US1557018A - Short-circuiting device - Google Patents

Description

Oct. 13, 1925- J L. BROWN SHORT CIRCUITING DEVICL') Filed Oct. 15. 19257 INVENTOR John LyaH Brown.

WITNESSES: 1

A'TTORNEY Patented Oct. 13, 1925.

UNITED STATES PATENT OFFICE.

JOHN LYALL BROWN, OF VEBONA, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SHORT-CIRCUITING DEVICE.

Application filed October 15, 1923.

To all whom it may concern:

Be it known that I, JOHN LYALL BROWN, a citizen of the United States, and a resident of Verona, in the county of Allegheny and State of Pennsylvania, hay e invented a new and useful Improvement in Short-Circuiting Devices, of which the following is a specification.

My invention relates to shortcircuiting devices or other speed responsive devices particularly adapted for electric machines, and it has particular relation to centrifugally-operated mechanisms for effecting a repulsion operation of a machine during the starting and an induction operation during the normal operating period.

My invention has for one of its objects to provide a simple, practical and relatively inexpensive device of the above character, wherein a plurality of members are simultaneously actuated centrifugally in a direction transverse to the axis of rotation, and concurrently in an axial direction to operate the short-circuiting means into engagement with the end of the commutator cylinder.

In the accompanying drawing,

Figure 1 is a front view of the device, in section on the line II of Fig. 2,

Fig. 2 is a view in cross section thereof on the line II--II of Fig. 1, and showing the application thereof to the commutator of an electric machine,

Fig. 3 is a side viewof the contact memhers,

Fig. 4 is a plan view of one of the contact members, and

Fig. 5 is an enlarged side view of one of the pivotal members upon which the centrifugal members operate.

In the practice of my invention, I provide a stud plate 1, preferably in the form of a flanged disc or head, centered upon the shaft 2 of the machine. The machine is provided with a commutator cylinder 3 which is mounted upon a supporting core or spider 3. The head 1 is secured in spaced relation to the end of the commutator spider 3 by means of a plurality of equidistantly spaced screws 4 upon which are fixedly mounted worm-studs or pivot members 5 having steep-threaded or spirally ribbed body portions 6 thereon, said worm-studs also serving as spacing means Serial No. 668,467.

between the stud plate 1 and the supporting spider 3 of the commutator cylinder 3.

A weighted centrifugal member 7 having a properly threaded eccentric opening 8 and a weighted body or enlarged portion 9, is provided to operatively engage upon the threaded portion 6 of each stud member 5.

The centrifugal members 7 are maintained under suitable tension by means of three similar spiral tension springs 10, the weight members 7 being normally held in engagement with the commutator shaft 2-by the tension of said springs 10. One end of each spring is connected to a pin 11 located at a certain distance from the operating center of one weight member and the other end of the spring is connected to a pin 12 located at a greater effective distance from the operating center of the next weight member. Since the springs are connected thus alternately, each spring tends to move one of its associated weight members to the in position and the other to the out position, the resultant effect, however, being to hold all members in their in or normal position.

Loosely mounted for lateral movement on the worm-studs 5 and adjacent to the end of the commutator cylinder, is a follower plate or disc 13 having a flanged rim 14 thereabout. The follower plate 13 is normally held in spaced relation to the end of the commutator by spiral compression springs 15 disposed upon the stud members 5. The follower plate 13 is provided, upon its inner face portion adjacent to the rim thereof, with a plurality of yieldable phosphor-bronze short-circuiting contactors 16 which are designed to have great resiliency and to provide a wiping action at the contact points, which is always desirable in securing good contact, especially when the contacting surfaces become corroded, as when the motor is idle for long periods. As shown in Figs. 3 and l, the contactors are arc-shaped pieces having their intermediate portions bent out, as at 17, but hav ing cup-shaped central depressions 18 to provide two contact points 19 for each contactor. The fiat terminals of the contactors are perforated and riveted to the follower plate as at 21.

In operation, at a predetermined speed of rotation of the armature to which the device is applied, the centrifugal force on the weighted members 7 begins to exceed the net closing moment of the springs. The weighted members immediatel and rapidly rotate to their outermost positions agalnst the rim of the stud plate 1, and in so rotating, travel axially also, by reason of the threads of the worm-studs 5 upon which they are pivotally mounted. The follower plate 13 is thus caused to move toward the commutator, overcoming the opposition of the small com ress'ion springs 15, and bringing the yiel able contactors 16 into firm engagement with the end of the commutator cylinder, thus short-circuitin the armature. Upon collapse of the centrifugal moment of the weight members 7, resulting from the stoppin of the motor, the springs restore the mechanism to the starting position.

