CA1044291A - Pushbutton electric switch with reset mechanism - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
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

CROSS REFERENCE ~0 _~LA~EDjAPPLICATIONS
This invention is related to the invention dis-closed in U.S. Patent 3~930~213 issued ~ecember 30~ 1975 to Edward L. Richards et al.
BACK~ROU~D OF THE INVENTION
Field of the Invention ~ .
Thls inventisn relates to a circuit interrupting device having switch tripp~g mechanism responsive to current overload ~d, more particularly, lt pertains to a pu~hbutton manually-operative switch which lncludes a re-set pushbutton~ the position oP which is a visual indi-cation o:E the tr~pped, or open condition o~ the sw~ tch.
Description o~ the Prior Art _ ' ~ ' . :

~i :

2~l Circuit ln-terrupters of some prior cons-truc-tion have been provided with circuit overload protection de-vices 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 patent No. 3,530,314 issued September 22, 19700 Some circuit breakers of that type are provided with toggle handles by which manual operation is accomplished. Other circuit breakers are provided with 2 pushbutton type of manual operation rather ~han a tog~le handle. I-t is desirable to provide a resetting mechanism, whereby the toggle mechanism is easily relatchedD Moreover, it is de- ;
sirable to provide a reset mechanism which includes a visual indication that the mechanism is in the tripped, or open positionO
SUMMARY OF THE INVENTION
In accordance with this invention it has been found tha-t the foregoing problems may be overcome by pro-viding a circuit interrupting device which comprises aswitch mechanis~. and an electrically insulating housing therefor, the switch mechanism, including relatively movable contact means and means releasable to effect automatic `~ opening of scid contact means, operating means for moving the contacts between open and closed position, the opera-ting means comprising an overcenter toggle and releasable arm operable to effect movement of the movable contact structure, a latch lever releasable connected to the re-leasable arm for retaining the releasable arm in the un-tripped position, means responsive to a current overload condition for actuating the latch lever to the tripped ~14~z~

posi-tion, the ho~lsing having an opening, and a reset pushbutton ex-ten~ing through -the opening and effective to move the releasable arm to the open position, a second pushbutton extending throu~h -the opening and e~ective to move the releasable arm to the closed position, the first pushbutton comprising opening means extending in a direction subs-tan-tizlly parallel -to the direction of movement of said flrst pushbutton, and a reset pushbutton within said opening means and effective -to move the re-leasable arm to the untripped position with respect tothe tripped leverO
The advantage of the device of this invention is that it provides a manually operated toggle switch hav-ing a pushbut-ton type of manual operation which avoids the problem of accidental operation of -the conventional toggle handle, and which incorporates a reset pushbutton which ~ :
provides a visual indication that the mechanism was tripped.
BRIEF DES _IPTION OF THE DRAWINGS
Figure 1 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;
Figure 2 i5 a vertical sectional view taken on ~ ;
the line II-II~of Fig. l;
- Figure 3 is a perspective view of one of the pushbuttons; -Flgure ~ is a plan view takan on the line of IV-IV of Figure l;
Figure 5 is a fragmentary sectional view showing 0 a reset button in the stop pushbutton showing the reset ;~ .

button in the latch~d position; a~d Fl~ure 6 ls a vlew slmilar to Flg. 5 showing the reset button in the tri~ped button.
~ ESCRIPTION OF THE PREE ERRED EMBODIMENT
In Flg . 1 a c ircuik interxupter is ger.erally: :
~ndicated at 7 and it eomprlses a manually operated switch 9 and an overload relay 11, both o~ which are mounted on a suppor~ing base 13.
In as much a~ a detailed description of the switch 9 is set ~orth in U,S. Patent 3,867 ,598 issued February 18, 1975, to Edward L. Richards9 the descrlption here is llmited to the partæ that are essential to the operation of the inventi on disclo~ed herein. Su~lce it to say, the switch 9 is a multi~pole, such as a, three~pole, switch which lncludes a pair of stationary contz.cts 17, a palr o~ movable contacts 19, as well as a movable contact carrier mea~ 21. The s~itch 9 also co~prise~ a manually operated overcenter toggle mechanism generally indicat~d at 23 whlch, in turn9 comprises a releasable arm 25 that is pivotally mounted on a pivot pin 27 that extends between a pair o~ uprlght Pra.mes 29 ~nd 31 (Fig. 2). The o~erload toggle mechanl~m 23 is enclosed ~lthin a houslng 33 ~f ~:~ electrically ~n~ulatlng material and ~ncludes a palr o~
: ; manually operated pushbuttons 35 and 36 which extend up-wardl~ through an opening 34 on the top sur~ace of the ~: hous~ng O '~
The le~t end of the releasable arm 25 is reta~ned in a latched posltlon in a manner disclos~d in U. ~O Patent . ,:!

