MXPA97009824A - Contact arm with internal spring the li - Google Patents

Abstract

The present invention relates to a circuit protection switch contact arm (56) that contains an elongated weight slot (112) that travels generally longitudinally to the contact arm, and is closed at both longitudinal ends. Adjacent to each slot, a respective side wall (106, 108) of a transverse bar (58) contains a bending groove (114) having a ball joint (116). A respective cylindrical impact open pin (118) passes through three of these slots. A small helical spring (120) occupies the weight slot of the contact arm and is compressed between the impact opening pin and the end of the contact arm slot that is close to a crossbar / contact arm hinge pin ( 110). The spring is laterally confined by the adjacent side walls of the transverse bar so that it remains in the contact arm slot around which the contact arm rotates. The spring acts between the impact-open pin and the contact arm to deflect the impact-open pin away from the crossbar / contact arm hinge shaft. When the impact open pin is below the ball joints of the flexed slots and the contact arm is closed, completing an interruptible circuit through the circuit protection switch, the spring exerts the beneficial force for a better contact of the contact arm contact (64) with a fixing contact (52). Placing the spring in the groove of the contact arm, space is used more efficiently

Description

ARM "DJE_C OR N TOUCH WITH I NTERNAL SPRING IN LINE FIELD OF THE INVENTION This invention relates generally to electrical circuit protection devices. In a more specific aspect, it relates to a circuit protective switch in which an impact-open pin deflection spring is associated with an impact-open pin in a crossbar and a contact arm assembly that executes a rotary motion to interrupt a circuit to the occurrence of a circuit failure.

BACKGROUND AND BRIEF DESCRIPTION OF THE NONDION A design criterion for a circuit protective switch holds that the occurrence of a load failure which creates an unacceptable release of a large amount of current (for example, a short-circuit current) through the closed contacts of a switch circuit protector, the mechanism of the circuit protector switch should open the contacts in a way that terminates the current flow quickly. It is known that certain circuit protective switches employ one or more pivotally mounted contact arms utilizing an electromagnetic or impact opening force to impact open the contact arm or arms to the occurrence of such sudden load failure. Although the impact opening force quickly initiates the movement of the contact arm to initiate the disconnection of the circuit protection switch, the current may continue to form an arc through the contacts as the contact arm rotates open. Accordingly, the design principles of the circuit breaker include minimizing (and ideally) such arcing as the disconnection continues. In addition, once the current flow has been terminated, any opportunity for its restoration must be excluded as the disconnection ends. Upon achieving the rapid arrest of the current arc formation through the impact-open contacts, it may be desirable for the circuit-breaker mechanism to increase the impact opening force as the disconnection continues until termination. But in doing so, increasing the force mechanism acting on the rotating arm or contact arms should not induce a rejection of the contact arms out of a stop to a degree that could potentially restore the current flow.

Consider, for example, a circuit protection switch that uses a lever mechanism on the spring loaded center that moves over the center during disconnection. As the mechanism advances over the center, an operating spring that has been effectively applied to the contact arm, a resistance to the force but does not prevent it, the disconnection, now suddenly applies its force to assist the disconnection, triggering the or the contact arms against the stop. This added force must not cause the contact arm to reject excessively from the stop. The design of the circuit protection switch must therefore take into account several factors that can create conflict. A better circuit protector switch design will take into account such factors as to provide a protective circuit breaker that will terminate a specific fault current within a specific response time, with greater assurance that the current will not be restored once the circuit protector switch has been disconnected. In addition, a successful circuit protector circuit breaker design must be efficient in terms of cost and space. It is towards these and other objectives that the present invention is directed.

A circuit protective switch comprises a transverse bar and one or more contact arms that are joined by a cylindrical hinge pin to form an assembly that is mounted within the housing of the circuit protection switch. This hinge pin allows assembly movement around the hinge axis, accompanied because it allows limited relative movement between each contact arm and the crossbar. When a fault occurs, an impact opening force acting on the contact arm allows the contact arm to begin to rotate slightly before the crossbar begins to move. This feature is intended to promote the quickest response to a fault since the inertia of the crossbar has not been overcome to initiate contact separation. The crossbar contains separate walls that provide a space to receive a corresponding contact arm between them. These walls contain bending grooves, generally transverse to the length of the corresponding contact arm and the corresponding contact arm contains a generally straight groove which generally travels along the contact arm and generally transverse to the rotational movement of the contact arm. A cylindrical impact opening pin passes through the walls of the groove and the groove of the contact arm so that the movement of the contact arm relative to the transverse bar causes the pin through the contact opening to move inside. of the respective slots. If there are plural contact arms mounted in a similarly pivotal manner on a common transverse bar, each has a generally straight slot and the immediately adjacent side walls of the transverse bar contain bending grooves. An impact opening pin passes through each contact arm slot and the bending grooves in the immediately adjacent side walls of the crossbar. In other arrangements, the impact opening pin has been spring loaded by one or more small springs that are positioned between the cross bar and the impact opening pin to deflect the impact opening pin away from the hinge axis of the assembly. crossbar / contact arm. Once the impact-open pin has moved in a direction from a first segment of the bending grooves, it passes the ball joints of the bending grooves, and into a second segment of the bending grooves during the impact opening, such springs urge the impact opening pin to remain in the second segment of the flexure grooves. During the initial rejection of the contact arm from a stop, an impact opening pin travels in the opposite direction through the ball joints of the flexure grooves after which the springs actuate the impact opening pin to remain in place. the first segments of the bending grooves. Such springs have previously been placed outwardly of the side walls of the transverse bar containing the bending grooves. The present invention relates to a construction that provides a more efficient use of the space for locating a spring that deflects an impact opening pin. Each contact arm comprises a vertical elongated passage groove which generally travels longitudinally to the contact arm and is closed at both longitudinal ends. Each adjacent groove of each side wall respective to the crossbar contains a bending groove having a ball joint. A respective cylindrical impact opening pin passes through these three slots. A coiled small helical spring occupies each contact arm groove and is compressed between the impact opening pin and the end of the contact arm groove that is close to the contact bar / contact arm hinge axis. Each spring is laterally confined by the adjacent side walls of the transverse bar to remain in that position in the respective contact arm slot. Therefore, each spring acts between the impact opening pin and the respective contact arm to deflect the impact contact pin in a