AUTOCLAVABLE POWER-PAK SEAL
United States Patent 3579269
Autoclavable power-pak having a bore in a stainless steel casing housing a lens-end light bulb with an externally threaded base, a heat and pressure resistant silicone rubber seal comprising a tubular body surrounding the bulb and an integral annular flange extending inwardly from its upper end for resilient engagement with the lens end of the bulb to effect a sealing action, and a brass sleeve threadedly mounted on the base of the bulb to effect a sealing action, and a brass sleeve threadedly mounted on the base of the bulb and having a lower outwardly extending flange engaging the case for electric current transfer purposes and the lower end of the tubular body to effect a second sealing action between the bulb and the casing.
US Patent References:
/1288304.html
Wacker - December 1918 - 1288304

Flashlight
Carter - August 1955 - 2716182

Flashlight structure
Stillfried et al. - June 1960 - 2942103

Portable flashlight casing
Ziegenbein - December 1960 - 2963573

Explosion-proof lamp
Rubens - June 1964 - 3137804


Application Number:
04/778288
Publication Date:
05/18/1971
Filing Date:
11/22/1968
View Patent Images:
Assignee:
Medical Products Corp. (Skokie, IL)
Primary Class:
Other Classes:
600/198, 600/133
International Classes:
A61B1/06; A61B1/06; F21L7/00
Field of Search:
240/10.66,10.68,10.65,10.6,11.2,26,11.2 (E.P.)/ 240/6.46,6.41,6.4 (F.E.)/ 128/6--9,11,13,16,18,22
US Patent References:
3103723Inspection deviceSeptember 1963Becker
Primary Examiner:
Horan, John M.
Assistant Examiner:
Greiner, Robert P.
Claims:
I claim

1. In an autoclavable power-pak having a bore in a casing member housing a lens-end light bulb, a heat and pressure resistant seal interposed between said bore and said bulb, comprising a tubular body surrounding said bulb, and an integral annular flange extending inwardly from the upper end of said body for sealing contact with said bulb.

2. In an autoclavable power-pak according to claim 1, wherein said bore defines an annular shoulder, means for exerting pressure longitudinally on said seal to engage the upper end thereof with said shoulder.

3. An autoclavable power-pak according to claim 2, wherein said pressure-exerting means comprises a sleeve interposed between said bulb and said seal having an outwardly extending flange engaging the lower end of said tubular body.

4. In an autoclavable power-pak according to claim 3, wherein said casing member is separably attachable to a second casing member held against said outwardly extending flange and constituting part of said pressure-exerting means.

5. An autoclavable power-pak according to claim 4, wherein said bulb has an externally threaded base, and said sleeve is a metallic conductor threaded thereon with said outwardly extending flange held in contacting engagement with said first casing member by said second casing member.

6. An autoclavable power-pak according to claim 1, wherein said seal is of silicone rubber and said annular flange is in resilient engagement with the lens end of said bulb to effect a sealing action.

7. In an autoclavable power-pak according to claim 1, wherein said annular flange is in resilient engagement with the lens end of said bulb to effect a sealing action, means for exerting pressure against the lower end of said body to effect a second sealing action between said bulb and said casing member.

8. An autoclavable power-pak according to claim 7, wherein said bulb has an externally threaded base and said pressure exerting means comprises an electrically conductive sleeve threaded thereon with an outwardly extending flange at its lower end engaging the lower end of said tubular body.

9. An autoclavable power-pak according to claim 8, wherein said pressure exerting means also includes means for holding said outwardly extending flange on said sleeve in electrical-contacting engagement with said casing member.

Description:
BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to autoclavable power-paks, and more particularly to a novel heat and pressure resistant seal interposed between the light bulb and the casing thereof.

2. Description of the Prior Art

Surgical and diagnostic instruments are known which incorporate means for illuminating interior portions of the human body, but until the invention of my copending application Ser. No. 574,431, filed Aug. 23, 1966, and now abandoned, they did not include battery powered light units or fiber optics devices capable of being autoclaved. That invention provides such autoclavable units, including a power-pak readily separable from and operatively attachable to a surgical instrument disposed in a body cavity, without removing the instrument from the cavity, and also capable of independent use and use with different type of instruments.

The autoclavable power-pak of that invention employs a lens-end light bulb mounted in a stainless steel casing and an O-ring seal interposed between the casing and the bulb. So long as bulbs are available with their dimensions within very limited tolerances, this construction provides a satisfactory heat and pressure resistant seal between the bulb and the casing, but it has been found that such lens-end bulbs vary quite widely in their dimensions and particularly in the vertical distance from the bottom surface of the base of the bulb to the curved intermediate surface of the lens or glass part of the bulb. This is the one dimension which the bulb manufacturers find most difficult to hold within close tolerances, but it also is critical in effecting a satisfactory seal with the O-ring for enabling the unit to be autoclaved.

SUMMARY OF THE INVENTION

The instant invention overcomes this difficulty and enables use of lens-end light bulbs having widely different vertical dimensions from the curved portion of the glass to the bottom of the base in such an autoclavable power-pak while, at the same time, providing an improved seal between the bulb and the casing of the unit and better electrical contact between the latter and the metal ferrule on the bulb base. This is accomplished by means of a heat and pressure resistant seal in the form of a resilient tubular body, preferably of silicone rubber, surrounding the bulb and having an integral annular flange extending from its upper end for engagement with the lens end of the bulb to effect a sealing action therewith. Means also are provided for exerting pressure against the lower end of the seal body to effect a second sealing action between the bulb and the casing which preferably comprises a brass sleeve threadedly mounted on the metal ferrule on the bulb base, with an outwardly extending flange at its lower end engaging the lower end of the seal body and also in electrical-contacting engagement with the case.

