Patent Description:
Such trays are typically used in the food industry where they are filled with a food product, after which the trays are provided with a lid and subsequently delivered to a point-of-sale.

Before and/or after the trays are filled with the food product they are conveyed one after another by high speed conveyors through the food processing and filling facility, and must at any time be properly aligned with all relevant apparatuses, such as other conveyors delivering the food product into the trays or apparatuses applying a lid to the trays after the trays are filled. It goes without saying that a correct alignment of the trays is critical, and that due to the high volume of trays alignment of the individual trays must also be carried out in the shortest possible time, without interrupting the steady flow of trays through the facility.

<CIT> discloses a device as defined in the introductory portion of claim <NUM>.

The invention aims at providing a novel conveying device, particularly useful in a facility as discussed above, where trays can be turned for proper alignment over a short conveyor length, with the conveyor running continuously and preferably at constant speed. A turning as referred to may eg. involve a tray being turned so that its longer side faces forward instead of its shorter side.

In view of this object, the conveying device includes a) a conveyor for continuously advancing the trays one after another, with the bottom of each tray being supported by the conveyor, b) a reorienting device arranged above the conveyor, for turning the trays, the reorienting device comprising a lower clamping part and an upper clamping part, a gap of adjustable gap width between the upper and lower clamping parts being at a level above the conveyor, the upper and lower clamping parts being arranged to receive in the gap a length of the peripheral edge of each tray advanced to the reorienting device by the conveyor at that level, the reorienting device carrying out the turning by a joint rotation about a common axis of the upper and lower clamping parts, simultaneously with the received length of the peripheral edge temporarily being clamped in the gap by adjustment of the gap width, the reorienting device configured to release the clamping of the received length of the peripheral edge by adjustment of the gap width after completion of the joint rotation about the common axis.

Further embodiments are defined in the dependent claims, reciting i. drives for providing the clamping and rotation.

The invention will now be explained in more detail below by reference to a presently preferred embodiment.

<FIG> shows a conveying device <NUM> of the present invention, used for advancing and reorienting a sequence of trays <NUM>.

Each tray <NUM> is of the type that comprises a bottom <NUM> connected with an upstanding peripheral side wall <NUM> with an outwardly projecting peripheral flange/edge <NUM> which may have a flat upper face and a flat lower face, the flat upper face being suitable for securing by heat welding a plastic foil lid (not shown) to the tray <NUM>. Alternatively, the lower face of the peripheral edge <NUM> may have a small recess for snap attachment of a lid to the tray <NUM>.

The side wall <NUM> may extend perpendicularly from the bottom <NUM> or, as shown, outwards at some angle to the bottom <NUM>. The width of the peripheral edge <NUM>, i.e. its extension outwards from the side wall <NUM>, may by way of example be in the order of <NUM>-<NUM>, and its thickness may by way of example be in the order of <NUM>-<NUM>. The trays <NUM> may eg. be of a plastic, cardboard or aluminium material and may, by way of example, be of a rectangular shape.

Such trays <NUM> are typically used in the food industry, and may be filled with a food product at a downstream filling station or may already have been filled with a food product (not shown) at an upstream filling station.

The conveying device <NUM> includes a continuously moving conveyor <NUM>, shown as a belt conveyor, running preferably at constant speed and having a upstream end <NUM> and a downstream end <NUM> and supporting the bottom <NUM> of the trays <NUM>, with the aforementioned outwardly projecting peripheral edge <NUM> being at a certain level above the conveyor <NUM>.

The trays <NUM> are advanced one after another by the conveyor <NUM> to a reorienting device <NUM>, to be discussed further below, which is arranged above the conveyor <NUM> and which is configured to seize and temporarily hold on to a short length of the peripheral edge <NUM> of each tray <NUM>, typically near a corner <NUM> of the tray <NUM>, and then to rotate, thereby turning the tray <NUM> by a selected angle up to a point where the peripheral edge <NUM> is then released. In <FIG> three positions of the same tray <NUM> that it assumes while being turned are shown; as seen, the tray <NUM> is turned by about <NUM>° such that its long side now faces forward.

