US3790731A

US3790731A - Spring charging switch operator with weld-breaking means

Info

Publication number: US3790731A
Application number: US00295456A
Authority: US
Inventors: K Date
Original assignee: McGraw Edison Co
Current assignee: Cooper Industries LLC
Priority date: 1972-10-06
Filing date: 1972-10-06
Publication date: 1974-02-05
Anticipated expiration: 1991-02-05
Also published as: CA1004262A

Abstract

A switch operator is provided in which an operating shaft is rotatable in opposite directions to charge a torsion spring for supplying a snap action opening or closing operation of a switch. The switch is operated by a switch shaft which is latched stationary while the operating shaft is being rotated to charge the spring. At the point during the rotation of the shaft at which the torsion spring reaches a desired degree of charge, the latch is released and the switch shaft and switch are allowed to snap either open or closed. A forcing mechanism is positioned within the torsion spring and provides a direct, non-spring connection between the operating shaft and switch shaft. The forcing mechanism provides a direct opening or closing force on the switch shaft and switch means to overcome friction or contact weld in the event that the spring is unable to rotate the switch shaft upon release of the latch.

Description

SPRING CHARGING SWITCH OPERATOR WITH WELD-BREAKING MEANS [75] Inventor: Kazuo H. Date, South Milwaukee,

Wis.

[73] Assignee: McG'raw-Edison Company, Elgin,

[22] Filed: Oct. 6, 1972 [21] Appl. No.: 295,456

[52] US. Cl. 200/153 SC, ZOO/DIG. 42 [51] Int. Cl. H0lh 3/30 [58] Field of Search..... 200/153 SC, DIG. 42, 67 C, 200/67 PK 56] References Cited UNITED STATES PATENTS 2,326,011 8/1943 Currie 200/67 C X 1,979,277 11/1934 McLoughlin et al..... 200/67 PK UX 2,870,282 1/1959 Brand 200/67 PK 1,918,248 7/1933 Cook 200/67 C X 3,211,870 10/1965 Lusk et a1. 200/153 SC Feb. 5, 197 4 [5 7] ABSTRACT A switch operator is provided in which an operating shaft is rotatable in opposite directions to charge a torsion spring for supplying a snap action opening or closing operation of a switch. The switch is operated by a switch shaft which is latched stationary while the operating shaft is being rotated to charge the spring. At the point during the rotation of the shaft at which the torsion spring reaches a desired degree of charge, the latch is released and the switch shaft and switch are allowed to snap either open or closed. A forcing mechanism is positioned within the torsion spring and provides a direct, non-spring connection betweenthe operating shaft and switch shaft. The forcing mechanism provides a direct opening or closing force on the switch shaft and switch means to overcome friction or contact weld in the event that the spring is unable to rotate the switch shaft upon release of the latch.

5 Claims, 5 Drawing Figures PATENTEDFEB 1914 3399.781 sum 3 or 4 SPRING CHARGING SWITCH OPERATOR WITH WELD-BREAKING MEANS BACKGROUND OF THE INVENTION DESCRIPTION OF THE PREFERRED EMBODIMENT Referring generally to the 'drawings, a vacuum load- Operators for loadbreak switches generally provide a break switch is shown as having switch means 2 and a snap opening and closing operation to minimize arcing during both the opening and closing of the switch contacts. Such arcing is, of course, undesirable due to switch operators generally are quite complex and ordinarily include several springs to provide the snap opening and closing movement. Also, loadbreak switch operators do not always provide a mechanism for contact weld breaking or overcoming friction when the springs are unable to open or close the switch due to these problems. When switch operators do provide weld breaking mechanisms, it is at the expense of considerable added complexity.

It is a general object of the invention to provide a simple and compact switch operator for a loadbreak switch.

It is a further object of theinvention to provide a switch operator in which rotation of a shaft in one direction provides snap action switch opening movement and rotation of the same shaft in the opposite direction provides snap action closing movement of the switch.

It is another object of the invention to provide a switch operator having a forcing mechanism providing switch opening or switch closing force independently of the switch snap action mechanism.

