect smaller workpieces (up to a maximum of about <NUM>). A second peripheral electromagnet is of an annular shape: it is meant to contribute with an auxiliary force to that of the first electromagnet when the workpiece to be collected exceeds <NUM> of weight, up to a maximum of about <NUM>. The activation of the electromagnets can be alternatively controlled on the two or simultaneously. A tool with triple-fold geometry and different load carrying capability is thus offered, programmable depending on the workpieces to be collected.

<FIG> shows in detail transfer platform <NUM> with relative linear actuator <NUM>, both mounted on frame T.

According to the embodiment shown, transfer platform <NUM> comprises a shelf <NUM> fastened to a moving slider <NUM> slidably mounted along a sliding axis Y. Sliding axis Y is preferably vertical.

Shelf <NUM> is provided with engagement means, with which it can be securely fastened, in a releasable manner, to a selected gripping tool.

It must be noted that shelf <NUM> supports cantilevered engagement means, at a certain distance from the moving slider <NUM> in the direction of the central axis of the gripping head. In particular, the engagement means are in a central area where they can engage, when desired, with retaining means of gripping tools U<NUM>-U<NUM>.

According to the embodiment shown, the releasable engagement means consist of a shaft <NUM>, supported in rotation on a terminal body <NUM>' of shelf <NUM> and driven into alternate rotation by a pneumatic actuator <NUM>.

The rotation axis of shaft <NUM> and of actuator <NUM> is identified as axis W in the drawings.

Shaft <NUM> has at least a portion wherein the crosswise section has two different orthogonal dimensions, a shorter and a longer one: for example, cylindrical-section shaft <NUM> is provided with two opposite lateral recesses 43a (<FIG>). Shaft <NUM> is meant to engage with a fork feature defined between the two retaining pins <NUM> of tools U<NUM>-U<NUM>, alternatively offering a larger or a smaller diameter and hence preventing from or allowing, respectively, a relative crosswise disengagement movement.

Accordingly, the two retaining pins <NUM> of gripping tools U<NUM>-U<NUM> have a narrower-section portion <NUM>'. In correspondence of such narrower section, the centre-to-centre distance between the surfaces of the two pins is greater than the smaller dimension of shaft <NUM> in correspondence of recesses 43a. Thereby, the two retaining pins <NUM> can freely slide crosswise across shaft <NUM> in correspondence of recesses 43a, while the crosswise displacement is prevented if the larger section of shaft <NUM> lies between the two narrower sections <NUM>' of pins <NUM>.

In other words, depending on the rotation angle taken up by shaft <NUM>, it is possible to keep the pair of retaining pins <NUM> crosswise captured or free, as will be better described further on.

The terminal body <NUM>' of shelf <NUM> furthermore has guiding parallel holes <NUM> to host the pair of retaining pins <NUM>. Guiding parallel holes <NUM> are orthogonal to shaft <NUM> and intersect the rotation seat thereof, on the two opposite sides of its rotation axis W. Thereby, when retaining pins <NUM> are inserted into guiding holes <NUM>, they can engage laterally with shaft <NUM>.

Moreover, on shelf <NUM> a pair of opening cam members <NUM> is installed, arranged on the opposite sides of shaft <NUM>, which are designed to come in contact and spread open elastic arms 29a and 29b in an attachment step.

Movable slider <NUM> is controlled in its rectilinear movement by means of a linear actuator <NUM>, for example ball screw <NUM> driven into rotation by an electric motor <NUM> by means of a transmission belt <NUM>.

Preferably, linear actuator <NUM> controls movable slider <NUM> by means of a floating joint <NUM> which transfers a driving force through an elastic member, for example a helical spring. Floating joint <NUM> has the purpose of compensating any misalignment between the linear actuator and the platform, ensuring that in any case the movement control along axis Y be transmitted to transfer platform <NUM> without jamming.

Actuator <NUM> is configured (<FIG>) to move transfer platform <NUM> between a home position, wherein movable slider <NUM> is in the upper position, an attaching position, wherein transfer platform <NUM> is attached to a desired tool (as will be described further on), and one or more operating positions wherein slider <NUM> descends to lower positions along axis Y and the tool attached to platform <NUM> is progressively extended below the gripping head.

In the home position (<FIG>), movable slider <NUM> is in its upper position and keeps shelf <NUM> with shaft <NUM> in a substantially centred position with respect to revolver-shaped carrier <NUM>: axis W is in the proximity of axis H. In this condition, revolver-shaped carrier <NUM> can freely rotate around axis H and the tools surround shelf assembly <NUM> and actuator <NUM> without interference. As a matter of fact, for such purpose, tools U<NUM>-U<NUM> are engaged with support body <NUM> at a radial distance from rotation axis H sufficient to leave space to shelf assembly <NUM> and to the actuator <NUM> thereof.

