US2518846A - Venetian blind slat and method of making same - Google Patents

Description

Aug. 15, 1950 R. H. WRIGHT v vsm-z'mn BLIND swr AND METHOD OF MAKING SAME File d Feb. 26, 1945 H M F .4; 155;

Flt-3L5- INVENTOR. BY f /f M Patented Aug. 15, 1950 omr STA-IE AT {EN'II GYFFFECE BIJIN'DfSLA'ItANDrMETHQD OE MiQK ING SAME.-

v Ricli'al'rPH; Wi'igliti Cleveland Heights, Ohio i Appjicatiomflebruary 26, 1945;,Serialz-No.-579;813

' 42*CIaiins; (o1. 1s0-405- My iIIVBHtiOIbaQPGItQziHS itor thelartof Venetian blinds.

In recentyears VenetiamblimLslatahav-e been madefrom metalin lieu of theeWOOd slat com:- monly used previously; andistillused ion many of such blinds Qwingeto the-scarcity OfiIWOQddl-Ildttl present war conditions; themetahslats forrveneitian-v blinds have. found wide. acceptance: inithe trade.

When. the metal typez'rofi Venetian blind; slat is employed; acommon practicetoday iatoformsthis slat of transverse.- COHCflVOZ-GOIIVBXmGIOSS section asthe slat .materialaisssupplied from azmllof thin sheet-steel.ordinarilyusedi. The forming of; the slat. in the above manner is; designedito.- give. it sufiicient. rigidity tor remain; straighhi when the slats areinstalled' initheevenetiamblind.unit yet permitting a certain-amount of latemlaflexingiof the slat-as; when it. may-a be. caught ati'its end or ends in: a curtainxon other. obstacles the? flexing being of; a. resilient nature so thatv-th'erslat will spring, back to its original;stnaightlformi after: so

flexed.

In. the: makingof' Venetian": blinds from thin sheet steel material, itiis: found: necessany toiuse pre-treated steel: sheet. metzailtinz orders that the ultimate. slat. produced may not'i-be formed with Wavy edges. Onewcfithe. obj ects: of my; invention is :to ado-away withxthe necessityroft usingitheepreztreated-.steel referred to and; indeed; .I:iiave? found that by therarticleof manufacture andimethodzof my present invention I;am nabledztoeemploy:soft metal such as aluminum; inrtheproduetiomofzthe VZenetian blind: slate as will bemore: fiilly later on pointed-out.

It. has i been: proposed; heretofore: make: slats of the 1 nature referred to from; sheetcmetal: and render the- 82311161? stiff; by, forming:- edgei flanges. Under: thBSGfOOIlditibHS,-.1'IUW8VEIZ the slats:

duced-arersosstiff. that. they willtnoii-ifieie for: the

purposes previously. mentioned; and; should; the end portions strike; any obstaclezinrtheamisingror loweringof the blind;.the':entire slatzisfaffectemby a permanent bendingt'ofi thezsaidtendionenmporttions.

In; the: carrying; out-f mm inventiom I: employ the. method of .manufacture of the blind slat largely similar to; thespresent methmhimsolfm as the materialisuch:asaa1uminumz,isssuppliezizinmoils of thewproper" width of material fbrfmalein'g ttheslat and is formed: into a curved: or coneavoz-cons vex crosssection'transverselwthereofi thamateria'l beingjcut off inproperJength-ab'y aicuttingemechianism associatedrwith. thei forming I machine.- to

make thearequinedilenethwfi stat. Imttiezfurttier.

carrying. out. of my inventionl have found that when Il'form the slatmateria-li intoitslcurvedcross seetion-referred...to. above .the edge portions-of. the material wilLwave or. kink at intervals .and'therefore. will. obviously not. retain. thestraight; conformation fromend'toend'thatis .requiredforthe purposes of the slat use. I therefore have found that if. I apply, pressure to..the. longitudinal. centralportion of the sl'at materialafter the forming thereof into the curved.crossesectionrequired to provide. the. necessary, stiffness to maintaimthe slatstraight, and by. suchmressure producea .very slight and almost imperceptible reverse bend. of the material at th longitudinal center Ilamiene abled to. eliminate the wavingon kinking-of the edge portions of the. slat. material producedcby the action of the forming. machinethat creates the-curved crosssectionmentioned. Themeverse bend. to. whichl refer. above, as. to-thedirection otireversal; meansthatthe bend is upon ancarc in a.direction;reverse:to thearc of. curvatureof the. concave. side of. the. s1at,,.as-,-produced-.bythe forming machine andeffected by the. passing,- of the slat material between a convex. peripheral roller and a-concave peripheral roller,

