US1418803A - Time-limit apparatus - Google Patents

Description

1. 1. KANE.

Patented June 6,1922.

TIME LIMIT APPARATUS.

APPLICATION r|LEn1uLY3o.1911. 1,418,803.

UNITED STATES PATENT i OFFICE..

JOHN J. KANE, O MILWAUKEE, WISCONSIN. ASSIGNOR TO ALLIS-CHALMERS MANU'- FACTURING COMPANY, OF .'MILXVAU'KEE, WISCONSIN, A CORPORATION Ol? DELA- WARE.

Y Application filed July 30,

i specification.

This invention relates in general to devices operative to elect desired results after a certain time limit, and has more kparticular relation to devices oi: this general character that are electrically operable and in which the time element involved in theeliective operation of the device is variable in a desired manner. y

ln electrical power systems, itis desirable to etl'ect inte 1ruption or other control of a circuit when thesame is subjected Lto abnormal operating conditions tor such, a priod of time that damage mightresult to the generators supplying the circuit orto any control apparatus connected thereto. The period ci' time during which `the apparatus can safely be subjected to abnormal conditions is ordinarily variable depending` upon the character or intensity of such abnormal conditions. n some cases it is desirable to permit the line to remain intact 'for a period ot timel that varies inversely as the value of an. abnormal. condition' up to a certain predetermined value, and, for all higher 'values of the abnormal condition, it is desirable that the circuit be interrupted after a time interval. which is comprarativelyT small and substantially constant-,or definite but which, neverth eless, insures freedom from interruption vduc to momentary disturbarces. Inni-der that the operation of several otj such time limit devices may be selective as to the time interval involved when the abnormal conditions are of the higher values, provisions are usually made 'for preliminarily selecting` or adjusting this minimum 'time interval so thatonly the `device nearest the source et the disturbance will operate.

It is an object ot' this invention to provide a time limit apparatus of improved design and construction and capable of effective operation alter a variable period of time on the occurrence of certain controlling conditions. f

lt is a. -further object ot' this invention to Specification of Letters Patent.

TIME-LIMIT APPARATUS.

Patented June 6, 1922.

i917.' seriai No. 183,989;

provide a time limit apparatus of improved design and construction and capable of effective operation after a variable period of time on the occurrence of certain controlling conditions, and wherein, for other controlling conditions, the vtime interval involved in the effective operation oi"y the apparatus 1s substantially constant or definite.

lt is a further object of this invention to provide an electrically operable time limit apparatus of improved design and constructlonfan-d capable of effective operation when subjected to abnormal controllling conditions for a period oi time that varies inversely7 as the intensity of the abnormal conditions up to a certain 'value thereof and is substantially constant or delinite and et appreciable duration "for abnormal conditions of greater intensities.v v

These and other objects and advantages are attained by this invention, the various novel features of which will be apparent from the 4description and drawings, disclosing one embodiment of such invention, `and will be particularly pointed out in the claims.

ln the accompanying drawings:

Fig.' lis a diagrammatic disclosure oit any embodiment of `this invention, a variable time limit relay device being shown in partial sectional elevation.

Fig. 2 is a plan view of a portion of the apparatus shown in Fig. l.

Fig. 3 is a sectional.' plan view on the line 3-.-3 of Fig. l. n v

In the embodiment of the invention illustrated, a circuitebreakerA 10, is `disposed in the line circuit a, Y), the circuit-breaker being held` in closed position by means of a latch 1l. The latch ll may be tripped to permit opening or the circuitfbrealer 10, on closure olf' the circuit ot `the tripping coil l2 with which the latch is electromagnetically asso# ciated. The circuit of the tripping coil l2 may be supplied from any suitable source, here shown asa local battery, and may be closed by means of a hand switch 13, or may be closed automatically through operation olf the relay device R embodying features of this invention.

