US2141416A - Indicator of detonations for internal combustion engines - Google Patents

Description

Dec. 27, 1938. M. Y. A. sE1QRuYs 2,141,416

INDICATOR 0F DETONA'IIONS FOR INTERNAL COMBUSTION ENGINES Filed Dec. 17, 1934 T Patented Dec. 21,1938

mmcs'ron or DETONATIONS FOR IN- TERNAL conmus'rron ENGINES Max Yves Antonin S erruys, Paris, France Application December 17, 1934, Serial No. 757,873

, In France December 21, 1933 '1 Claim. Apparatus for measuring the value of the impact due to the detonating action of internal. combustion engines are in use at the present.

time, and in particular the apparatus termed 5 'Bouncing'pin, which is mounted by the'General Motors Company upon certain engines used for testing. Such apparatus are characterized by the use of a small chamber or thin flat metallic diaphragm subjected to the pressure, a

10 vibrating rod in contact with the said diaphragm, an electric contact-device actuated by the said rod, and an electric apparatus for measuring the mean current passing through the said contact device.

Other detonation responsive devices are known, which include a diaphragm responsive to engine pressure. contact meansin'cluding a contact carried by the diaphragm and a second contact, and I indicating means responsive to separation or to mutual engagement of said contacts.

All the aforesaid apparatus are responsive to the pressure which prevails in the explosion chamber of the cylinder under test.

The primary object" of my invention is to pro- -vide a detonation responsive device which will be irresponsive to the pressure in the explosion chamber.

With this aim in view, I make use as a detonation responsivedevice of a device responsive to pressure-acceleration including a diaphragm responsive to engine pressure and contact means including a contact carried by the diaphragm, and in which resilient means normally hold a second contact in engagement with the first named contact, the force exerted by the resilient means and the mass of the second contact being such that under normal operation the second contact-will follow and remain in contact with the first, but under a detonation the second con-- 40 tact will separate from the first, and indicating means responsive to the opening of the contacts. The accompanying drawing shows by way of example an. embodiment of the invention.

As shown in the drawing, the detonation indicator, which is secured to the cylinder head I and is connected with the explosion chamber 2, comprises a small block 3 secured to a diaphragm I, which is mounted. by a non-leaking joint, in

the main body I of the indicator, and whose.

5 lower side 3 is connected, by a conduit with the explosion chamber 2. As shown in the drawing, the conduit I has practically the form of aventuri, thus aflordlng the most approved transmission of the instantaneous pressure' to the dia- 55 'phragm 4. A movable block 3 is placed indirect contact, in the idle position, with the block 3 by a spring 3. The block Sis guided by aninsulatins disc l0, and the diaphragm 4, the disc- Ill and a packing ring H are held in position by a go plug II. The block 3 is electrically connected through the spring 9 and a metallic rod l3, insulated at It, with an induction coil l5, whose primary is supplied by a source of current ll whose other end is connected to earth by the metal parts, as well as the cylinder head I. The

secondary l8 of the coil is connected with a neon tube' IS. The diaphragm, the blocks 3 and 8,

and the spring 9 are so designed that during the normal working of the engine, the spring 9 will constantly hold the block 8 against the block 3 but when the explosion in the chamber 2 has the-character of a detonation; the block 3 will be imparted an acceleration greater than that imparted to the block 8 by the spring 9, so that "the block 3 will separate from the block 8 .dur-

ing the return stroke of the diaphragm to its rest position, thus breaking the primary circuit l6 and producing an induced high-tension current in the secondary l8, hence lighting the neon tube l9.

It is important to note the following: 1. The block 8 is in direct contact with the block 3, without the interposition of any vibrating rod, which aifords a very small and light device.

2. The spring 9 can be easily adjusted in such way that the non-detonating explosions can never separate the contact blocks 3 and 8, but that any slight detonations will break this contact.

3. The neon tube may be permanently mounted on the front board or on the control board of an aeroplane or automobile, or testing bench containing the engine under test, or upon a moving part of said engine, and the position of this part, at the time when the tube lights up, will show the point of the cycle at which the detona-.- tion takes place; such an arrangement of the invention can be madeby any person skilled in the art, and need not be further described.

4. The apparatus "can be used notonly as an .apparatus for observation or control, but as a safety device, and especially upon an aeroplane, in order to attract the attention of the pilot each time that an improper maneuver or a defective operating of the engine causes it to detonate.

What. I claim is:

In a detonation responsive device for internal combustion engines means including a diaphragm responsive to engine pressure and contact means including a contact carried by the diaphragm, a second contact, resilient means for normally holding the latter in, engagement with the first-named contact, the force exerted by the resilient means and the mass of the second-contact being such that under normal operation the second contact will follow and remain in contact with the first, but under a detonation the second contact will separate from the first, and indicating means responsive to the opening of the contacts.

MAX YVES ANTONIN SERRU'YS.

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