Signal generator for emitting a light signal

Description

[0001] The invention relates to a signal generator for emitting a light signal according to the preamble of patent claim 1.

[0002] Traffic lights are used to control road traffic at a junction in the road network, particularly at intersections or junctions. They consist of signal heads suspended from masts or catenaries that emit light signals to road users approaching or waiting at the junction, such as drivers of motor vehicles or motorcycles, as well as cyclists and pedestrians. A signal head has one or more signal fields arranged in a row, each of which can emit a light signal. Three-field signal heads are often used, with the signal fields arranged one above the other. The upper signal field can emit a red light signal, the middle signal field a yellow light signal, and the lower signal field a green light signal. The duration and sequence of the light signals to be emitted are generated by controlling individual or multiple signal fields, which takes place according to a signal timing plan running in a control unit at the junction.

[0003] A signal generator of the type mentioned above is known, for example, from published patent application DE 10 2014 205 453 A1. It comprises a pot-shaped inner housing made of plastic with a front opening. Arranged in the inner housing are a light source with at least one light-emitting diode and a driver assembly for supplying power to the light source. The front opening is closed by an optical attachment for influencing the light emitted by the light source. The optical attachment has an internal Fresnel lens and an external diffuser. The Fresnel lens has a series of ring-shaped steps in an optically active region, through which light emitted by the point light source is bundled. The diffuser downstream in the optical path is colorless or colored and has a honeycomb, cobweb, or prism pattern, which ensures uniform light distribution across the diffuser.A symbol mask can be placed in the space between the Fresnel lens and the diffuser. The symbol mask serves to display a light signal with a symbol and covers a signal field except for the symbol to be displayed, for example, a pedestrian, standing or walking, a bicycle, or an arrow. This allows the respective symbol to be displayed to the road user in color, if necessary, by the light from the light source passing through it when the signal head is activated.

[0004] In the known signal generator, the front opening of the inner housing is sealed by the optics attachment in order to meet the manufacturer's guaranteed requirements for tightness against the ingress of moisture and dirt. The wide variety of types of such signal generators - with signal fields of different sizes, colorless or differently colored diffusers, without symbol masks or with different symbol masks, to name just a few - places considerable logistical effort on the manufacturer's production costs. Each of these signal generator types must be recorded in the materials management system under its own part number. A further disadvantage of the known signal generator is that when changing the symbol mask in the optics attachment, the signal generator insert must be opened, which can allow moisture and dirt to penetrate.

[0005] DE 20 2006 014 987 U1 discloses a signal generator for emitting a light signal for road traffic. The signal generator has a pot-shaped inner housing with a front opening in which a light source is arranged. An optical attachment is provided that covers the front opening and is designed to influence the light emitted by the light source. The optical attachment has an internal Fresnel lens and an external diffuser. Furthermore, a symbol mask is provided between the Fresnel lens and the diffuser, which partially covers the emitted light and displays a light signal with a symbol.

[0006] The invention is therefore based on the object of providing a signal generator of the type mentioned at the outset which overcomes the disadvantages of the prior art.

[0007] The problem is solved by a generic signal generator with the characterizing features of patent claim 1. Such a signal generator is designed and intended to emit a light signal for road traffic. It comprises a pot-shaped inner housing with a front opening. A light source is arranged in the inner housing. The light source can have one or more light-emitting diodes and a driver module for supplying and controlling the light-emitting diodes. The signal generator further comprises an optical attachment for influencing the light emitted by the light source. The optical attachment covers the front opening of the inner housing and has an internal Fresnel lens and an external diffuser. To display a light signal with a symbol, the signal generator has a symbol mask that partially covers the emitted light.According to the invention, the inner housing with light source and the optical attachment form a pre-assembled signaling device insert, in which the optical attachment seals the front opening. A cover containing the symbol mask is attached to the outside of the diffuser. This greatly limits the number of signaling device variants, as manufacturers are only able to offer signaling device insert types with a transparent cover. The desired symbol mask can be supplied separately or procured and installed on-site as required. Furthermore, the symbol mask can be installed and replaced without opening the inner housing of the signaling device insert.

[0008] The cover has a transparent protective screen with a fastening ring and an insert that fits against the protective screen and forms the symbol mask. The symbol mask, which can be manufactured and supplied separately, can be placed against the inside of the protective screen. This cover, consisting of two components, is then attached to the signal generator insert using the fastening ring. The protective screen holds the symbol mask and protects it from external environmental influences, such as weather, dirt or stone chips. The protective screen and insert are congruent with the lens and have matching curvatures. The fastening ring runs along the circular circumference of the protective screen and, when installed, engages over a collar of the lens, where it is secured, for example, by a clamp fit or a snap connection.

[0009] When retrofitted, the fastening ring surrounds an outer edge of the lens and is fixed there by an easily removable connection, such as a clamp fit or locking springs.

[0010] In a further advantageous embodiment of the signal generator according to the invention, the insert is designed as an injection-molded part. Due to the limited number of different symbols, the manufacturing costs per insert can be kept low by providing a few molds for a large number of symbol masks.

[0011] In a further advantageous embodiment of the signal generator according to the invention, the insert is designed as a plastic shell from which the symbol to be displayed is machined by milling or laser treatment. The underlying plastic shell is identical for each symbol and can therefore be produced cost-effectively in large quantities. The respective symbol is produced precisely and reproducibly using computer-aided programming algorithms that control a milling head or laser beam of a machine tool.

