US1341678A - Circuit-breaker - Google Patents

Description

F. W. ROLLER.

CIRCUIT BREAKER.

APPLICATRON FILED MAR. I4. 1917.

Patented June 1, 1920 2 SHEETS-SHEET 1.

INVEN TOR A TTORNEYS.

F. W. ROLLER.

ClRCUlT BREAKER.

APPLICATION FILED MAR. 14. 1917.

Patented June 1, 1920.

2 SHEETS SHEET 2 UNITED STATES PATENT-V OFFICE.

FRANK W. ROLLER, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO COMPANY, A CORPORATION OF NEW YORK.

ROLLER-SMITH CIRCUIT-BREAKER.

Specification of Letters Patent.

Patented June 1, 1920.

Application filed March 14, 1917. I Serial No. 154,696.

To all whom it may concern.

Be it known that I, FRANK W. RoLLER, a citizen of the United States, residing at East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Circuit- Breakers, of which the following is a specification.

This invention relates to a time limit type of circuit breaker, whereinthe passage of unusually heavy currents is permitted for a predetermined length of time before causing the circuit breaker to be opened, depending upon the value of-the currents and duration of their. passage. Another feature of the invention is the insuring of the opening of the circuit breaker instantly upon the passage of an abnormal current greater than a predetermined value.

One object of my invention is to obtain a circuit breaker of the above type, which will'be fully reliable in its operation with out the necessity of continued inspection and care and to avoid the use of dash-pots or other forms of devices'which are uncertain in their operation and which require more or less frequent attention and adjustment. Another object is to secure a refined adjustment of the automatic action of the breaker as regards the time limits permissible with certain values of current passing giving control within predetermined definite limits as desired, and also independently of any adjustment as to the action of the circuit breaker as regards its instantaneous operation by the passage of currents beyond a predetermined value. Another object is to secure refined adjustment as regards its instantaneous operation in a manner which will permit such adjustment independently of the adjustment for time limit operation. Another object is to secure the automatic opening of the circuit breaker under the predetermined conditions of operation by a quick and positive action. Another object is the provision of a simple form of construction and which may be readily assembled. Another object is to provide the above controlling and adjusting means in a form which may be simply and easily applied to various existing forms of circuit breakers. Other objects and advantages of my invention will appear from the following description and accompanying Figure 1 is a side view of the circuit breaker; Fig. 2 is an enlarged side view of part of the controlling and adjustable means; 1g. 3 1s a front View thereof; Fig. 4 1s a vertical cross section of the upper portion of the parts shown in Fig. 1; Fig. 5 is a horizontal cross section on the line 5-5 of Fig. 3; F 1g. 6 is a horizontal cross section on the line 6-6 of Fig. 2; Fig. 7 is a front elevation of a portion of'the releasing and tripping mechanism,'and Fig. 8 is a side elevation of a portion thereof.

The particular form of circuit breaker shown and described herein and to which my present invention is applied for illustration, is the type disclosed in the patent granted October 24, 1911, No. 1,006,522, on the application of C. O. Badeau. The breaker is mounted upon an insulating support 10 and comprises a fixed terminal 11, and a movable current carrying arm 12, which is pivotally supported at 13, which support extends between a vpair of side frames 14, which frames are secured to the base 10. Between the side frames 14 is pivotally mounted at 15 a hand operated lever 16. This lever carries a roller 17 at its inner end, which engages another roller 18 mounted on the switch lever 12. The circuit breaker is closed by pulling the handle of the operating lever 16 downwardly, which thereby brings the switch lever to the closed position as shown in Fig. 1, the axis of the roller 17 being allowed to rest in a final posltion slightly above the plane passing through the axis of the pivot 15 and the axis of the roller 18, the hand lever being stopped in its final position by adjustable pin 19 impinging upon the side frame 14.

