US1864158A - Quick-acting mechanism for electric switches and the like - Google Patents

Description

June 21,' 1932. T w. H.'WEINRICH ET AL 1,864,158

QUICK ACTING MECHANISM FOR ELECTRIC SWITCHES AND THE LIKE Filed July 18, I927 Patented dune 21, 1932 orrro sates Pram orrics wAnTna is. wnrnR-rcir annrnnnnnrox CARL GEILER, or DAYTON, on nssienons" re 'rnurnn MANUFACTURING coir/trimmer DAYTON, oi-iro, noonrone'rronior OHIO QUICK-ACTING MECHANISM son. nrncrnro SWITCHES Ann THE LIKE Application filed July 18, 1927. Serial No. 206,526.

Our invention relates to electric switches, and more particularly to an automatic cutout for opening and closing electric circuits under the influence of variations of pressure, temperature, or intensity of an actuating medium. While the invention is herein shown and described more particularly in its application to an electric switch it will be understood that the same actuating mechanism may be utilized for opening and closing valves, shifting a clutch into and out of operative position, or to perform other analogous operations. A very usual application of the present type of automatic cutout is the control of domestic type mechanical refrigerators, motor driven pumping. systems for water distribution, and compressed air apparatus. Such control or cutout devices are utilized in such systems to maintain pressure or temperature within predetermined range limits by setting in operation an actuating motor, opening a supply valveor by connecting an actuating mechanism whenever the temperature of a chill room or refrigeration chamber, or the fluid pressure within the tank fluctuates beyond the predetermined range and to automatically arrest the motor, or close the valve, as the case may be, when the predetermined normal condition has been restored. In many instances such cutout or control devices have been of a slow moving type having a tendency to dwell or lag under some conditions. The present construction is designed to not only overcome this objection but to provide a construction which will maintain a full, or even increased pressure upon the contact point until the instant of operation, where upon the disconnection or breakage will be effected with a quick snap-over action, eliminating any tendency to spark or are between the contact points.

The object of the invention is to simplify the structure, as well as the means and mode of operation, of such quick acting cutout mechanisms, whereby they will not only be cheapened in construction, but will be more efiicient in use, positive in operation, uniform in action, automatically controlled, and unlikely to get out of repair.

A further object of the invention is to provide a mechanism hav1ng a mmlmum number 'of operating parts. so shaped and designed that theyrmay'be economically manufactured by stamping or by punch press operation,and so arranged as to facilitate assembly. Economy of manufacture and simplicity of construction are of prime importance.

lVith the above primary and other inciden tal objects in view, as will more fully appear in the specification, the invention consists of the features of construction, the pa rts and combinations thereof, and the'm'ode of operation, or their equivalents, as hereinafterdescribed and set forth in the claims. V 1 Referring to thedrawing, Fig. 1 is'a side elevation of the assembled mechanismshow ing the switch parts in their closed "or contactingposition. Fig. 2 is a similar view showing the switch parts reversed, and the contact broken. I Fig. 3 is aside elevation from the right of Figs. 1 and 2. Figs-4i and 5 are detail views showing the application of the invention to a valve and a clutchrespectively. l

Like parts are indicated by similar charac ters of reference throughout the several views. 1 The operating parts of'the automatic quick acting cutout mechanism are mounte'd within a housing 1 with which is connected a pressure chamber 2 having therein a yielding diaphragm fluctuating'underi variations of fluid pressure, or, as illustrated in the present instance, an eXpansible and contractible bel lows 3 of the sylphon type. Carried by such bellows 3 is a stud or thrust member 4 engaged by a helical compression spring 5, against the yielding resistance of which the bellows 3 is actuated by fluid pressure admitted to the chamber'2 throughan inlet con duit 6. The tension or compression spring 5 abuts upon a nut or collar 7 carriedby an adjustable stud 8 mounted in the wall of the housing. 1. By adjustment of the stud 8 the tension or resistance of the spring 4 to movement of the bellows 3 may be regulated. Pivoted upon a stud 9 carried by the housin'g 1 is a bell crank lever 10, one arm of which pivotally engages with astudor pin 11 can ried by the thrust member or bellows stud 1. This bellows stud or thrust member is preferably, though not necessarily, slotted or re cessed to receive the end of the bell crank lever .10. The other arm of the bell crank lever IOis provided with oppositely inclined or beveled end faces 12 and 12, with which a roller 13 carried by a trip arm 14 alternately engages. The 'trip'lever 1 1 is preferably of hollowor box like formation comprising interconnected spaced side bars between which theroller13 is located. This trip arm is pivoted at 15 to one end of an oscillatory switch lever 16 pivotally mounted upon the stud 17 carried by the housing or main frame.

