Abstract: Disclosed is a system for limiting the acceleration applied to a body which is to be protected from damage. In one arrangement, the limiting device is mounted on a helicopter seat which is vertically slidable so as to permit limited downward movement of the seat relative to its supporting structure in a crash situation. The limiting device having strap mounted on a reel is mounted to the seat, with one end of the strap being connected to a support. A capstan spring wound on the reel prevents rotation of the reel and unwinding of the strap until a predetermined acceleration is reached, as sensed by an inertia element within the reel. The sensor applies an unwinding force to the capstan spring sufficient to permit braked rotary movement of the reel. In this fashion, the acceleration applied to the seat occupant's body is limited to a safe level.

Abstract: A pressurized gas spring having an extended useful operating life is provided. The cylinder is pressurized with a gas that exists in a gas-liquid phase equilibrium at the operating temperatures and pressures of the gas spring. The liquid within the cylinder promptly converts to the gaseous form upon any reduction in pressure within the cylinder. The equilibrium pressure between the liquid and gas phases assures constant cylinder pressure regardless of the gradual, normal leakage of gas from the cylinder, and the cylical changes in volume within the cylinder due to the reciprocating action of the piston rod during operation of the gas spring.

Abstract: In an optical instrument which provides an analog signal representing the intensity of the reflected light from a sample, the sample is irradiated with narrow band wavelength light with the wavelength being repeatedly swept through a range of values to produce a repeating analog signal. Sampling pulses are produced simultaneously with the repeating analog signal to determine a sampling interval. An analog-to-digital converter is connected to receive the analog signal and converts the analog signal to a binary value several times in response to each sampling pulse. The binary values produced in response to each sampling signal are averaged and fed to a digital computer. In the digital computer, the received values are again averaged with other values produced in response to the sampling pulse produced at the same point in the scan of the wavelength irradiating the sample.

Abstract: A fluid sample cell for the spectroscopic analysis of a sample includes a fluid-tight sample compartment defined by a radiant energy transmissive top, a side wall, and a bottom having a reflective surface. The bottom is heat conductive and comprises an external surface which defines a hollow well adapted to receive a hot plate. A fluid sample cell is also provided wherein a side wall of a sample compartment defines an entry port and an exit port such that, when the cell is in a substantially vertical position, one of the ports is located above and one below the compartment. A fluid sample cell is also provided wherein a side wall of the sample compartment is provided with a pocket for collecting impurities when the cell is in a substantially vertical position, wherein the pocket is disposed above and/or below the sample compartment.

Abstract: Control circuits for operating electric motors of the class having windings pulsed in sequence and a magnetic field, the class being exemplified by brushless d.c. motors. Improved apparatus is provided for accommodating flyback action when excitation current through any one of the windings is interrupted by the opening of a switch device (e.g., on-off controlled transistor), whether that device be a sequence power switch or a main switch having a common series relation to all of the power switches and operated with an adjustable duty cycle so as to permit adjustment of motor speed and torque. The flyback apparatus, as here disclosed, provides low loss flyback current paths so as to return inductively stored energy back into the winding when its excitation is interrupted, thereby to enhance motor efficiency while eliminating high open circuit voltages across the switching devices. Negative torque which might be created in the flyback circuits as a result of back e.m.f.

Abstract: A fluid sample cell for spectroscopic analysis of a fluid sample includes a fluid-tight compartment for the containment of a fluid sample which is defined by a radiant energy transmissive top, a side wall and a bottom. The bottom comprises a plurality of sectors and a Fresnel disc, whereby radiant energy passing through the compartment impinges upon at least one of the sectors and is specularly reflected from a reflecting surface of the sectors to respective focal points of the sectors.

Abstract: Constant or transient forces and displacements between a motion snubber and its associated load are detected and converted to an electrical signal. Electrical signals from the detection devices are transmitted to a receiving device which is electrically connected to a recording means. The signals from a plurality of detecting devices are encoded to identify the snubber having the detected force and displacement.

Abstract: A stretchable tube-like sleeve surrounds and frictionally grips an inner rod or tube. A coil spring surrounds the sleeve in position to resist movement of one end of the sleeve against the spring force. Moving the rod axially relative to the spring in a direction against the spring force on the sleeve decreases the inner diameter of the sleeve to produce a drag on the inner member. Movement of the opposite end of the sleeve is limited by a stop. This causes the sleeve to expand and allows the rod to slip with a constant drag which is determined by the strength of the spring. With the spring force in position to be applied to only one end of the sleeve, movement of the inner member in the opposite direction provides only a minimal drag as determined by the initial frictional interference between the sleeve and the inner member. Positioning the spring to resist movement of either end of the sleeve, provides a constant drag on the inner member with either direction of movement of the rod relative to the sleeve.

Abstract: In an instrument for optically analyzing particulate samples such as grain samples, the sample is introduced into a chute which is received in a vibrating apparatus to vibrate the grain in the chute and compact it. The chute is then dropped to a carriage which transports the chute and the grain through a beam of narrow band infrared light. A photocell is positioned to detect the amount of light passing through the grain sample.

Abstract: An energy absorber strut includes a pair of elongated drive nuts threaded internally to mate with a drive screw having high lead threads on opposite ends so that outward movement of the nuts on the screw rotates the screw in one direction and inward movement rotates the screw in the opposite direction. A mandrel mounted to rotate with the screw is restrained from rotation by a capstan spring which surrounds and grips it. Prestressed torsion springs connected to the ends of the capstan spring permit it to unwind slightly and drag with respect to the mandrel when the torsion springs are subjected to a predetermined torque.

