U.S. patent number 3,870,036 [Application Number 05/428,027] was granted by the patent office on 1975-03-11 for improved speculum barrel member.
This patent grant is currently assigned to Bio-Analytical Laboratories, Inc.. Invention is credited to John M. Fiore.
United States Patent |
3,870,036 |
Fiore |
March 11, 1975 |
IMPROVED SPECULUM BARREL MEMBER
Abstract
A disposable speculum barrel member of circular cross section
tapers to provide a larger proximal end and a smaller distal end.
The barrel member includes a sleeve means having a concentric
flange or window wall at one end which is joined to the proximal
end of the barrel with the sleeve portion extending therefrom. An
obturator in the barrel member may be withdrawn through the sleeve
means. A handle member to which the barrel member is releaseably
secured contains lighting means which is positioned around the
sleeve means and adjacent the window wall and isolated from the
interior of the barrel member.
Inventors: |
Fiore; John M. (Troy, NY) |
Assignee: |
Bio-Analytical Laboratories,
Inc. (Troy, NY)
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Family
ID: |
26939829 |
Appl.
No.: |
05/428,027 |
Filed: |
December 26, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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249110 |
May 1, 1972 |
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Current U.S.
Class: |
600/184 |
Current CPC
Class: |
A61B
1/0669 (20130101); A61B 1/31 (20130101) |
Current International
Class: |
A61B
1/31 (20060101); A61b 001/06 () |
Field of
Search: |
;128/4,5,6,7,8,9,10,11 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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14,508 |
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1906 |
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GB |
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196,069 |
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Apr 1937 |
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CH |
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Primary Examiner: Laudenslager; Lucie H.
Parent Case Text
This is a continuation, of application Ser. No. 249,110, filed
5/1/72, now abandoned.
Claims
What I claim as new is:
1. A single use disposable barrel member for use with a
proctoscopic device having a light source therein comprising in
combination
a. a cylindrical cross-section tapered barrel,
b. said tapered barrel having a smaller diameter opening at its
distal end than at its proximal end,
c. a sleeve means in the proximal end of said barrel and extending
out of said proximal end,
d. said sleeve means having a flange section at one end thereof
defining a radially inwardly projecting annular window wall between
the proximal end of said barrel and said sleeve means,
e. said annular window wall being positioned in said proximal end
of said barrel so that the light source of said proctoscopic device
is positioned behind said annular window wall to pass light through
said annular window wall and directly into the bore of said
barrel,
f. an obturator assembly in said barrel comprising a tip portion
fitting smoothly in said distal end and a stem means attached to
said tip portion and extending through said sleeve means,
g. said sleeve means being of sufficient size to pass said
obturator therethrough and out of said barrel member.
2. The invention as recited in claim 1 wherein said barrel includes
an outwardly flared proximal end portion, an axially projecting
cylindrical portion on said flared portion, and releaseable
securing means on said cylindrical portion adapted to be engaged by
a handle unit.
3. The invention as recited in claim 1 wherein said barrel member
is single use disposable of a synthetic resin material.
4. The invention as recited in claim 1 wherein said taper extends
over a major portion of the effective length of said barrel
member.
5. The invention as recited in claim 1 wherein said taper extends
over essentially the entire effective length of said barrel.
6. The invention as recited in claim 1 wherein said taper is
linear.
7. The invention as recited in claim 1 wherein said taper is
external.
8. The invention as recited in claim 1 wherein said barrel is
frusto conical.
9. The invention as claimed in claim 1 wherein said inwardly
projecting annular window member wall is the flange section of a
separate flanged sleeve assembly means wherein the flange section
is attached to the proximal end of said barrel.
10. The invention as recited in claim 1 wherein engaging means are
provided on said barrel sleeve means to engage a lighting unit
thereto.
Description
BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to speculum instruments generally, and more
particularly to proctoscopic speculums having enclosed,
contamination isolated light directing means at the proximal end of
the barrel through which an obturator may be withdrawn.
