Patent Description:
The invention is additionally directed to a positioning assembly for holding a flat flexible part, especially a sheet, on a holding surface. The positioning assembly comprises a base part with a fluid port, at least one positioning device of the type mentioned above, and a gasket being interposed between the base part and the positioning device. The positioning device is mounted on the base part such that the respective fluid ports are in fluid communication.

The invention further relates to a sheet material processing machine comprising at least one such positioning assembly.

Sheet material processing machines, positioning assemblies and positioning devices of the types mentioned above are known in the art. Sometimes the positioning devices are also called tablets.

Sheet material processing machines, such as paper or cardboard processing machines, often comprise a plurality of processing units or stations, wherein in each of the processing units or stations a certain type of treatment is performed on the sheet material, e.g. it is cut, stripped or blanked. Usually, a conveyor system is provided within such a machine in order to transfer the sheet material from one processing unit to the next.

In order to perform the corresponding treatment in a precise and reliable manner, each of the processing units may comprise a positioning assembly of the type mentioned above. The positioning assembly may comprise one or more positioning devices of the type mentioned above. The positioning of the sheet material performed by the positioning assembly and the positioning device may be static or dynamic, i.e. the sheet material may be stationary or move while being held against the positioning surface. In the first case, the positioning device may also be designated a holding device. In the second case it may be used for decelerating the sheet material. An example of such a device is known from <CIT> where a single suction bar (retarder) is made of several suction openings and several inputs of compressed air and provides a self-cleaning capability.

In all cases the sheet material to be processed spans between the positioning assembly with the at least one positioning device and a gripper unit of the conveyor system. The sheet material is held on the positioning surface such that it is precisely positioned within the machine. The sheet material is usually held on the corresponding positioning device by a suction force resulting from a fluid flow through a corresponding suction opening. A fluid port for providing or driving this fluid flow is usually provided on a base part of the positioning assembly. The gasket ensures the fluid-tight connection of the positioning device and the base part.

Consequently, known positioning assemblies always require a certain assembly effort.

It is an objective of the present invention to improve known sheet material processing machines, positioning assemblies and positioning devices. In particular, the assembly thereof shall be facilitated. Of course, the functionality of these components shall be at least kept at known levels of reliability.

The problem is solved by a positioning device of the type mentioned above, comprising an abutment protrusion being arranged on the connection surface for abutting the positioning device against a base part to which it may be mounted and a sealing protrusion being arranged on the connection surface for compressing a gasket being interposed between the positioning device and the base part. A height of the abutment protrusion by which it protrudes from the connection surface is bigger than a height of the sealing protrusion by which it protrudes from the connection surface. When mounting the positioning device on a corresponding base part, the abutment protrusion is simply abutted thereon. As a consequence thereof, the compression of a gasket being used in connection with the positioning device is determined by the difference between the height of the abutment protrusion and the height of the sealing protrusion. The compressed portions of the gasket will always be compressed to a thickness being substantially equal to this difference. Thus, the positioning device may be easily and reliably mounted to a corresponding base part of a positioning assembly. This leads to a predefined compression of the gasket. Additionally, the portions of the gasket which are compressed may be easily determined by the positions of the corresponding sealing protrusion. Undesired variations of the compression of the gasket are excluded or at least substantially reduced. The connection of the positioning device to the base part is therefore fluid-tight in the relevant areas.

The body of the positioning device according to the invention may be formed of one or a plurality of parts. However, the invention is generally independent from the number of parts from which the body is made.

According to a variant the sealing protrusion and the abutment protrusion are formed integrally with at least one part of the body of the positioning device.

The abutment protrusion and/or the sealing protrusion may be elongate when being regarded in a direction substantially perpendicular to the connection surface. Consequently, the positioning device may be abutted against a base part of a corresponding positioning assembly along a certain length. In doing so, the positioning device is precisely positioned with respect to the base part. An elongate sealing protrusion leads to a compressed portion of the gasket which is line-shaped. As a consequence thereof, the gasket offers reliable sealing properties.

Additionally or alternatively, the abutment protrusion and/or the sealing protrusion are closed geometries when being regarded in a direction substantially perpendicular to the connection surface. Consequently, an area within the sealing protrusion may be reliably separated from an area outside the sealing protrusion. Furthermore, such an abutment protrusion offers a jiggle-free abutment of the positioning device against a corresponding base part.

According to an embodiment, the abutment protrusion substantially surrounds a mounting area of the connection surface. In this context, a mounting area is to be understood as an area of the positioning device by which it is connected to a corresponding base part of a positioning assembly. If the abutment protrusion substantially surrounds the mounting area, it covers or encloses a relatively big portion thereof. This leads to a reliable and stable abutment of the positioning device against a corresponding base part.

