Abstract:
An improved hand piece apparatus for use with abrasive cleaning devices uses a control switch that can be controlled manually by an operator to controllably regulate the amount a mixture of a pressurized air with abrasive particles at the nozzle head inlet port of the nozzle head assembly.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a hand piece apparatus that can be used in cleaning devices in order to remove and capture dirt and debris from a surface by using abrasive particles with mixture of high pressurized air and vacuum. More particularly, the invention relates to a hand piece that can controllably regulate the amount of the pressure applied to a surface and the pressurized abrasive particles in hand piece can also be limited from circulation or can be blocked completely at the hand piece&#39;s nozzle head assembly for safe operational use. 
     BACKGROUND OF THE INVENTION 
     Abrasive cleaning devices are well known as surfacing applicators to treat surfaces for cleaning, smoothing, etching and resurfacing a damaged area such as human skin. These devices operate on a high stream of a pressurized air or vacuum suction to carry abrasive particles to be impinged against the surface. The high pressure of abrasive particles removes dirt and debris from a surface and provides an extremely satisfactory cleaning means. However, considerable risks are involved with such pressurized abrasive cleaning operations. Many of the cleaning operations such as resurfacing human skin are performed near or on the face area. The pressurized abrasive particles along with its dust form particles may cause hazardous health risk to the patient and the operator. Therefore, it is necessary for the operator to visually monitor and control the amount of pressure applied to a surface with a controllable hand piece that can conveniently function at the operator&#39;s command. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an improved hand piece apparatus for use with abrasive cleaning devices. This hand piece uses a control switch that can controllably regulate the amount of pressure applied on a surface. The control switch preferably is a dial switch and located inside the nozzle head assembly of the hand piece and easily accessible by an operator. 
     It is another object of this invention to enable the operator to use the control dial switch to limit or block the stream of the pressurized abrasive particles. This control switch conveniently provides three positions: full-flow pressure, low-flow pressure and shut-off or block position. 
     It is still another object of this invention to use a handle that is ergonomically designed for ease of operational use and conveniently enable the operator to access the control switch thereof. 
     It is also another object of the present invention to connect the nozzle head assembly inlet port and outlet port to a pair of vacuum tubes in order to reduce the residue of the hand piece material on a treating surface. The preference of this invention is to eliminate any lumens in the handle for purpose of high pressure passages. 
     These objects are attained by using a hand piece that comprises a housing assembly, a nozzle head assembly and a pair of vacuum tubes. The hand piece&#39;s housing assembly also includes a nosepiece with a protruded frontal hole for purpose of contacting the debris surfaces, a handle consist of two half members with flat sides and rounded on the top and bottom, and an end piece with an opening for passage of vacuum tubes. The housing assembly of the hand piece further accommodates the nozzle head assembly, which is preferably secured at the nosepiece and the handle. A pair of vacuum tubes from the vacuum source and control unit are connected to the inlet port and outlet port of the nozzle head assembly. The inlet port having a conical opening at the proximal end and an orifice at the distal end for ejecting a mixture of high pressurized air with stream of abrasive particles onto a surface. However, the outlet port of the nozzle head assembly retrieves the abrasive particles along with debris particles from the surface by means of vacuum suction. A control dial switch is placed inside of the nozzle head assembly to manipulate and restrict the applied pressure as enters into the inlet port of the nozzle head assembly. An operator can easily rotate the dial switch in direction of clockwise or counter-clockwise, to control the amount of abrasive particles or simply shut off the flow of abrasive particles in the nozzle head assembly. 
     Further objects and advantages of this invention will become apparent from consideration of the drawings and description that follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Exemplary embodiments of the invention will now be described in conjunction with the drawings in which: 
     FIG. 1 is a side view of the present invention showing a hand piece in conjunction with a vacuum source and control unit. 
     FIG. 2 is a partial cross sectional view of the tip portion of the hand piece shown against a surface. 
     FIG. 3 is a cross sectional view taken along line  3 — 3  in FIG.  2 . 
