Toothbrush with improved handle and detachable bristled cartridge

The present invention is directed towards an improved detachable head toothbrush which is simply constructed, easy to use, and includes features to promote a proper brushing technique. The handle includes a pair of deformable rigid tangs having outward extensions for engaging a corresponding surface in an interior passage through the bristle cartridge. The handle also includes a series of thumb depressions to assist in positioning the bristles over a tooth.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to dental care products and more specifically 
to toothbrushes with specially designed handles and disposable bristled 
cartridges. 
2. Description of Related Art 
The need for effective and regular dental care to prevent tooth decay 
and/or periodontal disease is well recognized. It is also recognized that 
in order to be effective, a program of dental care should include a daily 
regimen of brushing. In order to be effective, the brushing must be 
carried out with an effective and proper toothbrush having bristles which 
are not excessively worn or frayed. In this connection, it has been found 
that the bristles of even a high quality toothbrush can become worn or 
frayed after several weeks of normal use and that therefore even a high 
quality toothbrush should be replaced after approximately one month's use. 
It has also been found that a toothbrush should be replaced whenever the 
user thereof has had any type of illness in order to avoid infecting the 
user's gums during subsequent brushing. 
While the general concept of providing a toothbrush having a replaceable 
brush cartridge has been previously known, the previous attempts to 
construct toothbrushes of this type have generally been commercially 
unsuccessful for various practical reasons. Particularly, the previous 
inventions for toothbrushes with replaceable bristle cartridges have 
employed one of two designs. In one design the cartridges are frictionally 
attached to the toothbrush handle. With this design, the cartridge will 
either be insecurely attached, prone to becoming disconnected from the 
handle while in use; or the cartridge will be too securely attached, 
requiring a user to exert excessive force to attach or disconnect the 
cartridge. Some of the known frictional-attachment designs even require 
special tools for replacement of the cartridge. In the second typical 
design, the attached cartridge is secured to the toothbrush handle with 
one of various securing means to prevent inadvertent disconnection. 
However, these designs are complex and require excessive moving parts, 
such as compression springs, screws or pins. Moreover, some of these 
securing means are not disposed flush with the toothbrush handle and can 
cause trauma to oral tissues. 
For example, U.S. Pat. No. 4,030,845 issued June 1997 to Deckert discloses 
a toothbrush with self-contained dentifrice and having a disposable 
handle. The invention, directed primarily to the inclusion of dentifrice, 
discloses attaching the bristle cartridge to the handle either with an 
adhesive, or alternatively, by a pair of clips which frictionally receive 
the bristle cartridge. The invention does not disclose any locking means 
to ensure that the head does not become disconnected from the handle. 
U.S. Pat. No. 4,227,276 issued October 1980 to Ginsberg et al. discloses a 
toothbrush with a thermally deformable handle. The invention employs 
special pins which must be inserted into the bristle handle to release the 
securing hooks of the bristle cartridge. It also includes a handle made 
out of a deformable material which can be selectively angled or twisted by 
a user. Thus, this invention is more complicated than the instant 
invention and requires additional moving parts. 
U.S. Pat. No. 4,890,349 issued January 1990 to Nitzsche discloses a 
toothbrush with replaceable bristle insert. The insert snaps into the 
groove of a deformable plastic toothbrush head. Repeated deformation of 
the head's groove ledges, required for replacement of the insert, may 
compromise the integrity of the ledges so that the insert is not held 
securely within the head. 
U.S. Pat. No. 4,890,732 issued January 1990 to Shackelford discloses a 
toothbrush with a disposable bristle cartridge. The bristle cartridge 
frictionally slides onto the handle, but contains no means for locking the 
cartridge into place. 
U.S. Pat. No. 5,228,166 issued July 1993 to Gomez discloses a removable 
head toothbrush in which the head is pivotally connected to the handle. 
This complicated design includes compression springs and pins and does not 
lend itself to proper brushing technique. 
U.S. Pat. No. 5,247,716 issued September 1993 to Bock discloses an 
ultrasonic toothbrush with a removable brush-head. Removal of the brush 
head is difficult as it requires that the user either apply significant 
axial pulling force, or alternatively use a wedge shaped tool to pry the 
head off of the handle. Replacement of the cartridge of the present 
invention does not require excessive force or special tools. 