Ilhave found zth'at b theuse of.- mymethodl produce. a novel. article of; manufacture: in the form of. a Venetian. slat which is justas-efiective and: advantageouslyused asthose which are; to.-

day made, fromthinisheet steel. pretreated, my slat having. the requisite longitudinal. stiffness, and yet -being adapteditobe flexediinaaresilient manner, so thatif it-is-slightly flexed: or. bent at its-ends, it will,,by.- reason. of: theinherentqresiliiency, return to;its straight condition, ,muchwafter the. mannen of the action-of the steel slat-men.- tioned.. at theoutstart hereof 2 Moreover, have found thatI can'-produce.-.my,-blind-slat from relattivelyi soft materialsuch asaluminurm. armateria'l far. more available at= the present time; than steel.

A special advantage ofmymethod and article ofemanfacture lies.- in; the. fact-'. that the reverse center bend of my slatconstruction is scarcely visible to the; eye, so.- 171131139111 no way does: the method of treatment of my slatifon the purposes referred to detract from: the: appearance: on the slatwhen it:.is installed initheeblind-unitifor actual use;

A; 1111 understanding) of my; invention will: be

had; upon reference the-followinge detail: description and" to the accompanyingdrawing; the

' latter: illustratinga. suitable": type of. forming machine? useful for the'zpractice'of the=method O'fi my invention; and. also showing the form: of th mtterial iromiwhicl'nmyislatsaareeconstructed,

as supplied originally, as preliminarily formed to give the slat material a curved transverse cross section, and as secondarily formed to provide the slight longitudinal central reverse bend to which I have previously referred.

Referring to my drawings:

Figure l is a top plan view of a preferred form of my machine for practicing my invention.

Figure 2 is a side elevation.

Figure 3 is a view looking endwise of the machine to bring out more clearly the arrangement of the final forming rolls or rollers.

Figure 4 is a view in cross section of the slat material as it is supplied to the machine hereinafter described. Figure 5 is a similar view to Figure 4 but showing the material after the main forming operation of producing the concavo-convex transverse 1 Figure 7 is a view similar to Figure 3 but show- .L ing a slightly modified construction of the invention.

Figure 8 is a sectional view of avmodified form of the bending rollers.

'Referring to my drawings, I indicate at the outstart thereof that the machine which is now described is only one of many types of machines that may be utilized for the practice of my invention. 7

In its preferred form the machine as illustrated in the drawings comprises a pair of feed rollers I which, as shown, are mounted in a bracket A disposed upon the base C, between which rollers the slat material cut to the proper Width, usually approximately 2 is fed, said material being designated B. The material B will be supplied from a suitable roll of such material not illustrated, and when fed between the rollers I will be guided somewhat by an upper horizontal roller l2 that engages the upper forming rollers 2 and 9. The roller 9 is a convex 'on its surface and the roller 2 is concave.

The rollers 2 and 9 give to the strip of slat material B preliminary slight curved cross section, and the material then passes from the rollers 2 and 9 to the main or primary forming rollers 3 and I0 which are somewhat larger than the rollers 2 and 9 and which give to the material B its ultimate or final conc'avo-convex'curved cross section. From the rollers 3 and it the material 3 passes by guide roller 4 which is practically in the form of a ball, the peripheral contour'of which corresponds with the contour of the general curved cross section of the material B. Thereafter, the materialB passes the guide member d'between guide rollers 5 and H which are contoured at their peripheries so that the roller II is convex on its surface and the roller 5 is concave, the curvature of these portions likewise corresponding to the now fixed general curved cross section of the material B. As the strip of material B is fed on from the rollers H and 5 in the machine, it is received between the final forming rollers l and 8. Generally speaking the roller 8 has its periphery or rolling surface straight, whereas the roller 1 is a relatively narrow rimmed roller or peripheried roller with its v such material.

The roller 1 must be subjected to the action of pressure against the central longitudinal portion of the material B in order to effectuate the function which I have described in reference thereto, and this pressure is applied to the roller 7 by means of an adjustable screw mounted in a vertical standard l4 and acting by engagement with a coiled spring |6,.to press or exert a force against the carrier member 6 in which the axis shaft of the roller is mounted. The screw l3 provides for adjustment to obtain the desired pressure on the carrier 6 and the roller 1, such that the periphery of 'the roller l by bearing against the central longitudinal portion of the material will produce a very slight bend in a direction of curvature opposite to the arc of curvature of the body of the material B by which the curved transverse cross section of the latter is produced. The standard l4 may be carried on asu'itable base plate It onwhich the rollers 8' and 1 may be suitably supported upon their axis 'shaftsL 'Ihe obje'ct especially in using the screw member I3 is to'adjustthe same so that only the very slightest pressure will be produced on soft metal slat strip material B, just enough pressure to give the central longitudinal bend the required'arc.

