Abstract:
A connector comprises a housing having a plurality of terminals. The housing is provided with a first bearing portion made of rigid material and a second bearing portion made of an elastic material. The operating handle is rotatably supported by the first and second bearing portions. The operating handle comprises a cam mechanism which is operated by the rotation of the operating handle.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a connector for use in an electric endoscope, especially for connecting a main body with a scope part therebetween. 
     In a conventional endoscope-connector, a rotating handle (that is, a bayonet collar) is in the shape of a cylinder and has a cam. The bayonet collar is coaxially disposed through the bearing portions around an outer surface of a housing accommodating a plurality of connector terminals. When receiving the bayonet collar with the bearing portions, since the length along the axial direction of the bayonet collar is relatively longer, bearing portions are disposed on opposed ends of the bayonet collar, respectively, so that the opposed ends of the bayonet collar are received by the bearing portions. In this type of connector, in order to prevent looseness of connection between the connector and the main body and to improve the operation feeling, the bayonet collar is provided with an appropriate friction. 
     To supply the friction to the bayonet collar, a friction board which is made of wool puff, synthetic leather and the like is put into a space between the bayonet collar and the housing and between each bearing portion. Alternatively, a leaf spring which is made of metal or resin is added to supply a side pressure to the bayonet collar from an inside thereof. 
     However, the method of using the friction board is difficult to have a stable friction torque because of subtle different sizes of the friction board. The method of using the leaf spring has an extremely smaller friction coefficient at a contact point between the bayonet collar and the bearing portions in comparison with the method of using the friction board. Therefore, it is necessary for the method using the leaf spring to supply a larger load to the contact point to have a heavy friction torque. As a result, the leaf spring is subjected to a heavy abrasion of a resin of the contact point. 
     Conventionally, when washing or disinfecting the scope portion provided with this type of connector, a water proof cap is fitted to the end opening of the connector to avoid the wash water or disinfectant to inflow into the connector from the end opening thereof. 
     However, It is difficult to quickly mount or dismount the cap on or from the connector, because the water proof cap is screwed into the connector along a thread provided on a peripheral surface of the connector. 
     Therefore, in the case of the electric endoscope apparatus comprising the main body and the scope portion which are connected to each other by using this type of conventional connector, a need of an abrasion-proof would occur or a stable friction torque to the bayonet collar would not secured. Furthermore, because of the aforesaid problem, a great deal of time is lost when preparing for starting an examination or when washing and disinfecting. Especially, it is difficult to deal with the time loss when desired to quickly wash the scope portion in a short clinical time. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a connector which comprises a structural advantage of being capable of supplying a stable friction torque to the bayonet collar and of having no requirement of an abrasion-proof, and comprises an operational advantage of being capable of detaching the main body from the connector easily. 
     It is another object of the present invention to provide a connector which is capable of detaching the cap for use in washing and disinfecting the scope portion in a short time with an easy operation. 
     To accomplish the above mentioned objectives, the present invention provides a connector for use in connecting the main body with the scope portion comprising a housing and a plurality of terminals held in the housing. A first bearing portion is made of rigid material and attached to the housing. A second bearing portion is made of elastic material which is disposed apart from the first bearing portion on the housing. And, an operating handle is supported rotatably by the first bearing portion and the second bearing portion. The operating handle comprises a cam mechanism which is operated with the rotation of the operating handle. The second bearing portion is pressed and modified between the operating handle and the housing, and produces pressure when regaining the shape. 
     In the preferred embodiment, the cam mechanism comprises a groove formed in the inner surface of the operating handle in a inclined manner in an axial direction. A protrusion on the main body engages with the groove. The protrusion slides along the groove by rotating the operating handle to bring into close contact the housing with the main body. 
     In another preferred embodiment, the connector further comprises the water-proof cap having a protrusion which engages with the groove. The protrusion slides along the groove by rotating the operating handle to bring the water-proof cap into close contact with the housing. 
