You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates generally to submersible tools and, more specifically, to a Spa and Pool Step Vacuum.  
         [0003]     2. Description of Related Art  
         [0004]     Swimming pool and hot tubs (“spas”) need periodic cleaning to remove debris that either grows or falls into the pool or spa. When cleaning a pool, it is conventional to use a vacuum cleaning device that gets its suction from the pool&#39;s permanent filtration system. These “non-portable” vacuum cleaners will generally have a flexible hose that connects to one of the filter intake ports at the side of the pool. Items vacuumed up by the non-portable vacuum cleaners are taken out of the pool and into the main pool filter bank. The non-portable pool vacuum is very suitable for cleaning large, substantially flat and smooth expanses in the pool.  
         [0005]     When smaller, more intricate areas, such as spas or pool steps, need cleaning, the non-portable pool vacuum is not very effective. In response, a variety of manual and electric “portable” pool vacuums have been introduced. Portable pool vacuums are typically smaller than the non-portable types, and they further do not require a long hose connected to the pool or spa&#39;s filtration system. One version of a portable pool vacuum is depicted below in  FIG. 1 .  
         [0006]      FIG. 1  is a side view of the prior art pool vacuum apparatus  10  of Goertzen, III et al., U.S. Pat. No. 3,755,843. The Goertzen portable pool vacuum  10  has an onboard pump  26  that sucks water through the head  14  and hose  24 , and then filters out any entrained debris in an encapsulated filtration unit  16 . The pump  26  obtains its electrical power from an external battery  30 , via a waterproof cable  32 .  
         [0007]     While the Goertzen apparatus  10  appears to be more maneuverable than a non-portable vacuum, it still has more than one problem related to it. First, the head  14  includes a pair of fairly large wheels, and is therefore fairly unwieldy to move around. Next, the battery  30  power supply is not incorporated within the device  10 ; as a result, the user has to manage the cable  32  and the cell  30 . Further, the filter unit  16  is a specialized filter cartridge that is typically limited in availability and expensive. Finally, placing the pump  26  at the upper end of the apparatus  10  does not assist the user in forcing the vacuum against the bottom—placement at or near the bottom of the vacuum  10  (i.e. near the head  14 ) would be more advantageous. A portable pool vacuum is needed that solves at least these problems with the Goetzen vacuum  10 .  FIG. 2  depicts another prior pool vacuum.  
         [0008]      FIG. 2  is a side view of the prior art pool vacuum cleaner  1  of Schuman, U.S. Pat. No. 4,962,559. The Schuman vacuum cleaner  1  has a brush head  2  which is defined by an integrated hose/pipe through its center. The pipe/hose leads to a filter housing  25  for retaining a pleated filter element. After being filtered, incoming water flows out through a gap formed between the filter housing  25  and the adjacent motor housing  39 . Adjacent to the motor housing is the battery housing  53 , which transitions into the handle  57  that is held onto by the user.  
         [0009]     The Schuman device also has deficiencies. First, the battery housing  53  is located in a submerged portion of the device  1 —this adds substantial weight to the device in a place that will interfere with easy movement around the pool, and will further make battery change-out more difficult the vacuum  1  in the vicinity of the battery housing  53  must be completely dry before, during and after any battery maintenance is done. Furthermore, like Goertzen device, the Schuman vacuum uses a filter housing having a filter cartridge. The large size of Schuman also prevents the convenient cleaning of intricate areas. What is needed is a portable pool vacuum that solves these problems.  
       SUMMARY OF THE INVENTION  
       [0010]     In light of the aforementioned problems associated with the prior devices, it is an object of the present invention to provide a Spa and Pool Step Vacuum. The vacuum device should incorporate a submersible pump for maximum utility. The device should be lightweight and portable and not require a hardwired electrical supply. The device should further include a removable external filter sack or bag to provide maximum filtration capacity with the minimum of weight and drag. The vacuum should further provide a tapered nozzle having a roller to create the desired air gap between the tip of the nozzle and the surface being cleaned.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, of which:  
         [0012]      FIG. 1  is a side view of the prior art pool vacuum apparatus of Goertzen;  
         [0013]      FIG. 2  is a side view of the prior art pool vacuum cleaner of Schuman;  
         [0014]      FIG. 3  is perspective view of the spa and pool step vacuum of the present invention;  
         [0015]      FIG. 4  is a partially exploded perspective view of the vacuum of  FIG. 3 ;  
         [0016]      FIG. 5  is a partial cutaway side view of the vacuum of  FIGS. 3 and 4 ; and  
         [0017]      FIG. 6  is an exploded perspective view of the head assembly of the vacuum of  FIGS. 3-5 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a Spa and Pool Step Vacuum.  
         [0019]     The present invention can best be understood by initial consideration of  FIG. 3 .  FIG. 3  is perspective view of the spa and pool step vacuum  11  of the present invention. The vacuum  11  comprises an elongated handle assembly  13 , a head assembly  15  extending from the handle assembly  13 , and a filter bag  17  attached to the head assembly  15 . All of the submersible components are waterproof and suitable for submersing in water, and particularly in water having the chemical composition of a typical pool or hot tub/spa. If we now turn to  FIG. 4 , we can examine the present invention in more detail.  