In the attachment position (<FIG>), movable slider <NUM> is shifted vertically downwards by a measure sufficient to bring the body <NUM>' of shelf assembly <NUM> in engagement with a selected tool U, that is the tool which is in the lower position on revolver-shaped carrier <NUM>, for example tool U<NUM> in the drawing. In such condition, retaining pins <NUM> are engaged with guiding holes <NUM> and the respective reduced-section areas <NUM>' are in the proximity of the lateral surface of shaft <NUM>.

In this position, depending on the rotation angle taken up, shaft <NUM> is captured or released from the two retaining pins <NUM>.

In <FIG> shaft <NUM> is facing its larger diameter to the two opposite retaining pins <NUM> (as a matter of fact recess 43a is visible in the upper part of the shaft) and hence it is locked between them: in this condition, tool U<NUM> and transfer platform <NUM> are made integral, along a horizontal axis parallel to axis W due to the engagement of pins <NUM> with holes <NUM>, as well as a vertical axis parallel to axis Y due to the engagement of shaft <NUM> between pins <NUM>.

Viceversa, when shelf <NUM> is getting closer to chosen tool U, the relative movement along the vertical axis must be allowed and shaft <NUM> is rotated by <NUM>°, so that its smaller diameter parts (recesses 43a) are facing the two opposite retaining pins <NUM>. In the tool attachment step, the pair of opening wedges <NUM> comes in contact and spreads apart elastic arms 29a and 29b, which hence no longer retain tool U to the revolver-shaped carrier: as long as shaft <NUM> is not rotated and engages the two retaining pins <NUM>, the tool is maintained joined to the revolver-shaped carrier <NUM> only by the action of electromagnet <NUM>. Once the tool has been ultimately attached to transfer platform <NUM>, electromagnet <NUM> can be deactivated <NUM>, so that the tool is fully released from revolver-shaped carrier <NUM> and can be moved integrally with transfer platform <NUM>.

Once the desired tool U has been made integral to transfer platform <NUM> and released from revolver-shaped carrier <NUM>, shelf assembly <NUM> can be shifted into operating positions far away from the gripping head, by means of a further translation of slider <NUM> along vertical axis Y.

In <FIG> various views of the gripping head are shown with a tool U<NUM> extended downwards in an operating position, with slider <NUM> extended to its maximum extension.

In this condition, selected tool U is at a sufficient distance from the gripping head to be able to easily act on the workpieces to be collected without being affected by the greater bulk of revolver-shaped carrier <NUM> and by the entire gripping head T.

In order to prevent the weight resting on the gripping tool from being applied to linear actuator <NUM>, stopping means are preferably provided which, in the travel end operating position, securely fasten slider <NUM> directly to the structure of frame <NUM>. In the embodiment illustrated in <FIG>, these stopping means are in the shape of a pair of pins 42a integral with slider <NUM> which abut against a pair of hooks <NUM> integral with frame <NUM>. In this case, too, due to the presence of floating joint <NUM>, it is not necessary to provide a fine adjustment of the stopping means, because any mounting inaccuracies are absorbed by floating joint <NUM> without causing jamming or damage to the control members.

In <FIG> the different selection steps of the gripping head according to the invention are illustrated.

In <FIG> gripping head T is in a reference condition, with revolver-shaped carrier <NUM> which takes up a rotation angle of "zero" and transfer platform <NUM> in the upper home position.

In <FIG> tool U<NUM> has been selected, which is brought into the lower position by means of a rotation of revolver-shaped carrier <NUM> around axis H, for example with a rotation by <NUM>°.

In <FIG> transfer platform <NUM> is moved into the attachment position, so as to engage retaining pins <NUM> with guiding holes <NUM> and to spread apart elastic arms 29a and 29b. The tool is still retained on revolver-shaped carrier <NUM> by the action of electromagnet <NUM>.

In <FIG> the step of the final engagement of the tool with transfer platform <NUM> is shown. Pneumatic actuator <NUM> rotates shaft <NUM>, so as to determine the capture thereof between the two retaining pins <NUM> and clamp the tool U<NUM> to the transfer platform <NUM> also along movement axis Y. Electromagnet <NUM> is deactivated, so as to fully release the tool from revolver-shaped carrier <NUM>.

In <FIG> an operating step of the tool is shown. Slider <NUM> is extended downwards, bringing tool U<NUM> into an operating position, for example <NUM> below the attachment position. In this step tool U<NUM> is powered by the control line or by energy transfer consistent with the function thereof, for example a vacuum suction is activated along extensible pipe <NUM>'.

In this condition, gripping head T performs the programmed work with the selected tool in an operating position. For example, a fresh metal sheet is collected and it is transferred to the entry of a cutting centre.

At the end of this work cycle, in case it is necessary to perform a different grip with a different tool, the current tool is brought back into the attachment position and the power supply along the control line is discontinued (<FIG>).

