1. Field of the Invention
This invention relates broadly to a feeding, counting and dispensing apparatus. More particularly, this invention relates to a feeding and counting apparatus which uses vibration to control the flow of discrete items, such as tablets, being fed and counted.
2. State of the Art
Counters for counting tablets, capsules, caplets and the like (xe2x80x9ctabletsxe2x80x9d) have been known in the pharmaceutical industry for some time. It is generally the common goal of such counters to feed a collection of tablets in a manner which permits the tablets to be counted as they move past a sensor, such as an optical sensor.
Industrial pharmaceutical tablet counters are bulky and use a feed mechanism to transport large quantities of tablets to a counting system which counts the tablets. The counted tablets are then dispensed into a container. For example, a counter may be configured to count millions of tablets which are divided into individual containers of hundred tablets each. The industrial counters are typically very loud, employing large rotational or linear vibrators to feed the tablets to the counting system. Such vibrators are also complex in their structure and require special tuning for each system.
Counters used in pharmacy environment are generally different from those used in industrial applications. In a pharmacy, a pharmacist is required to count different quantities of different tablets in succession. For example, a pharmacist may count 30 caplets of a heart medication for one patient and then count 60 tablets of an allergy medication for the next patient using the same counter. Therefor, a pharmacy tablet counter must be able to rapidly count many different types of tablets and must be capable of ensuring that medications of different prescriptions are not mixed due to tablets from a prior prescriptions unintentionally remaining in the counter. Clearing the counter is essential, as it is important to reduce the risk of cross contamination. In addition, behind a pharmacy counter, space is typically crowded and at a premium. Therefor, the counter should be compact rather than bulky. Moreover, pharmacy counter should be substantially silent.
As a result, a quiet feed system is preferred for pharmacy tablet counters. One relatively quiet system is a simple gravity system, in which a pharmacist dispenses tablets in bulk into a plastic funnel, and the force of gravity moves the tablets through that funnel and past a counter sensor, and then through a second funnel with a narrow bottom opening. However, simple gravity feed systems have a substantial drawbacks. Funneling the objects through a small opening may result in clogging of the opening, and therefore requires safety features to ensure that clogging has not occurred. In addition, static electricity can build up between the funnel and the tablets (and in particular light weight capsules), causing them to stick to the funnel in spite of the gravitational force. This can obviously cause serious problems.
As such, many counters count tablets into a tray, and the tablets are then transferred from the tray to a prescription bottle. The tray is used to visually inspect the counted tablets to ensure that no tablets from a previous prescription was inadvertently left in the counter, later dislodged from the counter, and incorrectly provided to the wrong patient. Such could result in injury to the patient receiving the incorrect medication and liability for the pharmacy. However, the use of tray is undesirable as it adds an extra step in every prescription which is counted: the transfer of the tablets from the tray to a prescription bottle.
Therefore, there has been an effort to develop a system which overcomes the problem of stuck tablets and which does not require the intermediate use of a tray. One proposed manner to prevent the static electricity build up is to use a funnel which is made of metal, e.g., stainless steel, and thereby prevents static electricity build up between the tablets and the funnel. However, tablets bouncing off the walls and through a stainless steel funnel tend to make substantially more noise than can be comfortably accommodated in a pharmacy.
It is therefor an object of the invention to provide a device for counting discrete objects which safely dispenses the objects directly into a container and reduces the risk of any objects remaining in the device.
It is another object of the invention to provide a counting device, which requires no special tuning operation applied to each manufactured device, has few parts, and functions with high reliability.
It is another object of the invention to provide a counting and dispensing device having substantially silent counting and dispensing systems.
In accord with these objects, which will be discussed in detail below, an object counting device is provided which includes a feeding funnel, an object sensing system which senses objects provided into the feeding funnel, a dispensing funnel having an upper opening into which the objects are gravity fed after passing through the object sensing system and a relatively smaller lower opening, a vibration system which substantially silently vibrates the dispensing funnel solely in a horizontal plane, and counter and display system indicating the number of objects counted.
According to a preferred aspect of the invention, the vibration system includes a first weight, a rotating means for eccentrically rotating the first weight in an XY plane such that a rotation of the weight creates forces applied to the rotating means in all directions in the XY plane, and means for transferring the force in only one of the X and Y directions to the dispensing funnel, that direction preferably being a horizontal direction. Such arrangement minimizes the overall noise level, and reduces the number of parts.
According to the first embodiment of the invention, the vibrating system comprises a resilient vertical support for the dispensing funnel, a weight, a motor, a mounting block, and a resilient horizontal support. The weight is coupled to the motor, the motor is mounted on the mounting block, the mounting block is attached to one end of the resilient horizontal support, and the dispensing funnel is attached to the second end of the resilient horizontal support. The motor is adapted to rotate the weight in an eccentric manner to create vertical (Y) and horizontal (X) forces applied to the motor and consequently to the mounting block. When the weight is rotated, the resilient horizontal support flexes to substantially silently absorb all vertical forces created by the weight and thereby prevents the transfer of such vibration forces to the dispensing funnel. The dispensing funnel therefore vibrates substantially smoothly, reliably and silently in a horizontal direction, evacuating the discrete objects provided therein.
According to a second embodiment of the invention, two weights are counter rotated in a horizontal plane XZ. The weights rotate about their respective axes which are displaced along the Z direction, wherein X, Y and Z are perpendicular. The counter rotation of the weights cancels the total force applied to the vibrating system in the Z direction. The desired force in X direction is transferred to the dispensing funnel to smoothly and silently vibrate the dispensing funnel in the X direction.
Additional objects and advantages of the invention will become apparent to the skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.