US2083509A

US2083509A - Circuit breaker

Info

Publication number: US2083509A
Application number: US27176A
Authority: US
Inventors: Schmidt Lambert
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-06-18
Filing date: 1935-06-18
Publication date: 1937-06-08
Anticipated expiration: 1954-06-08

Description

L. SCHMIDT CIRCUIT BREAKER `lune 8, 1937.

2 Sheets-Sheet 1 Filed June 18, 1935 OR EY.

, INVENTOR. [aff/Hf ,f lf2/M June 8, 1937. SCHMIDT 2,083,509

CIRCUIT BREAKER Filed June 18, 1955 2 Sheets-Sheet 2 f5 "96 z' I Z5 17 Z3 3 35 l "di .3 3440 l 10 96 Z7 l L. 1&6 $0 L` K\| I l 0 I lt @Uy 62914 Q i 6g W5?, i 9l l 90 l ZZ gi fz i y A 9iV 91d g3 10451 g4( 93 MIL!!! l! 7/ han 7L@ /vxsfmll INVENTOR.

Patented June 8, 1937 I UNITED STATES PATENT OFFICE CIRCUIT BREAKER Lambert Schmidt, Leeds, N. Y.

Application June 18, 1935, Serial No. 27,176

15 Claims. (Cl. 200-116) This invention relates to circuit breakers and has for its object to provide certain improvements in circuit breakers of the type for which I now have pending an application for Letters Patent of the United States, Serial No. 702,153, dated December 13, 1933. By means of these improvements in the case of a short circuit or a flow of electricity greater than that normally intended, the circuit cannot be permanently closed.v Such closing of the circuit brings about a short circuit on the main circuit or burns out the parts of the circuit breaker.

An object of this invention, accordingly, is to provide, in circuit breakers of the above type, mechanism by means of which the breaker contacts may be maintained in an open position regardless of whether manual pressure is exerted upon the closing mechanism or not.

A further object of the invention is to provide, in combination with mechanism of the above character, a free tripping mechanism which serves as a connection between the manual operating mechanism and the movable breaker element, such mechanism rendering the connection between these elements inoperative to maintain the breaker contacts in closed position by continued manual mechanism.

A further object is to provide free tripping mechanism of the above character, the structure of which is independent of the structure of the circuit breaker, thus enabling the breaker elements to be of such construction that the breaker structure may be of minimum size.

A further object of the invention is to provide indicating means lby which a user may immediately detect whether or not an overload or short circuit is present. This indicating means Warns against operating the push-button of the circuit breaker and therefore enables the user to see whether or not the device is out of working order.

For this purpose an important feature of the invention lies in the freedom of the operating rod of the circuit breaker under spring action, so that the circuit will not be permanently closed. This is accomplished by giving the rod an unimpeded movement which will avoid the rod being held back and will enable it to be free to move without making permanent contact; in other Words, a free tripping device is provided.

The invention consists in further providing indicating means operative in such cases where therod itself does not close the circuit and where the circuit is under current flow above thepredetermined normal amount.

pressure upon the starting The invention is shown as embodied in the structure depicted in the drawings, and will be hereinafter more fully described in the light of this embodiment, and iinally set forth in the subjoined claims.

In' the accompanying drawings:-

Figure 1 is a vertical section taken through a circuit breaker showing my improvements embodied therein;

Figure 2 is a plan view `or section taken on line 2 2 of Fig. 1;

Figure 3 is a section similar to that of Fig. 1, but showing only certain parts of the device shown in Fig. 1 and showing them in different operative positions Figure 4 is a perspective View of the guide springs or rod-holding device;

Figure 5 is a. partial side view ofthe piston sleeve to operate the spring iingers shown in Fig. 4;

Figure 6 is a side View of the rod which enters the sleeve of Figure 5 and slides in respect thereto, and is either impeded by the spring ngers shown in Figure 4l or is left free to pass therethrough by the opening of the spring n'gers by the sleeve shown in Figure 5;

Figure 'l is a section of the parts 'shown in Figure 3 in different positions, and embodying a further improvement in the form oi' an indicating device;

Figure 8 is a side view ci an attachment plug of a different type 'than that shown in Figure 1, Figure 8 showing a thrust-in type of attachment plug which is also an embodiment of the invention;

Figure 9 is a section view of another embodiment of the signalling device;

Figure 10 is a plan view taken on .line lil-I0 of Figure 9;

Figure 11 is a sectional view of another embodiment;

Figure 12 is a similar view taken at right angles tc that of -Figure 11;

Figure 13 is a sectional view of another embodiment of the thermostatc control which acts to hold the switch rod and also acts as a contact device;

Figure 141s a plan view taken on line |4-i4 of Figure 11;

Figure 15 is a plan view taken on line I5-l5 of Figure 11; and

Figure 16 is a plan view of a contact plate. Similar characters of reference indicate corresponding parts throughout the various views.