A coil 20 has its inner end electrically connected to the switch lever 12 and is wound upon a soft iron core 21, which extends between the side frames 14, where the switch lever is pivoted. The coil 20 is also located between the side arms of the switch lever 12. A U-shaped armature 23 is also pivotally supported between the side frames as shown at the pivot 22, the said armature having its middle portion extending between the side frames and having a pair of extensions 24 extending downwardly. This armature is adapted to be adjusted, by a pin carried b an extension from side frame 14, to any esired normal position. When the current through coil or winding 20 of the breaker exceeds a certain predetermined amount, the U-shaped armature will, if otherwise unrestrained, be attracted by the magnetic field created by the current coil the arms 24 of the armature being raised toward the core 20 of the current coil, the

armature swinging about its pivot 22. This action will cause a projection 25 carried by the armature to impinge upon a projection 26 of the operating lever 16 forcing the operating lever to turn upon its pivot 15 in a clockwise direction and so cause the circuit breaker to be automatically opened. Fixed to one arm 24 of the armature and also pivoted upon the pivot 22 is a plate 27 which plate carries a pin 28 extending from its side. A latch 0r pawl 29 fixed to a shaft 30 has its hooked end extending over and above the pin 28 when the armature is in its lower normal unattracted position. It is therefore evident that the armature cannot be raised to cause the tripping or opening of the circuit breaker until the latch 29 has released the pin 28 of the armature. This causes the circuit breaker to be dependent in its action upon whether or not the latch 29 restrains the armature of the circuit breaker.

The auxiliary controlling means for effecting the operation of the latch 29 is inclosed in a casing 31 preferably of insulating material. The rear portion of the easing is shown as formed of a metal support 32. Within the casing is a conductor 33 which carries the current passed through the circuit breaker or some proper proportion thereof. This conductor is of any suitable material which is expansible upon being heated by the passage of an electric current. The upper end of the conductor 33 is in electrical connection with a terminal block 34, which latter has tapped therein one end of a bolt 35 adapted for connection in the circuit controlled by the circuit breaker or in the controlling circuit. The bolt 35 and terminal block 34 are insulated from the metal support 32 by an insulating bushing and insulating sheet material 36 as shown in Fig. 4. The terminal block 34 is shown provided with a forward extension 37 which latter has downwardly extending side portions 38. Between the extensions 38 is a vertically movable metal block 39 and to which block the upper end of the conductor 33 is firmly connected. A flexible conduc tor 40 electrically connects the block 39 with the terminal block 34. Secured to the block 39 is an upwardly extending bolt 41 which has a threaded engagement with an adjustable nut 42. The bolt 41 passes freely through the extension 37 and also passes freely through a metal plate 43. The plate 43 is held in position by a screw 44 which freely passes through an extension from i the plate, the screw 44 engaging the top portion of the inclosing casing 211'- also havtion prevents the plate 43 from rotation.

A pair of extensions 45 from the plate 43 support a screw 48 so as to permit the latter to turn, but having no threaded engageinent with the lugs 47. The screw 48 is supportedso as to have its thread engage with the gear cut surface of the adjustable nut 42 giving in effect a worm and gear form of connection for adjustment of the nut. The nut 42 carries a projecting pin 49 which is adapted to strike against a projecting stop 50 carried by the extension 37 for preventing the adjustment of the nut 42 beyond predetermined limits.

Another terminal block 51, electrically insulated from the terminal block 34, is mounted upon andvin electrical connection with the metal base 32, which latter by a metal conducting strip 52, or by any other suitable means, is in electrical connection with the outer end of the current coil 20 of the circuit breaker. The lugs 53 extending from the terminal block 51 has pivotally mounted thereon a downwardly extending lever 54. An extension 55 from this lever has connected thereto the lower end of the conductor 33. An opposite extension 56 from the lever 54 has connected thereto one end of a spring 57, the other end of the spring beingconnected to the lugs 53. A flexible conductor 58 gives good electrical connection from the lever 54 to the terminal block 51. The spring 57 thus places the conductor 33 in tension and any expansion or contraction of conductor 33 is reflected by a corresponding movement of the pivotal support, the lever 54 turning on its pivot in accordance with any change in length of conductor 33.

At the lower end of the casing 31 is a frame 59, supported upon the lower portion of the casing, and having side arms 60, which are connected together at their rear ends and supported upon the base frame 32, but electrically insulated therefrom as shown in Fig. 6. In the front end of the arms 60 is rotatably mounted the shaft 30 to which shaft the previously described latch 29 is fixed. Also fixed to the shaft 30 is a collar 61 located between the arms 60 and which collar has an upwardlv extending-bifurcated arm 62. A link 63 is pivotally connected to the arm 62 and has a slot 64 through which a pin 65 freely passes. the pin 65 being connected to the lower end of the previously described lever 54.

