US2835770A - Blade latch for disconnect switches - Google Patents

Description

May` 20, 1958 A. Fo'rl BLADE LATCH Fox lurscorqmac1 SWITCHES 5 Sheets-Sheet 1 Filed Sept. 10, 1954 lxwdl- NW m mf r mM 4 n A May 20, 1958 A. FoTl i2,835,770

BLADE LATCH FOR DIscoNNEcT SWITCHES Filed sept. 1o, 1954 5 ysheets-sheet 2 fr-:KIA

- IESA- u u INVENTOR. b ,eg/yf Far/ May 20, 1958 A. FoTx BLADELATCH EUR DIscoNNEcm SWITCHES 5 Sheets-Sheet 3 Filed Sept. 10, 1954 |W #Ell Q.

IN VEN TOR. Mes/v r/ @Jaw g//Zfk May Z0, 1958 A. FOTI l BLADE LATCH FOR DIscoNNECT SWITCHES 5 Sheets-Sheet 4 Filed Sept. 10, 1954 May 20, 1958 A, F0-rl 2,835,770

ADE LATCH FOR DISCONNECT SWITCHES Filed Sept. 10, 1954 5 Sl'leets---Sheetl 5 IN VEN TOR. 74E/W Fr/ 2,835,770 Patented May 20, 1958 BLADE LATCH Fon DISCoNNnor SWITCHES Arem Foti, Greensburg, Pa., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Application September 10, 1954, Serial No. 455,227

6 Claims. (Cl. 20G-169) My invention relates to a latch arrangement for disconnecting switches having high pressure contact engagement caused by rotation of the blade about its hinge and axis and is more particularly directed to latching means for the type of disconnecting switch disclosed in Patent No. 2,673,902 issued March 30, i954.

In high voltage outdoor disconnecting switches, it is necessary to lock or latch the switch biade in engaged position with the stationary contacts in order to prevent the blade from being moved out of the position for proper contact engagement by accidental forces, vibration, or electromagnetic forces created by the passage of short circuit current through the switch.

Heretoore, latch means provided for hook stick operated switches relied on the mechanical rigidity or" the latching means to maintain the switch blade in closed position. That is, the i'orce tending to move the switch blade from the closed to the open position was exerted directly on the latching member and this was called upon to withstand the full impact of the opening force.

In my novel latch arrangement, i utilize the inherent structural arrangement or" the disconnecting switch so that the latch provides a means whereby any opening force applied to the switch blade is resolved into a torsional force on the switch blade to thereafter be transmitted back to the closing means.

Thus, the torsional strength of the blade and the strength and rigidity of the stop means of the closing mechanism is utilized to maintain the switch in closed position. ln effect, the disconnecting switch is maintained in a closed position by the strength or' the stop means associated with the closing mechanism in addition to the latch associated with the blade.

in the disconnect switch of Patent No. 2,673,902, issued March 30, 1954, assigned to the assignee of the instant application, a closing mechanism is disclosed which has the inherent features to defeat unintentional opening ofthe switch blade.

The operating mechanism of this switch contains a toggle which is operated from a crank through one of the supporting insulators. When the switch is in the open position, the toggle may be moved towards its center position by rotating the crank through the insulator to cause closing operation.

The toggle has a fixed pivot at one end and a movable pivot at its other end. The movable pivot is connected to a cranli arm which is integral with a switch blade. Thus, when the toggle is moved from an olt-center position toward center position, it will have the dual eirect on the switch blade to rotate same about its hinge towards the closed position and also rotate the blade about its own axis.

in the closed position of the switch, the toggle is in the center position or slightly beyond the center position and applies a latchiug force near the hinge pivot of the switch blade.

The disconnecting switch is mechanically constructed so that the closed position stop means at the base of rotating insulator, the toggle, the closing crank and the rotating insulator are capable of withstanding opening forces applied to the blade even though these forces may be of suicient magnitude to permanently deform the blade.

