ANAESTHETIC VAPORIZER FILLER

Abstract

A filler for an anaesthetic vaporizer used for veterinary surgery. The filler is attached to a cylindrical bucket portion of the vaporizer. The filler is curved in shape and having a concave mounting surface that is obverse to the cylindrical bucket portion. The filler having fluid conduits therein interconnecting first apertures on the concave mounting concave surface and a filler-port unit, the first apertures on the mounting surface aligning with associated second apertures on said bucket. A gasket with a plurality of first holes aligned with first and second apertures is disposed between the bucket and the filler.

Claims

1. A filler for an anaesthetic vaporizer used for veterinary surgery, said filler attached to a cylindrical bucket portion of said vaporizer, wherein said filler is curved in shape and having a concave mounting surface that is obverse to said cylindrical bucket portion, said filler having fluid conduits therein interconnecting first apertures on said concave mounting concave surface and a filler-port unit, said first apertures on said mounting surface aligning with associated second apertures on said bucket, and a gasket with a plurality of first holes aligned with first and second apertures is disposed between said bucket and said filler.

2. A filler as claimed in claim 1, wherein said filler is provided with a plurality of third apertures, aligned with a plurality of fourth apertures in said bucket and a plurality of second holes in said gasket, said third plurality of apertures allowing for threaded fasteners to be inserted from external of said filler through said plurality of second holes in said gasket and through to said fourth apertures in said bucket to attach said filler to said bucket.

3. A filler as claimed in claim 1, wherein said threaded fasteners are captive screws that do not extend into the reservoir disposed within said cylindrical bucket.

4. A filler as claimed in claim 1, wherein said filler has a sight window disposed thereon at or near one end of said filler, and said opposed end has an upper portion overhanging a side mounting surface to which a filler port unit is attached, said filler port unit having a lower surface that is substantially flush with the bottom surface of said filler.

5. A filler as claimed in claim 1, wherein the fluidally connected breather holes in said filler are spaced both vertically and horizontally to each other.

6. A filler as claimed in claim 1, wherein the body of said filler is made of brass and coated with nickel.

7. A filler as claimed in claim 1, wherein said vaporizer is for vaporising anaesthetic liquid being dispensed to an animal patient via an associated anaesthetic delivery machine.

8. A vaporizer and filler in combination, said vaporizer having a cylindrical outer bucket containing a reservoir for containing anaesthetic, said filler having a concave mounting surface obverse to said outer cylindrical bucket, said filler mounted to said vaporizer via said concave mounting surface abutting against said cylindrical outer bucket with a gasket disposed there between, said filler attached to said vaporizer by captive screws fitted from external of said vaporizer.

9. A vaporizer and filler in combination as claimed in claim 8, wherein said filler has a filler-port unit attached thereto at or near a lower corner portion of said filler, and said filler-port unit having a lower surface that is substantially flush with the bottom surface of said filler.

10. A vaporizer and filler in combination as claimed in claim 8, wherein said filler has fluidally connected breather holes therein spaced both vertically and horizontally to each other.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0033] FIG. 1 is a perspective view of a “prior art” Tec 3 vaporizer with filler.

[0034] FIG. 2 is a perspective view of a vaporizer and filler in accordance with a first embodiment of the present invention.

[0035] FIG. 3 is an enlarged perspective view of the body of the filler shown in FIG. 1 with the valve and fill-port unit removed.

[0036] FIG. 4 is an enlarged perspective view of a gasket used with vaporizer and filler shown in FIG. 1.

[0037] FIG. 5 is a schematic of the rear view (concave surface) of the body of the filler shown in FIG. 3.

[0038] FIG. 6 is a schematic top view of the body of the filler shown in FIG. 3.

[0039] FIG. 7 is a schematic cross-sectional view of the body of the filler through G-G on FIG. 6.

BEST MODE OF CARRYING OUT THE INVENTION

[0040] FIGS. 2 to 7 depict a first embodiment of a vaporizer 1 and a filler 2 attached thereto. Vaporizer 1 is preferably an anaesthetic vaporizer used with anaesthetic machine for veterinary patients.

