US2460134A - Thermometric alarm switch - Google Patents

Description

Jan. 25, 1949.

J. o. LEE

THERMOMETRIC ALARM SWI TCH Filed Sept. e, 1945 2 Sheets-Sheet l oFF gms/wim QZ/ee oFF 0N Jan. 25, 1949.

J. O. LEE

THERMOMETRIC ALARM SWITCH 2 Sheets-Sheet 2 Filed Sept. 6, 1945 Patented Jan. 25, 1949 UNITED nain STAV'IIEZSA PATENT OFFICE THERMMETRIC ALARM SWITCH Jonathan O. Lee, Richmond, Va.

Application September 6, 1945, Serial No. 614,766

1 Claim. l

The instant invention pertains to thermoinetric alarm switches and its primary robject is the provision of a switch or circuit breaker which is adapted to close a circuit to sound an alarm when a predetermined 'temperature is reached and which is adapted to close a second circuit t'o sound another alarm more audible than the rst alarm when a higher predetermined temperature `characterist-ic of fire is reached.

Another object of the invention is the provision oi a switch which may be rendered inoperative before or after the alarm is sounded.

Other objects will appear from the hereinafter description.

The invention consists of certain novel eaturcs of construction, combination and arrange nient of parts, all oi 'which will be hereinafter set forth and particularly pointed out in the claim.

In the accompanying drawings which form a part oi this application, I have illustrated what I now consider to be the best form o my apparatus.

1n the drawings:

Figure 1 is a front elevation of the preferred embodiment of my invention;

Figure 2 is a wiring diagram;

Figure 3 is a iront view, partly in vertical section, of the thermo-metric tube and associated parts oi my device;

Figure 4 is an enlarged transverse section taken substantially on a plane as indicated by the line 4 4 of Fig. 3;

Figure 5 is right-hand (Fig. 3) side view or" :i

a portion of the thermo-metric tube;

Figure 6 is a diametral detail section of such tube portion.

In the drawing in which like characters of reference designate like or similar parts, numeral 7 indicates a housing of metal, plastic or other suitable material to house all or parts of the apparatus constituting the preferred embodiment of my invention. This housing is provided upon the upper intermediate portion of its back side with eye lne-ans 3 whereby it maf,7 be suspended on the wall oi a room. IThe upper portion Vof the front side of the housing has a plurality of slots 4 serving a purpose which will become clear as the description proceeds.

The front wall is also provided with an elonrectangular slot 6 the edges of which are beveled and which serves as a window for giving the operator of the device to be described a full or sufficient View of a thermo-metric scale 3,

comprising parallel lines indicating a certain temperature of mercury I0 enclosed in a glass tube generally indicated by i2. The scale can be so arranged that every line thereon indicates a tem perature five or ten degrees higher or lower than the next lower or higher line. The tube includes a spherical bulb i3, a lower tubular section ld of relatively small cross section and an upper section i5 of larger cross section.

The cylindrical sections of the tube carry a series of aligned contacts I1, preferably of platinum, each including a pin portion 8 which extends through one of a series of holes in the tube formed on a line of the scale, and also including an enlarged head I9 bearing against the tube. The tube is supported in the housing and behind the window in a suitable manner. The tube is surrounded above the bulb by the eye portion 2l of a holder 23 and at the top end by a similar eye of a holder. A screw 24l is threaded into the eye and bears with its inner end against the tube to firmly clamp the same to the holder. The opposite end of either holder is formed into an eye 2G. rIhe lower end of a guide rod 23 is inserted in the right-hand (Fig. 3) eye of the lower holder and supported therein by a flange 29. A similar guide is inserted with its upper end in the right-hand eye of the upper holder and depends therefrom in alignment with the lower guide rod. The two adjacent ends of the rods are held in alignment by a sleeve and separated from one another by a washer 3i, both of insulating material.

A sleeve 33 is slidably disposed on the lower rod and in electrical contact therewith and is part of a laterally extending Contact portion 35 adapted to contact any of the contacts Il and carrying an angular handle 36 extending around the lower guide rod and through a slot 3i in the front wall of the housing. The handle terminates in a hand kncb 38 disposed on the outside of the housing. A similar movable contact structure 33, 35, 35, and 38 is slidable on the upper rod. Each contact portion 35 carries near its free end a semi-circular guide 39 slidable on the thermometric tube (Figs. 3, 4).

Upon the lower portion of the front wall are a pair of switches 43 either of which controls a circuit now to be described.

A battery or other source of current 42 is disposed in the housing or elsewhere and has one of its poles connected to one of the switches which is also connected to a buzzer 44. The same is connected by a conductor 45 to a xed conducting sleeve 46 on the lower guide rod. A pin 41 extends through the wall of the bulb into the mercury and is connected on the outside by a conductor 43 to the other side of the battery.

One side of a second battery 59 is connected to the other 49 of the two switches which is also connected to an electric bell 52. The other side of the same is connected by a conductor 53 to a sleeve 5d on the lower end portion of the upper guide rod. A second pin lll' extends into the bulb and is connected on the outside by a conductor 55 to the other pole of the battery 59.

In order to operate the device the lower handle knob is manipulated so that its contact portion-l contacts the head of one of the pins having a scale number of the temperature which is to be announced. The upper hand knob is manipulated to set its contact on the head of the pin having a scale number of the fire temperature. The two switches are closed.

When the mercury in its expansion reachesrthe lower temperature for which the lower indicator has been set a circuit is completed. In this circuit the mercury bridges the left-hand bulb contact and the lower tube contact 35 and the buzzer is operated.

When the mercury reaches the upper scale number and xed contact associated therewith on which the upper movable contact 95 is set, a circuit is closed which includes the upper fixed Contact and the bulb contact to the right and sounds the bell indicating that the mercury has reached the scale number for re temperature. The slots 4 render the sound of the buzzer and `bell more audible.

VWhile I have shown and described the preferred embodiment of my invention it is of course to be understood that I reserve the right to make such changes in the form, construction and arrangement of parts as willv not depart from the spirit of the invention or the scope of the subjoined claim.

What I claim and desire to protect by Letters Patent is:

In a device of the class described, an expansible liquid thermo-meter including a bulb having a tube communicating therewith and rising therefrom, a series of longitudinally spaced terminal pins projecting through the wall of the tube of the thermo -meter above the bulb thereof and having contact heads exterior to the tube, a guide of electrical conducting material extending parallel to the tube, a movable electric contact slidably disposed on the guide and having a portion for selective engagement with the heads of the terminal pins, an arcuate guide element carried by the movable contact having portions disposed for engagement with the tube on either side of the heads of the terminal pins for maintaining said Ymovable contact portion in position to engage the terminal pin head disposed on the same plane as the movable contact, and a conductor pin extending through the Wall of the bulb and in constant Contact with the expansible liquid for completing an electric connection therefrom to the rst mentioned guide through the liquid and the terminal pin engaged by the liquid and movable contact.

JONATHAN O. LEE.

REFERENCES CITED The following references are of record in the file ol' this patent:

UNITED STATES PATENTS Number Name Date 338,090 Loomis Mar. 16, 1836 409,996 Meyer Aug. 27, 1889 478,701 Maxim et al July l2, 1892 783,141 Schick Feb. 2l, i905 935,460 Carpenter Sept. 28, 1909 1,600,896 Leines Sept. 21, i926 FOREIGN PATENTS Number Country Date 13,647 Great Britain 1895 529,571 France July 25, 1922

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