US3930214A

US3930214A - Pushbutton electric switch with reset mechanism

Info

Publication number: US3930214A
Application number: US513372A
Authority: US
Inventors: Edward L Richards; Charles R Paton; Daniel G Rooney
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1974-10-09
Filing date: 1974-10-09
Publication date: 1975-12-30
Anticipated expiration: 1992-12-30
Also published as: GB1517197A; BR7506568A; CA1044291A; ZA756057B

Abstract

A circuit interrupter characterized by a manually operated fast acting switch and an overload relay for tripping the switch in response to current overload as well as reset means therefor. The switch comprises a pair of pushbuttons for manually opening and closing the switch which pushbuttons are effective to move an operating lever for actuating an overcenter toggle mechanism. The reset button is provided in conjunction with one of the pushbuttons inoperable to provide visual indication of the ''''tripped,'''' or ''''open'''' positions.

Description

[11] 3,930,214 14 1 Dec. 30, 1975 United States Patent 1 91 Richards et al.

[ PUSHBUTTON ELECTRIC SWITCH WITH RESET MECHANISM Primary ExaminerHarold Broome Attorney, Agent, or Firm-L. P. Johns [75] Inventors: Edward L. Richards, Aliquippa;

Charles R. Paton, New Brighton; Daniel G. Rooney, Beaver, all of Pa.

ABSTRACT A circuit interrupter characterized by a manually operated fast.acting switch and an overload relay for tripping the switch in response to current overload as 22 Filed:

21 Appl. No.: 513,372

well as reset means therefor. The switch comprises a pair of pushbuttons for manually opening and closing 337/72; 200/159; 335/26; the switch which pushbuttons are effective to move an 2 operating lever for actuating an overcenter toggle Int. Cl. mechanism The reset button is provided in c0njunc 9 ms 71 mm m2 nm 6 6 7 7 3 3 m r. a e S Cl 0 d 1 e n 11 18 55 [I tion with one of the pushbuttons inoperable to provide visual indication of the tripped, or open positions.

6 Claims, 6 Drawing Figures US. Patent Dec. 30, 1975 Sheet 1 of2 3,930,214

U.S. Patant Dec. 30, 1975 Sheet20f2 3,930,214

FIG. 2

PUSHBUTTON ELECTRIC SWITCH WITH RESET MECHANISM CROSS REFERENCE TO RELATED APPLICATIONS This invention is related to the invention disclosed in the applications of Edward L. Richards et al., Ser. No. 345,396, filed Mar. 27, 1973; Ser. No. 513,370, filed Oct. 9, 1974; and Ser. No. 513,371, filed Oct. 9, 1974.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a circuit interrupting device having switch tripping mechanism responsive to current overload and, more particularly, it pertains to a pushbutton manually-operative switch which includes a reset pushbutton, the position of which is a visual indication of the tripped, or open condition of the switch.

2. Description of the Prior Art Circuit interrupters of some prior construction have been provided with circuit overload protection devices that function in response to abnormal current, such as overcurrents, ground fault currents, and short circuits, that occur in an electrical distribution system. A circuit breaker of that type is enclosed, for example, in U.S. Pat. No. 3,530,314. Some circuit breakers of that type are provided with toggle handles by which manual operation is accomplished. Other circuit breakers are provided with a pushbutton type of manual operation rather than a toggle handle. It is desirable to provide a resetting mechanism, whereby the toggle mechanism is easily relatched. Moreover, it is desirable to provide a reset mechanism which includes a visual indication that the mechanism is in the tripped, or open position.