     According to the connector of the present invention, at least one part of the bearing portion which receives the bayonet collar may be made of elastic resin or rubber. Because the elastic modification of the bearing portion produces a pressure to supply a stable friction torque to the bayonet collar or the housing, it is possible to absorb slight variations of the size in comparison with the conventional friction board. Consequently, the friction torque becomes stable which is for supplying to the bayonet collar or housing, and a mounting or demounting operation of the scope portion to the main body becomes easy. At the same time, it is preferred for enabling to perform the electrical connecting or disconnecting. Furthermore, there is an appropriate friction coefficient between the elastic bearing and the bayonet collar, the ratio of depending on the load is smaller than that of the conventional method of using the leaf spring. Therefore, there is no need to consider the abrasion. 
     According to the preferred embodiment of the present invention, the cam mechanism in the bayonet collar adds compression forces to the coil spring making a packing to cut off and release. Therefore, by the operation of the rotating handle, it is possible to fit the packing to the end opening of the housing and to make inner space of the housing to be cut off from the outside. The cam process of the rotating operation is substantially shorter than that of the conventional screwing system. Consequently, it is possible to detach the water-proof cap from the connector with easier operation In shorter time compared with the conventional method. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic side view with a partial cutaway cross section of a connector for use in an electrical endoscope of an preferred embodiment of this invention. 
     FIG. 2A an expanded sectional view of an elastic bearing portion provided for the connector of FIG. 1. 
     FIG. 2B is similar to FIG. 2A and is an expanded sectional view of the elastic bearing portion before mounting a bayonet collar on the elastic bearing portion. 
     FIG. 2C is an expanded sectional view similar to FIG. 2A and shows a modified example of the elastic bearing portion. 
     FIG.3 is a perspective view of the outline showing the scope portion connected with the main body by using the connector of FIG. 1. 
     FIG. 4 is a view showing the outline of a shield line which is formed by connecting the scope portion with the main body by using the connector of FIG. 1. 
     FIG. 5 is a side view of a water-proof cap for being mounted to the connector of FIG. 1. 
     FIG. 6 is a side view showing the connector of FIG. 1 connected with the water-proof cap. 
     FIG. 7 is a side view showing the cam mechanism provided on the connector of FIG. 1. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 is a schematic side view with a partial cutaway cross section of a connector for use in an electrical endoscope of one preferred embodiment of this invention. 
     An endoscope connector 100 of this preferred embodiment comprises a rigid cylindrical bearing portion 2 for receiving one end of the bayonet collar 1 and an elastic cylindrical bearing portion 3 for receiving the other end. The bayonet collar 1 is disposed coaxially with the housing comprising a cylinder portion 4, a shell (shield case) 5, and insulating material 8. The rigid bearing portion 2 and the elastic bearing portion 3 are separated from each other and disposed on the housing. FIG. 1 also shows a plurality of connector terminals 7, contact springs 9, a light guide 10, a suction channel 11, an air and water supplying channel 12 and an universal cord 13 of the scope portion. 
     As illustrated in FIG. 3, the rotating operation of the bayonet collar 1 enables connection or disconnection of the scope portion 15 from the main body 14 by the connector 100. 
     In the assembly mentioned above, the elastic bearing portion 3 may be made of resin or rubber, for instance, made of such resin as Rulon (Trade mark of NTN) producted by NTN Co. 
     Consequently the elastic bearing portion 3 is preferably made of fluororesin such as Teflon (polytetrafluoroethylene), and silicon rubber, more preferably, a rubber of polytetrafluoroethylene series. 
     The rigid bearing portion 2 is made of relatively rigid resin, preferably, fluororesin or silicone resin. The rigid bearing portion 2 comprises a cylindrical configuration which is fixed on the end of the insulation material 8. 
