Connector for releasably connecting and locking a first member to a second member

A connector for releasably connecting and locking a first member to a second member is provided. The connector includes a first member having a connecting element extending from the first member; a second member having a locking element extending from the second member; and an intermediate member having two ends and a passage extending through the intermediate member from one end to the other end. One end of the intermediate member is rotatably attached to the second member so that the locking element of the second member extends into the passage. The other end of the intermediate member is releasably attached to the first member so that the connecting element of the first member extends into the passage. The first member can be locked to the intermediate member by rotating the locking element relative to the connecting element. The connector may be used to releasably connect and lock a toothbrush head to a toothbrush handle.

FIELD OF THE INVENTION 
This invention relates to a connector for releasably connecting and locking 
a first member to a second member and, in particular, for releasably 
connecting and locking a toothbrush handle to a toothbrush head. 
BACKGROUND OF THE INVENTION 
It is desirable to provide a two-part toothbrush comprising a first handle 
portion and a second head portion. This necessitates a connection between 
the two portions. One reason for providing a two-part toothbrush is that 
toothbrushes readily wear out during use. Rather than being thrown out, 
the toothbrush is usually used beyond its useful life. A further reason 
for providing a two-part toothbrush is that a one-part toothbrush is 
ill-adapted for travelling and storage. In addition, it would be 
advantageous to have a clean toothbrush head available for use at one's 
destination or at any location at which it is desired to brush one's 
teeth. To make the toothbrush a more versatile item of dental hygiene, it 
would also be advantageous to provide different types of heads for use 
with a single handle. 
There are may types of connectors in the prior art but there still exists a 
need for a useful connector for releasably connecting and locking a 
toothbrush head to a handle. The main disadvantage of prior art 
connectors, such as the one disclosed in U.S. Pat. No. 2,416,684 to 
Fischer, is the risk of disconnection of the portions during actual use of 
the toothbrush. The risk of disconnection may be the result of an improper 
connection of the two separate portions by the user as well as the 
substantial forces applied to the toothbrush during use. Consequently, a 
need exists for a connector which may be positively locked after 
connection to prevent disconnection during use. 
SUMMARY OF THE INVENTION 
A connector for releasably connecting and locking a first member to a 
second member is provided. The connector includes a first member having a 
connecting element extending axially from one end of the first member; a 
second member having a locking element extending axially from one end of 
the second member; and an intermediate member having two ends and a 
passage extending through the intermediate member from one end to the 
other end. One end of the intermediate member is rotatably attached to the 
second member so that the locking element of the second member extends 
into the passage. The connecting element of the first member extends into 
the passage at the other end of the intermediate member. The first member 
may be locked to the intermediate member by the connecting member by 
rotating the locking element relative to the connecting element. 
The intermediate member may be a sleeve having a circular passage extending 
between the ends of the sleeve. One end of the circular passage may be 
tapered for receiving the locking element of the second member. 
A retaining means may be provided within the passage of the intermediate 
member for cooperating with and releasably retaining the connecting 
element. In this way, the locking element may extend into the passage of 
the intermediate member past the retaining means, such as a shoulder. The 
connecting element may include two resilient arms. The ends of each 
resilient arm may have retaining surfaces for cooperation with the 
shoulder of the intermediate member. Conical guide surfaces at the forward 
ends of each arm may cooperate with the surface of the passage. The ends 
of each arm may also have internal cam surfaces for cooperation with the 
locking element. 
A key means may be provided on the connecting element adjacent the first 
element. A complementary recess adjacent an end of the passage in the 
intermediate member receives the key means. 
The locking element may include a circular rod having a slot extending 
through the circular rod. Detent means may be provided on the outer 
surface of the circular rod. In turn, detent grooves having enlarged stop 
portions may be provided within the passage of the intermediate member for 
cooperation with the detent means. One end of the circular rod may have a 
pair of opposed tapered surfaces and a pair of opposed circular conical 
surfaces for cooperation with the connecting element to thereby lock it 
within the intermediate member. 
The first member may be attached to a toothbrush head or may be one end of 
a toothbrush head itself. The second member may be attached to a handle 
for a toothbrush or may be one end of the handle itself. 
