WO1994003101A1

WO1994003101A1 - Laryngoscope having removable blade assembly containing lamp

Info

Publication number: WO1994003101A1
Application number: PCT/US1993/007115
Authority: WO
Inventors: William Lacey
Original assignee: William Lacey
Priority date: 1992-07-28
Filing date: 1993-07-28
Publication date: 1994-02-17
Also published as: US5355870A

Abstract

This laryngoscope (10) has a cylindrical metal casing (12) serving as a handle. A blade assembly (40) is rotatably mounted on the casing (12) between angularly spaced operating and nonoperating positions. Batteries (18, 20) in the casing (12) apply positive electric polarity to an electrode (28) on the casing (12) and negative electric polarity to the casing (12). A lamp (46) having a bulb (47), a base (48) and an end terminal (50) is mounted on the blade assembly (40) with the terminal (50) in contact with a leaf spring (52) which in turn contacts the electrode (28) when the assembly (40) is rotated to an operating position. A flange (32) on the casing (12) contacts the base (48) to complete a power supply circuit for lighting the bulb (47). A light conductive rod (44) extends from the bulb (47) to project light into the patient's larynx while a blade (38) depresses the patient's tongue. A hook (62) on the blade assembly (40) enables easy mounting and removal of the assembly (40) from the casing (12).

Description

LARYNGOSCOPE HAVING REMOVABLE BLADE ASSEMBLY CONTAINING LAMP

1 . Field of the Invention This invention relates to improvements in laryngoscopes used for examining the larynx of a patient; and more particularly concerns a laryngoscope having a handle for accommodating a rotatable, removable blade assembly containing a light conductor and lamp powered by batteries in the handle .

2 . Description of the Prior Art It is known to provide a laryngoscope with a handle carrying a plurality of bat teries for energizing a lamp . The handle accommodates a removable blade which serves as a tongue depressor. The blade may carry a light conductor to convey light from the lamp to the larynx which is to be visualized. None of the prior art laryngoscopes have an inexpensive disposable blade carrying both lamp and light conductor rod, with contact means for energizing the lamp only when the blade is in operating position .

SUMMARY OF THE INVENTION The present invention is directed at providing an improved laryngoscope which avoids the deficiencies of prior known laryngoscopes . According to the invention , the laryngoscope has a metal cyl indrical casing containing a plurali ty of bat teries . The casing serves as a handle for the laryngoscope blade . At one end the batteries are in contact with a coil spring through which negative polarity is conveyed to the casing . At the other end the ba tteries are in contact with a central electrode which is maintained continuously a t posi ti ve polari ty . The casing has upstanding flanges wi th a cross pin rota table carrying a removable blade assembly. The blade assembly has an inexpensive , plastic body into which is inserted a transparent light conducting r--d in direct contact with the bulb of a lensed end lamp . The lamp has an electrically conductive base and a central terminal insulated from the lamp base . The blade assembly can be rotated between an operating an a nonoperating position on the casing or handle . In the operating position , a conductive leaf spring member is in direct contact with the central electrode having posi tive polarity . The leaf spring member is also in contact wi th the central terminal of the lamp, to apply a posi tive polari ty to the lamp . At the same time one of the flanges carrying the cross pin on which the blade assembly is mounted is in direct contact with a side of the metal lamp base so tha t negative electrical polarity is applied to the lamp base . This causes the lamp to light and to project i ts light through the light conductor rod carried by the blade body, forwardly to illuminate the larynx of a patient while the b lade is used to depress the tongue . When the blade assembly is rotated on the battery casing to a nonoperating posi tion , the flange on the casing separates from the lamp base and at the same time the leaf spring separates from the terminal electrode of the batteries . This opens the power supply circuit for the lamp and its light is extinguished . The blade assembly can easily be removed after use and discarded, and another blade assembly can be quickly mounted in its place on the battery casing. It is therefore a principal object of the present invention to provide a laryngoscope having an inexpensive and disposable laryngoscope blade .

It is a further object of the present invention to provide a laryngoscope having an inexpensive and disposable laryngoscope blade which has a sel f contained light source and fiber optic tube .

It is another object of the present invention to provide a laryngoscope having an inexpensive and disposable laryngoscope blade which utilizes a conventional lensed bulb as a source of l ight .

