US2792049A - Ripple remover - Google Patents

Description

y 4, 1957 I R. M. PEEBLES 2,792,049

RIFPLE REMOVER Filed July 21, 1952 3 Sheets-Sheet l INVENTOR. E0)" M. PEEBLEG @gbx.

ATTOENEY May 14, 1957 R. M. PEEBLES RIPPLE REIMOVER 3 Sheets-Sheet 2 Filed July 21, 1952 E &

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5 P0) M. PEEBLES ATTOENEY United States Patent RIPPLE REMOVER Roy M. Peebles, Atlanta, Ga.

Application July 21, 1952, Serial No. 299,998

6 Claims. (Cl. 153-54) This invention relates to a means and method of removing ripples from strips of sheet material and more particularly to a means and method of removing ripples from slit stock material commonly used in forming Venetian blind slats.

in manufacturing Venetian blind slats from rectangular sheets of steel or aluminum, the metal is first slit into long thin strips approximately two inches wide and these strips are rolled upon reels thereafter. The reels are next transported to an oven where the slat material is unreeled and passed between paint applying rollers, then through a baking oven and rewound upon a reel. The reel is next transported to a slat forming machine where the slat material is formed in its conventional curvilinear shape and cut in proper lengths, with apertures being formed adjacent the ends thereof to receive the customary supporting cords.

in order for the finished slat to be usable in a first grade Venetian blind, it is necessary that the edges of this slat be straight and parallel. Because of the stresses in the thin narrow Venetian blind stock resulting from the treatment of this stock prior to the time that it is received by the slat forming machine, many of the Venetian blind slats have edges which are rippled or wavy or uneven in length. If the finished slat has edges which are uneven in length, the slat is twisted longitudinally so that it is entirely unusable. Generally, it has been found that entire reels of the wavy or rippled Venetian blind stock must be rejected as scrap material, unless this material can be stretched or so treated that the ripples or waves are removed.

Many attempts have been made to utilize rippled Venetian blind stock, but none of the prior art methods have proven entirely satisfactory since no process, heretofore, has been more than about 50% effective in producing a satisfactory straight Venetian blind slat from rippled stock material. One method, very generally used in the art to remove ripples from Venetian blind slats, is to so arrange the rollers of a slat forming machine that a sway or slight longitudinal curve is placed in the slat, thus, in effect, making the edges of the concave slat slightly longer than the center. Slats formed in this manner are inferior; and, if incorporated with straight Venetian blind slats, the curved slat will be readily noticed.

Another method of removing ripples from Venetian blind slats is known in the art as center stretching and employs a complicated and expensive machine having a series of rollers through which the slat material is passed. In this center stretching method, an attempt is made to pull or longitudinally stretch the center of the slat material so that the center and the edges of this material are substantially the same length; however, a great deal of care must be exercised to effect the precise stretching desired. With too much stretching, the slat material readily parts or shears; and, even with the maximum amount of stretching, the center stretching method is only approximately 50% effective.

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Both methods mentioned above are time consuming and require the attention of a skilled operator who must make finite adjustments in the machinery in order to produce a slat which may or may not be usable. The industry has long searched for a convenient method of producing a straight finished slat from rippled stock material so that rejected reels of rippled slat material may be utilized to produce a straight slat having ripple-free edges.

Accordingly, it is an object of my invention to provide an improved means and method of producing a straight ripple-free Venetian blind slat from rippled stock material.

Another object of my invention is to provide a means and method of producing Venetian blind slats from rippled stock material which will provide substantially usable slats.

Another object of my invention is to provide a machine whioh will automatically remove ripples from strip material, which machine will operate in conjunction with a conventional slat forming machine.

Another object of my invention is to provide an inexpensive, durable and effective -ripple-removing machine, having few moving parts and which is capable of being operated by an inexperienced operator in conjunction with a slat forming machine.

Another object of my invention is to provide a process wherein the edges of strip metal material are bent beyond their elastic limits in. such a way as to realign the edges thereof.

Another object of my invention is to provide a machine for removing ripples from stock material in the manufacture of Venetian blind slats, which machine Will automatically detect the presence of ripples along the edges of the slat and thereafter automatically adjust itself to remove these ripples.

Other and further objects and advantages of my invention will become apparent from the following description when taken in conjunction with the accompanying drawings in which like characters of reference designate corresponding parts throughout the several views, and wherein:

Fig. l is a top plan view of a conventional slat forming machine, having my ripple removing machine incorporated therewith.

Fig. 1-A is a cross-sectional view of the conventional preforming rollers.

Fig. 1-B is a cross-sectional view of the conventional forming rollers.

Fig. 2 is a front view of a machine constructed in accordance with my invention.

