US3378941A - Holder for flexible sheet - Google Patents

Description

April 23, 1963 M D. POLLITT 3,378,941

HOLDER FOR FLEXIBLE SHEET Filed Aug. 15, 1966 5 Sheets-Sheet a.

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MILTON D. POLLITT ATTORNEY April 23, 1968 M. D. POLLITT 3,373,941

HOLDER FOR FLEXIBLE SHEET Filed Aug. 15, 1966 5 Sheets-Sheet IN VEN TOR.

MILTON D. POLLITT ATTORNEY April 1968 M. D. POLLITT 3,378,941

HOLDER FOR FLEXIBLE SHEET Filed Aug. 15, 1966 5 Sheets-Sheet .3

INVENTOR MILTON D. POLLI'II'T ATTORNEY United States Patent 3,378,941 HOLDER FOR FLEXIBLE SHEET Milton D. Pollitt, 6510 E. 14th, Wichita, Kans. 67206 Filed Aug. 15, 1966, Ser. No. 572,538 17 Claims. (CI. -10) ABSTRACT OF THE DISCLOSURE A sheet forming a chart or map is held in stable extended position by a spring ribbon secured at its ends to the sides of the sheet by means including members of U-shape cross-section receiving the edges of the sheet. The spring ribbon has a concave-convex cross-section in stable extended position and when straightened in cross-section has different properties such as roll-in, roll out or balanced charcteristics relative to coiling or uncoiling with the sheet.

My invention relates to a holder for a flexible sheet, such as one having printed material thereon forming a map or chart. The holder includes a coil spring ribbon longitudinally stressed to coil and transversely formed with a concave-convex cross-section when extended, whereby the flexible sheet will be held in coiled 01' extended position.

The invention applies to flexible sheets having printed material thereon or adapted to have information marked thereon. One example illustrating the invention, is an aeronautical chart. Two of the most frequently used aeronautical charts produced in the United States are World Aeronautical Charts and Sectional Aeronautical Charts published by the US. Coast and Geodetic Survey. These charts are normally folded when not in use. A large aircraft, particularly one having a navigator in addition to pilot and copilot, may have a chart table on which charts may be spread out. In smaller planes, however, going down in size to the private plane in which the pilot doubles as navigator in rather crowded quarters, a chart table most frequently will not be provided or is inapplicable when the operator must fly as well as navigate. It is difficult to fly a plane and fold, unfold and handle unsupported charts even under best conditions, and this be comes more difiicult in certain conditions such as rough weather. The objects of my invention include: (a) to provide a holder for a flexible sheet in extended and coiled positions, (b) more particularly, .to provide such a support for a flexible sheet having printed indicia thereon, and (0) even more particularly, to provide such a support for a map such as an aeronautical chart.

There are many applications in which a printed sheet is conveniently held in extended position when in use and in coiled position when not in use, such as maps and other reference materials for school room use; auto maps; drawings and the like, used at construction sites; production drawings and data in blue print or other form used in factories; charts for water navigation; architectural drawings; engineering drawings, graphs, diagrams, and tables; military maps; visual materials used in training, in school or in industry; visual materials used in industrial operations such as charts on sales, production and finance; sales and advertising materials; etc. A further object of my invention is to provide a holder permanently or temporarily secured to sheets of the types above described to hold the same in extended position in use and in coiled position when not in use.

In certain circumstances, such as in air currents or limited room, it is desirable to hold material printed on a flexible sheet in only partly exposed or extended position. It is an additional object of my invention to provide a holder for such sheet adapted to hold only one end portion of a sheet in cantilevered position from the remainder of the roll and adapted to hold such sheet in double rolled position so that a portion of the sheet will be exposed between the double rolls, selection of the exposed portion being accomplished by thumbing the sheet to roll more or less of the sheet on one of the double rolls than the other. It is a feature of my invention that the sheet supported by my holder can he often manipulated with one hand, such as in such thumbing operation, in holding a portion of the sheet in cantilevered position, and, to an extent, in general rolling and unrolling of the chart, i.e., in some circumstances the sheet can be rather conveniently extended with one hand and a knee such as when the other hand is occupied with the control wheel of an aircraft. Handling a sheet in a double roll can be done quite conveniently with one hand.

Other objectives includes to provide an economical, easily used, widely adaptable construction. Further advantages and objectives of my invention will be understood from the following description, read with reference to the drawings, in which:

FIGURE 1 is a top view of a specific embodiment of my invention in which an aeronautical chart is supported by a holder in extend position.

FIGURE 2 is similar to FIGURE 1 but is a bottom view.

