Patent Application
20090052973
3M Company has introduced a wide variety of products and services to help consumers and office workers communicate, organize, and manage their information. For example, Post-it® Flags, has proven to be an extremely useful tool for marking specific areas of documents, magazines, books, and the like. In general, the flag (also referred to as an “index”), is a polymeric or paper based material having a first and second end portions and first and second opposing major surfaces. The flag includes a repositionable adhesive one of a first or a second portion of its first or second major surface. In a polymeric flag, the first portion is typically transparent and is larger in size than the second portion, which is generally brightly colored. A plurality of flags is releaseably adhered to one another in a fan-fold (also referred to as “z-stacked”) configuration such that the repositionable adhesive in alternating flags is at alternating ends of the stack. The flags have been integrated into writing instruments such as pens and highlighters. For example, 3M Company sells Post-it® highlighters and Post-it pens. These integrated writing instruments provide a portable and convenient way to have flags readily available for a user wherever (s)he goes. Flags integrated into pens and highlighters are described in, e.g., U.S. Pat. No. 6,719,472 (Windorski et al.), US Patent Application Publications US 2004/0234326 and US 2005/091114, and in Japanese Patent Application Publication Nos. JP2000025385 and JP11139081.
Similarly, the Post-it® Durable Tabs, such as product no. 686-2GO, have found extensive use by consumers in many applications, such as for marking notebooks, labeling binders, and filing projects. Typically, the durable tabs are made of a stiffer polymeric material than the flags described in the preceding paragraph. The tabs are releaseably adhered to one another in a fan-fold configuration and dispensed from a substantially C-shaped dispenser. The stack of durable tabs is directly adhered to a bottom surface of the dispenser. The durable tabs have a visually transparent first portion, a repositionable adhesive on one major surface, and a brightly colored, adhesive-free second portion.
The Post-it® Pop-up page markers provide a combination of stacks of repositionable, paper-based notes and stacks of flags in a dispenser. Each stack of notes or flags is adhered to a carrier, as described in US Patent Application Publication US 2007/0175913.
Further information on the Post-it® products described above can be found at www.Post-it.com. While the foregoing products are very useful, there is continued innovation by those skilled in the art to provide other products.
The present invention provides a compact, non-shuttling sheet dispenser with a stack of sheets that are releaseably adhered to one another in a fan-fold configuration. Each sheet has from about 45% to 55% adhesive coverage. In a preferred embodiment, each sheet has about 50% adhesive coverage.
In one aspect, the present invention pertains to a sheet dispenser having a longitudinal axis and comprising or consisting essentially of (a) an upper member having a centrally located slot disposed transverse to the longitudinal axis, the slot having a width dimension as measured parallel to the longitudinal axis, (b) a lower member at least temporarily attached to the upper member forming a housing; and (c) a stack of sheets, the stack having a length dimension along its major axis, each sheet in the stack being releasably adhered to one another in a fan-fold configuration and disposed in the housing, each sheet comprising (i) a tab end portion, an adhesive end portion, and opposing first and second surfaces, and (ii) a coating of repositionable adhesive disposed on the adhesive end portion of the second surface of each sheet, the adhesive covering from about 45% to 55% of the second surface, wherein a bottom most sheet in the stack and is not attached to the lower member of the housing, and wherein the slot width is from about 1% to 10% of the length of the stack.
In another aspect, the present invention pertains to a sheet dispenser having a longitudinal axis and comprising or consisting essentially of (a) an upper member having a centrally located slot disposed transverse to the longitudinal axis and first and second upper walls attached respectively to opposing first and second end walls, wherein the slot has a width dimension disposed parallel to the longitudinal axis; (b) a lower member at least temporarily attached to the upper member forming a housing; and (c) a stack of sheets, the stack having a length dimension, each sheet in the stack being releasably adhered to one another in a fan-fold configuration and disposed in the housing, each sheet comprising (i) a tab end portion, an adhesive end portion, and opposing first and second surfaces, and (ii) a coating of repositionable adhesive disposed on the adhesive end portion of the second surface of each sheet, the adhesive covering from about 45% to 55% of the second surface. The dispenser has a length, as measured from a first lateral end wall to a second lateral end wall, that is at most 110% of the length of the stack. And a bottom most sheet in the stack and is not attached to the lower member of the housing.
