US1950005A

US1950005A - Reflector and method of making the same

Info

Publication number: US1950005A
Application number: US492473A
Authority: US
Inventors: Richard W Luce
Original assignee: AMERICAN GASACCUMULATOR CO
Current assignee: AMERICAN GASACCUMULATOR Co
Priority date: 1930-10-31
Filing date: 1930-10-31
Publication date: 1934-03-06
Anticipated expiration: 1951-03-06

Description

March .6, 1934. R. w. LUCE REFLECTOR AND METHQD OF MAKING THE SAME Filed Oct. 31, 1930' Patented Mar. 6, 1934 REFLECTOR AND METHOD OF MAKING THE SAME Richard W. Luce, Mountainside, N. J., assignor to American Gasaccumulator Company,

Elizabeth, N. .li., a corporation of New Jersey Application October 31, i930, Serial No. 492,478

lid Claims.

My invention relates to light reflectors constructed of sheet metal and it has for its general object to provide a reflector of improved novel construction and also to provide a novel method which may be employed in the manufacture thereof.

Although the invention is illustrated and described in connection with and as embodied in a reflector of central triple type it is to be understood that the invention may be embodied in reflectors of other types.

In connection with the process of producing reflecting surfaces by pressure upon sheet metal reflectors, as illustrated and described in United States application for Letters Patent filed June 2, 1928, Serial No. 282,464, it has been found from experience that, due to variations in the thickness of sheet metal after the first drawing operation, it sometimes is diflicult to cause the metal to completely fill the space between the punch and the die. This is necessary in order to reproduce the polish of the punch over or upon the entire reflecting surface of the reflector. To accomplish this requires extremely high pressure which is detrimental to the punch and die members and requires a very heavy press to produce even a relatively small reflector. If the sheet metal of which the reflector is being formed is not caused to fill completely the space between the punch and the die irregular unpolished areas will or may be left within the areas which should be polished. The metal, when subjected to such high pressure will, as a rule, acquire internal stresses, which may cause the reflecting surfaces to become distorted when removed from the die. 0, In order to overcome the difflculties noted I provide a number of grooves or depressions in the contacting surface or surfaces of one or the other of the die members. If the contactin surface or surfaces of the die member on the side of the sheet opposite that which is to be highly polished is or are provided with grooves or depressions of other shape some of the metal of the relatively thick portions of the drawn sheet metal piece will, due to the compressive pressure of the dies, flow into the said grooves or other depressions and thereby allow a continuous or perfeet contact of all of the metal upon the side of said sheet, the surface of which is to be polished, with the polished surface of the die for producing said polished surface; except those portions directly opposite the grooves or depressions in the faces of the.flrst named die member.

The presence of grooves or depressions in the forming face or faces of the die member, as'above (Cl. 29li48.2)

described, permits the production of satisfactory reflectors from sheet metal with lower pressures and by the use of thinner sheets than otherwise would be necessary. Because of the presence of the grooves (or depressions of other form) it is not necessary to move by pressure any part of the metal through so great a distance as would or might be necessary if the grooves or other depressions were not present.

The presence of unpolished narrow portions extending across the reflecting surface or surfaces of the mirror caused by the presence of the grooves in the face or faces of the die member will, of course, reduce the reflecting area but this loss is more than compensated for by the reduction .of pressure required and the assurance of a more uniform product.

As already indicated, the invention is illus trated as embodied in a central triple reflector and the method of my invention will be described in connection with the manufacture of a reflector of that type.

While, for various reasons, I prefer to locate these grooves or depressions in the die opposite the polished surface of the reflector and my drawing shows such construction, yet it is, of course, practicable to locate these grooves or depremions in the opposite or front die member, in which case ribs or protrusions will appear on the polished surface and my invention is understood and intended to include also this construction and the method thereby involved.

In the case of a triple reflector such as illustrated, it is preferable that the grooves in the three forming faces of the female member of the dies extend in crosswise relation to each other as shown because. in that way the distances through which the material is to be displaced in the pressure formation of the reflector are reduced to a minimum. Furthermore, the pro- 5 each other it is to be understood that the said de-' pressions may be of other form and that they may be otherwise arranged in the -forming faces 0 the female die member.

In addition to the depressions in the forming faces of the female die member of the forming tools it is to be noted also that the said die member is so constructed and so cooperates with the opposing cooperating die member of the tools as to permit flow of metal into the apical portions of the angles between the adjoining faces of the fe-' male die member; and the latter also is so formed as to permit the formation of slightly projecting portions along the lines between the outer or front edges of the flat reflecting portions of the reflector and the cylindrical portion thereof which terminates at the outer or front end of the reflector. v

The general object of the invention is to provide a method by the employment of which the manufacture of reflectors of sheet metal may be more easily accomplished and by the employment of which the pressures required in the formation of reflectors '(in which the polishing surfaces are formed by pressure) may be substantially decreased.

A further object of my invention is to provide a reflector of sheet metal having strengthening ribs or beads upon the outer sides thereof which are formed during the pressure polishing operation.

