U.S. patent application number 11/369528 was filed with the patent office on 2006-08-17 for disposable dental instrument.
Invention is credited to Brian Babson, Jerry W. Browning, Thomas P. Crooks, David G. Murphy.
Application Number | 20060183073 11/369528 |
Document ID | / |
Family ID | 33029954 |
Filed Date | 2006-08-17 |
United States Patent
Application |
20060183073 |
Kind Code |
A1 |
Browning; Jerry W. ; et
al. |
August 17, 2006 |
Disposable dental instrument
Abstract
A disposable dental instrument of the compressed air drive type
is disclosed for use in performing dental procedures on a
workpiece. The disposable dental instrument is constructed from two
mating shells and a core. Each shell incorporates a mating surface
and said shells are joined using various bonding methods to ensure
a waterproof, high quality dental instrument. An elongated body has
conduits penetrating a base at one end of the body. The conduits
allow entry of a light beam, a pressurized water stream, and a
compressed air stream into the body. The base includes attachment
threads for securing the body to a source of the light beam,
pressurized water stream, and compressed air stream. Pluralities of
passageways are in communication with the conduits for conducting
the light beam, the water stream, and the air stream through the
body. A head at the opposite end of the body rotatably mounts a
turbine shaft on bearing surfaces which inhibit vibration and
noise. The turbine shaft includes a turbine impeller and a clamping
hole for removable attachment of a dental bur to the shaft. The air
stream drives the impeller at a high speed for rotating the bur
about a rotational axis. An opening in the body adjacent to the
head allows release of the light beam, the pressurized water
stream, and a portion of the compressed air stream in a direction
toward the distal end of the bur so that the bur, the light beam,
the water stream, and the air stream may all converge on the
workpiece.
Inventors: |
Browning; Jerry W.; (Hemet,
CA) ; Murphy; David G.; (Otsego, MI) ; Crooks;
Thomas P.; (Corona Del Mar, CA) ; Babson; Brian;
(Fountain Valley, CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
33029954 |
Appl. No.: |
11/369528 |
Filed: |
March 7, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10548932 |
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PCT/US04/07641 |
Mar 12, 2004 |
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11369528 |
Mar 7, 2006 |
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10800144 |
Mar 12, 2004 |
7008224 |
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11369528 |
Mar 7, 2006 |
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60455078 |
Mar 13, 2003 |
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Current U.S.
Class: |
433/104 |
Current CPC
Class: |
A61C 1/08 20130101; F16C
2316/13 20130101; A61C 1/181 20130101; A61C 1/145 20130101; A61C
1/052 20130101 |
Class at
Publication: |
433/104 |
International
Class: |
A61C 1/18 20060101
A61C001/18 |
Claims
1. A disposable dental instrument driven by compressed air
comprising: an elongated body, said elongated body comprising: a
first shell, a second mating shell, and a core, said first and
second shells joined to form an exterior surface for manual
manipulation, said shells forming a cavity, said cavity comprising
a first set of integrally formed grooves within a cavity wall, said
core comprising a second set of integrally formed grooves matching
up with said first set of grooves, said first and second set of
grooves being matched in shape and location to define various
passageways as fluid conduits; a base, said base comprising: a
plurality of conduits, said base communicating with an outside
source of light, air, and water through said conduits, said
conduits communicating with said passageways defined by said
elongated body; a head located at the opposite end from said base,
said head comprising: a supporting shaft, bearings rotatably
supporting an upper and lower end of said supporting shaft, each
bearing positioned within a bushing, said bushings positioned
within said head, a turbine impeller, said turbine impeller
connected to said supporting shaft, said turbine impeller being
driven by said compressed source air through an air nozzle to
rotate a dental bur, a dental bur mounting system, a dental bur
removal system, said dental bur removal system having an access
hole to allow an object to push out said dental bur from said
supporting shaft; and various openings located proximate to said
head, said various openings delivering light, air, and water in the
general direction of said dental bur.
