ADJUSTABLE ELECTROMECHANICAL COMPONENT

Abstract: An electromechanical component, in particular a rotary potentiometer having an integrated centre click or optionally more fixed intermediate positions. The fixed intermediate position is obtained by a combination of two teeth (4) and a lug (6). The two teeth (4) are integrated with the element of the resistance path and the lug (6) with the element having the contact members of the component.

Description: The invention relates to a rotary potentiometer, which potentiometer comprises a housing and a sealing plate, which sealing plate has been provided with a resistance path, the potentiometer further comprising a rotary element, which element is movable with respect to said sealing plate, and which element comprises one or more contact members, the potentiometer also comprising a position indication mechanism. Such potentiometer is known from US 4,082,925. In this prior art component, the position indication mechanism consists of an integrated cam follower and an integrated identation. Said cam follower presses to said identation in radial direction in regard to the rotation axis of the rotor. This has the disadvantage that the bearing of the potentiometer experiences a tranverse load, resulting in greater detrition. US 3,703,613 describes a rather complicated shift selector switch, which comprises a position indication mechanism. The cup member 43 of said position indication mechanism is not integrated in the switch, but it consists of a loose element behind which a spring is present. Another component is known from U.S. Patent Specification 4,344,063 which describes a construction of a rotary potentiometer having a separate spring and a plate comprising a recess with which an intermediate position is obtained. In comparison with a rotary potentiometer without this provision the latter component is much more complicated and in series production requires extra steps in the mechanisation. It is the object of the invention to provide such a rotary potentiometer which is considerably simpler in structure and can be manufactured without expensive extra provisions in the machinery. The rotary potentiometer according to the invention is characterized in that said mechanism consists of the combination of two teeth and one lug, the teeth being integrated in the housing thus providing a lug fitting between the teeth, the lug being integrated in the rotary element, and in that the direction in which the lug presses against the teeth is parallel to the rotation axis of rotary element. According to the most usual embodiment the element with the resistance path consists of a housing having a substrate for its sealing plate on which the resistance path and the required connection lugs are present. The element with the contact members in that case is constructed as a rotor. The two functions, that of the element with the resistance path and that of the element with the contact member or the contact members, may, of course, be changed kinematically in known manner. The element with the resistance path is usually manufactured by injection moulding. In comparison with an element belonging to the construction without position indication, a matrix may be used which can simply be derived from the original matrix. The same applies to the other element and the rotor, respectively, a part of which may also consist of a synthetic resin and may be manufactured by injection moulding. When the rotor is punched from metal the provision of a lug in this special embodiment does not require great adjustments in the machine in question. According to a special embodiment on which higher requirements are imposed, the lug integrated with the rotor may consist of a combination of a ball with a compression spring. The invention will be described in greater detail with reference to a rotary potentiometer which is shown in the perspective exploded view in the Figure. The housing is denoted by 1; 2 is the rotor and 3 is the sealing plate of the housing which also forms the substrate and on which the resistance path is present on the rear side, hence not visible in the drawing. The sealing plate comprises connection lugs 7. The shaft with the bearing bush is not shown either in the Figure. A part of the housing 1 is shown in 1 a and the upper edge has not been drawn so that the two teeth 4 which represent a part of the invention are visible. In the drawing on the rear side of 1 a bearing bush with the rotary shaft is provided, if so desired. The metal contact with take-off contacts 5 is present on the rotor 2. A part of the rotor is shown in the rear view in Fig. 2 a so that the lug 6 which forms the other part of the invention is visible. The rotor 2 on which the contact springs 5 are secured is also manufactured from a synthetic resin in the embodiment shown in the drawing. The rotary potentiometer is constructed so that the direction in which the lug 6 presses against the teeth 4 is parallel to the rotor shaft. Placing the lug and teeth on the circumference of the rotor 2 would have the disadvantage that the bearing of the potentiometer experiences a transverse load resulting in greater detrition.

Claims: A rotary potentiometer, which potentiometer comprises a housing (1) and a sealing plate (3), which sealing plate (3) has been provided with a resistance path, the potentiometer further comprising a rotary element (2), which element (2) is movable with respect to said sealing plate (3), and which element (2) comprises one or more contact members (5), the potentiometer also comprising a position indication mechanism, characterized in that said mechanism consists of the combination of two teeth (4) and one lug (6), the teeth (4) being integrated in the housing (1) thus providing a lug (6) fitting between the teeth (4), the lug (6) being integrated in the rotary element (2), and in that the direction in which the lug presses against the teeth (4) is parallel to the rotation axis of rotary element (2). An electromechanical component as claimed in Claim 1, characterized in that the element having the resistance path consists of a housing having a substrate for its sealing plate on which the resistance path and the required connection lugs are situated. An electromechanical component as claimed in Claim 1 or 2, characterized in that the lug consists of the combination of a ball with a compression spring.

Inventors: VERMEULEN, FREDDY JOHNY
Applicants: N.V. PHILIPS' GLOEILAMPENFABRIEKEN
Application year: 1986
Main classification: H01H21
IPC codes: H01C10, H01H19