US2390981A - Timing apparatus - Google Patents

Timing apparatus Download PDF

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US2390981A
US2390981A US460239A US46023942A US2390981A US 2390981 A US2390981 A US 2390981A US 460239 A US460239 A US 460239A US 46023942 A US46023942 A US 46023942A US 2390981 A US2390981 A US 2390981A
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relay
electric discharge
discharge device
contacts
circuit
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US460239A
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Maurice E Bivens
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General Electric Co
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General Electric Co
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K11/00—Resistance welding; Severing by resistance heating
    • B23K11/24—Electric supply or control circuits therefor
    • B23K11/248—Electric supplies using discharge tubes

Definitions

  • timing intervals which may be identified as squeeze, heatj' coo weld," hold, and "o
  • the squeeze time allows for the operation of means employed for closing thewelding electrodes on the work with desired pressure before the welding current is applied thereto through the electrodes to make a weld.
  • the best time determines the duration of an impulse of welding current flow
  • the cool time determines the time between current impulses when a plurality of current impulses is used for making a weld, as is the case in interrupted spot welding. In'interrupted spot welding. a plurality of heat times spaced by one or more cool times is determined by the weld time.
  • the hold time determines the time that the electrodes remain on the work with full pressure after welding current ceases flowing and before the means for pressing the electrodes on the work is operated to release the work.
  • the of! time determines the time interval before the means for pressing the electrodes into engagement with the work is again operated when performing repeat operations. Preferably all the above time intervals are independently adjustable.
  • a further-object of my invention is to provide control apparatus in which a plurality of operations are timed by the alternate operation of a plurality of time delay circuits each of which embodies an electric discharge device provided with a plurality of timing circuits which are selectively connected to the-control element of the electric discharge device with which they are associated by switching means controlled by said time delay circuits.
  • the six timing intervals above referred to as employed in making a spot weld are determined by three time delay relays instead of using six for this purpose as in the past.
  • one time delay relay determines the heat and oil times
  • another time delay relay determines the squeeze, cool, and hold times
  • a third time delay relay determines the weld time.
  • the first and second time delay relays above referred to are arranged to operate with different time delays by reason of a plurality of timing circuits selectively connected to the control elements of the electric discharge devices forming part thereof. Switching means operated by one or more of these relays switch from one timing circuit to another timing circuit prior to the time that thetime delay relay controlled thereby is to operate with a, new time delay.
  • the welding machine has been diagrammatically represented at It. It comprises a plurality of electrodes i l which are connected to the terminals of a secondary I2 of a welding transformer I 3 having a primary winding ll.
  • the electrodes are moved toward and away from each other into and out of engagement with the work l5 by a fluid operated mechanism it which may be a piston and cylinder arrangement operated by the admission and exhaust of fluid from opposite ends of the cylinder trolled by the sequence timer constituting the remainder of Fig. 1 of the drawings. It comprises three time delay relays TDI, TD2, and TD3, and three switching relays CRI, CR2, and CR3.
  • relays are each provided with contacts which are interconnected with one another and hand operated switches SI, 22, and 23 to constitute a switching means which determines the sequence of operations or the welding machine, namely, the squeeze, heat, cool, weld, hold. and oil. times above referred to.
  • the operating windings of the relays as well as the operating winding It of valve II are connected across and energized from a supply circuit 24, 25 whose connection with a source of alternating current supply 26.is controlledby hand operated switches 21. Welding current is supplied to the primary of the welding transiorme'r l3 from a. source of supply 28.
  • time delay relays TDI, TD2, and TD3 are controlled by electric discharge devices 23, 30, and 3
  • the operating windings 35, 36, and 31' of these relays are connected in series with the anode-cathode circuits of these electric discharge devices across the supply circuit 24, 25 through switching means comprising their contacts, the contacts of relays CRI, CR2, and CR3 and hand operated switches SI, 22, and 23.
  • the time delays inthe operations of relays TDI, TD2, and TD3 are determined by the control voltages applied to the control elements 34 of their electric discharge devices 29,'
  • Relays TDI and TD2 are provided with a plurality of adjustable timing circuits for applying difierent control voltages to the control elements of their electric discharge devices 29 and 30 in order to control their operations after difierent time delays, each of which in itself is adjustable.
  • Time delay relay TD3 is provided with only one adjustable timing circuit.
  • TD3 depends on the magnitude of the negative potential of a capacitance which is connected to th control element of the electric discharge device torming part of each relay. This capacitance is charged through the control element circuit of the electric discharge device when its anode-cathode circuit is open and discharged when its anode-cathode circuit is closed at a rate determined by a resistance connected across its terminals.
  • a capacitance 38 is charged by the control-elementcathode rectification of electric discharge device 3
  • the magnitude of this negative potential of capacitance 38 is determined by the position of a slider 39 on a resistance 40 of a voltage divider comprising series connected resistances 4
  • the charging circuit is completed through this voltage divider, slider 38, capacitance 33, a current limiting resistor 43, control element 34, and cathode 33 of electric discharge device 3
  • the closure of this switch also impresses a positive alternating current voltage on the control element 34 of the electric discharge device, which in magnitude amounts to the voltage drop across resistor 4
  • resistor 42 Since resistor 42 is made several times larger in value than resistor 4l, the positiv potential applied to the control element 34 of the electric discharge device is not effective for rendering this device conductive due to the larger negative potential applied to its control element by capacitance 33.
  • capacitance 38 slowly discharges through a resistance 48 connected in shunt thereto and after a predetermined time interval determined by this resistance attains a voltage which is less than the positive voltage applied to the control element of electric discharge device 3
  • the time delay range is determined by the position of slider 39 on resistor 40 of the voltage divider and the value of a discharge resistance 48 in shunt to the capacitance.
  • a switch 43 is provided for increasing the range of adjustment by increasing or decreasing the amount of resistance 43 connected across capacitance 38.
  • relay TD3 The electric circuits of relay TD3 are more fully described in United States Letters Patent 2,171,348, Elbert D. Schneider, granted August 29, 1939, and assigned to the assignee of this invention.
  • and TD2 are similar to the timing circuit just described for relay TD3.
  • Relay TDI is provided with two of these timing circuits which are selectively connected to the control element 34 of electric discharge device 29 by contacts 50 and 5
  • Contacts 50 connect a capacitance 52 to a slider 53 on a resistance 55 of a voltage divider comprising series connected resistances 54, 55, and 56, and contacts 5
  • capacitance 52 of relay TDI is provided with a discharge resistance 59 and a switch 30 for controlling the amount thereof connected across the terminals of capacitance 52.
  • and resistances 82, 88, and 84 are also provided.
  • Relay TD2 is provided with three of these timing circuits which are selectively connected to the control element 84 or electric discharge device 88 by contacts 85 and 88 of relay CR2 and contacts 81 and 88 of relay TD3.
  • Contact 85 connects a capacitance 88 to a slider 18 on a resistance 1
  • Contacts 88 and 81 of relays CR2 and 'I'D3 connect capacitance 88 to-a slider 14 on a resistance 18 or a voltage divider comprising resistances 12, 15, and 18.
  • Contact 88 of relay TD8 connects capacitance 88 to a slider 18 on a resistance 11 of a voltage divider comprising resistances 12, 11, and 18.
  • capacitance 88 of relay TD2 is provided with a discharge resistance 18 and a switch 18 for controlling the amount thereof connected across the terminals of capacitance 88.
  • , 82, and 83 are also provided.
  • are of a high value and employed in order to insure stability of operation of these devices in response to their control voltages.
  • Capacitances 84, 85, and 88 are connected between the control elements 84 and cathodes 33 of these electric discharge devices for a like purpose, that is, to insure stability of operation.
  • Each of the electric discharge devices is provided with a shield grid 81 which is connected to its cathode.
  • the windings 85, 88, and 81 of the relays TDI, TD2, and 'ID8 are provided with smoothing capacitances 88, 88, and 88 in view of the fact that these exciting windings are traversed by a pulsating current whose flow is controlled by the electric discharge devices 28, 38, and 3
  • Relay CRI is provided with holding contacts 8
  • Relay TDI is provided with contacts 85 in circuit with the control winding 88 of relay CRI and contacts 81 in circuit with the operating winding 88 of relay CR3 and the anode-cathode circuit of electric discharge device.
  • Relay CR8 is provided, in addition to contacts 58 and 5
  • Relay TD2 is provided with contacts I84 in circuit with the operating winding 88 of relay CRI and contacts I85 which in conjunction with contacts I88 of relay 'ID8 control the energization of relays CR8 and CR2.
  • Relay CR2, in addition to contacts 41, 85, and 88 already referred to, is also provided with folding contacts I81.
  • Switches 21 and 25 are energized by closing switches 21 throughwhich they are connected to the source of alternating current supply 28.
