MXPA96004753A - Sliding trigger block - Google Patents

Abstract

The present invention relates to an automatic interlocking mechanism for aligning a removable element with a stationary enclosure, wherein the removable element can move in and out of the stationary enclosure between first, second and third positions, this automatic interlocking mechanism comprising: a guide bar fixedly attached to one of the stationary enclosure and the removable element. the guide bar extending substantially parallel to the direction of movement of the removable element in and out of the stationary enclosure, a sliding block slidably mounted on the guide bar, an element for locking the sliding block in place on the guide bar , to release the sliding block from its locked position when the removable element moves to the second position from the first position.

Description

SLIDING TRIGGER LOCK The present invention relates generally to automatic interlocking mechanisms, and more particularly, to an automatic secondary disconnection mechanism for a removable circuit device.

BACKGROUND OF THE INVENTION Circuit breakers for medium voltage switch gear applications, or circuit devices in general, typically are housed in a metal enclosure and are removable. The so-called "pull-out" apparatus is used to move the circuit breakers between a disconnected position, where the primary contacts of the circuit breaker are completely disengaged from the mating primary contacts inside the enclosure, and a connection position in the mains. where the primary contacts of the circuit breaker and the enclosure are fully coupled. A grid mechanism is normally employed to ensure the continuous movement and proper alignment of the circuit breaker as it moves between the disconnect and connect position. The circuit breakers are typically equipped with a variety of auxiliary electronic devices and related control circuitry, including switches, motors, solenoids and the like, to provide electronic control of the circuit breaker. For example, the automatic operation of the contacts of the circuit breaker can be achieved through the use of these auxiliary devices and control circuitry. Of course, power must be supplied to the auxiliary devices and to the control circuitry at some point. Typically, power is provided to the auxiliary devices and to the control circuitry through secondary coupling contacts mounted with the circuit breaker and the enclosure. At some point during the movement of the circuit breaker from the disconnected position to the connection position, the respective secondary contacts on the circuit breaker and the enclosure must be coupled in such a way as to provide power to the auxiliary devices and the electronic control. When removing the circuit breaker, the secondary contacts must be decoupled. Additionally, it is common to provide a test position between the switch-on and switch-off positions of the circuit breaker where the secondary contacts are coupled, but the primary contacts are not coupled. With the secondary contacts coupled, but the primary contacts decoupled, the auxiliary functions of the circuit breaker can be fully tested safely, while the switch is "dead". For example, automatic opening and closing of circuit breaker switches can be tested. In general it is desirable that the secondary contacts connect when the circuit breaker reaches the test position, and remain engaged when the circuit breaker continues to pass through the test position to the fully connected position. In the same way, when removing the circuit breaker, it is desirable for the secondary contacts to remain coupled as the circuit breaker moves from the ground connection position to the test position, but then decoupled as the Circuit breaker moves from the test position to the fully disconnected position. The mechanisms for connecting and disconnecting secondary contacts are generally referred to in the art as "secondary disconnections". Although some prior art switchgear gear devices provide a manual secondary cut-off mechanism, it is generally more desirable to provide an automatic secondary cut-off mechanism wherein the coupling and uncoupling of the secondary contacts are incident to the grid movement of the switch. circuit in and out of its enclosure. Netzel and Ericson and collaborators, Patents of the United States of North America Nos. 3,188,415 and 4,020,301, respectively, have both tried to satisfy the aforementioned objectives through the use of a secondary disconnection mechanism, wherein the secondary contacts comprise a pair of conductive strips fixedly mounted to the switch. circuit and the enclosure in a parallel relationship. As the circuit breaker moves to the test position, the respective contact strips begin to slide on top of each other. As the circuit breaker moves through the test position to the fully connected position, the respective contact strips continue to slide against each other, thus maintaining contact throughout the travel of the switch. circuit. When the circuit breaker moves out of the enclosure, the sliding contacts slide away from each other. Unfortunately, sliding contacts are subject to greater wear and require more frequent maintenance. Additionally, because the proper connection depends on the continuous coupling of the two contacts as they slide over each other, the sliding contacts are more likely to fail at some point during the movement of the circuit breaker. For these reasons, sliding contacts do not provide an acceptable solution.

