|Title of Invention||
HIGH TORQUE DUAL CHAMBER TURBINE ROTOR FOR HAND HELD OR SPINDLE MOUNTED PNEUMATIC TOOL
|Abstract||A high torque turbine rotor for a lightweight hand held tool for grinding and polishing having a rotor that includes two separate high pressure air chambers separated by a common housing wall, each air chamber having peripheral air expelling nozzles in a tangential direction to the rotor periphery. The rotor housing is lightweight and increases torque without generally increasing the overall size and weight of the tool housing.|
HIGHTOfeQDE DUAL CHAMBER TURBINE ROTOR uORHAND HELD OR
SPINBLE MOUNTED PNEUMATIC TOOL
BACKGROUND OF TEDS INVENTION
1. Field of the Invention
IMs invention relates to a pneumatically powered, hand held or spindle-mounted lightweight tool suitable for grinding and polishing and, more particularly, to a turbine rotor for a lightweight, grinding tool driven by an air-powered reaction turbine. The turbine rotor creates high torque for a drive shaft without a sigmficant increase iu size or weight of the grinding tool. 2. Description of Related Art
prior art, Light-weight pneumatic tools have been used for a variety of functions, such as grinding, polishing, metal or plastic finishing, engraving, drilling, and debating. The tool variations include hand-held and machine spindle-mounted embodiments. Hard-held, tools often include a narrow cylindrical exterior housing that includes a handle portion enclosing the rotor and a drive shaft that is held much like a pencil or pen. Lightweight pneumatic grinding tools can be hand held for longer periods of time than a comparable electric motor tool which is much heavier without harm to the user.
Prior art pneumatically-powered tools utilize either a vane-type fluid motor or a reactive rotor. The present invention does not employ a vane-pe motor but utilizes a reactive rotor. Hie reactive rotor expels high pressure, high velocity air tangentially from the rotor peripherally to obtain torque. lfce rotor is coupled to the primary drive shaftthetein.
Patent No. 5,566,770 which has a common assignee wfcfc Sae ptessat invention, provides an angled spindle that is relatively lightweight driven by a single chamber rotor, U.S Patent No. 4,776,752, which also has a cpmmca assignee with the -.
present invention, teaches a single chamber turbine rotor that is relatively ugnrweigttt and includes a high-speed governor.
Although the torque provided in current turbine rotors is adequate for grinding and polishing tools ttiat are lightweight and compact, higher torque in some application? of grinding and polishing is desirable. However, enlarging the too] rotor (and therefore the housing) to increase torque could greatly increase fee weight, sitae and volume of the tool housing and therefore reduce fee hand-held, lightweight advantages of the tool.
The present invention increases the torque of a rotor driven pneumatic tool significantly without concomitant increases in weight, size or complexity of operation or manufacture of the tooL In feet, an increase in torque becomes possible with a decrease in diameter of the tool. For example, where a rotor approximately one inch in diameter would provide approximately 0,2 horsepower at 50,000 revolutions per minute ("RPMs"), with fiie present invention a rotor of only 3/4 inch in diameter provides approximately 0.3 horsepower at 50,000 RPMs. In addition to an increase in power, the present invention provides for a slimmer tool profile. Moreover, the present invention also reduces the pressure that is necessary to idle the rotor in comparison to a single rotor of comparable size and material from three cubic feet per minute for the one inch single
rotor to two cubic fcet per minute for a 3/4 inch dual rotor.
The present invention uses a rotor comprising a single, compact body having
dual, high pressure air receiving chambers that share a common wait, to reduce size and weight for increased torque. Both rotor body chambers have tangential exhaust nozzles thai generate torque to rotate file rotor. The present invention may aiso include dual automatic speed governors without additional complexity,
A figntwetght tool fa also desirable in a spindle mount since the tool is supported on a. moveable arm.