The relay R has the general `form ot a solenoid magnet havinga'n energizing coil or winding lil, here shown as being in series 'with one side of the line circuit a, Z). The

coil 14. has associated thrcwitli and jiu fixed position relative thereto a tube 15 ol' noumagnetic n'iaterial, such as brass, the tube being closed in a liquid-tight manner at its upper end by a disc-like closure 1,6, preterably oi: insulating material, and being similarly closed at its lower end by a disclile closure 1.7. Mounted for tree reciprocation in the tube 15 is a. magnetizable'core 1S of a. compound character and movable in response to suiiicient energization ot the winding 1st. This core comprises a. main plunger portion 19, in the form of an inverted cup having a head portion 21 and a cylindrical extension 22 projecting downwardly Yfrom the head portion and oi' considerably less cross-sectional area. than the head, and an auxiliary portion 23 freely reciprocable within the cylindrical extension 22. This auxiliary core member 23 is provided with compa-ratively large openings 24- extending throughout its full length, and is normally urged to a position away from the head portion by means of a springs 25 disposed between the lower side of said head and the upper side oit the auxiliary core member. The normal position oi the core 23 determined by an abutment 26 carried by a bushing 27, preferably detachably threaded into the lower end oi the cylindrical part ot the main core member. This bushing 2T is preferably provided with spider arms 28 carrying a portion 29 which constitutes an abutment for the end of a hand screw 31 adjustable through the lower end closure 17 to vary the initial or normal position ot the bushing 27, the main core member 19 connected therewith and the auxiliary core member 23 carried thereby.

The core 18 is normally held in the position indicated by gravity, although a comparatively light spring 35 may be provided Vto assist or insure the ready movement oit the core to the position indicated subsequent to operation thereof. The casing 15 may be lilled with oil or other insulating iuid, as indicated, a comparatively small port 37 being provided through the head portion 21 to permit the fluid to pass therethrough to cause such equalization of the pressure on the two sides of the head portion as will allow upward movement of the core when the same is suliiciently energized by; the winding 14:. The speed of this upward movement of the core is determined by the rate at which oil may pass from the upper side of the head 21 to the lower side thereof. It will be obvious that by providing a passage through the head portion of the required size, comparatively any speed of movement of the core may be obtained. The head portion 21 is also provided with a comparatively large port 38 having a seat at its upper end normally closed by a ball check valve 39. During the upward movement of the core, the pressure developed on the upper side of the core holds the valve on its scali, but the core is permitted to travel downward to the position shown in a comparatively short space ot time.

To permit movement upward oi' the core 18 at di'l'liercnt speeds an additional port Ll-1 is provided in the head ,21, preferably at the center thereof, this port being preferably of conical shape to provide a seat for a concshaped valve i-2 adjustably mounted upon a rod or stem 4:3 and held in. adjusted position thereon by a lock nut 45. This valve i2 is provided with guide vanes i7 engageable with. the inner side oit' a cylindrical guide bushing LS attached to or iiitegral with the head portion 21 of the core, which serve to guide the valve in its movement to and from its seat. The lower end oi the valve rod or stem 43 is disposed in engagement with or comparatively close to the upper end ot the auxiliary core 23, when the latter is in its lowest position, as indicated, and in position to be engaged thereby and moved upward when the auxiliary core member is moved upward relatively to the main core member 19, against the action ot gravity and the spring 25.

An adjustable stop 5l, preferably in thc torm oll a rod adj ustably threaded through the head 21 and locked `in position relatively thereto by a lock nut 52, serves to adj ustably limit the upward movement ot' the auxiliary core member 23 relative to the main cere member 19.

A rod or extension 5G is provided on the upper side oi the head portion 21 and serves, when the main core is drawn upward, to engage the movable contact 61. ot a circuit closer in the circuit of the tripping coil 12, This movable contact 6l. is adapted to be moved into engagement with a Yfixed contact G2 of the circuit closer to cause closure oit lthe circ-uit oil' the tripping` coil. 12. The sup Dorts for the contacts 61 and 62 are mounted and insulated 'from each other in the upper closure 1 6 oit the tube 1.5.

Instead of having the energizing winding ll-l connected directly in series with the line circuit c, 7), an adjustable rheostat (35 may be provided in shunt to the winding to thereby reduce and permit variation of the proportion ol.E main line current passing through the winding. i

1With the relay R operatively connected rela-tively to the line circuit a, L, to effect control of the circuit-breaker 10, and the line current and current in the winding 14 normal, the parts o1 the relay are in the positions indicated. On the occurrence of current ot a certain predetermined value, which is just capable oil2 creating sullicient lflux-to cause the core 13 to move upward toward the center ot the energizing winding 14, the main core member 19 nieves upward, the

i l O speed of such movement being determined by the time required for the passage of fluid from the upper side of the core through the port 37 to the lower side thereof.

