SUSPENDABLE WRITING PAD ASSEMBLY

Abstract: Suspendable writing pad assembly (4, 14) comprising a plurality of sheets (1, 11) of paper or of a plastics material each adapted to be written on, said sheets (1, 11) provided in a superimposed arrangement and adhering to each other in areas along their to edges and being adapted to be withdrawn from each other and forming a pad (4, 14) which adheres releasably to a rear holding sheet (5). Having been withdrawn from the pad (4, 14), the sheets (1, 11) are self-adheringly attach­ able to a plane surface and may be provided with inscriptions. Sheets (1, 11) are adapted to be self-adheringly attachable to said plane surface a number of times and are reunitable repeatedly to form a pad (4, 14). Inscriptions written on them may be erased by wiping them off within a predetermined period of time. Holding sheet (5) has a portion (6) extending beyond the top edge of pad (4) and adapted to be releasably retained in clamp­ ing means (7) having on its rear surface (8) elements (9) to releasably affix clamping means (7) to a plane surface a number of times.

Description: The invention relates to a suspendable writing pad assembly comprising a plurality of sheets of paper or of a plastics material each adapted to accept writing, said sheets lying on top of each other and adhering to each other and being adapted to be withdrawn from each other and reunitable repeated to form a pad affixed in a releasably adhering manner to a rear holding sheet, whereat the writings thereon are erasable by wiping within a predetermined period of time and the holding sheet has a portion extending beyond the top edge of pad and releasably clampable in clamping means having on its rear surface elements by which clamping means may be releasably affixed to a plane surface a number of times. For lecturers and speakers it is desirable - particularly on travel - to have available an easily transported writing pad assembly of which the sheets can be written on in a suitable size and can be suspended re-usably from vertical surfaces or stands so that an audience may see them. Conventionally, paper sheets are used for this purpose; they are provided with means such as perforations by which they may be suspended from a stand or the like. The paper sheets may be united by means of a suitable adhesive along their top edges to form a pad. Once written upon, the individual sheets are placed on a vertical surface by means of adhesive tape or pins, resulting in residues of the adhesive remaining on the supporting surfaces or that surface sustaining damage. In many cases, it is not possible to re-use the adhesive tape once it has been withdrawn. Also, in many cases, a plurality of sheets of paper are placed side by side for demonstration purposes. In a prior writing pad assembly of the kind mentioned above (GB-PS 419 385) for the use more particulary of motorists a rectangular sheet metal or other reinforcement frame constituting a rigid backing plate and several memorandum cards are stacked to form a pad. The memorandum cards are secured at their outer edges by bent or folded portions. Said frame being provided near its upper edge with an aperture with metal eyelet. Said eyelet and so the writing surfaces (i.e. cards) are detachably connected with a rubber suction appliance the eyelet being anchored in the annular recess created between a stud-like portion and a portion which carries a suction cup. In the use of the writing pad assembly, the memorandum cards are rigidly supported upon or against a windscreen or instrument board of a motor vehicle adjacent to the driver's seat by engagement of said cup-shaped portion of the suction appliance with the screen or board. In a prior writing pad assembly of the kind mentioned above (European Patent Application 0 163 127), a plurality of sheets of paper or plastic is stacked to form a pad. Each sheet has a self-adhesive tape secured thereto on its top surface along an edge, said tape having a portion which extends beyond and along the respective edge of the sheet and the sheet being separable from that portion together with the adhesive tape secured thereon. The lowermost sheet of the pad rests on a rear holding sheet having such a length that the outer edges of the portions extending beyond the sheets of the adhesive tapes coincide with the corresponding edge of the holding sheet. In the area of that edge, the holding sheet has on its surface adjacent the pad a self-adhesive tape by which the pad is secured to the holding sheet. The individual sheets of the pad may be written on before or after they are withdrawn from the pad and may be attached to bulletin boards, telephones, plastic bags, windshields or the like for conveying information. In practical use, sheets of this kind can be attached a single time only; neither can they be reunited again to form a pad. Also, it is not possible to erase the information written on them by wiping it off. One disadvantage of the aforesaid pad system is that it is unsightly in appearance in the area of the top edge if the pad comprises a substantial number of sheets. The reason is that three different layer thicknesses are present in that top edge area: the sum thickness of the sheets to be written on, the sum thickness of the sheets and of the adhesive tapes in the overlap zone, and the thickness of the adhesive alone. It has been known a further writing pad assembly (European Patent Application 0 012 789) comprising a plurality sheets of paper, said sheets adhering to each other by means of a special adhesive provided on the backside of each sheet. In practical use, sheets of this kind can be attached several times and they can be reunited again to