Abstract:
The present invention provides an assembly of machined or precision cast components which combine to form a high pressure water powered rotary tool. The rotary tool includes a rigid metal housing, a high pressure water inlet, an impeller rotatably mounted within the housing, an output drive shaft, a backing disk and at least one handgrip or alternatively an extendable handle capable of articulation throughout an extended range. The rotary tool is attachable to a pump driven by an electric motor or internal combustion engine.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of applicant&#39;s co-pending U.S. application Ser. No. 11/102,110 entitled Water Driven Motor filed Apr. 7, 2005 the contents of which are hereby incorporated by reference in their entirety. 

   FIELD OF THE INVENTION 
   This invention relates generally to high pressure water powered tools. More specifically, the present invention relates to a high pressure water powered rotary tool used for grinding, polishing, or sanding of many surfaces, including stone, cement, fiberglass, wood and metal surfaces, wherein the tool is generally used in a water containing or wet environment. 
   BACKGROUND INFORMATION 
   Throughout industry and within the home, a need exists for tools that can be safely used within wet environments. This is particularly true of areas in and around swimming pools where a high risk of electrical shock exists with the utilization of conventional power tools. 
   Water driven rotational tools are known in the prior art. U.S. Pat. No. 1,905,424 issued to R. Schlieper, dated Apr. 25, 1933, shows a water driven washing apparatus which is a cleaning apparatus for cars that uses pressurized water supplied via a garden hose to provide rotary motion to a sponge. The exhausting water is deflected downwardly through a disc having a plurality of apertures into a sponge that is used to wash a vehicle. 
   U.S. Pat. No. 4,193,228 issued to Bowler, dated Mar. 18, 1980, provides a water-driven tool that can be used for polishing tile around a swimming pool or shower in a wet environment. 
   U.S. Pat. No. 4,463,525 issued to Sheber, dated Aug. 7, 1984, shows a hand-held cleaning tool with a remote water turbine power source contained in a floating housing. The outlet of the water turbine is connected to one end of a suction hose. A flexible drive cable assembly has one end connected to the cleaning tool and the other end connected to the water turbine. 
   U.S. Pat. No. 5,620,364 issued to Torrance et al., dated Apr. 15, 1997, shows a hand-held water-driven rotary tool. The tool uses water pressure to drive an internal impeller and reducer gear to create the torque required for use. A major drawback of this device is the requirement of an internal gear-train. The impeller must rotate at about 20,000 RPM to create the torque necessary to spin the cutting disc at 3,000 to 4,000 RPM, which is the required speed necessary to complete an ordinary job. The heat generated at 20,000 RPM tends to wear down the internal bearings which can ultimately lead to the bearing spinning faster than the shaft. This decreases the torque, creating cavitation, internal damage and insufficient performance. 
   U.S. Pat. No. 6,203,415 issued to Torrance-Castanza et al., dated Mar. 20, 2001, shows a direct-drive, water-driven rotary tool. The device includes a housing having a central cavity, an impeller with angled, beveled blades around its periphery, a drive shaft connected to a rotatable mounting pad or backing pad that contains a disc with a grinding or sanding surface that is removably attached thereto. The device also includes a high pressure water inlet conduit having a changeable nozzle to allow using the tool with different water sources to maintain a constant RPM. The water exiting the nozzle strikes the blades of the impeller, rotating the impeller, which rotates the backing pad and sanding disc. Exhausting water is diverted downwardly through a bearing mounting plate having holes that allows the expended water from the impeller to be expelled peripherally around the outside of the main cavity of the housing. The device also includes a manually-actuated trigger for the inlet water valve which can be held at the same time as a D-shaped handle affixed directly on the housing. 
   While the prior art devices are suitable for use in wet environments, they include numerous drawbacks. One such drawback has prevented the prior art devices from use in heavy duty applications. The drawback relates to the torque the prior art devices are capable of developing. Grinding soft surfaces or washing the paint on a vehicle only requires a small amount of torque to complete the task. However, heavy duty applications, such as grinding hard materials, e.g. granite or structural concrete, requires significantly more torque. The impeller constructions of the prior art typically utilize an impeller which has a single side plate. The single side plate includes a plurality of upwardly projecting curved blades which the water is impacted against. This construction does not adequately control the flow path of high pressure water. The single side plate allows the water to flow over the top of the blades to impact opposing blades causing drag on the impeller. The result is reduced efficiency and reduced torque. 