2. A disposable dental instrument driven by compressed air
comprising: an elongated body, said elongated body comprising: a
first shell, a mating second shell, and a core, said first and
second shells joined to form an exterior surface for manual
manipulation, said shells forming a cavity, said cavity comprising
a first set of integrally formed grooves within a cavity wall, said
core comprising a second set of integrally formed grooves matching
up with said first set of grooves, said first and second set of
grooves being substantially matched in shape and location to define
various passageways as fluid conduits; a base, said base
comprising: a plurality of conduits, said base communicating with
an outside source of light, air, and water through said conduits,
said conduits communicating with said passageways defined by said
elongated body; a head located at the opposite end from said base,
said head comprising: a rotatable turbine shaft, first and second
bushings mounted within said head and rotatably supporting said
turbine shaft, a turbine impeller located between said first and
second bushings and attached to said rotatable turbine shaft; said
turbine impeller being juxtaposed an air nozzle connected to said
compressed air source by one of said fluid conduits; and a dental
bur mounting apparatus attached at one end of said turbine
shaft.
3. The disposable dental instrument of claim 2, wherein said
elongated body is angled.
4. The disposable dental instrument of claim 2, wherein said
elongated body is made substantially entirely of plastic.
5. The disposable dental instrument of claim 2, wherein said
elongated body is made partially of plastic.
6. The disposable dental instrument of claim 2, wherein said
elongated body is made partially of metal.
7. The disposable dental instrument of claim 2, wherein exterior
surfaces of said shell halves are coated with rubber.
8. The disposable dental instrument of claim 2 having a fiber optic
conduit communicating with an outside source of light.
9. The disposable dental instrument of claim 2, wherein said
turbine impeller incorporates straight turbine blades.
10. The disposable dental instrument of claim 2, wherein said
turbine impeller incorporates curved turbine blades.
11. The disposable dental instrument of claim 2, wherein said
turbine impeller has a paddlewheel configuration.
12. The disposable dental instrument of claim 2, wherein said air
nozzle incorporates a venturi.
13. The disposable dental instrument of claim 2 having an opening
for delivering light in the general direction of said dental
bur.
14. The disposable dental instrument of claim 13 wherein the focus
of said light is adjustable.
15. The disposable dental instrument of claim 2 having an opening
delivering water in the general direction of said dental bur
16. The disposable dental instrument of claim 15 where said opening
for delivering water is adjustable.
17. The disposable dental instrument of claim 2, wherein said shaft
includes bearings mounted within said bushings supported by said
head
18. The disposable dental instrument of claim 17, wherein said
bearings are made of plastic.
19. The disposable dental instrument of claim 17, wherein said
bearings are made of metal.
20. The disposable dental instrument of claim 17, wherein said
bearings are sealed.
21. The disposable dental instrument of claim 17, wherein said
bearings are lubricated under pressure.
22. The disposable dental instrument of claim 21, wherein said
lubricant is oil.
23. The disposable dental instrument of claim 21, wherein said
lubricant is water.
24. The disposable dental instrument of claim 21, wherein said
bearings are floating within a lubricant.
25. The disposable dental instrument of claim 21, wherein said
lubricant is oil.
26. The disposable dental instrument of claim 21, wherein said
lubricant is water.
27. The disposable dental instrument of claim 21, wherein said
bushings are made of rubber.
28. The disposable dental instrument of claim 2, wherein said shaft
is rotatably mounted by bushings supported by said head and said
bushings provide internal bearing surfaces for said shaft.
29. The disposable dental instrument of claim 28, wherein said
bushings are made of plastic.
30. The disposable dental instrument of claim 28, wherein said
bushings are made of metal.
31. The disposable dental instrument of claim 28, wherein said
brushings are made of sintered metal.
32. The disposable dental instrument of claim 31, wherein one of
said conduits conducts water under pressure to said bushing so that
said water is forced through the walls of said bushings to
lubricate the internal bearing surfaces thereof.
33. The disposable dental instrument of claim 28, wherein said
bushings have an outer cone shaped configuration adapted to engage
a cone-shaped wall within said head to limit lateral movement of
said shaft within said head.
