GB2305452A

GB2305452A - Reflex reflector

Info

Publication number: GB2305452A
Application number: GB9619567A
Authority: GB
Inventors: Matti Taehkaepaeae
Original assignee: Talmu Oy AB
Current assignee: Hella Lighting Finland Oy
Priority date: 1995-09-21
Filing date: 1996-09-19
Publication date: 1997-04-09
Anticipated expiration: 2016-09-19
Also published as: FI98161B; DE19638610A1; IT1285175B1; GB9619567D0; FI954467A0; GB2305452B; ITMI961943A1; GB2305452A8; FI98161C; FR2739069A1

Description

2305452 1 Reflector, preferably two-sided reflector, and method for

manufacturing it The invention relates to a reflector comprising at least one prism reflector element made of a plastic material with good reflection properties and connected to a sealing means which surrounds the circumference of the prism reflector element and hermetically seals the prism surface from the environment. The invention also relates to a method according to the preamble of appended claim 12 for manufacturing a reflector of the invention.

It is generally known to use reflectors in various ways in the dark to reflect light so as to call attention to the person carrying the reflector. Reflectors are used, for example, in bicycles. In addition, reflectors can be'used to mark the limits of an area or in various equipment, such as automatic gates and doors.

Regardless of where the reflector is used, the reflecting surface, i.e. the prism surface, must be clean in order for the reflector to function efficiently. The reflecting prism surface of a prism reflector is protected against the environment to prevent dirt from accumulating or moisture from condensing on it. The protection against the environment can be implemented in many different ways by the use of various sealing means. One way is to glue or weld the prism reflector element to a back plate, which - in addition to being a sealing means - typically serves as a means for fixing the reflector; alternatively, it is possible to glue an aluminium film onto the reflector element. In the case of a two-sided reflector, such as a reflector to be fixed to the spokes of a bicycle, the reflector elements are placed against each other, and 2 glued or welded together, whereby the glue or the welded joint serves as the sealing means.

Finnish Patent Application No. 834 821 discloses a reflector to be fixed to the spokes of a bicycle. This known reflector comprises a frame serving as a means for fixing the reflector to the spokes. The reflecting elements of the reflector are made of the same plastic material as the fixing frame. Since the reflecting elements must, in practice, be made of a highly reflective plastic material, which is typically rather or extremely brittle, the fixing frame cannot serve as a reliable and secure means for fixing the reflector to the spokes of a bicycle.

Finnish Patent No. 35 793 discloses a one-sided reflector comprising a reflector element and a back plate attached to it. Since the back plate is of the same brittle material as the reflector element, it is not suited for being mechanically stressed.

German Offenlegungsschrift No. 24 34 907 discloses sealing the surface of the reflecting element in a reflector with foamed plastic to protect it against dirt and moisture. The fixing means of the reflector comprise holes which are provided in the brittle reflecting element and whose walls should not be subjected to any greater stress.

In summary, the known reflectors are either not suited for fixing particularly if they are subjected to mechanical stress during the fixing or when in position - or they are slow and expensive to manufacture.

The object of the present invention is to obviate the above-mentioned defects. To achieve this, the reflector of the invention is characterized in that said sealing means is a moulded product attached to said at least one prism reflector element without any glue 3 or ultrasonic welding, said moulded product being made of a tougher plastic material than the prism reflector element. According to a particularly preferred embodiment comprising a two-sided reflector, the moulded product surrounds the circumference of the prism reflector elements, covering the outer circumference of the mating surfaces of the prism reflector elements. other preferred embodiments of the reflector are disclosed in appended claims 2, 3 and 5 to 11. The method of the invention is characterized in that the sealing means is moulded from a tougher plastic material than the prism reflector element around the prism reflector element. A preferred embodiment of the method of the invention is disclosed in appended claim 13.

The most significant advantages of the reflector of the invention are that it can be manufactured rapidly and completely automatically, and it can be fixed to places in which it is subjected to great mechanical stresses. The method of the invention allows the reflector of the invention to be manufactured extremely rapidly without any glueing or ultrasonic welding.

In the following, the invention will be described in greater detail by means of three embodiments with reference to the accompanying drawings, in which Figure 1 is a cross-sectional side view of a two-sided reflector of a known type, Figure 2 is a cross-sectional side view of a one-sided reflector of a known type, Figure 3 is a cross-sectional view of a twosided reflector of the invention, taken along line III III in Figure 4, Figure 4 is a front view of the reflector of Figure 3, 4 Figure 5 is a front view of a bicycle spoke reflector of the invention, Figure 6 is a side view of the reflector of Figure 5, and Figure 7 shows a one-sided reflector of the invention.

The known reflector shown in Figure 1 comprises two prism reflector elements la, lb, connected to each other by a joint 2 made by ultrasonic welding. On account of the welded joint 2, the reflecting surfaces of the prism reflector elements la, lb, i.e. the prism surfaces 3a, 3b, are hermetically sealed from the environment. Instead of a welded joint 2, it is also known to use a glued joint.

The known one-sided reflector shown in Figure 2 comprises a prism reflector element 10, connected to an aluminium back plate 40 by a glued joint 20. The back plate 40 is provided with through holes 50 for fixing the reflector. The prism surface 30 is hermetically sealed from the environment.

