U.S. patent number 3,577,579 [Application Number 04/872,255] was granted by the patent office on 1971-05-04 for electric toothbrush.
Invention is credited to Douglas E. Beck, John P. Duve.
United States Patent |
3,577,579 |
Duve , et al. |
May 4, 1971 |
ELECTRIC TOOTHBRUSH
Abstract
An electric cordless toothbrushing device having a power handle
with a drive shaft extending from one end thereof and a toothbrush
attachment which is securable to the remote end of said shaft. The
power handle includes a battery-powered motor which by means of a
motion-converting mechanism drives the shaft so that the rotary
power of the motor is translated to an orbital motion at the
toothbrush attachment. An improved electric switch is provided to
control the energization of the motor.
Inventors: |
Duve; John P. (Brookfield,
IL), Beck; Douglas E. (Chicago, IL) |
Family
ID: |
25359179 |
Appl.
No.: |
04/872,255 |
Filed: |
October 29, 1969 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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824110 |
May 13, 1969 |
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Current U.S.
Class: |
15/22.1; 310/50;
74/23; 310/80 |
Current CPC
Class: |
A61C
17/3472 (20130101); A61C 17/3418 (20130101); B29L
2031/425 (20130101); A61C 17/3445 (20130101); Y10T
74/1804 (20150115) |
Current International
Class: |
A61C
17/16 (20060101); A61C 17/34 (20060101); A46b
013/00 () |
Field of
Search: |
;15/22,22 (A)/ ;15/22
(B)/ ;15/97 ;74/23 ;310/47,50,80 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Roberts; Edward L.
Parent Case Text
This is a division of application Ser. No. 824,110, filed May 13,
1969, assigned to the same assignee as the instant application.
Claims
We claim:
1. An electric toothbrushing device comprising an elongated housing
containing an electric motor, a drive shaft extending from said
housing and lying along a given axis, the remote end of said shaft
adapted for carrying a toothbrush attachment, bearing means in said
housing supporting said shaft for longitudinal movement along said
axis and for pivotal movement with respect to said axis,
motion-converting means disposed within said housing connecting
said motor with said shaft so that the rotary motion from said
motor causes said toothbrush attachment to move with an orbital
motion wherein said shaft simultaneously moves longitudinally and
pivotally with respect to its axis, said motion-converting means
including a member supported for rotation on an axis parallel to
and spaced from the shaft axis, said member being rotated by said
motor and having an eccentric offset from the axis of rotation of
said member, a fork attached to said shaft and disposed at an angle
less than ninety degrees to the shaft axis, said fork being
connected to said eccentric so that the rotation of said member
causes said eccentric to both oscillate said fork and to
reciprocate said fork for producing an orbital motion at said
toothbrush attachment.
2. The electric toothbrushing device of claim 1 wherein said fork
is formed with a radially extending longitudinal slot, said
eccentric being disposed in said slot, said eccentric formed with
means engaging opposite sides of said fork whereby the circular
movement of said eccentric forces said fork to simultaneously
oscillate and reciprocate.
3. The electric toothbrushing device of claim 2 wherein said
eccentric means includes two spaced annular shoulders which engage
said fork in rolling contact at opposite sides of said slot.
4. An electric toothbrush comprising a housing from one end of
which extends a drive shaft, the remote end of said shaft formed to
carry a toothbrush attachment, a motor in said housing rotating an
eccentric, a fork rigidly secured to said shaft and connected to
said eccentric, means supporting said eccentric and preventing
linear movement thereof in a direction parallel to said shaft, said
fork including first surface means engaging said eccentric so that
the rotation of said eccentric causes said shaft to oscillate, and
second surface means angularly engaging said eccentric so that the
rotation of said eccentric causes said shaft to reciprocate whereby
the rotation of said eccentric causes said toothbrush attachment to
have an orbital movement.
5. The electric toothbrush of claim 4 wherein said fork defines a
slot into which said eccentric extends, said eccentric formed with
opposed spaced chamfers which engage said fork second surface means
at opposite sides of said slot, said second surface means lying in
planes which are angularly disposed with respect to said eccentric
chamfers.