SUMMARY OF THE INVENTION In accordance with this invention it has been found that the foregoing problems may be overcome by providing a circuit interrupting device which comprises a switch mechanism and an electrically insulating housing therefor, the switch mechanism, including relatively movable contact means and means releasable to effect automatic opening of said contact means, operating means for moving the contacts between open and closed positions, the operating means comprising an overcenter toggle and releasable arm operable to effect movement of the movable contact structure, a latch lever releasable connected to the releasable arm for retaining the releasable arm in the untripped position, means responsive to a current overload condition for actuating the latch lever to the tripped position, the housing having an opening, and a reset pushbutton extending through the opening and effective to move the releasable arm to the open position, asecond pushbutton extending through the opening and effective to move the releasable arm to the closed position, the first pushbutton comprising opening means extending in a direction substantially parallel to the direction of movement of said first pushbutton, and a reset pushbutton within said opening means and effective to move the releasable arm to the untripped position with respect to the tripped lever.

The advantage of the device of this invention is that it provides a manually operated toggle switch having a pushbutton type of manual operation which avoids the problem of accidental operation of the conventional toggle handle, and which incorporates a reset pushbut- 2 ton which provides a visual indication that the mechanism was tripped.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a vertical sectional view through a three pole overload relay and a circuit interrupter, the latter of which comprises pushbuttons in accordance with this invention;

FIG. 2 is a vertical sectional view taken on the line 11-11 of FIG. 1';

FIG. 3 is a perspective view of one of the pushbuttons;

FIG. 4 is a plan view taken on the line of IVIV of FIG. 1;

FIG. 5 is a fragmentary sectional view showing a reset button in the stop pushbutton showing the reset button in the latched position; and

FIG. 6 is a view similar to FIG. 5 showing the reset button in the tripped button.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 a circuit interrupter is generally indicated at 7 and it comprises a manually operated switch 9 and an overload relay 11, both of which are mounted on a supporting base 13.

Inasmuch as a detailed description of the switch 9 is set forth in the application of Edward L. Richards, Ser. No. 404,579, filed Oct. 9, 1973, the description here is limited to the parts'that are essential to the operation of the invention disclosed herein. Suffice it to say, the switch 9 is a multi-pole, such as a three-pole, switch which includes a pair of stationary contacts 17, a pair of movable contacts 19, as well as a movable contact carrier means 21. The switch 9 also comprises a manually operated overcenter toggle mechanism generally indicated at 23 which, in turn, comprises a releasable arm 25 that is pivotally mounted on a pivot pin 27 that extends between a pair of upright frames 29 and 31 (FIG. 2). The overload toggle mechanism 23 is enclosed within a housing 33 of electrically insulating material and includes a pair of manually operated

pushbuttons

35 and 36 which extend upwardly through an opening 34 on the top surface of the housing.

The left end ofthe releasable arm 25 is retained in a latched position in a manner disclosed in the application of Edward L. Richards, Ser. No. 513,370, filed Oct. 9, 1974, for which reason the description herein is limited to the parts that are essential to the operation of the invention disclosed herein. Briefly, the trip mechanism comprises a latch lever 37 and a retainer lever 39. The latch lever 37 is an L-shaped or bell-crank type lever which is pivoted on a pair of similar trunnions 41 extending from opposite sides thereof into corresponding apertures in the spaced upright frames 29, 31. The latch lever 37 also includes an opening 43 in which the left end of the arm 25 is seated when in the latched position as shown in FIG. 1. The lower end of the latch lever 37 extends to and is engaged by the retainer lever 39 which is a substantially vertically extending member having similar trunnions 45 extending from opposite sides thereof and seated in corresponding apertures in the spaced upright frame 29, 31.

A hole 47 is disposed in the retainer lever 39 below the trunnion 45 and the lower end of the latch lever 37 is seated in the hole when in the latched condition. The lower end portion of the retainer lever 39 is disposed in an aperture 53 of a trip plate 55, which (FIG. 1) extends from the overload relay 11. When the trip plate is moved by the relay to the left (FIG. 1), the retainer lever 39 rotates clockwise until the lower extremity of the latch lever 37 moves out of the hole 47, whereupon the latch lever rotates counterclockwise. The releasable arm 25 rotates clockwise until it strikes a stop pin 57 which extends between the upright frame 29, 31. Movement of the retainer lever 39 and the latch lever 37 in the manner described constitutes tripping of the circuit interrupter 7 and causes the movable contact 19 to separate from the stationary contacts 17.

