US2553510A - Switch - Google Patents

Description

G. E. BREEZE May 15, 1951 SWITCH Filed Nov. 2, 1948 9 Sheets-Sheet 1 May 15, 1951 I BREEZE 2,553,510

SWITCH Filed Nov. 2, 1948 9 Sheets-Sheet 2 May 15, 1951 G. E. BREEZE 5 0 swI'rcH Filed Nov. 2, 1948 9 Sheets-Sheet 3 G. E. BREEZE May 15, 1951 SWITCH 9 Sheets-Sheet 4 Filed Nov. 2, 1948 Iaweniofl Geoaige EBHeeze,

y 15, 1951 G. E. BREEZE 2,553,510

SWITCH 9 Sheets-Sheet 5 Filed Nov. 2, 1948 G. E. BREEZE swr'r 9 Sheets-Sheet 6 Filed May 15, 1951 e. E. BREEZE 2,553,510

SWITCH Filed Nov. 2, 194B 9 Sheets-Sheet 8 Iaweaaion- 6802 e Eflr eeze, by 5&7, fl flfifirgs M y 1951 e. E. BREEZE 2,553,510

swrrcn Filed Nov. 2, 1948 9' Sheets-sheet 9 Akin-114mm: 4 I

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Patented May 15, 1951 UNITED STATES PATENT OFFlCE SWITCH Application November 2, 1948, Serial No. 57,905

14 Claims. 1

This invention relates to alternating current switches in which contacts meet each other axially along a shaft driven by a manually operable member, such as a hand-wheel, through a mechanism which causes the shaft to make and break the current without undue arcing, and without improper or undesired operation under the mo tion of the hand-wheel.

The following are some of the features of the invention which are believed to be new and important in the art, as contrasted with prior switches. The conventional sweep-contact type of rotary switch has the following weaknesses, (I) because of theuncontrolled speed of themoving contacts and the lack of sufficient maintained pressure, arcingoccurs, (2) there is also considerable contact wear that reduces the 'eiiiciency of thedevice and increases heating, (3) the phys ical design of the insulating membersof the arcsnufing mechanism is inadequate, causing the switch to be short-lived under continual operation at its rated capacity, t) in the conventional type rotary switch, there is no provision made to prevent instantaneous operation from an on position, through an off to another on position, which can be destructive in the case of-multiple power sources of reversed phase or polarity, (5) the conventional type rotary switch is bulky because of its large gaps between contacts, (6) most rotary switch designs are such that the spring members carry current, resultin in the loss of spring properties due to heating occasioned by an overload, and (7) most rotary switches'are actuated by a spring drive mechanism, so that if the spring drive fails, positive indexing of the contacts is dii'licult, if not impossible. Because of these weaknesses, the following features of my switch are believed to be novel and important.

For example, the following features of my switch are believed to be new and inventive, namely, (1) the idea of controlling the rate of contact separation, by means of detent mechanism, in combination with a contact operating cam, so that a minimum of arcing occurs, because the current is permitted to break while the contacts are close enough together to eliectively carry away the heat of the arc, and to partially exclude air, which would otherwise carry oxygen to help maintain the arc (this same mechanism tends to speed up the closing action of the contacts, thereby reducing the extent of arcing), (2) in my device, because of the linear and substantially non-sliding movement of the contacts, wear is reduced to a minimum, the contacts being moved by means of a cam-operated link which is guided by a slot in the housing, (3) the arc chambers are so designed that they reduce the amount of air which may approach the arc and also effect an increase in the gas pressure at the contacts upon breaking, thereby tending to blow out the arc, and effectively protect the switch from damage, and are easily replaceable, (4) a-simple delay mechanism will permit normal operation from on to ofi position without stopping, but in'a case of an attempt to move the hand-wheel too rapidly through this sequence, the mechanism will lock and cause a positive delay in the off position until turning pressure has'been released from the hand-wheel, as by a follower, herein a ball associated with two springs and a ramp arranged to cause locking of the driver, (5) it is possible to break and to maintain a 450 volt circuit open with a contact spacing of only three-eighths of an inch (this is further enhanced by the fact the large contacts elfectively fan out carry away current and heat originating at the very small area of the contact surfaces actually touchin each other, resulting in cooler contacts and current-carrying members), thus permitting the switch body itself to be smaller, and reducing weight and size of the overall device, (6) the contact spring are entirely divorced from the contacts themselves, and do not, therefore, carry current, thus ultimately reducing the heating, and increasing the life of the switch, and ('7) thecontact-operating cam and'the position-indicating means (marks on the handwheel) are rigidly tied together by the shaft, and the contacts can be positively pcsitioned, as desired, even though the detent mechanism fails or is completely removed from the device. Still other features will be pointed out during the course of the following description of one embodiment of the invention shown in the drawings, while its scope will be pointed out more particularly in the appended claims.

