US2425623A

US2425623A - Protective device

Info

Publication number: US2425623A
Application number: US474682A
Authority: US
Inventors: Clarence W Kuhn; Theodore F Rosing
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1943-02-04
Filing date: 1943-02-04
Publication date: 1947-08-12
Anticipated expiration: 1964-08-12

Description

Aug.12,'1947. C.W .KUHN ETAL 2,425,623

PROTECTIVE DEVICE- Filed Feb. 4, 194 2 Sheets-Sheet i INSULQTfJ/T lb [4 G 2 Patented Aug. 12, 1947 Rosing, Whitefish Bay, Wis assignors to Cutler-Hammer, Inc.,- Milwaukee, Wis a corporation of Del aware Application February- 4, 1943, Serial No? 4 745682 This invention relates toprotective devices for electric circuits and is particularly applicable to protective devices of the type disclosed in the Kuhn et al. Patent No. 2,310,531, of February 9; I943;

The aforementioned patent discloses an ambient temperature compensated: overload relay, andvthe present invention has among its objects to provide a relay of this type which is highly shocks-proof, or in other words capable ofperforming: properly and withstanding damage when subjected to shockss'u'ch as are encountered on board naval. vessels upon: bombing and: torpedo ing thereof.

Another object is to provide an overload relay ofthe: aforesaid t ype witl'l mechanism: which acts upon inertial movement of the: relayoperating mechanism under the action of: severe shock to prevent opening of. the relay contacts.

Another object is to provide a shock-moor mechanism for relays of the aforesaidwhich is simple,. ruggedi and: inexpensive 'in construction and positive'and reliable inoperation.

Various other objects and:- advantages oi the invention: will hereinafter appear-t The accompanying; drawings illustrate an embodiment of the: invention which willnow be described, iti'bein'gr understood that: various modifications may be made: i'n thefi embodiment; illustrated without departing from the spiritand scope of the appended claims';

In the drawings,

Figure 1 is a side elevational view ofa relay embodying: the invention, the relay: b'eirlg-v shown in: set positions and a part of the enclosing. casing therefor being removed}:

Fig. 2 is aview similar-to that show-n in Fi'g. 1 withupartssbroken'raway'andishown in sectibnl and illustrating inertial" operation oi: the relay: under the: action ofzshock; and,

Figs'r3 and 4" are secti'o'nalrviews: on lines 3 -3 and 4'-4, respectively, of Fig. 1;

Referring to the accompanying; drawings, the sameillustrate arr. overload: responsive relay of the type disclosed. in the; aforementioned patent, the operating mechanismof said relay being housed between two complementary casing sections l and l which are formed of molded in'- sulating-jmaterial and:are mounted upon the front face of a I vertically disposed insulating]: base Z;

Briefly described the relay" is providediwith a ofnormallyengaged. spring contact fingers 3 and l which are mountedupon-=the front face of insulating 'base, 12 and-are separable: by an insulatlng finger 5'." Finger- 5=- mounted upon a bar 8 fi'xed to a reciprocablepush button element 1: and saidpush button element is slid'ably sup ported between the casing: sections i and l and is biased tomove forwardly by a spring 8. Pushbutton element 1' is normally held" in the de'-' pressed position shown by full lines in Fig. 1 to maintain finger 5' out of engagement with con-- tact fingers 3 and: 4* by a thermal overload re sponsivemechanism including a latch 9 anda cooperating vertically disposed lever H3.

Latch 9 is pivotally mounted u-poh push button element 1- and is normally held againstthe action of a biasing spring H inengagement with the lower end 0t lever W by a solder type thermal responsive element-- r2. Element I2 is: mounted upon push button element 1 and is responsive underthe action of a heater coil l-3= to triplatch 9 outofengagement with lever It upon a-prede= terminedoverload current condition insaid coil; Upon tripping 0t latch 9 push button element I moves forwardly under the action ofspring 8 into the. dotted line; position shown in Fig. 1- to effect;

separation oicontact fingers

3 and 4 by movement of insulating finger 5- therebetween. Depressionof push button-element I effects resetting; ofthe relay in the positionshown' in Fig 1.