With my novel arrangement, I utilize the inherent features of the operating means by relying on the rigidity of these components on one end of the blade, and employ a latch on the other end to withstand the opening force and eliminate the possibility of the switch blade deforming as a result of cantilever force exerted thereon such as may occur during the existence of severe short circuit currents.

By providing a latch to engage only one side of a flattened portion of the switch blade, I resolve any external opening force into a torsional force on the switch blade and eliminate cantilever force which is exerted on the blade with the arrangement shown in Patent No. 2,673,902, issued March 30, 1954.

Since the switch blade has great torsional rigidity, the disconnecting switch will be maintained in closed position without deformation or distortion of any of the componente thereof when subjected to forces which tend to force the switch to the disengaged position.

The above advantages are achieved by placing the latch on one side of the switch blade so that an upward force on the blade will force the blade to rotate about its axis. The latch is so positioned that it will resolve the opening forces into a torsional force tending to rotate the switch blade about its axis in the same direction as its closing motion. Thus, the torsional force on the switch blade will be transmitted through the crank on the blade to the toggle means to thereby bring the closing crank` solidly against the closed position stop means at the switch base.

Accordingly, a primary object of my invention is the provision of means whereby a disconnecting switch can be maintained in the closed or engaged position without exerting cantilever force on the switch blade even though magnetic opening forces are exerted on the switch.

Another object of my invention is to provide an attachment means for a disconnecting switch which will resolve forces tending to jar or force the switch to the open r position into a torsional force on the switch blade which can be transmitted through the operating means so that the rigidity of the operating means will maintain thc switch in the closed position.

Another object of my invention is to provide a latch for the blade of a disconnecting switch which will tend to rotate the blade about its axis in the same direction as the closing motion.

Still another object ot' my invention is to provide c `er a rigid or resilient latch means for disconnecting swi es `o1? the type shown in Patent No. 2,673,902 issued Marc 30, 1954, which will resolve forces tending to jar or force the switch to t-he open position so that the rigidity ot the operating means will maintain the switch in closed position without reliance on the mechanical rigidity of `the switch 'blade as a cantilever beam to resist the forces.

These and other objects of my invention will be apparent from the following description when taken in connection with the drawings in which:

Figure 1 is a side view ofthe disconnecting switch with my novel latch means adapted thereto.

Figure la is an enlarged opposite side View of the jaw end of the disconnecting switch of Figure l. nfhis ligure illustrates the relationship of the jaw latch to the blade latch of my invention.

Figure 2 is a view taken in ythe direction of the arrows 2-2 of Figure l and illustrates the relationship of the jaw latch to the blade latch of my invention,

asssyrvo Figure 2a is an exploded view illustrating the jaw and blade latch of my invention.

Figure 3 is a view taken in the direction of the arrows 3--3 of Figure l and yshows `the base support and lower operating member of the disconnecting switch of Figure l.

Figure 4 is a cross-sectional view taken in the direction of the arrows 4 4 of Figure 1.

Figure 5 is a top view of the disconnecting switch of Figure l showing the position of the toggle mechanism when the switch is in the closed position. This ligure also illustrates a top view of the novel blade and jaw latch of my invention.

Figure 6 is a top view of the switch of Figure l and illustrates the position of the toggle mechanism waan the switch is in the disengaged or open position.

Figure 7 is a top view of the switch of Figure l and shows the position of the operating toggle after the movable contacts have entered the stationary contacts and have just started to rotate into high -contact pressure.

Figure 8a is a side view of the jaw latch used in my invention.

Figure 8b is a View taken in the direction of the arrows b-Sb illustrating the side view of the jaw latch.

are 8f.: is a View taken in the direction of the tic-8c ot Figure 8b illustrating the vtop view of the jaw latch.

Figure 9a illustrates a front view of the blade latch.

Figure 9b is a View taken in the direction of the arrow-s ,Gib- 9b of Figure 9a illustrating the side view of the blade latch.

