Patent GB-190408992-A (GB)
Title: Telephone Systems
Inventor: GLEESON THOMAS W
Filed: 1904-04-19
Granted: 1904-08-11
Abstract: 8992. Gleeson, T. W., and Hamilton, R. May 1, A.D. 1903, [date applied for under Patents Act, A.D. 1901]. Telephone systems.-Each station in a direct-call system, requiring only a single circuit, is arranged as shown diagrammatically in Fig. 1, and includes a telephone transmitter T', a battery c<3> for the transmitter and call bell d, an induction coil with a primary winding c' and a secondary winding b<3>, a telephone receiver R' in series with a condenser b<1>, an ordinary receiver hook H' with several contacts above and below, a bell push d<3>, a resistance d<Î>, and a calling-relay d<6>. A main battery, not shown, is inserted permanently in the line a, to operate step-by-step electromagnetic selecting-apparatus at each station, there being no motors to wind. The apparatus is arranged so that, when the receivers R<1> are hung on the hooks H<1> after a conversation, the electromagnetic apparatus automatically returns the parts to the zero position. The parts of the selecting-apparatus are shown separated in the diagram, Fig. 1, and the construction. is partly shown in section in Fig. 4. It contains two aligned shafts 11, 12. To call any station, the shaft 12 is turned by a handle 45, and carries a pointer near numbers on a stationary frame 9, representing other stations which may be called; it also carries a sliding sleeve 16, which is movable towards the other shaft 11 by a horizontal armature lever 35, Fig. 1, operated by two electromagnets 41, 42 ; after the handle 45 has been turned as stated, the calling operator removes his receiver from the hook-lever H<1>, which then connects the battery c<3> to the electromagnet 41, and this shifts the lever 35 forward from the position shown in Fig. 1. The lever 35 then operates a latch 44, Fig. 4, to engage a toothed disc 13 on the shaft 12, and lock this against turning. The lever 35 also holds a contact 36, Fig. 1, against either of two springs 37, 39, and in the forward position closes a contact between two springs 53. The shaft 11, Fig. 4, carries a V-toothed disc 10, which is driven by pallets on an anchor linked to an armature lever, when this is oscillated by an electromagnet 1, Fig. 1. The shaft 11, Fig. 4, also carries two discs 20, 17, the edges of which are provided with alternate conductive and non-conductive segments, forming a commutator to cause the step-by-step action of the electromagnet 1. The discs 20, 17 respectively make contact with springs 52, 51, Fig. 1, for this purpose. The sleeve 16 carries a cam to make contact between two springs 47 in the zero position, completing the circuit of the motor magnet 1 ; this contact is broken when the sleeve 16 is turned at the calling station, leaving the magnet 1 there in circuit with the disc 17 and contact 51. When the armature lever 35 moves from the contact 37 to the contact 39, the circuit of the motor magnet 1 is by the disc 20 and the contact 52, instead of the disc 17 and the contact 51, but the disc 20 at first has a non-conducting segment under the contact 52 ; the anchor is thus caused to make a stroke, turning the shaft 11 and discs 17, 20 so that the circuit of the magnet 1 is again closed. The anchors then vibrate and the shafts 11 turn at all the stations until a pin 18 on the disc 17 at the calling station is stopped by a projection on the sleeve 16. When the shaft 11 begins to turn, a roller carried by a disc 27 on it opens contact springs 30 to disconnect the electromagnet 41. A cam projection 55 on the disc 17 also drops a locking-lever 54 into a notch in the sleeve 16 at each station, to prevent turning of the handle 45 and shaft 12 ; the pin 18 on the disc 17 prevents endwise movement of the sleeve 16 when this has not been turned. The disc 27 on the shaft 11 carries a roller to close two pairs 31, 32, of contact springs. The angular positions of these rollers differ at different stations, so that connection with any station may be obtained by causing all the shafts 11 to turn to the required extent from the zero position, as one roller at a time closes the contacts 31, which are in the secondary telephone circuit b<1>, b<3>, R', in the station called. This circuit is normally broken by the separation of the receiver hook H<1> from a contact above it, but, when closed, is connected to the line-wire a, in parallel with the motor electromagnet 1 and its controlling-contacts 37, 47, 23. When the contacts 31 are closed, a pin 22 on the disc 20 simultaneously separates two contact springs 23 to prevent shortcircuiting of the receiver R<1> through the motor magnet 1 and contacts 47, 37, 31. The springs 23 are however connected together by two contacts touching an insulated part of the receiver hook H<1>, unless this is raised. For calling, when the receiver book H<1> at the calling station is raised, this hook touches a contact to place the bell push d<3> in circuit; at the called station, the receiver hook, not having been raised, touches a contact connecting the relay magnet d<6> in circuit with the contact 32 and line. When the push d<3> is pressed, the relay connects the local battery c<3> to the bell d. A resistance d<x> in series with the push d<3> reduces the calling current so that it may not cause the motor magnets 1 to operate. When the called operator raises his receiver, the circuit of the motor magnet 1 is open both at 23 and at the contacts below his receiver hook, so that the magnets 1 cannot be caused to change the connection. The secondary telephone circuit in the calling station remains open at 31, but is closed at the parallel contacts 53 when the armature lever 35 turns forward. The primary telephone circuit T', c', c<3> at any station is closed when the receiver hook H rises against a contact. When the receivers are replaced on the hooks H<1>, that at the calling station connects the battery c<3> to the magnet 42, through two springs 49, which are then held together by a cam on the shaft 12, thus moving the lever 35 back to the contact 37. The motor magnets 1 and the commutator discs 17, 20 then again act until the cam on the sleeve 16 at the calling station engages the armature lever 35 and is thus returned to its zero position. The cam 55 on the disc 17 then lifts the locking-lever 54, freeing the shaft 12.