Patent Description:
Such an apparatus is disclosed by <CIT>, and by <CIT>, which documents are about <NUM> years apart which demonstrates that the industry is continuously looking for improvement of the weighing operation on the poultry while it is moving in the conveyor line.

The chain tension control mechanism serves the purpose to reduce inaccuracies during the weighing operation which are caused by the chain obscuring the weight measurement. As particularly <CIT> demonstrates, the prior art has evolved into a complicated and accordingly relatively costly solution. The construction of <CIT> with two subsequent pulleys defining a path following two curved track sections in opposite directions, and a weighing track section in between those two curved track sections may disadvantageously give rise to swinging of the poultry, which is undesirable since it deteriorates the accuracy of the weight measurement. It also poses a risk of cross-contamination between the conveyed poultry, because their swinging may result in neighbouring poultry touching each other.

It is an object of the invention to simplify the design of the apparatus for weighing poultry when moving in a conveyor line, and to realize cost benefits without compromising the weight accuracy.

It is further an object of the invention to prevent progressive swinging motion of the poultry while being conveyed, particularly when passing through the weighing station.

The apparatus of the invention is therefore provided with features according to one or more of the appended claims.

According to a first aspect of the invention the chain tension control mechanism comprises a rotatable wheel having its circumference following the curved track section and pass the weighing track section, which rotatable wheel supports a series of engaging units that engage the chain and/or the carriers in the curved track section to tension the chain and is disengaged from the chain and the carriers in the weighing track section to release tension in the chain. With such a straightforward solution it is possible to avoid the complicated machinery of the prior art, whereas its effectiveness is uncompromised.

Suitably the engaging units are movable in a radial direction of the rotatable wheel for engaging and disengaging the chain and/or the carriers.

In a suitable embodiment the engaging units are slidably mounted on shafts that are provided on the rotatable wheel.

In a preferable embodiment of the apparatus of the invention, the apparatus comprises a stationary guide ring and the engaging units that are supported by the rotatable wheel are each provided with a guide wheel running in a track of the stationary guide ring. This enables that the track on the stationary guide ring can cause the engaging units to engage the chain and/or the carrier in the curved track section, and to be disengaged from the chain and the carriers in the weighing track section. This is an effective and reliable way to have the engaging units operate on the chain and/or the carriers exactly at the desired moment, that is when the poultry is passing the weighing station at the weighing track section.

To accommodate any possible curvature that may be applied in the curved track section, it is desirable that the track of the stationary guide ring which causes radial movement of the engaging units with reference to the rotatable wheel, has a first track section and a second track section wherein the first track section is farther away from a rotational axle of the rotatable wheel than the second track section so as to arrange that the first track section causes tensioning of the chain and the second track section causes releasing tension in the chain.

In a preferred embodiment the weighing track section is delimited both at its entry section and at its exit section with at least part of the curved track section. Since the weighing track section represents the shortest distance possible between the curved track sections on the opposite ends of the weighing track section, this measure contributes to releasing the tension in the chain when this part of the chain is in the region of the weighing track section.

To support the accuracy of the weight measurement it is preferred that the weighing track section is free from a direct connection with the curved track section, particularly when the weighing track section is suitably provided with a load cell of the weighing station.

The invention will hereinafter be further elucidated with reference to the drawing of an exemplary embodiment of an apparatus according to the invention that is not limiting as to the appended claims.

Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts.

Turning first to <FIG> and <FIG>, it shows an apparatus <NUM> for weighing poultry (the poultry is not shown, but the skilled person is generally familiar with how poultry looks) that are conveyable by carriers <NUM> in a conveyor line <NUM> which usually is embodied with a T-track. This is however not essential. The carriers <NUM> are supported by wheels <NUM> that run in the track of the conveyor line <NUM>, and the carriers <NUM> are linked to each other by a driving chain <NUM>. The conveyor line <NUM> comprises at least a curved track section <NUM>' and a weighing track section <NUM>", which is better shown in <FIG>. A weighing station with a load cell <NUM> of the weighing station is located along the weighing track section <NUM>", as depicted in <FIG>. It is further shown in <FIG> that the weighing track section <NUM>" is free from any direct connection with the curved track section <NUM>'.

The apparatus <NUM> of the invention comprises a chain <NUM> tension control mechanism that alleviates tension in the driving chain <NUM> in the part of the chain <NUM> being at or near the weighing station along the weighing track section <NUM>".

According to the invention the chain tension control mechanism comprises a rotatable wheel <NUM> having its circumference <NUM>' following part of the curved track section <NUM>' and also passing the weighing track section <NUM>'' (see <FIG> and <FIG>) where the weighing station is located. The rotatable wheel <NUM> supports a series of engaging units <NUM> that are movable on account of the rotation of the wheel <NUM> and also radially movable with reference to the wheel <NUM> so as to engage the chain <NUM> or carriers <NUM> in the curved track section <NUM>' to tension the chain <NUM>, and that disengage from the chain <NUM> and carriers <NUM> in the weighing track section <NUM>'' to release tension in the chain <NUM>. This effect is preferably brought about by providing that the apparatus comprises a stationary guide ring <NUM> (see <FIG>) and that the engaging units <NUM> that are supported by the rotatable wheel <NUM> are each provided with a guide wheel <NUM> running in a track <NUM> of the stationary guide ring <NUM>.