3,930,213 issued December 30, 1975 to Edward L. Rlchards3 for whlch .~

.

reason -the description herein i.s limited to the parts that are essential -to the operation of the invention dis-closed 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 ~3 in which the left end of the arm 25 is seated when in the latched position as shown in FigO 1.
The lower end of -the latch lever 37 extends to and is en-gaged by the retainer lever 39 which is a substantially vertically extending member having similar trunnions 45 extending from opposite sides thereof and seated in corres-ponding apertures in the spaced upright frame 29, 31.
A hole ~7 is disposed in the retainer lever 39 below the trunnion 45 and the lower end cf the latch lever 37 is seated in the hole when in the latched conditionO
The lower end portion of the retainer lever 39 is disposed 20 in an aperture 53 of a trip plate 55, which (Fig. 1) ex-tends from the overload relay 11. When the trip plate 55 is :moved by the relay to the left (FigO ~), the retainer lever :: 39 ro-tates clockwise until the lower extremity of the latch ~ .
lever 37 moves out of the hole 47, ~-hereupon the latch lever rotates counterclockwise~ The releasable arm 25 ro-tates clockwise until it strikes a stop pin 57 which extends between the upright frame 29, 310 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 ~0~2~

contacts 17~ ; -Inasmuch as -the overload relay is disclosed specifically in U.S. Patent 3,903,493 issued September 2, 1975 to E r L~ Richards, the description of -the relay is limited to the parts which are Pssential 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 550 When a current in excess of that for which the heater elements are rated to handle occurs, the heaters 10 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 O
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 (FigO 2). Both levers 79 are similar in construction, and are pivotally mounted at 81 (FigO 1)~
Each lever 79 is provided with a pair of outturned flanges :. or projections 83, 85 which are disposed in planes per-pendicular 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 3~. In addition, the rocker or operating levers 79 are secured to an inverted U-shaped lever 87 by similar pins 89, whlch lever 87 is pivotally mounked at the pivot point 81~
soth pushbuttons 35 and 36 have similar con-structionO ~The pushbutton 35 (Fig~ 3) includes a head portion 93 and a pair of spaced, downwardly-extending portion.s 95 and 97, whereby each pushbu-tton 35, 36 is a :
generally U-shaped member. In addi-tion, a shoulder 99 ex-tends around three sides of the head portion 93 which shoulder (FigO 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 330 ~In addition, the pushbutton 35 comprises sim-ilar opposite side surfaces 103, 105, one of which is shown :
in FigO 3, which are in surface-to-surface contact with inner surfaces of the housing and thereby facilitate guid- .
ing of the pushbuttons 35 and 36 when they are depressed.
Each pushbutton 35, 3~ includes a vertical pro-jection 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 lO9 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 113t 115 which are seated in similar grooves 117 and 119, respectivelyO The combination of the projections 105, 107, 3C 1].3, 115 and the surfaces 103, 105 cooperate with the inner .

surfaces of -the housing including the grooves 109, 111, 117, 119 to guid~ the movement of the pushbu~tons 35, 36 when they are actuated. A minimum of binding between the pushbutton and the housing existsO
The lower ends of the depending portions 95, 97 are kifurcated to provide spaced members 121, 123, 125 and 127. As shown in Fig~ ~, 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 ~5 of the operating lever 79 on the other side of the housing. Accordingly, when either push~
but-tcn 35, 36 is depressed, a force is applied against the projections 83 or 8~ to tilt or rock the operating lever 97 in one direction or the other, thereby actuating the switch between the open and closed posi-tionsO
In accordance with this invention when the cir-cuit 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 closedO ~For that purpose a reset device comprising a reset button 129 and -a bracket 131 (Figs. 5 and 6) are providedO ~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 mountedO
When the reset button 129 is in the posi-tion shown in FigO 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 -a-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 positiorl, such as against the lever 250 When the circuit interrupter 7 is tripped due -to a current overload, the latch lever 37 is rotated to the position shcwn in FigO 6 and the releasable arm 25 is rotated upwardly as set forth above, indicating the t~ipped pcsition of the circuit interruptern In that posi-ti.on 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 positionO 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. Af-ter the overcenter -toggle mechanism 23 is reset, the pushbutton 36 may be again depressed to move the con-tacts 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 'cripped or latched ~: position, and thereby satisfies a problem previously asso-ciated with the pushbutton manual method for actuating a circuit in-terrupter to the open or closed positionO

Claims (6)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

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 a 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 position, and the reset pushbutton being effective to move the re-leasable 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 posi-tion.

4. The circuit interrupting device of claim 3 in which the first pushbutton comprises opening means ex-tending 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 an 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 an operating lever is in the tripped position.