Abstract: A novel bistable actuator of the coaxial plunger type, requiring only a single electrical coil and a single permanent magnet, provides electrical remote control of extension and retraction of a locking pin in an usually long linear bidirectional power stroke whose two end positions are held stable magnetically to withstand environmental acceleration as required for missile or aerospace component locking requirements. The coil is located in a cylindrical soft iron stator shell that acts as a magnetic yoke handling the flux loop from the permanent magnet which, fitted with circular end pole plates, forms a moving armature/plunger driving the locking pin. The working magnetic air gap dimension and flux density remain substantially constant over a major central portion of the stroke so that the actuator is driven uniformly in the mode of a speaker voice coil. The magnetic holding force at the stroke ends can be independently adjusted in design.

Abstract: A novel bistable actuator of the coaxial plunger type, requiring only a single electrical coil and a single permanent magnet, provides electrical remote control of extension and retraction of a locking pin in a linear power stroke whose two end conditions require no power and are stabilized by the magnet against environmental acceleration as required for missile or aerospace component locking requirements. The coil is located in a cylindrical soft iron stator shell that acts as a magnetic yoke handling the flux loop from the permanent magnet which, fitted with circular end pole plates, forms a moving armature/plunger driving the locking pin. A specially shaped bobbin carries the coil in the shell/yoke and also forms a tubular guide that confines movement of the armature to axial sliding. The shell/yoke is shaped to form two radial air gaps in the flux loop path of the armature magnet: a working gap traversing a portion of the coil and a return gap outside the coil.

Abstract: A novel bistable actuator of the coaxial plunger type, requiring only a single electrical coil and a single permanent magnet, provides electrical remote control of extension and retraction of a locking pin in a linear power stroke whose two end conditions require no power and are stabilized by the magnet against environmental acceleration as required for missile or aerospace component locking requirements. The coil is located in a cylindrical soft iron stator shell that acts as a magnetic yoke handling the flux loop from the permanent magnet which, fitted with circular end pole plates, forms a moving armature/plunger driving the locking pin. A specially shaped bobbin carries the coil in the shell/yoke and also forms a tubular guide that confines movement of the armature to axial sliding. The shell/yoke is shaped to form two radial air gaps in the flux loop path of the armature magnet: a working gap traversing a portion of the coil and a return gap outside the coil.

Abstract: An ETVA (electrically-tunable vibration absorber) has a vibratable mass with a mechanical spring suspension supplemented by an electromagnetic spring simulation that can be adjusted electrically to vary the self-resonant frequency of the vibratable mass and tune it to a disturbing frequency that is to be suppressed. A flux path from the electromagnet traverses an air gap between a pair of oppositely-facing matching magnetic pole arrays, one of which is attached to the vibratable mass while the other pole array is substantially attached to the object structure that is being treated to suppress vibration.

Abstract: An electromagnetic active vibration actuator configuration combines two modes of operation to obtain the advantages of long stroke and linearity of voice coil type actuators and high efficiency of dual-gap solenoid type actuators. A coaxial stator shell surrounds an axially vibratable armature. Either the stator or the armature can carry one or more coils and/or permanent magnets, however usually the magnets are located on the armature for their contribution to vibrating mass. Alternate coils and alternate magnets are made opposite in polarity, the stator armature pole pieces being held symmetrically staggered relative to the stator pole pieces by end springs or flexures that allow axial vibration when AC is applied to the coils.

Abstract: An electromagnetic actuator is disclosed which is especially suitable for active vibration control applications. The actuator may be either of the moving coil or moving magnet type so that a moving element undergoes reciprocal motion in response to an electrical input signal. The invention allows the force of the moving element to be linearly related to the amplitude and direction of the input current with a high degree of efficiency. In one embodiment, the moving element is decoupled from any mechanical load so as to produce reaction forces which may be used to cancel vibrational forces.

Abstract: An acoustic compressor is disclosed for generating a high pressure acoustic waveform within a chamber containing a working medium. The compressor comprises an actuator body solidly mounted to the chamber with a vibrating armature spring-mounted within. The chamber and actuator body are resiliently mounted so as to be vibratable. Owing to reaction forces, vibration of the armature causes vibration of the chamber which generates an acoustic waveform in the medium. By matching the resonant frequency of the armature to the acoustic resonant frequency of the chamber and driving the armature at that frequency, extremely high pressures within the chamber may be obtained.

Abstract: A bidirectional belt-drive for printers and the like comprising a carriage assembly movable across a paper web and supporting a print head mounting bracket. A belt has upper and lower runs extending through guide passageways in the carriage assembly. Independent jam cleat assemblies are normally biased by single spring means to a neutral position so as to be displaced from both runs of the belt.Swingably mounted knurled supporting surfaces cooperate with the jam cleat assemblies to enhance gripping of the fabric belt. Each jam cleat assembly has a pair of cooperating arms whose free ends are arranged to engage one another and extend between the arms of the single torsion spring means.The carriage assembly print head slidably receives the mounting bracket which is urged in the forward direction by bias means and may be adjustably positioned by adjustable cam means to enable the carriage assembly to maintain a fixed position relative to the platen and requiring only movement of the print head mounting bracket.

Abstract: A pin-feed tractor assembly for advancing a web of indeterminate length through a printing station and including a timing belt having spaced teeth defining interspersed grooves. The drive sprocket is arranged to engage the notches for moving the belt. Sections of the belt between adjacent notches are rigid while the region of the notches is flexible to permit bending of the belt only at the notches, thereby providing equal stresses in the belt. The outer surface of the belt is provided with feed pins arranged at equi-spaced intervals. The pitch of the belt teeth is one-half the pitch of the perforations in the elongated web which receive the feed pins. The pitch circle of the equi-spaced feed pins is smaller than the pitch circle over the rigid flat portions causing the feed pin to retract somewhat from the web before starting its circular path around the drive sprocket to prevent the web from being damaged or torn.The belt is a molded one-piece member.