During the above-described operation, the interlocking of the springs 10 with the weight members 7 compels all of said members to operate simultaneously in spite of the difference in either spring or weight moments. For example, if one of the three weight members here shown should have a greater centrifugal moment than the other two, and as a result, it should start to open inadvance of the others, the action of the spring which tends to maintain this memher 7 in a closed position and at the same time tends to eflect an open position of an adjacent weight member connectedthereto would be unduly stresse' retardi the motion of the first Weight member an decreasin the resultant sprin force tending to ho d said adjacent wage member closed. Again, the pull of the spring which tends to open the first-mentioned member and at the same time tends to close the adjacent third member will be decreased. Such action will also tend to retard the movement of the first-mentioned member and to facilitate the operating of the third member.

While I have shown and described a certain embodiment of my invention, I desire that the disclosed embodiment'shall be regarded as illustrative only, and that the a pended claims shall be accorded the broadest construction consistent with the prior art.

I claim as m invention:

1. The combination with the commutator cylinder of a d namo-electric machine, of a member space from and secured to the end thereof by a plurality of spaced threaded pivot members, a c'entrifugal'ly actuated member pivotally and threadedly mounted on each ofthe threaded ivot members, and a short-circuiting mem r loosely dis osed between said spaced member and said commutator cylinder, said centrifugally-actuat'ed members adapted to pivot outwardly and simultaneously therewith to adjust themselves axially on their pivot members and force the short-cirwiting' mber into engagement with the end of t commutator cylinder.

2. The combinatimi with the commntltnr cylinder of a dynamo-electric machine, of a member s aced from, and secured to, the end thereof by a plurality of spaced pivot members, a centrifu ally-actuated member mounted on each 0' the pivot members,

means yieldingly connecting said centrifl ugally-actuated members to one another, a short circuitin'g member'ioosel disposed between said spaced member an said commutator cylinder and yielding means ndr mally holding the short-circulting member pivot members, and a cirbnitclosing memer 'slidably mounted on said piv'otineitibers, said centrifugally-actnated memben adapted to be pivotally actuated outwalfi by centrifugal force andconcurrentlyth with to adpi'st themselves akially'on said' threaded members to move the circuit-clue ing member into engagement with the end of the commutator cylinder.

4. The combination with the commutator cylinder of an electric machine, of a phirality of steep-threaded pivot members fixedly attached thereto in extending from the en thereof, s cc a trifugally-actuated member corres on threaded to, and mounted on, e'ac of pivot members, springs connecting said en. trifugally-actuated members to one anothe and a circuit-closing member slidalfl; mounted on said ivot members, said obntrifu'gally-actu members adapted to be pivotally actuated outwardly by centrifugal force and concurrently therewith to adjust themselves axially on said threaded members to move the circuit-closin memberinto aced mus um -1i0 engagement with the end of the commutaton cylinder.

5. The combination with the commutator cylinder of an electric machine, of a rurality of spirally ribbed pivot members xed'ly extending from the end thereof, a stop member secured to the outer ends thereoi, ;a weighted centrifugally-actuated member having a spirally ribbed opening therein movably fitted on each of said pivot members, a plurality of springs connecting said centrifugally-actuated members to one another, and a short-circuiting member movably mounted on said pivot members adjacent to the end of the commutator cylinder and adapted to be moved into engagement with the end of the commutator cylinder by the action of said centrifu al members.

6. The combination wit a commutator cylinder of an electric machine, of a plurality of spirally ribbed pivot members extending therefrom in spaced relation, a stop member secured to the outer ends thereof, a weighted centrifugally-actuated member having a spirally-ribbed opening therein movably fitted on each of said ribbed pivot members, a plurality of springs connecting said centrifugally-actuated members to one another, a follower member slidably mounted on said pivot members adjacent to said commutator cylinder, short-circuiting contacts carried by said follower member, and spring means for normally holding the contact carrying follower member out of shortcircuiting engagement with said commutator cylinder, said centrifugally-actuated members being adapted to swing outwardly and simultaneously therewith to move axially on said ribbed pivot members to actuate the contact carrying follower member into short-circuiting position.

7. A circuit making and breaking device comprising a substantially flat contact memher and a relatively movable contactor member, the latter comprising a supporting member and a resilient Contact member secured thereto at its two ends and having its intermediate portions bent out towards said substantially flat contact member, said outwardly bent intermediate portions having a cup-shaped central depression to provide two contact points for engaging said substantially flat contact member with a wiping action.

8. The combination with a substantially fiat contact member comprising the smooth end surface of the commutator segments of a dynamo-electric machine, of an axially movable contactor member, the latter comprising a supporting member and a resilient contact member secured thereto at its two ends and having its intermediate portions bent out towards said substantially flat contact member, said outwardly bent intermediate portions having a cup-shaped central depression to provide two contact points for engaging said substantially flat contact member with a wiping action.

In testimony whereof, I have hereunto subscribed my name this 9th day of October, 1923.

JOHN LYALL BROWN.

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