US1981996A - Switch - Google Patents

Description

T. FJELLSTEDT ET AL Nov. 27, 1934.

' SWITCH Filed March 28, 1929 v 5 Sheets-Sheet 1 Nov. 27, 1 934.

T. FJELLSTEDT ET AL SWITCH Filed March 28, 1929 5 Sheets-Sheet 2 Nov. 27, 1934. v T. FJELLSTEDT ET! AL 1,981,996

7 4 SWITCH Filed March 28, 1929 5 Sheets-Sheet 4 Patented Nov. 27, 1934 UNITED STATES PATENT OFFICE 0. Hampton, Chicago, 111., assignors to The Delta Star Electric Company, Chicago, 111., a

corporation of Illinois Application March 28, 1929, Serial No. 350,708

7 Claims.

This invention relates to disconnect switches of the vertical break type. 'Such switches, ac-

cording to present practice, are gang operated and the movable members or blade are of appreciable length to provide a long break or air gap necessitated by-the voltages commonly used.

In switches of this type, as the length of the arm or blade increases, the leverage effect due to friction between the blade and the contact, or due to freezing, increases so that appreciable power is required to open the blade. If the blade is opened with a single swinging movement, it is subjected to undesirable strain.

It has been heretofore proposed to overcome this objection by providing means whereby the end of the blade that is between the contacts is initially subjected to a rocking or rectilinear movement to free it from the contacts, and is then swung into its full open position. It is to switches of this type that this invention appertains, and it is a particular object of the invention to provide a switch having a rather long breakaway movement. This movement is in substantially a straight line extending lengthwise of the blade, thus reducing the bending stresses to a minimum, and the arrangement is such that a great mechanical advantage is obtained during. the switch opening movement so as to facilitate the breaking away of the blade from the contact when the same is held thereto by ice or corrosion.

It is a special object of the present invention to provide a switch wherein there is a positive connection between the switch blade and the actuating mechanism so that for each position of the mechanism there is but one possible position of the switch blade. As a result of this arrangement, the switch can be successfully operated when mounted in any position whatsoever, without making any changes in the parts. As a result of this arrangement, it is possible to operate the switch fast or slow, with any form of operating device, and either manually or automatically as desired. This is a distinct improvement in horizontally mounted switches since, by this arrangement, interference with ice 'is reduced to a minimum, and the usual impact of the blade on a stop, with its consequent danger of damaging the contact insulator stack, is eliminated.

The arrangement of parts in the present invention is such that the insulator for actuating the switch blade is rotated about its own axis, thereby elim nating any-bending or cantilever stresses in the insulator that might otherwise be present.

The actuating mechanism for the switch here shown includes a four link chain, the links being pivoted together to form a quadrilateral. The frame supporting the chain constitutes one of the links. The switch blade is rigidly secured to one of the'other links. The links constituting at least one pair of opposite sides of the quadrilateral are of unequal size so that upon collapsing or extending the link work, the link to which the blade is secured is given a compound motion. The degree of compounding depends upon the different positions of the parts and upon the relative sizes of the links. By properly adjusting the relative sizes of the links, as will be hereinafter more fully described, the desired degree of compounding may be obtained.

The attainment of the above and further objects of the present invention will be apparent from the following specification taken in conjunction with the accompanying drawings forming a part thereof. In the drawings: v

Figure 1 is an elevation of a switch constructed in accordance with our invention showing the switch blade in the closed position;

Figure. 2 is a top plan view of the switch;

Figure 3 is a section taken substantially on the line 3-3 of Figure 2, the dotted lines showing the position of the parts when the switch is open;

Figure 4 is a section taken substantially on the line 4-4 of Figure 3;

Figure 5 is a section taken substantially along the line 55 of Figure 3;

Figure 6 is a top plan view of a somewhat different form of switch embodying our invention;

Figure '7 is a section taken along the line 7-7 of Figure 6;

Figure 8 is an end view of switch taken along the line 88 of Figure 6;

Figure 9 is a view of a stationary contact assembly that may be used when the-switches shown are mounted in an underhung position;

Figure 10 is a bottom plan view of the contact assembly of Figure 9;

Figure 11 is a polar velocity chart showing the velocity at the contacting end of the switch blade that results from a constant angular rotation of the rotary insulator;

Figure 12 is a chart showing the vertical com-' ponent of the velocity of the blade tip; and

Figure 13 is a similar chart showing the horizontal component of velocity of the blade tip.