6. The electric toothbrush of claim 5 including bearing means
supporting said shaft for oscillation and reciprocation with
respect to the longitudinal axis of said shaft.
7. The electric toothbrush of claim 6 wherein said motor includes
an end bracket which supports said bearing means and a pin on which
said eccentric is rotatably mounted, said pin being parallel to
said shaft.
8. An electric toothbrush comprising a housing in which an electric
motor is positioned, a drive shaft extending from one end of said
housing and on which a toothbrush attachment is mountable, said
shaft being supported by spaced aligned bearings for oscillation
and longitudinal reciprocation, an arm secured to said shaft
between said bearings and extending away from the axis of said
shaft, eccentric means mounted in said housing for rotation by said
motor, means preventing linear movement of said eccentric means in
a direction parallel to the axis of said shaft, said arm having
surface means inclined with respect to the direction of the axis of
said shaft, said arm engaging said eccentric means so that the
rotation thereof causes said shaft to oscillate, and said arm
surface means engaging said eccentric in such a manner that the
rotation thereof causes said shaft to reciprocate whereby the
movement of said shaft imparts an orbital movement to said
toothbrush attachment.
9. The electric toothbrush of claim 8 wherein said eccentric means
includes a gear portion, a pinion mounted to said motor and
engaging said gear portion for rotating said eccentric means.
10. The electric toothbrush of claim 8 wherein said arm surface
means includes two flat surfaces which are parallel and spaced in
the direction of the shaft axis, said eccentric means having
contact means for simultaneously engaging both said surfaces.
11. The electric toothbrush of claim 9 wherein said contact means
is in rolling engagement with said flat surfaces.
12. The electric toothbrush of claim 11 wherein said arm has a slot
with parallel internal surfaces which engage said eccentric means
in a rolling engagement.
Description
BACKGROUND OF THE INVENTION
This invention relates to an electric appliance and more
particularly to a rechargeable battery-operated electric
toothbrushing device having a portable hand-held power handle with
a brush attachment at one end.
Power-driven toothbrushes for use in the home customarily include a
single power handle and a plurality of individual toothbrush
attachments for use by the members of the family. The toothbrush
attachment normally consists of a relatively hard plastic shaft
portion and a plurality of outwardly extending bristles anchored at
their inner ends to the shaft portion. The individual toothbrush
attachments, which are stored on a suitable recharging base for the
power handle, may be adapted to be attached to and detached from
the power handle by the user. The details of one readily releasable
mechanical drive connection for connecting a toothbrush attachment
to a power handle are disclosed in Spohr U.S. Pat. No. 3,187,360,
granted June 8, 1965, and assigned to the same assignee as the
present application.
The toothbrush power handle normally includes a battery in
electrical connection with a low-voltage direct-current motor which
is in driving relationship with a motion-converting means for
changing the rotary power of the motor to a desirable motion at the
toothbrush attachment bristles. This type of device is disclosed in
Spohr U.S. Pat. No. 3,274,631, granted Sept. 27, 1966, assigned to
the same assignee as the present application. The motion-converting
mechanism in this Spohr patent causes the brush attachment to have
a pure oscillatory motion wherein the brush attachment oscillates
about its axis with the generally radially extending bristles
moving through an angle of about 22.degree. . The resultant
oscillatory toothbrush attachment motion was found to perform very
well in cleaning the user's teeth. Other toothbrush power handles
reciprocated the toothbrush attachment in a direction parallel to
the drive shaft, and this motion has been found effective in
cleaning teeth. However, it is believed that a better cleaning
operation can be accomplished if the tips of the toothbrush
attachment bristles move in an orbital path to facilitate the
penetration of the bristle tips between the user's teeth. While it
is desirable to have the tips of the bristles moving with an
orbital motion, it is desirable to have as little movement as
possible of the toothbrush attachment shaft portion in order to
prevent the relatively rigid shaft portion from striking the user's
teeth and gums. The motion-converting means for accomplishing this
desired motion should be compact so that it may be conveniently
positioned within the relatively small power handle, and it should
be simply designed for economical manufacture.