Bould and olfe et al., Patents of the United States of North America Nos. 4,565,908 and 4,139,748, describe both mechanisms of secondary disconnection, wherein one of the halves or members of the secondary contact is fixedly connected to the circuit breaker, while the contact member Secondary coupling is slidably mounted on a guide pin attached to the switch gear housing. Each mechanism uses a spring to force the movable contact member against the fixed contact member on the circuit breaker. As the circuit breaker moves to the test position, the spring provides sufficient force in the opposite direction to allow the coupling contact members to engage. Once engaged, the contact members move together along the guide pin against the force of the spring as the circuit breaker continues to the fully connected position. When the circuit breaker is removed from the enclosure, the force provided by the spring keeps the connector halves together as the circuit breaker moves back out of the test position. When the circuit breaker passes continuously from the test position to the disconnection position, the movable contact member reaches the end of its travel along the guide pin and, consequently, the two contact members are disengaged. Although the use of a spring-loaded movable contact member can overcome some of the drawbacks of the sliding contact mechanisms described by Netzel and Ericson et al., The inventors have discovered that it is undesirable to force the movable contact member with a spring. Most notably, the use of a spring to force the movable secondary contact member makes it difficult to ensure proper alignment of the secondary contact members on the initial engagement in the test position. Additionally, the spring may prevent grid movement of the circuit breaker. Other secondary disconnection mechanisms are described in the United States Patents of North American Issues 4,743,715 - (Gerbert-Gaillard et al.), 4,761,521 (Bec et al.), 4,236,189 (Yosida) and 5,043,541 (Krafft et al.). However, each of these secondary disconnection mechanisms is too complex to be implemented efficiently or is not fully automatic. Accordingly, there was a need for an automatic secondary disconnection mechanism that was economical, that used few moving parts, and that overcomes the aforementioned limitations and deficiencies of known secondary disconnection mechanisms. Tempco et al., U.S. Patent No. 5,434,369, discloses a secondary disconnect mechanism that utilizes contacts slidably mounted within the switch gear enclosure. A sliding member moves along a guide bar that is fixed to the switch gear enclosure, and extends parallel to the grid movement of the circuit device. When the circuit device is disconnected, the sliding member is locked on the guide bar with spring-loaded arms engaging in the slots of the guide bar. As the circuit breaker moves from disconnection to the test position, the contacts of the circuit breaker engage with the contacts of the sliding member. Concurrently, a rigid tab member engages with the sliding member and forces the arms out of the slots, thereby releasing the lock. The friction between the contacts and between the tongue member and the arms, allows the sliding member to move back and forth along the guide bar with the circuit device. When the circuit device moves back to the test and disconnect positions, a stop device prevents the travel of the sliding block, overcomes the friction between the sliding block and the circuit device, and frees the circuit device from the secondary connection. Tempco and collaborators overcame many of the problems experienced by previous patents. However, if the sliding block were to be displaced from the locked position, the circuit breaker (by means of the rigid tongue) could still be coupled with the sliding member. Moreover, a misaligned circuit device could still free the sliding member of its locked poem. In such cases, the secondary contacts may not be coupled, but until the circuit device reaches the connection poem. Additionally, when the circuit breaker is moved from the connection position to the test position, only the friction provides the force to drag the regressing member to the locked position. This friction could be overcome at an undesirable point along the guide bar. Accordingly, there is a need for an improved automatic interlocking mechanism to be used as a secondary disconnection mechanism that ensures proper alignment of the secondary contacts, and which ensures coupling and uncoupling of the secondary contacts only at the appropriate places throughout from the guide bar.

SUMMARY OF THE INVENTION The present invention relates to an automatic interlocking mechanism for use in the alignment of a removable element, such as a circuit device with an enclosure, wherein the circuit device can be moved in and out of the enclosure between three different positions (later in the present, the disconnection, test and connection positions). In accordance with the present invention, the automatic interlocking mechanism comprises a guide bar mounted in the enclosure and positioned thereon, such that it extends substantially parallel to the direction of movement of the circuit device in and out of the enclosure. Although in the preferred embodiment the guide bar is mounted on the enclosure, the guide bar could be mounted on the removable element with all other elements of the invention adjusted in accordance with the same. The present invention further comprises a sliding block slidably mounted on the guide bar, and an element for locking the sliding block in place on the guide bar at a point corresponding to the test position of the circuit device. Elements are provided which cooperate with the locking element to release the sliding block from its locked position when the circuit device reaches the test position from the disengaged position, and to enable the sliding block to slide along the custom-made guide bar for the circuit device to move between the test and connection positions.

