Pedal switch for lamps with variable intensity

Abstract

 This invention concerns a pedal switch for an electrical feed circuit for lamps with variable luminous intensity.
It consists of a mobile contact (18), rotating by steps, and two or more pairs of fixed contacts (26-29) located radially and opposite each other two-by-two. One fixed contact (26) of at least one pair of fixed contacts (26,28) is connected to a semiconductor (33) to reduce the electric current into the lamp to be fed. The mobile contact (18) moves successively from a position of open circuit - light off, to a contact position with the pair of fixed contacts (26,28) connected to the semiconductor (33) for a lamp operating at reduced intensity, to a contact position with the other pair of fixed contacts (27,29) for a lamp operating at full intensity.

Description

[0001] This invention concerns a pedal switch with multiple positions, particularly for lamps with variable luminous intensity.

[0002] Lamps for illumination that have the possibility of varying the luminous intensity by modifying the power or electrical tension input are already well-known. At present, to vary the luminous intensity of a lamp it is necessary to make use of specific devices, such as luminosity regulators or as many switches as there are variations desired.

[0003] The aim of this invention, on the other hand, is to propose a pedal switch with a mobile contact, having various positions and a wiring that enables the tension into the lamp to he regulated, so as to vary the lamp's luminosity.

[0004] In this way it is possible to control lamps with variable luminous intensity both easily and comfortably, using a single pedal switch.

[0005] This aim is achieved with a pedal switch that has a mobile contact that rotates by degrees, designed to interact with two or more pairs of fixed contacts placed radially, passing through on/off phases, and where at least one fixed contact is connected to a semi-conductor for reducing the electrical tension into the lamp, thereby varying the latter's luminosity.

[0006] The designs enclosed show a non-restrictive example of the practical assembly of the pedal switch invented. In these designs:

Fig.1 shows a vertical cross-section of the switch;

Fig.2 shows a cross-section according to the arrows II-II in Fig.1, highlighting the wiring of the fixed contacts;

Fig.3 shows an exploded view of the command mechanism for the rotating contact; and

Figs 4,5 and 6 each show electrical plans illustrating, respectively, the switch when open (light off), when closed in conditions of reduced luminous intensity and when closed in conditions of full luminous intensity.

[0007] The switch in question consists of a body 11 which comprises two complementary elements 12, 13 that are spring-coupled, ad a button or command key 14on top which moves according to a return spring 15.

[0008] The two elements 12, 13, which form the body, define centrally, on the axis of the button 14, a support 16 - Fig.1 - which holds a transmission mechanism 17, activated from above by the button 14, and a mobile rotating contact 18 below. This mechanism 17 is suitable for transforming the axial movements of the button 14 into a one-way step-by-step rotary movement of the rotating contact 18.

[0009] In the illustrated example - Figs 1 and 3 - the mechanism consists of a pivot 19 and a small transmission rod 20, placed coaxially to one another and inserted into a tubular part 16' of the support 16, with the possibility of either transferring axially or rotating. The pivot 19 holds the rotating contact 18 and has peripheral cams 21; the small rod has frontal cams 22 that interact with the said peripheral cams of the pivot, as well as the radial cams 23, designed to cooperate with the command cams 24 inside the tubular section of the guide 16'.

[0010] The combination is such that, pressing the command button and then releasing it, causes, by means of the interacting cams 21-24, a coaxial movement of the small rod 20 with an initial light rotation of the pivot, then a further rotation of the pivot with the mobile contact 18 through a chosen angle, for example, 45°.

[0011] This is repeated every time the button is pressed and released.

[0012] The mobile contact 18 is stressed by a contrast spring 25 which tends to push the block comprising pivot and small rod 19, 20 back towards the command button 14 and to keep the mobile contact 18 pushed towards a plane on which the fixed contacts 26, 27, 28, 29 are located, within the body and on a concentric circumference around the rotation axis of the mobile contact.

[0013] In the example shown, there are four fixed contacts 26-29 - although they could be more - placed in opposition two-by-two and 90° apart, and the mobile contact 18 turns 45° at a time, so as to position itself on the first pair of opposing contacts 26,28, then on an interval between the pairs, then on the second pair of opposing contacts 27,29, and so on.

[0014] The switch is inserted on an electric feed cable 30 which goes from an entry plug 31, which can be inserted into an electric socket, to a lamp 32 whose luminous intensity is to be controlled.

[0015] For example, one of the phase leads is unbroken and goes directly from the input 31 to the lamp; the other phase lead 30'' is interrupted and is connected, on the one hand, to two consecutive fixed contacts 26,27 and, on the other, to the other two fixed contacts 28,29.

[0016] This connection to a fixed contact, such as 26, has at least one semiconductor or diode 33.

[0017] The planned electrical circuit corresponds with Fig.4 when the switch is open and the lamp is off, and with Figs 5 and 6 for the two conditions of reduced and full luminous intensity, respectively.

[0018] In practice, the step by step rotation of the rotating mobile contact brings about the following conditions:

[0019] When the mobile contact 18 is in either of the positions a, a' -Fig.2- between the fixed contacts 26-29, the circuit is open and the light is off. This condition is shown in Fig.4.

[0020] When the mobile contact 18 is closed in position on the two opposing fixed contacts 26,28 -Fig.2- the lamp is activated through the semiconductor 33, developing a reduced luminous intensity. This condition is illustrated by Fig.5.

[0021] Finally, when the mobile contact 18 is closed in position on the other two opposing fixed contacts 27,29 the lamp is activated and develops a full luminous intensity. This is the condition in Fig.6.

Claims

1. Pedal switch for electrical feed circuit for lamps with variable luminosity, characterized by a mobile contact (18), which rotates by degrees, ad two or more pairs of fixed contacts (26-29), set radially and in opposition two-by-two, equidistant and with intervals (a,a') between consecutive fixed contacts, by the fact that one fixed contact (26) of at least one pair of fixed contacts (26,28) is connected to a semiconductor (33) to reduce the electric current into the lamp to be fed, and by the fact that the mobile contact (18), rotating by steps, passes successively from one of the positions (a) corresponding to two intervals between the fixed contacts, which opens the electrical circuit and switches off the lamp, to a contact position with the pair of fixed contacts (26,28) which are connected to the semiconductor (33) and make the lamp operate at reduced intensity, to a contact position with one of the other intervals (a'), which opens the electrical circuit, to a contact position with the other pair of fixed contacts (27,29), which makes the lamp operate at full intensity, and so on.

2. Pedal switch as in revendication 1, in which said rotating mobile contact (18) is commanded by a key or button (14) by means of a mechanism designed to transform the movements of the key or button into a step-by-step rotation of the mobile contact, each step of pre-established length.

3. Pedal switch as in revendications 1 and 2, in which the phase lead of the feed circuit goes from the feed source, or from a plug, to the lamp to be fed, whilst the other phase lead is interrupted and connected on one side to two consecutive fixed contacts ad on the other to the second two consecutive fixed contacts, the semiconductor being inserted on one part of this phase lead which is connected to a fixed contact.

Drawing