A depending lug 66 extends from the colhr 61 and is connected by a spring 67 to an arm 68 fixed to a pin 6.9, which pin is rotatably mounted in extensions 70 from the side bars 60. Fixed to the pin 69 is another arm 71 extending upwardly and forwardly and the outer end of which carries a pin or screw 72. The outer end of the adjustable arm 71 passes over a perforated stationary arc shaped strip 73 which is conveniently carried by or secured to one of the side bars 60. The arm 71 is adapted to be adjusted to any desired angular position and held in such position by the screw 72 engaging any desired perforation of the strips 73. In this manner the tension of the spring 67 is adjusted to anyamount desired and thereby, through the medium of the parts already described, adjusts the force by which the retaining latch 29 presses against the pin 28. When the circuit breaker is closed, current passes through the current carrying partsof the breaker to and through the current coil 20 to the metal base 32, terminal block 51, thence through the conducting parts to the expansible conductor 33 and thence through the conducting parts to the terminal block 34 and to the outside circuit. Assuming the parts to be in proper adjustment, then when such a predetermined overload exists as to require the instantaneous opening of 'the breaker, the stray field created by the current coil 20 will be suflicient to attract the upper end of the latch 29 inwardly, the latch 29 being made of magnetic.material. This will permit the arms of the U-shaped armature of the circuit breaker to be attracted toward the core of the current coil and immediately open the circuit breaker in the manner already described.

In case a lesser current should pass through the circuit breaker when closed, which lesser current is undesirable if continued beyond a predetermined length of time, the passage of such current through the expansible conductor 33 will cause the same to gradually increase its length, which increase willgradually permit the spring57 to swing the lever 54 about its upper pivoted end and move the pin 65 to the right in the slot 64 until the pin 65 reaches the end of said slot when continued movement of the arm 54 and pin will then, by means of link 63 and arm 62 cause the rotation of shaft 30, which results in the latch 29 being moved inwardly until it finally releases the pin 28. The armature of the circuit breaker, having been adjusted by the adjusting pin 25 to such position that the passage of any current which is suflicient when continued to release the pin 28- will also cause the attraction of the armature. will be immediately attracted as soon as the pin 28 is released and thereby cause the opening of the circuit-breaker at the expiration of the time limit for which the controlling means is adjusted for a particular value of current passing. It is evident that will be shorter for heavier currents than with currents of lesser value.

\It is evident that the adjustment to any predetermined current value for securing instantaneous opening of the circuit breaker may be made independently of the adjustment for securing operation in a predetermined time limit, and vice versa. Thus the adjustment for the current which will give instantaneous opening is secured to a refined degree by adjustment of the arm 71 which controls the force exerted by the latch 29 in opposition to the opposing magnetic force exerted thereon bythe field created by the current coil. Moving the arm 71 downwardly will increase the tension exerted by the spring 67 and consequently increase the required value of the current for securing instantaneous opening of the circuit breaker; raising the arm 71 gives the opposite effect.

Adjustment of the time limit control is obtained by turning the screw 47 which by turning the nut 42 will raise or lower the block 39 and thus correspondingly adjust the normal position of the arm 54. For example, slight raising of the block 39 by this adjustment will, by means of the conductor 33 swing the lever 54 to the left to a new position. This will increase the distance to be traveled by the pin 65 in the slot 64 and consequently cause a greater expansion or lengthening of the conductor 33 to be necessary before the latch 29 will release the circuit breaker armature. Reverse adjustment of the upper end of the conductor 33 will give the opposite effect causing a lesser extension of the conductor 33 to operate the latch 29. Thus by adjustment of the screw 47, any desired time limit control may be obtained independently of the adjustment of the breaker and vice versa. It will be understood that this independence of adj ustment is due to the force exerted by spring 67 being comparatively small and not sufiicient to overcome or affect the action of spring 57 in moving lever 54.

In some cases the expansible conductor may be surrounded by material to increase or decrease the time interval of control. For example, by placing a tube around the conductor 33 and filling the same with sand or other like electrically non-conducting, heat absorbing material, the time interval would breaker armature corresponding to the armature controlled by the current coil'herein' be increased, or by enveloping the conductor described.

