US2339201A - Timing controller - Google Patents

Description

Jan. 11, 1944. C.ISTANSBURY TIMING CONTROLLER Filed May 16, 1959 2 SheetsSheet J.

III

I L [Ii I A I 1 Mww- Jan. 11, 1944.

v C. STANSBURY TIMING CONTROLLER Filed May 16, 1939 2 Sheets-Sheet 2 PatentedJan. 11, 1944 UNITED STATES PATENT OFFICE TIMING oom'nonma Carroll Stansbury, Wauwatosa, Wis assignor to Cutler-Hammer, Inc., Milwaukee, Wis a corporation of Delaware Application May 16, 1939, Serial No. 273,957

10 Claims.

This invention relates to timing controllers, and while not limited thereto is particularly applicable to resistance welding control systems in which an impulse operated switch is used to control the period of power application in the weld? ing circuit,

' The invention has among its objects to providean improved impulse operated switch for welding control systems of the aforesaid character which is exceedingly quick acting and reliable in operation and which is adapted to provide exceedingly short and accurately controlled periods of power application.

Another object is to provide an electromagnetically operated switch for use in systems of the aforesaid-character having mechanical means associated therewith which is adjustable to provide selected periods of current flow in the resistance welding circuit upon energization of the switch by a unidirectional current impulse of given value.

Another object is to providean electromagnetically operated switch of the double pole type having improved equalizing means associated therewith for insuring opening of the switch contacts simultaneously.

Various other objects and advantages of the .invention will hereinafter appear.

v The accompanying drawings illustrate an embodiment of theinvention which will now be described, it being understood that various mothilcations may be made in the embodiment illustrated without departing from the spirit and scope of the appended claims.

1n the drawings,

-. A Figure 1 is a schematic view of a resistance welding control system having a switch embodying the invention associated therewith;

Fig. 2 is a front elevational view of a mechanical embodiment of the switch schematically shown in Fig. 1;

Fig. 3 is a side elevational view of the operating magnet shown in Fig. 1, a. buffer device associated with the magnet being shown in section;

Fig. 4 is a sectional view on line 4-4 of Fig. l, the switch being shown in open position;

Fig. 5 is a sectional view on line 5-5 of Fig. 1 illustrating the switch in closed position, and

mounted upon opposite ends of a horizontally Fig. 6 is a plan view of the movable contact element shown in Fig. 1.

Referring to Fig. 1, the same schematically illustrates a two pole switch embodying the invention, each pole including a stationary contact I and a cooperating movable contact}. The movable contacts 2 are carried .by a rotatable arranged equalizer lever 5 and are insulated therefrom, and said equalizer lever is pivotally mounted intermediate its ends upon a rocker arm 1. Equalizer lever 5 is adapted to swing in a substantially horizontal plane with respect to rocker arm I and said rocker arm extends downwardly and rearwardly from said equalizer lever and is pivotally mounted intermediate its ends upon a pin 8 carried by a lever 9 fixed to operating shaft 3. The lower end of rocker arm I is normally held in engagement with a stop projection It on lever 8 by a spring II which engages the under side of lever 5. Spring H is adjustable by a screw device l2 which is carried by a forwardly projecting lug IS on lever 9.

Operating magnet 4 includes a fixed magnet frame M, an operating winding i5 mounted upon said frame, and a movable armature member l6. Armature member I6 is adjustably secured to shaft 3 and is provided with a tail piece H which extends downwardly from said shaft and cooperates with a buffer device iii of the character disclosed in the patent to Clarence T. Evans et al., No. 2,134,179, dated Oct. 25, 1938.

