US3735295A

US3735295A - Electric control devices with mechanical interlock

Info

Publication number: US3735295A
Application number: US00238839A
Authority: US
Inventors: K Grunert; J Conner; J Dauer
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1972-03-28
Filing date: 1972-03-28
Publication date: 1973-05-22
Anticipated expiration: 1990-05-22
Also published as: FR2178127A1; CA967202A; DE2314069C2; ES413063A1; BR7302231D0; CH566638A5; DE2314069A1; SE383437B; GB1380674A; AU5325673A; US3736538A; FR2178127B1; BE797366A; CA970802A

Abstract

An electric control system characterized by at least two control devices and interlock means therebetween, each control device comprising a stationary contact structure, a movable contact structure, and electromagnetic means associated with the movable contact structure for moving the movable contact structure between open and closed positions with respect to the stationary contact structure, the movable contact structure comprising a cross bar, the interlock means comprising a housing having a base, a cross beam, a pair of links, and a pair of actuators pivotally mounted within the housing, one actuator being disposed in the path of movement of the cross bar of one control device and the other actuator being disposed in the path of movement of the cross bar of the other control device, the upper ends of the link being pivotally attached to the cross beam at spaced locations from each other, and the lower ends of the links being pivotally mounted on the base at spaced distances greater than the space between the pivotal attachments of the upper ends of the links to the cross beam.

Description

United States Patent [191 Grunert et al.

[ May 22,1973

1 ELECTRIC CONTROL DEVICES WI'III MECHANICAL INTERLOCK Primary Examiner-Harold Broome Attorney- A. T. Stratton, Clement L. Mcl-lale & L. P. Johns [57] ABSTRACT An electric control system characterized by at least two control devices and interlock means therebetween, each control device comprising a stationary contact structure, a movable contact structure, and electromagnetic means associated with the movable contact structure for moving the movable contact structure between open and closed positions with respect to the stationary contact structure, the movable contact structure comprising a cross bar, the interlock means comprising a housing having a base, a cross beam, a pair of links, and a pair of actuators pivotally mounted within the housing, one actuator being disposed in the path of movement of the cross bar of one control device and the other actuator being disposed in the path of movement of the cross bar of the other control device, the upper ends of the link being pivotally attached to the cross beam at spaced locations from each other, and the lower ends of the links being pivotally mounted on the base at spaced distances greater than the space between the pivotal attachments of the upper ends of the links to the cross beam.

14 Claims, 18 Drawing Figures I62 7 I63 I80 cass- 167 Patented May 22, 1973 7 Sheets-Sheet 1 Fig.|

Patented May 22, 1973 '7 Sheets-Sheet 2 Eva? v w sx fi I, A a w Patented May 22, 1973 7 Sheets-Sheet 5 Pa tented May 22, 1973 7 Sheets-Sheet 4 Patented May 22, 1973 '7 Sheets-Sheet 5 Patented Ma 22, 1973 3,735,295

7 Sheets-Sheet 6 Fig.8.

Patented May 22, 1973 '7 Sheets-Sheet 7 ELECTRIC CONTROL DEVICES WITI-I MECHANICAL INTERLOCK CROSS-REFERENCE TO RELATED APPLICATION BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an electric control system having at least two circuit interrupters and an interlock therebetween.

2. Description of the Prior Art Interlocks are well known as control means between two or more circuit interrupters. The function of an interlock is to prevent both circuit interrupters from being actuated simultaneously. More particularly, a mechanical interlock limits the travel of two sets of electrical contacts to prevent the simultaneous closure of both contact sets and to prevent arcing of either or both sets.

A difficulty with most prior interlock mechanisms has been a failure to delay the closing of one set of contacts for a sufficient time after the opening of another contact set. Due to tolerances, minimum open gap, and over-travel requirements, most mechanical interlocks of the pivoted beam type have proven unsatisfactory because there is not a sufficient time interval between the opening of one set of contacts and the closing of another.

