DEVICE FOR MEASURING COMPRESSION OF PISTON ENGINES

• US 3,765,233 A
• Filed: 01/21/1972
• Issued: 10/16/1973
• Est. Priority Date: 01/26/1971
• Status: Expired due to Term

• Current Assignee: Reimar Germann
• Original Assignee: Reimar Germann
• Inventors: Germann, Reimar
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US05/219,624
• Time in Patent Office: 634 Days
• Field of Search: 73/116,117.2,115
• 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 device is disclosed for measuring and checking the compression of piston engines. The battery voltage or the current to the starter motor is picked up by clamps or split-wire type transducers, and the AC-component representative of the compression is transmitted to a peak-to-peak measuring device. The peak-to-peak value is storaged during the time for one or more revolutions of the engine and for each cylinder separately. The compression of each cylinder is displayed in relation to the compression of the cylinder having the highest value of compression.

Claims

1. An apparatus for measuring and testing the compression in the cylinders of a piston engine, comprising:

a measuring device for storing the maximum peak-to-peak value of an alternating signal proportional to the torque occurring during one full working cycle of the piston engine, an adjustable potentiometer for establishing a set voltage ratio and having an input connected to the output of said measuring device, a voltage comparator with a first and a second input, said first input being connected to the output of said potentiometer, said second input being connected to the input of said measuring device, a number of AND gates corresponding to the number of cylinders of the piston engine, each AND gate having a first and a second input, the first inputs of all AND gates being connected to the output of said voltage comparator, a number of bistable vibrators corresponding to the number of cylinders and each having a pulse input and a resetting input, the pulse input of each one of the bistable vibrators being connected to one of said AND gates, the resetting inputs of all bistable vibrators being connected to a common reset key, a number of optical indicators corresponding to the number of cylinders and each respectively connected to the output of one of said bistable vibrators, a first pulse generator for releasing a pulse for each working stroke of each cylinder, a second pulse generator for releasing a pulse for each working stroke of the first cylinder of the engine, a shift register with a number of stages corresponding to the number of cylinders of the engine, each stage of the shift register having a shift-stroke input, a set input and an output, the shift-stroke inputs of all stages being connected to said first pulse generator, the set input of one of the stages of the shift register being connected to said second pulse generator, and the outputs of said stages being connected with the second input of a respective one of said AND gates.

2. A device according to claim 1, wherein said alternating signal is the battery voltage and further comprising an a.c. voltage amplifier for feeding said signal to the input of said measuring device and to the second input of said voltage comparator.

3. A device according to claim 1, wherein the adjustable voltage divider is a potentiometer providing a digital indication of the slider position.

4. A device according to claim 1, wherein the optical indicators are incandescent or glow lamps.

5. A device according to claim 1, further comprising a d.c.-to-d.c. voltage converter for supplying a supply voltage, said converter being fed by the battery of the piston engine.