Referring now more particularly to the form of switch shown in Figure 1, the switch'includes a suitable main supporting base which may be formed of two channel members 1 disposed back to back and secured together in spaced relation in a known manner. Two insulator stacks 2 and 3 are rigidly secured on the base, these insulators being of known construction, and being rigidly secured in a known manner. A third insulator stack 4 is mounted on the base foroscillatory movement about a vertical axis by means of a ball bearing or other suitable anti-friction bear- 3 providing a support forthe contact jaws and associated members.

Above the bearing 5 is provided a member 6 which is pinned or otherwise suitably secured to a flange Tat the lower end of the insulator pin 8. The member 6 is adapted to receive an operating arm (-not shown) which may be secured thereto in any suitable or well known manner. In practice, in three phase work, the arms of the three movable insulators of the three switches are connected to be gang operated, as is well known. An operating member 10 is secured on the upper end of the insulator 4 to the insulator cap in a known *manner and is pinned or otherwise secured.

thereto against turning movement with respect to the insulator 4. This operating member extends through a stationary member 11, a ball bearing structure of suitable construction being interposed between the member 11 and the operating member 10 so as to insure ease of turning of the latter. I

A rectangular blade supporting bracket member 13 is secured to the insulator cap 12 on, the insulator stack 2 and provides a support for a blade '14 through suitable linkage connections.

The members 11 and 13 are connected by spacing strips 14' formed of pieces of galvanized steel of suitable gauge. Proper contact strips 15 ex-' tend along the outer faces of the spacing strip 14' and have their outer ends bent inwardly toward each other as indicated at 15c, and then outwardly to parallelism to form attaching elements 15b which are provided with aligned openings 16 for the reception of securing screws for securing one of the phase line conductors to the contact strips. the switch are rigidly bolted to means of two bolts 18.

The member 13 has a circular base which is bolted to the insulator cap 12 and includes two vertically extending arms 20 and 21 to which themembers 14' and 15 are bolted at 22 and 23. The

members 14' and 15 are provided with oval holes I at 22 and 23 to allow for adjustment. The upstanding arms 20 and 21 are each provided with projecting portions 25 and 26 which embrace the channel spacing strips 14 through which set screws 27 and 29 extend to secure the spacing strips 14 to the arms 20. A rear link 30 is pivoted to the spacing strip 14', and a forward link 31 is pivoted to the arms 20-21 of the member 13. The links 30 and 31 each comprises twosections one on each side of the. center line of the switch.

- A U-shaped link 32, to which the blade 14 issecured in a manner to be presently described, is pinned to the link 30 at 33, and to the link-31 at 34. Considering the portion of the spacing strip 14' that lies between the pivot point 35 of the link 30 and the pivot point 36 of the link 31 as a stationary or fixed link, the operating mechanism for the switch blade includes a four link chain, the otherithree links being the links 30, 31, and 32. Since the link 30 is hinged to the spacing strip 14', and the link 31 is hinged to the member 13,

The members 14' and 15 on each side of the member 11 by the above referred to patent.

and since those two members are relatively adjustable due to the oval holes previously mentioned, it may be seen that there is provided a certain amount of adjustability for the four link chain.

The link 32 has a portion 40 extending beyond the link 31. The portion 40 is integral with the link 32 and is provided with a socket 41 for receiving and holding the tubular blade 14. An operating or connecting rod 43 is secured to the portion 40 of the link 32 by means of a universal coupling 44. The coupling 44 is pinned to the portion 40 at the pivot pin 45. Braided con ductors 47, of copper or other suitable conducting material, connect the copper contact strips 15 with blade 14, the conductors 47 being -suitably bolted to the copper strips at one end and being secured in good electrical contact with the blade 14 at the other end in any suitable well known manner.