  • relay TDI immediately operates without time delay since its anode-cathode circuit is completed from conductor 24 through its winding 8-8 and electric discharge device 28, conductor I88 and contacts I88 of relay CR3 to conductor 28 before any negative potential can be built up across condenser 52 by its connection with the voltage dividers 84, 55 and 88 through contacts 88 of relay CR8.
  • relay TDI When the operator closes the push-button switch SI to initiate a welding operation, the prior closure of contacts 81 of relay TDI completes the energizing circuit for winding 88 of relay CR8 and the anode-cathode circuit of relay TD2.
  • the circuit through winding 88 of relay CR8 extends from conductor 24 through contacts I85 of relay TD2 and parallel connected contacts I88 of relay 'I'D8, contacts 81 of relay TDI, conductors I88, H8 and III, and contacts 2
  • the operating winding 88 of relay TD2 is completed from conductor 24 through electric discharge device 88, contacts 84 of relay CRI, conductors I I2, III and I I4, contacts 81 of relay TDI, conductors I88, I I8 and III and contacts 2I of switch SI to conductor 25.
  • relay CR8 switches the timing circuit of relay TDI by opening its contacts 58 and closing its contacts 5
  • this relay Upon completion of the anode-cathode circuit of electric discharge device 38 of relay TD2, this relay begins to time out and after a predetermined time delay period determined by the timing circuit which is connected to its control element through contacts 85 of relay CR2, operates to open its contacts I88 and close its contacts I84.
  • relay CRI which initiates the flow of welding current shown in the chart by a zig-zag line which indicates cycles of current flow.
  • relay TD2 operates and closes its contacts I04, a circuit through the operating winding 96 of relay CRI is completed from conductor 24 through conductor II5, winding 96, contacts 95 of relay TDI, contacts I02 of relay CR3, conductors H6 and H1, contacts I04 of relay TD2, contacts I06 of relay TD3, contacts I of relay CR3, conductors I09, H0 and III and contacts 2
  • contacts I04 of relay TD2 also completes the anode-cathode circuit of electric discharge device 29 of relay TDI from conductor 24 through the operating winding 35 and electric discharge device 29 of relay 'I'DI, conductors I08 and H1, contacts I04 of relay TD2, contacts I06 of relay TD3, contacts I00 of relay CR3, conductors I09, 0 and I II and contacts 2
  • Relay TDI consequently starts timing out under the control of its timing circuit completed by contacts of relay CR3.
  • relay CRI closes its contacts 9
  • the opening of contacts 94 deenergizes relay TD2, and this relay consequently opens its contacts I04 and closes its contacts I05.
  • the energization of relay TDI is nevertheless maintained as is the energization of relay CRI by the closure oi its contacts 9
  • relay CRI also closes its contacts 92 which completes the connection of the primary I4 of the welding transformer I3 to the source of supply 28.
  • Relay CRI also closes its contacts 93 and completes the energizing circuit of relay CR2 from conductor 24 through the operating winding 9 of relay CR2, contacts 93 of relay CRI, conductors H2, H3 and H4, contacts I00 of relay CR3, conductors I09, IIO and III and contacts 2
  • relay CR2 closes its holding contacts I01 which places its operating winding I I8 in a shunt circuit with the operating winding 98 of relay CR3. It also opens its contacts 65 and closes its contacts 66 to complete a new timing circuit for relay TD2 through the closed contacts 61 of relay TD3. It also closes its contacts 41 and thereby completes the anode-cathode circuit of the electric discharge device 3
  • relay TD3 is timing out as indicated by the shaded portion in the sequence chart of Fig. 2. 1
  • relay TD2 After the new time delay imposed on relay TD2, it operates and closes its contacts I04 thereby terminating the cool period and initiating another heat period.
  • This second heat period is followed by a second cool period, which in turn is followed by another heat period, during which the relays previously considered in connection with the first heat and cool periods operate in the manner above described.
  • relay TD3 times out and operates, closing its contacts 60 and opening its contacts 61 and I06.
  • the closure of contacts 68 and the opening of contacts 61 of relay TD3 connects the third timing circuit of .relay TD2 to the control element 34 of its electric discharge device 30.
  • Mean hile during this last heat period, relay TDI is timjng out and eventually operates to open its contacts as.
  • the opening of these contacts deenergizes relay CRI, which by opening its contacts 92 terminates the last heat period by disconnecting the source of supply 28 from the'primary I4 of the welding transformer I3.
  • the closure of contacts 94 of relay CRI completes the anode-cathode circuit of electric discharge device 30 of relay TD2, which after a new timing period operates and opens its contacts I05 and closes its contacts I04.
  • relay CR2 again connects the squeeze timing circuit of relay TD2 through its contacts 65 and opens the anode-cathode circuit of the electric discharge device 3
  • Relay TD3 consequently closes its contacts I06.
  • the deenergization of relay CR3 causes ,it to close its contacts 50 which connect the of! timing circuit of this relay to the control element 34 of its electric discharge device 29.
  • relay CR3 also causes it to open its contacts 99 and thereby deenergize the winding I9 of valve I1. This valve will thereupon cause mechanism I9 to withdraw electrodes II from the work I5 so that it may be removed or shifted relatively to the electrodes for another welding operation.
  • Switch 23 when closed, completes a shunt circuit about the contacts 91 of relay TDI. Consequently, it is possible to initiate an operation with switch 23 closed without waiting for the time delay period imposed by relay 'I'Dl. Furthermore, for repeat operations, it switch 23 is closed, relay TD2 is maintained energized and consequently eliminates the squeeze period imposed by this relay in the operation above described.
  • time delay relays TDI, TD2 and TD3 form part of a system in which switching means controlled by these relays impose a desired sequence of timed operations. It is, of course, apparent that time delay relays each provided with a plurality of timing circuits may be interconnected in another control system for accomplishing an other sequence of timed operations without in any way departing from my invention.
  • relays TDI, TD2 and TD3 have each been considered above as an entity in order to facilitate description thereof. It is to be understood, however, that each of them may be considered as a relay having an operating winding whose energization is controlled by a time delay circuit embodying the electric discharge device associated therewith as defined in some of the claims appended hereto.
  • a single voltage divider may be employed if a plurality of sliders engaging it are used in place of a slider engaging each of a plurality of parallel connected resistors such as described above. It is also obvious that the voltage divider need not be composed of resistances such as described since any other suitable impedance elements or sources of voltage may be used.
  • are of the type employing an ionizable medium such as a gas or vapor. It is, of course, apparent that other types of electric discharge devices may be employed. When the type of electric dischargedevice requires a time delay for cathode heating before the device may be rendered conductive without impairing the same, it is of course apparent that suitable time delay means may be employed for imposing this delay in the operation of the device. Furthermore, although the supply circuit 24, 25 has been described as being energized from a source of alternating current, it is apparent that without departing from my invention the circuit may be modified in order to employ a direct current source of supply for energizing the upply circuit.
  • Timing apparatus comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes effective for rendering said electric discharge device conductive a predetermined time after its anode-cathode circult is connected to said supply circuit, and means responsive to the flow of current through the anode-cathode circuit of said electric discharge device for controlling the operation of said last mentioned means to change the connection of the control element of said electric discharge device from one of said control voltages to another of said control voltages, disconnecting the anodecathode circuit of said electric discharge device from said supply circuit, and after a predetermined time delay again connecting the anodecathode circuit to said electric discharge device to said supply circuit.
  • Timing apparatus comprising a supply circuit, an electric discharge device having an anode. a cathode, and a control element, two timin circuits each of which when connected to the control element of said electric discharge devic renders it conductive after a predetermined time delay which is difierent for each timing circuit, transfer means for changing the connection of the control element of said electric discharge device from one of said timing circuits to another of said timing circuits, and means responsive to the flow of current through the anode-cathode circuit of said electric discharge device for controlling the operation of said transfer means and the anodecathode connection of said electric discharge device with said supply circuit.
  • Timing apparatus comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes effective for rendering said electric discharge device conductive a predetermined time after its anode-cathode circuit is connected to said supply circuit, and means responsive to the flow of current through the anode-cathode circuit of said electric discharge device for operating said last mentioned means to change from one of said control voltages to another of said control voltages.
  • Timing apparatus comprising a supply (in cuit, an electric discharge device having an anode,
  • a cathode and a control element
  • a relay having an operating winding
  • means responsive to the operation of said-relay for operating said last mentioned means to change from one of said control voltages to another of said control voltages.
  • Timing apparatus comprising an electric discharge device having an anode, a cathode, and a control element, means for selectively app ing to the control element of said electric discharge device a plurality of control voltages each or which becomes effective after a different timing period for controlling the conductivity of said electric discharge device, means responsive to the conductivity of said electric discharge device for operating said last mentioned means to change from one of said control voltages to another of said control voltages, a supply circuit, and means responsive to the conductivity oi said electric discharge device for connecting and reconnecting its anode-cathode circuit to said supply circuit and for disconnecting it from said supply circuit after it has become conductive.
