U.S. patent number RE35,941 [Application Number 08/552,113] was granted by the patent office on 1998-11-03 for mechanical toothbrush.
This patent grant is currently assigned to Pulse Innovations, Inc.. Invention is credited to Benjamin H. Stansbury, Jr..
United States Patent |
RE35,941 |
Stansbury, Jr. |
November 3, 1998 |
Mechanical toothbrush
Abstract
A power driven mechanical toothbrush is disclosed. A replaceable
toothbrush head member has tuft blocks retained generally
therewithin and extending laterally outwardly from the a cam shaft.
Each tuft block has at least one tuft of bristles, usually four,
secured within the tuft block and extending upwardly therefrom.
Each of the bristles has a distal end at a distance from its tuft
block, and the bristles in each tuft are generally parallel to each
other. The toothbrush head member is adapted to receive and retain
the tuft blocks in sliding relation therein, so that each tuft
block slides linearly in a direction parallel to the longitudinal
tuft axis as guided by guide rails within the head member, between
a retracted position and an extended position. Each tuft block is
driven from its retracted position to its extended position by the
rotatable cam shaft. In use, the tuft bristles are brought into
contact with the teeth by the user, before the respective tuft
block reaches its extended position, so as to thereby flex the
bristles and to cause a lateral motion of the distal of the
bristles along the surface of the teeth. The reciprocating action
of the tuft blocks causes a wiping action of the bristles and
bristle ends against the teeth, and the teeth are thereby
cleaned.
Inventors: |
Stansbury, Jr.; Benjamin H.
(Alexandria, VA) |
Assignee: |
Pulse Innovations, Inc.
(Ontario, CA)
|
Family
ID: |
25490056 |
Appl.
No.: |
08/552,113 |
Filed: |
November 2, 1995 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
950174 |
Sep 24, 1992 |
05259083 |
Nov 9, 1993 |
|
|
Current U.S.
Class: |
15/22.2; 15/22.1;
433/122 |
Current CPC
Class: |
A61C
17/3463 (20130101); A61C 17/32 (20130101); A61C
17/349 (20130101) |
Current International
Class: |
A61C
17/32 (20060101); A61C 17/16 (20060101); A61C
017/32 (); A61C 017/34 () |
Field of
Search: |
;15/22.1,22.2,201,97.1,184,22.4,28,29 ;601/139,141,142
;433/216,122 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
0 135 946 |
|
Apr 1985 |
|
EP |
|
33 06 176 |
|
Aug 1984 |
|
DE |
|
358 408 |
|
Jan 1962 |
|
CH |
|
2247297 |
|
Feb 1992 |
|
GB |
|
Primary Examiner: Graham; Gary K.
Attorney, Agent or Firm: Finnegan, Henderson, Farabow,
Garrett & Dunner, L.L.P.
Claims
What is claimed is:
1. A power driven mechanical toothbrush, comprising:
a cam shaft adapted to be rotatably driven, and having a central
longitudinal axis;
a driving means adapted to rotatably drive said cam shaft;
a toothbrush head member having a centrally disposed longitudinal
head axis, a bottom wall, an end wall, a pair of opposed side
walls, and guide means mounted within said toothbrush head
member;
a main housing adapted to retain said driving means therein, and to
retain said cam shaft in operative relation with said driving
means, and having said toothbrush head member mounted thereon;
at least one tuft block retained generally within said toothbrush
head member and mounted in driving relationship with said cam shaft
and extending laterally outwardly from said central longitudinal
axis, wherein said at least one tuft block has at least one tuft of
bristles secured within said tuft block and extending upwardly
therefrom, said bristles having a distal end at a distance from
said tuft block, said bristles in said at least one tuft being
generally parallel to one another, said at least one tuft having a
longitudinal tuft axis located generally along the centre
thereof;
wherein said toothbrush head member is adapted to receive and
retain said at least one tuft block in sliding relation therein
such that said at least one tuft block slides linearly in a
direction parallel to said longitudinal tuft axis as guided by said
guide means within said head member, between a retracted position
and an extended position;
wherein said at least one tuft block is driven from said retracted
position to said extended position by the rotation of said cam
shaft and the resulting interaction between said cam shaft and said
at least one tuft block; and
wherein, in use, said bristles are brought into contact with the
teeth by a user, before the respective said at least one tuft block
reaches said extended position so as to thereby flex said bristles
and cause a lateral motion of the distal end thereof along the
surface of the teeth, and so as to thereby to remove unwanted
substances from the teeth.
2. The toothbrush of claim 1, wherein said at least one tuft block
has a plurality of tufts, each tuft having its own longitudinal
axis, with each of said longitudinal tuft axes being substantially
parallel one to another.
3. The toothbrush of claim 2, wherein said head member is
elongated, and wherein there is a plurality of tuft blocks disposed
along said longitudinal axis of said toothbrush head member, with
said longitudinal tuft axes being substantially perpendicular to
said longitudinal head axis of said elongated head member and with
each of said longitudinal tuft axes being substantially parallel
one to another; and wherein there is a respective cam lobe disposed
along said cam shaft for each said tuft block.
4. The toothbrush of claim 3, wherein said plurality of tuft blocks
is substantially juxtaposed one to another.
5. The toothbrush of claim 4, wherein said guide means comprises
pairs of opposed guide rails extending inwardly from said opposed
side walls.
6. The toothbrush of claim 5, wherein each of said tuft blocks has
an aperture therein adapted to receive said cam shaft therethrough,
said aperture being defined in part by a first cam receiving
surface, wherein said cam shaft interacts with said first cam
receiving surface of each of said tuft blocks so as to drive said
tuft blocks from said retracted position to said extended
position.
7. The toothbrush of claim 6, wherein said aperture in each of said
tuft blocks is elongated in a direction that is transverse to both
of said central longitudinal axis of said cam shaft and to the
direction of said tuft axes.
8. The toothbrush of claim 7, wherein said cam shaft has a
plurality of lobes that are substantially circular in cross-section
and have a diameter "D", and wherein said lobes are connected by
connecting portions having a maximum thickness "D".
9. The toothbrush of claim 8, wherein said plurality of lobes are
radially spaced from a central axis of said cam shaft so that each
of said lobes will drive its respective tuft block to a
predetermined extent away from said central axis of said cam shaft;
and
wherein said predetermined extent is selectable from one cam shaft
of said toothbrush head member to another cam shaft of another
toothbrush head member, so as to thereby permit differing cleaning
actions for various respective ones of said toothbrush head
member.