34. A disposable dental instrument driven by compressed air
comprising: an elongated body, said elongated body comprising: a
first shell half, a second shell half, and a core, said shell
halves joined to form an exterior surface for manual manipulation,
said halves forming a cavity, said cavity comprising a first set of
integrally formed grooves within a cavity wall, said core
comprising a second set of integrally formed grooves matching up
with said first set of grooves, said first and second set of
grooves being matched in shape and location to define various
passageways as fluid conduits; a base, said base comprising: a
plurality of conduits, said base communicating with an outside
source of light, air, and water through said conduits, said
conduits communicating with said passageways defined by said
elongated body; a head located at the opposite end from said base,
said head comprising: a supporting shaft rotatably mounted within
said head, a turbine impeller, said turbine impeller connected to
said supporting shaft, said turbine impeller being driven by said
outside source of air through an air nozzle to rotate a dental bur,
a dental bur mounting system, a dental bur removal system, said
dental bur removal system having an access hole to allow an object
to push out said dental bur from said supporting shaft; various
openings located under said head, said various openings delivering
light, air, and water in the general direction of said dental bur;
and a shell half joining system incorporating said first shell half
and said second shell half, said first shell half incorporating a
square angled protruding surface along the entire joining edge of
said first shell half, said second shell half incorporating a
triangular shaped recess surface along the entire joining edge of
said second shell half, said square angled protruding surface
designed to integrally join with said triangular shaped recess
surface to form a strong, water and air proof connection.
35. The disposable dental instrument of claim 34, wherein said
elongated body is angled.
36. The disposable dental instrument of claim 34, wherein said
elongated body is made entirely of plastic.
37. The disposable dental instrument of claim 34, wherein said
elongated body is made partially of plastic.
38. The disposable dental instrument of claim 34, wherein said
elongated body is made partially of metal.
39. The disposable dental instrument of claim 34, wherein said
exterior surface is coated with rubber.
40. The disposable dental instrument of claim 34, wherein at least
one of said conduits communicating with said outside source of
light is made of fiber optics.
41. The disposable dental instrument of claim 34, wherein said
turbine impeller incorporates straight turbine blades.
42. The disposable dental instrument of claim 34, wherein said
turbine impeller incorporates curved turbine blades.
43. The disposable dental instrument of claim 34, wherein said air
nozzle incorporates a venturi.
44. The disposable dental instrument of claim 34, wherein the focus
of one of said openings delivering light is adjustable.
45. The disposable dental instrument of claim 34, wherein one of
said openings delivering water is adjustable.
46. The disposable dental instrument of claim 34, wherein said
shell half-joining system incorporates plastic heat welding.
47. The disposable dental instrument of claim 34, wherein said
shell half-joining system incorporates various frequencies of sonic
frequency welding.
Description
[0001] This application is a continuation of U.S. National Phase
application Ser. No. 10/548,932, Filed Sep. 12, 2005, entitled
"DISPOSABLE DENTAL INSTRUMENT", which claims priority from PCT
Application No. PCT/US2004/007641 Filed Mar. 12, 2004, entitled
"DISPOSABLE DENTAL INSTRUMENT", and this application is also a
continuation of U.S. patent application Ser. No. 10/800,144, Filed
Mar. 12, 2004, entitled "DISPOSABLE DENTAL INSTRUMENT." The above
applications all claim the benefit of U.S. Provisional Application
No. 60/455,078 filed Mar. 13, 2003 entitled "DISPOSABLE DENTAL
INSTRUMENT." The entire contents of each of the above applications
are hereby expressly incorporated by reference herein. This
application claims priority from each of the applications
referenced above.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a hand held
instrument for dental procedures, and more particularly to an
improved disposable hand held instrument for dental drilling
procedures.
BACKGROUND OF THE INVENTION
[0003] Many dental procedures necessitate the use of specialized
instruments such as, but not limited to, various dental hand tools
and syringes. It is well known that infectious agents such as
viruses and bacteria can be transmitted from one person to another
through re-use of incompletely sterilized medical instruments, such
as dental drills.
