# Patent

## Title
Electrical connector with resilient retaining ring to restrict radial expansion

## Abstract

Various electrically controlled devices of a bicycle are electrically coupled together by multi-conductor electrical cords. Preferably, the ends of the electrical cords have an electrical connector that mates with a corresponding electrical connector of an electrically controlled device. The electrical connectors are designed to be coupled together by a snap fit. Each electrical connector attached to the end of the electrical cord has an electrical contact housing with electrical contacts and an outer casing molded about the electrical contact housing to form a tubular portion radially spaced from the outer end of the electrical contact housing. A retaining ring is located in an annular groove formed in an exterior surface of the outer casing to provide an additional coupling force. Preferably, an annular sealing member formed of a resilient and compressible material is located in an annular space formed between the tubular portion and the electrical contact housing.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to an electrical connector. More specifically, the present invention relates an electrical connector that mates with another electrical connector via a snap-fit.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has also become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. Specifically, manufacturers of bicycle components have been continually improving performance, reliability and appearance of the various components.
Recently, bicycles have been provided with an electronic drive train for smoother shifting. These electronic drive trains include a rear multi-stage sprocket assembly with a motorized rear derailleur and a front multi-stage sprocket assembly with a motorized front derailleur. These derailleurs are electronically operated by a cycle computer for automatically and/or manually shifting of the derailleurs. The cycle computer is also often coupled to other components that are electrically controlled or operated. For example, some bicycles include electronically controlled suspension assemblies for adjusting the stiffness of the ride depending on a variety of factors.
The cycle computer uses one or more sensors to monitor various operations of the bicycle, such as speed, cadence, riding time and gear position, which are in turn used to electrically control or operate these electronic components. In this type of an arrangement, electrical wires or cords are utilized to transmit the electrical current to and from the various components and sensors. These electrical wires or cords are often connected to the components and/or sensors by electrical connectors.
Since the bicycle is typically utilized outdoors, the electrical connections of the electrical connectors are exposed to a variety of weather conditions. The electrical connections can often be contaminated so as to degrade performance of the operation of the electrically control component. If the electrical connections get too dirty, the bicycle components and/or sensors may not operate properly. Since the electrical connections are exposed to adverse weather conditions, it is important that the electrical connectors provide a good solid connection so that they can operate even though they may become slightly contaminated.
Additionally, in certain riding conditions such as off-road type riding, the cyclist often encounters obstructions such as bushes or tree limbs. Sometimes, these obstructions can catch the electrical wires or cords and affect performance of the electrical components and/or sensors. Additionally, in some situations, other obstructions such as clothing, bicycle lock cables or tools can catch on the electrical wires or cords. Typically, the electrical connectors of the electrical cords are secured to mating electrical connectors via non-releasable connections such as threads or the like. The problem with such non-releasable electrical connectors is that the electrical cord can get caught on an obstruction, which can result in the rider losing control over the bicycle and serious damage to the electrical cord.
Recently, electrical connectors have been proposed that couple together via a snap-fit. The snap-fit type of electrical connectors overcomes the above mentioned problem with the non-releasable electrical connectors. However, when the electrical connector is exposed to a variety of temperature changes, this causes parts of the electrical connector to expand or shrink in response to the temperature changes. This is especially problematic when the electrical connectors that utilize a snap-fit. These changes in temperature can affect the snap-fit between the electrical connectors. More specifically, the coupling force and click feeling between the mating connectors will decline after being exposed to various temperature changes over an extended period of time.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved electrical connector which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
SUMMARY OF THE INVENTION
One object of the present invention is to provide an electrical connector that is used with a mating electrical connector to provide a rigid connection therebetween as well as a watertight connection therebetween.
Another object of the present invention is to provide an electrical connector with a releasable connection therebetween in case of the electrical cord is accidentally caught on an object during riding in order to avoid serious damage to the cord and prevent the rider from losing control over the bicycle.
Another object of the present invention is to provide a male electrical connector, which is relatively simple and inexpensive to manufacture and assemble.
The foregoing objects can basically be attained by providing an electrical connector that comprises an electrical contact housing, at least one electrical contact, an outer casing and an resilient retaining ring. The electrical contact is retained within the electrical contact housing. The outer casing includes a tubular portion that is radially spaced from the electrical contact housing to form an annular space between an inner surface of the tubular portion and the electrical contact housing. The resilient retaining ring is coupled to the tubular portion to restrict radially expansion of the tubular portion.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.



BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the attached drawings which form a part of this original disclosure:
FIG. 1 is a partial, side elevational view of a bicycle with a bicycle computer, an electronically controlled front suspension and a front wheel sensor that utilize a bicycle electrical connector cord in accordance with a preferred embodiment of the present invention;
FIG. 2 is a top plan view of the handlebar portion of the bicycle with a cycle computer or control unit and a pair of shifting devices coupled thereto;
FIG. 3 is a diagrammatic illustration of the control system that uses electrical connectors of the present invention;
FIG. 4 is a side elevational view of a female electrical connector in accordance with a preferred embodiment of the present invention;
FIG. 5 is a longitudinal cross-sectional view of the female electrical connector as seen along section line 5—5 of FIG. 4;
FIG. 6 is a perspective view of the female electrical connector of the present invention, prior to being coupled to a male electrical connector;
FIG. 7 is a partial longitudinal cross-sectional view of the female and male electrical connectors as seen along section line 7—7 of FIG. 6;
FIG. 8 is an enlarged partial perspective view of the female and male electrical connectors coupled together with selected portions broken away for illustration;
FIG. 9 is an enlarged partial side elevational view of the female electrical connector illustrated in FIGS. 4-8 with selected portions broken away for illustration; and
FIG. 10 is an enlarged partial side elevational view of the male electrical connector illustrated in FIGS. 6-8 with selected portions broken away for illustration.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Selected embodiments of the present invention will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments of the present invention are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
Referring initially to FIGS. 1 and 2, a front portion of an electronically controlled bicycle 10 is illustrated to explain the present invention. The present invention relates to the electrical connections between the electronically controlled components of the bicycle 10. Therefore, the bicycle 10 and its various components are well known in the prior art, except for the electrical connection between the electronically controlled components. Thus, the bicycle 10 and its various components will not be discussed or illustrated in detail herein, except for the components that relate to the present invention. Moreover, various conventional bicycle parts such as brakes, or drive trains, etc., which are not illustrated and/or discussed in detail herein, can be used in conjunction with the present invention. Furthermore, it will be apparent to those skilled in the art that the bicycle electrical cord 28 could be utilized to connect various other electrical devices of the bicycle 10 as needed and/or desired.
Basically, the bicycle 10 has a frame 12, a handlebar 14, an electronically controlled front suspension 16a coupled to the handlebar 14 and a front wheel 18 coupled to the electronically controlled front suspension 16a. The bicycle 10 also includes a cycle computer 20, a front wheel sensor 22, a pair of electronic shifting devices 24a and 24b and a junction box or connection unit 26. The bicycle 10 is also preferably equipped with an electronically controlled drive train (not shown) that is operated by the electronic shifting devices 24a and 24b. Moreover, the bicycle 10 can have an electronically controlled rear suspension 16b, which is only diagrammatically shown in FIG. 3.
The various electrical devices (the cycle computer 20, the electronically controlled front suspension 16a, the electronically controlled rear suspension 16b, the electronic shifting devices 24a and 24b, the junction box 26, etc.) of the bicycle 10 are electrically coupled together by multi-conductor electrical cords 28a, 28b or 28c in accordance with a preferred embodiment of the present invention. In particular, the electrical connector cords 28a, 28b or 28c are provided with at least one female electrical connector 30a, 30b or 30c located at one of its ends. As seen in FIG. 3, the female electrical connectors 30a, 30b and 30c plug into mating male electrical connectors 32a, 32b and 32c, which are provided in the cycle computer 20, the electronically controlled front suspension 16a, the electronically controlled rear suspension 16b and the junction box 26. Also, the sensor 22 is preferably electrically coupled to in the cycle computer 20 using the female electrical connector 30a that is connected to the electrical cord 28a of the electronically controlled front suspension 16a. Thus, the various electrical devices (the cycle computer 20, the electronically controlled front suspension 16a, the electronically controlled rear suspension 16b, the sensor 22, the electronic shifting devices 24a and 24b, the junction box 26, etc.) of the bicycle 10 form an electronic control system 34.
As illustrated in FIG. 3, the electronic control system 34 is utilized to control the front and rear suspensions and the drive train as well as other components of the bicycle 10, which are not shown. In the illustrated embodiment of FIG. 3, the electrical cords 28a are six-line cords in which all or some of the lines or conductors are utilized as needed. The electrical control cord 28 is a fifteen-line cord with all or some of the lines or conductors being utilized as needed. The electrical control cord 28c for the rear suspension is preferably a two-line cord. In this illustrated embodiment, the electrical connectors 30a and 32b are six-pin electrical connectors with only some or all of the pins being utilized. The electrical connectors 30b and 32b are fifteen-pin electrical connectors with only some or all of the pins being utilized. The electrical connectors 30c and 32c are two-pin electrical connectors. Of course, it will be apparent to those skilled in the art from this disclosure that these connectors 30a-30c and 32a-32c can be utilized with other bicycle components and in other types of arrangements as needed and/or desired. The electrical connectors 30a-30c are all identical, except for their sizes and the number of electrical contacts or terminal pins. Similarly, the electrical connectors 32a-32b are all identical, except for their sizes and the number of electrical contacts or terminal pins. Accordingly, only the electrical connectors 30a and 32a will be discussed and illustrated in detail herein.