Current of this particular value is not intended to have any appreciable effect in causing upward movement of the auxiliary core member 23 relative to the main core 19 and quent opening of the circuit-breaker 10. The

winding 14 being deenergized through opening of the circuit-breaker 10, the core 18 is urged downward by gravity and the spring 35, this downward movement being a great deal faster than the upward movement, since fluid may pass comparatively quickly from the lower side of the core, through the relatively large port 38 and past the ball valve 39, to equalize the pressure on both sides of the core. During this operation of the relay at a current value corresponding to the lowest value at which the core is effectively operative, the flux produced by the energizing winding 14 in the head portion 21 of the main core 19 may be more or less effectively carried by the cylindrical core portion 22, the flux across the gap' between the head portion 21 and the auxiliary core member 23 not being sufficient to cause movement upward of the auxiliary core member, that is, movement upward relative to the main core member and. against the action of the spring 25. i

However, when the relay winding is subjected. to current of a higher value, the fiux created thereby is sufficient to substantially saturate the cylindrical core part 22 and to exert a pull on the auxiliary core 23, across the gap between the latter and the head 21, sufficient to cause the auxiliary core-to move upward to a greater or less extent against the action of gravity and the spring 25. Obviously, there is nothing to cause any appreciable retardation of the auxiliary core member 23 in its upward movement relative to the main core member 19, since the openings 24 through the auxiliary core member are of such size as to permit free and ready equalization of pressure on the two sides of this auxiliary core member and thus permit comparatively quick movement upward of the latter member. The upward movement of the main core member being retarded by the body of oil on the upper side thereof, such member acts as a relatively fixed abutment for the spring 25 and the latter is compressed more or less and the auxiliary core member 23 moved upward to a greater' or less degree, depending on the value of the current in the winding 14. Depending upon the position of the lower end of thc valve rod 43, the same is engaged by the auxiliary core member 23 when the relay is energized by current 'corresponding to an overload of a certain value. In its upward movement, the auxiliary core member engages the rod 43 and lifts the valve 42 from its seat'to a greater or less extent, depending upon the value of the overload. Opening of this valve 42 provides an additional port through the head 21, which has the effect of correspondingly decreasing the time required to move the rod 56 into engagement with the'circuit closing contact 62.

By proper determination of the size of the opening provided by the valve 42, the strength of the spring and the dimensions 'of the magnetizable core members, the auxiliary core member 23 may be effective to cause such variation in the time interval required to produce closure of the circuit of the tripping coil 12V as may be desired. T he higher the overload, the greater amount of flux is produced by the winding 14 and the greater is the flux across the gap between the head 21 and the auxiliary core 23, and, hence, the greater the tractive effort on the latter, with a corresponding variation in the opening of the valve 42, and a consequent decrease in the time interval elapsing before closure of the contacts 61, 62 of the circuit of the tripping coil 12.

It will be apparent that this variation of the time interval is inverse tov the variation in the degreeof the overload up to that overload value which causes the production of sufficient tractive effort on the auxiliary` core 23 to cause the same to be moved upwardly, against the action of the spring 25,`

into engagement with the stop 51. This stop 51 determines the upper limit of movement of the auxiliary core member 23, and, consequently, the maximum opening of the valve 42. All overloads of a value higher than that which causes movement of the core into engagement with the adjustable stop 51 have no further effect in increasing the size of the effective opening` through the port 41 past the valve42, and, hence, have no further eiect in causing appreciable decrease in the time interval involved in the closure of the circuit of the tripping coil 12 and opening of the circuit-breaker 10. Obviously, this maximum opening of the valve 42 with its consequent minimum time interval may be readily varied, as for the purpose of rendering several relays selective, merely by` adjustment of the stop rod 51.

