GB1120795A - Timer, paraticularly for electric or gas kitchen ovens - Google Patents

Abstract

1,120,795. Timer for ovens. ETS. CARPANO & PONS. 18 Nov., 1966 [29 Nov., 1965], No. 51792/66. Heading A4D. [Also in Division H1] A timer for turning an appliance such as an electric or gas oven on and off comprises a clock mechanism 5-8 driven by a motor 2, a clock dial 12, an hour-setting knob 10 driven by the clock mechanism and a knob 36 for showing the duration of time between turning on and turning off the appliance. To set the timer, the hour graduation on the dial 12 corresponding to the time at which the appliance is to be turned off is aligned with a mark 13 on a face plate 4 of the timer and a mark 11 on the knob 10 is aligned with the hour graduation on the dial 12 corresponding to the time at which the timer is turned on. A mark 37 on the knob 36 is set to register the duration of time for which the appliance is to be turned on. The motor 2 rotates the knob 10 at a rate of one revolution in twelve hours and a cam 24 is also rotated at the same speed by gears 21-23. The position of engagement on the cam 24 of a tip 39 of a lever 28 is determined by the knob 36, the lever being mounted on a bracket 32, a projecting part (not shown) of which engages a helical slot 33. The cam 24 rotates until the pre-selected time for turning on the appliance is reached, whereupon the tip 39 engages a cam surface 25 of the cam 24 so that the lever 28 rotates and its other tip 39<SP>1</SP> lifts a frame 40 upwards. An arm 41 of the frame 40 in turn lifts a lever 42 upwardly so that a projection 51 engages a projection 52 on a relatively rapidly rotating gear wheel 53. The lever 42 is thus moved horizontally and held in position by the engagement of projections 54, 55. An arm 45 of the lever 42 moves a slider 47 horizontally, a tongue 48 of the slider being coupled to a gas tap, for example, to turn on the gas or to a switch to turn on a heating element. A disc 14, having a notch 15 aligned with the mark 11, isalso driven at the same speed as the knob 10, so that when the notch 15 coincides with the pre-selected time for turning off the appliance, a projection 18 of an arm 16 enters the notch 15. The arm 16 carries a contact piece (not shown) which, as a result of the subsequent horizontal displacement of the arm 16, causes a break in the current supply leads 20, 20<SP>1</SP> to the motor 2. At the same time, the tip 39 of the lever 28 moves over an edge 26 of the cam surface 25 so that the frame 40 and the slider 47 return to their initial positions thus closing the gas tap or opening the electric switch. The gas tap or electric switch may also be controlled manually by setting the mark 37 on the knob 36 between letters A and M on the face plate 4. In this position, the tip 39 only engages the smooth cylindrical surface of the cam 24 and a projection 56 on the shaft 35 of the knob 36 engages a projection 57 to move the slider 47.