  • Timing apparatus comprising anelectric discharge device having-an anode, a cathode,'and a control element, means for selectively applying to the control element oi! said electric discharge device a plurality oi. control voltages each of which becomes effective after a different timing period for controlling the conductivity of said electric discharge device, time delay means for operating said last mentioned means to change from one of said control voltages to another of said control voltages after said electric discharge device has been rendered conductive a predetermined number of times with one or said control voltage applied to its control element, a supply circuit, and means for connecting and reconnecting the anode-cathode circuit of said electric discharge device to said supply circuit and for disconnecting it from said supply circuit after it has become conductive.
  • a timing device circuit comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for connecting the anode-cathode circuit of said electric discharge device across said supply circuit, means for selectively applying to the control element of said electric discharge device a plurality oi control voltages each of which becomes effective for controlling the conductivity of said electric discharge device after a diflerent timing period initiated by completing the connection of the anode-cathode circuit of said electric discharge across said source of supply, and means responsive to the flow of current in the anode cathode circuit of said electric discharge device for operating said last mentioned means to change from one oi said control voltages to another or said control voltages.
  • a timing circuit comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for connecting the anode-cathode circuit of said electric discharge device across said supply circuit, a relay having an operating winding whose energization is controlled by said electric discharge device, means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes effective for controlling the conductivity of said electric discharge device after a different timing period initiated by completing the connection of the anode-cathode circuit of said electric discharge across said supply circuit, and means responsive to the operation of said relay for operating said last mentioned means to change from one of said control voltages to another of said control voltages.
  • Timing apparatus comprising a supply circuit, an electric discharge device having an an d a cathode, and a control element.
  • a source of alternating current voltage an electric discharge-device having an anode, a cathode, and a control element
  • means comprising a capacitance energized from said source through the control-element-cathode circuit of said electric discharge device for impressing on said control element a potential negative with respect to its said cathode and tending to maintain said discharge device non-conductive
  • means for controlling the magnitude oi the negative potential to which said capacitance is charged by said source a switch connected in series relation with the anode-cathode circuit of said electric discharge device and arranged to efiect charging of said capacitance when in the open position and to initiate discharging of said capacitance when in the closed position to render said discharge device conductive a predetermined time after the closure thereof, means for closing said switch, means responsive to the flow of current through the anode-cathode circuit or said electric discharge device for operating said controlling means to change the magnitude oi the negative potential of said capacitance, and means for opening said
  • the anode cathode circuit of said discharge device being connected in series relation with said operating winding to control the energization thereof from said source, means comprising a capacitance energized from said source through the control element-cathode circuit of said electric discharge device for impressing on said control element a potential negative with respect to its said cathode and tending to maintain said discharge device non-conductive, a switch connected in series relation with the anode-cathode circuit or said electric discharge device and being arranged to eflect charging of said a capacitance when in the open position and to initiate discharging of said capacitance when in the closed position to render said discharge device conductive a predetermined time after the closure thereof, and means responsive to the operation of said relay for controlling the connection of said capacitance with said source and the magnitude of its negative potential.
  • a source of alternating current voltage an electric discharge device having an anode, a cathode, and a control element
  • a relay having an operating winding whose energization is controlled by said electric discharge device
  • means comprising a capacitance energized from said source through the control-elementcathode circuit oi said electric discharge device for impressing on said control element a negative conductive a predetermined time after the closure ,thereof, means for closing said switch, and means responsive to the operation of said relay for opening said switch, changing the connection of said capacitance with said source and the. magnitude of its negative potential and after a predetermined time delay again closing said switch.
  • a source of alternating current voltage a-relay having an operating winding
  • an electric discharge device having an anode, a cathode, and a. control element
  • the anodecathode circuit of said discharge device being connected in series relation with said operating coil of said relay to efi'ect energization thereof from said source when in a conducting condition
  • means tending to maintain said discharge device non-conducting comprising a voltage divider connected across said source and switching means for selectively connecting a capacitance between said control element and different points on said voltage divider, a switch connected in series relation with the operating coil of said relay and the anode-cathode circuit of said discharge device and being arranged to effect charging of said capacitance when in its openposition and to initiate discharge of said capacitance when in its closed position to render said discharge device conducting a predetermined time after the 010.
  • means for closing said switch and means responsive to the operation of said relay for opening said switch and for operating said switching means to change the connection of said capacitance from one point to another point on said voltage divider, said capacitance imposing on said control element when connected to at which one or said first mentioned timing circuits becomes efiective for rendering said first mentioned electric discharge device conductive
  • means for connecting the anode-cathode circuits of said electric discharge devices to said supply circuit means responsive to the conduction of current through the anode-cathode circuit of said .flrst mentioned electric discharge device for disconnecting the anode-cathode circuit orsaid first mentioned electric discharge device from said supply circuit, means responsive to the conduction of current through the anode-cathode circuit of said second electric discharge device for operating said transfer means, means for again connecting the anode-cathode circuit of said first mentioned electric discharge device to said supply circuit after said transfer means has been operated, and means responsive to conduction oi current through the anode-cathode circuit
  • Apparatus comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for connecting the anode-cathode circuit or said electric discharge device with said supply circuit, a relay having an operating winding whose energization is controlled by said electric discharge device, switching means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes effective after a different timing period for controlling the conductivity of'said electric discharge device, a second electric discharge device having an anode, a-cathode, and a control element, means for connecting the anodecathode circuit of said second electric discharge device with said supply circuit, a second relay having an operating winding whose energlzation is controlled by said second electric discharge device, a second switching means for selectively applying to the control element of said second electric discharge device a plurality of control voltages each of which becomes effective after a different time period for controlling the conductivity of said second electric discharge device, and
  • Timing apparatus comprising a supply circuit, an electric discharge device having an anode. a cathode, and a control element, a relay having an operating windingenergized by anode-cathode current conduction through said electric discharge device, a plurality of timing circuits each of which when connected to the control element of said electric discharge device becomes efiective i'or "controlling the conductivity of said electric discharge device after a different timing period initiated by connecting the anode-cathode circuit of said electric discharge device to said supply circuit, transfer means for changing the connection of the control element 01' said electric discharge device from one 01' said timing circuits to another of said timing circuits, a second electric discharge device having an anode, a cathode, and a control element, a second relay having an operating winding energized by anode-cathode current conduction through said second electric dischargddevicega timing circuit connected to the control element of said second electric discharge device for controlling the conductivity of said electric discharge device after a time period which
  • Apparatus comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for connecting the anode-cathode circuit of said electric discharge device with said supply circuit, a relay having an operating winding whose energization is controlled by said electric discharge device, switching means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes efiective after a'different timing period for controlling the conductivity of said electric discharge device, a second electric discharge device having an anode, a cathode, and a control element, means for connecting the anode-cathode circuit of' said second electric discharge device with said supply circuit, a second relay having an operating winding whose energization is controlled by said second electric discharge device, a second switching means for selectively applying to the control element of said second electric discharge device a plurality of control voltages each 01' which becomes eflective after a different time period for controlling the conductivity of said
  • an electronic timer including a supply circuit, an electric valve includ-- ing an anode, a cathode and a control member, means connecting said anode-cathode circuit to said supply circuit, two timing circuits for producing transient control voltages, means connecting one of said timing circuits to control the relative voltage of said cathode and said control member, means for initiating operation 01 said electronic timer by impressing the transient voltage of said one oi said timing circuits on said control member to effect a predeterminedechange in the conductivity of said electric valve at the end of a predetermined interval, with means responsive to said change in conductivity of said electric valve for transferring energization of said control member to the other of said timing circuits to change the interval between initiation of the operation of said electronic timer and the instant at which the transient voltage impressed on said control member is effective to produce said predetermined change in conductivity of said electric valve, and means for reinitiating the operation of said electronic timer by impressing the transient control voltage of the other
  • an electronic timer including a supply circuit, an electric valve including an anode, a cathode and a control member, means connecting said anode-cathode circuit to said supply circuit, two timing circuits for producing transient control voltages, means connecting one of said timing circuits to control the relative voltage of said cathode and said control member, means for initiating operation of said electronic timer by impressing the transient voltage of said one of said timing circuits on said control member to effect a predetermined change in the conductivity of said electric valve at the end of a predetermined interval, with means responsive to said change in conductivity of said electric valve for transferring energization of said control member to the other of said timing circuits to change the interval between initiation of the operation of said timer and the instant at which the transient voltage impressed on said control member is effective to produce said predetermined change in conductivity of said electric valve, a second timer initiated in operation in response to said predetermined change in conductivity of said electric valve, andmeans responsive to the operation of said lastmentione
  • an electronic timer including a. supply circuit, an electric valve havin an anode, a cathode and a control member, means connecting said anode-cathode circuit for energization from said supply circuit, a timing circuit including resistance and a capacitor, means connecting said timing circuit with said control member to energize said control member in accordance with the voltage of said capacitor, and means for initiating operation of said timing circuit to impress a transient control voltage on said control member to eilect a predetermined conductivity of said electric valve at the end oi a predetermined interval, with means responsive to said predetermined conductivity of said electric valve for altering said timing circuit to change the interval between initiation or the timing operation of said timer and the instant at which the transient voltage impressed on the control member is effective to produce said predetermined conductivity of said electric valve and additional means operable in response to the predetermined conductivity of said electric valve means for reinitiating the operation of said electronic timer with said timing circuit altered.