         [0020]      FIG. 4  is a partially exploded perspective view of the vacuum  11  of  FIG. 3 . The head assembly  15  comprises a motor/pump assembly  18 , from which extends a nozzle  20  and a socket member  22 . The socket member  22  is configured to accept an end of the handle assembly  13  therewithin, and more specifically, the extension member  25  element of the handle assembly  13 . The extension member  25  is accepted within a coupling  28  at its other end; the coupling  28  also forms one end of the battery compartment  27 . While the extension member  25  is detachable from the coupling  28  for storage, the coupling  28  is sealed to the battery compartment  27 . At the other end of the battery compartment  27  is attached the control module  30 . The control module  30  is sealed to the battery compartment  27 , and provides a switch  34  for turning the device on and off. The control module  30  also has a battery access cap  32 , which threadedly engages the head  30  to seal the interior of the compartment  27  against water intrusion. Still further, the head  30  has a power supply jack  36  for plugging in a DC power source for recharging the batteries within the battery compartment  27 . Proceeding to  FIG. 5 , we can delve deeper into the features of this invention.  
         [0021]      FIG. 5  is a partial cutaway side view of the vacuum  11  of  FIGS. 3 and 4 . In this embodiment, the rechargeable or nonrechargable batteries  38  are retained within the otherwise hollow extension member  25 . The coupling  28  provides the interconnection between the battery compartment  27  and the extension member  25 . The coupling  28  further provides electrical connection between the batteries  38  and the extension member  25  (for use in the head assembly  15 ).  
         [0022]     The extension member  25  is essentially hollow except for the electrical leads running down its length from the battery compartment  27  to the head assembly  15 . The head assembly  15  houses the battery-powered motor  49  which drives the pump impeller  46  to create water flow in through the mouth  42  and throat  40  of the head assembly  15 .  
         [0023]     Of particular note in this design are two features: the mouth  42  is at an angle to the axis defined by the extension member  25  in order to make it easier to place the opening of the mouth  42  flat or nearly flat against the surface being vacuumed. Second, the mouth  42  has a roller  44  extending slightly out from the throat  40  through the mouth  42 . The roller  44  provides the user with a place to rest the device while vacuuming, while also creating slight standoff or gap between the mouth  42  and the surface being vacuumed so that larger items can be sucked into the mouth  42  even while resting or rolling on the roller  44 . The gap created by the roller  44  also provides supplemental water flow into the throat  40  to assist in carrying debris through the pump and out through the discharge stem  48 . The filter bag (see  FIG. 3 ) is attachable to the discharge stem  48  to capture debris exiting the head assembly  15 . Allowing the filter bag (see  FIG. 3 ) to be attached to the exterior of the device  11  reduces the weight of the device  11 , and also makes filter changes and cleanings very simple. Furthermore, bag material is inherently less expensive than a pleated filter cartridge.  
         [0024]     In another non-depicted embodiment, the batteries  38  will be external to the device  11 . In this embodiment, the control module  30  will include a socket for accepting a conventional solid state battery pack, such as those now commonly used for power drills or saws. When recharging of the battery pack of this second type of vacuum is needed, it is a simple matter to release it from the end of the control module  30 , and then drop it into the charging base station (that came with the power tool). Finally turning to  FIG. 6 , we can review the elements of the head assembly  14 .  
         [0025]      FIG. 6  is an exploded perspective view of the head assembly  14  of the vacuum  11  of  FIGS. 3-5 . The roller  44  has an elongate ovoid shape and is further defined by a pair of pegs  60 , one each extending from the two ends. The pegs  60  cooperate with a corresponding pair of apertures  61  adjacent to the sides of the mouth  42 . When the pegs  60  are snapped into place in the apertures  61 , the roller  44  will be held firmly, while still being free to rotate (roll) around the axis formed by the pegs  60 .  
         [0026]     The nozzle  20  is defined by the mouth  42  at its leading end, and then transitions into the bell  56 . The bell  56  is formed with a plurality of tabs  58  extending outwardly therefrom to engage the collar  52  formed in the housing  50 , thereby by securely attaching the bell  56  to the housing  50 .  
         [0027]     Within the housing  50  is further found the motor  49  (within a waterproof container), to which the pump impeller  46  is attached. When the motor  49  is supplied with electrical power, its shaft will rotate and will drive the pump impeller  46  also to rotate. Rotation of the pump impeller  46  will create a suction within the bell  56 , which will draw water and debris into the nozzle  20  and out through the discharge stem  48 . As gasket  54  is held between the housing  50  and the bell  56  in order to prevent water leaking in through the point of connection between the two. The housing  50  then attaches to the extension member (see previous figures) via the socket member  22 .  
         [0028]     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.

Summary:
A Spa and Pool Step Vacuum is disclosed. The vacuum device incorporates a submersible pump. The device is lightweight and portable and does not require a hardwired electrical supply. The device further includes a removable external filter sack or bag to provide maximum filtration capacity with the minimum of weight and drag. The vacuum further provides a tapered nozzle having a roller to create the desired air gap between the tip of the nozzle and the surface being cleaned.