An operatingcrank arm 50 is suitably secured to the operating member 10 so that upon rotation of the insulator 4, and with it the member 10, the operating crank arm 50 is rotated. One end of the crank arm 50 is pivotally connected 106- by means of a universal joint to the connecting rod 43. The universaljoint or coupling indicated at 51 has complete freedom of motion in all directions. The crank arm 50 acting through the connecting rod 43 controls the four link chain previously described, and upon rotation of the crank arm 50 the switch blade 14 is actuated. The free end of the blade 14 is flattened to provide a contacting surface, and cooperates with Alfred Alsaker and Eric Nordhem, No. 1,842,707,

issued January 26, 1932, to which reference may be had for a more complete description of the structures involved. The contact assembly indicated at 60 is likewise of the same construction as the corresponding contact assembly in In the present structure the switch blade is always under the complete control of the actuating mechanism, hence a stop member forthe free end of the blade is not necessary. Aside from this, the contact assembly indicated at 60 and the housing thereof is identical with the corresponding part in the above referred to patent. The arcing horn 61 consists merely of a forked tube pivotally mounted on the blade 14, with the prongs of the fork embracing a horn 62 which comprises a tube bolted to the housing 60 containing the contact assembly.

The end of housing 60 that faces the insulator stack 2 is open and is provided with outwardlyflared wing members 63 for guiding the blade 14 into the housing 60. Within the housing there is provided a pair of spring pressed contacts between which the fiattenedside of the blade moves to, complete an electric circuit. The'contacts within the housing are connected to the terminal clip 64 by means of flexible braided copper conductors 65, all in the manner clearly set forth in the above referred to patent.

counter-balancing the blade and thereby reduce 15C 4 the effort necessary to open the switch. In the form of switch here shown, the blade is counterbalanced by means of a torsion spring (Figure 3) surrounding the pivot pin 34. One end of this spring bears against the stationary pivot pin 36 as indicated at 71, and the opposite end bears against the blade supporting portion 40 at the pivot pin 45. The end of the spring 72 that bears against the pivot rod 45 presses against that rod and thereby assists in the opening movement, the spring being under stress when the switch is closed. The spring acts upon the link 31 and, through the link'32. upon the link 30- in such a manner that the spring assists rather than interferes with the initial and final opening and closing movement of the blade into and out of engagement with the contact assembly mounted upon the insulator stack 3. The initial movement away from the contact assembly during the switch opening movement, and the final movement towards the contact assembly during the switch closing movement, is a horizontal straight line movement as will be pointed out hereinafter, and-the spring assists this movement. This is .so because the stroke of the spring never exceeds that which the blade produces on it during its arcuate movement. The torsion spring may be omitted if desired, as is generally the case on small switches having rather light weight blades.

The link work shown has been found to give a substantially straight line motion to the remote end of the switch blade during the initial switch opening movement. To produce this effect, the distance between the centers of 3634 has been made larger than the distance between the pivots 33-35. The distance between the pivots 3334 has been made equal to the distance be-' tween the pivots 35-36. While this is preferable in a link work of the proportions shown, in order to produce an extended substantially straight line motion of the remote end of the switch blade, it is not absolutely necessary, as the same effect" may be obtained by altering the proportions of the links 30 and 31. It is to be noted that the four link chain comprising the links 30, 31 and 32, as well as the portion of the support between the pivots 35' and 36, does not constitute a parallelogram. As is well known, if this four link chain were a. parallelogram, then the switch blade 14 would be maintained parallel to itself throughout the entire range of motion and the remote end of the blade 14 would move in the arc of a circle as seen in Figure 2, the connecting rod 43 draws the pivot pin 45 to the left, as seen in Figures 2 and 3. A complete freedom of motion is provided due to the universal shank or coupling at 51 and the corresponding universal joint coupling at 44 adjacent the pivot 45. The links 30 and 31 are rotated ina counter-clockwise direction and, due to the fact that they are of unequal sizes, an angular motion is imparted tothe link 32. During the first thirty degree movement of the rotary insulator the compound motion of the link 32 is such as to cause the end of the blade that is in engagement with the contact assembly'on the insulator stack 3 to be moved horizontally in substantially a straight line. This horizontal motion is sufiicient to draw the end of the blade out of engagement with the contacts and out of the housing 60. Further rotation of the rotary insulator causes the remote end of the switch blade to be swung away from the contact assembly. When the blade approaches its full open .position the link 32 and the link 30 pass through toggle position,-as indicated by the dotted lines in Figure 3. It is to be noted that-the toggle formed by these two links is a lap over toggle, whereby the weight of the moving mass tends to maintain the parts in toggle as the toggle position is approached, rather than out of toggle.

