US1868925A - Temperature actuated circuit closing device - Google Patents

Description

July 26, 1932. H. SPIR@ ET Al. 1,868,925.

TEMPERATURE ACTUATED CIRCUIT CLOSING DEVICE Filed Dec. 8, 1950 l JNVENTORS.

IVM-VM ATTORNEYS.

Patented July 26, 1932 unirse STATES- nAranci Price HARRY SPIRO, GF` SAN FRANCISCO, AND WALDEMAR F. ANDERSON, `OF ALAMEDA, CALI- FORNIA; SAID SPIRO ASSIGNOR T ADA JOEL SPIBO A TEMPERATURE ACTUATED CIRCUIT CLOSING DEVICE Application led December 8,1930. Serial No. 500,778.

This invention relates to a temperature actuated circuit closing mechanism particularly intended for use in conjunction with automatic tire alarm sounding devices, signal systems, and the like.

Temperature actuated circuit closing devices employing thermostatic switches, fusible alloys, etc., are in common use and are eX- tensively installed in warehouses, factories, ,10 and to some extent in private dwellings. The temperature actuated circuit closing mechanisms, whether a tliermostatically actuated switch, a fusible alloy, or the like7 are usually fairly expensive andas such are installed one or more in each room to be protected and preferably at a point adjacent the ceiling, hence if a fire is started in the room at a point remote from the circuit closing mechanism the lire may gain considerable'headway before the temperature adjacent the circuit 1' closing mechanism becomes suiiicient to operate the same. Furthermore, it is a well known fact that at times a lire will start between the joists and the walls of a building 26 and will under such conditions gain great headway before the tire attacks the inside of a room Vin a suthcient degree to actuate the circuit closing mechanism installed therein, hence considerable property may Vbe de- 30 stroyed and lives endangered before an alarm is sounded.` f

The object of the present 'invention is to generally improve and simplify theconstruction and operation of circuit closing devices of the character described; to provide a circuitclosing mechanism which is so cheap to manufacture and install that where one circuit closing device has heretofore been installed a half dozen or more may be installed 40 at the same or even less cost, thus making it possible to cover a greater area thanhas heretofore been considered economically practical; to provide, a circuit closing device which is particularly adapted for attachment `4:15 to multi strand cables without f any material increaseV in the cable diameter or'reduction in its flexibility, thus permitting a ,cable of this character with a circuit closing mechanism attached thereto tobe strung along' a picture molding in a room, tobe pulled between j oists, betweenl wall spaces and through conduits, in this manner protecting spaces and area heretofore considered inaccessible; to provide a circuit closing mechanism in the form of a cable with the circuit closing mech-` mechanism which can be readily reset after actuation.

' The circuit closing mechanism is shown by way of illusiration in the accompanying drawing, in which- V Fig. l is an enlarged view partly in section of an insulated two strand cable showing the circuit closing mechanism applied thereto, l f

Fig. 2 isa cross section on line. 2-2 of Fig. l, y Fig. 3 is a side elevation of an insulated cable showing circuit closingmechanisms as applied thereto,

Fig. 4 shows a long cable with a plurality of circuit closing mechanisms applied thereto,

F ig. 5 is a partial sectional view of a modi- A.tied structure, said view showing thema'nner in which the insulation is removed to expose ythe two strands of the cable, said view also showing the sleeve and the spring actuated member whereby the circuit between the two strands of the'wire is closed, j

Fig. 6 is a cross section taken on line `vi-viof rig. 5,

Fig. 7 is a'persp-ectivel view of the spring which closes the circuit,

Fig. 8 is a diagrammatic viewfshowing the cable connected with a source ot current supply andanalarm mechanism,

Fig. 9 is an enlargedv detail view of a portion of a cable showing the manner in which v a` portion ofthe insulation is removed to receive another modified form of circuit closing mechanism,

Fig. lOis anenlarged vertical lsectional View of a two strand cable showing a modified form of` circuit closing mechanism applied thereto,

' section,

in turn connected with a wire Fig. 12 is a cross section taken on line 12-12 of Fig. 10,

Fig. 13 is a perspective view of the spring arm shown in Figs. 10, 11 and 12, whereby the circuit between the two strands of the cable is closed.