The cycle computer 20 preferably includes a microcomputer formed on a printed circuit board that is powered by a battery unit. The microcomputer of the cycle computer 20 includes a central processing unit (CPU), a random access memory component (RAM), a read only memory component (ROM), and an I/O interface. The various components of the microcomputer are well known in the bicycle field. Therefore, the components used in the microcomputer of the cycle computer 20 will not be discussed or illustrated in detail herein. Moreover, it will be apparent to those skilled in the art from this disclosure that the cycle computer 20 can include various electronic components, circuitry and mechanical components to carryout the present invention. Of course, it will be apparent to those skilled in the art from this disclosure that the cycle computer 20 can have a variety of configurations, as needed and/or desired. Thus, the cycle computer 20 functions as a shift control unit and a suspension control unit in the illustrated embodiment.
Preferably, the cycle computer 20 displays various information to the rider via a display and operates the electronically controlled suspensions 16a and 16b and the electronically controlled shifting devices 24a and 24b based on input from the rider and/or input from the sensor 22. Thus, the front and rear suspensions 16a and 16b and the electronically controlled shifting devices 24a and 24b are operated or electronically controlled by the cycle computer 20.
Referring now to FIGS. 4-9, the first or female electrical connector 30a basically has an electrical contact housing 40 with a plurality of first electrical contacts 42, an outer casing 44 molded on the electrical contact housing 40, an annular sealing member 46 located between the electrical contact housing 40 and the outer casing 44, and a resilient retaining ring 47 coupled to the outer casing 44. The resilient retaining ring 47 coupled to the tubular portion to restrict radially expansion of the tubular portion.
More specifically, the electrical connector 30a is a six-pin type female electrical connector and preferably includes six terminal pins 42. Of course, it will be apparent to those skilled in the art that the first electrical contacts 42 could utilize more or fewer terminal pins as needed and/or desired. In the illustrated embodiment, the electrical connector 30a is designed to mate with the male electrical connectors 32a of the cycle computer 20.
The electrical contact housing 40 is constructed of an insulating material such as a hard, rigid plastic material. While the electrical contact housing 40 is illustrated as a female housing, it will be apparent to those skilled in the art from this disclosure that the electrical contact housing could be modified to be a male electrical contact housing without departing from the present invention. Basically, the electrical contact housing 40 has a first end 40a that is coupled to the free end of the electrical cord 28a and a second end 40b that mates with the corresponding male electrical connector 32a. The electrical contact housing 40 has a plurality of axial bores 48 extending between the first and second ends 40a and 40b. Each of these bores 48 has one of the electrical contacts 42 frictionally retained therein.
Between the first and second ends 40a and 40b are provided a pair of annular flanges or ribs 50a and 50b that assist in securing the outer casing 44 thereto. More specifically, the outer casing 44 is molded onto the electrical contact housing 40 such that the outer casing 44 surrounds the annular flanges 50a and 50b. Thus, axial movement between the electrical contact housing 40 and the outer casing 44 is prevented. Moreover, a watertight seal is formed between the electrical contact housing 40 and the outer casing 44 at these flanges 50a and 50b. 
The electrical contacts 42 are conventional contacts constructed of an electrically conductive material. Each contact 42 is coupled to the electrical conductors of the electrical cord 28a. Preferably, the electrical conductors are soldered to the electrical contact.
The outer casing 44 is constructed of a relatively hard, rigid material that has limited flexibility and resiliency. For example, the outer casing 44 can be constructed of any suitable insulating material such as a hard, rigid plastic material. One example of a suitable material is a polyester blend. The outer casing 44 is generally a tubular member having an attachment portion 60 and a tubular portion 62.
The attachment portion 60 is fixedly coupled to the first end 40a of the electrical contact housing 40, while the tubular portion 62 is radially spaced from the second end 40b of the electrical contact housing 40 to form an annular space 64 between the inner surface 62a of the tubular portion 62 and the second end 40b of the electrical contact housing 40. The annular space 64 has an inner end 64a and an oven end 64b. as best seen in FIG. 9.
