Method and apparatus for magnetically recording vehicle running conditions

• US 4,137,553 A
• Filed: 01/03/1977
• Issued: 01/30/1979
• Est. Priority Date: 04/09/1974
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Tokitsu, Naoki, Saito, Muneo
• Primary Examiner(s): Lucas, Jay P.
• Application Number:
  US05/756,065
• Time in Patent Office: 757 Days
• Field of Search: 179/15.55 T, 340/172.5, 346/33 M, 346/33 D, 360/6, 360/7, 360/8, 360/32
• US Class Current: 360/6
• CPC Class Codes: G01P 1/122 Speed recorders
• CPC Class Codes: G07C 5/0841 Registering performance data recording measured values G01D; information storage G11B
• CPC Class Codes: G07C 5/0875 using magnetic data carriers

Abstract

In a method for magnetically recording a vehicle condition, a voltage proportional to a vehicle speed is sampled at a predetermined interval and converted into a code signal which is temporarily memorized by a memory. When the memorized data reach a predetermined amount, the data are transferred to be recorded by a magnetic tape for a period which is short enough not to prevent the memory from memorizing. When all the data have been recorded, a completion signal is generated to stop the tape, whereby the inter record gap is limited to minimum length.

Claims

1. A method for magnetically recording vehicle running conditions comprising the steps of:

sensing a vehicle running condition to provide a continuous signal,

converting said signal into a pulse signal varying in frequency in proportion to the magnitude of the sensed running condition,

temporarily memorizing said pulse signals by alternately directing said signals for predetermined intervals to a pair of movable recording means,

alternately moving said recording means at first and second speeds during said intervals whereby when one of said recording means moves at the first speed, the other of the recording means moves at the second speed, said second speed being faster than the first speed,

transferring said temporarily memorized signals from said pair of movable recording means as each moves at said second speed and recording the transferred signals on a movable magnetic recording means, said transferring and recording occurring during further intervals each of which is shorter than one of said predetermined intervals, and

stopping said magnetic recording means between said further intervals.

2. An apparatus for magnetically recording vehicle running conditions comprising:

means for sensing a vehicle running condition to provide a continuous signal,

means for converting said signal into a pulse signal varying in frequency in proportion to the magnitude of the sensed running condition,

a pair of movable recording means,

means for alternately directing said signals for predetermined intervals to respective ones of said pair of movable recording means to thereby temporarily memorize said signals,

means for alternately moving the respective ones of the recording means at first and second speeds during said intervals whereby when one of the recording means moves at the first speed, the other of the recording means moves at the second speed, said second speed being faster than the first speed,

means for transferring said temporarily memorized signals from said pair of movable recording means as each moves at said second speed,

movable magnetic recording means,

means for recording the transferred signals on said magnetic recording means, said transferring and recording occurring during further intervals each of which is shorter than one of said predetermined intervals, and

means for stopping said magnetic recording means between said further intervals.

3. An apparatus for magnetically recording vehicle running conditions comprising:

sensing means for sensing vehicle speed as a vehicle running condition to produce a pulse train varying in frequency in proportion to the sensed vehicle speed;

trigger means for producing trigger pulses at a fixed frequency;

means for producing first and second pulses at respective first and second fixed frequencies in response to each of said trigger pulses, said first frequency being higher than the fixed frequency of said trigger pulses and lower than said second frequency;

a pair of input transfer means for transferring said pulse train during the conduction thereof, said pair of input transfer means being rendered conductive alternately in response to said trigger pulses;

a pair of temporary memory means, each being connected to a respective one of said pair of input transfer means for alternately memorizing said pulse train transferred through said pair of input transfer means, and each being activated alternately by said first and second pulses such that each of said pair of temporary memory means alternately memorizes said pulse train at said first frequency;

a pair of output transfer means, each being connected to a respective one of said pair of temporary memory means for transferring said pulse train memorized in the corresponding one of said temporary memory means and each being rendered conductive alternately in response to said trigger pulses such that said pulse train is transferred at said second frequency; and

a magnetic recording means for recording said pulse train transferred through said output transfer means, said magnetic recording means being operated periodically at said fixed frequency.