Fluid handling – With indicator – register – recorder – alarm or inspection means – Position or extent of motion indicator
Reexamination Certificate
1998-04-30
2001-01-23
Chambers, A. Michael (Department: 3753)
Fluid handling
With indicator, register, recorder, alarm or inspection means
Position or extent of motion indicator
C137S624140, C137S624180, C251S248000
Reexamination Certificate
active
06176258
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a control device for controlling reconditioning of a liquid treatment system, in particular regeneration of a water conditioning or softening apparatus having a control valve with a first or main piston and a second or brine piston.
Conventional liquid treatment apparatus, such as water softeners, require periodic regeneration of the resin bed used to treat the incoming raw water to obtain soft water. Typically, in a stage known as eduction, a brine solution is passed through the resin bed to chemically recharge the resin. The resin is then rinsed with raw water to remove any traces of the brine. In some cases, the eduction step is preceded by a backwash step, in which the flow of incoming water is reversed to remove sediment which has been separated from the water during the conditioning operation and which may interfere with the softening operation. The latter are known as “five cycle” systems, wherein regeneration involves a backwash, a brine rinse, a slow rinse a fast rinse and a refilling of the brine tank. The length of time consumed by each of the steps in the regeneration cycle is a factor of the condition of the raw water being treated.
As is well known in the art, water softeners are provided with various mechanisms for initiating regeneration. Some of such mechanisms are clock operated, and are triggered to begin at a preset time of day, while others are triggered by a threshold volume of treated water. Still other mechanisms trigger regeneration by a condition of the resin bed.
Conventional water conditioner control valves employ separate pistons for controlling the main flow of the raw water between source, the treatment tank and the drain on the one hand, and between the treatment tank, the brine tank and the drain on the other. Some such valves are also provided with cam mechanisms for controlling the position of at least one of the pistons.
A main drawback, however of conventional softener control valves is that the piston rods of such valve pistons are biased against the cam motion by spring force. Over time, the spring force changes, reducing the accuracy and efficiency of the operation of the valve. In other applications, the cam rotates transversely to the longitudinal axis of motion of the pistons, and a relatively complex mechanical linkage is required to transfer the piston movement instructions from the cam.
Another drawback of conventional water conditioner valves is that the existing cam surfaces have dwell points which do not accommodate the inertia of a driving motor. More specifically, conventional water conditioner valve control systems employ an electric motor to rotate the cam, which then causes desired regeneration movement of the valve pistons. During the regeneration cycle, the motor stops at varying intervals while certain operations of the cycle are performed. Once the signal is generated to stop the motor, the internal gears and linkages of the motor have some inherent inertia, which causes the motor to turn slightly after being turned off. In some cases, this inertial movement can cause unwanted movement of the cam, and consequential disruption of the regeneration cycle.
The configuration of conventional cam dwell points has been ineffectual in solving this problem. The length of prior art cam dwell points has also been inadequate, in that the switch signals for operating the motors have a designated duration. Depending on the speed of the motor, if the dwell point is too short, there may be insufficient time to receive the entire signal for directing the motor to cease rotation.
Still another problem of conventional water conditioner control valves is that they are inefficient because the duration of the fast rinse portion of the regeneration cycle is a function of the brine tank refill time.
Accordingly, a first object of the present invention is to provide an improved water conditioner control valve which positively controls the operation of the main and brine pistons in both operational directions.
Another object of the present invention is to provide an improved water conditioner control valve which does not require extensive linkages to translate the rotational movement of the cam into linear displacement of the main and brine pistons.
Yet another object of the present invention is to provide an improved water conditioner control valve in which cam dwell points are configured to accommodate motor inertial movement after motor shut down.
BRIEF SUMMARY OF THE INVENTION
The above-listed objects are met or exceeded by the present dual cam drive for a water conditioner valve, which features a cam member with separate cam tracks for a main piston and a brine piston, each piston having a respective rod with a cam follower configured to engage a respective one of the cam tracks. Thus, the axial reciprocal motion of the main and brine pistons is totally controlled by the cam member in both directions of motion. In addition, the cam tracks are provided with dwell points or flat spots which are configured to accommodate motor inertia as well as extended switch signals. Another feature is that the cam member also has switch cams which are in registry with corresponding dwell points on the cam tracks, so that the cam member coordinates the position of the pistons with the electronic valve control system. When used as a valve in a water conditioning apparatus with a regeneration cycle, the brine piston is configured to control the fast rinse cycle, and consequently increases flow rates through the system.
More specifically, the present invention provides a water conditioner valve including a main housing configured for providing fluid communication between a plurality of locations, and having first and second valve chambers. A main piston is mounted for reciprocal movement in the first valve chamber and has a main piston rod attached thereto, the main piston rod provided with a main cam follower. Similarly, a supplemental piston is mounted for reciprocal movement in the second valve chamber and has a piston rod attached thereto, the supplemental piston rod provided with a supplemental cam follower. The valve also has a cam member having an axis of rotation, a first cam track for receiving the main cam follower, and a second track for receiving the supplemental cam follower, the cam tracks being constructed and arranged on the cam member so that rotation of the cam member will cause movement of the pistons along a linear axis which is parallel to the axis of the cam member for controlling the relative positions of the pistons in the respective chambers to obtain the desired fluid flow.
In another embodiment, the present invention provides a water conditioner valve for a water conditioning device having a regeneration cycle including service, backwash, eduction, fast rinse and refill components. The valve includes a main housing configured for providing fluid communication between a raw water supply, a treatment tank, a brine tank and a drain, the housing having a main valve chamber and an eductor body. A main piston is mounted for reciprocal movement in said main valve chamber, and a brine piston is mounted for reciprocal movement in the eductor body. A control system is provided for manipulating the pistons in the respective chamber and body to achieve the desired fluid flow to complete the regeneration cycle. The brine piston is configured to perform at least the eduction and the fast rinse steps of the cycle.
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patent: 3457792 (1969-07-01), Fleckenstein
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patent: 5590687 (1997-01-01), Vaughan
Chambers A. Michael
Greer Burns & Crain Ltd.
United States Filter Corporation
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