In accordance with the invention, a method for releasably connecting and 
locking a first member to a second member is provided. The method includes 
the steps of: 
(a) providing a first member having a connecting element extending from the 
first member; 
(b) providing a second member having a locking element extending form the 
second member; 
(c) providing an intermediate member having two ends and a passage 
extending through the intermediate member from one end to the other end; 
(d) rotatably attaching the intermediate member to the second member so 
that the locking element of the second member extends into the passage; 
(e) releasably attaching the first member to the intermediate member so 
that the connecting element of the first member extends into the passage; 
(f) rotating the locking element relative to the connecting element so that 
the first member is locked to the intermediate member. 
In accordance with the invention, a method for releasably connecting and 
locking a first member to a second member is provided. The method includes 
the steps of: 
(a) providing a first member having a connecting element extending from the 
first member; 
(b) providing a second member having a locking element extending from the 
second member and rotatably attached to an intermediate member, the 
intermediate member having two ends and a passage extending through the 
intermediate member from one end to the other end so that the locking 
element of the second member extends into the passage; 
(c) releasably attaching the first member to the other end of the 
intermediate member so that the connecting element of the first member 
extends into the passage; and 
(d) locking the first member to the intermediate member by rotating the 
locking element relative to the connecting element.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, a toothbrush 30 comprises a handle assembly 32 and 
toothbrush head 34. The handle assembly 32 includes an intermediate 
portion 36. 
Referring to FIG. 2, a typical toothbrush head 34 is shown along with 
optional toothbrush heads 40 and 42 which may be selectively connected to 
the handle assembly 32. 
FIG. 3 shows the assembly point for connecting the toothbrush head 34 to 
the handle 38. The toothbrush head 34 has an end portion 44 which is ovoid 
in cross-section. A connecting element 45 comprises a pair of resilient 
arms 46 which extend axially from the end 52 of the end portion 44 for 
insertion into a first end of the intermediate member 26 and for 
connection to the intermediate member 36. The ends 48 of the resilient 
arms 46 are embossed with forward conical guide surfaces 54 and internal 
cam surfaces 56. Further, retaining surfaces 57 (as shown in FIG. 10) are 
provided rearward of the forward conical guide surfaces 54. In the 
preferred embodiment, there is a key segment 50 surrounding the base of 
the connecting element 45. 
It is to be noted that while the cross section of the parts of the 
connector is ovoid, a cross section of any other shape may be used. 
In FIG. 3, the handle 38 is shown rotated 90.degree. out of registry with 
intermediate member 36, the condition under which component assembly takes 
place. 
The intermediate member 36, shown in phantom in FIG. 4, is sleeve-like and 
has two ends, first end 37 and second end 39, respectively. A circular 
axial passage 63 extends between ends 37 and 39 of the intermediate member 
36. A tapered entry 76 is provided at second end 39 of the intermediate 
member 36. Further, the passage 63 has a first diameter at a first portion 
80 extending from said first end and a second larger diameter at a second 
portion 74 extending from said second end. The difference between the 
diameters is due to a sloping retaining shoulder 78 within the passage 63 
between the first portion 80 and the second portion 74 of the intermediate 
member 36. Opposing internal detent grooves 82 are provided near second 
end 39 of the intermediate member 36. Stops 84 at either end of the detent 
grooves 82 are provided. 
The intermediate member 36 is rotatably attached to the handle 38 as will 
be more particularly described hereinafter. In FIG. 4, handle 38 and 
sleeve 36 are shown axially aligned and disengaged. The handle 38 has a 
circular locking element 74 extending axially from one end of the handle 
38 for insertion into the second end of the intermediate member 36 as will 
be more particularly described hereinafter. A central slot 65 is provided 
in a portion of the locking element 64 which divides the locking element 
into thin segment portions 68 on the surface of which are located raised 
detents 66. The diameter of the locking element 64 taken across the raised 
detents 66 is greater than the diameter of the second portion 74 of the 
locking element 64. The forward end of the locking element 64 has a pair 
of opposed tapered surfaces 70 and a pair of opposed conical surfaces 72. 
