US3103003A - Capacity alarm system - Google Patents

Description

Sept. 3, 1963 C. K. ROBERTS CAPACITY ALARM SYSTEM Filed June 2, 1959 2 Sheets-Sheet 1 PROTECTED SAFE 2.

l/ INVENTOR. F I Y Charles KIRoberfis ATTORNEYS Sept. 3, 1963 c. K. ROBERTS ,103, I

CAPACITY ALARM SYSTEM Filed June 2, 1959 2 Sheets-Sheet 2 e2 7e ||||"l|||v\/\/v 76 .L 3/1 68 INVENTOR. 65 H L Lhwrbes KIRpberfis 67 SPDT FAQ MW & W

ATTORNEYS from defeat.

UnitedStates Patent Filed June 2, 1959, Ser. No. 817,517

3 Claims. (Cl. 340-258) The inventionrelates to an electronic capacitance alarm system o'r device for protecting specificobjects, such as money chests, safes, record files, metal. desks,

' open areas, fences, etc.; and more particularly to aburglar alarm system of the capacitance type with which the approach of an intruder to the immediate location of the protected object or contact of an animate or inanimate object with the protected object actuate-s a signal, alarm, or other selected device or equipment.

Many prior capacity alarm devices have been known I or used which generally include in the protective system a signal means connected with the protected object so I the system inoperative to givefian alarm of the presence of the intruder. p

Certain prior devices have been soconstructed as to prevent defeat measures from 'beingapplied to the signal means or to its line connection with the protected object.

However, no prior known capacity alarm system has been characterized by the inability to apply defeat measures to -the line or communication between thesignal means or protected object and the'monitor means.

Furthermore, prior capacity alarm systems have: been' complicated'in design and construction, have been ditficult to adjust andmaintain in adjustment in use, and some 2 monitor means, and in which the alarm device protects this single wire as well as the protected object.

Furthermore, it"is an object of the present invention to provide an improved, transistorized, self-protected capacity alarm device which when once adjusted upon installation requires no further adjustment during continued operation and use for long intervals of time. 7 Furthermore, it is an object of the present invention to provide an'i'mproved capacity alarm device which cannot be defeated by any known defeat measures heretofore capable of use to defeat prior systems.

Also, it is an object of the present invention to provide the improved capacity alarm system and device with acc'essory controls which enable the system per se, housed in a cabinet, to be protected against tampering at all times, even though the system is disconnected from the protected object for authorized use of the protected object, as in the day time.

Finally, it is an. object of the present invention to provide an'improved capacity alarm device which overcomes existing difficulties inthe art, solves existing problems in the an, and obtains the foregoing objectives and desiderata in a simple and inexpensive manner.

These and other objects and advantages apparent to those skilled in the art from the following description and claims may be obtained, the stated results achieved, and the described difficultie's overcome, 'by the systems, de-

'vices, apparatus, constructions, elements and arrangements which comprise the present invention, the nature of which is set forth in the following statement, preferred embodiments of which-illustrative of the best modes in which applicant has contemplated applying the principles-a-re illustrated in thedrawings and set forth in the following description, and are particularly and dis- 7 oscillator circuit, preferably of the tickler feedback regenhave been subject to malfunctioning by changes in at' mos pheric or weather conditions. 1 r

Accordingly, it is a general object of the present invention to provide a capacity alarnr system or device of improved construction and operation as compared with prior known systems and which is completely'transistorized with controllable sensitivity, which has reliability,

andwhich overcomes all known faults and avoids difii- Also, it is an object of the present invent-ion to provide an improved capacity al-arm'device which has-a very simplified and inexpensive construction from the' 'st'andp'oint of circuitry and circuitry elements, which is simple to set up, install, adjust and operate, which may be readily adjusted for sensitivity, which is unaifected vin operation by changes in atmospheric or weather conditions, and. which is reliable in use.

. Furthermore, it is a specific Also, it is another objectof the present: invention to provide an improved capacity alarm device in which only onewire is utilized to connect the signal means with the object of the present in-. veritionjto provide a new capacity alarm device which is completely transistorized with: the. use of only' one. transistor.

erativedesign, which may be simply called the signal means, supplies energy through a line connected with the protected object, such as a safe and the like, acting as an antenna, to establish a field of electromagnetic radiation or RF energyaround the protected object and the line connected between the protected object and signal means.

A single line also connects the signal means with a monitor means, which, inturn, actuates an alarm means. A field of electromagnetic energy supplied from the signal means also is established around this single line connection between the signal means and the monitor means. As any object moves into or out of the fields of radiation thus established around the protected object and the line connected therewith aswell asthe single line connected between. the signal means and monitor means, the monitor means detects such movement and actuates the alarm means. 7 p 3 By way of example, the improved capacity alarm device is shown somewhat diagrammatically in the accompanying drawings forming part hereof, wherein:

FIGURE 1 shows one arrangement of improved capacity alarm system including details of a signal means connected to the protected object and to a monitor means, the latter of which actuates an alarm means;

FIGURE 2 is a perspective view of a cabinet with the door closed, housing components of the improved-capacity alarm device;

3 is a view'similar to FIGURE 2. but showing the cabinet door open;

' FIGURE 4 is a fragmentary wiring diagram illustr'at ing an automatically compensated tamper switch which may the added to the capacity alarm system of FIG. 1 as an additional control device for the system;

collector 11 is electrically connected.

