US1831280A - Surgical instrument - Google Patents

Description

Novf l0, 1931. L. K. WRIGHT ET AL SURGICAL INSTRUMENT Filed oct. 1o,192e 2 sheets-snag 1 Clif/touw@ Nov. 10, 1931. L. K. WRIGHT ET Al. 1,831,280

SURGICAL INSTRUMENT Filed Oct. lO, 1928 2 Sheets-Sheet 2 SWW/micia s- MY/gm Patented Nov. 10, 1931 UNITED STATES azrrsur oFFlcE LEONARD KAY WRIGHT, F JACKSON HEIGHTS, AND WILLIAM 1?. MACLEOD, 0F

NEW YORK, N. Y.

SURGICAL INSTRUMENT AApplication filed October 10, 1928. Serial No. 311,533.

This invention relates to surgical instruments, andmcre particularly to electro-mag netic instruments, ot the type suitable for use in extracting chips or slivers of magnetic susceptible material from various portions of the human body.

It is quite noticeable that injuries resulting from the chipping and racturing of alloyed steels and'irons, in the various industries,

have increased With the increased use of theseY materials. In many instances these injuries result in serious losses both to the employee and the employer. Besides the direct physical injuries resulting from Wounds caused by sharp metallic particles there 1s a possibility of the Wound, no matter how small, becoming infected. lorkmen accustomed to having small metallic turnings, shaving etc. contacting Withl their body, may

have small particlesv of metal embedded in their flesh, Which While not visible sometimes results in infections and serious losses.

An object of this invention is to devise a surgical instrument for extracting iron, steel or other particles which may be attracted to a magnet, for use in'hospitals, emergency Wards, optical rooms,-etc.

Another object of this invention is to devise amagnetic surgical instrument lacking many of the disadvantages inherent in the magnetic equipment heretofore employed.

Another object of this invention is to devise a magnetic surgical device that may be easily adjusted to various positions for the extraction ot' particles from different parts of the human anatomy.

Another object of this invention is to provide an electro-magnet to which is attached means for conducting magnetic torce to an applicator or instrument suitable for extracting metal particles from the human body.

Still another object of this invention is to provide a flexible conduitl suitable for trans mitting magnetic force from a source to a point of application and to so construct said conduit that the same is capable of attachment to a plurality of magnetic applicators or instruments.

lith these and other objects in view which may be incident to our improvements, the invention consist in the parts and combinations to be hereinafter set forth and claimed, with the understanding that the several necessary elements comprising our invention, may be' varied in construction, proportions and arrangement, Without departing from the spirit and scope of the appended claims This invention embodies a solenoid which may be constructed ot the proper number ot turns of Wire to secure the desired magnetic effect. Mounted within the solenoid is-aslidable core member to which is attached a conduit suitable for conducting magnetic force from said coreto a point of application. The core and conduit are preferably formed ot tubular members, the tubular member forming the conduit being constructed of flexible materials. Magnetic material, such as iron particles or Wire, is placed Within these tubular members through which the magnetic force is conducted. The tree end of the flexible magnet-ic conduit is provided With a litting adapted to receive various applicators or instruments suitable for applying the magnetic attracting force to any desired portion of the body.

This invention also embodies a novel arrangement for varying the magnetic. intensity transmitted'through said conduit. As is Well known. When an electric current is conducted through the turns ot a solenoid there is a tendency for any magnetic susceptible object to be drawn into the central portion ef the solenoid. lNhen a core or body is in the central portion of the solenoid the flux density is at a maximum in the material, and as the material is Withdrawn from the cent-ral portion of the solenoid the flux density is gradually decreased depending upon the distance of the body from the central portion of the solenoid. This principle isutilized in this invention to vary the magnetic intensity transmitted to the applicator attached to the en d of the dexible con duit. and suitable means are provided for retaining the slidable core in any predetermined position.

In order to make our invention more clearly understood we have shown in the accompanying drawings means for carrying the same into practical effect, without limiting the improvements in their useful applications to the particular construction, which for the purpose of explanation, have been made the subject of illustration.

In the drawings:

Fig. 1 is a side elevation of an electromagnetically operated surgical instrument constructed in accordance with this invention.

Fig. 2 is an end view of the device shown in Fig. 1.

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2, showing the details of construction of the solenoid and the slidable core.