SUMMARY OF THE INVENTION It has been found in accordance with this invention that the foregoing problem may be overcome by providing an electric control system comprising at least two circuit interrupters and an interlock therebetween, each circuit interrupter comprising a stationary contact structure, a movable contact structure, and electromagnetic means for moving the movable contact'structure between opened and closed positions with respect to the stationary contact structure, the movable contact structure comprising a cross bar, the interlock comprising a housing including a base, linkage means including the base, a cross beam, a pair of links, and a pair of actuators. The upper ends of the links being pivotally attached to the cross beam at spaced locations from each other, the lower end of the links being pivotally mounted on the base at spaced locations greater than the pivotal mounting of the upper end of the links on the cross beam, an actuator above the end portion of each cross beam and movable between upper and lower positions, one of the actuators being disposed in the path of travel of the cross-bar of one of the circuit interrupters, the other actuator being disposed in the path of travel of the cross bar of the other circuit interrupter, and the actuators being pivotally mounted in place within the housing. The interlock also includes a second stationary contact structure and a second movable contact structure both of which are mounted on the housing proximate to at least one of the actuators, and the actuator being. provided with a cammingsurface operable to move the second movable contact structure between open and closed positions with respect to the second stationary contact structure.

The advantage of the device of this invention is that the various parts including the housing for the interlock and the actuators therefor may be fabricated as molded members with less care given to the tolerances between moving parts, because the actuators are pivotally mounted within the housing and are therefore movable with respect to their pivot points rather than with respect to the housing walls forming the openings in which the actuators are movably mounted, whereby binding between the actuators and the housing walls is substantially eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of an electric control device constructed in accordance with principles of this invention;

FIG. 2A is an exploded isometric view of the front part of the control device seen in FIG. 1;

FIG. 2B is an exploded isometric view of the back part of the control device seen in FIG. 1;

FIG. 3 is an isometric view of the arc-hood device seen in FIGS. 1 and 2A, with the device being turned over from the position in which it appears in FIGS. 1 and 2A;

FIG. 4 is a top plan view of the control device seen in FIG. 1;

FIG. 5 is a plan view with the arc-hood removed, of the control device of FIG. 4;

FIG. 6 is a bottom plan view of the front part (the part seen in FIG. 2A) of the control device of FIG. 1;

FIG. 7 is a sectional view taken generally along the line VH-VII of FIG. 4;

FIG. 8 is a sectional view taken generally along the line VIII-VIII of FIG. 7;

FIG. 9 is a side elevational view of an auxiliary contact device;

FIG. 10 is a left side elevational view of the auxiliary contact device seen in FIG. 9; 7

FIG. 11' is a sectional view taken generally along the line XII-XII of FIG. 10;

FIG. 12 is a sectional view taken generally along the line XH-XII of FIG. 8 of two identical control devices, of the type herein described, mounted in a substantially abutting side-by-side relationship with four auxiliary contact devices and a mechanical interlock shown in plan view in this figure;

FIG. 13 is an isometric view of the insulating contact carrier seen in FIGS. 2A and 7;

FIG. 14 is an isometric view of an interlock device constructed in accordance with the principles of this invention;

FIG. 15 is a vertical sectional view taken through the interlock shown in FIG. 14;

FIG. 16 is an end view, partly in section, of the device shown in FIG. 14; and

FIG. 17 is a vertical sectional view showing an electrical interlock associated with the mechanical interlock of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, there is shown in FIG. 1, an electric control device or contactor 5 comprising a metallic base plate 7 and a contactor structure 9. The contactor structure 9 comprises a back part 11 (FIG. 2B) and a front part 13 (FIG. 2A) which parts are connected together by means of two screws 15 (only one screw being shown in FIG. 2A). The contactor structure 9 is secured to the base plate 7 by means of two screws 17 (only one screw 17 being shown in FIG. 2B) which connect the back part 11 to the base plate 7 in a manner to be hereinafter specifically described.

As can be seen in FIG. 2B, the back part 11 of the contactor structure 9 comprises a back insulating housing part 19, a generally U-shaped magnetic core member 21, a coil structure 23, two generally Z-shaped supports 25 and two spring members 27 disposed over the supports 25.

As is best seen in FIGS. 2B, 7 and 8, the mounting plate 7 comprises a sheet metal plate member bent over at the four sides thereof to form four leg portions 29 that support the generally rectangular upper supporting plate part 31. The upper plate part 31 comprises a generally planar supporting surface having a hump 33 formed therein, which, as can be seen in FIGS. 7 and 8, is a generally convex surfact that serves to support the core member 21 in a manner to be hereinafter specifically described. A shock-absorbing resilient elastomeric or rubber member 35 is disposed on the plate 7 over the hump 33. A member 35 comprising a neoprene rubber member has been successfully tested in a control device of the type herein described.