SUMMARY OF THE INVENTION
[0004] The present invention is a disposable dental instrument of
the compressed air drive type for use in performing dental
procedures on a workpiece, such as a tooth or filling. In one
embodiment, an elongated body has conduits penetrating a base at
one end of the body. The conduits allow entry of a light beam, a
pressurized water stream, and a compressed air stream into the
body. The base includes attachments for securing the body to a
source of the light beam, pressurized water stream, and compressed
air stream. Pluralities of passageways are in communication with
the conduits for conducting the light beam, the water stream, and
the air stream through the body. The body includes an outer shell
and a core. The outer shell can be constructed as a hollow one
piece shell or a pair of mating shells. The mating shells are
joined to define a cavity within, and can be easily formed with
conventional injection molding techniques. The cavity wall
comprises a first set of integrally formed groves, and the core
provides a second set of integrally formed groves for mating with
the first set of grooves. When mated, the first set and the second
set of integrally formed grooves are matched in shape such that the
enclosed passageways are thereby formed along the longitudinal axis
of the body.
[0005] In one embodiment, a head at the end of the elongated body
retains bushings which provide a bearing support for a high speed
turbine impeller shaft. The rotatable shaft includes a turbine
impeller and a removable attachment device for attachment of a
dental bur to the shaft. The air stream drives the impeller at a
high rotational velocity for rotating the bur about a rotational
axis.
[0006] In another embodiment, the head contains bushings which
support separate bearings rotatably mounting the impeller shaft.
The shaft includes a turbine impeller and a removable attachment
means for attachment of a dental bur to the shaft. The air stream
drives the impeller at a high speed for rotating the bur about a
rotational axis.
[0007] An opening in the body adjacent to the head allows release
of the light beam, the pressurized water stream, and a portion of
the compressed air stream in a direction toward the distal end of
the bur so that the bur, the light beam, the water stream, and the
air stream all converge on the workpiece to enable illumination,
cooling, and removal of debris from the workpiece during the dental
procedures. Preferably, one passageway contains a transparent,
light-conducting rod for conducting the light beam efficiently from
the base to the opening. A major portion of the air stream is
directed to the turbine impeller, and a minor portion of the air
stream is diverted to move through one of the passageways, through
the opening, and toward the workpiece.
[0008] The preferred embodiments of this invention are inexpensive
to manufacture, thereby making it practical to dispose of after use
with one patient. Such use considerably reduces the risk of
spreading disease between patients. The preferred embodiments are
lightweight, easy to grasp and manipulate, and quickly connects to
a standard source of air, water, and light and facilitate quick and
easy replacement of various sizes and shapes of dental burs, making
it unnecessary to use more than one disposable drill with each
patient. Another feature of the preferred embodiment allows the
quick exchange of dental burs without significantly increasing the
size of the device. Another feature of the preferred embodiment
enable delivering water, air and light to the work site in a single
dental instrument. The preferred embodiments additionally provide a
high degree of torque and control to the dental bur, making it easy
and comfortable for the dental practitioner to use. Another
advantage of the preferred embodiments is that they can be mass
produced using advanced plastic welding practices to provide a
completely sealed housing eliminating possible air and water leaks
and include an improved bearing housing and production procedure to
ensure smooth, quiet bearing operation and increased durability and
additionally provide a high degree of torque and control to the
dental bur, making it easy for the dental practitioner to use.
[0009] Other features and advantages of the present invention will
become apparent from the following more detailed description, taken
in conjunction with the accompanying drawings, which illustrate, by
way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] These and other features, aspects and advantages of the
present invention will now be described with reference to the
drawings of a preferred embodiment, which is intended to illustrate
and not to limit the invention. The drawings comprise four
figures.
[0011] FIG. 1 is a side perspective view of a dental instrument in
accordance with a preferred embodiment of the present
invention.
[0012] FIG. 2 is an exploded view of the dental instrument
illustrating all components.
[0013] FIG. 3 is a partial left side cross-sectional view of the
dental instrument illustrating air passageways, a light rod, and an
impeller assembly.
[0014] FIG. 4 is a partial right side view of the dental instrument
illustrating a center core, the light rod and the impeller
assembly.
[0015] FIG. 5 is a cross-sectional right side view of the dental
instrument illustrating air and water passageways, and the impeller
assembly.
