Abstract:
An electrical circuit connects an electric motor of a sump pump to a power source and controls the energization of a sump pump assembly. The assembly includes a motor circuit having a sump pump motor actuation switch and a main winding switch combined into switch assembly. The sump pump motor actuation switch actuates the main winding switch from a normally open position to a closed position, thus energizing the sump pump assembly.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to sump pumps and, more particularly, to sump pump motor circuits for controlling sump pump motors. 
     There are many different types of sump pump motor circuits for use with a sump pump assembly to control a water level in a sump. Sump pump motor assemblies typically include a housing, a stator and a rotor assembly. The housing includes a shell and two end shields and encases at least a portion of the rotor assembly. The rotor assembly includes a rotor core and a rotor shaft coupled to a pump. Typically, the assembly also includes a run winding and a start winding. The start winding is energized during the initial excitation of the motor, and is de-energized as the motor reaches a predetermined operational speed. De-energization of the start windings is often accomplished by a centrifugal switch. 
     Sump pump motor assemblies also include, in addition to the centrifugal switch, a motor start windings switch and a sump pump actuator switch for controlling pump energization. The motor start windings switch energizes the pump when the water level in the sump reaches a predetermined level. The sump pump actuator switch de-energizes the pump when the water level in the sump is reduced below a predetermined depth. 
     Typically the sump pump actuation switch in these sump pump motor circuits is connected to a sump pump motor actuation switch mounted on an insulated circuit board assembly. The sump pump motor actuation switch is quick-connected to the motor start and motor main windings with two electrical leads permanently attached to the windings. A motor start switch is also required and is mounted to a separate insulated circuit board assembly. The motor start switch assembly is also quick-connected to the sump pump separate switch assemblies are required which increase the cost of manufacturing, increase the required assembly times, and increase the probability of mechanical or electrical failure occurring within the sump pump assembly. 
     Accordingly, it would be desirable to provide a more cost-effective and efficient sump pump assembly. In addition, it would be desirable to provide a sump pump motor circuit that is reliable, simple to assemble, and also cost-effective. 
     BRIEF SUMMARY OF THE INVENTION 
     In an exemplary embodiment of the invention, a sump pump motor circuit that is easy to assemble controls the energization of a sump pump assembly in a reliable manner. 
     The sump pump assembly includes a sump pump motor circuit including a sump pump motor actuation switch and a main winding switch. The two switches are included in one switch assembly and as such, only one switch assembly requires mounting hardware and fasteners. The switch assembly is electrically connected between a motor main winding and a power source, and controls the energization of the sump pump assembly without requiring additional switches, mounting fasteners, or mounting brackets. 
     Additionally, the switch assembly is connected to the motor windings using quick connect leads. The switch assembly includes five quick connect terminals which are sized to permit the proper connections with the sump pump assembly. The quick connect terminals mate with specifically sized receiving terminals which are attached to the motor windings. 
     The sump pump assembly requires fewer motor leads, switches, and electrical connections than known switch assemblies. As a result of fewer electrical connections, the probability of mechanical or electrical failure occurring within the sump pump assembly is reduced. Furthermore, the assembly of the sump pump motor circuit is not only simplified, but is more cost-effective than known sump pump assembly circuits. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a sump pump motor assembly in accordance with one embodiment of the present invention; 
     FIG. 2 is side view of a sump pump motor assembly in accordance with a second embodiment of the present invention; and 
     FIG. 3 is a circuit schematic of a switch assembly for the sump pump motor assembly shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a side view of a sump pump motor assembly  10  including a housing  12  including a shell  14 . Shell  14  includes a first end shield  16  and a second end shield  18 , which are mounted to shell  14 . Motor assembly  10  includes a stator assembly  20  and a rotor assembly  22 . Stator assembly  20  includes a stator core  24 , a plurality of stator windings  26 , and a stator bore  28  extending through stator core  24 . Stator windings  26  are positioned circumferentially around stator bore  28 . Rotor assembly  22  includes a rotor core  30 , a rotor bore  32  extending therethrough, and a rotor shaft  34  positioned within rotor bore  32 . 