For the user to control the operation of the toothbrush, it is
necessary to provide actuating means on the outside of the power
handle to control an electric switch disposed inside of the power
handle. It is appreciated that the power handle must be effectively
sealed to prevent the entrance of moisture which would interfere
with the operation of the internal power handle components. Since
the toothbrush is designed to be used by all members of the family,
the actuation of the switch should be simple enough so that a small
child can easily understand and manipulate it. Furthermore, the
actuating means for the switch should be of such a nature that the
user can operate it without studying the orientation of the
actuator with respect to the power handle and so that the actuator
may be moved easily when covered with water, toothpaste and saliva.
To accomplish these objectives, it is necessary that the actuator
should be pressed inwardly toward the housing rather than moved in
a rectilinear manner along the surface of the housing. The switch
itself disposed within the power handle should be designed for
economical manufacturing, and the orientation of the switch with
respect to the actuator means should be easily controlled.
SUMMARY OF THE INVENTION
Briefly, the electric cordless toothbrush of the present invention
includes a compact hand-held power handle having a rechargeable
battery and an electric motor adapted to be driven thereby. The
power handle is provided with a drive shaft to which the brush
attachments may be connected, and the attachments are driven in an
orbital manner by means of an improved motion-converting system
interconnecting the motor and the drive shaft. The power handle has
a generally cylindrical housing of convenient size, and an improved
switching mechanism is mounted to the housing for completing the
electrical connection between the battery and motor.
Accordingly, it is an object of the present invention to provide a
new and improved electric toothbrushing device including a
hand-held power handle having improved means for changing the
rotary power from the motor to an orbital motion at the toothbrush
attachment.
It is another object of the present invention to provide a new and
improved electric appliance switching mechanism which is easily
operated and economical to produce.
Further objects and advantages of the present invention will become
apparent as the following description proceeds and the features of
novelty which characterize the invention will be pointed out with
particularity in the claims annexed to and forming a part of this
specification.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference may
be had to the accompanying drawings in which:
FIG. 1 is a perspective view of a cordless hand-held power handle
and toothbrush attachment embodying the present invention;
FIG. 2 is an enlarged sectional view taken substantially along line
2-2 of FIG. 1 with the toothbrush attachment removed;
FIG. 3 is a fragmentary enlarged sectional view taken substantially
along line 3-3 of FIG. 1 wherein the switch is disclosed in its
closed position and the drive shaft is at its innermost
position;
FIG. 4 is a sectional view similar to FIG. 3 except that the drive
shaft is at its outermost position;
FIG. 5 is a sectional view taken substantially along line 5-5 of
FIG. 3 assuming that FIG. 3 shows the complete structure;
FIG. 6 is a fragmentary sectional view taken substantially along
line 6-6 of FIG. 4 assuming that FIG. 4 shows the complete
structure;
FIG. 7 is an enlarged fragmentary sectional view revealing the
switch in an open condition;
FIG. 8 is similar to FIG. 7 but shows the switch in a closed
condition;
FIG. 9 is a fragmentary view taken substantially along line 9-9 of
FIG. 7;
FIG. 10 is a fragmentary sectional view of the switch actuator
depicting the manner in which it is pivotally mounted to the power
handle housing;
FIG. 11 is an exploded assembly view of the upper housing member
and the motion-converting mechanism on the motor;
FIG. 12 is a fragmentary sectional view of the engagement between
the eccentric and the connector arm;
FIG. 13 is a view illustrating a portion of the eccentric and the
lines of contact between the eccentric and the connector arm;
and
FIG. 14 is an end view of a single bristle outer tip to show the
orbital path it follows.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein like reference characters
designate corresponding parts throughout the several views, there
is shown a cordless hand-held power handle generally designated by
the reference numeral 20 and a toothbrush attachment 21 mounted
thereto. Preferably, the toothbrush attachment 21 has a relatively
hard shaft 23 and a plurality of bristles 24 with their inner ends
anchored to the remote end of the shaft 23. The outer ends of the
bristles 24 are cut in a manner to produce a saw tooth
configuration as can be conveniently seen in FIG. 1. The toothbrush
attachment 21 is adapted to be releasably attached to a drive shaft
27 extending from one end of the power handle 20. Preferably the
releasable coupling between the toothbrush attachment 21 and the
drive shaft 27 is the same as disclosed in Spohr U.S. Pat. No.