Inasmuch as the overload relay is disclosed specifically in the application of E. L. Richards, Ser. No. 471,740, filed May 20, 1974, the description of the relay is limited to the parts which are essential to operation of the invention disclosed herein. The relay includes bimetals 71, bimetal heaters 73, a crossbar 75, a trip lever 77, and the trip plate 55. When a current in excess of that for which the heater elements are rated to handle occurs, the heaters 73 cause the bimetals to move the crossbar 75 against the lower end of the trip lever 77 causing the upper end thereof to rotate counterclockwise and pull the trip plate 55 to the left, whereupon the latch lever 39 is rotated clockwise as set forth above. In that manner the switch 9 is tripped automatically when the current overload occurs in the current supply.

In accordance with this invention the switch 9 comprises the

pushbuttons

35, 36 as well as a pair of rocker levers or operating levers 79 by which the overcenter toggle 23 is actuated to open and close the contacts 17, 19. The rocker operating levers 79 are provided in pairs which are separately mounted on the outer surfaces of the upright frames 29 and 31 (FIG. 2). Both levers 79 are similar in construction, and are pivotally mounted at 81 (FIG. 1). Each lever 79 is provided with a pair of outturned flanges or projections 83, which are disposed in planes perpendicular to the plane of the lever 79. The levers 83 are disposed at the lower end of and are actuated by the pushbutton 35. Similarly, the levers 85 are disposed at the lower end of and are actuated by the pushbutton 36. In addition, the rocker or operating levers 79 are secured to an inverted U- shaped lever 87 by similar pins 89, which lever 87 is pivotally mounted at the pivot point 81.

Both

pushbuttons

35 and 36 have similar construction. The pushbutton 35 (FIG. 3) includes a head portion 93 and a pair of spaced, downwardly-extending

portions

95 and 97, whereby each

pushbutton

35, 36 is a generally U-shaped member. In addition, a shoulder 99 extends around three sides of the head portion 93 which shoulder (FIG. 2) is normally seated against a surface 101 of the housing when the pushbutton 35 is fully extended as shown in FIG. 1. Thus, the shoulder 99 and the surface 101 cooperate to prevent the pushbuttons from escaping from the housing 33. In addition, the pushbutton 35 comprises similar opposite side surfaces 103, 105, one of which is shown in FIG. 3, which are in surface-to-surface contact with inner surfaces of the housing and thereby facilitate guiding of the

pushbuttons

35 and 36 when they are depressed.

Each

pushbutton

35, 36 includes a vertical projection 105 extending from the shoulder 99 to the lower end of the portions 95. A similar projection 107 is provided on the portion 97 of the

pushbutton

35, 36. The

projection

105 and 107 are disposed in

projection receiving grooves

109 and 111 respectively which grooves are disposed in the inner wall of the housing 33. Each

pushbutton

35, 36 is likewise preferably provided with a pair of

projections

113, 115 which are seated in

similar grooves

117 and 119, respectively. The combination of the

projections

105, 107, 113, 115 and the

surfaces

103, 105 cooperate with the inner surfaces of the housing including the

grooves

109, 111, 117, 119 to guide the movement of the

pushbuttons

35, 36 when they are actuated. A minimum of binding between the pushbutton and the housing exists.

The lower ends of the depending

portions

95, 97 are bifurcated to provide spaced

members

121, 123, 125, and 127. As shown in FIG. 2, the depending

portions

95 and 97 extend downwardly within the housing 33 with the

bifurcated portions

121 and 123 seated over and around one projection 85 of the rocker or operating lever 97. While the other

bifurcated portions

125, 127 are seated around the other projection 85 of the operating lever 79 on the other side of the housing. Accordingly, when either

pushbutton

35, 36 is depressed, a force is applied against the

projections

83 or 85 to tilt or rock the operating lever 97 in one direction or the other, thereby actuating the switch between the open and closed positions.