Vhile overloads higher than the lowest one which causes maximum upward movement of the auxiliary core 23 may produce somewhat greater tractive effort onthe core 2l. and thus put the fluid on the upper side of the head 21 under slightly greater pressure, nevertheless, there is no appreciable variation in this minimum time interval from this cause. In order to reduce to a minimum this variation in the time interval occurring with the higher overload values, the apparatus may be of such design that the head portion 21 of the core becomes fairly well saturated on the flow of current in the winding 1st` of a value which causes movement of the auxiliary core 23 to its upper limiting position.

It will be apparent that the value of current in the main line at which the relay is first operative may be varied either by the adjustment of the rheostat to vary the proportion o'l line current flowing in the energizing winding 14, or by adjustment of the hand screw 31 t0 adjust the initial position of the core 18.

The bushing 27 may be adjustable to any desired degree in the lower end of the cylindrical sleeve 22 of the core to thereby adjust the initial position oit the auxiliary core member 23 relative to the main core member 19, such adjustment varying the initial gap between the auxiliary core 23 and the head 21 of the main core. The rod 43 may be correspondingly adjusted relatively to the valve l2 to maintain the same or a slightly different relation between the lower end of the rod and the auxiliary corel member E23.

It will be apparent that in accordance with this invention an electrically operated time limit device is provided which is eflective to cause a desired controlling operation on the occurrence of an overload on the circuit to be controlled, the time element involved varying` inversely as the degree of the overload up to a certain point and, beyond the latter point, being' substantially constant or delinite.

It should. be understood that it is not desired that the invention claimed be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

lt is claimed and desired to secure by Letters Patent: d

Il. In a circuit-controlling apparatus, relatively movable contacts, an overload coil, a core member movable into said coil, means for retarding the movement of said core member into said coil, and a member of magnetic material which is movable independently of said first member and in response to energization of said coil to vary the retardation of said core member.

In a circuit-controlling apparatus, relatively movable contact members, and means for causing actuation of one of said contact members, said actuating means comprising an overload coil, two mechanically associated and relatively movable armatures for said coil having portions magnetically in series in the normal magnetic circuit o'lf' said coil, andA means for retarding he movement of one o'l" said armatures, the other ol'Y said armatures being effcctive to vary the retardation ol' said lirst armature to thereby cause effective operation of said acti'iating means to occur after a time interval which is an inverse function of the degree of the overload.

3. ln combination, a switch-actuating member, means for causing actuation of said member, said means comprising an electromagnet having an element of magnetic material movable in response to abnormal circuit conditions above a certain degree, and instrumentalities for causing effective movement of said element to occur after a time interval that varies inversely as the abnormalit-y of said conditions, said instrumentalities including an electroniagnetically-actiiated element luiviing a portion magnetically in series with and mechanically dependent upon said lirst element.

l. ln combination, a movable element of magnetic material, electromagnetic means effective, when energized to a j'n'edetcrmined degree, to cause effective operation ol' said element, fluid-controlled means for retard ing the operation of said element, a second electromagnetically-actuated elcn'ient magnetically and mechanically associated with said first element and capable of movement relative thereto and operative to control the movement ot said first element to cause energization of said electromagnetic means to a different degree to produce effective operation of said Yfirst element after a variable time interval.

5. An automatic overload circuit-breaker comprising a movable circuit-controlling member, an energizing winding, two cooperative, magnetically associated and relatively movable elements ot magnetic material operable through electromagnetic eilects produced by said winding, moven'ient ot one of said elements in response to sa id coil being damped and movement of the other element being undamped, movement ot' said undainped element controlling movement of the damped element luider conditions of moderate overload to thereby vary the time elapsing in the effective operation of said damped element, and means controlled by said damped element for causing actuation of said circuit-controlling member.

6. A time-limit device comprising a magnetizing coil, a casing containing a body of fluid, a movable, variably retarded, magnetizable means comprising relatively' movable parts within said casing and adapted to travel in the magnetic field ot said coil, the time interval involved in the operation of said device Avarying in response to the relative movement between said parts.

7. A time-limit device comprising a magnetizing coil, a casing containing a body of fluid, a variably retarded, movable magnetizable means within said casing and comprising relatively movable part-s, the effective speed of motion of said means being dependent upon the relative movement between said movable parts.

S. A time-limit device comprising a magnetizing winding, a casing containing a body of fluid, a movable, retarded, magnetizable core member within said casing and operable in response to eiiergization of said winding, and means within said casing and operative in response to predetermined conditions of the energization of said winding for varying the retardation -of said core member.