Fig. 3 is .a bottom view of the machine illustrated in Fig. 2.

Fig. 4 is a view of a detail.

Fig. 5 is a top view of a detail illustrating an optional arrangement of the pulley driving the machine illustrated in Fig. 2.

Fig. 6 is a partially broken side View of the pulley illustrated in Fig. 5.

Fig. 7 is an electrical wiring diagram illustrating the automatic ripple detector device which may be incorporated with the machine illustrated in Fig. 1.

Fig. 8 is a cross-sectional view of the Venetian blind stock material before it enters my machine.

Fig. 9 is a cross-sectional view of the Venetian blind stock material after it has passed through the machine illustrated in Fig. 2.

Fig. 10 is a cross-sectional view of the Venetian blind stock material after it has passed through the forming rollers of the machine illustrated in Fig. 1.

Fig. 11 is a cross-sectional view of the Venetian blind stock material after it has passed through the machine illustrated in Fig. 4.

3 Fig. 12 is a cross-sectional view taken along line 12--12 in Fig. 1.

Fig. 13 is a cross-sectional view taken along line 13-13 in Fig. 1.

Fig. 14 is a crosssectio1al view taken along line 14-14 in Fig. 1.

Referring now to the embodiment chosen for purpose of illustration, in Fig. 1 is shown a Venetian blind slat forming machine including a base 12, alignment roller 13, pre-forming rollers 14, pie-forming roller arm 14, forming rollers 15, 15, guide rollers 16, idler 17, limit switch 18, feed rollers 19, aperture punches 26, cutter 21, and micro-switch 22, all arranged in conventional manner, said forming rollers 15, 15' being generally of the type illustrated in U. S. Patents No. 2.262- 550 and No. 2,370,215.

Mounted on arm 14 and spaced between alignment roller 13 and pre-forming rollers 14 is my ripple removing machine which is denoted by numeral 23 in Fig. 1 and which is also shown in detail in Figs. 2 and 3. Slat stock material 24 is fed from reel 25 on base 12, around alingnment roller 13 and through my ripple removing machine 23; then the stock material 24 is fed through the remaining parts of the machine as shown in Fig. l. Forming rollers 15, 15 are driven by motor (not shown) which is controlled by limit switch 18, and a separate motor (not shown) drives feed rollers 19, all as is well understood in the art. A continuous belt 25 extends around pulley 26' on forming roller 15 and to machine 23 to provide power therefor.

In Figs. 2 and 3, my ripple removing machine 23 is shown as comprising a substantially rectangular frame having upper arm 27 and lower arm 28, spaced from each other by an end joining side 29 and a gear supporting side 30. Aligned axle pins 31, 31' pass respectively through arms 27 and 28, adjacent end joining side 29 and support for rotation, female roller 32 therebetween. The female roller 32 is a solid symmetrical cylindrical roller whose ends and center section are substantially the same diameter, with the center section comprising substantially one-third of the length of the roller. Between the center section and either end thereof, roller 32 is machined to a smaller uniform diameter, with concaved fillets between the ends and this smaller section and concaveconvex sections between the center portion and the smaller sections.

A male roller 33, which is knobbed on either end thereof to substantially correspond with the small diameter sections of the female roller 32, is mounted adjacent this female roller and is fixed to shaft 34 which is journaled in aligned apertures in arms 35, 35 of yoke 36. Yoke 36 is slidably retained by apertures 37 in upper and lower arms 27 and 28. Male roller 33 has a convexed periphery, adjacent each end thereof to correspond with the concaved fillet sections adjacent either end of the female roller 32, the major diameter of the male roller 33 being substantially the sarne as the major diameter of the female roller 32. Male roller 33 is so formed that when in contact with female roller 32 only the periphery adjacent the end portions are contiguous with female roller 32, with the diameter of the knobbed sections tapering slightly toward the center; thus when stock material 24 is passed between rollers 32 and 33, with these rollers exerting pressure thereon, only the edges of this stock material will be firmly held by these rollers and the material bent, as indicated in Fig. 9. It is very important since only the edges are to be held tightly and that center section of male roller 33 be of sutliciently small diameter that there is substantial clearance between the center section of female roller 32 and the center section of male roller 33, so that the center section of roller 33 will not touch the metal stock material as it is acted on by my machine.

In Fig. 4, is illustrated a second species of my invention which consists in substituting for female roller 32, in Fig. 2, female roller 32' in Fig. 4. Female roller 32 is a solid cylindrical roller of substantially the same diameter as the small diameter of female roller 32 and having belled or fillet sections forming the end portions thereof, which are identical with the ends or fillet sections of female roller 32.

