Patent Application
20080103035
High speed envelope manufacturing machines must meet the demands to produce large quantities of high quality, envelopes in an inexpensive manner. These envelope machines have the capability of producing envelopes at speeds well in excess of 1,000 envelopes per minute and are typically microprocessor controlled high speed web machines which are designed to perform every aspect of envelope manufacturing, beginning with the unwinding of a continuous web of fibrous material. The fibrous material is then fed through the envelope machine where it may be printed with desired information, provided with an adhesive material, cut to create a window area, provided with a transparent window for the window area, cut to form individual envelope units, and folded over a desired package as to create a stuffed envelope.
A shortcoming of the aforementioned envelope manufacturing machines is that they must operate at a relatively slow rate when producing envelopes with windows. That is, the speed is limited by the speed at which a window area can be created in the fibrous material and by the rate at which a transparent window can be placed overtop the window area. A manufacturer will therefore have to choose between producing envelopes at a slower rate and producing envelopes that do not contain a window. However the envelope windows are beneficial in that they allow for the display of information about the contents of the envelope or about the individual to whom the envelope will be sent, such as the recipient's address.
To increase the rate of the envelope manufacturing process, the roll of fibrous material may include pre-cut openings and transparent windows. However, the roll of fibrous material consists of thousands of envelope units and will therefore contain thousands of transparent windows. These transparent windows typically have a thickness on the order of 1.25*10−3 inches, which will add to the total thickness of the envelope unit at the areas in which the window cover is placed over top of the fibrous material.
A web of fibrous material with transparent windows will therefore have a non-uniform thickness. When this web is wound into a roll, it will have an asymmetrical diameter. Given the size and weight of the roll and the speed at which the roll is unwound during the envelope making process, any asymmetry in the roll will cause the unwinding process to be uneven and erratic. In turn, this can cause shuddering or shaking in the envelope machine, which can result in damage to the machine or fibrous material. For this reason, it is important that the cylinder of fibrous material have a circular cross-section when it is wound.
An aspect of the present invention is to create a web of fibrous material having transparent windows, while maintaining a substantially uniform thickness throughout the length of the web. When the web is then wound onto itself, the resulting roll will have a substantially symmetrical diameter throughout. In this manner, the problems associated with unrolling asymmetrical rolls at high speed can be avoided.
In one embodiment, a portion of the web of paper is embossed either before or after placement of the window, so as to increase the thickness of the paper. However, the areas that are covered by the transparent window are not embossed, so that the thickness of the paper at the covered areas is less than the thickness of the paper at the non-covered areas. The embossing is performed so that the increase in thickness of the paper at the non-covered areas is substantially the same as the thickness of the transparent window. Therefore the combined thickness of the transparent window and paper at the covered areas will be substantially uniform to the thickness of the embossed paper at the non-covered areas. In this way, when the paper is wound upon its self along its length, the resulting roll will have a substantially symmetrical diameter.
In another embodiment, a portion of the web of paper is shaved off as to decrease the thickness of the paper at the areas which are covered by the transparent window. The shaving is performed so that the decrease in thickness of the fibrous material at the covered area is substantially uniform to the thickness of the window cover itself. As a result, when the transparent window is placed over top the open area, the combined thickness of the transparent window and the paper at the covered area will be substantially uniform with the thickness of the paper at the non-covered area. Therefore, when the paper is wound upon itself along its length, the resulting roll will have a substantially symmetrical diameter.
In another embodiment, a portion of the web of paper is compressed either before or after placement of the window, so as to decrease the thickness of the paper at the areas which are covered by the transparent window. The compression is performed so that the decrease in thickness of the paper at the covered area is substantially uniform to the thickness of the window cover itself. As a result, when the transparent window is placed over top the open area, the combined thickness of the transparent window and the paper at the covered area will be substantially uniform with the thickness of the paper at the non-covered area. Therefore, when the paper is wound upon itself along its length, the resulting roll will have a substantially symmetrical diameter.
In other embodiments, a combination of embossing, shaving, and/or compression may be used in order to create a substantially uniform thickness across the paper at both the covered areas and non-covered areas.