BRIEF SUMMARY OF THE INVENTION
A high-torque ttwhiae rote BfroMaSed in a band-held or spindle mounted pneumatic toot narrow housing on a drive shaft. The rotor body has a threaded central aperture Stat receives and is fixedly attached to the threaded drive shaft. The rigid drive shaft is partially hollow and has two pairs of openings that serve as inlets to the rotor body for high-pressure air that provides the motive force on the rotor body for turning die drive shaft A grinder member for grinding is affixed to one end bf the drive shaft The opposite end is attached to a flexible air hose or high-pressure air supply.
The cylindrical rotor body has a rigid cylindrical outer wall and an inner central wall dividing the rotor body into two separate compartments, wife an open front and an open back. The cylindrical iptor body has a first annular chamber, a second annular chamber, and a common inner wait. A front wail and a back wall are connected to the rotor cylindrical wail forming two separate air receiving chambers.
The front, back and inner rotor walls each have a threaded apertnre for attachment; to the threaded drive shaft The rotor cylindrical body and the front, inner and bade walls provide two separate chambers in the rotor, a first annular chamber and a second annular chamber. The rotor cylindrical wall has a plurality of fcaagentially directed passages strategically spaced to direct high pressure internal air outwardly, 'resulting in torque on the rotor and thus, the shaft
In the preferred embodiment,, each rotor chamber in, the rotor body receives high pressure sit from the drive shaft inlets. Each totor body chamber has a cylindrical ineriot shape and uualudes four separate tangential ak passages, that exhaust high-pressure air taagcntiaUy aad peripherally, causing 3 reactive force as the air is expelled from both chambers. The inside peripheral wall of each chamber has four tapered portions proceeding from a narrow portion to a thicker portion, the thicker portion
accommodating the four tangential exhaust air passages. The housing tangential air exhaust passages are spaced approximately 90 degrees apart around the annular chamber. In the preferred embodiment, there are two separate chambers separated by the common inner wall, each of which has four separate exhaust passages that are peripheral and tangential. Thus, for each rotor body there are eight separate exhaust passages. The use of eight separate passages greatly increases torque for a single rotor.
In the preferred embodiment each rotor body chamber (the "frist chamber and second chamber) includes a governor to limit the overall EPM of the rotor and therefore die shaft as described in U,S Patent No. 4,776,752. The governor and each chamber described in the 752 patent includes an annular perforated barrier and a resilient o-ring that fits on the inside of the annular perforated barrier. The rotor chamber walls include annular grooves for retaining the annular perforated barrier. As the RPMs of the rotor increase, the resilient o-ring expands under centrifugal' force outwardly, resiliently engaging the annular perforated barrier, thereby shutting off air under pressure from die air inlet to the peripheral exhaust nozzles to regulate the amount force and therefore the RPMs of the rotor.
There are various types of turbine rotors available. However, to increase the, amount of torque obtained ina current rotor, the turbine rotor housing wvaldh&ve to,be enlarged, causing a larger housing, increased weight and possible vibration, chatter aod inefcsed wear on iheturtune parts and operator fefigue.
It is ah object of fee present invention to provide a Hjtweigbt pneumatic grinding tool that is able to maintain a constant rotational speed when subjected to a load without producing unwanted vibration, which also provides Increased torque while retaining a narrow tool housing for comfortable holding during use.
It is also an object of fee present invention to provide a lightweight grinding tool having a reaction rotor that generates high torque at a relative small size and weight
It is stiB another object of the present invention to provide a turbine rotor for the drive shaft of a tool as aforanentioned which is jrelaiSveiy lightweight and compact and which produces a significant increase in torque over that of the prior art
In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
BRIEF DESCRBPHON OF THE SEVERAL VIEWS OF THE DRAWINGS
Figure 1A is an exploded, perspective view of the preferred embodiment of the invention.
Figure IB is a side elevational view of an alternative embodiment of the invention.
Figure 2 is a cross-sectional, side eleventional view of the preferred embodiment of (he invention.
Figure 3 A is a perspective view of the preferred invention.
Figure 33 is a cross-sectional side elenvation view of the preferred invention.
Figure 4 is a partially exploded, sectional perspective view of the preferred embodiment.