FIGURE 3 is an enlarged, fragmentary view, partly in section, taken on line 33 of FIGURE 2.

FIGURE 4 is an enlarged, fragmentary view, party in section, taken on line 4-4 of FIGURE 2.

FIGURE 5 is an enlarged, fragmentary view, partly in section, taken on line 5-5 of FIGURE 2.

FIGURE 6 is a view like that of FIGURE 1 but with the chart in double-rolled position.

FIGURE 7 is an end view of the double-rolled chart of FIGURE 6, with a hand shown to illustrate thumbing the double roll, the view also in dotted lines indicating the position of the chart with one end portion supported extended in cantilevered position.

FIGURE 8 is an enlarged, fragmentary view, partly in section, taken on line 8-8 of FIGURE 6.

FIGURE 9 is an end view of the chart in a single roll.

FIGURE 10 is an illustration of a modified form of the invention in which a map is permanently supported from a box, this being an end view partly in section.

FIGURE 11 is a front view of the structure shown in FIGURE 10.

FIGURE 12 is a perspective view of spring ribbon and end securing means, the ribbon being of adjustable length by telescoping means.

FIGURE 13 is a partial top view of a modified form of the invention in which a tubular passage is formed on the back of the sheet and receives a spring ribbon.

FIGURE 14 is a sectional view taken on line 14-14 of FIGURE 13.

My holders utilize unique spring ribbons 10. This type of ribbon is most completely described in US. Pat. No. 2,956,795, issued Oct. 18, 1960, to E. E. Foster, entitled Spring. To avoid unnecessary detailed description, Patent 2,956,795 is incorporated by reference herein and the description of the properties of such spring ribbons, the method of forming, etc., will be only briefly described herein. Spring ribbons of this type are also on the market, such as Lineator: spring ribbons currently sold by Wallace Barnes Steel Division, Associated Spring Corporation, Bristol, Conn. A specific example in size is 1" wide and .005 thickness.

As described in the Foster patent, coil spring ribbon 10 may be constructed of any suitable material such as steel, brass or the like. It may be formed according to Fosters prior Patent 2,609,191 into a spiral coil composed of a plurality of tightly wound convolutions producing residual stresses including a longitudinal component tending to move the ribbon into coiled position. The ribbon 1t) is also formed by suitable means such as described in Patent 2,956,795 with a concave-convex cross-section in extended position (noncoiled, rectilinear disposition) with the convex side toward what would be the center of the ribbon when the ribbon is in coiled position. Forming the concave-convex cross-section also produces residual stresses including a cross component which may be termed the force required to flatten the cross curvature. To a degree the above-mentioned longitudinal and cross components of residual stresses are in opposition, the former tending to coil ribbon and the latter tending to hold ribbon 10 in extended, rectilinear position. To express these properties in other words, the forming process used to coil ribbon 10 produces stresses tending to coil the ribbon but this is opposed by the nature of the concave-convex cross-section which is directed to oppose coiling, so that the concave-convex cross-section has to be tin-canned into flat or opposite curvature before ribbon 10 will coil.

Depending on whether the longitudinal component or the cross component of residual stresses is greater, the ribbon will be self-coiling (longitudinal component greater) or self-extending (transverse component greater). The ribbon will be balanced so that some continuous force will be needed both to extend and to retract the spring if these components are substantially equal. There are other factors present such as inertia, influence of associated structure, initial force to move the spring as contrasted to the force needed to complete an extension or retraction cycle, etc. For example, it is preferred in the present invention to use a ribbon having moderate self-coiling properties but this does not mean that the ribbon Wont have considerable stability in extended position. In other words it is only when some force has tended to bias a portion of ribbon 10 from its normal concaveconveX cross-section disposition into flat or opposite curvature that the self-coiling property continues the action until the structure is completely coiled. A ribbon 10 of self-extending or balanced properties is also applicable, although the self-coiling structure has advantages in handling a chart or the like.

In the drawings, particularly FIGURE 8, ribbon 19 is shown as being preferably flat transversely in coiled position, but, as described in Patent 2,956,795, a ribbon can be usable which has some transverse curvature in coiled position. The transverse concave-convex curvature in extended position shown in the drawings, particularly FIG- URE 5, is merely exemplary and other degrees of curvature may be used, and this may be further influenced by the kind and grade of material used to form the ribbon. The essential features of ribbon 10 which are used in my invention, are that the ribbon is permanently stressed to form a plurality of closely wound convolutions when the ribbon is coiled in repose and the ribbon is formed with a concave-convex cross-section when extended with the convex side facing toward what would be the center of the ribbon when coiled, so that the ribbon when extended will have some stability so as to tend to stay in extended position, even when one end portion is supported in a cantilevered manner, until the ribbon is tincanned into a relatively flatter contour, or even a reverse curvature.

