US 2127538 A
Description (OCR text may contain errors)
Aug. 23, 1938. H, w $E|GER 2,127,538
SIGNALING DEVICE Filed Sept. 26, 1936 20 -INVENTOR Hfle Y 11/. 55/652 w, W z '417 A TTO/ZNE Y5 Patented Aug. 23, 1938 UNITED sTATEs PATENT OFFICE 4 Clalms.
This inventlon relates generally 'to alarm systems, and more particuiarly to an electrical dev-ice for use in signaling the wetting of a bed or bed clothes by the occupant thereof.
An object of the inventlon is to provide a device which, in its association witn'an infant in its crib, activates a suitable visual or aud-lble signal when the infant urinates, so as to enable the infant's diaper to be changed immediately in order to avoid prolonged exposure of the infant to a cold wet diaper, with the attendant danger of contracting bronchopneumonia, which is the chief cause of high mortality in infants under eight months of age. The'reduction in diaper rashes and irritations, due to prolonged contact of the infant's delicate skin with its urine', is another direct beneflt resulting from use of the device.
Another object of the inventlon is to provide a Wet diaper signaling device which is structurally characterized" to enable -its use without discomfort to the infant and in entire safety from electrical shock or injury, while insuring that the signal will be activated upon the closing of a circuit by the electrolytic action of salts in the infant's urine forming a current conducting bridge between normally insulated conductors embedded in the device.
A further object of the inventlon is to provide a signaling device characterized by its structural simplicity and sanitary features, requiring no replacement of any circuit controlling element or substance rendered inactive and unfit for further use by urine, as embodied in devices heretofore proposed.
With these and other objects in view, the inventlon consists in the following combinations and arrangements of elements as set forth in the following specification and particuiarly pointed out in the appended claims.
In the accompanying drawing,
Figure 1 is a plan view of the inventlon;
Figure 2 is a longitudinal sectional view taken on the line 2-2 of Figure 1;
Figure 3 is a diagrammatic view iliustrating a preferred form of electrical circuit embodied in the invention;
Figure 4 is a plan view of a modified form of the invention.
Referring specifically to the drawing and particularly to Figures l to 3, inclusive, the invention comprises a relatively thin and fiexible pad ID of soft material such as elastic rubber having high electrical insulating properties. The pad is rectangular in Outline and its marginal edge is beveled as indicated at so as to avoid any shoulder or corner which might cause discomfort to an infant when the pad is disposed beneath the diapered portion of the infant lying in its crib.
Embedded in one side of the pad and bonded thereto so as to be exposed and flush with the top surface of the pad, are contact elements C and C' constructed from thin and flexible sheet metal to provide rectilinear bars |2 and |2a from which project at a right angle and in opposite directions fingers |3 and |3a. The fingers of the respective bars are altemately arranged in parallelism so as to interfit in sufiiciently spaced relationship to be normally insulated electrically from each other by the pad, all as clearly shown in Figure 1.
Conductor wires M and I 5 are embedded in the pad and are connected to the respective bars i2 and 12a. These wires extend through a flat handle IS formed integrally with the pad at one end thereof, and are included in a relay circuit with a local battery |1 of 41/2 or 6 volts, and the winding of a relay |8.
The fixed contact |9 of the relay forms part of an alarm circuit including the battery I'l, a signal 20 which may be audible or visual and the relay armature 2| which is associated with the relay winding to close the alarm circuit when the winding is energized by closing of the relay circuit, all as clearly shown in Figure 3. A main switch 22 is included in the relay circuit to control the latter.
The operation of the inventlon is as follows:
With the signal 20 located at a suitable place to be seen or heard by one in attendance to an infant, and with the pad I!! disposed beneath the diapered portion of the infant when lying in its crib, it will be clear that when the infant urinates, the wet diaper will form a current conducting bridge across one or more of the flngers |3 and |3a to electrically connect the contact elements C and C', thus closing the relay circuit, it being assumed, of course, that the main switch 22 is closed.
As the relay |8 is now energized, the alarm circuit will be closed through the relay switch formed by the contact |9 and armature 2|, so as to activate the signal 20 and thus indicate that the infant's diaper should be changed. The main switch 22 can be opened should circustances prevent the immediate changing of the diaper, so as to prevent continued activation of' the signal. It will be appreciated that the alarm circuit can be provided with a domestic source of current supply and a suitable step-down transformer (not shown) in order to avoid a large drain of current upon the local battery H.
Should the dlaper be changed immediately, it is, of course, not necessary to open the main switch 22, as the relay circuit will be broken upon removal of the wet diaper from the pad. The device requires no adjustment or handlirig to render it ready for re-use, and it is not necessary that the pad be dried or wiped off after each operation. The pad can be washed occasionally to maintain it in a proper sanitary condition, but other than this operation, the device requires no servicing. The fiow of current in the relay clrcuit by the closing thereof as a result of the electrolytic action of salts in the infant's urine is so small as to be incapable of causing any Sensation to the infant even though its bare buttocks were to rest directly on the contact elements. Thus no harm to the infant would result from the use of the device, and the flexible pad would cause no discomfort.
The form of device shown in Figure 4 operates upon the same principle as the form just described and differs structurally therefrom by the provision of a circular or ovate pad Ina in the top surface of which are embedded so as to be ex' posed and flush therewith, contact elements C2 and C3. The elements are in the form of flexible wires spirally arranged alternately in sufiicientiy spaced relation for their adjacent convolutions to be normally insulated electrically from each other by the pad. As the operation of this form of the invention is identical to that of the form previously described, further description is deemed unnecessary.
It will be appreciated that it is not necessary to use a wet diaper to create an electrical bridge between the contact elements on the pad IO, but that any absorbent material wet with urine or even a sufficiently thick film of urine alone will act as the electrical bridge across the contact elements. Thus with a pad of a larger size, the device can be used as a signal by adults with mental disorders. motor and sensory paralysis ananasa around the bladdei' area, er any form of involnntary emptylng oi' the hladder.
What is claimetl is:
1. In a signalng device of the class dcscribed, a thin pad of soft :lrubber which is non--absoi'bent to aqueous solutions and which is adapted to be disposed beneath the tliapered portlon of an iniant in its crib; and contact elements embedded in the pad to be exposed from and fiush With a euriace of the pad in suiilciently spaced relationship to be normally insulated electrically from each other by the pad, yet be electrically bridgcd by urine wetting the :infant's diaper.
2. In a signaling device of the class described, a pad of insulating material which .is non' absorbent to aqueous solutions; and fiexible contact elements embedded in the pad and composed of a multiplicity of portions distributed over the area of the pad embedded therein and exposed tfrom one surface thereof in sufficiently spaced relationship to be normally insulated electrlcally from each other by the pad but which are adapted to be bridged by an electrolyte.
3. In a signaling device of the class described, a pad composed of an integral body of flexible and electrically insulating material which is nonabsorbent to aqueous solutions, and fiexible contact elements of current conducting material having portions embedded in and exposed from one surface of the pad and spaced apart so as to be electrically insulated from each other but which will be bridged by an electroiyte.
4. In a signaling device of the class described, a pad of insulating material which is nonabsorbent to aqueous solutions, contact elements embedded in the pad and exposed from one face thereof and substantially fiush With a surface of the pad, said contact elements being spaced suificiently from each other to be normally insulated electrcally from each other by the material in the pad, said contacts adapted to be bridged by an electroly te.
HARRY W. SEIGER.