form a pad. It has been known (U.S. Patent 4 138 523) in the production of blackboards to apply to the board surface a film of a plastics material such as polyethylene or polypropylene which is flexible and can be written on, said film having on its surface facing away from the board a colored coat of polyurethane. In the production of the boards, the film material may be withdrawn in sections from a coil and be affixed to the board surface by means of a vinyl acetate resin emulsion adhesive in such a manner that the colored coat forms a surface to be written on from which writings are readily erased. There have also been known ink compositions (U.S. Patents 3 949 132 and 3 834 823) which may be used in felt-tipped pens or other so-called board marker pens to write on a board or panel of a hard non-porous plastics material and having a smooth surface, with the writings readily wiped from the board surface by means of a fabric or paper cloth. The essential ingredients of ink compositions of this kind include water, a water-soluble coloring material, a silicone component and a release agent in which the water-soluble coloring material is insoluble. In the office area, it has been known to use clamping means such as clamp strips, magnets, buttons and the like for posting slips of paper and the like (e.g. US-Ps 3 150 296). The object underlying the invention is to provide a writing pad assembly of the kind initially specified and useful particularly for lecturing halls and the like to provide lecturers in an effective manner with an assembly that handles easily (especially in relation to the clamping means and in to readily suspending the so-called flip charts) and comprises a plurality of film-like sheets from which inscriptions may easily be removed, which sheets after having been written on may be suspended individually, may be re-suspended elsewhere without sustaining damage, and may be re-united to form an easily handled unitary article. In accordance with the invention, this object is accomplished by a writing pad assembly of the kind mentioned above, which is characterized in that said sheets adhering to each other in an area along their top edges, being adapted to be attached self-adheringly to a plane surface and to be written on after having been withdrawn from the pad and are self-adhesively attachable to the plane surface a number of times, in that the clamping means consists of a flexible plastics material and has a length equal to the width of holding sheet, in that said clamping means comprising two elongated members interconnected in hinge-fashion and movable by hand into and from a clamping position wherein they clamp holding sheet, and in that elements on rear surface of clamping means comprise two spaced self-adhesive foam materials pads which adhere firmly to the plane surface in response to clamping means being pressed thereonto and may be withdrawn from said surface a number of times without damage. Advantageous further developments of the inventive writing pad assembly follow from the dependent claims. The elements on the rear surface of the clamping device have the form of fastening or affixing means suited to readily suspend the so-called flip-chart from a vertical surface and to change its position thereon. The sheets preferably are formed from polymer films that are suited for use without additional coatings. However, the sheets preferably comprise two or three layers each, with two-layer sheets accepting writing on the front surface only and three-layer sheets accepting writing on both the front and the rear surfaces thereof. In the case of a two-layer construction of the sheets, the film consists of biaxially oriented polypropylene, high-density polyethylene or isotactic polypropylene with an additional coat of polyvinylidene chloride which may be applied to one or both surfaces, with each one of the polymer films being combinable with each one of the other polymer films. An additional acrylic coat may be provided on the rear surface. In the case of a three-layer construction of the sheets, each one of the front and the rear surfaces comprises a writable sheet made up of the aforesaid polymer films, with the intermediate film preferably being polyester, paper, polyvinyl chloride or polycarbonate. The film may also consist of biaxially oriented polypropylene having on both sides a coat of ethylene-propylene copolymer. The film may consist of a polymer coat on a paper layer. The film may also by opaque or translucent and - like the paper layer - be colored, provided with multi-colored printing, or be left all white. Each sheet of the pad is provided in the area along its top edge with a re-usable adhesive strip which serves as a fastening or affixing means. The said adhesive strip may comprise an adhesive tape double-coated to provide different adhesive strenghts on its two sides. The same effect may be obtained by coating the film with a special adhesive which when used in combination with an adhesion promoting material adheres strongly to the coated film surface, but by itself adheres relatively weakly to the rear surface of the film opposite the coated film surface so that the individual films may be withdrawn readily from each other. For applying this special adhesive, the film should first be coated with the adhesion promoting material, which will then receive the coat of adhesive. The rear holding sheet preferably is formed of paper and may have therethrough in the portion extending beyond the top edge of the pad a plurality of openings - such as holes or slots intersecting in cross shape - to be used for suspending the writing pad assembly. The clamping means may be provided with magnets on the