   Another problem with the devices shown in the prior art is that they do not sufficiently control the exhausting water. The failure to control the exhausting water prevents their use in environments that must be kept substantially dry. For example, it is becoming common to cast counter tops from structural concrete. The counter tops are cast in place within the home. After casting, the concrete requires grinding and polishing to create a suitable surface finish for home interiors. The devices shown by Torrance-Castanza exhaust water in a generally uncontrolled manner through a plurality of apertures in the lower portion of the device. The water is directed downwardly around the entire periphery of the device onto the backing pad. The backing pad spins at a high rate of speed causing the exhausted water to spray outwardly throughout a large circumference, making this construction unsuitable for working in environments which must be kept substantially dry. 
   The present invention overcomes these problems by providing a high torque water-driven tool which provides a controlled exhaust. The device includes a hydrodynamically designed impeller within a hydrodynamically designed housing to provide substantially increased control of water flow when compared to the prior art. The controlled flow of high pressure water through the motor provides increased efficiency and directed exhaust. The device can be specially adapted for a plurality of uses within a wet environment such as a pool where it would not be practical to provide electrical power directly to the tool due to the dangers of electrocution. The device can also be utilized within closed generally dry environments without the destructive over-spray of the prior art. The grinding device may be utilized for grinding or polishing stones, cement, fiberglass, and even wood and metal surfaces. 
   Also, from a versatility standpoint, the assembled device is lightweight and easily manipulated. The device includes at least one fixed handgrip for tasks in close proximity to the operator. The device accommodates an extendable handle which permits a complete range of articulation for tasks which require extended operator reach. 
   There are also commercial considerations that are satisfied by the viable water driven rotary tool device; considerations which are not entirely satisfied by state of the art products. The water driven rotary tool is formed of relatively few component parts that are inexpensive to manufacture by conventional techniques. In addition, the device components are formed of corrosion resistant materials for long useful life. 
   BRIEF DESCRIPTION OF THE INVENTION 
   The present invention provides an assembly of machined or precision cast components which combine to form a high pressure water powered rotary tool. The rotary tool includes a rigid metal housing, a high pressure water inlet, an impeller rotatably mounted within the housing, an output drive shaft, a backing disc and at least one handgrip, or alternatively an extendable handle for an extended reach. The rotary tool is attachable to a water pump driven by an electric motor or internal combustion engine. 
   The housing is generally constructed from a material such as anodized aluminum. The housing includes a centrally located impeller cavity for containing the rotatably mounted impeller. The housing preferably includes an upper portion and a lower portion, the lower portion includes a removable and replaceable bearing suitable to support the drive shaft. The drive shaft extends through the impeller, the bearing, the housing and a backing disk to insure rotation of the backing disk with the impeller. 
   The impeller cavity includes a unique exhaust channel which diverts the water away from the impeller and through an exhaust aperture in a controlled manner. The exhaust channel is generally oval in shape and extends around a portion of the impeller cavity. The centrifugal force generated by the spinning impeller causes the water to flow away from the impeller and through the exhaust aperture. This method allows the duration that the water contacts the impeller to be accurately controlled, reducing drag and thereby increasing the efficiency of the device. This construction also allows the maximum power to be produced by the high pressure water supplied to the device. 
   The housing also includes a plurality of integrally formed bosses. One of the bosses is utilized for attaching a rigidly mounted handgrip or an extended handle. The handle may include extensions for long reach applications and/or a universal type coupling pivotal movement throughout an extended range. An integrally machined inlet conduit is utilized to attach the water powered rotary tool to a source of high pressure water. A removable and replaceable water nozzle is positioned within the water inlet to direct a high pressure water jet into the impeller at an angle substantially perpendicular to the impeller&#39;s axis of rotation. Directing the water into the impeller perpendicular to the impeller&#39;s axis of rotation results in a high impulse-momentum force being imparted to the impeller for a given water pressure or flow. The water nozzle is interchangeable to control the rotational speed and/or torque developed by the tool. The water nozzle includes an inner aperture which may be varied in diameter and/or constructed to direct a narrow or wide angle high pressure spray into the impeller to cause the water to strike one or more of the chevron shaped impeller vanes causing rotation. The various nozzle configurations may be utilized to produce the desired torque and/or revolutions per minute suitable for the working surface. 