  • an electronic timer including a supply circuit, an electric valve havin an anode, a cathode and a control member, means connecting said anode-cathode circuit for energization from said supply circuit, a' timing a circuit including resistance and a capacitor, means connecting said timing circuit with said control member to energize said control member in accordance with the voltage of said capacitor, and means for initiating operation of said timing circuit to impress a transient control voltage on said control member and to eiTect a predetermined conductivity of said electric valve at the end of a predetermined interval, with means responsive .to said predetermined conductivity of said electric valve for altering said timing circuit to change the interval between initiation of the timing operation of said timer and the instant at which the transient voltage impressed on the co trol member is eilective to produce said predetermined conductivity of said electric valve, a second timer initiated in operation in response to said predetermined conductivity of said electric valve and means responsive to th expiration of the timing interval of said second time

Description

Dec. 18, 1945-. M. E. BIVENS TIMING APPARATUS Filed Sept. 50, 1942 2 Sheets-Sheet 2 mmbdiw MEN: Q n
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Q QISS NWML Inventor: Maurice E. Bivens, b5 JV CJMWZ M His Attorneg.
Patented Dec. 18, 1945 UNlTED STATES PATENT OFFICE 2.390.981 I minus APPARATUS Maurice E. Blvens, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application September so, 1942, Serial No. 469,239
' 21 Claims.
purpose may involve six timing intervals which may be identified as squeeze, heatj' coo weld," hold, and "o The squeeze time allows for the operation of means employed for closing thewelding electrodes on the work with desired pressure before the welding current is applied thereto through the electrodes to make a weld. The best time determines the duration of an impulse of welding current flow, and the cool time determines the time between current impulses when a plurality of current impulses is used for making a weld, as is the case in interrupted spot welding. In'interrupted spot welding. a plurality of heat times spaced by one or more cool times is determined by the weld time.
The hold time determines the time that the electrodes remain on the work with full pressure after welding current ceases flowing and before the means for pressing the electrodes on the work is operated to release the work. The of! time determines the time interval before the means for pressing the electrodes into engagement with the work is again operated when performing repeat operations. Preferably all the above time intervals are independently adjustable.
In the past such a sequence control has been accomplished by six independent timing units. In accordance with my invention a smaller number of timing units is employed for accomplishing the same sequence by causing one or more A further-object of my invention is to provide control apparatus in which a plurality of operations are timed by the alternate operation of a plurality of time delay circuits each of which embodies an electric discharge device provided with a plurality of timing circuits which are selectively connected to the-control element of the electric discharge device with which they are associated by switching means controlled by said time delay circuits.
It is also an object of my invention to provide control apparatus in which a time delay circuit embodying an electric discharge device and a plurality of timing circuits for its control element is controlled by a time delay relay which operates to change the connection of the control element of the electric discharge device from one of said timing circuits to another of said timing circuits.
Further objects of my invention will become apparent from a consideration of the electric of the timing units to operate repeatedly with different time settings.
It is an object of my invention to provide a. new and improved time delay circuit.
it is also an object of my invention to provide a new and improved timing cincuit which open ates in accordance with the delayed conduction of an electric discharge device provided with a control element which is selectively connected to a plurality of timing circuits each of which renders it conductive after a predetermined'time delay which is different for each of the timing circuits.
control diagrammatically represented in Fig. 1
of the accompanying drawings and the sequence chart for this control which is shown in Fig. 2 of these drawings.
In accordance with my invention, the six timing intervals above referred to as employed in making a spot weld are determined by three time delay relays instead of using six for this purpose as in the past. In the system about to be described, one time delay relay determines the heat and oil times, another time delay relay determines the squeeze, cool, and hold times, and a third time delay relay determines the weld time. The first and second time delay relays above referred to are arranged to operate with different time delays by reason of a plurality of timing circuits selectively connected to the control elements of the electric discharge devices forming part thereof. Switching means operated by one or more of these relays switch from one timing circuit to another timing circuit prior to the time that thetime delay relay controlled thereby is to operate with a, new time delay.
In Fig. 1 of the drawings, the welding machine has been diagrammatically represented at It. It comprises a plurality of electrodes i l which are connected to the terminals of a secondary I2 of a welding transformer I 3 having a primary winding ll. The electrodes are moved toward and away from each other into and out of engagement with the work l5 by a fluid operated mechanism it which may be a piston and cylinder arrangement operated by the admission and exhaust of fluid from opposite ends of the cylinder trolled by the sequence timer constituting the remainder of Fig. 1 of the drawings. It comprises three time delay relays TDI, TD2, and TD3, and three switching relays CRI, CR2, and CR3. These relays are each provided with contacts which are interconnected with one another and hand operated switches SI, 22, and 23 to constitute a switching means which determines the sequence of operations or the welding machine, namely, the squeeze, heat, cool, weld, hold. and oil. times above referred to.
.The operating windings of the relays as well as the operating winding It of valve II are connected across and energized from a supply circuit 24, 25 whose connection with a source of alternating current supply 26.is controlledby hand operated switches 21. Welding current is supplied to the primary of the welding transiorme'r l3 from a. source of supply 28.
The operations of time delay relays TDI, TD2, and TD3 are controlled by electric discharge devices 23, 30, and 3|. Each of these electric discharge devices' is provided with an anode 32, a cathode 33, and a control element 34. The operating windings 35, 36, and 31' of these relays are connected in series with the anode-cathode circuits of these electric discharge devices across the supply circuit 24, 25 through switching means comprising their contacts, the contacts of relays CRI, CR2, and CR3 and hand operated switches SI, 22, and 23. The time delays inthe operations of relays TDI, TD2, and TD3 are determined by the control voltages applied to the control elements 34 of their electric discharge devices 29,'
30, and 3|. Relays TDI and TD2 are provided with a plurality of adjustable timing circuits for applying difierent control voltages to the control elements of their electric discharge devices 29 and 30 in order to control their operations after difierent time delays, each of which in itself is adjustable. Time delay relay TD3 is provided with only one adjustable timing circuit.
The delay in the operations of relays TDI TD2,
' and TD3 depends on the magnitude of the negative potential of a capacitance which is connected to th control element of the electric discharge device torming part of each relay. This capacitance is charged through the control element circuit of the electric discharge device when its anode-cathode circuit is open and discharged when its anode-cathode circuit is closed at a rate determined by a resistance connected across its terminals.
For example, in the circuit of relay TD3, a capacitance 38 is charged by the control-elementcathode rectification of electric discharge device 3| toimpress a negative potential on its control element 34. The magnitude of this negative potential of capacitance 38 is determined by the position of a slider 39 on a resistance 40 of a voltage divider comprising series connected resistances 4|, 40, and 42 connected across supply circuit 24, 25. The charging circuit is completed through this voltage divider, slider 38, capacitance 33, a current limiting resistor 43, control element 34, and cathode 33 of electric discharge device 3| and the shunt circuits comprising a resistance 44 and resistances 45, 43 and operating winding 31 of relay TD3. When the anodecathode circuit of electric discharge device 3| is open and conductor 25 of the supply conductor is at a positive potential, it will be obvious that the potential to which capacitance 33 is charged will depend on the position of slider 39 on resistor 40. It will amount to the voltage drop across resistor 42 and the right-hand portion of resistor 4|) determined by the position of slider 39 thereon. This charging circuit for the capacitance is interrupted, however, when the anode-cathode ciredit of electric discharge device 3| is completed, for example, by the closing of contacts" of relay CR2 and the consequent connection of the cathode of the electric discharge device through a circuit described below to conductor 25 of the supply circuit. The closure of this switch also impresses a positive alternating current voltage on the control element 34 of the electric discharge device, which in magnitude amounts to the voltage drop across resistor 4| and the left-hand portion of resistor 40 determined by the position of slider 39 thereon. That is, when supply circuit conductor 24 is at a positive potential and a positive potential is consequently applied to the anode 32 of electric discharge device 3|, its control element 34 is also at a positive potential relative to its cathode 33 by the above referred to voltage drop across resistor 4| and the lefthand portion of resistor 40. Since resistor 42 is made several times larger in value than resistor 4l, the positiv potential applied to the control element 34 of the electric discharge device is not effective for rendering this device conductive due to the larger negative potential applied to its control element by capacitance 33. However, capacitance 38 slowly discharges through a resistance 48 connected in shunt thereto and after a predetermined time interval determined by this resistance attains a voltage which is less than the positive voltage applied to the control element of electric discharge device 3| when its anode is at. a positive potential and consequently capable of conducting current. The time delay range is determined by the position of slider 39 on resistor 40 of the voltage divider and the value of a discharge resistance 48 in shunt to the capacitance. A switch 43 is provided for increasing the range of adjustment by increasing or decreasing the amount of resistance 43 connected across capacitance 38.
