Electromechanical intervalometer, and method of using same

Claim 2

An intervalometer for supplying firing pulses in timed relationship to a bank of rockets or the like, which comprises: a stepping switch operated by a solenoid, means to apply actuating power to said solenoid at predetermined intervals, said stepping switch stepping from one station to the next upon each of said power applications to said solenoid, and means associated with said stepping switch to supply firing current to different rockets in the rocket bank connected to said stepping switch, thus firing such rockets and generating shock forces that are applied to said intervalometer during a predetermined period following such firing, said means for applying power to said solenoid including timing means correlated to the firing times and firing characteristics of said rockets, and also to the distance between said rockets and said solenoid, for maintaining said solenoid in energized condition throughout said predetermined period when the shocks and vibrations incident to the firings of said rockets are applied to said solenoid, whereby to prevent erratic firings of said rockets.

Claim 3

The invention as claimed in claim 1, in which said means to supply firing current to said rockets includes means for supplying such firing current during periods when there is no power applied to said solenoid.

Claim 4

The invention as claimed in claim 2, in which said means to apply said power to said solenoid includes means for applying such power sufficiently soon after said supplying of firing current to said rockets that said solenoid is substantially fully energized when said shocks and vibrations reach said solenoid, and in which said means to apply said power to said solenoid includes means for applying the same for time periods sufficiently long to maintain said solenoid substantially fully energized until said shocks and vibrations are dissipated.

Claim 5

The invention as claimed in claim 45 including unidirectional means for isolatIng said storage means from said solenoid and from said rocket firing current.

Claim 6

The invention as claimed in claim 1, in which said means to apply power to said solenoid for predetermined time periods and at predetermined intervals includes means for energizing said solenoid with a duty cycle of at least 50 percent.

Claim 7

The invention as claimed in claim 5, in which said duty cycle is in the range of 60 to 90 percent.

Claim 8

The invention as claimed in claim 1, in which said means to apply power to said solenoid includes means for effecting application of such power thereto for an aggregate time longer than the aggregate time during which application of such power is discontinued, during each firing sequence of the intervalometer.

Claim 9

The invention as claimed in claim 7, in which said aggregate time during which such power is applied to said solenoid is at least several times longer than said aggregate time during which application of such power is discontinued.

Claim 10

The invention as claimed in claim 1, in which said means to apply power to said solenoid includes means for maintaining the same substantially fully energized for a first period of time, means for discontinuing application of power to said solenoid for a second period of time shorter than said first period of time, means for applying power to said solenoid for said first period of time, means for discontinuing application of power to said solenoid for said second period of time shorter than said first period of time, and means for repeating said long-short relationship until completion of firing of said bank of rockets.

Claim 11

The invention as claimed in claim 9, in which said second period of time has a duration which is much smaller than said first period of time.

Claim 12

The invention as claimed in claim 1, in which said means to apply power to said solenoid includes means for applying thereto a first pulse of current which is relatively short but still sufficiently long to effect retraction of the armature of said solenoid, means for thereafter discontinuing application of power to said solenoid for a relatively short time period, means for thereafter applying to said solenoid a second pulse of current which is much longer than said first pulse, means for thereafter discontinuing application of power to said solenoid for said relatively short time period, means for thereafter applying to said solenoid a third pulse of current which is much longer than said first pulse, and means for thereafter continuing to supply relatively long pulses of current followed by relatively short periods of discontinuation of application of power to said solenoid.

Claim 13

The invention as claimed in claim 11, in which said means to supply firing current to said rockets includes means for supplying such firing current during periods when there is no power applied to said solenoid.

Claim 14

The invention as claimed in claim 1, in which said means to supply firing current to said rockets is a source of current pulses including electronic switching means external to said stepping switch.