2. Description of Prior Art
Speculum instruments may be defined broadly as instruments
adaptable for insertion into a body opening, human or animal, in
order to medically observe or treat an inner portion. In particular
rectal speculums, defined generally as proctoscopic speculums,
including anoscopes and sigmoidoscopes, have become increasingly
important in routine and preventative medical examinations as well
as for medical treatment. More specifically, there is increased use
of sigmoidoscopes for examination and treatment of the upper
reaches of the colon, and disposable sigmoidoscopes for this
purpose are very desirable. However, a notable limitation of these
proctoscopic devices such as sigmoidoscopes relates to the lack of
optimum lighting means employed therewith.
In the use of medical speculum devices generally a light source is
desirable to increase the accuracy of more precise types of
diagnostic examinations, and also to facilitate various treatment
processes carried on through the device. Ordinarily such a light
source may be one which is generally external to the instrument, or
one which is attached thereto at the proximal end, and arranged in
either instance, to have light directed into or through the
speculum. These and other similar arrangements suffice for
short-length speculum devices where relatively low lighting power
of the light source is sufficient. However, in the longer speculum
instruments such as a sigmoidoscope, where the effective length may
be on the order of 25 centimeters or more, and where the instrument
is of necessity an enclosing cylinder, more lighting power is
necessary because of distance involved and the nature of the parts
to be examined. Because of this notable requirement, it is usual
design practice in sigmoidoscopes to have the light source placed
inside the instrument and adjacent the distal end thereof. In this
position, however, the light source is subject to contamination
from contact with the patient directly or indirectly so that
without means for maintaining the light source in a sterile or
sanitary condition, impending reuse for other patients without
intervening cleansing is prohibited. Therefore, the highly
desirable disposability concept of the sigmoidoscope is limited by
its being combined and employed with a lighting means which is not
disposable or immediately reusable.
Another problem associated with the above described and other
lighting means incorporated with the speculum, relates to the
requirement of ease of assembly and detachability of the lighting
means to the speculum so that the speculum may be of a single use
disposable type and the lighting means readily and easily detached
therefrom without requisite skill. A further problem with
proctoscopic devices employing an obturator relates to some
provision for removing the obturator while the lighting means is in
position, without changing the circumferential configuration of the
sigmoidoscope or obturator, to minimize assembly steps prior to
use. Reference is made to U.S. Pat. No. 3,373,736 -- Fiore et al.
and British Pat. Nos. 1,034,222; 1,047,140; 1,048,600 and 1,081,849
for further description of a disposable sigmoidoscope and lighting
means therefore.
OBJECTS OF THE INVENTION
Accordingly, it is an object of this invention to provide an
improved speculum instrument barrel.
It is another object of this invention to provide an improved
single use disposable proctoscopic instrument barrel with an
isolated lighting means area therein.
It is a further object of this invention to provide an improved
single use disposable proctoscopic instrument barrel with an
isolated lighting means area incorporated at the proximal end
thereof.
It is a still further object of this invention to provide an
improved single use disposable sigmoidoscope barrel having a
lighting means area incorporated in the proximal end thereof in
enclosed, protected, and contamination isolation relationship
thereto.
It is yet another object of this invention to provide an improved
single use disposable sigmoidoscopic instrument barrel with
protected lighting means area in the proximal end thereof through
which an obturator may be withdrawn.
It is another object of this invention to provide a single use
disposable sigmoidoscope barrel where the barrel tapers from
proximal to distal end to provide a window walled area behind which
lighting means are isolated, and through which the obturator may be
withdrawn.
It is another object of this invention to provide an improved
single use disposable sigmoidoscopic barrel which tapers to provide
a larger proximal end in which a separate annular window walled
sleeve means defines a protected lighting means area directly
viewable from the distal end, and through which an obturator may be
withdrawn.