     Referring to FIGS. 2A and 2B, the elastic bearing portion 3 comprises a curved portion 3a and a straight line portion 3b. An inner peripheral surface of the straight line portion 3b is fixed on an outer surface of the cylinder portion 4. 
     As shown in FIG. 2B, the curved portion 3a swells radially outwardly when the bayonet collar 1 is not mounted. In this condition, an outer radial (r) of the curved portion 3a is larger than an inner radial (R) of the bayonet collar 1 (r&gt;R). The curved portion 3a has a free end movable toward the radial and the axial directions. 
     The curved portion 3a is pressed radially toward the inner direction by the inner surface of the bayonet collar 1 when mounted. 
     As a result, as illustrated in FIG. 2A, the curved portion 3a is compressed radially toward the inner direction, and extends toward the axial direction with a modification. The curved portion 3a produces and supplies a predetermined pressure to an inner peripheral surface of the bayonet collar 1 with the modification thereof. The curved portion 3a supplies a predetermined pressure as a reversion force to the inner peripheral surface of the bayonet collar 1. 
     FIG. 2C is an expanded sectional view, similar to FIG. 2A showing a modified example of the elastic bearing portion 3. In this embodiment of the modification, the outer peripheral surface of the straight line portion 3b&#39; of the elastic bearing portion 3&#39; is fixed on the inner peripheral surface of the bayonet collar 1&#39;. The curved portion 3a&#39; is compressed radially outwardly by the outer peripheral surface of the cylinder portion 4&#39;. The curved portion 3a&#39; supplies the predetermined pressure produced by the restitutive force to the outer peripheral surface. 
     Although, the elastic bearing portion 3 comprises a single cylindrical rubber member which is fitted around the cylinder portion 4 in the preferred embodiment of this invention, the elastic bearing portion 3 may comprise a plurality of cylindrical rubber members. 
     The rigid bearing portion 2 securely supports the bayonet collar 1 to avoid an eccentricity of the bayonet collar 1 to the housing. The elastic bearing portion 3 is arranged apart from the rigid bearing portion 2 and supports the bayonet collar 1. The elastic bearing portion 3 presses the inner peripheral surface of the bayonet collar 1 and supplies the predetermined friction torque to the bayonet collar 1 when operated to be rotated. 
     The elastic bearing portion 3 is provided with a predetermined elasticity. Therefore, the elastic bearing portion 3 can effectively absorb the size differences between the bayonet collar 1 and cylinder portion 4 because of its elasticity. The elastic bearing portion 3 supplies the stable friction torque to the bayonet collar 1. Consequently, it becomes stable to connect or disconnect the scope portion 15 to or from the main body 14. Furthermore, there is the appropriate friction coefficient between the elastic bearing 3 and the bayonet collar 1, so that this structure depends on the load between the elastic bearing 3 and the bayonet collar 1 less than the conventional method of using the leaf spring. Therefore, there is no need to consider the abrasion of the rigid bearing portion 2, the elastic bearing portion 3 and the bayonet collar 1, respectively. 
     It is possible to provide an opposed connector (not shown) for the main body 14 for connecting with the connector 100 in order to have an electrical connection or disconnection between the main body 14 and the scope portion 15, at the same time with the connection or disconnection of the connector 100. In other words, when connecting the scope portion 15 with the main body 14 by using the connector 100, it is possible to dispose the opposed connector on the side of the main body 14 which engages with the connector 100, such that the connectors form mutual connections between signal lines, and between shield cases used for shielding electromagnetic radiation. 
     In this embodiment, a shell 5 is disposed around the terminals 7 as a shield case for shielding electromagnetic radiation and comprises connecting springs 9. 
     As illustrated in FIG. 4, when the connector on the side of the main body 14 is connected with the connector 100 on the side of the scope portion 15, a shield line is formed to extend from the main body 14 to a top end of the scope portion 15. 