Furthermore, locking elements are provided which cause the sliding block to lock on the circuit device only when the sliding block and the circuit device are engaged in a position on the guide bar corresponding to the test position of the circuit device. If the sliding block is not in that position, the locking elements prevent the circuit device from engaging with the sliding block. One of a pair of coupling secondary contact members is coupled to the sliding block, while the other secondary contact member is coupled to the circuit device. The secondary coupling contact members are disposed one relative to the other, such that, when the sliding block is in its locked position on the guide bar, the secondary contact members will engage as the circuit device move from the disconnected position to the test position. In the preferred embodiment, wherein the guide bar is mounted on the enclosure, the other contact member is coupled with the circuit device. Preferably, the guide bar has a groove formed therein close to the point corresponding to the test position of the circuit device, and the locking element comprises at least one trigger pivotally mounted on the slidable block and adapted to pivot towards inside the slot, thus blocking the sliding block in the guide bar. An arm, rotatably mounted on the sliding block, is forced to push the trigger into the slot of the guide bar, and to prevent the trigger from pivoting. In this way, the slide bar will lock onto the guide bar until the arm is turned away from the trigger. One or more springs can be used to force the arm towards the trigger. According to the preferred embodiment, the release member of the sliding block preferably comprises a rigid coupling connector member coupled to the circuit device and adapted to engage with the arm and to rotate the arm away from the trigger when the circuit device reaches the test position from the disconnection position. Also in accordance with the preferred modality, the locking element comprises the rigid coupling connector having a slot therein, such that the trigger pivots inwardly of the slot and of the coupling connector when the release element causes the trigger to pivot outwardly from the groove of the guide bar. In accordance with another aspect of the present invention, when the circuit device is moved back to the test position from the connection position, and to the disengagement position, the slide bar is automatically released. The rigid coupling connector engages the trigger and draws the sliding member back along the guide bar. When the sliding member reaches the locking position, so that the trigger is aligned with the groove of the guide bar, the trigger pivots back into the groove of the guide bar and out of the groove of the connector coupling. As a result, the slide bar can not travel past the locked position, and the secondary contact members are automatically uncoupled. As explained more fully hereinafter, the secondary disconnect mechanism of the present invention makes it possible for the coupling secondary contact members to automatically engage when the circuit device is moved from the disconnected position to the test position, to remain coupled and move with the circuit device (by means of the sliding block) as the circuit device moves between the test position and the connection position, and which are automatically decoupled as the circuit device is moves through the test position back to the disconnected position. Although it is preferable to mount the guide bar and the sliding block in the enclosure while the coupling connector is fixedly attached to the circuit device, the opposite configuration can be employed wherein the guide bar and the sliding block are mounted on the device circuit, and the coupling connector is fixedly mounted on the enclosure. In addition, although the secondary disconnect mechanism of the present invention is particularly suitable for use with removable circuit breakers, the secondary disconnect mechanism of the present invention can be employed with any removable element where the positive alignment and positive alignment characteristics are desirable. lock These and other different advantages and features of novelty characterizing the invention are pointed out with particularity in the claims appended hereto and forming a part hereof. However, in order to have a better understanding of the invention, of its advantages, and of the objects obtained through its use, reference should be made to the drawings that form an additional part of the present, and to the accompanying descriptive matter, wherein illustrates and describes a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above summary, as well as the following detailed description of the preferred embodiment, is better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the invention, the drawings show a modality that is currently preferred, it being understood, however, that the invention is not limited to the methods and instrumentalities specifically described. In the drawings: Figure 1 is a sectional side view of an exemplary switching apparatus employing a secondary disconnect mechanism in accordance with the present invention. Figure 2 is an isometric side view in section of the preferred embodiment of the automatic interlocking mechanism in the position running from the disconnection position of the circuit device. Figure 2A is an isometric top view of the preferred embodiment of the automatic interlocking mechanism in the position corresponding to the disconnection position of the circuit device. Figure 2B is an isometric top view of the preferred embodiment of the automatic interlocking mechanism in the position corresponding to the test position of the circuit device. Figure 2C is an isometric top view of the preferred embodiment of the automatic interlocking mechanism in the position corresponding to the connection position of the circuit device.