     FIG. 4 is an exploded view of the nozzle head assembly. 
     FIG. 5 is a similar view to FIG. 2, except the control dial switch shown in reduced or low- pressure position. 
     FIG. 6 is a cross sectional view taken along line  6 — 6  in FIG.  5 . 
     FIG. 7 is a similar view to FIG. 2, except the control dial switch shown in block or shut off position. 
     FIG. 8 is a cross sectional view taken along line  8 — 8  in FIG.  7 . 
     FIG. 9 is an alternative embodiment of the present invention showing the top view of a hand piece and its dial switch located on the top of the device. 
     FIG. 10 is a frontal view thereof. 
     FIG. 11 is a side elevation thereof. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is showing a side view of a hand piece  10  accordance with the present invention for use in abrasive cleaning devices. The hand piece  10  comprises a housing assembly  11 , a nozzle head assembly  18  and a pair of vacuum tubes  24 ,  26 . The housing assembly  11  of the hand piece  10  further includes a nosepiece  16 , a handle  14 , and end piece  12 . The nosepiece  16  having a protruded opening  17  for contacting a surface such as human skin  32  and at its distal end  16   a  connected to the proximal end of a handle  14   b.  The distal end of the handle  14   a  is also connected to the proximal end of the end piece  12   a.  The handle  14  also formed in a curvature or bend shape to provide an ergonomic way of using the hand piece  10  and ultimately provide the ease of the operational use to an operator&#39;s hand  30 . 
     Referring to FIG.  1  and FIG. 2, the nozzle head assembly  18  is secured within the housing assembly and located between the nosepiece  16  and handle  14 . The nozzle head assembly  18  includes a main body  18   a  with inlet port  50  and outlet port  60 , and a control dial switch  20 . 
     A vacuum source  28  provides a high pressurized air with mixture of abrasive particles  26  and passing it through a vacuum tube  27 . Then the pressure enters the inlet port  50  of the nozzle head assembly  18 . The conical opening  50   a  of the inlet port  50  direct the pressure into the controllable dial switch  20  and then passes it into a smaller bore known as a nozzle port  40 . The pressurized abrasive particles  26  eject from the nozzle orifice  52   b  with a high velocity and strike against a surface  52  to remove and release the debris particles from a surface  52 . The applied pressure  38  on the surface  52  can also be manipulated with dial switch  20  to provide various velocities and desire pressure to strike the surface  52 . The control dial switch  20  pivotally connected  58  to the central hole  66  of a main body  18   a  of the nozzle head assembly  18  and rotates in direction of clockwise or counter-clockwise to provide various pressure settings as best shown in FIG.  4 . Furthermore, the dial switch includes two various nozzle ports  20   a,    20   b  and a blockage wall  20   c  to restrict the flow as needed by an operator. 
     After striking the particles onto a surface  52 , a vacuum suction retrieves the particles  54  and directs them into the suction vacuum port  56  of the nozzle head assembly  18  and ultimalty exited from the outlet port  60 . The particles return to a vacuum source and a control unit  28  to be filtered and to be used again in the recycling process. 
     FIGS. 2-3 and FIGS. 5-8 showing a different position of the dial switch  20  with respect to pressurized abrasive particles  26  and the function of a hand piece  10 . 
     In FIGS. 5-6, the dial setting is set for a smaller nozzle port  20   b  to provide a smaller amount of pressurized abrasive particles to a surface. 
     In FIGS. 7-8, the dial setting is set for a block wall  20   c  to block the pressurized abrasive particles from circulation. 
     FIGS. 9-11 is shown the alternative embodiment of the hand piece  80  with straight handle  84 , a nosepiece  88  and end piece  86 . The control switch  82  is located on the top of the hand piece  80 . 
     While this invention is susceptible of embodiments in many different forms, this specification and the accompanying drawings disclose only some specific forms as examples of the invention. The invention is not intended to be limited to the embodiments so described, however, the scope of the invention is pointed out in the appended claims.