These and other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by the reference to the following detailed description when considered in connection with the accompanying drawings in which : BRIEF DESCRIPTION OF THE DRAWINGS

Fig . 1 is a side elevational view of the laryngoscope embodying the invention , wi th blade assembly shown in operating posi tion , the power supply circuit to the lamp being closed; Fig. 2 is a fragmentary front elevational view taken along line 2-2 of Fig . 1 ;

Fig . 3 is an axial sectional view taken along line 3-3 of Fig. 1 ;

Fig . 4 is a side elevational view similar to Fig. 1 , with blade assembly shown rotated to nonoperating position;

Fig. 5 is a fragmentary exploded perspective view of an end part of the bat tery casing or handle and an end portion of the blade assembly, which engages rotatably on the end part of the bat tery casing; Fig . 6 is a perspective view of the leaf spring per se which serves as a contact member to the central electrode of the batteries and to the terminal of the lamp;

Fig . 7 is a perspective view of the blade assembly per se shown in an inverted position; and Fig . 8 is an enlarged fragmentary sectional view taken along line 8-8 of Fig. 8 , showing associated parts of the blade assembly .

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings wherein like reference characters designate l ike or corresponding parts throughout , there is il l ustrated in Figs . 1 to 4 , a l aryngoscope 10 having a hollow cylindrical metal casing

12 . The casing has scoring or knurl ing 1 4 on the outside to provide a sl ip-proof handgrip to the casing 12 which serves as a handle for the laryngoscope . A screw cap 16 and a gasket 15 are removabl e engaged in the bottom of the casing 12. The cap 16 carries a coil spring 1 7 which extends axially upwardly in the interior of the casing 16. Inside the casing 12 are a pair of dry-cell batteries 18 , 20. The coil spring 1 7 bears upwardly against the bottom of a metal case 22 of the bat tery 20 thereby applying a negative electrical polari ty to the casing 12 . A positive terminal 24 of the upper battery 18 bears against a metal plug 26 which terminates in a central upwardly projecting terminal electrode 28 at the top of the casing 12. Positive electrical polarity is applied to the electrode 28 from the terminal 24 of the battery 18. An annular insulator 30 set in the top of the casing 12 surrounds the electrode 28 and holds i t in place . Extending upwardly from the top of the casing 12 are two integral metal flanges 31 , 32 . The flanges 31 , 32 are parall el and carrying a horizontal cross pin 34 ; see Figs . 2 and 5 .

A blade assembly 40 generally designated as reference numeral 40 is rotatably and removable mounted on the pin 34 . The blade assembly 40 has an opaque plastic body 36 terminating at its forward end in a bl ade 38 which serves as a tongue depressor in a patient . The body 36 has a longitudinal , l a teral channel 42 in which is set a transparent plastic l ight conductor rod 44 . Rearwardly of the rod 44 is a lamp assembly 46; see Figs . 7 and 8 . The lamp assembly 46 is disposed axially parallel to the rod 44 and is comprised of a transparent lensed light emitting lamp bulb 47 , a metallic base 48 and a central , metal terminal 50. A leaf spring 52 as best shown in Fig . 6 has a generally L-shaped configuration . A flexible tongue 54 , from the leaf spring 52 extends laterally out of a channel

56 in the plastic body 36. The rear end portion 58 of the spring 52 extends through the channel 56 in the body 36 and makes firm contact wi th the terminal 50 of the bulb 47; see Figs . 3 , 7 , and 8 . The body 36 is formed wi th an integral hook 62 which can easily be engaged on the cross pin 34 and can easily be removed therefrom . When the blade assembly 40 is in the upright position, as shown in Figs . 1 , and 2 , the conductive tongue 54 contacts the exposed to of the central electrode 28. This applies a positive electrical polarity to the bulb 47 via the bulb terminal 50. At the same time the flange 32 is pressed into firm direct contact with a side 49 of the base 48; see Fig . 3 . This applies a negative electrical polarity to the bulb 47 and the bulb lights, as soon as and as long as the blade assembly 40 is held in the raised position shown in Fig . 1 . When the blade assembly 40 is lowered to the position shown in Figs . 4 , the tongue 54 separates from the top of the central electrode 28 , and at the same time the side 48 of the bulb 47 separates from the flange 32. Thus the positive and negative circuit paths from the batteries 18 , 20 are simul taneously broken . The blade assembly 40 thus serves as a single throw, double pole switch to close and open the power supply circuit for the lamp assembly 46.

