US 2429363 A
Description (OCR text may contain errors)
Oct. 21, 1947. J. A. M LAREN 2,429,363
. ELECTRIC ALARM AND INDICATING DEVICE Filed Oct. 6, 1945 INVENTOR.
'- 84 JOHN A MGLAQEN BY I I 86 1| mb/ew ATTORNEY Patented Oct. 21, 1947 UNITED STATES PATENT OFFICE 2,429,363 ELECTRIC ALARM A INDICATING DEVICE John A. McLare'm Los Angeles, Calif. Application October 6, 1945, Serial No. 620,800
This invention relates generally to the art of signals and indicators, and more particularly to devices adapted to warn of a -.predetermined condition existing at a location remote from the device.
It is an object of this invention to provide a combined alarm and indicator particularly adapted, although not necessarily, for association with a refrigeration or an air conditioning system, to give an audibleand visual signal at a convenient location such as the kitchen, should the correct operating temperature of the system fail to be maintained by a remotely located refrigeration or air conditioning unit, so that a sufficiently advance warning will be given to prevent loss or inconvenience should the unit not be functioning properly; should the current supply fail either temporarily, or by a burned out fuse, or by inadvertent or accidental removal of the electric plug from the source of current supply.
It is another object of this invention to provide an alarm and indicating system or device of the above described character which is compcsed of a simple, rugged and relatively inexpensive structure of neat and attractive appearance, Whose parts positively co-act to give a dual warning in the event of improper functioning of the system which it is operatively connected with remotely, by sounding an alarm and rendering a visual indicatoractive for observation at any time, so that should the alarm be sounded when no one is in attendance, and ceases before anyone is in hearing distance, the visual indication will remain as a constant warning, all to theend of affording maximum protection to the owner against loss or inconvenience incident to failure of the refrigeration or air conditioning system to function properly,
With these and other objects in View, the invention resides in-the combinations and arrangements of elements as set forth in the following specification and particularly pointed out in the appended claims.
In the accompanying drawing,
Figure-1 is a vertical longitudinal sectional view of one form of alarm and indicating device embodying-this invention;
Figure 2 is a horizontal sectional view taken on the line 2--2 of Figure 1;
Figure 3 is a fragmentary view similar to Figure 1, and illustrating a second form of alarm and indicating device embodying this invention;
Figure 4 is a fragmentary view in front elevation of a third form of alarm 'and indicating device embodying this invention;
Figure 5 is a fragmentary View similar to Figure 1, and illustrating a fourth form of alarm and indicating device embodying this invention; and
Figure '6 is a View in front elevation partly '2 broken away, of the form of the invention shown in Figure 5.
Ref ng pec icall to th drawing and particularly to Figures 1 and 2, this form of the invention is compqsedof a streamlined case C of sheet metal which incl des a rectangular back or supporting plate l having top and bottom flanges J l a 2 a d a em a e r m cover ie en ed to be secured to the back plate l 0 by suitable l 14 on h lat ce v n c w 011 h cover.
it n the asin C is a a arm de c and an indicating element I operatively associated therewith. alarm device may comprise a conventional form of electricbell or buzzer whose base is secured to the plate ill by bolts 2|, and supports the usual stationary electromagnet 2;, a vibrating armature 23 mounted on the base 20 by a spring 24 andhav ng a clapper 25 disposed to strike the bell -25. Current for operating the bell may be supplied by a local battery of 6 volts provided by three series-connected dry cells 21 supported in a row on the bottom flange l2 of the case at one end of the latter, and confined against displacement by a partition gs. This bell circuit includes conductors 29 and 30 with which the cells 21 and the bell are in series, are connected to terminal sockets 3,l and 32 mounted on the bottom flange 12. Jacks 33 and 34 are adapted to be plugged into these sockets and are carried by conductors 35 and 36 which lead to a remote location at which the refrigeration, air conditioning or other apparatus which incorrect operation is to be warned against.
The conductors 35 and 30 are connected to contactsS-l and 38 of a conventionalthermostatic or pressure controlled switch S located at the unit so as to directly subject-to variations in the temperature or pressure in the unit as the case maybe. This switch includes a diaphragm ;3 9 carrying a bridging contact All for the contacts 3'5 and 30, and is adapted to respond to a predetermined dangerous temperature rise in thecold c ambe o a r fr g at n uni b e pand n a gas in the thermostatic tube 4 of the switch S sufficiently ;for the contact .40 to close-the normally open bell-oi cuit so as to ring tht bell 2$ and thussound an alarm to warn of the incorrect operation of the unit.
