IE46289B1 - Synthetic plastics sheets for use in window shades - Google Patents

Abstract

A window shade sheet member formed from a material having the characteristics, with respect to strength, formability and shape retention, of plastic, and having a non-planar surface comprising raised portions and recessed portions is provided with one or more continuous cut lines, the penetration of which is so controlled that the contour of the cut which forms the cut-line substantially reflects the contour of the surface in which the cut is made, whereby the sheet member can be quickly and accurately sized to width at the time of installation by the final user, by separating the sheet material along a cut line. In a method of manufacturing said sheet member, the material is temporarily and locally flattened during the cutting operation by simultaneous application of pressing and stretching forces.

Description

This invention relates to synthetic plastics sheets for use in window shades, the term window shades being used herein to include roller blinds and folding curtains generally.

Window shades-are conventionally available for purchase in a single width of continuous, uninterrupted sheet material from the upper or top edge, which is usually attached to a roller assembly, to the bottom or lower edge which is frequently formed into a pocket having a slat therein. It is necessary for the purchaser to know the exact dimension between the sides of the window frame to which the window shade is to be attached at the time of purchase. After making allowance for clearance, so that the window shade, after installation, will run free, the exact required width of the window shade to be purchased can be deduced.

Since the required shade width is seldom the same as the width' of the window shade assembly carried in stock by the retail outlets, the shade assembly normally must be cut to width by the vendor's personnel at the time of purchase by use of special, rather bulky, and spaceconsuming equipment located near the point of sale. As a consequence, personnel must be available to interpret the purchaser's requirements, which requirements, with -respect to width, are frequently somewhat vague and 6 28? - 3 indefinite, and have the mechanical ability and time to operate the aforesaid special shade-cutting equipment.

To the above requirement is added the possibility that, despite the care taken by the vendor's personnel in the width cutting of the window shade, the product which is sized to width at the time of purchase is, all too frequently, too long or too short, and the purchasing process becomes a source of customer dissatisfaction through no fault of the vendor.

Frequently a window shade vendor will stock a number of different widths of shade so that a five foot shade need not be altered to produce a 31 inch window shade, thereby reducing the cost to the consumer somewhat by roughly initially matching the unaltered shade width to the customer's required width. However, although this results in a cost saving from the standpoint of conservation of material, the other disadvantages of high labor costs, investment in shade-cutting equipment, use of valuable merchandising space for the cutting equipment, avail20 ability of trained personnel, somewhat limited selection of window shades, and a potential for customer dissatisfaction are all present even when a plurality of basic widths are stocked.

With these considerations in mind, the main aim of the present invention is to provide a sheet member especially adapted for use in window shade assemblies whioh are easy to purchase and install properly by the consumer, thereby eliminating all of the aforementioned disadvantages of conventional window shade assemblies.

Accordingly, the invention is directed to a sheet member for use in a window shade assembly (as defined herein), the sheet member having a first end, a second - 4 end, and two sides, and being formed of a synthetic plastics material or a material having the characteristics with respect to compressibility, strength and formability, of synthetic plastics, in which: (a) the sheet member has at least one linear cut therein which is located generally adjacent and parallel to a first side of the sheet; (b) the said cut commences in the surface of the sheet member and penetrates into the body of the sheet member a distance less than the thickness of the sheet member; (c) the portion of the uncut body of the sheet member lying beneath the bottom of the cut is sufficiently thick to resist separation of the sheet member when exposed to normal manufacturing, transportation and handling stresses to which it may be subjected prior to and during final installation, while being sufficiently thin to be readily separable by the application of human handapplied separation forces on two sides of the cut adjacent one end portion of the sheet member; (d) the surface of that portion of the sheet member in which the cut is formed has a non-planar configuration, and therefore high and low points with respect to a linear reference line which is parallel and co-planar with the plane of the out; (e) the said cut is continuous from the first end portion to the second end portion of the sheet member; and (f) the said cut penetrates into the sheet member to a substantially constant depth at all points along its drop from the first end portion to the second end portion of the sheet member, including the high points and the low points along the cut. 6 3^ - 5 By reason of the formation of one or more continuous cut lines as described above, the penetration of which is controlled to carefully defined parameters, the sheet member can be quickly and accurately sized to width at the time of installation by the final user.

The invention is illustrated by way of example in the accompanying drawings, wherein: Figure 1 illustrates the step of sizing a window shade assembly in accordance with the invention during the installation process by the final user, which, in this instance is shown to be a home dweller? Figure 2 illustrates the subsequent step of stripping the window shade assembly to its proper width following the sizing step; Figure 3 illustrates the subsequent step of preparing means for securing the upper end portion of the sheet member of the window shade assembly to a roller assembly; Figure 4 illustrates the subsequent step of securing the upper end portion of the sheet member to the roller assembly; Figure 5 illustrates the step of inserting a slat into the lower end portion of the window shade assembly; Figure 6 is a top view of a portion of the sheet material from which a window shade is formed? Figure 7 is a view taken on the line 7-7 in Figure 6 with the depth dimension shown on an enlarged scale; Figure 8 is a view taken on the line 8-8 in Figure 6 with the depth dimension shown on an enlarged scale; Figure 9 is a view taken on the line 9-9 in Figure 6 with the depth dimension shown on an enlarged scale; Figure 10 is a schematic view of an essential step in the method of manufacturing a window shade in accordance with the invention; 463^ - 6 Figure 11 is a detailed view to an enlarged scale of the cutting operation in the shade manufacturing method illustrated in Figure 10; Figure 12 is an exploded, perspective view of the 5 cutting apparatus illustrated in Figure 10 and ll; and Figure 13 is an end view of the cutting apparatus illustrated in Figures 10 to 12 inclusive.

Figure 1 shows a window frame 10 to which an improved window shade of this invention is to be secured, the frame consisting of a left-side frame member 11, a right-side frame member 12 and a top-frame member 13. Window shade brackets are indicated at 14 and 15, the right-hand bracket 15 being adapted to receive a flatted end pin of a window Shade roller assembly, and the left-hand bracket 14 being adapted to receive a round end pin.

The window shade assembly is indicated generally at 17. It includes a sheet member 18, a telescopic roller assembly 19 and a slat assembly 20.

The sheet member 18 is formed from a synthetic plas20 tics material or a material having the characteristics, with respect to compressibility, strength and formability of synthetic plastics. One suitable material is polyvinyl chloride, although other materials such as polyethylene, polypropylene and polyolefins may equally well be used.

The product sold under the Registered Trade Mark Mylar may also, in certain circumstances, be employed. For purposes of further description, it will be assumed that a polyvinyl chloride flexible sheet material whose thickness lies in the range of from 3.5 mils to 8 mils will be used.

It should be understood, however, that the thickness, or depth, of the material from which the sheet member is formed may be somewhat thinner, or somewhat thicker than 6 8«? the above-mentioned range, dependent upon other factors, such as cost, handling ability, side strength, and cutting ability. Preferably plastics material used will be one having a memory whereby the material, when deformed, as by cutting to a depth less than the thickness of the material, tends to return to its original configuration.

The telescopic roller assembly illustrated in Figure 1 consists of an outer, larger-diameter section 22 and an inner, smaller-diameter section 23. The inner section 23 is received within the outer section 22, and the inner section 23 is slidable with respect to the outer section 22 so that the overall length dimension of the telescopic roller assembly (which represents the width of the window shade) may be adjusted as needed. As indicated in Figure 1, the left-hand portion 24 of the upper end portion 25 of the sheet member 18 is affixed to the outer, larger diameter roller section 22 by any suitable means, and, in this instance, is wrapped once around the said roller section 22.

The right-hand portion 26 of the upper end portion of the sheet member is not connected to the telescoping roller assembly at the commencement of the sizing operation in the installation process, for purposes which will be explained below.

The left-hand end of the outer roller section 22 includes a conventional flatted end pin assembly 28, and the right-hand end portion of the inner roller section includes a round end pin assembly 27. The telescopic roller assembly includes a shade motor assembly, but since the construction and operation of the shade motor is conventional, it is not illustrated or described.

