Method of checking the aseptic nature of washing before opening at least one door of a washing machine

• US 6,523,204 B1
• Filed: 10/23/2000
• Issued: 02/25/2003
• Est. Priority Date: 10/27/1999
• Status: Expired due to Term

• Current Assignee: Electrolux Systems de Blanchisserie
• Original Assignee: Electrolux Systems de Blanchisserie
• Inventors: Maziere, André, Drot, William
• Primary Examiner(s): Stinson, Frankie L.
• Application Number:
  US09/694,219
• Time in Patent Office: 855 Days
• Field of Search: 815/8, 815/9, 68/120.2, 68/120.3, 68/121.2, 68/121.8, 68/121.9, 134/113
• US Class Current: 8/158
• CPC Class Codes: D06F 2103/16 Washing liquid temperature
• CPC Class Codes: D06F 2103/18 Washing liquid level
• CPC Class Codes: D06F 2103/22 Content of detergent or additives
• CPC Class Codes: D06F 2105/52 Changing sequence of operational steps; Carrying out additional operational steps; Modifying operational steps, e.g. by extending duration of steps
• CPC Class Codes: D06F 33/30 Control of washing machines characterised by the purpose or target of the control controlling processes of washer-dryers D06F33/50
• CPC Class Codes: D06F 95/00 Laundry systems or arrangements of apparatus or machines; Mobile laundries D06F31/00 takes precedence

Abstract

Method of checking the aseptic nature of washing before opening at least one door of the washing machine.

A washing machine (10) is fitted with at least one door (14) capable of being opened into a clean room (20) at the end of each washing-rinsing-spin drying cycle. So as to avoid this opening operation being performed if the conditions for asepsis of the washing are not ensured, opening is conditional on an opening authorization signal being emitted by a control unit (36). This unit checks, successively, the introduction of water into the tank (22) of the machine, the presence in the tank of detergent products, heating of the water to a minimum temperature and the maintainence of this temperature for a predetermined time interval. If any one of these conditions is not fulfilled, the automatic opening signal is not emitted.

Claims

1. Method of checking an aseptic nature of a washing prior to opening at least one door of a washing machine, said method comprising, in order, the following successive steps:

checking for an arrival of a minimum quantity of water in a tank of the machine;

checking for a presence of detergent products in said tank;

verifying that a minimum temperature is achieved by the water contained in said tank;

emission of a signal authorizing the opening of said door, a predetermined interval of time after obtaining said minimum temperature in said tank.

2. Method according to claim 1, in which the check on the arrival of said minimum quantity is followed by a check of rotation of a drum of the machine.

3. Method according to claim 1, in which the washing machine is integrated into a sealed partition separating a contaminated room from a clean room and has at least one door opening into each of said rooms, and in which each door opening into the clean room is locked in a closed condition, until the emission of said opening authorization signal.

4. Method according to claim 1, in which the arrival of said quantity of water is checked by using at least one of the techniques consisting of measuring a flow rate of the water admitted to the tank, measuring a volume of water admitted to the tank, measuring a mass of water admitted to the tank and measuring a height of water in the tank.

5. Method according to claim 1, in which the presence of detergent products is checkcd by using at least one of the techniques consisting of measuring a pH of the water contained in the tank, measuring the total hardness of said water and of checking an arrival of the detergent products in the tank.

6. Method according to claim 5, in which one verifies that the pH of the water contained in the tank is at least about 9.

7. Method according to claim 1, in which one verifies that the water reaches a minimum temperature of at least about 60°

C.

8. Method according to claim 1, in which the signal for opening the door is emitted about 20 minutes after said minimum temperature has been obtained.