Figure 5 is a perspective view of an alternative ecodirneivL
Figure 6 is a side elevation view of an alternative embodiment of the invention. HEFAffJSD DESCREFriDNOF WB iNVENTK
Referring now to the drawings, in particular Figs. 1A through. 4 the instaat turbine rotor is illustrated generally at L& An outside elongated toot housing that is hand-held and that encloses the rotor, shaft and bearing? is shown in Figure IB. Tbe
turbine rotor 10 is used in. a hand held or spindle mounted tqal as shown in Figure IB, suitable for work such as grinding and polishing.
The turbine rotor body 10 preferably has two separate internal high pressure air receiving chambers (a first chamber and a second chamber), formed by a fitmt wall 12, a middle inner wall 14 and a back watt 16. The rotor body 10 is generally cylindrical. The ftontwall 12 and the back wall 16 may be identical The ftoatwali 12, inner wall 14 and back wall 16 fit together fractionally and are generally air tight For example, the front wall 12 and the back wall 16 each, has a peripheral flange which engages and extends over tiie edge of the periphery of the chamber walls of the middle wall 14. Ia the preferred embodiment, the front wait 12 and the back wall 16 are press fit against the middle wall 14. However, the front wall 12 and the back wall 16 and the inner wall 14 may also be glued together or releasably or permanently attached by other, equivalent elements such as a metal clip.
Hie front wait 12 includes a central threaded bore 18; la the preferred embodiment, the bote IS is threaded to correspond with threads on a drive shaft 60, as shown in Figure 2? 4 and S. The drive shaft 6ft comprises hollow openings that serve as inlets for high pressure air to enter the rotor body 10 chambers to propel the rotor body 10. Other forms of attachment with the drive shaft 60, both releasabie and permanent, are contemplated, such as gluing, welding or Motional engagement with the drive sttaft 60. The front wall 12 and the back wall 16 may be made of plastic, metal or other suitable lightweight, rigid material that can he generally airtight. When the rotor body is engaged with the shaft; torque produced on the rotor is transferred to the shaft, causing the shaft to rotate.
Hie common inner waU 14 may also be made from plastic, metal or other suitable material. The inner wall 14 includes a threaded central bote 44 to correspond with threads on the drive shaft 60 of the tool.
The rotor body 10 in the preferred embodiment includes a governor in each rotor housing chamber as described in the '752 patent Preferably, the governor comprises a first annular chamber area 20 oa the front surface 48 of the inner wall 14. Extending from the outer portion 52 of the first annular chamber 20 is at teasfQUs first arcuate chamber 24. As show in Figures 1 through 4, in foe preferred embodiment, four (4) first arcuate chambers 24 are provided which extend from, the outer portion 52. of the first annular chamber 20 to the circumference 56 of the inner wall 14. The arcuate chambers 24 open to first circumferential openings 58.
A first resilient valve o-rmg 32 is mounted in the first annular chamber 20 to regulate and restrict the flow of the air from the first annular chamber 20 to the first arcuate chamber 24. Extending amy frotn (he first valve o-ring 32 is an annular first perforated barrier 22. Mien high pressure air (approximately 90 psi) is introduced into the rotor body 10, and the rotor speed reaches apredetemrined number of revolutions per minute, tile valve o-ring 32 deforms against the perforated barrier 22, thereby restricting air flow and decreasing the RPMs of the rotor.
As shown in Figure 3vtfaerofoi body 10 includes a second annular chamber 26 on the tear surface 50 of the toner waD-14, Extending fipni the outer portion 54 of the second atoutar
second arcuate chambers 30 are aligned, as are the first and second circumferential openings 58, 62. The air passages openings 58, 62 are dhectiormlly tangential to the cylindrical rotor body 10 and expel high pressure air tangeotiaUy to provide force to rotate the rotor body 10. However, fee alignment of the openings 58; 62 is not accessary for operation of the invention.
The second annular chamber 26 also contains a second resilient valve o-ring 34 to regulate and restrict the flow of fixe air from the second anaular chamber 36 to the second arcuate chamber 30. Located radially away from the second valve o-ring 34 is an annular second perforated barrier 28. Thus, when the air is introduced into the turbine rotor 10 and the rotor reaches a predetermined RPM speed, the second resilient valve ring 34 deforms against fhe perforated barrier 28 as the mtorins, thereby resfcricrii air flow and slowing down the rotor.
