Method and apparatus for recording the compression pressure of internal combustion engines

Apparatus for recording the compression pressure of internal engines, comprising:

• (A) s recording sheet;
• (B) a support for the recording sheet;
• (C) a stylus mounted on and movable into contact with the recording sheet;
• (D) a recording arm and a pressure-sensitive element connected to move the support and the stylus relative to each other;
• (E) means for placing the stylus upon the recording sheet constructed in such a way that the stylus, at the deflection of one of the support and stylus is lifted off from its position of rest and from the recording sheet, and is movable under pressure at the maximum movement point into contact with the recording sheet, before the return of one of the support and the stylus to its initial position.

The method for recording the compression pressure of internal combustion engines, comprising in succession the steps:

• moving a stylus and a recording sheet relative to each other by a pressure-sensitive element;
• bringing the stylus and recording sheet into contact with each other during a part of the movement;
• subjecting the element to the compression pressure and pivoting one of the stylus and recording sheet from its position of rest into the maximum position determined by the compression pressure;
• bringing the stylus and recording sheet into mutual contact;
• relieving pressure from the element, whereby the deflected stylus or recording sheet is pivoted into its position of rest while producing a written line and
• deflecting the recording sheet.

The apparatus for recording the compression pressure of internal combustion engines, comprising the following means:

• a recording sheet, a support for the recording sheet;
• a stylus mounted on and movable into contact with the recording sheet;
• a recording arm and a pressure-sensitive element connected to move the support and the stylus relative to each other;
• means for placing the stylus upon the recording sheet constructed in such a way that the stylus, at the deflection of one of the support and stylus, is lifted off from its position of rest and from the recording sheet and is movable under pressure at the maximum movement point into contact with the recording sheet, before the return of one of the support and the stylus to its initial position;
• the support for the recording sheet comprising a Bourdon spring coupled with a segment mechanism having an output shaft on which the disc is mounted;
• a key-shaped pin projecting from the center of the disc, with a circular recording sheet provided with a keyhole slid upon the pin;
• a valve for the relief of the pressure-sensitive element coupled with the means for placing the stylus upon the recording sheet in such a way that the valve is switched, when the stylus is placed upon the recording sheet into a position of relief;
• the recording arm which supports the stylus being mounted on a rod displaceable coaxially to the stylus and against the force of a spring, said rod being provided with a curved-path slider whereon a pin that actuates the valve slides;
• stops provided at one end of the rod, which, when released, enable the stylus to be moved by the spring into a position that facilitates the placement of a recording sheet upon the support;
• the recording arm being pivotable away from the support for the recording sheet for the purpose of placing the recording sheet thereon;
• the stylus being displaceable on the recording arm and perpendicularly to the plane of the recording sheet;
• a window shield being arranged above the recording arm rigidly connected herewith, and
• a radially extending oblong hole being provided in the window shield, in which oblong hole the stylus is mounted in a longitudinally displaceable manner.