US3458736A - Laminated magnetostrictive transducer apparatus - Google Patents

Description

July 29, 1969 R. c. HEIM 3,458,736

LAMINATED MAGNETOSTRCTIVE TRANSDUCER APPARATUS Filed March 15, 19.67

FIG.2.

WTNESSES' INVENTOR Rlchord C. Heim.

United States Patent O 3,458,736 LAMINATED MAGNETOSTRICTIVE TRANSDUCER APPARATUS Richard C. Heim, Ellicott City, Md., assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Mar. 15, 1967, Ser. No. 623,348

Int. Cl. H04r 15/00 U.S. Cl. 310-26 2 yClaims ABSTRACT OF THE DISCLOSURE A transducer assemblage in which a plurality of thin corrugated magnetostrictive elements are vibratorily coupled at their one end to a radiating plate and arranged such that the laminations abut one another in space-separated stacks, each stack comprising two or more laminations in which the respective corrugations nest within one another, and alternate stacks being reversed in direction for abutment of stack corrugation ridges to obtain substantial adjacent stack separation.

BACKGROUND OF THE INVENTION Field of the z'nvention.-Magnetostrictive transducer apparatus for ultrasonic agitation of a liquid.

Description of the prior LWL-Ultrasonic transducer apparatus in which thin magnetostrictive laminations are bonded to a radiating plate with distributed spacing between each lamination, as disclosed in U.S. Patents 3,161,792 and 3,173,037, are being employed with considerable success in most instances; the latter patent disclosing use of corrugation containing laminations arranged to obtain self-spacing between each adjacent laminations. Under certain circumstances, such as Iwhere the liquid volume being ultrasonically vibrated by the radiating plate contains a high volume of solid material, such as workpiece parts to be cleaned in an ultrasonic bath, or where the liquid bath contains gas or air bubbles, the performances of such transducer apparatus tends to become degraded according to the degree such conditions prevail.

SUMMARY According to the present invention improved -performance of a spaced lamination magnetostrictive transducer is obtained by a novel arrangement of the self-separating type of laminations containing corrugations or ribs as shown in U.S. Patent 3,173,037, for example wherein the laminations are bonded to the radiating plate in spacedapart stacks of two or more, often three, where the respective corrugations of the several laminations of each stack nest within one another, and the series of stacks in a particular array alternate in direction of facing to obtain self-separation by abutment of stack corrugation ridges.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an end elevation view of an exemplified 1amination array bonded to a radiating plate which is shown in cross-section; and

FIG. 2 is a fragmentary bottom view in outline of the array of FIG. 1, showing details of the array of selfspaced stacks of corrugation-containing laminations in accord with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, the transducer apparatus of the present invention comprises a radiating plate 5 for subjection to a liquid, such as a cleaning fluid, to impart vibrations thereto for cavitation as in ultrasonic cleaning of parts immersed in such liquid, for example. Often such radiating plate will constitute the 'bottom of a cleaning tank and at other times may constitute the vibratory wall of an immersible transducer disposed within a separate liquid-containing tank. Vibratorily coupled at their one edge to the bottom, or, driven side, of the radiating plate 5, as by epoxy cement 7, are a plurality of thin (less than six mils, for example) laminations 8 of magnetostrictive material (nickel, for example) each of which is formed to`have one or more corrugations 10, or other bends, which extend along its length. On one face of each lamination a respective corrugation represents an indentation and on the opposite face such corrugation represents a raised part or rib. In accord with the present invention, the laminations are ranged in groups 12 of two or more, three being exemplified in the drawing, which face mutually in the same direction such that the corrugation 10 or corrugations 10 of the several laminations of each group nest in one another and provide substantial abutment between such grouped laminations, and the groups are alternated in their facing directions, wherein one group abuts another along corrugation areas that provide separation spaces 13 between substantial portions of adjacent groups.

It is to be noted that the laminations 8 in each stack or group 12 has been shown as having corresponding nested corrugations of different sizes and with right-angled edges. This is merely by way of simplifying a showing of such nesting. In practice, all laminations 8 may be made of the same shape and proportions, and nesting is readily accomplished by exerting a compressing force to opposite ends of an overall array of suitably arranged stacked groups 12; the yieldability of the laminations, due to thinness and ductility, enabling suiiicient deformation to accommodate the desired nesting.

IIn accord with the practice set forth in Patent 3,173,037, each lamination has a pair of spaced-apart slots 15 which are aligned in each stacked array of laminations `8 to accommodate the energizing coil (not shown herein) for such array to obtain the vibratory response of such laminations and hence vibration of the radiating plate 5.

I claim as my invention:

1. A transducer assemblage comprising a radiating plate for subjection to a liquid to which vibration is to be imparted,

a plurality of thin magnetostrictive laminations each having at least one longitudinal corrugation therein Iand each bonded at its one edge to said radiating plate,

said laminations being arranged in `a series of altermately-facing corrugation-ridge abutting groups of corrugation-nested laminations having substantial abutment between the laminations of each group and space separating substantial portions of each adjacent group.

2. The transducer assemblage of claim 1, wherein the laminations have equally-proportioned respective convolutions and are made of ductile nickel less than six mils thick.

References Cited UNITED STATES PATENTS 2,391,678 12/ 1945 Bundy. 2,489,768 11/1949 Firth 318--118 X 3,173,037 3/ 1965 Heim 310-26 MILTON O. HIRSHFIELD, Primary Examiner D. F. DUGGAN, Assistant Examiner U.S. Cl. X.R.

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