US2527924A - Switch construction - Google Patents

Description

0t 31, 1950 T. FJELLsTED-r ETAL 2,527,924

C SWITCH CONSTRUCTION Filed July 21, 1947 2 Sheets-Sheet 1 Oct 31, 1950 T. FJELLsTEDT ETAL. 2,527,924

SWITCH CONSTRUCTION Filed July 21, 1947 2 Sheets-Sheet 2 Patented Oct. 31,1950

SWITCH CONSTRUCTION Thorsten Fjellstedt, Ingleside, Vand Stanley C.

Killian, Glen Ellyn, Ill., assignors to The Delta- Star Electric Company, Chicago, Ill., a corporation yof Illinois Application July 21, 1947, Serial No. 762,470

6 Claims.

l This invention relates, generally, to switch constructions, and it has particular relation to disconnecting switch constructions that are employed for sectionalizing high voltage electricl power transmission lines and opening the circuit to circuit breakers and other apparatus.

The present invention more particularly relates to improvements in the switch construction shown in Patent No. 2,231,992, issued Februaiy 18, 194'1, to one o the inventors herein and which israssigned to the assignee of this application. The disconnecting switch construction disclosed in this patent comprises two stationary insulators carrying line terminals with a rotatable insulator therebetween. When the rotatable insulator is rotated the switch blade is rst turned primarily about its longitudinal axis in the switch closed position to disengage the high pressure small area contacts carried by one of the stationary insulators and is also rotated about an axis that is transverse to the longitudinal axis for providing an air gap in the circuit. The switch blade is mounted in part on a frame member that is carried by the other stationary insulator. The frame member also includes a circular bearing which cooperates with the upper end of the rotatable insulator.

The rotatable insulator carries a crank member which has a pin that extends at an angle of 45 to the vertical and cooperates with a correspondingly positioned bearing carried by a blade carriage in which the switch blade is mounted. The blade carriage has a contact surface provided thereon which is engaged by contact fingers to complete the circuit through the switch. In the commercial form of switch this contact surface is shaped so as to provide small area high pressure contact engagement with the contact lingers. It is diicult to machine and hence increases the cost of construction of the switch.

Among the objects of this invention are: To modify the'switch construction shown in the patent referred to above to the end that the cost thereof will be reduced and its operating characteristics improved; to mount the crank means on the rotatable insulator independently of the frame support so as to avoid the necessity for the circular bearing mentioned above; to employ a stationary contact member on the frame support for engagement by the switch blade in the switch closed position and thus avoid the necessity for providing contact surface on the blade carriage or blade hinge; and to provide a bearing pin or arm on the blade hinge and mount it in a bearing carried by a crank pin that is mounted on and rotates with the rotatable insulator. y l y Other objects of this invention will, in part, be obvious and in part appear hereinafter.

Accordingly, this invention is disclosed in the embodiment thereof shown in the accompanying drawings, and it comprises the features of construction, combination of elements and arrangement oi parts which will be exemplified in the construction hereinafter set forth and the scope of the application of which will beindicated in the appendedclaims.

For a more complete understanding vof the nature and scope of this invention, reference can be had to the following detailed description taken together with the accompanying drawings, in which:

Figure 1 is a view, in side elevation, of a switch embodying the present invention and shown in the closed position;

Figure 2 is a view of the upper portions of the insulators with the switch being illustrated in the open position;

Figure 3 is a view, partly in side elevation and partly in section, showing the details of construction of the hinge and of the switch blade and parts carrying the same; l Figure 4 is a detail sectional view taken along the line 4-4 of Figure 3; and A Figure 5 is a detail sectional View showing the construction of the switch'blade at its outer end.

Referring now particularly to Figure 1 of the drawings, it will be observed that the reference Vcharacter I0 designates a channel iron base that is mounted horizontally. It will be understood thatthe base I0 can be mounted vertically and that it can be mounted in an inverted position. For illustrative purposes, however, it is shown in a horizontal position, but it can be mounted otherwise as stated. Accordingly, Ythe Words horizontal and vertical as used in the specification and claims with respect to axes of certain elements of the switch are to be considered to express certain relative positions of the axes with respect to each other since, while the words accurately identify the axes which are illustrated in the drawing, the vertical and horizontal positions might change if the switch of this invention were mounted in other than a horizontal position.

The base I0 carries insulators Il, I2 and.l3 which are of conventional construction and,. as shown, may be of the pin type. 'I'he insulators l l and 4I3 at the ends of the base l0 are stationary of hard .drawnv copper.

and are mounted on suitable spacers I4 and I5 to position them at the desired elevation. As

indicated, the intermediate insulator l2 is rotatable. For this purpose a bearing I 5 is mounted on the base I 9 and, as will appear hereinafter, constitutes the sole bearing support for the insulator I2. An octagonal shank .Il projects below the base I0 and is arranged to receive suitable crank means for rotating the insulator I2.