9. A time-limit device comprising amagnetizing windino', a casing, a magnetizable core member movable within said casing in response to energization of said winding, fluid-controlled means wlitliin said` casing for retarding the movement of said core, and means also responsive to the energization of said winding for varying the rate of retardation of said core.,`

10. A time-limitdevice comprising-a magnetizing winding, a magnetizable core movable in response to energization of said winding, means for'retarding saidfcore, said core comprising relatively movable parts, and means effective to permit simultaneous movement and prevent appreciable relative movement of said parts oiilenergization of said winding rby current of less than a certain value and to permit relative movement of said parts on energization of said winding by current of a value greater than said latter` value, relative movement between said kparts vbeing effective to cause variation in the retardation of said core.

1.1. In a time-element apparatus, the combination of an element movable in response to controlling conditions and provided with an orifice, '2a body of fluid which movement of said element .tends to force through said orifice, and means mechanically associated with nsaid element for varying the size of the orifice in response to the same controlling conditions.

12. In a tiine-elen'ient device, a dashpot having relatively movable parts and an orilice, electromagnetic means comprising an energizing winding responsive to controlling conditions for causing relative movement between said parts,` and meansymagnetically and mechanically associated with one of said relatively movable parts and responsive to the same controlling conditions for varying the size of said orice.

13. A selective time-limit controlling device for an electric switch, including in combination a controlling magnet responsive lto an overload current, operating means for said switch actuated thereby, means for retarding said operating means, and means responsive to the energization of said controlling magnet for controlling said retarding means. v

14. A'selective time-limit controlling device for electric switches, including a solenoid responsive to an overload current, `operating means for the switch actuated thereby, a fluid-controlled timing device to regulate the speed of motion of said operating means, a regulating valve for said timing device, and means mechanically associated with said operating means and responsive to the energization of said solenoid for automatically adjusting said valve according to the strength of the overload.

15. An apparatus for controlling an electric circuit, comprising mechanism operative to exert a controlling effect on said circuit, and time-limit means responsive to an abnormal condition of said circuit and operative to cause operation of said mechanism after a period of time which is an inverse function of the intensity of the abnormal condition for values thereof up to a certain point and a desired effective period of time for all values of the abnormal condition, said time-limit means comprising an electro-magnet having an energizing winding and aretarded core therefor, and means magnetically associated with said core and responsive to energy due to said winding for varying the speed of movement thereof.

16. In combination, a circuit-controlling device, and time-limit means responsive to abnormal electrical conditionsand operative to cause operationof said'circuit-controlling device `after a time interval that is an inverse function of the abnormality of said conditions up to a certainv value thereof and constitutes a desired effective time interval for all higher values of the abnormal conditions, said time-limit means` comprising an electromagnet having an energizing winding and a retarded core therefor, and means magnetically and mechanically associated with said core and variably responsive to said abnormal conditions for varying the retardation of said core.

17. A time -limit controlling apparatus comprising an electromagnetic device including an energizing winding and a magnetizable core movable in the magnetic circuit of said winding, saidcore comprising relativelyV movable magnetizable' elements, one of said elements being operative to canse the desired circuit-controlling operation, means for retarding moverrienty of' said kmember, a second one of said core members beingvariably movable relatively to the first member in response 'to energization of said winding to control the retardation of said 'first member.

is. A selective time-limit apparatus for CTT CJi

controlling electrical circuits, comprising an electromagnetic device including an energizing Winding and a magnet-izable element movable in response to energization of said Winding to effect a circuit-controlling operation, and means magnetically and mechanically associated with said magnetizable element and variably responsive to energication of said Winding and effective to cause the speed of movement of said magnetizable element to vary inversely the degree of encrgization of said Winding. l

19. A selective time-limit apparatus for controlling electrical circuits, comprising an electromagnetic device including an energizing Winding and a magnetizable element movable in response to energization of said Winding to effect a circuit-controlling operation, and means magnetically and mechanically associated with said magnetizable element and variably responsive to energization of said Winding and effective to cause the speed of movement of said magnetizable element to vary inversely as the degree ofi energization of said Winding up to a predetermined value of said energization and to be substantially const-ant or definite for all values of energization above said predetermined value.

