US2231809A - Electric switch - Google Patents

Description

Feb. 11, 1941. T. F. .JQHNSON ELECTRIC SWITCH Filed Mary 12, 1958 3 Sheets-Sheet 1 v i 7 l I Ii i 6 L j Q Feb. 11, 1941.

T. F. JOHNSON ELECTRIC SWITCH Filed May 12, 1958 .3 sn e-z s snem 2 Feb, '11, 1941. T. F. JOHNSON ELECTRIC SWITCH Filed May 12, 19-38 3 Sheets-Sheet 3 115. c k zwam Patented Feb. 11, 1941 Y 7 2,231,809

warren STATES PATENT OFFICE ELECTRIC SWITCH Tomlinson F. Johnson, Atlanta, Ga. Application May 12, 1938, Serial No. 207,596 Claims. (Cl. 200-48) This invention relates to high tension electric per pin 22 extends through a horizontally switches and, among other objects, aims to proelongated slot 24 in the rear end of the blade vide greatly improved articulated swinging switch tip and the rear end of the tip also has an inarms or blades having means to operate them in tegral downwardly extending lug 25 adapted to such manner as to produce powerful leverage for engage the top edge of the arm I5 when the opening and closing them, thereby enabling high switch is closed, as shown in Fig. 3. Each of pressure contacts to be employed and permitting the links l8 also has a rearwardly extending arm easy operation even when the contacts are cor- 26 assuming the form of an ordinary bell crank. roded or covered with ice. The main idea is These arms have integral stub pins 21 to carry to provide improved articulated switch arms and tension springs 28 which are connected at their blade tips capable of initiating opening moveforward ends to the end portions of the pins ment by striking an effective hammer blow and, 20 projecting beyond the sides of the forward thereafter, imparting compoundi longitudinal and links ll. The arrangement is such that the swinging movement to the tips. switch arm and blade tip are substantially rigid Other aims and advantages of the invention when the switch is closed and the contact end will appear in the specification, when considered 29 of the tip rests on the shelf 3|]. The lug in connection with the accompanying drawings, 25, contacting the top edge of the arm l5 when wherein: the switch blade is in this position, limits the Fig. 1 is a side elevation of a switch unit of the downward swinging movement of the blade; rocking insulator type embodying the invention; while the springs tend to break the joint and Fig. 2 is a fragmentary enlarged top plan view move the blade tip to the position shown in of Fig. 1; Fig. 5. However, the spring jaws, which may be Figs. 3, 4 and 5 are enlarged side elevations far more powerful than those of ordinary showing the blade tip in different operated switches, prevent any such movement.

positions; The forward end of the arm I5 is shown as 5 Fig. 6 is a side elevation of a rotating insulator terminating in a curved horn 3| acting as a stop switch embodying the invention; and member against the lower edge of the tip I6 Figs. '7 and 8 are fragmentary, enlarged top slightly in advance of the pivot pin E9, the arplans, partly in section, showing two positions rangement being such that this horn and. the two of the blade tip. links hold the tip and arm in the positions shown Referring particularly to the drawings and to in Fig. 5 after the tip has been initially Ved the rocking insulator switch unit shown in Figs. to that position. Further movement beyond that 1 to 6, inclusive, the switch structure is shown position will be imparted to both the arm and as being supported on an ordinary structural the tip as if they were a rigid unit. channel it! carrying a stationary insulator H Referring now to the operation of the switch, on which the spring switch jaws [2 are mounted. assuming that the contact is corroded or frozen, A rocking insulator l3 having the usual operatit will be noted that initial swinging movement ing arm id is also mounted on the channel and imparted to the arm 15 as shown in Fig. 4,;will carries a rigid switch arm l5 bolted toqits cap. swing the links H and I8 so that the rear ones A blade tip it is shown as being connected to will move rearwardly and the upper pivot pin 22 the arm by pairs of spaced links 11 and I8, will strike the bottom or rear end of the elongated with its rear end portion overlapping and spaced slot 24, thus imparting a hammer blow to the from the forward end of the arm. rear end portion of the tip and tending to swing Referring to the linkmechanism, the two forit both rearwardly and upwardly at the same ward links ii on opposite sides of the arm and time. This is most effective because of the 5 tip are connected to them by pivot pins l9 and length of the lever arm between the pivot pin 29, the latter extending through a vertically 22 and the contact end 29 of the tip. At the elongated slot 2! in the arm I5 to provide for a same time, the vertical slot 2| at the forward slight lost motion when the switch arm is iniend of the arm 15 moves upwardly until the tially raised and the contact is corroded or frozen. pivot pin 20 is seated in the bottom of the slot. 50 The rear links it are connected to the tipand This initial movement stretches the springs 28 arm by ivot pins 22 and 23, the distance between and, when the hammer blow breaks the frozen the pivot pins 28 and 23 being much shorter contact, they act to move the pivot pins 29 and than that between the pivot pins I9 and 22; that 22 back to their original positions in the respecis to say, the links diverge upwardly. The uptive slots, as shown in Fig. '3. Further upward movement of the arm l5 will impart a compound longitudinal and upward swinging movement to the blade tip through the links until the horn 3| strikes the bottom edge of the tip, as shown in Fig. 5, and completion of the opening movement will be accomplished as a unit. Incidentally, when the horn 3i strikes the bottom edge of the tip a slight hammer blow it will start the contact end 29 of the tip on its backward movement out of the top of the jaws. When the blade is swung to closed position it will be seen that powerful endwise pressure is applied to the tip, due tothe lever action.