Lever H) has it'supper end pivoted-upon a'pi-n 3| carriedbetween the-casing sections I andl and saidil'ever isoperable by atemperature responsive' diaphragm: device [4 against theaction of an adiust'able loading spring I5 to automati callyad justthermal responsive element: I 2 with respect to heater. coil 13' so that overload operation of the relayv is substantially uninfliienc'ed by ambient temperature changes...

When the above described relay is in set position severe shock mayprouucc accelerating forces Whicl'i' eiiect forward" movement Ofpilsfi button element 1' and the parts connected thereto against the biasing" action ofloading spring'. [5; In accordance with the present inventionthe mechanism which will now be" described isprovided for positively blocking insulatingr finger 5 out of engagement with

contact fingers

3 and 4 uponrorwar'd movement of push button element 1 under the action of'shocli.

Insulatingfinger 5 -is piyotallymountedupon-a pin it carried by anupstanding part1 fixed to the rear end of bar Wanda is yieldingly held against counterclockwise -rotation -outof: the'vertical positiom shown in Figc'lby: a spring I8.

Upon tripping of: the relayunder ovcrload condh tionsspringl8-maintains insulating-finger i in s in the vertical position shown in Fig. 1 during movement thereof between

contact fingers

3 and 4.

A bell crank lever 19 having

arms

20 and 2| is provided for blocking insulating finger 5 against movement into engagement with

contact fingers

3 and 4 upon forward movement of push button element 1 out of the position shown in Fig. 1 under the action of shock. Bell crank lever I 9 is fixed to the lower end of a vertically disposed pivot pin 22 and said pivot pin is rotatably supported within a bearing bushing 23 held within an opening formed in the opposing faces of walls 24 and 24 on the interior of casing sections l and l Arm 20 extends rearwardly from pivot pin 22 and is bent upwardly for engagement with insulating finger 5 at a point above the pivot pin it. Arm 2i has a forwardly extending link 25 pivotally connected to the free end thereof and as shown in Fig. 4 said link is located to one side of lever i and is slidably supported within a groove 26 in casing section l Link 25 has an inwardly bent portion 21 on the front end thereof to be engaged by lever l0 upon forward movement of said lever beyond the range through which it moves for ambient temperature compensation. Bell crank lever I9 is biased to rotate in a counterclockwise direction (Fig. 4) by a coil spring 28 and said lever is normally held in the position shown in Fig. 4 against the action of said spring by engagement of arm 2| with a stop surface 29 on casing section l With bell crank lever I9 in th position shown in Fig. 4 the arm 20 thereof is out of the path of insulating finger and the relay is thus adapted to operate as hereinbefore described under overload conditions. However, upon forward movement of the push button element 1 under the action of shock, lever l0 engages projection 21 on link 25 to move bell crank lever I 9 in a clockwise direction out of the full line position shown in Fig. 4 so that arm 20 assumes a position in the path of insulating finger 5. This operation occurs prior to movement of insulating fingei- 5 into engagement with

contact fingers

3 and 4. Upon continued forward movement of push button element I under the action of shock insulating finger 5 engages arm 20 of bell crank lever l9 and is rotated against the action of spring i8 as shown in Fig. 2 to prevent engagement thereof with

contact fingers

3 and 4. As is apparent, rotation of insulating finger 5 against the action of spring [8 permits full movement of push button element 1 against the action of loading spring [5 into the dotted line position shown in Fig. 1 for dissipation of the accelerating forces produced by shock.

As shown in Fig. 3,

stationary contacts

3 and 4 are located between projections 30 and 30* on the interior of casing sections l and l Said proj ctions prevent separation of

contacts

3 and 4 under the action of shock by limiting vibrational movement thereof.

