Abstract
A lubrication package for lubrication of paper shredders wherein a lubricant is sandwiched between two coversheets which are sealed together near their peripheral edges to contain the lubricant. When the package is inserted into an operating paper shredder, the coversheets are shredded and release the lubricant to lubricate the shredding mechanism. The lubricant is prevented from all migrating towards one of the peripheral edges by interior seals that divide the package into at least two interior regions that do not contact sealed together peripheral edges of the package.
Claims
1. A lubrication package to be shredded by a paper shredder so as to lubricate the paper shredder, said package comprising: two juxtaposed cover layers having peripheral edges; a peripheral seal bonding the peripheral edges of the two cover layers together; a lubricant disposed in a space between the two bonded cover layers; and inner seals spaced apart from the peripheral seal, said inner seals not in contact with the peripheral seal or in contact with or continuous with any seals in contact with the peripheral seal, to separate the space into at least two interior regions not in contact with the peripheral seal and one peripheral region in contact with the peripheral seal, wherein the inner seals do not contact the peripheral seal.
2. The lubrication package according to claim 1 comprising two interior regions.
3. The lubrication package according to claim 1 comprising at least three interior regions.
Description
DESCRIPTION OF THE FIGURES
(1) FIG. 1 is a drawing of a surface view of a prior art lubrication package;
(2) FIG. 2 is a cross-section view of the lubrication package to show the lubricant sandwiched between the impervious sheets;
(3) FIG. 3 is surface view of a prior art lubrication package wherein interior regions are formed by interior seals that extend from one peripheral edge to an opposite peripheral edge and vent holes are used to avoid squirting lubricant;
(4) FIG. 4 is a surface view of one embodiment of the present invention wherein the lubrication sheet is divided by interior seals that do not extend from one peripheral edge to an opposite peripheral edge and divide the sheet into two interior regions surrounded by a third region;
(5) FIG. 5 is a surface view of another embodiment of the present invention wherein the lubrication sheet is divided by interior seals that do not extend from one peripheral edge to an opposite peripheral edge and divide the sheet into three interior regions surrounded by a fourth region; and
(6) FIG. 6 is a surface view of another embodiment of the present invention wherein the lubrication sheet is divided by interior seals that do not extend from one peripheral edge of the sheet to an opposite peripheral edge and divide the sheet into two interior regions surrounded by a third region where the interior regions are further subdivided by interior seals.
DETAILED DESCRIPTION OF THE INVENTION
(7) The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventors of carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the general principles of the present invention have been defined herein specifically to provide an improved design for substrate-free lubrication packages that ensure even distribution of the lubricant and do not require the use of vent holes.
(8) FIG. 1 shows a surface view of a prior art lubrication package as disclosed in U.S. Pat. No. 7,793,876. The lubrication package 10 is formed from two cover layers 12 (only one of which can be seen in this view) laminated together at an outer peripheral seal 14 (in the figure the cross-hatched region represents the seal where the two cover layers are sealed together). FIG. 2 is a cross-section of the lubrication package 10, and the cavity or space between the two cover layers 12 is filled with lubricant in the form of liquid oil 16. Generally, the cavity or space is quite thin and has been exaggerated in the drawing for sake of clarity. Any lubricating oil of mineral, animal or vegetable origin can be used. Preferably, the oil will be colorless and non-toxic. As shown in FIG. 1, an inner peripheral seal 18 is spaced apart (by about 1 cm) from the outer peripheral seal 14 thereby preventing the oil-filled cavity or space from extending entirely from edge to edge. The peripheral seals 14, 18 are essentially identical and are formed by a heat-sealing tool that simultaneously forms the two parallel seals. Other welding processes such as ultrasonic welding or use of adhesives could also be used to form the seals. A single or (as here) a double row of vent holes 20 are punched through both cover layers in the peripheral region 22 between the two peripheral seals 14, 18.
(9) When this lubrication package 10 is fed through the shredding mechanism of a paper shredder, the enclosed oil 16 and any entrapped air may become pressurized as the sheet is squeezed. When this happens, the air and oil are able to force their way past the inner seal 18 which is not particularly strong. If the vent holes 20 were not present, the air and oil could also force their way past the outer peripheral seal 14 and spurt out along the edge of the lubrication package 10 possibly exiting the shredder or striking some part of the mechanism that should not be lubricated. However, with the vent holes 20 present the oil and air exit the vent holes 20 and coat the rotating blades. As explained above, a potential problem with such a lubrication package is a tendency for the lubricant to pool and become unevenly distributed in response to gravity.