The valve onrings 32, 34 are generally resilient and are made of rubber. The entire turbine rotor 10 (except for the valve o-rings} may be nade of rigid plastic materials. The turbine rotor 10 bearings do not need lubrication Ike perforated barriers 22, 28 oaay be made of piastremetal or otiier suitable material. Also the perforated barriers 22, 2S may be formed intrinsically with die inner wall 14, or ceteasably or permanently attached to thefront surface 48 and the rear surface SO of the inner wall 14. Thfl pecfcraisd barriers 22, 28 may be a fence-like structure as illustrated in Figure I, However, euivafent strnctoes are also contemplated.
Also in the preferred embodiment a groove 36 -in- fee front wail 12 and a
corrcspotidtng gcoove4Q in the front s\irfece of the inner wall 14 are situated so file first
perforated barrier 22 is aligned proper wifMi the tnrbin Similarty.a
groove 38 in the back wall 16 and a corresponding gcodve 42 in the rear surface 50 of the inner wall 14 are situated so the second perforated barrier 2 is ahgi prorx b: the
turbine rotor body 10. A single groove may also be used to properly align the perforated barrier.
fa, operation, the preferred embodiment of the turbine rotor 10 -works as follows. Air under pressure (approximately 90 psi) enters fee turbine rotor 10 from the drive shaft 60 into the central bones 18,4A9 46 in the front wait 12, inner wall 14 and back wall 16. The air under pressure enters the first and second annular chambers 20,26 and travels around the first and second valve o-rings 32, 34 through the first and second perforated barriers 22,28 into the first and second arcuate chambers 24,30. Hie air then is forced under pressure from fee arcuate chambers 24, 30 through circumferential openings 58, 62 in the circumference 56 of the inner wall 14. These peripheral openings operate as tangential nozzles, providing air streams generating torquiag force to rotate the turbine. The reactive force of the air causes the turbine rotor 10 to rotate.
The preferred embodiment includes a revolutions per minute ("RPM") governor described in U.S. Patent No. 4,776,752 in each drive chamber. The resilient deformation of the valve o-rings 32,34 against the perforated barriers 22, 28 caused by centrifugal force forces the turbine 10 to turn at a predetermined, somewhat constant rate. As the turbine rotor 10 rotates at a high RFM speed, the first and second valve CHrings 32, 34 deform, pressing against the perforations of the first and second perforated barriers 22, 28. The deformation of die valve o-rings 32, 34 restricts air flow through fee , perforations in the barriers 22, 28, thereby reducing rotational forces. Eventually equilibrium is reached whereby a constant speed of rotafion for the turbine rotor 10 is achieved.
Tlie torque of the turbine rotor 10 in die present invention is greatly increased over that of prior art rotors. For example, when compared to two stacked turbine rotors,
the present invention provides less weight, vibration, chatter and run through of the air and fewer moviag parts that may wear.
Figures 5 and 6 Illustrate an alternative embodiment of the invention. As shown in Figures 5 and 6 the rotor housing is narrowed, for less weight and a further increase in torque.
The design of the turbine rotor 10 with multiple annular chambers and multiple arcuate chambers provides an increase in torque from prior art air turbines without a significant increase in fixe weight of the spindle apparatus. Moreover, there is less vibration than would be if single turbine rotors were stacked on top of each other. It is also contemplated in an alternative embodiment that additional annular chambers and arcuate chambers could be formed between in the first and second chambers. These additional chambers may have valve o-rings and perforated barriers as described herein for governing the RPMs. Furthermore, although the invention has been described to work with air, other gases are also contemplated for other applications.
