USRE17840E - Cut-out - Google Patents

Description

Reisrued ocr. 21, 1930 UNITED fjsTA'rEfs MAURITS J'. SANDIN, 0F WILKINS TOWNSHIP, ALIiEGHENY COUNTY, PENNSYLVANIA,

A SSIGNOR T WESTINGHOUSE ELECTRIC @c MANUFACTURING COMPANY, A (20B.-`

PORATION 0F PENNSYLVANIA l lcurr-ourl original liu. 1,630,358, ma may al, 1927, serial no'. 548,659, nlea april l, loza. application' for remue,l

led'Janl-lary'l5, 1929.` Serial No. 332,755..

My invention relates to cut-out mechanism and particularlyto thermal-responsive cirareeprovided forso regulating the thermalf l cuit-interruptingmechanisln for protecting` electric apparatus from excessive current.

One object of my invention is to provide a. cut-out mechanism .that may be resetA repeatedly and that may be installed in a casing .or receptacle similar in sllapega'nd dimensions to a standard cartridge fuse of equal capacity and which may be mounted in standard fuse clips or jawsand lsubstituted for standard fuses. f. Another object of my invention is to rovide a cut-out. device, havin the abovel c aractelistics, that will open t e lcircuit under prcdetermined'overload conditions and within a predetermlned time and whereln means' responsive. element thereof that it .will res ond to diierent predetermined current conltions.

Another object of my invention is to pro,`

vide a thermal cut-outthat may be manually'. closed or res/et, or manually released lor opened, and which is responsive to predeter mined current conditions.

Another object of my invention is to provide a cut-out device wherein a barrieri'siniterposedbetween one of the contact members of the conductors andthe vactuating mecha nismtherefor for preventing damage to the latterwhen the circit is interrupted.

. vide a'cut-out mechanism that is simple and Another object-of my invention is toproinexpensive to manufacture.

These and other objects, that willlbe made l apparent throughout the further; description mylinventon, are attained'b means of,v

the apparatus hereinafter'descri vd', andfiwl. lustrated in the accompallying.;-v drawings, wherein:

Figure 1 'is a longitudinal l through a cut-out. or switch mechanism v"embodying features of my invention; U-

Fig. 2 is a view similar to Fig. 1, showingcertain elements in inoperative position;

Fig. 3 is atransverse sectional view taken on the'line III-III of Fig. 1;

Fig. 4 is afragmentary longitudinal sectional view of a modified form of cut-out construction, and Fig. 5

s agfvlew of a portion ofa modified ,form of latch mechanism.

, Referring tof the' drawings, the cut-out mechanism includes a. tubular insulating casing 5 having end ferrules 6 and 7 substan` tially closing the end of the tube or casing, The insulating tube and the errules are similar in shape land dimensions to those of cartridge fuses having an equal capacity and, therefore, the casing is adapted to be inserted in standard fuse cllps'and jaws, it being the purpose of the device, in some cases, to take the place of standardfuses,lthe advantage' comprlsing a heating coil lpr'eferabl .made v of'a high-resistance meta is embe ded in a tubular sheath of heat-absorbing .insulating-material that is enclosed within the metal 'sleeve 14. One end of the coi1'12 is 'conductively attached to the'ferrule 6 and the other end is conductively connected. to the rod 8, as'l indicated in' Fig. 1.

A bimetallic thermal-responsive element is mounted -upon the conductor 8 and 4comprisesitwo metal strips that are welded toand have different coeilicients of ex- Increases ofthe temperature of the blmetallic elel'nentl cause the' free end thereof to be moved toward the walls of the proxlmity to the heating met 11 and,

fwhen heated,- serves tomovefarlatch member 16 away from the contact member 8L An insulatin inthe ferrule for longitudinal movement and carries', at its inner end, a. relentconductor "18 having anoifset portion 19 is 5. The element is `laced in` close rod-17 is slidablymomma] i adaptedfto automatically slip into a notch 20 in the conductor 8 to make good conductive contact with the member when the rod 17 is movedto its innermost position, as indi cated in Fig. 1.