The insulator Il at the upper end carries a terminal bracket i8 that may be a bronze casting and it has a terminal pad I9 formed integrally therewith to which a terminal connector 29 may be secured as shown. Mounted on the lterminal bracket I8 is a U-shaped contact member 2I of hard drawn copper or the like, the blade portions of which are curved so as to provide small area high pressure contact engaging surfaces.

A generally U-shaped reenforcing spring 22 serves to urge the arms of the contact member 2l toward each other to provide the required contact pressure. If desired straight contact bars secured along the sides of a terminal casting and backed up by leaf springs can be employed as a substitute for` the U-shaped contact member 2| i;

and spring 22 as will be understood readily.

At its upper end the insulator i3 carries a frame, support Y25 thatmay be a bronze casting. vIt `has a ter-minal pad 2S for receiving a terminal connector 21.- It will be understood that the conductors of the. circuit in which the switch is connected are connectedto the terminal connectors 29 and 2l..

In accordance with this invention, the frame support 25 carries a `U-sbaped contact member 2-8i which is similar in construction to the contact member 2I describedA above. As illustrated more clearly in Figure 4, the arms of the contact member 28 are formed so as to provide longitudinally extending raised portions 28 which provide the desired small area contact engaging surfaces which are urged toward each other by a U-shaped reenforcing spring 29. The contact member 28 is secured to the frame support 25 by bolts -38 as shown in Figure 3. -The contact construction employing the straight contact bars and leaf reenforcing springs described above can be employed in lieu of the U-shaped contact -member 28 and spring 29.

The U-shaped Contact members 2I and 28 with reenforcing springs-2,2 andg or the equivalent construction using straight contact bars and reenforcing leaf springs are considered as U -shaped contact members herein.

The U-shaped contact members 2l and 28 :are interconnected in theswitch closed position by a tubular switch blade 3l that may be formed Its outer end is deformed, as shown in Figure 5, at 32 to provide small area surfaces 33 which cooperate with the corresponding ycontact surfaces of the arms of the contact member 2l. A plug 3 4, held in place by .bolt 35, serves -to maintain the shape of the deformed .end 32 and prevents the same from collapsing when it is subjected to the pressure incidentto the-.switch vblade 3i being placed in and remaining inthe switch closed position. :If the wall thickness rof the tubular switch blade 3| is sulicient, the plug may be omitted.

Atits other end, as shown in Figure 4, the switch blade SI is deformed as indicated at 36 to-provide small .area AContact engaging surfaces 3'I vfor engaging the corresponding surfaces 28 .of ,the contact member 28. A plug 38 is positionedwithin the end of the switch blade 3! A. l adjacent the deformed part 36 and is held in place by a bolt 39. The purpose of the plug 38, like the plug 34 previously mentioned, is to prevent the walls of the switch blade 3I from collapsing when it is subjected to the pressure exerted by the spring 29 in applying the relatively high contact pressure in the switch closed position. As before, if the wall thickness of the tubular switch blade 3| is sufficient, the plug 38 can be omitted. The switch blade 3| is carried by a blade hinge 43 which may be a bronze casting that is suitably machined to the shape illustrated. The blade hinge 49 may be secured to the switch blade 3i by a bolt 4I which, as shown in Figure 3, may

be located in a tapped hole 42 to one side of the blade hinge 40 rather than on top as illustrated in Figure 1. If desired, the bolt 39 can be omitted and the plug 38, if used, can be held in position by the bolt 4 I.

The blade hinge 48 is rotatably mounted by ball bearings 43 in a blade guide 44 which, as shown in Figures 1 and 2 is mounted by bolts 45 on,K the frame support 25 to rotate about a horizontal axis through the longitudinal axis of y. bi

the bolts 45.

In order to rotate the blade 3I about its longitudinal axis as permitted by the ball bearings 43 in the blade guide 44 and also to swing `the switch blade 3I to the open position as shown in Figure 2, the blade hinge 40 is provided with an arm 4,5 that extends atan angle of 45 away from the longitudinal axis vof Vthe switch blade3I.

As illustrated more clearly in AFigure 3 of the drawings, the arm i6 whichextends at an angle of 45 from the blade hinge .49 vis carried by ball bearings 41 in a bearing portion 48 of a cram; pin 49 that is secured by bolts 59 tothe rotatable insulator I2 and rotates therewith when the same is turned.

