U.S. patent application number 11/450432 was filed with the patent office on 2006-12-21 for dental handpiece with pressure regulating mechanism.
Invention is credited to Kiyoshi Kawakubo.
Application Number | 20060286505 11/450432 |
Document ID | / |
Family ID | 37003363 |
Filed Date | 2006-12-21 |
United States Patent
Application |
20060286505 |
Kind Code |
A1 |
Kawakubo; Kiyoshi |
December 21, 2006 |
Dental handpiece with pressure regulating mechanism
Abstract
The present dental handpiece has a burr sleeve, a head section,
an air supply passage for introducing compressed air into the head
section for driving the burr sleeve, and an air discharge passage
for discharging the compressed air. The air supply passage includes
a through hole axially extending through the rear terminal part of
the handpiece, and a tubular pressure regulating member and an air
supply tube connected in series between the through hole and the
head section. The pressure regulating member has an aperture for
allowing communication with the air discharge passage, and an
annular valve body arranged axially slidably for opening/closing
the aperture. When the pressure of compressed air passing through
the air supply passage exceeds a predetermined level, the valve
body is slid to open the aperture to discharge the compressed air
for regulating the pressure of the compressed air to be supplied to
the burr sleeve.
Inventors: |
Kawakubo; Kiyoshi;
(Kanuma-shi, JP) |
Correspondence
Address: |
HAHN & VOIGHT PLLC
1012 14TH STREET, NW
SUITE 620
WASHINGTON
DC
20005
US
|
Family ID: |
37003363 |
Appl. No.: |
11/450432 |
Filed: |
June 12, 2006 |
Current U.S.
Class: |
433/132 ;
433/133 |
Current CPC
Class: |
A61C 1/0038 20130101;
A61C 1/0069 20130101; A61C 1/052 20130101; A61C 17/022
20130101 |
Class at
Publication: |
433/132 ;
433/133 |
International
Class: |
A61C 1/05 20060101
A61C001/05; A61C 1/12 20060101 A61C001/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 16, 2005 |
JP |
2005-176549 |
Claims
1. A dental handpiece comprising: a burr sleeve for receiving a
dental treatment tool therein, a head section housing and rotatably
supporting said burr sleeve therein, an air supply passage for
introducing compressed air into the head section for rotatably
driving the burr sleeve with the compressed air, and an air
discharge passage for discharging the compressed air, wherein said
air supply passage comprises: a through hole axially extending
through a rear terminal part of the dental handpiece, and a tubular
pressure regulating member and an air supply tube connected in
series between the distal end of the through hole and the head
section, said tubular pressure regulating member having an aperture
in its intermediate part for allowing communication with the air
discharge passage, and an annular valve body arranged axially
slidably for selectively opening and closing said aperture,
wherein, when a pressure of compressed air passing through the air
supply passage exceeds a predetermined level, said annular valve
body is slid to open the aperture, whereby the compressed air is
discharged through the aperture into the air discharge passage for
regulating the pressure of the compressed air to be supplied to the
burr sleeve.
2. The dental handpiece according to claim 1, wherein said tubular
pressure regulating member further comprises: a first tubular
member, a second tubular member inserted in said first tubular
member to form a gap therebetween, and a spring for biasing said
annular valve body, wherein said aperture of the tubular pressure
regulating member is provided in each of said first and second
tubular members at a predetermined position for allowing
communication between the interior of the tubular pressure
regulating member and the air discharge passage, wherein the
annular valve body and the spring are arranged in the gap between
said first and second tubular members, wherein said annular valve
body is biased by the spring into a position to prevent
communication between the apertures in the first and second tubular
members, and is arranged to receive pressure from the compressed
air passing through the air supply passage, wherein, when the
pressure of the compressed air passing through the air supply
passage exceeds a predetermined level, the annular valve body is
slid by the pressure against the force of the spring to provide
communication between the apertures.
3. The dental handpiece according to claim 1, wherein the tubular
pressure regulating member is connected at one end thereof directly
to the through hole, and at the other end thereof with the head
section by the air supply tube.
4. The dental handpiece according to claim 1, wherein the tubular
pressure regulating member is connected at one end thereof with the
through hole by the air supply tube, and at the other end thereof
with the head section by the air supply tube.
5. The dental handpiece according to claim 1, wherein the tubular
pressure regulating member is connected at one end thereof with the
rear terminal part by the air supply tube, and at the other end
thereof directly to the head section.
