WO1991012905A1

WO1991012905A1 - Machine for washing laboratory equipment

Info

Publication number: WO1991012905A1
Application number: PCT/AU1990/000580
Authority: WO
Inventors: Paul Andrew Vassett
Original assignee: Scitronics Pty. Ltd.
Priority date: 1990-03-02
Filing date: 1990-12-06
Publication date: 1991-09-05

Abstract

Machine for washing laboratory equipment comprising an enclosure (17) containing the cleaning liquid and having supported therein four baskets (31) into which the equipment (80) is positioned. Each basket projects along radial axes from an axially rotatable drive shaft (36) mounted centrally of the enclosure. The drive shaft has four equally spaced radially extending support shafts (38) mounted thereon, a basket being detachably located on each support shaft. Abutment means (50) is positioned on a locus of the radial extremity of the baskets to mesh with the extremity of each basket (40) to cause rotation of each basket about the longitudinal axis of shaft (38) as the array of baskets rotate about the drive shaft (36) i.e. each basket rotates in two mutual perpendicular axes. The machine can be coupled to a source of hot/cold water or distilled water and includes hot air drying facilities to both wash and dry laboratory equipment.

Description

TITLE

MACHINE FOR WASHING LABORATORY EQUIPMENT

FIELD OF THE INVENTION

This invention relates to a machine for washing laboratory equipment. PRIOR ART

Laboratory equipment such as test tubes, scintillation vials, small bottles, plastic tubes, vials and other similar equipment has proved very difficult to wash efficiently. It is important that the washing process is thorough and efficient and that each item is thoroughly dry before it can be used again. Conventional machines such as dish washers tend to leave a residue of water in the equipment thus rendering the drying step difficult to effect. It is thus common practice to wash and dry laboratory equipment by hand which, in a large laboratory, proves a very time consuming and thus expensive exercise. The present invention provides a machine that can be used to automatically wash and dry laboratory equipment. SUMMARY OF THE INVENTION

According to the present invention there is provided a machine for washing laboratory equipment comprising an enclosure capable of containing cleaning liquid, the enclosure having supported therein a plurality of baskets into which the equipment is positioned, and means to cause rotation of each basket simultaneously about two mutually perpendicular axes.

Preferably the baskets project along radial axes from an axially rotatable shaft mounted centrally of the enclosure, each basket being mounted to be also rotatable about the radial axis.

In a preferred embodiment, abutment means positioned on the locus of the radial extremity of the baskets meshes with the extremity of each basket to cause rotation of each basket about the radial axis as the array of baskets rotate about the axis of the shaft.

Preferably the enclosure is capable of being connected to a source of hot/cold water, detergent and distilled water. DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of the front of a machine for washing laboratory equipment with a cover in the open position;

Figure 2 is a side-on cross sectional view of the machine;

Figure 3 is a frontal cross sectional view of the machine illustrating a washing chamber and taken along the lines 3-3 of Fig. 2;

Figure 4 is a rear cross sectional view taken along the lines 4-4 of Fig. 2; Figure 5 is a cross sectional view taken along the lines 5-5 of Figure 2;

Figure 6 is an exploded perspective view of a basket for use in the machine, and

Figure 7 is a cross sectional view of a modified form of the machine. DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in the accompanying drawings, a machine 10 for washing laboratory equipment comprises a rectangular casing 11 defined by vertical front and rear walls 12 and 13 bounded by side walls 14 and 15 and a base 16. The casing also includes a lid assembly 20 that is hinged to the rear wall 13 to pivot open as shown in Figure 1. The main body of the casing 11 includes a washing/drying chamber 17 with an open rectangular mouth 18 at the top of the chamber. As shown in Figure 4, the rear wall 13 of the casing is provided with a distilled water and mains water inlet 21 and 22 which through suitable valves communicate with the washing/drying chamber 17. The base of the washing chamber 17 has an outlet 25 which is coupled to a pump 26 to draw the water from the chamber 17 through the discharge pipe 27.

Mounted within the washing chamber 17 is an array of four substantially cylindrical baskets 31 of open mesh like construction. Each basket 31 has a frusto-conical base portion 35 and is supported with its longitudinal axis extending radially about a shaft 36 that is mounted centrally of the casing with its longitudinal axis in a horizontal plane as shown in Figure 2. Thus, the longitudinal axis of each basket is mutually perpendicular to the longitudinal axis of the shaft 36. As shown in Figure 2, the washing/drying chamber 17 is defined by spaced vertical front and rear walls 23 and 24 joined by a base with sides that merge into the sides 14 and 15 of the casing 11. The shaft 36 projects outwardly of the rear wall and is enclosed in a fixed outer sleeve 34. The shaft 36 is driven by means of an electric motor through a suitable gearbox (not shown) via sprockets 32, 33 and chain 34.