10. The toothbrush of claim 8, wherein said connecting portions are
ramped so as to facilitate positioning of said cam shaft into the
respective aperture in each of said tuft blocks.
11. The toothbrush of claim 10, wherein said cam shaft is made from
a metal wire.
12. The toothbrush of claim 8, wherein each of said apertures is
further defined by a second cam receiving surface, which is opposed
to said first cam receiving surface, wherein said first and second
cam receiving surfaces are separated by a distance generally
equivalent to the distance "D".
13. The toothbrush of claim 7, wherein said cam shaft is oscillated
through an oscillation arc of from 90.degree. to 180.degree., so as
to impart vertical motion to said tuft block.
14. The toothbrush of claim 4, wherein each tuft block has four
tufts of bristles which include two inner tufts and two outer
tufts, with one inner tuft and one outer tuft disposed at each side
of said longitudinal head axis.
15. The toothbrush of claim 3, wherein there are more than three
and fewer than nine juxtaposed tuft blocks.
16. The toothbrush of claim 3, wherein there are six juxtaposed
tuft blocks.
17. The toothbrush of claim 16, wherein said cam shaft has a total
of six lobes identified as a, b, c, d, e, and f, respectively, and
wherein when said cam shaft is rotating, the lobes pass a given
circumferential reference point in the order a, e, b, f, c, d.
18. The toothbrush of claim 3, wherein each of said respective cam
lobes disposed along said cam shaft is radially spaced through a
total cam lobe radial spacing of 360.degree..
19. The toothbrush of claim 18, wherein said cam lobes are evenly
radially spaced.
20. The toothbrush of claim 1, wherein said at least one tuft block
moves from said retracted position to said extended position a
distance of between 0.015 inches and 0.050 inches.
21. The toothbrush of claim 1, wherein there is only a single tuft
block, having one proximal brush attached thereto.
22. The toothbrush of claim 1, further comprising a flexible seal
attached in sealed relation to said toothbrush head member and to
said at least one tuft block, and wherein said flexible seal
receives said at least one tuft block through a respective opening
therein, said flexible seal being thereby adapted to preclude
foreign matter from entering the interior of said toothbrush head
member.
23. The toothbrush of claim 22, wherein said flexible seal is
mechanically attached to said toothbrush head member, and is
further mechanically attached to said at least one tuft block, so
as to be in sealed engagement with said toothbrush head member and
said at least one tuft block.
24. The toothbrush of claim 22, wherein said flexible seal acts as
a spring means.
25. The toothbrush of claim 1, further comprising a flexible seal
attached in sealed relation to said toothbrush head member and to
said at least one tuft block, and wherein said flexible seal
receives said tufts through respective openings therein for each of
said tufts, said flexible seal being thereby adapted to preclude
foreign matter from entering the interior of said toothbrush head
member.
26. The toothbrush of claim 25, further comprising a flexible seal
attached in sealed relation to said toothbrush head member and to
said at least one tuft block, and wherein said flexible seal
receives said tufts through respective openings therein for each of
said tufts, said flexible seal being thereby adapted to preclude
foreign matter from entering the interior of said toothbrush head
member.
27. The toothbrush of claim 26, wherein said flexible seal has a
first lip portion adapted for sealed engagement into an undercut in
the outer sides of said opposed walls of said toothbrush head
member, and a second lip portion for said at least one tuft block,
with said second lip portion being in sealed engagement with a
portion of said at least one tuft block.
28. The toothbrush of claim 25, wherein at least a portion of said
flexible seal contacts at least a portion of the respective opening
for each of said tufts, so as to thereby create a snug seal between
said flexible seal, each of said tufts, and said at least one tuft
block.
29. The toothbrush of claim 25, wherein said flexible seal acts as
a spring means, whereby said at least one tuft block is biased
towards said retracted position.
30. The toothbrush of claim 1, wherein said cam shaft is locked
into assembled position by way of a snap connection into said end
wall of said toothbrush head member.
31. The toothbrush of claim 1, wherein the frequency of stroke of
said at least one tuft block is greater than 2000 times per
minute.
32. The toothbrush of claim 1, wherein the frequency of stroke of
said at least one tuft block is between about 2000 and 10,000 times
per minute.
33. The toothbrush of claim 32, wherein the frequency of stroke of
said at least one tuft block is about 6000 times per minute.
34. The toothbrush of claim 33, wherein said bristles extend
outwardly from said at least one tuft block a distance of about 3/8
inches.
35. The toothbrush of claim 33, wherein said bristles have a
diameter of 0.005 to 0.008 inches.
36. The toothbrush of claim 1, wherein said driving means is an
electrically powered motor.
37. The toothbrush of claim 1, further comprising at least one
spring member, whereby said at least one tuft block is biased
towards said retracted position. .Iadd.
