Patent GB-692295-A (GB)
Title: Improvements in or relating to apparatus for hardening or tempering glass articles or sheets
IPC: C03B27/06
Filed: 1951-10-19
Abstract: 692,295. Hardening glass. ABBEY, A. (American Optical Co.). Oct. 19, 1951, No. 24498/51. Class 56. A hardening device for making glass more resistant to shock &c. comprises a chilling unit and a heating unit in spaced relation, a work holder movable to and from stations in which the work may be respectively positioned in the heating and chilling units, restraining means to maintain the work holder at the first, heating, station against a force urging it to the second station, and control means operably associated with the restraining means to free the work holder for movement by the force to the second station upon the lapse of a predetermined interval of time and which is rendered operative with movement of the work holder to the first station. The apparatus comprises a base 9 and housing 10 with compartments 11, 12, 13. The lower compartment 11 houses a rotary air compressor unit 14 embodying a motor 15, centrifugal blower 16, and filter 17 which is connected through pipes 18 to a pair of spaced aligned air jets 19, e.g. venturi nozzles. The glass article 20 is supported between clamps 21 carried by spaced uprights 22 which are pivoted at 23 to a support 24 on the top of compartment 11. The jaws 25, 26 have spaced grooved ceramic contacts 27, 28 and are pivoted to the uprights at 29, 30. The uprights interlock at the lower ends by means of a slot 31 and projection 32, and are rocked by a lever 34 on one upright and held normally closed by a spring 35. The support 24 is attached by brackets 31 to a vertical slide 38 comprising spaced plates 40 with extensions 42 and grooved rollers 41, 43 which engage the bevelled edges of guide plates 46, 47. A furnace 49 with heating coils &c. 52 is supported in compartment 13 and has a passageway 53 through which the article 20 enters when the slide 38 is raised, a refractory 50 on the holder 21 closing the passage 53. A pin 56 on slide 38 is engaged by a latch member 57 which is pivoted at 58, the pin engaging the tapered edge 59 rocks the member 57 which is retained in holding relation with the pin by a spring 61 connected to the latch extension 60. A solenoid 63 has a vertically movable core 64 with a latch 65 which is engaged by a projection 66 on the member 60. Clockwise movement of member 57 is restricted by an arm 67. The solenoid is connected to a timing device 69 having a dial 70 and control 71. When the slide 38 is raised adjustable member 72 engages the contact 73 of a microswitch 74, tripping the switch and energizing the timer 69 so that after a set time the solenoid is energized and moves core 64 upwardly, when the arm 60 is swung and the latch 57 disengaged from pin 56 so that the slide 38 and holder 21 are freed and move downwardly. This movement is cushioned by means of a piston 77 connected to the slide by arm &c. 78, 79 sliding in a cylinder 76, the latter having an adjustable bleeder valve 80. When the slide is fully lowered an adjustable member 81 engages the contact 82 of a microswitch &c. 83 electrically connected with the compressor 14, so that the motor 15 is energized and blowing commenced. A framing 84 secured to the slide 38 has a base plate 85 which is engaged by a cam 86 journaled on shaft 87, and when the latter is operated by means of lever 89, the slide 38 is raised to disengage contacts 81, 82, and check the air flow. The framing 84 has a cam portion 90 which engages a roller 91 on a crank 92 connected to a shaft 93 which is journaled in bearings 94 on the furnace base adjacent the passageway 53, and which carries a door 95. The door 95 is normally held so that it closes passageway 53 by means of spring 96, but when the holder 21 is raised on slide 38 the cam surface 90 engages the roller 91 to rotate the shaft 93, and the door opens and is held open while the roller 91 engages the edge 98. A controller, e.g. of the potentiometer type, with a setting device 100 is connected to coils 52 to regulate and maintain the temperature with a minimum of variation, and a pilot light 103 indicates when the temperature is satisfactory. The heating system also includes a rheostat 104 and galvanometer 10.5. When the time and temperature adjustments have been made the holder 21 is raised by handle 34 into the furnace, the door 95 opening to commence the process. The circuit diagram of the apparatus is given.