     A mounting hub  36  is located adjacent an opening  38  which extends through second end shield  18 . Rotor shaft  34  extends through opening  38  and is coupled to a pump impeller (not shown). Motor  10  is cooled by cooling fan  40  mounted on rotor shaft  34 . 
     End shield  16  includes an outer surface  42  upon which a sump pump float switch housing  44  is mounted. A switch assembly (not shown in FIG. 1) is positioned within housing  44  and is electrically connected to a set of three stator winding leads  50 ,  52 , and  54  of motor  10 . A sump pump motor actuation switch  58  is electrically connected to the switch assembly within housing  44  and is connected to a float (not shown). An actuator lever  60  is mechanically connected between a centrifugal actuator mechanism  62  and the switch assembly. Centrifugal actuator mechanism  62  is positioned on rotor shaft  34  within shell  14 . 
     A power source  64  includes leads  66  and  68  which electrically connect to the switch assembly to supply power thereto. Additional lead  72  is not connected to the switch assembly as will be described in detail below. 
     Sump pump motor assembly  10  is typically installed in sumps that accumulate drainage which should not exceed a certain level. Sump pump motor assembly  10  prevents a level of drainage from exceeding a certain level. Sump pump motor assembly  10  is positioned so that, as the drainage level rises, the float connected to sump pump motor actuation switch  58  moves upwardly and actuates the switch assembly. When motor  10  is energized, windings  26  generate a rotating magnetic field that causes rotor shaft  34  to rotate and thereby cause the rotation of the sump pump impeller (not shown). As motor  10  reaches operating speeds, centrifugal mechanism  62  is actuated and the motor start windings (not shown) are cut-out while the motor main windings (not shown) remain energized. 
     FIG. 2 is a side view of an alternative embodiment of a sump pump motor assembly  100  including a housing  112  having a shell  114 . A first end shield  116  and a second end shield  118  are mounted to shell  114 . Sump pump assembly  100  also includes a stator assembly  120  and a rotor assembly  122 . Stator assembly  120  includes a plurality of windings  124  including a start winding (not shown) and a run winding (not shown), a stator core  126 , and a stator bore  128  extending through stator core  126 . Stator windings  124  are positioned circumferentially around stator bore  128 . Rotor assembly  122  includes a rotor core  130 , a rotor shaft  132 , and a rotor bore  134  extending through rotor core  130 . Rotor shaft  132  is positioned within rotor bore  134 . 
     A mounting hub  136  is positioned adjacent an opening  138  in second end shield  118 . Rotor shaft  132  extends through opening  138  and is coupled to a pump impeller (not shown). Cooling fan  140  controls the temperature of motor  100  and is mounted on rotor shaft  132  within shell  114 . 
     A protective housing  142  is mounted on an outer surface  144  of end shield  116  and is secured thereto by means of threaded fasteners  146 . Sump pump float switch housing  148  is mounted to end shield  116  and is positioned within protective housing  142 . Sump pump float switch housing  148  encases a switch assembly (not shown in FIG.  2 ). A set of three stator winding leads,  150 ,  152 , and  154  electrically connect the switch assembly (not shown) to motor  100 . A sump pump motor actuator switch  158  is electrically connected within sump pump float switch housing  148  to the switch assembly (not shown). Sump actuator switch  158  may also be connected to a float (not shown). 
     An actuator lever  160  is electrically connected between the switch assembly (not shown) positioned within sump pump float switch housing  148  and a centrifugal actuator mechanism  162 . Centrifugal actuator mechanism  162  is positioned on pump drive shaft  132  between protective housing  142  and end shield  116 . 