In the drawings:

Fig. 1 is a plan (an end view) of a switch embodying the invention;

Fig. 2 is a sectional view on line 2-2 of Fig. 1; Fig. 3 is asectional view on line 3--3 of Fig. 2; Fig. 4 is a'sectional view on line tl of Fig. 3; Fig. 5 is a sectional view On line E5 of Fig. 2; Fig. 6 is a sectional view on line 6-6 of Fig. 2; Fig. 7 is a sectional view on line !'i of Fig. 2; Fig. 8 is sectional view on line 83 of Fig. 2, Fig. 9 is a view partly in elevation and partly in section looking in the direction shown by the arrow 9 in Fig. 8;

Fig. 9A is a development of the cam-track;

Fig. 10 is a sectional view on line IQ-Ifi of Fig.

Fig. 11 is a plan view of the lower contact member, and

Fig. 12 is an elevation of the lower contact member as viewed from the right-hand side of Fig. 11.

Referring to the drawings and to the embodiment of the invention illustrated therein as an example, there i shown a three-pole switch (see Fig. 1) comprising a hand-wheel or other handle I4, a panel indicator I5, 2. housing I8, comprising a top-plate 28, a bottom-plate 22 (see Fig. 2) connected by studs 2 and nuts 26 and surrounded by insulating sleeves 28. A shaft 3e,-

affixed to the hand-wheel I l, extends through the top and bottom plates 2E and 22, which afford bearings for the shaft. This shaft is square (see Fig. 3) and has a corner which is chamfered at 32 to serve like a spline as a means to ensure proper assembly of the parts on the shaft. About the shaft, there is an insulating sleeve 34 (see Fig. 2) also square, to which are fitted certain parts hereinafter described.

In its simplest form, the switch may have but one set of upper and lower contacts or contact members, but actually there are three sets. For a proper understanding of the invention, for the present, but one set will be described. This set comprises an upper contact comprising a bridge 36 and a pair of projections 38A, 333, all of copper. For convenience of manufacture, the projections are in the form of studs having shanks 49A, 46B, staked in place, and then soldered. For the sake of durability the studs are faced with disks 42A, 42B, comprising 59% silver and 50% tungsten, soldered in place with silver solder. Also, for best results, the disks have their contacting faces convex.

There are similar lower pairs of contacts, in this case, one a stud 54A having a shank l a affixed to a bar MA, and the other contact 4428, in this case formed on a bar 483 for convenience of manufacture. In this case, also, there are disks 58A, 5913, as before. The exact form of the bars 48A, 4813 (see Fig. 8) will differ from each other according to the circumstances. In the case of the bar 38A, (see Fig. 11) for example, there are other contacts affixed thereto for cooperation with other upper contacts. In the case of the bar 4813 (see Fig. 8), the form is simple, and there are no other studs attached thereto.

Returning now to Fig. 9, it will be observed that the upper and lower contacts are shielded and surrounded by bodies of insulating material, in this instance, thick disks 52 and 5 closely fitted about the contacts. Furthermore, there are sleeves 55A, 563, to shield the confronting faces and the sides of the upper and the lower contacts. These sleeves are made of insulating material, for example, grey fiber tubing, which is found to be the best for the purpose, far better than others tried. These sleeves shield the ends of the contacts by limiting the air about them to a minimum amount. By these sleeves and these disks failures due to large overloads are avoided. The importance of thi feature can hardly be overestimated.