The electric circuits of relay TD3 are more fully described in United States Letters Patent 2,171,348, Elbert D. Schneider, granted August 29, 1939, and assigned to the assignee of this invention.
The timing circuits of time delay relays TD| and TD2 are similar to the timing circuit just described for relay TD3. Relay TDI is provided with two of these timing circuits which are selectively connected to the control element 34 of electric discharge device 29 by contacts 50 and 5| of relay CR3. Contacts 50 connect a capacitance 52 to a slider 53 on a resistance 55 of a voltage divider comprising series connected resistances 54, 55, and 56, and contacts 5| connect capacitance 52 in circuit with a slider 51 on a resistance 58 of a voltage divider comprising series connected resistances 54, 58, and 56. As in the case of relay TD3, capacitance 52 of relay TDI is provided with a discharge resistance 59 and a switch 30 for controlling the amount thereof connected across the terminals of capacitance 52. In like manner, a current limiting resistance 8| and resistances 82, 88, and 84 are also provided.
Relay TD2 is provided with three of these timing circuits which are selectively connected to the control element 84 or electric discharge device 88 by contacts 85 and 88 of relay CR2 and contacts 81 and 88 of relay TD3. Contact 85 connects a capacitance 88 to a slider 18 on a resistance 1| of a voltage divider comprising series connected resistances 12, 1|, and 18. Contacts 88 and 81 of relays CR2 and 'I'D3 connect capacitance 88 to-a slider 14 on a resistance 18 or a voltage divider comprising resistances 12, 15, and 18. Contact 88 of relay TD8 connects capacitance 88 to a slider 18 on a resistance 11 of a voltage divider comprising resistances 12, 11, and 18. As in the case of relay TD8, capacitance 88 of relay TD2 is provided with a discharge resistance 18 and a switch 18 for controlling the amount thereof connected across the terminals of capacitance 88. In like manner, a current limiting resistance 88 and resistances 8|, 82, and 83 are also provided.
The resistances 88, 82, and 45 connected across the anode-cathode circuits of electric discharge devices 28, 38, and 3| are of a high value and employed in order to insure stability of operation of these devices in response to their control voltages. Capacitances 84, 85, and 88 are connected between the control elements 84 and cathodes 33 of these electric discharge devices for a like purpose, that is, to insure stability of operation. Each of the electric discharge devices is provided with a shield grid 81 which is connected to its cathode. The windings 85, 88, and 81 of the relays TDI, TD2, and 'ID8 are provided with smoothing capacitances 88, 88, and 88 in view of the fact that these exciting windings are traversed by a pulsating current whose flow is controlled by the electric discharge devices 28, 38, and 3| which act as rectiflers and permit current flow in only one direction, namely from their anodes to their cathodes.
Relay CRI is provided with holding contacts 8|, contacts 82 for controlling the energization of the primary I4 of welding transformer I8, contacts 88 for controlling the energization of relay CR2, and contacts 84 in the anode-cathode circuit of electric discharge device 88. Relay TDI is provided with contacts 85 in circuit with the control winding 88 of relay CRI and contacts 81 in circuit with the operating winding 88 of relay CR3 and the anode-cathode circuit of electric discharge device. Relay CR8 is provided, in addition to contacts 58 and 5| above mentioned, with contacts 88 in circuit with the operating winding I8 of valve I1, contacts I88 in shunt to contacts 81 of relay TDI, contacts |8I in circuit with switch 22 in shunt to the contacts 2| or the switch SI, contacts I82 in circuit with the operating winding 88 of relay CRI and contacts I 88 in the anode-cathode circuit of the electric discharge device of relay TDI. Relay TD2 is provided with contacts I84 in circuit with the operating winding 88 of relay CRI and contacts I85 which in conjunction with contacts I88 of relay 'ID8 control the energization of relays CR8 and CR2. Relay CR2, in addition to contacts 41, 85, and 88 already referred to, is also provided with folding contacts I81.
The control exerted by the several relays and their contacts above identified is not completely described in each instance, and consequently a better understanding of my system will'be obtained from a consideration of the operation oi! the control apparatus 01' which they form a part.
In the control apparatus shown in Fig. l, the various relays are shown in their deenergized positions.
Supply conductors 24 and 25 are energized by closing switches 21 throughwhich they are connected to the source of alternating current supply 28. Upon e closure of switches 21, relay TDI immediately operates without time delay since its anode-cathode circuit is completed from conductor 24 through its winding 8-8 and electric discharge device 28, conductor I88 and contacts I88 of relay CR3 to conductor 28 before any negative potential can be built up across condenser 52 by its connection with the voltage dividers 84, 55 and 88 through contacts 88 of relay CR8.
When the operator closes the push-button switch SI to initiate a welding operation, the prior closure of contacts 81 of relay TDI completes the energizing circuit for winding 88 of relay CR8 and the anode-cathode circuit of relay TD2. The circuit through winding 88 of relay CR8 extends from conductor 24 through contacts I85 of relay TD2 and parallel connected contacts I88 of relay 'I'D8, contacts 81 of relay TDI, conductors I88, H8 and III, and contacts 2| of switch SI to conductor 25. The operating winding 88 of relay TD2 is completed from conductor 24 through electric discharge device 88, contacts 84 of relay CRI, conductors I I2, III and I I4, contacts 81 of relay TDI, conductors I88, I I8 and III and contacts 2I of switch SI to conductor 25.
The operation of relay CR8 switches the timing circuit of relay TDI by opening its contacts 58 and closing its contacts 5|. It also opens the anode-cathode circuit of electric discharge device 28 of relay TDI by opening its contacts I88. It also closes its contacts I88 which are in shunt to contacts 81 of relay TDI so that the opening oi. TDI does not interrupt the energizing circuit for its winding 88 or the winding 88 of relay TD2. It also closes its contacts 88 and thereby connects the operating winding I8 of valve I1 across the supply conductors 24, 25. Valve I1 is consequently operated to supply fluid to the electrode operating mechanism I8 and cause this mechanism to force the electrodes II into engagement with the work I5.
Upon completion of the anode-cathode circuit of electric discharge device 38 of relay TD2, this relay begins to time out and after a predetermined time delay period determined by the timing circuit which is connected to its control element through contacts 85 of relay CR2, operates to open its contacts I88 and close its contacts I84.
The operation just described for the various relays is indicated in the sequence chart of Fig. 2 whereupon the closure of switch SI when TDI is in its up" position, relays CR3 and TD2 are energized, and the electrodes are moved toward one another by the operation of mechanism I8 under the control of valve I1. The timing period fo TD2 is indicated as a shaded block extending to the right from the beginning of the squeeze periodywhich is initiated by the operation of valve I1 to bring the electrodes into engagement with the work. The movement of these electrodes into engagement with the work I5 is indicated in the sequence chart by the sloping portion of the line labeled Electrodes. Weldin current does not yet flow, and neither of relays CRI, CR2 or TD3 are energized, as indicated by the straight lines labeled Weld. R R2" and TD3" of this sequence chart.
The squeeze period which is provided for bringing the electrodes into positive engagement with the work terminates with the operation of relay CRI which initiates the flow of welding current shown in the chart by a zig-zag line which indicates cycles of current flow. When relay TD2 operates and closes its contacts I04, a circuit through the operating winding 96 of relay CRI is completed from conductor 24 through conductor II5, winding 96, contacts 95 of relay TDI, contacts I02 of relay CR3, conductors H6 and H1, contacts I04 of relay TD2, contacts I06 of relay TD3, contacts I of relay CR3, conductors I09, H0 and III and contacts 2| of switch SI to conductor 25. The closure of contacts I04 of relay TD2 also completes the anode-cathode circuit of electric discharge device 29 of relay TDI from conductor 24 through the operating winding 35 and electric discharge device 29 of relay 'I'DI, conductors I08 and H1, contacts I04 of relay TD2, contacts I06 of relay TD3, contacts I00 of relay CR3, conductors I09, 0 and I II and contacts 2| of switch SI to conductor 25. Relay TDI consequently starts timing out under the control of its timing circuit completed by contacts of relay CR3.
The operation of relay CRI closes its contacts 9| and opens its contacts 94. The opening of contacts 94 deenergizes relay TD2, and this relay consequently opens its contacts I04 and closes its contacts I05. The energization of relay TDI is nevertheless maintained as is the energization of relay CRI by the closure oi its contacts 9|.
The operation of relay CRI also closes its contacts 92 which completes the connection of the primary I4 of the welding transformer I3 to the source of supply 28. Relay CRI also closes its contacts 93 and completes the energizing circuit of relay CR2 from conductor 24 through the operating winding 9 of relay CR2, contacts 93 of relay CRI, conductors H2, H3 and H4, contacts I00 of relay CR3, conductors I09, IIO and III and contacts 2| of switch SI to conductor 25.