BRIEF DESCRIPTION
This invention in one of its preferred forms includes a single use
disposable sigmoidoscopic barrel having a tapered, bore to provide
an enlarged proximal end. A smaller sleeve means has a clear
plastic flange at one end which is concentrically attached to the
enlarged end of the barrel with the flange providing an annular
window wall radially within the enlarged end of the barrel and the
sleeve projecting axially therefrom. A handle lighting unit is
fitted coaxially over the sleeve so that light from a lamp therein
is directed through the annular window and down the barrel. The
sleeve aperture is slightly larger than the opening of the distal
end of the barrel so that an obturator may be withdrawn through the
sleeve, and the sleeve protects the lighting means from
contamination.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention will be better understood when taken in connection
with the following description and drawings in which
FIG. 1 is a side elevational view of one preferred embodiment of
this invention.
FIG. 2 is an illustration of a separate sleeve means for this
invention.
FIG. 3 is a cross-section and axial view from the proximal end of
the embodiment of FIG. 1 along line 3--3.
FIG. 4 is a cross-section and axial view from the distal end of the
embodiment of FIG. 1 along line 4--4.
FIG. 5 is an illustration of a detachable handle and light assembly
for FIG. 1 along line 5--5.
FIG. 6 is a side elevational view of a modified barrel member of
FIG. 1.
FIG. 7 is a side elevational view of a modified proximal end
arrangement of the FIG. 1 embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1 the speculum instrument 10 is preferably a
protoscopic instrument, which in an exemplary embodiment, is a
sigmoidoscope. Instrument 10 is best described as incorporating two
separable structures, e.g., a barrel member or barrel 11 which is
preferably a single use disposable item, and a handle lighting unit
12 which is usually of a permanent or semi-permanent nature.
Barrel 11 may be expeditiously manufactured from a material which
is readily and economically single use disposable. The material
must be one which is ordinarily sterilizable and which retains
sufficient rigidity without brittleness. In one preferred form of
this invention the material for barrel 11 may be a moldable and
extrudable synthetic resin such as linear polyethylene and
polypropylene as noted in the aforementioned U.S. patent and the
applications referred to therein.
It is a salient and foremost feature of this invention that barrel
11 includes a tapering or gradual enlargement preferably from the
distal end 13 to the proximal end 14 thereof. A tapered barrel is
one that is generally frusto conical or flared over its effective
length, i.e., the length of barrel 11 which is inserted in a body
opening. This tapering or flaring provides an opening or diameter
of the enlarged proximal end 14 which is significantly larger than
the distal end 13 opening. It is preferred that the taper retain
the circular cross-section of barrel 11, and that the taper
commence at or very close to the distal end 13 of barrel 11. The
defined taper may be linear, as frusto conical, or it may be
curvilinear, such as being flared or bell mouthed, i.e., inwardly
bowing, or slightly convex or domed, i.e., outwardly bowing. Under
some conditions the tapering may commence at a point between the
proximal and distal ends of barrel 11. The proximal end of barrel
11 may include a more abruptly flaring or radial part 15, which may
also extend sharply radially to define an end shield or hand guard
16.
In order to define a walled area which is an isolated and protected
light position or chamber, an end sleeve means 17 is positioned
adjacent flare part 16 of barrel 11 and suitably attached thereto.
Ordinarily, sleeve means 17 is considered a part of barrel member
11. As illustrated in FIG. 2, the sleeve means 17, in one preferred
embodiment includes a generally cylindrical section 18 and a flange
or window wall section 19. In one form of this invention, flange
window wall 19 is press fitted into a locking shoulder 20 on
flaring part 16 of barrel 11. A number of other suitable joining
means may be gainfully employed to secure window wall 19 to flare
part 16. For example, direct locking means may take the form of
mating screw threads on each part, a snap fit, or a suitable
interlock. Indirect means may take the form of cementing of the
parts or a press fit of the parts. Alternatively sleeve means 17
may be molded as an integral part of barrel 11, or may in fact be a
separate device attached to handle unit 12.