The upper contact is moved up and down by mechanism including a link 58 affixecl as by a stud GI} to the contact and having at its upper end a follower such as a roller 62 turning about a pin 64. The follower moves under control of a cam 65 having a track 6%, the form of which will be hereinafter described. Thus, the cam, as

the top of the node H6.

it turns, lifts and lowers the upper contact. The mechanism to turn the cam will be described presently. Referring to Figs. 7 and 8, in this instance, there are two other sets of upper and lower contacts generally similar to those just described, including two upper contacts IB and I2 operated by links 1'4 and It, similar to the link 58 and carrying like follower I8 and 80 in the track 68 of the cam 56, as before. In the case of the upper contact T0, the latter bridges lower contacts 82 and fi l, one on the bar 48A and the other on a bar 35. In the case of the upper contact E2, the latter bridges lower contacts 88, 99, one on a bar 92 and the other on the bar 48A (see Fig. 11). This particular arrangement contemplates a triple-throw switch for certain purposes, indicated by markings 1, 2, and 3 on the hand-wheel I4 (see Fig. l), and by markings 0 which are for open positions to correspond with the first-named markings. The handwheel I4 may be turned in either direction. There are also markings Load, 1, 2, and 3 on the bars 48A, 48B, SIS and 32 (see Fig. l).

The cam is mounted on the sleeve 34 (see Fig. 6), and is housed within a housing 94, having slots 96, 91, and 98 for the links. The cam carrise a set of springs I66) (see Fig. 2) whose upper ends rest against a pair of thrust washers I02 below a housing disk IM of insulating material held by the tie-rods 25. Below the cam. 86 there are similar thrust washers I06, seated in an annular groove I68 in the insulating disk 52, and the cam 86 has a depending portion to seat upon said washers. Thus, the cam is retained between upper and lower thrust washers which limit backlash, and with the springs, transmit the motion of the cam to the movable contacts, applying pressure in the closed position of the contacts. The cam has, at its upper end, an annular groove III) in which there is a split ring I I2 seated to complete the assembly of the cam 66, the washers I02, and the springs ms.

It will be remembered that the sleeve 34 and the shaft 353, both being square, turn together, and are driven by the hand-wheel I4, subject to the control of a detent mechanism and of a delay mechanism, hereinbefore mentioned. The detent mechanism will now be described, still referring to Fig. 2. About the shaft 33 (but not about the sleeve 34) there is a star-wheel or cam II4 indexed to it by the chamfer 32 on the shaft, and having nodes IIG (see Fig. 5) between which there are valleys IIB. Cooperating with this star-wheel II I, there are followers in the nature of the wedges I293, to ride from one valley IE8 to another valley while passing over the nodes IIG, under the control of springs I22 pressing against the follows I20. The outer ends of the springs are seated against seats I24 presented by a metallic lining I26 for a housing I28 of insulating material affixed to the rods 26. In this embodiment there are other springs I38 within the springs I22 to reinforce the latter. Thus, the described detent mechanism enforces upon the cam 66 a proper movement to impel and to impart to the moving contacts a proper or normal speed and hence to prevent, or at least to minimize, arcing, to reduce wear of the contacts, and to reduce heating.

The form of the track 68 of the cam 66 (see Fig. 6) is such that in normal operation the breaking of the circuit occurs within one-half of a cycle. The break occurs when the follower IZil is climbing from the valley II8 toward On the other hand,

.to be desired. One factor, and an important one, is the form of the cam-track (see Fig. 9A) in which it will be observed that the totalmovement takesplace, in this instance, in angular distance 101A", while the remainder. of thetrack is straightas shown. Thatis, while the shaft is turning through 120 the bridge is reciprocated during substantially fiVBv-SiXthS of this period with equal periods of restat the. extremes of the period. Each bridge, .it willbe understood, is also at rest in raised position during two-thirds of the shaft revolution wherein the third of the cam including the .rise is in the sector ofthe circle in which lie one or the other of the ;other.two pairs of contacts. This form gives the desired breakingof the circuitwithin one-half .of a cycle, at times much less than onehalf cycle.