The roller 13 'carried'bythe trip arm 14 is yieldingly held in engagement with one or the other inclined face 12.12v of the bell crank :lever by a tension spring 18 connected at one end toasuch arm 14: and at its opposite end to the bell'crank lever 10. Asia matter of convenienceand economy of manufacture the endofithe spring 18 is engaged inan irregular opening 19in the bell cranklever 10 through which extends apin 20 carriedby the mainframe orhousing 1 which serves to limit the oscillation of thebell crank lever 10 in either direction. At its opposite end the spring 118 isadjustably connected to the end of the springarm 14 by an adjusting nut 21. The trip arm 14 is capable of a limited to and fro reciprocatory movement as the roller 13 engages alternately-the inclined faces of the bell crank lever 10. This reciprocation of the trip arm effectsan oscillatory movement of theswitch lever 16 about its pivotal connection '17 and in turn effects the reciprocationwofa plunger 22 connected to the lower endof .the oscillatory lever 16. The plunger 22 has a sliding bearing in the terminal block 23 f .insulating material. Terminals or binding posts'24 upon the block 23 are associated with stationary contacts which are engaged by -1novable:contacts 25 carried upon spring arms26=connected with the reciprocatory plunger.

In Fig. :1 the roller 13 is shown in engagement with'the beveled face-12 of the bell crank lever 10 .and theswitch lever 16 and plunger 22 are intheiroperat-ed positions. The switch contacts 25 are engaged with the circuit terminals upon the terminal bar 23. As the fluid pressure within the chamber 2 decreases, the reaction of the compression spring upon the thrust member or bellows stud 1 tends to oscillate the bell crank lever about its pivotal connection 9. This movement is yieldingly resisted by the roller 13 and tens ionrspring .18. The camming'action of the inclined face 12 forces the roller upwardly against the yielding resistance of the-spring 18 until the-apex ofthe 'bellcrank lever arm passes beyond deadcenter relation with the roller 13, shown ibydotted lines in Fig. 1, whereupon thetreaction of the tension spring upon the bellows or diaphragm 3 and against the expansive action of the compression spring 5 oscillates the bell crank lever 10 in the opposite direction. The inclined face 12 exerting its camming action upon the roller 13 oscillates the trip arm 14. about its pivotal connection against the yielding resi stance of the tension spring 18 until the apex of the inclined faces 12-12 passes beyond the dead centerrelation with the roller 13. Thereupon the reaction of the tension spring 18 exerting pulling-influenceupon the triparm l4 draws the roller .13 down the inclined face 12. Inasmuch as the bell .cr-ank'lever 10 resists movement, the camming action between the roller and inclined face 12=effects areciprocation'of the arm l ito again oscillate the lever 16-about its pivot 17 to effect contact of the members with their correspondingterminalsupon the insulation mounting 23.

While the apparatus has been illustrated in connection with movable electrical switch contacts 25 it will be obvious that theplunger 22 may be-extended beyond the housing land be connected with a valve as M25 in Fig. 4, or with aclutch element 26 as shownin Fig. 5. Otherwisethe operation of the device is as before described.

From the-above description it will'be apparent thatthere is thusprovided a'construction of the character described, possessing the i 7 particular features of advantage before enumerated as desirable, but which obviouslyis susceptible of modification in its form, proportions,-and arrangement of parts, without departing from the principle involved or sacrificing any'of its advantages.

VVhilein order to comply with the statute the invention is described in language more-or less specific as to structural features, it is to be understood that the invention is not limited :to' the specific details shown, but that the means and construction herein disclosed comprise the preferred form of-several modes of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

Having thus described our invention, we claim:

1. In a quick acting switch mechanism, or

the like, an oscillatorycam arm having oppositely beveled'faces, means :for oscillating said arm, a trip arm engaging one or the other beveled faces of the cam arm, and a spring under the tension of which such-engagement is effected said spring having its ends movably mounted, the limited movement of said cam arm being sufficient to shift the point of engagement of the trip'arm past the apex of the oppositely beveled faces, the reaction of said spring causing said engaging point to travel upon the beveled face and by the camming action thereon causing reverse movement of the trip arm.