38. The toothbrush of claim 1, wherein the toothbrush head member
is detachably mounted on the main housing..Iaddend..Iadd.39. A
toothbrush head member, comprising:
a housing, including a centrally disposed longitudinal head axis, a
bottom wall, an end wall, a pair of opposed side walls, and guide
means mounted within said toothbrush head member;
a cam shaft retained in said housing, said cam shaft having a
central longitudinal axis and being adapted to be rotatably driven
by a power unit;
at least one tuft block retained generally in said housing wherein
said at least one tuft block having at least one tuft of bristles
secured within said tuft block and extending upwardly therefrom,
said at least one tuft having a longitudinal tuft axis located
generally along the centre thereof;
wherein said housing is adapted to receive and retain said at least
one tuft block in sliding relation therein such that said at least
one tuft block slides linearly in a direction parallel to sad
longitudinal tuft axis as guided by said guide means within said
head member, between a retracted position and an extended position;
and
wherein said at least one tuft block is driven from said retracted
position to said extended position by the rotation of said cam
shaft and the resulting interaction between said cam shaft and said
at least one tuft block..Iaddend..Iadd.40. The toothbrush head
member of claim 39, wherein at least one tuft block is mounted in
driving relationship with the cam shaft and extends laterally
outwardly from the central longitudinal axis..Iaddend..Iadd.41. The
toothbrush head member of claim 40, wherein said at least one tuft
block has a plurality of tufts, each tuft having its own
longitudinal axis, with each of said longitudinal tuft axes being
substantially parallel one to another..Iaddend..Iadd.42. The
toothbrush head member of claim 41, wherein said at least one tuft
block moves from said retracted position to said extended position
a distance of between 0.015 inches and 0.050
inches..Iaddend..Iadd.43. The toothbrush head member of claim 41,
wherein there is only a single tuft block, having one proximal
brush attached thereto..Iaddend..Iadd.44. The toothbrush head
member of claim 41, further comprising a flexible seal in sealed
relation to said toothbrush head member and to said at least one
tuft block, and wherein said flexible seal receives said at least
one tuft block through a respective opening therein, said flexible
seal being thereby adapted to preclude foreign matter from entering
the interior of said toothbrush head member..Iaddend..Iadd.45. The
toothbrush head member of claim 44, wherein said flexible seal is
mechanically attached to said toothbrush head member, and is
further mechanically attached to said at least one tuft block, so
as to be in sealed engagement with said toothbrush head member and
said at least one tuft block..Iaddend..Iadd.46. The toothbrush head
member of claim 45, wherein said flexible seal acts as a spring
means..Iaddend..Iadd.47. The toothbrush head member of claim 41,
further comprising a flexible seal attached in sealed relation to
said toothbrush head member and to said at least one tuft block,
and wherein said flexible seal receives said tufts through
respective openings therein for each of said tufts, said flexible
seal being thereby adapted to preclude foreign matter from entering
the interior of said toothbrush head member..Iaddend..Iadd.48. The
toothbrush head member of claim 47, further comprising a flexible
seal attached in sealed relation to said toothbrush head member and
to said at least one tuft block, and wherein said flexible seal
receives said tufts through respective openings therein for each of
said tufts, said flexible seal being thereby adapted to preclude
foreign matter from entering the interior of said toothbrush head
member..Iaddend..Iadd.49. The toothbrush head member of claim 48,
wherein said flexible seal has a first lip portion adapted for
sealed engagement into an undercut in the outer sides of said
opposed walls of said toothbrush head member, and a second lip
portion for said at least one tuft block, with said second lip
portion being in sealed engagement with a portion of said at least
one tuft block..Iaddend..Iadd.50. The toothbrush head member of
claim 48, wherein said flexible seal acts as a spring means,
whereby said at least one tuft block is biased towards said
retracted position..Iaddend..Iadd.51. The toothbrush head member of
claim 47, wherein at least a portion of said flexible seal contacts
at least a portion of the respective opening for each of said
tufts, so as to thereby create a snug seal between said flexible
seal, each of said tufts, and said at least one tuft
block..Iaddend..Iadd.52. The toothbrush head member of claim 41,
wherein said cam shaft is locked into assembled position by way of
a snap connection into said end wall of said toothbrush head
member..Iaddend..Iadd.53. The toothbrush head member of claim 41,
wherein the frequency of stroke of said at least one tuft block is
greater than 2000 times per minute..Iaddend..Iadd.54. The
toothbrush head member of claim 41, wherein the frequency of stroke
of said at least one tuft block is between about 2000 and 10,000
times per minute..Iaddend..Iadd.55. The toothbrush head member of
claim 54, wherein the frequency of stroke of said at least one tuft
block is about 6000 times per minute..Iaddend..Iadd.56. The
toothbrush head member of claim 55, wherein said bristles extend
outwardly from said at least one tuft block a distance of about 3/8
inches..Iaddend..Iadd.57. The toothbrush head member of claim 55,
wherein said bristles have a diameter of 0.005 to 0.008
inches..Iaddend..Iadd.58. The toothbrush head member of claim 41,
wherein said power unit is an electrically powered
motor..Iaddend..Iadd.59. The toothbrush head member of claim 41,
further comprising at least one spring member, whereby said at
least one tuft block is biased towards said retracted
position..Iaddend..Iadd.60. The toothbrush head member of claim 41,
wherein said housing includes an elongated portion, and wherein
there is a plurality of tuft blocks disposed along said
longitudinal axis of said housing, with said longitudinal tuft axes
being substantially perpendicular to said longitudinal head axis;
and wherein there is a cam lobe disposed along said cam shaft for
each said tuft block..Iaddend..Iadd.61. The toothbrush head member
of claim 60, wherein said plurality of tuft blocks is substantially
juxtaposed one to
another..Iaddend..Iadd.62. The toothbrush head member of claim 61,
wherein said guide means comprises pairs of opposed guide rails
extending inwardly from said opposed side walls..Iaddend..Iadd.63.
The toothbrush head member of claim 62, wherein each of said tuft
blocks has an aperture therein adapted to receive said cam shaft
therethrough, said aperture being defined in part by a first cam
receiving surface, wherein said cam shaft interacts with said first
cam receiving surface of each of said tuft blocks so as to drive
said tuft blocks from said retracted position to
said extended position..Iaddend..Iadd.64. The toothbrush head
member of claim 63, wherein said aperture in each of said tuft
blocks is elongated in a direction that is transverse to said
central longitudinal axis of said cam shaft and to the direction of
said tuft axes..Iaddend..Iadd.65. The toothbrush head member of
claim 64, wherein said cam lobes are substantially circular in
cross-section and are connected by connecting portions having no
greater diameter than the diameter of the circular
cross-section..Iaddend..Iadd.66. The toothbrush head member of
claim 65, wherein said lobes are radially spaced from a central
axis of said cam shaft so that each of said lobes will drive its
respective tuft block to a predetermined extent away from said
central axis of said cam shaft..Iaddend..Iadd.67. The toothbrush
head member of claim 65, wherein said connecting portions are
ramped so as to facilitate positioning of said cam shaft into the
respective aperture in each of said tuft blocks..Iaddend..Iadd.68.
The toothbrush head member of claim 67, wherein
said cam shaft is a metal wire..Iaddend..Iadd.69. The toothbrush
head member of claim 65, wherein each of said apertures is further
defined by a second cam receiving surface, which is opposed to said
first cam receiving surface, wherein said first and second cam
receiving surfaces are separated by a distance generally equivalent
to the diameter of the circular cross-section of the cam
lobes..Iaddend..Iadd.70. The toothbrush head member of claim 64,
wherein said cam shaft can be oscillated through an oscillation arc
of from 90.degree. to 180.degree. so as to impart vertical motion
to each of said tuft blocks..Iaddend..Iadd.71. The toothbrush head
member of claim 60, wherein each of said tuft blocks has two inner
tufts and two outer tufts, one inner tuft and one outer tuft
disposed at each side of said longitudinal head
axis..Iaddend..Iadd.72. The toothbrush head member of claim 60,
wherein there are more than three
and fewer than nine juxtaposed tuft blocks..Iaddend..Iadd.73. The
toothbrush head member of claim 60, wherein there are six
juxtaposed tuft blocks..Iaddend..Iadd.74. The toothbrush head
member of claim 73, wherein said cam shaft has a total of six lobes
identified as a, b, c, d, e, and f, respectively, and wherein when
said cam shaft is rotating, the lobes pass a given circumferential
reference point in the order a, e, b, f, c, d..Iaddend..Iadd.75.