Claim 15

An intervalometer for supplying firing pulses in timed relationship to a bank of rockets or the like, which comprises: a stepping switch having numerous stationary contacts adapted to be engaged sequentially by a movable contact, each of said stationary contacts being connected to the firing means for at least one rocket in said bank thereof, said movable contact being initially in a safety position out of engagement with any of said stationary contacts, a solenoid motor mechanism connected to said stepping switch and so related thereto that the first energization of the solenoid in said mechanism effects shifting of said movable contact from said safety position to a first position in engagement with the first of said stationary contacts; the second energization of said solenoid effects shifting of said movable contact from said first position into a second position in engagement with the second of sAid stationary contacts, and subsequent energizations of said solenoid effect successive shifting of said movable contact into successive positions in engagement with others of said stationary contacts, and means associated with said stepping switch and with said solenoid motor mechanism to first supply to said solenoid a first current pulse sufficiently long to shift said movable contact from said safety position to said first position, to then send firing current through said then-engaged movable contact and first stationary contact, to then supply to said solenoid a second current pulse sufficiently long to shift said movable contact to said second position and also sufficiently long to maintain said solenoid substantially fully energized throughout the time when the shocks and vibrations incident to firing of the rocket connected to said first stationary contact are received by said stepping switch and by said mechanism, to then send firing current through said then-engaged movable contact and second stationary contact, and to then repeat in alternation all of such steps of supplying current pulses to said solenoid and sending firing current through the engaged contacts, excepting the first-mentioned step of shifting said movable contact from said safety position to said first position, whereby the rocket in said bank are fired sequentially in a non-erratic manner.

Claim 16

An intervalometer for supplying firing pulses in timed relationship to a bank of rockets or the like, which comprises: a stepping switch having numerous stationary contacts adapted to be engaged sequentially by a movable contact, each of said stationary contacts being connected to the firing means for at least one rocket in said bank thereof, said movable contact being initially in a safety position out of engagement with any of said stationary contacts, a solenoid motor mechanism connected to said stepping switch and so related thereto that the first energization of the solenoid in said mechanism effects shifting of said movable contact from said safety position to a first position in engagement with the first of said stationary contacts; the second energization of said solenoid effects shifting of said movable contact from said first position into a second position in engagement with the second of sAid stationary contacts, and subsequent energizations of said solenoid effect successive shifting of said movable contact into successive positions in engagement with others of said stationary contacts, and means associated with said stepping switch and with said solenoid motor mechanism to first supply to said solenoid a first current pulse sufficiently long to shift said movable contact from said safety position to said first position, to then send firing current through said then-engaged movable contact and first stationary contact, to then supply to said solenoid a second current pulse sufficiently long to shift said movable contact to said second position and also sufficiently long to maintain said solenoid substantially fully energized throughout the time when the shocks and vibrations incident to firing of the rocket connected to said first stationary contact are received by said stepping switch and by said mechanism, to then send firing current through said then-engaged movable contact and second stationary contact, and to then repeat in alternation all of such steps of supplying current pulses to said solenoid and sending firing current through the engaged contacts, excepting the first-mentioned step of shifting said movable contact from said safety position to said first position, whereby the rocket in said bank are fired sequentially in a non-erratic manner.

Claim 17

The invention as claimed in claim 14, in which said last-named means effects discontinuation of application of power to said solenoid for a substantial time period after the end of each of said current pulses thereto, during which time period said firing current is supplied through the then-engaged contacts.

Claim 18

The invention as claimed in claim 15, in which said last-named means is so constructed that the duration of each of said second and subsequent pulses of current to said solenoid is substantially longer than the duration of the period during which application of power to said solenoid is discontinued.

Claim 19

The invention as claimed in claim 16, in which said means to apply said pulses to said solenoid includes, an electrical power supply, a timing circuit energized from said power supply for applying said pulses for the aforesaid periods, and storage means responsive to said power supply for receiving and storing electrical energy therefrom and for supplying such stored energy to said timing circuit to maintain the energization thereof during periods of loss of power from said power supply.

Claim 20

The invention as claimed in claim 16, in which the duration of each of said second and subsequent pulses is on the order of several times longer than the duration of each period of discontinuation of application of power to said solenoid.

Claim 21

The invention as claimed in claim 14, in which said last-named means effects discontinuation of said first current pulse to said solenoid a relatively short time period after commencement thereof, said short time period being barely sufficient to insure stepping of said movable contact from said safety position to said first position, said short time period having a duration much shorter than that of said second and subsequent current pulses to said solenoid.

Claim 22

The invention as claimed in claim 14, in which said last-named means supplies said current pulses to said solenoid sufficiently soon after sending of said firing current to insure that said solenoid is substantially fully energized when said shocks and vibrations reach said solenoid, and in which said last-named means delivers said current pulses to said solenoid throughout time periods sufficiently long to insure that said shocks and vibrations are dissipated before said solenoid is de-energized.