[0016] FIG. 6 is a cross-sectional right side view of the dental
instrument illustrating internal components.
[0017] FIG. 7 is a detailed perspective view illustrating the
impeller assembly, bearings, and drill bur.
[0018] FIG. 8 is a detailed cross sectional right side view
illustrating the impeller assembly.
[0019] FIG. 9 is a detailed cross sectional left side view
illustrating the impeller assembly;
[0020] FIG. 10 illustrates another embodiment of the impeller
assembly having a paddle-wheel vane configuration; and
[0021] FIG. 11 is a detailed cross-sectional view of the impeller
assembly of FIG. 10 in which the impeller shaft rotates on internal
bearing surfaces of cone shaped bushings supported within the body
of the dental instrument.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] With reference to FIG. 1 an overall view of a disposable
dental instrument of the compressed air drive type is shown. The
disposable dental instrument is used in performing dental
procedures on a workpiece, such as a tooth or filling. A portable,
elongated body 10 has an exterior surface 12, which can have a
variety of different textures or coatings suited for allowing firm
grasping and manipulation of the body 10. Conduits 14 penetrate a
base 16 of the body 10 at one end of the body 10 and allow entry of
a light beam 18, a pressurized water stream 20, and a compressed
air stream 22 into the body 10. Conduits 14 further provide an exit
from the body 10 of a return air stream. The base 16 further
includes an attachment system 24 for securing the body 10 to a
source (not shown) of the light beam 18, pressurized water stream
20, and compressed air stream 22. Preferably the attachment system
24 can be an external thread formed integrally on the base 16, for
mating with an internal thread on the source (not shown). A gasket
(not shown) between the end of the base 16 and the source will
prevent leakage of air and water past this internal thread of the
source and the external thread of the base. A plurality of internal
passageways 26 (shown in FIG. 2) are in communication with the
conduits 14 for conducting the light beam 18, the water stream 20,
and the air stream 22 through the body 10. In one embodiment of the
invention, water is introduced into the air stream for providing
lubrication to the turbine shaft and additional power for driving
the turbine described below. Preferably, the present invention can
be made entirely or partially of a relatively inexpensive material,
such as plastic, whereby the invention is inexpensive enough to be
disposed of after use, or given to a patient perhaps to be used at
a later date.
[0023] As seen in the embodiment of FIG. 2, the body 10 can be
constructed from a left shell half 30, a right shell half 32, and a
core 34. The left and right shell halves 30, 32 are joined to
establish the exterior surface 12 of the body 10 and to define a
cavity 36 within, and can be easily formed with conventional
injection molding techniques. The cavity 36 comprises a first set
40 of integrally formed groves aligned generally with the
longitudinal axis of the body 10. The core 34 provides a second set
42 of integrally formed groves for mating with the first set 40 of
grooves. When mated, the first set of grooves 40 and the second set
42 of integrally formed grooves are matched in shape such that the
enclosed passageways 26 are thereby formed primarily along the
longitudinal axis of the body 10.
[0024] FIG. 3 shows a detailed perspective view of the left side of
the core 34 without the shell halves 30 and 32. In one embodiment
of the present invention the integrally formed grooves 42 allow
compressed air and water to enter through the base 16 and travel
laterally along the core 34 towards a head 44.
[0025] FIG. 4 shows a detailed perspective view of the right side
of the core 34 without the shell halves 30 and 32. Returning air
from the head 44 travels laterally along the right side of the core
34 to return to the base 16. A light tube 52 can be positioned
within the right side of the core 34 to allow light to travel from
the base towards the head 44.
[0026] In another preferred embodiment of the invention, the body
10 can be constructed from a one-piece hollow outer shell (not
shown) and the core 34. Similarly to the left and right shell
halves 30, 32, the one-piece hollow shell comprises the exterior
surface 12 of the body 10 and defines the cavity 36 within. The
core 34 is advantageously positioned in the cavity 36 within the
one-piece outer shell. The one-piece outer shell can also be easily
formed with conventional injection molding techniques. All internal
cavities within the body 10 matching the core 34 are identically
constructed in both the two-piece outer shell embodiment as well as
the one-piece outer shell embodiment.