SUMMARY OF THE INVENTION The objects of the invention are accomplished by providing a switch blade shaft and a switch operating shaft connected by resilient means charged by rotational movement of the switch operating shaft. Latch means holds the switch blade shaft stationary until the resilient means is charged. Upon charging of the resilient means, means responsive to rotation of the operating shaft releases the latch means and permits the resilient means to snap the switch blade shaft and thereby a switch connected to it to either an open or closed position. The switch blade shaft may be latched in either an open or closed position corresponding to open and closed positions of the switch means. The operating shaft may be rotated in either of opposite directions to charge the resilient means and cause release of the latch means.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a front elevational view of a loadbreak switch including a switch operator according to the instant invention;

FIG. 2 is a side elevational view showing switch means and the switch operator of the loadbreak switch in their closed positions;

FIG. 3 is a side elevational view similar to FIG. 2 with portions of the switch operator removed showing the switch means and switch operator in their open positions.

FIG. 4 is a front elevational view of the forcing mechanism of the switch operator; and

FIG. 5 is a cross sectional view taken through the lines A-A of FIG. 4 with elements of the loadbreak switch added for purposes of clarity.

switch operator 4 both supported on support means 6. The support means 6 includes

insulators

8 and 10 on which the switch means 2 is mounted. Electrically

conductive terminals

12 and 14 comprise part of the sup- 0 port means 6 and are mounted on the ends of

insulators

8 and 10. The

terminals

12 and 14 are connected to electrical cables (not shown) comprising part of an electrical power system. The terminal 12 has a stationary contact 34 including latch means 30 engaging the switch means 2 when it is in its closed position. The switch means 2 is pivotally mounted on the terminal 14 and includes

links

16 and 18 attached to the switch operator 4 to permit pivotal movement of the switch means 2 by the switch operator 4 between a closed position in engagement with the stationary contact 34 and out of engagement to an open positioned spaced from stationary contact 34.

The switch means 2 includes

conductive blades

20 and 22 engaging the stationary contact 34 and the terminal 14 for carrying current between the

terminals

12 and 14 when the switch means 2 is in its closed position. The switch means 2 also includes vacuum interrupter means 24 for interrupting current flowing between the

terminals

12 and 14. The switch means 2 is described in greater detail in co-pending US. Pat. application Ser. No. 295,527, filled Oct. 6, 1972, and assigned to the assignee of this application. The switch means 2 is shown and described herein only to the extent necessary to illustrate the operation of the switch operator 4. It should be understood that any of various types of switches may be substituted for switch means 2. For example, a switch which merely consists of a pivotable switch blade connecting the

terminals

12 and 14 could be utilized with the switch operator 4.

The switch operator 4 includes a rotatable blade shaft 40, a rotatable operator shaft 42, a handle 44, a spring operating mechanism 46 and latch means 48. The switch operator 4 also includes a forcing drive means 50. An arm 28 extends from and is rigidly affixed to the rotatable blade shaft 40. The arm 28 is also pivotally connected by means of pin 32 to both of the

links

16 and 18. When the rotatable blade shaft 40 is rotated in either a clockwise or counterclockwise direction about its longitudinal axis, the switch means 2 is pivoted between its open and closed positions. This rotation of the switch means 2 occurs with a snap action due to the snap action operation of the switch op erator 4 as will be described in greater detail hereinafter.

The switch operator 4 is supported by

side plates

52 and 54 attached to the support means 6 by

bolts

56 and 58,

nuts

60 and 62 and

spacers

64 and 66. The latch means 48 of switch operator 4 is supported on support plate 52 by bolts 68 and C-rings 70. The latch means 48 is held in a position spaced from the plate 52 by spacers 72. The spring operating mechanism 46 is supported on the rotatable operator shaft 42 and is spaced from the support plate 54 by a spacer 74. The forcing drive means 50 is supported on the blade shaft 40 and operator shaft 42 and is spaced from the support plate 52 by a spacer 76.

The spring operating mechanism 46 includes a first L-shaped drive member 80 rigidly affixed to the blade shaft 40, a second L-shaped drive member 82 rigidly affixed to the rotatable operator shaft 42, a spring 84 having opposite ends respectively attached to the

drive member

80 and 82 and having a longitudinal axis aligned with the longitudinal axes of the two shafts 40 and 42. As may be seen in FIG. 1, the rotatable shafts 40 and 42 respectively have

ends

86 and 88 positioned adjacent one another and surrounded by the spring 84. The spring operating mechanism 46 also includes a support bar 90 attached to the shaft 42 and a tube 92 held centered by the support bar 90 adjacent the drive member 82. The tube 92 extends through the spring 84 to thereby support the spring 84 and hold it in position.