rear surface. For affixing the clamping means to textured surfaces, it may have thistle-cloth means on its rear surface. The pad preferably comprises 20 to 50 or even more sheeets each 15 to 150 µm and preferably 50 µm thick. Depending on the nature of the surface, inscriptions on these sheets may be erased by means of a suitable pad or simply by means of a soft paper cloth for a period up to four days, for example, after the time of writing. The size and format of the sheets may be selected in accordance with the intended use; exemplary dimensions are 5 x 5 cm² to 1.5 x 1.5 m². The inventive writing pad assembly is space saving in construction for easy transport. lts flip-chart portion and the clamping device may be sold and/or shipped separately. After a lecture, the flip-chart portion can readily be rolled up on the clamping strip, for example. After use, the re-usable sheets are readily adhered to each other for joint clamping by the clamping device. By means of the clamping device, the inventive writing pad assembly may be affixed easily to vertical surfaces or stands; after a lecturer has written on the sheets, they may be grasped and withdrawn from the pad individually to be suspended so that the audience may see them readily. As the sheets are very thin, the weight of the writing pad assembly is relatively low so that the adhesive elements provided on the clamping device will safely support the writing pad assembly on a wall or vertical surface. Since the sheets are reusable, the inventive writing pad assembly is cost-effective and may be put to use in an effecient and flexible manner. One particular advantage is that the sheets of the writing pad assembly may be adhered to and removed from a plane surface repeatedly. These repositioning properties of the sheets may be realized a number of ways. On the one hand, and as mentioned above, the sheet material made of paper or a plastics material may be coated with a suitable adhesion promoting material and an adhesive, and on the other hand the sheet material made of paper or of a plastics material may be laminated with a so-called double-coated adhesive tape having different adhesive strengths on its two sides, with the high-adhesion side connected firmly with the sheet. Also, repositioning properties may be obtained by a coat of adhesive spots in a raster array pattern. The sheets of the flip-chart portion are easily fastened in the clamping device to hang down freely to be grasped individually. In case it is not desired for the sheets to be repositionable, a high-strength adhesive may be used. Preferred embodiments of the inventive writing pad assembly will now be explained in greater detail under reference to the attached drawings. Fig. 1 shows a plan view of a sheet of the writing pad assembly which is provided with an adhesive strip, and Fig. 2 shows a schematical side view in section of the inventive writing pad assembly; and Fig. 3 is a side view similar to Fig. 2 showing a plurality of sheets having their adhesive strips on the front and rear sides thereof. Fig. 1 shows a plan view of a paper or plastics sheet 1 of the inventive writing pad assembly which is provided in the area along its top edge on the side opposite the surface to be written on with an adhesive strip 3 which allows sheet 1 to be adhered to and removed from a plane surface a number of times without being damaged. Fig. 2 shows a number of sheets 1 of the aforesaid nature assembled in an overlying relationship and connected to the adjacent sheet 1 by adhesive strip 3 along top edge 2 of each sheet 1 so as to form a pad 4. The lowermost sheet 1, i.e. the sheet 1 Fig. 2 shows at the left-hand end of pad 4, is attached by means of adhesive strip 3 to a holding sheet 5, said holding sheet 5 having a portion 6 extending beyond the top edge of pad 4 for being releasably retained in a clamping device 7. Holding sheet 5 may be paper or a transparent and/or colored polymer material such as polypropylene. Holding sheet 5 should be made of a relatively stable or stiff sheet material having a thickness in the range of 50 to 200 µm so as to impart to the pad sufficient stability and satisfactory handling properties. On rear surface 8 of clamping device 7, which may comprise two members interengaged in hinge fashion, there are provided affixing means such as spaced self-adhesive foam material pads 9, self-adhesive thistle-cloth means, magnets, or the like, to enable the inventive writing pad assembly to be safely affixed to and removed from a plane surface a number of times. Fig. 3 shows the manner of providing an adhesive 13 on the front and rear surface of each individual paper or plastics sheet 11 in the vicinity of its top edge 12. Taken together, sheets 11 form a pad 14. In order that each sheet 11, once withdrawn from pad 14, may be repositioned on other surfaces with its front surface as well as its rear surface, each sheet 11 is provided on both sides with a pressure-sensitive adhesive 13 applied to sheet 11 with the aid of an adhesion-promoting primer 15. This way, an adhesive strip is created which may be released and reapplied a number of times. That surface of adjacent sheet 11 which lies opposite pressure-sensitive adhesive 13 has thereon a coating 16 which ensures ready release of sheet 11 from pad 14. As shown in Fig. 3, the front surface of each sheet 11 is provided at the top edge thereof with primer 15 and pressure-sensitive adhesive 13, with release coating 16 being provided therebelow. On its rear surface, each sheet 11 is coated correspondingly in a mirror-image arrangement, i.e. coating 16 is provided along top edge 12, with primer 15 and pressure-sensitive adhesive 13 provided therebelow.