As discussed above, turning of the trays <NUM> by a selected angle may be desirable for many reasons, such as to correctly align the trays <NUM> with a downstream machine applying lids to the trays <NUM>, or to correctly align the trays <NUM> with a downstream machine that fills a product into the trays <NUM>. It is noted that the invention may also find use for reorienting trays <NUM> of the aforementioned type onto which a lid has been fixed to the peripheral edge <NUM>, as long as the peripheral edge <NUM> of the tray <NUM> is at least indirectly engageable by the reorienting device <NUM>. The release of the trays <NUM> may eg. be controlled by a timer/encoder.

The rotation of the reorienting device <NUM> may be brought about by a motor M, or alternatively as a result of frictional forces between the bottom <NUM> of the trays <NUM> and the moving conveyor <NUM> pulling the tray <NUM> towards the downstream end <NUM> of the continuously moving conveyor <NUM> while being held near a corner <NUM> by the reorienting device <NUM>.

Turning now to <FIG>, which shows the conveying device <NUM> seen from above, shown is a tray <NUM> at the moment it has reached the reorienting device <NUM>, advanced thereto by the conveyor <NUM> and guided by an optional guiding plate <NUM>. The position, such as its angle relative to the sides of the conveyor <NUM> and its distance from the sides of the conveyor <NUM>, of the guiding plate <NUM> may be varied as necessary by an arm <NUM>, such as in accordance with the dimensions of the trays <NUM>. At the moment shown in <FIG> a length of the peripheral edge <NUM> has entered a gap <NUM> defined by the reorienting device <NUM> and being at a level aligned with the level above the conveyor of the peripheral edge <NUM>, as shown in <FIG>, which is a cross-sectional view identified by line A-A in <FIG>.

More specifically, the reorienting device <NUM> that is arranged above the conveyor <NUM> comprises a lower disc-shaped clamping part <NUM> and an upper disc-shaped clamping part <NUM> that each have a clamping face for pressing against the lower and upper face, respectively, of the length of the edge <NUM>. The aforementioned gap <NUM> has a gap width defined as the distance between the opposed clamping faces of the upper and lower clamping parts <NUM>, <NUM>. The gap width is adjustable to provide for the aforementioned temporary holding on to a length of the peripheral edge <NUM> that has entered the gap <NUM>. In the shown embodiment the upper clamping part <NUM> carries the lower clamping part <NUM> by having a tubular structure <NUM> receiving a pin <NUM> attached to the lower clamping part <NUM>; the tubular structure <NUM> is such that the pin <NUM> may move a pre-set distance along the length thereof, without permitting relative rotation of the pin <NUM> with respect to the tubular structure <NUM>. A further structure <NUM> carries the upper clamping part <NUM> and provides a bearing allowing the upper clamping part <NUM> together with the lower clamping part <NUM> to rotate about a common axis A relative to the further structure <NUM>; as explained below this rotation may be brought about by motor M shown in <FIG> and also in <FIG>.

Once a desired length of the peripheral edge <NUM> has entered the gap <NUM>, as determined by a sensor, a drive D, which is carried by the tubular structure <NUM> and which may eg. be an electromagnetic, pneumatic or hydraulic drive acting on the aforementioned pin <NUM>, is activated to raise the lower clamping part <NUM>, thereby adjusting/reducing the gap <NUM> width, i.e. the distance between the two clamping parts <NUM>, <NUM>, to a certain minimum value whereby a clamping force is applied onto the edge <NUM> by the clamping parts <NUM>, <NUM> pressing against the upper and lower face, respectively, of the edge <NUM>; this configuration is shown in <FIG>. Simultaneously the reorienting device <NUM> is activated to rotate, namely to carry out a joint rotation about the common axis A of the upper and lower clamping parts <NUM>, <NUM>. When a pre-set rotation about the axis A, such as by <NUM>°, has been completed the reorienting device <NUM> releases the received length of the peripheral edge <NUM> by readjustment of the gap width by controlling the drive D. The released and now turned tray <NUM> is then advanced forward to the downstream end <NUM> by the conveyor <NUM>. Completion of the rotation may be determined by the motor M having rotated in predetermined number of steps or, if no motor is used, by sensors registering rotation of the upper clamping part <NUM> relative to the aforementioned further structure <NUM>. The rotation about the axis A is in the direction shown by arrow R in <FIG>, to turn the tray <NUM> forward towards the downstream end <NUM> of the conveyor <NUM>. By way of example only, the drive D may be configured to vary the gap width between <NUM>, corresponding to a typical edge <NUM> thickness, and <NUM>, where in the latter case when the clamping structures <NUM>, <NUM> are moved fully apart.

