This invention relates to automated packaging machines for small round produce, such as blueberries and cherry tomatoes, and in particular a dispensing mechanism for an automated conveyer driven produce packaging system.
Thin plastic containers have become increasingly popular as containers for small produce, such as blueberries, cherry tomatoes, and other small fruit. These containers include a xe2x80x9cclam shellxe2x80x9d lid, which is integrally attached to one edge of the container and thus may be moved from an open position to a closed position in which the corners of the lid engage the corners of the receptacle to thereby close the container until it is opened by the consumer.
Automated systems have been developed for packaging small produce in clam shell containers. Conventional packaging systems include a variety of automated conveyers and mechanisms, which perform various packaging functions. Generally conveyers are used to transport produce and containers through the various automated work stations, where an automated mechanism performs some packaging operation, such as metering produce into the container or closing the containers after it is filled with produce. While automated systems reduce the time and man power required to get produce to market, cost, complexity and lack of flexibility present several practical and operational draw backs for small produce growers and packagers.
Conventional automated packaging systems use large gravity feed dispensing apparatus. The dispensing apparatus generally include a large hopper and an adjustable gate, which meters the flow of produce from the hopper into the containers, as the containers are carried along a conveyer. The size of the gate opening can be adjusted to increase or decrease the volume of produce flowing into the containers. Generally the gates are located at the bottom of the hoppers, which are suspended directly over the conveyers such that the produce falls directly downward into the containers. The mouth of the gate is elevated above the containers only a short distance to prevent the produce from being damaged by the fall.
Conventional gravity feed dispensing apparatus have had several draw backs. Conventional dispensing mechanisms often damage the produce as it is metered into the containers. Since the metering gates of overhead dispensing hoppers are located directly over the containers and conveyers, the weight of the bulk produce inside the hopper exerts significant pressure on the produce at the mouth of the gate. The pressure on the produce can shear and bruise the produce as it is force through the gate opening. The location of the hoppers directly above the conveyer mechanism, can also contribute to produce damage. If the gate opening is not adjusted to generate the appropriate flow rate, the containers may be over filled. Since the gate is elevated above the containers only a short distance, overfilling the container will result in the excess produce being scrapped off and out of the container by the sides of the gate, as the container is transported along the conveyer. Over filling not only results in shear damage and loss of produce, but may also prevent the container from being closed.
Conventional dispensing mechanisms fail to consistently meter the same volume of produce into each successive container on the conveyer. The location of metering gates in overhead dispensing hoppers creates a xe2x80x9cplowing effect,xe2x80x9d which prevents conventional dispensing mechanisms from metering a consistent volume of produce. The size of individual pieces of produce (berries and the like) varies greatly. As containers pass under the dispensing gate of an overhead hopper, large individual pieces of produce, caught in the gate and not sheared off by the gate of an overhead hopper, block or xe2x80x9cplowxe2x80x9d smaller pieces of produce from entering the containers. As a result, the volume of produce metered into each successive container varies greatly, with some containers being under filled and others being over filled. In addition, locating the hopper and gate directly over the conveyer also makes regulating the volume and flow rate of the produce through the gate more difficult. The pressure on the produce at the mouth of the gate exerted by the weight of the bulk produce fluctuates with the volume of produce inside the hopper. While the hopper is a gravity feed system, the fluctuation of the pressure exerted on the produce can influence the flow rate of the produce into the containers. Often, the volume of produce inside the hopper is not consistently maintained. As a result, the gate opening must be constantly adjusted to regulate the flow rate of the produce into the containers. While this problem can be reduced by using conveyers to deposit a steady stream of bulk produce into the dispensing hopper, additional conveyers add to the cost and complexity of the packaging system.
Recently, dispensing hoppers for produce packaging machines have been developed to address some of these problems. For example, one packaging system mechanism manufactured by AandB Blueberry Packaging of Hartford, Mich., includes a side located dispensing hopper, which meters produce through a gate in the container at an angle, instead of vertically from an over head hopper. Other dispensing hoppers have included internal baffles, which divert the flow of produce and reduce the pressure on the produce at the mouth of the metering gate. Nevertheless, these apparatus have not adequately addresses the problems of gravity feed dispensing apparatus.
The dispensing mechanism of this invention is used for dispensing produce into clam shell type containers as part of an automated packaging system. The dispensing mechanism is mounted to a packaging machine that includes a conveyer mechanism for transporting the containers past the dispensing mechanism. The dispensing mechanism is mounted to a subframe, which extends over the conveyer track of a conventional packaging machine. The dispensing mechanism of this invention includes a side mounted hopper, a guide shoot, and a pair of elongated produce stops. The interior of the hopper is divided by internal partitions into a large bin and a dispensing queue. The body of the hopper has an inclined floor, and converging side and end walls that funnel produce toward two vertically oriented metering gates. One gate meters produce from the large bin into the queue and the second gate meters produce from the queue into the containers. The guide shoot is pivotally connected to the hopper beneath the second gate. The guide shoot directs the produce from the hopper into the containers, and also is used to adjust the speed of produce from the hopper into the containers. The produce stops are located in front of the shoot and run directly over and substantially parallel to the conveyer track to prevent the loss of produce and direct the produce into the center of the container base. The stops can be adjusted horizontally and vertically to insure that the containers are filled evenly and without loss of produce.
The dispensing mechanism combines several unique features to address the draw backs of the conventional produce dispensing apparatus. The use of a divided hopper interior and two vertically oriented metering gates, along with the side mounted location of the hopper, allows produce to be dispensed into containers with less damage to the produce and with greater control of the flow rate. The angular attitude of the hopper and the shoot can be independently adjusted to vary the speed of the produce moving through the hopper and over the shoot, respectively. The weight of the bulk produce is exerted directly onto the metering gates. Produce flow through the gate openings at an angle to the direction of gravitational force; consequently, the force exerted on the produce passing through the mouth of the gate is significantly less and the flow rate is less effected by the volume of produce inside the hopper. Dividing the interior of the hopper into a large accumulating bin and a smaller dispensing queue divides the total weight of the produce in the hopper into two areas. The first gate meters produce from the bin into the queue to maintain a relatively constant volume of produce inside the queue. Maintaining a constant volume of produce inside the queue, allows the shoot gate to consistently meter constant flow rate from the hopper, which is unaffected by the volume of the produce inside the bin. In addition, the smaller volume of produce inside the queue, compared to the larger volume in the bin, exerts less pressure on the produce, which has less influence on the flow rate from the hopper into the containers. Consequently, the flow rate through the gate from the queue can be consistently maintained and controlled.
Accordingly, an advantage of this invention is to provide for a dispensing mechanism for an automated conveyer driven packaging system, which dispenses produce at a consistently controlled flow rate to evenly fill each successive container with a uniform volume of produce.
Another advantage of this invention is that the dispensing mechanism reduce damage to the produce.
Another advantage of this invention is that the dispensing mechanism reduces the effect of fluctuations in the volume of bulk produce in the hopper on the flow rate of produce into the containers.
Another advantage of this invention is that each functional component can be readily adjusted to control the volume, speed and flow rate of the produce.
Other advantages will become apparent upon a reading of the following description.