The combination includes ribbon 10, a flexible sheet 12, and means 14 securing coil spring means 10 to sheet 12 at least near the side margins of the sheet. Ribbon 10 extends substantially from side to side of sheet 12 and usually will be on the rear face of the sheet to avoid covering important printed material. Although more than one ribbon 10 can be used, one is usually sufiicient and about an inch wide is sufficient for most purposes.

As before indicated, sheet 2 can be used for various purposes. Most often it will bear printed material, although the sheet instead initially can be blank and adapted to have information placed thereon. A partial list of types of usages have already been given. It will be understood that most often sheet 12 will be paper, although any flexible sheet would be applicable. The specific examples given herein are of maps in which FIG- URES l-9 concerns aeronautical chart and FIGURES l0 and 11 represent a geographical map such as may be used in a primary school classroom.

Dealing with charts as an example, The US. Coast and Geodetic Survey publish various charts including World Aeronautical Charts, Sectional Aeronautical Charts, and Universal Water Charts. Most of the World Aeronautical Charts covering the land area of the United States have been approximately 22 wide by 29" long which means for this purpose ribbon it will be preferably slightly under 29" long. (The US. Coast and Geodetic Survey is contemplating changing the basic length to over 50" and to print maps on both sides. If this is adopted, tape 10 can be located in a sheet area reserved for scales and miscellaneous data.) The Sectional Aeronautical Charts presently are approximately 23 /2" wide and have varying lengths, and for this purpose ribbon 10 may be made long enough for the longest chart and the edge securing means 14 may be slotted or otherwise adapted for the excess ribbon to extend beyond the end of the chart, or the excess ribbon may be cut off or various length ribbons can be provided for various widths charts, or a dual-ribbon telescoping assembly may be provided, as shown in FIGURE 12, in which ribbon 10 has two sections 20, 22, each section having at its end a loop 24, 26 (which can be formed by a loop of plastic or other material) slidably receiving the other section.

Securing means 14 can take various forms. For example, ribbon 10 can be even directly bonded to sheet 12 along its length or at least at its end portions, but this is not an ideal construction for many applications, because, among other reasons (a) ribbon 10 and sheet 12 will always bend about somewhat different radi at each location which leads to sheet wrinkling, (b) it is desirable to provide edge stifleners in the securing mechanism to provide sheet lateral support in extended position, and (c) oftentimes it is desirable to temporarily secure a sheet so that sheets 12 can be interchanged with the same ribbon 10 and securing means 14.

FIGURES 1-9 and 12 show a preferred securing means in which U-shaped strips 30 receive opposite edge portions of sheet 12. Strip 30 may be an extruded plastic either translucent (so as not to obscure any printed material at sheet edge margins-40 the extent sheet margins are not blank) or opaque. The plastic or other material such as metal preferably should have resilient properties and be formed so that flanges 32 of U-shaped strip 30 are resiliently pressed together, thereby to positively clip the sheet margins. The resilient pressing of flanges 32 together is of a low order so that sheet 12 may be readily threaded into the groove of the U-shaped strip 30. Sheet 12 also may be more securely fastened to securing means 14 by an adhesive tape 34 bonded to strip 30 and to sheet 12. Tape 34 preferably is doubled back at one end to form a tab 36 without exposed adhesive material, for convenience in attaching and detaching of tape 34 relative to sheet 12. With a suitable grade of adhesive tape, 34 can be attached and detached many times relative to sheet 12 without much impairing the adhesive properties or without much damage to sheet 12. If tape 34- is translucent, this will avoid obscuring a portion of sheet 12.

The ends of ribbon 10 are secured in strips 30 by the resilient action of strip flanges 32 and/ or by an adhesive tape 40 (formed like tapes 34 and likewise having a nonadhesive tab 42). Flanges 32 may be deformed centrally in the area of ribbon 10 to enlarge access to the groove of the U-shaped strip 30, although the enlargement should have sufficiently small size to still accomplish some gripping action of ribbon 10 by flanges 32. A reason for enlargement 44 is the tendency, if ribbon is too tightly gripped, to flatten ribbon 10 from the concave-convex configuration, which is particularly unfortunate if ribbon 10 is self-coiling, which is the preferred ribbon condition. If strips are formed of thermosplastic material, the central enlargement 44 may be formed by pressing a heated wedge between flanges 32 and into the groove of the U-shaped strip. However, it has been found that if the spring strength of flanges 32 of strips 30 is held to a low enough value, enlargement 44 is not necessary as the ends of ribbons will not be held tightly enough by strips 30 to accidentally flatten the same and cause coiling.

