Fiber optic cable connector and adaptor for optical laser transmitter system

The combination of an adaptor and a male connector are configured for screwing onto a female optical fiber connector consisting of electrically conductive material electrically connected to a sense node of a controller. A ground clip partially surrounds but is electrically isolated from the female connector. An adaptor consisting of an insulator ring having a first ring of electrically conductive material on a front face, a second ring of electrically conductive material on a back face, and a resistor mounted in a transverse groove of the insulator ring, with the resistor having its ends electrically connected between the first and second electrically conductive rings. The insulator includes a threaded centrally located hole for screwing onto the female connector, whereby the first ring is secured against the ground clip to ground the associated end of the resistor. A male connector having an electrically conductive housing is configured for carrying an optical fiber holder that plugs into a cylindrical cavity of the female connector when the male connector is screwed onto the female connector, with a front face of the male connector mechanically and electrically engaging the second ring to electrically connect the other end of the resistor to the female connector, whereby the controller responds by permitting activation of an associated laser transmitter to transmit laser light into an optical fiber carried by the optical fiber holder.

FIELD OF THE INVENTION

The present invention relates generally to optical transmitter systems, and more particularly to optical fiber connector configurations for such systems to permit a controller thereof to detect the presence of an acceptable fiber optic cable connected thereto, to initiate operation of the laser transmitter system to transmit laser light into an associated fiber optic cable.

BACKGROUND OF THE INVENTION

Optical laser transmitter systems, for reasons of safety, often include mechanisms for preventing operation of the system in the absence of a fiber optic cable being connected to the system, or in the event of an improper cable being connected to the system. In this manner, injury to operating personnel is substantially reduced, and the insurance of proper transmission of laser light from the system through an appropriate fiber optic cable for intended usage is enhanced.

SUMMARY OF THE INVENTION

An optical laser transmitter system includes a controller that has an electrical connection to an optical fiber female connector consisting of electrically conductive material. Ground clip means are electrically isolated from and surround the female connector for providing a connection to ground. A ring shaped adaptor consists of a centrally located insulator ring formed from electrically insulative material, and having a centrally located threaded hole for screwing the adaptor onto the female connector. First electrically conductive means secured to a front end or face of the insulator ring is tightened against the ground clip means by screwing the adaptor onto the female connector, for grounding one end of an electrical resistor electrically connected to the first electrically conductive means. The other end of the resistor is electrically connected to a second electrically conductive means secured to a back end or face of the insulator ring. When a male optical cable connector is screwed onto the female connector and tightened against the second electrically conductive means, third electrically conductive means are provided for electrically connecting the second electrically conductive means to the female connector, whereby the resistor is then electrically connected into a resistive voltage divider circuit of the controller. The controller includes means for sensing whether the resistor is of a predetermined value or within a range of values to permit operation of the optical laser transmitter system. If not, the controller will prevent activation or operation of the laser transmitter system. The male optical cable connector carries one end of an optical fiber cable, and further includes means therein for inserting an optical fiber carried by the cable into a cylindrical cavity of the female connector, in proper alignment therewith, for optimizing the transfer of a laser beam from the optical laser transmitter system to the optical fiber.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1A,1B, and2show relatively generalized embodiments of the invention. More specifically, optical laser transmitter system2includes in association therewith a controller4, and front panel assembly components which are shown in generalized form to include a printed circuit board8upon which are mounted within an opening11a female optical fiber connector6, and a ground clip10in this example. The ground clip10is generally U-shaped, electrically isolated from the connector6, and mounted at an angle with the latter, as shown in this example. The female optic fiber connector6consists of electrically conductive material, typically any suitable metal material, that includes threads3on its outer circumference. A ring configured adaptor12includes a centrally located electrically nonconductive insulator ring17sandwiched between a pair of opposing electrically conductive brass rings14and16, in this example and embodiment. A resistor chip13is electrically connected between the brass rings14and16, with the resistor chip13being held within a recessed channel in an edge or circumferential portion of the insulator ring17, as shown.