Claims: Suspendable writing pad assembly comprising a plurality of sheets (1) of paper or of a plastics material each adapted to accept writing, said sheets (1) lying on top of each other and adhering to each other and being adapted to be withdrawn from each other and reunitable repeated to form a pad (4) affixed in a releasably adhering manner to a rear holding sheet (5), whereat the writings thereon are erasable by wiping within a predetermined period of time and the holding sheet (5) has a portion (6) extending beyond the top edge of pad (4) and releasably clampable in clamping means (7) having on its rear surface (8) elements (9) by which clamping means (7) may be releasably affixed to a plane surface a number of times, characterized in that said sheets (1) adhering to each other in an area along their top edges, being adapted to be attached self-adheringly to a plane surface and to be written on after having been withdrawn from the pad and are self-adhesively attachable to the plane surface a number of times, in that the clamping means (7) consists of a flexible plastics material and has a length equal to the width of holding sheet (5), in that said clamping means (7) comprising two elongated members interconnected in hinge-fashion and movable by hand into and from a clamping position wherein they clamp holding sheet (5), and in that elements (9) on rear surface (8) of clamping means (7) comprise two spaced self-adhesive foam materials pads which adhere firmly to the plane surface in response to clamping means (7) being pressed thereonto and may be withdrawn from said surface a number of times without damage. Writing pad assembly as in claim 1, characterized in that sheets (1) consist of biaxially oriented polypropylene with a coat of polyvinylidene chloride. Writing pad assembly as in claim 1, characterized in that sheets (1) consist of high-density polyethylene with a coat of polyvinylidene chloride. Writing pad assembly as in claim 1, characterized in that sheets (1) consist of isotactic polypropylene with a coat of polyvinylidene chloride. Writing pad assembly as in claim 1, characterized in that sheets (1) are two-layered in construction and have a writable layer formed of biaxially oriented polypropylene, high-density polyethylene or isotactic polypropylene, and in that a coat of polyvinylidene chloride may be provided on one or both sides, with each one of said polymer films being combinable with any other of said polymer films. Writing pad assembly as in claim 1, characterized in that sheets (1) are three-layered in construction, with the outer writable layers being formed of two polymer films selected from the group comprising biaxially oriented polypropylene, high-density polyethylene or isotactic polypropylene and the intermediate layer being polyester, paper, polyvinyl chloride or polycarbonate. Writing pad assembly as in claim 1, characterized in that sheets (1) are formed of a biaxially oriented polypropylene coated on both sides with ethylene-propylene copolymer. Writing pad assembly as in claim 1 and 5, characterized , by each sheet (1) being 50 µm thick. Writing pad assembly as in claim 1 and 7, characterized by sheets (1) being printed. Writing pad assembly as in claim 1 to 8, characterized by sheets (1) being transparent. Writing pad assembly as in claim 1 to 8, characterized by sheets (1) being opaque or translucent. Writing pad assembly as in claim 1 to 9, characterized by sheets (1) being colored. Writing pad assembly as in claim 1 to 10, characterized by sheets (1) being white. Writing pad assembly as in claim 1 to 13, characterized in that each sheet (1) of pad (4) has in the area along its top edge (2) an adhesive strip (3) capable of adhering a number of times. Writing pad assembly as in claim 1 to 14, characterized in that sheets (1) are impermeable to liquids. Writing pad assembly as in claim 1, characterized in that pad (4) has a width of 70 cm and a length of 100 cm and comprises a plurality of sheets (1) of high-density polyethylene each 50 µm thick. Writing pad assembly as in claim 14, characterized by reusable adhesive strip (3) provided on each sheet (1) being a double-coated adhesive tape having different adhesive power on its two sides, with a substrate such as polymer film or a nonwoven material being provided between the two adhesives. Writing pad assembly as in claim 1 or 16, characterized by the height of portion (6) of sheet (5) which extends beyond pad (4) corresponding to the width of clamping means (7). Writing pad assembly as in claim 1 or 18, characterized in that clamping means (7) is 70 cm long and 3 cm wide. Writing pad assembly as in claim 1 and 11, characterized by each sheet (1) of pad (4) being coated in the area along its top edge (2) with dots of an adhesive applied in a raster array pattern.

Inventors: KRECKEL, KARL W., LAVOISIER, PHILIPPE RESIDENCE DU GROS SAULE, VIELCANET, BEATRICE, Lavoisier, Philippe Résidence Du Gros Saule, Vielcanet, Béatrice
Applicants: MINNESOTA MINING AND MANUFACTURING COMPANY
Application year: 1988
Main classification: B42D5
IPC codes: B43L1, B42D5