When the insulator I2 is rotated in either direction from the position shown in Figures 1 and 3, the switch blade 3| will be rotated about its longitudinal .axis to relieve the pressure between the high Apressure contact surfaces 33 and 3'! and their respective stationary contact members 2i and `28, and to move the small area high pressure contact sur-faces 33 and 37 out of engagement with the corresponding surfaces of the contact members 2l and 28. Simultaneously, the rotation of the insulator I2 and of the crank pin 49oauses the-switch blade 3| to rotate about the horizontal axis through the bolts 115. Reference in the claims to rotation of the switch blade about its longitudinal axis to relieve pressure between it and a stationary, small area, high pressure contact member `(or members) is intended to cover both of the following sequences of action: (l) where Vthe pressure is relieved and a slight separation of the contacts ,results from rotation of the switch blade about ,aration'results only following arcuate movement of the blade about said transverse axis out of the neighborhood of the stationary contacts. It will be appreciated that our invention embraces `both types of separation of the contacts and either one maybe had by appropriate proportioning of the respective dimensions of the contacts. Correspondingly, reference in the claims to swinging said switch blade -out of engagement with contacts.

said stationary, high pressure, small area contact member (or members) is intended to embrace both of thefollowing actions (related to actions I and 2 setforth above) z (1) where the contact on the switch blade has already separated from the stationary contact by rotation of the switch blade about its own longitudinal axis, with the swinging movement thereafter carrying the contact of the switch blade out of the neighborhood of the stationary contact to provide a substantial air gap, and (2) where the Vblade contact has been rotated to relieve most of the pressure between it and the stationary contact but the two do not separate until the swinging movement has carried the contact on the switch blade out of the neighborhood of the stationary When the movement of the insulator I2 -has been completed the switch blade 3| is moved to the full open position as shown in Figure 2 and it has rotated about its longitudinal axis.

The blade guide 44 permits the switch blade 3|v vto rotate about its longitudinal axis' and this movement is facilitated by the ball bearings 43. The blade guide 44 itself is rockably mounted on the frame support 25 about a horizontal axis through the longitudinal axis of the bolts 45 on opposite sides. This movement of the blade guide 44 guides the switch blade 3| in its movement through 90 from the switch closed position shown in Figure 'l to the switch open position shown in Figure 2 and vice versa. Since the blade hinge 40 isfastened to the switch blade 3| and its arm, which extends at 45", is rotatably mounted by ball bearings 41 in the bearingportion 48 of the crank pin 49, rotation of the insulator l2 about its vertical axis causes the crank pin 49, which is secured thereto, to rotate aboutthis vertical axis and, initially, the switch blade 3| to rotate principally about its longitudinal axis and thereafter principally about the horizontal axis through the bolts 45.

When the insulator I2 is rotated in the reverse direction, Vthe switch blade 3| is swung through 90 to the switch `closed position. At the same time the switch blade 3| is rotated about its longitudinal axis, its final rotation about this axis taking place as it approaches the horizontal position so that the nal movement thereof into high pressure contact engagement with the contact members 2| and 28 takes place while there is a small amount of arcuate movement thereof about its horizontal axis. This permits the necessary torque to be transmitted through the switch blade 3| for rotating it into the switch closed position with the contact surfaces under relatively high pressure.

It will be observed that when the switch construction disclosed herein is employed, it is unnecessary to provide a bearing extension from the frame support 25 for guiding the upper end of the rotatable insulator l2. This materially simplies the construction of the frame support 25 and eects a corresponding reduction in cost.

When the contact member 28 is provided on the frame support 25, it is unnecessary to provide a contact surface on the blade hinge 40 and to machine it as an eccentric in order to provide small area high pressure contact engagement therewith. The blade hinge 40 can be shaped by suitable simple machine operations which further go toward reducing the cost of the switch construction. At the same time by placing the contact member 28 on ,the frame support 25 and causing it to engage directly the switch blade 6. 3l, a lower resistance current carrying path is provided.

The construction of the crank pin or arm 49 is simplified by arranging to have it carry the ball bearings 41 and by providing the arm 4E integral with the blade hinge for journalling the same. It will be observed that the axis of rotation of the blade guide 44 about bolts 45, the longitudinal axis of the switch blade 3|, the axis of rotation of the crank pin-49, and the axis ofthe arm 46 all intersect at a common point.

Since certain changes can be made in the foregoing switch construction and different embodiments of the invention can be made without departing from the spirit and scope thereof, it is intended that all matter` shown in the accompanying drawings and described hereinabove shall be interpreted as illustrative and not in a limiting sense.

What is claimed as new is:

l.A In a disconnecting switch, in combination,

. a pairof stationary U-shaped high pressure small area contact members in insulated spaced relation, a tubular switch blade withv the ends providing small area contact engaging surfaces for engaging said stationary U-shaped contact members, a frame support, a blade guide mounted for rotation about a horizontal axis on Said frame support, a blade hinge secured to said blade intermediate said contact engaging surfaces at its ends and rotatably mounted on said blade guide about the longitudinal axis of said switch blade and having an arm extending at an angle of forty-five degrees thereto, and a crank pin rotatable about a vertical axis intersecting said horizontal and longitudinal axes'and having a bearing portion rotatably mounting said arm whereby on rotation of said crank pin about.

said vertical axis said switch. blade is rotated about its longitudinal axis to relieve the pressure between it and said contact members and about said horizontal axis to swing said switch blade out of engagement with one of said contact members to provide an air gap between it and said switch blade.

