US 3412731 A
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Description (OCR text may contain errors)
Nov. 26, 1968 w. REYNOLDS 3,412,731
ELECTROPHORETIC TOOTHBRUSH Filed March 29, 1965 INVENTOR. LUTHER Hf REV/VOL 0S wfzz ATTORNEY United States Patent 3,412,731 ELECTROPHORETIC TOOTHBRUSH Luther W. Reynolds, 254 S. 16th St., Philadelphia, Pa. 19102 3,412,731 Patented Nov. 26, 1968 "ice silver (+0.80), the cell has a theoretical voltage of 2.35 volts. Thus, the highest voltages are obtained by using metals spaced the furtherest apart on the electromotive series.
Filed Mar. 29, 1965, $61. No. 443,185 5 TABLE I 3 Claims. (Cl. 128-1721) Normal electrode potential (volts) Element: referred to hydrogen electrode K 2.92 ABSTRACT OF THE DISCLOSURE N 2 71 An electrophoretic toothbrush is described having Mg connecting electrodes in the handle and brush head which Zn provides a flow of current when the head is inserted Fe in the users mouth so that fluoride ions when present 511 in the users mouth will flow to the users teeth. Similar- Pb ly, this electrical source is described as useful to power 15 H other devices such as a radio transmitter and an electric Bi wrist watch. Hg +0.80 The present invention relates to a source of electrical +0'80 power, and more particularly to an electrical power source I have discovered that, when two electrodes of different for lo power o erated portable de i e metals on the electromotive series are placed in spaced re- With the advent of miniaturized electrical components ation on the epidermal surface of an animal, including and low power operated electrical circuits, there has a human, the body of the animal acts as a solid electrolyte been developed many portable electrical devices, such and a cell is created which provides a low voltage curas radio receivers, radio transmitters, toothbrushes, hearrent. The metals for such electrodes should be as far ing aids, watches, shavers, etc. However, all of the devices apart on the electromotive series as possible so as to have one common drawback. The power source for operatprovide maximum voltage, but must be metals which do ing these devices is a battery which has a limited usenot adversely react with the skin of the animal; for examable life. Thus, the batteries must be replaced from time ple, electrodes of silver and magnesium. Although solid to time, or, if rechargeable, must be accompanied by metal electrodes are preferred, the electrodes may also devices for recharging the battery. The need for replacing be organic or inorganic compounds of the metals. the batteries or for a special device to recharge the Although, as stated above, the theoretical calculated battery not only adds to the expense of the device, but EMF for a silver-magnesium couple is 2.35 volts, exmakes the device unreliable since it cannot always be periments showed that the open circuit voltage for this determined with certainty when the battery will go bad. couple when attached to the human skin is 1.2 to 1.4 Therefore, it is desirable to have a power source for such volts. This reduction in volta is believed to be Caused portable devices which is reliable, has a long life and is by an imperfect electrical function at the interface of inexpensive. the electrodes and the epidermis, and by the fact that An object of this invention is the provision of an the epidermis does not provide a uniform electrolyte. electrophoretic toothbrush. The electrical power obtainable with a silver-magnesium Other objects will appear hereinafter. pair of electrodes secured in spaced relation on the human For the purpose of illustrating the invention, there is skin was calculated by connecting konwn resistances across shown in the drawings forms which are presently prethe circuit and measuring the voltage drop. From these ferred; it being understood, however, that this invention 4? data, the current was calculated. The current multiplied is not limited to the precise arrangements and instrua by the voltage gave the power output. It was found that mentalities shown, a maximum power of 250 micro watts was obtained at FIGURE 1 is a schematic view of an audio transmitter 0.5 volt and 500 micro amps. having the power source of the present invention. It has been found that the size of the electrodes and FIGURE 2 is a view of an electric wrist watch having the spacing between the electrodes affects the power outt-he power source of the present invention. put obtainable. Table II shows the variation in the power FIGURE 3 is a view of an electrophoretic toothbrush output with variations in the size of the electrodes and having the power source of the present invention. the spacing between the electrodes. The electrodes used In general, the electrical power source of the present were asilver-magnesium couple. It can be seen from Table invention is based on the principal that, when two dif- II that the larger the area of the electrodes and the ferent metals of the electromotive sources are placed in closer they are, the higher the power output.