The latch means 48 includes a first latch device 94 pivotally mounted on the plate 52 by bolt 68, a second latch device 96 pivotally mounted on the plate 52 by another bolt 68 and a spring 98. The latch device 94 comprises a latching bar 100 rigidly attached to a biasing finger 102 having an end 104. The second latch device 96 comprises a latching bar 106 rigidly attached to a biasing finger 108 having an end 110. The latch means 48 also includes a latched bar 112 rigidly affixed to the rotatable balde shaft 40 and having latch surfaces 114 and 116. The spring 98 is attached to the ends 104 and 110 of the biasing

fingers

102 and 108 to bias the latching bars 100 and 106 toward latching engagement with the latched bar 112 in either the open condition of the latch means 48 and spring operating mechanism 46 or the closed condition of the latch means 48 and spring operating mechanism 46 respectively. The open and closed conditions of the latch means 48 and spring operating mechanism correspond to the open or closed position of the switch means 2. The latch means 48 also includes a latch release bar 118 mounted on the second drive member 82 which rotates into engagement with either the biasing finger 102 or biasing finger 108 when the drive member 82 and handle 44 are rotated.

As shown in FIG. 4, the forcing drive means 50 includes a first drive bar 120, a second drive bar 122 and a third drive bar 124. Each of the drive bars have the generally rectangular shape of drive bar 120 as shown in FIG. 5. The first drive bar 120 extends radially from the blade shaft 40 and is rigidly affixed to the shaft 40 at its end 86. As can be seen in. FIG. 4, the first drive bar 120 has an opening 126 into which the end 88 of operator shaft 42 extends and which thereby supports the shafts 40 and 42 and their respective longitudinal axes in alignment. The third drive bar 124 extends radially from the rotatable operator shaft 42 and is rigidly affixed thereto. The third drive bar 124 includes a drive pin I28 attached to an outer end 130 of the drive bar 124. The second drive bar 122 extends radially from the operator shaft 42 and is freely mounted on the operator shaft 42 so that it is rotatable independently of the shaft 42. The drive bar 122 is, however, held stationary relative to the longitudinal axis of shaft 42 by the

spacers

136 and 138. The second drive bar 122 has a drive pin 132 attached to its outer end 134. The pin 128 extends into the path of rotation of the second drive bar 122 and the pin 132 extends into the path of rotation of the first drive bar 120. In either the closed or open condition of the shafts 40 and 42 and the forcing drive means 50, the pin 128 wll be spaced from the second drive bar 122 and the pin 132 will be spaced from the first drive bar 120. In FIG. 4, the shafts 40 and 42 and the forcing drive means 50 are shown in their closed condition. Thus, rotation of the operator shaft 42 through the first portion of its rotation in a clockwise direction to open the switch means 2 results in rotation of the pin 128 from a disengaged position into engagement with the second drive bar 122. In turn, rotation of the drive bar 122 due to the driving force of pin 128 results in the drive pin 132 rotating from a disengaged position into engagement with the drive bar 120. The position of the three

drive bars

120, 122, and 124 and the drive pins 128 and 132 is such that when the operator shaft 42 rotates in either a counterclockwise or clockwise direction the drive bars 124 and 122 act to rotate the drive pin 132 into engagement with the drive bar 120 just after the latch release 118 is released by the latch means 48. Consequently, forced opening or closing rotation for the switch means 2 independently of the spring operating mechanism 46 is provided. If this forcing rotation of the blade shaft 40 by the forcing drive means 50 is required, the operator shaft 40 continues to rotate during a second portion of its rotational movement to overcomevthe friction or break the welding and thereby permit the spring 84 to discharge and snap the switch means 2 to its closed or open position.

As shown in FIG. 2, when the switch means 2 is in its closed position, the latched bar 112 is held stationary by the latching bar 100. This latching action also holds the drive member and blade shaft 40 in a stationary condition. The spring 84 is in a discharged condition as indicated by

drive members

80 and 82 extending from the shaft 40 and 42 at the same angle. A switch opening operation is initiated by rotating the handle 44 and operator shaft 42 in a counterclockwise direction so that the drive member 82 also rotates counterclockwise and charges the spring 84. When the drive member 82 has rotated a predetermined distance, the latch release bar 118 engages the biasing finger 102 and moves it upward relative to the views of FIGS. 2 and 3. This is shown by the phantom lines indicating the'position of finger 102 when engaged by the bar 1 18 in FIG. 3. Only the biasing finger 102, latch release bar 118 and drive member 82 are shown in phantom lines in FIG. 3 for purposes of simplicity in showing the releasing position of latch means 48. Movement of the biasing finger 102 by the latch release bar 118 also moves the latching bar out of engagement with the latch surface 114. The latched bar 112 and drive member 80 are thereby free to rotate under the biasing effect of spring 84 and rotate the blade shaft 40 and snap the switch means 2 to its open position in FIG. 3. The latched bar 1 12 rotates with the shaft 40 to its latched position shown in FIG. 3 in which the latched bar 112 engages the latch surface 116 of latching bar 106. The drive member 80 extends from the shaft 40 at the same angle as the drive member 82, as shown in full lines in FIG. 3, so that the spring 84 is again in a discharged condition.