direction away from the transverse bar hinge axis / contact arm. It is considered that this construction eliminates the need for space between adjacent pairs of sidewalls of the transverse bar to accommodate the springs that deflect the impact opening pin. Therefore, an aspect of the present invention relates to a circuit protective switch comprising a contact arm having a pivot shaft, a pivotally mounted mounting of the contact arm about its pivot axis for rotary movement for the protective switch circuit, separate side walls which are proximal side sides of the contact arm and with respect to which the contact arm can rotate, a passage opening in the contact arm defining a groove whose length is generally transverse to the rotational movement of the arm of contact, a pin that passes through the groove of the contact arm but is constrained by the slot for movement along the length of the grooves, the separate lateral walls comprising the grooves receiving portions of the pin and restricting the pin to move longitudinally to the sidewall slots, a spring placed in the slot contact arm and laterally confined by the side walls separated to exert a force on the pin that drives the pin along the length of the contact arm slot and where the relative movement of the contact arm and the side walls cause that the pin moves longitudinally of the groove of the contact arm and longitudinally of the side wall grooves, changing the spring force exerted by the spring on the pin. Another aspect of the present invention relates to a circuit protective switch comprising a contact arm having a pivot shaft, a pivotally mounted mounting to the contact arm about its pivot axis for rotary movement to interrupt a circuit, the contact arm having a through opening whose length is generally transverse to the rotational movement of the contact arm, a pin passing through the opening of the contact passage although restricted by the through opening to move along the length of the passage opening, a slotted track placed under the contact arm and engaging the pin to restrict the pin from moving longitudinally of the slotted track, a spring contained in the passage opening of the contact arm to exert a force on the pin by actuating the pin along the length of the contact arm slot and where the movement relati The contact arm and groove track cause the pin to move longitudinally of the groove of the contact arm and longitudinally to the grooved track, changing the spring force exerted by the spring on the pin. Even another aspect of the present invention relates to an elongated contact arm having longitudinally opposite end portions between which is an intermediate portion, a longitudinal end portion comprising a pivot shaft for mounting the contact arm for rotary movement about of a pivot axis, the other longitudinal end comprising a contact, and the intermediate portion comprising an elongated passage slot having a length in the same direction as the length of the contact arm. The foregoing, just with features, advantages and additional benefits of the invention, will be observed in the following description and claims, which are accompanied by drawings. The description and the drawings describe a currently preferred embodiment of the invention in accordance with the best mode contemplated at this time to carry out the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a bottom plan view of a circuit protection switch that modalizes the principles of the invention. Figure 2 is a cross-sectional view in the direction of the arrows 2-2 in Figure 1 and illustrates a disconnect condition of the circuit-breaker switch. Figure 3 is a view of a portion of two load terminal assemblies and a separate transverse bar of the circuit protection switch. Figure 4 is a top plan view of a load terminal assembly itself on a larger scale than that of Figure 3. Figure 5 is an elevation view of the load terminal assembly in the direction of the arrows 5-5 in Figure 4. Figure 5A is a fragmentary view in the direction of arrow 5A in Figure 5. Figure 6 is a perspective view of an operating mechanism assembly of the circuit protective switch separated from the switch circuit protector.

Figure 7 is a side elevational view of the operating mechanism assembly of Figure 6. Figure 8 is a top plan view of the operating mechanism assembly of Figure 7. Figure 9 is a view generally taken in direction of arrows 9-9 in Figure 8. Figure 10 is a cross-sectional view in the direction of arrows 10-10 in Figure 8. Figure 1 1 is an enlarged view looking at the left portion of Figure 2, although the circuit protective switch is in an ignition position and with certain portions of the operating mechanism separated to reveal a relative operating association of the operating mechanism assembly, a contact arm and a bolt. Figure 1 2 is a view similar to Figure 1 1, although it includes some of the portions that are separated in Figure 11. Figure 13 is a view similar to Figure 11, although it represents the movement of the contact arm during discharge. Figure 14 is a view in the same direction as the views of Figures 11-1 3, omitting certain portions of the operating mechanism assembly for illustrative convenience, although it includes a disconnect mechanism.

Figures 15-18 are perspective views, on the upper floor, in the upper lateral elevation and in the respective right lateral elevation of the component of the disconnection mechanism, separated from the disconnection mechanism. Figures 19-21 are views in front elevation, in left lateral elevation and in the respective lower floor of another component of the disconnection mechanism, separated from the disconnection mechanism. Figures 22-24 are top plan views, in left lateral elevation and in the respective lower floor of yet another component of the disconnection mechanism, separated from the disconnection mechanism. Figures 25 and 26 are respective right and left side views of another component of the circuit protective switch shown by itself on an enlarged scale, spaced apart from the circuit breaker. Figure 27 is a perspective view of the upper part showing the inside of the circuit protective switch with the cover and certain internal parts removed for purposes of illustration.

DESCRIPTION OF THE MODALI DAD PREFERI DA Figures 1 -10 show the arrangement and arrangement of an illustrative circuit protector switch 40 including the principles of the present invention. In the following description, position and direction references will be made in relation to the orientations of the Figures, and such references should not necessarily be considered as implying that they are absolute references. For example, the references above and below are not necessarily considered to mean a vertical sense. The circuit protective switch 40 comprises a base 42 and a cover 44 which are assembled together to form a housing that encloses the internal components insofar as it provides the external connection of the electric current conductors and for the manual operation of the circuit protective switch to the on and off positions. Manual operation is achieved by a handle 46 shown in Figure 2, in the disconnected position. The position of the handle shown counterclockwise in shaded form is the off position, and the position shown in the clockwise direction in shaded form is the on position. As shown in Figure 27, the connections 220, 221 provide for the connection of the circuit protection switch to a voltage source having phases A and B, when the circuit protection switch is installed for use. First and second bands 48 and 50 are disposed at the bottom of the base 42 to provide connection to the load. The strips 48 and 50 extend into the interior of the housing where a first fixed contact 52 (see Figures 1 1 -1 3 as well) is placed on the band 50. A second fixed contact 52 is placed on a part of the conductor that is in contact on the piece 220. The pair of separate fixed contacts 52 are positioned for cooperation with movable contacts 54 which are mounted on the ends of the respective contact arms 56. Figure 3 shows the two contact arms in association with a bar transverse 58. Each contact arm forms a portion of a load terminal assembly 60, a first of which is shown by itself in Figures 4 and 5. In addition to its contact arm 56, a load terminal assembly 60 comprises a belt 62, a bimetal