Figures 3A, 3B, 4A, 4B are isometric views separated in section of the preferred embodiment of the automatic interlocking mechanism, as it moves from the disconnected position to the test position, illustrating the locking of the trigger to the coupling connector .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, in which like numerals indicate like elements throughout, Figure 1 illustrates an exemplary switching apparatus 8 employing a secondary disconnection mechanism 10 in accordance with an embodiment preferred of the present invention. As shown, the example switching apparatus 8 comprises an enclosure 12 and a removable circuit device 14, which in the present example, comprises a circuit breaker having first and second primary contacts 16a and 16b. The primary coupling contacts 18a and 18b are provided on a rear wall 26 of the enclosure 12. A grid mechanism 22 facilitates the movement of the circuit breaker 14 in and out of the enclosure 12 between the disconnect positions (D), of test (T) and connection (C), which are indicated in Figure 1 with reference to a front edge 21 of the circuit breaker 14. The arrows 23 indicate the direction of movement of the circuit breaker 14 in and out of enclosure 12. Circuit interrupter 14 further comprises a pole assembly 20, which contains a pair of switch switches (not shown), and a housing 26 containing auxiliary devices and control circuitry (not shown). As described hereinafter in more detail, power is supplied to the auxiliary devices and control circuitry through a pair of secondary coupling contact members 40 and 42, which form part of the automatic secondary disconnection mechanism 10. of the present invention. Figure 1 shows the circuit breaker 14 in the deenergized position (D), where both the primary contacts 16, 18, and the secondary contacts 40, 42 are decoupled. Although the secondary disconnect mechanism 10 of the present invention is illustrated in Figure 1 in relation to a removable circuit breaker, it is understood that the secondary disconnect mechanism of the present invention can be employed with any removable circuit device equipped with members. of secondary contact. Referring to Figure 2, a preferred embodiment of the automatic interlocking mechanism 10 of the present invention is shown. In accordance with the preferred modality, the automatic interlocking mechanism comprises a guide bar 30 mounted in the enclosure 12, such that it extends substantially parallel to the direction of movement 23 of the circuit breaker 20 in and out of the enclosure 12. In the switching apparatus of Example 8 of Figure 1, the guide bar 30 is mounted at the ends opposite an external wall 28 of the enclosure 12 using a pair of bases and associated mounting hardware 32a, 32b. A sliding block 34 is slidably mounted on the guide bar, and can operate to slide back and forth along the guide bar 30. In the preferred embodiment, the sliding block 34 is mounted to the guide bar 30. by means of an opening 60 extending lengthwise through the center of the sliding block 34. The automatic interlocking mechanism 10 further comprises an element for locking the sliding block in place on the guide rail at a point (T1) corresponding to the test position (T) of the circuit device 14. According to the preferred embodiment, the blocking element comprises at least one slot 31 formed on the guide bar 30, and at least one trigger 36 pivotally mounted on the sliding block 34 and adapted to pivot inwardly and engage with the groove of the guide bar 31, thereby blocking the sliding block 34 on the guide bar 30 at the point (T1) That, as will be apparent later herein, corresponds to the test position (T) of the circuit device 14. As described hereinafter in more detail, the trigger 36 pivots about an arrow 37 disposed in an upper portion. of the sliding block 34. The trigger 36 is forced and locked in the groove of the guide bar 31 by an arm 35 rotatably mounted on the upper part of the sliding block 34. Preferably a spring 50 is provided to force the arm 35 towards the trigger 36, such that the trigger 36 is forced into the groove of the guide bar 31 when the sliding block 34 is placed in T 'and the circuit device is in the disconnected position (D). The automatic interlocking mechanism 10 further comprises an element for releasing the sliding block 34 from its locked position T 'on the guide bar 30 when the circuit device 14 reaches the test position (T) from the disconnection position (D) , and to maintain its release to enable the sliding block 34 to slide freely along the guide bar '30 as the circuit device 14 moves between the test (T) and connection (C) positions ). In the preferred embodiment, wherein the locking element comprises a slot 31, a pivotally mounted trigger 36, and a rotatably mounted arm 35, the releasing element comprises a rigid coupling connector 44 having a slot 32 formed therein, and is fixedly attached to the circuit device 14, the coupling connector 44 is adapted to engage with the arm 35 and to rotate the arm 35 away from the trigger 36 when the circuit device 44 reaches the test position (T). As can be seen, once the arm 35 is rotated away from the trigger 36, the sliding block 34 is free to slide along the guide rail 30. The sliding of the sliding block 34 towards the position corresponding to the position of connecting the circuit device while the arm 35 is thus arranged, forces the trigger 36 to pivot outwardly from the guide slot 31. Simultaneously, the locking element operates to lock the sliding block 34 in the coupling connector 44 when the device of circuit 14 moves to the test position. As previously reported, when the arm 35 is rotated away from the trigger 36 by the coupling connector 44, the trigger 36 pivots out of the groove of the guide bar 31. The trigger 36 thus pivots upwards through the groove of the coupling connector 32, and locks the coupling connector 44 in the sliding block 34. As mentioned above, a pair of mating secondary contact members 40 and 42, through which power is supplied to the control circuitry over the circuit