Noctilucent Reflective Helmet

Abstract

A helmet used for securing traffic safety for the pedestrians at night which is possessed of a noctilucent reflector affixed onto the outer surface thereof consisting of a reflective layer formed by mixing a highly reflective powdered metal and transparent granules, which make the helmet extremely easily recognizable from all the directions in the dark.

Parent Case Text

This application is a continuation of application Ser. No. 727,231 filed May 7, 1968, now abandoned.

Description

The present invention relates, generally speaking, to a helmet and a method of producing same, and, more particularly, to a helmet used for the purpose of securing traffic safety for the pedestrians at night by virtue of providing the helmet over its entire surface with a kind of reflector.

Conventional helmets publicly known presently as serving for the purpose of maintaining the safety of night pedestrians are made up by pasting a so-called reflector, that is usually a strip of noctilucent texture, onto the middle part of the external surface of the helmet proper in the direction before and behind with a suitable, publicly known adhesive as securely as if incorporated with the helmet. Referring to the said noctilucent texture, it is specially manufactured by Kyoto Orimono (Textile) Co. Ltd. seated at Sakyo-ku, Kyoto City, Japan, and its structure is such that the texture face is coated with a special resin so as to constitute thereover a reflective layer to which very fine granular lenses ar made to adhere uniformly and in in parallel rows.

As regards, however, the helmets having such a reflector as aforementioned, because of the fact that the reflector is provided only on the middle part of the helmet proper, it can hardly be caught into view in the angle of vision other than a certain fixed direction only, they are far from serving the purpose of the maintenance of safety for night pedestrians, still as a problem awaiting solution. Accordingly, for the solution of the problem, the men in the art have attempted to paste the said reflector onto the entire surface of the helmet proper. Nevertheless, it has become explicit through copious experiments that affixing the reflector, that is, the said noctilucent texture, uniformly and evenly to the semi-spherical helmet is extremely difficult technically and, moreover, satisfactory helmets have as yet failed to be realized despite of a great deal of time and labour expended in the said affixation of the reflector.

Furthermore, in the aforementioned helmets, such a thing would occur often with the pasting of the reflector to the helmet proper that the adhesive or the like, as means for the adhesion of reflector, is apt to be applied to parts other than the portion to be applied so that the work of affixing might be considerably hampered.

The principal object of this invention is to provide a helmet so adapted as to exhibit at its maximum the effect of maintaining the traffic safety of night pedestrians by affixing a reflector whose reflection coefficient is extremely high onto the whole of the external surface of the helmet proper.

The other object of this invention is to provide a helmet so adapted as to have the reflector evenly and uniformly applied to the whole of the external surface of the helmet proper.

Another object of this invention is to provide a helmet so adapted that the work of applying the reflector to the entire surface of the helmet proper is very simple requiring no skill by any means.

Another object of this invention is to provide a helmet so adapted that the time and labour required for the work of applying the reflector to the entire surface of the helmet proper can be greatly reduced.

Still another object of the present invention is to provide a helmet so adapted, in affixing the reflector to the whole surface of the helmet proper, that the necessary material and cost can be saved and reduced by using no adhesive means.

For the purpose of achieving the foregoing varied objects of the invention, the present invention will be characterized by applying to the entire external surface of the helmet proper a reflector which is composed of transparent granules and a reflective layer formed by mixing an adhesive resin material with a highly reflective powdered metal.

The helmet of this invention has, moreover, proved as a result of experiments that because of the reflective layer and the transparent granules which constitute the reflector the light reflective coefficient is markedly promoted so that the helmet can be certainly recognized from a distance as far as 200 to 300 meters even at the time of dusk that is most difficult for identification or recognition.

It is believed firmly that other objects and advantages of the invention will become apparent and be fully understood from the following description taken in connection with the appended drawings in which:

FIG. 1 is a vertically cross-sectional view schematically showing the helmet according to this invention (wherein the binding straps are shown in two-dot chain lines); and

FIG. 2 is an enlarged cross-sectional view showing fragmentally the essential portion of the helmet.

Now, referring to FIG. 1 for describing the outline of the helmet made according to this invention, numeral 10 in the figure denotes the helmet proper which is shaped like an ordinary cap composed of a metallic material or a synthetic resin material or other similar material. As such a helmet as this is publicly known in itself, no detailed description will be made herein. The said helmet proper 10 is provided with common binding straps 11a, 11b which are securely attached incorporatedly thereto through their one end by known suitable means, their other end being free but affixed to binding metals 11c, 11d respectively; these straps 11a, 11b as well as binding metals 11c, 11d are very well known therefore being shown just schematically in the appended drawings.

The said helmet proper 10 is also provided on its entire external surface with a reflector 14 consisting of innumerable transparent granules 13 and a reflective layer 12 which is to be fully described later. The said reflective layer 12 is composed of by mixing fine-powdered aluminium or a powdered reflective metal 12a and 12b in the form of crystals of basic lead carbonate with an adhesive resin material composed mainly of a polymer of acrylic acid ester such as, for example, the polymer of ethyl acrylate and butyl acrylate. In this embodiment of the invention, acrylic acid esters are adopted for use as the said adhesive resin material but, in the present invention, the adoption of the resin material is not limited to the said acrylic acid esters alone. For example, suitable resin materials such as vinylic resins like styrol resin or synthetic rubber or the like may be as well employed alike.