In accordance with this invention when the circuit interrupter 7 is tripped, such as by overload current, it is necessary to reset the overcenter toggle mechanism 23 before the contacts 17 and 19 can be closed. For that purpose a reset device comprising a reset button 129 and a bracket 131 (FIGS. 5 and 6) are provided. The pushbutton 35 which is the stop pushbutton is provided with an inner compartment 133 in which the reset button 129 and the bracket 131 are slidably mounted.

When the reset button 129 is in the position shown in FIG. 5, that is, when the upper end of the button is flush with the upper end of the pushbutton 35, the end of the releasable arm 25 is seated in the opening 43 of the latch lever 37. In that position, a spring 135 within the chamber 133 presses upon an arm 137 of the bracket 133 to hold the reset button 129 in that position, and the bracket 131 is in the fully depressed position, such as against the lever 25.

When the circuit interrupter 7 is tripped due to a current overload, the latch lever 37 is rotated to the position shown in FIG. 6 and the releasable arm 25 is rotated upwardly as set forth above, indicating the tripped position of the circuit interrupter. In that position the reset button 129 extends above the top surface of the pushbutton 35, indicating to an operator that the circuit interrupter 7 is in the tripped position. Pressing the button 129 downwardly until it is in the position of FIG. 5, causes the bracket 131 to move the releasable arm 25 back to the reset position as shown in FIG. 5. After the overcenter toggle mechanism 23 is reset, the pushbutton 36 may be again depressed to move the contacts 17 and 19 to the closed position.

In conclusion, the combination of the reset button located in the pushbutton 35 provides a convenient solution to the problem of visually determining whether or not the circuit interrupter is in the tripped or latched position, and thereby satisfies a problem previously associated with the pushbutton manual method for actuating a circuit interrupter to the open or closed position.

What is claimed is:

1. A circuit interrupting device comprising a switch mechanism and an electrically insulating housing therefor, the switch mechanism comprising relatively movable contact means, operating means for moving the contact between open and closed positions and comprising an overcenter toggle and releasable arm operable to effect movement of the movable contact structure, the releasable arm also being movable between tripped and latched positions, a latch lever releasably connected to the releasable arm for retaining said arm in the latched position, means responsive to a current overload condition for actuating the latch lever to the tripped position, the housing having an opening, a reset pushbutton extending through the opening and effective to move the releasable arm to the latched position with respect to the trip lever, a first pushbutton extending through the opening and effective to move the releasable arm to the open position, and a second pushbutton extending through the opening and effective to move the releasable arm to the closed position.

2. The circuit interrupting device of claim 1 in which the contacts being operable between open and closed positions when the releasable arm is in the latched 6 position, and the reset pushbutton being effective to move the releasable arm into releasable connection with the trip lever.

3. The circuit interrupting device of claim 2 in which the reset pushbutton is unaligned with one of the first and second pushbuttons when in the tripped position.

4. The circuit interrupting device of claim 3 in which the first pushbutton comprises opening means extending in a direction substantially parallel to the direction of movement of said first pushbutton, and the reset pushbutton being seated in said opening means.

5. The circuit interrupting device of claim 4 in which the reset pushbutton is substantially aligned with the first pushbutton 'when the operating lever is in the latched position.

6. The circuit interrupting device of claim 4 in which the reset pushbutton is unaligned with the first pushbutton when the operating lever is in the tripped position.

Claims

2. The circuit interrupting device of claim 1 in which the contacts being operable between open and closed positions when the releasable arm is in the latched position, and the reset pushbutton being effective to move the releasable arm into releasable connection with the trip lever.

5. The circuit interrupting device of claim 4 in which the reset pushbutton is substantially aligned with the first pushbutton when the operating lever is in the latched position.