Without undertaking to set forth more fully the general purposes and objects of the invention I shall proceed to a detailed description thereof and to facilitate such description shall make reference to the drawing accompanying this specification wherein:

Fig. l is a view in central vertical section of portions of die members in the relative positions occupied thereby after a forming operation, a reflector formed thereby being-shown in longitudinal section;

Fig. 2 is a top plan view of the female die member of the forming tools;

Fig. 3 is a horizontal transverse sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a view in front elevation of a reflector embodying my invention manufactured in accordance with the method invented by me;

Fig. 5 is a longitudinal sectional view of the reflector taken on the line 55 of Fig. 4; and

Fig. 6 is a view in central vertical section of the upper portion of the female die member.

In the drawing I have shown cooperating dies including a female die member comprising separable parts 1, 2 and 3 which are adapted to be assembled, as indicated, to form said die member. Each of the forming faces of the female die member is provided with grooves 4 and 5, the former extending in directions lengthwise of the die member and the latter in directions in right angular relation to the former. These grooves may vary in width and depth as may be desired to suit conditions which may be found to exist in any particular case.

The sides or faces of the cavity of the female die member form. with each other at their lines of intersection acute angles. The upper edge portions of the members 1,2 and 3 are cut away,

as is shown at 6, which results in the formation of grooves 6. The presence of these grooves causes or'may cause the formation of elongated beadlike or thickened circular portions at '7 upon the reflector which correspond to the lines of juncture between the outer or front edges of the polished reflecting faces 8 with the inner or .rear edge of the cylindrical portion 9 of the said reflector.

faces 8 of the reflector.

The reflector produced according to my method consists of sheet metal and in its formation it is pressed and shaped between the female member of the die structure and the male member or punch 10. The inner, forming end of the latter, in the construction as illustrated, comprises three highly polished faces corresponding to the The said male member or punch 10 is provided outwardly of said faces with a cylindrical portion 11 which, in cooperation with a cylindrical portion of the female die member; forms the outer or front cylindrical portion 9 of the reflector.

The corners of the member 10 are rounded, as indicated at 11', so that the said corners do not correspond in shape with the angles between the adjoining faces of the female die member. follows that spaces 11" are provided between the rounded corners of the punch 10 and the adjoining opposing corner portions of the female die member. The presence of these spaces permits a flow of metal to the corners between the adjoining sides of the reflector so that the metal at said corners in a completed reflector is or may be somewhat thicker than is that of the sides of the said reflector.

It will be observed that the female die member is provided at its rear apical portion with a recess. as indicated at 12, in which the rear ends of the grooves 4 terminate.

In the operation of forming the reflector by pressure a plate of suitable metal is employed and it is subjected to such pressing operations as may be necessary to reduce it to the final form required, such for example as is shown in Figs. 4 and 5 of the drawing. The dies shown in the drawing operate to perform the final press ing and shaping operation in the formation of the reflector. In the formation of the reflector by pressure it is apparent that the metal of the plate must be caused to flow under the pressure exerted by the cooperating members of the die structure and it also will be apparent that but for the presence of the grooves4 and 5 and the groove 6' it would be necessary to cause portions of the metal to flow through relatively great distances.

The presence of the said grooves or depressions of other shape or configuration, which may be provided in the forming'face of the female die member into which the displaced metal is extruded eliminates the necessity that the metal shall be moved or displaced through relatively great distances in order to permit or cause the forming surfaces of the male die member 10 of the die structure to contact with and polish every portion of the reflecting faces or reflecting face of the reflector except those portions which overly the grooves or other depressions provided in the face of the female die member of the structure so that the force with which the pressure must be applied may be substantially decreased. As previously indicated the grooves or depressions of other form may be located in the forming face or faces of the male instead of the female die member.

It may be noted that in order to insure satisfactory operatlon and results in the formation of a reflector from sheet metal by pressure it is necessary that the grooves or depressions of other form shall be of a depth and capacity such that they are not completely filled by the metal which is extruded or projected thereinto by the compressive pressure of the dies.

Upon reference to the drawing it will be noted that the outer sides of the reflector after the completion of the forming thereof by pressure are provided with bead-like projections, as indicated at 16 and 17, which extend in angular relation to each other,'and also similar projections, as indicated at 7. The presence of these bead-like projections or bulges serves to strengthen and render more rigid the reflector structure. It is thereby less likely to be distorted by handling when being installed or embodied in a reflector structure for use as a sign or signal.

As already suggested, the inside surfaces of the reflectors in opposed relation to the grooves or other depressions provided in the female die member are not polished by the pressure polishing operation. This is due, of course, to the fact that the metal of the plate directly overlying the grooves or depressions is not held against the forming surfaces or surface of the punch member with sufficient force to eflect the polishing thereof. But as stated previously the presence of small unpolished areas embodied within the area of the polished reflecting surface or surfaces of the reflector does not consti= tute practically a serious objection.

