Patent GB-1221805-A (GB)
Title: Telecommunication exchange
IPC: H04Q3/00
Filed: 1968-02-22
Abstract: 1,221,805. Automatic exchange systems. SOC. LAMY D'ETUDES ET DE RECHERCHES "SOLER". 22 Feb., 1968 [23 Feb., 1967], No. 8647/68. Heading H4K. [Also in Division H1] In a telecommunication exchange the subscriber lines are characterized by binary codes such that the codes of any two lines uniquely identify crosspoint elements and a junctor for use in an interconnection between them, and when a junctor circuit is taken into use an allotting chain prepares for the selection of an alternative junctor circuit for use for any other call requiring the engaged junctor. The crosspoint elements may be relay, solid state devices or operated by electrically, pneumatically or hydraulically controlled bars or strips. As described, the junctors are associated with a crossbar switch adapted to connect both the inlet and outlet of the junctors to selected outlets of the network. As shown in Fig. 3 longitudinally displaceable bars T1 to T3 and T5 to T7 are each adapted when in one position to connect a junctor between a preselected inlet conductor A1 to A4 and a preselected outlet conductor B1 to B6. E.g. to establish a connection between inlet A2 and outlet B6 a frame (not shown) in the plane of the inlet conductors A2 and A4 is displaced in one direction of the arrow CA1 to select the inlets in that plane and a further frame (not shown) is displaced in one direction of the arrow CB1 to select the outlets B2, B4 and B6 in its plane then the connecting bar T3 is displaced to operate the contacts at the intersections of the connecting bar with the two frames, i.e. at the intersections circled. This arrangement is duplicated a number of times with different sets of inlets and different sets of outlets associated with a connecting bar. Each connecting bar operates an additional contact which is changed from one position to the other as the bar is displaced and these additional contacts are arranged in an allotting tree (Fig. 11, not shown) which for each operated connecting bar (i.e. one maintaining a connection) selects another connecting bar (in a different one to the duplicated arrangements) for use in place of that connecting bar. In an actual physical arrangement (Fig. 6) the inlet and outlet conductors are on printed circuit cards IM1 and IM1<SP>1</SP> and resilient contacts 11 are mounted on the cards. To select say the contact at the top right of Figure a frame including a bar CA3 and other bars (not shown) is displaced. The bars are apertured and accommodate balls R which are moved by the displacement into notches 12 in the connecting bars T<SP>2</SP>, and into recesses 13 behind resilient insulating tongues 14 on fixed bars p2 3  and P<SP>2</SP>2. The ball R<SP>2</SP>3 is the only ball shown which is so displaced. When the connecting bar T<SP>2</SP> 1  is subsequently displaced to the right, the ball R<SP>2</SP> 3  remains in the notch 12 and moves with it. As it moves behind the enlarged end of its insulating tongue 14 the tongue is forced outwardly and closes the contact 11. Two such contacts (one associated with the inlet and one with the outlet) are in fact simultaneously closed and established a connection between the selected inlet and outlet via a junctor circuit (not shown). The frames and connecting bars are positioned by simultaneously displacing every one and positioning code bars so that abutments on the code bars block the return of selected frames or connecting bars