Description
FIELD OF ART
[0001] The present invention relates to a dental handpiece, in
particular to a dental handpiece wherein the pressure of compressed
air passing through an air supply passage is down-regulated when
the pressure exceeds a predetermined level.
BACKGROUND ART
[0002] Dental handpieces that are rotatably driven by compressed
air are conventionally known, such as those having an air turbine
or an air motor. An example of such a conventional dental handpiece
is shown in FIG. 5.
[0003] FIG. 5 is a sectional view of head section 40 of an
air-turbine dental handpiece. This dental handpiece includes burr
sleeve 42 for receiving and detachably holding dental treatment
tool 41 therein, rotor 43 provided on the burr sleeve 42 for
rotatably driving the burr sleeve 42 with compressed air, and upper
and lower ball bearings 44 provided above and below the rotor 43
for rotatably supporting the burr sleeve 42. These parts are all
accommodated in cartridge case 45, which is in turn housed in head
housing 46. Head housing jacket 47 supporting the head housing 46
contains therein air supply passage 48a for supplying compressed
air to the rotor 43 and air discharge passage 48b for discharging
the compressed air supplied to the rotor 43.
[0004] The air-turbine dental handpiece discussed above has
drawbacks in that, if the handpiece is operated at an air pressure
that exceeds the acceptable level predetermined for each handpiece,
the revolution speed of the turbine becomes too high, and the
dental treatment tool may be damaged. Further, the lubricant may
run out prematurely to cause wearing of the bearings, which
disadvantageously reduces their service life.
[0005] In order to avoid these drawbacks, a dental unit which
supplies compressed air to the handpiece is given functions to
regulate the pressure of the compressed air to be supplied to the
handpiece, so as to keep the air pressure in the air supply passage
in the handpiece within the predetermined range. However, the
pressure of the compressed air needs to be adjusted properly for
each kind of dental handpiece, and such pressure adjustment
requires complex operations. Thus the user may tend to use the same
air pressure for different kinds of handpieces, and as a result,
the above problems will occur.
[0006] In order to solve the above problems, the assignee of the
present application has proposed in JP-2003-019144-A a dental
handpiece having a pressure reducing member. This dental handpiece
has a pressure reducing member arranged in the handpiece body
section, or in the coupling (connector section) to be connected to
the rear end of the handpiece body section. FIG. 6 illustrates
dental handpiece 50 as the former embodiment.
[0007] The dental handpiece 50 includes grip section 51 and head
section 52 provided at the distal end of the grip section 51. The
head section 52 houses and rotatably supports a burr sleeve (not
shown) for receiving dental treatment tool 53 therein. The grip
section 51 accommodates air supply tube 54, air discharge passage
55, and water supply line 56, and pressure reducing member 60 is
disposed in the intermediate part of the air supply tube 54. A
flexible tube (not shown) extending from a dental unit for
supplying compressed air is connected to the rear end of the grip
section 51, so that the compressed air is supplied through the air
supply tube 54 to the head section 52 to rotatably drive the dental
treatment tool 53.
[0008] In the dental handpiece 50 discussed above, when the
pressure of the compressed air supplied from the dental unit
exceeds the acceptable level, the air pressure is automatically
regulated by discharging the compressed air out of the air supply
tube 54 through the pressure reducing member 60 into the air
discharge passage 55.
[0009] The dental handpiece 50 disclosed in JP-2003-019144-A is
advantageous in that the air pressure is automatically regulated.
However, since the pressure reducing member 60 is disposed
projecting in the intermediate part of the air supply tube 54, the
grip section 51 inevitably becomes thicker, which poses problems in
grippability.
[0010] In addition to the embodiment shown in FIG. 6,
JP-2003-019144-A also discloses a dental handpiece having the
pressure reducing member provided in the coupling. However, for
providing the pressure reducing member in the coupling, relatively
complex material processing is required during the production
process, and thus further improvement is required.
[0011] Besides the handpieces disclosed in JP-2003-019144-A, there
are other conventional dental handpieces that have a pressure
reducing section integrally incorporated in the rear terminal part
of the dental handpiece body. However, the above problems, such as
the difficulties in making the grip section compact, and relative
complexity in production process, still remain in these dental
handpieces.
SUMMARY OF THE INVENTION
[0012] The present invention aims to solve the above problems in
view of the drawbacks in the prior art. It is an object of the
present invention to provide a dental handpiece which is capable of
automatically regulating the pressure of the compressed air
supplied from a dental unit, when it exceeds an acceptable level,
to prevent the revolution speed of the dental treatment tool from
becoming too high; which requires less complexity in material
processing in its production process; and which is easy for medical
practitioners to grip.