By the employment of the method of my invention I am enabled to produce pressure polished reflectors from sheets or plates of suitable metal by the employment of pressures substantially less than are necessary when other methods than that of my invention are employed. The ability to produce reflectors of sheet metal wherein the reflecting surfaces are produced by pressure by the use of a punch and die by the employment of substantially reduced pressures results in sub-: stantial economy in manufacture. cal advantages incident to my invention there= Tore will be apparent. But not only is the cost of manufacture decreased but the character oi the product is improved in that by the employ-= ment of a given pressure a better polish may be imparted to the light-reflecting areas of the reflector and also the rigidity of the completed structure and its capacity to resist forces tend ing to cause distortion are substantially increased.

Having thus described my invention what I claim and desire to secure by Letters Patent is: 1. The method of producing reflecting surfaces by pressure, which comprises the subjection of a section of metal plate to suficient pressure between male and female die members to produce a reflecting polish thereon and, by the pressure exerted, simultaneously extrude portions oi the metal into depressions provided for that purpose in one of the die members.

2. The method of producing a reflector, which comprises the subjection of a section of metal plate to sufllcient pressure between male and female die membersto produce a reflecting polish thereon and, by the pressure exerted, simultaneously 'extrude portions of the metal of the sheet to the exterior opposite the polished surface thereof into depressions in the working face of one of said die members.

3. The method of producing a light reflector, which comprises the subjection of a section of sheet metal to pressure to form the same into the shape desired and to polish by pressure predetermined areas of one side of the said sheet to render the same light-reflecting and simultaneously causing extrusion oiportions of the metal of the said sheet to the rear oi the latter to form projections in opposed relation to the portions of the surface of said plate intermediate the polished areas thereof.

The practi-=- 4. The method of producing a light reflector from sheet metal, which comprises the subjec and form the same and to impart a high polishto predetermined surface areas of one side thereof, leaving the portions of the surface upon said side intermediate the highly polished areas unpolished and simultaneously causing the production of projections upon the opposite side or" the said sheet in opposed relation to the said unpolished surface portions.

6. The method of producing a light reflector from a section of sheet metal of selected thickness, which consists in subjecting said section to pressure to form the same to the shape desired and to impart a high polish to selected surface areas of one side thereof to render the same light-reflecting, said areas being separated by narrow unpolished portions, simultaneously causing by the said pressure the extrusion of metal to the side of the said sheet opposite the unpci ished areas, and simultaneously producing ina joining relation to the front edges of the highly polished reflecting surfaces projections of the metal upon the side of said sheet opposite that upon which the reflecting surface areas are pro vided.

7. The method of producing a central triple reflector, which consists in the subjection of a r,

section of sheet metal to pressure to form the same to the shape desired and to simultaneously 7 produce upon the inner surface of the three sides of the formed sheet highly polished surface areas and simultaneously causing an extrusion of metal to the outer surfaces of said sides to thereby pro= vide, projections upon said outer surfaces in op= gular relation to each other, simultaneously izn &

parting by pressure to predetermined areas of the inner surfaces of said sides high polish for the reflection of light, leaving unpolished the portions of the surfaces of said sides intermediate the said polished areas, simultaneously caus- I 'ing extrusion of the metal of said plate to the exterior thereof to provide projections in opposed relation to the said unpolished portions, and simultaneously causing an outward extrusion of the metal at the apical portions of the angles between adjoining sides.

9. The method of producing a central triple reflector, which consists in subjecting a section of metal plate to pressure to form the e into shape with three sides in approximate right on relation to each other, simultaneously iin parting to predeteed areas 01 the inner surfaces of said sides highpolish for the reflection of light, leaving unpollshed the portions oi the surface of said sides intermediate the said pols ished areas, simultaneously causing an extrusion of the metal of said plate to the exterior thereof to provide projections in opposed relation to the said unpolished portions, simultaneously causing an outward extrusion of the metal at the apical portions of the angles between adjoining sides, and also simultaneously causing an extrusion of metal to the outer side of said plate along areas in adjoining relation to the front edges of the sides of the reflector. I

10. The method of producing alight reflector from a section of sheet metal, which comprises the shaping of said sheet by pressure and simultaneously imparting a high polish by pressure to predetermined areas less than the total area of the reflecting surface and leaving unpolished predetermined areas intermediate the said polished areas.

11. A sheet metalreflector having a plane, unbroken surface and provided with strengthening projections upon the opposite surface thereof, said projections consisting of extruded portions of the metal of said sheet of greater thickness than the reflecting portions and produced during the formation of said reflector.

12. A sheet metal reflector having a plane, unbroken surface and provided with strengthening bead-like projections'upon the opposite surface thereof, said bead-like projections consisting of extruded portions of the metal of said sheet produced during the formation of said reflector and of greater thickness than the reflecting portion of the reflector.

13. A reflector consisting of sheet metal presse into the shape desired with a plane, unbroken,

light-reflecting surface upon one side thereof and RICHARD w. LUCE.