Abstract: An electrical contact is disclosed in which a contact pin having a head portion is reciprocated relative to a contact housing between upper and lower positions. The contact housing has a cylindrical portion with two oppositely opposed diagonal slots formed in the wall of the housing. A dowel pin is inserted through the slots and connected to the lower portion of the contact pin. When the contact pin is pushed to its lower position, as by placement of a corresponding contact on the contact pin, the dowel pin slides down the slots, including rotation in the contact pin about its axis. The rotation causes the contact pin head portion to be wiped against the corresponding contact, cleaning the head portion and preventing the build-up of undesirable oxides, dirt or other debris on the surface of the head portion.
Abstract: Apparatus and method for securing a speaker within a radio housing includes a bezel connected to the grill of the radio and a rim having vertical side walls disposed along the perimeter of the bezel. The rim defines a cavity in which to position the speaker adjacent to the bezel. "U-shaped" clips having engaging barbs slidably attach to the rim until the clips provide a downward securing force against the base of the speaker. The barbs engage the rim to prevent the clips from loosening, allowing the speaker to vibrate.
Abstract: A partial frame detector provides detection of a frame synchronization pattern in an environment of burst noise that prohibits detection by correlation. A frame synchronization pattern capable of sustaining a minimum of 17 bits clustered in error plus random errors while still providing frame detection is achieved by utilizing a 64 bit Barker derived frame synchronization pattern and an additional process included in a correlation algorithm.
Abstract: A theft prevention device for use in the mounting of automotive audio equipment, such as a two-way radio to a secure structure, such as a "U" bracket or trunnion. The invention is a generally conical-shaped mounting knob that threadably attaches the audio equipment to the mounting bracket. Attached to one end of the knob enclosure is a key lock and attached to the opposite end is a threaded stud that is able to rotate about the longitudinal axis of the enclosure. In operation, the knob, in its unlocked position, is rotated clockwise until the threaded stud is securely attached to its threaded counterpart on the radio. In this position, the lock assembly rotates a cam plate so that an engaging disc engages both the knob enclosure and a stud plate allowing torque applied to the enclosure to be transferred to the threaded stud. The knob is then locked.
Abstract: An apparatus and a method of mounting a power semiconductor (10) to an external heat sink (18) when both fastening faces (11, 13) of the semiconductor are inaccessible during the assembly process. The apparatus comprises a nut plate (20) that mates with the semiconductor (10) and a thermally conductive layer (28) that engages the nut plate (20) and wraps around the semiconductor (10) in a captive manner. The external heat sink (18) threadably engages the nut plate (20) without the need to access either fastening face (11, 13) of the semiconductor (10).
Abstract: A transceiver that allows scanning to occur with the microphone in an off hook position. The transceiver includes a main unit, external microphone, and hook for holding the microphone. The external microphone includes a push-to-talk button, which may be pressed in order to allow audio signals to be converted into electrical talk signals and sent to the main unit. The main unit scans a plurality of channels according to a predetermined sequence. One channel is designated as a "priority" channel. Scanning continues when the microphone is off hook. When the unit detects channel activity on a specific channel that it is monitoring at a particular time, it discontinues the scanning both during the channel activity and for a predetermined wait period after the absence of such activity on the specific channel. Should a talk signal occur within the wait period following activity on the specific channel, the talk signal is processed on the specific channel.