strip 64 and a loading terminal 66. Both charging terminals 66 are fixedly mounted on the lower part of the base 44. The loading terminal of the assembly shown in Figures 4 and 5 it is in conductive contact with the band 48. The charging terminal 66 of the second charging terminal assembly, which can be seen in Figure 2, has a shape different from that of the loading terminal of the first assembly. of cargo terminal. This second load terminal extends in the clockwise direction of Figure 2 and then, as shown in Figure 27, continues at a right angle to make a conductive contact with the connection 221. A load terminal assembly 60 therefore provides a current path for its contact 54, through its contact arm 56, through its belt 62, through the bimetal element 64 and through the loading terminal 66. When each contact 54 is closed against the respective fixed contact 52, a respective current path is completed through the respective load terminal assembly between one of the bands 48 and 50 and a respective one of the line connections 220 and 221 . Therefore, the illustrated protective circuit breaker mode provides, by way of example, two interruptible current paths and it is appreciated that the principles of the invention can be incorporated in both single pole and multi pole circuit protective circuit breakers. . Figures 6-10 show in detail an assembly of the operating mechanism 68. The assembly 68 comprises: side frames 70, 72 on opposite sides of the assembly; an upper lever 74; a handle arm 76; a support 78; a bra 80; and a spacer bar 82. The handle arm 76 generally comprises L-shaped sides, immediately inward of the respective side frames 70, 72, the L-shaped side, immediately inward of the side frame 70, is easily visible in Figure 9. The free end of each "L" projects upwardly in Figure 9 to provide the handle 46 to be attached to the handle arm 76. The other end of each "L" forms a side of a yoke that is completed by a bridge 83 of the handle arm extending perpendicularly between the L-shaped sides and containing a central flexing tongue 84, having a central notch 86. The upper lever 74 is fitted between the sides in the shape of L of the handle arm 76 and comprises sides immediately inward thereof. The opposite ends of each of the upper lever sides contain respective forks 88, 90. A bridge 92, next to the forks 88, joins the two sides of the upper lever. A portion of the support 78, wedged between the sides of the upper lever 74, comprising sides immediately inward thereof. The sides of the support are joined by a bridge 94 which is positioned behind the upper lever 74 and the handle arm 76, as shown in Figures 9 and 10. One side of the support that is close to the side frame 72 has a different form of the other support side, and that form is adapted for cooperation with a fastener 80 in a manner that will be explained subsequently. The side frames 70, 72 contain large openings, from a lower edge of which the brackets 95 project. The pivot pins 97 at the free ends of these brackets provide for the pivotal mounting of the bracket 78 around an example. 96. Integrally provided between the side frames 70, 72 and the handle arm 76, are the pivots 99 which provide pivotal mounting of the handle arm 76 about an axis 98. I ntegralmente provided between the support 78 and the lever upper 74 are the pivots 1 01 which are engaged by the forks 90 of the upper lever 74 to provide a pivotal connection between the upper leg 74 and the support 78 around an axis 1 00. The side frames also contain aligned pivot receptacles 102 for pivotal mounting of a disconnect bar, described below about an axis 1 04. The spacer bar 82 attaches to the frame members, serving as a structural member by keeping the sides of the frame in fixed relation. Figure 2 shows the operating mechanism assembly 68 supported on the bottom of the base 42 by the side frames 70, 72 (although only 70 can be seen), and in the process, which captures the cross bar 58 on the bottom of the base by means of the notches 105 which are formed in relation to the portions of the transverse bar to IX which are coupled, to allow limited pivoting of the crossbar on the base 42. Figure 3 shows the crossbar comprising two pairs of mutually parallel walls 106, 108 that are parallel to the side frames. Between each pair of walls 106, 108 there is a slot providing the space for receiving a portion of the respective contact arm 56. The position illustrated by Figure 3 is that of the contacts 54 making contact with the contacts 52, although the latter does not is shown in that Figure. Each contact arm 56 comprises a hole 59 (Figure 5), which provides pivotal mounting of the contact arm on the transverse bar. A respective hinge or pivot pin 1 10 (Figures 3 and 11-13) passes through each of the contact arm holes and through the aligned holes in the cross bar on each side of the contact arm. Each contact arm further comprises an elongated vertical groove 1 12 which is generally longitudinally displaced from the contact arm, therefore, generally transverse to the direction of the rotating contact arm, and is closed at both ends. Adjacent to each slot 1 12, each wall 106, 108 contains a corresponding slot 114 (FIG. 12) having a ball joint 1 16. The slots 114 are generally transverse to the length of the contact arm. Each slot 114 has a segment on the vertical patella 116 and a segment under the vertical patella 116 as seen in Figure 12, which forms a track. The segments above and below the ball joint of each of the grooves 114 form an obtuse angle facing towards the longitudinal end of the contact arm containing the contact 54. A respective cylindrical impact open pin 118 passes through the slot 112 and two bending tabs 114 to each side. The two pins 118 prevent contact with each other by an integral formation in the crossbar 58. Figure 12 shows the relative positions of the pins 118 and the slots 112, 114, when the contacts 54 are making contact with the contacts 52. Additionally, a small helical compression spring 120 occupies each slot 112 and is compressed between the pin 118 and the end of the slot 112 that is close to the contact arm pivot hole 59. Each spring 120 is laterally confined by the walls 106. 108 so that they remain in the position described in the respective slot 112. A lower lever 122 (Figures 11-13) acts between the upper lever 74 and the crossbar 58. The lower lever 122 comprises sides each having pivot connections 124, 126 at opposite ends. The respective pins 125 project outwards a short distance from each wall 106, 108 of each pair of walls 106, 108. The connections 124 engage the pins 125, while the connections 126, engage a spring pin 128. detail of the spring pin 128 appears in Figures 25 and 26, which show it comprising: a cylindrical body 128a, which is circular, although for a central slot 128b; and circular cylindrical ends 128c of smaller diameter than the body 128a. The spring pin 128 operatively couples the forks 88 of the upper lever 74 and the connections 126 of the lower lever 122 create a lever mechanism. An operative spring 130 shown schematically in Figure 12 extends between the tab 84 of the lever arm 76 and the spring pin 128 to form the lever mechanism, like a lever mechanism on the spring loaded center. A spring end 130 is engaged around the slot 128b while the opposite end is engaged over the end of the tab 84 by means of the notch 86. In the position of the circuit-breaker 40, the spring 130 is toward a side on the center, where its force drives the lever mechanism to force the cross bar 58 counterclockwise as seen in Figures 11 and 12. The cross bar 58 in turn operates by means of each impact-open pin 118 for forcing the contacts 54 against the contacts 52. This force is considered desirable for promoting better conductive contact between the closed contacts 52, 54. Crossbar 58 continues to rotate around pivot point 110 after contacts 52 and 54 meet to provide adequate contact when contacts begin to be used. When the circuit protective switch 40 is being disconnected due to the short circuit fault, the initial movement of the contact arms 56 away from their respective contacts 52 due to the impact opening forces, results in a pin opened by impact. 