As shown with particular reference to Figures 2, 3 and 6, each basket 31 includes a pair of spaced apart strengthening rings 41 and 42 which with the open mesh like wall defines a cylindrical enclosure 43. The frusto-conical end 35 terminates in a hollow bush 44 which is arranged co-axial with a central bush 45 in a removeable end plate 46 that is arranged to clip to the strengthening ring 41 by a bayonet type fastening 47. Removal of the end plate 46 allows laboratory equipment 80 such as test tubes and vials to be placed into the basket adjacent the lower or frusto-conical end 35. A perforate location plate 48 with a central aperture 49 is placed within the enclosure 43 over the tubes and vials 80 and is pressed down against the tubes and vials by a large coil spring 55 that is positioned between the location plate 48 and end plate 46.

The drive shaft 36 terminates with the washing chamber 17 in four equally spaced radially extending support shafts 38 onto which each basket 31 is a free sliding fit about the bush 44 and 45 in the end portion 35 and plate 46 respectively.

The strengthening ring 41 of each basket is also provided with a radial friction member or tyre 40 that is arranged to run in a groove 51 of a circular track 50 that is secured to the rear wall 24 of the washing chamber 17. The effect of the tyre 40 running in the track 50 is to cause each basket to rotate about the longitudinal axis of the shaft 38 as the four baskets rotate about the drive shaft 36. In other words, the frictional forces between the tyres and the track has the effect of imparting axial rotation to each basket so that during the washing/drying operation each basket rotates in two mutual perpendicular axes. By designing the baskets 31 to have an open mesh like wall structure and ensuring that the speed of rotation is very slow, laboratory equipment placed in the baskets is rotated through the two axes to ensure that water within the washing chamber 17 is in constant movement against all the surfaces of the equipment that require cleaning. As shown in Figures 1 and 3, the top of the track 50 is provided with a cut out 52 to allow each basket when aligned with the cut out to be pulled off the shaft 38 to enable removal of the end plate 46 to load and unload the laboratory equipment 80.

Access to the chamber 17 is through the open mouth 18 at the top of the casing and lid assembly 20 is provided to close and seal the chamber 17. When the machine is washing or rinsing the instruments, the distilled or fresh water enters the chamber 17 through a pipe 59 that is in communication with the inlets 21 and 22.

After washing and rinsing, the machine introduces a blast of hot or cold air into the chamber 17 via the lid assembly 20. Air enters the rear of the machine through air inlet 62 and is forced by an electric fan 63 up into the underside of the lid assembly 20 via a duct 64 and aperture 65 in the lid.

The underside of the lid 20 as shown in Figure 1 has a plurality of small air apertures 66 as well as a large rectangular air duct 67 and lateral return ducts 68 and 69. The air enters the lid assembly 20 via the aperture 65 and is distributed to the outlets 66 and 67 by channelling 70 shown in Figures 1 and 5. The return air enters the lid 20 through the return ducts 68 and 69 and escapes through outlets 71 positioned in the rear of the lid, see Figure 5. The small apertures 66 ensure that air blows directly down into the chamber 17 from the top. The air duct 67 communicates with a vertically mounted air box 80 in the front of the chamber 17. As shown in Figure 2, the air box 80 has a rear wall 81 that has a plurality of openings 82 to allow air to flow laterally into the chamber 17. The air box 80 also terminates in a large base opening 83 that ensures air reaches the base of the chamber 17. This arrangement ensures thorough contact with the equipment 80 to ensure that the drying is complete.

A compartment 9 at the base 16 and rear of the washing chamber 17 is arranged to house the electric motor 39 and gearing that drives the central shaft 36 at a speed of between 2 and 3 revolutions per minute. The compartment 9 may also enclose suitable heating means to, if necessary heat the water entering the washing chamber 17 and to heat the air which is pumped into the machine by the fan 63. A control panel 90 is mounted on the front 12 of the machine and it is understood that well known existing solid state circuitry could be incorporated to effect washing, rinsing and drying cycles, drying times and other control variable that are conventional in machines of this kind.

Although the baskets are preferably constructed of a suitable plastics, it is understood that they may alternatively be made of an open frame work of stainless steel.