Any convenient means for adjusting the distance between the ripple removing rollers, male roller 33 and female roller 32 or female roller 32 may be incorporated with my invention. In Figs. 2 and 4, for example, I have provided a pressure adjusting screw 38 which threadably engages yoke 36 and is fixed to bevel gear 39, supported in an appropriate aperture within gear supporting side 30. A second bevel gear 39' engages bevel gear 39 and extends through upper arm 27, being provided with an external knurled operator knob 40. A pulley 41 is fixed to shaft 34 and when my ripple removing machine 23 is mounted on the slat forming machine, as illustrated in Fig. 1, this pulley is driven by belt 26. It will be remembered that rollers 15, 15' are driven by a motor (not shown) which is controlled by limit switch 18. Therefore, since belt 26 is driven from pulley 26', and pulley 26 is affixed to roller 15, the travel of belt 26 and hence the rotation of pulley 41 is controlled by limit switch 18.

According to my invention, when the ripple removing machine 23 is mounted on the slat forming machine, as illustrated in Fig. 1, the slat forming machine may normally be operated with good stock material by passing the stock material through the ripple removing machine 23, but applying no pressure thereto. If ripples are detected in the finished Venetian blind slat, the operator need only rotate the operator knob 40 to thereby move male roller 33 into close proximity with female roller 32, thus applying pressure to the slat stock material 24 passing therebetween. Before the slat stock material 24 enters machine 23, it has a cross-section as illustrated in Fig. 8; however, with pressure applied to this material by rollers 32 and 33, the cross-section is changed to that illustrated in Fig. 9. In Fig. 9, the slat stock material has sharp bends adjacent each edge thereof and other sharp bends substantially one-third of the distance in from either edge thereof. Of course, if female roller 32 is substituted for female roller 32, sharp bends will only appear adjacent each edge thereof, as shown in Fig. 11.

From my ripple removing machine 23, the slat stock material next enters the pro-forming rollers 14 and the forming rollers 15, 15 where the center of the stock material is curved, as illustrated in Fig. 10. It is to be remembered that my machine should be arranged so that the convexed roller of the pre-forming rollers 14 and forming rollers 15, 15 will act against the same side of the slat stock material that was previously acted against by the male roller 33, thus causing the center section of the slat stock material 24 to be concaved first in one direction and then in the other.

Generally, I have found that stresses in the Venetian blind stock material, which result in rippled or twisted finished slats, manifest themselves in the stock material as waves of long wave length and low amplitude and generally result in a stock material having edges which are uneven in length; therefore minute and proper adjustments longitudinally of the stock material will eliminate these waves or ripples causing sharp bends immediately adjacent these edges, and transversely thereof, will induce realignment of the metal adjacent these bends sufliciently to re-align the structure of the slat stock material to such an extent that the ripples or waves are removed therefrom.

According to my invention, it is desirable for belt 26 to drive pulley 41, and hence male roller 33, at such a velocity that the slat stock material 24 is driven through my machine 23 at substantially the same speed as it is pulled through the forming rollers 15, 15; therefore, there is only sufficient tension placed on the stock material between the ripple removing machine 23 and the forming rollers 15, 15' to hold the slat stock material 24 in alignment.

Referring now to Figs. 5, 6 and 7, I have provided an automatic control which will regulate the amount of pressure applied on the slat stock material 24 by rollers 32 and 33. In Fig. 7, I have arranged a light source 42 which shines on the bottom or ccncaved side of the Venetian blind stock material 24. This light source 42 may be located at any convenient place along the travel of the Venetian blind stock material after it has passed between the forming rollers 15, 15'. Electric eyes 43, 43 are located adjacent the edges of slat stock material 24 so that it may detect the light shining on the opposite edge only when a ripple appears on the edge adjacent the electric eye. When light falls on either electric eye 43 or 43, a circuit is completed which will energize solenoids 44 and 45, thus closing switches 46 and 47, respectively. With switch 46 closed, current will be passed to reversible motor 48 driving adjusting screw 38 in a direction to move male roller 33 toward female roller 32.