Referring nowto the drawings, and more particularly to Figure 1, the plug casing I has a threaded portion II and a contact piece I2, as is well known. Disposed within the plug casing i0 is a socket member I3 to which is pivotally attached a sp'ring plate I4 having an opening I5, the edge of which opening is adapted to be engaged by the plug I6 on the rod II. When the plug I6 engages the edge of the opening I5, the rod |"I is held in downward locked position. This locking device forms the basis of my above-mentioned pending application.

A thermostatic member I8 of horse-shoe form is supported by the studs |861., and this member is so arranged that when current in excess of that which can be considered normal, passes through the member I8 the iree end of the latter descends and the plate I4 is actuated in a downward direction. When this plate I4 is moved downwardly the edge of the opening I5 is dis-engaged from the plug I6 and the latter with the rod I'I is free to move upwardly under the action of the spring I9 which spring is seated in the bottom .of the socket portion and acts against the plug I6. 'The rod I'I has a contact member adapted to engage three or more spring-like prongs indicated by 2|. When the contact member 20 which is of plunger form, is forced into spring-like members 2| and engaged thereby and held in position therein, the electric current passes through the contact members, that is, the electric circuit is closed when the member 20 engages the members 2|. The member 20 is held in position within the springlike contact members 2| and the rod I`I has its plug I6 locked by the spring plate I4, as above described. Upon the operation of the horse-shoe member I8 by an excess current, the spring plate unlocks itself by reason of the spring member I9 and the rod I'I is forced upwardly whereupon the

members

29 and 2| are disengaged and the circuit is broken.

This unlocking action can also be accomplished by means of an external push-button 22, having a rod 23 which extends through casing I0 and through the recessed end IBD of the thermostatic member I8 to the spring-plate I4. Downward pressure on button 22 presses the plate I4 downwardly and unlocks rod II. Thus rod I1 under its spring action, as above described, may ascend and break the circuit.

It has been found that in cases where the thermostatic couple operates to release the rod, the rod will again be presse-d downwardly and, when the parts are under an overload current, they burn out or short circuit results. If a user repeatedly presses down on the push-button, as 25, short circuits in the entire system may result. To overcome this, my improvement which forms the basis of the present application consists in the following mechanism:

Spring fingers 26 provided with jaws 21, such as shown in Fig. 4, are arranged within the pushbutton 25. These spring fingers extend upwardly from a base portion 28, which base portion seats in a suitable recess` 29 at the lowermost portion of the push-button 25. A sleeve 30 has a rounded end portion 3| (shown also in Fig. 5) and a plate 33. In the embodiment, the sleeve 30 is supported upon or is made integral with the plate 33 which is held to the casing I0 by screws 34, a spring 35 of spiral shape being interposed between the plate 33 and the bottom of the pushbutton 25. This is clearly shown in Fig. 1, where the spring is shown in extended position, and in Fig. 3 where the spring is shown in compressed position.

The operation oi the embodiment described is explained as follows: When an excess of current acts upon the thermostatic couple I8, this member is moved downwardly, whereby the plate I4 is unlocked from plug I5, and rod l1 is free to move upwardly under the action of its spring I9. If the push-button is now pressed down, the jaws 2l of the spring fingers 26, will engage the flat end Ila of the rod il and move it downwardly. This downward movement of the rod i'I continues until the push-button arrives at a position wherein the bent portions 32 `oi the spring ngers 26 meet the rounded portion 3| of the sleeve 30, through which the rod is free to slide. Upon further downward pressure applied to the push-button 25, the rounded portion 3l opens the jaws 2l, and the rod Il is free to pass therethrough. The spring i9 then forces the rod il upwardly with great rapidity.' in the meantime, the contact member 20 has made momentary contact with the contact member 2|, but this is only instan-- taneous. The user pushing the push-button, can do so repeatedly and each time the rod il will jump upwardly with great rapidity, and no harm can result therefrom. This result is predicated upon the fact that the overload acts upon the thermostatic couple I8 which in turn presses the spring rod downwardly to prevent the spring rod from locking the rod il. lin consequence oi the downward pressure of the push-button 25, the rod is :First pushed down by the jaws 2l and then passes through the jaws 2l, as shown in Fig. 3, and while this causes the

