Patent Description:
In many industries, but especially in foods and pharmaceuticals, product inspection with regard to at least one product parameter is a crucial step. Brand protection requires that off-spec product is identified and removed from the production line. There are many product parameters that can be measured as the product moves along a conveyor line. For purposes of illustration only, these include weight, presence of a contaminant, product color, defect in the container, and improper labelling. Once a product is identified as being off-spec, it needs to be removed as soon as possible from the conveyor.

The applicant has extensive experience in providing systems for removing off-spec product from a production line, particularly with regard to product that falls outside of a predetermined weight tolerance. This experience is summarized in a <NUM> White Paper titled "How to Choose the Right Reject System". That paper lists types of reject devices and types of reject receptacles.

Overhead sweep rejecters of the prior art, such as those described in the White Paper or as disclosed in <CIT>, <CIT>, and <CIT>, operate with a pendulum action that originates from a pivot point above the conveyor. Before use, the pendulum arm is drawn back into an "armed" position to swing across the direction of motion of the conveyor when released. As the bottom of the arm swings on an arcuate path centered about the pivot point, it moves downwardly towards the conveyor, past a low point when the arm is vertical, and then upwardly. Unlike a pusher rod that acts strictly horizontally, the arcuate motion of the pendulum can provide a vertical component to the force applied to a product being moved to a reject receptacle. The arcuate motion is also smooth and positive, which is desirable in moving larger delicate products. When reject receptacles are provided on each side of the conveyor, the overhead sweep rejecter as known can be arranged to move from an "armed" position on one side of the vertical to a corresponding "armed" position on the opposite side, so that products are removed alternatingly to opposite sides of the conveyor, using both reject receptacles.

<CIT> relates to an apparatus for removing objects which are advanced on a conveyor. The apparatus comprises a part of the conveyor on which the objects are advanced and supports for the objects removed from the conveyor. The apparatus also includes a pivotal cradle which is placed over the conveyor. The pivotal cradle has two through flow channels each with an inlet and an outlet. The pivotal cradle is also provided with a stop pivotal between the outlets of the two through flow channels. In particular <CIT> discloses a device according to the preamble of claim <NUM>.

When these types of overhead sweep rejecter are used, the vertical approach of the bottom of the pendulum arm toward the conveyor surface presents a potential for crushing or shearing an object in the path. This is a hazard for personnel which has not been solved in the known prior art.

It is an unmet objective, therefore, to minimize or eliminate this hazard while retaining the desirable aspects of the overhead sweep action as fully as possible.

This and other objects are met by a device for removing an object from a conveyor belt of a conveyor line, comprising a housing and a kicker portion. The housing is adapted for attachment to the conveyor line and the kicker portion is suspended for rotation about a pivot axis from the housing, such that a vertical separation of a lower end of the kicker portion from the conveyor belt remains constant during rotation.

According to the invention, the housing has a rear wall and a top wall; and the kicker portion comprises a wall that wraps around the sides and front of the top wall and extends downwardly, defining an interior of the kicker portion.

In some of these embodiments, the wall further comprises a portion that interacts with a slot in the rear wall to delimit angular rotation of the kicker portion in one direction away from the vertical.

According to the invention, the device also comprises a contacting plate, arranged for sliding movement along a front side of the wall of the kicker portion.

In some of these embodiments, the device also comprises a vertical slot in the wall of the kicker portion and a plate connected though the vertical slot to the contacting plate, delimiting the sliding movement of the contacting plate.

In some of these embodiments, the device also comprises a guide rail housing, affixed to the housing and a pair of guide rails, restrained by the guide rail housing to horizontal movement, an end of each of the guide rails pivotally fixed to the contacting plate.

In some embodiments, the device further comprises a hydraulic cylinder, extending through a rear wall of the housing, a rod with a first end contained in the hydraulic cylinder and a second end directed toward an interior wall of the kicker portion, and a pair of plates, affixed to the interior wall of the kicker portion on each side of the second end of the rod and coupled thereto.

In some of these embodiments, each of the pair of plates has an elongate slot formed therein; and a short rod, coupled to the second end of the rod and extending transverse to an axis of the rod, each end of the short rod engaged in a respective one of the elongate slots, delimiting horizontal movement of the rod.

Some embodiments of the device comprise a first and a second side plate, removably secured to a rear wall of the housing, covering lateral faces of the kicker portion.

Other objects are met by a method for removing an object from a conveyor belt of a conveyor line, comprising:.

In some of the method, a contacting plate on a wall of the kicker portion moves along the wall while the device is in the actuated condition to maintain the vertical separation.

A better understanding of the inventive concept will be had when reference is made to the accompanying drawings, wherein identical parts are identified by identical reference numbers and wherein:.