Fig. 4 is a somewhat detailed view of the connection between the flexible conduit and the applicator. f

Fig. 5 is a sectional view taken on line 5-5 of Fig. 4:.

Fig. 6 shows a somewhat detailed view of a means for retaining a slidable core in a predetermined position.

Fig. 7 is a detailed view of the retaining means unattached.

Fig. 8 is a modified form of the device for retaining the slidable core in a predetermined position.

Fig. 9 is a view of the. end portion of the solenoid taken on line. 9 9 of Fig. 8 and showing the relation of the modified retaining means to a slidable core member.

Fig. 10 shows still another modified form of core retaining means.

Fig. 11 shows a somewhat detailed construction of the means for connecting the flexible conduit with a modified form of applicator receptacle.

Fig. 12 is a sectional view taken on line 12-12 of Fig. 11 showing the detailed con struction of the means for retaining the ap plicator within its receptacle.

Fig. 13 is a view of a curved applicator such as is employed in this invention.

' Fig. 14 shows an applicator with an attached sleeve for use in certain applications of this invention.

Fig. 15 is a View of an applicator receptacle provided with a switch for controlling the operation of the solenoid.

Y Fig. 16 shows a modified form of applicator receptacle equipped with a switch for controlling the operation of the'solenoid.

Referring to the drawings our invention embodies a source of magnetism which, in this particular instance, is asolenoid 1, adapted to be placed on a table or other suitable supporting means. This solenoid comprises atube 2 which is preferably constructed of non-magnetic material and on which are mounted two spaced heads ordiscs 3 formed of rubber, condensed phenolic compounds or other insulating substances.Tube 2, with its heads ordiscs 3 mountedV in place, forms a spool upon which is wound the magnetizing coil 4.

The winding of the coil l will depend upon the type of current supplied to the coil and upon the magnetic force to be generated, among other conditions. Some of the conditions which must be considered in constructing the solenoid coil are the cross-sectional area of the wire, the radii of the windings, the ratio of the length of the coil to its average radius, the diameter of the solenoid, and electrical effects, such as heating and inductance. In some instances thetube 2 should be slotted to allow for expansion and contraction due to temperature changes.

In constructing coils for use with alternating current it is best to provide an extra loop of wire so that the chatter, incident to the alternating current, may be eliminated. Also in the design of coils for alternating current it is customary to place mica, oiled linen, paper, sheet condensed phenolic compounds, sheet rubber etc., between the layers and treat the whole coil with insulating and impregnating varnishes or other compounds. The coil should be constructed in a manner best suited for the purposes for which it is to be used.

A tubular casing 5 is fitted over theend discs 3 so as to completely enclose the coil 4l. This `casing or shell is preferably constructed of non-magnetic material which has a polish or easily cleaned surface. Supporting end caps 6 are constructed so as to threadedly engage with the shell 5 to enclose the solenoid. It will be noted that the central portion of these caps is provided with flanged openings adapted to receive the ends of thetube 2. Supportinglegs 7 are formed integrally with theend caps 6 and serve to support the solenoid. The end caps 6 are securely fastened to the shell 5 so as to provide a tight casing for the solenoid. A compound, such as glycerine and litharge, or shellac, may be applied to the threads when assembling to provide a mea-ns of sealing and holding the parts together.

If found necessary the casing may be provided with cooling flanges or other means for radiating heat, but it has been found that the heating effects are not serious, and as the whole device should be capable of `easy cleaning it is preferable to have the surfaces smooth and polished. The upper portion of the shell 5 may be provided with a suitable handle 5 so that the solenoid can be easily handled.

The lower portion of each of thelegs 7 lis provided withplug receptacles 8 and 8 adapted to receiveplugs 9 and 9. One contact of thereceptacle 8 is connected to one contact of the receptacle 8' and the other contacts ofreceptacles 8 and 8 are connected together through the coil 4. With these connections the power line 1() can be plugged vmagnetic material. One end of this tube is internally threaded to receive a threadedvplug 14 which serves as a closure for the tube.Y The tube at its other end is externally threaded to receive a fitting orcoupling 15 which serves to connect aflexible tubing 16 to thetubular core piece 13.