(10) FIG. 3 shows an improved prior art lubrication sheet 10 showing a simple but elegant solution to this pooling problem. A plurality of interior seals 24 (formed similarly to the peripheral edge seals 14, 18) are used to divide the interior cavity into four or more sub-cavities or regions 26. In the drawing paired interior seals 24 are shown as having dimensions similar to the peripheral edge seals. The invention would operate if only single (as opposed to spaced apart double) or even multiple seals were used. Nor is it necessary for the interior seals to be parallel to each other. The notion is to prevent the interior cavity from extending the width (or length) of the lubrication package 10 from edge to edge to prevent edge pooling of the lubricant. In the package 10 shown in FIG. 3, the interior is divided into four major sub-cavities or regions 26 as well as five minor sub-cavities 28. This type of division is adequate to ensure essentially even distribution of the lubricant although it is possible to employ a larger or smaller number and different arrangement of sub-cavities.
(11) The operation of this solution is illustrated by the reference signs A, B, C, and D. If the lubrication sheet 10 is stored with A representing the lowermost edge, the lubricant will move towards the peripheral seal marked a. Because of interior seal 24a lubricant from the upper half does not move past the center of the sheet thus ensuring improved distribution of the lubricant. Similarly, turning the sheet to make B, C or D the lowermost edge causes lubricant to move towards the peripheral seals marked b, c or d, respectively. This is prevented by interior seals 24b, 24c or 24d, respectively. Thus, the present invention solves both the problem of lubricant spurting and the problem of lubricant pooling near one edge of the lubrication sheet in response to gravity during storage.
(12) The interior seals 24 are most simply implemented by having the seals 24 run approximately parallel to the peripheral seals 14, 18. However, this orientation is not obligate. The interior seals 24 could be configured to make various angles other than right angles with the peripheral seals 14, 18. Also, it is not required that the interior seals form straight lines as long as they are disposed to prevent migration of a majority of the enclosed lubricant to one of the peripheral seals 18.
(13) FIG. 4 shows a first embodiment of the improved lubrication sheet 10 of the present invention. The two layers of oil impervious material 12 (only top sheet shown in drawing) are sealed together near their peripheral edges by an edge seal 14 (in these drawings the patterned area represents the sealed region where the two layers are adhered) as in the prior art device. Interior seals 30 that do not reach the peripheral edges are used to create two interior regions 32, 34 that have no direct contact with the peripheral seal 14. Rather, a small region 36 surrounds the two regions 32, 34 and makes direct contact with the peripheral seal 14. The liquid lubricant can be disposed in all of the regions or just in the interior regions. As shown in FIG. 5, it is also effective to increase the number of interior seals to make three (32, 34 and 38), four (not illustrated) or more independent regions surrounded by small region 36. Because the overall length and area of the various regions are limited, the pressure that develops in the prior art device of FIG. 1 does not develop as strongly so that it is not necessary to employ vent holes as in the prior art device. Of course, including vent holes is acceptable although a double peripheral seal is necessary in that case unless the small surrounding region 36 is free from lubricant and the vent holes are located therein. Note that all the interior regions are shown as being rectangular. This is done only for simplicity of illustration. The interior regions can be of almost any shape, and it is not necessary that the seals forming these regions be parallel to the peripheral edge seals.
(14) FIG. 6 shows an additional modification that can be made to further ensure even distribution of lubricant. Additional interior seals 31 are provided to subdivide each of the interior regions into sub-regions 42, 52, 62, etc. and 44, 54, 64, etc. In the drawings, some of the additional interior seals 31 contact the interior seals at one end only (see sign 46) or at neither end (see sign 48). Thus, the sub-regions are not actually separated completely from each other. Nevertheless, the additional interior seals 31 are sufficient to impeded migration of the liquid lubricant in response to gravity. It is also possible to have openings through a middle region of the additional interior seals 31 (see sign 50). In either case the openings are sufficiently small that the lubricant is unable to freely migrate in response to gravity. However, when the shredding process pressurizes the lubricant in one region, it is able to redistribute through the openings thereby avoiding buildup of pressure, thereby avoiding the need for vent holes.
(15) It is advantageous to have the interior seals in one interior region not be parallel to the seals in the other region (assuming there are only two interior regions). Thus the sub-regions in one interior region are oriented to avoid pooling of lubricant if the sheets are stored in one orientation whereas the sub-regions in the other interior region are oriented to avoid pooling of lubricant if the sheets are stored in an orientation perpendicular to the first orientation. In fact, it does not matter in what orientation the sheets are stored since at least one area of the sheet will resist pooling and ensure even lubrication of the shredding mechanism. It will be appreciated that the additional interior seals do not necessarily have to be parallel to each other or even straight, for that matter.
(16) The following claims are thus to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted and also what essentially incorporates the essential idea of the invention. Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope of the invention. The illustrated embodiment has been set forth only for the purposes of example and that should not be taken as limiting the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.
