Apparatus for monitoring a boundary line

• US 4,375,289 A
• Filed: 08/04/1980
• Issued: 03/01/1983
• Est. Priority Date: 07/19/1977
• Status: Expired due to Term

• Current Assignee: Precitec Gesellschaft Fur Prazisionstechnik und Elektronik mbH & Company Entwicklungs und Vertriebs-KG
• Original Assignee: Precitec Gesellschaft Fur Prazisionstechnik und Elektronik mbH & Company Entwicklungs und Vertriebs-KG
• Inventors: Schmall, Karl-Heinz, Sendor, Piotr
• Primary Examiner(s): Oechsle, Anton O.
• Application Number:
  US06/174,936
• Time in Patent Office: 939 Days
• Field of Search: 273/371, 273/411, 273/1 B, 273/29 R, 273/31, 273/127 R, 273/58 G, 340/323, 340/552, 340/561, 340/562, 340/564, 340/565, 340/567, 340/572
• US Class Current: 273/371
• CPC Class Codes: A63B 2071/0611 Automatic tennis linesmen, i.e. in-out detectors
• CPC Class Codes: A63B 63/004 Goals of the type used for football, handball, hockey or the like
• CPC Class Codes: A63B 71/0605 Decision makers and devices using detection means facilitating arbitration
• CPC Class Codes: A63D 15/20 Scoring or registering devices
• CPC Class Codes: G08B 21/18 Status alarms G08B21/02 takes precedence
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H04B 5/263 Multiple coils at either side

Abstract

Apparatus for registering a chance event, particularly the passage of a ball over a closed boundary line in a game, is described wherein the ball contains an oscillatory circuit. Two parallel conductors, fed by an a.c. generator in phase opposition extend along the boundary line so that a receiving conductor extending between the transmitting conductors is subject to a resultant zero voltage until the ball approaches and passes the boundary line so disturbing the electromagnetic fields radiated by the transmitting conductors. The receiving conductor current then passes through an amplifier, phase comparison means, a pulse generator and display device. The phase comparison means is connected to distinguish the direction in which the ball crosses the line and also enables a zero setting device to accommodate prolonged extraneous signals. A compensating antenna and circuit eliminate stray field effects. The transmitting and receiving conductors can encircle a goal structure.

Claims

1. Apparatus for registering a chance event, comprising an object to be projected randomly over a boundary line, and means for monitoring a boundary line marking out an area in space and detecting the random passage of said object over the boundary line, said monitoring means comprising at least two approximately linear transmitting conductors provided along said boundary line for emitting electromagnetic fields of opposite polarity, electrical supply means for supplying alternating voltage in phase opposition respectively to said conductors so as to produce said fields, at least one first receiving means arranged for voltages to be generated therein by said electromagnetic fields and located so that said generated voltages normally counteract one another, an amplifier connected to said first receiving means, indicator means connected to said amplifier, said objects including means for influencing said electromagnetic fields of said transmitting conductors when passing over said boundary line thereby disturbing said counteracting voltages in said first receiving means and causing a signal to appear at said indicator means to indicate passage of said object over said boundary line, said monitoring means further comprising at least one second receiving means spaced from and outside of said electromagnetic fields of opposite polarity but arranged to receive interference signals generated by electromagnetic transmitting sources other than the said linear transmitting conductors and said means included in the object, which interference signals are also received by said first receiving means and passed to said amplifier, said second receiving means being connected to said amplifier by way of compensation means for converting interference signals received by said second receiving means and feeding to said amplifier oppositely coupled signals relative to interference signals from said first receiving means so that interference signals received by said first and second receiving means are effectively compensated and suppressed.