In a variant, two or more abutment protrusions are provided on the connection surface. Thus, generally speaking, abutment protrusions may be provided on the positioning device in a number and position as needed in a specific application. The assembly of the positioning device on a corresponding base part may, thus, be facilitated, as needed.

Preferably, the sealing protrusion encloses the fluid port. Thus, the fluid port may be reliably sealed against an environment. At the same time, a portion of the gasket is selectively compressed where a sealing functionality is needed. As a consequence thereof, the gasket may be easy in structure and production.

It is possible that two or more fluid ports are provided and each of the fluid ports is enclosed by a respective sealing protrusion. As a consequence thereof, all fluid ports may be reliably sealed with respect to each other and with respect to an environment. At the same time, the gasket is only compressed in those areas where it is necessary.

A snap contour for attaching a gasket on the connection surface may be provided. Thus, especially during an assembly procedure for mounting the positioning device on a corresponding base part, the gasket is reliably held on the connection surface. The corresponding mounting procedure is therefore easy and may be performed quickly. In particular, the gasket does not move during this mounting procedure.

Additionally or alternatively, a positioning protrusion for positioning a gasket is provided on the connection surface. Such a positioning protrusion especially serves the positioning of the gasket within a plane parallel to the connection surface. To this end, the gasket preferably is abutted against the positioning protrusion. Consequently, the gasket may be reliably positioned on the positioning device.

Preferably, the snap contour is arranged on the positioning protrusion. This leads to the effects and advantages which have already been explained in connection with the snap contour in general. By providing the snap contour on the positioning protrusion, the reliability of holding the gasket in a predefined position is further enhanced.

In a variant, the height of the sealing protrusion is at least <NUM>%, in particular at least <NUM>%, of the height of the abutment protrusion. This leads to a reliable compression of a gasket used in connection with the positioning device.

According to an alternative, the height of the sealing protrusion is at least <NUM>,<NUM>, in particular at least <NUM>,<NUM>. Such sealing protrusions are simple in production and offer a sufficient amount of compression for a gasket.

According to another alternative, the height of the abutment protrusion is at least <NUM>,<NUM>, in particular at least <NUM>. It is understood that the height of the abutment protrusion always exceeds the height of the sealing protrusion. Such an abutment protrusion can be manufactured with standard machinery. Consequently, it can be provided at relatively low cost.

The problem is also solved by a positioning assembly of the type mentioned above, comprising at least one positioning device according to the invention, wherein a gasket is interposed between the base part and the positioning device, and wherein the positioning device is mounted on the base part such that the respective fluid ports are in fluid communication. The abutment protrusion of the positioning device abuts against the base part and the sealing protrusion at least locally compresses the gasket against the base part. In such a positioning assembly, the fluid ports of the base part and the positioning device are reliably connected and reliably sealed with respect to an environment. At the same time, the positioning device may be mounted on the base part in a simple and reliable manner since it arrives in its correct position by simply abutting the abutment protrusion on the base part. As has been explained before, the compression of the gasket, which is at least local, is determined by the difference in height of the abutment protrusion and the sealing protrusion.

The gasket may comprise an elastic material such as rubber, an elastomer in general, a silicone material, a neoprene material, a fluorine elastomer material, an ethylene propylene diene material, or a polyurethane material. The gasket may also comprise a non-elastic material like polytetrafluoroethylene, paper, mica, glass, leather, metals, or a fiber material.

Beyond that, all effects and advantages which have been mentioned in connection with the positioning device also apply to the positioning assembly and vice versa.

The problem is also solved by a sheet material processing machine of the type as mentioned above, comprising at least one positioning assembly according to the invention. Due to the fact that the positioning assembly may be assembled in a fast and easy manner, the same applies to the sheet material processing machine as a whole. As has been explained before, the positioning assembly is reliable and precise in operation. The same, thus, applies to the sheet material processing machine.

Beyond that, all effects and advantages which have been mentioned in connection with the positioning assembly and the positioning device also apply to the sheet material processing machine and vice versa.

The invention will now be explained with reference to an embodiment which is shown in the attached drawings. In the drawings,.

<FIG> shows a sheet material processing machine <NUM> (in the following: machine <NUM>).

In the example shown, the machine <NUM> is configured for cutting a sheet material and is composed of five units each performing a certain treatment on the sheet material.

A first unit is a feeder unit 10a for providing or feeding sheets <NUM> to be processed. For illustrative purposes, only one sheet <NUM> is represented in the feeder unit 10a.

The second unit comprises a platen press <NUM> which is configured for cutting the sheet <NUM>. Consequently, the second unit is a platen press unit 10b.

The third unit is a stripping unit 10c which is configured for eliminating certain waste elements from the cut sheet <NUM>.