The toothbrush head member of claim 60, wherein each of said cam
lobes disposed along said cam shaft is radially spaced through a
total cam lobe radial spacing of 360.degree...Iaddend..Iadd.76. The
toothbrush head member of claim 75, wherein said cam lobes are
evenly
radially spaced..Iaddend..Iadd.77. A toothbrush comprising:
an elongated hollow shaft having a head portion at one axial end
thereof and a bore;
a cam shaft co-axially disposed for rotation in the bore of the
hollow shaft, one axial end of the cam shaft being adapted for
driving connection with a power unit and the other axial end of the
cam shaft defining a plurality of adjacent cam surfaces each cam
surface being disposed to define a path of rotation that is
separate from an axially adjacent cam surface; and
a plurality of tuft blocks disposed in the head portion of the
hollow shaft for independent reciprocal movement on parallel axes
perpendicular to the cam shaft axis, each tuft block carrying at
least one tuft of bristles extending along the axis of
reciprocation and each tuft block being engaged by a respective one
of the cam surfaces to generate the reciprocal
movement in response to the rotation of the cam
shaft..Iaddend..Iadd.78. The toothbrush of claim 77, further
comprising a power unit which includes a housing, a motor,
including a rotatable drive shaft disposed for selective engagement
by the one axial end of the cam shaft, and electric circuitry for
selectively connecting the motor to a power source, wherein said
hollow shaft is detachably mounted onto the
housing..Iaddend..Iadd.79. The toothbrush of claim 77 comprising
four tuft blocks..Iaddend..Iadd.80. The toothbrush of claim 77
comprising six tuft blocks..Iaddend..Iadd.81. The toothbrush of
claim 77, wherein the cam surfaces are substantially equidistantly
radially spaced about the cam shaft..Iaddend..Iadd.82. The
toothbrush of claim 77, wherein each tuft block comprises an
aperture therein for receiving said cam shaft therethrough, said
aperture being elongated in a direction transverse to both the axis
of reciprocation and to the cam shaft axis..Iaddend.
Description
FIELD OF THE INVENTION
This invention relates to toothbrushes and more particularly to
portable hand-held mechanical toothbrushes. Specifically, a novel
toothbrush head is disclosed.
BACKGROUND OF THE INVENTION
Manual toothbrushes of one form or another have been used to clean
teeth for many years. Depending on the exact technique used in
conjunction with such manual toothbrushes, results obtained through
their use are generally adequate.
Mechanical, and especially electromechanical toothbrushes that
provide a means for an individual to brush his teeth more
effectively, properly and thoroughly than by use of a simple manual
toothbrush, have been available for several years. Most of these
mechanical or electromechanical toothbrushes rotate or oscillate in
some manner so as to vigorously clean the teeth. Typically,
electromechanical toothbrushes are powered by rechargeable
batteries that power an electric motor that in turn drives the
toothbrush head or heads. It has been found that in general such
electromechanical toothbrushes do indeed produce improved results
compared to brushing with a manual toothbrush.
There is a technique, which is known among professionals as the
"Bass Technique", that can be used to achieve superior results in
terms of cleaning one's teeth through use of a manual toothbrush.
In basic terms, the "Bass Technique" requires the user to position
the brush over a zone of the teeth use very short strokes to
vibrate the brush so as to "brush" that zone of the teeth as
described above for a period of time sufficient to remove foreign
material therefrom. These short strokes are made in a direction
transverse to the orientation of the bristles. Towards the end of a
given stroke, the bristles flex so as to become oriented such that
the ends thereof point generally away from the direction of travel
of the bristles across the teeth. At this point, the bristles have
started to sweep across the teeth, which is not very effective for
removing foreign material from the teeth, and therefore the
direction of the stroke is changed, and a new stroke begun in the
opposite direction. At the beginning of this new stroke, the still
flexed bristles are pointed in the direction of the stroke which
causes the bristle to chisel the foreign material from the teeth
for a moment before the bristles again flex so as to again sweep
across the teeth. Generally, this type of brushing takes more than
20 strokes at each separate location and there are typically about
40 different brush locations that are required to brush all of a
person's teeth. At a vigorous pace of three strokes per second,
this procedure would take over four minutes using a manual
toothbrush, which is unacceptably lengthy. It has been found that
for virtually any procedure for cleaning the teeth, most people are
apt to quit brushing after about one minute. This means that in the
case of the "Bass Technique", the cleaning procedure would normally
not be done properly using a manual toothbrush.
The advantage of using the "Bass Technique" is that the bristles
are emulating a chiseling action, instead of a sweeping action, and
this is the most effective way of removing foreign material from
the teeth.
It is believed that superior results would also be possible through
use of a mechanical or electromechanical toothbrush that takes
advantage of the chisel type cleaning demonstrated by the "Bass
Technique". Indeed, it is possible that the chiseling action
demonstrated by the "Bass Technique" could be improved on by
providing a more direct chiseling and flexing action of the
bristles. In order to do this, such a toothbrush would need to have
bristles that approach the teeth substantially directly along the
longitudinal axis of each bristle and then bends slightly, so that
each bristle chisels and generally undercuts any foreign material
from the teeth so as to lift the foreign material away.
As will be discussed in greater detail hereafter, the present
invention provides a mechanical or electromechanical toothbrush
that will effectively emulate the "Bass Technique". The toothbrush
that is provided by the present invention may be used, in the sense
of the manner that it is held in the hand and somewhat in the
manner that it is moved around the mouth, in much the same manner
as a conventional toothbrush. Thus, the mechanical action of the
present invention will provide for the bristles to thrust forwardly
in a direction that is generally perpendicular to the teeth, along
the longitudinal axes of the bristles, and the bristles will flex
or bend slightly when they contact the teeth due to the pressure
being applied against them by the user as he holds the toothbrush.
However, the bristles of the toothbrush then exhibit a mechanical
oscillating action in short strokes along their longitudinal axes,
which occurs as a consequence of the bristles being mechanically
driven. As the user manipulates the toothbrush of the present
invention in much the same manner as an ordinary toothbrush would
be manipulated, the pressure of the brush against the teeth
deflects the bristles of the toothbrush around the complex
topography of the teeth. Thus, the cleansing action which is
somewhat as a chisel or scraper would act against a surface will
generally undercut any foreign material, which is then lifted or
washed away. That cleansing or cleaning action occurs as the distal
end of the bristles which are more or less tangential, or at least
at an acute angle, to the tooth surfaces.