The closing operation of the switch means 2 is similar to the opening just described. The handle 44 and operator shaft 42 are rotated from their positions shown in FIG. 3 in a clockwise direction to thereby also rotate the drive member 82 and charge the spring 84. The latched bar 112, drive member 80 and blade shaft 40 remain stationary due to the holding of the latched bar 112 by the latching bar 106. As the shaft 42 rotates clockwise, the latch release bar 118 moves into engagement with the biasing finger 108 to move it and the latching bar 106 downward and release the latched bar 112. The drive member 80 and blade shaft 40 are now free to rotate and snap the switch means 2 to its closed position under the biasing force of spring 84. The switch means 2 and the switch operator 4 now assume the positions shown in FIGS. 1 and 2.

In describing the operation of the switch operator 4 and switch means 2, it has been assumed that the blade shaft 40 is free to rotate at the time of release of the latched bar 112 by thelatching means 48. In the event that the blade shaft 40 is not free to rotate upon release of the latched bar 112 due to friction or contact welding, the forcing drive means 50 will operate as previously described to overcome the friction or break the weld and permit the shaft 40 to rotate under the influence of Spring 84.

It may thus be seen that a switch operator has been provided in which rotation of an operating shaft will result in rotation of a switch and switch means with a snap action to a closed position and rotation of the operating shaft in the opposite direction will result in rotation of the switch shaft and switch means to an open position with a snap action. The switch operator includes resilient means which supplies the snap action operation. In the event that the resilient means is ineffective to open or close the switch means, forcing means which operates independently of the resilient means supplies a direct forcing action on the switch shaft and the switch means to supply additional opening or closing force. The resilient means and the forcing mechanism are extremely compact and relatively simple in construction so that an overall simple and economical switch operator is provided.

While only a single embodiment of the invention has been shown herein, it will be realized that many modifications thereof are feasible without departing from the spirit and scope of the invention. It is accordingly intended that the scope of the invention is not to be limited to the specific embodiment disclosed.

I claim:

1. In a load break switch including support means and switch means insulatively mounted on said support means, a switch opening and closing operator connected to said switch means and mounted on said support means comprising:

a first rotatable shaft means for opening said switch means and having a radially extending first drive member;

a second rotatable shaft means for providing rotational force to the first shaft means;

a resilient means connected between said first and second shaft means and being responsive to a predetermined amount of rotation of the second shaft means to rotate the first shaft means;

and a drive means mounted on and extending radially from the second shaft means, said drive means having a disengaged and an engaged position with the radially extending first drive member, said drive means being effective when in said engaged position with the first drive member to rotate the first shaft means in the event that the resilient means is unable to rotate the first shaft means upon the predetermined amount of rotation of the second shaft means, and the rotation of said second shaft exceeds said predetermined amount.

2. The combination according to claim 1 wherein:

said second shaft means has first and second rotational movement portions;

said resilient means is movable to a charged condition during the first rotational movement portion of the second shaft means as said second shaft means is rotated said predetermined amount; and

said drive means comprises a second drive member freely mounted on and extending radially from the second shaft means, a third drive member rigidly attached to and extending radially from the second shaft means, said third drive member being rotated toward engagement with the second drive member during the first rotational movement portion of the second shaft menas and while the resilient means if being charged, said second drive member being in engagement with the third drive member and with the first drive member during the second rotational movement portion of the second shaft means so that the first shaft means is rotated by the drive means only during the second rotational movement portion, following said predetermined amount of rotation of said second shaft means.