The coil structure 23 comprises a conducting coil 37 (FIGS. 7 and 8) encapsulated in an insulating shell 39.

Two slab-type terminal conductors 41 (FIG. 2B) extend from the insulating shell 39 to enable connection of the coil 37 in an electric circuit. As can be seen in FIGS. 23, 7 and 8, the coil structure 23 has two openings therein which receive the two legs of the generally U-shaped magnetic core member 21. The magnetic core member 21 comprises a plurality of laminations forming two leg parts 43 (FIG. 8) that extend upward to provide two pole faces 45 having shading coils 46 supported therein. The core member 21 also comprises two extensions 47 (FIG. 8). During assembly of the contactor 5, the shock absorbing pad 35 (FIG. 2B) is first placed on the supporting part 31 of the plate 7 just over the hump 33. The magnetic core member 21 is then set down on top of the pad 35. Thereafter, the insulating housing part 19 is placed down over the core 21 with the core protruding through an opening in the housing part 19 and with two ledges 49 (FIG. 8) being disposed just over the extensions 47 of the core 21. The Z'shaped supports 27 are then placed in position and the screws 17 are passed up from the bottom of the plate 7 through suitable openings in the insulating housing part 19 and threaded into tapped openings in the lower legs of the supports 25 in the manner disclosed in FIG. 7. Thus, the screws 17 draw the supports 25 and insulating housing part 19 toward the plate 7. This movement, because of the engagement of the ledges 49 (FIG. 8) of the housing part 19 with the extensions 47 of the core member 21, pulls the magnetic core member 21 against the resilient pad 35 to thereby mount the core 21 on the hump portion 33 of the plate 7.

Referring to FIGS. 1, 2A, 7 and 8, the top or front part 13 of the contactor structure 9 comprises an upper housing part 53 of molded insulating material, a molded insulating contact carrier 55, a generally U- shaped magnetic armature 57 and an insulating archood device 59.

The generally U-shaped armature 57 has a separate pole face 58 (FIG. 7) at the outer end of each of the two leg portions thereof. As is best seen in FIGS. 2A

and 5, four pairs of conducting straps 61 are secured to the insulating housing top part 53 by means of screws 63. A separate terminal plate 65 (FIGS. 1 and 2A; not shown in FIGS. 4, 5 and 7 for the purpose of clarity) is connected to the outer end of each of the conducting straps 65 by means of a terminal screw 67. A stationary contact 60 (FIGS. 2A and 7) is brazed or otherwise suitably secured to the inner end of each of the conducting straps 61. A separate bridging contact member 71 is provided to bridge each pair of separated stationary contacts 69. As can be seen in FIG. 7, each of the bridging contact members 71 comprises a conductor 73 and two stationary contacts 75 secured to opposite ends of the conductor 73. As is best seen in FIG. 2A, the insulating contact carrier 55 has four window openings therein. Each of the bridging contact members 71 is supported on the contact carrier 55 in a separate window openings. In each of the openings a separate compression spring 77 biases a spring support 79 against the associated bridging contact member 71 to retain the member 71 in place and to provide for resilient contact engagement. As can be seen in FIG. 7, the insulating contact carrier 55 has an opening therein and a generally U-shaped laminated magnetic armature 57 is supported in the opening on the contact carrier 55 by means of a supporting pin 81 that passes through a suitable opening in the right portion of the U-shaped armature 57 and is supported on ledges on a surface of the insulating contact carrier 55. A generally resilient shock absorbing pad 82 is mounted between the armature 57 and contact carrier 55. During assembly of the upper or front part 13 of the contact structure 9, the insulating contact carrier 55 and the magnetic annature 57 are moved up through an opening from the bottom of the insulating housing part 53 and, thereafter, the bridging contact members 71 are mounted in position in the window openings 'of the contact carrier 55 to thereby secure the insulating contact carrier 55 and armature 57 along with the bridging contact members 71 in position on the upper housing part 53. As can be seen in FIG. 3, the arc-hood device is a molded insulating member having four are chambers 85 formed therein to extinguish the arcs drawn between the separating contacts of the four poles of the contactor 5. The insulating contact carrier 55 is provided with two upper extensions 87 that protrude through two openings 89 (FIG. 2A) in the arc-hood device 59 to provide alignment of the contact carrier 55. The arc-hood device 59 is secured to the upper part 53 of the insulating housing by means of two screws 89 (FIGS. 1 and 2A) that are screwed into tapped openings 91 (FIG. 2A) in the upper housing part 53. The front or upper part 13 (FIG. 2A) is secured to the back or lower part 1 1 (FIG. 2B) of the contactor structure 9 by means of two screws 15, only one of which is shown in FIGS. 2A and 7. Each of the two screws 15 is threaded into an upper tapped opening in a different one of the two supports 25. The two screws 15 connect the top part (FIG. 2A) with the bottom part (11 FIG. 2B) of the contactor structure 9. The two springs 27 engage the contact carrier 55 at 90 (FIG. 6) to bias the contact carrier 55, armature 57, and bridging contact members 71 to the upper unattracted position seen in FIG. 7. Tubular conducting socket members 91 (FIGS. 2A, 6 and 8) are suitably supported at opposite sides of the insulating housing part 53 to cooperate with the two stab members 41 (FIG. 2B). A separate terminal screw 93 (FIG. 2A) is connected to each of the tubular socket members 91 to enable connection of the tubular sockets 91 in an electric circuit. When the top part 13 (FIG. 2A) is connected to the bottom part 11 (FIG. 2B), the two conducting stabs 41 that are electrically connected to the energizing coil 37 (FIG. 7) are forced into the openings of the tubular conducting sockets 91 to connect the terminal 93 to the coil 37 whereby when conductors (not shown) are connected to the terminals 93 the coil 37 will be connected in the electric circuit of the conductors.