The other end of theflexible conduit 16 is provided with a combined fitting and closure which will be described later. Thus it will be seen that thetubular core member 13 and theconduit 13 are connected and pro vided with closures to form a closed compartment. Mounted within this enclosure provided by thecore piece 13 and the flexible conduit 1G are a plurality of ferro-magnetic particles 17, such as shown diagrainmatically in the several figures of the drawings. Vhile for purposes of illustration this ferro-magnetic material is shown in the -form of finely divi ded particles, we wish it to be understood that they may consist of ferro-magnetic balls, granules, dust, chips small pieces or even bundles of wire. The purpose of the contents of thetubular core 13 and the flex-YIible conduit 16 is to convey the magnetizing force, energy, or flux from the solenoid to the fitting 2O mounted on the end of theflexible conduit 16.

In order to keep the contents ofthetubular core 13 and theflexible conduit 16 in contact with each other, apiston 13 is mounted within thetubular core piece 13 and is forced against the ferro-magneti c particles by means of aspring 19. The sprin-fr operatedpiston 18 exerts a pressure upon the magnetic particles within thecore 13 andconduit 16, thereby insuring good metallic contact between the magnetic particles.

In order to provide a flexible tube which may be moved to various positions, rubber or other flexible materials are used. If finely divided material is to be used in the tubular core and flexible conduit, it is necessary that the material forming the flexible conduit have isuiiicient strength to withstand the pressure jnetic 'forces induced in theplunger orcore 13 varies with the position of the core orplunger 13 with respect to thesolenoid 1. Thus if it is desired to vary the intensity of magnetization induced in the core 13 it is necessary to move it to various positions within thetube 2.

In order to prevent the core 13 from being drawn into thetube 2 where it will receive the maximum magnetizing force thetubular core 13 is provided with a plurality of grooves 21in which aremounted stop rings orshackles 22. The stop rings orshacks 22 may be made in the fori-n shown in Figure 7 of the drawings. In this construction, awire 23 is bent into a circular form and is provided with two protruding arms or ends 24; and These arms are provided with indentations orgrooves 26 and 27 into which alink 28 is adapted to fit.

lhen it is desired to lock the tubular eore in a predetermined position theshackle 22 is slipped into one of theannular grooves 21 and thelink 23 is placed on thearms 24 and 25 and slipped into the grooves provided therein to retain the shackle in position on thecore piece 13. lVhen the magnetic force acts to draw thetubular member 13 into the central portion of the solenoid, theshackle 22 abuts against the annular projection on theend cap 6 and serves to prevent thecore piece 13 from being drawn all the way into thesolenoid 1. Figure 6 shows a spring shackle mounted in operative position on thetubular core 13.

A somewhat modified form of retaining mechanism is shown in Figures 8 and 9 of the drawings. ln this form of our invention the end cap is provided with aprojection 29 having a channel therein, in which slides aoperating button 30. A yoke 31 is positioned about thecore piece 13, as shown in Figure 3` and its lower portion is adapted to enter one of the annular grooves 'formed on the core piece to retain the latter in desired positions. The upper portion of th yoke 31 .is pro fi ded with arodlike projection 32 on which is mounted theoperating button 30.

Spring means 33 are provided in the channel of theprojection 29 and aboutrod 32 to force thebutton 30 in an upward position, thereby causing the lower portion of the yoke 31 to engage in one of the grooves ofcore piece 13. The lower portion of end piece- 6 is provided with a projection in which is threadedly mounted ascrew 34. The screw 34e projects through aslot 35 in the projection extending from the lower portion of the yoke 31. This slotted connection serves to retain the yoke 31 in operative position.

lVhen it is desired to adjust the position of thecore piece 13 within thetube 2 it is merely necessary to press on thebutton 30, pushing it in a downward direction against the action of thespring 33. By pushing thebutton 30 downwardly the lower portion of y lli the elliptical yoke 31 is moved out of one of thegrooves 21 thereby permitting free move-v termined position is shown in Figure 10. In

this form ahasp 36 is pivotally mounted on aprojection 37 on theend cap 6. Thehasp 36 is so constructed that when it is in a down- Ward position it engages in one of thegrooves 21 of thecore piece 13, as is clearly shown in Figure 10. In order to prevent accidental displacement of thehasp 36 from the grooves 21 a pivoted latch member is provided. In operation the latch member is moved down so as to engage thehasp 36 to retain it in operative position.

