Video endoscope

Abstract

A video endoscope including an elongated shaft, a main body, a cable for conducting control signals, video signals and/or illumination light, wherein the cable includes: a core having an optical fiber bundle, a video signal line, and/or a control signal line; a mechanical protective layer; and a sheath tube; a junction body sealingly inserted into the main body on to sealingly receive the sheath tube; an anti-kink sleeve disposed around the sheath tube to engage over the junction body, a clamping ring supported on the junction body pulled towards the main body by a first clamping nut presses the junction body against a round cord seal between the junction body and the main body and presses the anti-kink sleeve against the junction body such to seal a cavity between the anti-kink sleeve and the junction body.

Claims

1. A video endoscope comprising: an elongated shaft, a main body disposed proximally of the shaft, a cable fixedly connected to the main body at a junction between a main body side of the main body and a cable side of the cable, the cable being configured to transmit one or more of control signals, video signals and illumination light to and/or from the main body, wherein the cable comprises: a core comprising one or more of: at least one optical fiber bundle configured to transmit the illumination light to and/or from the main body, at least one video signal line configured to transmit the video signals to and/or from the main body, and at least one control signal line configured to transmit the control signals to and/or from the main body; a mechanical protective layer surrounding the core; and a sheath tube surrounding the protective layer; a junction body disposed at the main body on the main body side of the junction and disposed at the sheath tube on the cable side of the junction such that the junction body is sealed relative to both the sheath tube and the main body; a round cord seal disposed between the junction body and the main body; an anti-kink sleeve disposed around the sheath tube in a region of the junction, the anti-kink sleeve being configured to engage over the junction body; and a clamping ring supported on the junction body; a clamping nut configured to pull the clamping ring in a direction of the main body to press the junction body against the round cord seal disposed between the junction body and the main body and the clamping nut being further configured to press the anti-kink sleeve against the junction body such that a cavity formed between the anti-kink sleeve and the junction body is sealed off from an interior of the main body and from an outside environment.

2. The video endoscope according to claim 1, wherein the main body comprises an external thread on the cable side, the first clamping nut having an internal thread configured to matingly engage with the external thread.

3. The video endoscope according to claim 1, wherein a material of each of the first clamping nut, the clamping ring and the anti-kink sleeve is such that a friction coefficient of a material pairing of the first clamping nut with the clamping ring is lower than a friction coefficient of a material pairing of the clamping ring with the anti-kink sleeve.

4. The video endoscope according to claim 1, wherein the clamping ring and the first clamping nut have complementary radial stop surfaces.

5. The video endoscope according to claim 1, wherein: the junction body comprises a first partial body and a second partial body, the first partial body being configured to seal relative to the sheath tube, and the second partial body is configured to press against the round cord seal.

6. The video endoscope according to claim 5, wherein a largest outer diameter of the first partial body is smaller than a smallest inner diameter of the main body.

7. The video endoscope according to claim 6, wherein the main body is disposed over the first partial body, and the round cord seal is disposed between the main body and the first partial body such that the round cord seal seals the main body relative to the first partial body by the compressive force of the second partial body.

8. The video endoscope according to claim 5, wherein the first partial body and the second partial body having first and second mating threads, respectively, to fix the first partial body to the second partial body.

9. The video endoscope according to claim 5, wherein the first partial body comprises a second clamping nut configured to compress an elastic sealing element disposed between the first partial body and the sheath tube.

10. The video endoscope according to claim 9, wherein the clamping ring is configured to press the anti-kink sleeve against the second clamping nut.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The embodiments are explained in more detail below with reference to a number of exemplary drawings, the embodiments shown being intended solely to provide a better understanding of the invention without limiting it, in which:

(2) FIG. 1 illustrates a video endoscope,

(3) FIG. 2 illustrates a cable,

(4) FIG. 3 illustrates the cable connection of a video endoscope.

DETAILED DESCRIPTION

(5) FIG. 1 shows a video endoscope 1 with a main body 2 and an elongated shaft 3. In the distal portion of the shaft 3 an objective lens 4 and an electronic image converter not shown are disposed. The shaft 3 is closed at the distal end by a window 5.

(6) A supply and signal cable 6 is used to connect the video endoscope 1 to a light source not shown and to a control unit also not shown. Finger switches 7, 8 are provided on the main body 2 of the video endoscope 1, by which the video endoscope 1 and, if necessary, the light source and/or the control unit may be controlled.

(7) FIG. 2 shows the structure of the cable 6 in cross-section. The cable 6 comprises a core, which includes an optical fiber bundle 10, video signal lines 11, 12, and a signal line 13.

(8) The optical fiber bundle 10 is coated with a special protective sleeve 15 to protect the sensitive fibers.

(9) The video signal line 11 is configured as a coaxial cable with an inner conductor 16, a dielectric 17, an outer conductor 18, and a sheath 19. The structure of the video signal line 12 is similar to video signal line 11. The two video signal lines 11, 12 enable transmission of a stereo video signal when the video endoscope 1 is configured as a stereo video endoscope. The cable 6 may also comprise only a single video signal line.

(10) In the example shown, the signal line 13 comprises three individually insulated cores 13a, 13b, 13c within a common sheath. The signal line may be used, for example, to transmit the signals from the finger switches 7, 8.

