Abstract: In accordance with the invention, an interface between an incumbent local exchange carrier's central office terminal and a competitive local exchange carrier's remote terminal is provided by an Integrated Services Digital Network interconnection. Such a connection provides two basic data channels of 64 Kbps each and at least one utility channel. The ISDN signal can be carried over a single wire pair. The interface may be used to interconnect one or two digital channels. The channel units may be designed to remove the robbed bits from the data channels and place them in the utility channels. Further, the utility channel may be employed to transmit frame phasing information so that the networks can synchronize their robbed bit signaling so that both networks use the same bit positions for robbed bit signaling thus minimizing data bandwidth reduction due to robbed bit signaling.

Abstract: Several unique features of a key switch housing and plunger are disclosed which may be employed to provide a keyboard having improved noise and feel characteristics. A system of key plunger up-stops is used to reduce the noise produced by key return while preventing removal of the plunger from the chimney of the switch housing. The system comprises a pair of relatively weak and resilient up-stops which have a relatively small contact area which act to restrict upward movement of the keycap/plunger combination during normal operation and a pair of relatively strong and rigid up-stops which do not contact the switch housing during normal keyboard use, but which prevent the pull-out of the key switch plunger from the chimney of the key switch housing. An additional feature disclosed is a unique key switch housing and plunger design which minimizes key wobble while providing smooth key action.

Abstract: An accessory (10) that can be connected to, and detached from, various forms of headwear comprising a means of attaching units (20) such that the accessory (10) and the headwear forms a continuous surface. Such a continuous surface increases coverage to the neck and ear areas.