In addition to their functions to secure the edges of sheet 12, strips 30 also serve as edge reinforcement to reduce folding of sheet 12 laterally about ribbon 10 when the assembly is in extended condition. Although this is not a necessary feature, it is a desirable feature (especially where cost is not too pressing a consideration) and this means that even where ribbon 10 is secured to sheet 12 in some other manner, an edge reinforcement may be provided such as a strip secured to the sheet, whether the strip has a U-shaped groove or is otherwise secured to the sheet.

The drawings, particularly FIGURES 1-9 show the operation of the sheet holder, in which FIGURE 9 shows the assembly in coiled position and FIGURES 1 and 2 show the assembly in extended position. The assembly of the structure in original installation, or in interchange of sheets, will be readily understood. The assembly is easiest made if strips 30 are slipped on the edges of sheet 10 and tapes 34 are bonded to sheet 10 before ribbon 10 is installed. Ribbon 10 is merely extended and each end is disposed in enlargement 44 in strips 30 (if enlargement 44 is present). The ribbon may be slightly flexed to get the second end in place if the distance between the inner edges of strips 30 is slightly less than the length of ribbon 10. Tapes are then bonded to strip and ribbon.

FIGURES 6 and 7 demonstrate the use of the assembly with double rolls, thereby exposing a selected portion of the chart as shown in the view of FIGURE 6. In the double-rolled configuration, minimum space is taken and the assembly is readily handled with one hand. The exposed portion of the chart in FIGURE 6 can be changed with one hand by thumbing the assembly as illustrated by the hand in FIGURE 7. This view also demonstrates, in dotted lines, the holding of one end portion (or even half or more) of the chart in cantilevered position (with the remainder of the chart rolled), and, as viewed, this can be done with one hand. In fact, going to the rolled position of FIGURE 9 from an extended position can be readily accomplished with one hand and a knee, for example, (or with one hand by snapping the sheet), and, somewhat less conveniently, likewise the chart can be partly or completely extended in a similar manner.

To reduce likelihood of inadvertent snapping of the sheet into the coiled FIGURE 9 position (and to reduce the rate of coiling when done deliberately), providing one or more null points in ribbon 10 is sometimes advantageous. The formation of null points is described in the referenced Foster Patent 2,956,795, which can involve changing either or both of the longitudinal or lateral stresses (i.e., from a self-extending to a self-coiling or to a balanced condition) or I have found this can also be provided by the notches shown in FIGURE 2. Null points or portions at least having reduced self-coiling characteristics are particularly advantageous near the end of ribbon 10 (or the complete end portions may be brought to null conditions) because this is the most likely place for inadvertent ceiling to begin in a self-coiling ribbon, particularly if the securing means 14 tends to straighten the concave-convex section. I have also found that a null effect can be accomplished by securing (laminating with tape, bonding, etc.) a short length of ribbon (see FIG- URE 12) to the ends of the main ribbon 10 in which the added ribbon 55 has ditferent characteristics, i.e., adding a self-extending section 55 to the end of a selfcoiling ribbon 10. With .005" ribbons, this can be done without undue bulk. Alternatively, ribbon 10 can be provided in raw stock (by original manufacturer) with null points every 6" or so and this stock can be used with regard to the locations of the null points or without considering their locations.

Ribbon 10 can be provided with printed indicia 57 (see FIGURE 2) on its exposed face which can be merely advertisement or may serve a useful purpose such as being a table, data pertaining to the type of sheet 12 being used, etc. When ribbon 10 is only secured at its ends to sheet 12, any printed material on the back of sheet 12 under ribbon 10 can be viewed merely by flexin'g ribbon 10 away from the sheet.

FIGURES 10 and 11 show a construction in which the sheet 12 is preferably permanently mounted and in which the assembly supports a school room map or the like from a box 60 used to house the map in coiled condition when not in use. The construction is much like that of the other figures but the securing means 14 includes end strips 62 bonded to the lower margin of sheet 12 and bonded to the upper margin of sheet 12 and to the inside of box 60, a lower fastener 64 securing the lower end of ribbon 10 to strip 62, and an upper fastener 66 securing the upper end of ribbon 10 to strip 62 and to box 60. A cord 68 and the common type of metal cord end piece 69 are used to assist in pulling down the map, the cord being secured by fastener 64. Cord 68 will be long as the lower edge of sheet 12 becomes the center of the coil 70 when the assembly is in retracted position, and cord 68 must coil with the assembly. It will be understood that this construction can be advantageous over prior school map boxes in which maps are stored on spring rollers, like window blind roller assemblies.