It will be readily seen that while any of the stop mechanisms above described preventvthe core piece 13 being drawn into thesolenoid 1 they permit rotation between thecore piece 13 and thetube 2 of the solenoid. This is desirable because in some instances it may be found necessary to rotate theliexible conduit 16 and thecore piece 13 to apply the inaglnetizing force where desired.

To facilitate the adjusting ot thecore piece 13 in the solenoid the former may be provided with indicia to indicate the magnetic force induced into the core at each of the several positions at which the core piece may be retained.

l/Vhile we have described and shown the preferred forms of retaining mechanisms, ve do not wish to hold ourselves to any particular device, as it is within our conception to utilize a core with teeth provided thereon, similar to a rack, which can be operated by a pinion or other adjusting wheel. lt is also `possible to prevent the core 13 being drawn into the solenoid by merely drilling or providing holes in the core piece in which a pin or Cotter may be inserted -to serve as a step mechanism.

`As previously mentioned the free end oi theAflexible conduit 16 is connected to aiitting 20. The manner of connecting the conduit to the fitting 20 is more clearly shown in Figure 4. As shown in this figure the fitting 20 is provided with a tapered opening into which the end of theflexible conduit 16 eK- tends. A taperedshell 39 is inserted within the end of theconduit 16 to force the latter into a tight connection with the inner walls of the tapered opening of the lit-ting Q0. As is shown in Figure 4, a threadedplug 40 is inserted into the threaded opening 41 of the fitting 20. Thisplug 40, when in place, serves to retain the taperedshell 39 in operative position to insure a tight connection between theflexible conduit 16 and the fitting 20. Theplug 40 also serves as a closure for theconduit 16. Apin 44 is extended through the fitting 20 into the taperedshell 39 to prevent any undesirable movement between theconduit 16 and the fitting 20.

The threaded opening 41 is adapted to receive the threadedend 42 of an instrument or applicator. As shown in Fig. 4 theend 42 oi' theinstrument 43 is conical shaped and theplug 40 is provided with a conical recess against which theend 43 abuts. This form of construction insures good metallic contact between theparts 40 and 43. The abutting surfaces need not necessarily be conical however, but may be flat as shown in Fig. l1.

rl`he instruments orapplicators 43 may be o't a variety of shapes and forms so as to meet the various purposes for which they are designed. It is highly desirable that they be detachably connected to the fitting 2O so that before and after use they may be removed and sterilized.

A somewhat modified arrangement for connecting the applicators or instruments to theflexible conduit 16 is shown in Figures 11 and 12. ln this form of our invention theconduit 16 is connected to the fitting` 20 in a manner similar to that shown in F igures 4 and A threadedplug 40 is mounted within the threaded end oi' the fitting 20 somewhat similar to the plug shown in Figures 4 and The threaded end ot anadapter 45 is inserted in the threaded opening of the fitting 20. This adapter is provided with a socket into which ends of instruments orapplicators 46 may be inserted.

As shown in the drawings the connection between theadapter 45 and theinstrument 46 by means o't' a bayonet oint. The plug extension 47 ot' theinstrui'nent 46 is of a cross section which when inserted within the socket in theadapter 45 will prevent rotation between theinstrument 46 and the adapter, that is a flat portion 47 is provided. ln order to prevent the instrument 46 'from being accidentally displaced from the socket in theadapter 45 the plug 47 is provided with a recess into which aspring operating ball 48 is forced. A passage is provided in theadapter 45 into which theball 48 is placed. The lower portion of the passage is provided with a flange or seat to prevent-'the ball passing into the societ, formed in the adapter. Aspring 49 acts to torce theball 48 onto its seat and is held in position by a removable plug member 50, which is threadcdly secured within theadapter 45.

Thus when the projection 47 is inserted within the socket ot' the adapter theball 48 is forced upwardly until engaged by therecess 51 vformed in the projections@ whereupon it drops into this recess to prevent theinstrument 46 being accidentally removed. The ball when seated, together with plug 50,

oel

invention.

seals the passage sufficiently to allow the adapter to be subjected to sterilization without damaging the spring operated ball mechanism.

With the use of theadapter instruments 46 provided with the bayonet means of attachment may be utilized as well as instruments provided with the screw threaded attaching means. The bayonet type of connection has some advantages over the screw threaded type particularly that of rapid action. For instance, to connect an instrument having a bayonet type connection it is merely necessary to push it into place, and to disconnect it from its receptacle it is merely necessary to pull it out, whereas for connecting and disconnecting instruments of the screw threaded type it is necessary to rotate the instrument several times.