What we claim as new and desire to secure by Letters Patent is:

1. The combination with a switch having operating means biased for movement to effect a given condition of said switch, means engaging a part of said operating means when moved to effect a. different given condition of said switch and subjecting said part to a preponderating bias against which it has play under shock, and movable means operating as a function of such play of said part positively to block change in the condition of said switch for a temporary period terminated by subsequent stabilization of said part under said preponderating bias.

2. A condition responsive switch having an associated control mechanism including a member normally movable within a given range and movable beyond said range under an abnormal condition, and means associated with said member for preventing a change in the condition of said switch upon movement of said member beyond said range.

3. In a protective device, in combination, a movable switch element, an operating member therefor biased to move into a given extreme position, a yieldable operating connection between said element and said operating member for moving said switch element into a given circuit controlling position upon biased movement of said operating member into said given extreme position, an overload responsive mechanism for normally holding said operating member out of said given extreme position and for subjecting the same to a Dreponderating bias against which it has a play under shock, and means operating as a function of said play of said operating part for positivel blocking said switch element against movement into said circuit controlling position for a temporary period terminated by subsequent stabilization of said part under said preponderating bias.

4. In a protective device, in combination, a movable switch element, an operating member therefor biased to move into a given extreme position, a yieldable operating connection between said switch element and said operating member for moving said switch element into a given circuit controlling position upon biased movement of said operating member into said given extreme position, an overload responsive mechanism for normally holding said operating member out of said given extreme position and for subjecting the same to a preponderating bias against which it has a play under shock, and means operating as a function of such play of said operating member for positively blocking said switch element against movement into said circuit controlling position, said yieldable operating connection acting upon blocking of said switch element to permit full movement of said operating member into said given extreme position under the action of shock.

5. In a protective device, in combination, a movable switch element, an operating member therefor biased to move into a given extreme position, a yieldable operating connection between said switch element and said operating member for moving said switch element into a given circuit controlling position upon biased movement of said operating member into said given extreme position, an overload responsive mechanism for normally holding said operating member out of said given extreme position and for subjecting the same to a preponderating bias against which it has a play under shock, means operating as a function of such play of said operating member for positively blocking said switch element against movement into said circuit controlling position, said yieldable operating connection acting upon blocking of said switch element to permit; full movement of said operating member into said given extreme position under the action of shock, and a temperature responsive device for adjusting said overload responsive mechanism to maintain the action thereof substantially uniform under varying ambient temperature conditions.

6. In a protective device, in combination, a

movable switch element, an operating member therefor biased to move into a given extreme position to move said switch element into circuit interrupting position, a current responsive overload latching mechanism associated With said member, a condition responsive device having a spring biased part normally engaged by said latching mechanism to hold said operating member out of said given extreme position, said spring biased part being adjustable through a given range by said device to vary the current value at which said latching mechanism responds, and being movable against its bias beyond said range under the action of shock, and means associated with said spring biased member and acting upon movement thereof beyond said range to positively block said switch element against movement into circuit interrupting position.

7. In a protective device, in combination, a movable switch element, an operating member therefor biased to move into a given extreme position to move said switch element into circuit interrupting position, a current responsive overload latching mechanism associated with said member, a condition responsive device having a spring biased part normally engaged by said latching mechanism to hold said operating member out of said given extreme position, said spring biased part being adjustable through a given range by said device to vary the current value at which said latching mechanism responds, and being movable against its bias beyond said range under the action of shock, means associated with said spring biased member and acting upon movement thereof beyond said range to positively block said switch element against movement into circuit interrupting position, and a yielding operating connection between said operating member and said switch element permitting full movement of said operating member into said given extreme position under the action of shock upon blocking of said switch element.

CLARENCE W. KUHN.

THEODORE F. ROSING.

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

UNITED STATES PATENTS