Switching means for an electro-surgical device including particular contact means and particular printed-circuit mounting means

[57] ABSTRACT

An electrical switching device is disclosed herein and comprises the major components suitable for use as a

Hi] 3,801,766

[45] Apr. 2, 1974 compact, easily installed switching device and also in an electro-surgical tool which, through the operation of the switching device, is readily adaptable for different intended uses and highly reliable. In one embodiment, the switching device includes a tubular housing having an intermediate longitudinally extending slot formed in its wall and a pair of longitudinally extending diametrically opposed recesses formed on its inner surface. A rectangularly shaped printed circuit board is mounted within the diametrically opposed recesses and includes at least three spaced apart electrical contacts which are positioned so as to be accessable through the slot formed in the housing. An integrally formed, elongated spring contact member is disposed in electrical conducting engagement with the center one of these electrical contacts and includes opposing energy absorbing coils, each of which is adapted to engage reliably a corresponding one of the otherwise free contacts. In this regard, in order to increase further the reliability of the engagement of the contacts, means are provided for securing the printed circuit board against inadvertent longitudinal movement within the housing. An arcuately shaped insert is mounted within the aforedescribed slot and engages portions of the lower surface of the circuit board for further securing said insert in place. In addition, the arcuately shaped insert includes a longitudinally extending slot adapted to receive therein a portion of a longitudinally extending rocker type switch actuator for pivotal movement about an axis generally normal to the axis of alignment of the electrical contacts. The free ends of the aforedescribed spring contact member are positioned within recess guides formed in the actuator and move into engagement with their corresponding contacts in response to selective pivotal movement.

Claims, 7 Drawing Figures

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SWITCHING MEANS FOR AN ELECTRO-SURGICAL DEVICE INCLUDING PARTICULAR CONTACT MEANS AND PARTICULAR PRINTED-CIRCUIT MOUNTING

MEANS ·

BACKGROUND OF THE INVENTION

The present invention is related generally to an electrical switching device and more particularly to such a device especially suitable as part of an electro-surgical tool.

In the field of medicine generally and in the field of surgery in particular, surgical tools utilizing electrical power are being used more and more. One such tool being used by surgeons today operates on electrical current to perform, for example, cutting and coagulating or cauterization operations. Finger-actuated slidetype electrical switches for actuating a single circuit of such a tool, or for selectively actuating a plurality of circuits, are well known and such are illustrated by United States Letters Patent No. 3,217,112. This patent discloses a rocker-type switch for selectively actuating a plurality of circuits, the actuating element between the rocker and the switch contact being perpendicular to the longitudinal axis of the casing. This switch has limited application and its construction results in a rather bulky device not susceptible for use in connection with an elongated pencil-shaped surgical tool which is prefered by and easily held in one hand ot the physician during operations.

Finger-actuated surgical devices for the dual purpose of cutting and cauterizing tissue by the selective application of high frequency current of a selected type and power, are also well known as exemplified by United States Letters Patent No. 1,813,902, and related United States Letters Patent Nos. 2,611635 3,058,470, 3,089,496 and 3,100,489. Advantages’of a surgical tool of this type having a finger-actuated 40 switch over surgical tools having a foot pedal-operated switch or one operated by an assistant are amply set forth in these patents and need no further amplification herein. The finger-actuated surgical tools of the prior art are, however, somewhat bulky in construction, do 45 not lend themselves to facile sterilization procedures and techniques, and cannot be manufactured by relatively inexpensive plastic molding techniques.

A more recent development in switching devices especially suitable as part of an electro-surgical tool is ⁵⁰disclosed in U.S. Letters Patent No. 3,648,001. In this patent, an electrical slide switch particularly adapted for use in surgical tools is disclosed which is incorporated in a pencil-type case for ease in handling and is readily adaptable for sterilization with standard steril- ⁵⁵ization procedures. In addition, it can be readily and inexpensively manufactured by conventional plastic molding techniques.