In another embodiment, brass ring16is replaced by a spring biased electrically conductive switch plate or ring138, spaced apart from a centrally located threaded nickel plated brass ring131as described below relative toFIGS. 8A through 8J, in the preferred embodiment. As shown inFIG. 1A, a male fiber optic connector18includes a cylindrical housing or shell19including a centrally located through hole or cylindrical cavity23having a threaded front portion25, with the remainder being unthreaded. Cylindrical cavity23is configured also for receiving ferrule20that includes a reduced diameter front portion providing an optical fiber holder21, and an enlarged cylindrical rear portion providing an optical fiber cable holder22for receiving an optical fiber cable24carrying or enclosing an optical fiber (not shown). During assembly, the optical fiber cable24has an outer sheathing cut back to provide for a front portion of the optical fiber to reside within the cylindrical cavity23of the optical fiber holder21of the ferrule20. The front of the fiber holder21includes a centrally located small through hole for passing laser light from the optical laser transmitter system2into the optical fiber (not shown). Centrally located threads26of the adaptor12provide for screwing it on to the female connector3for securing the brass ring14against the ground clip10to insure good electrical connection therebetween, thereby grounding one end of resistor chip13. Next, the male connector18is screwed onto the female connector3securely against the brass ring or washer16(or the switch plate or ring138, not shown) for causing the other end of resistor13to be electrically connected through the electrically conductive material of the female connector6to a sensing node7for completing a resistive voltage divider contained within controller4. More specifically, inFIG. 1B, the resistive voltage divider includes a resistor15connected between a source of DC voltage +VPto the sensing node7, and further with the resistor chip13being connected between the sensing node7and ground, as previously described. The controller4includes means (not shown) for sensing the value of voltage at node7, +VS. If the sensed voltage +VSis in a predetermined voltage range, this confirms that the optical fiber of the interconnected optical fiber cable24is an acceptable fiber and that proper connection has been made to the laser transmitter system2. Accordingly, sensing circuit means (now shown) of controller4permits activation of the optical laser transmitter system2for transmitting a laser lightbeam into optical fiber (not shown) of optical fiber cable24. Note that typically the other end of the fiber optic cable24is connected to a laser probe (not shown), that may be of a design for use in ophthalmic surgery, for example. However, the invention is not limited to such use. Note that this embodiment, and other embodiments of the invention to be described, can, for example, be used for connecting an ophthalmic laser probe to a laser transmitter system as shown and described in U.S. Pat. No. 5,085,492, issued on Feb. 4, 1992. However, as previously indicated, the various embodiments of the present invention are not limited to such use. Note further that when the various embodiments of the present invention are used in association with the laser transmitter device as taught in the aforementioned patent, the optical fiber (not shown) of the fiber optic cable24typically has an outside diameter ranging from 0.003 inch to 0.010 inch, and the value of resistor chip13in this example typically is 6,190 ohms. However, the invention is not limited to this resistance value.

A male connector48assembly for a more specific first embodiment of the invention is shown inFIGS. 3A to 3E. As shown, this male connector assembly includes an optical fiber holder28consisting of a suitable metallic material for receiving a fiber optic cable24in a first portion32, and optical fiber from the latter in a second portion30, as shown. The second portion32includes a cutout slit34proximate its front end for receiving a retainer tube36that is crimped onto the second portion32of the optical fiber holder28to retain the cable24therein. In this embodiment, the connector shell38consists of a single piece of electrically conductive material, such as aluminum, or stainless steel. The shell38includes a cavity40for retaining a spring42, with the spring also being mounted over the second portion32of the optical fiber holder28. The shell38also includes a centrally located back through hole44, and a centrally located threaded front through hole46, as shown. As will be described in greater detail below, the assembled connector for this embodiment with the optical cable24secured within the first portion30of optical fiber holder28. The spring42insures proper alignment of portion30of fiber holder28within a centrally located through hole9of the female connector6. Note that the optical fiber holder28and retainer tube36in another embodiment of the invention can be provided via a single piece of appropriate material. This completes the assembled connector48for a first embodiment of the invention.

Assembly of the male connector48will now be described with reference toFIG. 3A. First, the spring42is installed by pushing it through hole46into cavity40of connector shell38. Next, an end portion of optical fiber cable24is stripped of its outer covering to expose a desired length of an optical fiber (not shown) and pushed through the back through hole44and front hole46. The exposed optical fiber and a portion of the optical fiber cable24are pushed through the retainer tube36. The optical fiber is then pushed into a hole in the center of the first portion30of optical fiber holder28, with a substantial portion of the unstripped optical fiber cable24positioned in the second portion32optical fiber holder28. The end of the optical fiber is also pushed out of a central hole through the end of the front portion30of optical fiber holder28. The retainer tube36is then pushed with cable24onto the second portion32of optical fiber holder28, and tube36is crimped to retain the optical fiber and associated optical cable24in the optical fiber holder28. Excess optical fiber protruding from the face of optical fiber holder is cut off, and the face is lapped to obtain a desired finish to the end of the optical fiber. Note that the assembly sequence for other male connector embodiments is substantially similar.