   The impeller is a unique design having a predetermined number of vanes, each vane includes a chevron shape and cusped edges to improve performance and more equally disperse the load across a plurality of vanes. The impeller includes a pair of side discs which control the flow of the water by preventing the water from spilling over either the top or the bottom of the vanes thereby increasing rotational torque developed by the device. The output drive shaft is secured through the center of the impeller extending outwardly from either side. The drive shaft includes sufficient length to engage the impeller and the bearing incorporated into the lower portion of the housing to provide bearing support for the impeller and the backing disc. The drive shaft includes sufficient length to extend through the impeller as well as an aperture in the lower portion of the housing for securement to the backing disc. The backing disc includes a means of attaching polishing, sanding or grinding materials, well known in the art, thereto. 
   A hand actuated trigger assembly may be attached to the hand grip or extended handle to operate a water inlet valve assembly. The water inlet valve assembly allows the water to be turned on and off to the device. The high pressure water is typically supplied by a gas engine or electric motor turning a pump as is well known in the art. These devices typically supply between 1 and 8 gallons of water per minute at about 1000 pounds per square inch or more. 
   The water inlet valve includes a valve actuating trigger or lever that can be squeezed with a person&#39;s hand. Water received from the high pressure water source comes through an inlet conduit and the nozzle to strike the impeller, causing the drive shaft to rotate as the impeller rotates, which in turn rotates the backing pad. The water that is expended against the impeller blades is centrifugally evacuated through the exhaust channel which directs the water outwardly through the exhaust aperture and away from the backing pad. 
   It is therefore an objective of this invention to provide a high-pressure water driven rotary tool capable of delivering high torque especially used for sanding, grinding or polishing within a dry or wet environment without danger of electrical shock. 
   Another objective of the instant invention is to provide a water driven rotary tool which includes a unique impeller construction having a pair of side plates to produce high torque rotary motion. 
   It is yet another objective of the present invention to provide a water driven rotary tool which includes a unique exhaust channel which utilizes centrifugal force to provide controlled exhaust of water in contact with impeller vanes to reduce parasitic losses caused thereby. 
   Other objectives and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 

   
     BRIEF DESCRIPTION OF THE FIGURES 
       FIG. 1  is a top perspective view of the instant invention; 
       FIG. 2  is a front elevational view of the instant invention; 
       FIG. 3  is a top view of the instant invention; 
       FIG. 4  is a bottom perspective exploded view of the water motor utilized in the instant invention; 
       FIG. 5  is a section view of the instant invention taken along line  1 - 1  of  FIG. 2 ; 
       FIG. 6  is a section view of the instant invention taken along line  2 - 2  of  FIG. 3 ; 
       FIG. 7  is a section view of the instant invention taken along line  3 - 3  of  FIG. 3 ; 
       FIG. 8  is a top view of the impeller utilized in the instant invention illustrating the vane construction, the upper side plate having been omitted for clarity; 
       FIG. 9  is a bottom view of the upper portion of the housing, the remaining components having been omitted for clarity. 
       FIG. 10  is a perspective view illustrating a valve assembly suitable for use with the instant invention; 
       FIG. 11  is a side view of an extended handle for use with the instant invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
   Referring to  FIGS. 1-9 , the preferred embodiment of the water powered rotary tool  10  is illustrated. The water powered rotary tool generally includes a housing  12 , the housing including an upper portion  14  and a lower portion  16 . The lower portion includes a removable and replaceable first bearing  18 . The first bearing is axially aligned within a centrally located impeller cavity  20 . A water inlet  28  is centrally located within an integrally formed conduit  29  for allowing high pressure water into the impeller cavity  20 . The impeller cavity includes an upper portion  22  and a lower portion  24 . The lower portion of the impeller cavity having a substantially cylindrical shape when viewed from the top while the upper portion of the impeller cavity includes an exhaust channel  26  giving the exhaust channel a substantially oval shape. The exhaust channel  26  is constructed and arranged to utilize centrifugal force to direct the high pressure water to a water exhaust  30  for exhausting the high pressure water from the impeller cavity. A water inlet nozzle  82  and the exhaust channel  26  are positioned to control the duration in which the high pressure water is in contact with the impeller  40 . In a most preferred, but non-limiting embodiment, the water remains in contact with the impeller between 90 and 180 degrees. In this manner the instant invention eliminates a substantial portion of the parasitic losses found within the prior art. 
