Liquid purification or separation – With alarm – indicator – register – recorder – signal or...
Reexamination Certificate
2000-03-08
2001-10-16
Drodge, Joseph W. (Department: 1723)
Liquid purification or separation
With alarm, indicator, register, recorder, signal or...
C210S100000, C210S469000, C210S482000, C116S264000, C116S284000, C222S023000
Reexamination Certificate
active
06303023
ABSTRACT:
BACKGROUND AND FIELD OF THE INVENTION
This invention relates to filter devices; and more particularly relates to replaceable filters for liquid containers, particularly water, and to a novel and improved means for monitoring the number of uses of the filter.
There is increasing popularity and demand for filtered drinking water and, both in home and offices, water dispensers are in use which require a replaceable filter to remove contaminants from the water. In the past, typically the approach has been to monitor the number of times that the same container is filled with water and then filtered but are not capable of monitoring the number of times that each filter is placed on a different bottle. Nevertheless, in most widespread use both in the home or office are water services of the type in which the container, once empty, is replaced by another container filled with water or at least requires removal of a cap in order to refill the empty container. Accordingly, there is a need for a filter use limitation device in which the number of times that the filter is used is correlated with the number of times that it is removed and replaced onto one or more containers.
Representative prior art patents are U.S. Pat. No. 5,190,643 to Duncan et al, U.S. Pat. No. 5,328,597 to Boldt, Jr. et al, U.S. Pat. No. 5,536,394 to Lund et al and U.S. Pat. No. 5,299,701 to Barker et al.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide for a novel and improved filter use limitation device which is highly accurate and dependable in use.
Another object of the present invention is to provide for a filter cartridge in which the usage of the filter is based upon the number of times that it is threaded or otherwise placed onto one or more liquid containers.
It is a further object of the present invention to provide for a novel and improved liquid container assembly for accurately monitoring and limiting use of a filter to its useful life and wherein the monitoring and indicating means may be incorporated into a cap or cover for the container.
It is a still further object of the present invention to provide for a novel and improved disposable filter use limitation device made up of a minimum number of parts and which is greatly simplified and inexpensive in construction.
It is an additional object of the present invention to provide for a novel and improved filter use limitation device which is conformable for use with different types of containers and which may either be of the disposable type or permit selective resetting each time that the filter element is replaced.
In accordance with the present invention, there has been devised for use in a liquid container assembly in which a container is provided with a normally open connecting end a filter use limitation device which comprises a cap adapted to be connected to the end of the container, a filter cartridge positioned at least partially within the cap having a filter in a hollow portion of the cartridge and a resilient pawl at one end of the cartridge, and further a disk is interposed between the cartridge and end wall of the cap having an indicator aligned with a slot in the cap, and index means including a plurality of ratchet teeth are engageable in succession by the pawl to rotate the disk with respect to the cap a distance corresponding to the distance between each pair of adjacent ratchet teeth each time that the cap is connected to the end of the container. In this way, the indicator is incrementally advanced relative to the slot a distance proportional to the advancement of the pawl between adjacent ratchet teeth each time that the cap is threaded onto the end of a container.
In the preferred form, the ratchet teeth and pawl are so constructed and arranged as to prevent resetting once the pawl reaches the last ratchet tooth, as a result of which the entire filter cartridge, disk and cap must be replaced. In a modified form of invention, the ratchet teeth and pawl are designed such that a resetting wrench can be employed to return the pawl to its starting point and similarly to return the indicator to its starting point and, in this setting, contemplates replacement of the filter element each time that the device is reset.
Assuming that the filter cap cannot be reset, another feature of the invention is the utilization of an anti-reverse mechanism between the disk and filter cartridge to prevent accidental reverse movement of the disk relative to the cap, for example, when the cap is unthreaded from the end of the container. It will be appreciated that the number of bottles which can be filtered by each filter is regulated by the number of ratchet teeth on the disk. It is therefore desirable that the number of ratchet teeth and their arrangement may be modified in accordance with the size of container or bottle with which it is to be used, since the filter will maintain its effectiveness with a greater number of containers as the size of the containers decreases.
The above and other objects, advantages and features of the present invention will become more readily appreciated and understood from a consideration of the following detailed description of preferred and modified forms of the present invention when taken together with the accompanying drawings in which:
REFERENCES:
patent: 4769135 (1988-09-01), Norton
patent: 5050772 (1991-09-01), Brane et al.
patent: 5065901 (1991-11-01), Brane et al.
patent: 5190643 (1993-03-01), Duncan et al.
patent: 5525214 (1996-06-01), Hembree
patent: 5527451 (1996-06-01), Hembree et al.
patent: 5622618 (1997-04-01), Brane et al.
patent: 5997734 (1999-12-01), Koski et al.
patent: 6033557 (2000-03-01), Gebhard et al.
Gebhard Albert W.
Parker Robert M.
Drodge Joseph W.
Reilly John E.
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