In action, therefore, the mechanical bristle action occurs such
that the original stroke which is imparted to the bristle is
transmitted to where the bristle end is flexed, so that the tip of
each bristle moves in the same direction as the bristle axis, with
a positive or negative motion of the bristle end in that direction
as a consequence of the reciprocating motion imparted to the
bristles.
Other known techniques, especially of prior mechanically driven
toothbrushes, merely sweep the high spots, never entering the area
between the teeth or the small irregularities in the teeth. Various
types of toothbrushes that use these other known techniques are
discussed hereafter, with respect to the Prior Art.
PRIOR ART
One type of prior art falls under the category of rotating brush
heads. Electric toothbrushes that have rotating brush heads or
tufts merely "sweep" the ends of the bristles of the brush heads
across the teeth and cannot effectively clean between the teeth or
clean in the irregular surfaces of the teeth.
A second type of prior art is an electric toothbrush having
reversing rotating brush heads. Such a toothbrush is exemplified in
U.S. Pat. No. 4,156,620 issued May 29, 1979 to CLEMENS, which
discloses an Apparatus and Method for Cleaning Teeth. The apparatus
has a plurality of short and long tufts that are driven in a
reversing rotating manner by a reciprocating gear rack that is in
turn driven by crank arm. The crank arm is driven by a crown gear
that is in turn driven by a smaller crown gear that is driven by an
electric motor. Again, the brush heads or tufts merely "sweep" the
ends of the bristles of the brush heads across the teeth for most
of the rotating action. As the rotating heads change direction, the
bristles can momentarily push directly onto the teeth and to some
degree chisel the foreign material on the teeth.
The third type of prior art mechanized toothbrush is one that
performs a scrubbing action, which is basically analogous to a
scrub brush cleaning a floor, especially a textured contoured
floor. The brush is moved back and forth over the teeth, preferably
with vigorous short back and forth strokes. Each bristle basically
sweeps over the tooth over most of its stroke. At the end of each
stroke, where the direction of the brush is changed, the ends of
the bristles can momentarily push directly onto the teeth and to
some degree chisel the foreign material on the teeth. Initially,
when the change in direction occurs, the bristle is pointing in the
new direction of the upcoming stroke until pushed back by friction,
wherein it resumes its passive sweeping motion. Mechanized
toothbrushes having scrubbing actions are exemplified by the
following three patents.
U.S. Pat. No. 1,517,320 issued Dec. 2, 1924 to STODDART discloses
an electromechanical toothbrush having a plurality of sections,
each section mounted on a central shaft, with the sections
juxtaposed to one another. Each section is driven by a separate
eccentric that is in turn rotated by a central shaft. The sections
are precluded from rotating 360.degree. by two opposed fulcrum
points, one on each side of the sections. Each section is rotated
somewhat eccentrically until the side of the section contacts the
appropriate fulcrum point, which contact stops the rotating. The
bristle portions of each section basically move across the teeth,
thus giving a scrubbing action. Alternating sections move in
opposed directions.
U.S. Pat. No. 3,160,902 issued Dec. 15, 1964 to AYMAR discloses an
electromechanical toothbrush wherein the brush portion oscillates
along its longitudinal axis and also oscillates back and forth
around its longitudinal axis. An electric motor turns a small
beveled gear which in turn rotates a larger beveled gear. The large
beveled gear drives a crank pin that is connected to the brush rod,
onto which the brush is securely attached.
Swiss Patent 358,408 to WYDLER discloses an electro-mechanical
toothbrush having a toothbrush head that oscillates about a central
area defined by a central axis. The toothbrush head is driven by a
pair of parallel rotating drive shafts with eccentric ends that
alternatingly push opposite sides of the toothbrush forward towards
a person's teeth. The drive shafts are rotated by a single gear
attached to a motor drive shaft. It would appear that such a unit
would cause excessive vibration in a person's mouth when used.
A fourth type of mechanical toothbrush is a reciprocating
mechanical toothbrush where the reciprocation is generally in a
direction parallel to the axis of the bristles; which is basically
the same classification as the present invention. There are three
such prior art devices known, and in these prior art devices, as
well as in the present invention, the bristles of the toothbrush
reciprocate back and forth along their longitudinal axis so as to
basically impact against the teeth. These three prior art patents
will now be described.
U.S. Pat. No. 2,935,755 issued May 10, 1960 to LEIRA et al,
discloses a toothbrush having a plurality of bristles that move in
and out of a toothbrush head along their longitudinal axis. These
bristles are passively operated by the action of the toothbrush
head over a person's teeth. The bristles are pushed into the
toothbrush head by way of contact with a person's teeth, and pushed
outwardly against the person's teeth by means of a flexible band
spring member. No chiseling action takes place, whatsoever.
U.S. Pat No. 4,346,492 issued Aug. 31, 1982 to SOLOW, discloses a
mechanical toothbrush with individual tuft drives wherein
individual tufts of bristles are pneumatically driven along their
respective longitudinal axes to impact generally perpendicularly on
a person's teeth. One important aspect of the SOLOW invention, as
emphasized in that patent, is that due to the pneumatic powering of
the tufts of bristles, each tuft stops when it impacts the teeth,
and therefore there is no true chiseling effect. Indeed, the
bristles in the SOLOW toothbrush are generally short and stiff so
that they do not flex. Further, the bristles are directed towards
the teeth all at the same time, and therefore, according to
Newton's third law of motion, cause the head of the toothbrush to
essentially vibrate oppositely to the tufts, which causes excessive
and undesirable vibration against a person's mouth.
A further U.S. Pat. No. 4,223,417 issued Sep. 23, 1980 to SOLOW,
discloses a gliding, mechanized toothbrush having a pair of opposed
toothbrush pistons that are positioned to each contact one side of
a tooth at the same time. These pistons oscillate up and down both
within a common head such that the bristles of each piston are
moved in a direction along the longitudinal axes of the bristles.
The pistons are pneumatically powered which causes the same problem
of stopping at impact, as discussed with respect to SOLOW U.S. Pat.
No. 4,346,492. Further, the bristles on each piston are not
separated into sections, and it is therefore easy for a few
bristles to contact the teeth and slow down or even stop the action
of the piston.
