US2272506A - Switch - Google Patents

Description

Feb. 10, 1942. A. J. BOWiE SWITCH Filed Jan. 3, 1939 Heme 1 FIGURE '2.

5 Sheets-Sheet 1 INVENTOR.

ATTORNEYS.

Feb. 10, 1942.

F/euef 7 A. J. sown-z 2,272,506

SWITCH Filed Jan. 3, 1939 3 Sheets-Sheet 2 Have: 6

WQ @W? IN VEN TOR.

ATTORNEYS.

Feb. 10, 1942.

A. J. BOWIE SWITCH Filed Jan. 3, 1939 3 Sheets-Sheet 5 HeueE 9 ATTORNEYS.

Patented Feb. 10, 1942 UNITED STATES PATENT OFFICE SWITCH Augustus Jesse Bowie, San Francisco, Calif. Application January 3,1939, Serial No. 249,055-

14 Claims. (Cl. 200162) The object of this invention is to provide improvements in switches, particularly for heavy amperages. The improved features herein de- Single pole hookstick operated switches illustrated herein are adapted for operation by a switch stick inserted in an eye lever carried by the switch blade. For gang operation, any of the well known forms of operating mechanism can be correspondingly applied to the eye lever to operate the switch.

In common practice the hookstick operated switch consists of a blade hinged on a hinge casting and making contact with the clip on the other end. A hinge bolt with spring washers serves for the hinge trunnion, the washers being adjusted to give the desired contact pressure. In operation the hinge pressure is present during the entire stroke and the clip pressure only when the blade is entering or leaving the clip. Where heavy amperages are used,'to insure proper contact, the hinge pressure must be sufficiently great to require material effort to operate the switch during the entire stroke, and this endangers the scoring of the contacts through friction. The only time when high pressure should preferably be used on contacts is after the contact is fully engaged in order not only to prevent scoring but also to avoid unusual operating effort. In practice in many switches different forms of high pressure have been applied to the receiving clip but the hinge clip must operate under its full pressure or else be shunted by flexible conductors which form an unwieldy and unsightly construction for very high currents. For this reason I utilize in my switch generally a blade pivoted on the hinge casting and attached thereto by a swivel joint, which operates throughout the entire stroke under only a moderate hinge pressure. .After the-blade has fully closed and contact motion has ceased I then apply high pressure to both hinge and receiving clips.

This may be accomplished in a number of dif ferent ways but preferably for the single pole switch it is accomplished by having a blade cperated by an eye lever pivoted thereon. This eye lever is held in position, preferably by a pair of toggle links, the toggle being broken for ex: ample by a trip on the clip cap when the blade is nearly closed. After the toggle is broken further motion of the eye lever sets the high presure on both ends of the blade. This is accomplished by having the motion of the eye lever impart a pressure to resilient members which press simultaneously against both clip and hinge end. This may be accomplished in different ways, either by straightening out a pair of toggle links to practically complete toggle when high pressure is fully set, or by providing a pair of rollers and a cam which is part of, or controlled by the blade eye lever. If the rollers are used for transmission of motion they can be. mounted on the sides of the blade and rotation of the cam will be caused through motion of the blade eye lever. In the preferable construction I make the clip and hing end of the blade of tongue members, with blades contacting externally. Mounted on the outside of the blade are spring members running between the two contacts divided longitudinally at the center. These springs are forced apart by ither of the two methods just mentioned and simultaneously exert pressure on both ends on both clips.

In the reverse operation of opening the blade the toggle links which connect the eye to the blade are first straightened out and locked by mechanism controlled by the eye lever, after which further motion of the eye lever has the blade under-positive control. Blades may also be mounted to expand internally into the contacts supported by a yoke sufficiently strong to stand the pressure utilizing the same features of invention herein described. Of course, the springs need not be continuous rods but can be located at anydesired point. Many other possible arrangements of the springs can be put in to accomplish the same result but an important feature is the fact that the springs are a direct gauge of the pressure at each contact.