[0013] In order to solve the above problems, according to the
present invention, there is provided a dental handpiece
comprising:
[0014] a burr sleeve for receiving a dental treatment tool
therein,
[0015] a head section housing and rotatably supporting said burr
sleeve therein,
[0016] an air supply passage for introducing compressed air into
the head section for rotatably driving the burr sleeve with the
compressed air, and
[0017] an air discharge passage for discharging the compressed
air,
[0018] wherein said air supply passage comprises:
[0019] a through hole axially extending through a rear terminal
part of the dental handpiece, and
[0020] a tubular pressure regulating member and an air supply tube
connected in series between the distal end of the through hole and
the head section,
[0021] said tubular pressure regulating member having an aperture
in its intermediate part for allowing communication with the air
discharge passage, and anannular valve body arranged axially
slidably for selectively opening and closing said aperture,
[0022] wherein, when a pressure of compressed air passing through
the air supply passage exceeds a predetermined level, said annular
valve body is slid to open the aperture, whereby the compressed air
is discharged through the aperture into the air discharge passage
for regulating the pressure of the compressed air to be supplied to
the burr sleeve.
[0023] According to the dental handpiece of the present invention,
since pressure regulation of the compressed air to be supplied to
the head section is performed by means of a tubular pressure
regulating member, and this tubular pressure regulating member is
formed as a separate part from the rear terminal part of the dental
handpiece, neither the coupling (connecting section) or the rear
terminal part of the dental handpiece has to undergo complex
material processing, which is required in conventional dental
handpieces, and thus the production cost may be reduced.
[0024] In addition, the tubular pressure regulating member is
connected in series with the rear terminal part and with the air
supply tube to form itself a part of the air supply passage through
the dental handpiece. Its tubular form allows compact arrangement
of this member in the dental handpiece. Further, the tubular
pressure regulating member has an outlet aperture for the
compressed air in the intermediate part of its tubular body, and
the valve body for opening/closing the outlet aperture is formed in
an annular shape and arranged coaxially in the tubular body. Thus
the tubular pressure regulating member may be made thin, and thus
the grip section of the dental handpiece may be made relatively
thin.
[0025] In a preferred embodiment of the dental handpiece according
to the present invention, the tubular pressure regulating member
further comprises:
[0026] a first tubular member,
[0027] a second tubular member inserted in said first tubular
member to form a gap therebetween, and
[0028] a spring for biasing said annular valve body,
[0029] wherein said aperture of the tubular pressure regulating
member is provided in each of said first and second tubular members
at a predetermined position for allowing communication between the
interior of the tubular pressure regulating member and the air
discharge passage,
[0030] wherein the annular valve body and the spring are arranged
in the gap between said first and second tubular members,
[0031] wherein said annular valve body is biased by the spring into
a position to prevent communication between the apertures in the
first and second tubular members, and is arranged to receive
pressure from the compressed air passing through the air supply
passage,
[0032] wherein, when the pressure of the compressed air passing
through the air supply passage exceeds a predetermined level, the
annular valve body is slid by the pressure against the force of the
spring to provide communication between the apertures.
[0033] Since the dental handpiece according to the present
invention is provided with a tubular pressure regulating member,
the pressure of the compressed air received from a dental unit may
automatically be adjusted properly when it exceeds the acceptable
level, so that the revolution speed of the dental treatment tool
will not become too high. Further, since the tubular pressure
regulating member is connected in series with the rear terminal
part and with the air supply tube, the overall dental handpiece may
be made compact for allowing easy gripping by medical
practitioners.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a side view, partially in section, of the dental
handpiece according to the present invention.
[0035] FIGS. 2(a) and 2(b) are sectional views of the tubular
pressure regulating member used in the present invention.
[0036] FIGS. 3(a) to 3(c) schematically illustrate the series
arrangement of the rear terminal part, the pressure regulating
member, and the air supply tube in the handpiece body.
[0037] FIG. 4 is a side view showing the pressure regulating member
of FIG. 2 applied to a dental handpiece of a type different from
that of FIG. 1.
[0038] FIG. 5 is a sectional view of the head section of a
conventional dental handpiece.
[0039] FIG. 6 is a sectional view, partially in section, of a
conventional dental handpiece having a pressure regulating
mechanism.
PREFERRED EMBODIMENTS OF THE INVENTION
[0040] The present invention will now be explained in more detail
with reference to preferred embodiments taken in conjunction with
the attached drawings, which are illustrative only and do not
intend to limit the present invention.