[0027] FIGS. 5 and 8 illustrate one embodiment of the invention
where in one of the conduits 14, designated as a tubular conduit 46
for carrying the water stream 20 is positioned to penetrate the
base 16. The water stream 20 is directed from the conduit 46
laterally around the core 34 to reach a position generally lateral
to the core. Thereafter, the water moves longitudinally adjacent to
the under surface of the core 34 to reach a water stream opening or
nozzle 48 for ejection of the water stream 20.
[0028] A light opening 54 in the body 10 adjacent to the head 44
allows release of the light beam 18. A portion of the compressed
air steam 22 or a portion of the returning compressed air can
surround the stream water opening 48 where the pressurized water
stream 20 along with the portion of compressed air flow in a
direction toward the distal end of a dental bur 56. The dental bur
56, the light beam 18, the water stream 20, and the air stream 22
all converge on the workpiece to enable illumination, cooling and
removal of debris from the workpiece during the dental procedure. A
light-conducting rod 58 (FIG. 6) fills the light opening 54. Other
light transmitting systems such as, but not limited to fiber optics
are also possible. Preferably, one of the passageways 26 contains
the transparent, light conducting rod 58 having a highly polished
surface for conducting the light beam 18 efficiently from the base
16 to the light opening 54. Likewise, one of the tubular conduits
14 preferably contains a highly polished light conducting rod stub
60 for efficiently conducting the light beam 18 through the base 16
from the source of the light (not shown) to the light conducting
rod 58.
[0029] The head 44 at the other end of the body 10 contains
bearings 64 that are positioned in bushings 66 attached to an upper
portion 68 and a lower portion 70 of a supporting shaft 72. The
bushings 66 can simplify the bearing installation, decrease noise
and vibration, and provide a cushioning effect allowing the dentist
to receive a feedback feeling while working. The bushings 66 can be
made from a variety of different materials including, but not
limited to, rubber, plastic, metal, or a composite. The bearings 64
can be attached to the bushings 66 by a press fit, a specific
fastener, glue, or an epoxy. The bushings 66 allow for accurate
positioning of the bearing 64 within the head 44 inhibiting
disturbing vibration and noise that can occur while performing a
procedure on a workpiece. A reduction of vibration and noise allows
for a more comfortable environment for the patient during a dental
procedure.
[0030] As illustrated in FIG. 7, the supporting shaft 72 includes a
turbine impeller 74 and a bur removal system, preferably a through
hole 80 for inserting a removal tool to poke a dental bur 56 out of
the supporting shaft 72. Other dental bur removal systems such as a
dental bur ejector, where a built in mechanism is incorporated in
the disposable dental instrument to assist in the removal of the
dental bur are also possible. The air stream 22 drives the impeller
74 at a high speed for rotating the bur 56 about a rotational axis.
The dental bur 56 is supported by a clamping system (not shown) in
a downwardly projecting direction from the head 44. The dental bur
56 includes a bur mounting shaft 82, and can be any of a number of
different dental tools for example, but not limited to a drill bit,
a prophylactic cup, a polisher, or a diamond cutting tool.
[0031] The head 44 further includes a pair of mounting cavities 84
(FIG. 2) for accepting the bushings 66. The bearing 64 are
advantageously positioned within the bushings 66. The mounting
cavities 84 are formed so as to urge the bushings 66 and as a
result the outer races of the bearings 64 toward each other to
achieve a predetermined amount of preload. As such, the support
shaft 72 is confined to rotational motion only, with lateral motion
of the support shaft 72 being significantly limited.
[0032] As the disposable dental tool of the present invention does
not require long-term functional reliability, the bearings 64 can
be conventional, metallic bearings, or, alternatively, may be
formed from less expensive, non-metallic materials such as hard
plastic. In one preferred embodiment of the present invention, the
bearings 64 can be designed as floating bearings where the bearings
are completely surrounded by a floating medium such as water, air,
oil, or any combination thereof. The floating medium can be
supplied to the floating bearings under pressure or the bearings
can be enclosed in a chamber filled the floating medium to ensure
minimal friction decreasing vibration and noise.