Because of the defined taper of barrel 11, the flange section 19
defines an inwardly projecting annular window wall 19, which in
combination with cylindrical section 18 defines an area remote from
or isolated from the main channel through barrel 11. Window wall 19
projecting inwardly, as it does, has an unobstructed view of the
distal end opening 13 of barrel 11, and for this reason window wall
19 is made of a transparent material such as a clear synthetic
resin, or has suitable clear sections or lenses therein. Therefore,
a lighting means in handle lighting unit 12, and behind window wall
19, will transmit light down barrel 11 to the distal end.
Cylindrical section 18, however, is of limited transparency and
preferably non-transparent, either because of the material from
which it is produced, or by reason of suitable coloring or
coatings.
An obturator assembly (shown in dashed line outline) includes a
smooth ovate tip portion 21 whose maximum diameter closely
approximates the internal diameter of the smooth rounded distal end
opening 13 of barrel 11. A stem means 22 extends from the tip
portion 21 through barrel 11 to project from the proximal end
thereof. An obturator is employed primarily to facilitate insertion
of a speculum 10 or barrel 11 into a body orifice such as the
rectum, and this use is an accepted and established practice. After
insertion of the barrel a short distance into the rectum, just
beyond the sphincter muscle, the obturator is withdrawn.
Thereafter, in accordance with present well known sigmoidoscopes, a
lighting means would be inserted into barrel 11, such as for
example the lighting means of U.S. Pat. Nos. 3,373,736 or
3,032,031.
In the noted present practice the lighting means in the barrel is
exposed to contamination by being near the open distal end and
because withdrawal of the obturator ordinarily contaminates the
inside of the barrel. Additionally when certain instruments are
passed into the barrel, or where swabbing practices take place, the
inside of the barrel as well as the lighting means therein are
further contaminated. Accordingly, the lighting means must be of a
stringent design so as to be of a readily sterilizable or
sanitizable nature, or suitably protected. There are a number of
problems associated with each facet noted. Sterilization of the
lighting means or the barrel is an undesirable and uneconomical
process which is subject to error. The protective sleeve and other
protective arrangements are usually cumbersome and lacking in
handling as well as lighting efficiency.
It has been discovered that the noted problems are significantly
overcome by the use of tapered barrel 11, as illustrated in FIG. 1,
which, in combination with a sleeve means 17 provides for obturator
removal with lighting means remaining in position and not being
contaminated. For example, in the illustrated arrangement of FIG.
1, sleeve means 17 has an internal bore diameter larger than the
maximum diameter of distal end opening 13 so that an obturator tip
may easily pass therethrough. Suitable guiding ramps may be
provided as extensions on sleeve means 17 into barrel 11 or as
raised surfaces on the inner surface of barrel 11 to facilitate
withdrawal of the obturator. Contact of sleeve means 17 with
obturator tip 21 is not a problem since sleeve means 17 is disposed
of with barrel 11.
The handle lighting unit 12 comprises generally, a handle part 23
and a lighting head 24 which connects to barrel 11 and contains the
lamps 25. The lighting head 24 comprises an annular part 26 having
a distal end facing recess 27 therein. Recess 27 which may be
annular or suitably compartmentalized is next adjacent annular
flange window wall 19, and closed off by cylinder 18 so as to be
isolated chamber containing therein a plurality of usually equally
circumferentially spaced lamp means 25. As illustrated in FIG. 1
four such lamp means are utilized, and while a single lamp may
provide some degree of lighting, two or more are preferred. A
single ring or pair of half ring lamps may also be used to good
advantage. The important concept, however, is to have the lamp
means not only isolated and remote from the main channel of barrel
11 but yet to remain in exposed or viewing relationship to the
distal end of barrel 11. By this means the main channel of barrel
11 remains open for the unobstructed passage of various
instruments, swabs, and the obturator without danger of
contamination of the lighting means.
