Patent GB-638659-A (GB)
Title: Improvements relating to electric toasters
IPC: H01H43/30
Filed: 1947-12-29
Abstract: 638,659. Electric toasters. HOOVER, Ltd. Dec. 29, 1947, No. 34419. Convention date, Dec. 31, 1946. [Class 28(i)] [Also in Groups XIII, XXXV and XXXVII] In electric bread toasters provided with timing mechanism comprising a bi-metallic thermal element 39 adapted to be heated during the toasting period and, when hot, to switch off the toaster heaters, said mechanism also includes a thermal mass 53 which is contacted with the element 39 while the latter is being heated up so that the toasting period is determined by the time taken for the heaters to heat up the said mass and element together. Preferably an assembly 50 of such masses in the form of plates is provided, together with means, such as a pawl 57 on an arm 54 of the carrier plate 19 of the bread supports 15, for bringing them successively into contact with the element 39 for successive toasting periods, the thermal plates being mounted on a shaft 48 which is rotatable in spring- controlled tiltable arms 45 and has a ratchet wheel 51 for engagement by said pawl 57. The plate 19 is mounted between a pair of vertical posts 14 through guiding rollers 21 and is movable, together with the supports 15, from the upper position shown to the toasting position, by a U-shaped lever 30 which has a handle 32 and controlling spring 35 and the arms 27, 28 of which are pivoted to the walls of the toasting chamber 11 and are linked at 26 to the said plate. The arm 54 of the carrier plate, and a second arm 55, are also formed with cam'surfaces 56 in alignment with the ends of the shaft 48, and the plate itself has a bracket 68 upon which is mounted a pair of contacts 69 connected by a conducting plate 70 adapted to bridge fixed contacts 71 located on the base plate 13 of the toaster in the circuit of the toaster heaters. The arrangement is such that, after applying the bread slices to the carriers 15 through the usual openings 12 and depressing the lever 30 and with it the carrier plate 19, first the pawl 57 will engage the ratchet 51 of the shaft 48 to cause the lowermost thermal plate 53 to move into a position immediately in front of the bimetallic strip 39, then the cams 56 will engage the shaft 48 and move the entire assembly 50 until the plate 53 contacts the strip 39 and, finally, the hooked ends 62 of latch mechanism 61 will snap into openings 66 in the carrier plate 19 and lock the latter in its lowermost or toasting position with the electric contacts 69 bearing on the contacts 71 to close the circuit through the heaters. The resultant toasting operation then continues until the strip 39 bows rearwardly towards the toast chamber 11 and moves a lever 63 which is associated with the latch mechanism 61 and effects release of the latter to permit return of the carrier plate 19 to its initial position. A shutter 73, slidably mounted on the back of the partition 17 between the toast chamber and mechanism compartment in front of the strip 39. is provided for shielding the strip to a greater or lesser extent and varying the toasting period, said shutter being adjustable by a knob 75 on the front of the toaster through a crank arm 76 and a link 77.