Apparatus for monitoring acceleration

Abstract

There is disclosed an apparatus for monitoring acceleration of a body which utilizes liquid flow technology thus avoiding the need for electrical power. The apparatus includes steel balls of predetermined mass (hereafter 'proof masses') disposed in annular cavities of a casing, the cavities containing a damping fluid. The cavities are grouped in pairs, each pair aligned with a principal axis of the body. The pairing allows for detection of acceleration in opposite directions along the respective axis. Movement of the proof masses in these respective cavities is proportional to the time integral of acceleration along the corresponding axis. This movement develops a force which opens a check valve arrangement allowing for displacement of the fluid through a temperature compensating mechanism to a first piston-chamber arrangement which registers the total movement of all such proof masses. Fluid is returned to the cavity by a second path connected between the cavity and the chamber. Disposed in a second chamber is another piston like arrangement. The piston or float member is in a neutrally buoyant condition. When the apparatus is made operable, the float member is urged from an initial position to a second one which takes a prespecified amount of time. If during this time, the total movement of the proof masses (as combined by the movement of the piston in the first chamber) reflects a time integral of acceleration above a predetermined amount, the first piston interrupts the movement of the float member. Thus the apparatus is suitable for registering when a 'zero' G condition has existed for a prespecified period of time, in that, under such a condition, the piston in the first chamber will not have moved the distance required to interrupt the movement of the float member.