Briefly described the buffer device I8 is provided with a headed pin 19 having butt engagement with the tail piece l1 and connected to a piston 20 movable ,within a closed housing 2|. Piston 20 is normally held against the front end of housing 2| by a spring 22 and the pin I9 associated with said piston acts as a stop to normally hold the movable switch parts against the action of gravity in a position to provide a relatively narrow air gap between the movable contacts 2 and their cooperating stationary contacts I and also between armature member I5 and magnet frame H. Upon energization of the magnet 4 to effect closure of the switch, tail piece I1 is entirely free to move away from the pin l9. Upon opening of the switch, tail pieceJl engages pin l9 and the buffer device then acts to frictionaliy dissipate the kinetic energy present in the moving switch parts and to bring the moving switch I 6 towards its attracted position rocker arm I moves with respect to lever 9 against the action forth the function and operation of the aforedescribed switch a simplified showing'of a timing controller of the character disclosed in my aforementioned application is included in Fig; 1. The switch is connected to supply current from a single phase alternating current supply circuit indicated by lines L -L to the welding circuit (not shown) through the medium of a transformer T. The

timing control means shown includes a condenser 23, a pilot switch 24, a rectifier and a gaseous electron tube .28 having a heated cathode 26, a grid 23 and an anode 28. Pilot switch 24 is provided with normally closed contacts 24" and normally open contacts 24 and the former contacts serve to normally connect condenser 23 and rectifier 25 in series across a single phase alternating current circuit indicated by lines Ii -L to eifect charging of said condenser. However, upon opening of contacts 24 and closure of contacts 24' of the pilot switch the operating winding l5 of the switch is connected in series with condenser 23 through the medium of 'tube 26 and said condenser then discharges through said winding to effect response of the switch by a single unidirectional current impulse. Grid 26 is controlled by means not shown in the drawings, but disclosed in my aforementioned .copending application, to provide for discharge of condenser 23 through the operating winding i5 01 the switch only at a definite point in the A. 0. cycle of the supp y circuit L -L?.

In accordance with the present invention condenser 23 is adjusted to provide a unidirectional current impulse which is of sufficient value to effect rapid movement of contacts 2intoengagement with their associated stationary contacts I but insufilcient to effect acceleration of the moving switch parts after the contacts are brought into engagement. Upon arrest of the movable contacts in circuit closing position the moving switch parts continue to move inwardly against the action of spring H, and said springis 50 adjusted that inward movement of said parts is arrested prior to sealing of armature member IS with the pole faces of magnet frame I4. Thus upon closure of the switch substantially the entire energy pres- I cut in the moving switch parts is stored in sprin H, and upon cessation of inward movement of said parts the same are accelerated in circuit opening direction under the action of said spring. It is thus apparent" that the speed at which the contacts 2 are moved out of engagement with the stationary contacts I is substantially the same as the speed at which said movable contacts are moved into engagement with said stationary contacts. In practice it has been found that when the switch is energized by a current impulse of a given value the interval during which the contacts remain in closed position is substantially proportional to the degree of continued movement of the moving switch parts which occurs after the contacts are moved into closed position. Thus y varying the degree Of compression of spr I I the degree of inward movement of the moving switch parts after the contacts are brought into engagement may be varied tovarythe periods of power application in the welding circuit. In practice it has been found that a switch constructed and operated as above described is adapted to provide exceedingly small and accurately controlled periods of powerapplication corresponding to as low as /2 cycle of the current in the supply mains L --L Referring now to Figs. 2 to 6, inclusive, the same illustrate a mechanical embodiment of the switch schematically illustrated in Fig. 1. As shown ,in Fig. 2, the switch is mounted upon a vertical insulating panel 28, and each pole thereof has a blowout device 29 associated therewith of the construction disclosed in the copending application of T. B. Jochem et al., Serial No. 217,194, filed July 2, 1938. Each of the stationary contacts l is fixed to' the front end of an arc horn 30 associated with its respective blowout device (Fig. 4) and each of said arc horns is mounted upon the front face of panel 28 and is connected to a terminal element 3| throughthe medium of a blowout coil 32.