breaker 14, engage the slide member 34 and the circuit breaker 14, respectively. In accordance with the preferred embodiment, the secondary contact member 40 engages with the sliding block 34 using a right angle mounting bracket 38. The mounting bracket 38 can be fixedly attached to the sliding block 34 using any suitable hardware. Alternatively, the clamp 38 can be formed integrally with the sliding block 34. The other secondary coupling contact member 42 engages the circuit device 14 by means of the clamp 46. As explained hereinafter, the respective contact members 40, 42 are disposed one in relation to the other (by means of the respective mounting brackets 38, 46), such that, when the sliding block 34 is locked to the guide bar in the position T ', the contact members 40, 42 will be fully engaged by the time the circuit breaker 14 reaches the test position T. In this aspect, the locked position of the sliding block 34 at the point T' is said to be " corresponds to the test portion (T) of the circuit device 14. Preferably, the mounting hardware used to mount the contact member 42 to the clamp 46, prevents movement of the contact member 42 (in relation to the circuit device 14) in the direction of movement 23 of the circuit device 14, but allows some movement of the contact member 42 in directions perpendicular to the direction of movement of the circuit device 14. If the contact member 42 moves or "floats" perpendicular to the direction of movement of circuit device 14, any misalignment of coupling contact members 40, 42 is compensated as they begin to engage near the test position. In general, only a small degree of movement is needed to compensate for any misalignment. As described hereinafter, when the circuit device 14 moves from the disconnected position (D) to the test-position (T), the coupling connector 44 passes through an opening 39 in the clamp of assembly 38, and possibly engages with the arm 35. Preferably, the guide bar 30, the arm 35, the trigger 36, the coupling connector 44 and the clamps 38 and 46 are formed of metal. The slide bar 34 is preferably formed of a plastic material. Figures 2, 3A, 3B, 4A and 4B illustrate together the locking of the trigger 36 to the coupling connector 44. As illustrated in Figure 2, the automatic interlocking mechanism 10 is in the locked position when the coupling connector 44 is in the position corresponding to the disconnection position of the circuit device 14. As illustrated in Figure 3B, when the coupling connector 44 engages the arm 35, the trigger 36 is forced to impact the guide bar 30. As illustrated in Figure 3C, the trigger 36 thus begins to pivot toward the groove of the mating connector 32 and out of the groove of the guide bar 31. FIG. 4A illustrates the trigger 36 that continues upwardly through of the slot of the coupling connector 32, as the coupling connector 44 further engages and rotates the arm 35 away from the trigger 36. FIG. flange of the trigger 36 with the coupling connector 44. The trigger 36 now has pivoted completely out of the slot 31 of the guide bar, and the sealing block 34 has started to travel the guide bar 30. The uncoupling of the coupling connector 44 and the sliding block 34 is done by reversing the coupling sequence. In this decoupling sequence, the coupling connector 44 would drag the sliding block 34 to a point corresponding to the disconnection position of the circuit device 14. Because the trigger 36 remains interlocked with the coupling connector 44, the sliding block 34 will travel with the circuit device 14 as the coupling connector 44 pulls against the trigger 36. When the trigger 36 reaches the slot 31 of the guide bar, the force of the coupling connector 44 against the top of the trigger 36 , will counteract the pivoting of the trigger 36 back into the slot 31 of the guide bar and out of the slot 32 of the coupling connector. In this way, the coupling connector 44 will unlock from the sliding block 34 as the circuit device 14 continues to travel to the disengagement position, and the trigger 36 impacts on the groove 31 of the guide bar. When the coupling connector 44 of the sliding block 34 is engaged, the arm 35 rotates back towards the die-cutter 36, blocking the trigger 36 and, consequently, the sliding block 34, to the guide bar 30. Then, the trigger 36 will act as a block, blocking the sliding block 34 to the guide bar 30, as well as a stop, stopping the sliding block 34 so that it can not continue passing through the point corresponding to the test position of the circuit device 14. As will be appreciated, the interaction of the trigger 36 with the grooves 31, 32 of the guide bar and coupling connector prevents the coupling connector 44 and the sliding block 34 from engaging or disengaging, unless the die 36 is placed inside the slot 31 of the guide bar. To further demonstrate the invention, Figures 2A, 2B and 2C show the arrangement of the sliding block 34 in relation to the coupling connector 44 in the three different positions of the circuit device 14 (ie disconnection, testing and connection). Figure 2A shows a top view of the sliding block 34 in the initial locked position on the guide bar 30. The arm 35 is rotated on the trigger 36. In this position, the sliding block 34 is not free to traverse the guide bar 30. In Figure 2B, the coupling connector 44 has reached a point corresponding to the test position of the circuit device 14. As indicated in the drawing, the coupling connector 44 has been fully engaged with the sliding block 34, and the trigger 36 has been locked to the coupling connector 44. Figure 2C illustrates that the sliding block 34 can travel the guide bar 30 when the coupling connector 44 has locked to the sliding block 34, and has moved away from the slot 31 of the guide bar. The present invention can be incorporated into other specific forms without departing from the spirit or its essential attributes, and in accordance with the foregoing, reference should be made to the appended claim, rather than to the above specification, to indicate the scope of the invention. invention.