     A power source  164  is electrically connected to the switch assembly (not shown) with leads  166  and  168 . Additional lead  172  is not connected to the switch assembly, but instead by-passes the switch assembly (not shown) and is connected to a grounding lug (not shown) within sump pump switch housing  148 . The connection of lead  172  ensures that any external metallic parts (not shown) of sump pump motor assembly  100  will be grounded. 
     Sump pump motor assembly  100  is typically located in a sump that accumulates drainage which should not exceed a certain level. Sump pump motor assembly  100  prevents the drainage from exceeding that level. Sump pump assembly  100  is positioned so that, as the water level rises, a float (not shown) connected to sump actuation switch  158  will move upwardly and will actuate the switch assembly (not shown). As motor  100  is energized, windings  124  create a rotating magnetic field which causes rotor shaft  132  to rotate and thereby rotate the sump pump impeller (not shown). As motor  100  reaches operating speeds, centrifugal mechanism  162  will be actuated and the motor start windings (not shown) will be cut-out and the motor main windings (not shown) will remain energized. 
     FIG. 3 is a circuit schematic of a motor circuit  198  for a sump pump motor assembly (not shown), such as sump pump motor assembly  10  shown in FIG.  1 . Motor circuit  198  includes a sump pump switch assembly  200  which is enclosed within a switch housing  202 . Switch assembly  200  includes a sump pump motor actuation switch  204  located within switch housing  202  and a main winding switch assembly  206  also located within switch housing  202 . Sump pump motor actuation switch, or float switch,  204  is connected to main winding switch assembly  206 . Main winding switch assembly  206  includes first main winding switch  208 , electrically connected between a first quick disconnect terminal  210  and a second quick disconnect terminal  212 . Main winding switch assembly  206  also includes a second main winding switch  214  electrically connected between a third quick disconnect terminal  216  and a fourth quick disconnect terminal  218 . Sump pump motor actuation switch  204  is adjustable to control the fluid level in a sump such that when elevated, sump pump motor actuation switch  204  can simultaneously actuate first main winding switch  208  and second main winding switch  214  from the open positions to closed positions which energizes motor circuit  198 . 
     A source of electrical power  220  is electrically connected to switch assembly  200 . A first power lead  222  is electrically connected within switch housing  202  to first terminal  210 . A second power lead  224  electrically connects power supply  220  to a third terminal  216 . Lead  226 , similar to lead  72  shown in FIG. 1, extends from a source of ground potential at power supply  220 , by-passes switch assembly  200 , and is connected to a grounding lug  228  located within switch housing  202 . The connection of lead  226  ensures that any external metallic parts (not shown) of motor  10  will be grounded. 
     Switch assembly  200  is also electrically connected to a motor (not shown) positioned within motor housing  240 . A first motor lead  242  is electrically connected between second terminal  212  and a motor main winding  244 . A thermal protector  245  is electrically connected between motor main winding  244  and first main winding switch  208 . Thermal protector  245  can be a conventional thermally activated switch which will open in response to a predetermined temperature of motor main winding  244 . A second motor lead  246  extends from motor housing  240  and is electrically connected between fourth terminal  218  and motor main winding  244 . A third motor lead  248  extends from motor housing  240  and is electrically connected between a fifth quick disconnect terminal  250  positioned within switch assembly  200  and a motor start winding  252 . A centrifugal mechanism switch  254  is electrically connected in circuit  198  between motor start winding  252  and fifth terminal  250 . Centrifugal mechanism switch  254  is normally closed and actuates a centrifugal mechanism (not shown). As the motor (not shown) is initially energized, motor start winding  252  and motor main winding  244  are energized. When the motor reaches operating speeds centrifugal mechanism switch  254  opens and disconnects motor start winding  252  from the source of electrical power  220 . 
     The present invention provides a motor circuit for a sump pump having a minimum number of electrical circuit connections. The circuit is inexpensive, simple, and quick to assemble as compared to known sump pump motor circuits. As such, a cost effective sump pump assembly is provided. 
     While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.