Also included for this first embodiment of the invention is an adaptor50shown inFIGS. 4A through 4D. As shown, electrically nonconductive insulator ring17includes reduced diameter outwardly protruding step portions52on its front and back surfaces, for receiving and centering the brass rings14,16, respectively, in this example. An appropriate adhesive can be utilized for rigidly securing the brass rings14,16to the insulator17, which can be made of any suitable plastic or polymer material such as Delrin®, Teflon®, ABS polycarbonate, nylon, and so forth. Also, although brass is considered a preferred material for the rings14and16, other materials can be used such as beryllium copper, gold, silver, and so forth, provided that the material is electrically conductive. Each of the brass rings14and16include small slots cut into a portion of the circumference thereof, for receiving the ends of a resistor chip13therebetween. Note that the brass rings14and16are identical, in this example. Also, the plastic ring17includes a small open transverse groove or slot56for receiving a portion of the resistor chip13. In this example, the resistor13is installed into slot56. Ends of the resistor chip13are respectively in electrical contact with and soldered to the brass rings14and16, within slots54, respectively. The plastic ring17further includes a centrally located threaded through hole58, and two axially spaced apart relatively small diameter holes60, for receiving a tool to be described below, for facilitating mounting of the adaptor50onto the optical fiber female connector6of the optical laser transmitter system2.

A tool62for facilitating the installation of the adaptor50to the female connector6, and other adaptors of various embodiments of the invention described below, is shown inFIGS. 10A-10C. As shown, the tool62consists of a single piece of plastic material, such as Delrin®, or a suitable metal material, such as aluminum, or stainless steel, for example. The tool62includes at one end an outwardly projecting U-shaped portion64having two spaced apart circular fingers66dimensioned for fitting into the holes60of the adaptor50, in this example. The tool62further includes a circular handle68, as shown.

Operation of the first embodiment of the invention will now be described. The adaptor50is first screwed onto the female connector6, preferably through use of the tool62, or otherwise screwed on, to mechanically secure the brass ring14tightly against the ground clip10, thereby insuring electrical contact therebetween. Next, the connector48is installed in the female connector6by first pushing the first portion30of fiber holder28into the hole9of female connector6, and then screwing the threaded hole portion46onto the female connector6. Also, the connector48must be screwed on to insure that the front face of the connector shell38is tightly against the brass ring16of adaptor50, for insuring good electrical conductivity therebetween. In this manner, an electrical circuit is established from the sense node7of controller4, through female connector6, through brass ring16, through resistor13, through brass ring14, and through clip10to ground, thereby effective installing resistor chip13into the resistive voltage divider circuit ofFIG. 1B, as previously described. Also as previously described, the result is that the optical laser transmitter system2is enabled to be selectively energized for transmitting laser beam into an optical fiber carried by the optical fiber cable24.

A second embodiment of the invention includes a connector70as shown inFIGS. 5A through 5D. The connector70includes a housing or connector shell72, which in the preferred embodiment consists of a single piece of plastic material, such as Delrin, or any other suitable plastic material including Teflon®, ABS polycarbonate, nylon, and so forth. Connector housing or shell72includes a back portion74having a relatively enlarged diameter, followed by a major housing portion76of relatively smaller diameter, as shown. The back portion74includes a centrally located through hole78terminating into a relatively larger inside diameter circular cavity80for retaining therein a spring79consisting of suitable electrically conductive material, and the optical fiber holder28with retainer tube36. Note that the second portion32, and centrally located enlarged outside diameter portion33are contained within the circular cavity80, with the second portion32within spring79. Note further that sufficient mechanical contact is maintained between the optical fiber holder28and the spring79to insure an electrically conductive circuit path is being established therebetween. The housing72further has its circular cavity80terminating into a relatively enlarged circular diameter front end cavity82. Permanent magnet84has an outside diameter dimensioned to insure that it can be pressed fitted into the front end cavity82of housing72. Alternatively, or in addition, the magnet84can be adhesively secured or glued into the circular cavity82.

Assembly of connector70will now be described. An electrically conductive bare wire86has one end attached to the spring79by soldering or welding in a manner insuring electrical contact or conductivity therebetween. The spring79is then installed into cavity80of housing72. Before installation of the magnet84into the housing72, a free portion of the wire86is threaded out of the front77of the housing72, followed by installation of magnet84. Next, excess wire is cut flush with magnet84at the front end77of the housing72. The optical fiber holder28is then installed in the housing72, using a similar process as described above for male connector48. The wire86provides an electrical connection from optical fiber holder28, to spring79, to wire86, through to magnet84. The magnet84includes a centrally located through hole88, as shown in phantom inFIG. 5A. The first portion30of the optical fiber holder28protrudes out of the housing72. Also, optical fiber retaining portion30of optical fiber holder28protrudes through and out of the central hole88of magnet84by a sufficient length to permit it to be installed into the through hole9of female connector6, as will be described further below. Note further that the housing72includes a circular reduced diameter step down portion90around through hole78on the back face92.

