US3343010A

US3343010A - Ultrasonic power apparatus

Info

Publication number: US3343010A
Application number: US457723A
Authority: US
Inventors: Alvin A Snaper
Original assignee: Individual
Current assignee: APT FINANCAL CORP A CORPOF NV; INSTITUTE FOR SOCIAL AND SCIENTIFIC DEVELOPMENT 376 EAST 400 SOUTH NO 315 SALT LAKE CITY UTAH 84111 A CORP OF UTAH; SOLOMON JACK D
Priority date: 1965-05-21
Filing date: 1965-05-21
Publication date: 1967-09-19
Anticipated expiration: 1984-09-19

Description

Sept. 19, 1967 A. A. SNAPER ULTRASONIC POWER APPARATUS 2 Sheets-Sheet l Filed May 21, 1965 OSCALLATQR R O T A L m C S O v0 .e m e .7M 7 l/ www@ @MMM M7 www@ Q m vnf r 6 6 ,l f ih h .|ll *hm/ .l| IO 5 Hf Hf m m R R 1 w m m u m n U m M u c M C m u 5 n u ,D n o o m m w Q m illy@ {fd} /A/l/E/VTOI? A L V//v A. SA/Apf/e A. A. SNAPER ULTRASON I C POWER APPARATUS Sept. 19, 1967 2 Sheets-Sheet 2 Filed May 2l, 1965 VENTO/2 4.4 V//v A SNAPEQ By @ML E. @11% A 770/2NEY w mb//fm/ e MNHWWQ n i J 5 L fr 5 2 3 4 .I .-.Illl .0H VO L /Hhn rmi; j huh \/Vul||m\ j j .iv 1 .z F .Huf .Hf Hf Hf R om n R n R R o O m O q Y m M M m m A A L L .LLL u L u, .LL m m Q u L u LL O d u O O u O O m q L w w mL w m United States Patent O 3,343,010 ULTRASONIC POWER APPARATUS Alvin A. Snaper, 9722 Casaba Ave., Chatsworth, Calif. 91311 Filed May 21, 1965, Ser. No. 457,723 2 Claims. (Cl. S10-20) ABSTRACT OF THE DISCLOSURE This invention deals with ultrasonic means for driving a shaft to produce mechanical power. The ultrasonic vibrations produced also have the effect of producing an air cushion between the shaft and the means to considerably reduce friction.

The present invention relates in general to the field of ultrasonics, and more particularly relates to an ultrasonically-driven motor apparatus.

The point of novelty of the present invention is in employing ultrasonic power to rotatively drive a shaft-like member at an angle to the ultrasonic gun that drives it and without, or substantially without, physical contact existing -between the ultrasonic gun and the shaft-like member. More particularly, in a preferred embodiment of the invention, electrical oscillations supplied by an oscillator at an ultrasonic frequency are converted to corresponding ultrasonic mechanical vibrations by means of a transducer coupled to the oscillator. An acoustical matching block is mechanically bonded or affixed to the transducer and, therefore, vibrates with it, and it has been discovered that when a hole is placed in the block at an angle to its longitudinal axis and a shaft placed in the hole, the shaft will rotate and will do so with very little, if any, contact with the sides of the hole. Consequently, a new type of motor apparatus has been invented that has many advantages associated with it not found in the prior art.

More specifically, the present invention makes it possible to drive a drill bit at an angle to the main body of the driving apparatus, for example, a right angle which, in turn, expedites and facilitates drilling operations in places that are difficult to reach or almost inaccessible, lsuch as the hollow of a cylinder of a relatively small diameter. A further advantage obtained from the present invention is that no lubrication is needed between the walls of the hole and the shaft mounted therein, it having been found that so little contact is made between them. Thus, embodiments of the present invention would find useful application in space activities where the proper and continued lubrication of moving parts has been and will continue to be a diicult problem. Still another advantage of the present invention, when it is appraised in the light of the prior art, lies in the fact that it makes it possible for a number of shafts to be driven simultaneously by a single apparatus. In the case of a drill, for example, this Would mean that several drill bits, either of the same or of different diameters, could be used at one time.