1 18 that moves up into the segment below the ball joint of the slots 114 below the ball joint 1 16. Before a pin opened by impact reaches ball 1 16, the movement of the contact arm is slightly resisted but not prevented by increasing the compression of the respective spring 120. Although once the pin passes over the ball joint into the segments on the ball joint of slot 1 14, the spring will help, instead of opposing, the opening movement of the arm contact. The circuit protective switch 40 further comprises a disconnect mechanism which, as will be described in detail below, operates, as an impact opening pin 118 that moves within the slot 114, to release the operating mechanism assembly 68. from the condition locked in this way the disconnection condition is allowed to operate. After a pin 1 18 has crossed over the patella 1 16 in the second segment of slots 1 14, the respective rotatable contact arm 56 impacts the spring pin 128 to either side of the slot 128b which forces the spring pin to Start the movement with the rotating contact arms. The cross bar 58 is therefore forced to pivot with the contact arms and the spring pin. The result is that the lever mechanism begins to collapse, although against the spring resistance 1 30 until the lever mechanism goes over the center. Once the lever mechanism goes over the center, the spring 1 30 helps instead of opposing the opening movement of the contact arm. The opening movement of the contact arm 56 is stopped by the splice with internal stops 129 (shown in Figure 2) in the cover 44. The mechanism limits the rejection of the contact arm from the stops 129 so that the contact arms they do not rotate back towards a point that would otherwise cause the spring loaded lever mechanism to return over the center and actuate the contact arms in a new closure of their contacts 54 with the fixed contacts 52. The reject energy is partially absorbed because the cross bar 58 continues 2 .. pivoting momentarily in the clockwise direction as the contact arms are bouncing in the counterclockwise direction. Relative opposition movements cause the impact opening pins 18 to move downwardly within the segment on the ball joints of the slots 114 and backwardly within the ball joints 1 16, the springs 120 comprising until they go over the ball joints. When the impact opening pin 118 enters the segment below the ball joint of the slot 1 14 below the ball joint 1 1 6, the respective spring 120 begins to expand and to supply force in a direction that drives the respective contact arm further completely within the space between the respective pair of side walls 106, 108 in the cross bar 58. It is seen in Figures 3-5 and 1 3 that the upper edge surface of each contact arm 56 is formed with two surface portions of edge 56a, 56b at an obtuse angle to form a V-shaped notch. Figure 13 shows, by way of example, a V-shaped notch contacting the body 128a of the spring pin 128 in two different locations, one being in the edge surface portion 56a and the other is in the edge surface portion 56b. In this form, Figure 13 in effect shows the spring pin 128 seated in a V-shaped notch, once its contact arm has been driven to engage the spring pin. As a result of the interaction of the V-shaped notches with the circular cylindrical exterior of the spring pin, the force applied by each contact arm open by rotation towards the spring pin occurs along an arc whose shape is defined to the geometric shape of the V-shaped notches in conjunction with the geometry of the pivot axes involved. The edge surface portions 56a, 56b are angled so that the main component of the contact arm force is directed in a direction that completes or at least approximately maximizes the force effect of the contact arm which is rotating in collapse with the lever mechanism. Although the support 78 is pivoted about the axis 96 and the upper lever 74 about the axis 100, the arc of displacement of the axis of the spring pin is a compound arc, instead of a strictly circular one. As the contact arms actuate the spring pin, the direction and / or magnitude of the main component of the contact arm force applied by the V-shaped notches can vary to a lesser degree due to the geometry of the various axes pivot that are involved, although the inclusion of the V-shaped notches and their geometry provide an important contribution to maximizing the effectiveness of the impact separation force of the contact arms at the termination of the disconnection. An additional benefit is that the subsequent excessive contact arm rejection is avoided due to the reject geometry which promotes a more efficient absorption of the reject energy by the operation spring 1 30. This aspect of the circuit protection switch 40 is the subject matter of the commonly assigned patent application, pending CI RCUIT BR EAKER WITH IMPROVED TRI PM ECHAN I SM Serial No. (case of attorney-in-fact No. 96P76600 US). Figures 6-10 show the operating mechanism assembly 68 in the disconnected state after the keylock 80 has been unlocked. The operation of the circuit protector switch 40 from a state of ignition to a state of disconnection occurs because a driver 80 has been unlocked by the operation of the aforementioned disconnect mechanism. Therefore, it is now appropriate to describe the disconnection mechanism. Figures 2 and 14-24 show the disconnection mechanism 140 and some of its components. The disconnect mechanism 140 comprises a magnetic disconnect actuator 142, and a thermal cut-off actuator 144. The magnetic cut-off actuator 142 comprises a ferromagnetic part 146 fixed to a base portion 42. The ferromagnetic part 146 comprises separate parallel sides. The respective sides 147 of a disconnection member 148 are mounted on respective sides of the ferromagnetic portion 146 which provides pivotal movement of the disconnection member about an axis 150. The disconnection member further comprises a bridge 152 extending between its sides 147 and including a lever 154 projecting from the bridge. An end portion of a ferromagnetic member 156 is positioned against, and attached to, the hidden side of the bridge 152. The opposite end of the member 156 projects from the bridge in the opposite direction from the lever 154. Figure 14 shows the mechanism of disconnect 140 in its state without disconnecting. The member 156 is spaced parallel with a portion of the loading terminal 66. A spring 149 (see Figure 2) biases the disconnect member 148 toward a maximum clockwise position where the sides of the disconnect member. 147 butts 158 are joined in the ferromagnetic part 146. The bimetal sheet 64, the details of which are shown in Figures 22-24, form the thermal shut-off actuator 144. The bimetal 64 is known to those skilled in the art. In the present embodiment, the bimetal 64 actually comprises three metallic layers and can be considered a trimetai or a multimetal, although it can still be referred to as a bimetal. The active or high-expansion side of the bimetal 64, which is connected to the charging terminal 66, is a metal charge comprising nickel, chromium and iron. The inactive or low expansion side of the bimetal 64, which is connected to the belt 62, is a metal layer comprising I NVAR, which is a metal of composition having a relatively high content of nickel and iron. The middle layer of bimetal 64 comprises copper, as well as two percent silver (2%). The bimetal 64 used in the present embodiment is known as Hood HR50, and is available from Hood &; Co., Inc. of Hamburg, Pennsylvania. As is also known, the thickness of the bimetal 64 is generally used depending on the Ampere scale of the circuit protection switch. For example, in a 225 Ampere scale circuit protective circuit breaker, the bimetal Hood HR50 is 0.1 1 cm (0.045 inches) thick, and CDA 1 10, which is 0.31 cm (0.125 inches) thick copper , it is used for the load terminal 66. In a scale circuit protective circuit breaker of 200 Ampere, the load terminal 66 uses CDA 260, which is 0.31 cm (0.125 inches) of brass. One reason why the one manufactured is to increase the heating effect in lower currents and is also known. It is also considered that circuit protection switches of scale 150 and 1 75 Ampere can use Hood HR50, 0.81 cm or 0.88 cm (0.032 or 0.035 inches) thick with the load terminal 66, using CDA 260. It should be understood that comparable bimetals (either trimetal or multimetal) are, of course, products available from other sources and are known, as are the types of materials