3,187,360, granted June 8, 1965, and assigned to the same assignee
as the present application. Therefore, it should be appreciated
that the brush attachment is rigidly securable to the drive shaft
27 whereby any movement of the shaft is transmitted to the
attachment.
To facilitate the use of the power handle 20, it is by necessity
relatively small and lightweight. The power handle includes an
elongated housing 30 on the exterior of which is mounted a switch
actuator 31. The housing 30 is made up of a relatively long lower
cup-shaped member 33 and a relatively short upper cup-shaped member
34 which are oppositely disposed with their open ends facing each
other to define a chamber 35 therebetween. A plastic housing end
cap 36 overlies a part of and is in snap engagement with the member
34 for reducing the amount of moisture and toothpaste reaching the
drive shaft where it enters into the chamber 35. Positioned within
the chamber 35 are a nickel cadmium battery 38, a low-voltage
direct-current motor 39, and a motion-converting mechanism 40 which
transmits the power from the motor to the drive shaft 27. Inasmuch
as the motor 39 is supplied power by the battery 38, it is
necessary from time to time to recharge the battery. For this
purpose, the lower housing member 33 is molded with an opening at
its bottom for receiving a cup-shaped plastic terminal support 42.
A suitable O-ring seal 43 is used to establish a watertight
connection between the support 42 and the member 33. As can be seen
in FIG. 2, the support 42 carries terminal means 44, which is in
electrical communication with the battery 38, by means of circuit
wiring 46. Thus, when it is desired to recharge the battery 38, the
power handle 20 is placed on a suitable charging base (not shown)
which may be similar to the base shown in copending application
Ser. No. 823,698, filed May 12, 1969, and assigned to the same
assignee as the present application.
Preferably, the housing members 33 and 34 are molded from a
suitable plastic material which does not conduct electricity and is
not adversely affected by moisture or chemicals found in toothpaste
or the like. The upper housing member 34 is molded to define a
substantially horizontally extending bight portion 50 and a
depending annular sidewall 51. The bight portion 50 includes a
raised section 54 defining an opening 55 through which the drive
shaft 27 extends. As can best be seen in FIG. 11, the sidewall 51
includes an annular collar 57 and a plurality of downwardly
extending resilient fingers 49, each of which defines a square
aperture 60. In the embodiment disclosed in the drawings, the
housing member 34 has three equally spaced resilient fingers
59.
At the upper end of the motor 39 is a plastic bracket 63 having an
integral disc-shaped plate 64 and an upright column 65 extending
normal to the plate 64 and having a tapered C-shaped cross section.
The plate 64, which is rigidly secured to the motor 39, has a
plurality of integral radially extending protuberances 67 which are
in alignment with the apertures in resilient fingers 60. As can be
seen in FIG. 11, the motion-converting mechanism 40 is carried by
the bracket 63. Thus, when the motor 39 and bracket 63 are
assembled to the upper housing member 34, the motion-converting
means 40 is disposed within the cup-shaped member 34. To assemble
the bracket 63 to the member 34, the bracket is inserted within the
member so that the shaft 27 passes through the raised section
opening 55 until the protuberances 67 engage the resilient fingers
59 deflecting them outwardly and snap into the apertures 60. Thus,
the bracket 63 to which the motor 39 is attached can be secured to
the upper housing member 34 to form a subassembly without the
benefit of screws or other separate fastening means. To insure that
the bracket protuberances 67 do not inadvertently become disengaged
from the resilient fingers 59, the lower housing member 33, when
assembled to the upper housing member 34, is immediately beside the
resilient fingers 59 preventing their outward deflection. As a
result, it is only possible to remove the bracket 63 from the
member 33 when the lower member 33 is not assembled with the upper
member 34. It should be appreciated that moisture should not be
permitted to enter into the chamber 35, and to this end a suitable
O-ring seal 68 is positioned between the members 33 and 34 adjacent
to the collar 57.