It is, therefore, an object of the present invention t provide an ultrasonic apparatus for rotatively driving a shaft-like member.

It is another object of the present invention to provide an ultrasonic motor.

The -novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which several embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention.

FIGURE 1(a) is a top view of a preferred embodiment of the invention;

FIGURE 1(b) is a side view of the same embodiment;

FIGURE 1(0) illustrates a rst modification that may be made in the construction of said preferred embodiment;

FIGURE 1(d) illustrates this first modification in somewhat greater detail;

FIGURE 1(e) illustrates a second modification that may be made in this preferred embodiment;

FIGURE 1( f) illustrates still a third modification that may be introduced in it;

FIGURE 2 illustrates a second embodiment of the invention in which the shaft is either the same size 0r shorter than the depth of the hole;

FIGURE 3 illustrates a third embodiment of the invention in which the hole and the shaft therein have been adapted to provide useful servo applications; and

FIGURE 4 illustrates still a thirdembodiment of the invention in which a mechanism is combined with the shaft to permit the interchangeability of parts.

For a consideration of the invention in detail, reference is now made to the drawings wherein like or similar parts or elements are given like or similar designations throughout the several figures. In FIGS. l(a) and 1(1)), the embodiment is shown to include a transducer 10, in this case a magnetostrictive transducer in the shape of a core, that is coupled to a variable oscillator 11 by means of primary and

secondary windings

12 and 13, respectively, wound upon the core and connected to the oscillator. For reasons that are Well known in the art, magnetostrictive transducer 10 is suitably biased by means of a pair of permanent magnets 14a and 14b, respectively mounted on opposite ends of the transducer. Bonded or otherwise rigidly affixed to the forward end of transducer 10 is an acoustical matching block, generally designated 15, that may be made of metal, ceramic, glass or any material for that matter that has good or efficient acoustical transmission properties. The shape of the matching block is relatively unimportant and, therefore, it may be a rectangular block or plate, it may be triangular in shape, or, on the other hand, it may be given a step-down configuration with a narrow nose 15a protruding from a larger and wider base portion 15b as is shown in the gure. However, whatever its shape, the matching block should be designed for maximum power transfer, taking into consideration the parameters of the transducer, the power requirements and the range of frequencies under which the device is or may be operated. In the matter of frequency, any ultrasonic frequency from about 18 kilocycles per second to approximately 300 kilocycles per second may be employed, 20 kilocycles per second, 40 kilocycles per second and 85 kilocycles per second being examples of typical operating frequencies.

Extending through nose 15a, preferably at its forward end, is a hole 16 through which there extend-s, in a nonfrictional t, a shaft 17. Elaborating somewhat on what is meant by a nonfrictional lit, the shaft cannot be mounted too tightly in the hole or else it will not rotate, or if it does, it will do so only with great difficulty. On the other hand, the spacing between the shaft and the walls of the hole cannot be too large or else the shaft will wobble as it rotates. Accordingly, a somewhat loose tit should be provided between these two extremes. Hole diameters varying from 0.003 inch to 0.375 inch have been employed successfully, and there is no reason t0 assume that smaller or larger diameters could not be used as well.

To prevent the shaft from falling through the hole at any time, a pair of retaining lips are therefore mounted on the shaft on either side of nose 15a, the lips being designated 18a and 18b. The shaft itself, as well as the lips thereon, may be made of any sturdy material, such as metal, ceramic, rigid plastics, etc. A gear or some other such utilitarian device would normally be mounted on one or both ends of shaft 17 so that the rotation of the shaft may be utilized in a practical manner. However, such utilitarian devices are not considered a part of the present invention and, furthermore, the manner in which they would be mounted on or otherwise coupled to the shaft is so well known that it was not deemed necessary to an understanding of the invention to show them. Considering now its operation, the electrical oscillations generated by oscillator 11 are applied via

