Cardiac pacemakers

Claim 1

A cardiac pacemaker including implantable housing means (8,501) electrical signal generating means enclosed within said housing, an electrode conductor (6,644) for conveying pacing signals to the heart, and apparatus for maintaining sealable electrical interconnection between said generating means and said electrode characterised in that said apparatus comprises: (a) first terminal means (2) having one end (18) sealed and embedded within said housing, and its other end defining a channel opening to the outside of said housing, said first terminal means having screw threading (14) along at least a portion of said channel, a void (18) at the embedded end of said terminal, and a frustoconical, electrically conductive surface (16) intermediate said void (18) and said threading (14), said surface tapering outwardly to said threading and being adapted for electrical connection (602) with said generating means; and (b) second terminal means (4), disjoint from said housing and adapted for mating connection into said first terminal means (2), said second terminal means defining an axial channel (28) therethrough for carrying said conductor (6,644) into a first end, through said axial channel, and out of the opposite end, said second terminal means having a frustoconical camming portion (32) at said opposite end for engagement with the frustconical surface of said first terminal means, said second terminal means further having a threaded portion (30) intermediate said camming portion -and said first end, for engagement with said threading of said first terminal means; (c) said second terminal means (4) being adapted to carry said conductor (6,644) into said void (18), and with increasing engagement of said threaded portion (30) and =said threading (4), to cause said camming portion (32) to grasp said conductor (6,644) and to establish an electrical circuit between said conductor and said generating means via said frustoconical surface (16) and said camming portion (32).