Abstract: Systems are disclosed for the combined measurement of linear and angular displacements, with high sensitivity, wide measurement band at low frequency based on the configuration of the folded pendulum, and a linear and angular displacement sensor for applications of monitoring and control. Examples of possible applications of the combined sensor subject-matter of the present invention are sensor for the seismic monitoring, sensor for systems of monitoring and/or control of civil and industrial buildings, dykes, bridges, tunnels, etc., sensor for system of monitoring and/or control for the realization of systems of seismic attenuation and inertial platforms.

Abstract: A building settling detection system having at least one sensor configured between a guide rail track of an elevator system and a pit of the elevator system and a controller in communication with the at least one sensor, the controller configured to monitor an output of the at least one sensor and transmit a notification to a remote location when the output of the at least one sensor meets or exceeds a predetermined threshold indicating that the predetermined threshold is met or exceeded.

Abstract: The invention concerns a folded pendulum, comprising: a support (F); a test mass (PM); a simple pendulum (SP); an inverted pendulum (IP); the simple pendulum and the inverted pendulum being connected at one of their ends to the test mass (PM) and at the other end to the support (F) by means of 4 corresponding joint systems (G), the test mass being not connected to the support (F) and being therefore free to oscillate, each joint system (G) relevant to the simple pendulum (PS) comprising one or more joints in tension, the folded pendulum being characterized in that: each of the joint systems (G) relevant to the inverted pendulum (IP) comprises one or more joints in compression. The invention further concern a seismic sensor utilizing the folded pendulum according to the invention.

Abstract: An underwater seismic system for reducing noise due to ghost reflections or motion through the water from seismic signals. The system includes two motion sensors. One sensor has a first response and is sensitive to platform-motion-induced noise as well as to acoustic waves. The other sensor has a different construction that isolates it from the acoustic waves so that its response is mainly to motion noise. The outputs of the two sensor responses are combined to remove the effects of motion noise. When further combined with a hydrophone signal, noise due to ghost reflections is reduced.

Abstract: A folded pendulum is described. The folded pendulum can be a monolithic pendulum and is positioned in the vertical configuration. The folded pendulum allows for more compact realizations through high decouplings of a vertical degree of freedom from other degrees of freedom as well as optimal mechanical quality factors.

Abstract: A sensor structure includes a substrate having a main extension plane, a first seismic mass and a second seismic mass, the first and the second seismic masses being deflectable relative to the substrate along a direction of deflection essentially perpendicular to the main extension plane. The first and second seismic masses are coupled together via a rigid coupling rocker pivotable around a rocker axis parallel to the main extension plane. The first seismic mass is suspended from the substrate with the aid of a first suspension spring, and an essentially rigid first coupling bar is situated between the first suspension spring and the first seismic mass.

Abstract: A rotational seismometer having a housing that encases an optical lever having a light source for emitting a beam of light through a slit defined by the optical lever that is focused by a lens for focusing the beam of light to a balance bob suspended within the housing is disclosed. The balance bob includes a mirror secured to a plate attached to the housing through an arrangement that includes a thin fiber attached to a stiff wire such that the stiff wire bends and the thin wire does not bend when a tilt motion is applied to the rotational seismometer.

Abstract: A machine for detecting earthquake precursory signals that comprises a spring loaded balance wheel that is in reality an oscillating seismometer, the oscillating seismometer employed as a local oscillator in a seismic wave receiver, a clock together with its balance wheel make up the seismic wave receiver which detect the precursory micro-seismic vibrations that precede the earthquake, extreme sensitivity—UNMATCHED BY EFFORTS WORLD WIDE—is accomplished by the immense storage capacity of the clock, for each individual swing of the balance wheel, a miniscule interruption takes place that will go unnoticed but after tens of thousands of swings, which would take place over night for example, a buildup of these interruptions will eventually have their effect.

Abstract: A releasable latch for a marine instrument is provided for a transom mounted sensor on a marine vessel which enables the sensor to be rotated about a pivot point when an object is struck by the vessel.

Abstract: A seismic sensor contains a geophone (4) disposed within a housing (12). The sensor is also provided with locking means (14, 19, 21) that can either lock the geophone 4 relative to the housing, or can allow the geophone to rotate within the housing. The geophone (4) is enclosed in a casing (1) which is so constructed that the overall mass distribution of the casing and geophone is uneven. The casing and geophone assembly thus adopts a preferred orientation when the sensor is unlocked. A liquid can be disposed within the housing, so that the casing (1) and geophone (4) can float when the sensor is unlocked.