For transmitting the power from the motor 39 and converting its
rotary movement to a desired movement at the toothbrush attachment,
the motion-converting mechanism 40 is disposed within the upper
cup-shaped housing member 34 and extends between the motor 39 and
the drive shaft 27. As can conveniently be seen in FIG. 3, the
drive shaft 27 is supported in spaced bushing bearings 69 and 70
which are carried in the bracket column 65. The bearing 70 is
positioned near the upper member raised section opening 55, and in
order to protect this bearing from the adverse effects of moisture,
a suitable flexible gasket 72 is clamped between the bearing and
the raised section and secured to the drive shaft 27. To provide
support for the shaft 27 at the bearing 70, the column 65 is molded
with a pair of oppositely disposed recesses 74 which are aligned to
engage with projections 75 molded integrally with the raised
section 54 as can be seen in FIG. 11. Thus, when the bracket 63 is
assembled to the member 34, the projections 75 enter into the
recesses 74 whereby the bracket 63 is securely locked to the member
34 at both the recesses 74 and protuberances 67. Since the drive
shaft 27 is mounted in two spaced bushing bearings, it is free to
rotate and also free to move along its longitudinal axis 77.
Securely attached to the drive shaft 27 between the bearings 69 and
70 is a plastic connector 80 having a fork or arm 81 extending at
an angle of less than 90.degree. from the drive shaft longitudinal
axis 77. In the present embodiment, the included angle defined
between the arm 81 and the drive shaft axis is approximately
73.degree.. The arm 81 is molded with a slot 84 parallel to the
drive shaft axis 77 and the slot extends completely through the
upper side 85 and lower side 86 of the arm 81. As may be seen in
FIG. 12, the slot 84 is defined by parallel spaced side surfaces 88
and 89 and parallel-spaced chambers 90--93.
To interconnect the arm 81 and the motor 39, the motor includes an
upwardly extending armature shaft 96 on the end of which is
securely mounted a drive pinion 97. Projecting upwardly from the
bracket plate 64 and parallel to the armature shaft 96 is pin 99 on
which is rotatably mounted member 100 having an integral gear 101
in driven engagement with the drive pinion 97 and an integral
eccentric 103 which is offset from the pin 99 and parallel to the
drive shaft axis 77. The pin 99 has locking clips 104 at each end
to prevent the member 100 from moving in a direction parallel to
the drive shaft axis 77. Thus, when the motor 39 is energized, the
pinion 97 rotates the member 100 so that the eccentric 103 moves in
a circular path. Preferably, the member 100 and the drive pinion 97
are molded from a suitable plastic material. For the eccentric 103
to make a proper connection with the arm 81, the eccentric is
formed with a reduced cylindrical surface 106 at the ends of which
are opposed spaced annular shoulders or chambers 108 and 109. With
this configuration, the eccentric 103 is adapted to cooperate with
the arm 81 by the cylindrical surface 106 being disposed within the
arm slot side surfaces 88 and 89 and the shoulders 108 and 109
oriented to engage with the arm chamfers 90--93. In order to
understand the resultant movement imparted to the drive shaft 27 by
the rotation of member 100, it should be first realized that a
single rotation of the eccentric causes the connector 80 to
oscillate through a given angle which is determined by the diameter
of the circular path followed by the eccentric 103 and the distance
between the center of the pin 99 and the drive shaft axis 77. In
the present embodiment, the rotation of the eccentric 103 causes
the drive shaft 27 to oscillate through an angle of approximately