The lower end portion of the sheet member has been doubled back and fastened to itself to form a slat pocket 6 2ST - 8 30 in which a slat assembly 20 is received. Any suitable means may be employed to secure the doubled back edge of the sheet member to the body of the sheet member. In this instance a plurality of heat seals 32 have been employed, which heat seal locations are carefully selected as will later be apparent.

In the sizing step illustrated in Figure 1, the installer, here a home dweller, is holding the telescopic roller assembly up to the window shade brackets 14 and 15 in order to size the shade. The inner telescopic roller section 23 is then slid inwardly, or to the left as viewed in Figure 1, into the outer telescopic roller section 22 in order to correctly adjust the overall length of the telescopic roller assembly, and thereby the width of the shade. Preferably the telescopic roller assembly is placed in the brackets 14 and 15 to ensure correct sizing.

Thereafter, the roller is removed from the bracket without changing the relative positions of the inner and outer telescoping roller sections. The window shade is then placed on a flat surface such as a table or a floor as indicated in Figure 2.

Referring now to Figure 2, it will be noted that the right portion 26 of the upper end portion 25 of the shade has a series of tabs formed therein, two of which are indicated at 34 and 35. Each tab is formed by a cut which extends completely through the material from which the sheet member is formed, commencing from the top edge. As will be explained in detail below, each tab actually represents the terminus of a continuous cut line which is formed within the body of the flexible material, each tab being defined by the ends of the cut lines. Each cut line extends continuously from the upper end portion of 6 2-39 - 9 the sheet member to the lower edge 37, and penetrates inwardly from one surface of the sheet member a distance less than the thickness of the sheet member. Typical depth of penetration in a material having a thickness of 3¾ mils to 8 mils is 1.5 mils to 1.75 mils. It should be understood, however, that penetrations of greater or lesser depth may be employed, the only requirement being that the depth of penetration of the continuous cut line be sufficient to enable the excess material to be peeled or stripped easily, and that depth of material lying between the bottom of the continuous cut and the other side of the shade has sufficient strength to resist deformation of the sheet member when exposed to normal manufacturing, transportation and handling stresses to which the sheet member may be subjected prior to and during final installation.

As illustrated in Figure 2, the installer had determined that the cut line which lies between tabs 34 and 35 represents the correct shade width, and, accordingly, after grasping the sheet member to the left of the cut line with one hand, and to the right of the cut line with the other hand, the excess material, represented at 38, is being stripped away.

The heat seals 32 are located between adjacent continuous cut lines. Accordingly, when the peeling action reaches the bottom of the shade, the installer, with exercise of reasonable care, is able to tear around the slat pocket so that the entire excess portion 38 may be easily removed. It will be understood of course that the slat assembly 31 will have been removed prior to the stripping of the excess portion of the sheet member. 38^ - 10 After the sheet member has been stripped to its proper width, the installer pulls a protective paper strip 40 away from an adhesive substance 41 which is coated on the inner section 23 of the telescopic roller assembly as best illustrated in Figure 3. The protective paper strip is peeled away only to the point where the right edge of outer telescopic roller section 22 begins. After the protective paper strip has been peeled away, the remaining unattached portion 36 of the upper end portion of the sheet member is wrapped around the inner telescopic roller section 23 and secured thereto by means of the adhesive 41, as best illustrated in Figure 4. Thereafter the slat assembly 20 is reinserted in the slat pocket 30, and the window shade is inserted in the brackets 14 and 15 so as to be ready for use.

Figures 6, 7, 8 and 9 show the construction of the body of the sheet member of the window shade in greater detail. From an examination of those Figures, it will be noted that the shade is made from a typical embossed material, with the result that high points and low points appear. In this particular instance, high points and low points appear in both the upper surface and the lower surface of the shade. More specifically, and referring now to Figures 6 and 8, it will be noted that a series of elevated areas appear as a result of ridges 43, and a series of low points are formed as a result of the valleys 44 which are formed between adjacent ridges 43. The under surface (or exterior side when installed in the brackets 14 and 15) reflects high points and low points which are the opposite of those described in connection with the top (or, when installed,) interior surface of the sheet member. 6as«} - 11 As will be noted from Figure 9, tha shade may be embossed in the direction of the drop of the shade as well as the direction of the width as illustrated in Figures 6 and 8. In Figure 9, a rather substantial depression is formed in the sheet member as a result of the embossing of a major rib 45, the exterior surface of the sheet member including a rather deep impression, indicated at 46.