   Still referring to  FIGS. 1-9 , the housing includes a plurality of integrally formed bosses  32  on an external surface thereof. Each boss includes a threaded aperture  34  for removable attachment of a handgrip  36  or extendable handle  38  ( FIG. 11 ). 
   Referring to  FIGS. 4-8  the preferred embodiment of the impeller  40  is illustrated. The impeller includes an upper side plate  42  and a lower side plate  44 . Extending between said side plates are a plurality of chevron shaped vanes  46  having cusped edges  47  for increased performance. In a most preferred embodiment the impeller includes about nineteen vanes arranged around the perimeter of the impeller. The impeller also includes a centrally located aperture  48  for a drive shaft  50 . The drive shaft  50  defines an axis of rotation A for the impeller. The drive shaft  50  extends through the impeller aperture  48  and engage the impeller as well as the first bearing  18 . The drive shaft includes sufficient length to extend through aperture  52  centrally located in said lower portion of the housing  16  for attachment to a backing disc  54 . The upper portion of the drive shaft  56  includes an inner key-way  58  and a threaded stem  60 . The key-way aligns with outer key-way  62  in the impeller aperture  48  and lock-nut  64  engages the threaded stem  60  to secure the impeller and the drive shaft securely together. In this manner the impeller and the drive shaft rotate together, and the upper and lower impeller side plates are prevented from separation. The lower portion of the drive shaft  62  includes a threaded portion  64  and a flange  66  for attachment to the backing disk  54 . The backing disk  54  is constructed and arranged for attachment of an abrasive medium (not shown) to the drive shaft, wherein rotation of the impeller causes rotation of the backing disk for grinding, polishing etc. The backing disk may include hook and loop, adhesive, snaps or other means of securing the abrasive medium to the backing disk which are well known in the art. 
   Referring to  FIGS. 1-6  and  11 , a handgrip  36  for operator manipulation of the water powered rotary tool is illustrated. The handgrip  36  includes a threaded stem  70  for removable attachment to one of the integrally formed bosses  32 . The handgrip may be removed and the extendable handle  38  may be secured in its place via a standard fastener placed through aperture  72 . The extendable handle includes a universal joint  74  which allows the handle to be articulated through a large range. The extendable handle may include a telescoping section (not shown), well known in the art for varying the length of the extendable handle. 
   Referring to  FIG. 10 , a water inlet valve  76  is illustrated. The water inlet valve is generally constructed and arranged for connecting the water powered rotary tool  10  to a source of high pressure water. Sources of high pressure water are well known in the art and may include an internal combustion engine or electric motor for rotating a water pump. A flexible hose member  78  extends between the source of high pressure water and the water inlet valve. A hand actuated trigger assembly  80  may be attached to the water inlet valve, hand grip or universal handle to operate a water inlet valve assembly. The valve actuating trigger may be squeezed with a person&#39;s hand to allow the water to be turned on and off to the device. The water inlet valve may be threadably coupled directly to the water inlet  28  or alternatively, a second flexible member  82  may be utilized in conjunction with the extendable handle. 
   Referring to  FIGS. 1-10 , in operation high pressure water is received from the high pressure water source through the flexible hose member  78 . Depression of the valve assembly trigger  80  allows the water to flow into inlet conduit  28  and the nozzle  82  to strike the impeller  40 , wherein the high pressure water impacts the impeller vanes  46  at an angle substantially perpendicular to the axis of rotation A causing rotation of the impeller and the drive shaft  50  which in turn rotates the backing pad  54 . The water that is impacted against the impeller vanes is centrifugally evacuated through the exhaust channel  26  which directs the water outwardly through the exhaust aperture  30  and away from the backing pad. 
   In the preferred embodiment, the components comprising the housing are formed of, but not limited to, a suitable metal material through the process of machining or precision casting. In a most preferred embodiment the housing is formed of hard anodized aluminum for minimum weight and corrosion resistance. In the preferred embodiment, the components comprising the impeller and drive shaft are formed of, but not limited to, a suitable metal material through the process of machining or precision casting. In a most preferred embodiment the impeller and the drive shaft are formed of stainless steel. The result is that the components comprising the water powered rotary tool  10  are lightweight and corrosion resistant leaving the external surface in a generally smooth condition for aesthetic purposes, as shown in  FIG. 1 . 
   All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. 
   It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification. 
   One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.