As can be seen in FIG. 5, the contactor that is herein disclosed is a four-pole contactor with four separate controlled conducting paths extending lengthwise through the contactor. The contactor is herein described as having a length and width; but it is to be clearly understood that the word length is not necessarily limited to a dimension that is longer or as long as the width of the contactor. As can be seen in FIG. 5, the conductors 61 are shaped to provide that the plurality of conducting paths converge from each of the two opposite ends thereof toward the center to thereby provide additional space at each of the two opposite sides of the plurality of conducting paths for the terminals 93. Additional openings 95 are provided in the housing part 53 to receive additional conducting sockets 91 and terminal screws 93 when a dual voltage coil is utilized in the contactor. As is seen in FIGS. 1 and 2A, each of the four conducting paths is separated and electrically insulated from the adjacent paths by means of insulating barriers that are molded integral with the housing part 53.

With the provision of the conducting paths converging from the terminals toward the bridging contact members, the terminals can be separated to provide adequate electrical clearance between adjacent terminals and adjacent wires that would be connected to the ter minals, and the contactor is still provided with four conducting paths across the top thereof along with room at each of the two opposite sides of the four conducting paths for the

coil terminals

91, 93.

Although the relay contactor that is herein described provides four normally open contact positions, it can be understood that the shape and form of these contacts can be changed in order to provide normally closed operation in a manner that is well known in the contactor art. It is also to be understood that the contactor can be constructed with more or less than four poles.

Referring to FIG. 7, the contactor 5 is shown therein with the contact carrier and armature biased to the upper unattracted position by means of the springs 27. When the contact carrier 55 is in this position, the four bridging contact members 71 are in the upper position separated from the stationary contacts 69 so that the four poles of the contactor are normally opened. Upon energization of the coil 37, the armature 57 is pulled, against the bias of the springs 27, into engagement with the generally U-shaped magnetic core member 21. This movement is limited by engagement of the two pole faces 58 of the generally U-shaped armature 57 with the adjacent two pole faces 45 of the generally U- shaped core member 21. During this movement, the springs 27 are compressed and charged and the four bridging contact members 71 are moved down into engagement' with the contacts 69 whereby each of the bridging contact members 71 closes a circuit between the associated stationary contacts 69. Each of the springs 77 is compressed slightly during the closing operation to provide contact pressure between the closed contacts. With the armature 57 in engagement with the magnet yoke 21, and with the contact carrier 55 in the lower position charging the springs 27, when the coil 37 is deenergized, the charged springs 27 will expand moving the insulating contact carrier 55 upward to the position seen in FIG. 7 to move the armature 57 and the four bridging contact members 71 upward to the unattracted position. This movement is limited by engagement of shoulder portions 96 (FIG. 7) on the insulating contact carrier with ledge portions 98 on the insulating housing part 53. The contactor can then be again operated in the same manner by energizafion of the coil 37.