29.degree.. It is important to note that since the eccentric 103 is
being rotated through a circular path that the engagement between
the cylindrical surface 106 and the arm surfaces 88 and 89 is a
rolling contact thereby lessening the friction between the
eccentric and the arm slot 84. Furthermore, as the eccentric 103
follows a circular path, it moves towards and away from the drive
shaft, and, consequently, since the chamfers 90--93 are oriented to
engage the shoulders 108 and 109, the connector 108 is forced to
move parallel to the drive shaft as causing the drive shaft to
reciprocate. To more clearly understand the manner in which the
drive shaft is reciprocated, reference may be had to FIGS. 3 and 4
wherein the eccentric 103 is shown in FIG. 3 at near the inner end
of the slot 84 and the drive shaft 27 is at the end of its
innermost travel towards the motor 39 whereas in FIG. 4 the
eccentric has moved through approximately 180.degree. and is at the
outer end of the arm slot 84 with the result that the connector 80
and drive shaft 27 have moved outwardly to the end of its travel
away from the motor 39. As the eccentric moves to force the drive
shaft outwardly, the eccentric shoulder 109 slides in rolling
engagement against arm chamfers 92 and 93, and, correspondingly, as
the drive shaft moves inwardly the eccentric shoulder 108 slides in
rolling engagement against arm chamfers 90 and 91. Referring to
FIG. 13, it can be seen that the eccentric shoulders are engaging
the arm chamfers along parallel lines of contact to accomplish a
controlled amplitude of reciprocation of the drive shaft.
Therefore, a single revolution of the member 100 causes the drive
shaft 27 to simultaneously oscillate and reciprocate to produce an
orbital movement at the outer tips of the toothbrush attachment
bristles. The resultant movement is depicted in FIG. 4 which shows
the path followed by the outer tip of a single bristle 24 wherein
the orbital path moves through an arc b of approximately 0.280
inches and reciprocates through distance a of approximately 0.090
inches. However, even though the outer tips of the bristles are
following an orbital path, the toothbrush attachment shaft 23,
which is relatively hard, has a relatively restricted movement of
the same degree of oscillation and reciprocation as the drive shaft
27 with the result that the accidental engagement of the hard shaft
23 with the user's gums or teeth is not very noticeable or
discomforting. Thus, the motion-converting mechanism 40 causes the
tips of the bristles 24 to move vigorously through an orbital path,
which is found to be most advantageous in cleaning the user's teeth
because the oscillating movement sweeps the bristles along the
user's teeth while the reciprocating motion assists the bristle
tips to move in between adjacent teeth where food particles tend to
lodge. Furthermore, the mechanism 40 consumes very little power
because of the small amount of friction between the eccentric and
the arm due to the rolling engagement between the contacting
surfaces, and friction power losses are a major concern in a
battery-operated appliance which is used frequently.
In accordance with the present invention, the power handle 20 is
provided with an electric switch which is generally designated by
the reference numeral 115. The purpose of the switch 115 is to
control the energization of the motor 39 by permitting the battery
39 to supply power to it through circuit wiring 46. This is
accomplished by the switch 115 being in electrical series with the
motor and the battery in a circuit arrangement which is well known
in the art but, preferably, is the same as is shown in the
hereinbefore mentioned copending Spohr Pat. application Ser. No.