The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment It is recognized, however that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art
Listing of Claims:
Please amend the following claims :
I. (Currently Amended) A high torque turbine rotor for a hand held or spindle mounted pneumatic tool, comprising:
a rotor body having an inlet attachable to a high pressure air source, including: a first annular chamber, a second annular chamber; and
a common inner wall, wherein said first annular chamber and said second annular chamber are separated by said common inner, wall;
said rotor body being cylindrical and including a plurality of tangential peripheral nozzles, in fluid communication with said housing first chamber and said hougisg second cliamber for expelling high pressure air to rotate said rotor body;
said time wall including a central bore for receiving an uttuchmeat to a drive shaft
2. (Original) The high torque turbine rotor of claim 1, wherein said rotor farther comprises:
an RPM governor in said first chamber and in said second chamber.
3. (Original) The high torque turbine rotor of claim 2, wherein said RPM
a front wall;
at least one sniialing wall barrier extending from die outer portion of each, annular chamber,
a valve o -ring within each annular chamber;
an annular perforated barrier within each annular chamber extending outward from the yalve o- ring and
4. (OriginaJ) The high torque turbine rotor of claim 3, wherein each perforated barrier is integral with the rotot body ofthe rotos.
5. (Original) The high torque turbine lotor of claim I, whereas four arcuate chambers radiate from each annular chamberr
6. (Original) The high torque turbine rotor of claim 3,wherein the feoat wall and a front interior surface of the inner wail are grooved for fitting a first perforated barrier, and the back wall and a back interior surface of the inner wall a^ grooved for fitting a second perforated barrier.
7. (Original) the high torque turbine rotor of claim 3, wherein the valve o-ring is resilient rubber.
E. (Original) The high torque toxbine rotoi of claim3, wherein the common inner wall comprises:
one or more additional annular chambers and additional spiriting wall barriers located between the two annular chambers and the two spiraling wail barriers, an additional annular perforated barrier located within each additional annular chamber and located radially outward fiom an additional valve o-ring, and said additional valve o-ring located radially inward from tfoe additional annular perforated barrier.
9. .(Original) Hie high torque turbine rotor of claim 1, wherein the inner wall comprises a narrow waist. -
10. (Original) The high torque turbine rotor of claim 3, wherein the components except for the valve o-ring are made of plastic.
11. (Original) The high toque turbine rotor of claim 3, wherein the front wall and the back watt ate reieasably attached to the inner wall.
12. (Original) Hie high torque nnhine rotor of claim 114 wherein the ftacl waft and the back wall are attached to the inner wall by Motional force.
13. (Original) The high torque turbine rotor of claim 1, wherein the plurality of tangsfrtiai peripheral nozzles in communication with the first annular chamber are aligned with the plurality of tangential peripheral nozzles in communication with -the second annular chamber.
14. (Curreatly Amended) A rotor body to a high torque turmne roror, comprising; a rotor body including a central bote, and
said rotor body having a cylindrical outer wall and a central inner wall; a front surface, including at least one first annular channel ending in at least
one first arcuafc channel ending m at (east one first circumferential opening; aai
said first annular channel having a first groove for fitting a first perforated
barrier and said second annular channel having a second groove foe fitting a second
- Perforated barrier, and
a back surface, including at least one second annular channel ending in at least
One second arcuate channel ending in at least one second circumfe ;sntial opening.
(Original) The mtor body of claim 14, further comprising:
the first perforated barrier;
the second perforated barrier,
a first valve o-ring located between the fiist perforated barrier and the central bore; and
a second valve o-rmg located between the second perforated barrier and the
(Original) A hand held pneumatic tool, comprising:
a high tdrque turbine rotor body located circumferentially around a primary shaft, wherein the turbine rotor body includes:
a front watt and a back wall adapted for String with an inner wall, each including:
a central bore;
the inner wall adapted for fitting with the front wall an4 the back wall, the inner wall including:
at least two annular chambers;
at feast one arcuate chamber radiating from the outer portion of each annular chamber;
a valve o ring within each annular chamber,
an annular perforated barrier within each annular chamber located radially
outward from the valve o-ring; and
a central bore.
(Original) A hand held pneumatic tool, corrnmsing:
a high torque turbine rotor having an oilier wall and art axis of rotation, means
for mounting said turbine rotor for rotation about said axis of rotation on a drive shaft said turbine rotor having an outer wall and at least two high pressure ak receiving chambers, means for directing pressurized air into the two chambers, said turbine rotor having an air passage in each chamber, said ak passage ending in tangential nozzles in said outer wall of the rotor; said nozzles directing a pressurized fluki therefrom to impart rotation to said turbine rotor.
