fig1 shows the interrelationship between detachable chuck 10 and an interfacing handle 11 . the portion of handle 11 pertinent to the replaceable chuck is shown , the remaining detail and interrelationships of the elements in handle 11 being otherwise immaterial to this invention . however , the apparatus contained within housing 11 is described in considerably greater detail in copending application entitled improved electro - surgical instrument by esty and taylor . as described in that application , the body of interfacing instrument 11 is substantially flat so as to provide the general feel of a passive surgical instrument but can include switching apparatus for selecting electro - surgical procedures as desired . an extension probe 12 at one end of body 11 has reduced dimensions and is adapted to be inserted into a complementary socket or recess in the end of chuck 10 so that the total assembly has continuous substantially flat passive instrument - like dimensions . chuck 10 includes two transversely extending , upper and lower external grooves 13 and 14 on opposite surfaces thereof . grooves 13 and 14 are relatively shallow to enhance gripping of the chuck 10 for attachment or removal from probe 12 of handle 11 . chuck 10 of fig1 is shown by way of example as retaining a needle point electro - surgical electrode 15 . however , it will be readily recognized that a detachable electro - surgical electrode chuck in accordance with the present invention can include any of the wide variety of surgically useful exposed portions . for instance , fig2 a shows a knife blade or scalpel type of electrode 16 which is retained within a replaceable chuck housing 17 . thus the blade 16 can be used for some passive surgical procedures although its primary utility is for electro - surgical functions . further , fig2 b shows a ball 18 retained within chuck 19 such as might be particularly useful for selected cauterizing operations or the like . fig2 b also illustrates a potential modification of the grip enhancing transverse grooves in the form of serrated grooves 13a and 14a . fig2 c illustrates a closed loop wire arrangement 20 retained within chuck 21 . as is well known , high frequency or rf electro - surgical signals introduced to a loop configuration can be used for surgically cutting tissue . the aforementioned examples of exposed electrode configurations for electro - surgical applications are all so - called unipolar in that the electrical circuit is actually completed by an electrical circuit return path attachment to the patient so that a single conductor passes through the chuck housing . however , it will be readily recognized that the present invention is not restricted to a single electro - surgical electrode but can support a multiplicity of such electrodes . for instance , bipolar contacts wherein a pair of electrodes are passed through the chuck housing and into a pair of receiving connectors in the housing frame of the handle can also be provided and thus not require separate return path . one example is shown in fig7 which will be described later . fig4 is an exploded view of the electrode retaining chuck 10 of this invention . preferably chuck 10 is fabricated from two identical casing halves or sections such as upper housing 22 and lower housing 23 so as to be of flat generally rectangular configuration . casings 22 and 23 are preferably molded from polycarbonate plastics such as merlon m - 50 , lexan 2014 or equivalent . each of these casings is formed with an interior lateral channel 24 and a posterior chamber or end socket 25 into which electrode 15 partially extends . electrode 15 is retained by transversely extending nubs 26 and 27 which fit into transverse slots 29a and 29b across the top and bottom of electrode 15 . the casings are preferably sonically welded after electrode 15 is located therein . although fig5 illustrates the underside of the upper casing 22 , the lower casing 23 is correspondingly formed other than for the exceptions hereinafter noted . thus , as seen in fig5 opposite sides of each casing half converge forwardly from the straight parallel sidewalls on opposite sides of the chamber 25 . in addition , a raised head 28 extends around one side of the lower surface of casing 22 and the opposite side of the upper surface of casing 23 as well as around the periphery of collars 30 and 31 . further , a pin 32 is molded to project from one side of each casing for insertion into a matching socket 33 which is molded into the confronting surface of the other casing to facilitate alignment and interconnection of the casings . accordingly , after appropriately locating electrode 15 within the channel 24 of each casing 22 and 23 via ridges 26 and 27 and slots 29 , sonic welding along the contacting surfaces of the casings will effect bonding between those two casings , and bonding between the ridges 26 and 27 and slots 29 as well as the collars 30 and 31 will also effect a complete bonding peripherally around the electrode so as to completely seal it within the interior of the casing assembly . notches 35 and 36 on opposite sides of the chamber 25 of both casings 22 and 23 provide a detent for receiving locking tabs , such as , is shown at 38 on opposite sides of the probe 12 in fig1 . still further , a longitudinally extending groove such as 40 is formed to extend centrally along the inner surface of each substantially flat wall 39 above and below the chamber 25 so as to accomodate alignment ridges 41 and 42 on the probe 12 in attaching the chuck 10 to housing 11 . an exemplary mating extension probe 12 of the interface handle 11 is shown in section in fig3 . an electrical connector in the form of a sleeve 44 with an enlarged base collar 45 is