     In this case, as illustrated in FIG. 4, a head driver 15b, a scope memory 15c, the terminals 7 are covered with an electromagnetic interference (EMI) shield 30 on the side of the scope portion 15 except CCD 15, and main body side terminals 40, a camera control unit 41 are covered with the EMI shield 30 on the side of the main body 14. The EMI shield 30 is earthed to the camera control unit 41. The camera control unit 41 is connected with an isolation trance 42 disposed outside the EMI shield 30. The numeral 43 designates the shield connecting point. 
     The camera control unit 41 is supplied with an electric power from the isolation trance 42 and produces a vertical synchronizing signal for driving a CCD 15a and a control signal used for a horizontal synchronizing to be sent to the head driver 15b. The head driver 15b receives a control signal from the camera control unit 41 and produces the vertical synchronizing signal to move the CCD 15a. The scope memory 15c stores characteristic informations of the scope, for instance, a scope ID, a color characteristic, a mask configuration and so forth. 
     The contact springs 9 compose the shield connecting point 43. A plurality of the connecting point springs 9 are arranged on the inner surface of the shell 5 and have predetermined spaces between one another. The contact springs 9 are fixed and electrically connected to the inner surface of the shell 5. 
     FIG. 5 is a side view of a water-proof cap 200 mounted on the connector 100 of FIG. 1. 
     As illustrated in FIG. 6, the water-proof cap 200 interfaces with the connector 100 and is capable of connecting with the main body 400. 
     That is, the water-proof cap 200 comprises a packing 16 which comes into close contact to the connector end (the end of the shell 5) of the housing and which is capable of cutting off and releasing the inner space of the housing. The housing is composed of the cylinder portion 4, the shell 5 and the insulation material 8. The waterproof cap 200 also comprises a spring 17 which enables the packing 16 to cut off and release by the variation of pressure forces energized by the cam mechanism of the rotating handle 1. The water-proof cap 200 further comprises a pair of guide pins 18 which engage each other with the cam of the bayonet collar 1. The water-proof cap 200 further yet comprises an armoring member 22 which is composed of members 19, 20, 21, the cylinder member 23 supporting the packing 16 and the spring 17, and other members. 
     FIG. 7 shows an example of the cam mechanism. On the inner surface of the bayonet collar 1, a pair of guide grooves 50 are formed for engaging with the guide pins 18, respectively. The guide grooves 50 are inclined in an axial direction with a predetermined angle and extend, for example, about one fourth of the inner periphery of the bayonet collar 1. Only one of the guide grooves 50 is shown in FIG. 7, the other guide groove 50 not shown in FIG. 7 is formed on the opposed surface of the inner periphery of the bayonet collar 1. 
     When the guide grooves 50 of the bayonet collar 1 is engaged the guide pins 18 on the water-proof cap 200 and the bayonet collar 1 is rotated, the guide pins 18 slide along the guide grooves 50. With a thrust forth produced by the operation mentioned above, the water-proof cap 200 and the main body 400 come into close contact each other. Consequently, the spring 17 presses the packing 16 against the end of the shell 5 to bring the packing 16 into close contact with the shell 5 each other. 
     Accordingly, it is accomplished by one rotating operation of the bayonet collar 1 to isolate an inner space of the housing from the outside. The cam process accompanied with the rotating operation is substantially shorter than the conventional screwing process. Therefore, it is possible to connect or disconnect the water-proof cap 200 to or from the main body 400 with an easier operation in a shorter time. 
     Referring to FIG.7, the reference numeral 500 designates the connector on the side of the main body 400, and 501 designates the guide pin. When the guide pin 501 engages the guide grooves 50 to rotate the bayonet collar 1, the connector 500 connects with the main body 400. In this case, it is possible to acquire the same operation and effect of water-proof cap mentioned above. 
     Furthermore, though the housing in the above embodiment is constructed with the cylinder portion 4, the shell 5, and the insulating material 8, the housing may be formed integrally with the same material.