US2243577A - Centrifugal switch - Google Patents

Description

y 1941- c. P. PEPPER CENTRIFUGAL SWIT CH Filed Nov. 1-, 1939 2 Sheets-Sheet 1 Inventor:

- Carl P. pepper",

I byMd HIS Attor'ney.

' y 1941- c. P. PEPPER CENTRIFUGAL SWITCH Filed Nov. 1,' 1939 2 Sheets-Sheet 2 IIIIIII/ L. w P n o P e o MP W A 1m m afl C Y. b

Patented May 27, 1941 UNITED STATES PATENT OFFICE CENTBIFUGAL SWITCH Carl P. Pepper, Fort Wayne, Ind, asslgnor to General Electric Company, a corporation of New York Application November 1, 1939, Serial No. 302,383

(c1. zoo-so) 18 Claims.

My invention relates to centrifugal switches such, for example, as those used in dynamo-electric machines for controlling the circuits of starting windings.

ticularity in the claims annexed to and forming a part of this specification.

In the drawings, Fig. 1 is a partial sectional side elevation of my improved centrifugal switch mechanism attached to an end of a rotatable member of a dynamo-electric machine shown in its stationary position; Fig. 2 is apartial sectional side elevation of the centrifugal switch mechanism illustrated in Fig. l, the rotatable member having attained running speed; Fig. 3 is an end view of the centrifugal switch mechanism illustrated in Fig. 1; Fig. 4 is an exploded perspective view of the supporting plate, pivot plates, weight members, and collar of the centrifugal mechanism; Fig. 5 is a side elevation of the end of the dynamo-electric machine in Fig. l showing the centrifugal switch mechanism with the stationary switch.

Referring to the drawings, in Fig. 1 I have illustrated a centrifugal operating mechanism attached to an end of a rotatable member ll of a dynamo-electric machine, which mechanism may be used to actuate a switch which is attached'to a stationary member and is in the starting winding circuit. This centrifugal operating mechanism includesa collar I l which is axially movable on a shaft l2. This collar II has an annular shoulder member which may abut against the stationary switch member designated generally by the numeral M in Fig. 5. This stationary switch structure forms no part of my invention and the structure generally shown in Fig. 5 is described and claimed in U. SrPatent 2,149,096, Morrill et al., which is assigned to the same as.- signee as this invention. The collar member II also has notches ll formal inthe outside surface on diametrically opposite sides thereof in any suitable manner. In the illustrated construction these notches II, are formed by the space between axially spaced rib members it and II. The collar is preferably made of electric insulating material, such as a heat treated phenolic condensation product with a suitable filler material and is actuated bya pair of outwardly moving weights ll arranged eccentrically of the axis of the shaft l2 and extending trans- I versely of the shaft. Each of the weights I8 is a fabricated unitary metal stamping or a die;

casting and has a pair of rigid arms ll having a portion extending at right angles from the weights and a further portion extending angularly therefrom. This structure may be also seen in Fig. 4. These arms is are provided with arouate faces 20 at the ends thereof, which are pivotally connected to the collar by slidably and pivotally engaging the notches ii. The opposing arcuate faces 20 of each weight member abut against each other in the notch II and upon movement of the weight members, roll on each other, thus providing a minimum of friction at this point. In order 'pivotally to support the weight members It they are provided with angularly extending fingers 2| which project into slots 22 in pivot plates 23.- In order to provide an arrangement for lower speed operation where more mass is necessary than that provided by the weights ll, the weights may have bent-out sections 24 and tongue members 25 on to which additional weights may be attached. The pivot plates 22 are mounted on a supporting or back plate 26 through projecting ear members 2!, 2|, and 28 and therefore, the weights are held in axial relation with respect to the supporting or back plate. The back plate is held to the end of the rotor Ill by bolts 20. The projecting ear member 21 extends over the edge II of the back plate 26, while the projecting ear member 2|, being bent, extends into a slot 22 in the back plate. Thus it will be seen a knife edge pivot is formed between the projecting member 21 on the pivot plate and the edge II on the back plate 26. A knife edge pivot is also formed between projecting ear member 29 and the back plate 26. In order to bring the knife edge pivot 21, 2| into substantial alignment with the knife edge pivot 26, 29, the projecting ear member 21 is offset at 3.3. This is desirable in order to prevent relative movement of parts. The projecting ear member 28 on the pivot plate serves to hold the pivot plate and back plate in correct axial and transverse alignment, since it fits into the slot 32 in the back plate.

