Antenna cable break detector for construction machine wireless communication apparatus and construction machine wireless communication apparatus

• US 7,902,832 B2
• Filed: 05/24/2007
• Issued: 03/08/2011
• Est. Priority Date: 05/26/2006
• Status: Expired due to Fees

• Current Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Inventors: Tsukada, Hidenobu, Shimamura, Tadatoshi
• Primary Examiner(s): NATALINI, JEFF WILLIAM
• Application Number:
  US12/091,987
• Publication Number:
  US 20090267612A1
• Time in Patent Office: 1,384 Days
• Field of Search: 324/539, 324/543
• US Class Current: 324/539
• CPC Class Codes: E02F 9/24 Safety devices , e.g. for preventing overload E02F9/226 takes precedence
• CPC Class Codes: E02F 9/26 Indicating devices E02F5/145 takes precedence
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72

Abstract

An antenna cable break detector used with a construction machine wireless communication apparatus to detect a break in an antenna cable. The antenna cable 4 includes a central wire 6 and an armor wire 7 that is positioned concentrically outside the central wire. One end of the central wire and the armor wire is connected to a communication device. The other end of the central wire is connected to an antenna 3. The other end of the armor wire is grounded. The antenna cable break detector has a direct current shutoff device that is connected to the armor wire to shut off the flow of direct current 15 from the armor wire to the communication device. There is also a current shutoff detection device that is connected to the armor wire to detect the shutoff of the flow of a direct current to the armor wire.

Claims

1. An antenna cable break detector for a construction machine wireless communication apparatus that includes a communication device mounted in a construction machine, an antenna, and an antenna cable, the antenna cable including a central wire and an armor wire that is positioned concentrically outside the central wire, one end each of the central wire and the armor wire being connected to the communication device, the other end of the central wire being connected to the antenna, the other end of the armor wire being grounded, the antenna cable break detector comprising:

a direct current shutoff device that is connected to the armor wire of the antenna cable to shut off a direct current flow from the armor wire to the communication device; and

current shutoff detection device that is connected to the armor wire of the antenna cable, that applies a direct current to the armor wire from a power supply for detecting a break in the antenna cable, and detects the shutoff of the direct current.

2. The antenna cable break detector according to claim 1, further comprising:

an alternating current shutoff device for shutting off an alternating current flow from the armor wire of the antenna cable to the current shutoff detection device.

3. The antenna cable break detector according to claim 1, further comprising:

processing means that performs a communication breakdown process when the current shutoff detection device detects the shutoff of the direct current flow in the armor wire.

4. A construction machine wireless communication apparatus that includes a communication device mounted in a construction machine, an antenna, and an antenna cable, the antenna cable including a central wire and an armor wire that is positioned concentrically outside the central wire, one end each of the central wire and the armor wire being connected to the communication device, the other end of the central wire being connected to the antenna, the other end of the armor wire being grounded, the construction machine wireless communication apparatus further comprising:

an antenna cable break detector for detecting a break in the antenna cable;

wherein the antenna cable break detector includes

a direct current shutoff device that is connected to the armor wire of the antenna cable to shut off a direct current flow from the armor wire to the communication device, and

a current shutoff detection device that is connected to the armor wire of the antenna cable, that applies a direct current to the armor wire from a power supply for detecting a break in the antenna cable, and detects the shutoff of the direct current.