Claim 23

The invention as claimed in claim 14, in which said last-named means is an electronic circuit incorporating electronic switching means to supply said current pulses to said solenoid, and also incorporating electronic switching means to supply firing current to said rocket bank through the engaged contacts of said stepping switch, said first-mentioned and second-mentioned electronic switching means operating in alternation to supply said current pulses to said solenoid and to supply said firing current to said rocket bank.

Claim 24

The invention as claimed in claim 14, in which said last-named means is an astable, asymmetrical multivibrator adapted to supply current to said solenoid during the long-period portion of each oscillatory cycle, and adapted to supply current to the engaged contacts of said stepping switch during the short-period portion of each oscillatory cycle.

Claim 25

The invention as claimed in claim 22, in which said means to supply current to said solenoid includes, an electrical power supply connected to energize said multivibrator, and storage means responsive to said power supply for receiving and storing electrical energy therefrom and for supplying such stored energy to said multivibrator to maintain the energization thereof during periods of loss of power from said power supply.

Claim 26

The invention as claimed in claim 23 including means for providing a unidirectional low impedance path to ground for voltage steps that are caused by said solenoid upon loss of power from said power supply.

Claim 27

The invention as claimed in claim 22, in which start-switch means are provided for said multivibrator, and in which means are provided to insure that said multivibrator starts to oscillate at the long-period portion of the first cycle upon closing of said start-switch means, and also to abbreviate greatly the duration of such long-period portion of the first cycle.

Claim 30

The invention as claimed in claim 26, in which said method further comprises supplying rocket-firing current through said switch to one of said rockets during said time period when supply of power to said solenoid is discontinued, but a sufficiently short time before application of power to said solenoid that said solenoid will be energized before said shocks and vibrations reach said solenoid.

Claim 31

The invention as claimed in claim 27, in which each of said periods during which power is applied to said solenoid is on the order of several times longer than each of said periods when no power is applied thereto.

Claim 32

The invention as claimed in claim 28, in which each of said periods of power application is about three times longer than each of said periods of no power application.

Claim 33

The invention as claimed in claim 26, in which said method additionally comprises employing a switch which is initially in a safety position at which none of the operative switch contacts are engaged with each other, and in which said method further comprises supplying to said solenoid, in advance of the first-mentioned one of the specified applications of power to said solenoid, a relatively short pulse of power adapted to rotate said switch from said safety position to the first operative position.

Claim 34

An intervalometEr, which comprises: a stepping switch, a solenoid-type stepping motor connected to said switch to drive the same, a free-running multivibrator, means responsive to the ''''on'''' condition of one side of said multivibrator to supply energizing pulses of current to the solenoid of said stepping motor, and means responsive to the ''''on'''' condition of the other side of said multivibrator to supply firing pulses of current to said switch and thus to the devices connected thereto.

Claim 35

An intervalometEr, which comprises: a stepping switch, a solenoid-type stepping motor connected to said switch to drive the same, a free-running multivibrator, means responsive to the ''''on'''' condition of one side of said multivibrator to supply energizing pulses of current to the solenoid of said stepping motor, and means responsive to the ''''on'''' condition of the other side of said multivibrator to supply firing pulses of current to said switch and thus to the devices connected thereto.

Claim 36

The invention as claimed in claim 31, in which said switch is connected to the firing devices in a rocket launcher, in which said multivibrator is an asymmetrical or unbalanced multivibrator, in which said multivibrator and said means responsive to the ''''on'''' condition of said one side supply relatively long-period pulses to said solenoid, and in which said means responsive to the ''''on'''' condition of said other side supply relatively short-period pulses to said switch.

Claim 37

The invention as claimed in claim 32, in which said multivibrator is highly unbalanced, the degree of unbalance being such that said one side thereof is in ''''on'''' condition at least several times as long as said other side thereof.

Claim 38

The invention as claimed in claim 31, in which said multivibrator further incorporates means to perform both of the following functions: a. cause said one side of said multivibrator to achieve the ''''on'''' condition prior to the other side thereof, upon initiation of multivibrator action, and b. abbreviate the duration of the first ''''on'''' condition of said one side, upon initiation of multivibrator action, while leaving unabbreviated the durations of subsequent ''''on'''' conditions of said one side.

Claim 39

The invention as claimed in claim 34 including an electrical power supply connected to energize said multivibrator, and storage means responsive to said power supply for receiving and storing electrical energy therefrom and for supplying such stored energy to said multivibrator to maintain the energization thereof during periods of loss of power from said power supply.