Figure 9c is a view taken in the direction of the arrows 9c9c of Figure 9b and illustrates a top View olf the blade latch.

Figure l0 is a fragmentary enlarged top view of the crank and link mechanism for operating the contact arm vand corresponds to Figure 6` This figure illustrates the position of the 4toggle when the Iswitch is in the fully open position.

Figure 1l is a top view similar to Figure l() but illustrating the position of the toggle after the conta-ct arm has entered the stationary contact jaws but has not yet lbeen rotated to the closed position and corresponds to the position illustrated in Figure 7.

Figure l2 is a top View similar to Figures l() and ll and illustrates the position of `the toggle when the switch is in the fully closed position. This gure illustrates the toggle moved over its center line position during the final stroke of the closing operation.

Referring first to Figure 1, the disconnecting switch l@ is mounted on the base 1l which is a suitable longitudinal structural support, in this case shown horizontally arranged for a horizontally or upright mounted disconnecting switch.

The base ll has secured thereto in any suitable manner as by the insulator spacers 1.2 and 13 the stationary upright supporting posts 14, 15 on the upper portions of which are mounted insulators i6, 17.

Base li is also provided with the bearing 2@ appropriately secured thereto in any s-uitable manner as by the bolts 2i and carrying the rotatable vertical shaft 22, to the upper end of which is keyed the insulator 23 for rotation with the vertical shaft or post 22.

Below insulator 23 there is keyed to the shaft 22 the crank Si) secured thereto in any suitable manner as by the bolts 3l connected to the flange or crank plate 315. Bolts 2 which secure the bearing 2t) in position also secure the stop plate 3ft in position, the stop plate being provi-ded it opposite ends with `the adjustable stops 36, 37 which engage at either end with the stop 3S on the operating crank 3?.

While stops 36, 37 are herein provided, the construction and operation of my novel switch is such that it may operate properly without the stops at individual poles; in

such case, the stops would be provided at the operating means for the entire switch.

Shaft 22a extends above ythe insulator 23 as an effectively continuation of vertical shaft 22, being, however, spaced therefrom by insulator 23. Crank ttl at the upper end of shaft 22a is preferably integral therewith and. therefore, rotates therewith.

Crank itt extends horizontally or at least parallel with the base supporting structure 1l and rotates in the horizontal plane. Crank 4d is shown herein as tubular although it may have any desired cross-section consistent with the mechanical loads imposed thereon. The outer end of crank itl is flattened at il and is provided with a circular opening 42 through which pin 43 may pass.

A clevis member ii receives extension 4l and is provided at its opposite legs 45, i6 with openings register-ing with opening d2 in extension 4l of the crank di) and receiving the pin d3.

:Clevis fill is integral with the threaded extension which enters into the tapped opening 5l in the forked link 52. The threaded extension Sil is so arrange-d that when the threaded extension 59 rotates `with respect to the forked link 52 and its tapped opening 5l, it has linear movement with respect thereto.

Pin .69a passes through openings 58, 59 and 6G hinging the forked 'link 52 to the crank 6l. Where desirable, insulating bushings 6% (see Figure 4) may serve as `bearings and to effectively electrically insulate crank 61 from pin oder and its forked link 52. rihe blade support sleeve casting 62 carries the tubular switch blade 63 `secured therein and rotatable therewith.

The outer end of the tubular switch blade is liattened at 64 (Figure l) is provided with appropriate contacts 65 engageable with the stationary contact jaws 66.

The blade support sleeve casting 6L?. is mounted for rotation around its longitudinal axis on an extension of the hinge casting 7d. The hinge casting 7? is, in turn, rotatably mounted by the hinge bearings indicated generally at 72 on the fori/:ed trame casting 733.

The frame casting 73 cured in any suitable manner as by the bolts r75 to the top of insulator lo. The si ies 76 of the frame provide supports for the hinge bearings 72 forming the members 76e', 7652. Sides to extend back to the solid portion 77 which is provided with an opening 78 (Figures 5, 6 and 7) appropriately recessed tc form a bearing for crank 40' and its shaft 22a.