used in the load terminals that are to be used with such bimetal elements in various Ampere scale circuit protection switches. Figure 14 shows the bimetal strip 64 in its non-disconnected state. The strip is flat and is parallel with the member 156, which passes from its mounting on one end of the loading terminal 66 through the open space between the sides of the ferromagnetic part 146 and the disconnection member 148. The disconnection mechanism 140 further comprises a disconnection hammer 160, a disconnection striker guide 162, a disconnection bar 164, a disconnection lever 166, a calibration screw 168 and a torsion spring 170. The detail of the disconnection striker guide 162 is shown in Figures 15-18, while the disconnection striker 160 is shown in Figures 19-21. The disconnect striker guide 162 comprises a vertical side 72 by means of which it is supported vertically as shown in Figure 14. An open flange 174 is formed at the upper end of the side 1 72. In one of its free corners, the tab 1 74 is formed with a detent 1 76 on which an end of the spring 149 is hooked. Figure 2 shows the opposite end of the spring 149 engaged on a tongue of the disconnection member 148, the tab not shown in Figure 14 for clarity of the illustration. The flange 1 74 contains a rectangular shaped opening 180 which provides both the proper orientation and the displacement guide for the disconnect striker 160. Figures 19-21 show the disconnect striker 160 for compressing a head 182 and a tang 184. The pin portion 184 immediately proximal of the head 182 has a rectangular cross section to pass relatively close through the opening 180. On the short sides of its nominally rectangular cross section, the pin 182 comprises the respective notches 186, 188 which extend proximally from the distal end of the spike along a portion of the spike. The groove 186 extends from the distal end of the peg, a distance less than the groove 188. The adjustment of the peg 182 to the opening 180 circumferentially orientates the striker 160 so that it can not rotate to any appreciable extent in the opening. The proximal ends of the notches 186, .10 188 terminate in respective surfaces 190. 192, respectively. As shown by Figure 14, those surfaces 190, 192, are positioned for a respective constraint with the lever 154 and the bimetal 64 respectively. Figures 22 and 24 show the free end of the bimetal 64 to comprise an opening 194. Figure 14 shows the portion of the tang 184 below the surface 190 extending through the opening 194. The free end is also shown. of lever 1 54 to comprise a projection 196 positioned to one side of pin 184 and located between surfaces 190 and 192. A portion of the margin of bimetal opening 194 confronts a portion of surface 190. A projection portion 196 confronts a portion of surface 192, namely 192a. When the disconnect mechanism 140 is operated by the actuator 142, the projection portion 196 facing the surface 192 acts against that Surface to push the disconnect striker 160 upwardly from the position shown in Figure 14. Similarly, when the disengagement mechanism is operated by the actuator 144, the portion of the opening margin 194 confronting the surface portion 190, namely the surface 190a, acts against that surface to push the disconnect striker 160 upwards from the position shown in FIG. Figure 14 .eleven The detailed explanation in the operation of the actuators 142, 144 will be given later. The windings of the torsion spring 1 70 (see Figure 2) are placed around the outside of the disconnect bar 164 next to the locker 80. An arm 1 70a of the spring 1 70 extends to engage the locker 80. The other arm 1 70b of the spring 1 70 extends to engage the upper surface of the disconnect lever portion 166 projecting to rest on the disconnect striker 160. The torsion spring 1 70 therefore acts between the tracker 80 and the bar of disconnection 164 to drive the disconnect bar clockwise about the axis 104 and the plunger 80 clockwise about the pivot joint 195 on the sides of the frame 70, 72. The screw Calibration 168 is screwed into a hole in the disconnect lever 166 to align with the disconnect striker head 182. Because the disconnect bar and the lever are offset s clockwise about the axis 104, the lower end of the screw 168 is deviated in abutment with the top of the head 1 82, as shown in Figure 14. This forces the head 182 against the surface upper of the tab 174, defining a downward limit of the displacement for the disconnection striker. In the state shown in Figure 14, the disconnect lever 166 is in interference with the driver 80, holding the lock in the locked position. The detail of how the bracket and bracket interact will be presented later. The displacement of the disconnection mechanism 140 can be initiated by any actuator 142, 144. Upon starting either of the two disconnecting actuators a disengagement movement is initiated, the striker 160 is pushed upward in Figure 14, causing the disconnect bar 164 and lever 166 pivot counterclockwise. Although the movement of the disconnection striker upwards, it is resisted by the spring 1 70 (and also by the spring 149 when the actuator 142 triggers a disconnection). the force of the spring opposing the displacement of the striker is relatively slight so that the upward movement of the striker 160 is not resisted appreciably. A certain amount of displacement of the striker upwards pivots the disconnect lever 166 out of the interference with the tracker 80. At that point, the lock is released, thus allowing it to pivot in a counter-clockwise direction around the pivot joint 195, out of interference with the support 78, unlocking the locking mechanism assembly 68 so that the support 78 is free to pivot clockwise about shaft 96. It is considered that to obtain maximum effectiveness of the force of the rotating contact arms, the operating mechanism assembly 68 must be unlocked before its spring 130 go over the center. It can be seen that the extent to which the qualification screw 168 is screwed into the lever 166 determines how much displacement of the striker 160 is necessary to move the tracer 80 out of interference with the support 78. The calibration screw serves to fix a desired disconnection point, compensating the tolerance variation in a bimetal strip produced in mass 62. The force of the operation spring 130 is continuously applied to the lever mechanism by means of a spring pin 128. This force is transmitted through of the upper lever to also act on the pivots 101, which transmit the force to the support 78. The unlocking of the operating mechanism assembly by the disengagement mechanism and the lock results in the support 78 being able to pivot in the direction of clock hands. The driving force that is exerted by the operating spring 130 on the spring pin 128 now moves both of the upper lever 74 and the unclamping support 78. Once the spring-loaded lever mechanism has been collapsed enough to go to the center, spring 1 30 becomes active to further collapse the lever. This is because the spring force that has been applied to the support 78 radially of the support pivot shaft 96 on the supports 95, is now applied to the rotary contact arms 56, in such a way that it drives them further in clockwise until they butt up the stops 129. The detail of how the support 78 and the interlock 80 interact will now be explained with reference to Figures 2, and 6-14. The binder 80 has two tabs 200 on opposite sides that fit into small holes 202 in the frame sides 70, 72 to form a pivot joint 195. Below and to the right of the pivot joint 195 (as seen with reference to Figure 2), the binder 80, contains a slot 204 shown in Figure 8. This slot is proximal to the frame side 70. The arm 1 70a (not shown in Figures 6-10) of the spring 1 70 fits within the slot 204 for pushing the keypad clockwise around the pivot joint 195. The keyway also has other tabs 206, in approximate alignment with the bottom of the slot 204, which fit into holes 208 on the sides of frame. While the orifice edges 208 could limit the extent to which the plunger 80 can pivot about the pivot joint 195, it is not considered to interfere with the functional relationship between the plunger and the support. The side of the support 78 next to the side of the frame 72 has an arm 21 0 having a curved edge surface 212. The clockwise end of the arm 210 has a