<FIG> shows a frame F supporting the reorienting device <NUM> and configured for adjustable positioning of the level of the gap <NUM> above the conveyor <NUM>, in accordance with the general height of the trays <NUM>, such that the reorienting device <NUM> remains aligned with the peripheral edge <NUM> where the latter is higher above the conveyor <NUM>. This positioning may by way of example be by means of telescoping bars <NUM>, <NUM>. Often, where the trays <NUM> are higher the thickness of the peripheral edge <NUM> remains the same and so there is no need to change the configuration of the drive D.

The reach of the reorienting device <NUM> across the conveyor <NUM> from the side S is preferably also adjustable by the further structure <NUM> being connected to an elongated bar <NUM> slidably connected with an upper end of one of the telescoping bars <NUM> by a set screw <NUM> so that the position where the reorienting device <NUM> meets the trays <NUM> can be varied, which may be relevant where the trays <NUM> enter the upstream end <NUM> of the conveyor <NUM> very close to a side S of the conveyor <NUM>. <FIG> also shows a belt drive B with an appropriate number of loops connecting the motor M with the upper clamping part <NUM>.

As may be understood, the aforementioned guiding plate <NUM> may be useful in aligning the edge <NUM> with gap <NUM> such that the edge <NUM> is advanced by the conveyor <NUM> directly into the gap <NUM>. Preferably, a sensor is arranged along the length of the conveyor <NUM> for determining the position of trays <NUM> moving along the conveyor <NUM> and communicating with a controller <NUM> that is programmed to activate the reorienting device <NUM> to turn the trays <NUM> by a set angle about the axis A and to then release the trays <NUM> by adjustment of said gap width, i.e. by moving the clamping parts <NUM>, <NUM> apart. Controlling may be as follows: A first sensor registers a tray <NUM> approaching the reorienting device <NUM>; this triggers a timer determining when the clamping parts <NUM>, <NUM> are to be brought into the clamping configuration shown in <FIG>. Reaching the clamping configuration triggers another timer which decides when the tray is released, with due regard to the speed of rotation about axis A brought about by motor M.

Claim 1:
A conveying device (<NUM>) for advancing and reorienting trays (<NUM>), said trays (<NUM>) each comprising a bottom (<NUM>) connected with an upstanding peripheral side wall (<NUM>) with an outwardly projecting peripheral edge (<NUM>), the conveying device (<NUM>) including:
a) a conveyor (<NUM>) for continuously advancing said trays (<NUM>) one after another, with said bottom (<NUM>) of each tray (<NUM>) being supported by said conveyor (<NUM>),
b) a reorienting device (<NUM>) arranged above said conveyor (<NUM>), for turning said trays (<NUM>), characterised in
said reorienting device (<NUM>) comprising a lower clamping part (<NUM>) and an upper clamping part (<NUM>),
- a gap (<NUM>) of adjustable gap width between said upper and lower clamping parts (<NUM>, <NUM>) being at a level above said conveyor (<NUM>),
- said upper and lower clamping parts (<NUM>,<NUM>) being arranged to receive in said gap (<NUM>) a length of said peripheral edge (<NUM>) of each tray (<NUM>) advanced to said reorienting device (<NUM>) by said conveyor (<NUM>),
said reorienting device (<NUM>) carrying out said turning by a joint rotation about a common axis (A) of said upper and lower clamping parts (<NUM>, <NUM>), simultaneously with said received length of said peripheral edge (<NUM>) temporarily being clamped in said gap (<NUM>) by adjustment of said gap width,
said reorienting device (<NUM>) being configured to release said clamping of said received length of said peripheral edge (<NUM>) by adjustment of said gap width after said joint rotation about said common axis (A).