The tubular portion 62 of the outer casing 44 has an inwardly extending annular protrusion 62b that forms an annular detent. In other words, the annular protrusion 62b is an annular ring that mates with the corresponding electrical connector 32b to form a snap-fit therebetween as explained below. Accordingly, the material of the outer casing 44 should have limited resiliency such that a snap-fit connection can be formed between the pair of electrical connectors 30a and 32a, while providing a strong and firm connection that will not accidentally separate under normal use. In other words, the snap-fit connection between the electrical connectors 30a and 32a should be sufficiently strong such that they cannot be separated once coupled together during normal use. Accordingly, the annular protrusion 62b has an abutment surface 62c that faces away from the second end 40b of the electrical contact housing 40 for retaining the mating electrical connector 32a therein. The annular protrusion 62b also has an annular inclined surface 62d that serves as a ramp to aid in the insertion of the mating electrical connector 32a. The resilient retaining ring 47 is located in an annular groove 62e formed in an exterior surface of the tubular portion 62 of the outer casing 44.
The annular sealing member 46 is preferably molded within the outer casing 44 such that the annular sealing member 46 cannot be accidentally removed. More specifically, the annular sealing member 46 is an O-ring with more than half of the diameter of the O-ring being embedded within the outer casing 44. The annular sealing member 46 is preferably formed of an elastomeric material such as an acrylonitrile-butadiene rubber (NBR) or any other suitable resilient and compressible material that can be utilized to carry out the present invention. In this embodiment, the annular sealing member 46 extends in a radial direction from the inner surface 62a of the tubular portion 62 of the outer casing 44. Thus, the annular sealing member 46 is compressed in a radial direction by the mating electrical connector 32a. 
The resilient retaining ring 47 is located longitudinally between the annular sealing member 46 and the abutment surface relative to a center longitudinal axis of the electrical connector 30a. The resilient retaining ring 47 coupled to the tubular portion 62 to restrict radially expansion of the tubular portion 62.
Preferably, the resilient retaining ring 47 is a split ring that is located in an annular groove formed in an exterior surface of the outer casing 44. The resilient retaining ring 47 is formed of a different material with than the outer casing 44 such that the temperature effects on material of the outer casing 44 does not affect material of the resilient retaining ring 47 in the same manner. By constructing the resilient retaining ring 47 out of material that is substantially not affected by the changes in temperature, a constant coupling force can be attained when the electrical connector 30a and the mating electrical connector 32a are coupled together. Since the retaining ring 47 is split, the retaining ring 47 will resiliently flex together with the tubular portion 62 when the mating electrical connector 32a is coupled thereto. Thus, the retaining ring 47 ensures a consistent coupling force and a good snap-fit. Preferably, the resilient retaining ring 47 is formed of a substantially rigid spring material such as a metallic spring material. More preferably, the resilient retaining ring 47 is formed of a weather resistant material that will not corrode when exposed to the weather for an extended period of time such as stainless steel.
The electrical contact housing 40 also has an axially extending slot 52 on its exterior surface that acts as a polarizing slot to ensure correct orientation between the electrical connectors 30a and 32a as explained below. The outer casing 44 is preferably formed as a one-piece, unitary member that is integrally molded about the electrical contact housing 40 and the annular sealing member 46. Alternatively, the outer casing 44 can be constructed of two pieces (a non-compressible material and a compressible material) such that the annular sealing member 46 is formed as part of one of the pieces of the outer casing 44.
The male electrical connector 32a preferably has an electrical contact housing or terminal housing 80 that is molded about a plurality of electrical contacts or terminal pins 82. The male electrical connector 32a is designed to mate with the female electrical connector 30a via a snap-fit. More specifically, the electrical contact housing 80 of the male electrical connector 32a is formed as a one-piece, unitary member that is molded. The electrical contact housing 80 of the male electrical connector 32a basically includes a body portion 84 and a tubular portion 86. The body portion 84 has a main section 84a that is molded around the terminal pins 82 such that the terminal pins 82 are fixedly retained to the body portion 84 of the electrical contact housing 80. The body portion 84 also has an annular flange 84b extending radially outwardly from the main section 84a. This annular flange 84b can be utilized to mount the electrical connector 32a to the cycle computer 20 or one of the other electrical devices.
The tubular portion 86 is a cylindrically shaped member that extends axially from the main section 84a of the body portion 84, and is designed to form a snap-fit with the female electrical connector 30a. Accordingly, the tubular portion 86 has a cylindrical outer surface 86a with an annular protrusion 86b and an annular recess 86c. The inner surface 86d of the tubular portion 86 is cylindrical and spaced from the free ends of the terminal pins 82. The electrical contact housing 80 is preferably constructed of a hard, rigid insulating material such as a hard, rigid plastic material. For example, the electrical contact housing of the male electrical connector can be constructed of a polyester blend material.