"Ifhe indicating element 1 comprises a lighte h a m h n a u t b Wa nin ndi ia suchas t w Dan e heme whi ar i p otal -m m a ol fixe ax 9 1521 plate 1 -a i en ihe al rmfl wh and n c qse roximity to the endof thecas e C. The case is provided with an openingin the form of a slot 52 disposed to .freely pass the arm during movement thereof ,from its .nonesignaling .con- .ce'aled position within the case as shown in iull lines in Figure ,1, to .its signaling ,position wherein arm and a movable part of the bell, in the present instance the armature 23 to which the other at 55. In its nor mal non-signaling position, the arm 50 is tilted end of the cord 54 is connected slightly from the perpendicular in a direction to gravitate inwardly of the case, and is'maintained traction of the armature by closing of the bell circuit, whereby the element 82 wil1 be free to be moved by the spring 84 to its signaling position.
It will be manifest that in all forms of the invention, the activation of the audible signal will cause a visual indication to be given and main- ;tained for observation at any time. It will be in that position by the cord 54' which is pulled,
taut under this gravitating action of the arm, as shown in full lines in Figure 1.
However, upon closing of the bell circuit at the contacts 3'! and 38, the initial attraction of the armature 23 by the electromagnet 22, jerks the cord with sufiicient force to tilt the arm 50 in a direction outwardly of the case, so that the arm positively gravitates to its signaling position shown in broken lines in Figure 1. With the arm 50 in signaling position, the distance between the points of connection 53 and 55 of the cord 54 to the arm and armature, respectively, has been shortened suificiently for the cord to be slack as shown in broken lines in this figure, and thus enable free and unrestricted ringing of the bell to be efiected.
It will be clear that should there be no one in attendance at the device or in hearing distance of the bell during the period it is ringing until the battery cells become exhausted, the arm will provide a constant and permanent indication for observation at any time later, thus providing further assurance that the warning given by the device will be noticed.
In the form of the device shown in Figure 3, there is substituted for the flexible connection 54 a lug 68 on the bell armature 23a which co-acts with alug 6| on the indicating arm 50a to normally retain the latter in the slightly outwardly tilted non-signaling position shown in full lines, against the action of gravity tending to swing the arm downwardly and outwardly of the case Cl through the slot 52a to the signaling position shownin broken lines. Thus, completion of the bell circuit will disengage the lug 63 from the lug 6| upon initial attraction of the armature 23a by the electromagnet, to render the arm 56a free to gravitate to signaling position.
In the form of the invention shown in Figure which may include either of the above described operating mechanisms for the signal arm, the case C2 is provided with a window 78 suitably located to expose the arm 50b to view within the case when the arm has moved to its signaling position, thus confining all moving parts in the case.
In the form of the invention shown in Figures 5 and 6, the warning indicia 88 such as the word Danger can be applied to a conveniently visible wall 8| of the case C3 and can be normally covered by a shield element 82 pivoted on the case at 83 and urged by a suitable hinge spring 84 to the lowered position shown in broken lines in Figure 5, to expose the warning indicia to view.
A spring-pressed latching pin 85 mounted in the case C3, normally co-acts with a keeper 86 on the element 82 to latch the latter up in the non-signaling position shown in full lines in Figure 5. A cord 8! or other flexible operative connection is trained over a pulley 88 in the case, and is connected to the latch pin 85 and to the bell armature 23b so as to release the latching pin from the keeper 86 in response to initial atnoted from Figure 1 that if it is desired, a push button switch 90 for testing the bell circuit can be mounted on the case 0 and connected across the conductors 29 and 30 so as to complete the bell circuit when the button is pushed.
1. An alarm and indicating device comprising: an audible signal including an electromagnet and an armature vibrated thereby in response to the supply of current to the electromagnet; an indicating arm pivotally mounted about a fixed axis and normally gravitating in one direction to a non-signaling position; and a flexible connection between said arm and said armature, operable in response to initial attraction of the latter by the electromagnet when energized, to exert a pull upon said arm sufficient for the arm to gravitate in the other direction to a signaling position.
2. An alarm and indicating device comprising: an audible signal including an electromagnet and an armature vibrated thereby in response to the supplying of current to the electromagnet; an indicating arm pivotally mounted about a fixed axis and normally gravitating in one direction to a non-signaling position; and a flexible connection between said arm and said armature, operable in response to initial attraction of the latter by the electromagnet when energized, to exert a pull upon said arm suflicient for the arm to gravitate in the other direction to a signaling position; said flexible connection being drawn taut by said arm when gravitating to non-signaling position, so as to act in determining such position of the arm; said flexible connection being slack when said arm occupies signaling position so as to render said armature free to continue vibrating.
3. An alarm and indicating device comprising: a case having a vertical slot in an exterior wall thereof; an alarm device in the case including an electromagnet and an armature vibrated thereby when current is supplied to the electromagnet; an indicating arm pivoted about a horizontal axis adjacent said slot to mount the arm for movement from a non-signaling position in the case to a signaling position wherein the arm projects from the case through said slot; and a flexible member connected to said arm and to said armature to normally be pulled taut by the arm in tending to gravitate to non-signaling position; said member being responsive to movement of the armature by the electromagnet when energized, to jerk the arm suificiently for the latter to reversely gravitate to signaling position, with said member being slack following such operation thereof, so as to render the armature free for vibration as aforestated.
J. A. McLAREN.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS