US 4,937,795 AGranted

Access alarming method and apparatus for working vehicle

AssigneeTokyo Keiki Co., Ltd.

InventorsRyohei Motegi, Yoichi Hirokawa, Yukio Yoshida, Junichi Furuki, Tetsuya Ishii, Isao Takiguchi, Hiroshi Kono, Takehiko Suyama, Tomohiro Gocho, Satohiko Tanaka, Narimasa Yamabe, Yoshimitsu Hashimoto

Life of this patent

Estimating the term…

patentgrep

Loading patent…

Abstract

An access alarming method and apparatus for activating an alarm in the event of the access of a working vehicle, such as a road roller, to an object, such as a worker, in the same working area as the vehicle. An ultrasonic wave transmitted by a transmitter on the object is received by a receiver on the vehicle. The received signal is processed and used to determine the relative position of the vehicle with respect to the object. An alarm is activated, and/or the vehicle is braked when it is judged that the object is within a hazard area determined in relation to the position and course of the vehicle.

Claims19

Dependent claims

An access alarming method for a working vehicle, comprising:

transmitting a searching supersonic wave of a first frequency from the working vehicle for searching for an object;
enabling a searched object to transmit a response supersonic wave of a second frequency upon receipt of the searching supersonic wave;
receiving the response supersonic wave by receiving means located on the working vehicle and measuring the time required for the supersonic waves to travel between the working vehicle and the object, thereby determining the distance between the vehicle and the object;
comparing the determined distance with a predetermined distance;
and
activating an alarm circuit when the determined distance is smaller than the predetermined distance, the working vehicle having a single transmitting/receiving means for transmitting the searching supersonic wave and for receiving the response supersonic wave, the object having a single transmitting/receiving means for receiving the searching supersonic wave and transmitting the response supersonic wave.

3 more elements

An access alarming apparatus, comprising:

a searching supersonic wave transmitting/receiving means provided on a working vehicle capable of transmitting a searching supersonic wave for searching for an object;
a response supersonic wave transmitting/receiving means provided on said object that is capable of transmitting, upon receipt of said searching supersonic wave, a response supersonic wave of a frequency that is different from the frequency of said searching supersonic wave;
a time difference detection circuit provided on said vehicle that is capable of determining the time corresponding to the distance between said working vehicle and said object on the basis of said response supersonic wave transmitted by said response supersonic wave transmitting/receiving means;
a signal processing circuit provided on said vehicle that is capable of producing an alarm activating signal when the output from said time difference detection circuit is smaller than a predetermined reference value;
and
means for activating an external device in accordance with the output from said signal processing circuit, wherein said working vehicle has a single transmitting/receiving means for transmitting said searching supersonic wave and for receiving said response supersonic wave, said object having a single transmitting/receiving means for receiving said searching wave and transmitting said response supersonic wave.

3 more elements

Dependencies are inferred from the claim text.