Users of each type automatic drip coffeemaker machine must seek the correct shaped filter in their supermarket or other store when they resupply themselves with these consumable filter products. Some automatic drip coffeemaker manufactur- ers of cone-type machines have incorporated expensive "permanent"metal filters within their machines in order to reduce the need for disposable paper based filters and thus help the consumer avoid purchasing the incorrect shaped disposable paper filters.

Because of the difference in the structure of the automatic drip coffeemakers for holding cone-shaped filters and basket-shaped filters, the industry has provided dispos- able filters which have utility for only one type of machine, namely a cone-type or a basket type automatic drip coffeemaker.

Summary of the Invention An object of this invention is to provide a disposable filter which may be readily converted for use as either a cone or basket type filter.

A further object of this invention is to provide such a filter which is manufactured for use as a cone or basket-type filter but which includes fold lines to facilitate manipulating the filter for conversion to the other type of filter.

A still further object of this invention is to provide methods or techniques for converting such filters.

In accordance with one aspect of this invention a disposable convertible filter is made by forming a filter member from a layer of filter material having a continuous side wall and an end or bottom edge and an open top. The side wall and bottom edge are secured together to form a container having the open top. A generally horizontal fold line is provided near the bottom of the container. When in the normal or unfolded condition, the shape of the filter is such as to function as a cone filter. When it is desired to use the filter as a basket-type filter, the bottom of the filter is folded against itself at the fold line so that the depth of the filter is decreased and the bottom of the resultant folded filter is increased in width and becomes flatter when the filter is opened to more closely accommodate a basket.

In an alternative practice of the invention the filter is initially a basket-type filter having a generally flat bottom. When it is desired to convert the filter to a cone filter, the bottom wall is pushed outwardly and the filter is folded upon itself vertically to result in four layers of filter material, each of which has a generally cone-shape. One of the layers is pushed away from the remaining three layers to form a container between the one layer and remaining three layers in a resultant cone filter.

The Drawings: Figure 1 is a front elevational view of a cone filter which may be converted to a basket-type filter in accordance with this invention; Figure 2 is a top plan view of the filter shown in Figure 1; Figure 3 is a view similar to Figure 1 showing the filter converted to a basket type filter in accordance with this invention; Figure 4 is a top plan view of the filter shown in Figure 3; Figure 5 is a rear elevational view of the filter shown in Figures 3-4; Figure 6 is a perspective view of the filter shown in Figures 1-2; Figure 7 is a cross-sectional view taken through Figure 6 along the lines 7-7; Figure 8 is a perspective view of a modified form of filter similar to that shown in Figures 1-7; Figure 9 is an elevational view partly in section and partly broken away showing the filter of Figures 1-7 optionally used as a cone filter and a basket-type filter; Figure 10 is a perspective view of a basket-type filter in accordance with a further embodiment of this invention; Figure 11 is a perspective view of the filter of Figure 10 showing the bottom wall pushed outwardly in the first stage of conversion to a cone filter; Figure 12 is a perspective view of the filter shown in Figures 10-11 in the next stage of conversion to a cone filter; Figure 13 is a perspective view of the filter shown in Figures 10-12 in the final stage of conversion to a cone filter; and Figure 14 is a perspective view of an alternative form of filter similar to that of Figures 10-13.

Detailed Description Generally, different manufacturing equipment is used for producing cone filters as compared to basket-type filters. The filters themselves, also generally differ from each other. A cone filter is frequently longer than a basket-type filter and has a shallower or more cone-like lower end, it being understood that the actual shape of a cone filter is a frusto-conical shape. Basket-type filters generally have a longer bottom wall which has more flatness than a cone filter and is generally shallower or of less depth than a cone filter.

The present invention would generally be practiced using materials customarily used for filters in accordance with the end purposes. Thus, the filter material would be liquid pervious to permit water or other liquids to pass through. The filter material itself may function to remove contaminants and/or add materials which could be included in the liquid such as to enhance the flavor of the liquid.

Reference is made to my U. S. Patent Nos. 5,304,305 and 5,567,461, as well as my co-pending application Serial No.

08/911,597 filed August 14,1997, all of the details of which are incorporated herein by reference thereto. These patents and application disclose suitable filter material and flavor enhancing materials. Accordingly, the filter member may also or alternatively include some flavor or beverage taste enhancing substance to treat the liquid passing through the filter and/or some substance to remove contaminants, includ- ing caffeine. Thus, for example, the filter member may be coated or printed with such substances or may include pockets containing such substances. Such substances may include a nutritional supplement additive or a decaffeination layer.

The most conventional material used for forming filters is liquid pervious paper. Accordingly, the invention will be described with respect to such materials although other materials such as cloth could be used within the practice of this invention.

Figures 1-2 show a disposable filter 10 in accordance with this invention. As shown therein, the filter 10 comprises a filter member made from a layer of filter material 12 which has a pair of side edges secured together by seam 14 as is generally known to form a continuous side wall. The filter member 12 also includes an end or bottom edge 16 closed by seam 14 and an open top 18 when the two layers shown in Figure 2 are spread apart as illustrated, for example, in Figure 6. In the condition shown in Figure 6 an open top container results into which ground coffee 20 or other material may be placed. When the filter is mounted in its automatic drip coffeemaker 22 (shown in phantom in Figure 9), the filter in the condition shown in Figures 1,2 and 6 functions as a standard cone filter. As noted above, the general shape of the filter is actually frusto-conical with the lower edge 16 approaching the point of a cone.

