Patent GB-1431305-A (GB)
Title: Cooking time adjusting device for use in electronic oven
IPC: G04F3/00
Filed: 1973-04-05
Abstract: 1431305 Oven timers MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 5 April 1973 [6 April 1972 (2)] 16379/73 Heading A4D [Also in Divisions G4-6] Timer: A timer device for use in an electric oven 1, Fig. 1, comprises a timer 6, Fig. 8, having an operating shaft 18 for setting a cooking time, a panel 2 having a window 5, a pointer 4 movable across the window 5 when the shaft 18 is rotated, and means for visually presenting information pertaining to cooking various foodstuffs. The timer 6 is set to switch off a high frequency magnetron energized by a push-button switch 8. Rotation of the shaft 18 sets the timer 6 and also moves the pointer 4 to a given position on the display means, whence it returns to an OFF position and indicates the elapse of the cooking time. A drum 3, Fig. 3, has a menu and cooking times printed on it and is rotated, to bring information about a given foodstuff into register with the needle 4, by a ring 10 extending through a slot 9 in the panel 2. The shaft 18 is rotated by a knob 7. Drum: The drum 3 has axial projections 12, 14 with the ring 10 and a ring 11 respectively mounted thereon and supported by bearings 13a, 13b respectively, secured to a chassis 21. The drum 3 is biased by a spring mounted between the ring 11  and a washer, towards the bearing 13a. A time scale is suspended adjacent the drum 3. Drive mechanism: A drive wheel 19 is rigidly secured to the shaft 18 and moves the pointer 4 via a cable 20 guided by pulleys 22-26 and tied at its ends to a spring 27. A pair of projections 28, 29 helps in securing the cable 20 around the pulleys 22-26 and to the spring 27 by engaging loops 30, 31 respectively during the securing procedure. The cable 20 is secured to the pointer 4 by means of a block 32 slidable in a channel 34 on the chassis 21 and a plate 33 which is longer than the block 32. The drive wheel 19 is rigidly coupled to the shaft 18 so that the timer 6 and the pointer 4 move together. Alternatively, the shaft 8 and the drum 3 are coupled together so that one rotation of the drum 3 corresponds to the maximum cooking time, and the information is arranged helically on the drum 3. Lighting: The drum 3 is made of transparent material and is illuminated by an axially extending cylindrical lamp or a lamp near the bearing 13b and adjacent the periphery of the drum 3, whose inner surface is coated with white paint and the information characters perforated on an opaque film on the outer surface. If an opaque drum 3 is used, a plurality of lamps shielded by a removable cover may be used. Alternatively, the drum 3 is partly enclosed by a covering having an opening in alignment with the window 5 and illuminated by a lamp. A lamp is used to light the interior of the oven 1 and may also be used to illuminate a belt 88, Fig. 18a. Alternative display means: The information may, alternatively, be presented on scales (82), Fig. 17a, (not shown) inserted in a double-walled portion of the panel 2 through an opening. The belt 88 of synthetic film may, alternatively, be used to present the information. The belt 88 is mounted on rolls 89, 90 which are rotated by gears 85-87 and a knob. The belt 88 may be endless or have ends secured to the rolls 89, 90. A backing plate 98 supports the belt 88 which is light-transmitting and is cleaned by brushes and protected from scratching by a protective film. The belt 88 has three portions corresponding to re-heating, cooking and defrosting times respectively, which are indicated by an index on the operating knob. A pin on the shaft 84 of the gear 85 prevents rotation of the index over more than 360 degrees. The information may be presented on strips (109), Fig. 23a, (not shown) secured by magnetism to strips (110) on the panel 2.