Claim 40

The invention as claimed in claim 27, wherein said motor includes a solenoid, and means for providing a unidirectional low impedance path to ground for voltage steps that are caused by said solenoid upon loss of power from said power supply.

Claim 41

The invention as claimed in claim 34, in which said means is a threshold means, and in which said multivibrator is unbalanced, the unbalance being such that the durations of the second and subsequent ''''on'''' conditions of said one side are substantially longer than the durations of the ''''on'''' conditions of said other side.

Claim 42

The invention as claimed in claim 31, in which the time constants in said multivibrator are such that the time required for each full cycle of operation, during the steady-state operation thereof, is in the range of about 40 milliseconds to about 60 milliseconds.

Claim 43

The invention as claimed in claim 38, in which said time constants are such that said other side of said multivibrator is in ''''on'''' condition for about 15 milliseconds.

Claim 44

An electromechanical intervalometer adapted to effect firing of a bank of rockets, which comprises: an unregulated D.C. lead connected to the positive terminal of a D.C. power source through a pilot-operated switch, a ground lead connected to the negative terminal of such power source, a regulated D.C. lead connected to said unregulated D.C. lead through a biasing resistor, a zener diode connected between said regulated D.C. lead and said ground lead, a first NPN transistor the base of which is connected through a second resistor to said regulated D.C. lead, the collector of said first transistor being connected through a third resistor to said unregulated D.C. lead, a second NPN transistor the base of which is connected To said regulated D.C. lead through a fourth resistor, the emitter of said second transistor being connected through two series-related diodes to said ground lead, the anodes of said diodes being relatively adjacent said emitter of said second transistor, the collector of said second transistor being connected through a fifth resistor to said regulated D.C. lead, a first capacitor connected between the base of said first transistor and the collector of said second transistor, a second capacitor connected between the collector of said first transistor and the base of said second transistor, a solenoid-operated stepping motor, a rotary switch connected mechanically to said motor for driving thereby, a third NPN transistor the base of which is connected to the emitter of said first transistor, and the emitter of which is connected to said ground lead, the collector of said third transistor being connected through the solenoid of said stepping motor to said unregulated D.C. lead, and a fourth NPN transistor the base of which is connected to the junction between said third resistor and the collector of said first transistor, the emitter of said fourth transistor being connected to said regulated D.C. lead, the collector of said fourth transistor being connected to the base of a fifth and PNP transistor, the emitter of said fifth transistor being connected to said unregulated D.C. lead, the collector of said fifth transistor being connected to the movable contact of said rotary switch, the stationary contacts of said switch being respectively connected to rockets in said bank of rockets.

Claim 45

An electromechanical intervalometer adapted to effect firing of a bank of rockets, which comprises: an unregulated D.C. lead connected to the positive terminal of a D.C. power source through a pilot-operated switch, a ground lead connected to the negative terminal of such power source, a regulated D.C. lead connected to said unregulated D.C. lead through a biasing resistor, a zener diode connected between said regulated D.C. lead and said ground lead, a first NPN transistor the base of which is connected through a second resistor to said regulated D.C. lead, the collector of said first transistor being connected through a third resistor to said unregulated D.C. lead, a second NPN transistor the base of which is connected To said regulated D.C. lead through a fourth resistor, the emitter of said second transistor being connected through two series-related diodes to said ground lead, the anodes of said diodes being relatively adjacent said emitter of said second transistor, the collector of said second transistor being connected through a fifth resistor to said regulated D.C. lead, a first capacitor connected between the base of said first transistor and the collector of said second transistor, a second capacitor connected between the collector of said first transistor and the base of said second transistor, a solenoid-operated stepping motor, a rotary switch connected mechanically to said motor for driving thereby, a third NPN transistor the base of which is connected to the emitter of said first transistor, and the emitter of which is connected to said ground lead, the collector of said third transistor being connected through the solenoid of said stepping motor to said unregulated D.C. lead, and a fourth NPN transistor the base of which is connected to the junction between said third resistor and the collector of said first transistor, the emitter of said fourth transistor being connected to said regulated D.C. lead, the collector of said fourth transistor being connected to the base of a fifth and PNP transistor, the emitter of said fifth transistor being connected to said unregulated D.C. lead, the collector of said fifth transistor being connected to the movable contact of said rotary switch, the stationary contacts of said switch being respectively connected to rockets in said bank of rockets.