The solid portion 77 ot the trarne casting 73 then ex tends beyond to form the terminal titl to which appropriate leads may be connected.

The jaws comprises the plurality of contacts and on each side biased toward each other by the spring fingers 92, and so a ranged that when the blade 63 enters at an angle to the horizontal position during the closing operation, it will clear the contacts 9d and 91 on each side.

rthese Contact members lare so arranged, however, that when the blade is rotated from the position of Figure 7 to the position of Figures l, 2 and 5 tl blade 55 in turning to the horizontal position will spread the contacts 9i? and 9i on each side against the force of springs 92 and 93 creating the Yesired contact pressure.

The spring fingers 92, 93 are current conducting and are connected in any suitable manner as by the bolts 98 to the base plate il@ which, in turn, is mounted in any suitable manner as by bolts iilti at the top of the insulator i7.

The base of stationary contact structure 66 has an extension lili. which serves as a terminal block or connecting member. Thus, when the disconnecting switch is in the closed position of Figures l and 5, the current enters through terminal titi, passes through the frame casting 73 to the hinge bearings 72, then through the current carrying connection in the hinge bearing 72 to the hinge casting 70, then through the current carrying has horizontal section 74 seasesgtvn U connection from the hinge casting 70 to the contact blade 63, then through the contact 65 on the contact blade 62tto the stationary contact elements 90, 91 and then through the base 99 to the terminal extension 101.

The mechanical operating elements which operate the contact assembly for annular rotation at the bearings 72 and after the contact eiernent 56 has entered the stationary Contact continue on to rotate the blade 63 into appropriate 'contact pressure are shown in side view in Figure i, but their operation is illustrated more clearly in Figures 5, o and 7 which show, respectively, the full closed position, the full open position, and the partly closed position where the blade has been rotated for entry into the stationary contact without having been rotated on its longitudinal axis to the closed position of Figure 5,

The relationship ofthe crank to the link at each of the operating positions is also demonstrated in Figures l0, ll and l2 which show these elements and correspond, respectively, to Figures 6, 7 and 5.

The corresponding operation of the lower operating crank is illustrated schematically in Figure 3.

The basic problem here is to utilize the single operating crank in such a manner that by a continuous motion it will iirst rotate the contact assembly angularly about the hearing i2 and after the end of the blade 63 has registered with the stationary contact jaws 66, it will rotate the blade so that its contact element 65 will be in appropriate high pressure engagement with the stationary contact and will be locked into closed position engagement by the past center crank position so that any magnetic or mechanical or weather forces will tend to drive the parts in the closing or engaging direction. Movement past center provides for possible contact en gageinent over a substantial arc so that the contact will engage despite minor misalignments caused by wear or other factors.

The successive steps from the open to the closed position require, therefore, that the crank 4Q, link 52, and the sleeve crank 6i be connected in such manner that these various operations may occur.

in this full closed position, the sleeve crank 6i extends substantially vertically in the case of an upright mounted switch and, therefore, in a plane which includes the axis of supporting posts 15, i4 and 22.

As the crank 40 on post 22 is rotated with the lower operating crank Sil from the position of Figure 5 toward the position of Figure 7, the end of link 52 adjacent crank 40 rotates laterally with the crank 4t). This results in pulling the sleeve crank 61 laterally or angularly, thereby rotating the sleeve casting 62 around the extension Zitti. This in turn rotates the blade 63 with the sleeve 62 in order to effect a rotation of contact 65 out of horizontal position and, therefore, out of pressure engagement with the stationary contact jaws 66.

This is the condition which is reached at Figure 7. Thereafter, further rotation of crank 4t! from the position of Figure 7 and ll to the position of Figure 6 and l0 results in moving the link 52 toward the left (with respect to Figures 6 and 7) thereby pulling crank 61 toward the left and lifting the entire contact assembly angularly around the hinge bearings 72 which act as the rotatable bearing therefor.

