Aktiebolaget Electrolux

Electrolux Research & Innovation Aktiebolag

Henrik E Troberg

Per-Marcus Bergquist

Stefan Jonsson

Fredrik Sjöberg

Curt E Nyberg

This invention relates to a dust indicator in a vacuum cleaner, which dust indicator () is arranged in a wall () at least partly defining a space of the vacuum cleaner that is set under negative pressure with respect to the outside of the wall during operation of the vacuum cleaner. The dust indicator comprises an air channel () having an air inlet () arranged at an outer side of the wall, and an air outlet () arranged at an inner side of the wall, such that an airflow is directed into the space during operation of the vacuum cleaner due to the negative pressure. The dust indicator further comprises a sensor () arranged for detecting dust by means of sending and/or receiving an electromagnetic signal which is transmitted through the space. The air channel is arranged such that the airflow prevents dust from sticking in an area of the path of the electromagnetic signal of the sensor. The sensor is arranged behind a transparent window () such that it is shielded from dust and debris within said space.

Dust indicator for a vacuum cleaner

Device for applying an insulating layer to a surface of an object

A relay including a control circuit which via a movement creating or actuating arm and a transmission mechanism activates a contact means in order to switch on or switch off a main circuit. The actuating arm includes two elongated parallel parts which are separated by a thermally and electrically insulated layer. The two parallel parts each have a first end fastened to a housing or holder. The two parallel parts each have a second end fixed to each other, forming a movable end of the arm. One or both parallel parts of the arm are provided with a heat creating or producing element. The actuating arm, attached at one end and movable at the other end, together with the heat producing element, constitutes the first part of the control circuit or relay. When a control current flows through the heat producing element, one of the two parallel parts of the arm is heated thereby causing a movement of the movable end of the arm to thereby activate the control means through the transmission mechanism. The transmission mechanism includes a finger extending mainly perpendicular to the length direction of the movable arm, with the finger acting on a leaf spring. The leaf spring is generally parallel to the arm, the spring supports said contact means which switch on or off the main circuit.

Relay

An arm preferably for electric switches, the arm being controlled by electricity, and having a first fixed end the other end of which is movable perpendicular to the length direction of the arm. The arm comprises two parallel portions (47) separated by an air gap (17) or some other heat insulating material, and which are secured to each other at each end. At least one of the portions, being heated by electricity and, through longitudinal differential expansion with respect to the other portion, achieves said movement. The portions are so shaped that, adjacent the fixed end (at 45) with respect to the rest of the portions, they have a reduced bending resistance about an axis which is perpendicular to the length direction of the arm and with respect to said direction of movement.

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Tumba, Sweden

Henrik E Troberg