surface of the edge 214 that forms a corner 21 7 with the surface of the rim 212. The binder 80 has a notch 216 immediately above and to the right of the tab 206 (as seen with reference to Figure 2) that fits within the hole 208 in the frame side 72. This notch 216 has an edge surface 218 that is perpendicular to the frame side 72. When the driver 80 is in the locked state and locking the operator mechanism assembly 68 and the support 78, as shown in Figures 11-14 with the lever disconnection 166 in interference with the driver as shown particularly in Figure 14, the corner 21 7 is placed in the notch 216 with the edge surfaces 214 and 218 in mutual splicing. Because the keylock 80 is thus prevented by the disengagement lever pivoting counterclockwise around the pivot joint 195, the forced mutual splicing of the edge surfaces 214 and 218 is maintained, and therefore the lock 80 prevents the support 78 from moving additionally in the clockwise direction, with the 3f >; which holds the operating mechanism assembly 68 locked. However, once the keylock 80 is unlocked by the disengagement mechanism 140, the support 78 is no longer constrained by the disconnect lever 166 and is therefore capable of pivoting in clockwise direction. The mutually engaging edge surfaces 214 and 218 are in a geometric relationship with each other and with the spring force acting to rotate the support in a clockwise direction, which, once the disconnect lever has released the trabador, converts the force that is being applied from the operative spring 1 30 into a cams disposition action. This action of arranging the cams is caused by the support arm 210 which applies a cams arrangement to the locker 80 outside the counter-clockwise direction, so that it allows the spring force to actuate the support in the direction clockwise and to further collapse the lever mechanism as explained above. This drives the rotary contact arms 56 to open further until they abut the stops 129. The handle arm and the handle move to the disengage position in the process. Once the fault has caused a disconnection to be corrected and the disconnect actuators 142, 144 of the disconnect mechanism 140 are able to allow the circuit protection switch 40 to be restored, the operation of the handle 46 from the position of disconnection to the off position will reset the circuit protection switch. When the handle moves to the off, the handle arm 76 pivots counterclockwise. Its bridge 83 is forced against a lower edge surface 222 of the support side 78 that contains the arm 210, forcing the support to pivot counterclockwise about the axis 96. As the support pivots in the opposite direction to the clockwise, the edge surface 21 2 moves along the keystone 80 initiating the restoration of the keylock to the locked condition. Once the handle of the circuit protective switch reaches the off position, the driver 80 has been moved by the spring 1 70 to a position that catches the corner 21 7 and places the edge surfaces 21 4 and 218 in confrontation for splicing mutual. The disconnect lever 166 is also returned to the interference with the lock. With the support now in the locked position it can not pivot clockwise until the lock 80 is unlocked again. Operation of the handle 46 from the off position to the on position causes the handle arm 76 to pivot in a clockwise direction, with the bridge 83 moving away from the edge surface of the holder 222. The tongue of the handle arm 84 is now pulled on the end of the spring 1 30 hooked thereto, and the spring is in turn pulled on the spring pin 128. This action begins to expand the lever mechanism, forcing the pin of the lever. spring against the lower lever 122, to pivot the cross bar 58 in a counterclockwise direction, and also cause the contact arms 56 to pivot. Because the impact opening pins 11 8 have moved toward behind the patella 116 of the grooves 114, as described above, the springs 1 20 oppose the forces acting to move the closed contact arms 56 against the contacts 52. According to the spring-loaded lever mechanism goes over the center, the operating spring 1 30 becomes effective to force the contact arms for the final position (i.e., ignition position) where their contacts 54 are forced against the contacts 52. Detailed explanations of the operation of the magnetic cut-off actuator 142 and the thermal cut-off actuator 144 to effect disconnection of the circuit-breaker 40 can now be understood more significantly.

As they are manufactured, bimetal 64 is nominally flat and straight. In a state without disconnection of the thermal actuator 144, the bimetal 64 remains flat and vertical; however, when it is heated to a certain point, its shape starts to twist, pushing the disconnection hammer 160 upwards. I ncrementando the thermal energy in the bimetal increases the bimetal twist. This twisting is caused by the construction of the bimetal, which consists of lamina in conjunction 64a, 64b which are respective materials characterized by different coefficients of thermal expansion, being that 64a is smaller than that of 64b. The loading terminal 66 has a nominally rectangular cross section. The bimetal 64 has a first end portion 64c placed flat against, and attached to an end portion 66a of the loading terminal 66 and a second end portion 64d positioned in spaced relationship to the loading terminal 66. This separation of an end portion 64d in superjacent relationship in parallel to an underlying portion of the load terminal occurs due to a phase shift bending 66b, formed in the load terminal 66 for attaching the end portion 66a to the rest of the load terminal. In this sense, the bimetal is seated in cantilever over the loading terminal 66 by means of joining the end portions 64c and 66a. The end portion 64c can be considered an inactive portion of the bimetal while the end portion 64d can be considered an active portion. It is considered that when the electric current flows in the load terminal 66, the current passes between the braid 62 and the load terminal portion 66a substantially only through the inactive portion 64c of the bimetal so that no current flows substantially through the active portion of bimetal 64d. Therefore, it is considered that the bimetal should be subjected to less stress than would otherwise be the case. The flow of current through the inactive bimetal portion 64c creates some ohmic, localized heating that consequently flows by thermal conduction to the active bimetal portion. The complete bimetal is also exposed to the temperature of its surroundings. While the ohmic heat entering the bimetal can dissipate to the surrounding heat to keep the thermal energy in the bimetal below a certain level of disconnection energy, the active portion of the bimetal will not be twisted far enough to allow disconnection. By confronting the lower coefficient of thermal expansion material of the bimetal away from the end portion of the loading terminal 66a, the twisting of the strip will occur in the direction away from the loading terminal. Whenever the thermal energy in the bimetal exceeds the disconnection energy level, the active portion of the bimetal will have to be twisted sufficiently from its inactive non-twisted shape shown in the Figures to have the striker 160 pushed up enough to have the pivoted scroll bar 164 and the lever 166 and the released support 78, allowing a disconnection. The disconnection is completed by the disconnection operation of the spring-loaded lever mechanism described above. It should be noted from Figures 19 and 20 that only the right portion 190a of the surface 190, as seen in Figure 14, is perpendicular to the length of the striker pin 182. The spring 190b of the surface 190 is tilts up away from the left end of that rightmost portion so that only the rightmost portion 190a which is contacted by the bimetal strip 64. This construction for the surface 190 is considered to provide the best interaction between the striker and the bimetal strip as the bimetal strip is braided. This aspect of the circuit protective switch 40 is the subject matter of the commonly assigned patent application., co-pending THERMAL SENSI NG BI-METAL TRI P ACTUATOR FOR A CI RCUIT BREAKER Serial No. (attorney's file No. 96P7599US). It is considered that the thermal energy in the active portion of the bimetal depends not only on the energy conducted