In order to provide a force to oppose the centrifugal force of the weight members caused by rotation thereof. it is of course necessary to provide a biasing spring arrangement. In the illustrated embodiment of my invention the biasing force is transferred to the weights through its pivot plate. Each pivot plate 23 is therefore provided with a post or ear member 34 over which a spring member 35 is attached. The other ends of the spring members 35 are attached to hooks 36 which are on upstanding portion 31 of the back plate 26. It may be seen therefore that the springs 35 exert a force on all the movable parts which tends to rotate them in a clockwise direction with respect to the back plate 25, see Fig. 3, thus preventing relative movement of the movable parts which would result from torsional pulsations of the rotatable member. It is important to prevent such movement, since such movement would cause objectionable noise and wear. It may also be seen that since all the metal parts are held snugly together the springs create pressure at all contact points, that is: against 20; 2! against 22, 21 against 3|, and 29 against 26. Such a structure tends to create .pivotal instead of sliding contacts, which of course means minimum wear.

As has already been mentioned, it may be desirable to provide low speed machines with additional weights. In order to provide this additional mass I provide U-shape members 38 which extend around the upstanding portions 31 of the back plate and which snap over the projecting tongues on the bent-out sections of the weight members. In order securely to hold these members 38 I also provide inturned lugs 39 which project into cooperating notches 40 on the upturned portions 31 of the back plate 26.

In order to provide for extreme quiet operation of this centrifugal mechanism I also provide a cushion ring member 4! on the back plate 26 and which is held by a tight fit on the shaft. This cushion performs a double function of cushioning the elements at both extremities of movement; that is, when the weights are forced outwardly under centrifugal action the collar is cushioned by contacting with this ring as shown in Fig. 2, and when the weights are in their inward position, as shown in Fig. 1, they themselves contact the side of the ring at the circular portion 42. Furthermore, the pressure of the collar ll against the cushion ring ll caused by the weight arms l9 prevents torsional movement of-the collar Ii relative to the other parts. In order to prevent noise by the U-shape members contacting the base plate, Iprovide a band 43 of resilient or cushioning material around the upstanding portion 31 of the base plate just below the notches 40.

The operation of this centrifugal switch may be described as follows:

When the centrifugal switch is in the position as shown in Figs. 1 and 5, the rotor is stationary and the collar abuts against pad members 44 which are on the end of a forked member 45 which carries the movable contact. The starting winding 48 is then connected in circuit. As I have already said, this stationary switch structure is described in U. 8. Patent 2,149,096, Morrill et a1. It is of course to be understood that any other suitable switch construction may be used. when power is applied to the motor the rotor begins to rotate, and when the rotor comes up to the speed where the starting winding is no longer necessary, the centrifugal force caused by the rotation of the weight members l8, and, if the machine is of the slow speed type, the weight members 38 also, will overcome the' biasing action of the spring members 35. I'his will cause the weight members to move outwardly and cause a corresponding axial movement of -the angularly extending arms I! which project into the notches IS on the collar member. This axial movement of the arms l9 will cause the opposing arcuate faces 20 to roll on each other and abut against the surface of the rib II. This action will also cause the forked member 45 to move axially and the movable contact therefore will separate from the stationary contact, thus disconnecting the starting winding.

In view ofthe foregoing, it will be seen that I have provided a centrifugal switch which can be readily manufactured and which is operated by a mechanism, the movement of which operates with a minimum of friction and noise.

Although I have shown and described particular embodiments of my invention, I do not desire to be limited to the particular embodiments described, and I intend in the appended claims to cover all modifications which do not depart from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A centrifugal switch including an axially movable collar, means including outwardly movable weights having opposing arcuate faces for actuating said collar, resilient means biasing said weights toward each other so that said opposing arcuate faces are in abutting relation, said weights upon outward movement causing said faces to roll on each other so that said collar is actuated by said means, and a circuit controlling device arranged to be actuated by said collar.

2. A centrifugal switch including an axially movable collar having notches thereon, means including outwardly moving weights having rigid arms extending therefrom with opposing arcuate faces for actuating said collar, resilient means biasing said weights toward each other so that said opposing arcuate faces are in abutting relation, said weights upon outward movement causing said faces to roll on each other and in said notches so that said collar is actuated by said means, and a circuit controlling device arranged to be actuated by said collar.

3. A centrifugal switch including an axially movable collar having notches thereon, a supporting plate, outwardly movable weights having rigid arms extending therefrom and engaging said notches, pivot plates supported by said supporting plate to hold said weights in axial relation with respect to said supporting plate, resilient means for resisting the outward movement of said weights, and a circuit controlling device arranged to be actuated by said collar.

4. A centrifugal switch including an axially movable collar having notches thereon, a supporting plate, outwardly movable weights having rigid arms extending therefrom and engaging said notches, pivot plates pivotally supported by said supporting plate to hold said weights in axial relation with respect to said supporting plate, resilient means for resisting the outward movement of said weights, and a circuit controlling device arranged to be actuated by said collar.