[0041] External bucket 3 and the internal reservoir (not shown) disposed therein of vaporizer 1 are made of aluminium that is nickel coated by electroless process for heavy corrosion resistance, and then chrome finished for aesthetic purposes. The nickel coating material delivered by the electroless process is impervious to modem anaesthetics such as halothane and isoflurane and penetrates deeper bores over older conventional plating.

[0042] The body of filler 2 is preferably made of solid brass and nickel coated and chrome finished for aesthetic purposes.

[0043] In manufacture the single block of brass used to manufacture the body of filler 2, can have the various holes/bores machined on an inexpensive three-axis CNC machine. Filler 2 is curved entirely in one plane and has a concave mounting surface 12 that is substantially obverse to the outer surface 5 of cylindrical bucket 3. Concave mounting surface 12 of filler 2 abuts against the outer surface 5 of bucket 3 via a thin sheet gasket (seal) 4.

[0044] As can be seen in FIG. 3, the width of the body of filler 2 at its top end is about the same as its height dimension, which is significantly different to the prior art filler 102 as shown in FIG. 1, which looks significantly elongate with its height dimension significantly greater than its width. Furthermore, the depth of filler 2, namely the dimension to which it extends outwardly from bucket 3, is smaller than that of prior art 102. This configuration of filler 2, possible as result of concave mounting surface 12 has significant advantages which will be detailed later on.

[0045] Filler 2 has three apertures 6, through which three attachment screws 7 pass through to vaporizer 1 via gasket 4. Screws (captive screws) 7 are accessible from the external side of filler 2, and the three apertures 6 are disposed in an L-shaped recess 8, that can be covered by a sticker once filler 2 is attached to vaporizer 1.

[0046] Filler 2 has a fluid level sight-glass 20 disposed at one end 30 thereof where an elongate void 39 is disposed. On the opposite end 31, an upper portion 32 is disposed over (overhangs) a conventional filler-port unit (filling lock mechanism) 21 that is mounted to a set-back flat mounting surface 33. Filler-port unit 21 is a conventional device similar to that employed on the prior art Cyprane Tec 3 and is configured to receive a key-fill adaptor used with liquid anaesthetic bottles. Filler-port unit 21 when attached to mounting surface 33 does not extend below the bottom of the body of filler 2 and bucket 3, and preferably substantially flush therewith. This means that vaporizer 1 can be placed on a flat surface upright, making maintenance, removal and replacement straightforward.

[0047] Mounting surface 33 has attachment apertures 35 for mounting filler-port unit 21, fill aperture 36, breather aperture 37 and air breather return aperture 38. Breather return apertures 37, 38 are fluidally connected to breather hole 27, air return hole 28 and sight glass breather hole 29 shown on concave surface 12 of filler 2. Breather aperture 37 and air return 38 near the bottom of filler 2 are spaced apart from the associated fluidally connected breather hole 27 and air return hole 28 horizontally, and additionally they are disposed near opposite ends of filler 2. This spacing both horizontally and vertically between breather hole 27 and air return hole 28 and their respective associated breather aperture 37 and air return 38 means that the breather conduit connecting them within filler 2 is of greater length and therefore greater internal surface area. This means that should there be a droplet of liquid anaesthetic therein it has greater area to spread and there is less of a chance of spillage of anaesthetic during handling of vaporizer 1. This spacing of breather holes is possible because of the dimensional configuration, where the top end width of filler 2 is about the same as the height dimension, and as a result of the concave mounting surface 12 that allows for this width of filler 2 to mount to the cylindrical outer surface 5 of bucket 3.

[0048] Also, the significant vertical spacing between breather hole 27 and aperture 37 means that it is impossible to overfill vaporizer 1. This significantly reduces the risk of exposure of the anaesthetic to a user when filling and draining vaporizer 1.

[0049] Gasket (seal) 4 is of thin sheet of PTFE material. As shown in FIG. 4, gasket 4 has three holes 16 that align with apertures 6 in filler 2. The three smaller holes near the uppermost hole 16 are gasket breather hole 17, gasket air return hole 18 and sight glass breather hole 19, which align with the breather hole 27, air return hole 28 and sight glass breather hole 29 of filler 2. Hole 15 of gasket 5 aligns with fill hole 25 on concave surface 12 of filler 2. In this embodiment gasket 4 is a rectangularly shaped and of constant thickness. However, in another not shown embodiment the gasket may have a narrow stepped peripheral border of greater thickness than the remaining central portion of the gasket.