U.S. Pat. No. 5,511,276 issued April 1996 to Lee discloses a toothbrush 
with a replaceable bristle cartridge. The invention employs a special 
releasing pin and spring in the bristle handle which must be depressed to 
release the locking tooth of the bristle cartridge. U.S. Pat. No. 
5,564,152 issued October 1996 to Jeannet et al. discloses a toothbrush 
with a removable bristle cartridge. The bristle cartridge is replaced by 
screwing it onto a spring-loaded pre-stressed pin secured within the 
handle. Thus, these inventions are more complicated than the instant 
invention and require additional moving parts. 
European Pat. No. 0 083 787 issued July 1983 to Lang et al. (Zahnburste mit 
einem auswechselbaren Burstenkopf) discloses a toothbrush with a 
detachable bristle head. The bristle head retaining means comprises a 
metal tongue extending from the handle. The metal tongue has a hole 
passing therethrough which receives a detent disposed on the surface of 
the inner chamber of the bristle head for frictional connection therewith. 
The invention does not disclose the inclusion of a locking means to ensure 
that the portions do not become separated. 
P.C.T. Pat. App. No. WO 93/07778 issued April 1993 to Hodosh et al. 
discloses a toothbrush with a replaceable tip portion. The cartridge head 
retaining means comprises detent means which releasably retain the 
projection of either the head or handle portion of the toothbrush in 
engagement in the cavity of the other portion. The frictional retaining 
means of the invention does not disclose the inclusion of a locking means 
to ensure that the portions do not become separated. 
U.K. Pat. App. No. 2 272 631 issued May 1994 to Woo discloses a toothbrush 
comprising a removable head, a handle and a washer. The removable head is 
attached to the handle in one of two methods. One method entails screwing 
the head onto the handle until a pair of pointers disposed on the two 
parts are aligned. No means are disclosed to prevent the head from 
rotating out of alignment during brushing. In an alternate push-fit 
embodiment, the handle recess includes a notch ridge which frictionally 
engages the head protrusion. The invention does not disclose the inclusion 
of a locking means to ensure that the portion do not become separated. 
Moreover, none of these inventions include a handle having specially spaced 
thumb and finger depressions which promote proper brushing technique. 
Thus, a need exists for a simply designed toothbrush having a removable 
bristle cartridge which securely locks in place for use and further having 
a handle designed to promote proper brushing technique. None of the above 
inventions and patents, taken either singly or in combination, is seen to 
describe the instant invention as claimed. 
SUMMARY OF THE INVENTION 
The present invention is directed towards an improved detachable head 
toothbrush which is simply constructed, easy to use, and includes features 
to promote a proper brushing technique. The improvements include an 
improved toothbrush handle and an improved detachable bristled cartridge. 
The toothbrush handle, while shaped similarly to conventional handles, 
includes features which enable improved manipulation and control of the 
toothbrush. Particularly, the top surface of the toothbrush handle 
possesses six axially interspaced thumb depressions. Each depression has a 
diameter of approximately 10 mm. and a depth of approximately 2 mm. The 
distance between any two adjacent depressions is approximately 4 mm. The 
diameter and depth of the thumb depressions are designed for more 
comfortable gripping, to enable improved manipulation and control of the 
toothbrush. The depressions are spaced upon the handle at a unit distance 
equal to the distance on center from one tooth to an adjacent tooth. 
In use, by holding the hand and brush in the same distance from the mouth 
and moving the thumb from one depression to an adjacent depression, the 
user can move the toothbrush the necessary unit distance from alignment 
with one tooth to alignment with an adjacent tooth, thereby pinpointing 
the bristled cartridge over a tooth for proper execution of an up and down 
brushing motion without moving the user's hand in a back and forth motion. 
This is preferable because brushing in a back and forth motion causes 
erosion trauma to the tooth at the gumline and gingival recession. 
Gingival recession is one cause of temperature sensitivity in the teeth. 
Additionally, the bottom surface of the toothbrush handle possesses two 
axially interspaced finger depressions, disposed rearwardly of the thumb 
depressions. These finger depressions provide better gripping by the 
fourth and fifth fingers, improving the user's stability in controlling 
the toothbrush. The finger depressions also enable greater control while 
the user is brushing molars and wisdom teeth in the rearward portions of 
the mouth. 