\S (Original) The hand held pneumatic tool of claim 18, wherein said rotor bad] includes a chamber wail separating said two chambers.
(Original) The hand held pneumatic tool of claim 18, ftirther comprising a resilient sealing means located in each said annular chamber means;
said resilient sealing means being movable outwardly by centrifugal force U restrict pressurised flow through perforated barrier means, allowing pressurized fltii to flow unrestricted by said resilient sealing means until said resilient sealing mean has been moved outwardly by centrifugal force to restrict pressurized flow throng] the perforated baicrier means.
20 (Currently Amended) A high torque turbine rotor for a hand held or spind! mounted pneumatic tool, comprising:
means for generating torque with a cylindrical body having an inlet attachabl to a high pressure air source, including:
means for generating torque in a first chamber of said body; means for generating torque in a second chamber of said body, means for directing pressurized air into the two chambers; means for separating said first chamber from said second chamber; and means comaectrag said torque generating means to a shaft (Original) The higjb. torque turbine rotor of claim 21, wherein said rotor forth/ comprises means for governing die revolutions per minute of the rotor disposed within sai fristmeans for generating torque and said second means for generating torque.
(Original) A high torque turbine rotor for a. hand held or spindle mounted pneumatic tool, comprising:
aa inlet attachable to a high pressure air source; a first annular chamber,
a first plurality of tangential peripheral nozzles in communication with said first annular chamber;
a second annular chamber;
a second, plurality of tangential peripheral nozzles in communication with the second annular chamber; and
a common inner wall including a central bore &>i receiving and attachment to
a drive shaft, wherein said first annular chamber and said second annular chamber are
separated by said common inner wall
(Current!}' Amended) The high torque turbine rotor of claim 23, further
comprising a first RPM governor in said first annular chamber and a second RPM governor is
in said second annular chamber.
(Original) The high torque tabine rotor of claim 24, wherein said first and second RPM governors each comprise:
at least one spiraling wall barrier extending outward from the outer portion of the annular chamber;
a valve o-nag within fee annular chamber, and
an annular perforated barrier within the annular chamber extending outward from flic valvexwisig.
(Original) The high torque turbine rotor of claim 25, wherein each perforated barrier is integral with the rotor body.
(Original) The high torque turbine rotor of claim 23, wherein four arcuate chambers radiate from each annular chamber
(Original) The high torque turbine rotor of claim 23, further cQinprisrag: a front wail adjacent to the common inner wall; and a back wall adjacent to the common inner wall; wherein the front wall and a front interior surface of the common inner wall are grooved for fitting a.first perforated barrier and the back wail and a back interior surface of the common inner wall are grooved for fitting a se^K^ perforated harrier. (Original) The high torque turbine rotor of claim 25, wherein the valve oaring is constructed of resilient rubber.
. (Currently Amended) The high torque turbine rotor of claim 25, wherein the components, except for the valve o-rmg, are constructed of plastic.
(Currently Amended) Hie high torque turbine rotor of claim 28, wherein fee front wall and the back wall are releaaably attached to the common inner wall, (Curreafty Amended) The high torque turbbe rotor ofclaim wherein the front wall and the bade wall are attached to the inner waU by factional force. (Currently Amended) The high torque turbine rotor of claim 23, wherein tbe first plurality of tangential peripheral nozzles are aligned with the second plurality of tangential peripheral nozzles.
|Indian Patent Application Number||2466/CHENP/2007|
|PG Journal Number||07/2012|
|Date of Filing||08-Jun-2007|
|Name of Patentee||AIR TURBINE TECHNOLOGY, INC.|
|Applicant Address||1225 BROKEN SOUND PARKWAY, N.W, SUITE D, BOCA RATON, FLORIDA 33487,|
|PCT International Classification Number||F01D1/18|
|PCT International Application Number||PCT/US04/41257|
|PCT International Filing date||2004-12-08|