| Hand held electric polisher -> Monitor Keywords |
|
|
  Hand held electric polisherUSPTO Application #: 20060228994Title: Hand held electric polisher Abstract: A polisher has a polishing disc on a shaft driven by a brushless DC motor driven by a motor controller mounted spaced from the polisher and adjacent a ground fault interrupt circuit and a power plug. Power and control wires form a cord that provides communication between a speed control switch, and a speed set switch, mounted on a handle of a polisher housing, which is a magnetic field sensor responsive to a movable magnet. The speed set switch sends a signal to the motor controller either to maintain the current speed of the motor or to allow the speed of the motor to vary in accordance with the output of of the speed control switch. The speed control switch is a variable output switch which can be an optical potentiometer constructed by reflecting light from a light source off a reflective surface forming part of a spring loaded trigger. (end of abstract) Agent: Stiennon & Stiennon - Madison, WI, US Inventor: Charles D. Syverson USPTO Applicaton #: 20060228994 - Class: 451006000 (USPTO) Related Patent Categories: Abrading, Precision Device Or Process - Or With Condition Responsive Control, By Optical Sensor The Patent Description & Claims data below is from USPTO Patent Application 20060228994. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS REFERENCES TO RELATED APPLICATIONS [0001] Not applicable. STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT [0002] Not applicable. BACKGROUND OF THE INVENTION [0003] The invention relates to handheld polishing tools in general, and particularly to tools suitable for polishing glass and plastic. [0004] Glass and plastic windows are essential for all vehicles which are driven or occupied by humans where it is desirable to both be protected within the vehicle and yet be able to observe the environment surrounding the vehicle. Whether visibility is necessary for navigation, safety, reconnaissance, or enjoyment, it is important that the windows formed of glass and plastic be as free of scratches as possible so as not to obscure the vision through the window. However, by their very nature, vehicles such as planes, automobiles, trains, or boats move through the air, and are thus often abraded by particles entrained in the air. Furthermore, windshield wipers can entrap abrasive particles which are then rubbed against the surface of the window, producing scratches. In addition, the chemical activity of rain, cleaning fluids, sea water, or other fluids can chemically etch glass or plastic thereby reducing its transparency. Replacing vehicle windows which have impaired transparency is often not cost-effective. [0005] To extend the life of vehicle windows, techniques have been developed to remove surface imperfections such as scratches, crazing, and chemical etching, by polishing the window surface to remove the optical imperfections, and creating a smooth polished surface. Variable speed drills and polishers exist which can be used with flexible polishing disks which may have polishing surfaces, or which may use polishing compounds which are placed between the polishing disks and the window surface. The polishing process can require a number of steps depending on the depth of the optical imperfections to be removed. It can also be important to control the speed of the polishing disk to control the polishing action, and at the same time to avoid overheating of the window surface. Overheating may result in the formation of particles clumping which can result in scratches, or overheating may cause damage to the window material itself. What is needed is a durable polisher which can operate at high speeds, which can maintain set speeds, and which is lightweight and easy to control. SUMMARY OF THE INVENTION [0006] The handheld electric polisher of this invention has a housing, and a polishing shaft supported on bearings on the housing. The housing has a handle extending at approximately right angles to a polishing shaft and integrally formed with the housing. The polisher is driven by a brushless DC motor which has a rotor of permanent magnets mounted to a motor shaft. The motor shaft is mounted to the housing by bearings. The motor shaft terminates in a helical gear which forms a helical pinion gear with a helical wheel gear mounted to the polishing shaft. The gearing ratio between the pinion and the wheel is approximately five, so that when the motor speed is varied between 12,500 rpm to 27,500 rpm, the speed of the polishing shaft varies between about 2,500 and 5,500 rpm. [0007] The brushless DC motor has a steel laminated core with three or six windings which are driven by a motor controller which is mounted with a ground fault interrupt circuit at a power plug. The motor controller