The male electrical connector 32a of the cycle computer 20 basically includes an electrical contact housing 80 with six (or fewer) terminal pins 82. The terminal pins 82 have a circular cross-section and are arranged in a pattern to mate with the first electrical connector 30a. The housing 80 preferably is configured with a mating structure for releasably retaining the electrical connector 30a thereto via a snap-fit as mentioned above. The housing 80 is constructed of a non-conductive material such as a hard, rigid plastic material. The terminal pins 82 are constructed of a conductive material.
The female electrical connector 30a is coupled to the male electrical connector 32a by applying an axial force between the female and male electrical connectors 30a and 32a to create a snap-fit therebetween. More specifically, the female electrical connector 30a is oriented such that the polarizing slot 52 of the electrical contact housing 40 of the female electrical connector 30a aligns with the polarizing rib 88 of the electrical contact housing 80 of the male electrical connector 32a. Once the polarizing slot 52 and the polarizing rib 88 are aligned, the female electrical connector 30a is moved axially such that the terminal pins 82 enter the bores of the electrical contact housing 40 of the female electrical connector 30a to electrically engage the electrical contacts 42. The tubular portion 86 of the male electrical connector 32a is received in the annular space between the electrical contact housing 40 and the outer casing 44. The tubular portion 86 is continued to be moved axially within the annular space of the female electrical connector 30a until the annular protrusion 86b of the male electrical connector 32a passed beneath the annular protrusion 62b of the outer casing 44. Thus the abutment surfaces of the annular protrusions 62b and 86b contact each other to prevent axial separation of the female and male electrical connectors 30a and 32a. Moreover, the annular sealing member 46 is compressed by the tubular portion 86 of the male electrical connector 32a to form a watertight connection therebetween.
Referring back to FIG. 1, the sensor 22 is preferably a front wheel speed sensing unit that includes a sensing portion 22a and a magnet 22b. The sensing portion 22a is preferably a magnetically operable sensor that is mounted on the front suspension 16a of the bicycle 10 and senses the magnet 22b that is attached to one of the spokes of the front wheel 18 of the bicycle 10. In the illustrated embodiment, the sensing portion 22a includes a reed switch for detecting the magnet 22b. The sensor 22 generates a pulse each time wheel 18 of the bicycle 10 has turned a prescribed angle or rotation. The sensor 22 outputs a bicycle speed signal to the computer 20 by detecting magnet 22b mounted on front wheel 18 of the bicycle 10. In other words, the sensor 22 detects the rotational velocity of the front wheel 18 of the bicycle 10.
Referring to FIG. 3, the front and rear suspensions 16a and 16b are not critical to the present invention. There are currently numerous types of adjustable suspensions for the bicycle 10 that can be utilized to carry out the present invention. Preferably, the front and rear suspensions 16a and 16b utilize two conventional air shocks with hydraulic dampening mechanisms that have been modified to carry out the present invention. An electric motor is electrically coupled to the cycle computer 20 that selectively operates the electrical motor to adjust the stiffness of the front and rear suspensions 16a and 16b. 
In the manual mode, shifting of each of the motorized derailleurs FD and RD (diagrammatically shown in FIG. 3) is performed by via manual shifting devices 24a and 24b. While the shifting devices 24a and 24b illustrated herein utilizes down and up shift buttons, it will be apparent to those skilled in the art from this disclosure that various other types of shift devices can used, such as levers, without departing from the scope of the invention as defined in the appended claims. Depressing one of the shift buttons of the shifting devices 24a and 24b generates a predetermined operational command that is received by the central processing unit of the cycle computer 20. The central processing unit of the cycle computer 20 then sends a predetermined operational command or electrical signal to move or shifting one of the motorized derailleurs FD and RD.
In the automatic mode, shifting of each of the motorized derailleurs FD and RD is preferably at least partially based on the speed of the bicycle 10. Thus, the cycle computer 20 further includes at least one sensing/measuring device or component that provides information indicative of the speed of the bicycle 10 to its central processing unit of the cycle computer 20. In the illustrated embodiment, the sensor 22 generates a predetermined operational command indicative of the speed of the bicycle 10. Of course, additional sensing/measuring components can be operatively coupled to central processing unit of the cycle computer 20 such that predetermined operational commands are received by the central processing unit (CPU) to operate the motorized derailleurs FD and RD or other components.
The junction box 26 preferably includes a single power input or electrical control cords 28b for receiving signals from the shifting device 24a and 24b and three power outputs or electrical control cords 28c for sending signals to the rear and front motorized derailleur FD and RD and the rear suspension 16b. The power input operatively couples the cycle computer 20 to the junction box 26.
The terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms should be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies.
While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