from the inactive portion, but also on its natural surroundings. By placing the active portion of the bimetal element towards a relatively close surface in an underlying portion in the load terminal 66, the thermal energy that results from the current flow through that underlying portion of the load terminal can transfer convectively and / or radiant towards the bi metal, increasing the thermal energy in it. This is considered useful in acceleration disconnection, particularly when a fault is caused by a short circuit and it is further considered that the potential to damage the bimetal to the occurrence of a fault, especially a short circuit type fault, is reduced. This aspect of the circuit protection switch 40 is the subject matter of the commonly assigned, co-pending patent application TH ERMAL SENSI N G B I-M ETAL TRI P ACTUATOR FOR A CI RCU IT BREAKER Serial No. (attorney's file No. 96P7599US). In the state without inactive disconnection of the magnetic actuator 142, the ferromagnetic member 56 is positioned substantially in parallel with the loading portion 66 positioned behind it. When the magnitude of the current flow of the charging terminal 66 exceeds a limit at which the actuator 142 must allow a disconnection, the corresponding electromagnetic force applied to the member 156 due to current flow in the charging terminal will be pivoted to the member of disconnection 148 counterclockwise about the axis 1 50 against the opposing spring force 149 to a sufficient degree to cause disconnection. As the disconnect member pivots counterclockwise from the position shown in Figure 14, the portion of the opening margin 196 facing the striker surface 192 acts against that surface to push the disconnect striker 160 toward above. When the striker 160 has been pushed up sufficiently to obtain the pivoted disengagement bar 164 and the lever 166 to release the support 78, the disconnection is completed by the displacement operation of the spring-loaded lever mechanism described above. It should be noted that the surface 192 has a construction 192a, 192b similar to that of the surface 190 which is considered to provide a better interaction between the firing pin and the disengagement member as the disengagement member pivots. The rightmost portion 192a is perpendicular to the length of the firing pin portion. The portion 192b is tilted up away from the left end of that portion further to the right so that only the rightmost portion 192a is connected by the projection 196 of the lever 154.

In light of the above description, it should be recognized that only one of the two displacement actuators 142 or 144 is able to be actually pushed on the striker 160 at any given time. In other words, it is considered that the ascending forces are less likely to be applied simultaneously to both surfaces 190a, 192a by both actuators 142, 144. Therefore, two separate actuators, each of which is capable of operating independently of the striker , can sometimes be pushing simultaneously from the firing pin, while at other times only another of them can be pushed. Its incorporation as a whole within a protective circuit breaker, however, is towards the objective of completing a disconnection initiated upon opening by impact in a minimum or at least a shorter amount of time from the occurrence of a failure that could cause the circuit protective switch is disconnected. Because the fault may be due to current, temperature or a combination of both, the disconnection mechanism described and the two displacement actuators are considered to address all faults that could cause a circuit breaker to trip. . It is considered that the disconnection mechanism and the actuators are efficiently organized to coerce with the operating mechanism 68 which represents an important advance in circuit breaker technology. While the disconnection mechanism 140 has been shown as an integral part of the circuit protection switch 40. The disconnection mechanism itself could be packaged as a disconnection unit which is functionally associated with a circuit protection device containing a interruptible circuit path that is interrupted by the disconnect unit upon the occurrence of a fault. The disconnection mechanism and the actuators are the subject matter of the patent application commonly assigned, co-pending CI RCUIT B REAKER COM BI NATION TH ERMAL AN D MAG N ETI C TRIP ACTUATOR Serial No. (attorney's file No. 96P7598US). While the disconnection mechanism 140 has been shown as an integral part of the circuit protection switch 40, the disconnection mechanism itself could be packaged as a disconnection unit that is functionally associated with a circuit protection device that contains a path interruptible circuit that is interrupted by the disconnection unit to the occurrence of a fault. While the present invention has been described, with reference to a preferred embodiment as currently contemplated, it should be understood that the invention is not intended to be limited to that embodiment. Accordingly, it is intended that the invention encompass several modifications and arrangements that are within the scope of the claims.

Claims (22)

1. RETIREMENT NDI CATION 1 . A circuit protective switch, characterized in that it comprises: a contact arm having a pivot axis; a pivotally mounting by mounting the contact arm about its pivot axis for rotational movement to interrupt a circuit; separate side walls which are side sides proximal of the contact arm, and with respect to which the contact arm can rotate; a through opening in which the contact arm defines a groove whose length is generally transverse to the rotational movement of the contact arm; a pin that passes through the groove of the contact arm although it is constrained by the groove of the contact arm along the length of the groove; and the separated side walls comprising grooves receiving portions of the pin and restricting the pin to move longitudinally of the grooves of the side walls; a spring placed in the groove of the contact arm and laterally confined by the separated side walls to exert a force on the pin that drives the pin along the length of the groove of the contact arm; and wherein the relative movement between the contact arm and the side walls causes the pin to move longitudinally of the groove of the contact arm and longitudinally of the lateral wall slots, changing the spring force exerted by the spring on the pin.
2. 2. The city in accordance with the re-ordination 1, characterized in that the extreme end length of the contact arm groove is closer towards the pivot axis than an opposite long end of the contact arm groove, and the spring is a compression spring which it is compressed between the pin and a longitudinal end of the groove of the contact arm to drive the pivot towards the opposite longitudinal end of the contact arm groove.
3. 3. The circuit protection switch complies with claim 2, characterized in that the spring is a coiled helical compression spring.
4. 4. The circuit protective switch according to claim 3, characterized in that the separate sidewall grooves are flexed, each having a ball joint positioned between a segment above the ball joint and a segment below the ball joint.
5. 5. The circuit protective switch according to claim 4, characterized in that the pivot axis is close to a longitudinal end of the contact end, the segment above the ball joint of the separate wall grooves is vertical, the segment below the ball joint of the separate-walled grooves is vertical and in the ball joint, the segments above the ball joint and below the ball joint of each of the grooves with separate walls form an obtuse angle facing towards the opposite longitudinal end of the contact arm .
6. 6. The circuit protective switch according to claim 1, characterized in that the separate-walled grooves are flexed, each having a ball joint placed between a segment above the patella and a segment below the patella.
7. 7. The circuit protective switch according to claim 6, characterized in that the segment above the ball joint of the separated wall grooves is vertical, the segment below the ball joint of the separated wall grooves is vertical, and in the ball joint , the segments above and below the patella of each of the slots with separate walls form an obtuse angle facing towards the longitudinal end of the contact arm.