[0041] FIG. 1 shows dental handpiece 10 according to the present
invention in a side view, partially in section.
[0042] The dental handpiece 10 of the present invention includes
grip section 11 having casing 11a. At the distal end of the grip
section 11 is provided head section 12, which houses and rotatably
supports a burr sleeve (not shown) for receiving dental treatment
tool 13 therein. In the proximal end of the grip section 11 is
formed rear terminal part 14 for detachably connecting to a
coupling (not shown) as a connector section. The grip section 11
also has air supply tube 15 therein, and pressure regulating member
20 is connected between the air supply tube 15 and the rear
terminal part 14. The coupling (not shown) to be connected to the
rear terminal part 14 is in turn connected to a dental unit (not
shown) via a flexible tube (not shown) extending from the rear end
of the coupling to the dental unit, so that compressed air is
supplied from the dental unit through the rear terminal part 14 to
the head section 12 to rotatably drive the burr sleeve.
[0043] The rear terminal part 14 is fixed in the casing 11a of the
grip section 11 by means of fixing member 16. The rear terminal
part 14 has air inlet 14a in the form of a through hole for
allowing passage of the compressed air supplied through the
coupling, and air outlet 14b and air outlet groove 14c for
discharging the compressed air into the coupling. The casing 11a
has hollow 11b inside, which functions as an air discharge passage
for guiding the air discharged from the head section 12 back
through the air outlet 14b and the air outlet groove 14c.
[0044] The pressure regulating member 20 is connected to the air
inlet 14a at its proximal end 21, and to the air supply tube 15 at
its distal end 22, so that the pressure regulating member 20 is
connected in series with the distal end of the rear terminal part
14 and with the air supply tube 15 along a generally common axis.
Compressed air taken in through the rear terminal part 14 passes
through the pressure regulating member 20 in the direction of arrow
A, and then through the air supply tube 15 to the head section
12.
[0045] Referring to FIGS. 2(a) and 2(b), the pressure regulating
member 20 includes first tubular member 23, second tubular member
24 inserted partially into the first tubular member 23 to form gap
25 there between, and anannular valve element 26 slidably disposed
in the gap 25. The valve element 26 is biased in the direction of
arrow B by means of spring 27 also disposed in the gap 25. The
first and second tubular members 23 and 24 have apertures 23a and
24a, respectively, penetrating the members and arranged
alternately. The apertures 23a and 24a are arranged such that, when
the annular valve element 26 is in the position as shown in FIG.
2(a) under the biasing force of the spring 27, the apertures 23a
and 24a are not in communication with each other and are thus
closed, whereas when the annular valve element 26 is in the
position as shown in FIG. 2(b), the apertures 23a and 24a are in
communication with each other via the gap 25 and are thus opened.
Air vent aperture 23b is provided through the first tubular member
23 for opening the gap 25 to allow sliding motion of the annular
valve element 26. The second tubular member 24 has flange 24b
protruding near the aperture 24a. The annular valve element 26
biased by the spring 27 engages with this flange 24b and is stopped
at the position shown in FIG. 2(a). When the annular valve element
26 is in the position as shown in FIG. 2(a), the rear surface 26a
of the annular valve element 26 receives the pressure from the
compressed air through the aperture 24a and the gap 25.
[0046] As discussed above, since the pressure regulating member 20
is formed as a separate member from the rear terminal part 14 of
the dental handpiece body, the rear terminal part 14 does not have
to undergo complex material processing as in the conventional
handpiece. This may contribute to reduction in production costs.
Since the pressure regulating member 20 is in a tubular form, and
is connected in series with the rear terminal part 14 and with the
air supply tube 15 to form itself a part of the air supply passage
through the dental handpiece, the pressure regulating member 20 may
be accommodated in the dental handpiece in a compact manner.
Further, the pressure regulating member 20 may be formed by
inserting the second tubular member 24 into the first tubular
member 23 and arranging the annular valve element 26 in the gap 25
between the first and second tubular members 23 and 24, and the
apertures 23a and 24a are selectively opened and closed simply by
the sliding motion of the annular valve element 26 in the gap 25.
Thus the pressure regulating member 20 may be formed with a reduced
thickness, which allows to relatively reduce the thickness of the
grip section 11 of the dental handpiece.
[0047] Incidentally, the rear terminal part 14, the pressure
regulating member 20, and the air supply tube 15 may be connected
in series in a manner different from the embodiment shown in FIG.
1.