## Claims

1. An electrical connector comprising:
an electrical contact housing; 
at least one electrical contact being retained within said electrical contact housing; 
an outer casing at least partially surrounding said electrical contact housing, said outer casing including a tubular portion radially spaced from said electrical contact housing to form an annular space with an inner end and an open end between an inner surface of said tubular portion and a peripheral surface of said electrical contact housing; and 
a resilient retaining ring coupled to said tubular portion, said resilient retaining ring having an inner surface that contacts an outer surface of said tubular portion to restrict radial expansion of said tubular portion of said outer casing, said resilient retaining ring being located radially outwardly of said annular space to be at least partially longitudinally disposed between said inner end and said open end of said annular space.

2. The electrical connector according to claim 1, wherein
said tubular portion of said outer casing has a free end and an inwardly extending protrusion with an abutment surface that faces away from said free end.

3. The electrical connector according to claim 2, further comprising
an annular sealing member is an O-ring formed of a resilient and compressible material that is located in said annular space.

4. An electrical connector comprising:
an electrical contact housing; 
at least one electrical contact being retained within said electrical contact housing; 
an outer casing at least partially surrounding said electrical contact housing, said outer casing including a tubular portion radially spaced from said electrical contact housing to form an annular space between an inner surface of said tubular portion and a peripheral surface of said electrical contact housing, said tubular portion of said outer casing having a free end and an inwardly extending protrusion with an abutment surface that faces away from said free end; 
a resilient retaining ring coupled to said tubular portion to restrict radial expansion of said tubular portion; and 
an annular sealing member located in said annular space, said annular sealing member being an O-ring that is formed of a resilient and compressible material, 
said resilient retaining ring is located longitudinally between said annular sealing member and said abutment surface relative to a center longitudinal axis of said electrical connector.

5. The electrical connector according to claim 4, wherein
said resilient retaining ring is a split ring.

6. The electrical connector according to claim 5, wherein
said split ring is located in an annular groove formed in an exterior surface of said outer casing.

7. The electrical connector according to claim 6, wherein
said split ring is formed of a different material with than said outer casing.

8. The electrical connector according to claim 1, wherein
said outer casing is constructed of a non-compressible, non-metallic material, and said split ring is formed of a metallic material.

9. The electrical connector according to claim 1, wherein said electrical contact includes a plurality of electrical contacts.

10. The electrical connector according to claim 1, wherein said resilient retaining ring is a split ring.

11. The electrical connector according to claim 1, wherein
said resilient retaining ring is located in an annular groove formed in an exterior surface of said outer casing.

12. The electrical connector according to claim 1, wherein
said resilient retaining ring is formed of a different material with than said outer casing.

13. The electrical connector according to claim 1, further comprising
an annular sealing member is an O-ring formed of a resilient and compressible material that is located in said annular space.

14. The electrical connector according to claim 2, wherein
said resilient retaining ring is spaced farther from said free end of said tubular portion than said inwardly extending protrusion.