Abstract: An inertial acoustic pickup (300) for use with a string musical instrument (700) having a soundboard (702) for delivering acoustic energy, comprises a chassis (302) including a coil (304) coupled to the soundboard (702), an armature including upper and lower substantially parallel planar suspension members (310) having planar perimeter regions (308) coupled to the chassis (302), and comprising a plurality of independent planar circular non-linear spring members (312) arranged regularly about a central planar region (314) within the planar perimeter region (305), an inertial mass (316) suspended between the upper and lower planar suspension members (310) about the central planar region (314) and having an axis (342) extending therebetween and including a plurality of permanent magnets (320) arranged regularly about a perimeter of the inertial mass (316), whereby acoustic energy coupled to the chassis (302) from the soundboard (702) is transformed through the planar non-linear spring members (312) into motional

Abstract: An taut armature, resonant impulse transducer (100) includes an armature (12), including an upper (14) and a lower (16) non-linear resonant suspension member, each including at least two juxtaposed planar compound beams (202, 204 and 206, 208) connected symmetrically about a contiguous planar central region (210), and further connected to two contiguous planar perimeter regions (212, 214), an electromagnetic driver (24, 26), coupled to the upper and lower non-linear resonant suspension members (14, 16) about the two contiguous planar perimeter regions (212, 214), the electromagnetic driver (24, 26) effecting an alternating electromagnetic field in response to an input signal, and a magnetic motional mass (18) suspended between the upper and lower non-linear resonant suspension members(14, 16) about the contiguous planar central region (210), and coupled to the alternating electromagnetic field for generating an alternating movement of the magnetic motional mass (18) in response thereto, the alternating moveme

Abstract: A dual mode transducer (600) includes an electromagnetic driver (604), an armature including upper and lower substantially parallel planar suspension members (610) coupled to the driver (604), and a magnetic motional mass (616) suspended between the suspension members (610). The suspension members (610) include a plurality of independent planar non-linear spring members (612) arranged regularly about the central region (614) within a perimeter region (608). The spring members (612) are defined by members having maximum opposing widths tapering to minimum opposing widths at midpoints thereon, the maximum opposing widths are coupled to the central region (614) and to the perimeter region (608). The motional mass (616) couples to the electromagnetic field which alternately moves the motional mass (616), the movement being transformed through the spring members (612) and the driver (604) into motional energy. A soundboard (1014), coupled to the driver (604), couples the motional energy to a user.

Abstract: An impulse transducer that does not use eccentric, motor-driven weights is constructed of a permanent magnet movable armature that oscillates within a housing and impacts resilient bumpers to produce vibrations. The armature is accelerated by a varying magnetic field energized by an alternating current. The dimensions of the enclosed housing and the mass of the movable armature as well as the strength of the magnetic fields can be optimized for the impulse magnitude that is desired.

Abstract: A resonant armature system (109, 114, 116) for generating a vibrating motion in response to an alternating excitation force includes at least two planar suspension members (109), substantially parallel to each other and separated by a distance. The planar suspension member (109) includes a plurality of independent planar spring members (112) arranged regularly about a central planar region (110) within a planar perimeter region (108). The resonant armature system (109, 114, 116) further includes at least one movable mass (114) positioned between and coupled to the at least two planar suspension members (109) for resonating with the at least two planar suspension members (109) at a fundamental mode resonant frequency.

Abstract: A shock isolator (30) is provided within the housing (38) of a selective call receiver to substantially increase the natural frequency of vibration of the housing (38) and the printed circuit boards (54, 56) within the housing. The shock isolator (30) is a body of elastomeric material, preferably butyl rubber, which has component receiving apertures (32) molded therein for receiving the components (46, 48, 50) on the printed circuit board while at the same time contacting the printed circuit board. The butyl rubber has a damping of at least 25% (preferably 50%) and a Durometer of between 50 and 70 type A (preferably 60).

Abstract: An apparatus for effecting a vibrating motion comprises a resonant planar armature, a housing, an electromagnetic device attached to the housing for effecting an alternating electromagnetic field, a magnetic device coupled to the armature and to the electromagnetic field for alternatively moving the armature in a first and a second direction in response to the electromagnetic field. The resonant planar armature comprises a plurality of planar spring members arranged regularly about a central planar region within a planar perimeter region of the armature, and the spring members provide a restoring force normal to a movement of the central region of the armature caused by the alternating electromagnetic field.

Abstract: A piezo-electric resonant vibrator is described comprising a resonant armature having a centrally located weight, and at least four planar circular spring members which provide a restoring force normal to the movement of the weighted armature within a non-magnetic housing which encloses and supports the armature. A piezo-electric driver is coupled to the armature for inducing movement of the armature at a predetermined resonant frequency. A ferromagnetic plate is mounted to the housing and magnetically couples to a magnet which is coupled to the weight to maintain tension on the armature when an excitation signal is not supplied to the piezo-electric driver, and the armature is at equilibrium.

Abstract: An expandable chassis includes a four sided frame with a central opening to receive a plate or "shield" which is allowed to move within the frame between two predetermined positions. Protuberances on the shield contact the frame and limit its inward movement while outward movement is limited by a spring clip on the shield that snaps into an aperture in the frame. Tabs on the frame support integrally formed spring fingers on the shield which tend to force the shield outward. A membrane switch contact assembly and a speaker are respectively attached to the inside and outside surfaces of the shield. By compressing the shield partially into the frame, the chassis assembly slides into a molded plastic housing. A rubber key actuator pad on the outside of the housing has a plurality of keys each having a protrusion or "actuator" that extends partially into an actuator hole in the housing. When the key is depressed, the actuator depresses and activates one of the switches in the membrane switch contact assembly.

Abstract: A static protective housing includes a plastic housing having an outer wall and an interior. A metallic fastener extends into the housing from the outer wall. A static vault within the housing receives the metallic fastener for insulating the fastener from the housing interior. The static vault is provided with a well portion which receives the fastener and a cover which closes the well portion.

Abstract: A battery door latching mechanism comprising two cantilevered posts incorporated in the base housing of a radio receiving device that interface with a headed rib on the base of a battery door. A recessed area in the battery housing surrounds the two cantilevered members, and prevents them from becoming overstressed due to deflection during shock, yet allowing them to deflect enough for attachment of the battery door to the housing.

Abstract: An electrical contact assembly is provided which is capable of accommodating batteries for other electrical devices exhibiting a plurality of different physical sizes. A V-shaped contact arm having a hook-shaped member at one end thereof and a double torsion spring at the remaining end thereof is mounted to a battery housing surface. The double torsion spring end of the V-shaped member is mounted on a support post and is fixedly held in position such that the torsion spring does not freely rotate. The hook-shaped end of the V-shaped member is engaged by a second post adjacent to the first post so as to place the contact arm under tension. The tip of the V-shaped member thus forms an elbow which deflects to a greater or lesser degree depending upon the size of the electrical device to be contacted.