Patent GB-191305938-A (GB)
Title: Improvements in Telegraphones.
Inventor: MCKENNA THEODORE
IPC: H04M1/65
Filed: 1913-03-10
Granted: 1914-04-14
Abstract: 5938. McKenna, T., [Fankhauser, C. K.]. March 10. Telephone signals, recording and reproducang.- Relates to telegraphone apparatus of the kind comprising a pair of spools for carrying the recordreceiving wire or the like, and consists in (1) mounting a rotatable disk adjacent to each spool whereby the spools are adapted to be driven or braked through friction means mounted on the flat sides of the spools and disks, the disks being controlled so that the friction between either reel and its disk may be varied, whereby either disk can drive the reels; (2) in arranging that the following reel is always retarded by its disk so as to keep the wire taut; (3) in an electro-magnetic device for controlling the speed of the motor ; (4) in means for adjusting the talking-head to any desired position; and (5) in means for automatically moving the talking-head during the operation of the apparatus. In the construction shown in sectional elevation in Fig. 2, the apparatus is enclosed in a casing 1 having a cover 2 and shelf 3 carrying the toothed disks 4, 5 which are geared together and secured to the hollow shafts 7, 8 respectively, the shaft 8 being rotated by an electric motor. Arranged above the disks are the wire-carrying spools 16, 17 adapted to rotate freely on the shafts 7, 8. These spools are driven fr m the disks by the engagement of the annular surfaces 20 and 6. The surfaces 6 are formed with recesses, in each of which a spring is mounted carrying a friction block adapted to engage the surfaces 20 even when the spools are raised. The spo@ls are raised by electromagnets 22, 23 acting through rods 27, 31 passing through the hollow shafts. Upon raising one of the spools, the friction between this spool and its disk is reduced, and this spool becomes the follower and is retarded by the friction blocks on the corresponding disk which is rotati g in the reverse direction to the spool. The talking-head or device for recording, reproducing, and obliterating the message on the wire, shown in detail in Figs. 7 and 8, is mounted adjacent to the spools on a rod 52, and comprises a frame 58 carrying coils 59, 60 having cores 61, 62 pointed at the ends 63 adjacent to the record receiving wire 57. The pivoted member 68 is snapped under the screw head 70 to secure the wire in position in the slots 67. The rod 52 is controlled by the worm 36 through a cam arrangement so as to guide the wire correctly on to the spools. The talking held may be adjusted in position by hand at any part of its movement. Fig. 14 shows diagrammatically the various parts and electrical connexions of a complete apparatus. The series motor 15, for driving the disks and spools, is connected to the supply 79 through an electromagnetically-controlled armature contact 82, whereby should the speed of the motor increase a resistince 138 is introduced into the circuit by the lifting of the armatore contact 82. This contact will oscillate under the action of the spring 96 and electro-magnets 83, 93 until the speed of the motor again becomes normal. One or other of the spool. raising electro-magnets 22, 23 is placed in circuit simultaneously with the motor by a foot operated switch 162. Figs. 17 and 18 show longitudinal and transverse sections respectively of a constructional form of the foot-operated switch 162. The plate 154 shaped to receive the foot is pivoted at 55 on a pin 153 rotatably mounted in a base 151, whereby the plate can be given both an horizontal and vertical movement. The toe end of the plate is formed with a dependent portion adapted to engage one or other of the rods 158, 159 which engage at their lower end resilient prongs 161, 162 c onnected to the supply lead 163. Contacts 90, 92 are mounted below the prongs so as to contact therewith when the foot plate is depressed. A helical spring normally retains the plate so that its dependent portion engages the rod 159. The talking-head is c nnected up through a plug contact 139 with a combined listening and talking set 122, 123 or other known arrangement. The coil 59 of the talkiog-head receives a steady current from battery 105, and functions as an obliterating-magnet by magnetically saturating the wire. The coil 60 carries two currents, one to demagnetize the wire and the other, originating from the secondary of the coil 103, records n:agnetically on the wire the messages given to the transmitter 122.