SUMMARY OF THE INVENTION
A power driven mechanical toothbrush is disclosed. The power driven
mechanical toothbrush comprises a cam shaft adapted to be rotatably
driven, and having a central longitudinal axis, and a driving means
adapted to rotatably drive said cam shaft. There is a toothbrush
head member having a centrally disposed longitudinal head axis, a
bottom wall, an end wall, and a pair of opposed side walls. At
least one tuft block--usually four to seven blocks are used--is
retained generally within the toothbrush head member extending
laterally outwardly from the central longitudinal axis. One tuft
block is used for a proximal toothbrush whose purpose is
specifically to clean and massage the gingival margins and
interproximal areas of the teeth.
The at least one tuft block has at least one tuft of
bristles--usually four tufts are used--secured within the tuft
block and extending upwardly therefrom. The bristles have a distal
end at a distance from the tuft block, and the bristles and tufts
of bristles are all generally parallel to each other. Each bristle
tuft has a longitudinal tuft axis located generally along the
centre thereof. The toothbrush head member is adapted to receive
and retain the tuft block or tuft blocks in sliding relation
therein, such that the tuft block or tuft blocks slide linearly in
a direction parallel to the longitudinal tuft axes, as guided by
guide means within the head member. Each tuft block slides between
a tuft block retracted position and a tuft block extended position.
Each tuft block is driven from its tuft block retracted position to
its tuft block extended position by the rotation of the cam shaft
and the resulting interaction between the cam shaft and the tuft
block.
In use, the bristles impact the teeth of a user before the
respective tuft block reaches its extended position, so as to flex
the bristles and cause a lateral motion of the distal end thereof
along the tooth surface, thereby to remove unwanted substances from
the teeth.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described by way
of the accompanying drawings, in which:
FIG. 1 is a cut-away side view of a preferred embodiment of the
toothbrush of the present invention.
FIG. 2 is an enlarged top view of the toothbrush head member of the
toothbrush of FIG. 1;
FIG. 3 is a side view of the toothbrush head member of FIG. 2;
FIG. 4 is a top view similar to FIG. 2 except showing an
undetermined number of tuft blocks;
FIG. 5 is a cross-section of the toothbrush head along lines 5--5
of FIG. 2, showing two tufts in an extended position and two tufts
in a retracted position;
FIG. 6 is a partial view of the cam shaft found within the
toothbrush head member;
FIG. 7 is an enlarged partial view of the attachment means that is
used to removably attach the toothbrush head member to the driving
means;
FIG. 8 is a partial enlarged cross-section view of a tuft block
showing bristle tufts being inserted therein;
FIG. 9 is an isometric view of a tuft block having tufts inserted
therein;
FIG. 10 is a view similar to FIG. 3, showing a toothbrush in use
against the teeth of a user;
FIG. 11 is a side view of a proximal brush head, which is otherwise
in keeping with the present invention; and
FIG. 12 is an enlarged cross-section of the proximal brush head of
FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made to FIG. 1 which shows the toothbrush 20
of the present invention having a two-part main housing 22 and a
toothbrush head member 24 removably attached thereto. Within the
main housing 22 is a high speed electrical motor 26 that acts as a
driving means and has a drive shaft 28 extending therefrom into the
toothbrush head member 24. The interfacing of the drive shaft 28
with the toothbrush head member 24 will be discussed in greater
detail subsequently. Powering the high speed electrical motor 26
are batteries 30, which are connected to the electrical motor 26 by
wires 32. Preferably, the batteries 30 are rechargeable and an
induction coil or other charger circuit 34 exists within the main
housing 22 so as to allow for charging of the batteries 30.
The toothbrush head member 24 mounts on the main housing 22 by way
of an elongated shaft 36. Mounted within the head portion 38 of the
toothbrush head member 24 is a plurality of tuft blocks 40 that fit
through an opening 35 therein. In a preferred embodiment as
illustrated, there are six tuft blocks 40. It is indeed possible to
have any number of tuft blocks 40, with quantities of one through
eight tuft blocks being contemplated as usable. The tuft blocks 40
slide up and down within the head portion 38 of the toothbrush head
member 24 between an extended position and a retracted position, as
will be described in more detail subsequently. The tuft blocks 40
are driven by way of a cam shaft 42 that fits through an aperture
60 in each of the tuft blocks 40. The cam shaft 42 is attached to
the drive shaft 28 by way of attachment portion 29. The cam shaft
42 is thereby adapted to be rotatably driven by the driving
means--the electrical motor 26.
Reference will now be made to FIGS. 2 through 10 in order to
describe the workings of the toothbrush 20 of the present invention
in detail. The head portion 38 of the toothbrush head member 24
includes a pair of opposed side walls 44, an end wall 46, and a
bottom wall 48. There is a centrally disposed longitudinal head
axis 50 along the head portion 38 of the toothbrush head member
24.
The tuft blocks 40 extend laterally outwardly from the central
longitudinal axis 50 of the cam shaft 42. Each tuft block 40 has at
least one tuft 52 of bristles 54 secured within the tuft block 40,
and extending upwardly therefrom. Each tuft has a longitudinal tuft
axis 53 located generally along the center thereof. The bristles 54
have a distal end 56 at a distance from the tuft blocks 40.
Preferably, the bristles 54 extend outwardly from the tuft blocks
40 a distance of about 3/8 inches, and are of a diameter of about
0.005 to about 0.008 inches. The bristles 54 in the tuft blocks 40
are generally parallel to each other, and the tufts 52 are also
generally parallel to each other within the same tuft block and
also with respect to the tufts 52 in other tuft blocks 40. The
preferred number of tufts 52 within a tuft block 40 is four;
however, any number is acceptable with one tuft 52 per tuft block
40 to about six tufts 52 per tuft block 40 being contemplated as
generally useful. The four tufts of bristles include two inner
tufts and two outer tufts, with one inner and one outer tuft being
disposed at each side of the longitudinal head axis 50. Generally,
the outer or distal ends of the bristles and the tufts are even,
but they may be contoured as to the ends of the individual bristles
in a tuft or as to the ends of adjacent tufts.
As shown in FIG. 8, the tufts 52 are inserted into the tuft blocks
40 in the following manner. The bristles 54 are bent around a wire
pin or blade 80, which is preferably made of stainless steel, to
form tufts. The tufts 52 are then forced into orifices 57 in the
tuft blocks 40, in the manner of usual toothbrush manufacture. The
ends of the pin or blade 80 are retained by interference of the pin
or blade with the material of the tuft block into which it has been
forced.