[0048] That is, in the dental handpiece 10 illustrated in FIG. 1,
as shown schematically in FIG. 3(a), the pressure regulating member
20 is connected at one end thereof directly to the rear terminal
part 14, and at the other end thereof, with the head section 12 by
the air supply tube 15, to form the series arrangement.
Alternatively, as shown in FIG. 3(b), the pressure regulating
member 20 may be connected at one end thereof with the rear
terminal part 14 by the air supply tube 15, and at the other end
thereof with the head section 12 by the air supply tube 15, or as
shown in FIG. 3(c), the pressure regulating member 20 may be
connected at one end thereof with the rear terminal part 14 by the
air supply tube 15, and at the other end thereof directly to the
head section 12.
[0049] Next, the function of the dental handpiece 10 is explained
with reference to FIGS. 1 and 2.
[0050] The compressed air fed from the dental unit is received via
the coupling through the air inlet 14a of the rear terminal part
14, passed through the pressure regulating member 20 and the air
supply tube 15, and supplied to the head section 12 to rotatably
drive the burr sleeve (not shown) having the dental treatment tool
13 received therein. On the other hand, the compressed air
discharged from the head section 12 is passed through the hollow
11b of the dental handpiece 10, through the air outlet 14b and air
outlet groove 14c, and is discharged outside via the coupling or
the like.
[0051] Here, when the pressure of the compressed air through the
air inlet 14a, the pressure regulating member 20, and the air
supply tube 15 is within the tolerance level, the annular valve
element 26 biased by the spring 27 engages with the flange 24b to
stay at the position shown in FIG. 2(a ), whereby all the
compressed air is allowed to pass through the pressure regulating
member 20.
[0052] On the other hand, when the pressure of the compressed air
through the air inlet 14a, the pressure regulating member 20, and
the air supply tube 15 exceeds the tolerance level, that is, when
the compressed air entering through the aperture 24a of the second
tubular member 24 and the gap 25 applies pressure on the rear
surface 26a of the annular valve element 26 that exceeds the
biasing force of the spring 27, the annular valve element 26 is
slid to the direction of arrow C. This causes the aperture 24a of
the second tubular member 24 to communicate with the aperture 23a
of the first tubular member 23 via the gap 25, i.e., the apertures
24a and 23a to open, as shown in FIG. 2(b), to allow the compressed
air to be discharged out of the pressure regulating member 20 into
the hollow 11b as shown by arrows A'. In this way, when the
pressure of the compressed air exceeds the predetermined level, the
pressure regulating member 20 discharges the compressed air into
the hollow 11b, so that the pressure of the compressed air in the
air supply tube 15 downstream of the pressure regulating member 20
is maintained constantly within the predetermined range. This
allows automatic regulation of the revolution speed of the dental
treatment tool 13 within the predetermined level.
[0053] Another embodiment is explained with reference to FIG. 4.
FIG. 4 is a side view, partially in section, of dental handpiece
30, wherein the pressure regulating member 20 of FIG. 2 is applied
to a dental handpiece of a different type. The dental handpiece 30
includes grip section 31 and head section 32 provided at the distal
end of the grip section 31. The head section 32 houses and
rotatably supports a burr sleeve (not shown) for receiving dental
treatment tool 33 therein. The grip section 31 accommodates air
supply tube 34, air discharge passage 35, and water supply line 36,
with the air supply tube 34 and the water supply line 36 extending
beyond the rear end of the dental handpiece 30. Air discharge tube
37 is attached to the rear end of the dental handpiece 30. The
pressure regulating member 20 is disposed in the intermediate part
of the air supply tube 34, and a flexible tube (not shown)
extending from an apparatus such as a dental unit (not shown) for
supplying compressed air is connected to the rear end of the grip
section 31, so that the compressed air is supplied through the air
supply tube 34 to the head section 32 to rotatably drive the dental
treatment tool 33.
[0054] Incidentally, the pressure regulating member 20 of FIG. 2 is
slightly modified for adapting to the embodiment of FIG. 4 in that
its proximal and distal ends 21a and 22a are formed to be
connectable to the air supply tube 34 of FIG. 4, while the other
structure and function of the member 20 remain the same in both
embodiments.
[0055] Although the present invention has been described with
reference to the preferred embodiment, it should be understood that
various modifications and variations can be easily made by those
skilled in the art without departing from the spirit of the
invention. Accordingly, the foregoing disclosure should be
interpreted as illustrative only and is not to be interpreted in a
limiting sense. The present invention is limited only by the scope
of the following claims.
* * * * *