Referring to the 'drawing in detail and particularly Figs. 1 tol, inclusive, and 8, A indicates a multi strand electric cable or conductor, which, in this instance, consists of two strands or conductors indicated at 2a and 3a which are surrounded and separated by insulating material such as indicated at 4a. One strand of the cable is, in this instance, connected with one side of a source of current supply as a battery 5 while the battery is in turn connected through a wire 5a with a bell or other sounding device 6 and this is 7 with the other lwire or strand of the cable. Applied to the cable at spaced intervals, for instance, a loot or more apart, are sleeves generally indicated at 8a and mounted within each sleeve is a springla which is adapted to engage the two strands of the cable and thereby close the circuit through the same.

The cable is particularly intended for use jin conjunction with fire alarm sounding devices and the like and the circuit closing mechanism applied to the cable at spaced intervals is accordingly intended to be heat actuated so that when any one of the circuit closing mechanisms are subjected to a certain temperature a circuit through the battery and `the soundingdevice 6 will be automatically closed and an alarm given.

The specic construction of the one formof the circuit closing device is shown in Figs. 1, 2 and 4. Any ordinary two strand insulatingcable may be employed. In applying the circuit closing Ymechanism to the cable the insulating material is cutv away as indicated at 10aY so as to expose the strands 2a and 3a.. A

' sleeve such as shown at Sais then slipped over the cable and within the sleeve is mounted a helical wound contractable spring ring 9a.

.The spring ring lies within an annular recess 11a formed centrally of the sleeve and is retained in an expanded condition in the recess by means 'of a low temperature fusing alloy or other suitable material, such as wax, or

i the like indicated at 14a. Vhen the sleeve is Yslipped over the cable the annular recess 11a containing the spring ring is placed directly l the' cable.

V'shown at 15a.

in alignment to the cut away portion `1Oaof The ends of theV sleeve are then crimped sok as to-bite or grip the cable as When a suitable number of circuit making mechanisms have been applied Y and the cable has been installed in the building, it is obvious that whenever arpredeter- 2 Y l l 1,868,925

mined temperature is obtained the fusible alloy or other material employed fuses thereby releasing the spring ring and permitting the same to contract. Then the spring ring is released and contracted it Y engages the strands 2a and 3a and thus closes the circuit through the same thereby sounding the alarm mechanism indicated at 6.

VThe specific construction of a modified form of circuit closing mechanism is shown in Figs. 5 to 7 inclusive. Any ordinary two strand insulated cable maybe employed and the circuit closing mechanisms may be applied as closel or as tar apart as may be desired. In applying the circuit closing mechanism to the cable the insulation is cut away on opposite sides of the cable as indicated at 10 so as to expose the strands 2y and 3. A i

sleeve such as shown at 8 is then slipped over the cable and within the `sleeve is mounted a spring such as shown at 9. The spring lies within an annular recess '11 formed centrally of the sleeve and the ends of the spring are turned substantially at right angles as shown atv 12, these ends projecting into or partially through openings 1.3 formed on opposite sides of the sleeve. They are here secured by lmeans of a low temperature fusing alloy or any other suitable material such as wax or A Y the like lindicated at 14. When the sleeve is slipped over the cable the annular recess 11 containing the spring is placed directly in Y alignment with the cut away portons 10 of the cable. The ends of the sleeve are then crimped so as to bite or grip the cable as shown at 15. When the sleeves have been applied and the cable has been installed `ina building, it is obvious that whenever a predetermined temperature is attained the fusible alloy or i lIn Figs. 9 to 13 another modified form of 4 L the circuitclosing mechanism as applied to a cable is shown. The cable employed, in this instance, is flattened or substantially e1- kliptical in cross section, see Fig. 12. l In preparingit for the purpose of applying one or more of the circuit closing mechanisms the upper portion of the insulating material is cut away first on an angle asshown at 16 and then vertically as shown at 17 so as to expose a .portion of the two strands indicated at 2b and 3b whichV pass through the, cable. vA sleeve such as shown at 18substantially U- shaped as indicated by the dotted lines at 19,

Vsee Fig. 12, is then applied. This sleeve contains a spring arm which issecured as at 20 Vto one end'of'the sleeve. Thel opposite end of the spring arm lindicated at 21, see Fig. 1?), is provided with a head member 22 which 1s formed by bending the wire as shown. The free end of the wire is turned upwardly to form a pin 28 and when it is placed in the U-shaped sleeve the arm is bent upwardly against the upper surface of the sleeve until the pin projects through a perforation formed therein. It is here secured with a fusible material. The sleeve containing the spring arm in said position is slipped over the cut away portion of the cable shown at 16 and 17 in Fig. 12 and the free ends 19 are then bent around the cable and clinched. A suitable number of the circuit closing devices are applied to the cable at spaced intervals and the cable so prepared may be installed wherever desired and when a certain predetermined temperature is encountered the fusible material releases the spring arm and it moves inwardly against the strands 2b and 3b thereby causing the head member 22 to engage the same and close the alarm circuit.