During each closing operation of the contactor 5, the shock absorbing pads 35 and 82 reduce the shock of the impact between the armature 57 and core 21. The core 21, being disposed over the hump 33 of the mounting plate 7, can move universally to the limited extent in any direction to provide automatic alignment of the pole faces 45 of the core 21 with the pole faces 48 of the armature 57. This cushioning dampens shocks from armature impacts not only in its own contactor assembly but also in adjacent units to thereby reduce contact bounce and wear between the contacts and also between the pole faces of the magnet yoke and armature. The self-aligning feature comprising the core mounting means saves wear on the parts and it also contributes to provide for a quieter operation of the contactor. Moreover, with the provision of a metallic mounting plate 7 comprising a raised supporting part 31 and four feet 29, the raised supporting part 31 will flex slightly during each closing operation and some of the energy of the impact of the armature against the yoke will be absorbed due to internal strain energy in the mounting plate. Thus, the particular mounting arrangement of the yoke 21 serves to aid in reducing: contact bounce and contact wear, magnet yokearmature pole face wear, fatigue in the structural members, and the noise level of the operation of the contac- There is shown in FIGS. 9-11, three views of an electrical interlock or auxiliary contact device 101. The auxiliary contact device 101 comprises an insulating housing 103 having two upper conductors 105 supported therein and two lower conductors 107 supported therein. A separate stationary contact 109 (FIG. 11) is welded or otherwise secured to each of the conductors 105 and a separate stationary contact 111 is welded or otherwise suitably secured to the conductors 107. The conductors 105 extend out through openings at the side of the insulating housing 103 and a separate terminal screw 113 is supported at the outer end of each of these conductors to enable connection of the contacts 109 in an electric circuit. The conductors 107 extend out through the side of the insulating housing and a separate terminal screw 115 is provided at the outer end of each of these conductors to enable connection of the contacts 111 in an electric circuit. An insulating operating member and contact 117 is mounted for reciprocal rectilinear vertical movement in the insulating housing 103. The member 117 is provided with a widow opening therein and two bridging

contact members

119 and 121 are supported in the opening by means of a spring 123. The bridging member 119 comprises a conducting member 125 and two contacts 127 or otherwise secured to the opposite ends of the members 125. The bridging contact members 121 comprises a conductor 131 and two contacts 133 welded or otherwise secured to the opposite ends of the member 131. An operating spring 117 biases the member 117 and therefore the two

bridging contact members

119 and 121 to the upper position shown in FIG. 11. A lower resilient spring steel clip member 139 is secured to the housing 103 and an upper resilient spring steel clip member 141 is secured to the upper part of the housing 103. The auxiliary contact device 101 is operated by depression of the member 117 which movement charges the operating spring 137. This downward (FIG. 11) movement of the member 117 moves the upper bridging contact member 119 from the normally closed to an open position. This movement of the member 117 also moves the lower bridging contact member 121 from the normally open to a closed position. Upon release of the depressed operating member 117, the operating spring 137 will move the operating member 117 back up to the position seen in FIG. 11 wherein the upper bridging contact member 119 is in the upper normally closed position and the lower bridging contact member 121 is in the lower normally open position. It is to be understood that these contacts can also be mounted to provide two normally open sets or two normally closed sets of contacts in a manner well known in the art.