An adaptor96for the second embodiment of the invention is shown inFIGS. 6A through 6G. As shown inFIG. 6A, an exploded assembly view, the insulated ring98preferably consisting of a single piece of plastic material as previously described for insulative ring17, but has a different mechanical configuration from the latter. More specifically, the electrically insulative ring98includes a centrally located portion100of relatively large diameter, a centrally located circular mounting stud102of substantially smaller outside diameter than central portion100, and on the opposite face of the central portion100a circular step-down portion104of slightly reduced outside diameter relative to central portion100, as shown. An electrically conductive ring103is preferably made of brass material, but as previously described for similar components above, can otherwise consist of any suitable electrically conductive metal material. The brass ring103, in this example, includes a centrally located open area10S as shown inFIG. 6C, having a diameter dimensioned to permit the ring to be press fit onto portion104of insulator washer98. The brass ring103can otherwise be adhesively secured or glued onto the insulator ring98. A ring106consisting of a ferromagnetic material such as iron, 400 series stainless steel, or any other suitable ferromagnetic material, includes a centrally located hole108for mounting upon the circular protrusion or mounting stud102of insulator ring98, and the two are adhesively or glued together. Note that a centrally located hole109is provided through insulative ring98, that is completely through its mounting stud102, central portion100, and ring mount step104, respectively. Note that the hole109through insulative ring98is threaded to provide for screw on mounting onto the female connector6.

Operation of the second embodiment of the invention will now be described. First, the adaptor96is screwed onto the female connector6to insure that brass ring103is mechanically secured against the ground clip10for insuring a low resistance electrical contact therebetween. Next, the connector70is pushed onto the female connector6the first portion30of the optical fiber holder28being inserted into the central hole9of connector6. Connector assembly70is then further pushed onto female connector6for insuring that its permanent magnet84is magnetically attached to the face of the ferromagnetic ring106of adaptor96. Also, it is important to note that spring79serves to insure that the optical fiber holder28is extended the greatest amount possible from the front portion77of housing72to insure necessary centering and penetration of the fiber holding first portion30of fiber holder28into the central hole9of the female connector6. As with previously described embodiments, this insures efficient transfer of laser light from the laser transmitter system2into the optical fiber (not shown). After the aforesaid installation of the adaptor96and the connector70onto the female connector6, an electrical circuit path is provided from the sense node7through female electrical connector6, through the optical fiber holder28, through spring79, through wire86, through magnet84, through ferromagnetic ring106, through resistor13, through brass ring103, and through grounding clip10to ground. The aforesaid form a series electrical circuit path for inserting resistor chip13into the sensing circuit ofFIG. 1B. As a result, as previously described, provided that resistor13has a predetermined acceptable, resistance value, optical laser transmittal system2can then be energized.

A connector for a third embodiment of the invention is shown inFIGS. 7A through 7C. An elongated housing or shell116consists of any suitable plastic material, as previously described for other embodiments of the invention. The front portion of the housing116includes a circular cavity118for containing a spring120mounted over retainer tube36crimped onto portion32of optical fiber holder28. Housing116is provided in two sections, a front or first section117, and a back or second section119, for ease of assembling connector115, as will be described below. The first section117includes the circular cavity118that has a centrally located threaded through hole122opening from front face113. The first section117also includes a reduced diameter extension121that terminates to a chamfered locking collar123, for snapping into an interior circular locking groove129in the second section119. When so joined, an antirotation tab125of section117is pushed into slot127of section119. A hole135of the second section119is receptive of extension121and locking collar123. As previously described, fiber optic cable24is securely retained within portion32of optical fiber holder28via the crimped on retainer tube36, using a process similar to that for connector48(see above), except that the second section119is first pushed onto optical fiber cable24. Next, the optical fiber cable24is pushed through the first section117as indicated, the optical fiber and cable24portion are secured in the optical fiber holder28as previously indicated. This step is followed by joining the first section117to the second section119to provide completed housing116with assembled connector115. An optic fiber end portion (not shown) from optical cable24is enclosed within a central hole (not shown) of portion30of optical fiber holder28, as previously described. The second section119also includes a hollow elongated circular cavity portion124that follows from the locking groove129, as shown. A portion of the optical fiber cable24extending from optical fiber holder28is enclosed within elongated portion124. Note that the elongated second section119is provided in the preferred embodiment to assist a user in screwing the connector115onto the female connector6. However, in a less preferred embodiment, the housing116can be made substantially shorter than shown.