Claims (22)

1. An automatic interlocking mechanism for aligning a removable element with a stationary enclosure, wherein the removable element can move in and out of the stationary enclosure between first, second and third position, this automatic interlocking mechanism comprising: a fixedly attached guide bar one of the stationary enclosure and the removable element, the guide bar extending substantially parallel to the direction of movement of the removable element in and out of the stationary enclosure; a sliding block slidably mounted on the guide bar; an element for locking the sliding block in place on the guide bar, to release the sliding block from its locked position when the removable element moves to the second position from the first position, to enable the sliding block to move in relation to the guide bar when the removable element moves between the second and third positions, to lock the removable element to the sliding block when the removable element moves to the second position, and to prevent the removable element from engaging with the block Sliding at a point other than the second position.

2. An automatic interlocking mechanism as in claim 1, wherein the guide bar has a slot formed therein proximate a point corresponding to the second position of the removable element, and wherein the first element comprises: a pivotally trigger attached to the sliding block; and a second element for forcing the trigger into the groove of the guide bar when the removable element is in the first position and the sliding block is at the point corresponding to the second position of the removable element.

3. An automatic interlocking mechanism as in claim 2, wherein the second element comprises an arm rotatably mounted to the sliding block, which forces and locks the trigger into the groove of the guide bar, when the removable element is in place. the first position, to prevent the sliding block from moving relative to the guide bar.

4. An automatic interlocking mechanism as in claim 3, which further comprises a spring that forces the arm towards the trigger.

An automatic interlocking mechanism as in claim 3, wherein said element further comprises a coupling connector attached to the other of the stationary enclosure and the removable element, which engages and rotates with the arm away from the trigger, and makes it possible for the Trigger pivots out of the guide bar groove when the removable element reaches the second position from the first position.