The contact member 18 is conductively con nected to the ferrules 7 by means ofca flexible conductor 21 that is attached, at one end, to the contact member 18 and, at the other end, to the ferrule 7. The contact member 18 is normally yieldingly retained in spaced relation to the conductor y8, or in open position, by means of a helicalspring ,22 that is secured, at one end,.to the inner, end of the rod 17, and, at the other end, tov

the ferrule 7. The inner end of the rod 17 is. provided'with a barrier-member .23 that is slidable longitudinally within thev casing.

' The barrier serves to protect the flexible conductor and the spring 22 from the arc produced when the contact members 8 and 18 are separated. The latch member 16 is provided with a yoke member 24 that straddles th'e conductor 8 and the offset portion 19 of the `contact member- 18. The yoke 24 is provided with inwardly-turned projections 25 that engage the innerface of the offset portion 19 of the to be withdrawn from the contactv member ist' 8 with a vsnap-action. A

In order that 'the thermal-responsive element 15 may be adjusted to release the con tact member 18 under different predeter-- mined current conditions, it is provided with an adjusting screw 26 having threaded engagement withthe latch member 16. The end of the screw 26 engages the yfree end f .the bimetallic member 15 and, by turning the screw 26, the posi/tion ofthe latchmember 161elative to the end of the bimeta-llie element may be varied. By reasonfof this adjustment,the cut-out mechanism maybe made to operate at dilerent time intervals with a given current or at equal time intervals with different currents.

In order to provide convenient means for actuating the latch member 16 manually, the latch 16 is provided with a tube 27 that surq rounds theshank of the screw 26 and extends through an opening 28 in the casing 5. They outer end of the tube is provided with anv insulating handle 29 which may be gripped for manuallyv operating and tripping the `latch 16 tocause the circuit to be interrupted.' The h and1e'29 is provided with` a central ning 31l which permits of vmovement of. mtheiscrew 26 therein. The head of the screw r 18 is withdrawn from engage4 the contact members of the cartridge type, with the handle 29 extending outwardly in an accessible posi-- tion. The screw 26 is adjusted to'release the latch 16 under desired 'current conditions. When an overload occurs in the circuit for av predetermined length of time, the-heating element 11 transmits heat to the bimetallic element which causes outward movement of the free end thereof, thus causing the offset portion 19 of the contact member 18 to be f withdrawn from the notch'20. lVhen the contact member 18` has been released, the

spring '22 causes it to be withdrawn to the open position indicated in Fig. 2 with a snapl action. When it is desired to open the cil outwardly and the contact member 18 is released by the latch member 16.

Referring to Fig.` 4, wherein a modified form of construction is illustrated, it will be J seen that the bimetallic element serves as a heating element, thereby eliminating the necessity for an auxiliary heater, such as is illustrated in Fig. l. The construction of the casing, end errules and manual-releasing mechanism is identical to that of the device above described. In the modified form, howcuit manually, the handle or knob 29 is pulled ever, the bimetallic element 15 is directly connected to the end ferrule 6, and the conductor or contact member 8 is insulated from the errule. The free end of the bimetallic strip 15 is connected to the contact member 8 by means of a flexible conductor 32. In this construction, excess current, passing through the bimetallic element 15, causes it lto be heated. This action causes the free lend of the element 15 to move outwardly and to release the olfset portion 19 of the contact member 18 from engagement with the contact niember 8 and the circuit to be broken by ille opening movement ofthe contact mem- 'A more sensitive latching device is illustra-ted in Fig. 5, wherein the contact member 18 is provided with a relatively light spring 33 that engages the notch 20 and retains thc contact member in engagement with the conductor 8. A deviceotl this character releases at relatively lowcurrentfva-lues.

It will be apparent' from the foregoing that the constructlon provides a simple and eiit'ectivecubout device that may be used where :artridge fuses have heretoforeV been e m" ployed. While the device is capable of interruptingI short-circuits, it may be advisable to placer afnse of greater capacity than the cut-out device in series for the purpose of preventing injury tothe cut-out mechanism under severe short-circuit conditions.

fWhile I have shown a device as applied to y a cartridge `inse of' the ferrule type, it is obtioned that they are not actuated by normal starting currents but will cause the circuit to be Aopened when an overioad has prevailed a predetermined tinie. y

W'hile I have described and illustrated but two embodiments of myinvention., it will be apparent to those skilled in the art that variout changes, modifications, additions, substitutions and omissions may be made inthe apparatus illustrated without departing departing from the spirit and scope of my invention as set forth in thev appended claims; I claim as my invention: l f 1. A cut-out device comprising a tubular insulating casing, terminal members mounted on the ends of the casing, relatively movable contact members connected to the terminal members and adapted to c'onductively connect the terminal members, latching means for securing the Contact members iii engagement, means for separating the contact membei's in a direction longitudinally of the cas'- ing upon their release by the-latching means,

y and a barrier' on one of the members extending transversely of the casing.