Instruments or applicators of all types and forms may be used in connection with our For instance, sharp pointed instruments may be used when itis necessary to insert the same into a wound to withdraw small particles. In some cases it may be necessary to use longcurved instruments 52, such as shown in Figure 13. Although theinstrument 52 is shown provided with a screw threaded connectingend 53, it is to be understood that any and all types of instruments maybe provided with either the bayonet type of connection or the screw threaded type.

For 'certain types of operations itis desirable and sometimes necessary to equip an instrument with a guard or mask. An embodiment of this form of our invention is shown in Fig. 14 of the drawings, in which aninstrument 54 shown equipped with a screw threaded connecting means by way of illustration, is surrounded by atubular guard 55. .This guard or mask may be formed of any material suitable for the purpose, and

. is preferably secured to the instrument by means ofscrew threads 56, although any other type of connection will suffice.

In using this guarded instrument, it is centered over the embedded Vparticles and the current turned on so that the particles are attracted to the point 57 and held there. The

instrument .can be withdrawn from the wound without any danger of the small particles being scraped off of the instrument as may easily` happen with an unprotected instrument. vThe shield 'also may be used to protect blood vessels from being pierced by the action of the particles when attracted to andl moving Vtoward the magnetized instrument end.

It is sometimes desirable to have the solenoid control switch in a location easily reached by the operator. This can be accomplished by having a switch mounted on the instrument receptacle. An embodiment of this detail of ourk invention is shown in Fig. 15 in which the fitting 20 is provided with a dovetail groove or slot adapted to receive adovetail projection 58 extending from aswitch body 59 carrying apush button 60 and mounted on thelitting 20 and held in position by means of thelug 58. For purposes of illustration the switch is shown to be of the push button type but we wish it to be clearly understood that it may be of any type desirable or suitable for the purpose.

A modified form of solenoid control switch is shown in Fig. 16. This form employs a handle or grip which is attached to the instrument receptacle, and serves as a means for holding and guiding the instrument during operation. with a slot or groove 61 which receives a lug 62 carried by theyoke 63 of the handle orgrip 64. This lug and slot connection serves to retain the parts rigidly connected to each other. Thehandle 64 is equipped with apush button switch 65 which is adapted to make and break an electrical connection between the two wires located in the conduit 11.

With either this or the previously described construction, the current supplied to the solenoid can be easily controlled by the operator without removing his hand from the handle or the receptacle for the instrument. Such an arrangement is particularly desirable when it is necessary to alternately open and close the electrical circuit through the solenoids over a plurality of short time intervals.

When our invention is to be' used to remove any metallic particles from a portion of a y persons body, the' several parts are assembled as shown in Fig. 1. Thesolenoid 1 may be placed` on a table or stand near the operating table or chair. Thecore 13 is moved to the position in thetube 2 of the solenoid at which the desired magnetic force will be induced in the core. This position may be determined by experiment or by indicia on thetubular core member 13.

After thetubular core 13 is adjusted to the i proper position it is secured in position by any of the forms of locking or retaining devices hereinbefore described. An instrument formed of ferro-magnetic material of the types described and suitable for the particular operation to be performed, is sterilized or otherwise treated to prevent the introduction of undesirable organisms into the wound. After the instrument or applicator. has been rendered sterile it is placed in the receptacle mounted on the end of theflexible conduit 16.

When desired the electrical circuit through the solenoid is completed by closing the proper switch which as described may be located in the iitting mounted on the end ofconduit 16 or in the handle for holding and guiding the instrument. The instrument is then inserted in the wound to gather the magnetical- The fitting 2O is provided ly attracted particles and after gathering the same is withdrawn. l y

Any particles adhering-tothe instrument can be removed therefrom merely by breaking the electrical circuit through the solenoid which stops the magnetization of the core and instrument.

Since the conduit between the core 13 andv the fitting 2() is flexible, the instrument rigidly connected to the fitting 20 can, together' with the fitting, be 4moved to any desired position and the magnetic 'susceptible particles can be approached in any direction regardless of the position of the solenoid. It can easily be seen that our novel form of conduit permits many types of magnetic operations to be performed which were heretofore considered impracticable because of the impossibility of moving a heavy bulky electromagnet to various positions.

