Patent GB-474284-A (GB)
Title: Improvements relating to tuning devices for radio receiving apparatus
IPC: H03J1/04
Filed: 1936-03-24
Abstract: 474,284. Adjusting wireless apparatus. WOODLEY, W. E. March 24, 1936, No. 8813. [Class 37] The names of the transmitting stations are indicated in turn in an order other than that of wavelength, for example, alphabetically, by a selector device, a single control knob or other control member being operable to move the selector device in either direction to indicate any station and automatically to adjust the tuning element thereto. In one embodiment, the station names are arranged radially and in alphabetical order upon a disc 1, Figs. 1, 2, rotated frictionally through a wheel 5, Fig. 4, to bring the names into indicating position behind a window 4, the names being viewed directly or projected on an enlarged scale upon a viewing screen arranged in the window Spring pressed balls 6 coact with notches 7 in the disc 1 to lock it in its indicating positions. Rigid with disc 1 is a disc 8 having slots 9 pertaining to each station name and providing variable abutment for a pin 16 on an arm 12 pivoted to an arm 11 rigid with a shaft 10 connected to the tuning means. The arm 12 is biassed by a spring 17 anchored at 19 and also by a stronger spring 18 connected to a rocking arm 20. To adjust the apparatus to a fresh station a knob 29, Fig. 4, is first depressed to move the shaft 25 axially against the action of a spring 31 until the conical portion 30 of the knob engages a recess 32 in the freely mounted wheel 5 which is then rotated by the knob to adjust the disc 1. During the axial movement of shaft 25, which is prevented from rotating, a pin 35 thereon travels along a helical groove 34 in a sleeve 33 which is thereby rotated to rock the arm 20 to the position 20<11> to allow the spring 17 to rock the arm 12 clockwise against a stop 36, and thus remove the pin 16 from the operative slot 9. After rotation of the disc 1 to the fresh indicating position, release of the knob 29 and consequent axial movement of shaft 25 by spring 31, rocks the arm 20 to the position 201 and the spring 18 rocks the arm 12 until the pin 16 engages the inner end of the operative slot 9, thereby tuning in the indicated station. The arms 11, 12 are normally in line and move together to adjust the tuning mechanism through shaft 10, the adjustment being indicated by a pointer 37 in register with arm 12 and extending between the disc 1 and panel 2. If a slight adjustment of the tuning position thus obtained is required a knob 23, Fig. 2, is rotated and through a pinion 15 and rack 14 on an extension of arm 12 rocks the arms 11, 12 out of alignment as shown in Fig. 1, the slots 9 being recessed at 22 to take account of the consequent downward movement of pin 16. Before another station can be tuned the arms 11, 12 must of course be brought back in line with each other. If desired the station names on the disc 1 may appear at the window 4 together with the names of stations adjacent thereto in order of wavelength, and with indications 38 which register with the pointer 37 when the pin 16 abuts against the end of the corresponding slot 9. The volume control (not shown) may be actuated by the axial movement of shaft 25 to reduce the noise from undesired transmissions during tuning and the wave-range switch may be automatically operated, for example, by cam means on the shaft 3 of disc 1. Alternatively, a manually operated wave-range switch may be used and an indication of the appropriate range made to appear at the window 4 with each station name simultaneously with the selective exhibition of a corresponding wave-range panel having tuning indicating means moving over a scale graduated in wavelengths and station names. The apparatus may also be provided with normal tuning arrangements. Thus the arm 12 may be rocked by a manually operated cam 40 to various tuning positions indicated by the pointer 37 against a wave-range or station name scale 39 when in the indicating position behind window 4 the pin 16 moving along a corresponding slot 9 in the disc 8. A plurality of such scales are provided around the disc 1. In another embodiment, Fig. 5, the station names are arranged alphabetically in a column on a member 60 rigid with a vertically slidable plate 61 having notches 63 corresponding to the slots 9 and presenting variable abutment to a pin 67 on an arm 64 connected through a shaft 65 with the tuning mechanism. Adjustment of the mechanism is effected by rotating a shaft 68 in either direction, each rotation thereof through 180‹ first rocking the arm 64 clockwise through a pin 72 or 73 on arm 71 to remove the pin 67 from the operative slot 63, after which a toothed sector 69 or 70 on the shaft 68 elevates or depresses the plates 60, 61 through a rack 74 to bring the next station name behind the window 4, and the arm 64 is then released and moved to the left by a spring 66 to adjust the tuning mechanism to the indicated station. The shaft 68 may be stepped from a remote point and the control elements 68, 69, 70, 72, 73 with or without remote control may be used with the rotary discs 1, 8 of Fig. 1. The rectilinearly sliding member 60 bearing the station names may be geared by a rack to a slotted disc such as 8, Fig. 1, for controlling the tuning instead of the plate 61. According to the Provisional Specification the station names may be arranged alphabetically around an internally illuminated drum, one end of which is provided with two sets of stop members adapted to co-operate with spring pressed members one of which is connected to the tuning mechanism and the other to the wave-range selecting mechanism. The control knob is depressed to remove the spring pressed members from the stops and then turned to rotate the drum to select a station. Upon release of the knob the spring pressed members advance to engage the stops corresponding to the selected station, and respectively adjust the tuning mechanism and the wave-range switch. The drum may be moved axially for fine adjustments. The automatic tuning means may be thrown out of operation and wavelength tuning used, the necessary indications being also provided on the drum.