20. A selective time-limit apparatus :l'or controlling electrical circuits, comprising an electromagnetic device including an energizing Winding, a magnet-izable element movable in response to energization of said Winding' to efllect a circuit-controlling operation, means for retarding free movement of said magnetizable element, and means mechanically associated with said. magnetizable element and magnetically responsive to encrgization of said Winding to control the `retardation of said magnetizable element so as to cause effective operation of said element to occur after a time interval that varies inversely as the degree of' said energization.

2l. A time-limit controlling apparatus for electric circuits, comprising an electromagnetic device including an energizing Winding and a. maguctizable core movable in the magnetic circuit of said Winding in response to overloads on the circuit to be controlled said core comprising relatively movable members, and instrument-alities :for insuring simultaneous movement of" said members on the occurrence of' lower overload values and relative movement between said members on the occurrence of higher overload values to thereby effect a variation in the retardation of said core in its circuit-controlling operation.

22. A time-limit controlling apparatus comprising` an electromagnetic device including an energizing Winding and a magnetizable core member movable in the magnetic circuit of said winding, a closed fluid-containing receptacle in Wliich said core is movable, a bypass through said core, a valve for controlling the flow of fluid through said bypass, a magnetizable member carried by said core member and capable of movement rela-ve thereto on suflicient energization of said Winding and operative to vary the opening of said valve to thereby vary the retardation of said core.

23. A selective time-limit controlling device fer electric switches, including in combination overload responsive means for operating a switch comprising an energizing winding, an d an element movable in response to a predetermined degree of energization ot' said Winding, a device for retarding said operating means, and means responsive to energization of said Win ding to a degree corresponding to a predeterlnined overload for variably adjusting said retarding device and causing the time interval involved in the effective operation of said operating means to vary inversely as the degree of the overload.

2li. A selective time-limit controlling device for electric switches, comprising overload responsive operating means for a switch comprising an energizing Winding, and an element movable in response to energization of said winding to a degree corresponding to a predetermined overload, a retarding device for said operating means, and means responsive to energization of said Winding to a degree corresponding to overload conditions for variably adjusting the time interval in the effective operation ot' said operating means up to a certain overload value and for maintaining a substantial. and desired effective time interval tor all higher overload values.

25. A time limit device, comprising an energizing winding, a variably retarded member movable in response to magnetic ef- `fects due to said Winding, and a movable element responsive to energizing efl'ects produced by said Winding for causing the retardation of said member to vany inversely as the energization of said Winding.

26. ln a circuit controlling device, fixed. and movable contacts, a coil adapted to carry current proportional to the current in the circuit to be controlled, a member movable in response to inductive effects produced thereon by said coil, said member being op.- erative to cause the operation of said circuit controlling device wholly through inductive effects on the occurrence of abnormal conditions in said circuit, and means for causing effective operation of said member to occur after a time interval that varies inversely as the intensity of the abnormal conditions, said means comprising an element movable along substantially the same path as said member in response to inductive effects produced by said coil.

27. A time limit device, comprising a mag- CTX electromagnetic device including an energizing Winding, and an element movable in response to energization of said Winding to effect a circuit controlling operation, and means magnetically and mechanically associated with said element and variably re' sponsive to energization of said Winding and effective to cause the production of a time interval in the effective operation of said apparatus that varies inversely as the degree ot energization of said Winding up to a predetermined value and constitutes a desired effective and substantially definite time in terval for values of said energiZat-ion above said predetermined value.

29. A retarded time limit device, comprising a magnetizing coil and a magnetic circuit ttor said coil comprising a plurality of members having portions magnetically in series in the normal magnetic circuit ot said coil and relatively movable in substantially the same path, one of said members being eliifective to cause the time interval involved in the effective operation of another of said members to vary inversely as the degree of energization of said coil.

30. In a controlling apparatus, an electromagnetically responsive device comprising an energizing Winding, and an operating element movable in response to a predetermined energization of said Winding, and means for variably retarding said operating element to a degree dependent upon the enl ergization of said Winding, said latter means including an element responsive to the energization of said Winding.

In testimony whereof7 the signature of the inventor is afixed hereto.

JOHN J. KANE.

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