6. An automatic interlocking mechanism as in claim 5, wherein the coupling connector has a groove formed therein that receives the trigger when the trigger pivots out of the groove of the guide bar and into the groove of the guide bar. coupling connector, when moving the removable element from the first position to the second position, thereby locking the removable element in the sliding block, and releasing the dieparator when the dieparator pivots out of the slot of the coupling connector and into the groove of the guide bar, when the removable element moves from the second position to the first position, unlocking in this way the removable element of the sliding block.

7. An automatic interlocking mechanism for aligning a removable element with a stationary enclosure, wherein the removable element can be moved in and out of the stationary enclosure between first, second and third positions, this automatic interlocking mechanism comprising: a guide bar fixedly attached to one of the stationary enclosure and the removable element, this guide bar extending substantially parallel to the direction of movement of the removable element in and out of the stationary enclosure; a sliding block slidably mounted on the guide bar, a first element for locking the sliding block in place on the guide bar at a point corresponding to the second position of the removable element, a second element cooperating with the first element to release the sliding block from its locked position, and to lock the coupling connector with the sliding block when the removable element moves the second position from the first position, to enable the sliding block to move relative to the bar of guide when the removable element moves between the second and third positions, and to prevent the removable element from engaging with the sliding block at a point other than the second position 8.

An automatic interlocking mechanism as in claim 7, wherein the guide bar has a groove formed therein close to the point corresponding to the second position of the removable element, and wherein the first element comprises; a trigger pivotally linked to the sliding blog; and an element for forcing the trigger into the groove of the guide bar when the removable element is in the first position.

An automatic interlocking mechanism as in claim 8, wherein the forcing element comprises an arm rotatably mounted on the sliding block, which forces the trigger into the slot of the guide bar when the removable element is in the first position, to prevent the sliding block from moving in relation to the guide bar.

10. An automatic interlocking mechanism as in claim 9, which further comprises a spring that forces the arm toward the trigger.

11. An automatic interlocking mechanism as in claim 9, wherein the second element comprises a coupling connector having a groove formed therein, which engages and rotates the arm away from the trigger, and forces the trigger against the groove. the guide bar, thus forcing the trigger to pivot out of the groove of the guide bar and into the groove of the coupling connector, to lock the removable element to the sliding block, to release the sliding block from the locked position, and to enable the sliding block to travel the guide bar when the removable element moves to the second position from the first position.

12. An automatic interlocking mechanism for aligning a removable element with a stationary enclosure, wherein the removable element can move in and out of the stationary enclosure between first, second and third positions, this automatic interlocking mechanism comprising: a guide bar fixedly attached to the stationary enclosure, this guide bar extending substantially parallel to the direction of movement of the removable element in and out of the stationary enclosure, this guide bar having at least one slot formed therein close to a point corresponding to the second position of the removable element; a sliding block slidably mounted on the guide bar; a rigid coupling connector coupled to the removable element, and adapted to engage with the sliding block, the coupling connector having at least one slot formed therein; at least one trigger pivotally mounted on the sliding block, and which can operate to pivot inwardly of the groove formed on the guide bar when the sliding block is positioned at the point corresponding to the second position of the removable element, and the connector the coupling is disengaged from the sliding block, the trigger being operable to pivot out of the groove formed on the guide bar and into the groove formed on the coupling connector, when the coupling connector is engaged in the sliding block, making it possible in this way for the sliding block to travel the guide bar; and an arm rotatably mounted on the sliding block, and which can operto force and lock the trigger in the groove formed on the guide bar, when the coupling connector disengages from the sliding block, and which can operto rotaway from the trigger when the coupling connector engages in the sliding block, thus making it possible for the trigger to pivot.

13. An automatic interlocking mechanism as in claim 12, which further comprises a spring that forces the arm toward the trigger.

