Surgery – Endoscope – Having imaging and illumination means
Reexamination Certificate
1999-11-23
2001-12-11
Dvorak, Linda C. M. (Department: 3739)
Surgery
Endoscope
Having imaging and illumination means
C600S133000
Reexamination Certificate
active
06328691
ABSTRACT:
TECHNICAL FIELD
This invention refers to an endoscope wherein a distal end window has at least one surface provided with a solderable layer.
This invention refers to an endoscope with the features given in the preamble of claim
1
.
BACKGROUND ART
Endoscopes of the present type are generally known with both rigid and flexible designs and are used not only for examining cavities, for instance in motors and turbines, but also in medicine for diagnostic or therapeutic purposes. Since endoscopes in operation are frequently used in cavities filled with often aggressive fluids or in cavities with high humidity, it is necessary for the distal end window to close the outer tube, in which the endoscope's optical system is disposed, in a fluid- and gas-tight manner.
Stringent demands are made on this fluid-and gas-tight juncture of the end window to the outer tube, since the outer tube with the end window can not only be located in aggressive media, but it can also be exposed to high temperatures. Especially in the case of medical endoscopes the connection of the end window to the outer tube is subjected to severe stress by being placed in a sterilizing solution and/or by being sterilized by hot steam at approximately 140° C. in an autoclave. The proximal eyepiece window undergoes the same hard treatment as the distal end window during the sterilization procedure.
In most known endoscopes the end windows are glued into the outer tube or the eyepiece cup. However, experience has shown that adhesions age and become leaky particularly when exposed to fluctuating temperatures and additionally to aggressive media. After a certain operating time moisture and/or fluids can penetrate into the endoscope.
For this reason, a proposal according to DE 37 40 417 A1 is to mount a metallic film on the peripheral surface of the distal end window and to solder this metallic film to the outer tube, which generally consists of a noncorrosive metal.
A so-called “close-joint soldering” is required for this. However, it is very difficult to check for faults, etc. in the soldering layer created in a close-joint soldering process. For this reason, in serial production it is possible to overlook faults in the joint, the result of this being that after a certain time the end window of the endoscope no longer has a fluid-tight seal.
DISCLOSURE OF THE INVENTION
The object of the invention is to further develop an endoscope of the type described above in such a manner that the end window or windows is/are securely joined to the outer tube or the eyepiece cup so as to be fluid tight, in a manner which can be easily checked.
According to the invention the distal end window and/or the eyepiece are glued in a manner known per se by their rim into the outer tube, the eyepiece cup or an adapter set into the outer tube or eyepiece cup. In addition, a ring-shaped layer suitable for soldering is applied to at least one end surface of the window or windows, preferably to the end surface facing the interior, for additionally joining the window to the outer tube, the eyepiece cup, or the adapter by means of a solder layer.
Thus, two joints independent of one another are provided in accordance with the invention, so that even if one of the connections is damaged or improperly produced, the endoscope stays fluid and gas tight regardless of extreme operating conditions.
Furthermore, the chemical resistance is increased over that of known endoscopes.
The gap gluing provided here in a manner that is known per se is relatively simple to carry out and to check as compared to a close-joint soldering process. Contrary to the close-joint soldering proposed in DE 37 40 417 A1, the additional, soldered joint is provided on an outer surface. For this reason, not only is it easily produced, but the resulting soldered joint can also be visually checked in a simple and reliable manner.
To create the disclosed connection, the soldered joint is preferably produced first. The gap gluing follows. If soldered joints are provided on both end surfaces, the soldered joint on the proximal end surface, i.e. the one facing the interior, is preferably produced first. Then the gluing and subsequently the soldering on the distal end surface are carried out. With this procedure the individual connections can easily be checked visually.
At any rate, the joint according to the invention has the advantage that the end window can be thinner than in the prior art without detracting from the quality of the connection between the end window and the outer tube.
By the use of two different connecting techniques the transfer of forces is more favorable than with only one connecting technique, particularly where thermally induced stresses are involved.
If an adapter is used, it can be connected or attached to the outer tube and/or the eyepiece cup in a variety of manners. Aside from the use of known connecting techniques, it is especially possible to attach the adapter in the outer tube or the eyepiece cup in accordance with the invention in the same manner in which the window is attached.
The connection according to the invention is suitable for endoscopes in any field of use and for any angle of vision.
The solderable layer applied to a surface of the end window is preferably a metallic layer which is applied by vacuum metallization or deposited electrolytically or by immersion. The soldered joint is preferably formed from a hard solder.
The melting temperature of the solder used and the softening temperature of the glue can be selected depending on the field of use of the endoscope. In the case of medical endoscopes to be sterilized by autoclaving, these selected temperatures must of course be high enough that the connecting layers are not damaged by the temperatures used in the sterilization process.
This condition is met, for example, if a solder that melts at a temperature substantially above the autoclaving temperature (approx. 140° C.) and a UV-hardenable glue are used.
The distal end window can consist in a known manner of quartz glass, BK 7, or a sapphire material, for example.
The disclosed procedure of applying the solder layer not to the peripheral surface as in the prior art, but rather to one or both end surfaces, has the added advantage that the ring-shaped layer produced can simultaneously serve as an aperture diaphragm or as a scattered-light diaphragm of the endoscope objective.
REFERENCES:
patent: 4779613 (1988-10-01), Hashiguchi et al.
patent: 4916534 (1990-04-01), Takahashi et al.
patent: 5188092 (1993-02-01), White
patent: 5536244 (1996-07-01), Muller et al.
patent: 5599278 (1997-02-01), Hibbard
patent: 5842972 (1998-12-01), Wulfsberg
patent: 3740417 A1 (1989-06-01), None
patent: WO 95/24857 (1995-09-01), None
Dvorak Linda C. M.
Karl Storz GmbH & Co. KG
Ram Jocelyn
St.Onge Steward Johnston & Reens LLC
LandOfFree
Endoscope with at least one glued and additionally welded... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Endoscope with at least one glued and additionally welded..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Endoscope with at least one glued and additionally welded... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2579941