The operation of relay CR2 closes its holding contacts I01 which places its operating winding I I8 in a shunt circuit with the operating winding 98 of relay CR3. It also opens its contacts 65 and closes its contacts 66 to complete a new timing circuit for relay TD2 through the closed contacts 61 of relay TD3. It also closes its contacts 41 and thereby completes the anode-cathode circuit of the electric discharge device 3| of relay TD3 as follows: From conductor 24 through the winding 31 and electric-discharge device 3| of relay TD3, contacts 41, conductors H2, H3 and H4, contacts I 00 of relay CR3, conductors I09,
H0 and. III and the contacts of switch 2| to contacts 91. The closure of contact 91 has no effect since the parallel connected contacts I00 of relay CR3 are also closed. The opening of contacts 95 deenergizes relay CRI which thereupon opens its contacts 9|, 92 and 93 and closes its contacts 94. The closing of contacts 94 reenergizes relay TD2 which immediately starts timin out with a diiierent delay since the control element of its electric discharge device 30 is now connected to a timing circuit completed by the closure of contacts 66 oi! relay CR2 and contacts 61 of relay TD3. The opening of contacts 93 of relay CRI has no effect on the energization of relay CR2 whose operating winding II! has been placed in parallel with the operating winding 99 of relay CR3 by the closure of contacts I01 of relay CR2. The opening of contacts 92 of relay CRI interrupts the flow of welding current and consequently terminates the heat period. Meanwhile, relay TD3 is timing out as indicated by the shaded portion in the sequence chart of Fig. 2. 1
After the new time delay imposed on relay TD2, it operates and closes its contacts I04 thereby terminating the cool period and initiating another heat period.
This second heat period is followed by a second cool period, which in turn is followed by another heat period, during which the relays previously considered in connection with the first heat and cool periods operate in the manner above described.
During the last heat period, relay TD3 times out and operates, closing its contacts 60 and opening its contacts 61 and I06. The closure of contacts 68 and the opening of contacts 61 of relay TD3 connects the third timing circuit of .relay TD2 to the control element 34 of its electric discharge device 30. Mean hile, during this last heat period, relay TDI is timjng out and eventually operates to open its contacts as. The opening of these contacts deenergizes relay CRI, which by opening its contacts 92 terminates the last heat period by disconnecting the source of supply 28 from the'primary I4 of the welding transformer I3. The closure of contacts 94 of relay CRI completes the anode-cathode circuit of electric discharge device 30 of relay TD2, which after a new timing period operates and opens its contacts I05 and closes its contacts I04.
The concurrent opening of contacts I05 of relay TD2 and contacts I06 of relay TD3 deenergizes relays CR2 and CR3. Upon deenergization, relay CR2 again connects the squeeze timing circuit of relay TD2 through its contacts 65 and opens the anode-cathode circuit of the electric discharge device 3| of relay TD3 and thereby deenergizes its operating winding 31. Relay TD3 consequently closes its contacts I06. The deenergization of relay CR3 causes ,it to close its contacts 50 which connect the of! timing circuit of this relay to the control element 34 of its electric discharge device 29. The closure of contacts I03 of relay CR3 also completes the anode-cathode circuit of the electric discharge device 29 of relay TDI, which after the oil timing period will energize the operating winding 35 of relay TDI and cause this relay to close its contacts 91 and open its contacts 95.
The deenergization of relay CR3 also causes it to open its contacts 99 and thereby deenergize the winding I9 of valve I1. This valve will thereupon cause mechanism I9 to withdraw electrodes II from the work I5 so that it may be removed or shifted relatively to the electrodes for another welding operation.
If the contacts 2| of switch SI are maintained closed, after the time delay period of relay TDI, the sequence of operations will be repeated again.
The above operation of the system has been described when the contacts 2| oi switch SI are maintained closed by the operator. It switch 22 were closed, it would only be necessary for the operator to maintain switch SI closed until relay CR8 had operated, closing its contacts lill. In which case, the various circuits traced previously instead of being completed by conductors H and Ill and contacts 2| of switch SI would be completed through contacts ll of relay CR3 and switch 22. Consequently, switch 22 permits a equence of operations to be completed by momentary closure of switch SI.
Switch 23, when closed, completes a shunt circuit about the contacts 91 of relay TDI. Consequently, it is possible to initiate an operation with switch 23 closed without waiting for the time delay period imposed by relay 'I'Dl. Furthermore, for repeat operations, it switch 23 is closed, relay TD2 is maintained energized and consequently eliminates the squeeze period imposed by this relay in the operation above described.
The .time delay relays TDI, TD2 and TD3 form part of a system in which switching means controlled by these relays impose a desired sequence of timed operations. It is, of course, apparent that time delay relays each provided with a plurality of timing circuits may be interconnected in another control system for accomplishing an other sequence of timed operations without in any way departing from my invention.
Furthermore, relays TDI, TD2 and TD3 have each been considered above as an entity in order to facilitate description thereof. It is to be understood, however, that each of them may be considered as a relay having an operating winding whose energization is controlled by a time delay circuit embodying the electric discharge device associated therewith as defined in some of the claims appended hereto.
It is obvious that where a plurality of timing circuits is employed, a single voltage divider may be employed if a plurality of sliders engaging it are used in place of a slider engaging each of a plurality of parallel connected resistors such as described above. It is also obvious that the voltage divider need not be composed of resistances such as described since any other suitable impedance elements or sources of voltage may be used.
In the system disclosed, the electric discharge devices 29, 30 and 3| are of the type employing an ionizable medium such as a gas or vapor. It is, of course, apparent that other types of electric discharge devices may be employed. When the type of electric dischargedevice requires a time delay for cathode heating before the device may be rendered conductive without impairing the same, it is of course apparent that suitable time delay means may be employed for imposing this delay in the operation of the device. Furthermore, although the supply circuit 24, 25 has been described as being energized from a source of alternating current, it is apparent that without departing from my invention the circuit may be modified in order to employ a direct current source of supply for energizing the upply circuit.
In view of the several arrangements above disclosed, various other arrangements will occur to those skilled in the art for selectively applying to the control element of an electric discharge device a plurality of control voltages in order to selectively adjust its timing characteristics.
While I have shown and described my invention as applied to a particular system of connections and as embodying various devices diagrammatically shown, it will be obvious to those skilled in the art that changes and modifications may be made without departing from my invention. and
I therefore aim in the appended claims to cover all such modifications and changes as fall within 5 the true spirit and scope of my invention.
What I claim as new and desire to secure by Letters Patent of the United States is:
1. Timing apparatus comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes effective for rendering said electric discharge device conductive a predetermined time after its anode-cathode circult is connected to said supply circuit, and means responsive to the flow of current through the anode-cathode circuit of said electric discharge device for controlling the operation of said last mentioned means to change the connection of the control element of said electric discharge device from one of said control voltages to another of said control voltages, disconnecting the anodecathode circuit of said electric discharge device from said supply circuit, and after a predetermined time delay again connecting the anodecathode circuit to said electric discharge device to said supply circuit.
2. Timing apparatus comprising a supply circuit, an electric discharge device having an anode. a cathode, and a control element, two timin circuits each of which when connected to the control element of said electric discharge devic renders it conductive after a predetermined time delay which is difierent for each timing circuit, transfer means for changing the connection of the control element of said electric discharge device from one of said timing circuits to another of said timing circuits, and means responsive to the flow of current through the anode-cathode circuit of said electric discharge device for controlling the operation of said transfer means and the anodecathode connection of said electric discharge device with said supply circuit.
3. Timing apparatus comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes effective for rendering said electric discharge device conductive a predetermined time after its anode-cathode circuit is connected to said supply circuit, and means responsive to the flow of current through the anode-cathode circuit of said electric discharge device for operating said last mentioned means to change from one of said control voltages to another of said control voltages.
4. Timing apparatus comprising a supply (in cuit, an electric discharge device having an anode,
a cathode, and a control element, a relay having an operating winding, means for connecting said operating winding in series relation with the anode-cathode circuit of said electric discharge device across said supply circuit, means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes effective for rendering said electric discharge device conductive a predetermined time after its anode-cathode circult is connected to said supply circuit, and means responsive to the operation of said-relay for operating said last mentioned means to change from one of said control voltages to another of said control voltages.
5. Timing apparatus comprising an electric discharge device having an anode, a cathode, and a control element, means for selectively app ing to the control element of said electric discharge device a plurality of control voltages each or which becomes effective after a different timing period for controlling the conductivity of said electric discharge device, means responsive to the conductivity of said electric discharge device for operating said last mentioned means to change from one of said control voltages to another of said control voltages, a supply circuit, and means responsive to the conductivity oi said electric discharge device for connecting and reconnecting its anode-cathode circuit to said supply circuit and for disconnecting it from said supply circuit after it has become conductive.