members

20 and 2| to contact, there is nothing to hold the rod in its downward position or to maintain it in its downward position, and therefore under the action of the spring I9, it immediately and instantaneously jumps upwardly until the plug IB reaches the plate 33. While Contact is made between the contact members, it is insuflicient to cause a destructive current `to pass through the

members

20 and 2|. By virtue o this arrangement of parts, the push-button 25 can be pushed down repeatedly but the rod I1 will always jump through and refrain from making a permanent electric circuit, and therefore all danger of short circuiting to the system is obviated.

With the embodiment shown in Fig. 1, it may possibly be that the user will continue to press down and cause rod I1 to be moved downwardly and instantaneously jump back and at the same time wonder why no current passes through to light the lamp or the like, and in order to prevent such repeated action, an indicating device is provided. An embodiment thereof is shown in Fig. 7, in which a plate 4D has two upwardly extending rods 4| which pass through openings 42 in the top of the casing I0, and upon these rods 4I enlargedfportions or buttons 43 of a suitable color, such as results from a bright bakelite, preferably red, are arranged. The plate 4U has a central opening 44 somewhat larger than the diameter of the rod I'I, so as to permit the rod I'I to freely move through said opening 44. A spring 45 is interposed be` tween the plate 40 and the plate 33, which in this embodiment, has a shoulder portion 46 in order to act as a seat for one end of the spring 45. In the normal closed position of the device the plate 40 is ln'the position shown in Fig. 7, that is, with the buttons 43 hidden in rtheir sockets 4'I. The plate 40 is disposed immediately above the plug I 6 on the rod I'I, and on the upward movement of the rod I'I and its plug I6, the plate 49 is carried along and thereby the buttons 43 are exposed exteriorly to the casing, whereby they are visible. When visible, the user will see the danger indication and will refrain from pressing down the button 25. -Thus when the plug I6 of the rod I1 presses upwardly against the plate 33,l through the plate 40, the danger signal will be visible. When, however, the rod Il makesa permanent contact through the

members

29 and 2|, then vthe spring 45, presses the plate 40 downwardly, and this causes the signals 43 to disappear in their sockets.

When, however, the circuit is in a normal condition and the plate I8 is in its open position and it is desired to close the circuit, then l5 the push-button 25 is pressed downwardly and the jaws 21 engage the nat end I 1a of the rod I1, whereby on the downward pressure of they push-button 25 with the jaws 21 in contact with the flat end I'Ia of the rod I1, the rod I1 is '20 pressed downwardly and the spring plate I4 locks the plug I5 in position, whereby the

contact members

20 and 2| are made permanent and the circuit is closed.

From the foregoing, it will be seen that with 25 the arrangement of the sleeve 30 upon the rod I1, which sleeve has a roundedportion 3| to move the jaws 21 outwardly and open the same. the rod II may freely move up and down without permanent engagement of the contact 30

members

20 and 2|. On the other hand, when the rod I1 encountersthe jaws 21, the downward pressure of the push-button 25 forces the contact members 2l) and 2| in permanent engagement with each other under the locked po- 35 sition of rod i1. ,The current path through the foregoing mechanism flows from the shell Il to the lower post |8a in Figure 2 which is seen as being insulated from the plate I3. From this post the current flows through element |8,

40 plate I3, rod I1 and

contact terminals

20 and 2| to the central contact I2.

It is also to be noted that the arrangement of the plate with the indicating buttons 43 provides a very simple and assured means of indi- 45 cati'ng a danger sign to the user of the device, in case either excess current moves the member I8 downwardly against the plate I4, or the rod 23 is pressed normally downwardly against the plate I4.

The various embodiments which have been described have been shown in connection with Figure 1 as applied to a screw-threaded plug, but it is clear that instead of a screw-threaded portion, the thrust-in prongs may be used in place 55 thereof, the mechanism described being as well applicable to the form shown in Figure 8, as to the form shown in Figure 1.

In Figure 8, the casing 50 has a button 5| similar to push-button 25l with circuit conduc- 60

tors

52 and 53, and with metallic contact prongs 54 and 55.