The movable contacts 2 are fixed to brackets 33 which are mounted upon insulated arms 34 of equalizer lever 5 and each of said contacts has a flexible lead 35 associated therewith which is connected to a terminal element 36 mounted upon the front face of insulating panel 23. v As hereinbefore stated, equalizer lever 5 is pivotally mounted intermediate its ends upon a rocker arm I. As shown in Fig. 5, said equalizer lever is provided with a forwardly extending projection 31 having an upwardly extending spindle 38 formed on the upper side thereof which is rotatably supported .within an opening in a bearing projection 39 formed on the upper end of rocker arm 1. The upper face of projection 31 on equalizer lever 5 is held in frictional engagement with the lower face of bearing projection 39 by a screw 40 extending through an opening in spindle 38. As shown in Fig. 5 the upper end of screw 40 has a spring washer 4| associated therewith which is held under compression against the upper face of bearing projection 39 by a nut 42 on the upper end of said screw.

As hereinbefore stated, and as shown in Fig. 5, rocker arm 1 extends downwardly and rearwardly with respect to equalizer lever 5 and is pivotally mounted intermediate its ends upon a pin 8 carried by a lever 9 fixed to operating shaft 3. Also as hereinbefore set forth, the lower end of rocker arm I is normally held in engagement with a stop projection ID on lever B by a spring I I which is adjustable by a screw device l2'carried by a forwardly projecting lug l3 on lever 9.

As shown in Fig. 5, the upper end of spring H is held within a recess in the underside of projection 3'! on equalizer lever 5 and the screw device i 2 is associated with the lower end of said spring. Screw device l2 includes an internally threaded bushing 43 which contains a screw 44 having an enlarged head 45 on the upper end-thereof for engaging the lower end of spring I I. Bushing 43 is rotatably mounted within an opening in projection l3 on lever 9 and the lower end of said bushing has an adjusting knob 46 fixed thereto, while the upper end thereof is provided with an enlarged circular head 41 which engages the upper .face of said projection. Head 41 of bushing 43 has teeth formed on the periphery thereof and said bushing is releasably held against rotation by a spring pressed ball 48 which engages said teeth and is supported within a drilled opening in the hub portion of lever 9. Screw 44 is held against rotation by a pin 49 which is fixed to the head 45 of said screw and extends forwardly into a vertical slot 50 in a U-shaped gauge member mounted upon projection iii of lever 9.

Upon rotation of sleeve 43 by knob 46 the screw 44 i adjusted vertically to vary the degree of compression of spring ll, As hereinbefore set forth, the period of power application in the welding circuitis determined by the degree of compression of spring ll. As is apparent, the position'of pin 49 within the slot 50 indicates the degree of compression of spring II and in practice the front face of gauge member 5| is provided with markings 52 for indicating the periods of power application which result from various settings of .said spring.

As shown in Fig. 2, theright end of shaft 3 is journaled upon a pin 53 carried by a bracket 54 mounted upon the front face of insulating panel v 28 and the left end of said a pin 55 carried by a bracket 56 associated with the magnet frame H of operating magnet 4. Bracket 56, as shown in Fig. 3, is securedto the front face of insulating panel 28 by bolts 51 and the same i provided with two forwardly extending arms 58 and 59 which carry the pin 55.

Armature member 16 of magnet 4 is rotatably mounted upon pin 55 and is operatively connected to shaft 3 through the medium of a down wardly extending lever 60 which is fixed to said shaft. As shown in Fig.2, the lower end of lever 60 is provided with a horizontal extension 5i having a vertical face 62 which is engaged by a bushing 63 mounted within an opening in the tail piece ll of armature member l6. Bushing 63 is clamped against the vertical face 62 of lever 65 by a screw 64 which extends through the opening in said bushing and is threaded into the extension shaft is journaled upon 6| on said lever. The opposing faces of bushing 63 and extension 6| on lever Ell are formed to provide interlocking teeth 65 and as is apparent said teeth provide a rigid coupling between armature member l6 and said lever. The interlocking teeth 65 on bushing 63 and extension Bl extend in the direction shown in Fig. 3, and as is apparent upon loosening screw 64 lever 60 may be adjusted with respect to bushing 63 to vary the angular position of shaft 3' and its associated contacts 2 with respect to armature member l6. Such adjustment provides for variation of both of the air gaps between movable contacts 2 and their associated stationary contacts I and it should be noted that the equalizing mechanism associated with movable contacts 2 renders it practical to employ a single means for effecting adjustment of both of the air gaps.