In yet another aspect, the present invention pertains to a writing instrument having a central axis and comprising or consisting essentially of: (a) a barrel portion having opposing first and second ends, an exterior grip surface disposed therebetween, and a first internal cavity; (b) a marking element extending from the first end of the barrel portion and disposed in the first internal cavity; and (c) a dispensing portion having opposing first and second ends, the first end of the dispensing portion in communication with the second end of the barrel portion, the dispensing portion comprising: (i) a sheet dispenser comprising a cover having (1) a top joined by two substantially symmetrical sidewalls and a rear, each sidewall having a curved profile, the rear abutting the second end of the dispenser portion, (2) a slot disposed about midway along the top and transverse to the central axis of the writing instrument, and (3) a securing mechanism for attaching to the cover to the dispensing portion; and (ii) a lower member integrated into the dispenser portion such that when the cover is attached to the dispensing portion, a housing is formed between the cover and the lower member; and (iii) a second internal cavity adjacent to the lower member of the dispenser and in communication with a portion of the first cavity.
One advantage of the present invention is that because the sheet dispenser is a non-shuttling dispenser, it is more compact (i.e., has a smaller footprint) than the dispenser described in U.S. Pat. Nos. 4,770,320; 4,907,825; 6,719,472 and 6,837,395 where the stack typically shuttles from one end wall to the opposite end wall when a sheet is removed. Thus, the inventive dispenser can be integrated into writing instruments, which inherently has limited space, at a smaller footprint. Also, as a stand alone dispenser, the compactness of the inventive dispenser allows for efficient use of space, which becomes more and more important for many people, including on-the-go workers, who may not have a dedicated work area but instead move from one work area to another. Such on-the-go workers have a practical limit as to the amount and size of material that can be manually transported to and from the various work areas.
As used in this document, the term “nonshuttling dispenser” generally means that upon initiating the removal of a first sheet in the stack through the slot, the next subsequent sheet also begins the dispensing process by moving into the slot without requiring the stack to first move from one end wall to an opposing end wall of the dispenser. In this way, the end walls of the dispenser that defines the length of the dispenser is only slightly larger than the length of the stack of sheets.
The present invention can be better explained with reference to the drawings, wherein:
The drawings present the invention by way of representations and not limitation. Numerous other modifications and embodiments can be devised by one skilled in the art which fall within the scope and spirit of the principals of this invention. The figures are idealized, are not drawn to scale, and are intended merely for illustrative purposes.
An exemplary prior art sheet dispenser is shown in
As shown in
In
At most, adhesive coating 124 covers about 45% to 55% of the surface area of the second surface of the sheet. Preferably the adhesive covers about 50% of the surface area. At an adhesive coverage area greater than about 55%, the stack of sheet will no longer be able to fan out in like an accordion because of the adhesive overlap from one sheet to the next subsequent sheet. Because of the fan-fold configuration, the overlap occurs at the midsection of the stack. Thus, a stack of sheets where each sheet has about 60% adhesive coverage would result in a stack that is essentially a block of sheets. While the present invention is operable where individual sheets have adhesive coverage of 60%, the force required to dispense such a sheet from the stack can be excessively high, which is an undesirable feature for the consumer. Furthermore, in a flag application wherein the sheet is typically used to mark or to index a document, each sheet needs to have a sufficient amount of adhesive so as to remain adhered to the document. Thus, while the present invention is operable with a sheet having less than 45% adhesive coverage, such a sheet may not be as useful in a flag-type application.
Optionally, the tab end portion of the sheet is brightly colored to highlight the area of the document that has been marked. Any color can be used, so long as it is capable of attracting a consumer's attention. If desired, the tab end portion can also include indicia or graphics. In one embodiment, the adhesive end portion is substantially transparent, so as not to obscure any text present on a document that may happen to lie underneath the sheet. The sheet can be made of a variety of materials including paper, synthetic paper, and polymeric films. In a preferred embodiment, the sheet is a polymeric film such as, but not limited to, cellulose acetate and polypropylene.
Each sheet in the stack has about 50% adhesive coverage, although as previously stated, the adhesive coverage can be from about 45% to 55%. As shown best in
In
The exemplary sheet dispenser as shown in
Further, the sheet dispenser is described as having separate upper and lower members. It should be noted that the upper and lower member can be formed integrally and have an opening therein for inputting a new stack of sheets. The dispenser may be made from a variety of materials including, but not limited to, plastic, paper, glass, metal, or a combination thereof. Desirably, the dispenser is formed from a moldable plastic material. In one embodiment of the present invention, the upper member comprises a molded plastic material and the lower member comprises a paper substrate. In some cases, it is desirable for the upper member to be formed from a transparent material so that a user can see the interior of the sheet dispenser.