Referring to FIG. 1, it will be noted that the insulating housing part 19, the insulating cover 39 of the coil structure 23 and the insulating housing part 53 mate and cooperate, along with the insulating arc-hood device 59 to form the insulating housing structure of the contactor structure 9. The insulating

parts

19, 39 and 53 are formed to provide four cavities, one at each of the back four corners of the contactor structure. The cavities are identified as C C C and C The cavity C.,, which cannot be seen in FIG. 1, is seen in FIG. 12. Each of the four cavities is either identical or symmetrically identical to each of the three other of the four cavities. The insulating housing part 53 overhangs the four cavities C C C and C, at the four comers 0 0;, and 0 thereof (FIGS. 1 and 6) respectively. The four corners P P P and P (FIGS. 1, 2B and 12) of the mounting plate 7 serve as the four bases of the cavities C C C and C, respectively. The mounting plate, at each of the four comers thereof, is formed with a depression 147 stamped therein, and two openings 149 that are provided one at each of the two opposite edges of each corner. Referring to FIG. 12, there is shown therein, in section, one of the control devices and part of another of the control devices 5, which devices are mounted in a substantially abutting side-by-side relationship. As can be seen in FIG. 12, the contactor 5 (on the right) is provided with an electric interlock 101 in the cavity C an open cavity at C one-half of a mechanical interlock indicated generally at 153 in the cavity C and an open cavity C Two auxiliary contact devices 101 are disposed outside of the cavity C and dotand-dash lines are drawn into the cavity C in order to indicate that either of these electrical control devices could be mounted in the cavity C by means of a rectilinear movement into the mounted position. Thus, it is to be noted that an electrical interlock can be mounted in any of the four cavities of the contactor in either of the two positions indicated at the cavity C in FIG. 12. When one of the auxiliary contact devices 101 is moved into the mounted position in the associated cavity, the lower spring clip 139 (FIGS. 9-11) passes through the associated opening 149 and the clip is additionally spring charged when the end part thereof engages the lower depression 147 to provide frictional support. The upper spring 141 engages in an associated notch 155 (FIGS. 1 and 6) and is spring charged against the overhang in the notch 155 to provide spring pressure whereby the

springs

139, 141 of the auxiliary contact device maintain the contact device 101 in the mounted position in the cavity. Referring to FIG. 6, it will be noted that the insulating contact carrier 55 is provided with four corners A A A and A, molded as integral parts of the contact carrier. Each of the corners A A A and A serves as an actuating part moving in the associated cavity rectilinearly in a vertical (FIGS. 7 and 8) direction with the insulating contact carrier to thereby engage and actuate the operating member 117 of an auxiliary contact device if the auxiliary contact device is disposed in the cavity. The auxiliary contact 101 will be actuated by the associated actuating part of the contact carrier 55 in either of the two possible mounted positions (see C of FIG. 12). It will be noted that the operating member 117 of the auxiliary contact device is wide enough so that it will be-disposed in the inside corner portion of the cavity just under the actuating part of the contact carrier regardless of the direction of mounting (see C of FIG. 12) of the rectifier contact device in the cavity. With the auxiliary contact device in position, the terminals 113 and 115 (FIG. 9) are accessible for connection of the associated contacts in an electric circuit. As can be seen in FIG. 12, when the auxiliary contact device 101 is mounted in the cavity (the auxiliary contact device being shown fully mounted in the cavity C the contact device 101 does not extend past the length and width dimensions of the insulating

housing parts

19, 39, 53 (FIG. 1) and, since the base plate 7 serves as the base of the cavity and because the insulating member 53 overhangs the associated cavity space, it can be understood that the auxiliary contact device is disposed such that it will not take up additional space in a panelboard or control center. The auxiliary contact device 101 is readily removably mounted in position by merely being moved into the mounted position with the spring clips 139, 141 serving to retain the auxiliary contact device in position. If desired, additional attaching means such as screws could be used to secure the auxiliary contact device in position. It is to be noted that the operating member 117 of the auxiliary contact device is automatically operatively connected to the contact carrier of the container merely by means of the mounting operation.