Figures 11, 12 and 13 show the instantaneous velocities at the contacting end of the switch blade during its entire range of travel on the basis of a uniform angular velocity being imparted to the rotary insulator 4. In Figure 11 the curve A shows the locus of the contacting end of the switch blade during the opening movement thereof. The end of the switch blade traces exactly the same path during the closing movement of the blade. The instantaneous positions of the switch blade for each ten degrees of travel of the rotary insulatoris indicated. The curve indicated at B shows the instantaneous velocity of the contacting end ofthe switch blade through-- out its range of travel. In that figure, the line indicated, for instance, at C. shows the position of the switch blade when the rotary insulator has rotated through degrees, and the line a b.' which is an extension of line C, indicates the instantaneous velocity of the blade tip when in that position. A tangent to the curve A at the the contacting end of the switch blade. The

curve V of Figure 12 shows the vertical component of the motion of the contacting end of the switch blade, and the curve H of Figure'13 shows the horizontal component of the motion of the contacting end of the switch blade. It will be noted that during the first 25 or 30 degrees the end of the blade is moved in substantially a straight line extending lengthwise of the blade,. to draw the blade away from the contact. This is what is known as the ice-breaking" movement, and it will be noted that the velocity of the blade is very small and that it is substantially 100% horizontal. Because of the slow movement of the blade tip there isexerted a tremendous leverage effect tending to free the blade from any ice or corrosion that may tend to hold the blade in engagement with the contacts. -Afte'r the blade has been freed from the contacts, it is swung away from the contact assembly with an increasing velocity until it is quite a distance from the contact assembly and then its velocity gradually decreases.

It will be noted that the blade shown is under the rigid control of the operating mechanism throughout its entire range of travel, and that for any given position of the rotary insulator there is only one possible position of the switchblade. As a result, of this arrangement, it is possible to mount the switch in the underhung position. It is further to be noted that because of the control of the blade through its entire range of travel the contacting end of the blade travels through 145 the same path in closing as it'does in opening,

position of the blade is the same regardless .of

' responding insulator.

4- I 1,9s1,99e

whether the blade is moving toward or away from the contact assembly. As may be seen from the curve shown in Figure 11 the switch is closed by a swingingmovement followed by a plunging movement at a very' low velocity. Due to the fact that the switch blade moves at a very low velocity when it comes adjacent to the stationary contact assembly, it is not necessary to provide a bumper or other stop means on the insulator stack 3 for stopping the switch blade.

Reference may now be had to Figures 6,-7. and 8.

showing a somewhat difierent form of switch blade mounting and a diflerent form of adjusting means for the links. The blade supporting member 80 is bolted to the insulator 2 by means of four peripherally spaced bolts 81 in the same manner that the corresponding member 13 in the switch previously described is secured to the cor- The member 80 consists of a circular plate which fits upon the insulator cap on top of the insulator 2, and has two upstanding arms 82 and 83'. The ends of the channel shaped spacing strips 14. are secured to the arms 82 and 83, respectively, by means of suitable bolts and nuts indicated at 84. The upstanding arms 82 and 83 provide a bearing for the pin 36 about which the link 31 is pivotally mounted as previously described. The pin 36 extends through both arms 82 and 83 and is held against endwise displacement by the spacing strips 14' which are not provided with-holes adjacent the pin. An arm 90 is bolted to the blade supporting member 80 by means of two bolts 91; The arm 99 extends upward and to the rear of the portion of the blade supporting member 80 to which it is secured. The

, uppbrend of the arm 90 provides a support for just given, the switch blade in each of the embodiments of our invention above describedareunder the rigid control of theoperating mechanism throughout the entire range and travel of 115 the switch blade and for each position of the rotary insulator there is but-one possible position of the switch blade.

the pivot pin 35 to which the links are pivoted.