5. A centrifugal switch including an axially movable collar having notches thereon, a supporting plate, outwardly movable weights having rigid arms extending therefrom and pivotally engaging said notches, rigid fingers extending from said weights, pivot plates pivotally mounted by said supporting plate, said weights being pivoted on said pivot plates through said rigid fingers, resilient means for resisting the outward movement of said weights, and a circult controlling device arranged to be actuated by said collar.

fingers extending into said slots so that said weights arepivotally supported by said pivot plates, resilient means for resisting the outward movement of said weights, and a circuit controlling device arranged to be actuated by said collar.

7. A centrifugal switch including an axially movable collar having notches thereon, a supporting plate, outwardly movable weights having rigid arms extending therefrom and pivotally engaging said notches, pivot plates supported by said supporting plate and each having an ear, said pivot plates holding said weights in axial relation with respect tosaid supporting plate, resilient means cooperating with said ears for resisting the outward movement of said weights,

and a circuit controlling device arranged to be gaging said notches, rigid fingers extending from said weights, pivot plates mounted on said supporting plates and each having slots and an ear, said fingers extending into said slots so that said weights are pivotally supported by said pivot plates, resilient means cooperating with said ears for resisting the outward movement of said weights, and a circuit controlling device arranged to be actuated by said collar.

9. A centrifugal switch including an axially trolling device arranged to be actuated by said collar.

- 10. A centrifugal switch including an axially movable collar having notches thereon, a supporting plate, outwardly movable weights having rigid arms extending therefrom and pivotally engaging said notches, rigid flngers extending from said weights, pivot plates mounted on said supporting plate and each having slots and an ear, said fingers extending into said slots so that said weights are pivotally supported on said pivot plates, means including springs engaging said ears and said supporting plate for resisting the outward movement of said weights, and a circuit controlling device arranged to be actuated by said collar.

. 11. A centrifugal switch including an axially movable collar having notches thereon, a supporting plate having hooks, outwardly movable weights having rigid arms extending therefrom and pivotally engaging said notches, rigid fingers extending from said weights, pivot plates mounted'on said supporting plate and each having slots and an ear, said fingers extending into said slots so that said weights are pivotally supported on said pivot plates, and means including springs engaging said ears and said hooks for resisting the outward movement of said weights, and a circuit controlling device arranged to be actuated by said collar. 4

12. A centrifugal switch including an axially movable collar having notches thereon, a supporting plate, outwardly movable weights having rigid arms extending therefrom and engaging said notches, pivot plates cooperating with said weights and having a plurality of ear members, said ear members forming with cooperating portions on said supporting plate knife edge pivots, resilient means cooperating with said pivot plates for resisting the outward movement .of said weights, and a circuit controlling device arranged to be actuated by said collar.

13.,A centrifugal switch including an axially movable collar having notches thereon, a supporting plate, outwardly movable weights cooperating with said collar and having tongues projecting therefrom, resilient means for resisting the outward movement of said weights, U- shaped members clamped over said tongues to provide additional mass for slow speed operation, and a circuit controlling device arranged to be actuated by said collar.

14. A centrifugal switch including an axially movable collar having notches thereon, a supporting plate having slots, outwardly movable weights cooperating with said collar and having tongues projecting therefrom, resilient means for resisting the outward movement of said weights, U-shaped members having lugs, said U-shaped members being clamped over said tongues, and said lugs extending into saidslots so as to provide additional mass for slow speed operation, and a circuit controlling device arranged to be actuated by said collar.

15. A centrifugal switch including an axially movable collar having notches thereon, a supporting plate having upstanding portions, outwardly movable weights cooperating with said collar and having tongues projecting therefrom, resilient means for resisting the outward movement of said weights, U-shaped members clamped over said tongues and extending around said upstanding portions, cushioning means surrounding said upstanding portions so that said U-shaped members are prevented from hitting said upstanding portions, and a circuit controlling device arranged to be actuated by said collar.

16. A centrifugal mechanism having a plurality of relatively movable parts including outwardly movable weights and an axially movable push collar, some of said parts having portions loosely pivoted to portions of other of said parts, means for mounting said centrifugal mechanism on a rotatable body, and resilient means operatively connected between said rotatable body and said relatively movable parts producing forces on said relatively moving parts, biasing said parts in one direction about the,axis of rotation of said rotatable body for-substantially preventing ielative movement of saidrelatively movable parts due to torsional pulsations of said rotatable body.

17. A centrifugal mechanism including a back plate, a plurality of pivot plates and a plurality of weight members forming relatively movable parts, said parts being mounted on a rotatable body, and resilient means operatively connected between said back plate and said pivot plates so as to exert a force on said relatively moving parts in a direction substantially perpendicular to the axis of rotation of said rotatable body for substantially preventing relative movement of said relatively movable parts due to torsional pulsations of said rotatable body;

18. A centrifugal switch including an axially movable collar, a supporting plate, outwardly movable weights, means for operativeiy connecting said weights to said collar, pivot plates pivotally mounted on said supporting plate, said CARL P. PEPPER.

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