For certain applications, it is desirable to prevent simultaneous operation of two control devices that may be mounted in a side-by-side relationship. The mechanical interlock 153 (FIG. 14) is provided for this purpose. As shown in FIGS. 14 and 15, the interlock 153 comprises an insulating housing structure 154, two actuators or operating

members

155 and 156, a cross beam 157, and a pair of links 158 and 159 (FIG. 15). The interlock 153 also includes a mounting bracket 160. Basically, the interlock 153 is a structure for transmitting vertical motions of the ends of the cross beam into vertical motions of the contactor actuating corners A and A The housing structure 154 is comprised of front and rear molded

portions

161 and 162 having a parting line 163. As shown in FIG. 15, the housing structure 154 includes a base 164 and provides a chamber in which the several parts 155-159 are disposed. The cross beam 157 is supported on the

links

158 and 159, the upper ends of which are pivotally mounted by

pivot pins

166 and 167, respectively, at spaced locations on the cross beam. The lower ends of the

links

158 and 159 are pivotally mounted at 168 and 169 at spaced locations in the base 164. For that purpose the lower ends of the links may be either provided with pivot pins (not shown), or, preferably, the base is provided with a pair of spaced tapered grooves 170 and 171 in which the lower ends of the links are pivotally disposed. A coil spring 172 is disposed between the cross beam 157 and the base wherein the lower end of the spring is seated in an opening 173, whereby the cross beam 157 is retained in the uppermost horizontal position as shown in FIG. 2 when in the unoperated position.

The

actuators

155 and 156 are disposed in spaced

openings

174 and 175 on the upper side of the housing 154. Each molded

portion

161 and 162 of the housing include an upright portion 176. A pivot pin 177 extends between the spaced upright portion 176 and each actuator 155 and 156 is separately mounted on the pin, whereby the pins are enabled to rotate slightly clockwise and counterclockwise in the direction of the arrows 178 and 179. Accordingly, if the actuator 155 is depressed by the corner A the cross bar 157 is moved to an inclined position and the right end rises against the actuator 156 and the corner A due to the linkage assembly of the

links

158, 159 and the cross beam 157. Conversely, when the actuator 156 is depressed by the corner A the right end of the cross beam, as viewed in FIG. 15, is depressed causing the left end to rise against the actuator 155 and to prevent the corner A 4 from being lowered simultaneously. When neither corner A or A is lowered, a coil spring 180 extending between the

actuators

155 and 156 holds the actuators in a neutral position as shown in FIG. 15.

The mounting bracket 160 includes a U-shaped member 181 and a base 182 which are secured together in a suitable manner such as a metallurgical bond at 183. The base 182 is provided with openings 184 for securing the interlock 183 in a suitable manner on a base plate (not shown). As shown more particularly in FIG. 16, the molded

portions

161 and 162 are mounted between the upright portion of the U-shaped member 181 which members are provided with similar vertical slots 185(FIG. 14) through which a clamping bolt 186 with a nut 187 are provided for securing the vertical placement of the interlock 153 in the bracket. In addition, an adjusting screw 188 is secured in a threaded opening (not shown) in an out-tumed flange portion 189 for adjusting the level of the interlock. In conjunction with the screw there is provided an outturned flange 190 at the top of the housing, the under surface of which bears against the screw head. A slot 191 is provided for the insertion of the blade of the screw-driver.

As shown in FIGS. 14 and 17 the interlock 153 may be provided with an integral electrical interlock generally indicated at 192. Electrical interlock 192 includes a stationary contact structure comprising a conductor bar 193 having a stationary contact 194 and a terminal including a terminal screw 195 to which a wire lead is attached. The electrical interlock 192 also includes a movable contact structure including an elongated conductor 196, the lower end of which is secured by suitable means such as a rivet to the housing and a conductor bar 197 which in turn leads to a terminal including a screw 198 by which a lead wire is attached thereto. In addition, the movable contact structure includes a movable contact 199 which is movable between open and closed positions with respect to the contact 194.

The upper end of the conductor 196 includes an intumed curved portion 200 for engaging an inclined camming surface 201 on the side of the actuator 156. The camming surface 201 is located at the lower end of a vertical recessed surface 202 of the actuator 156. Accordingly, when the actuator 156 is lowered, the curved surface 200 of the conductor 196 moves inwardly over the camming surface 201 to the recessed surface 202 and thereby disengages the

contacts

194 and 199. Conversely, when the actuator 156 is in the elevated position as shown in FIG. 14, the curved portion 200 of the conductor is below the cammin g surface 202 whereby the

contacts

194 and 199 are engaged. It is to be noted, however, that the electrical interlock 192 may be so constructed that the

contacts

194 and 199 are disengaged or engaged when the actuator 156 is in the position opposite those described above.