Although the hand-wheel it may be turned in either direction, nevertheless, .the desired slow break and the fast make can be achieved because of the fact that the make 1 occurs when the follower 12a is descendingirom the top of the node toward the valley, whereas break occurs whenthe follower is ascending the rise from the valley.

Thus, the combination of the cam ,andthe detent mechanism produces results hereinbelore described, namely, (1) the controlof the rate of contact separation, so that a minimum amount of arcing occurs, because the current is permitted to break while the contacts are sufficiently close to effectively carry away the heat of the arc, and to partially exclude air which would otherwise carry oxygen to help maintain the arc, (2) positive indexing of the shaft, its associated cam the contacts and the handwheel in the various on and ,ofi positions, so ,that the contacts may not be left in a partially opened or partiallyclosed relation .to each other.

The star wheel ilt and spring-pressed followers I21! imposesubstantial resistance to rotation of. the shaft enforcing a slowinitial movementresulting, when the movementis for 6 0 in the example shown from an .on to. an off position, in a slow break. The resistance may be substantiallythe limit of a manscapacity. Thus he cannot daily onthe way but must take the hill on the rush so to spealnthus ensuring that separatingmovement is fully effected. As the detents pass the crests of the star. wheel teeth the stored energy inthe springs is releasedso the detents then coast down the hill rapidly tending to drive the wheel an d cause ing, when the shift isfrom an .ofi to an fon position, a quick make. The effortrequired by the operator to surmount the hill is such that he cannot holdback during this action.

It might be possible however that after movingfrom an on position the impetus imparted to the shaft under continued forced exerted by.

. plate is afiixed to the shaftflll, turnsin housing disk I34 afiixed to the rods 24 (see Fig. 3) and carries one or more, herein three disks I36 each having afiixed to it fiat springs I33 whose outer ends are anchored to the plate I32. Thus, each disk I36 can turn in the plate I32 and will return to its normal position under the influence of its springs :38. Ample space for the play of the springs is provided by slots M9 in the I32. Each disk I 36 carries a follower, herein a ball I42 which can play to and fro within a slot Hit and its travel in one direction (outwardly) is assisted by a spring Hill. This ball is thrust outwardly by the spring against the inner margin 143 of the housing I34, and this margin has one or more, herein three ramps, cams, or teeth I55, which project into the path of the ball. (See Fig. 3.) The inner end of the spring M6 has a rider I52 resting against a fixed plate I55.

The combination of the tooth angle and the forces of the springs I38 and the springs I 48 is such that in the slow or normal operation of the switch, the ball M2 will ride over the tooth I56 without interference. However if the shaft 30 is moving at excessive speed the inertia of disks E36 and the parts carried thereby tending to cause them to move along the tangent is greatly increased (proportionately to the square of the velocity). When the ball strikes the obliquely presented side of tooth Hill the equal and 0pposite counteriorce is correspondingly great and its component perpendicular to the slot M l overcomes the resistance of springs i338, causing the disk to swin (counterclockwise vie-wing Fig. 2 if the shaft is turning clockwise) to a position wherein the slot is more or less parallel to the slope of the tooth, and the ball is caught between the side of the slot and the side of the tooth and locks them against further approximation. This locking action can be removed only by releasing rotational pressure of the hand-wheel i and the shaft 32 upon the driving plate 532. It will be apparent from comparison of Figs. 1 and 3 that the teeth 1% are in alignment with the off positions of the switch and the detents are so angularly related to the bridges that the detents come into apposition to the teeth as the bridges move to the off position. If the teeth were angularly spaced from the off positions the angular relation of the detents to the bridges would be similarly modified. Thus if the shaft is turning too rapidly as it comes to the oiT position it will be locked and its motion arrested without possibility of overthrow to thesucceeding on position.

