Mechanical toothbrush

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.

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 electro-mechanical 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.

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.