Claim 46

The invention as claimed in claim 40, in which a ripple switch is connected between said unregulated D.C. lead and the junction between the emitter of said first transistor and the base of said third transistor.

Claim 47

The invention as claimed in claim 40, in which a capacitor is connected between said ground lead and the collector of said second transistor.

Claim 48

The invention as claimed in claim 40, in which the time constant formed by the combination of said fourth resistor and said second capacitor is substantially larger than the time constant formed by the combination of said second resistor and said first capacitor, whereby said first transistor is on for a relatively long portion of each oscillatory cycle.

Claim 49

The invention as claimed in claim 40 in which an isolating diode is connected between said power source and said biasing and third resistors, in which a first storage capacitor is connected between said ground lead and the side of said isolating diode that is connected to said resistors, in which a second storage capacitor is connected between said ground lead and the collector of said second transistor, in which said motor includes a solenoid coil, and in which a coil EMF shunting diode is connected between said ground lead and said solenoid coil.

Claim 50

An intervalometer for supplying firing pulses in timed relationship to a bank of rockets or the like, which comprises: a stepping switch operated by a solenoid, means to apply actuating power to said solenoid for predetermined time periods and at predetermined intervals, said stepping switch stepping from one station to the next upon each of said power applications to said solenoid, and means associated with said stepping switch to supply firing current to different rockets in the rocket bank connected to said stepping switch, thus firing such rockets, the timing of said means for applying power to said solenoid being correlated to the firing times and firing characteristics of said rockets, and also to the distance between said rockets and said solenoid, in such manner that said solenoid is energized when the shocks and vibrations incident to the firings of said rockets are applied to said solenoid, whereby to prevent erratic firings of said rockets, said means to apply said power to said soleNoid including an electrical power supply, a timing circuit energized from said power supply for applying said power for the aforesaid periods, and storage means responsive to said power supply for receiving and storing electrical energy therefrom and for supplying such stored energy to said timing circuit to maintain the energization thereof during periods of loss of power from said power supply.

Claim 51

An intervalometer for supplying firing pulses in timed relationship to a bank of rockets or the like, which comprises: a stepping switch operated by a solenoid, means to apply actuating power to said solenoid for predetermined time periods and at predetermined intervals, said stepping switch stepping from one station to the next upon each of said power applications to said solenoid, and means associated with said stepping switch to supply firing current to different rockets in the rocket bank connected to said stepping switch, thus firing such rockets, the timing of said means for applying power to said solenoid being correlated to the firing times and firing characteristics of said rockets, and also to the distance between said rockets and said solenoid, in such manner that said solenoid is energized when the shocks and vibrations incident to the firings of said rockets are applied to said solenoid, whereby to prevent erratic firings of said rockets, said means to apply said power to said soleNoid including an electrical power supply, a timing circuit energized from said power supply for applying said power for the aforesaid periods, and storage means responsive to said power supply for receiving and storing electrical energy therefrom and for supplying such stored energy to said timing circuit to maintain the energization thereof during periods of loss of power from said power supply.

Claim 52

An intervalometer for supplying firing pulses in timed relationship to a bank of rockets or the like, which comprises: a stepping switch operated by a solenoid, means to apply actuating power to said solenoid for predetermined time periods and at predetermined intervals, said stepping switch stepping from one station to the next upon each of said power applications to said solenoid, and means associated with said stepping switch to supply firing current to different rockets in the rocket bank connected to said stepping switch, thus firing such rockets, the timing of said means for applying power to said solenoid being correlated to the firing times and firing characteristics of said rockets, and also to the distance between said rockets and said solenoid, in such manner that said solenoid is energized when the shocks and vibrations incident to the firings of said rockets are applied to said solenoid, whereby to prevent erratic firings of said rockets, said means to apply said power to said solenoid operating to apply such power sufficiently soon after said supplying of firing current to said rockets that said solenoid is substantially fully energized when said shocks and vibrations reach said solenoid, said means to apply said power to said solenoid applying the same for time periods sufficiently long to maintain said solenoid substantially fully energized until said shocks and vibrations are dissipated, and means for providing a unidirectional low impedance path to ground for voltage steps that are caused by said solenoid upon loss of power from said power supply.