Light transmission may be further increased by the use of
pre-focused lamps, lamps with an integral mirror surface, or by the
use of focussing reflectors 28 in recess 27 of lighting head 24.
The combination of an annular transparent window wall 19, lamps 25,
and reflectors 28 may be suitably integrated in function and effect
to focus and direct a substantial amount of light at the center
line of the distal end of barrel 11. This invention may also
provide for a high intensity light source in handle light unit 12
which is merely reflected by a suitable mirror or other light
directing and amplifying means in the space or recess 27 presently
occupied by lamps 25.
Light transmission down barrel 11 and its quantity and direction is
important to the practice of sigmoidoscopic examination. The
lighting means as described is advantageous because it permits the
use of plural lamps, or a single lamp in ring form, with greatly
increased wattage and more distal end light, as compared to a
single lamp in barrel 11 and in spite of the more rearward location
of lamps 25.
The effectiveness of the lighting means is increased by avoiding
glare in barrel 11 and, for this reason the inner surface of barrel
11 may be treated, colored, or formed so that glare is reduced, and
effective light transmission increased.
The annular flange window wall 19 has an effective light
transmitting height, measured generally from the upper surface of
cylindrical section 18 to the inner surface of the end of the taper
of barrel 11, which is dependent on the amount of taper in barrel
11. While the taper may vary to a considerable degree, an effective
light transmitting height need be no more than from about
one-sixteenth to about one-eighth inch. It is most desirable to
concentrate the lamp means 25 as near to the center line of barrel
11 as expedient in order to provide as much uninterrupted light
transmitting down barrel 11, and for this reason excessive taper of
barrel 11 is not necessary for lighting purposes.
The lighting head 24 is provided with means to releaseably secure
it to barrel 11. Releaseable securing is intended to mean those
attaching or affixing devices not ordinarily intended to be of a
permanent nature, and are intended to be a part of or utilized in
the operation of the device. Quick disconnects, latches and the
like which play a significant role in one cycle use are further
examples of releaseable securing devices. One example of a
convenient releaseable securing means is illustrated in FIG. 1 by
the mating screw thread or camming means 29 on annular part 26 as
well as on cylindrical extension 18. Other locking devices
including snap acting, detent and such interlocking devices may
also be utilized with good advantage not only between the annular
part 26 and cylindrical extension 18, but also in lieu thereof,
between or together with annular part 26 and radial part 16 of
barrel 11.
In some instances it may be desirable to include a biasing or
spring acting interlock between lighting head 24 and barrel 11.
Such spring loading releases may forcibly eject the barrel 11 from
lighting unit 12 by operation of a release mechanism by the medical
practitioner. The forcible ejection as a practical matter need only
move the barrel assembly a fraction of an inch to be effective. One
such eject mechanism is disclosed and claimed in combination with a
vaginal speculum in copending application Ser. No. 529,444 -- Fiore
now U.S. Pat. No. 3,533,088.
The lighting head 24 includes a handle unit extension 23 which may
be separably attached or, ordinarily an integral part thereof.
Handle part 23 may be of various configurations and primarily is of
a generally cylindrical shape for ease in handling as well as to
serve as a conveniently shaped housing for a power unit such as a
battery 30 (shown in dotted lines in FIG. 1) preferably of the
rechargeable type as described in the above noted U.S. patent. The
battery or batteries 30 in handle part 23 may be suitably connected
to a combined on-off-rheostat element 31 and then to lamps 25 so
that the medical practitioner may exercise light control when
needed or desirable. Battery 30 may be suitably recharged by
inserting the handle part 23 in a recharger for recharging as known
in the art. Alternatively, battery 30 may be removed from handle
part 23 by removing an end cover and placing the battery 30 itself
in a recharger as well known in the art. Provision may also be made
to provide an electric extension lead connected to lamps 25, or to
a transformer and then to lamps 25, to obtain electrical power from
a domestic or commercial power source or outlet.