Referring now to the modified form of switch shown in Figs. 6, '7 and 8, the switch unit is supported on the usual channel 40 carrying the, stationary insulator 4| on which the jaws 42 are mounted to receive the switch blade when swung in a horizontal direction, the jaws being identical with those shown in the other form of switch. A rotating insulator 43 having an operating arm 44 is mounted on the other end of the channel 40 and carries a rigidly connected, horizontally swinging arm 45, conveniently in the form of a piece of copper pipe. The forward end of the arm 45 is shown as carrying a fitting 46 to which a blade tip 47 is connected by means of pairs of toggle links 48 and 49. In this instance, the

fitting 46 has a flattened forward end 50 and the toggle links 48, parallel with the axis of the switch arm, are connected to the rear end of the tip and the flattened portion 50 on the arm by pins 5! and 52 without any lost motion. The other links 49 are connected at their rear ends to the flattened end 50 by a pin 53 which is arranged fairly close to the pin 52 and these links diverge forwardly and outwardly from the links 48, being connected by a pin 54 to the tip through a laterally extending, elongated slot 55. In this instance, a pair of tension springs 56 are connected between the outer ends of the pin 52 and a pin 51 which extends through an ear on the back side of the blade tip, the axis of said springs being shown as parallel with the longitudinal axis of the links when the blade is in closed position, as best shown in Fig. 7. The forward end of the flattened portion 50 on the fitting 46 cooperates with a rearward stop projection or nose 58 on the rear end of the tip to provide a stop to limit the closing movement of the jointed ends when the contact portion 59 of the tip strikes the shelf 60,, the parts assuming a stiff leg position shown in Fig. '7. The forward end of the arm or the fitting is also shown as having an angularly extending horn 6| which acts as a stop to strike against a shoulder 62 on the tip when the parts are swung to the position shown in Fig. 8 so that the tip and arm may move as a unit to open the switch.

Referring now to the operation of this modified form of switch, it will be noted that initial clockwise movement of the switch arm 45, as viewed in Fig. 7, will tend to break the toggle joint between its forward end and the tip. If the contact is free, however, the tension of the springs 56 will assist in swinging the arm and tip to the position shown in Fig. 8, with the pivot pin 54 for the links 49 still remaining in the bottom or back portion of its elongated slot 55. However, if the contact is corroded or frozen over, the tip will remain in its closed position and the forward end of the arm will then swing relative to the rigid rear end of the tip. This initial movement will break the stiff leg or kneejoint and cause the pin 54 at the forward ends of the links 49 to move toward switch opening position and strike the forward or front ends of the elongated slot 55, thus imparting a hammer blow to the rear end portion of the tip 41 and moving it slightly rearwardly and at the same time in an arcuate path to loosen the contact. Further movement of the arm 45 will swing the rear end of the tip to the position shown in Fig. 8 until the horn 6| strikes the stop shoulder 62 on the tip when the arm and tip will move as a unit to the fully opened position.

It is not necessary to describe the action of the links during closing movement of either form of switch. It is suflicient to state that their closing movements are the reverse of the opening movements and the final movement is imparted with very powerful leverage so that great spring pressure can be applied to the jaws, thus providing the best possible contact.

From the foregoing description, it will be seen that the invention provides greatly simplified and very effective switch units capable of being used in the coldest climates and the operation is as easy as that of ordinary switches for the same purpose. There are no delicate parts which require replacement and after the toggle joints are made, it is not necessary to make any further adjustments.

Obviously, the present invention is not restricted to the particular embodiments thereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly, since they may be employed advantageously in various combinations and sub-combinations.

What is claimed is:

1. In a high tension electric switch of the class described, a vertically swingable blade comprising an arm; a tip portion pivotally mounted on said arm; spaced pairs of links forming a part of said pivotal connection holding the arm and tip normally spaced and having a slight lost motion relative to the tip; and a spring connection between the arm and the tip to take up the lost motion and permit the arm to contact with and impart a hammer blow to the tip when it is stuck in the switch jaws and the arm is initially moved toward switch opening position.