Abstract: A device for welding thin metallic diaphragms which can be combined to form a bellows arrangement and method for using same is disclosed. The device uses a pair of weld spools (22), in a spaced apart relationship, each having a circumferential groove (26) formed therein to receive the surfaces defining the inside diameters of the diaphragms. A pressure roller (20) is provided and has a plurality of circumferential grooves (38) formed therein, the axial spacing between the circumferential grooves (38) approximating the desired pitch of the resulting diaphragm convolution. Each of the circumferential grooves (38) receives a surface defining the outside diameter of a diaphragm and pressure is applied thereto by the pressure roller (20). Rotation of the pressure roller (20) and the pair of weld spools (22) by their respective drive shafts (44,32) causes the diaphragms to rotate about their axes permitting a welding torch (50) to weld the surfaces defining the inside diameters of the diaphragms.

Abstract: A device for welding thin metallic diaphragms which can be combined to form a bellows arrangement and method for using same is disclosed. The device uses a pair of weld spools (22), in a spaced apart relationship, each having a circumferential groove (26) formed therein to receive the surfaces defining the inside diameters of the diaphragms. A pressure roller (20) is provided and has a plurality of circumferential grooves (28) formed therein, the axial spacing between the circumferential grooves (28) approximating the desired pitch of the resulting diaphragm convolution. Each of the circumferential grooves (28) receives a surface defining the outside diameter of a diaphragm and pressure is applied thereto by the pressure roller (20). Rotation of the pressure roller (20) and the pair of weld spools (22) by their respective drive shafts (42,32) causes the diaphragms to rotate about their axes permitting a welding torch (50) to weld the surfaces defining the inside diameters of the diaphragms.

Abstract: In a colorimetry system, the test surface, the color of which is to be measured, is illuminated by a fiber optic cable. Light transmitting ends of the optic fibers of the fiber optic cable are uniformly distributed into an annulus with the transmitting ends of the optic fibers pointed inwardly at 45 degrees toward the axis of the annulus. A light pipe, or a second fiber optic cable, is positioned to have one end on the axis of the annulus to receive diffusely reflected light from the test surface and transmit the reflected light to photodetectors through different color filters. The output signals of the photodetectors are applied to the colorimetry console which converts the photodetector signals to standard color index values.

Abstract: Relative axial motion of a pair of strut members is converted into rotation of an escapement mechanism, which in turn oscillates a balance wheel. If the rotational velocity exceeds a predetermined minimum, the balance wheel inertia initiates a momentary motion snubbing action.The device used to convert reciprocation of the strut members into rotary motion is releasable so as to permit the operational testing of the motion snubbing mechanism while the strut is mounted in its operational environment.

Abstract: A device that can individually separate thin nested metallic diaphragms prior to welding same to form bellows is disclosed. The device uses a threaded rod (16) which is tilted upwardly with respect to the horizontal. One end of threaded rod (16) is received through the inside diameter of a stack (32) of nested diaphragms while the other end thereof is received in a collet (18) attached to a gear motor (20). As threaded rod (16) is rotated by gear motor (20), each diaphragm (10) is carried in its own groove provided by the threads on the threaded rod (16) to the free end thereof where one diaphragm is discharged for each revolution of the threaded rod (16).

Abstract: Relative axial motion of a pair of strut members is converted into rotation of a shaft which drives a rotatably mounted inertia element. Rotation of the shaft in the opposite direction drives a second rotatably mounted inertia element. The inertia elements are interconnected by a coil spring with the result that the inertia element driven directly by the shaft drives the other inertia element. At a predetermined acceleration, the inertia element driven by the spring will lag, and this lagging motion is used to actuate a braking action to limit the acceleration.

Abstract: A shoulder strap retractor mechanism employs a gear system and clutch that connects a rewinding spring to the strap to shift from a direct high tension mode to an indirect drive reduced tension mode for a limited range of strap movement to improve the user's comfort, while maintaining the strap lightly against the user's shoulder.

Abstract: A compact, rugged sensor for use in the measurement of particle sizes in a fluid stream is disclosed. The sensor permits the use of a light emitting diode as a light source by mounting a high grade optical system with its focal point at the point light source provided by the light emitting diode to collimate the generated light. This collimated light passes through an aperture formed in one dimension by the width of the fluid flow stream and formed in a second perpendicular dimension by a narrow transparent slit in an otherwise opaque shield adjacent the fluid flow stream. The collimated light source, together with the use of the flow stream as a light path boundary, substantially increases the accuracy of the sensor. All of this is accomplished in conjunction with a solid state light emitting diode source which permits the sensor to be used in shock and vibration environments which would have prohibited particle measurement using prior art sensors.

Abstract: A mounting pin of circular cross-section is rendered eccentric and used to artifically agitate a motion snubber used to shock mount components of a nuclear power plant, thereby making possible testing of such a snubber without dismounting it.

Abstract: An adjustable locking strut is connected to a pair of relatively movable mechanical elements and permits relative motion between these elements below a predetermined motion threshold. Above this predetermined motion threshold relative movement between mechanical elements is prohibited through the engagement of nonoverhauling threaded members connected to the mechanical elements. These nonoverhauling threaded members are specially designed so that when synchronized they do not engage one another. One of the nonoverhauling threaded members which is internally threaded forms a relatively large tubular inertia mass for sensing accelerated movement between the relatively movable mechanical elements.