14. An automatic interlocking mechanism for an electrical switching apparatus having an enclosure and a removable circuit device, wherein the circuit device can be moved in and out of the enclosure between the connection, test and connection positions, comprising this automatic interlocking mechanism: a guide bar mounted on the enclosure extending substantially parallel to the direction of movement of the circuit device in and out of the enclosure; a sliding block slidably mounted on the guide bar and adapted to slide back and forth along the guide bar; a blocking element disposed on the sliding block for locking the sliding block in place on the guide bar at a point corresponding to the test position of the circuit device; a releasing element disposed on the circuit device and adapted to cooperwith the blocking element to release the sliding block from its locked position, to lock the sliding block to the circuit device at the point corresponding to the test position of the circuit device , when the circuit device moves to the test position from the off position, and to enable the sliding block to slide along the guide bar as the circuit device moves between the positions of test and connection, and to prevent the circuit device from coupling with the sliding block at a point other than the point corresponding to the test position of the circuit device.

15. An automatic interlocking mechanism as described in claim 14, which further comprises a pair of mating secondary contact members, one of the secondary contact members engaging with the sliding block, the other engaging the secondary contact members. with the circuit device, the secondary contact members engaging one in relation to the other, such that, when the sliding block is in its locked position, the secondary contact members will be engaged as the circuit device move from the disconnected position to the test position.

16. An automatic interlocking mechanism as described in claim 14, wherein the guide bar has a groove formed in the member close to the point corresponding to the test position of the circuit device, and wherein the blocking member comprises: at least one trigger pivotally mounted on the sliding block, and adapted to pivot inwardly of the slot, thereby locking the sliding block in the guide bar at that point; and an element for forcing the trigger into the groove of the guide bar.

An automatic interlocking mechanism as in claim 16, wherein the forcing element comprises an arm rotatably mounted on the sliding block, which pushes the trigger into the groove of the guide bar when the removable element is in the position of test, and which locks the trigger in the groove of the guide bar, thus preventing the sliding block from moving relative to the guide bar.

18. An automatic inter-logger mechanism as described in claim 17, which also includes a spring that forces the arm towards the trigger.

19. A mechanism of automatic secondary disconnection, as described in claim 17, wherein the releasing element comprises a rigid coupling connector coupled to the circuit device, having a slot formed therein, and adapted to be coupled to the sliding block, forcing and turning the arm away from the trigger, and forcing the trigger against the groove of the guide bar, making it possible for the trigger to pivot out of the groove of the guide bar and into the groove of the connector coupling when the circuit device reaches the test position from the disconnected position.

20. An automatic interlocking mechanism for an electrical switching apparatus having an enclosure and a removable circuit breaker, wherein the circuit breaker can be moved in and out of the enclosure between the disconnect, test and connection positions, comprising this automatic secondary disconnection mechanism: a guide bar mounted on the enclosure and extending substantially parallel to the direction of movement of the circuit breaker in and out of the enclosure, this guide bar having at least one slot formed therein next to a point that corresponds to the test position of the circuit breaker; a sliding block slidably mounted on the guide bar and adapted to slide back and forth along the guide bar; at least one trigger pivotally mounted on the sliding block, and which may operate to pivot inwardly of the groove formed on the guide bar when the sliding block is positioned at the point corresponding to the test position of the circuit breaker, defining this point therefore a locked position of the sliding block; a rigid coupling connector coupled to the circuit breaker, having a groove formed therein, and adapted to engage with the trigger and to pivot the trigger out of the groove of the guide bar, and into the groove of the guide bar; coupling connector, when the circuit breaker reaches the test position from the disconnected position, thus making it possible for the sliding block to slide along the guide bar, and preventing the sliding block from engaging with the coupling connector at a point on the guide bar other than the point corresponding to the test position; and a pair of mating secondary contact members, one of these secondary contact members engaging with the sliding block, the other of the secondary contact members being coupled with the circuit breaker, the mating secondary contact members being arranged one on the other. relationship with the other, such that when the sliding block is in its locked position, the secondary contact members will engage as the circuit breaker moves from the off position to the test position.

21. An automatic interlocking mechanism as described in claim 20, which further comprises an arm rotatably mounted on the sliding block for forcing and locking the trigger in the groove of the guide bar when the sliding block is at the corresponding point to the locked position of the sliding block, and the coupling connector disengages from the sliding block.

22. An automatic interlocking mechanism as described in claim 21, further comprising a spring coupled with the arm and operable to force the arm towards the trigger.