823,698. Referring to FIGS. 6--10, the switch 115 includes two
substantially parallel-spaced contact blades 117 and 118 which are
received in spaced slots 119 and 120 respectively defined in upper
housing member 34. Once the blades are locked in the slots 119 and
120, their lead ends can be considered as being stationary, and the
free ends thereof extend adjacent to a circular access opening 122
molded in the housing member 34. Both blades are bent slightly
before being assembled into their respective slots so that their
free end tends to move towards the opening 122. As can be seen in
FIG. 7, the blade 118 lies against inside surface 125 of the
housing member sidewall 51. However, the free end of blade 117 is
maintained out of engagement with blade 118 by the free end of
blade 117 resting against housing member step 127. The blade 118 is
formed with a notch 129 so that it may pass clear of the step 127
to rest against the inside surface 125. To prevent moisture from
entering into the chamber 35 through opening 122, a circular
diaphragm seal 131 is received within circular counter bore 132
which is concentric with the opening 122. The diaphragm seal 131 is
rigidly clamped in position by a circular stamping fastener 133
which is pressed into the counterbore 132. Preferably, the
diaphragm seal 131 is relatively flexible and can be easily
extended through the opening 122 to act upon the contact blades 117
and 118. Acting upon the seal 131 and the blades 117 and 118 is the
switch actuator 31 which is preferably molded from plastic and is
formed to define an angular lever 136 and a pair of outwardly
extending trunnions 137. The actuator 31 is pivotally supported to
the outside of the housing 30 by the trunnions 137 being received
and captured within square-shaped recesses 139 which are formed at
the joining of the upper and lower housing members 33 and 34 by the
lower member 34 being molded with notches 141 which cooperate with
corners 142 in the upper member 34 as can be conveniently seen in
FIG. 10. Thus, the actuator 31 is pivotally supported to the
housing 30 when the upper and lower housing members 33 and 34 are
connected together by the trunnions 137 being nested within the
recesses 141. Extending inwardly from the lever 136 is an integral
finger or projection 145 which has an outer inclined end 146 and
intermediate enlarged detent or annular ridge 147. A resilient
metallic wire 150, formed to have a somewhat L-shaped configuration
as seen in FIG. 7, is bent to have two parallel-spaced legs 151 and
152 with a bight portion 153 at one end and being inwardly bent at
free ends 154. The wire 150 is received within parallel spaced
grooves 156 and 157 which extend on both sides of the counter bore
132. The free ends 154 are hooked behind a groove 158 and the bight
end 153 is trapped underneath the trunnions 137 as can be seen in
FIG. 7. With this construction, the wire legs 151 and 152 are
retained in their respective grooves 156 and 157 because the ends
of the wire 150 are locked to prevent motion away from the opening
122. Furthermore, it should be appreciated that the legs 151 and
152 being within their respective grooves tend to inhibit the
separation of the legs which extends across the counterbore 132.
When it is desired to close the switch 115, the lever 136 is
pressed to force the seal projection 145 into the opening 122 until
the projection end 146 faces the seal to deflect the contact 118
into electrical engagement with the blade 117 as depicted in FIG.
8. As the finger 145 extends through opening 122, the annular ridge
147 passes between the legs 151 and 152 causing them to spring away
from each other and snap toward each other behind the ridge with
the result that the finger 145 is locked at an inner position
wherein the switch 115 is closed. When it is desired to open the
switch, the lever 136 is pressed so that the lever pivots moving
the finger 145 outwardly through the opening 122 and causing the
ridge 147 to again spring the wire legs 151 and 152 away from each
other sufficiently to let the ridge pass therethrough. In the
switch-open position shown in FIG. 7, the wire legs 151 and 152
again hold the lever against movement.
The hand-held power handle 20 hereinbefore described is relatively
inexpensive to manufacture. The plastic upper housing member 34 is
formed to receive the motor 39, motion-converting mechanism 40,
bracket 63 and switch 115 without the need of separate fasteners.
Furthermore, these members can be conveniently assembled together
to form a subassembly which can be easily attached with the
remainder of the power handle. The relatively simple
motion-converting mechanism transmits the power from the motor to
the drive shaft and imparts a very desirable orbital motion to the
bristle tips on the toothbrush attachment while at the same time
limiting the movement of the toothbrush attachment shaft. The
electric switch to energize the motor is basically assembled to the
upper housing member 34 and expeditiously interrelates the various
switch components with the actuator which is mounted to the
exterior of the housing. All of the parts of the power handle
cooperate together in a logical manner to result in a device which
is easily manufactured and functions well for its intended use.
While there have been shown and described several embodiments of
the present invention, it will be apparent to those skilled in the
art that numerous changes and modifications may occur, and it is
intended in the appended claims to cover all such changes and
modifications which fall within the true spirit and scope of the
present invention.
* * * * *