As can be best seen in FIG. 2, the tuft blocks 40 are substantially
juxtaposed one to another and are disposed along the longitudinal
head axis 50 of the toothbrush head member 24. The longitudinal
tuft axes 53 are substantially perpendicular to the longitudinal
head axis 50 of the elongated toothbrush head member 24.
The head portion 38 of the toothbrush head member 24 is adapted to
receive and retain the tuft blocks 40 in sliding relation therein
such that the tuft blocks 40 slide linearly in a direction parallel
to the longitudinal tuft axes 53. The tuft blocks 40 are guided by
guide means within the head portion 38 of the toothbrush head
member, with these guide means comprising pairs of opposed guide
rails 39. The opposed guide rails 39 extend inwardly from the
opposed side walls 44. The tuft blocks 40 have indentations 40a
(shown, for example, in FIG. 9) at the four corners thereof so as
to accommodate the opposed guide rails 39.
The cam shaft 42 has a cam portion 43 at the one end thereof, at
the opposite end to the attachment portion 29. The cam portion 43
of the cam shaft 42 has a plurality of lobes 45 thereon, each lobe
45 having a cam surface defining the perimeter thereof. Each lobe
45 is preferably substantially circular in cross-section, having a
diameter "D", and is used to drive one tuft block 40 from its
retracted position to its extended position. If there are six tuft
blocks 40 in the toothbrush head member 24, there would
correspondingly be six lobes 45 on the cam portion 43 of the cam
shaft 42. The lobes 45 are connected by connecting portions 47,
with the connecting portions 47 having a maximum thickness "D". The
connecting portions 47 are ramped so as to facilitate positioning
of the cam shaft 42 into the respective apertures 60 in each of the
tuft blocks 40.
In a preferred embodiment as shown in FIGS. 1 to 3, for example,
the cam shaft has a total of six lobes 45 thereon with the lobes
identified as a, b, c, d, e, and f, respectively. When the cam
shaft 42 is rotating, the lobes 45 may pass a given circumferential
reference point in the order a, b, c, d, e, f. Alternatively, the
lobes may pass a given circumferential reference point in any given
order; one of which may be such as the order a, e, b, f, c, d. If
the cam shaft were to have a total of four lobes, for example, the
lobes 45 would be identified as a, b, c, and d and would pass a
given circumferential reference point in the order a, b, c, d, or
other order as chosen. If the cam shaft were to have a total of
seven lobes, for example, the lobes 45 would be identified as a, b,
c, d, e, f, and g and would pass a given circumferential reference
point in the order a, b, c, d, e, f, g, or other order as
chosen.
In general, all of the cam lobes that are spaced along a cam shaft
are radially spaced around 360.degree.. In general, that radial
spacing of the cam lobes is even. Thus, where there are four lobes,
one lobes would be found at each of 90.degree., 180.degree.,
279.degree., and 0.degree./360.degree.. Likewise, if there are six
cam lobes, they would be spaced at 60.degree., 120.degree.,
180.degree. . . 0.degree./360.degree.. As noted above, the lobes
may pass a given circumferential reference point in any given
order. When the lobes are evenly radially spaced, and particularly
where the order of the rise and fall of the lobes is sequential
along the cam shaft, there is a reduced vibration of the toothbrush
head, and a reduced impact of the mass of the toothbrush head
against the teeth and gums. Moreover, the power requirement for
mechanical torque required to drive the cam shaft is reduced.
In an alternative embodiment, the cam shaft 42 is made from metal
wire which is bent into its proper configuration. If the cam shaft
is a bent metal wire, then the apertures 60 in the tuft blocks may
be thinner. Otherwise, the camming action of the bent wire is much
the same as a molded cam shaft.
The distal end 41 of the cam shaft 42 has a head portion 41a
thereon that may fit into a co-operating snap connection 51 in the
end wall 46 of the toothbrush head member 24.
Each of the tuft blocks 40 has a generally centrally located
elongated aperture 60 therein that is adapted to receive the cam
shaft therethrough. The aperture 60 is defined in part by a first
cam receiving surface 61 and in part by a second cam receiving
surface 62, which is opposed to the first cam receiving surface 61.
The first and second cam receiving surfaces 61, 62 are separated by
a distance generally equivalent to the distance "D", which is the
diameter of the cam shaft 42 along the cam portion 43 thereof. The
distance "D" between the first and second cam receiving surfaces is
generally equivalent to the distance "D" that is the diameter of
the lobes 45 so that the lobes 45 are retained within the aperture
60 without undue looseness. The cam shaft 42 interacts with the
first cam receiving surface 61 of each of the tuft blocks 40 so as
to drive the tuft blocks 40 from their retracted position to their
extended position, and also with the second cam receiving surface
62 of each of the tuft blocks 40 so as to drive the tuft blocks 40
from their extended position to their retracted position. Any undue
looseness between the lobes 45 and the first and second cam
receiving surfaces 61, 62 would cause hammering of the first and
second cam receiving surfaces by the lobes 45, which in turn would
cause undue vibration and noise.
The apertures 60 are generally elongated in a direction that is
transverse to both the central longitudinal axis 25 of the cam
shaft 42 and the tuft axis 53 so as to accommodate laterally
directed displacement of the lobes 45 of the cam shaft 42, and so
as to preclude driving of the tuft blocks 40 in that same
direction. Also, the single-axis reciprocating motion of the tuft
blocks is assured.
The tuft blocks 40 are driven from their retracted positions to
their extended positions by the rotation of the cam shaft 42 and
the resulting interaction between the cam surfaces 44 of the lobes
45 and the first and second cam receiving surfaces 61, 62 of the
tuft blocks 40. Preferably, the tuft blocks 40 move from their
retracted position to their extended position a distance of between
about 0.015 inches and 0.050 inches.
It should be noted that the throw of the cam shaft 42, which is
shown at "T" in FIG. 6, may be varied for different cam shafts, and
therefore for different toothbrush head members 24, all of which
may otherwise fit on the same housing member 22. The throw "T" may
be short or long, or otherwise, to accommodate different users such
as children or adults. Of course, the thickness, length, and
stiffness of the bristles may also be varied, so that a wide
variety of choices may be offered to prospective users both in
respect of the bristle length, the bristle hardness, and the
distance that the ends of the bristles move. Therefore, choices of
a variety of toothbrush heads may be made available to various
members of a family, for example, where a single driving unit or
handle is used for all of the different toothbrush heads.