Now, the process of affixing the reflector 14 evenly and uniformly onto the entire external surface of the helmet proper 10 will be illustrated in reference to FIG. 2. In the first place, a kneaded material to be used as the reflective layer is manufactured by mixing 24 percent of the said acrylic acid ester polymer, for example, and 4 percent of fine-powdered aluminium or other similar, highly reflective, powdered metal, and regulating the resultant mixture with 72 percent of a ketonic solvent such as acetone, xyrol or the like so as to have the solid content of the acrylic acid ester polymer and the mineral content maintained at 24 percent and 4 percent respectively. In addition, as means for regulating the said kneaded material, a publicly known kneader(not shown) or the like may be employed.

The kneaded material thus obtained will thence be coated over the helmet proper 10; for this occasion, there should first be provided a hopper-like pouring member(not shown) to be located in the central part of the external surface of the said helmet proper 10. Now, the said kneaded material is slowly put into the said pouring member in amounts of 20 to 30 grams as per one helmet; the kneaded material thus poured down will thereupon be dropped first onto the center of the external surface of the helmet proper 10, and the kneaded material thus dropped will flow evenly over and along the curved surface of the helmet proper 10 by virtue of its own fluidity and 3,000 to 5,000 C.P. viscosity characteristic, so that a coated, reflective layer 12 having an equal thickness all over may be obtained.

Further, as means for the said coating, spray coating or brush coating or the like may also be employed, but it has been found as a result of experiments that the formation of a uniform smooth reflective layer is very difficult to be realized due to the high viscosity of the said kneaded material with these conventional means.

When the reflective layer 12 is formed any way over the entire external surface of the helmet proper 10, it is left at rest for 5 to 7 minutes at the temperature of about 25.degree.C, whereupon the transparent granules 13 are dispersed through a 200-mesh glass dispersing sieve(not shown) from the top of the said reflective layer 12, preferably from the position as high as 30 cm. At this occasion, the said helmet proper 10 is brought to be borne by a rotary support member (not shown) which has been connected with a drive mechanism such as motor through a gear; the said rotary support member is rotated by transmitting the driving force of the said drive mechanism thereto through the said gear upon operating the said drive mechanism, which is very well known therefor being not shown in the drawings. The rotation velocity of the said rotary support member will be 10 rpm in practice while the rotation number of the helmet proper 10 from the start to the termination of dispersion of the transparent granules will be more or less five times. Further, the refractive index of the said transparent granules 13 will be in the range of 1.7 to 2.1, especially preferably 1.9, and the diameter of the said transparent granules 13 will be in the range of 40 to 80 microns, especially preferably 50 microns.

When the said transparent granules 13 have been thus dispersed, they are dried at the temperature of 50.degree.C for 10 minutes, followed by effecting further thereon a heat treatment for 3 minutes at 120.degree.C, so that a reflector can be satisfactorily applied onto the whole of the external surface of the helmet proper 10.

Moreover, another advantage obtainable from the treatment as aforementioned will be in that the powdered reflective metal adheres to and along the periphery of the portion where the transparent granules 13 are imbedded in the reflective layer 12, and that 60 percent approximately of the entire surface of the transparent granules dispersed is imbedded within the reflective layer 12. Having such an interrelation with each other, the reflector composed of the reflective layer and the transparent granules is provided as affixed onto the entire external surface of the helmet proper, and thus the light rays from every direction of the helmet may be caught and the return reflection may be achieved to be effectuated. Another further advantage will be in that the surface hardness of the helmet proper can be outstandingly enhanced so that damages on the external surface thereof caused by frictions or impacts may be prevented.

Claims

I claim:

1. A method of forming a helmet made of metallic or synthetic resin material having a reflector affixed to the entire external surface thereof, said reflector being composed of a reflective layer having transparent granules partially embedded therein, said method comprising the steps of providing an adhesive resin composition comprising an adhesive resin, a reflective powder, and a solvent for the resin, said composition having a viscosity of about 3,000 - 5,000 centipoises; pouring said composition onto the center of the external surface of said helmet in a quantity of about 20 - 30 grams per helmet from a pouring member positioned above the central portion of the external surface of said helmet so that said composition will flow evenly over said surface to form a reflective layer of substantially uniform thickness thereover; maintaining said reflective layer at a temperature of about 25.degree.C for about 5 - 7 minutes; dispersing transparent granules onto said reflective layer through a 200 mesh glass dispersing sieve from a position as high as 30 cm above said layer while rotating said helmet on the order of about 5 times with a rotational velocity of about 10 rpm so that said granules are dispersed evenly onto the entire curved surface of said reflective layer; drying said layer with the granules thereon at a temperature of about 50.degree.C for about 10 minutes; and then heating said layer and granules for about 3 minutes at about 120.degree.C.

2. A helmet made of metallic or synthetic resin material having a reflector affixed to the entire external surface thereof, said reflector being composed of a reflective layer having transparent granules partially embedded therein, said reflective layer being of substantially uniform thickness over the entire external curved surface of said helmet and being the dried residue of an adhesive resin composition comprising about 24 percent of an acrylic acid ester polymer, about 4 percent of reflective aluminum powder, and about 72 percent of a ketonic solvent, said composition having a viscosity of about 3,000 - 5,000 centipoises at the time it is uniformly spread over said surface; and said transparent granules having a refractive index of about 1.7 - 2.1 and diameters of about 40 - 80 microns, said granules being uniformly dispersed about said reflective layer, approximately 60 percent of the entire surface of said transparent granules being embedded within said reflective layer.