The connection between link 52 and sleeve crank 61 has already been described. This connection formed by pin 66a through openings 58 and 39 of link 552 and open-- ing 6b of sleeve crank 61 permits rotation of the link 52 with respect to the sleeve crank 6l in that plane only which includes both the axis of the link 52 and the axis of blade 63.

However, the connection between the crank 413 and link 52 must be such as to permit rotation in two planes. ln addition, since the link 52 first rotates with sleeve crank 61 and sleeve 62 about the stationary bearing 210i) while crank 46* is `rotated in a horizontal plane to move the switch to its upright position, there must not only be a connection between the crank 4u and link 52 which permits relative rotation in two planes but also the connection must permit of some adjustment in the length of link 52 in order to compensate for the fact that crank 4t) always rotates horizontally about a vertical axis, while the crank 61 to which the other end of link 52 is connected rotates during the initial portion of the closing operation vertically about a horizontal axis and at the end of the closing operation rotates about another horizontal axis normal to its first axis of rotation.

Link 52 must also, therefore, have an automatically adjustable composite motion to maintain appropriate driving connection between crank 40 and crank 61. Preferably, as shown, the adjustment is made by means of left hand threaded screw 50 at the connection between elements 40 and 52. This cooperates, as hereinafter pointed out, with the right hand thread of nut 255 to have an additive effect to compensate for the necessary differences in link length required as the elements 40 and 52 move from an angular position -through a straight line position to an angular position on the other side of the straight line positions.

As the crank 40 rotates initially from the closed position of Figure 5 toward the released position of Figure 7, its initial angular movement caused only a relatively very small translatory movement in a longitudinal direction of rink s2.

After the crank 40 has reached and even passes the position of Figure 7 on its way to the full open position of Figure 6, the increasing angle which the crank makes with the link produces relatively greater translatory movement of `the link 52.

At this time, therefore, the link 52 is drawn rapidly to the left to open the switch rapidly; but at the initial opening movement the translatory motion imparted to the link S2 is relatively very small (the major motion imparted being the rotation about a longitudinal axis of link 52), and the amount of compensation required in the connection between crank 40 and link 52 to permit an effective lengthening of the link 52 is also relatively small.

Compensation is provided by a clevis member 44 having the tines 45, 46 in which are placed aligned openings 47, 48. The elevis member 44 ts over extension 41 of the crank 4t) with the openings 47, 48 thereof aligned with the opening 42 in extension 41. An appropriate pin 43 is passed through all of the openings 47, 48, 41 and is locked in position in any suitable manner.

The clevis member 44 now is secured to the crank 40 so that it may rotate in a horizontal plane with respect thereto, while it may have a translatory movement in the horizontal plane. The elevis member 44 is preferably shaped to allow a rocking motion to prevent binding at the pin 43.

The opposite end of the elevis member constitutes a left-hand thread screw 50 entering into threaded engagement with the similarly threaded tapped opening 51 at the left-hand end of link 52.

The screw threads 51 and 50 are so arranged that when the crank 40 is moved from the position of Figures 5 and l2 to the position of Figures 7 and l1, resulting in rotation around a longitudinal axis of the link 52 and crank 61, the resultant relative rotation between the link 52 and the elevis member 44 will cause a screwing out of the end 50 of the elevis member 44 from the tapped opening 51 of the link. The pitch of the threads 50 and 51 are, therefore, such that this screwing out of member 50 from the tapped opening 51 will substantially equal the amount by which the link S2 must be extended during this rotational operation in order to remain engaged with the crank 61. This operation is achieved by a left hand thread on screw 50.