Transfer platform <NUM> is brought back into the attachment position, the current tool is released from shaft <NUM> and taken back by electromagnet <NUM> (<FIG>). After that, transfer platform <NUM> returns into its home position (<FIG>), the tool is securely engaged again also by elastic arms 29a and 29b and revolver-shaped carrier <NUM> can rotate again to perform a new selection of the desired tool.

Due to the specific layout of the head according to the invention, all the tools onboard the revolver-shaped carrier are in any case securely engaged, through electromagnet <NUM> and elastic arms 29a and 29b, as well as correctly (electrically or pneumatically) supplied: therefore they are perfectly operative and there is no hindrance with respect to the transfer platform in a home position. Therefore that allows to exploit an additional operating mode. As a matter of fact the tools, despite remaining onboard the revolver-shaped carrier, can be used to collect workpieces of a non-excessive weight (because the load is supported by rotation axis H and by releasable engagement means which do not impart a high force, at least in the layout provided in the preferred embodiment).

Thereby, the workpieces can also be rotated on a horizontal axis (that is axis H) and then can be brought from a horizontal attitude to an inclined attitude, to be laid onto racks or feeders in a row of adjacent workpieces (instead of stacked one on top of the other). A welding station, an anthropomorphic robot or in any case an automation station could benefit from a non-horizontal deposition. As illustrated in the sequence of <FIG>, a workpiece P can be collected in a horizontal attitude and then progressively rotated into a vertical attitude by rotating the revolver-shaped carrier around axis H.

As can be clearly understood from the description reported above, the gripping head for a sorting apparatus and the relative operating method according to the present invention allow to perfectly reach the set objects.

As a matter of fact, the gripping head is arranged so as to have onboard a series of different tools, mounted on a revolver-shaped carrier: therefore the selection of the required tool can occur in a short time, without having to move the gripping head in a peripheral carrier area where to perform the change of tool. That allows understandable time savings in the operating cycle.

The provision of a revolver-shaped carrier, which supports a plurality of fully operating tools in a rotary manner around a horizontal axis, offers further advantages in the handling of the workpieces.

Moreover, the pick-up action of the selected tool to the transfer platform allows to displace the individual tool at a sufficient distance from the tool carrier, so that no particular work constraints of the tool arise despite the bulk of the same tool carrier. The gripping head can hence operate in an identical manner to the conventional single-tool handlers, but in a much faster and flexible manner.

However, it is understood that the invention must not be considered limited to the particular embodiment illustrated, but that different variants are possible, all within the reach of a person skilled in the field, without departing from the scope of protection of the invention, which is only defined by the following claims.

For example, although in the description reference has always been made to a revolver-shaped carrier with four tools and relative releasable engagement means, it is not ruled out that more than four tools can also be mounted on the carrier unit, also depending on the bulk of each of said tools.

Moreover, it is understood that by the expression 'revolver-shaped carrier' it is also meant a rotating tool rack, tool carousel, tool turret, but also carrier units for multiple tools with a different selection movement are recomprised, for example a linear movement or movement with more complex displacements, provided they allow a selection of a desired tool which is housed in a certain position of a movable carrier from which it can be picked up and spaced away by the transfer platform.

Claim 1:
Gripping head (T) of a handler in a sorting machine, comprising
a support frame (<NUM>)
a plurality of gripping tools (U1-U5), equipped with at least a socket (<NUM>) for a control line and first retaining means (<NUM>, <NUM>),
furthermore comprising
a revolver-shaped carrier (<NUM>) mounted on said support frame (<NUM>) equipped with an engaging body (<NUM>) provided with a plurality of first releasable engagement means (29a, 29b, <NUM>) apt to be coupled with said first retaining means (<NUM>, <NUM>) of a respective gripping tool of said plurality of gripping tools (U1-U5), said plurality of gripping tools (U1-U5) furthermore having second retaining means (<NUM>),
at least a transfer platform (<NUM>), equipped with second releasable engagement means (<NUM>, <NUM>) apt to be coupled with said second retaining means (<NUM>),
said transfer platform (<NUM>) being movably mounted on said support frame (<NUM>) along a sliding axis (Y) between at least
a home position
wherein said first retaining means (<NUM>, <NUM>) of a selected gripping tool of said plurality of gripping tools (U1-U5) are engaged with said first releasable engagement means (29a, 29b, <NUM>) of said revolver-shaped carrier (<NUM>),
an attachment position
wherein said second releasable engagement means (<NUM>, <NUM>) are coupled with said second retaining means (<NUM>) of said selected gripping tool (U1-U5), and
an operating position
wherein said first retaining means (<NUM>, <NUM>) of said selected gripping tool (U1-U5) are uncoupled from said first releasable engagement means (29a, 29b, <NUM>) and said selected gripping tool (U1-U5) is spaced away from said revolver-shaped carrier (<NUM>), and characterised in that said engaging body (<NUM>) is rotatably mounted around a selection axis (H) which is perpendicular to said sliding axis (Y).