The fourth unit is a blanking unit 10d. In this unit the actually desired portion of the cut sheet <NUM> is withdrawn therefrom and put on a pile <NUM>.

The fifth unit is a waste evacuation unit 10e and serves for the elimination of further waste elements of the cut sheet <NUM>.

The sheet <NUM> is transported through the machine <NUM> by a conveyor system <NUM> essentially comprising a conveyor belt <NUM> to which a plurality of gripper units <NUM> are attached, which are configured for selectively gripping the sheet <NUM>.

The platen press unit 10b, the stripping unit 10c and the blanking unit 10d additionally comprise a positioning assembly <NUM> for holding the sheet <NUM>, on a holding surface <NUM>.

In the example shown in <FIG>, the holding surface <NUM> is a top surface of the positioning assembly <NUM>.

During the processing of the sheet <NUM> in any one of the platen press unit 10b, the stripping unit 10c and the blanking unit 10d, a leading edge of the sheet <NUM> will be gripped by a corresponding gripping unit <NUM> and a trailing edge of the sheet <NUM> will be held by the corresponding positioning assembly <NUM> (cf. travelling direction T).

<FIG> shows the positioning assembly <NUM> in more detail.

It comprises a base part <NUM> with a fluid port <NUM>.

The fluid port <NUM> is designed as a fluid inlet.

Thus, pressurized air can be supplied to the base part <NUM> via the fluid port <NUM>.

The base part <NUM> also comprises a plurality of fluid ports <NUM> which are in fluid communication with the fluid port <NUM>.

These fluid ports <NUM> are designed as fluid outlets.

Moreover, the base part <NUM> comprises a cleaning fluid port <NUM> being designed as a fluid inlet. Thus, a cleaning fluid may be supplied to the positioning assembly <NUM> via the cleaning fluid port <NUM>.

The base part <NUM> additionally comprises cleaning fluid ports <NUM> which are designed as fluid outlets being in fluid communication with cleaning fluid port <NUM>.

In the example shown in <FIG>, two positioning devices <NUM> are mounted on the base part <NUM> via fastening means <NUM>, e.g. bolts or rivets.

A gasket <NUM> is interposed between the base part <NUM> and each of the positioning devices <NUM>.

The positioning device <NUM> will be explained in more detail with reference to <FIG>. Since the two positioning devices <NUM> shown in <FIG> are substantially identical, the following explanations apply to both of them.

The positioning device <NUM> comprises a body <NUM>.

One outer surface of the body <NUM> is a positioning surface <NUM>.

In the representation of <FIG> the positioning surface <NUM> is the top surface of the body <NUM>.

The body <NUM> also comprises a connection surface <NUM> also being an outer surface thereof.

The connection surface <NUM> is arranged opposite the positioning surface <NUM> and thus is a lower surface of the body <NUM> in the representation of <FIG>.

On the positioning surface <NUM> suction openings <NUM> are provided. These suction openings <NUM> are configured for aspiring the sheet <NUM> such that it is held on the positioning surface <NUM>.

On the connection surface <NUM> fluid ports <NUM> are provided. These fluid ports <NUM> are designed as fluid inlets and are in fluid communication with the suction openings <NUM>.

Additionally, cleaning fluid ports <NUM> are arranged on the connection surface <NUM>. These cleaning fluid ports <NUM> are designed as fluid inlets.

The body <NUM> also has a lateral surface <NUM> which connects the positioning surface <NUM> and the connection surface <NUM>.

On the lateral surface <NUM> fluid ports <NUM> are provided. These fluid ports are in fluid communication with the fluid ports <NUM> and the suction openings <NUM>. They are designed as fluid outlets.

On the connection surface <NUM> the body <NUM> has an abutment protrusion <NUM> for abutting the positioning device <NUM> against the base part <NUM> as will be explained below.

The abutment protrusion <NUM> is elongate when being regarded in a direction perpendicular to the connection surface <NUM>.

Furthermore, the abutment protrusion <NUM> is a closed geometry when being regarded in this direction.

Additionally, the abutment protrusion <NUM> substantially surrounds a mounting area <NUM> of the connection surface <NUM>, i.e. the abutment protrusion <NUM> substantially extends along a border of the area of the connection surface <NUM> which is arranged opposite the base part <NUM> in its mounted state (cf.

The abutment protrusion <NUM> protrudes from the connection surface <NUM> by a height Ha of at least <NUM>.

Additionally, a total of six sealing protrusions <NUM> are arranged on the connection surface <NUM>.

The sealing protrusions <NUM> are configured for compressing the gasket <NUM> as will be explained below.

Also the sealing protrusions <NUM> are elongate when being regarded in a direction perpendicular to the connection surface <NUM>.

Moreover, the sealing protrusions <NUM> are closed geometries when being regarded along this direction.