windings

12 and 13 to transducer 10 which, as is well known, thereby begins to mechanically vibrate in a longitudinal direction at the same or substantially the same frequency as the electrical oscillation. As a result, acoustical block 15 also begins to vibrate in the same direction and this, 1n turn, it has been discovered, causes shaft 17 to rotate at a relatively high speed. Consequently, the electrical energy produced by the oscillator has now been converted to mechanical energy of a rotative nature, and useful work can be done with it, as in the case of any motor. Thus, if one or more gears are mounted on the shaft, they may be used to drive still some other pieces of apparatus. On the other hand, if the end of the shaft is a drill bit, then, because of the relatively small dimensions of nose 15a and because of the angle that the drill bfi-t forms with the nose, holes may be drilled in places that would normally be inaccessible or difficult to reach with ordinary drills. Rotational speeds .of 3,600 r.p.m. and 12,000 r.p.rn. for the shaft have already been observed.

One further point should lbe made with respect to the operation of this apparatus, namely, that in add-ition to the discovery that the mechanical vibrations of acoustical block 15 cause shaft 17 to rotate, it has also been discovered that these same mechanical vibrations cause a cushion of air to be formed between the shaft and the walls of hole 16, as well as between nose 15a and retaining lips 18a and 18b, that maintains or supports the shaft in a central position in the hole, that is to say, keeps it away from the sides of the hole. Thus, as a result, there is a minimum contact, if any at all, between the elements of the shaft and the acoustical matching block. A minimum of such lcontact has also been found to exist in an airless environment, such as in a vacuum chamber or in space, the explanation being that contact between the two parts occurs only during a very small part of the entire oscillatory or vibrational cycle. It is thus seen that the present invention reduces frictional forces to a minimum and thereby avoids the necessity of providing a lubricant for them.

In the FIG. 1 embodiment, the hole 16 has been described as going entirely through the -bar or nose 15a with the shaft 17 extending through the hole on both sides. However, this can be modified in the manner shown in FIG. 1(0) wherein the hole 16 is shown to go only partially through the nose. With this kind of modification, the shaft inserted in the hole normally is longer than the depth of the hole and, therefore, protrudes from one side. Thus, in this case, one end of shaft 17 is laterally retained at one end by the nose itself, and on the otherend (not shown) by any well known device, such as a simple bearing, the utilitarian device, such as the gear previously mentioned, being mounted on the shaft between the two supports. By way of a specific example of how this could be done, reference is made to FIG. l(d) wherein two identical units of the present invention are shown both driving and supporting lshaft 17 in unison, a gear designated 20 mounted on the shaft between them. In other words, FIG. 1(d) illustrates how two identical units of the kind shown in FIG. 1(0), driven by the same oscillator, may be combined to provide a motor drive in a substantially frictionless manner.

The FIG. l embodiment may be modified in still other ways, as is shown in FIGS. 1(e) and 1(1). More specifically, as is shown in FIG. l(e), bar 15a may be provided with a plurality of holes 16 of the kind shown both in FIG. 1(a) and in FIG. 1(c). Hence, a number of shafts 17 may ybe coupled to and driven by a single acoustical matching block, each shaft and the elements mounted thereon performing -their functions simultaneously with all the others. In FIG. 1(1), the modification is shown to consist of a hole 16 that is drilled through nose 15a at an angle other than that is to say, at an angle different than those of the holes previously discussed. Thus, the present invention has great versatility and makes it possible to drive a shaft that is oriented in almost any direction. Needless to say, hole 16 in FIG. 1(1) may be a blind hole as in FIG. 1(0) or extend all the way through as in FIG. 1(11).

In the embodiment of FIG. 2, the hole 16 is a blind hole, that is to say, it only goes partially through the bar, the shaft 17 positioned or inserted in the lhole being the same length as or even shorter than the depth of the hole. When this embodiment is activated or operated in the manner previously described, shaft 17 moves out or is thrust out of hole 16, and when deactivated, the shaft returns to or goes back into the hole. In this embodiment, therefore, the shaft extends itself from the hole when operation is initiated and rotates as before in this extended position. Upon deactivation, however, the shaft retracts into the hole and awaits the next cycle of operation, Assuming that the shaft would be properly adapted for such purposes, an arrangement of the kind shown in FIG. 2 would be useful for internal drilling operations or as an internal pin-locking device. It should also Ebe pointed out that here too, as in the case of the FIG. 1(e) modification, a number of holes 16 and shafts 17 that extend and retract may be combined to simultaneously perform a number of functions. The same may be said with respect to the FIG. 1(1) modification so that, in the FIG. 2 embodiment, the holes may likewise be slanted.