6. Timing apparatus comprising anelectric discharge device having-an anode, a cathode,'and a control element, means for selectively applying to the control element oi! said electric discharge device a plurality oi. control voltages each of which becomes effective after a different timing period for controlling the conductivity of said electric discharge device, time delay means for operating said last mentioned means to change from one of said control voltages to another of said control voltages after said electric discharge device has been rendered conductive a predetermined number of times with one or said control voltage applied to its control element, a supply circuit, and means for connecting and reconnecting the anode-cathode circuit of said electric discharge device to said supply circuit and for disconnecting it from said supply circuit after it has become conductive.
7. A timing device circuit comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for connecting the anode-cathode circuit of said electric discharge device across said supply circuit, means for selectively applying to the control element of said electric discharge device a plurality oi control voltages each of which becomes effective for controlling the conductivity of said electric discharge device after a diflerent timing period initiated by completing the connection of the anode-cathode circuit of said electric discharge across said source of supply, and means responsive to the flow of current in the anode cathode circuit of said electric discharge device for operating said last mentioned means to change from one oi said control voltages to another or said control voltages.
8. A timing circuit comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for connecting the anode-cathode circuit of said electric discharge device across said supply circuit, a relay having an operating winding whose energization is controlled by said electric discharge device, means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes effective for controlling the conductivity of said electric discharge device after a different timing period initiated by completing the connection of the anode-cathode circuit of said electric discharge across said supply circuit, and means responsive to the operation of said relay for operating said last mentioned means to change from one of said control voltages to another of said control voltages.
9. Timing apparatus comprising a supply circuit, an electric discharge device having an an d a cathode, and a control element. means for connecting the anode-cathode circuit oi! said electric discharge device to said supply circuit, a relay having an operating winding whose energize.- tion is controlled by said electric discharge device, means for selectively applying to the control element of said electric discharge device a plurality or control voltages each or which becomes effective for controlling the conductivity of said electric discharge device after a different timing period initiated by connecting or the anodecathode circuit of said electric discharge device to said supply circuit, and means responsive to the operation of said relay and eflective after a predetermined time delay tor operating said last mentioned means to change from one 01' said control voltages to another of said control voltages.
10. In combination, a source of alternating current voltage, an electric discharge-device having an anode, a cathode, and a control element, means comprising a capacitance energized from said source through the control-element-cathode circuit of said electric discharge device for impressing on said control element a potential negative with respect to its said cathode and tending to maintain said discharge device non-conductive, means for controlling the magnitude oi the negative potential to which said capacitance is charged by said source, a switch connected in series relation with the anode-cathode circuit of said electric discharge device and arranged to efiect charging of said capacitance when in the open position and to initiate discharging of said capacitance when in the closed position to render said discharge device conductive a predetermined time after the closure thereof, means for closing said switch, means responsive to the flow of current through the anode-cathode circuit or said electric discharge device for operating said controlling means to change the magnitude oi the negative potential of said capacitance, and means for opening said switch and closing it again after said capacitance has obtained its controlling potential determined by said controlling means.
11. In combination, a source of alternating current voltage, a relay having an operating winding, an electric discharge device having an anode, a
cathode, and a control element, the anode cathode circuit of said discharge device being connected in series relation with said operating winding to control the energization thereof from said source, means comprising a capacitance energized from said source through the control element-cathode circuit of said electric discharge device for impressing on said control element a potential negative with respect to its said cathode and tending to maintain said discharge device non-conductive, a switch connected in series relation with the anode-cathode circuit or said electric discharge device and being arranged to eflect charging of said a capacitance when in the open position and to initiate discharging of said capacitance when in the closed position to render said discharge device conductive a predetermined time after the closure thereof, and means responsive to the operation of said relay for controlling the connection of said capacitance with said source and the magnitude of its negative potential.
12. In combination, a source of alternating current voltage, an electric discharge device having an anode, a cathode, and a control element, a relay having an operating winding whose energization is controlled by said electric discharge device, means comprising a capacitance energized from said source through the control-elementcathode circuit oi said electric discharge device for impressing on said control element a negative conductive a predetermined time after the closure ,thereof, means for closing said switch, and means responsive to the operation of said relay for opening said switch, changing the connection of said capacitance with said source and the. magnitude of its negative potential and after a predetermined time delay again closing said switch.
13. In combination, a source of alternating current voltage, a-relay having an operating winding, an electric discharge device having an anode, a cathode, and a. control element, the anodecathode circuit of said discharge device being connected in series relation with said operating coil of said relay to efi'ect energization thereof from said source when in a conducting condition, means tending to maintain said discharge device non-conducting comprising a voltage divider connected across said source and switching means for selectively connecting a capacitance between said control element and different points on said voltage divider, a switch connected in series relation with the operating coil of said relay and the anode-cathode circuit of said discharge device and being arranged to effect charging of said capacitance when in its openposition and to initiate discharge of said capacitance when in its closed position to render said discharge device conducting a predetermined time after the 010. sure thereof, means for closing said switch and means responsive to the operation of said relay for opening said switch and for operating said switching means to change the connection of said capacitance from one point to another point on said voltage divider, said capacitance imposing on said control element when connected to at which one or said first mentioned timing circuits becomes efiective for rendering said first mentioned electric discharge device conductive, means for connecting the anode-cathode circuits of said electric discharge devices to said supply circuit, means responsive to the conduction of current through the anode-cathode circuit of said .flrst mentioned electric discharge device for disconnecting the anode-cathode circuit orsaid first mentioned electric discharge device from said supply circuit, means responsive to the conduction of current through the anode-cathode circuit of said second electric discharge device for operating said transfer means, means for again connecting the anode-cathode circuit of said first mentioned electric discharge device to said supply circuit after said transfer means has been operated, and means responsive to conduction oi current through the anode-cathode circuits or both of said electric discharge devices for disconnecting the anode-cathode circuits of said electric discharge devices from said supply circult.
15, Apparatus comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for connecting the anode-cathode circuit or said electric discharge device with said supply circuit, a relay having an operating winding whose energization is controlled by said electric discharge device, switching means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes effective after a different timing period for controlling the conductivity of'said electric discharge device, a second electric discharge device having an anode, a-cathode, and a control element, means for connecting the anodecathode circuit of said second electric discharge device with said supply circuit, a second relay having an operating winding whose energlzation is controlled by said second electric discharge device, a second switching means for selectively applying to the control element of said second electric discharge device a plurality of control voltages each of which becomes effective after a different time period for controlling the conductivity of said second electric discharge device, and means responsive to the operation of said first mentioned relay for operatlng'said first mentioned switching means to apply a different connecting the anode-cathode circuit of said electric discharge device to said supply circuit, two timing circuits each of which when connected to the control element Of said electric discharge device renders it conductive after a predetertrol voltage to the control element of said first mentioned electric discharge device, for opening the anode-cathode connection of said first mentioned electric discharge device with said supply circuit and for completing the anode-cathode connection of said second electric discharge device with said supply circuit, and means responsive to the operation of said second relay for operatin said second switching means to apply a different control voltage to the control element of said second electric discharge device, for interrupting the anode-cathode connection of said second electric, discharge device with said supply circuit and for completing the anode-cathode connection of said first mentioned electric discharge device with said supply circuit.
16. Timing apparatus comprising a supply circuit, an electric discharge device having an anode. a cathode, and a control element, a relay having an operating windingenergized by anode-cathode current conduction through said electric discharge device, a plurality of timing circuits each of which when connected to the control element of said electric discharge device becomes efiective i'or "controlling the conductivity of said electric discharge device after a different timing period initiated by connecting the anode-cathode circuit of said electric discharge device to said supply circuit, transfer means for changing the connection of the control element 01' said electric discharge device from one 01' said timing circuits to another of said timing circuits, a second electric discharge device having an anode, a cathode, and a control element, a second relay having an operating winding energized by anode-cathode current conduction through said second electric dischargddevicega timing circuit connected to the control element of said second electric discharge device for controlling the conductivity of said electric discharge device after a time period which is initiated by connecting the anodecathode circuit of said electric discharge device to said supply circuit and which is longer than the timing period of the one 01 said first mentioned timing circuits which is first connected to the control element of said first mentioned electric discharge device, means for connecting the anode-cathode circuits of said electric discharge devices to said supply circuit, means responsive to the operation of said first mentioned relay by saidfirst mentioned electric discharge device becoming conductive for disconnecting the anode-cathode circuit of said first mentioned electric discharge device, from said supply circuit, means responsive to the operation of said second relay by said second electric discharge device becoming conductive for operating said transfer means to change the connection of the control element of said first mentioned electric discharge device from one of said timing circuits to another of said timing circuits and for maintaining said connection with said other timing circuit so long as said second electric dis charge device remains conducting, means for reconnecting the anode-cathode circuit of said first mentioned electric discharge device with said supply circuit and for maintaining the anodecathode connection of said second electric discharge device with aid supply circuit, and means responsive to the operation of said first mentioned relay by said first mentioned electric discharge device again becoming conductive while said second electric discharge deviceremains conductive for disconnecting the anode-cathode cir. cuits of said electric discharge devices from said supply circuit and 'thereby deenergizing said relays.