In the present example the sealing protrusions <NUM> are circle-shaped.

Moreover, each of the sealing protrusions <NUM> encloses one of the fluid ports <NUM> or one of the cleaning fluid ports <NUM>.

The sealing protrusions <NUM> protrude from the connection surface <NUM> by a height Hs of at least <NUM>.

The height Hs of the sealing protrusions <NUM> is always smaller than the height Ha of the abutment protrusion <NUM>. In other words, the height Ha of the abutment protrusion <NUM> is always bigger than the height Hs of the sealing protrusion <NUM>.

In the example shown, the height Hs of the sealing protrusions <NUM> amounts to <NUM>% of the height Ha of the abutment protrusion <NUM>.

Furthermore, on the connection surface <NUM>, two positioning protrusions <NUM> are provided for positioning the gasket <NUM> on the body <NUM> within a plane substantially parallel to the connection surface <NUM>.

In the example shown the positioning protrusions <NUM> are pin-shaped. They can also be called positioning pins.

Optionally, a snap contour <NUM>, indicated by a dotted line in <FIG>, can be provided on the positioning protrusion <NUM>.

In the example of <FIG> the snap contour <NUM> is a snap collar circumferentially surrounding the positioning protrusion <NUM>.

Using the snap contour <NUM> the gasket <NUM> can be attached to the connection surface <NUM>.

When the positioning assembly <NUM> is assembled, the gasket <NUM> is arranged on the connection surface <NUM> of the body <NUM> of the corresponding positioning device <NUM>.

In doing so, the gasket <NUM> is positioned on the body <NUM> using the positioning protrusions <NUM>.

Furthermore, the gasket <NUM> is attached to the body <NUM> using the snap contour <NUM>.

Then, the assembly of the positioning device <NUM> and the gasket <NUM> is mounted on the base part <NUM>.

This is done such that each of the fluid ports <NUM> of the base part <NUM> is in fluid communication with a corresponding one of the fluid ports <NUM> of the body <NUM> and the each of the cleaning fluid ports <NUM> of the base part <NUM> is in fluid communication with a corresponding one of the cleaning fluid ports <NUM> of the body <NUM>.

For the ease of explanation, it will now be assumed that the gasket <NUM> has a substantially uniform thickness which is substantially equal to the height Ha of the abutment protrusion <NUM>.

The positioning device <NUM> is mounted on the base part <NUM> such that the abutment protrusion <NUM> abuts against the base part <NUM> (cf.

Consequently, those portions of the gasket <NUM> being in contact with a sealing protrusion <NUM> are compressed against the base part <NUM>.

The amount of compression equals to the difference between the heights Ha, Hs of the abutment protrusion <NUM> and the sealing protrusions <NUM>.

Consequently, the gasket <NUM> is locally compressed by a predefined amount.

As a consequence thereof, the ports <NUM>, <NUM>, <NUM> and <NUM>, <NUM>, <NUM> are fluidically connected as mentioned above, respectively. These connections are fluid-tight with respect to an environment.

Thus, a driver fluid may be supplied via fluid port <NUM> and leave the positioning assembly <NUM> via fluid ports <NUM>.

A jet pump being incorporated in the body <NUM> and acting on the suction openings <NUM> as an aspirator is driven by the driver fluid.

It is understood that in the embodiments described in connection with the Figures, the sheet <NUM> is used as a representative example of a flat flexible part. This means that the machine <NUM>, the positioning assembly <NUM> and the positioning device <NUM> can also be used in connection with any other flat flexible part.

Claim 1:
Positioning device (<NUM>) for holding a flat flexible part, especially a sheet (<NUM>), on a positioning surface (<NUM>), the positioning device (<NUM>) comprising a body (<NUM>) having a suction opening (<NUM>) for aspiring the flat flexible part, wherein the suction opening (<NUM>) is arranged within the positioning surface (<NUM>) being an outer surface of the body (<NUM>), and a fluid port (<NUM>) being in fluid communication with the suction opening (<NUM>), wherein the fluid port (<NUM>) is arranged within a connection surface (<NUM>) being an outer surface of the body (<NUM>),
characterized by an abutment protrusion (<NUM>) being arranged on the connection surface (<NUM>) for abutting the positioning device (<NUM>) against a base part (<NUM>) to which it may be mounted and a sealing protrusion (<NUM>) being arranged on the connection surface (<NUM>) for compressing a gasket (<NUM>) being interposed between the positioning device (<NUM>) and the base part (<NUM>),
wherein a height (Ha) of the abutment protrusion (<NUM>) by which it protrudes from the connection surface (<NUM>) is bigger than a height (Hs) of the sealing protrusion (<NUM>) by which it protrudes from the connection surface (<NUM>).