A particular feature of this invention is the provision for alignment of the contact surfaces and the equalization and proper distribution of applied pressure to the contacting surface of the blade and clips. Whereas in low amperage switches a certain amount of flexibility exists due to the lighter current carrying sections used, in high amperage switches the current carrying parts must be so heavy as to preclude material deflection, and it is also more important in the latter that perfect contact be maintained over the entire contact area. The heavier parts necessitate greater rigidity in the mounting which prevents automatic adjustment to equalize contact pressures by deflection of the parts. In the invention herein described, independent resilient members are utilized to apply contact pressure, operated positively from a common means,

and floating and resilient members are otherwise utilized in a novel manner to provide for the necessary movement to equalize pressures and allow such motion of the parts as will prevent distortion oi the contact areas and insure proper contact over the full contact surface when pressure is applied. The construction provided also insures proper contact pressures at both hinge and clip ends even though the several parts of the mechanism expand unequally under the rise in temperature occurring when the switch is closed, or should they wear unequally in operation, and eliminates the necessity of accurate ad- Justment in manufacture and erection.

While. I have herein described three forms of my invention, I do not desire to be limited to the precise constructions shown. In each of such forms I have shown a practical embodiment of my invention, which may be constructed at a reasonable cost. The features herein described as new may be utilized in various ways. It is ob-- vious that numerous changes may be made in the form, construction, location and correlation of the various parts, members and features, all without departing from the true spirit of. the invention as set forth in the appended claims.

In addition to the above detailed objects it is a further object of this invention to provide such a switch which will give long serviceable life, which is fool proof in operation, simple and reasonable to erect and construct and which rigidly and strongly constructed provides the flexibility necessary to eflect and maintain full electrical contact.

With the above and other objects in view which will be apparent from a reading of the following specification, I herein describe three adaptations of the features of my invention.

Fig. l is a plan view of the preferred form of my switch with tongue type contacts and with springs external to the blades.

Fig. 2 is a side elevation thereof, showing the means for expanding the springs as a pair of toggle links.

Fig. 3 is a partial central longitudinal section of Fig. 2 with high pressure relieved and the switch out of contact.

Fig. 4 is a side elevation of the switch.

Fig. 5 is a plan view of a corresponding switch which uses an expanding cam, parts being shown in section.

Fig. 6 is a side elevation of the same, parts being broken away.

Fig. 7 is a partial central longitudinal section of Figure 5 showing the switch high pressure out of engagement.

Fig. 8 shows a plan view of a development of the cam member 2! taken along the radial line A--A of Fig. 6.

Fig. 9 is a plan view of a switch adapted for gang operation wherein high pressure is applied to both the hinge and receiving contacts, parts being shown in section along E-E of Fig. 10,

Fig. 10 is a side elevation of Fig. 9 showing the high pressure set and the contacts in engagement, parts being shown in section along line F-F of Fig. 9.

I is a base on which is mounted insulators 2, 2. I is a receiving clip and 4 is a hinge clip mounted on the insulators 2. 5, 5 are terminals attached to the clips for taking current to and from the switch. 9, i are switch blades pivoted on pin 1 and provided with shoes 9, 8 opposite both hinge and receiving clips. 9, 9 are resilient members which are preferably jointed in the center as at in and are held together by fulcrum bolts Ill, ll through washers H, II which provide for simultaneous adjustment of the operating tension on opposite resilient members 9. i2 is an operating lever eye on pivot I! which operates the blade through a pair of toggle links |8--i9 which are connected by pin 30. These links are in a direct line, see Fig. 3, except when the switch is closed and the pressure is on. In opening when the blade moves upward they move into a position in line and in toggle and when in this position tension on the centers of the springs 9, 9 is relieved in the following manner. A second set of toggle links i5, i5 are carried by pin 3| journaled in member i6, which is operated by lever i2 through pin H. The outer end of links l5, l5 terminate in trunnions H, H which are Journalled in members 32, 32, the latter being attached by pins 33, 33 to the resilient members 9, 9.