2. A' cut-out device comprising an insulating casing, terminal members mounted on the ends of the casing, relatively movable contact members connected to the terminal members and adapted to coiiductively connect the terminal members, means for separating the contact members in a direction longitudinally of the casing, and a barrier on one of the members extending transversely of the casing.

3. A thermal electric cut-out comprising an enclosing base, apair of terminals secured to said base', a support of heat-conducting .material mounted within said base, a movable bimetallic thermal-responsive element hav-- ing one end secured to said support and electrically connected to one of said'terminals lto be heated in accordance with the current in the circuit controlled by the cut-out, a spring contact secured to said base and electrically connected to the other of said terminals, said contact being arranged to-be flexed., to com plete a circuit betweensaid terminals,`into a latching engagement in which it is mechani- Icallv iiiterlocked `with the free end of said element, and an electrical heater connected in said circuit for heating said support to supply heatto said thermal-responsiveelement and thereby cause the free end of said thermal' element to move and tliereby'release said latching engagement.

4. A thermal elect-ric cut-out comprising an enclosing base, a pair of terminals secured to said base, a support of lieat--coiiducting Vmaterial mounted within said b ase, a

movable bini'etallic thermal-responsive element having one end secured to said support and electrically connected to one of said terminals to be heated ii accordance with the current in the circuit controlled by the cut- 'port to supply heat to said thermal-responsive elenient and thereby cause the free end of said thermal element to move and thereby .release said spring contact member.

5. A thermal electric cut-out comprising` an enclosing base, a pair of terminals secured to said base, a heater connected in a circuit between said terminals and mounted within said base, a' thermal-responsive aggregate comprising abinietallic member in heat-absorbing. relation -to said heater, a biased contact arranged so that when latched it completes a circuit between said terminals, and means for causing movement of said bimetallic member to release said latch.

6. A thermal electric cut-out comprising an enclosing base, a pair of terminals secured to said base, a heater connected in a circuit which is closed between said terminals at all times when current flows through said cutout and mounted within said base, al thermalresponsive aggregate comprising a. bimetallic member in heat-absorbing relation to said heater, a spring contact arranged to b'e fixed into a latching engagement'to complete a circuit between said terminals and means for causing movement of said bime'tallic meniber to release said latching engagement.

7.' A thermal electriccut-out comprising an enclosing base, a pair of terminals secured to 'said base, a support of 'heat-conducting material mounted within said base, a movable bi-metallic thermal-responsive element having one end secured to said support and electrically connected to the otherof said terminals, said contact being arranged to be flexed into a latching engagement, controlled bythe free end of said element, to complete a c ircuit between said terminals, and an electrical heater connected'iii'said circuit for heating said support to supply heat to said thermalres onsive element and thereby cause the free Y en of said thermal element to move and v thereby release said spring contact member.

between sai terminals, said engagement be- 8. A thermal electric cut-out comprising an enclosing base, a pair of terminals secured to said base, a. support of heat-conducting material mounted wlthin said base, a movabie bimetallic thermal-responsive element having one end secured to said support and electrically connected to one of sald terminals tobe heated inaccordance with the current in the circuit controlled b the cut-out, a spring contact secured to saidybase and electrically connected totheother of said terminals, saidl,

contact being arranged to be flexed into a latching en agement to complete a circuit ing released by the free end of said element,

and an electrical .heater connected in said circuit for heating said support to supply heat to said thermal-responsive element and there= by cause the free end of said thermal element to move and thereby release vsaid spring contact member. f" l A In ltestimony whereof, I have hereunto subscribed my name this 10th day of January,

MAURITS J SANDIN.

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