It will also be understood that although I have described a preferred form of embodiment of'my invention, the same'may' be exemplified in various forms of construction Without departing from the scope of thisinvention in its various aspects. 7 I claim:

1. The combination of a switch, an overload coil and a movable armature for caus ing the opening of said switch, anauxiliary member normally restraining the movement of said armature, said member being affected by said coilito release said armature upon passage of a predetermined excessive .current, and a time-limit device also controllin the action of said member to release sai armature upon, the passage of a lesser current for an interval oftime.

2. The combination of a switch, a cen-' trolling coil andarmature for causing the opening of said switch, means for normally restraining the movement of said armature actuated by the passage of a predetermined overload current to release said armature, and an auxiliary time-limit overload current device for actuating said means to release said armature.

3. The combination of a switch, an overload coil and armature for causing the opening of said switch, means for normally restraining the movement of said armature actuated to release said armature upon the passage of a redetermined overload current, a time l1mit overload current device for actuating said means to release said armature, and means for adjusting the action of said time limit device independently of the effect of said predetermined overload current upon said first named means.

4. The combination. of a switch, an overload coil and armature for causing the opening of said switchfmeans for normally restrainin the movement of said armature actuated to release said armature upon the passage of a predetermined overload current, a time limit overload current device for actuating said means to release said armature, and means for adjusting the value of the predetermined overload current which will cause the actuation of said means independent'ly of the adjustment of said time limit devlce. v

5. The combination of a switch, an overload coil and armature, for causing the open- .load coil and armature for causing the opening of said switch, a device for normally restraining the movement of said armature,

' ,said device being controlled upon predetermined overload by the field created by said coil to release said armature, and expansible time limit controlling means for also controlling said device to release said armature. a

7. The .combination'of a switch, an overload coil and armature for causing the opening of said switch, a device normally restraining the movement of said armature said device being caused to release said armature u n the passa e of a predetermined over oad' current t rough said coil,

and means for also causing said device to release said armature after the assage of a? lesser current for an interval 0? time.

8. The combination of a switch, an overload coil and armature for causing the opening'ofsaid switch, a pivoted device for normally restrainin the movement of said armature, said evice being influenced by the magnetic field of saidcoil to release said armature u on the passage of a predetermined over oadcurrent through said coil, and expansible means for also causing said device to be moved to release said armature upon the passage of a current less than said predetermined current for an interval Y justing said second-named means independently of said first-named means.

10. The combination of a switch, and thermostatic means for causing the opening of said switch, said means comprising an expansible element, a worm and gear adjustment for adjusting one end of said element to any desired fixed position, and a movable support for the other end of said element.

11. The combination of a switch, and thermostatic means for causing the opening of said switch, said means comprising an expansible element, a pivoted lever for supporting the movable end of said element, said lever extending in a direction approximately parallel to said element and a spring connected to said lever and extending in a direction approximately parallel to said element for imposing a strain on said element.

12. The combination of a switch, and thermostatic means for causing the opening of said switch, said means comprising an expansible element, a pivoted lever for supporting the movable end of said element, said lever extending in a direction approximately parallel to said element, a spring connected to said lever and extending-in a direction approximately parallel to said element for imposing a-strain on said element and means for adjusting the stationary end of said element.

13. The combination of a switch, an overload coil and armature for causing the opening of said switch, a latch for restraining the movement of said armature, said latch being'subjected to the magnetic field of said coil for releasing said armature upon predetermined overload current through said coil, an expansible element, means for taking up the expansion of said element, and a lost motion connection between said means and said latch for releasing said latch upon a lesser overload current for aninterval of time.

14. The combination of a switch, an overload coil and armature for causing the opening of said switch, a latch for restraining the movement of said armature, said latch being subjected to the magnetic field of said coil for releasing said armature upon predetermined overload enrrent throu h said coil, an expansible element, means or taking up the expansion of said element, a lost motion connection between said means and said latch for releasing said latch upon a lesser overload current for an interval of time, means for adjusting the tension upon said latch, and means for adjusting the range of movement of said expansible element.

FRANK W. ROLLER.

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