At the outset, th.e advantages, the objects-and the. general functions were outlined fully, andit is deemed unnecessary to repeat them here,-in View of the full description of the operation of each mechanism. It will suffice to say-that the combination of the severalmechanisms achieves important results never hereinbeiore achievedin a switch, so far as I am aware.

laving describedmone,embodiment of-the invention, what I claim is:

east of bridge pieces similarlyranged around the shaft for movement in the axial direction to and from said faces, a cam of the axially operating type on the shaft within the axially projected area of the group of contacts, followers cooperating with the cam and connected to bridges respectively providing for successive operation of the bridges on continued rotation of the shaft, a wheel on the shaft having lobes at its edge angularly coordinated with the contacts and spring loaded followers normally thrust inwardly toward said wheel and providing substantial resistance to the turning of the shaft as the followers climb a lobe contemporaneously with the action of the cam in separating a bridge from its contacts and provided for release of spring-stored energy when the followers have passed the crest of the lobe to facilitate further turning of the shaft as the cam is approximating a bridge and its contacts.

2. A switch as defined in claim 1 wherein the followers cooperating with the wheel are radial plungers supported by radially arranged compression springs.

3. A switch par 'icularly adapted for the distribution of high potential alternating current which is organized within a restricted cylindrical volume and comprises an axial rotatable shaft having provision at one end for applying turning force thereto, a group of contacts ranged around the shaft radially remote from the same and presenting contact faces in the axial direction, a set of bridge pieces similarly ran ed around the shaft for movement in the axial direction to and from said faces, a cam of the axially operating type on the shaft within the axially projected area or" the group of contacts, followers cooperating with the cam and connected to said bridges respectively providing for successive operation of the bridges on continued rotation of the shaft, and an indexing mechanism cooperating with said shaft defining the closed positions of the several bridges and intermediate open positions.

4. A switch as defined in claim 3 wherein the contacts and the bridges are arranged in chambers in a body of insulating material closely fitting their lateral contours and having a wall extending across the plane of contact between them.

5. A switch as defined in claim 3 wherein the portions of the connections from the bridges to the cam followers which project from the latter and the cam are encircled by a sleeve of insulating material having channels the walls of which closely approximate those portions of the connecting elements not directly opposing the cam.

6. A switch comprising an axial rotatable shaft having provision for applying turning force thereto, pairs of contacts located in sectors of a circle about the shaft and radially remote from the shaft, bridges which connect the contacts by closing thereon in a generally axial direction, means for driving the bridges from the shaft to reciprocate the bridges to and from the pairs of contacts successively on rotation of the shaft through corresponding sectors, a lobed indexing wheel on the shaft having twice as many lobes as there are pairs of contacts to provide for indexing the bridge in on positions and intermediate off positions and a spring-pressed follower cooperating with said wheel to be displaced by the lobes when the shaft is started into movement.

7. A switch as defined in claim 6 wherein the driving means for the bridge reciprocates it during the major portion of the period of rotary 8 movement of the shaft between successive on positions of contacts with substantially equal periods of rest at the extremes of said period.

8. A switch as defined in claim 6 wherein there are three pairs of contacts and the driving means for the bridge reciprocates it during substantially five-sixths of each one-third turn of the shaft with substantially equal periods of rest at the extremes of said period.

9. A switch comprising an axial rotatable operating shaft, pairs of contacts presenting contact faces in the axial direction located in sectors of the circle about the shaft, bridges, a driving mechanism connecting the shaft to the bridges effective on rotation of the former, through corresponding sectors to reciprocate the bridges successively to on positions bridging the several pairs of contacts, an indexing means yieldable to rotating pressure on the shaft for positioning it in the several on and intermediate off positions and including an energy storing device in which energy derived from the shaft is charged during movement of the bridge from on position and which is released to the shaft during movement of the bridge toward on position.