[0050] Filler 1 is provided with a valve 9 for filling and draining, that is fitted to upper opening 40 of filler 2. A corrosion resistant spring-loaded PTFE nub seal (not shown), namely a dynamic valve stem fill/drain seal, is disposed on the shaft (not shown) of valve 9. This is a long-life seal with an expected service life of up to fifteen years.

[0051] Seals (not shown) for the fluid level sight glass 20 are three PTFE O-rings which are highly resistant to anaesthetic and have been proven to last more than five years if inserted and seated correctly. Fluid sight glass 20 is significant taller than in prior art arrangements, because there is a significant vertical height difference of the breather holes. This also results with a higher capacity tank for liquid anaesthetic. Filling vaporizer 1 is therefore easier as the user can easily watch the sight glass (fill gauge) 20 and the bottle in the same field of view. This is an improvement over the prior art window (sight glass) systems.

[0052] Preferably the body of filler 2 is machined to have a curved outer surface 24 and curved corners 26. The curved outer surface 24, curved corners 26 together with the mount location of filler-port unit 20, as well as the depth (the amount it projects from bucket 3) minimises the catch or snag potential when compared to prior art vaporizer/filler units.

[0053] An important feature of the present embodiment is that filler 2 is secured from the outside of the internal reservoir of vaporizer 1 using captive screws 7. As such the captive screws 7 are substantially clear of anaesthetic corrosion. Because captive screws 7 are removable from an external location without disassembly of the internal components of vaporizer 1, this makes servicing of vaporizer 1 and filler 2 easier and without less risk to the technician, than that posed by the prior art units.

[0054] In summary, as a result of the concave mounting surface 12 of filler 2 the following features are possible and advantageous. [0055] Firstly, filler 2 is manufactured in a size where its top end width is about the same size as its height (see FIG. 3), and mountable to cylindrical outer surface 5; [0056] Secondly, filler 2 has sight window 20 disposed thereon at one end of filler 2, and said opposed end has an upper portion overhanging a side mounting surface 33 to which filler port unit 21 is attached, and filler port unit 21 having a lower surface that is substantially flush with the bottom surface of filler 2. As such vaporizer 1 can be stood on a flat surface unlike the prior art standard Tec 3 model. [0057] increased fluid level and reservoir capacity and the size of sight glass 20, as a result of breather hole spacing (vertically and horizontally), which provides less chance for spillage and better visual in the sight glass 20 for accurate filling

[0058] Further advantageous features of the present embodiment are as follows: [0059] filler 2 as a result of external screws 7 accessible from external location, can be removed from vaporizer 1 without disassembly of the latter; [0060] the spring-loaded valve shaft seal of valve 9 would require less servicing and last two to three times longer than prior valve seals. For example, it would be serviceable after ten years instead of two-five years of the prior art; [0061] whilst valve seat is serviceable it will not be required for the life of vaporizer 1; [0062] : and [0063] no outer sharp corners, as a result of curved corners 26 minimising catch and snag points.

[0064] The embodiment of the filler 2 shown above utilises filler-port unit 21 to receive a key-fill adaptor used with liquid anaesthetic bottles as commonly used in the United Kingdom and Australia. However, it should be understood that in another not shown embodiment, the filler of the present invention, whilst still maintaining a curved mounting surface 12 in a similar fashion to filler 2 and mountable on bucket 3, could instead of filler port unit 21, use a not shown funnel-fill port (as preferred in the United States of America) located on the upper surface of the filler, at the location where valve 9 and upper opening 40 are disposed on earlier mentioned filler 2. In such not shown embodiment, the “overhang” configuration as provided in filler 2 for the filler port unit 21 is not required. As such in this not shown “filler” embodiment, the top and bottom widths would preferably be the same. However, as in the earlier embodiment, this not shown filler would not extend below the bottom of bucket 3, and preferably is substantially flush therewith, meaning vaporizer 1 to which it is attached can be placed on a flat surface upright, making maintenance, removal and replacement straightforward.

[0065] The terms “comprising” and “including” (and their grammatical variations) as used herein are used in an inclusive sense and not in the exclusive sense of “consisting only of”.