FIGURES l3 and 14 show a modified structure in which ribbon 10 is secured to sheet 12 by forming a tunnel or longitudinal enclosure on preferably the rear of the sheet. As shown, the enclosure can be formed by a strip of paper or the like having its side margins 82 bonded to sheet 12. Strip 80 may be transparent so that material printed on sheet 12 below strip 80 may be seen, or strip 80 itself may be printed in the same manner as sheet 12 so that the area of strip 80 is usable for printing of whatever data sheet 12 is devoted to. Preferably edge reinforcing strips 84 of some length are used to minimize folding of sheet 12 laterally about ribbon 16 in the extended position of the assembly.

Having thus described my invention, I do not wish to be understood as limiting myself to the precise details of construction shown and described, but instead wish to cover those modifications thereof which will occur to those skilled in the art after learning of my invention, and which are properly within the scope of my invention.

I claim:

1. A holder for a flexible sheet, comprising:

(a) spring means extending substantially from side to side of said sheet.

(b) securing means securing said spring means to said sheet at least near the side margins of said sheet.

(c) said spring means including a spring ribbon permanently longitudinally and transversely stressed to form a plurality of closely wound convolutions when the ribbon is coiled in repose and forming a concave-convex cross-section when the ribbon is extended with the convex side facing toward what would be the center of the coil when the ribbon is in coiled position, whereby the sheet may be coiled by means of and with the spring means and whereby when said spring means is extended, it will tend to hold said sheet in extended position.

2. The subject matter of claim 1 in which the longitudinal stress of said ribbon relative to transverse stress is such that said spring means is self-coiling.

3. The subject matter of claim 1 in which the longitudinal stress of said ribbon relative to transverse stress is such that said spring means is self-extending.

4. The subject matter of claim 1 in which said securing means includes means clipping said margins of said sheet.

5. The subject matter of claim 1 in which said securing means includes means adhesively bonding to said sheet.

6. The subject matter of claim 1 in which said securing means includes a strip at each end portion of said spring means with paired flanges forming a generally U-shaped cross-section which receives portions of said margins of said sheet, the strips also serving as edge stiffeners for said sheet for convenience in supporting said sheet in extended position.

7. The subject matter of claim 6 in which said strips are formed of resilient material and the edges of said paired flanges are pressed together thereby clipping said margins of said sheet.

8. The subject matter of claim 7 in which each strip is enlarged centrally to receive an end portion of said ribbon.

9. The subject matter of claim 7 in which there is an adhesive tape securing each strip to an adjacent portion of said ribbon.

10. The subject matter of claim 6 in which there is an adhesive tape at each end portion of each strip securing said strips to said sheet.

11. The subject matter of claim 10 in which each tape has an end tab without exposed adhesive material for use in attaching and detaching the tape relative to said sheet.

12. The subject matter of claim 1 in which said securing means is entirely detachable from said sheet so that one sheet may be removed and another sheet substituted.

13. The subject matter of claim 1 in which said ribbon has at least one null point so that the coil will be unbiased at the null point and coiling or uncoiling past the null point will require force.

14. The subject matter of claim 1 in which at least one end portion of said ribbon has different stress characteristics than the central portion of said ribbon so as to have less tendency to coil, whereby said end portion of said ribbon will more readily support said sheet in extended condition.

15. The subject matter of claim 1 in which the holder is part of a map display means comprising an elongated horizontal box with an open bottom and said securing means at one side of said sheet secures said sheet and ribbon to the inside of said box to coil therewithin in retracted position and to depend therefrom in extended position, whereby the map can be displayed on said sheet.

16. The subject matter of claim 1 in which said ribbon has two sections connected to each other in a telescoping manner thereby to accommodate sheets of different sizes.

17. The subject matter of claim 1 in which said securing means includes a strip extending from side to side of said sheet and secured thereto and forming a longitudinal enclosure receiving said ribbon.

References Cited UNITED STATES PATENTS 1,932,475 10/l933 Pcteler l-29 2,173,188 9/1939 Van Dersal 40-86 2,188,612 l/l940 Owen et al. 40-85 2,874,770 2/1959 Rohr et a1. -23

EUGENE R. CAPOZIO, Primary Examiner.

W. I. CONTRERAS, Examiner.

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