17. Apparatus comprising a supply circuit, an electric discharge device having an anode, a cathode, and a control element, means for connecting the anode-cathode circuit of said electric discharge device with said supply circuit, a relay having an operating winding whose energization is controlled by said electric discharge device, switching means for selectively applying to the control element of said electric discharge device a plurality of control voltages each of which becomes efiective after a'different timing period for controlling the conductivity of said electric discharge device, a second electric discharge device having an anode, a cathode, and a control element, means for connecting the anode-cathode circuit of' said second electric discharge device with said supply circuit, a second relay having an operating winding whose energization is controlled by said second electric discharge device, a second switching means for selectively applying to the control element of said second electric discharge device a plurality of control voltages each 01' which becomes eflective after a different time period for controlling the conductivity of said second electric discharge device, means responsive to the operation of said first mentioned relay for operating said first mentioned switching means to apply a difderent control voltage to the control element of said first mentioned electric discharge device, for opening the anode-cathode connection of said first mentioned electric discharge device with said supply circuit and for completing the anodecathode connection or said second electric discharge device with said supply circuit, and means responsive to the operation of said second relay for operating said second switching means to apply'a difi'erent control voltage to the control element of said second electric discharge device, for interrupting the anode-cathode connection of said second electric discharge device with said supply circuit and for completing the anodecathode connection of said first mentioned electric discharge device with said supply circuit, a third electric discharge device, means for connecting the anode-cathode circuit of said third electric discharge device with said supply circuit, a third relay having an operating winding whose energization is controlled by said third electric discharge device, means for applying to-the control element of said third electric discharge device a: control voltage which becomes effective after a predetermined timing period, means responsive to the operation of said second relay -for completing the connection of said third electric discharge device with said supp y circuit, means responsive to the operation of said third relay for operating said received switching means, and means responsive to the concurrent operation of said second and third relays for operating said first and second switching means, for opening the anode-cathode connection of said second and third electric discharge devices with said supply circuit and for completing the connection of said first electric discharge device with said supply circuit.
18. 'The combination of an electronic timer including a supply circuit, an electric valve includ-- ing an anode, a cathode and a control member, means connecting said anode-cathode circuit to said supply circuit, two timing circuits for producing transient control voltages, means connecting one of said timing circuits to control the relative voltage of said cathode and said control member, means for initiating operation 01 said electronic timer by impressing the transient voltage of said one oi said timing circuits on said control member to effect a predeterminedechange in the conductivity of said electric valve at the end of a predetermined interval, with means responsive to said change in conductivity of said electric valve for transferring energization of said control member to the other of said timing circuits to change the interval between initiation of the operation of said electronic timer and the instant at which the transient voltage impressed on said control member is effective to produce said predetermined change in conductivity of said electric valve, and means for reinitiating the operation of said electronic timer by impressing the transient control voltage of the other of said timing circuits on said control member.
19. The combination of an electronic timer including a supply circuit, an electric valve including an anode, a cathode and a control member, means connecting said anode-cathode circuit to said supply circuit, two timing circuits for producing transient control voltages, means connecting one of said timing circuits to control the relative voltage of said cathode and said control member, means for initiating operation of said electronic timer by impressing the transient voltage of said one of said timing circuits on said control member to effect a predetermined change in the conductivity of said electric valve at the end of a predetermined interval, with means responsive to said change in conductivity of said electric valve for transferring energization of said control member to the other of said timing circuits to change the interval between initiation of the operation of said timer and the instant at which the transient voltage impressed on said control member is effective to produce said predetermined change in conductivity of said electric valve, a second timer initiated in operation in response to said predetermined change in conductivity of said electric valve, andmeans responsive to the operation of said lastmentioned timer for reinitiating the operation of said electronic timer with said other timing circuit controlling the voltage of said control member.
20. The combination of an electronic timer including a. supply circuit, an electric valve havin an anode, a cathode and a control member, means connecting said anode-cathode circuit for energization from said supply circuit, a timing circuit including resistance and a capacitor, means connecting said timing circuit with said control member to energize said control member in accordance with the voltage of said capacitor, and means for initiating operation of said timing circuit to impress a transient control voltage on said control member to eilect a predetermined conductivity of said electric valve at the end oi a predetermined interval, with means responsive to said predetermined conductivity of said electric valve for altering said timing circuit to change the interval between initiation or the timing operation of said timer and the instant at which the transient voltage impressed on the control member is effective to produce said predetermined conductivity of said electric valve and additional means operable in response to the predetermined conductivity of said electric valve means for reinitiating the operation of said electronic timer with said timing circuit altered.
21. The combination of an electronic timer including a supply circuit, an electric valve havin an anode, a cathode and a control member, means connecting said anode-cathode circuit for energization from said supply circuit, a' timing a circuit including resistance and a capacitor, means connecting said timing circuit with said control member to energize said control member in accordance with the voltage of said capacitor, and means for initiating operation of said timing circuit to impress a transient control voltage on said control member and to eiTect a predetermined conductivity of said electric valve at the end of a predetermined interval, with means responsive .to said predetermined conductivity of said electric valve for altering said timing circuit to change the interval between initiation of the timing operation of said timer and the instant at which the transient voltage impressed on the co trol member is eilective to produce said predetermined conductivity of said electric valve, a second timer initiated in operation in response to said predetermined conductivity of said electric valve and means responsive to th expiration of the timing interval of said second timer for reinitiat-
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Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2459041A (en) * 1946-02-09 1949-01-11 William H Mitsch Automatic timing device
US2485785A (en) * 1944-06-07 1949-10-25 Sunbeam Corp High-frequency induction heating system
US2574939A (en) * 1949-03-08 1951-11-13 Square D Co Welder control system
US2634320A (en) * 1950-03-07 1953-04-07 Square D Co Electric control circuit
US2639361A (en) * 1948-04-02 1953-05-19 Westinghouse Electric Corp Timer for welding systems
US2653209A (en) * 1950-08-19 1953-09-22 Westinghouse Electric Corp Electronic timer
US2656461A (en) * 1951-03-10 1953-10-20 Weltronic Co Electrical timing apparatus
US2676230A (en) * 1951-02-23 1954-04-20 Weltronic Co Electrical control apparatus
US2734133A (en) * 1956-02-07 riley
US2735006A (en) * 1956-02-14 stadum
US2840686A (en) * 1955-02-28 1958-06-24 Westinghouse Electric Corp High speed resistance welding control
US2841691A (en) * 1955-06-30 1958-07-01 Stuart C Rockafellow Negative forge timing for resistance welders
US2888550A (en) * 1955-12-13 1959-05-26 Westinghouse Electric Corp Electric discharge apparatus
US2908406A (en) * 1954-06-01 1959-10-13 John D Macarthur Electrically controlled feeding apparatus
US2933588A (en) * 1957-10-15 1960-04-19 Westinghouse Electric Corp Metals joining apparatus
US3089948A (en) * 1952-02-21 1963-05-14 Westinghouse Electric Corp Electric discharge apparatus

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2735006A (en) * 1956-02-14 stadum
US2734133A (en) * 1956-02-07 riley
US2485785A (en) * 1944-06-07 1949-10-25 Sunbeam Corp High-frequency induction heating system
US2459041A (en) * 1946-02-09 1949-01-11 William H Mitsch Automatic timing device
US2639361A (en) * 1948-04-02 1953-05-19 Westinghouse Electric Corp Timer for welding systems
US2574939A (en) * 1949-03-08 1951-11-13 Square D Co Welder control system
US2634320A (en) * 1950-03-07 1953-04-07 Square D Co Electric control circuit
US2653209A (en) * 1950-08-19 1953-09-22 Westinghouse Electric Corp Electronic timer
US2676230A (en) * 1951-02-23 1954-04-20 Weltronic Co Electrical control apparatus
US2656461A (en) * 1951-03-10 1953-10-20 Weltronic Co Electrical timing apparatus
US3089948A (en) * 1952-02-21 1963-05-14 Westinghouse Electric Corp Electric discharge apparatus
US2908406A (en) * 1954-06-01 1959-10-13 John D Macarthur Electrically controlled feeding apparatus
US2840686A (en) * 1955-02-28 1958-06-24 Westinghouse Electric Corp High speed resistance welding control
US2841691A (en) * 1955-06-30 1958-07-01 Stuart C Rockafellow Negative forge timing for resistance welders
US2888550A (en) * 1955-12-13 1959-05-26 Westinghouse Electric Corp Electric discharge apparatus
US2933588A (en) * 1957-10-15 1960-04-19 Westinghouse Electric Corp Metals joining apparatus

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