In accordance with this invention the filter 10 may be manipulated by the user to be converted from a cone filter to a basket-type filter. This is accomplished by bending the bottom portion of the filter member 12 upon itself as shown in Figures 3 and 5. In order to facilitate the bending and particularly to assure that the bending takes place at the correct location a fold line or crease 24 is formed in at least one side of filter member 12. Fold line or crease 24 is generally horizontal and is generally parallel to the open top 18 of filter member 12. It is to be understood, however, that where the open top is arcuate, the straight fold line 24 will not be completely parallel to the arcuate open top.

While a fold line is preferred, the invention may be prac- ticed without an actual crease or fold line. Such practice is not as desirable, however, since it relies upon the user to select where the folding should take place and depends upon the user being careful to have a generally horizontal fold result from the bending of the bottom portion of filter member 12.

If desired, after the filter is folded to the condition shown in Figure 5, the two lower corners may be folded over the already folded filter. Further fold lines could be provided to facilitate such folding. This further folded filter would fit more easily into a basket style coffeemaker.

When filter member 12 is folded to the position shown in Figures 3 and 5 the filter 10 functions as a basket- type filter. In this respect, the two layers of filter member 12 are spread apart to create the open top 18 until the top reaches a generally circular shape. The bottom edge of the filter at fold line 24 will result in a basket-type filter having a greater bottom edge dimension with more flatness to the bottom than the bottom edge 16 when the filter member 12 is in its unfolded condition as a cone filter. Thus, the basket-type filter could be placed in the coffeemaker 22 as shown in solid lines in Figure 9.

The invention is thus based on first producing a filter which has a truncated cone shape similar to commercial cone filters and then providing a fold or fold line a suitable distance from the truncated filter bottom such that when folded upwardly and when the two sides of the cone are manually separated, the former cone shaped filter becomes essentially circular at the top and simulates a basket shape which can then be fitted properly and conveniently in a self- supporting position in a basket style coffeemaker.

Although the drawings illustrate a single fold line 24, a plurality of parallel horizontal fold lines could be provided to give the user selectivity in picking the desired size basket-type filter.

The filters 10 may be constructed in so called cone sizes #2, #4, #6 or other smaller or larger sizes to fit one- cup, two-cup, four-cup, eight-cup, ten-cup, twelve-cup or other basket sizes as required. As noted, the materials of the filter may be paper or may be cloth or other food applicable material and as noted the filters may include the various features described in my above noted patents and application.

Any suitable dimensions may be used for the <BR> <BR> <BR> <BR> filters. For example, where a cone filter is about 7 2 inches wide at its widest point with the filter layers in their flat condition shown in Figure 2, the frusto-conical lower end would be about 2 inches long and the fold line 24 <BR> <BR> <BR> <BR> would be located about 1 Z inch upwardly from the bottom edge 16. Thus, the height of the flattened filter would be reduced from about 5 inches to about 3 k inches.

In the preferred practice of the invention the cone-shaped filter 10 has straight sides. Figure 8, however, illustrates a variation where the sides may be fluted. In the preferred practice of the invention there is no fluting for filter 10.

Figures 10-14 illustrate an alternative embodiment of the invention wherein the initial filter 30 is a basket style or basket-type filter. As illustrated therein the filter has fluted sides. The invention, however, may be practiced with straight sides. As further illustrated, the bottom 32 of filter 30 is flatter than and of greater dimension in width than the conventional cone filter illustrated in Figures 1 and 6. In order to convert the filter 30 from a basket-type filter to a cone filter, a number of manipulations are performed on filter member 34.

Initially, the flat bottom 32 is pushed outwardly so that the resultant two layers generally take the shape shown in Figure 11. The two layers are then folded centrally upon each other along a vertical line 36, i. e. a line extending from the open top 38 to the bottom 32. Preferably, line 36 is a crease or fold line. Line 36 could be a crease resulting from the fluted side or could be an added crease line. If desired, however, the folding may take place without any crease line even where the filter is not fluted. When the two layers are folded midway upon themselves, a four layer construction results which is shown in Figure 12 and which has a generally conical shape. The four layers are indicated by the reference numerals 38a through 38d. In order to form a container one of the end layers such as layer 38a or layer 38d is moved away from the remaining three layers and the remaining three layers are pressed together as shown in Figure 13. A cone type container 40 thus results between layer 38d and the group of layers 38a, 38b and 38c. The filter 30 may then be placed in a coffeemaker, such as coffeemaker 22 and function as a cone filter.

If desired, the three layers 38a-38c may be held together in any suitable manner such as by a clip 42 shown in Figure 14. Alternatively, layer 38a or layer 38c may have an upwardly extending tab which would then be folded around the two adjoining layers to hold the three layers, such as layers 38a-38c together.

The invention takes advantage of the fact that, for example, when using a cone filter it is not necessary that the upper edge of the filter extend completely up to the upper edge of its support surface in the coffeemaker. Thus, for example, where a shallower filter may result by conver- sion from a basket-type filter, the resultant cone-type filter will still properly function by simply being placed into its support and located upwardly from the bottom of the support a sufficient distance to hold the ground coffee or other material. Similarly, it is not critical that the bottom edge of the cone filter or basket filter precisely conform to the bottom of the support. What results from the invention is that a filter will have a shape whereby it forms a container through which water or other liquids may be poured and flow through the filter to be treated in the desired manner by removing contaminants and/or enhancing the flavor of the liquid. The overall shape of the filter may be selected by the user to more closely approach either a cone filter or a basket-type filter.