As pressure is applied to stock material 24 by rollers 32 and 33, it is obvious that more power will be required to drive roller 33. I have therefore substituted for pulley 26 a pulley 49 illustrated in Figs. and 6 which is journaled on shaft 49' of forming roller and resiliently held to roller 15 by spring 50 as illustrated in Fig. 6. Normally, the tension in spring 50 is sulficient to allow pulley 49 to drive belt 26 without appreciable relative angular displacement of pulley 49 with respect to forming roller 15'. slot 52 on pulley 49. An electrical contact 53, positioned appropriately in slot 52, is connected to slip ring 54 on pulley 49; and, with suflicient angular displacement of shaft 49' with respect to pulley 49, pin 51 will be rotated to engage contact 53. Pin 51 is electrically connected to slip ring 55 on shaft 49', and slip rings 54 and 55 are provided with appropriate brushes 56, 56', respectively, which lead therefrom. In Fig. 7, it will be seen that when the circuit between brushes 56, 56' is closed, power is supplied to reverse motor 48, thereby moving roller 33 away from roller 32. In addition, current is passed through solenoid 57 and solenoid 58, thereby opening switch 46 and closing switch 59. Switch 46 is a normally open switch and therefore, unless ripples are detected by electric eyes 43, 43', no current will be passed to tighten roller 33; however, if both circuits energizing solenoids 45 and 58 are simultaneously closed, one by the detection of ripples in the slat stock material 24 and the other by an indication of an overload on pulley 49, both switches 47 and 59 will be closed to energize alarm 60 to indicate to the operator that the machine is not functioning properly. Thus it may be seen that after a short section of slat material has passed through rollers 32 and 33, the automatic control is sufliciently adjusted that substantially no other ripple should appear. Of course, since the electric eyes 43, 43' are located in the path of the slat, after it has been formed, the ripples which are detected by the electric eyes cannot be removed in the operation, but since the ripples generally follow a pattern throughout the reel of stock material, substantially the entire reel thereafter will be ripple free.

It will be obvious to those skilled in the art that many variations may be made in the embodiment chosen for the purpose of illustration without departing from the scope of my invention as defined in the appended claims.

I claim:

1. In a machine for removing ripples from strip material, opposed male and female rollers, said male rollers being provided with knobbed end sections and a center section of substantially smaller diameter than said end sections thereof, said female roller having a center section of substantially the same length as the center section of the said male roller and having flaring ends thereof of A pin 51 is fixed to shaft 49' and rides in a substantially the same diameter as its said center section, said female roller being provided with intermediate sections between said ends thereof and said center section thereof and of smaller diameter than said center sections and end sections thereof, the relative dimensions of roller sections named being such that when the rollers are in closed operative position the knobbed end sections of the male roller enter into the grooves formed by the intermediate sections, flaring end sections, and center section of said female roller, and act in cooperation with the female roller to grip the edge portions outwardly of the center portion of the strip material and further such that a clearance exists between the center section of the male roller and the center portion of the strip material when the edge portions of the strip are gripped as aforesaid.

2. The structure defined in claim 1 wherein said flaring ends are curved, said knobbed ends of said male roller have convexed extreme peripheries substantially corresponding to and adapted to register with the curvature of said flaring ends of said female roller, said knobbed ends also having flat peripheral portions merging with said convexed peripheries and each tapering toward said center section of said male roller.

3. The structure defined in claim 1 including a frame supporting for rotation said rollers, and means connected to said frame for moving one of said rollers toward the other of said rollers to apply pressure to said strip material therebetween.

4. The structure defined in claim 1 including a frame, axle means carried by said frame on which one of said rollers is rotatable, a yoke carrying for rotation the other of said rollers, said yoke being movable in said frame, means for moving said yoke, and power means for driving one of said rollers.

5. The process of forming curved Venetian blind slat strip material from substantially flat strip material com prising the steps of gripping and holding only the edge portions of the strip material and bending the same to form a groove adjacent each of its edges and an intermediate groove which faces in the opposite direction, and thereafter progressively bending said slat material into a smooth curved cross-sectional shape.

6. The process of forming curved Venetian blind slat strip material from substantially flat strip material comprising the steps of progressively gripping and holding the edge portions of said strip material to form grooves adjacent each of its edges and an intermediate groove which faces in the opposite direction, said grooves adjacent the ends having fiat surfaces in substantially the same plane and said intermediate groove having a flat surface in a plane substantially parallel to the aforesaid plane, and thereafter progressively bending said slat material in a direction such that said intermediate groove is deformed in the direction of said grooves adjacent the ends to form said slat material into a smooth curved cross-sectional s ape.

References Cited in the file of this patent UNITED STATES PATENTS 471,407 Westaway Mar. 22, 1892 1,125,984 Dumas Jan. 26, 1915 1,649,613 Olson Nov. 15, 1927 1,929,771 Burns Oct. 10, 1933 2,176,115 Yoder Oct. 17, 1939 2,183,969 McKinney Dec. 19, 1939 2,333,282 Wilson Nov. 2, 1943 2,471,490 Mercer May 31, 1949 2,562,447 Colburn July 31, 1951 2,717,625 Johnson Sept. 13, 1955 2,717,626 Sherwood Sept. 13, 1955 FOREIGN PATENTS 264,534 Great Britain June 30, 1927

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