The second improvement of the present invention relates to the improved 
locking means for releasably securing a detachable bristled cartridge to 
the toothbrush handle. The locking means holds the cartridge on the 
toothbrush handle securely, but does not require additional parts such as 
springs or pins, and does not require the user to exert excessive energy 
when changing the cartridge. 
The bristled cartridge comprises a generally rectangular housing having a 
first end, a second end and an interior passage running therebetween. The 
interior passage has a top passage surface, a bottom passage surface and a 
pair of opposing side passage surfaces. The top and bottom passage 
surfaces each have an interiorally protruding ridge disposed between the 
pair of opposing side passage surfaces. The two protruding ridges extend 
from the first end to the second end. The pair of opposing side passage 
surfaces extend from the first end to a preselected distance between the 
first end and the second end. Each side passage surface has an 
interiorally protruding vertical lip portion which extends from the top 
passage surface to the bottom passage surface. Each vertical lip portion 
has an interiorally angled surface generally facing the first end of the 
housing and further has an interiorally extending locking surface 
extending normal to the side passage surface and facing the second end of 
the housing. 
The attachment end of the toothbrush handle further comprises an H-shaped 
guide positionally disposed between a pair of deformably rigid tangs. The 
H-shaped guide is sized to receive the interiorally protruding ridges of 
the top and bottom passage surfaces of the bristle cartridge. The 
attachment end further includes locking means for releasably securing the 
attached bristled cartridge in position on the toothbrush handle. 
The locking means are incorporated into the pair of deformably rigid tangs 
disposed upon the attachment end of the toothbrush handle. The deformably 
rigid tangs are biased in laterally spaced opposition. Each tang has a tip 
possessing an outwardly extending locking surface sized and disposed for 
mating with one of the interiorally extending locking surfaces of the side 
passage surface vertical lip portions. The pair of deformably rigid tangs 
are also sized for and movable between a depressed position and a biased 
locking position. 
Thus, the deformably rigid tangs may be depressed by a user for passage of 
the attachment end through the first end of the interior passage of the 
bristled cartridge. When the deformably rigid tangs are released to the 
biased locking position, the deformably rigid tangs releasably secure the 
attached bristled cartridge in position upon the attachment end of the 
toothbrush handle. It is highly preferable if the H-shaped guide and the 
pair of deformably rigid tangs are pre-sized to be disposed in flush 
alignment with the second end of the bristled cartridge when the cartridge 
is attached to the attachment end of the toothbrush handle to prevent 
trauma to oral tissue. 
Accordingly, it is a principal object of the invention to provide a 
toothbrush with an improved handle including features which promote a 
proper brushing technique. 
It is another object of the invention to provide an improved toothbrush of 
the type having a detachable bristled cartridge. 
It is a further object of the invention to provide an improved toothbrush 
of the type having a detachable bristled cartridge including locking means 
for releasably securing the attached bristled cartridge in position on the 
toothbrush handle. 
Still another object of the invention is to provide an improved toothbrush 
of the type having a detachable bristled cartridge which does not require 
the use of springs, pins or additional moving parts. 
It is an object of the invention to provide improved elements and 
arrangements thereof in an apparatus for the purposes described which is 
inexpensive, dependable and fully effective in accomplishing its intended 
purposes. These and other objects of the present invention will become 
readily apparent upon further review of the following specification and 
drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention is directed towards an toothbrush having a detachable 
bristled cartridge and an improved handle for promoting proper brushing 
technique. FIG. 1 and FIG. 2 are an exploded top view and side view, 
respectively, of the bristled cartridge 10 and the toothbrush handle 11 
according to the present invention. The toothbrush handle 11 has a rear 
end 12, an attachment end 13, a top handle surface 14, and a bottom handle 
surface 15. The top handle surface 14 possesses a plurality of thumb 
depressions 16 spaced apart by a predetermined unit distance to enable the 
user to move the toothbrush from one tooth to another without moving the 
hand in a back and forth motion, for promoting proper brushing technique. 
By holding the hand and brush in the same distance from the mouth and 
moving the thumb from one depression 16 to an adjacent depression 16, the 
user can move the toothbrush the necessary unit distance from alignment 
with one tooth to alignment with an adjacent tooth, thereby pinpointing 
the bristled cartridge over a tooth for proper execution of an up and down 
brushing motion without moving the user's hand in a back and forth motion. 