It is desirable, in the practice of sigmoidoscope examinations, to
have a suitable closure member and lens assembly at the proximal
end of a sigmoidoscope as well as at the same end of a host of
other speculum instruments. Accordingly, in the present invention a
suitable end cap unit 32 is affixed to the lighting head 24 and may
be hinged as a rotary slide opening or a gate hinge type opening,
as is known in the art. Alternatively the end cap unit may be a
separate eyepiece which is suitably attached as desired. End cap
unit 32 is usually provided with an optical lens 33 to facilitate
examination. As such, the lens 33 may be a magnifying lens, or lens
assembly including if desirable suitable optical adjusting means
for focussing, for example.
In some instance either a positive air pressure or a negative air
pressure (from room conditions) is desirable in connection with
sigmoidoscopy. For example, a negative pressure is generated by
gentle suction to remove gases, smoke from cauterization and the
like. A positive pressure may be employed to slightly distend
certain areas of the colon to facilitate examination. Both suction
and pressure is applied through a nipple or conduit 34 which
projects from lighting head 21 and communicates to the interior of
barrel 11 through an appropriate opening or slot 35 (not shown) in
cylindrical section 18.
Sealing means are employed to retain pressure or suction at the
proximal end of the instrument 10. For example, a seal is provided
between radial part 16 of barrel 11 and the adjacent face of
annular lighting head 24. Such a seal is preferably in the form of
a ring type gasket 36 retained in a seal cavity 37 in the face of
lighting head 24. Ring seal or gasket 36 may be of a number of
configurations and materials including relatively soft O rings of
medically serviceable materials. In one embodiment of this
invention ring seal 36 is of a neoprene material and U shaped to be
expanded, by air pressure, into contact with opposed walls. A
further ring seal such as a relatively soft O ring 38 is employed
between end cap unit 26 and lighting head 24. Ring seal 38 may also
be disposed in a suitable recess 39 in lighting head 24. Seal 36 is
compressed by engagement of lighting head 24 to the radial flange
16 in combination with screw threads 29. Seal 38 may be compressed
by means of a suitable cam clip 40 engaging cam groove 41 in
lighting head 24. Seals 36 and 38 effectively close off the
proximal end of the speculum instrument so that gentle pressure is
exerted through the distal end of barrel 11. During examination
certain gaseous results of treatment are also removed by gentle
suction.
The radial flange part 16 of barrel 11 may serve as a hand guard
unit as employed with sigmoidoscopes generally and may be further
radially extended, and also curve towards the proximal end, for
this purpose. Alternately, a separate hand guard may be attached to
the barrel 11 or molded integrally therewith.
The speculum instrument 10 of this invention is readily adaptable
for use as other speculum type instruments particularly
proctoscopes and anoscopes generally. In this connection barrel 11
may be made shorter to serve as an anoscope, for example, or of
smaller diameter for smaller body openings. The handle unit 12 is
further adaptable to a wide variety of uses in medical practice
where a good source of light is needed. As such, it may be
gainfully employed with other medical instruments, disposable or
otherwise, which may be adaptable thereto including, for example,
opthalmoscopes and otoscopes.
FIG. 3 illustrates a view of the speculum 10 from the proximal end
thereof along line 3--3. In FIG. 3 the lamps are shown in phantom
to illustrate their position adjacent window member 19. The
diameter difference between window wall 19 and barrel 11 is
correlated to the difference in diameters of opening 13 and barrel
11. This difference which represents the taper of barrel 11
provides the direct exposure of a portion of lamp 25 to distal end
opening 13. While four lamps 25 are shown, the number may be
suitably varied for example by the use of two or three lamps. In
some instances varying degrees of lighting might require a maximum
of four lamps, and other instances a less number of lamps. The
on-off switch 31 may be suitably provided with a step switching
means to control the number of lamps energized.