Prior to describing the present invention in detail, it is noted that the term “substantially” as used throughout this specification denotes both the precise and imprecise case of the adjective it modifies. For example, the phrase “substantially circular cross-section” as used in this specification is intended to denote both the case in which the “cross-section” is precisely circular and the case in which the “cross-section” is approximately, but not exactly, circular.
The present invention pertains to a web of fibrous material containing a plurality of transparent windows, which can be wound into a cylinder or roll of a substantially uniform diameter.
An embodiment of the present invention is shown in
The fibrous material 2 may have any variety of length, width, and thickness that is desired for the manufacturing of an envelope. Typically, the distance between each open area 4 will be constant throughout the length of the fibrous material 2, however the distance between each open area 4 will be determined by the size of the envelopes that will be created from the web of fibrous material 2. In addition, the perimeter of open area 4 can be made of any dimension required to allow the contents of the manufactured envelope to be seen before the envelope is opened. The lines 14 on the web of fibrous material 2 designate where the web of fibrous material 2 may be separated when the web is fed into an envelope manufacturing machine.
One embodiment of the present invention includes the method of manufacturing a web of fibrous material with pre-cut windows, as shown in
In the preferred embodiment of the present invention, fibrous material is processed using the
In one embodiment of the present invention, the process of modifying the fibrous material is preformed by compressing a portion of the fibrous material.
The raised plate 506 has a dimension that is substantially equivalent to the covered area 8. In addition, the raised plate 506 is positioned as to come in contact with the entire area 8 and, the surface of the top roller 502 will have a circular circumference that is equal to the spacing between each window. In this way, the raised plate 506 will come into contact with entirety of each area 8.
Upon passing through the material modifying section 408A, each of the areas 8 will be compressed by the raised plate 506. As shown in
In another embodiment of the present invention, the process of modifying the fibrous material is preformed by embossing the fibrous material as to increase its thickness.
The non-embossing areas 608 have a dimension that is substantially equivalent to the window covered area 8. In addition, the non-embossing areas 608 are positioned as to come in contact with the area 8, and the surface of the top roller 602 and bottom roller 604 will have a circular circumference that is equal to the spacing between each window 6. In this way, the non-embossing area of the top roller 602 and bottom roller 604 will come into contact with entirety of each window covered areas 8. Upon passing through the material modifying section 408B, the entirety of the fibrous material 2 will be embossed with the exception of areas 8. After the transparent windows are applied, the covered area 8 will have a substantially uniform thickness in relation to the non-covered area of the fibrous material 2.
Any conventional embossing pattern may be used for the rollers 602 and 604, such as pebbles, linen, grooves vertical and linen weave.
The spacing between the rollers 702 and 704 of
In yet another embodiment of the present invention, the process of modifying the fibrous material is preformed by grinding or shaving off a portion of the fibrous material as to decrease its thickness.
In order for the fibrous material 2 to be modified by the grinding tool 802, the fibrous material 2 should enter the material modifying section 408C before the windows have been applied to the open areas 4. The raised printing plate 606 has a dimension that is substantially equivalent to the area of the window that will be applied, covered area 8. The raised printing plate 806 is positioned as to come in contact with the entire covered area 8, and the surface of the bottom roller 804 will have a circular circumference that is equal to the spacing between each open area 4. As the raised plate 806 comes into contact with the fibrous material 2, it will bring the fibrous material 2 into contact with the grinding tool 802. Upon passing through the material modifying section 408C the covered area 8 will be reduced in thickness
The spacing between the grinding tool 802 and bottom roller 804 is preferably adjustable by a micrometer 808, so that the shaving process decreases the thickness of the covered area 8 by an amount sufficient to compensate for the increased thickness from the application of a window. The pitch between the grinding tool 802 and the bottom roller 804 that is required to allow for sufficient shaving will be determined by the type of fibrous material 2 that is being used, the thickness of the fibrous material 2, the thickness of the window, and the amount of adhesive that is used to attach the window.
In another embodiment of the material modifying section 408C, the grinding tool 802 contains blades, which can shave off the desired portions of the fibrous material 2.
In yet another embodiment, the material modifying sections 408A and 408B of machine 400 may be located so as to modify the fibrous material 2 after the window 6 has been applied over top open area 4. In addition, the material modifying sections 408A, 408B, or 408C may be used in combination in order to create a fibrous material with pre-cut windows having a substantially uniform thickness throughout.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