Referring to FIG. 12, it will be noted that when the two control devices 5 are mounted in a substantially abutting side-by-side relationship, the adjacent cavities C and C of the two devices provide a common pocket into which the mechanical interlock 153 can be disposed. The interlock 153 may be removably secured to the mounted position by means of spring clips 154 (similar to the clips 139 of FIGS. 9-1 1). As can be seen in FIG. 12, the mechanical interlock 153 is disposed within the confines of the associated pocket that comprises the adjacent cavities C C, so that the interlock does not take up additional panelboard space. It is to be understood that a mechanical interlock 153 could also be similarly mounted in the upper adjacent cavities C C It is noted in FIG. 12, that the two operating members 161 are disposed at the inside corners of the associated cavities C C so that each of the members 161 would be disposed under the associated actuating part & or A of the insulating contact carrier.

Accordingly, the interlock of the present invention satisfies disadvantages and problems inherent in prior known devices for interlocking two or more circuit interrupters, and provides for a satisfactory means for mounting separately movable actuators in the housing of an interlock, thereby eliminating the source of binding between the actuators and the walls of the housing.

What is claimed is:

1. An electric control system comprising at least two control devices and an interlock, each control device comprising a stationary contact structure, an electromagnet including a magnet armature, a magnetic core, and a coil, a movable structure movable as a unit and comprising a movable contact structure, the magnetic armature being movable relative to the core to move the movable contact structure between an operated position and an unoperated position to control an electric circuit, the interlock being between the control devices and comprising linkage means including a base, a cross beam and a pair of links, the cross beam being spaced above the base, the lower end of each link being pivotally mounted on the base at spaced locations from each other, the upper end of each link being pivotally mounted on the cross beam at locations spaced from each other, the links being unparallel to each other, an actuator above an end portion of each cross beam and movable between upper and lower positions, one of the actuators being disposed in the path of travel of the movable contact structure of one of the control devices, the other actuator being disposed in the path of travel of the movable contact structure of the other of the control devices, and the actuators being pivotally mounted in place.

2. The electric control system of claim 1 in which the spacing between the lower ends of the links is greater than the upper ends thereof.

3. The electric control system of claim 1 in which the longitudinal axes of the links converge upwardly.

4. The electric control system of claim 1 in which a housing including the base is provided for the cross beam and the links, and in which the housing includes an open upper side through which the actuators extend.

5. The electric control system of claim 4 in which the actuators are pivotally mounted on the housing.

6. The electric control system of claim 5 in which a second stationary contact structure is mounted on said housing proximate to at least one actuator, in which a second movable contact structure is mounted on the housing proximate to said second stationary contact structure, and in which the actuator is provided with a camming surface operable to move the second movable contact structure between open and closed positions with the second stationary contact structure.

7. The electric control system of claim 4 in which the interlock comprises a mounting bracket for adjustably mounting the housing in place between two control devices.

8. The electric control system of claim 4 in which spring means are provided for the actuators for biasing the actuators in retracted positions from the cross beam.

9. The electric control system of claim 4 in which biasing means are provided for holding the cross beam in a horizontal position.

10. The electric control system of claim 8 in which biasing means are provided for holding the cross beam in a horizontal position.

11. A mechanical interlock for use between two circuit interrupters of the electromagnetic type for preventing both interrupters from being closed simultaneously, the interlock comprising housing, a cross beam, a pair of links, and a pair of actuators, the lower ends of the links being pivotally mounted within the housing, the upper ends of the links being pivotally mounted on the cross beam at spaced locations from each other, the links being unparallel to each other, the actuators being pivotally mounted in the housing, each actuators being positioned above one corresponding end portion of the cross beam, and the housing having an upper side through which the actuators extend.

12. The mechanical interlock of claim 11 in which the housing includes a base on which the lower ends of the links are pivotally mounted at spaced locations from each other.

13. The mechanical interlock of claim 11 in which the links are pivotally mounted at spaced locations from each other by a distance greater than the spacing between the pivotal mountings of the links on the cross beam.

14. The mechanical interlock of claim 11 in which a second stationary contact structure is mounted on said housing proximate to at least one actuator, in which a second movable contact structure is mounted on the housing proximate to said second stationary contact structure, and in which the actuator is provided with a camming surface operable to move the second movable contact structure between open and closed positions with the second stationary contact structure.