The cut lines referred to above are illustrated best in Figures 7, 8 and 9. Figure 7 shows the sheet member in its condition prior to the stripping-to-width operation illustrated in Figure 2. A series of cut lines 48, 49, 50, 51, 52, 53, 54 and 55 are formed in the body of the sheet member adjacent one side, i.e. the right-hand side edge 56. It will be noted that the cut lines 48 to 55 are straight and parallel to one another, and that the right-hand side edge 56 is parallel to the closest cut line 55. Further, it will be seen that the cuts 48 to 55 penetrate downwardly from the top surface 57 of the sheet member 18 by a substantially equal distance. Thus, an uncut thickness 58 exists between the bottom 59 of each cut and the lower surface 60 of sheet member 18.

As will be appreciated from Figures 1-4, the cuts extend completely through the flexible sheet material for a short distance at the upper end of the sheet. If desired, cuts may be made at the lower end thereof. As best seen in Figures 1, 2 and 3, the result of through cutting is the series of tabs, two of which are indicated at 34 and 35. The purpose of forming tabs in at least one end of the flexible sheet member is, firstly, to provide an indication to the consumer as to where the material should be grasped to facilitate a subsequent sizing-to-width by stripping and, secondly, to facilitate the commencement 6 3SA - 12 10 o£ the stripping action.

Referring specifically now to Figure 8, the condition of the sheet member is illustrated.after the sheet member has been formed to its final size by tearing along a cut line, such as cut line 50 which is located between tabs 34 and 35. As can be appreciated, the portion of the sheet member to the right of the cut line 50 has been determined to be excess material, and the user, after grasping the sheet member on either side of cut line 50, and preferably at tabs 34 and 35, has stripped the sheet along the cut line 50, thereby severing the portion of the sheet member to the right of that cut line. The severed area which corresponds to the uncut thickness 58, is illustrated, in a greatly exaggerated form for purposes of illustration, at 61. Since the thickness of the sheet member is only a few mils, it will be appreciated that the severed area 61 is, for all practical purposes, not detectable by the human eye.

Figures 10 to 13 illustrate a method of manufacturing the window shade illustrated in Figures 1-9, and apparatus for manufacturing the shade using that method.

In Figure 10 a source of supply of the flexible sheet material from which the sheet members 18 are formed is indicated generally at 63. The flexible sheet material is shown' in roll form of a suitable width which may, for example, be up to 72 inches, or even wider. It passes from the source of supply to a pair of idler rollers 64, 65, the purpose Of which is to ensure that the flexible sheet material approaches the support structure, here roller 66, at the proper angle and under some tension.

From the support structure 66, and following the cutting action which occurs there, the material passes to another A-6 2 $9 - 13 idler 67, a drive roller 68 and a final idler 69 from where it moves towards a subsequent processing station.

This station may, for example, be a cutting station which cuts the flexible sheet material into sheet members of the desired drop distance, and simultaneously forms the tabs 34, 35 in one end of the sheet by any suitable means, such as a separation under vertically-applied pressure forces.

The apparatus for forming the continuous cut lines 48-55 in the flexible sheet material is indicated generally at 71 in Figure 10, and illustrated in greater detail in Figures 11-13 inclusive. The cutting apparatus 71 includes a cutting assembly 72 which is, in this instance, pivotally suspended at 73 from the balance of the cutting apparatus at the cutting station. The cutting assembly 72 includes a cutter, in this instance an elongated blade 74, which is secured by retainer screws 75 and a blade retainer plate 76 to a press member 77, and a blade holder 78. The press member 77 may be secured directly to the blade holder 78 by retainer screws 79. It will be understood that, by using slots in the cutter 74 and the press member 77 which are disposed with their major axis perpendicular to the edge of the cutter, the relative positions of the cutter and the press member can be varied with respect to one another and to the blade assembly holder 78, all as illustrated in the exploded perspective view of Figure 12.