Covering the opening 35 in the head portion 38 of the toothbrush
head member 24 is a flexible seal 70, which is attached in sealed
relation to the toothbrush head member 24 and to the tuft blocks
40. The flexible seal 70 generally precludes foreign matter such as
toothpaste, saliva, and so on, from entering the interior of the
head portion 38 of the toothbrush head member 24 and ultimately
reaching the tuft blocks 40 and cam shaft 42. The flexible seal 70
has a first lip portion 72 adapted for sealed engagement into an
under-cut 74 in the outer sides of the opposed side walls 44 of the
head portion 38 of the toothbrush head member 24. The flexible seal
70 also has at least one second lip portion 76, each of which is in
sealed engagement with a portion of each of the tuft blocks 40. In
a preferred embodiment, the flexible seal 70 receives the tufts 52
through openings 78 at the bottom of depressions 77 that are formed
therein. The openings 78 are created when the bristles 54 are
inserted into the tuft blocks 40. Alternatively, each of the tuft
blocks 40 may extend through a preformed opening in the flexible
seal 70.
As can best be seen in FIG. 8, a portion of the flexible seal 70
enters the orifice 57 when the bristle tufts are inserted therein,
as shown at 71. The pressure of the tufts 42 thereagainst helps
create a snug seal between the flexible seal 70 and the tuft blocks
40. Essentially, a mechanical lock between the flexible seal 70 and
each of the tuft blocks 40 is developed. Moreover, the flexible
seal 70 can also act as a spring means to cause the tuft blocks 40
to return from their extended position to their retracted
position.
Reference is made now to FIGS. 11 and 12, which show a proximal
brush which is otherwise in keeping with the present invention.
Here, a single tufted proximal brush 82, having a plurality of
tufts 84, is captured and held securely in a special tuft block 86
which is particularly designed for this purpose. The reciprocal
action of the tuft block 86 comes as a consequence of it being
driven by a single lobe cam shaft 42. The mounting and sealing
arrangement for the proximal brush is otherwise as described above,
and it serves the particular purposes intended for a proximal
brush, especially in reaching the gingival and interproximal
regions of the teeth and gums. The orientation of the proximal
brush 82, perpendicular to the head portion 24, is particularly
advantageous in reaching the rear molars of the user, when in
use.
With reference now to FIG. 10, it is clear that the toothbrush of
the present invention is brought into contact with the teeth 100 by
the user in much the same way as an ordinary toothbrush is used.
Thus, the bristles 54 are generally flexed at least to some extent
even before any mechanical action of the toothbrush of the present
invention occurs. For example, the amount of flex of the portion of
a bristle tuft 59 may be quite significant, and is shown as the
distance "F" by which the distal end 56 of the bristle group 59 has
flexed from the axis of the tuft. After the toothbrush head is
brought into position near the teeth in much the same manner as the
user would use a manual toothbrush, and the toothbrush is powered
so that the cam shaft is rotating as discussed above, the tuft
blocks 40 will travel from their retracted position to their
extended position in the manner discussed above. Because the tuft
blocks 40 are driven from their retracted position to their
extended position by the cam shaft 42, which is a positive
mechanical driving means, the bristles 54 will continue to be
forced against the teeth 100 and will flex even more. This will, in
turn, cause the distal ends 56 of the bristles 54 to move laterally
along the surface of the teeth 100, where the lateral motion of the
distal ends 56 of the bristles is relative to the longitudinal axes
53 of the bristles 54. As noted above, the lateral motion of the
distal end 56 of the bristles 54 will essentially chisel unwanted
substances, plaque, and so on away from the surface of the teeth,
and thereafter they are removed away from the teeth. Because there
is a positive mechanical linkage between the cam shaft 42 and the
bristles 54, there is thereby ensured the lateral motion of the
distal ends 56 of the bristles, thereby assuring the continuous
cleaning action of the bristles against the teeth. Moreover, as the
tuft blocks move towards their retracted position, there will be a
sweeping or scrubbing action of at least the ends of the bristles
against the teeth, to assist in the removal of foreign matter that
has otherwise been dislodged from the surfaces of the teeth. The
oscillating or back-and-forth motion of the distal ends 56 of the
bristles is such as that which is indicated by the doubled-headed
arrow 61 in FIG. 10.
The frequency of strokes of the tuft blocks is preferably greater
than 2000 times per minute, with a preferred range between about
5000 times per minute and 10,000 times per minute, with an ideal
frequency being about 6000 times per minute. It should be noted
that, even at a stroke frequency of about 6000 times per minute, or
more, there is no undue or undesirable vibration which may cause
discomfort to the insides of the cheeks and lips of the user. This
frequency coupled with the short stroke of the bristles, precludes
any undue abrasion to the gums or gingival regions, which might
cause discomfort or bleeding.
For example, in the case where there may be four tuft blocks, each
having four tufts, where each tuft has 64 bristles, there are
therefore 1024 bristles present for a cleaning or cleansing action
against the teeth. If the stroke frequency of the tuft blocks is
6000 times per minute, then there will be 102,400 individual
bristle strokes with the concomitant chiseling action of the
bristles, per second. In a toothbrush of the present-invention
having six tuft blocks, each with 4 tufts of 64 bristles, there
would be 153,600 individual bristle strokes, each with the
concomitant chiseling action, per second.
In an alternative embodiment, it is contemplated that spring
means--or even the reaction of the bristles being pressed against
the teeth and gums--could be used to help return the tuft blocks
from their extended position to their retracted position. In this
alternative embodiment, it is not necessary that the apertures 60
in the tuft blocks 40 would have a second receiving surface 62. The
spring means or reactive pressure from the teeth and gums could,
themselves, be used to force the tuft blocks to return to their
retracted position, without being driven to the retracted position
such as by the lobes of the cam shaft driving against the second
receiving surfaces 62 of the tuft blocks. In any event, an assured
and positive driving motion of the tuft blocks away from their
extended position towards their retracted position is assured.
It is, of course, possible that oscillating cams may be used rather
than continuously rotating cam shafts, to lift the tuft blocks at
least towards their extended position, with such as the spring
means or reactive pressure from the teeth and gums being utilized
to drive the tuft blocks towards their retracted position. In
general, the cam shaft may be oscillated, in these circumstances,
through an oscillation arc of between 90.degree. and 180.degree. so
as to impart vertical motion to the tuft block.
It is noted that other driving means may be provided for rotating
the cam shaft. For example, a water-pressure turbine could be used,
where the toothbrush can be driven from a turbine that is powered
by the water pressure of the running water being used as the teeth
are being cleaned. An air-driven turbine could also be used.
Other modifications and alterations may be used in the design and
manufacture of the mechanical toothbrush of the present invention
without departing from the spirit and scope of the accompanying
claims.
* * * * *