While the electrical switching device described in the above-referenced patent is a novel electrical switching device which is particularly adapted for its intended use, the present invention provides a novel electrical switching device which is particularly adapted for use in electro-surgical tools and which provides highly reliable switching and electrical engagement in an uncomplicated, compact and easily maneuverable design, all of which will become apparent hereinafter.

OBJECTS OF THE INVENTION

In accordance with the foregoing, an object of the present invention is to provide a novel electrical switching device.

Another object of the present invention is to provide a novel three-position electrical switching device.

Another object of the present invention is to provide a switching device of the last-mentioned type which is easily movable between positions and which reliably engages the selected position.

Another object of the present invention is to provide a switching device of the last-mentioned type including a novel contact member for providing reliable electrical engagement.

Another object of the present invention is to provide an electrical switching device of the last-mentioned type including a novel rocker-type actuator adapted to cooperate with the spring contact member in providing a reliable electrical engagement.

Another object of the present invention is to provide a contact member which is designed to effect a wiping action across associated electrical contacts for providing reliable electrical engagement of the latter.

Another object of the present invention is to provide a novel two-position electrical switching device and spring contact member therefor.

Another object of the present invention is to provide a novel housing for the electrical switching device of the aforementioned type.

Another object of the present invention is to provide a novel pencil-type electro-surgical tool utilizing the switching device of the aforementioned type.

Another object of the present invention is to provide a novel switching device inexpensive to manufacture and easily installed or removed from a predetermined location such as the surface of an item.

These and other objects and features of the present invention will become apparent from the following descriptions.

DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view of a pencil-type electrosurgical tool utilizing .a preferred embodiment of an electrical switching device constructed in accordance with the present invention;

FIG. 2 is an exploded perspective view of the components comprising the electro-surgical tool of FIG. 1;

FIG. 3 is a sectional view taken generally along line 3—3 m FIG. 2 and particularly illustrating a spring contact member which is constructed in accordance with the present invention and which comprises part of the electrical switching device;

FIG. 4 is a longitudinal sectional view of the electrosurgical tool of FIG. 1, taken generally along line 4-4 in FIG. 1;

^F'^G/- ^cross'^sectional view of the electro-surgical tool of FIG. 1 taken generally along line 5—5 in FIG.

FIG. 6 is a cross-sectional view of the electro-surgical tool of FIG. 1, taken generally along line 6—6 in FIG 1; and ^FJ^G,.^{7 is an} exploded perspective view of another embodiment of a switching device constructed in accordance with this invention.

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DETAILED DESCRIPTION OF THE DRAWINGS

Turning now to FIGS. 1-6 of the drawing, wherein like components are designated by like reference numerals throughout the various figures, a pencil-like electro-surgical tool, constructed in accordance with the present invention, is illustrated in FIG. 1 and generally designated by the reference numeral 10. The electro-surgical tool 10 includes a surgical cutting and coagulating means such as blade 12 connected with a multi-frequency electrical power supply (not shown) through suitable leads, the conduit being generally designated by the reference numeral 14, and an electrical switching device 16 which is constructed in accordance with the present invention. As will be seen hereinafter, the device 10 is a highly reliable, easily manipulated, uncomplicated and economically produced threeposition switch providing for an intermediate or neutral position adapted to prevent current from reaching blade 12, a second position adapted to provide, for example, current of one type to reach the blade for cutting operations and a third position adapted to allow current of a second type to reach blade 12 for providing a coagulating operation. While the electrical switching device 16 is especially suitable as part of a pencil-like electro-surgical tool such as tool 10, it is to be understood that the switching device could be readily used in other types of electrical switching operations.

