US 3151846 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
' Oct. 6, 1964 P. D. GEORGE 3,151,846
VIBRATORY DEVICE FOR CLEANING DENTURES AND THE LIKE Filed Sept. 21, 1962 i l 24" e:-
..n I INVENTOR.
PETER D. GEORGE AT TOR N EYS United States Patent 3,151,846 VIBRATORY DEVICE BOB CLEANING DENTURES AND TEE LIKE Peter 1). George, Quincy, Mass. (156 Crabtree Road, Squantum, Mass.) Filed Sept. 21, 1962, Ser- No. 225,256 1 Claim. (Cl. 25991) This invention relates generally to vibratory cleaning devices and more particularly concerns a new and improved tank cleaning apparatus for removing surface impurities from various types of articles such as denture plates and the like.
While it is well known in the art to clean the surfaces of all types of solid articles by submerging them in a suitable liquid and then introducing high frequency vibrations to the liquid, all of the devices heretofore available have been relatively complicated instruments, sensitive to high temperatures and generally quite expensive. Furthermore, these devices, by reason of their specialized design, do not readily lend themselves to popular use being primarily designed and intended for industrial applications.
Accordingly, it is an object of the present invention to provide improvements in vibratory cleaning devices.
Another object of this invention is to provide an efficient, low-cost, vibratory tank cleaning device for use in removing surface impurities from various types of articles particularly artificial dentures.
Still another object of this invention is to provide a vibratory tank cleaning device of simple, rugged constructoin having utility in both industrial and home applications.
More particularly, this invention features a vibratory cleaning apparatus comprising a vessel for containing a liquid cleaning medium in which the articles to be cleaned are submerged, mounted to the wall of the vessel is a novel transducer head employing a number of concentric annular shoulders to generate and amplify vibrations through the cleaning medium when the transducer driving apparatus is actuated. The driving mechanism for the transducer comprises a coil which surrounds an elongated metallic rod connected fast to the transducer. Upon the application of an A.C. current to the coil, the rod will be vibrated axially at a frequency corresponding to the current applied to the coil. The vibrating rod thus transfers its vibrations to the transducer which in turn causes the liquid cleaning medium to be cavitated, resulting in a highly efficient cleaning action.
In a modification of the invention, the driving mechanism is provided with adjustment means for varying the vibrating action of the transducer.
But these and other features of the invention, along with further objects and advantages thereof, will become more fully apparent from the following and detailed description, taken in connection with the accompanying drawings in which:
FIG. 1 is a view in perspective of a preferred embodiment of the invention,
FIG. 2 is a sectional view in side elevation of the device of FIG. 1,
FIG. 3 is a perspective view of the transducer element employed in the invention, and
FIG. 4 is a sectional view in side elevation of a modification of the invention.
Referring now to FIGS. 1 to 3 of the drawings, the reference character generally indicates a vibratory cleaning apparatus having a lower housing 12 and an upper cup-shaped vessel 14 adapted to contain a liquid cleaning medium 16 such as water or other suitable liquid. in practice, the vessel 14 is formed from a suitable mate- "Ice rial such as molded plastic, typically polyethylene, and is provided with a marginal lip 18 which is adapted to lock in snapping engagement with a cover 22 which may also be fabricated from polyethylene, if desired. The hous ing 12 may be formed from aluminum or the like and, as shown, has a lower annular flange 24 which engages the marginal edge of a plate 26 by means of a resilient annulus 28 which is split about its inner periphery for clamping engagement with the flange 24 and the edge of the plate 26.
Mounted within the housing 12 is a solenoid 31 having a coil 32 wound about a vertical copper tube 34. The tube 3-4 is mounted within a rectangular metal frame 36 which surrounds the coil 32. The bottom wall of the frame 36 is provided with a circular opening 33 having a diameter slightly smaller than the tube 34- so as to form an annular shoulder upon which is seated a collar 4i). The collar 49 provides a limit stop for a cylindrical core or stem 42 which is received in the tube 34. A coil spring 44 is mounted within the collar and has its upper end extending slightly above the upper end of the collar for reasons that will presently appear. The coil 32 may be connected to an alternating current power source by means of leads 46 passing out of the housing 12 through a grommet 48.
The stem 42 typically is fabricated from a suitable ferrous material such as chrome steel or the like and at its upper end supports the vessel 14. As best shown in FIG. 2, the stem engages the vessel 14 by means of a screw 50 passing through the center of a transducer head 52, through the bottom wall of the vessel 14, through a. washer 54 and into the tapped upper end of the stem 42. The transducer head 52 preferably is fabricated from stainless steel or the like and has a circular configuration characterized by a plurality of concentric annular ribs 56. In the preferred embodiment, the transducer has a diameter of 1% inches with a convex upper surface which, in cooperation with the annular ribs, amplifies and transmits vibrations into the cleaning medium 16 when the coil 32 is energized with an alternating current.