retained within housing 11 by a tubular section 46 which typically may be a longitudinally split arrangement , and the ends of the connector 44 in opening or bore 48 are somewhat outwardly flared and generally spring - biased in closing relation . this connector 44 is electrically attached to wire 49 which extends through the length of handle housing 11 to ultimate connection at the electro - surgical generator as is described in the aforementioned copending application entitled improved electro - surgical instrument . after a chuck has been assembled as has been described hereinbefore for fig4 and 6 , the transverse ridges 13 and 14 facilitate gripping of this chuck , and the arcuate guiding ridges 41 and 42 of probe 12 mate with the internal axial grooves 40 of chuck 10 so as to provide alignment as the probe is inserted until tabs 38 have snap - locked into engagement with internal notches 35 and 36 within the inner chamber 25 . further , a shank or cylindrical end 50 of electrode 15 which protrudes into chamber 25 will enter the bore 48 of probe 12 and slide against tubular section 46 of connector 44 so as to insure electrical contact . the split , spring - biased arrangement of tubular section 46 can further augment this wiping action . in any event , complete assembly of the chuck onto the receiving probe 12 results in a configuration which is relatively continuous in contour with handle 11 and also rigidly attached so that transverse forces between chuck 10 and handle 11 are substantially carried by the casings 22 and 23 and housing 11 and not translated to the electrical connection . the generally flat attachment configuration thereby prevents any unintended rotation of the electrode while in use . for electrodes such as 16 and 20 shown in fig2 a and 2c , respectively , such inadvertent rotation is obviously highly undesirable but has been a hazard associated with prior art devices . still further , the encasing arrangement which results wherein chuck 10 surrounds the probe 12 provides isolation of opening or bore 48 from the environment of potential contamination migration . the complete sealing of chuck 10 around electrode 15 means that it can be easily detached and replaced with other chucks during the operating procedures and also be easily removed for thorough cleaning and sterilization . this enclosing action of chuck 10 relative to probe 12 further insures the integrity of sterilization of that element . a further advantage of this arrangement is that the electrical connection between the electrodes such as 15 and internal connectors 44 are thoroughly insulated from the hand of the operator and likewise from the edge or sides of any wound involved in the surgical procedure . the environmental isolation of the electrode handle interface represents a particularly important advantage of this invention since the liquids associated with surgical operations such as blood are frequently good electrical conductors . their introduction or migration into handle 11 can result in disruption of the intended electrical function therein as well as producing a conductive path to the outside of housing 11 thereby hazarding burns to the surgeon . fig7 depicts one arrangement for adapting the present invention for bipolar electrode applications . the chuck housing 52 in this example is preferably fabricated similar to the chuck described above for fig4 - 6 . receiving handle 53 has an extension probe portion 54 and a circuit board 55 is mounted within handle 53 . two electrical contacts 56 and 57 are attached to the end of board 55 so as to extend forwardly into probe 54 . contacts 56 and 57 can be leaf - type connectors preferably spring - biased to assure wiping contact when electrode 58 is inserted therebetween . electrode 58 is preferably composed of an insulating inner core 59 which has conductor strips 60 and 61 extending along opposite sides thereof . thus an electro - surgical procedure can be performed such as across end face 64 of electrode 58 without requiring a circuit return path through the patient . contacts 60 and 61 through their connection into connectors 56 and 57 , respectively , in handle 53 provide the necessary circuit connections . note that connectors 56 and 57 typically are attached to conductors or circuit board 55 which are in turn coupled to an electro - surgical generator . it will also be recognized that the apparatus can easily be modified to accommodate two or more separate electrodes through the chuck housing which would connect with matching connectors within the handle housing probe . although the exemplary preferred embodiments of this invention have been described with particularity , various applications , changes , modifications and additions relative to the present invention will be readily apparent to those having normal skill in the art without departing from the spirit of this invention .
a generally flat insulator chuck is arranged to retain surgical electrodes so that the working area of the electrodes extends externally on one end and an electrical circuit accomodating prong is contained within a recessed chamber at the other end . the recessed chamber is dimensioned so as to effect continuous contouring relative to a receiving control handle apparatus in such a manner that the physical stress is translated between the insulator sidewalls of the chuck and the insulator of an extended plug on the handle . the electrical connection extension prong within the recess slidingly engages an electrical connector embedded within the handle extension so as to provide electrical contact free of physical stress from usage . locking and guiding arrangements cooperate between the handle and the chuck to further insure firm attachment .