As hereinbefore tated, the switch is provided with a buffer device I8 which is associated with armature member l6 and acts to effect arrest of the moving switch parts in open position without rebound. As shown in said buffer device is mounted upon the rear face of insulating panel 28 and the headed pin 19 which cooperates with the tail piece ll of armature member l6 extends forwardly through an opening in said panel.

What I claim as new and desire to secure by Letters Patent is:

1. In a timing controller for an electric circuit, in combination, a normally open switch for controlling said circuit, an operating member therefor, a spring operating connection between said member and said switch acting upon movement Fig. 3, the housing 2| of of said operating member in one direction out o! a given normal position to efiect closure of said switch, said spring operating connection permitting overtravel of said operating member upon closure of said witch, a power operated device responsive to move said operating member out-of normal position, and means for controlling said device to provide for movement of said operating member out of normal position under the action of. a predetermined power impulse to effect closure of said switch and to also effect over-travel of said operating member after closure of said switch solely by inertia against the action of said spring operating connection to thereby provide for momentary closure of saidswitch.

2. In a timing controller for an electric circuit, in combination, a normally open switch for controlling said circuit, an operating member therefor, a spring operating connection between said member and said switch acting upon movement of said operating member in one direction out of a given normal position to effect closure of said switch, said spring operating connection permitting overtravel of said operating member upon thereby ing, member closure of said switch, electroresponsive means for moving said operating member out of normal position, means for energizing said electroresponsive means by a predetermined power impulse to effect closure of said switch and to also effect over-travel of said operating member after closure of said. switch solely by inertia against the action of said spring operating connection to maintain said switch in closed position for an interval which is substantially proportional to the degree of over-travel of said operating member, and means for adjusting said spring operating connection to vary the degree of over-travel of said operating member under the action of said predetermined power impulse. 3. In a timing controller for an electric'circuit, in combination, a switch for controlling said circuit, said switch including a plurality of movable contacts biased to open position and providing a plurality of gaps in said circuit, an operating member for said switch, a single spring operating connection between said operating member and said movable contacts acting upon movement of said operating member in one direction out of a given normal position to move said contacts into closed position, said spring operating connection permitting over-travel of said op-. erating member upon closure of said contacts, an

electroresponsive device for moving said operatout of normal position, means for operating said device by a predetermined current impulse to effect movement of said contacts into closed position and to also effect over-travel of said operating member after-- closure of said contacts solely by inertia against the action of said spring operating connection to thereby maintain said contacts in closed position for an interval which is substantially proportiona1 to the degree of over-travel of said operating member, and means for adjusting said spring operating con- I nection to vary the degree of over-travel of said operating member for variation of the interval during which said contacts are maintained in closed position.

4. In a timing controller for an electric circuit, in combination, a control switch including a plurality of movable contacts biased to open position and providing a plurality of gaps in said circuit, an operating magnet therefor including a stationary magnet frame and a cooperating movable armature member, a single spring operatto the degree of ing connection betwecnsaid armature member and said movable contacts for eflecting closure I of the latter upon attraction or said armature member out or a given normal position, said spring operating connection permitting overtravel of said armature member upon closure of said contacts, and means for energizing said operating magnet by a current impulse which is of a given value to efiect closure of said contaow and to also eflect overtravel of said operating member upon closure of said contacts solely by inertia against the action or said spring to temporarily maintain said switch in closed position tor a period which is substantially proportional overtravel of said armature member.