A form of signalling device was described in connection with Figure '1. Another embodiment of the same is shown in Figure 9. A spring 65 plate 80 is secured by the screw 8| to the casing IIJ. This spring plate 80 has a bore 82, through which the rod I1 freely passes. The free end of the plate 89 has an opening 83, to enable al visible, either by being ush with the casing or extending slightly above it. The stud 84 can be given a suitable color and, when visible, acts to signal that contact is broken so as to tell the user not to keep on pushing the push button 25. The manual release 1| is shown, but needs no further description in connection with this embodiment.

Another embodiment of the thermostatic control is shown in Figures 11 to 16. 'I'he control now serves a triple function, first it acts' as a thermostatic control, secondly, it acts to hold the switch rod, and thirdly, it acts as a contact.

The control 90 is placed on the bottom of the casing. It has enlarged spring plate portions 9|a fitted to frictionally and huggingly engage the lower enlarged end 9| of the switch rod I1 when inserted therein. The control consists of two like parts,'each having one end secured together by an adjustable screw device 93. The parts may be manually separated by a wedgelike member 94 on a pivoted elbow lever 95, acted upon by the exterior push button 1|, as shown in Figures 12 and 15. To avoid arcing, a shunt contact device 96 is secured to the switch rod I1 and this extends down to a high resistance stud 91 secured to the contact plate 98 in electrical contact with the exterior contact plate I2.

The plate 98 has recesses IIlI engaged by tongues |02 of the control 98, and abuts against a shoulder |04. The plate 51 has diametrically ar ranged tongues or strips 61a formed into screwthreaded portions as seen in Figure 11, over which the screw-threaded socket li ts. When an excess of current passes through the control 90, it releases its hold on the enlarged part 9| of the switch rod I1, and permits it under the action of its spring I9 to ascend and leave the control. Electrical connection is still established through the rod 96 and stud 91. When the switch rod has ascended sufficiently .so as to separate the end of the rod 96 and stud 91, then the ilnal interruption of electrical contact takes place. The arrow 99 in Figure 13 shows the direction of movement of the rod I'I. By this means, all injurious arcing is avoided at thev thermostatic control 90. Vents |00 are provided in the casing I0 to permit the ow of gas therethrough. The -ow of current through the device shown in Figures 11 through I6 is from the shell I'I through wires 61a and plate 61 to the shaft I1, contact member 9;, bi-metal element 9|, to the central terminal The various embodiments justdescribed show the application of the different thermostatic control and contacts, in connection with the push button action described in detail in the first part of this specii'lcation, and not repeated in connection with Figure 11.

The embodiment shown in Figure 9, is also embodied in the form shown in Figure 12.

The free tripping device then operates to insure against any repeated downward pressing of the push button, because the signal 84 will be visible to act as a warning. For instance, assuming an overload, after the plug 9| has engaged the control 90, this overload will release the plug 9| from the control 90, and move the rod |1 upwardly regardless in which position the push button finds itself, which gives the signa1 84 by the plug I6 acting on the plate 89. When the push. button is then pressed downwardly, the sleeve 30 opens the jaws 26 and the rod I1 can pass freely through the ngers 21. Hence, no matter how many times the push button is pressed downwardly the rod is always released. The same eect as just described in connection with an overload is naturally attained when the push button 'il is pressed down to mechanically unlock the control.

Having shown various embodiments of my invention and described the same, l do not wish to be limited to the particular embodiments described, as other forms may be proposed within the spirit of my invention as defined by the appended claims.

li claim:-

l. A circuit breaker having casing, a movable rod therein for making or breaking the circuit, a spring plate for locking the rod in position, a thermostatic plate ior operating the spring plate in case of overload; a push-button for operating the rod, said button having means for pushing the rod in closed Contact position and permitting release of said rod from said contact position when the overload unlocks the rod while the button is pushed in.

2. A circuit breaker having a casing, a movable rod therein for making or breaking the circuit, a spring plate for locking the rod in position, a thermostatic plate for operating the spring plate in case of overload; a push-button for operating the rod, said push-button having spring fingers with jaws therein for engaging said rod, means in the path of said spring fingers 'for opening said jaws and permitting the rod to pass therethrough when unlocked by the spring plate.

3. A circuit breaker having a casing, a movable rod therein for making or breaking the circuit, a spring plate for locking the rod in position, a thermostatic plate for operating the spring plate inv case of overload; a plug on said rod to engage the locking spring plate, a springdisposed between said plug a fixed part of the casing, a fixed sleeve supported by the casing having a bore for the passage oi the rod, a push-button having spring nngers with jaws, said jaws being adapted to engage the end oi the rod passing through the spring fingers, said `iaws being adapted to be opened to permit the passage therethrough of the rod, upon the jaws riding on said fixed sleeve upon the movement oi the push-button in respect'thereto, whereby upon the presence of an overload the rod is free to move between the jaws and to be forced by its spring out or contact with the circuit.