Referring to FIGS. 5, 6 and 7, the method of assembly of the locking 
element 64 within the intermediate member 36 is shown. FIG. 5 depicts the 
components prior to assembly. FIG. 6 depicts initial assembly with the 
locking element 64 partially inserted into the axial passage 63 of the 
intermediate member 36. The conical tapered entry 76 of the intermediate 
member 36 facilitates insertion of the locking element 64. The thin 
segment portions 68 bias inwardly to permit the passage of the locking 
member 64 into the passage 63 of the intermediate member 36. The biasing 
force is released when the detent grooves 82 receive the detents 66 
thereby rotatably connecting the handle 38 to the intermediate member 36 
along the arc length of the grooves 82. It is to be noted that the segment 
portions 68 are fully released only at the stops 84 (see FIG. 15). Through 
all of the intermediate points along the arc length of grooves 82, the 
segment portions 68 are slightly biased inwardly. The detents 66 snap 
outwardly into place at the stops 84 and eliminate slack in the rotatable 
connection. The rotational alignment of the second member to the 
intermediate member may be maintained during use and the user has a 
further positive indication when the limit of relative rotation has been 
reached. 
In FIG. 7, it can be seen that the end of the locking element 64 extends to 
the retaining shoulder 78 of the intermediate member 36. 
In the preferred embodiment, the intermediate member 36 is permanently 
assembled to the handle 38 and all that remains to be done is for the user 
to connect and lock the toothbrush head 40, 42 or 34 to the handle 
assembly 32. 
Referring to FIGS. 8, 9 and 10, the assembly of the connector is now 
described. The connecting element 45 is releasably secured within the 
intermediate member 36 by insertion at the first end 37, into the passage 
63. The front portion of the passage 63 contains a recess 60 shaped to 
receive the key segment 50 of connecting element 45 which aligns the 
connecting element within the intermediate member and the locking element 
as will be described. Locking of the connector is achieved by rotating the 
handle 38 through angle 0 (shown in FIG. 3) relative to the connecting 
element 45. 
FIG. 9 shows the partially assembled connector. Since the diameter of the 
first portion 80 of the axial passage 63 is smaller than the diameter 
presented by the conical guide surfaces 54, the resilient arms 46 bias 
inwardly during insertion as shown in FIG. 9 and snap outwardly when the 
retaining shoulder 78 is reached as shown in FIG. 10. At this point, the 
retaining surfaces 57 of the arms 46 engage the shoulder 78 and the key 
segment 50 is in the recess 60. It is to be noted, however, that at this 
stage a pulling action on the head 42 will also release of the connecting 
element 45 from the intermediate member 36. Thus, means must be provided 
to lock and secure the connecting element 45 within the intermediate 
member 36. This is generally achieved by rotation of the handle 38 and 
consequent rotation of the locking element 64 such that the conical 
surfaces 72 of the locking element 64 are rotated to cooperate with cam 
surfaces 56 of the connecting element 45 as shown in FIGS. 12 and 13. This 
prevents the arms 46 from being urged inwards and thus permitting 
withdrawal of the connecting element 45. 
It can be appreciated that the ovoid cross-section of the connector will 
give a visual indication of relative rotation between the handle 38 and 
intermediate member 36. Thus, in FIG. 3 the handle 38 is shown at one 
limit of its relative rotation which corresponds to the locking element 64 
being aligned within the intermediate member 36 to present the tapered 
surfaces 70 to the cam surfaces 56. The connecting element 45 is 
releasably secured within the intermediate member 36 in this position. The 
tapered surfaces present a narrow wedge to the cam surfaces 72 and the 
connecting element 45 may be both inserted and withdrawn. Rotation of the 
handle 38 to the other limit of rotation, as shown in FIGS. 11 and 12, 
results in a toothbrush having a smooth external surface and locks the 
connector by presenting the conical surfaces 72 to the cam surfaces 56 on 
the connecting element. The conical surfaces 72 present a thick cone to 
the cam surfaces 56 which locks the connecting element 49 within the 
intermediate member 36 behind the retaining shoulder 78. In the locked 
condition a pivoting action on the first member will result in the cam 
surfaces 56 immediately abutting against the conical surfaces 72 which 
prevents the resilient arms 46 from biasing inwardly and they remain 
secured behind the retaining shoulder 78. 
It should also be noted that the connector may be reversed so that the 
locking element may be located on the first member and the connecting 
element on the second member. 
While preferred embodiments of the invention have been described in detail, 
it will be understood by those skilled in the art that variations may be 
made to such embodiments without departing from the spirit of the 
invention or the scope of the appended claims.