supplies power through three wires extending between the controller and a polisher housing so that the motor controller is spaced from the polisher housing. Four control wires run along the three power wires, to form a seven wire cable that provides a communications link to a speed control switch, and to a speed set switch mounted on the handle. The speed control switch is the variable output switch. The output of the variable switch is used to control the speed of the motor through the controller. The speed set switch sends a signal to the motor controller either to maintain the current speed of the motor or to allow the speed of the motor to vary in accordance with the output of of the speed control switch. The speed set switch is a magnetic field sensor which is mounted in the handle of the housing and actuated by a movable magnet. The speed control switch is an optical potentiometer constructed by reflecting light from a light source off a reflective surface mounted to a spring loaded trigger. [0008] It is a feature of the present invention to provide an electric handheld polisher with increased durability. [0009] It is another feature of the present invention to provide an electric handheld polisher of lighter weight. [0010] It is a further feature of the present invention to provide an electric handheld polisher on which a water spray is mounted. [0011] It is yet another feature of the present invention to provide an electric handheld polisher which separates the motor controller from the motor housing. [0012] Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0013] FIG. 1 is an illustrative view of the polisher of this invention, with one half of the housing removed. [0014] FIG. 2 is enlarged fragmentary view of the speed control trigger and sensor of the polisher of FIG. 1. [0015] FIG. 3 is an enlarged fragmentary view of a speed set switch and magnetic sensor of the polisher of FIG. 1 [0016] FIG. 4 is a schematic view of the polisher of FIG. 1 including a plug-mounted speed controller and a water supply. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0017] Referring more particularly to FIGS. 1-4 wherein like numbers refer to similar parts, a handheld polisher 20 is shown in FIG. 1. The polisher 20 has a housing 22 comprised of a right hand portion 24 shown in FIG. 1 and a left-hand portion 25 shown in FIG. 4. A polishing disk 26 constructed of rubber or other flexible material is mounted for rotation on a shaft 28. The shaft 28 is supported on the housing 22 by a first bearing 30 and a second bearing 32 and has a forty-one tooth helical wheel gear 34 which is keyed to the shaft 28 between the first bearing 30 and the second bearing 32. The first bearing 30 is larger than the second bearing, and receives the majority of the thrust load from the polishing disk 26. The shaft 28 decreases in diameter as it enters the first bearing 30, and to a lesser extent as it enters the second bearing 32 so that thrust loads are applied principally to the first bearing but also to the second bearing. [0018] The shaft 28 to which the polishing disk 26 is mounted is driven by a three phase brushless DC motor 36. The motor 36 has a four pole permanent magnet rotor 38 mounted to a motor shaft 41 which terminates in a seven tooth helical pinion gear 40 which drives the forty-one tooth helical gear 34. The gears 40, 34 in FIG. 1 are illustrated with straight teeth for simplicity. The motor shaft 41 is mounted to the housing 22 between a third bearings 42 and a fourth bearing 44. A radial fan 46 as well as the rotor 38 are mounted between the bearings 42, 44. The fan 46 fits within a fan housing 48 formed by portions of the housing 22 and draws air from portions 50 of the housing 22 which contain the motor 36. Air vent holes 54, shown in FIG. 4, allow air to be drawn into the housing past the motor 36, and to then be vented through openings 56 in the fan housing 48. A motor stator 52 is mounted to the housing 22. The stator 52 surrounds the rotor 38 and is mounted within the motor containing portions 50 of the housing 22. Continue reading... Full patent description for Hand held electric polisher Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Hand held electric polisher patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Hand held electric polisher or other areas of interest. ### Previous Patent Application: Process control in electrochemically assisted planarization Next Patent Application: Mechanical grinding apparatus for blending defects on turbine blades and associated method of use Industry Class: Abrading ### FreshPatents.com Support Thank you for viewing the Hand held electric polisher patent info. IP-related news and info Results in 0.50765 seconds Other interesting Feshpatents.com categories: Software: Finance , AI , Databases , Development , Document , Navigation , Error |
||