Preferably, each depression 16 has a diameter of approximately 10 mm. and a 
depth of approximately 2 mm. The distance between adjacent depressions 16 
is approximately 4 mm. These dimensions maximize both the gripping comfort 
and the usefulness of the depressions 16 to guide the user in properly 
positioning the brush over a tooth. 
The bottom handle surface 15 possesses two finger depressions 17 rearward 
of the thumb depressions 16 to provide better balance and gripping for 
promoting proper brushing technique. FIG. 1 and FIG. 2 also generally show 
the bristles 20 disposed upon the bristled cartridge 10. 
FIG. 3 is an exploded perspective cutaway view of the attachment end 13 of 
the toothbrush handle 11 and the bristled cartridge 10 depicted without 
the bristles according to the present invention. The bristled cartridge 10 
comprises a generally rectangular housing having a first end 21, a second 
end 22 and an interior passage 23 running therebetween. The interior 
passage 23 has a top passage surface 24, a bottom passage surface 25 and a 
pair of opposing side passage surfaces 26. The top and bottom passage 
surfaces 24,25 each have an interiorally protruding ridge 27 disposed 
between the pair of opposing side passage surfaces 26 which extend from 
the first end 21 to the second end 22. The pair of opposing side passage 
surfaces 26 extend from the first end 21 to a preselected distance between 
the first end 21 and the second end 22. 
Each side passage surface 26 has an interiorally protruding vertical lip 
portion 28 which extends from the top passage surface 24 to the bottom 
passage surface 25. Each vertical lip portion 28 has an interiorally 
angled surface 29 generally facing the first end 21 of the housing and 
further has an interiorally extending locking surface 30a extending normal 
to the side passage surface 26 and facing the second end 22 of the 
housing. 
The attachment end 13 of the toothbrush handle 11 further comprises an 
H-shaped guide 31 positionally disposed between a pair of deformably rigid 
tangs 32. The H-shaped guide 31 is sized to receive the interiorally 
protruding ridges 27 of the top and bottom passage surfaces 24,25 of the 
bristle cartridge 10. The attachment end 13 further includes locking means 
for releasably securing the attached bristled cartridge 10 in position on 
the toothbrush handle 11. 
The locking means comprises a pair of deformably rigid tangs 32 disposed 
upon the attachment end 13 of the toothbrush handle 11. The deformably 
rigid tangs 32 are biased in laterally spaced opposition. Each tang 32 has 
a tip 33 possessing an outwardly extending locking surface 30b sized and 
disposed for mating with one of the interiorally extending locking 
surfaces 30a of the side passage surface 26 vertical lip portions 28. The 
pair of deformably rigid tangs 32 are also sized for and movable between a 
depressed position and a biased locking position. 
Thus, the deformably rigid tangs 32 may be depressed by a user for passage 
of the attachment end 13 through the first end 21 of the interior passage 
23 of the bristled cartridge 10. When the deformably rigid tangs 32 are 
released to the biased locking position, the deformably rigid tangs 32 
releasably secure the attached bristled cartridge 10 in position upon the 
attachment end 13 of the toothbrush handle 11. 
Preferably, the tabs 32 are sized to be in flush alignment with the second 
end 22 when in the locked position. Properly sizing and shaping the tabs 
so that tabs 32 and second end 22 form a single smooth exterior surface 
prevents trauma to the user's mouth. 
FIG. 4 is a rear view of the bristled cartridge 10, clearly depicting the 
first end 21 thereof. The bristled cartridge 10 has an interior passage 
23. The interior passage 23 has a top passage surface 24, a bottom passage 
surface 25, and a pair of opposing side passage surfaces 26. The top and 
bottom passage surfaces 24,25 each have an interiorally protruding ridge 
27 disposed between the pair of opposing side passage surfaces 26. Each 
side passage surface 26 has an interiorally protruding vertical lip 
portion 28 which extends from the top passage surface 24 to the bottom 
passage surface 25. Each vertical lip portion 28 has an interiorally 
angled surface 29 generally facing the first end 21. Also, bristles 20 are 
disposed upon the bristled cartridge 10. 
It is to be understood that the present invention is not limited to the 
sole embodiment described above, but encompasses any and all embodiments 
within the scope of the following claims.