APPARATUS FOR TESTING AUTOMOBILES

• US 3,667,289 A
• Filed: 01/05/1970
• Issued: 06/06/1972
• Est. Priority Date: 01/05/1970
• Status: Expired due to Term

• Current Assignee: Anders Yngve Back
• Original Assignee: Anders Yngve Back
• Inventors: Back, Anders Yngve
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US05/001,070
• Time in Patent Office: 883 Days
• Field of Search: 73/116,117.2,117.3,118,117 346/3 324/15,16
• US Class Current: 73/114.23
• CPC Class Codes: G01L 23/085 by measuring fluctuations of starter motor current or of battery voltage battery testing arrangements G01R31/36; testing of electrical installation on transport means G01R31/005; battery testing arrangements G01R31/36

Abstract

A measuring and recording apparatus for testing of motor cars in accordance with a predetermined test program including a program unit having a plurality of measuring data inputs connected to different measuring points of a motor car, particularly points of the motor and electrical system thereof. Said inputs are successively switched through to the measuring system of a recording instrument, the successive switching actions being timed in synchronism with the rotation of the motor when disabled and rotated by the starter. During one revolution of the motor, the relative compressions of the cylinders are recorded by recording the starter current, during another revolution, the primary current of the ignition system is recorded, and further single or double measurements may be carried out during any subsequent revolution. Then, the successive switching actions are timed in dependence on time so that during a fixed period, for example, the motor is blocked and the starter is energized, the starter current being recorded during this measuring period. In this way, a test operation results in a series of successive records of magnitudes, essential for the performance of the motor car, are obtained.

Claims

1. An apparatus for testing a vehicle having an engine by measuring and recording various quantities relating thereto comprising plural electrical leads each being connected at one end to a separate measuring point or pick-up attached thereto of the vehicle, a permanently recording measuring unit, a switching means disposed between the other ends of said electrical leads and said measuring unit and in electrical connection thereto for connecting said leads, to said measuring unit and means responsive to the angle of rotation of the main shaft of the engine for actuating said switching means to sequentially connect at least some of said leads.

2. Apparatus as recited in claim 1 further including a timing circuit activated by said switching means for supplying a control signal to actuate said switching means independently of said means responsive to the angle of rotation of the main shaft.

3. Apparatus as recited in claim 2 wherein said switching means responsive to said timing circuit further includes means for connecting more than one of said leads to said measuring unit at one time.

4. The apparatus as recited in claim 1 wherein said measuring unit includes means for producing upon a single piece of material a permanent record of the data transmitted thereto by said electrical leads.

5. Apparatus as recited in claim 4 wherein said means for producing a permanent record comprises a measuring system for producing a permanent output responsive to the input to said measuring system, a web of paper, means for enscribing said permanent output on said paper and a paper feed means for moving said web of paper transversely past said enscribing means.

6. Apparatus as recited in claim 5 further including means for controlling the speed of said feed means.

7. Apparatus as recited in claim 6 wherein said paper feed means is electrically powered and said feed speed control means comprises plural leads from a source of electrical power which are connected to said measuring unit by said switching unit simultaneously with said measuring leads and a variable resistor is provided on at least one of said plural power leads for controlling the current supplied to said paper feed means.

8. The apparatus as recited in claim 5 wherein said means responsive to main shaft rotation produces an electrical pulse which activates each succeeding switching stage and is passed through said de-activating means to de-activate the next preceeding switching stage.

9. Apparatus as recited in claim 1 wherein said switching means comprises a plurality of switching stages for connecting individual leads to said measuring unit when said stages are sequentially activated by said means responsive to main shaft rotation and means inter-connected between said stages are provided for de-activating the next preceeding switching stage when each succeeding switching stage is energized.

10. The apparatus as recited iN claim 9 further including an impulse shaping circuit connected between said means responsive to main shaft rotation and said switching stages for converting said pulses into standard pulses of approximately identical form, duration and amplitude before they are fed to said stages.

11. Apparatus as recited in claim 1 wherein said engine is of the spark ignition type and said means responsive to main shaft rotation comprises a capacitive impulse transmitter, at least one square centimeter in area, which is applied around a spark plug cable of the engine spark ignition which transmitter produces a pulse by capacitive action with said cable when a pulse passes through said spark plug cable in response to the rotation of the distribution rotor of which, in turn, rotates in proportion to the shaft rotation of the main engine shaft.

12. Apparatus for testing the relative cylinder compression of an internal combustion engine having plural cylinders, an electrical starter motor and a battery which supplies electrical power to said starter motor which apparatus comprises means for measuring the starter motor current required to completely rotate the main shaft of said engine by said starter motor and thus cause a sequential compression in each cylinder, said means including an electrical lead connected to the output terminal of said battery, and containing a series resistor, a recording unit responsive to electrical signals for producing a permanent record of electrical signal amplitude, a switching means which is adapted to connect said electrical lead and resistor to said recording unit so that said recording unit measures the voltage drop across said battery and resistor when said switching means is activated and means responsive to the rotation of the main shaft for activating said switching means.

13. Apparatus as recited in claim 12 wherein said means responsive to main shaft rotation comprises a capacitive impulse transmitter at least one square centimeter in an area which is applied around a spark plug cable of the engine which transmitter produces a pulse by capacitive action with said cable when a pulse passes through said spark plug cable in response to the rotation of the distribution rotor of the ignition circuit which, in turn, rotates in proportion to the shaft rotation of the main engine shaft.