Turning now to another aspect of the present invention,
The dispenser portion 220 has a first end 221, a second end 223, and a sheet dispenser 240 disposed between the first and second ends. The sheet dispenser includes a cover 230 that mates with a lower member 260 to form a housing for a stack of sheets 250. The stack of sheets has from about 45 to 55% adhesive coverage. The stack of sheets of
In the exploded perspective view of
When the cover is assembled onto the dispensing portion of the writing instrument, a housing is formed for the stack of sheets. A combination of the set of first alignment devices 267 and of the set of second alignment devices 237, along with the end braces 235 helps the stack of sheets 250 to remain centered with respect to the slot 238. The distance between the first contact surface 237a of the second alignment device 237 and the end brace 265 parallel to the center axis, is the length of the dispenser. At most, the dispenser length is about 110% of the length of the stack of sheets. Thus, when an individual sheet is removed, given the amount of adhesive coverage on each sheet and given the tight tolerance between the length of the dispenser and the length of the stack of sheet, there is little, if any, shuttling of the stack during the sheet removal process.
The adhesive used on the sheets of the present invention can be a variety of materials. The adhesive can be a pressure sensitive adhesive. The adhesive can also be a pressure sensitive repositionable adhesive. One suitable repositionable adhesive is a microsphere-based adhesive. An exemplary microsphere-based adhesive includes polyacrylic derivatives. The repositionable adhesive can be solvent based, water based, or can be a solventless, hot melt adhesive. Suitable repositionable adhesives includes those disclosed in the following U.S. Pat. Nos. 3,691,140 (Silver); 3,857,731 (Merrill et al.); 4,166,152 (Baker et al.); 4,495,318 (Howard); 5,045,569 (Delgado); 5,073,457 (Blackwell) and 5,571,617 (Cooprider et al.), 5,663,241 (Takamatsu et al.); 5,714,327 (Cooprider et al.); U.S. RE 37,563 (Cooprider et al.); and 5,756,625 (Crandall et al.); 5,824,748 (Kesti et al.); and 5,877,252 (Tsujimoto et al.).
The force required to dispense a polymeric sheet, having dimensions of 0.375 inch (9.5 mm) wide by 1.75 inch (44.4 mm) long, from a stack of sheets was done using an Instron machine. The sheets were stacked in a fan-fold configuration. The stack was held in a dispenser integrated with a writing instrument, such as a Post-it® Flag Highlighter, available from 3M Company. U.S. Pat. No. 6,179,472 shows a schematic view of the dispenser used in this testing. The dispenser had a length of about 2.3 inch (59 mm) with a slot width of about 0.0625 inch (1.6 mm).
The highlighter was attached to the Instron fixture using double sided tape. In addition, two pieces (about 5 inches in length) of Scotch® Magic tape, product no. 810, was used to further secure the highlighter to the fixture. The two tape pieces straddled the dispenser region of the highlighter.
The tab end portion of the sheet was fed into the jaws of the Instron fixture, which pulled the tab end portion from stacks of sheets inside the dispenser at a rate of about 100 inches per minute. This type of testing is similar to a 90 peel test commonly used in evaluating peel adhesion. The peak force required to dispense the sheet was then recorded in gram-force.
The dispenser discussed in the “Dispensing Force Test Method” above was retrofitted with two spacers, each about 7.6 mm in length and 9.5 mm wide. Each spacer was used to block an end of the dispenser. Thus, the effective length of the dispenser was about 43.8 mm, or a reduction of about 25% from the original length.
A stack of sheets, each sheet having about 50% coverage of repositionable adhesive on its second surface and its adhesive end portion, was placed in the retrofitted dispenser with the tab end portion extending through the slot. The peak dispensing force required to remove an individual sheet from the dispenser through the slot was measured. Three different stacks of sheet were used, each stack having about 50 sheets. In the first two stacks, eight samples each were tested (for a total of 16 sheets) and in the third stack, nine samples were tested, for a sum total of 25 samples for the three stacks. The peak load required to dispense each sample is reported in Table 1 along with the average of the peak load values.
This example was done as in Example 1 above except that each of the flag had a minimum repositionable adhesive coverage of greater than about 60% (on average, about 63%) on its second surface at its second end. Again, as in Example 1 above, three different stacks were used for a total of 25 samples. The stacks were manufactured by 3M Company, St. Paul, Minn. and sold as part of the Post-it® Flag Highlighter as flag refills. The peak load required to dispense each sample is reported in Table 1 along with the average of the peak load values.
As the data in Table 1 shows, the dispensing force for the inventive compact, non-shuttling dispenser, as embodied in Example 1, is about an order of magnitude less than the dispensing force for a prior art flag, i.e., a flag having on average about 63% adhesive coverage on its second side, dispensed through the same compact non-shuttling dispenser. While the prior art flag can be dispensed through the non-shuttling dispenser of the present invention, the pulling force required to remove (i.e., to dispense) the flag is on average about 749 grams, which is similar to having a consumer forcefully yank the flag out of the dispenser. Such a high dispensing force is undesirable.
This application is related to an application having an attorney docket number 63062US002, entitled Compact Sheet Dispenser, both applications being filed even date herewith.