In Fig. 1 when the links i5--l5 are in line the pins i1, ll will press in turn against resilient members 9, 9 thus setting the pressure against the hinge and receiving clips respectively, the members 9, 9 acting like beams fulcrumed in the middle by bolts Iii-l9. Pin 20 passes through the blades and supports link it] thereon. Link i8 is trunnioned at one end on pin 2| which connects it to the lower end of lever i2. 22 is a profection of the link i8 which impinges on stop 29 in closing the switch. This stop is readily adjusted so that when 22 strikes it near the end of the closing stroke the toggle links i8, ii are broken and further motion of the lever I2 is allowed. This motion moves the member IS with its cooperating pairs of toggle links l5, l5 and sets the pressure on both hinge and receiving clips, see Fig. 2. In the reverse operation when the switch starts to open toggle i8, i9 straightens out as in Fig. 3 and is further assisted in this by spring 24 which serves to reset the toggle. Springs 9, 9 are in effect four independent springs which are held and adjusted by bolts l0, ill and independently exert definite pressure against the contacts. The outer ends of springs 9, 9 when the pressure is set, convey pressure directly on the contacts. It is obvious that it is not essential that the members 9 on opposite sides of the blade both be resilient. The resilient action of members 9 on one side is effective to give resilient pressure to the opposite side of the contact. 2| is a latch trunnioned on pin 29 in lever eye I2 which serves as a positive latch against pin 2| set in the blades, thus locking the high pressure linkage positively in closed position. While the high pressure lever eye I2 is shown as latched on the blade it can correspondingly be latched on the receiving clip instead, this latch being of any design commonly used in switch construction. In Fig. l the dotted lines BC and BD show the center line positions of links i5, i5, when the high pressure is not engaged, and trunnions i1, i1 do not press on springs 9, 9.

In the construction shown in Figs. 5 to B inclusive, 25, 25 are rollers carried on supports 28, 2t. 21 is a cam member which is part of eye lever l2a. The cam is so made that when the switch is not fully closed in the position shown in Fig. 7 the narrow neck of the cam lies between rollers 25, 25. When, however, the switch is fully closed, as shown in Fig. 6, the cam will rotate and the rollers will ride up on the bossed surface, see Fig. 8, thus serving as an alternate means of applying pressure to the springs 9, 9, which cause pressure to be applied to the contacts. Other ae'rasoo 3 parts are identical with Figures 1 to 3 and are correspondingly numbered.

Other means may be utilized where several poles of the switch are operated simultaneously as when a gang switch is used. Figs. 9 and 10 show application of high pressure to both ends of a gang operated switch, the pressure in any case being simultaneously applied only after contact motion has ceased. The left-hand insulator 2a which is trunnioned in the base also carries a shaft 85 which projects from hearing 36 and carries top crank 31 with universal joints 38, 38 at its outer ends connecting through connecting rod 88 to a pin 40 which operates the blade. 4| is a pin on the outer end of crank 31 which attaches not only to the universal 38 but also carries at the bottom end a roller 42 which engages a cam 43 mounted on shaft 44 in bearing 45. This cam attaches tolever 46 in which mounts pin 41. 48, 48 are rigid bridge connections between the hinge cap 4 and bearing 36. 49 is a lever trunnioned on pin 49a which is carried by bridge member 50 attached to blades 8, 6. Member 50 is rigidly attached to one of the blades and is preferably resiliently attached to the other blade, as by spring washers 50a, to allow a slight lateral flexibility to the blades so as to permit them to make perfect contact. is a heavy spring supported by member 50.

The contacts in this type of switch consist of yokes 3a and 4a carrying respectively terminals 5, 5 and the bridges 48; 48 both of which contact the blades 6, 5 and convey the current to and from the switch. The normal operation of the switch is efiected through the rotation of the lefthand insulator and top crank 31 through connecting rod 39 and lever 49 which is practically held stationary with reference to the blade by the heavy spring 5|. When the switch is closed in the position shown in Fig. 9 there is practically no motion of the connecting rod 39 for slight rotation of crank 31, and scarcely any motion when close to the closed position shown. Advantage is taken of this to apply pressure at such a time. However, with a very rigid switch and practically no yield in the blades it is desirable to furnish the connecting rod with spring take-up at the extreme end of the stroke, spring 5| serving that purpose. The motion, however, in this spring is extremely small and occurs only after the application of high pressure to the contacts.