In order to achieve reliability, easy manipulation, simplicity and economy in manufacture, the electrical switching device 16 includes a plurality of carefully designed cooperating components including an elongated tubular housing 18 (see FIG. 2) within which a rectangular printed circuit board 20 is disposed. An integrally formed spring contact member 22 (see FIG. 3) is mounted on the circuit board 20 and an end cap 24 is adapted for insertion into the rearwardmost end of housing 18 and is provided for securing the printed circuit board within the housing to prevent inadvertent longitudinal movement of the circuit board relative to the housing. A front cap 26 is mounted over the front of housing 18 and provided for supporting and/or shielding the cutting and coagulating blade 12 and limits forward movement of the circuit board. A rocker type actuator switch 28 is pivotally supported by an arcuately shaped insert 30 and cooperates with spring contact member 22 for providing easily manipulated selection of the various switch positions.

Turning to FIG. 2, attention is specifically directed to tubular housing 18 which is constructed from an elongated tube, preferably of molded plastic, and having a cylindrical bore 32 extending therethrough. For reasons to be described hereinafter, housing 18 includes a longitudinally extending slot 34 which is formed in the housing wall intermediate the ends of the housing and which has a circumferential extent exceeding 180°. The housing also includes a pair of longitudinally extending, diametrically opposed recesses 36 formed on the inner surface of the housing, as best illustrated in FIG. 6. The recesses extend the entire length of housing 18 and receive and support rectangular circuit board 20 in a plane which is parallel to a plane passing through the longitudinal edges of slot 34 as will be seen hereinafter.

Attention is now directed to rectangular circuit board 20 which is illustrated best in FIG. 2. Circuit board 20 includes on its top surface two or more spaced-apart, generally longitudinally aligned electrical contacts 38, 40, and 42 which are respectively connected to corresponding ones of a plurality of electrical 5 leads 44 through a printed circuit (not shown) located on the underside of the circuit board. Leads 44 extend through aforedescribed conduit 14 and are connected in a conventional manner to appropriate circuitry. The contacts 38, 40 and 42 are shown as being connected 10 by the printed circuit to a conductive coupling member 46, which is suitably mounted to the forwardmost end of the circuit board. Coupling member 46 is provided for connecting blade 12 to the output of the RF power source via one of the leads 44 and the printed circuit. 15 The tool 10 shown in the drawings does not contemplate switching power directly to the blade 12 but same could be accomplished by using the proper type of contacts 38, 40 and 42. Circuit board 20 is mounted within diametrically opposed recesses 36 of housing 18 20 such that contacts 38, 40 and 42 are accessable through slot 34. In this position, coupling member 46 is appropriately located for receiving blade 12 in electrical engagement, as will be described hereinafter.

In order to secure printed circuit board 20 within 25 housing 18 in the manner described above so as to prevent inadvertent longitudinal movement of the circuit board relative to the housing, end cap 24 and nose cap 26 are provided. The end cap 24 includes a radially extending boss portion 48 which is formed on an annular ³⁰ portion 50 extending radially from a tapered head 52.

As illustrated best in FIGS. 4 and 6, end cap 24 is disposed within cylindrical bore 32 of housing 18 through the back end of the latter so that boss portion 48 is suit³⁵ ably seated within a cooperating recess 54 formed adjacent the end of the housing and so that head 52 of cap 24 is contiguous with the back end thereof. Positioned in this manner, it should be noted that the annular portion 52 extends into the housing a distance sufficient to ⁴⁰ engage abuttingly against the back end of circuit board 20. Hence, annular portion 50 prevents the circuit board from inadvertent longitudinal movement in the rearward direction. As will be seen hereinafter, front cap 26 prevents the circuit board 20 from inadvertent ⁴⁵ longitudinal movement in a forward direction. As seen best in FIG. 4, both annular portion 50 and head portion 52 of end cap 24 together define an open ended passage 58 for allowing the conduit 14 to pass therethrough. As also illustrated in FIG. 4, front cap 26, which is hollow, includes a cylindrical rearward portion 51 and an inwardly tapering forward portion 53 adapted to receive balde 12 in the manner illustrated. The inner surface of the rearward portion 51 and the ₅₅ Outer surface of the adjacent end of the housing have a complemental boss and recess formed therein to provide frictional intercoupling thereof in the same manner as described above with the end cap 24 and the end of housing adjacent thereto. When the front cap 26 is ₆θ mounted on the housing 18, coupling member 46 will electrically engage the blade 12 and cap 26 will prevent the circuit board 20 from moving forward.