An adaptor128for the third embodiment of the invention is shown inFIGS. 8A through 81. As shown in the exploded assembly view ofFIG. 8A, the third embodiment adaptor128includes an electrically insulative washer or ring130consisting of a single piece of suitable plastic material, as previously described for other embodiments. A reduced diameter step down portion132relative to the main larger diameter portion134is dimensioned for centering, and receiving, preferably for press fit of a brass ring136. An appropriate adhesive can also be used to rigidly secure ring136onto insulator ring130. A small slot144is provided in the circumferential edge portions of insulator130, for receiving a portion of resistor13. A cutout or edge slot146is included in brass ring136for receiving one end of resistor13. A relative small diameter brass ring131, in this example, is rigidly press fitted into a hole135of insulator130. A centrally located threaded hole142is included through ring131for screwing the adaptor128onto female connector6. A switch plate or ring138consisting of electrically conductive material, preferably spring steel, is included in the configuration as shown inFIGS. 8A,8D,8F,8H, and8I, respectively. A spring tab140is provided on the semicircular bat-like configured switch plate or ring138, as shown. The switch plate or ring138is rigidly secured via an appropriate adhesive to a back face133of insulator ring130, as shown. The switch plate138includes a cutout or edge slot or notch139for receiving the other end of resistor13.

Operation of the third embodiment of the invention will now be described. First, the adaptor128for the third embodiment of the invention is screwed via threaded hole142of ring131onto the female connector6with the switch plate or ring138facing outward. It must be insured that the brass ring136is screwed tightly against the ground clip10. Next, the connector115is screwed onto the female connector6via its threaded hole122, in a manner insuring that the first portion30of the optical fiber holder28first goes into the through hole9of female connector6. Connector115must be screwed on in a manner forcing the front face113thereof against a tab140of switch plate or ring138, forcing the tab140into mechanical and electrical contact with the conductive ring131in insulator ring130. In this manner, a series electrical circuit is established between the sensing node7of the sensing circuit ofFIG. 1B, female connector6, electrically conductive ring131, switch plate or ring138, resistor13, brass ring132, and ground clip10to ground. Once this series circuit is established, the optical laser transmitter system2can then be energized as previously described, provided resistor13has a resistance value within an acceptable range.

An alternative embodiment for a connector assembly for use with the second embodiment adaptor96(FIGS. 6A-6G), as previously described, is shown inFIGS. 9A through 9G. More specifically, this embodiment includes a permanent magnet84for installation into an alternative housing or connector shell152that differs from the connector shell72of the second embodiment connector70(FIGS. 5A-5D). Cavity154extends completely through to the front end of housing152. A circular channel155is cut into the front end of the housing152, as shown, for receiving the permanent magnet84, thereby providing better securement of the magnet via the circular channel155and inner circular wall157. The circular channel also includes an outer wall159. Cavity154is configured for receiving the spring120, and an optical fiber holder28installed thereon to retain the optical fiber cable24, as previously described for the connector70. As shown inFIGS. 9E and 9F, the housing153, in a preferred embodiment, relative to housing152, further includes a pair of wire slots158. An exploded assembly view is shown inFIGS. 9E and 9Ffor the alternative preferred connection embodiment160. The assembly sequence for connector150(seeFIG. 9E) is similar to the assembly of connectors48and70as given above, except that the wire86is positioned within a wire slot158before installing magnet84.

A tool62for facilitating the installation of adaptor50(seeFIGS. 4B and 4D) is shown inFIGS. 10A through 10C. Tool62includes spaced apart circular prongs or fingers66dimensioned to fit into tool holes60of adaptor50, to permit a user to screw adaptor50onto the female connector6by turning tool handle68. Also, tool62can be similarly used to remove adaptor50from female connector6. The fingers66of tool62are part of a U-shaped end member64, as shown. Note that holes60can also be provided in adaptors96and128in their back faces for permitting use of tool62to similarly facilitate installing these adaptors on female connector6.

Although various embodiments of the invention have been shown and described, they are not meant to be limiting. Those of skill in the art may recognize certain modifications to these embodiments, which modifications are meant to be covered by the spirit and scope of the appended claim. For example, if at least the first section117of housing116consists of suitable electrically conductive material, housing116can be substituted for housing or shell38of the first embodiment of the invention. Also, although preferred materials are indicated for various components of the invention, such materials are not meant to be limiting, and other suitable materials can be substituted.