US2958332A

US2958332A - Ultrasonic cleaning apparatus basket assembly

Info

Publication number: US2958332A
Application number: US762040A
Authority: US
Inventors: Hassan E Schueler
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-09-19
Filing date: 1958-09-19
Publication date: 1960-11-01
Anticipated expiration: 1977-11-01

Description

Nov. 1, 1960 ER 2,958,332

ULTRASONIC CLEANING APPARATUS BASKET ASSEMBLY Filed Sept. 19, 1958 A T TOKPNE V United t tes Hassan E. Schueler, St. Albans, N.Y. (110 Gristmill Lane, Saddle Rock, Great Neck, N .Y.)

Filed Sept. 19, 1958, Ser. No. 762,040

'4 Claims. (Cl. 134-469) The instant invention relates to ultrasonic cleaning devices for particularly surgical instruments, hypodermic needles, syringes, cannulae, glassware and generally all types of articles having an internal bore of relatively small diameter.

Ultrasonic cleaning is commercially feasible at frequencies of from 15 kilocycles to about 1,000 kilocycles per second of such amplitude that cavitation is produced in a cleaning liquid. Cavitation is generally accepted as the rapid generation and violent collapse of very minute bubbles in the cleaning liquid which results in numerous though small and intense impacts on solid surfaces within the liquid. The intense high-frequency vibrations required in the cleaning liquid are transferred from an electrical oscillation generator to the liquid by a transducer converting the electrical power into mechanical motion. The transducers may be of the piezoelectric, for example, barrium titanate, or the magnetostrictive, for example nickel, types and require relatively large radiating surfaces. The transducers most frequently are coupled to the bottom of the cleaning tank, but may be, and sometimes are, mounted on the sides of the tank to permit greater depths of cleaning fluid so that the material to be cleaned is as close as possible to the radiating surface of the transducer. The cleaning liquid may be water or an aqueous or solvent solution from which excessive air or vapor has been removed, and at a temperature which is generally lower than the temperature of the cleaning fluid of other cleaning methods.

One of the difliculties which has slowed up general adoption of ultrasonic cleaning apparatus in hospitals is that it has been noted that the small bore instruments were not readily cleanable in their interiors. More often than not, the cores were still dirty and clogged with foreign matter, such as dried blood, solution stains, etc., even after long periods in the ultrasonic cleaning apparatus. It would appear that the air entrapped in the narrow bores of the needles, syringes, etc., when placed in the cleaning tank did not permit the cleaning fluid to enter the bore and that cavitation therewithin thus could not take place, or that the metal of the instrument cut off the cavitation within the bores. Whether thi is the correct explanation or not I am uncertain, but the observed fact of dirty and clogged bores even after lengthy periods in the liquid in ultrasonic cleaning tank cannot be disputed.

An object of this invention is to provide an accessory device for ultrasonic cleaning apparatus by which cleaning of the bores of small articles, such as surgical needles, cannulae, syringes and the like where antiseptic cleanliness is a must, is accomplished by cavitation in the liquid within the bore.

I accomplish the foregoing object, and others, by providing an insert into the cleaning tank which has a plurality of spaced upwardly projecting wires of preferably spring metal which fit into the bores of the instruments to be 2,958,332 Patented Nov. 1, 1 960 cleaned with some clearance radially. that the projecting wires may vibrate within the bores and produce cavitation of'the cleaning liquid within the bores. The wire projections may be of various diameters and various lengths to fit difierent size bores and different lengths thereof, with the projecting wire lengths such that the preferable extend somewhat through the open upper end of the bores. The base of the insert of my invention is positioned close to the transducer radiating surface to permit the full effect of cavitation to occur. To have the upwardly projecting wires vibrate mechanical as much as possible, the lower end regions thereof may be in the form of an open helix, and the lower ends of successive pairs of the projection wires may be integral with each other.

My invention will more readily be understood from the following description of an illustrative embodiment thereof when read in conjunction with the appended drawing of which the sole figure shows, in elevational section, a batch-type ultrasonic cleaning apparatus equipped with the tank basket of my invention.

The ultrasonic cleaning apparatus comprises a cleaning liquid containing tank 1 supported on the housing 2 of the transducers 3, actuated by oscillation generator 4-, the latter being shown as external to the housing 2 but which may well be incorporated therewith. The transducers 3, of which there are a plurality, for example twenty-eight arranged in four rows of seven each, are mechanically coupled directly to the bottom 5 of the tank in which cleaning fluid 6 is filled to a predetermined level. For ease of illustration, the tank has been taken as rectangular in shape but it may be of any desired shape.

The basket 7 of my invention is provided with a plurality of spaced wires projecting upwardly substantially vertically which may be of identical shape, and length, altho I have shown several different forms on a single basket. Thus projecting wires 8 through 15 have a helical lower end region which is coaxial with the upper straight wire portion thereof, and wires 16 through 18 are straight their whole length. While

wires

10, 15 and 16 are attached to the bottom of the basket 7,

wires

8 and 9, 11 and 12, 13 and 14, and 17 and 18, are continuous in pairs having their individual lower ends pass through the bottom of the basket so that the interconnecting portion of each pair rests on tank bottom 5 with the basket in place. It will be noted that the bore of each needle, for example 19, to be cleaned, is threaded on the straight portion of the upright projection, the helical lower end, if any, of the upright projecting wire being of such diameter and length that the larger bore end of the needle, or other article, rests on the basket bottom. The open basket 7 has a plurality of perforations 20 in each of its side walls, as also its bottom, to permit free flow of the cleaning liquid therethrough, and a pair of finger apertures 21 at the top region of at least a pair of opposite side walls to permit ready placing thereof into, and removal from, the tank. A plurality of feet 22, of relatively small height, may be integral with the basket bottom exterior to provide spacing between the basket and the tank bottom.

What I claim is:

1. A basket for supporting small bore articles in ultrasonic cleaning tanks having a bottom and side walls defining a plurality of apertures for flow of liquid into the basket on insertion into a tank, a plurality of spaced supporting wires extending upwardly from the basket bottom have at least their upper portion straight, and at least some Wires of the plurality having their lower end region wound in an open helix coaxial with a straight upper portion of the wire.

2. The tank basket according to claim 1 in which at least some of two adjacent supporting wires having the helical regions are interconnected at their lower ends, the interconnecting portion thereof passing through and along the bottom of the basket.

3. The tank basket according to claim 1 in which the diameters of the straight portion of the supporting wires 6 References Cited in the file of this patent UNITED STATES PATENTS Van Horn Nov. 12, 1895 Nesbitt Dec. 31, 1912 Abbott Mar. 1, 1938 Murdoch Sept. 30, 1958 FOREIGN PATENTS Switzerland July 14, 1956 Germany Jan. 30, 1937 Great Britain Feb. 5, 1958