In the third embodiment, shown in FIG. 3, to which reference is now made, both the hole and the shaft are threaded to provided a specific torque factor, Stated differently, since the hole and shaft are threaded, when the mechanism is placed in operation, the shaft will wind through the hole in one direction or the other at a predetermined speed. Where a specific rotation causes a predetermined extension or retraction of a shaft, such mechanisms are useful for servo applications. It will Ibe recognized that the rate of movement of shaft 17 and, therefore, its displacement in one -direction or the other not only depends upon the speed of its rotation but also upon the pitch of the thread, both of which may be accurately controlled.

A fourth and final embodiment of the present invention is presented in FIG. 4 and, as shown therein, it includes a shaft 17 that has a retaining lip 18b at one end and a chuck 21 rigidly mounted on the other end. Chuck 21 is useful where interchangeable drill bits, gears, -or other mechanisms to be rotated are to be attached to the shaft.

The operation of the FIGS. 2, 3 and 4 embodiments is the same as it was presented in connection with the FIG. l embodiment is that upon activation of the transducer, the resultant vibrations of acoustical block 15 cause the shaft to rotate at a fairly high speed and to do so in `a substantially frictionless manner for the reasons previously given. Accordingly, to avoid being unduly redundant, nothing further need be said about it. However, it should be mentioned that the speed and direction of rotation are a function of or, stated differently, are affected by the frequency of lthe electrical oscillations. Hence, as may be expected, both may be changed by changing the frequency and, as a matter of fact, at one point in the frequency spectrum the direction of rotation of the shaft is reversed if the frequency is changed beyond that point. However,

the location of that point is dependent upon the weight and size of the shaft, the configuration of the acoustical matching block, and similar type factors, with the result that this cross-over frequency is respectively different for different structural arrangements and, therefore, cannot be specified at this time.

Although a number of particular arrangements of the invention have been illustrated above by way of example, it is not intended that the invention be limited thereto. Thus, for example, although a magnetostrictive type of transducer Was shown and described herein, other kinds of transducers, such as the piezoelectric kind, may be used as Well. Accordingly, the invention should be considered to include any and all modications, alterations or equivalent arrangements falling within the scope of the annexed claims.

Having thus described the invention, what is claimed is:

1. Ultrasonically-driven motor apparatus comprising: means for producing electrical oscillations at a frequency in the ultrasonic range of frequencies; a rectangularshaped transducer element coupled to said means and operable in response to the oscillations therefrom to mechanically vibrate in the direction of its longitudinal axis at a frequency corresponding to that of the electrical oscillations; an acoustical matching block mounted on one end of said transducer element and extending therefrom symmetrically with respect to the longitudinal axis thereof, said acoustical matching block having a hole therein that intersects said longitudinal axis at an angle therewith; and a shaft rotatably positioned in said hole and operable to rotate in response to said longitudinally-directed mechanical vibrations.

2. Ultrasonically-driven motor apparatus comprising: means for producing electrical oscillations at a frequency in the ultrasonic range of frequencies; lirst and second rectangular-shaped transducer elements positioned with their longitudinal axes parallel to one another, said rst and second transducer elements being coupled to said means and operable in response to the oscillations therefrom to mechanically vibrate in the direction of said axes at a frequency corresponding to that of the electrical oscillations; first and second acoustical matching blocks respectively mounted on one end of said rst and second transducer elements and extending in the same direction therefrom symmetrically with respect to said longitudinal axes, said rst and second acoustical matching blocks respectively having axially aligned iirst and second holes therein that intersects said longitudinal axes at an angle therewith; and a single shaft rotatably positioned in said holes and operable to rotate in response to the mechanical vibrations of said transducer elements.

References Cited UNITED STATES PATENTS 3,058,218 10/1962 Kleesattel et al 310-26 X MILTON O. HIRSHFIELD, Primary Examiner. D. F. DUGGAN, Assistant Examiner.