The pitch of the thread of screw 50 may be adjusted to provide the equalizing factor above noted. This may,

however, require a special non-standard pitch to obtain the in and out camming effect required. The screw Sil is essentially a cam for this purpose. However, the righthand thread of nut 255 permits the blade assembly 63- 62-61 to move out from casting 70 when screw Sil moves out of the opening 51 and vice versa, thereby having an additive effect with screw 50 by moving the pivot 57 of link 52. This additive effect permits the required adjustment to take place without the use of special screw pitches. This is possible especially since the height of contact jaws 66 permits the contact to be made Without limitatio-n to an exact area of contact but at various points within the jaw area.

On release of the contact 65 from the stationary contact 66, the clevis member 44 including its threaded end 50 will now pull on the link 52, drawing it to the left and to the open position of Figures 6 and 10.

Similarly, when the contact member is moved from the position of Figure 6 to the position of Figure 7, there will first be a full translating movement, the threaded member permitting such rotation of link S2 with respect to crank 4t) to occur as will permit this translating movement to take place.

Thereafter when the crank moves from the position of Figures 7 and ll tothe position of Figures 5 and l2, the threaded member 50 will be screwed into the tapped opening 51 of link 52 as the relative rotation occurs between crank tu and link 52 to achieve the fully closed position, and this entry of member 50 into opening 51 will,in` cooperation with the additive effect of nut 255, be substantially sufficient to compensate for the necessary reduction in link length, and permit the crank to move past center as above described.

The stationary contacts 66 have been partially described in connection with the operation of the blade 63 and its cooperating contacts 65.

lt will be noted that the jaw end of the disconnecting switch may have the straight line construction as illustrated in the figures and in copending application Ser. No. 389,099, led October 29, 1953, or may be of the construction shown in Patent No. 2,673,902, issued March 30, 1954.

The stationary contact comprises the base 99 which is secured in any suitable manner as by bolts 1d() to the top of insulator 1'7". It will be noted that the jaw latch 110 is provided with a base 111 having openings 1112 therein. The bolts d which serve to secure the base 99 to the insulator 17 also serve to secure the jaw latch 11i) to the base 99. The base 99 has a casting extension member to support the conducting portion of the stationary contact comprising the jaws 9h, 9i and the terminal 101.

The spring fingers 92, 93 are secured by the bolts 98 to the terminal 101. Each of the spring fingers 92, 93 is sufficient in cross-section to carry the current from its associated contact member 90, 91. The contact member 9o, 91 are secured at one end to the spring iingers 92, 9?. The contact faces of the contact members 94), 92. are under cut at 95 to prevent upward movement of the movable Contact 65 when it is turned in the horizontal position. Each of the contact members 90, 91 is provided with an under cut ledge t) at its outer side to; facilitate the securment of the contact members to spring fingers 90, 92, 93.-

The spring 92, 93 bias the contact members 90, 91 toward each other. However, these contact elements are properly adjusted to permit free entry of the movable contact 65 when it is turned at a substantial angle to the horizontal but are so spaced that they will be spread apart by the vrotation of the movablel contact members 65 to the lower horizontal position. Thereafter the spring members 92, 93 force the contacts 90, 91 inwardly to exert. appropriate'contact pressure on the side of the movable contact 65.

A blade latch casting 120 is secured by means of the bolt 121, which passes through the opening 122, to the end 64 of the blade 63. The blade latch 120 is provided with an extended portion 123 having a latching surface 124. When the switch is in the closed position as indicated in Figures l, la, 2, 2a, the latching surface 124 of the blade latch 120 is positioned below the latching surface 125 of the jaw latch 110.

As heretofore noted, the blade 6E is rotated about its own axis when it is moved to the closed position. ln the evznt the latch member 11) is a rigid unit, the latching surfaces 12d, 125, respectively, of the blade latch 12) and the jaw latch 11G) may be displaced at an appropriate distance from the axis of the blade to permit rotation of the blade during the closing operation without engaging the latch 11i?.