It will be understood that when the coil is energized, the stem 42 will reciprocate at the same frequency as the current in the coil. The displacement of the stem will be of relatively small order but will be sufiicient to generate effective vibrations in the vessel 14. Although normally operated at cycles obviously the frequency at which the transducer will be actuated may be varied over a wide range according to the desired effect which is to be achieved. By providing the spring 44, the stem 42 is prevented from coming into direct striking contact with the collar 40 thereby maintaining a low noise level during operation of the device.
It will be appreciated that the device described above may be fabricated at a relatively low cost yet provides a simple, rugged and efiicient cleaning unit. The invention has particular utility for home applications and has been found to be effective in cleaning such items as denture plates, jewelry such as broaches, rings and the like, and other similar articles. In practice, it has been found that water with a slight amount of detergent added is an excellent cleaning medium although other liquids may also be employed depending upon the particular article which is to be cleaned. It will be understood that the cleaning effect is achieved by cavitations in the cleaning medium developed by rapid vibration of the transducer head. As is well known in cleaning devices of this type, the cavitation is the result of relatively high energy vibrations transmitted through the liquid with the result that a very great number of minute cavities are formed which, when they strike an article within the liquid, collapse and release their energy with an implosive force which r; Gt produces the cleaning action. It has been found that in using the particular device, it should be operated for a minute or so before introducing the articles to be cleaned. It has been found that a certain amount of deaerating of the liquid is necessary before the cleaning action can be achieved. Therefore, by running the device fora short while all of the free oxygen within the liquid will be liberated so as to leave a substantially degassified liquid. While plain water may be used as the cleaning medium, the usual results are that only loose particles are freed from the articles being processed, whereas the addition of a small amount of detergent will produce complete cleaning of the article. It has also been found that optimum agitation is achieved at a frequency of 120 cycles. Obviously, the frequency may be varied according to the particular cleaning medium and according to the physical characteristics of the article which is being cleaned.
Referring now more particularly to FIG. 4, there is illustrated a modification of the invention and, in this I embodiment, a cup 60 is pivoted for vibratory movement to a permeable iron arm 62. The arm is coupled to the cup by means of a stub shaft 64 fastened to a washer 66 which in turn is connected to a transducer head 68 of a configuration similar to that of the principal embodiment. The arm 62, as shown, is pivotally connected at one end to a vertical leg of a laminated solenoid body 70 which carries a central coil 72. The coil 72, in turn, is wound about a coaxial tube 74 which carries a coil spring 76 mounted snugly therein. The upper end of the spring 76 bears against the lower portion of the arm 62 so as to provide a resilient cushion for the arm when the assembly is actuated. An adjustment screw 78 is threaded to a circular opening formed at the bottom of the solenoid body 70 and may be raised or lowered so as to vary the pressure of the spring 76 against the arm 62. For this purpose, an axial opening 80 has been formed through the bottom portion of the apparatus to provide access to the adjustment screw. The solenoid body shown is mounted on a plate 82 which in turn is disposed below the pad and has mounted thereto a housing 88 similar in shape to that of the principal embodiment. The coil 72 may be energized through a lead 90 which may connect to a power source of fixed frequency or to a variable frequency generator 92. By connecting the cleaning device to the variable frequency generator, a wide range of operating conditions may be met. It will be understood that with different articles to be cleaned and with different cleaning mediums optimum cleaning action will be best provided at a certain frequency. By having a variable frequency source, the apparatus is considerably more flexible than would be the case when only one frequency is available.
In operation, when the coil 72 is energized, the arm 62 will oscillate about its pivot pin 94 causing the transducer 68 to vibrate at the frequency of the energizing current. The coil spring 76 serves to cooperate with the alternating magnetic field to vibrate the arm 62 without its striking the solenoid body 40.
While the invention has been described with particular reference to the illustrated embodiments, it will be understood that numerous modifications thereto will appear to those skilled in the art. It will also be understood that the above description and accompanying drawings should be taken as illustrative of the invention and not in a limiting sense.
Having thus described my invention, what I claim and desire to obtain by Letters Patent of the United States is:
A cleaning device, comprising a receptacle of resilient material adapted to contain a liquid cleaning medium and articles to be cleaned, a rigid disc shaped metallic head fixed centrally on a bottom wall of said receptacle and below the level of said medium, said head having a convex outer surface formed with a plurality of evenly spaced concentric annular ribs separated by a plurality of evenly spaced concentric annular grooves adapted to cavitate said cleaning medium on vibration thereof, a moveable core of magnetically attractive material rigidly connected to said head and said receptacle and extending through said wall, a coil having an axial opening formed therethrough for receiving one end of said core and a resilient element mounted within said opening adjacent said one end of said core, said core being adapted to vibrate axially upon the application of an alternating current to said coil.
References Cited in the file of this patent UNITED STATES PATENTS 2,356,004 Price Aug. 15, 1944 2,543,818 Wilcox Mar. 6, 1951 2,724,393 Heise Nov. 22, 1955 2,776,558 Vang Jan. 8, 1957 2,815,193 Brown Dec. 3, 1957 2,875,989 Toulmin Mar. 3, 1959 2,906,111 Long et al Sept. 29, 1959 FOREIGN PATENTS 666,244 Great Britain of 1952 1,055,493 France Oct. 14, 1953