Claim 53

An intervalometer for supplying firing pulses in timed relationship to a bank of rockets or the like, which comprises: a stepping switch operated by a solenoid, means to apply actuating power to said solenoid for predetermined time periods and at predetermined intervals, said stepping switch stepping from one station to the next upon each of said power applications to said solenoid, and means associated with said stepping switch to supply firing current to different rockets in the rocket bank connected to said stepping switch, thus firing such rockets, the timing of said means for applying power to said solenoid being correlated to the firing times and firing characteristics of said rockets, and also to the distance between said rockets and said solenoid, in such manner that said solenoid is energized when the shocks and vibrations incident to the firings of said rockets are applied to said solenoid, whereby to prevent erratic firings of said rockets, said means to apply said power to said solenoid operating to apply such power sufficiently soon after said supplying of firing current to said rockets that said solenoid is substantially fully energized when said shocks and vibrations reach said solenoid, said means to apply said power to said solenoid applying the same for time periods sufficiently long to maintain said solenoid substantially fully energized until said shocks and vibrations are dissipated, and means for providing a unidirectional low impedance path to ground for voltage steps that are caused by said solenoid upon loss of power from said power supply.

Claim 54

An intervalometer for supplying firing pulses in timed relationship to a bank of rockets or the like, which comprises: a stepping switch operated by a solenoid, means to apply actuating power to said solenoid for predetermined time periods and at predetermined intervals, said stepping switch stepping from one station to the next upon each of said power applications to said solenoid, and means associated with said stepping switch to supply firing current to different rockets in the rocket bank connected to said stepping switch, thus firing such rockets, the timing of said means for applying power to said solenoid being correlated to the firing times and firing characteristics of said rockets, and also to the distance between said rockets and said solenoid, in such manner that said solenoid is energized when the shocks and vibrations incident to the firings of said rockets are applied to said solenoid, whereby to prevent erratic firings of said rockets, said means to apply power to said solenoid applying thereto a first pulse of current which is relatively short but still sufficiently long to effect retraction of the armature of said solenoid, thereafter discontinuing application of power to said solenoid for a relatively short time period, thereafter applying to said solenoid a second pulse of current which is much longer than said first pulse, thereafter discontinuing application of power to said solenoid for said relatively short time period, thereafter applying to said solenoid a third pulse of current which is much longer than said first pulse, and thereafter continuing to supply relatively long pulses of current followed by relatively short periods of discontinuation of application of power to said solenoid, said means to apply said power to said solenoid including an electrical power supply, a timing circuit energized from said power supply for applying said power for the aforesaid periods, and storage means responsive to said power supply For receiving and storing electrical energy therefrom and for supplying such stored energy to said timing circuit to maintain the energization thereof during periods of loss of power from said power supply.

Claim 55

An intervalometer for supplying firing pulses in timed relationship to a bank of rockets or the like, which comprises: a stepping switch operated by a solenoid, means to apply actuating power to said solenoid for predetermined time periods and at predetermined intervals, said stepping switch stepping from one station to the next upon each of said power applications to said solenoid, and means associated with said stepping switch to supply firing current to different rockets in the rocket bank connected to said stepping switch, thus firing such rockets, the timing of said means for applying power to said solenoid being correlated to the firing times and firing characteristics of said rockets, and also to the distance between said rockets and said solenoid, in such manner that said solenoid is energized when the shocks and vibrations incident to the firings of said rockets are applied to said solenoid, whereby to prevent erratic firings of said rockets, said means to apply power to said solenoid applying thereto a first pulse of current which is relatively short but still sufficiently long to effect retraction of the armature of said solenoid, thereafter discontinuing application of power to said solenoid for a relatively short time period, thereafter applying to said solenoid a second pulse of current which is much longer than said first pulse, thereafter discontinuing application of power to said solenoid for said relatively short time period, thereafter applying to said solenoid a third pulse of current which is much longer than said first pulse, and thereafter continuing to supply relatively long pulses of current followed by relatively short periods of discontinuation of application of power to said solenoid, said means to apply said power to said solenoid including an electrical power supply, a timing circuit energized from said power supply for applying said power for the aforesaid periods, and storage means responsive to said power supply For receiving and storing electrical energy therefrom and for supplying such stored energy to said timing circuit to maintain the energization thereof during periods of loss of power from said power supply.