After a single use, the entire blase assembly 40 can be removed by lifting i t off of the cross pin 34 . The plastic body 36, the rod 44 , the lamp assembly 46 and the leaf spring 52 can all be discarded at the same time , so that the cross pin 34 is ready to receive another replacement blade assembly 40 for reuse of the laryngoscope 10. The double pole switch arrangement of the spring 52 and the side 48 of the bulb 47 insures an uninterrupted power supply to the lamp assembly 46 when the blade assembly 40 is in the operating posi tion of Fig. 1 and insures that the lamp assembly 46 is extinguished when the blade assembly 40 is in the nonoperating position of Fig.

4 . This conserves the bat teries against accidental turn-on and unnecessary power consumption .

The lensed bulb 47 may be a conventional flashlight bulb such as Penli te 222. If desired a parabolic reflector 59 as ill ustra ted in phantom in Fig . 8 , may be inserted over the bulb 47 to increase the light intensity of the light transmitted to the conductor rod 44.

It should be understood that the foregoing relates only to a limited number of preferred embodiments of the invention which have been by way of example only, and that is intended to cover all changes and modifications of the examples of the invention herein chosen for the purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention .

Claims

WHAT IS CLAIMED:

1 . A laryngoscope, comprising an electrically conductive casing closed at one end and having an electrode at said other end of said casing; battery means in said casing arranged to apply a positive electric polarity to said electrode and a negative electric polarity to said casing; an elongated insulated blade assembly, removably mounted near one end thereof, on said other end of said casing and rotatable thereon, between operating and nonoperating posi tions spaced angularly apart; a lensed end lamp mounted on said blade assembly near said one end thereof, said lamp having a bulb, a base and an end terminal ; first circui t means carried by said blade assembly and arranged to contact said end terminal of said lamp to apply said positive electric polarity thereto from said electrode when said blade assembly is in said operating position; and second circui t means carried by said casing and contacting said base of said lamp, for lighting said lamp only when said blade assembly is in said operating position , and for extinguishing said lamp when said blade assembly is rota ted to said nonopera ting posi tion .

2. A laryngoscope as claimed in Claim 1 , wherein said blade assembly has an axial projecting blade at another end thereof, to depress the tongue of a patient , when said lamp ill umina tes the larynx of a patient during examination thereof.

3. A laryngoscope as claimed in Claim 1 , further comprising a light conducting rod mounted on said blade assembly in contact wi th said bulb of said lamp at one end of said rod to conduct light therefrom, said rod having its other end disposed on said blade for conducting light from said lamp through said rod to the larynx of said patient when said bulb depresses said tongue of said patient .

4 . A laryngoscope as claimed in Claim 3 , wherein said casing has a pair of parallel flanges at said one end of said casing, and a cross pin connecting said flanges to serve as a support for said blade assembly in rotating thereon between said operating and said nonoperating positions .

5. A laryngoscope as claimed in Claim 4 , wherein said one end of said blade assembly is formed with a hook detachably engaged with said cross pin for rotating thereon , and for removing said blade assembly therefrom.

6. A laryngoscope as claimed in Claim 4 , wherein said lamp base is laterally exposed on said blade assembly for contacting one of said flanges when said blade assembly is rotated to said operating posi tion , to apply said negative electrical polarity from said casing to said lamp .

7. A laryngoscope as claimed in Claim 6, wherein said first circuit means comprises a metallic electrical conductor having one portion in contact with said end terminal of said lamp and a free portion engageable with said electrode when said blade assembly is in said operating position .

8. A laryngoscope as claimed in Claim 7 , wherein said one flange constitutes said second circuit means for applying said negative polarity from said casing to said lamp .

9 . A laryngoscope as claimed in Claim 8 , wherein said metallic electric conductor and said one flange cooperate to constitute said single throw, double throw switch means for lighting said lamp when said blade assembly is in said operating posi tion .

10. A laryngoscope as claimed in Claim 3 , further incl uding a parabolic reflector surrounding said lamp for increasing the intensi ty of l ight transmitted to said light conducting rod .