FIG. 4 illustrates a view somewhat opposite to that of FIG. 3. The
FIG. 4 view is from the distal end opening 13 along line 4--4 of
FIG. 1 and assumes an angle view from the center line of FIG. 1.
Accordingly that portion of window wall 19 which is directly
exposed to distal end opening 13 is clearly shown.
FIG. 5 illustrates the handle unit 12 of this invention separate
from barrel 11 and readily adaptable for insertion into a battery
charging unit or other storage device. FIG. 5 also illustrates the
adaptability of handle unit 12 as a general light source alone or
with other instruments.
The foregoing describes one complete embodiment of this invention.
Other embodiments and modifications may also be provided, the
important feature being the taper of the barrel to provide an
isolated or protected lighting area without any significant change
in the operation, effectiveness and use of the instrument. However,
barrel 11 may be tapered externally and/or internally to provide
this feature. In FIG. the barrel may be described as having an
external taper to provide the enlarged proximal end. Internal
tapering may also provide an enlarged proximal end, as illustrated
in FIG. 6.
In FIG. 6 barrel 38' is similar to barrel 11 of FIG. 1 and includes
the same general dimension of the proximal end as barrel 11. Barrel
38 includes an internal taper which is provided by a wall thickness
39 which increases towards the distal end. This thick wall section
at the distal end serves as a support 40 for the obturator 21'. To
accommodate the internal taper the obturator 21' may be slightly
smaller than obturator 21 of FIG. 1 and/or the proximal end
dimensions may be somewhat larger. The internal taper may not be
required over the effective length of the barrel but only need be
utilized close to the distal end with the remaining wall lengths
being of relatively constant thickness.
The combination of tapers, both internally and externally, may be
an advantageous compromise because a slight taper is usually
employed to facilitate removal of a barrel from an injection mold
process, when such a process is employed. This pre-taper may be
incorporated in this invention.
A further modification of this invention is illustrated in FIG. 7.
FIG. 7 comprises a sectional and top view of a modified lighting
head 41 similar to lighting head 24 of FIG. 1, and flare part 42 of
barrel 11', similar to flared part 15 of FIG. 1. FIG. 7, flared
part 42 includes a flange portion 43, and a projecting portion 44
which projects into and engages lighting head 41. Lighting head 41
includes a recess 45 into which projecting portion 44 is positioned
and retained. The retaining means includes the combination of a
circumferential groove 46 in projecting portion 44 and a plurality
of circumferentially spaced spring biased balls commonly known as
ball detent devices, one of which is shown schematically at 47.
Lighting head 41 also includes a pair of oppositely disposed bell
crank or angle members 48 and 49 which are pivoted at 50 and 51 so
that the arms 52 and 53 engage the free end of projecting portion
44.
As illustrated the application of a depressing force on the exposed
arms of angle members 48 and 49 will cause a pivoting action so
that arms 52 and 53 bear against projection 44 and move the barrel
assembly axially outwardly from the lighting head 41. When the free
edge of projecting portion 44 passes by the spring biased balls of
detent devices 47, a camming action occurs to positively release
and eject the barrel from the lighting head. Various other positive
ejection, electrical or mechanical means may be employed to cause
removal of the barrel assembly from the lighting head without the
necessity of the practitioner touching a potentially contaminated
barrel assembly. This releasing mechanism accomplishes a positive
release and automatic ejecting mechanism which greatly expedites
the use of this invention.
The flare part 42 of barrel 11 also provides direct lighting
through the distal end of the barrel in that the circular row of
lamps 58 are at least partly exposed to the distal end, as
illustrated in FIG. 3, for example. Ordinarily a straight line may
be drawn from a lamp through the distal end of the barrel without
crossing any barrel structure which would obstruct light
passage.
While other modifications of this invention and variations of
apparatus may be employed within the scope of this invention and
have not been described or illustrated, the invention is intended
to include all such modifications as may ordinarily be embraced
within the following claims.
* * * * *