4. A circuit breaker having a casing, a movable rod therein for making or breaking the circuit, a spring plate for locking the rod in position, a thermostatic plate for operating the spring plate in case of overload; a push-button for operating the rod, said b`uttonhaving means for pushing the rod in closed contact position and permitting release of said rod from said contact position when the overload unlocks the rod, a plate Within the casing and an indicator on said plate normally within the casing, said plate being moved by the rod to force the indicator into an indicating position, when said rod is unlocked from the spring plate.

5. A circuit breaker having a casing, a movable rod for making or breaking the circuit, means to urge the rod into an open circuit position, a push-button for operating the rod, said button having means for pushing the rod into a circuit-making position, means for moving said aoeasoe 6. Means for breaking an electric circuit comprising a casing, a movable member therein for making or breaking the circuit, means for urging the member into an open circuit position, means for holding the member in and releasing it from a closed circuit position, means for moving the member into circuit closing position, and means mounted on the casing within the path of the means for moving the member into circuit closing position for rendering the lastnamed means inoperative, said last-named means being independent of the structure of the means for breaking the circuit.

'7. A circuit breaker having a casing, a movable member therein for making or breaking the circuit, means for urging the member into an open circuit position, means for holding the member in and releasing it from a closed circuit position, means ior moving the member into circuit closing position, and means rendering the last-named means inoperative.

8. A circuit breaker having a casing, a movable member therein or making or breaking the circuit, means for urging the member into an open circuit position, means for holding the member in a closed circuit position, thermostatic means for releasing the holding means, means for moving the member into circuit closing position, and means operative during the flnal closing motion of the member to render the lastnamed means inoperative.

9. A circuit breaker having a casing, a movable member therein for making or breaking the circuit, means for urging the member into an open circuit position, means for holding the member in a closed circuit position, thermostatlc means for releasing the holding means, yielding means for moving the member into circuit closing position, and means rendering the last named means inoperative.

iii. A circuit breaker having a casing, a movable member thereln for making or breaking the circuit, means for urging the member into an open circuit position, means for holding the member in a closed circuit position, thermostatic means ior releasing the holding means, an operating member, means movably mounted on the operating member for engaging the movable member to transmit motion from the operating member thereto, and means to disengage the last named member from the movable member.

ll. A circuit breaker having a casing, a movable member therein for making or breaking the circuit, means for urging the member into an open circuit position, means for holding the member in a closed circuit position, thermostatlc means for releasing the holding means, an operating member, means movably mounted on the operating member for engaging the movable member to transmit motion from the operating member thereto, and means operative during the final motion of the movable member into circuit closing position to dlsengage the last named member from the movable member.

12. A circuit breaker having a casing, a movable member therein for making or breaking the circuit, means for urging the member into an open circuit position, means for holding the member in a. closed circuit position, thermostatlc means for releasing the holding means, an operating member, means movably mounted on the operating member for engaging the movable member tc transmit motion from the operating member thereto, and a shouldered member on the casing to dlsengage the last named member from the movable member during nal closing motion of the movable member. l

13. A circuit breaker having a casing, a movable member therein for making or breaking the circuit, means for urging the member into an open circuit position, means for holding t'ne member in a closed circuit position, thermostatic means for releasing the holding means, an operating member, means movably mounted on the operating member for engaging the movable member to transmit motion from the operating member thereto, a sleeve on the casing through which the movable member moves, and a shoulder on the sleeve in the path of the last named member to engage the same and disengage the said last named member from the movable member.

14. A circuit breaker having a casing, a movable member therein for making or breaking the circuit, means for urging the member into an open circuit position, means for holding the member in a closed circuit position, thermostatic means for releasing the holding means, means for moving the member into circuit closing position, means rendering the last named means inoperative, an indicator, means to mount the indicator in the casing to be yieldingly urged into a nonindicating position, and means to move the indicator into an indicating position by the movable member.

15. A circuit breaker having a casing, a movable member therein for making or breaking the circuit, means for urging the member into an open circuit position, means for holding the member in a closed circuit position, thermostatic means for releasing the holding means, a spring pressed push button, yielding means on the button for engaging the member to move the member into circuit closing position, and means on the breaker to disengage the yielding means from the member during the nal closing motion of the latter.

` LAMBERT SCHMIDT.