2. In a disconnectingv switch, in combination, a stationary frame support, a pair of high pressure small area contact members one mounted on said frame support and the other in insulated spaced relation thereto, guide lmeans rotatably mounted on said frame support, a switch blade having small area contact engaging surfaces near its ends for engaging said contact members mounted for rotation intermediate its ends about its longitudinal axis on said guide means, and crank means independent of said frame support for rotating said switch blade about its longitudinal axis to relieve the pressure between it and said contact members and about the axis of rotation of said guide means to swing said switch blade out of engagement with said contact members to provide an air gap between said other contact member and said switch blade.

3. In a disconnecting switch, in combination, a stationary frame support, a pair of U-shaped high pressure small area contact members one mounted on said frame support and the other in insulated spaced relation thereto, a blade guide mounted for rotation kabout a horizontal axis on said frame support, a tubular switch blade with the ends providing small area contact engaging surfaces for engaging said stationary contact members, a blade hinge secured to said blade intermediate said contact engaging surfaces at l its ends and rotatably mounted on said blade guide about the longitudinal axis of said switch blade and having an arm extending at an angle of forty-live degrees thereto, a crank pin rotatable about a vertical axis intersecting said horizontal and longitudinal axes and having a bearing portion rotatably mounting said arm whereby on rotation of said crank pin about said vertical axis said switch blade is rotated about its longitudinal axis to relieve the pressure between it and said Contact members and about said horizontal axis to swing said switch blade out of engagement with said other contact member to provide an air gap between it and said switch blade, and bearing means mounting said crank pin for rotation independently of said frame support.

4. The invention, as set forth in claim 3, wherein ther tubular switch blade extends through the blade guide and blade hinge to engage the contact member mounted on the frame support.

5. In a disconnecting switch, in combination, a pair of stationary Contact members in insulated spaced relation, at least one of said pair cornprising a high pressure, small area Contact member; a switch blade having contact engaging surfaces near its ends for engaging said stationary Contact members, at least one of said contact surfaces of the switch blade having a small area for engagement with said stationary, high pressure, small area contact member; a frame support; a blade guide mounted for rotation about a horizontal axis on said frame support, a blade hinge element secured to said switch blade intermediate said contact engaging surfaces at its ends and rotatably mounted on said blade guide about the longitudinal axis of said switch blade, and a crank pin element rotatable about a vertical axis intersecting said horizontal and longitudinal axes, an arm extending from one of said elements at an angle of 45 with respect to the longitudinal axis of the switch blade, and a bearing for rotatably mounting said arm, said arm and bearing interconnecting the blade hinge element and crank pin element, said crank pin element, when rotated about said vertical axis, causing said switch blade to be rotated simultaneously about its longitudinal axis to relieve the pressure between it and said stationary, high pressure, small area contact member and about said horizontal axis to swing said switch blade out of engagement with said high pressure, small area contact member to provide an air gap between the latter and said switch blade.

6. In a disconnecting switch, in combination, a frame support; a pair of stationary U-shaped high pressure, small area contact members in insulated spaced relation, one of said contact members being mounted on the frame support; a tubular switch blade with the ends providing small area contact engaging surfaces for engaging said stationary U-shaped contact members; a blade guide mounted for rotation about a horizontal axis on said frame support; a blade hinge secured to said switch blade intermediate said contact engaging surfaces at its ends and rotatably mounted on said blade guide about the longitudinal axis of said switch blade and having an arm extending at an angle of 45 with respect to said blade, said 'tubular switch blade extending through the blade guide and blade hinge to engage the U-shaped Contact member which is mounted on said frame member; and a crank pin rotatable about a vertical axis intersecting said horizontal and longitudinal axes and having a bearing portion rotatably mounting said arm whereby, upon rotation of said crank pin about said vertical axis, said switch blade is rotated about its longitudinal axis to relieve the pressure between it and said contact members and about said horizontal axis to swing said Switch blade out of engagement with one of said Contact members to provide an air gap between it and said switch blade; the axis of rotation of the blade guide, the longitudinal axis of the switch blade, the axis of rotation of the crank pin, and the axis of said arm all intersecting at a common point.

THORSTEN FJELLSTEDT. STANLEY C. KILLIAN.

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

UNITED STATES PATENTS Number Name Date 1,695,868 Stolz Dec. 18, 1928 1,793,797 Hampton et al Feb. 24, 1931 2,231,992 Fjellstedt Feb. 18, 1941 2,420,074 Froland May 6, 1947

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