The mounting of the baskets 31 ensures balances support for the baskets whilst at the same time allowing the frictional engagement with the track to impart rotatio of each basket along its longitudinal axis. The hinged li assembly 20 provides open access to the washing chamber 17 to allow equipment to be placed in or taken out of the machine. The machine illustrated in Figures 1 to 6 is loaded from the top by pivoting the lid 20 to an open vertical position allowing access to the washing chamber 17. There are circumstances in which it is inconvenient to load the machine from the top and thus in the embodiment shown in Figure 7, the machine has been adapted to be loaded from the front. In this embodiment, the washing chamber 117 is a self-contained unit that carries on its rear face the motor and drive assembly 139. The washing chamber 117 is arranged to be secured to the casing 111 of the machine 110 to pivot about a horizontal axis x that extends transversely across the front 112 of the machine. The washing chamber 117 is secured about a hinge at the front of the base of the chamber 117 so that the washing chamber can pivot from a in use vertical position shown in full line to the loading position shown in dotted profile in Figure 7. The arrangement is such that the washing chamber 117 can pivot through about 20 degrees to allow ready access to the chamber through its upper portion. A machine of this type has the advantage that it can be operated whilst located under a bench and there is no need for the lid to pivot open as in the first embodiment. It is understood that a suitable latching means (not shown) would be provided to hold the washing chamber in the vertical position whilst in use and that for loading and unloading this latching means could be released to allow the chamber to pivot forward to the position shown in dotted profile in Figure 7. It is further understood that suitable rubber seals will be provided between both inlet and outlet air ducts 167 & 168 of the washing chamber to ensure efficient flow of hot air during the drying operation when in the in use position.

It is further understood that those skilled in this art would readily appreciate that the machine could incorporate many other features that are used in dishwashing machines.

Claims

— o —CLAIMS :

1. A machine for washing laboratory equipment comprising an enclosure capable of containing cleaning liquid, the enclosure having supported therein a plurality of baskets into which the equipment may be positioned, and means to cause rotation of each basket simultaneously about two mutually perpendicular axes .

2. The machine according to Claim 1 wherein the baskets project along radial axes from an axially rotatable drive shaft mounted centrally of the enclosure, each basket being mounted to be also rotatable about the respective radial axis.

3. The machine according to Claim 2 wherein the drive shaft has four equally spaced radially extending support shafts mounted thereon, a basket being detachably located on each support shaft.

4. The machine according to any one of the preceding claims wherein abutment means is positioned on a locus of the radial extremity of the baskets to mesh with the extremity of each basket to cause rotation of each basket about the radial axis as the array of baskets rotate about the axis of the drive shaft.

5. The machine according to Claim 4 wherein the abutment means comprises an annular track defined by a pair of slightly spaced apart concentric rails.

6. The machine according to Claim 5 wherein the pair of rails has an arcuate cut out adjacent the top of the machine whereby each basket can be slid off the support shaft when aligned with the cut-out.

7. The machine according to either Claim 5 or Claim 6 wherein one end of each basket is provided with an annular rim, the periphery of which extends between the pair of rails to run in the track, the friction between the rim and the rails causing axial rotation of the baskets about the drive shaft to impart radial rotation of each basket about the axis of the rim.

8. The machine according to any one of claims 2 to 7 wherein each basket comprises a substantially cylindrical cage open at one end, the other end of the cage having a centrally positioned collar through which one of the radially extending support shafts extends, a removable closure plate being detachably secured to the open end having a central aperture through which the support shaft locates .

9. The machine according to Claim 8 wherein a perforated circular plate with a central aperture is arranged to be sliding fit over the support shaft and a coil spring is positioned between the plate and the end plate to urge the plate towards the base of the basket whereby in use laboratory equipment may be placed in the basket and located in the base of the basket by pressure of the plate urged by the spring.

10. The machine according to any one of the preceding claims wherein the enclosure is supported within a housing that contains means to drive the drive shaft, means to pump air into the enclosure and fluid control means to ensure that the enclosure can be filled with cleaning liquid.

11. The machine according to Claim 10 wherein the fluid control means is arranged to be connected to a source of hot/cold water and sterilized water and fluid to control flow of either the hot, cold or sterilized water.

12. The machine according to either Claim 10 or 11 wherein the enclosure has an open top that is closed by a lid that pivots from the rear of the housing, the lid having an air duct that causes air to be expelled into the top and sides of the enclosure to dry laboratory equipment held in the baskets .

13. The machine according to Claim 12 wherein a fan drives air through the duct into the enclosure.

14. The machine according to Claim 13 wherein heating means is provided to heat the air that is passed through the duct.

15. The machine according to either Claim 10 or 11 wherein the enclosure is pivotable to an open position in which the enclosure extends forwardly of the housing to allow access to the interior of the enclosure through the top of the enclosure.

16. The machine according to any one of the preceding claims wherein the base of the enclosure is provided with a liquid outlet that is in communicating with a pump that draws liquid out of the enclosure.

17. The machine according to any one of the preceding claims wherein the drive means is a geared electric motor arranged to drive the drive shaft at a speed of between 2 and 3 revolutions per minute.

18. The machine according to any one of the preceding claims wherein control means is provided to control the timing and operation of the washing, rinsing and drying cycles.

19. A machine for washing laboratory equipment substantially as described herein with reference to and as illustrated in the accompanying drawings.