In the drawing:

FIG. 1 is a vertical longitudinal section through a power-pak unit embodying the features of this invention;

FIG. 2 is a view similar to FIG. 1 on an enlarged scale through the upper end portion or casing member separated from the unit with a light bulb and my novel seal mounted therein; and

FIG. 3 is similar to FIG. 2 but showing a different bulb having a greater length than that of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring more particularly to FIG. 1, a power-pak unit designated generally by reference numeral 26 is shown which is substantially the same as that of said application for U.S. Pat., Ser. No. 574,431, filed Aug. 23, 1966, and now abandoned, and comprises an upper end portion or casing member 27, a central tubular section or second casing member 28 and a lower end portion 29. It is preferred that this casing be made from a suitable stainless steel, although any desired material may be employed which will not be affected by the very substantial heat encountered in autoclaving. The inner ends of the outer sections 27 and 28 are threaded on their outer surfaces and the ends of the central section 28 are complementally adapted to receive them, while O-rings 31, preferably made of silicone rubber, are interposed between the end surfaces of section 28 and annular flanges 32 formed on each of the end sections 27 and 29. The upper casing member 27 is provided with a longitudinally extending bore forming an open-ended recess 33 at its outer end and a light bulb receiving recess 34 of larger diameter at its inner end separated therefrom by an angularly disposed annular shoulder 35. The end casing member 27 comprises a receptacle for a suitable lens-end high-intensity light bulb 36, the filament-enclosing glass envelope of which is curved intermediate its ends at 37 to provide a reduced outer lens-end adapted to extend freely into the recess 33.

In the unit of said application Ser. No. 574,431, an O-ring seal (not shown herein) is interposed between the curved portion 37 of the bulb 36 and the annular shoulder 35, and pressure is exerted lengthwise of the bulb 36 against that seal by an insulating washer interposed between the base portion 41 of the bulb (usually comprising an outer threaded brass ferrule) and a shoulder 42 defining the inner end of the tapped portion of the central casing section 28. The other or outer end of the casing section 28 also is provided with a similar inner shoulder 42, and an insulating washer 43 is interposed between that shoulder 42 and the inner end of the lower casing section 29. Disposed within the central casing section 28 between this insulating washer 43 and the inner end of the base portion 41 of the light bulb 36 is a source of electric energy in the form of one or more electric cells 44 which are highly heat resistant and preferably enclosed within a suitable insulating tube 45. The lower end portion 29 of the casing of this power-pak 26 also is bored to provide an inner portion 46 of relatively small diameter and an outer portion 47 tapped to receive the threaded portion 48 of a control switch member 49. The latter also includes an inner end portion 51 slidably extending through the inner bore portion 46 and an outer end portion 52 which preferably is knurled to facilitate manual rotation thereof. The inner and outer portions 46 and 47 of the bore receiving the switch member 49 are joined by an annular surface defining a shoulder 53 against which a seal, preferably in the form of an O-ring 54 of silicone rubber, is maintained by means of a coil spring 55 mounted on the inner end 51 of the switch member and interposed between the outer threaded portion 48 thereof and a washer 56. The parts so far described are similar to those disclosed in said patent application Ser. No. 574,431 and are designated herein by the same reference numerals as are therein employed.

In the instant invention, an improved heat and pressure resistant seal between the bulb 36 and the casing member 27 is provided which comprises a resilient tubular body 101 surrounding the bulb 36 and having an integral annular flange 102 extending inwardly from the upper end thereof for sealing contact with the curved intermediate portion 37 of the glass envelope of the light bulb 36. This seal 101, 102 preferably is of silicone rubber and the inner circular dimension of its flange 102 is such as to provide an interference fit with the glass portion of the bulb to effect a sealing action therewith. Means are provided for exerting longitudinal pressure upwardly against the lower end of the tubular body 101 of this seal to effect a second sealing action between the bulb 36 and the upper casing member 27. As previously noted, the bulb 36 customarily includes an externally threaded base or brass ferrule 41, and this pressure exerting means comprises a brass sleeve 103 threaded thereon with an outwardly extending flange 104 at its lower end contacting the lower end of the tubular body 101. As will be appreciated from FIG. 1, this pressure exerting means also includes means for holding the outwardly extending flange 104 on the sleeve 103 in electrical-contacting engagement with the upper casing member 27, which means comprises the upper shoulder 42 in the central casing section 28 and the threaded portions of the casing sections 27 and 28 cooperating to retain the same together in operative relationship.

In addition to providing an extremely effective high temperature and pressure resistant seal between the bulb 36 and the casing section 27 housing it, this construction enables use of light bulbs having fairly wide variations in their vertical dimensions extending from the curved portion 37 of the glass envelope to the bottom of the base 41. This is well illustrated in FIGS. 2 and 3, the light bulb 36a in FIG. 3 having a considerably longer such vertical dimension. Because of this greater length of the bulb 36a, as compared with that of bulb 36 in FIG. 2, the annular flange 102 on the upper end of the tubular body 101 of the seal is merely displaced upwardly from its position of FIG. 2 to that illustrated in FIG. 3 wherein the same sealing effect is provided. And because the aperture in the flange 102 when the seal is in a relaxed condition is smaller than the glass envelope of the bulb, the desired sealing effect will be obtained when the seal and the bulb are operatively assembled, and this will be so even if the glass envelope or an end portion thereof is cocked at an angle to the bulb axis, which often is the case. It also will be appreciated that in addition to its functions of accurately locating the bulb 36 with respect to the seal 101, 102 and the head or end casing section 27 of the power-pak and insuring proper electrical contact between the bulb base ferrule 41 and the casing, the flanged sleeve 103, 104 simplifies and makes more convenient bulb replacement whenever that is required.




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