5. In a timing controller for an electric circuit, in combination, a control switch for said circuit including a plurality of movable contacts biased to open position and providing a plurality of gaps in said circuit, an operating magnet therefor including a stationary magnet frame and a cooperating movable armature member, a single spring operating connection between said armature member and said movable contacts for ettecting closure 01' the latter upon attraction of said armature member out of a given normal position, said spring operating connection permitting overtravel or said armature member upon closure of said contacts, means for energizing said operating magnet by a current impulse which is of a given ,value to effect closure of said contacts and to also efl'ect overtravel or said armature member upon closure of said contacts solely by inertia against the action of said spring to maintain said conta'cts in closed position for a period which is substantially proportional to the degree of overtravel of said armature member, means for adjusting said spring to vary the degree of inertial overtravel of said armature member, and means associated with said adjusting means for indicating periods or closure of said switch corresponding to different settings of said Spring.

6. An electromagnetically operated control switch comprising a pair of stationary contacts, movable contacts cooperating with said stationary contacts and biased out of engagement there-. with, an equalizer lever carrying said movable contacts, said'equalizer lever being bodily movable to eil'ect simultaneous operation of'said movable contacts and being pivotally'supported to permit self-alignment of said movable contacts with respect to said stationary contacts, an operating magnet for said movable contacts including a stationary operating winding and a movable armature member to be attracted out of a given normal position by said winding, and a single spring operating connection between said armature member and said equalizer lever for moving said movable contacts into circuit closing position upon attraction 01' said armature member out of normal position,

01' said movable said operating member s d spring oncrating connection permitting overtravel of said ,movable out 01' normal switch comprising operating member, upon said operating member and carrying said equalizer lever, a spring normally holding said am in a given angular position with respect to said operating member, an operating magnet including a stationary operating winding and a movable armature member fixed to said operating member, said armature member being biased toward a given normal position to maintain said movable contacts in open position and being movable out oinormal position by said winding to move said movable contacts into closed position through the medium of said spring and said armature member being capable oi overtravel against the action or said spring upon arrest of said movable contacts in closed position.

8. An electromagnetically operated control switch comprising a pair of stationary contacts, movable contacts cooperating therewith, an equalizer lever carrying said movable contacts, said lever being bodily movable to voperate said contacts simultaneously and being pivotally supported intermediate said movable contacts to permit self-alignment of the latter with respect to said stationary contacts, a rotatable operating member, an arm pivotally mounted upon izer lever, a spring normally holding said arm in a given angular position with respect to said operating member, an operating magnet including a stationary operatingwinding and a movable armature member fixed to said operating member, said armature member being biased toward a given normal position to maintain said movable contacts in open position and being position by said winding to move said movable contacts into closed 9051-- tion through the medium or said springsaid armature member being also capable of overtravel against the action I said spring upon arrest 01 said movable con cts in closed position, and means for adjusting said spring to vary the opposing action thereof upon overtravel of said armature member.

9. An electromagnetically operated control a pair of stationary contacts, movable contacts cooperating therewith, an equalizer lever carrying said movable contacts, said lever being bodily movable to operate said contacts simultaneously and ported intermediate said permit self-alignment of movable contacts to ing member, an arm pivotally mounted upon said operating member and carryi g said equalizer lever, a spring normally holding said arm in a given angular position with respect to said operating member, an operating magnet including thereof upon overtravel oi. said armature member, and means for adjusting said operating meman arm pivotally mounted and carrying said equal-,

being pivotally sup-,

the latter with respect to said stationary contacts, a rotatable operat-,

, able armature member to be attracted out or a given normal position by said winding. 9. single spring operating connection between said armature member and said equalizer lever for moving said movable contacts into circuit closing position upon attraction of said armature member out of normal position, said spring operating connectlon permitting overtravel of said armature member upon closure of said movable contacts, and means tor adjusting said equalizer-"lever with respect to said armature member to provide for variation of the normal air gaps between said stationary and movable contacts.

CARROLL BTANBBURY.

Images