10. A switch comprising a rotatabl operating shaft, pairs of contacts presenting contact faces in the axial direction located in sectors of the circle about the shaft, bridges for the pairs, a driving mechanism connecting the shaft to the bridges eff ective on rotation of the former through corresponding sectors to giv the bridges movements of axial reciprocation from on position bridging a pair of contacts, through an intermediate off position to an on position, an energy storing means organized in force transmitting relation with the shaft to receive energy therefrom during movement of a bridge from on position and to release such energy thereto during movement of a bridge to on position and. a locking mechanism for preventing rapid movement of the shaft through off position comprising a balanced detent revolving with the shaft and responsive to inertia on excessive speed of the shaft to move into locking position between the shaft and a fixed member, the angular relation of the fixed member to the off" position of the bridge corresponding to the angular relation of the detent to the bridge itself.

11. A switch particularly adapted for the distribution of high potential alternating current comprising a rotatable shaft having provision for applying turning force thereto, pairs of contacts ranged around the shaft radially remote from the same, bridge pieces for connecting the contacts of the several pairs connected to the shaft for movement thereby successively to on positions and through intermediate off" positions on ro tation of the shaft and delay means to prevent the bridge, if the shaft turns at excessive speed, from passing through an off position comprising a detent moving around with the shaft, a fixed tooth external to the detent, the two being angularly positioned to appose one another substantially when the bridge comes to 01f position, the detent being spring balanced and normally moving freely over the tooth when the shaft turns slowly but yielding to inertia on excessive speed of the shaft to move into locking relation to the tooth.

12. A switch particularly adapted for the distribution of high potential alternating current comprising a rotatable shaft having provision for applying turning force thereto, pairs of contacts ranged around the shaft radially remote from the same, bridge pieces for connecting the contacts of the several pairs connected to the shaft for movement thereby successively to on positions and through intermediate off positions on rotation of the shaft, an indexing disc on the shaft and spring-supported positioning device cooperating therewith to position the bridges in their several on and off positions, the cooperation of said parts resisting rotation of the shaft and effecting energy storage in the supporting spring as a bridge is moved from such a position and releasing such energy to the shaft as the bridge then moves to the next position and delay means to prevent the switch, if the shaft turns at excessive speed, from passing through an off position comprising a detent moving around with the shaft, a fixed tooth external to the detent, the two being an'gularly positioned to appose one another substantially when the bridge comes to off position, the detent being spring balanced and normally moving freely over the tooth when the shaft turns slowly but yieldingly to inertia on excessive speed of the shaft to move into looking relation to the tooth.

13. A switch particularly adapted for the distribution of high potential alternating current comprising a rotatable shaft having provision for applying turning force thereto, pairs of contacts ranged around the shaft radially remote from the same, bridge pieces for connecting the contacts of the several pairs connected to the shaft for movement thereby successively to on positions and through intermediate off positions on rotation of the shaft and means comprising a movable part revolving with and about said shaft and a fixed part angularly located to be in apposition to said part when the bridge comes to off position, the movable part being displaceable by inertia on excessive of the shaft to effect a locking engagement with the fixed part.

1.4. In a switch, the combination of a rotary shaft, contacts which are separated or approximated on determined rotative movements of the shaft, a pair of contacts operated bysaid shaft, and delay mechanism to delay operation of said shaft in case of abnormal, rotational speed of the shaft, including a stationary tooth, a plate affixed to the shaft, a follower on the plate arranged normally to ride over said tooth, and means to prevent said follower from riding over said tooth at a speed greater than normal, said means including a disc arranged to turn about an axis on said plate, a spring to return said disc to a normal position with reference to said plate, said follower being carried by said disc, and a spring to thrust said follower toward said tooth, the combination of the tooth angle and the forces of said springs being such that normally said follower will ride over said tooth, but when too rapid rotation of the shaft occurs, the follower is prevented from ascending said tooth.

GEORGE E. BREEZE.

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

UNITED STATES PATENTS Number Name Date 677,455 Von Kando July 2, 1901 987,698 Cheney Mar. 28, 1911 1,495,612 Rockwell May 27, 1924 1,896,904 Laven Feb. 7, 1933 2,086,401 Coolidge et al July 6, 1937 2,274,097 Sheerer Feb. 24, 1942

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