TABLE II Electrode Voltage Current Resistance Power Location area (volts) (micro (ohms) (micro (cm!) amps) (K. watts) Forearm 1 cm. apart 24. 5 0. 5 500 l 250 Forearm 4 cm. apart 24. 5 0. 24 510 475 120 One on each arm 24.5 0.45 450 1 202 Forearm 2 cm. apart 9. 6 0.30 300 1 90 an electrolyte, there is created a cell which provides an electrical current. Table I is an abbreviated list of these metals. When a cell is made of two of these metals in a uniform electrolyte, the EMF of the cell is determined from the individual potential values of the metals used. For example, if the metals are magnesium (-l.55) and Referring to FIGURE 1 of the drawing, there is shown an audio transmitter 10 using the power source of the present invention. The electrical circuitry of the transmitter 10 may be any well-known audio transmitter circuit which will operate from a low power source. The power input terminals of the transmitter 10 are connected by wires 12 and 14 to flat disc or strip electrodes inserted on the inner surface of straps 16 and 18. As stated above, the electrodes are of two different metals of the electromotive series, such as silver and magnesium. The straps 16 and 18 are secured in spaced relation around the arm 20 of a person with the electrode contacting the surface of the skin. The transmitter 10 is provided with a microphone 22 and an aerial 24 in the manner well known in the art. The signal from the transmitter 10 can be received by a radio, generally indicated as 26, which is tuned to the frequency of the transmitter.
Referring to FIGURE 2, there is shown an electrical wrist watch 28 using the power source of the present invention. Wrist watch 28 can be of any well-known construction for a watch operated by a battery. However, instead of a battery, a pair of electrodes 30 and 32 of the present invention were secured on the inner surface of the straps 34 and 36 respectively. The electrodes 30 and 32 are connected to the power input terminals of the electrical circuit operating the watch by wires 38 and 40 which extend along the straps 34 and 36 and through the case of the watch. Thus, when the watch 28 is secured to the users arm, the electrodes 30 and 32 contact the skin of the user at spaced points to complete the electrical circuit and provide the power to operate the watch.
Referring to FIGURE 3, there is shown an electrophoretic toothbrush 42 which uses the power source of the present invention. It is known that when a direct electrical current is passed through a solution, the ions in the solution will migrate toward the side of the charge opposite to that of the ions. It is also known that fluorides are effective to prevent decay of teeth and that the better the penetration of the fluorine into the teeth, the more effective the fluoride is. An electrophoretic toothbrush is a toothbrush which provides an electrical current through the fluoride so as to cause migration of the fluorine ions into the teeth.
Toothbrush 42 of the present invention comprises a handle 44 having a head 46 at one end thereof. The handle 44 and head 46 are of an electrically insulating material, such as a plastic. Bristles 48 are provided on the head 46. A negative electrode 50, such as a strip of magnesium, is secured to the surface of the head 46 at the bottom of the bristles 48. A positive electrode 52, such as a strip of silver, is secured to the end of the handle 44. A wire 54 extends along the handle 44 and electrically connects the positive electrode 52 and the negative electrode 50.
To use the toothbrush 42, toothpaste containing fluoride is placed on the bristles 48. The user holds the handle 44 so that the positive electrode 52 contacts the skin of the users hand. When the head 44 of the toothbrush 42 is placed in the users mouth, the negative electrode 50 contacts the user so as to complete the electrical circuit and provide a flow of current through the fluoride toothpaste. Thus, the fluorine ions migrate from the bristles to the positive charged teeth so as to cause greater contact between the fluorine and the teeth. It is believed that the flow of electricity also stimulates the gingiva and provides a beneficial effect.
The power source of the present invention can be used to operate any other electrical devices which operate on low power. Since the power source of the present invention includes an animal, such as a human, it is preferably used for portable devices. or any such electrical devices it is only necessary to replace the batteries which are normally used to operate the device with a pair of the electrodes of the present invention. The electrodes are connected to the power input terminals of the electrical circuit of the device and are provided with means, such as straps, for using the electrodes to the skin of the animal. The power source of the present invention has the major advantage that it is extremely reliable in that it provides a steady output and has a long life.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.
1. An electrophoretic toothbrush comprising a handle of an electrical insulating material, a head of an electrical insulating material at one end of said handle, bristles secured to said head and extending from a surface of said head, an electrode secured to said handle, a second electrode secured to said surface of said head, said electrodes being of different metals of the electromotive series, and means extending along said handle and electrically connecting said electrodes to each other.
2. An electrophoretic toothbrush in accordance with claim 1 in which one of said electrodes contains silver and the other electrode contains magnesium.
3. An electrophoretic toothbrush in accordance with claim 2 in which the electrode on the handle contains silver.
References Cited UNITED STATES PATENTS 415,274 11/1889 Kane 128-381 XR 5/1958 Kauai 128-172.1
FOREIGN PATENTS 3/1963 Switzerland.