The cutter includes a shank section 80 which terminates at its working end in a blade or cutter 81. The blade is formed by the intersection of two planes as can be best seen in Figure 12 and 13. The angle of the blade may be varied considerably and still produce an acceptable cut, but a blade angle on the order of about 20 degrees is preferred. 28 - 14 As can best be noted from Figures 11 and 13, the press member 77 abuts the cutter 74 and is displaced inwardly, as viewed in Figure 13, or outwardly, as viewed in Figure 11, a short distance.

The cutting action can best be appreciated from Figure 11. Here the flexible sheet material 63 passes around the support structure 66 under substantial tension derived from suitable adjustment of idler rollers 64, 65, 67, and the force imposed by drive roller 68. Further, the cutting assembly 72 is pressed against the outer surface of flexible sheet material 63, as viewed with respect to the centre of support structure 66 in Figure 11, by a force derived from the action of gravity acting upon the cutting assembly 72 and, to a lesser extent, by a yieldable, externally applied force derived from a leaf spring 82. The spring 82 is supported from a fixed support 83 and bears against the rear or outer face of blade assembly holder 78, as best illustrated in Figure 10. The spring 82 also serves to dampen undesirable oscillation of the cutting assembly 72 due to machine vibration, irregularities in the surface of the flexible sheet material 63, or other causes.

As best noted in Figure 11, the force imposed against the flexible sheet material 63 from the press member 77 is sufficient to depress the sheet material into continuous abutting contact with both the external surfaces of the support structure 66, and the internal pressing surface 83 of the press member 77. As a result, the cutter 74 will always cut to a uniform depth.

Since the flexible sheet material has a plastic memory, the material will return to its pre-cutting shape which is typified by Figures 6 to 9. Since the cut area 46287 - 15 62 of Figures 8 and 9 was cut when the condition of the flexible sheet material was deformed so that the upper and lower surfaces 57 and 60 of the sheet material were flat and parallel to one another, the bottom of the cut will assume the substantially sinuous configuration illustrated in Figures 8 and 9.

Claims (6)

1. A sheet member for use in a window shade assembly (as defined herein), the sheet member having a first end, a second end, and two sides, and being formed of a synthetic 5 plastics material or a material having the characteristics, with respect to compressibility, strength and formability, of synthetic plastics in which: (a) the sheet member has at least one linear cut therein which is located generally adjacent and parallel 10 to a first side of the sheet; (b) the said cut commences in the surface of the sheet member and penetrates into the body of the sheet member a distance less than the thickness of the sheet member; 15 (c) the portion of the uncut body of the sheet member lying beneath the bottom of the cut is sufficiently thick to resist separation of the sheet member when exposed to normal manufacturing, transportation and handling stresses to which it may be subjected prior to and 20 during final installation, while being sufficiently thin to be readily separable by the application of human handapplied separation forces on two sides of the cut adjacent one end portion of the sheet member; (d) the surface of that portion of the sheet member 25 in which the cut is formed has a non-planar configuration, and therefore high and low points with respect to a linear reference line which is parallel and co-planar with the plane of the cut; (e) the said cut is continuous from the first end 30 portion to the second end portion of the sheet member; and 4 6 28? - 17 (f) the said cut penetrates into the sheet member to a substantially constant depth at all points along its drop from the first end portion to the second end portion of the sheet member, including the high points and the low 5 points along the cut.

2. A sheet member according to claim 1, wherein the cut extends completely through the entire thickness of the sheet member for a short distance at one end portion of the sheet member . 10

3. A sheet member according to claim 1 or claim 2, wherein a plurality of such cuts are formed in the sheet member adjacent the said one side.

4. A sheet member according to claim 3, wherein the cuts are spaced substantially constant distances from one 15 another in a direction generally perpendicular to the major orientation of the cuts from point to point along each cut.

5. A sheet member according to claim 3 or claim 4, wherein the cuts are uni-directional. 20

6. A sheet member according to claim 1 substantially as described herein with reference to the accompanying drawings.