Should it` be found necessary to change instruments while operating, the same can be easilyv accomplished vwith either the screw threaded connected instruments or with the bayonet connected instrument, the latter being capable of quicker changes. o

If it is necessary to vary the intensity of the magnetism induced in thecore 13 for any reason whatever, the same c an be effected by merely changing the position of the core 13 with respect to thetube 2 on which the coil of the solenoid is wound. After the,core 13 is moved to its new position it can be retained in placeV by utilizing any of thelocking or retaining means hereinbefore described.

In operation a magnetic field is generated in thetube 2 by the current flowing through the coil of the solenoid. As thecore 13, constructed of magnetically susceptible material is placed in the magnetic field, themagnetic lines of force flow through the same and render it magnetic. The magnetism induced in the particles in thecore 13 is conveyed through the particles in theconduit 16 to the fitting on the end thereof and thencel into the instrument metallically connected to the fitting.

Our invention, as is obvious from the foregoing description, provides a surgical instrument having a rather wide range of utility. It provides an apparatus capable of efficilently extracting metallic particles from the fiesh of a human body.

The flexible cable-like conduit employed in our invention together with the quicklyv detachable instruments or applicators cooperate to produce results heretofore unattainable with magnetic instruments. Also thenovel means for varying the magnetic forces induced in the core piece, and the conveniently mounted solenoid control switch cooperate.

with the other parts of our invention .to produce an easily, conveniently, and. rapidly operated device.

While we have shown and described the nssnaso preferred embodiment of our invention, we wish it to be understood that we do not confine ourselves to the precise details of construction herein set forth, by way of illustration, it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invent-ion, or exceeding the scope of the appended claims.

7e claim:

1. A surgical instrument comprising a source of magnetic force and means for conducting said magnetic force from said source to a point of application, said means comprising a flexible casing containing a plural- L ity of ferro-magnetic particles.

Q.. A surgical instrument comprising a source of magnetism and means for transmitting magnetism from said source to a point of application, said means comprising a flexible tubular member containing a plurality of magnetic particles, and means for retaining said particles in a compact condition.

3. A surgical instrument comprising a source of magnetic force and means for conducting said magnetic force from said source to a point of application, said means comprising a fiexible tubular member containing a plurality of magnetic particles and spring operated means for exerting pressure on said particles for retaining the same in contact with each other.

4. A surgical instrument comprising a solenoid, a movable core adapted to be moved in and out of said solenoid, means having metallic contact with said core for transmitting magnetic force induced in said core to a point of application, said means comprising a flexiblevcasing containing a pluralityof magnetic particles, the casing being connected to said core and other means for retaining said core in a predetermined position in said solenoid.

5. Asurgical instrument comprising a solenoid,- af movable core mounted therein, said core comprising a tubular member, a flexible conduit connected with said tubular member, a plurality of magnetic particles in said tubular member, said-flexible conduit adapted Ato transmit magnetism from said solenoid to an applicatorattached to said flexible conduit.

6. Asurgicalinstrumentcomprising a solenoid, a moveable core mounted therein, said core comprising a tubular member, a flexible conduit connected with said tubular Ymember, a plurality of magnetic particles in said tubular member and said flexible conduit,

adapted vto transmit magnetism from said Ysolenoid to an applicator attached to said flexible conduit, and spring operated means in said tubular vmember adapted toforce said magnetic particles into contact with each other. y i

7. Asurgicalinstrument comprising a solenoid, a tubular movable core adapted to be moved in and out of said solenoid, a flexible casing connected to said core, a itting adapted to receive an applicator connected to ,said casing, said casing and core being lled with magnetic particles, a removable plug pos tioned in the end of the core opposite the end of said casing, a spring operated piston positioned in the core, the spring bearing against said plug and said piston, said piston in contact with the magnetic particles so as to `force the same against an end of said fitting.

8. A surgical instrument comprising a source of magnetic force, means for conducting said magnetic force from said source to a point of application together With means for controlling the intensity of the magnetic force, said conducting means comprising a HeXible casing containing a plurality of magnetic particles.

In testimony whereof We affix our signatures.

LEONARD KAY l/VRIGHT. VILLIAM P. MAGLEOD.

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