[0012] In a further advantageous embodiment of the signal generator according to the invention, the insert is designed as a transparent film, which is printed with black ink, leaving the symbol exposed. The symbol can be printed onto the film using a laser or inkjet printer, or applied by screen printing. By applying a printing technique, the manufacturer can easily and flexibly design the symbols.

[0013] Further advantages and features of the invention will become apparent from the following description of an embodiment with reference to the drawings, in which FIG 1 a pedestrian signal head with two signal fields in perspective view, FIG 2 a signal head insert for the two signal fields from FIG 1 in exploded view and FIG 3 the pre-assembled signal transmitter insert from FIG 2 with an inventive cover in exploded view is illustrated schematically.

[0014] According to FIG 1 A pedestrian signal generator 1 has, arranged one above the other, an upper signal field 2S for emitting a blocking signal and, below it, a lower signal field 2G for emitting an enabling signal. The blocking signal is represented by a red light signal with a symbol in the form of a standing pedestrian, and the enabling signal is represented by a green light signal with a symbol in the form of a walking pedestrian. The symbol S for the standing pedestrian is shown surrounded by a solid line because it is currently illuminated, while the symbol G for the walking pedestrian is shown surrounded by a dashed line because it is not currently illuminated. Each signal field 2S, 2G comprises an outer housing 3 with a front housing door 4 in which a circular opening is provided for receiving a signal generator insert 5. The housing doors 4 can be hinged to the outer housing 3 via laterally arranged hinges.For better visibility of the light signals, 4 protruding chutes 6 are attached to the front doors to shield from extraneous light.

[0015] Each signaling device insert 5 comprises FIG 2 a pot-shaped inner housing 7 with a front opening 8, which projects into the outer housing 2. A light source with at least one light-emitting diode 9 is arranged in the inner housing 7. The at least one light-emitting diode 9 is arranged on a bottom wall 10 of the inner housing 5. Furthermore, a driver assembly 11 for supplying power to the at least one light-emitting diode 9 is arranged in the inner housing 7 and is mounted on one of the inclined side walls 12 of the inner housing 5. The bottom wall 10 and / or side walls 12 of the inner housing 7 are at least partially lined on the inside by a cooling plate 13. The front opening 8 of the inner housing 7 is sealed by an optical attachment 14, which influences the light emitted by the light source. The optical attachment 14 has an internal Fresnel lens 15 and an external red or green diffuser 16.The edges of the front opening 8 of the inner housing 7, the Fresnel lens 15, and the diffuser 16 engage in a profile seal (not shown) that runs along the opening in the outer housing. Axial air ducts 17 are incorporated into the circumference of the Fresnel lens 15, allowing heated air to flow from an interior space enclosed by the inner housing 7 and the Fresnel lens 15 into a space enclosed by the Fresnel lens 15 and the diffuser 16. The pre-assembled signal generator insert 5 can be used by the manufacturer for a variety of different signal generators 1.

[0016] The signal head insert 5 is now used as the upper signal field 2S of a signal head 1 for pedestrians according to FIG 3provided with a cover 18 placed externally on the diffuser 16. The cover 18 is constructed in two components and has a transparent protective screen 19 with a fastening ring 20 and an insert 21 resting on the inside of the protective screen 19 and forming the symbol mask.

[0017] The protective screen 19 serves to protect the symbol mask 21 from external influences, such as weather or dirt. In the retrofitted state, the fastening ring 20 engages around the outer edge of the lens 16 and is secured there by an easily detachable connection, such as a clamp fit or detent springs. The insert 21 can be designed as an injection-molded part. Alternatively, the insert 21 can also be designed as a plastic shell from which the symbol S is machined by milling or laser treatment. Likewise, the insert 21 can be designed as a transparent film printed with black ink, leaving the symbol S to be displayed free. In each alternative, the insert 21 forming the symbol mask can be added, replaced, or rotated without having to open the inner housing 7. It is sufficient to remove the protective screen 16 from the cover 14 to access the insert.

Claims

1. Signal generator (1) for emitting a light signal for road traffic, comprising - a pot-shaped inner housing (7) with a front opening (8), in which inner housing a light source is arranged, - an optical attachment (14) covering the front opening (8) for influencing the light emitted by the light source, which comprises an internal Fresnel lens (15) and an external diffusing lens (16), and - a symbol mask (21), which partially covers the emitted light, for representing a light sign with a symbol (S, G), - wherein the inner housing (7) with the light source and the optical attachment (14) form a pre-assembled signal generator insert (5), in which the optical attachment (14) seals the front opening (8), characterized - in that a cover (18) comprising the symbol mask (21) is placed on the diffusing lens (16) from the outside, - wherein the cover (18) comprises a transparent protective plate (19) with a fastening ring (20) and an insert part which lies against the protective plate (19) and which forms the symbol mask (21), and - wherein the fastening ring (20) comprises an outer edge of the diffusing lens (16) in the retrofitted state and is fixed here by an easily releasable connection, such as a clamping seat or locking springs.

2. Signal generator (1) according to Claim 1, - wherein the insert part (21) is formed as an injection-moulded part.

3. Signal generator (1) according to Claim 1, - wherein the insert part (21) is formed as a plastic shell from which the symbol (S, G) is produced by milling or by laser treatment.

4. Signal generator (1) according to Claim 1, - wherein the insert part (21) is formed as a transparent film, which is printed with black ink while leaving the symbol to be represented (S, G) free.

5. Signal generator according to any of the preceding claims, wherein axial air channels (17) are incorporated at the circumference of the Fresnel lens (15), so that heated air from an interior enclosed by the inner housing (7) and the Fresnel lens (15) can enter an intermediate space enclosed by the Fresnel lens (15) and the diffusing lens (16).