However, in some applications, it may be desirable to make the latch member a iiexible or resilient inember to improve operation under ice loading. Thus, with this arrangement, the latch lili) will be so positioned relative to the lade latch 12th that rotation of the blade 63 during the closing operation will bring the extended portion 123 into engagement with the upper portion 126 of the latch 110.

Thus, a supporting portion 127 of the latch 11i) will be forced to deflect to the right as viewed in Figures 2a and 8o, thereby breaking any ice previously formed thereon.

During the initial opening operation, the blade latch 12o is rotated free of the latch surface 125 of the jaw latch 110.

ln the event the switch is in the closed position, as indicated by Figures l, la, 2 2a, 3, 5 and l2, the cooperation of the latch surface 124 with the latch surface 125 due to external forces respectively of the blade latch 12b and the jaw latch 1.21 will impart a torsional force on the blade 63 when there is a force which tends to jar or force the blade 63 out of engagement with the jaw il, 91. That is, if the blade 63 is accidentally engaged by a moving object or is moved in the open direction by vibration or a force created due to the occurrence of a short circuit current, the blade 63 will be moved upwardly so that the latch surface 124 of the blade latch 129 will engage the latching surface 125 of the jaw latch 10.

Since the right side of the blade will be prevented from having further upward movement due to the engagement of these two latch surfaces, a torsional force will be exerted on the blade 63 due to the lever arm 123.

As heretofore noted, since the link and crank or toggle dil-52 are in the overcenter position indicated in Figures 5 and l2, the torsional force on the blade 63 will tend to drive the members ttl- 52 further overcenter. Since this motion will be transmitted through the rotating insulator 23 to the operating crank 3ft), this member will be solidly against the stop 36 as indicated in Figure 3. Thus, even though there is a force which tends to open or disengage the disconnect switch 16, the rigidity of the stop member 36, column 22 and members Sii- 52 will prevent upward or opening movement of the switch blade 63.

However, since there is engagement between the blade latch and the latch 127 on one side of the blade 63, the force tending to litt the blade out of the jaw contact will be resolved into torsion in the blade 63. Hence, the disconnect switch will be maintained in the closed position without reliance on the mechanical rigidity of the cantilever beam created by the blade 63. That is, the blade 63 will only be required to resist the torsional force caused by the engagement of the latch 116 and E29 and the mechanical rigidity of the operating means 36, 3i), 22, 4t), 52 will resist the opening force.

Thus, with the novel arrangement of the blade latch 32) and the, jaw latch 110 positioned on the right side of the blade 63, it is possible to transmit a torsional assetto force to the blade which is in the same direction as the motion of the blade about its own axis during the closing operation to thereby enable the operating parts to withstand the force tending to jar or open the switch without subjecting the switch blade d3 to a cantilever force.

lt will be noted that the invention has been described in connection with a switch which has clockwise rotation about its hinge and longitudinal axis during the closing operation. However', it will be apparent to those skilled in the art that my novel arrangement can be adapted to a switch having a countercloclcwise rotation about its airis during the closing operation. ln this case, the latch would merely be reversed to the left side so that it will be able to transmit a torsional force to the contact blade which is in the same direction as its motion during the closing operation. That is, the latch members 110 and are so placed that forces tending to lift the blade out of contact are resolved into torsional forces which impart motion to the blade which is in the same direction as the closing motion.

ln the foregoing, l have described my invention only in connection with preferred embodiments thereof. Many variations and modifications of the principles of my invention within the scope ol` the description herein are obvious. Accordingly, l prefer to be bound not by the specic disclosure herein but only by the appending claims.

l claim:

l. ln a disconnecting switch having a hinge end, a jaw end and a movable blade; said movable blade pivotally mounted at said hinge end and having an engaged and disengaged position with respect to said jaw end; said blade rotated about its hinge end and about its longitudinal airis when moved from said disengaged to said engaged position; latch means secured at the jaw end of said movable blade; said latch means being operatively positioned and constructed for resolving forces which tend to move said movable blade from said engaged position to said disengaged position into a torsional force which is in the same direction as the motion of said movable blade about its longitudinal axis when said movable blade is moved from said disengaged position to said engaged position; said latch means being comprised of a jaw latch and a blade latch; said jaw latch being mounted on jaw end of said disconnect switch; said blade latch being mounted on said movable blade of said disconnect switch; said jaw latch being spaced from said blade latch when said movable blade is in said engaged position.