The high pressure is applied through the motion of the cam 43 and crank 46 which gives a small motion to the rod end 5| and its attaching goose-neck connection 52 which is provided with a pin 53 at its outer end. This in turn gives motion to a yoke 54, connecting rod 55 and second yoke 55. 54 and 56 both carry pins 57, 51 which in turn carry each a pair of links i5, IS with outer pins ll, ll which are mounted on springs 9, 9 centered on shoes 8, 8. 58, 58 are adjustable screws for regulating pressure against the contacts serving as fulcrums for the resilient members 9. In the position shown in Fig. 9 each pair of links l5, I5 is expanded, applying pressure to both hinge and receiving clips through the springs reacting on supports 58, 58.

The position shown in Fig. of pin 53 shows the switch in closed position with the pressure on. When the switch starts to open the first motion of the cam 43 is to withdraw the pin 53 to the dotted position shown which is on the center line of the hinge where it remains during the balance of the switch operation until the cation of high pressure to both clips of the switch simultaneously after blade motion has ceased, and high pressure is applied through springs which react independently preferably directly upon the contact clips. It is possible, of course, to substitute the cam type of motion shown in Figs. 5and 6 for the pair of toggle links as'shown in Figs. 1 and 2 and to apply this or other modification thereof to the construction shown in Figs. 9 and 10. It is an important consideration in this matter to apply the pressure to both hinge and receiving clip simultaneously and after blademotion has ceased, as it is highly undesirable, particularly with soft contact surfaces to engage the contacts under any material pressure which may cause abrasion. The blades are trunnioned on pins 1, l and are preferably provided with a light hinge pressure which is on continuously in this and the other designs as shown.

Having thus described my invention I claim and desire to secure by Letters Patent:

1. An electric switch'including a base structure, a pair of contact members mounted in spaced relation thereon, a blade member mounted for movement on said base structure and adapted to engage said contact members to transfer electric current therebetween, means for moving said blade member to effect such engagement, and mechanism for applying pressure between the blade and contacts and associated with said blade moving means for operation thereby, said mechanism including a pair of resilient levers, means for deflecting said levers and adapted to act upon a portion thereof, each of said levers being adapted to apply pressure between the blade member and a contact member through a portion of such lever spaced from said first named portion, one of said levers being adapted for applying pressure between the blade and one I of said contacts and the other of said levers being adapted for applying pressure between the blade and the other of said contacts, whereby pressure is resiliently applied between the blade member and each of the contact members.

2. An electric switch including a base structure, a pair of contact members mounted in spaced relation thereon, a blade member mounted for movement on said base structure and adapted to engage said contact members to transfer electric current therebetween, means for moving said blade members to efiect such engagement, and mechanism for applying pressure between the blade and contacts and associated with said blade moving means for operation thereby, said mechanism including a resilient lever adapted to limit the pressure applied to the contact surfaces, said blade moving means including an independent resilient member through which blade moving forces are transmitted, said blade moving means being so constructed and arranged that relative movement permitted by said resilient member is ineffectual in actuating said prestric current therebetween, means for moving said blade member to effect such engagement, and mechanism for applying pressure between the blade and contacts and associated with said blade moving means for operation thereby, said blade moving means including a crank, a crank arm plvotally associated with said blade member, a resilient member through which said crank arm transmits movement to said blade, and rigid connecting means between said crank and said crank arm.

4. An electric switch including a base structure, a pair oi contact members mounted in spaced relation thereon, a blade member mounted for movement on said base structure and adapted to engage said contact members to transfer electric current therebetween, means for moving said blade member to eflect such engagement, and mechanism for applying pressure between the blade and contacts and associated with said blade moving means for operation thereby, said pressure applying mechanism including a pair of levers adapted to transmit pressure to the con tact surfaces, one of said levers being resilient, a fulcrum member common to both said levers and mounted to float laterally relative to the axis of said blade member, and means for deflecting said levers to apply such pressure.

5. An electric switch including a base structure, a pair of contact members mounted in spaced relation thereon, a blade member mounted for movement on said base structure and adapted to engage said contact members to transfer electric current therebetween, means for moving said blade member to effect such engagement, and mechanism for applying pressure between the blade and contacts and associated with said blade moving means for operation thereby, said blade moving means including a lever movably mounted on said blade member, means for preventing movement of said lever relative to said blade member and means for rendering such preventing means ineffective at a predetermined position of said blade member, said pressure applying mechanism including a resilient lever, and means associated with the first named lever for deflecting said resilient lever a predetermined amount responsive to relative movement between said first named lever and said blade member to apply pressure to the contact surfaces.