The link 32 is pivoted to the link 31 at the pivot pin 34, and it is pivoted to the link 30 at the pivot pin 33. The pin 33 is mounted in an eccentric 91 mounted in the link 30. Theeccentric 91 may be adjusted to adjust the effective length of the link 30, and is held in its adjusted position by means" of a set screw 92. Since it is the relative sizes of the links that determine the path of motion of the switch blade this adjustment is of importance in that it permits an adjustment of the switch so that the exact degree of straight line motion desired is obtained.

The two arms of the link 32 extend beyond the link 31, as indicated at 93, and are joined together by a pair of cross members 94 and another pair of cross members 95. Two arms 96 and 97 of a trussed type of switch blade are suitably bolted to the extended. portion of the link 32 by means of two sets of bolts and nuts 98 and 99. Copper contact strips 15 lie in the channels of the spacing of the strips 14', said copper contact strips being connected to the blade portions 98 and 9'lby means of suitable flexible conductors. The flexible conductors are formed by inserting the end of a piece of braided copper conductor into a piece of coppertubing of suitable length and conductor. e of those pieces of tubing, indicated at 100, is secured in intimate contact with the copper spacing strips by the same bolts that secure the spacing strips to the arms 82 of the m'ember aBO, and the flattened copper-tubing at the other eridoi the same braided conductor'is Y secured in intimate contact with the switch arm 9.6 by the golts 98. This piece of copper tubing is form of contact assembly to be mounted on the stationary insulator 3. This form of'contact assembly is preferable when the switch is mounted 1 in the under-hung position.

tact assembly the housing 115, which is closed at n the top and is open at the bottom and. at the 145 side 1-16,is bolted to the insulator pin 117 by means of suitable'bolts 118 passing through the V usual flange 119 upon' the insulator pin and a corresponding flange 120 integral with the hous- The incoming phase line conductor is con- 15o ed conductor'secures the switch arm 97 to the copper contact strip at the opposite side of the switch. It is to be noted that the copper contact strip 15 in this embodiment of'our invention lies. between the flanges of the channel spacing strip 30 14' and in contact with the web portion between said flanges. This is somewhat different from the location of the copper contact strip in the switch shown in Figurel for in that switch the contact strips are spaced from the corresponding web portion of the channel member 14. It is, of course, understood that in either of the two forms of switches shown, the contact strip may be located as desired.

Pivoted about the pin which passes between the members 93 extending from the links 32, is a universal joint or coupling 105. This universal joint is similar to the joint indicated at 44 in connection with the switch shown in Figures 1, 2 and 3. The links for actuating the switch blade 9697 comprising the links 30, 31. 32 and the portion of the spacing strip between the links 35 and 36, are actuated in the same manner as are the corresponding links of the switch shown in Figure 1 previously described. For this pur- 10 pose a connecting rod such as 43 in Figure 1 is provided, which connecting rod is actuated by a rotaryzinsulatoras' previously explained. It is to'be noted that the arms 96 and 97 of the switch blade converge, said arms being secured together where they meet to provide a flat contacting surface in a manner well known in the art. Arcing horns such as 61, previously described, may be secured to the contacting end of the switch blade As may be readily seen from the description As a result of the structural arrangement provided, the switch may be successfully operated and mounted in any position whatsoever. It is apparent from the description thus far given that if either of the switches described is mounted in the underhung position, the behavior of the switch throughout its entire range a of travel will be the same as when the switch is mounted in an upright position.

It a spring such as the spring '70 (Figure 3) is provided in a switch that is mounted in the underhung .position, the direction of force of the spring is, of course, reversed. Under those conditions the end 72 of the spring is mounted on the opposite side of the pivot pin 45 or universal joint from that shown in Figure 3. Under those conditions, during the initial switch opening movement, the spring tends to sustain the switch blade against the action of gravity. This is the same function that the spring has in the switch shown in Figure 1.