2. In a disconnecting switch having a jaw end, a hinge end and a movable blade; said movable blade pivotally mounted at said hinge end; said movable blade having an engaged and disengaged position with respect to said jaw end; a blade latch secured to said switch blade at said jaw end; a jaw latch secured to said disconnecting switch at said jaw end; said switch blade having rotation about its axis when moved from said disengaged position to said engaged position; said jaw latch spaced from said blade latch when said switch blade is in said engaged position; said blade latch engaging said jaw latch when external forces tend to move said switch blade from said engaged position to said disengaged position; engagement of said jaw latch by said blade latch resolving said external forces into a torsional force on said switch blade to rotate said switch blade in a direction about its own axis to thereby maintain said disconnecting switch in closed position.

3. In a disconnecting switch having a jaw end, a hinge end and a movable blade; said movable blade pivotally mounted at said hinge end; said movable blade having an engaged and disengaged position with respect to said jaw end; a blade latch securec said switch blade at said jaw end; a jaw latch secured to said disconnect switch at said jaw end; said switch blade having rotation about its axis when moved from said disengaged position to said engaged position; said jaw latch spaced from said blade latch when said switch blade is in said engaged position;

-said blade latch engaging said jaw latch when external forces tend to move said switch blade from said engaged position to said disengaged position; engagement of said jaw latch by said blade latch resolving said external forces into a torsional force on said switch blade to rotate said switch blade in a tir-st direction about its own axis to thereby maintain said disconnecting switch in closed position.

4. Latch means for a disconnecting switch comprising a blade latch and a jaw latch; said disconnect switch having a blade pivotally mounted at one end for movement to and from yclosed and opened position, said blade latch being mounted on lsaid blade, said blade latch displaced from said jaw latch when said disconnect switch blade is in a normally closed position; said blade latch engaging said jaw -latch when external forces are created to open said disconnecting switch blade; said blade latch and said jaw latch being operatively positioned and lconstructed whereby engagement of said jaw latch by said blade latch is operative to resolve said external forces to maintain said disconnect switch blade in a closed position.

5. Latching means for a disconnecting switch comprising a blade latch and a jaw latch; said disconnect switch having an engaged and disengaged position; a blade having a hinge end and a free end; said blade pivotally mounted at the hinge end thereof; said blade moved from disengaged position to said engaged position by rotation of said blade about said hinge end and about the longitudinal axis thereof; said blade latch secured to the free end of said blade; said `blade latch spaced from said jaw latch when said blade is in engaged position; said blade latch engaging said jaw latch when external forces tend to move said blade from said engaged position to said disengaged position; said engagement of said jaw latch by said blade latch imparting a torsional force on said blade in the same direction as the motion of said blade about its axis when moved from said disengaged position to said engaged position.

6. Latching means for a disconnecting switch comprising a blade latch and a jaw latch; said disconnect switch having an engaged and disengaged position; a blade having a hinge end and a free end; said blade pivotally mounted at the hinge end thereof; said blade moved from disengaged position to said engaged position by rotation of said blade about said hinge end and about the longitudinal axis thereof; said blade latch secured to the free end of said blade; said blade latch spaced from said jaw latch when said blade is in engaged position; said blade latch engaging said jaw latch when external forces tend to move said blade from said engaged position to said disengaged position; said engagement of said jaw latch by said blade latch imparting rotation to said blade in the direction said blade is rotated when moved to said engaged position thereby forbidding motion of said blade from said engaged position to said disengaged position.

Scheuermeyer Nov. 21, 1950 Jamison Aug. 2, 1955

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