2. In a high tension electric switch of the class described, a swinging articulated blade comprising an arm; a blade tip having its rear end overlapping and slightly spaced from the forward end of said arm; and spring urged links having a slight lost motion connecting the arm and tip, so arranged as to cause the arm to impart compound swinging and endwise movement with powerful leverage during the initial opening and final closing movement of the arm.

3. In a high tension electric switch of the class described, a swinging articulated blade comprising an arm; a blade tip having its rear end overlapping the forward end of said arm; and spaced pairs of links pivotaliy connecting the arm and tip in spaced relation with a slight lost motion and so arranged that the arm imparts compound swinging and endwise initial opening movement to the tip with powerful leverage and the arm will move relative to and strike the tip with a hammer blow, if it is stuck when the arm swings toward open position.

4. In a high tension electric switch of the class described, a vertically swingable blade comprising an arm; a blade tip having its rear end overlapping the forward end of said arm; spaced pairs of links pivotally connecting the arm and tip in strike the tip with a hammer blow when the tip is stuck; and means on the arm to engage the tip beyond the link connections after the initial opening movement ;is imparted to the tip to cause the arm and tip to complete the opening movement as a unit.

5. In a high tension electric switch of the class described, a swinging articulated blade comprising an arm and a blade tip having its rear end overlapping the forward end of said arm; spaced pairs of links pivotally connecting the arm and tip holding their overlapping ends normally spaced from each other and arranged to impart compound swinging and endwise initial opening movement to the tip with powerful leverage when the arm swings toward open position; said links having slotted connections permitting the arm to swing into contact with the tip when the tip is stuck and impart a hammer blow to loosen the tip; means on the arm to engage the tip beyond the link connections after the initial opening movement is imparted to the tip to cause the arm and tip to complete the opening movement as a unit; and stop means between the rear end portion of the tip and the arm to limit the relative pivotal movement to the closed position.

6. In a high tension electric switch of the class described, a swinging articulated blade comprising an arm; a blade tip having its rear end overlapping the forward end of said arm; links connecting the arm and tip in spaced relation so arranged as to impart compound swinging and endwise movement with powerful leverage during the initial opening and final closing movement of the arm, said links having a slight lost motion permitting the arm to swing initially before the tip is moved and then contact with and impart a hammer blow to the tip when it is stuck in the aws.

'7. In a high tension electric switch of the class described, a swinging articulated blade comprising an arm; a blade tip having its rear end overlapping the forward end of said arm; links connecting the arm and tip with their overlapping 45 ends in spaced relation and so arranged as to impart compound swinging and endwise movement with powerful leverage during the initial opening and final closing movement of the arm, said links having a slight lost motion permitting the arm to start its movement independently of the tip so that it will contact with and impart an initial hammer blow to the tip when it is stuck in the jaws and loosen the tip; and a tension spring between the tip and blade biasing them toward open position when the switch is closed and supplementing the power of the hammer blow.

8. In a high tension switch of the class described, a stationary insulator carrying powerful spring jaws; a rocking insulator having operating means; a blade mounted on said rocking insulator comprising a rigid arm and pivotally connected tip having spaced pairs of links pivoted to the blade and tip to permit the blade to close and to open initially with powerful leverage, one pair of said links having a slight lost motion, whereby the arm can initially move into contact with and impart a hammer blow to the tip to loosen it when it is stuck in the jaws.

9. In a high tension switch of the class described, a stationary vertical insulator carrying powerful horizontal spring jaws; a rotating vertical insulator; a blade mounted on said rotating insulator for horizontal swinging movement; said blade carrying a tip; means to limit the closing movement of the tip; and compound links providing a knee joint between the arm and tip normally holding them spaced apart and having a slight lost motion permitting the arm to swing initially and engage the tip to impart a hammer blow to the tip when it is stuck in the jaws.

10. In a high tension switch of the class described, a stationary vertical insulator carrying powerful horizontal spring jaws; a rotating vertical insulator; a switch arm on the rotating insulator connected to swing horizontally; a blade tip; spaced pairs of links pivotally connecting the arm and tip in spaced relation and arranged to impart compound swinging and endwise initial opening movement to the tip with powerful leverage when the arm swings toward open position; means on the arm to engage the tip beyond the link connections after the initial opening movement is imparted to the tip to cause the arm and tip to complete the opening movement as a unit; and stop means between the rear end portion of the tip and the arm to limit the relative pivotal movement to the closed position.

TOMLINSON F. JOHNSON.

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