[0033] Another preferred embodiment of the invention is shown in
FIGS. 10 and 11 in which bushings 125 and 126 are mounted within
the head 127 of the dental instrument. The impeller shaft 130 is
rotatably supported by these bushings and the interior wall of the
bushings provide the bearing surface for the impeller shaft to
rotate at a high velocity. Bushings 125 and 126 may be constructed
from a suitable metal including scintered metal or a suitable
plastic such as Teflon.
[0034] Advantageously, the bushings 125, 126 have a cone-shaped
external configuration 135 in engagement with a corresponding
cone-shaped cavity 136 within head 127 to limit lateral movement of
the shaft 130 relative to the bushings 125, 126.
[0035] Conduits 150 in the cone shaped cavity can be used to
introduce water or other lubricant under pressure to the interior
bearing wall surfaces of the bushings which support the impeller
shaft 130 when the impeller shaft 130 is caused to rotate to
thereby further reduce friction between the shaft 130 and bearing
surfaces of the bushings 125, 126. In one embodiment, the water
under pressure is forced through the walls of bushings 125, 126
formed of a porous material such as sintered metal to lubricate
this internal bearing surface. The use of a lubricant also enables
quieter operation of the drill for the benefit of both the dental
practitioner and the patient.
[0036] In one preferred embodiment of the invention shown in FIGS.
7-9, the bur clamping system of the support shaft 72 includes a
clamping hole 88 that is aligned with the rotational axis of the
support shaft 72. The clamping hole can have a smaller diameter
than that of the bur mounting shaft 82, whereby the clamping hole
can provides an interference fit to the bur mounting shaft 82. The
clamping hole can have a series of relief cutouts (not shown) to
permit a sidewall (not shown) to be forced open to accommodate the
bur mounting shaft 82. The bur 56 can be inserted into the clamping
hole to be held tightly in place by the sidewall. The head 44
further includes an access hole 86 aligned approximately with the
rotational axis of the support shaft 72 and the bur removal system,
whereby the dental bur 56 may be disengaged from the support shaft
72 so as to insert a new dental bur. The support shaft 72 provides
for self-center and allows repeated disengagement and insertion of
the dental bur 56.
[0037] FIGS. 8 and 9 illustrate detailed views of one embodiment of
the dental instrument head 44, the air, water, and light
distribution area, and the mating surfaces used to ensure a strong,
precise connection free of air and water leaks. The mating surfaces
will be described in greater detail below.
[0038] A major portion of the air stream 22 is directed to the
turbine impeller 74. The impeller 74 has a plurality of blades 90
for receiving the stream of air 22. The air stream 22 can be
directed against the impeller blades 90 through at least one
separate air passage 92. The air passage can comprise a variety of
different shaped nozzles 100 allowing for efficient transfer of
compressed air energy against the blades 90 to provide rotational
torque to drive the impeller 74. One or more of the nozzles 100 can
be positioned relative to the impeller 74 so that at least one of
the blades 90 receives a portion of the air stream 22 primarily
orthogonally to the surface of at least one of the blades 90 at
each rotational position of the impeller 74. This precise injection
of air onto the surface of the impeller blades 90 can provide a
consistent high rotational torque force on the dental tool.
[0039] The air nozzle 100 for directing the air stream 22 against
the blades 90 of the impeller 74 can be designed using different
shapes. A second embodiment of the present invention can
incorporate a venturi to accelerate the air stream to provide a
faster air stream. A faster air stream can allow for an improvement
turbine driving efficiency.
[0040] Various different shapes of turbine blades can be used to
efficiently turn the impeller 74 and provide more efficient torque
as well as quieter operation providing a comfortable environment
for the dental instrument user and patient. For example, a cup
shaped turbine blade can be used to more efficiently translate the
compressed air energy into a strong rotational torque. Another
embodiment of the impeller blade is shown in FIG. 10, wherein the
impeller 140 has paddle-wheel configured blades 145 to provide
improved rotational torque.