8. 8. The circuit protection switch according to claim 1, characterized in that the separated walls are part of a transverse bar with respect to which the contact arm can execute limited pivotal movement about the pivot axis.
9. 9. The circuit protective switch according to claim 1, characterized in that it further includes: a second contact arm having a pivot axis; a second pivotally mounting by mounting the second contact arm about its pivot axis for rotational movement to interrupt a circuit; second separate side walls that are close to the lateral sides of the second contact arm and with respect to which the second contact arm can rotate; a passage opening in the second contact arm defining a groove whose length is generally transverse to the rotational movement of the second contact arm; a second pin passing through the second contact arm slot although restricted by that slot for movement along the slot length; and the second separated side walls comprising slots receiving portions of the second pin and restricting the second pin of the longitudinal displacement of the second side wall slots; a second spring placed in the second contact arm groove and laterally confined by the second spaced apart side walls to exert a force on the second pin which urges the second pin along the length of the second contact arm groove; and wherein the relative movement between the second contact arm and the second side walls causes the second pin to move longitudinally from the second contact arm groove and longitudinally of the second side wall grooves, changing the spring force exerted by the second spring on the second pin.
10. 10. The circuit protective switch according to claim 9, characterized in that all the side walls are part of a transverse bar with respect to which each contact arm can execute the limited pivotal movement about its pivot axis, and the axes of pivot of the contact arms are located on a common axis. eleven .
11. A circuit protective switch, characterized in that it comprises: a contact arm having a pivot axis; a pivotally mounting by mounting the contact arm about its pivot axis for rotational movement to interrupt a circuit; the contact arm having a through opening whose length is generally transverse to the rotational movement of the contact arm; a pin passing through the passage opening of the contact arm although restricted by the passage opening for movement along the length of the passage opening; and a grooved track positioned in addition to the contact arm and engaging the pin to restrict the pin to the longitudinal displacement of the grooved track; a spring contained in the passage opening of the contact arm to exert a force on the pin that drives the pin along the groove length of the contact passage; and wherein the relative movement between the contact arm and the slotted track causes the pin to move longitudinally of the contact arm slot and longitudinally of the slotted track, by changing the spring force exerted by the spring on the pin.
12. 12. The circuit protection switch according to claim 1, characterized in that the passage opening in the contact arm comprises a longitudinally extending groove of the contact arm, a longitudinal end of the contact arm groove is closer to the contact arm. pivot shaft having an opposite longitudinal end of the contact arm slot and, the spring is a compression spring that is compressed between the pin and a longitudinal end of the contact arm slot to drive the pivot towards the opposite longitudinal end of the contact arm slot.
13. 13. The circuit protective switch according to claim 12, characterized in that the grooved track has a ball joint placed between a segment above the ball joint and a segment below the ball joint.
14. 14. The circuit protective switch according to claim 1 3, characterized in that the pivot axis is close to a longitudinal end of the contact arm, the segment above the ball joint of the groove of the grooved track is vertical, the segment by below the patella of the grooved track is vertical and at the patella, the segments above the patella and below the patella of the grooved track form an obtuse angle confronting the opposite longitudinal end of the contact arm.
15. The circuit protective switch according to claim 1, characterized in that the grooved track comprises separate side walls which are close to the lateral sides of the contact arm and with respect to which the contact arm can rotate, separate side walls comprising grooves receiving portions of the pin and restricting the longitudinal displacement pin of the sidewall grooves.
16. 16. The circuit protective switch according to claim 15, characterized in that the separate-walled grooves are flexed, each having a ball joint placed between a segment above the ball joint and a segment below the ball joint.
17. 17. The circuit protective switch according to claim 16, characterized in that the segment above the ball joint of the separated wall grooves is vertical, the segment below the ball joint of the separated wall grooves is vertical, and in the ball joint , the segments above and below the patella of each of the grooves of spaced-apart walls form an obtuse angle facing towards a longitudinal end of the contact arm.
18. 18. The circuit protective switch according to claim 11, characterized in that it further includes: a second contact arm having a pivot axis; a second pivotally mounting by mounting the second contact arm about its pivot axis for rotational movement to interrupt a circuit; a passage opening in the second contact arm defining a groove whose length is generally transverse to the rotational movement of the second contact arm; a second pin passing through the second contact arm slot, although restricted by that slot for movement along the slot length; and a second grooved track positioned in addition to the second contact arm and engaging the second pin to restrain the second pin from longitudinally displacing the second grooved track; a second spring contained in the passage opening of the second contact arm to exert a force on the pin, driving the second pin along the length of the second contact arm slot; and wherein the relative movement between the second contact arm and the second grooved track causes the second pin to move longitudinally from the second contact arm groove and longitudinally from the second grooved track, changing the spring force exerted by the second. spring on the second pin.
19. 19. The circuit protective switch according to claim 18, characterized in that the grooved tracks are part of a transverse bar with respect to which each contact arm that can execute limited pivotal movement about its pivot axis, and the axes of pivot of the contact arms are located on a common axis.
20. 20. In a current-sensitive circuit protection device, such as a circuit protection switch, an elongated contact arm having longitudinal opposite end portions between which is an intermediate portion, a longitudinal end portion comprising a pivot shaft for mounting the contact arm for rotational movement about a pivot axis, the other longitudinal end comprising a contact and the intermediate portion comprising an elongated passage groove having a length in the same direction as the length of the contact arm. twenty-one .
21. The elongated contact arm according to claim 20, characterized in that the elongated passage slot length is vertical.
22. 22. The elongated contact arm according to claim 21, characterized in that it further includes an elongated pin that extethrough the transverse passage groove to the length of the contact arm and a spring placed in the elongated passage slot and that exerts a spring force against the pin. R ESUMENT OF THE I NVENTION A circuit protection switch contact arm (56) that contains an elongated pitch slot (1 12) that travels generally longitudinally to the contact arm, and is closed at both longitudinal e Adjacent to each slot, a respective side wall (1 06, 108) of a transverse bar (58) contains a bending groove (114) having a ball joint (1 16). A respective cylindrical impact open pin (118) passes through three of these slots. A small helical spring (120) occupies the passage groove of the contact arm and is compressed between the impact opening pin and the end of the contact arm slot which is proximal to a transverse bar / arm hinge pin. contact (1 10). The spring is laterally confined by the adjacent side walls of the transverse bar so that it remains in the contact arm groove around which the contact arm rotates. The spring acts between the impact-open pin and the contact arm to deflect the impact-open pin away from the transverse bar / contact arm hinge shaft. When the pin opened by impact is below the ball joints of the flexed slots and the contact arm is closed, completing an interruptible circuit through the circuit protective switch, the spring exerts the beneficial force for better contact of the arm contact of contact (54) with a fixing contact (52). By placing the spring in the groove of the contact arm, space is used more efficiently.