Turning to FIG. 3, attention is directed to the integrally formed spring contact member 22 which, as illus₆₅ trated, includes a substantially straight center portion 60 having energy absorbing coils 62 and 64 formed at each end thereof. Each of the coils 62 and 64, respectively, has a generally L-shaped portion 66 and 68

3,801,766 which extends outwardly therefrom and which has a generally arcuately shaped free end including a convex part 70 and 72, respectively.

The center portion 60 of contact member 22 is suitably secured in electrical conducting engagement with the center contact 40 of circuit board 20 while the free ends of the L-shaped portions 66 and 68 are, respectively, normally disposed generally above and out of electrical conducting engagement with contacts 38 and 42, respectively. In fact, as illustrated in FIG 3 the convex parts 70 and 72 of L-shaped portions 66 and 68 are positioned above the contacts 38 and 42. As will be seen hereinafter, each of the convex parts engages its respective contact in a wiping-type action when the convex part is brought into electrical conducting engagement therewith. This, in turn, provides for a more reliable electrical engagement.

Returning to FIG. 2 in conjunction with FIG 5 the arcuately shaped insert member 30 is shown. The insert member includes an elongated body portion 74 having a curvalmear cross-section with a radius of curvature equal to that of housing 18. The body portion 74 is complementally mounted within slot 34 of housing 18 as best illustrated in FIGS. 1 and 5, and includes a longitudinally extending slot 76 formed through its wall intermediate the longitudinal ends thereof. As will be seen hereinafter, the slot 76 is provided for receiving therein the rocker-type actuator 28.

Insert member 30 also includes a pair of longitudinally extending but radially inwardly directed fingers 8 (seeFIG. 5) which when mounted within the slot 34, are disposed in the same plane in which lies one of he surfaces of diametrically opposed recesses 36. As also seen in FIG. 5, longitudinal channels 82 are formed on opposite sides of slot 34 in housing 18 and extend the length of the slot 34. In this manner, the radially inwardly directed fingers 78 of insert member 30 engage the lower surface of the circuit board 20 and member 30 is secured within said slot as a result thereof.

In order to support rocker-type actuator 28 in a manner to be described hereinafter, a pair of aligned recesses 84 are formed on the inner surface of insert member 30 and are disposed transversely to the longitudinal axis thereof. This is best illustrated in FIG 5

Jurning to FIGS. 2, 4 and S, attention is directed specifically to rocker-type actuator 28. As illustrated, the actuator includes transversely disposed trunnions 86 extending outwardly from opposite sides of abody portion 88 and disposed with the aligned recesses 84 of insert member 30. In this manner, a centrally located rocker portion 90, formed on the under side of body portion 88 is disposed to contact a portion oF the printed circuit board 20 such that the actuator 28 is pivotally movable about an axis generally normal to the axis of alignment of the electrical contacts 38, 40 and 42 of printed circuit board 20;

