Abstract:
A single pump control unit can be coupled to first and second float switches and a pump for purposes of removing fluid from a region such as a sump. A supplemental set of contacts can be provided to couple an alarm indicating signal to a remote alarm. An alarm state can also be transmitted wirelessly.

Description:
FIELD OF THE INVENTION 
   The invention pertains to control units for pumps. 
   BACKGROUND OF THE INVENTION 
   Control units for use with various types of fluid pumps, for example, sump pumps, are known. One such system has been disclosed in Kochan, Jr. U.S. Pat. No. 5,449,274 entitled “Sump System Having Timed Switching of Plural Pumps” which issued Sep. 12, 1995. The &#39;274 patent is owned by the assignee hereof and is incorporated herein by reference. 
   The system of the &#39;274 patent provides for alternating control of first and second different pumps. Not all installations need multiple pumps. 
   In another configuration, float switches are known which have a so-called piggy-back plug. The plug includes a socket for a plug for a pump motor. The float switch is in series with the motor. When the float indicates high water the float switch closes and the motor is energized. Pumping continues until the level falls enough to open circuit the switch. 
   While the above configuration is simple, the float switch is subject to full motor current, including start-up currents as well as arcing. Further, there is no convenient way to incorporate a back-up, high water float, or to energize displaced alarms. 
   There continues to be a need for control devices which can be used with a single pump. Preferably, such units would be readily connectable to respective pumps and float switches. It would also be preferable if such units could take advantage of float switches which incorporate piggy-back plugs of a standard variety while at the same time minimizing float switch currents and arcing. 
   Preferably any such connections would be readily changeable for maintenance purposes in the event that either the pump or the associated float switch failed. It would also be desirable to be able to provide remote indications as to the presence of an alarm condition. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of a pump control unit in accordance with the present invention. 
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
   While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention, as well as the best mode of practicing same, and is not intended to limit the invention to the specific embodiment illustrated. 
   Pump control units which embody the present invention can be used with any appropriately sized pump and with a switch having a piggy-back plug. As those of skill in the art understand, in such configurations, the pump motor and switch cable are separate from one another. 
   A pump control unit which embodies the present invention incorporates a housing. The housing carries a fluid level indicating switch receptacle, an alarm switch receptacle, a pump receptacle and an alarm indicating output receptacle. The unit can be energized by locally available AC power. Switches which incorporate piggy-back plugs are readily connectable to the float switch receptacle. A jumper can be connected to a receptacle end of the piggy-back switch. 
   An AC plug coupled to the pump can be plugged into the pump receptacle. If desired, an alarm or monitoring unit can be plugged into the alarm indicating output receptacle. Visual and audible status indicators can also be provided on the unit. 
   The present control unit can be used with any switch that is effective to indicate a fluid level. These include but are not limited to pressure switches, float switches, vertical switches, solid state switches, ultrasonic based switches, all without limitation. 
   An optional RF output port can be included in the unit. The RF output port can wirelessly transmit status information such as normal or alarm to a remote receiver. 
     FIG. 1  illustrates a pump control unit  10  in accordance with the invention. The unit  10  includes a housing  12 , which might be wall mountable. Housing  12  carries a plurality of connectors, which could be implemented as standard AC-type receptacles. 
   The connectors include connector  14   a  to which can be coupled a piggy-back-type switch plug. A second connector  14   b  can be used to couple an alarm switch to the unit  10 . As noted above, unit  10  can be used with a variety of fluid level indicating switches. 
   Output connector or receptacle  14   c  can be used to provide electrical energy to a pump via a standard AC-type plug. Output connector or receptacle  14   d  can be used to couple an electrical state, normally open, normally closed, of a switchable output device to a remote alarm or monitor  16 . 
   Electrical energy can be provided to the unit  10  via a standard AC-type plug and cord  20 . Electrical energy received from the plug and cord  20  can be used in part to energize a power supply, for example, a 12 volt AC or DC power supply  22 . 
   One output from the supply  22  can be used to energize a “power on” indicating light emitting diode  24   a . The output from the supply  22  can be coupled to contacts on connectors or receptacles  14   a, b  via line  22   a . Electrical signals in the form of relatively low voltage or a low current from supply  22  via line  22   a  can be coupled via connector  14   a  to a level indicating switch  30   a  via a piggy-back connector/receptacle  30   b . Feedback, a voltage or current can be coupled via line  22   b , in response to a normally closed switch  30   a  to a switch module  32 . 
   The switch module  32  whose outputs can switch utility supplied AC received via plug and cord  20  can be used to couple electrical energy to pump receptacle  14   c  to energize pump  36  in response to a switch closure at the switch  30   a . Simultaneously, status indicator  24   b  can be energized to emit output light indicative of normal operation of the pump  36 . 
   Alternately, in the event of a failure of the primary pump switch  30   a , if the alarm level switch  30   c  is closed (or opened) due to the high water, electrical signals via line  22   a  can be coupled via line  22   c  through an isolation diode D 2  to cause the switch module  32  to change state and activate pump  36 . Simultaneously, alarm indicating visual indicators, such as light emitting diode  24   c  or audible alarm indicating output  24   d  could be activated. 
   The unit  10  will continue to energize the pump  36  until either or both the alarm indicating switch  30   c  or normal level indicating switch  30   a  return to their unactivated states. 
   When the alarm indicating signal is coupled via line  22   c  to the switch module  32 , it can also be simultaneously coupled to an alarm indicating output switch module  38 . The switch modules  32 ,  38  could be implemented as electromechanical or solid state switches that can provide normally closed, normally opened output contacts via connector  14   c, d  to energize pump  36  or to indicate an alarm condition to the remote alarm or monitor  16 . 
   RF output port  40  can be provided with an appropriate antenna  40   a  to wirelessly communicate alarm conditions via a remote receiver. 
   To take advantage of the configuration of the piggy-back switch receptacle/plug  30   b  a jumper  30   d  can be provided and coupled thereto to complete the circuit between lines  22   a, b  when the switch  30   a  has changed state and gone from an open circuit condition to a closed circuit condition (or vice versa). As those of skill in the art will understand, unit  10  limits the current and voltage coupled to float switches  30   a, c . For example, output voltage from supply  22  can be limited to 12 volts AC or DC with currents limited to milli-amps. In addition, motor start-up currents do not flow through switches  30   a, c . They flow through power output contacts of switch modules  32 ,  38 . These circuit configurations should not only promote longer operating lives for the switches such as  30   a, c , but they provide additional operational flexibility for the user. 
   If desired, a battery back-up can be provided for the power supply  22 . It will also be understood that the control circuits of unit  10  could be implemented, at least in part, with a programmed processor and associated control software. 
   From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.