The circuit closing mechanism is in reality nothing more or less than a flexible insulating cable containing two or more wires or strands, which is provided with a suitable number of circuit closing mechanisms such as described. The circuit closing mechanisms are enclosed by the metal sleeves shown and these are crimped over the cable wherever the insulation is cut away to permit their application. The diameter of the cable is not materially increased by the application of the sleeves nor is the flexibility at points intermediate the sleeves in any way impaired. It is accordingly possible in employing a cable thus prepared to pass it between wall partitions, to string it between beams, joists, etc., to support it on a picture molding, and in fact, to place or install it wherever desired and it is due to the ease with which it may be strung between partitions, etc., that it is possible to protect against fireplaces which heretofore would be considered inaccessible. The construction of the circuit closing mechanism is so cheap and simple and so easy to apply that the cost is negligible. For this reason it is possible to employ a materially increased number of circuit closing devices when comparison is made with thermostatic switches and like devices heretofore employed.

While the flexibility of the cable remains substantially the same as before, it will be noted that the sleeves enclosing the circuit closing mechanism affords sufficient rigidity at the point of application to prevent bending or injury of the circuit closing mechanism. lt should also be noted that the projecting ends of the spring arms whereby the circuit is closed are visible, hence permitting ready inspection of a cable before installation. For instance, by referring to Fig. 1, the hole 13 through which the end 12 of the spring arm 'l projects is plainly shown. If the spring arm larly,A if' a fir-e has started in a building equipped with'the circuit closing device here shown and an alarmhas been sounded, it is possible toinspect the cable and determine which particularA circuit closing, mechanism hasfbeenv separated, that is,providingthe fire wasput out'before any-damage was donetov the-cable. In that case where one or more of the circuit closing devicesV have released and closed the circuit itis possible toremove them and either apply new sleeves and'springs ortov reset the'old ones. Y

Another important feature which should be stressed is the fact'that the fusible material whereby the .spring arms are secured in extendedj position isl placed directly in the sleeve, that is, in the'openings 13. They are here exposed ,directlyto the heatedatmosphere andA as; suchV are exceedingly sensitive and rapid. in operation as it is not necessary to heat the entire sleeve or the interior mechanism before the spring arms may be released;`

lVhile,certain features of the ,present in.- vention' are more or less specifically de'- scribed, we wish it understood that various changesv may be resortedto withinthe scope ofthe vappended claims. Similarly, that the materials and finish of the several parts employed may be such as the manufacturer may decide, or varying conditions or uses may demand.

Having thus described our invention, what we claim and desire to secure by Letters Patent is 1. An electric current carrying exible cable comprising a pair of conductors enclosed in insulating material and insulated with relation to each other, a portion of said insulating material being removed to expose the conductors, an elongated sleeve enclosing the exposed portions of the conductors, a contractable spring ring mounted within the sleeve and adapted during contraction to engage the conductors to close a circuit therethrough and .temperature actuated means normally retaining the spring ring against retraction.

2. An electric current carrying cable comprising alpair of conductors insulated with relation to each other, said insulating material being removed at spaced intervals to expose the conductors, a plurality of elongated sleeves lenclosing the exposed portions of the conductors, circuit closing means within each sleeve engageable with the conductors to close a circuit through the same, temperature actuated means normally maintaining the circuit closing means out of engagement Vwith the conductors, and means for visibly indicating the position of the circuit closing means. y

3. An electric current carrying cable comprising a pair of conductors insulated with relation to each other, said insulating material being removed at spaced intervals to eX- pose the conductors, a plurality of elongated sleeves enclosing the exposed portions of the conductors, circuit closing means Within each sleeve engageable with ,the conductors to close a circuit through the same, and fusible means carried by the sleeves and normally maintaining the circuit closing means out of engagement with the conductors, said fusible means visibly indicating the position of the circuit closing means.

4. An electric `current carrying cable comprising ay pair oit' conductors insulated With relation to each other, said insulating material being removed at spaced intervals to eX- pose the conductors, a plurality of elongated sleeves enclosing the exposed portions 'of the conductors, spring actuated means Within each sleeve and engageable with the conductors to close a circuit through the same, and temperature actuated fusible means vcarried by each sleeve, and normally retaining the spring actuated means out of engagement with the conductors, said fusible means visibly indicating the position of the'spring actuated means.

HARRY SPIRO. WALDEMAR F. ANDERSON.

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