Small object counting apparatus

• US 3,928,753 A
• Filed: 01/22/1974
• Issued: 12/23/1975
• Est. Priority Date: 01/22/1974
• Status: Expired due to Term

• Current Assignee: Ampak, Inc.
• Original Assignee: Jesse P.T. Harris, Robert J. Champion, William D. Kivett
• Inventors: Kivett, William D., Champion, Robert J., Harris, Jesse P. T.
• Primary Examiner(s): Thesz, Jr., Joseph M.
• Application Number:
  US05/435,499
• Time in Patent Office: 700 Days
• Field of Search: 235/92PK,98C,92V 221/211,7 198/287
• US Class Current: 377/6
• CPC Class Codes: G06M 1/101 by electro-optical means
• CPC Class Codes: G06M 7/00 Counting of objects carried by a conveyor

Abstract

Small objects, such as pharmaceutical capsules from a production stream, are counted with speed and accuracy. The objects are delivered to a hopper from which they are picked up by a rotating suction drum and transported through an orientation means to an object pick-off or drum stripping means. Following separation from the drum, the objects pass sequentially through an electrooptical sensing device which delivers electrical pulses to an electronic counter means which has the ability to display both count and rate of count. The counted objects are delivered to a suitable batch container.

Claims

1. An apparatus for counting large quantities of small objects with accuracy comprising an object infeed hopper, a horizontal axis object transport drum having plural spiral rows of suction ports mounted for rotation at the object discharge end of the hopper, means to turn the drum on its horizontal axis in one direction, means to create a partial vacuum in the drum during its rotation so that said suction ports may pick up objects from the hopper, an excess object rejection device fixedly mounted relative to the periphery of the drum and spaced from the hopper and allowing only one object to be transported by each suction port of the drum beyond said device, an object pick-off member fixedly mounted at the side of the drum remote from the hopper and spaced from said device and having inclined object guidance channels corresponding in number to the number of suction ports in each spiral row on said drum, said pick-off member removing objects from said suction ports with a scraping action during rotation of the drum and causing such objects to slide through said channels, electro-optical object sensors on the pick-off member adjacent to each channel thereof responding to the sequential passage of objects through the channels and producing sequential electrical pulses representative of the number of objects passing through the channels, counter means electrically coupled to said electro-optical sensors for totalizing the number of objects sequentially passing through all of said channels until a present count is obtained, means arranged above said hopper, drum and pick-off member for directing ionized air downwardly to agitate and clean objects resTing in the hopper and for aiding the passage of objects through said object guidance channels, and said last-named means comprising an ionization chamber having a slotted bottom wall, a metal plate having a multiplicity of dependent needles positioned within said chamber above said slotted bottom wall, means for applying high voltage alternating current to said plate, and means for directing air forcibly into said chamber.

2. The apparatus of claim 1, and said excess object rejection device comprising a comb-like member extending axially of said drum for substantially its entire length and having plural equidistantly spaced equal width slots formed therein and said slots corresponding in number to the suction ports in each spiral row and aligned with the ports circumferentially of the drum.

3. An apparatus for counting large quantities of small objects with accuracy comprising an object infeed hopper, a horizontal axis object transport drum having plural spiral rows of suction ports mounted for rotation at the object discharge end of the hopper, means to turn the drum on its horizontal axis in one direction, means to create a partial vacuum in the drum during its rotation so that said suction ports may pick up objects from the hopper, an excess object rejection device fixedly mounted relative to the periphery of the drum and spaced from the hopper and allowing only one object to be transported by each suction port of the drum beyond said device, an object pick-off member fixedly mounted at the side of the drum remote from the hopper and spaced from said device and having inclined object guidance channels corresponding in number to the number of suction ports in each spiral row on said drum, said pick-off member removing objects from said suction ports with a scraping action during rotation of the drum and causing such objects to slide through said channels, electro-optical object sensors on the pick-off member adjacent to each channel thereof responding to the sequential passage of objects through the channels and producing sequential electrical pulses representative of the number of objects passing through the channels, counter means electrically coupled to said electro-optical sensors for totalizing the number of objects sequentially passing through all of said channels until a present count is obtained, said electro-optical sensors each comprising a light source disposed on one side of each guidance channel and a photo-sensitive element on the other side of each channel optically aligned with the light source for that channel, each channel having a light transmitting passage extending thereacross adjacent to said light source and photo-sensitive element, and an automatic brightness intensity control circuit for each light source electrically connected with the source and the associated photo-sensitive element, whereby a reliable count for objects of varying translucency may be had, each brightness control circuit being a transistorized circuit including a time constant network constructed so that the source current can respond only to relatively slowly varying changes in time constant input voltages.

4. The apparatus of claim 3, and said brightness control circuit additionally comprising a single pulse generator which generates a pulse of a longer time duration than the maximum light beam interruption time of an object being counted thus insuring that only a single fixed time pulse is generated for each beam interruption, said brightness control circuit additionally comprising a differentiator circuit adapted to form short duration pulses which may be gated into a single counter circuit.