Claim 56

In an intervalometer for supplying firing pulses in timed relation to a bank of explosive devices, said intervalometer having a stepping switch adapted to step from one position to another to successively apply firing pulses to different ones of said devices, singly or in groups, thus firing said devices and producing shock and vibration forces that are transmitted to said intervalometer during a known period following each such firing, a stepping switch drive motor armature, and a coil capable of being energized to shift the motor armature to a given position from which it is released when the coil is de-energized, the improvement comprising timing means for repetitively and alternately energizing said coil and feeding firing pulses to said devices through said stepping switch, said timing means comprising: means for delivering a relatively brief firing pulse to said stepping switch, means for delivering to said motor coil an energizing pulse that initiates energization of said coil at a time following said firing pulse that is less than the time required for said shock forces produced by said firing to be transmitted to said intervalometer, said last mentioned means including means for maintaining said coil energizing pulse for a time at least equal to said known period whereby all substantial shocks and vibrations will dissipate before the coil is de-energized, each said brief firing pulse being initiated during a time when said coil energizing pulse is absent, whereby said motor coil is energized and said armature is held in position by energization of said coil during the occurrence of shock and vibration resulting from said firing.

Claim 57

In an intervalometer for supplying firing pulses in timed relation to a bank of explosive devices, said intervalometer having a stepping switch adapted to step from one position to another to successively apply firing pulses to different ones of said devices, singly or in groups, thus firing said devices and producing shock and vibration forces that are transmitted to said intervalometer during a known period following each such firing, a stepping switch drive motor armature, and a coil capable of being energized to shift the motor armature to a given position from which it is released when the coil is de-energized, the improvement comprising timing means for repetitively and alternately energizing said coil and feeding firing pulses to said devices through said stepping switch, said timing means comprising: means for delivering a relatively brief firing pulse to said stepping switch, means for delivering to said motor coil an energizing pulse that initiates energization of said coil at a time following said firing pulse that is less than the time required for said shock forces produced by said firing to be transmitted to said intervalometer, said last mentioned means including means for maintaining said coil energizing pulse for a time at least equal to said known period whereby all substantial shocks and vibrations will dissipate before the coil is de-energized, each said brief firing pulse being initiated during a time when said coil energizing pulse is absent, whereby said motor coil is energized and said armature is held in position by energization of said coil during the occurrence of shock and vibration resulting from said firing.

Claim 58

The intervalometer of claim 48 wherein the duration of said energizing pulse to said motor coil is considerably greater than the intervening time in which no pulse is supplied thereto whereby the motor coil is fully energized and the armature is held the majority of the time during each cycle of operation.

Claim 59

In an intervalometer for supplying firing pulses in timed relation to a bank of explosive devices, said intervalometer having a stepping switch adapted to step from one position to another to successively apply firing pulses to different ones of said devices, singly or in groups, thus firing said devices and producing shock and vibration forces that are transmitted to said intervalometer during a known period following such firing, a stepping switch drive motor armature, and a coil capable of being energized to shift and hold the motor armature in a given position from which it is released when the coil is de-energized, the improvement comprising: means for energizing said motor coil to hold said armature against movement immediately after each firing and before said shock and vibration forces are transmitted to said intervalometer, said means including means for retaining energization of said coil and thereby retaining said armature in said held condition for a time substantially equal to said known period and sufficient to insure substantial dissipation of shock and vibration forces produced by said firing, and means for initiating firing and releasing the energization of said motor coil, only after said shock and vibration forces having substantially dissipated to thereby permit said armature to be moved.

Claim 60

In an intervalometer for supplying firing pulses in timed relation to a bank of explosive devices, said intervalometer having a stepping switch adapted to step from one position to another to successively apply firing pulses to different ones of said devices, singly or in groups, thus firing said devices and producing shock and vibration forces that are transmitted to said intervalometer during a known period following such firing, a stepping switch drive motor armature, and a coil capable of being energized to shift and hold the motor armature in a given position from which it is released when the coil is de-energized, the improvement comprising: means for energizing said motor coil to hold said armature against movement immediately after each firing and before said shock and vibration forces are transmitted to said intervalometer, said means including means for retaining energization of said coil and thereby retaining said armature in said held condition for a time substantially equal to said known period and sufficient to insure substantial dissipation of shock and vibration forces produced by said firing, and means for initiating firing and releasing the energization of said motor coil, only after said shock and vibration forces having substantially dissipated to thereby permit said armature to be moved.