<FIG> shows that the track <NUM> which causes radial movement of the engaging units <NUM> with reference to the rotatable wheel <NUM> has a first track section <NUM>' and a second track section <NUM>", wherein the first track section <NUM>' is farther away from a rotational axle <NUM> of the rotatable wheel <NUM> than the second track section <NUM>" so as to arrange that the first track section <NUM>' causes tensioning of the chain <NUM> and the second track section <NUM>" causes releasing tension in the chain <NUM>. It is thus the track <NUM> of the stationary guide ring <NUM> which causes that the engaging units <NUM> engage the chain <NUM> and/or the carrier <NUM> in the curved track section <NUM>', and to disengage from the chain <NUM> and the carriers <NUM> in the weighing track section <NUM>".

The weighing track section <NUM>" is delimited at both its entry section and at its exit section with at least part of the curved track section <NUM>'. Since the weighing track section <NUM>" represents the shortest distance possible between the curved track sections <NUM>' on the opposite ends of the weighing track section <NUM>", this contributes to releasing the tension in the part of the chain <NUM> which is in the region of the weighing track section <NUM>". This also applies when the weighing track section <NUM>'' is curved.

<FIG> shows that the engaging units <NUM> are slidable on shafts <NUM> that are at one end mounted to supports <NUM> on the rotatable wheel <NUM>. This is however not essential. Also other ways of mounting the engaging units <NUM> on the rotatable wheel <NUM> are conceivable.

During use the apparatus <NUM> of the invention operates as follows.

As the carriers <NUM> are conveyed in a conveying direction T, they reach a curved track section <NUM>' of the conveyor line <NUM>. The chain <NUM> is driven by driven means as known in the art (not depicted) to convey the carriers <NUM> along the track. The curved track section has a radius R1. As the carriers <NUM> reach the curved track section <NUM>', they are engaged by the engaging units <NUM>. As explained above the engaging units <NUM> are slidably mounted on shafts <NUM> on the rotatable wheel <NUM>. Thus, the engaging units <NUM> are conveyed along the curved track section <NUM>' by rotation about a rotational axis <NUM> of the rotatable wheel <NUM>, and are also radially movably relative to the axis <NUM> through sliding over the shafts <NUM>.

As will be clear from combining <FIG> with <FIG>, the guide track <NUM> of the stationary guide ring <NUM> guides the engaging units <NUM> via their wheels <NUM> that run in the guide track <NUM>. The first guide track section <NUM>' exhibits a radius R2, and the second track section <NUM>" near the weighing track section <NUM>'' is closer to the axle <NUM>, e.g. by exhibiting a radius R3 which is smaller than R2. In a different embodiment the second track section <NUM>'' may be rectilinear.

As explained above, the carriers <NUM> are coupled to the driving chain <NUM> so that the carriers <NUM> move in the direction T towards the beginning of the curved track section <NUM>'. There, the chain engaging units <NUM>, which are rotating together with the rotatable wheel <NUM>, engage the chain <NUM> and/or the carriers <NUM> with their engaging means <NUM>. The rotatable wheel <NUM> is arranged to rotate because the chain <NUM> drives the engaging units <NUM> as they are contacting the chain of carriers. This means that there is no need for a separate actuator driving the wheel <NUM>, although it can be added as long as the motion of the rotating motion of the engaging units <NUM> around axle <NUM> of the rotatable wheel <NUM> is synchronized with the motion of the carriers <NUM>.

As the engaging units <NUM> are being conveyed, their guide wheel <NUM> is moved along the track <NUM> of the stationary guide ring <NUM>. The engaging units <NUM> follow a curved path above the curved track section <NUM>'. However, once a unit <NUM> reaches the weighing track section <NUM>", the engaging units <NUM> slide radially toward the axle <NUM> of the rotating wheel <NUM> because the radius R3 of the track <NUM> near the location of the weighing track section <NUM>" is smaller than the radius R2 of the track <NUM> following the curved track section <NUM>'. Due to the radial inward movement of the engaging units <NUM>, the chain <NUM> is released from the engaging means <NUM> of the engaging units <NUM> at the weighing track section <NUM>'.

As the wheel <NUM> of a single carrier <NUM> reaches the weighing track section <NUM>", the load cell <NUM> measures the weight of the carrier <NUM> transporting the poultry. Since at the weighing track section <NUM>" the tension is removed from the chain <NUM>, the distortion of the weight measurements due to the tension of the chain <NUM> is reduced. Once the single carrier <NUM> leaves the weighing track section <NUM>'', the engaging unit <NUM> moves again radially away from the rotation axle <NUM> of the rotatable wheel <NUM> and its engaging means <NUM> engages again the chain <NUM> or its carriers to provide tension to the chain <NUM>.

Embodiments of the present invention can include every combination of features that are disclosed herein independently from each other. Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the apparatus of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the invention. The discussed exemplary embodiment shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment.

Claim 1:
An apparatus (<NUM>) for weighing poultry in a conveyor line (<NUM>), comprising carriers (<NUM>) for the poultry, which carriers (<NUM>) are linked to each other by a driving chain (<NUM>), said conveyor line (<NUM>) comprising at least a curved track section (<NUM>') and a weighing track section (<NUM>"), wherein a weighing station is located along the weighing track section (<NUM>"), and that the apparatus (<NUM>) further comprises a chain tension control mechanism that alleviates tension in the driving chain (<NUM>) at or near the weighing station along the weighing track section (<NUM>"), characterized in that the chain tension control mechanism comprises a rotatable wheel (<NUM>) having its circumference following the curved track section (<NUM>') and pass the weighing track section (<NUM>"), which rotatable wheel (<NUM>) supports a series of engaging units (<NUM>) that engage the chain (<NUM>) and/or the carriers (<NUM>) in the curved track section (<NUM>') to tension the chain (<NUM>) and is disengaged from the chain (<NUM>) and the carriers (<NUM>) in the weighing track section (<NUM>'') to release tension in the chain (<NUM>) .