Figure 3 shows a prism reflector according to the invention, comprising two prism reflector elements la' and lb'. The prism reflector elements la', lb' are of PMMA (polymethyl methacrylate), SAN (styreneacrylonitrile) or PS (polystyrene). It is also possible to use some other highly reflective plastic. An annular moulded product 6' is mounted on the circumference of the prism reflector elements la', lb' so that it covers the outer circumference 71 of the mating surfaces of said prism reflector elements. The moulded product 6', which is preferably of PA (polyamide) or some other plastic which is tougher than PMMA, SAN or PS, is attached to the circumference of the prism reflector elements la 1, lb 1 by a shrink fit so that it presses the prism reflector elements against each other. The reflecting surfaces 3a', 3b' are thus hermetically sealed from the environment. Alternatively, the joint between the moulded product 6' and the prism reflector elements la', lb' may comprise plastic material of both the prism reflector elements and the moulded product, melted into each other. Such joints can be provided during the manufacture of the moulded product 6'.

The moulded product 6' is provided with holes 5' for fixing the reflector.

Figure 4 is a front view of the reflector of Figure 3.

Figures 5 and 6 illustrate a two-sided reflector for bicycle spokes. The circumference of the prism reflector elements la'', lb'' is surrounded by a moulded product 6Y1. which covers the outer circumference 7'' of the mating surfaces of the prism reflector elements. The prism reflector elements la'', lb I ' are made of the same plastic material as in the embodiment of Figure 3. The plastic material of the moulded product 6'' is the same as in the embodiment of Figure 3. During the moulding, the moulded product 6' is melted into, pressed against or shrunken around the prism reflector elements la', lb', depending on the plastic materials employed.

The moulded product 6' 1 comprises diametrically opposite flexible frame elements 8a'', 8b'' provided with grooves 9all, (not shown).

9b'' for receiving bicycle spokes The reflector of Figures 5 and 6 can be easily and reliably fixed to the spokes of a bicycle without the risk of the moulded product 6' ' breaking during the mounting or in use.

Figure 7 shows a one-sided reflector of the invention. The reflector comprises a prism reflector element 10 ' ' ', to which a moulded product 60' 1 1 is 6 attached. The moulded product 60' ' ' covers the outer circumference 70' 1 ' of the mating surfaces of the prism reflector element 10''' and the back plate 40111, sealing thus the prism surface 30 hermetically from the environment. The moulded product 60... is provided with holes 50'' ' for fixing the reflector. The prism reflector element 10 1 1 ' and the moulded product 60 ' 1 1 are of the same materials as in the embodiments of Figures 3 and 5. The back plate 401 1 1 may be of the same material as the moulded product 60 ' 1 '. On account of the moulded product 60', the mating surfaces 70111 do not have to be glued together or joined by ultrasonic welding.

The reflectors of the invention are manufactured by moulding the sealing means 6'; 6''; 60... around the prism ref lector elements la 1, lb 1; la 1 1, lb ' 1; 10 ' 1 1. The sealing means is preferably moulded with the same injection moulding machine as the prism reflector element(s) and in successive steps such that the prism reflector elements are moulded at first, and in the next step the sealing means is moulded around the prism reflector element (s). The manufacture is effected automatically in one process without any additional sealing or connecting steps. It is also possible to mould the prism reflector elements in a first injection moulding machine, and to remove the prism reflector elements from the first machine and transport them to a second moulding machine, where the sealing means is attached to the prism reflector elements.

In the above, the invention is described merely by means of three embodiments. It should be noted that the details of the invention can be modified in many ways within the scope of the appended claims: e.g. the shape of the reflector and structure of the fixing means can be different from what is illustrated in the drawings.

Claims

1. A reflector comprising at least one prism reflector element made of a plastic material with good reflection properties and connected to a sealing means which surrounds the circumference of the prism reflector element and hermetically seals the prism surface from the environment, wherein the sealing means is a moulded product attached to the at least one prism reflector element without any glue or ultrasonic welding, the moulded product being made of a tougher plastic material than the prism reflector element.

2. A reflector according to claim 1, wherein the moulded product is attached to the prism reflector element(s) mechanically by a shrink fit.

3. A reflector according to claim 1, wherein the moulded product is melted into the prism reflector element(s).

4. A two-sided reflector according to claim 1, 2 or 3, comprising two prism reflector elements positioned against each other, wherein the moulded product surrounds the circumference of the prism reflector elements, covering the outer circumference of the mating surfaces of the prism reflector elements.

5. A reflector according to claim 4, wherein the moulded product is arranged to press the prism reflector elements against each other.

-g-

6. A reflector according to any one of the preceding claims for fixing to the spokes of a bicycle, wherein the moulded product comprises diametrically opposite flexible frame elements each provided with a groove for receiving a spoke.

7. A reflector according to any one of the preceding claims, wherein the prism reflector element(s) is/are made of PMMA.

8. A reflector according to any one of claims 1 to 6, wherein the prism reflector element(s) is/are made of SAN.

9. A reflector according to any one of the preceding claims, wherein the moulded product is made of PA.

10. A method for manufacturing a reflector comprising at least one prism reflector element made of a plastic material with good reflection properties and connected to a sealing means which surrounds the circumference of the prism reflector element and hermetically seals the prism surface from the environment, the method comprising moulding the prism reflector element from plastic, and attaching the sealing means to the moulded prism reflector element, the sealing means being moulded from a tougher plastic material than the prism reflector element around the prism reflector element.

11. A method according to claim 10 for manufacturing a two-sided reflector, said method comprising moulding the prism reflector elements in an injection moulding machine, whereafter the prism reflector elements are placed against each other and connected to each other, and the moulded product is moulded around the outer circumference of the mating surfaces of the prism reflector elements, placed against each other, as a sealing frame by the same injection moulding machine as the prism reflector elements.

12. A reflector substantially as described herein, with reference to Figures 3 to 7 of the accompanying drawings.

13. A method substantially as described herein, with reference to Figures 3 to 7 of the accompanying drawings.