Electronic non-use power interruption safety device for an electric flat-iron

• US 4,520,257 A
• Filed: 01/26/1984
• Issued: 05/28/1985
• Est. Priority Date: 02/02/1983
• Status: Expired due to Fees

• Current Assignee: SEB SA
• Original Assignee: SEB SA
• Inventors: Schwob, Pierre, Mieg, Christian
• Primary Examiner(s): Bartis, A.
• Application Number:
  US06/574,140
• Time in Patent Office: 488 Days
• Field of Search: 219/250-253, 219/257, 219/259, 219/247, 219/242, 219/492, 219/493, 38/82, 200/61.52, 340/635, 340/686, 340/655
• US Class Current: 219/250
• CPC Class Codes: D06F 75/26 Temperature control or indicating arrangements
• CPC Class Codes: G01P 13/00 Indicating or recording presence, absence, or direction, of movement electric switches H01H; counting moving objects G06M7/00

Abstract

An electronic safety device for automatically interrupting the supply of electric current to a heating resistor of an iron at the end of a predetermined interval of non-use, comprising a movable body adapted to control a position of contacts of an associated switch so that at least one opening-closing sequence of the switch contacts is obtained upon displacement of the movable body. Associated with the switch is a resistor bridge supplied with a rectified voltage E and comprising a first resistor R₁ and a second resistor R₂ in series with the switch contacts. A capacitor is connected to the terminals of resistor R₂, a voltage V_o being collected at the terminals of said resistor R₁ and being applied to one input of a counter which is reset to zero each time voltage V_o is higher than E/2, that is, upon closing of the contacts. The counter is connected to an input of a comparator for transmitting a voltage V₁ when the counter attains a predetermined counting threshold. The comparator is connected to a trigger of a triac having one terminal connected to a current supply and another terminal connected in series to the heating resistor. The comparator is adapted to deliver turn-on pulses to the trigger as long as no voltage V₁ is applied and to stop these turn-on pulses as soon as a voltage V₁ is applied, thereby interrupting the current supply to the heating resistor.

Claims

1. An electronic safety device for automatically interrupting the supply of electric current to a heating resistor of an iron at the end of the predetermined interval of non-use, said device comprising a movable body which is capable of displacement within a housing of the iron when the iron is being moved, said movable body being adapted to control a position of contacts of an associated switch so that at least one opening-closing sequence of said switch contacts is obtained upon displacements of said movable body, means associated with said switch consisting of a resistor bridge supplied with a rectified voltage E and comprising a resistor R1 and a resistor R2 in series with said switch contacts, a capacitor connected to the terminals of said resistor R2, there being a voltage Vo at the terminals of said resistor R1, the respective values of said resistors R1 and R2 being such that said voltage Vo is lower than E/2 when said switch contacts are open or closed and higher than E/2 at the time of transition of said contacts from open to closed position, means to apply said voltage Vo to one input of a counter which is reset to zero each time said voltage Vo is higher than E/2, said counter being connected to an input of a comparator for transmitting a voltage V1 when said counter attains a predetermined counting threshold, said comparator being connected to a trigger of a triac having one terminal connected to a current supply and another terminal connected in series to said heating resistor, said comparator being adapted to deliver turn-on pulses to said trigger as long as no voltage V1 is applied and to stop said turn-on pulses as soon as a voltage V1 is applied to said one input of said comparator, thereby interrupting the current supply to the heating resistor.