In Figures 9 and 10 we have-shown a different In this form of connected to the terminal lug 121 in the usual manner. The stationary contact 122 within the housing 115 comprises a strip of copper or other suitable contacting material, of rectangular cross section and suitably secured within the housing to the terminal lug 121. As shown, the terminal lug 121 and the contact 122 are bolted to the top of the housing. The end of the blade 14 is flattened and spring pressed contacts are secured thereto. The contacts secured to the blade 14 are of a construction such as shown in Figure 10a of the patent of Alfred Alsaker, No. 1,815,392, issued July 21, 1931, difiering somewhat therefrom as will be presently pointed out. This contact comprises a pair of angularly flared jaws 130 of copper or other suitable conducting material spaced from the end of the switch blade and secured thereto by means of a pair of flexible copper bars 131. Springs 132 force the contacts together. The contact jaws embrace the opposite sides of the contact 122. Upon the initial opening movement of the switch the blade 14 is drawn as a unit in substantially a straight line until the contact jaws are out of engagement with the contact 122, and thereafter the blade swings the contacts downward away from the contact 122. It is, of course, understood that with slight modification this form of contact assembly may be used upon a switch mounted in the upright position and, if desired, a contact assembly such as is used in connection with the switch shown in Figure 1, as previously described, may be used with an under-hung type of switch.

In compliance with the requirements of the patent statutes we have herein shown and described a few preferred embodiments of our invention. It is, however, to be understood that the invention is not limited to the precise embodiments herein described, the same being merely illustrative of the invention. What we consider new and desire to secure by Letters Patent is:

1. In an electric switch, a support, three links pivotally connected and pivoted on the support to form a quadrilateral with the support consti-, tutingone side of the quadrilateral, a switch blade carried by one of the links, an actuating mechanism secured to one of the links and operable to move the links with respect to the support for moving the switch blade to the open and closed position, and means including an eccentric at one of the pivots for adjusting the length of at least one of the sides of the quadrilateral, thereby altering the motion of the remote end of the blade for a given motion of the actuating mechanism.

2. A switch comprising a base, a contact supporting insulator mounted on the base, a contact mounted thereon, a blade supporting structure and a blade mounted on the base, said blade cooperating with the contact and being substantially parallel to the base when in engagement with the contact, said supporting structure-comprising two links to which the blade is pivoted at spaced points and which are themselves pivoted about spaced stationary pivots, one or said. links being rotatable through an angle substantially greater than 180 and the other link through mounted thereon, a switch blade cooperating with said contact, means efiective to first impart a substantially rectilinear motion to the contacting end of the-blade and thereafter to swing the contacting end of the blade in a substantially circular path and in a direction away from the supporting structure .and from the contact, to

increase the striking distance to both; said means including a pair of links pivoted about spaced stationary axes and insulated from the supporting structure, said links being pivoted to the blade and constituting a-support for the blade,

a rotatable insulator mounted on the supporting structure and having a. driving connection with said links, and means at one of the pivots for adjusting the relative lengths of the links for varying the extent of the rectilinear motion.

4. In combination, a stationary insulator, an insulator cap mounted thereon, a rotary insulator, spacing strips connecting the insulator cap with the rotary insulator, an arm mounted on the insulator cap and extending between the spacing strips and towards the rotary insulator, a pivot pin supported by said arm, a second pivot pinsupported by the insulator cap and held against side movement by the spacing strips, said pivot pins being parallel to and spaced from one another, links mounted on the respective pivot pins. for" pivotal movement, a switch bladepivoted to both links, andmeans connecting the rotary insulator with the linkwork to actuate the switch blade. 115

5. A switch including an insulator, a blade supporting member mounted on the insulator and having a pair of spaced arms, insulator bracing means secured to said arms, a switch blade supporting link pivoted to said arms, a stationary 12 arm extending upwardly and rearwardly of said supportingmember and rigid with respect thereto, a link pivoted to said last mentioned arm, and a switch blade pivoted to both of said links.

6. A switch including a switch blade and means for imparting a compound motion to the blade, said means comprising a pluralityof pivoted links having pivotal connection with the blade, at least one of the pivots comprising an eccentric joining the two parts that are pivoted together, said eccentric being adjustable to vary the effective center of its pivot. i

'7. A switch including a pair of links pivoted about spaced pivots, a switch blade pivoted to said links at spaced points, and means for ad- 135 center 01' its pivot.

. THORSTEN FJELLS'I'EDT. WELDON 0. HAMPTON.

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