2. In a quick acting switch, an oscillatory cam arm having oppositely inclined faces capable of a limited degree of oscillation, an oscillatory operating lever capable of a degree of oscillation greater than the cam arm, a trip arm pivoted to the operating lever and having engagement with one or the other of the inclined faces of the cam arm, a spring connected at one end to the cam arm and at the other end to the trip arm against the tension of which said trip arm is oscillated by the camming action of the inclined face of the cam arm upon oscillation of the latter during movement from one limit of its range of movement to the other, to enable the engaging point of the trip arm to pass from one incline-d face to the other, the reaction of said spring causing said point of engagement to travel upon the inclined face and by the resultingcamming action oscillate said operating lever. v

3. In a device of the character described, a prime mover having convergent faces and capable of limited to and fro movement, a reciprocatory trip arm riding upon one or the other of the convergent faces, a tension spring urging the reciprocatory trip arm into engagement with the engaged face, the limited movement of the prime mover serving to present the converging faces alternately for engagement of said reciprocatory trip arm said prime mover further changing the ten sion of said spring according to the direction of its movement whereby the trip arm will move in one direction under greater spring tension than in the opposite direction, the reaction of said spring serving to move the trip arm along the engaged face and by the camming action thereof effect longitudinal movement, and a member to be moved to alternate positions operatively connected with said reciprocatory trip arm.

4. In a device of the character described, a prime mover having convergent cam faces, a trip arm having engagement with one or the other of said faces and capable of both oscillatory and reciprocatory movement, said prime mover being capable of limited to and fro movement sufficient to shift the point of engagement of the trip arm past dead center relation in either direction, means for so shifting the prime mover and holding said member against further movement and spring means actuating the trip arm upon the engaged face to afford camming action by which said trip arm is moved longitudinally and means for varying the. tension of said,

spring in accordance, with the direction of movement of the prime mover.

5. In an apparatus of, the character de- I scribed, a pivoted bell crank lever, one end of whichis provided with oppositelybeveled cam faces, means for applying pressure in alternate directions to the other arm of said leverto effect oscillationthereof, stop' means limiting the lever to a short range of action, a pivoted operating lever, a trip arm pivoted to said operating lever and resting upon one or the other of said beveled cam faces, and a spring connected to the crank ing thebell crank lever to present the beveled faces alternately in position for engagement of said trip arm the tension of said spring being changed accordingly as one bevel face or the other is presented in engagement with said trip arm.

6. In an apparatus of the character described, a pivoted bell crank lever, means engagin one end of the bell crank lever for oscillating it in alternate directions, a reciprocating trip arm having operative engagement with one arm of the crank lever, a spring connected with the other arm of said crank lever and actuating the trip arm in alternate direction in accordance with the movement of the crank lever, the movement of the crank lever in one direction serving to increase the operative tension of said spring, and its movement in the opposite direction tending to decrease such operative tension.

7 In a quick acting switch mechanism, a prime mover, a movable trip member, and a spring against the tension of which the trip is movable to alternate position, said spring being connected to the prime mover and the trip member and tensioned by the relative movement of said members, the tensioning eifect being to different degrees during the operation ofthe mechanism into and out of contact engaging condition.

8. In a quick acting switch mechanism, a

prime mover, a trip member movable to alternate positions, and aspring connecting the trip member and prime mover, said prime mover and trip member having movement in the same direction to effect movement of the trip member in one direction under which the spring is tensioned to minimum degree and movable in opposite directions to eflect the movement of the contact member in a reverse direction under which the spring is tensioned to maximum degree.

9. In a snap over switch, atrip member movable to alternate positions, an actuating spring therefor, said spring member having its endsmovably mounted, a movable control member coacting with the trip member eneby its change of position determining the direction of movement ofi .athe trip: member, said spring being variably 'tensione'd 'inaccordance with the direction of movement of the control member.

10. In a snap over meehnism, an operated member movable to alternate positions,- an actuating spring. therefor and a control member governin-gthe movement of the actuated member and simultaneously varying the tension 01" the actuating spring Wherebythe actuated member is moved in one direction under gresmterv springtension than in the opposite direction.

In testimony whereof, W8 have hereunto setaour hands this 10th day of J uly', A. D. 192.

WALTER H. WEINRIQH; FREDERICK CARL GEILER.

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