(11) The core of the cable 6 is enclosed by a mechanical protective layer 20, which may be a steel helix, for example. The protective layer 20 is surrounded by a sheath tube 21, which also provides insulation for the cable 6.

(12) An elastic membrane 22 may be provided on the inside of the protective layer 20 to protect against damage to the core of the cable 6 by the edges of the steel helix.

(13) The arrangement of the components of the core of the cable 6 is shown with greatly enlarged spaces to allow a better view. In fact, the optical fiber bundle 10 and the individual lines 11, 12, 13 are arranged close together in the core of the cable 6 to minimize the cross-section of the cable 6.

(14) FIG. 3 shows the cable connection of a video endoscope in longitudinal section. The cable 6 is shown on the right side, wherein for clarity only the mechanical protective layer 20 and the sheath tube 21 are shown. The core of the cable 6 is not shown. On the right side, the main body 2 is shown.

(15) Between the main body 2 and the cable 6 a junction body 25 is shown, which consists of a first partial body 26 and a second partial body 27.

(16) The first partial body 26 has a tubular extension 30 on the cable side, which engages over the endoscope side end of the cable 6. An elastic sealing element 31 is disposed between the extension 30 and the cable 6, which is axially tensioned by a clamping nut 32 screwed onto the extension 30. The sealing element 31 expands radially and thus forms a seal between the sheath tube 21 and the extension 30.

(17) To improve the effectiveness of the sealing element 31, the sheath tube may be supported from the inside at its end on the endoscope side by a sleeve not shown. The sleeve may be arranged between the protective layer 20 and the sheath tube 21 or within the protective layer 20.

(18) The cable connection further comprises an anti-kink sleeve 35 which fits tightly on the sheath tube 21 and engages over the extension 30 of the junction body 25.

(19) For sealing the junction body 25 against the main body 2, a round cord seal 40 is provided, which contacts a support ring 41 on the endoscope side and the main body 2 on the outside. The support ring 41 serves to provide a sufficiently large contact surface for the round cord seal 40.

(20) On the inside, the round cord seal 40 contacts the first partial body 26 of the junction body 25, and on the cable side, the second partial body 27 of the junction body 25 contacts the round cord seal 40.

(21) On the cable side, the second partial body 26 has a radial stop surface 42 which is in contact with a clamping ring 45. The clamping ring 45 is screwed onto the main body 2 with a clamping nut 46. For this purpose, the main body 2 comprises an external thread which is not shown.

(22) The clamping nut 46 and the clamping ring 45 have complementary radial stop surfaces 47, 48.

(23) By tightening the clamping nut 46, the clamping ring 45 is pulled in the direction of the main body 2. In the process, the second partial body 27 presses against the round cord seal 40 so that the latter expands radially and, in the process, sealingly contacts the first partial body 26 and the main body 2. This reliably protects the inside of the main body 2 against the intrusion of moisture from the outside.

(24) At the same time, the cable-side end of the clamping ring 45 presses against the anti-kink sleeve 35 so that it is pulled tightly against the first partial body 26 or against the clamping nut 32. As a result, the cavity 36 is reliably sealed against the intrusion of soiling or germs from the outside.

(25) In order to prevent twisting of the clamping ring 45 when the clamping nut 46 is tightened, the materials of the clamping ring 45, the clamping nut 46 and the anti-kink sleeve 35 are selected such that a friction coefficient of the material pairing of the clamping nut 46 and the clamping ring 45 is significantly lower than a friction coefficient of the material pairing of the clamping ring and the anti-kink sleeve 35. This ensures that the clamping nut 46 slides on the clamping ring 45 so that the latter is only pulled in the axial direction towards the main body 2.

(26) The clamping nut 46 may be made of a thermoplastic material such as PEEK, while the clamping ring 45 itself may be made of metal, for example medical grade stainless steel. The anti-kink sleeve 35 may be made of silicone, for example.

(27) The surface of the clamping ring 45 may be visually and haptically adapted to the needs of a user by having a coating. For example, a coating with tin nitrate can be used to achieve a surface that is resistant to chemicals.

(28) On the cable side, the clamping nut 46 and the clamping ring 45 comprise a conical outer contour. The inner surface of the clamping nut 46 contacts an outer surface of the clamping ring 45 without any gaps as far as possible. The above-mentioned materials make it possible to manufacture the components with correspondingly close tolerances at reasonable cost.

(29) If the interior of the main body 2 needs to be accessed for maintenance or repair purposes, the described cable connection may be easily disassembled. To do this, the clamping nut 46 is loosened and slid to the right over the cable 6. Then the clamping ring can also be slid to the right over the cable 6.

(30) Next, the second partial body 27 is loosened from the first partial body 26 and also pushed to the right over the cable 6. Then the main body 2 itself with the support ring 41 and the round cord seal 41 may be slid over the cable 6 to expose the components to be serviced.

(31) After disassembly of the cable connection, the elastic round cord seal 41 may have to be replaced. To do this, the old round cord seal 41 can be cut to remove it. The new round cord seal, when internal connections of the lines 11, 12, 13 running in the cable 6 and of the optical fiber bundle 10 have been loosened, can be easily slipped over the corresponding connectors and over the first partial body 26. Then, the round cord seal must be passed internally through the support ring 41. After the maintenance has been completed, the cable connection is assembled in reverse order.

(32) While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.