<FIG> shows a perspective view of a portion of a product inspection line <NUM> having a conveyor belt <NUM>, a parameter inspection unit <NUM>, an overhead sweep rejecter <NUM> and a reject receptacle <NUM>. Objects to be inspected are placed on the conveyor belt <NUM> and pass, along a direction of travel of the conveyor belt, through the parameter inspection unit <NUM>. In the depicted embodiment, the parameter inspection unit <NUM> comprises a device <NUM> for detecting metal contaminants in the object and a checkweigher <NUM> for determining whether the object falls within an acceptable variance from a predetermined target weight. Other exemplary parameters that may evaluated include color of the product, contamination by radiation, defect in the packaging, and the like. Data from devices <NUM>, <NUM> are provided to an evaluation unit <NUM> for comparison against predetermined product quality targets.

When an object under inspection fails to meet a predetermined target range of the parameter being inspected in the parameter inspection unit <NUM>, an output signal is generated by the evaluation unit <NUM> cause actuation of the overhead sweep rejecter <NUM>. As the object passes on the conveyor belt <NUM> that is between the overhead sweep rejecter <NUM> and the reject receptacle <NUM>, an actuating impulse causes the overhead sweep rejecter to remove the off-spec object from the conveyor belt <NUM> into the reject receptacle <NUM>. As seen in <FIG>, the overhead sweep rejecter <NUM> is affixed to the conveyor along a siderail thereof.

<FIG> provides a front perspective view of an exemplary embodiment of an assembled overhead sweep rejecter <NUM> and <FIG> provides the side elevation view of it. Viewed generally in this assembled condition, the rejecter <NUM> has several parts. These include a housing <NUM>, a kicker portion <NUM> that is pivotably suspended from the housing and a support <NUM> that is adapted to affix the housing adjacent to the conveyor with the kicker portion being positioned at a fixed predetermined gap above the conveyor belt. In <FIG>, the kicker portion <NUM> is in a non-actuated position in which it is generally retracted into the housing <NUM>. Other features seen in <FIG> are a hydraulic cylinder <NUM> containing a rod that receives the output signal from the evaluation unit, and a pair of guide rails <NUM>, contained within a guide rail housing <NUM>. A contacting plate <NUM> of the kicker portion <NUM> is positioned to be the primary element that contacts an object being moved off of the conveyor belt into the reject receptacle. As a safety feature, a pair of side plates <NUM> constitute a portion of the housing <NUM> that substantially covers moving parts of the overhead sweep rejecter <NUM> other than the contacting plate <NUM>. Since a feature of the inventive concept is to provide a device that minimizes or eliminates the potential of injury, the side plates <NUM> of the depicted embodiment are shown removably fastened as by screws <NUM>, or a similar fastener, to a portion of the housing from which the kicker portion <NUM> is suspended, as by a pin <NUM> or similar pivotable mounting means.

<FIG> reveals internal features of the overhead sweep rejecter <NUM> and the kicker portion <NUM> in a rear perspective view in which one of the side plates <NUM> and part of a wall <NUM> of the kicker portion <NUM> removed to show internal structures. The side plate <NUM> on the far side of the housing <NUM> is in place, but only the screws <NUM> that would attach the side plate on the near side are shown. These screws <NUM> connect the side plate <NUM> to a rear wall <NUM> of the housing <NUM>. The rear wall <NUM> is shown as being a separate element from a top horizontal wall <NUM>, the respective walls being removably joined together by screws <NUM>, bolts or the like, but some embodiments may have these walls formed monolithically and other embodiments may have them integrally joined, as by welding or the like. It is the top horizontal wall <NUM> that provides the pivotal suspension of the kicker portion <NUM>, using pin <NUM>. Wall <NUM> of the kicker portion <NUM> is shown in <FIG> with a portion removed to show other features. This wall <NUM> wraps around the sides and front of top horizontal wall <NUM>. It is wall <NUM> that is pivotably pinned to the top horizontal wall <NUM>, and, notably, the pivotal connection at <NUM> is the only connection between the kicker portion <NUM> and the housing <NUM>. In the depicted embodiment, a portion <NUM> of the wall <NUM> is shaped and positioned to delimit rotation of the kicker portion <NUM> toward the rear wall by interacting with a slot <NUM> in the rear wall.