Abstract: A method and a seismic sensor using symmetrical spring geometry to overcome the temperature sensitivity problems associated with seismometers. The seismic sensor includes a base having a pivot point and a vertical axis. The sensor also includes a neutral axis and a carriage that is mounted to the base at the pivot point. The carriage includes a mass, a boom, a center of gravity, and a neutral position. The carriage is in the neutral position when the center of gravity of the carriage is along the neutral axis. Also included in the sensor is a spring, that is attached to the carriage. The spring suspends the carriage in the neutral position and supplies a force that impels the carriage into the neutral position. The spring being symmetrical about the neutral axis while the carriage is in the neutral position. The sensor further includes a first point and a second point for attaching the spring to the carriage and a detector. The detector is attached to the base and senses the displacement of the carriage.

Abstract: A method and apparatus for filling a void in a printed image which has been printed by a thermal transfer printing process employs of a heat-sensitive pigmented material on a foil. A piece of the foil is provided with a dot of the pigmented material having the same color as that bordering the void to be filled and approximately the same size as the void. The foil is positioned on the printed image, with the dot facing and superposed over the void. Heat is applied to the back of the foil, opposite to the dot, while at least the heated portion of the foil is pressed against the image to transfer the pigmented material from the foil to the void in the image. Instead of a dot, the pigmented material can take the form of an image and be transferred from the foil to a receptor material.

Abstract: An inverted pendulum seismometer mechanism has a massive boom (20) mounted in friction free crossed leaf spring pivot bearings (24) clamped in V grooves 28 on a frame (10). To lock the boom for transport, without straining the bearings, a camshaft (70) turns and, sequentially, cams (72) lift pivot clamping levers (30), guide webs (80) embrace the boom, and a cam (74) lifts the boom off the V grooves until probes (56) on adjustable locking screws (54) in the frame top cross beam (14) engage recesses (58) in the top end of the boom. Further rotation of the camshaft reverses the sequence to reconnect the boom to the frame in an operative state.

Abstract: An earth movement sensor is provided which consists of a housing having a top shelf and an intermediate shelf. An electrically energizing signalling alarm is carried in the housing. An electrical power source is carried in the housing for the alarm. A pendulum operated switch is suspended from the top shelf in the housing and is operatively connected between the power source and the alarm, to energize the alarm from the power source when there is earth movement.

Abstract: A device detects seismic motion by linear motion of a seismic detection ball within an inner casing. Radial protrusions on the inside surface of a bottom wall of the inner casing maintain linear back-and-forth motion of the seismic detection ball while in contact with the casing bottom wall. On the inside surface of the perimeter wall of the inner casing, radially inward protrusions are formed parallel to one another to prevent rotation of the seismic detection ball in a circular path along the casing perimeter when it is lifted up from the casing bottom wall. The seismic detection ball is formed from a material unaffected by magnetic fields. The inner casing is suspended within an outer casing, in a condition of damped swaying. The inner casing is composed at least partially of a metallic material to provide sufficient weight to insure reliable automatic centering.

Abstract: An accelerometer-based direction finding and ranging transducer such as a hydrophone uses piezoelectric ceramic as the active material. Orthogonally arranged accelerometers share an inertial mass and resonance control system and the accelerometers together with a pressure hydrophone and electronics are all housed within one pressure vessel.

Abstract: A sonar system for a water craft including a transducer assembly mounted to the hull of the water craft, and a control circuit for applying signals to the transducer for forward transmission by the transducer and for sensing signals reflected from objects forwardly of the craft and for causing actuation of an alarm. The transducer assembly is mounted for pivotal movement relative to the hull such that during pitching motion of the craft, the signals transmitted by the transducer remain in a horizontal plane.

Abstract: Two sector-shaped pendulums are supported by crossed leaf springs at two axes on the same horizontal level respectively in a symmetrical manner so that each pendulum can swing about the axis thereof, sector-shaped surfaces of the pendulums being connected to each other by mutually-crossing flexible wires, each pendulum having a movable weight and a rigid extension so that a coiled spring connects the rigid extensions of the two pendulums, and each pendulum has a means for adjusting the center of gravity thereof by moving said weight and for adjusting the location of joints of said coiled spring.

Abstract: A vertical seismometer comprises a horizontal boom 2 carrying a mass 1 frictionlessly pivoted about a horizontal axis 3. The boom is supported by a pre-stressed vertically extending flat spring 4 having one end rigidly attached to the boom adjacent to and intersecting this axis so that movement of the boom applies a turning moment to the flat spring at its attachment end. A further pre-stressed flat spring 5 pivoted at right angles to the other end of the first-mentioned flat spring has its other end rigidly connected to the frame 13 of the seismometer and applies a constant force along the longitudinal axis of the latter spring towards the end attached to the boom.