3. In a load break switch including support means and switch means insulatively mounted on said support means, a switch opening and closing operator connected to said switch means and mounted on said support means comprising:

a first rotatable shaft connected to said switch means and having rigidly affixed first and second drive members;

a second rotatable shaft having rigidly affixed third and fourth drive members;

a releasable latch means for holding the first rotatable shaft in a stationary position and being releasable in response to a predetermined rotation of the second shaft when said latch means is engaged by said second drive member whereby the first shaft is released to rotate;

resilient means connected between the first and third drive members and having a charged and a discharged condition and is movable to said charged condition in response to rotation of the second shaft in either direction, said resilient means being movable to its discharged condition in response to release of the first shaft by said releasable latch means, and being responsive to rotation of said second shaft for selectively rotating said first shaft together with the first drive member whereby said switch means is normally opened when said second shaft is rotated through a predetermined rotation in a first direction and said switch means is normally closed when said second shaft is rotated through a predetermined rotation in a second direction opposite said first direction, and said second and fourth drive members having positions in engagement when said second shaft is rotated through a rotation greater than said predetermined rotation and said switch means has failed to open when said second shaft is rotated in the first direction, or has failed to close when said second shaft is rotated in the second direction, so as to effect actuation of said switch means independently of the resilient means.

4. The combination according to claim 3 wherein:

said second shaft means has first and second rotational movement portions;

movement portion of the second shaft means so that the first shaft means is rotated by said fifth drive member only during the second rotational movement portion.

5. The combination according to claim 4 wherein said second, fourth, and fifth drive members are within said resilient means, said resilient means being a helical spring, one end of which is in driving engagement with the first drive member and the other end of which is in engagement with the second drive member.

Claims

1. In a load break switch including support means and switch means insulatively mounted on said support means, a switch opening and closing operator connected to said switch means and mounted on said support means comprising: a first rotatable shaft means for opening said switch means and having a radially extending first drive member; a second rotatable shaft means for providing rotational force to the first shaft means; a resilient means connected between said first and second shaft means and being responsive to a predetermined amount of rotation of the second shaft means to rotate the first shaft means; and a drive means mounted on and extending radially from the second shaft means, said drive means having a disengaged and an engaged position with the radially extending first drive member, said drive means being effective when in said engaged position with the first drive member to rotate the first shaft means in the event that the resilient means is unable to rotate the first shaft means upon the predetermined amount of rotation of the second shaft means, and the rotation of said second shaft exceeds said predetermined amount.

2. The combination according to claim 1 wherein: said second shaft means has first and second rotational movement portions; said resilient means is movable to a charged condition during the first rotational movement portion of the second shaft means as said second shaft means is rotated said predetermined amount; and said drive means comprises a second drive member freely mounted on and extending radially from the second shaft means, a third drive member rigidly attached to and extending radially from the second shaft means, said third drive member being rotated toward engagement with the second drive member during the first rotational movement portion of the second shaft menas and while the resilient means if being charged, said second drive member being in engagement with the third drive member and with the first drive member during the second rotational movement portion of the second shaft means so that the first shaft means is rotated by the drive means only during the second rotational movement portion, following said predetermined amount of rotation of said second shaft means.

3. In a load break switch including support means and switch means insulatively mounted on said support means, a switch opening and closing operator connected to said switch means and mounted on said support means comprising: a first rotatable shaft connected to said switch means and having rigidly affixed first and second drive members; a second rotatable shaft having rigidly affixed third and fourth drive members; a releasable latch means for holding the first rotatable shaft in a stationary position and being releasable in response to a predetermined rotation of the second shaft when said latch means is engaged by said second drive memBer whereby the first shaft is released to rotate; resilient means connected between the first and third drive members and having a charged and a discharged condition and is movable to said charged condition in response to rotation of the second shaft in either direction, said resilient means being movable to its discharged condition in response to release of the first shaft by said releasable latch means, and being responsive to rotation of said second shaft for selectively rotating said first shaft together with the first drive member whereby said switch means is normally opened when said second shaft is rotated through a predetermined rotation in a first direction and said switch means is normally closed when said second shaft is rotated through a predetermined rotation in a second direction opposite said first direction, and said second and fourth drive members having positions in engagement when said second shaft is rotated through a rotation greater than said predetermined rotation and said switch means has failed to open when said second shaft is rotated in the first direction, or has failed to close when said second shaft is rotated in the second direction, so as to effect actuation of said switch means independently of the resilient means.

4. The combination according to claim 3 wherein: said second shaft means has first and second rotational movement portions; said resilient means is movable to a charged condition during the first rotational movement portion of the second shaft means; and a fifth drive member freely mounted on and extending radially from the second shaft means, said fourth drive member being rotated toward engagement with the fifth drive member during the first rotational movement portion of the second shaft means and while the resilient means is being charged, said fifth drive member being in engagement with the fourth drive member and with the second drive member during the second rotational movement portion of the second shaft means so that the first shaft means is rotated by said fifth drive member only during the second rotational movement portion.