[0041] In operation, a dental practitioner selects an approximate
dental bur 56 for the required dental procedure and inserts the bur
mounting shaft 82 of the dental bur 56 into the clamping hole of
the support shaft 72. The sidewall (not shown) of clamping hole 88
flexes to allow insertion of the bur mounting shaft, at least some
of the sidewall material is displaced into relief cutouts (not
shown). The dental practitioner then uses the attachment system 24
of the body 10 to connect the base 16 of the body 10 to a source of
pressurized water, pressurized air, and light. During a typical
dental procedure, the dental practitioner activates the pressurized
air and light together at the source, and activates the pressurized
water with a foot pedal or other actuator for cooling the workpiece
and flushing away debris.
[0042] When he activates the pressurized water source, such as
through a foot pedal or other control means on the source (not
shown), water is forced through one of the conduits 14 of the base
16 at a position above the core 34. The water then travels
laterally around the core 34 to reach a position lateral to the
core 34, and then through one groove or passageway 42 toward the
head 44. The stream of water then exits through the water stream
opening 48 in a direction toward the distal end of the dental bur
56, so as to flush away debris and apply water to the workpiece for
cooling. The water stream opening 48 can be adjustable to allow
more or less water to flow from the disposable dental
instrument.
[0043] When the light source is activated, light travels through
the light conducting rod stub 60 through the base 16 to the light
conducting rod 58, where it is passed through the opening 54 toward
the workpiece, thereby illuminating the workpiece. Fiber optics can
also be used in place of the light-conducting rod 58. The focus of
light exiting the opening 54 can be adjustable to provide the
operator with a well-illuminated work area.
[0044] When the pressurized air source is activated, the air stream
22 flows through one of the conduits 14, through one of the grooves
or passageways 42, and passes through the air nozzle 100 for
directing the air stream 22 against the blades 90 of the impeller
74. The force of the air against the blades 90 causes the impeller
74 to rotate, thereby driving the dental bur 56. The air then
leaves the head 50 through at least one return air passage 102. A
minor portion of the returning air stream 22 can be diverted to
move through an aperture 104 surrounding the water nozzle 48. This
minor portion of the air stream 22 can be directed along with the
water stream 20 toward the workpiece to remove debris from the
workpiece. The returning air can also blow away debris from the
workpiece without water to dry the workpiece.
[0045] Once the dental procedure requiring the bur 56 has been
completed, the dental practitioner then pokes an elongated object
through the access hole 86 of the head 44 to remove the dental bur
56 from the clamping hole 88. A new bur may be inserted, or, if all
procedures are complete, the disposable hand tool of the present
invention may be discarded.
[0046] To ensure high quality, completely aligned, leak free mating
of the two shell halves 30 and 32, specific mating surfaces are
incorporated into each shell half. FIG. 8 illustrates a protruding
square angled mating surface 108 that is positioned along the outer
edge of the right shell half 32 and advantageously surrounds the
end of the light rod 58 and the apertures 98. FIG. 9 illustrates a
triangular shaped recess surface 110 along the outer edge of the
left shell half 30 that advantageously surrounds the end of the
light rod 58 and the apertures 104. The triangular shaped recess
surface 110 is positioned directly opposite from the square angled
mating surface 108 of the right shell half 32.
[0047] The shell halves 30, 32 can be joined together using a
variety of different production procedures including, but not
limited to, heated plastic welding, sonic plastic welding etc. As
the two shell halves 30 and 32 are positioned together during
production, the angular surface of the triangular shaped recess 110
of the shell half 30 allows the square angled mating surface 108 of
shell half 32 to advantageously align itself with the triangular
shaped recess surface 110. During the joining procedure the extra
material of the square angled mating surface provides sufficient
material to allow for a complete joining of the two shell halves 30
and 32. The sufficient material and accurate alignment joining
design provide a strong, a leak-free disposable dental instrument
that operates efficiently.
[0048] Of course, the foregoing description is that of a preferred
construction having certain features, aspects, and advantages in
accordance with the present invention. Various changes and
modifications may be made to the above-described arrangements
without departing from the spirit and scope of the invention, as
defined by the appended Embodiments.
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