' The arrangement of the roller 7 in operating upon'the material B is well shown in Figures 2 and 3, and in respect to Figure 3 I have shown in Figure 7 asimilarview illustrating, however, the omission of the spring l6 intermediate the screw 13 and'the roll carrier 6. While the construction of'Figure 3 is well adapted for employment in conjunctionwith the material B of relatively soft metal such asaluminum, under some conditions where harder metal is employed, it is desirable to have the screwll3 act'directly upon the carrier 6 for producing'the desired pressure to form the harder metal with the longitudinal central reverse bend, as I term it in this specification.

In Figure'the condition of the material B as it iS'fBdItO therolls l of my machine is illustrated. In Figure 5 the illustration of the material is in the form which is produced by the final main forming -'rollers'3 and I0, and in Figure 6 the material 3' is illustrated in its condition of actual use to be cut upinto the blind slats, Figure 6 showing the main transverse concave-convex cross sectional form of the strip of material as well as the manner in which the central longitudinal portion is bent to produce the reverse bend feature to which I have heretofore referred.

The small longitudinal bend B of the material B is formed subsequently to the curved cross section of the body of the said material, see Figure 6.

Also, it is noted that the periphery of the roller l, at its point of bending contact with the strip B, engages a little beyond-to the right of, as seen in Figure 1the point of peripheral contact of the roller 8, the right end of the strip being under tension by. the feed rolls carrying the strip B onward-and rightward from the rollers l' and 8. This enables the roller 1 toeffectthe proper formand 8a as seen in Figure 8. The roller la has an external bending rib 1b surrounding same, and the roller 811 has a matching annular groove 8b so that as the strip B passes therebetween, the bend B will be formed. The external portions of the rollers la and 8a are contoured lik the rollers 5 and H and the axes of the rollers 1a and 8a will be transversely alined instead of disalined, as are those of the rollers 1 and 8.

By the use of my invention, I avoid the necessity of employing the pre-treated strip steel first referred to herein, steel that is longitudinally stretched between the edges thereof along a central line, and which is required to be subsequently stretched at its edges.

The rollers 1a and 8a may act on the strip B after it has been formed into its curved transverse cross section or they may be the forming rollers actually operating to impart such cross section to the strip, in which event they would be substituted for the rollers 3 and 10, respectively, of mymachine.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

-1. The method of producing thin sheet metal Venetian blind slats, which includes the steps of bending by pressure a long strip of thin flexible resilient metal into a transverse concavo-convex uniform cross-section from edge to edge effecting stretching of the side edge portions of the strip and waving at said portions, and applying" pressure to the strip of metal along a line centrally and longitudinally thereof to produce slight bending of the metal on an are opposite to that of the concavo-convex cross section for eliminating waving of the edges of the strip incistrip along its side edge portions, and then subjecting the. strip so formed to pressure along a central longitudinal line of the strip to deform the material. thereof on a, slight curve cross-sectionally thereof and in a, direction reverse to the general concavo-convex curvature before mentioned to stretch the central longitudinal portion of the strip to take out waves at its edges produced by the said concavo-convex bending operation and to straighten the edges while maintaining the resiliency of the strip angularly of its longitudinal axis.

3. The method of making Venetian blind slats which includes the steps of subjecting a long strip of thin flexible and resilient sheet metal of single thickness from longitudinal edge to opposite longitudinal edge. to pressure to bow the same to concavo-convex form in cross section, and pressure rebending the metal of the slat along a narrow longitudinally central area, the entire length of the slat but in a direction opposite to the arc of curvature produced by said bowing to eliminate waving of the slat at its longitudinal edges.

4. As a new article of manufacture, a Venetian blind slat comprising a slat length strip of thin flexible and resilient sheet metal of single thickness, the body of which is bowed transversely of its longitudinal axis into concavo-convex cross section with all portions of said cross section from edge to edge on a single relatively large arc of curvature except the central longitudinal area of the slat from end to end, the latter having a narrow shallow bend therein of a depth approximating that of the thickness of the metal and the cross sectional arc of which bend extends in a direction opposite that of the large arc of curvature of the above mentioned cross sectional formation of the body of the slat.

RICHARD H. WRIGHT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,367,240 Cornell Feb. 1, 1921 1,773,459 Kellogg Aug. 19, 1930 1,949,653 Moore Mar. 6, 1934 2,073,174 Potter Mar. 9, 1937 2,209,355 Schmitz July 30, 1940 2,346,990 Oftedal et a1. Apr. 18, 1944

Images