Actuator 28 also includes longitudinally extending recesses 92 and 94 formed in the lower surface of the housing portion 88 adjacent each end of the housing portion. These recesses 92 and. 94 are provided as guide means for respective free ends of the L-shaped portions 66 and 68. More specifically, a part of the free end of each L-shaped portion 66 and’ 68 of spring contact member 22 is disposed within a corresponding one of the recesses 92 and 94 such that the L-shaped portions are guided by and’ move with the actuator. In ⁶ this regard, the actuator includes a finger-engaging portion 96 on the top side of housing 88, the fingerengaging portion being disposed outside of housing 18 and insert 30 through slot 76. The finger engaging portion 96 is adapted to be engaged by the finger of an operator for selectively rotating the actuator in opposite directions whereby upon application of a force to the actuator, the latter is pivotally moved. If this movement, is, for example, forward movement (toward the left as viewed in FIG. 1), the recess 92 formed in body portion 88 of the actuator will guide the convex part 70 of L-shaped portion 66 into electrical conducting engagement with contact 38 of circuit board 20. This in turn may, for example, close an electrical circuit for switching the power supply, thereby passing current to blade 12. Simultaneously, energy will be stored in the coil 62 associated with convex part 70 of L-shaped portion 66 and, upon removing the force from the actuator, energy will be released from the coil thereby causing the convex part 70 of the free end of L-shaped portion 66 to move out of electrical conducting engagement with contact 38, whereby the electrical circuit will be opened. The same type of pivoting action results with respect to convex part 72 of L-shaped portion 68 and contact 42, when force is applied to the actuator in a rearward fashion. In this regard, it should be noted that as each of the convex parts engages its respective contact, it, in effect, wipes across the contact so as to provide a more reliable engagement. This wiping action results, in part, from the use of a recess having a greater width than the diameter of the material used to form the free end of the L-shaped portion that is disposed therein.

In FIG. 7 is shown an exploded perspective view of a different embodiment of a switching device 100 constructed in accordance with this invention. The switching device 100 comprises a base member 102, a spring contact member 104 which is identical in construction to spring contact member 22, a switch actuator 106 which is similar or identical to switch actuator 28 a cover member 108 which is functionally similar to the arcuately shaped insert 30, and means 110 for attaching the switching unit to a surface of an item.

The base member 102 includes a plurality of spaced apart, generally sligned electrical contacts 112, 114 and 116 which are substantially similar to electrical contacts 38, 40 and 42. As shown in FIG. 7, each electrical contact is connected by suitable means to a corresponding one of a plurality of electrically conductive leads.

The cover member 108 includes an annular recess in which is to be disposed the base member 102. The cover member 108 is secured to said base member 102 byJhe frictional interface developed between abutting surface portions thereof. The right end of the base member 102 is foreshortened suitably to permit the electrical leads to remain attached thereto when the cover member 108 is mounted thereon. It will be appreciated, however, that the right end of the cover member 108 may be suitably lengthened to accomodate the location of the electrical leads as aforesaid. Although not shown, it will be readily appreciated that any suitable strain relief means may be employed to prevent separation of the electrical leads from the base member 102 when same are objected to a tensile force.

3,801.

The attaching means 110 as shown comprises a flexible member having opposite surfaces thereof coated with a pressure sentive material 118. Although other suitable attaching means may be employed, it will be readily appreciated that through the use of the attach- 5 ing means 110 the switching device 100 may be readily installed or removed from a predetermined location such as the surface of any item. It will also be readily appreciated that the switching device 110 is not only compact in size but also quite inexpensive to manufac- '° ture. Further, it will be understood that the switching device 100 may be constructed with either two or three spaced apart generally aligned electrical contacts. Additionally, the switch actuator and the spring contact member may be appropriately modified where only two *⁵electrical contacts are used.

From the foregoing, it should be readily apparent that an electrical switching device especially suitable for use as part of an electro-surgical tool has been dis- ₂o closed and that the device is highly reliable, easily manipulated, economical to produce and uncomplicated in design.

It is to be understood that this invention is not limited to the exact embodiment of the device described and 25 shown which is merely by way of illustration and not limitation, as various other forms and modifications will be apparent to those skilled in the art. For example, it will be understood that the integrally formed, elongated spring contact member may comprise an energy ³⁰absorbing means having a part thereof adapted to be disposed in electrical conducting engagement with one electrical contact of an electrical switching device and a generally L-shaped portion attached to said energy absorbing means wherein said L-shaped portion has a ³⁵free end adapted to be disposed normally out of electrical conducting engagement with another electrical contact of an electrical switching device.