6. An electric switch including a base structure, a pair of contact members mounted in spaced relation thereon, a blade member mounted for movement on said base structure and adapted to engage said contact members to transfer electric current therebetween, means for moving said blade member to efl'ect such engagement, and mechanism for applying pressure between the blade and contacts and associated with said blade moving means for operation thereby, said pressure applying mechanism including a pair of levers adapted to transmit pressure to opposite iaces of each of said contacts, one of the levers each pair being resilient, and means for simul-- taneously deflecting said levers to apply pressure to both faces of both contacts.

7. A switch as described in claim 6 and including a fulcrum member mounted to allow transverse movement and common to both levers of each pair.

8. An electric switch including a base structure, a pair or contact members mounted in spaced relation thereon, a blade member mounted for movement on said base structure and adapted to engage said contact members to transfer electric current therebetween, means for moving said blade member to eilectsuch engagement, and mechanism for applying pressure between the blade and contacts and associated with said blade moving means for operation thereby, said mechanism including a cam, a pair or rollers adapted to be forced in opposite direction thereby and means for transmitting the forces applied to said rollers to produce pressure between the surfaces of said blade member and a contact, said transmitting means including a resilient lever operatively associated with one of said rollers and relatively fixed at one portion thereof, another portion thereof bearing opposite a contact surface to resiliently apply pressure thereto responsive to operation of said blade moving means.

9. An electric switch as described in claim l and including means for preventing operation of said pressure applying mechanism except in engaged position of the blade and contact memhere.

10. An electric switch as described in claim 1 and including means for preventing operation of said pressure applying mechanism and means actuated by movement of the blade member upon reaching the contact engaging position for releasing said preventing means to permit application of pressure.

11. An electric switch including a base structure, a pair of contact members mounted in spaced relation thereon, a blade member mounted for movement on said base structure and adapted to engage said contact members to transfer electric current therebetween, means for moving said blade member to effect such engagement, and mechanism for applying pressure between the blade and both of the spaced contact members, said blade moving means being adapted for fixed limited movement relative to said blade member, said relative movement being adapted to actuate said pressure applying mechanism including a pair of spring bars deflectable by such relative movement at one portion thereof and adapted to press the contact and blade members together at another portion thereof spaced from said first named portion whereby the pressure applied is limited by deflection of spring bars.

12. An electric switch including a base structure, a pair of contact members mounted in spaced relation thereon, a blade member mounted for movement on said base structure and adapted to engage said contact members to transfer electric current tlierebetween, means for moving said blade member to effect such engagement, and mechanism for applying pressure between the blade and contacts and associated with said blade moving means for operation thereby, said pressure applying mechanism including a pair of levers carried by said blade member and fulcrumed at opposite sides thereof one of which is resilient, and an expanding mechanism also carried by said blade member and adapted for movement relative to said blade member when said blade member is in a predetermined position, said expanding mechanism being adapted for operation by said blade moving means to actuate said levers to apply contact pressure during such relative movement the portion 01' said levers subjected to actuation by said expanding mechanism being longitudinally spaced from that portion adapted to apply pressure between the blade and contact members, whereby such pressure is resiliently maintained.

13. A switch as described in claim 12 and including a tie member between said levers adapted for floating movement relative to said blade member whereby such pressure is equalized.

14. An electric switch including a base structure, a pair of contact members mounted in spaced relation thereon, a bifurcated blade member mounted for movement on said base structure and adapted to engage opposing faces of said contact members to transfer electric current therebetween, means for moving said blade member to eiiect such engagement, mechanism for applying pressure between the blade and both of the spaced contact members, said mechanism being associated with said blade moving means, for operation thereby at a predetermined position of said blade, and including a pair of resilient levers, each adapted to press one portion of said bifurcated blade member against one of said contact members at substantially the center of contact surface thereof, a second pair of levers, each adapted to press the opposite por-

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