Viewed externally, contacting plate <NUM> appears to be affixed to wall <NUM>, as seen in <FIG> and <FIG>, but as will be seen in <FIG>, <FIG> and <FIG>, the contacting plate is arranged for sliding movement on wall <NUM>. The removal of a part of wall <NUM> in <FIG> permits internal structures to be seen and understood. Rod <NUM> has a first end in the hydraulic cylinder <NUM>, which extends through the rear wall <NUM>, the hydraulic cylinder being secured to the rear wall on an interior side of the rear wall. Preferably, all moving parts of the hydraulic system, and especially the rod <NUM>, are contained within the housing <NUM>, minimizing any hazard presented. <FIG> also shows fittings <NUM> and <NUM> for connection to a source of hydraulic fluid. A second end <NUM> of rod <NUM> is coupled to a short rod <NUM> that is transverse to an axis of rod <NUM>. Each end of short rod <NUM> is engaged in one of a pair of elongate slots <NUM> formed in a pair of plates <NUM> that are on each side of second end <NUM>, where each plate is affixed to a rear surface <NUM> of the wall <NUM> of kicker portion <NUM>. This engagement of the ends of short rod <NUM> in the elongate slots <NUM> delimit the horizontal movement of rod <NUM>, as will be further seen in <FIG> and <FIG>.

<FIG> also shows that a lower end <NUM> of contacting plate <NUM> is pivotably fixed at each side to the pair of guide rails <NUM>, with a pivotal fixing means, such as a pin <NUM>. <FIG> also shows that these guide rails <NUM> are restrained to horizontal movement by the guide rail housing <NUM>.

A final feature of note in <FIG> is plate <NUM>, which appears to be directly affixed to a rear surface <NUM> of contacting plate <NUM>, but which in fact enables delimited sliding movement of contacting plate <NUM> along wall <NUM>, as will be seen in <FIG> and <FIG>.

<FIG> and <FIG> illustrate, in side sectional elevation view, how the overhead sweep rejecter <NUM> operates. In <FIG>, the rejecter <NUM> is in a non-actuated condition; in <FIG>, the rejecter is in the actuated condition. The mechanism disclosed in these figures retains the advantages of a pendulum motion for moving an object, while eliminating the crushing or shearing hazard posed by the lower end of a fixed length pendulum.

In the retracted position of <FIG>, the kicker portion <NUM> of the overhead sweep rejecter <NUM> hangs downward from the pivotal attachment to the housing. In this position, the lower surfaces of the guide rails <NUM> are suspended above the conveyor belt by a predetermined minimum distance, which is preferred to be about <NUM>. In this position, a lower edge of the contacting plate <NUM> is also suspended at the predetermined minimum distance.

Upon an actuation signal, an actuator sends hydraulic fluid to the hydraulic cylinder <NUM> to act on the rejecter <NUM>, moving it from the <FIG> position to the fully-actuated <FIG> position, using an impetus imposed upon the kicker portion <NUM>. In the depicted embodiment, the hydraulic cylinder <NUM> is arranged as a pusher that imposes a horizontal impetus through rod <NUM>. It could also be arranged to impose a horizontal impetus on the pair of guide rails <NUM>, or, although not as preferably, it could be arranged to apply rotational torque at pin <NUM>.

In any of the particular cases, and as viewed in <FIG> and <FIG>, the impetus applied though rod <NUM> causes clockwise rotation of kicker portion <NUM> about a pivot axis defined by pin <NUM>. Particularly when this occurs through rod <NUM>, plates <NUM> bear against the rear surface <NUM> of wall <NUM>, effectively increasing the distance, as measured along the rear surface between the plates and the pin. As the rotation occurs, the horizontal force applied to an object by the contacting plate <NUM> resolves into a resultant vector having both horizontal and vertical components. The vertical component will tend to lift the object rather than merely to slide it, reducing the contact area between the object and the conveyor belt. This provides the advantageous effect of a pendulum rejecter.

However, the rotation of a conventional pendulum with a fixed length causes vertical separation between the bottom of the pendulum and a horizontal surface below it, giving rise to the shearing or crushing hazard. In the rejecter <NUM> of the inventive concept, this is avoided by providing a pendulum-type effect where the length of the pendulum arm effectively changes during rotation, so that vertical separation above the surface remains constant.

Claim 1:
A device (<NUM>) for removing an object from a conveyor belt (<NUM>) of an inspection line (<NUM>), comprising:
a housing (<NUM>), adapted for attachment to the inspection line (<NUM>); and
a kicker portion (<NUM>), suspended for rotation about a pivot axis (<NUM>) from the housing (<NUM>), such that a vertical separation of a lower end (<NUM>) of the kicker portion (<NUM>) from the conveyor belt (<NUM>) remains constant during rotation,
characterised in that:
the housing (<NUM>) has a rear wall (<NUM>) and a top wall (<NUM>); and
the kicker portion (<NUM>) comprises a wall (<NUM>) that wraps around the sides and front of the top wall (<NUM>) and extends downwardly, defining an interior of the kicker portion (<NUM>); and in that the device (<NUM>) further comprises:
a contacting plate (<NUM>), arranged for sliding movement along a front side of the wall (<NUM>) of the kicker portion (<NUM>).