I 3 FIGURE is a fragmentary enlarged view of the meter relay incorporated in the system of FIG. 1 equipped with a reset controlyoperating cam positioned in ,Day

tected, herein termed the protected object, may be a safe .gener-allyindic-ated at 1 or any other metallic ob jeot, such as a money chest, a record file, a metal desk, a fence and the like. The improved capacity alarm system is intended primarily ior the protection of such spe cific object and the atmosphere, zone or area immediately surrounding the protected object such as, for example, within one, two or three feet of such protected object, Thesaie 1, or protected object, preferably rests on some insulating material to. electrically insulate the object from the ground to obtain maximum sensitivity for the system, but the protected object lneed not be so insulated.

The protected object 1 is connected by a single wire 3 'line 2 at point 3 into the electrical circuit of a signal means generally indicated at 4. The signal means, circuit 4 comprises generally lines 5, 6, 7 and 8 and related components including battery 9 or power supply and transistor .10. The signal means 4 comprises a trane sistorized RF oscillator circuit, of known tickler feed from the positive side of diode 17ato the ground at'22, I

complete the circuit of monitor. means 13.

As the oscillator of signaltmeans "4 charges the mag netic field, the rectified current is applied to charge capacitor 18 in the circuit of monitor means 13. As the electromagnetic field becomes saturated, a fixed voltage j and current balance is reached in the monitormeans circuit. The series'capacitor 13 reaches this level, current l 7 ceases to flow in the monitor 'means'circuit and the 7 tion of major circuit components. The objectto be-proi back regenerative design, supplying RF energy at the collector L1 of transistor 10 and at point 3 to which When the system is in operation a field of RF energy is established'around wire 2 and the protected object 1 acting as an antenna, this field of electromagnetic radiation drawing energy from the transistorized RF oscillator circuit comprising signal means'4. I

In, accordance with the invention, a single wire .12 also connects point 3 with a monitor means generally indicated at 13 comprising a monitoring circuit. The monitor means 13 actuates an alarm ,means generally indicated at 14. In accordance with the invention, a field of RF energy is alsoestablished around the single linewire 12 connected between the signal means and monitor means.

When the system is placed in operation, an electromagnetic energy balance is reached as the field is saturatedaround theprotected object 1 (serving as an antenna) as well as around single wire 2and single '-wire 12 and no additional energy is drawn from the oscillator circuit or signalmeans 4 other than that required to sustain the field. As anyobject moves'within or into or out of this established field of radiation it will either absorb energy and create a greater demand on the oscillator circuit of the signal means, or reduce the field and lessen the required potential that previously existed. Since the sys tem depends upon a difierence above ground,- greater sensitivity'may be. obtained if the protected object is insulated from the ground. it

The self-balancing monitor means 13 monitors the energy potential available at the oscillator circuit or signal means with respect to the static field, and initiates an alarm if a change greater than a preselected amount occurs, such as, for example, plus or minus two micro- .amperes.

Single wire '12 is connected through capacitor 15 with monitor means 13 at point 16 between 'a pair of diodes 17a and 17b'to rectify the RF energy into direct current;

A series capacitor 18, a Wesson sensitive relay 2-0-2 micro-ampere sensitrol '19 and a resistor 20 shunting the capacitor 18. and relay 19, together with a capacitor-21 Wesson relay 19 will balance with indicator, 23 thereof at the zero position.

' Any change of. the oscillator energy in the "oscillator circuit of signal means 4 results in current flow'inone direction or theother in the monitor circuit of monitor means 13, and, in turn, results in either a positive or 7 v a negative, swing of the Wesson relay. indicator 23. "This indicates that .the series capacitor 1 8 is absorbing more charge or discharging its energy through the shunting resistor 20.

A control circuit for the alarm means 14 consists of wire 24 from the +side=ot main power battery 9, through bell test button 25, resistance 26, resistance 27, blade 28.

of relay 29 (normally closed when de-energized), wire 30, wire 31, coil 32 of bell 33, armature coil 34 of means relay 35 whose blade 36 is normally in upper position when the relay is energized, wire 37 and wires 6 and 7 to the side of battery 9. This control circuit i normally holds relay3 5 energized, with its blade 36 normally open. The resistances 26 and 2'] reduce the current flow to an amount insuificient to operate the bell, V

though the circuit for energizing relay 35 passes through the coil 32 of hell 33. I

The bellltest button 25 is normally closed to maintain the control circuit for the alarm means 14 energized "so that alarmmeans relay 35 is energized with its blade 36 in the open position shown. When the belltest button 25 is actuated to test operation of the bell 33, it opens 40, blade 36a, and wire 41 to battery 38, energizing the bell 33. The bell if functioning, thus rings when bell test button 25is actuated to determine Y whether bell is. operative. .After release of the bell test button 25, for test purposes, the control circuit for the "alarm means 14 is again energized, energizing relay 35 which raises relay blade '36 to the upper positionshown in full lines, and

opening the alarm circuitso that thebell ceases to ring. I Wesson relay 19 has two contacts 42 and 43 connected f by wires 44 and 45 with the armaturecoil 46 of relay 3' 29 and with the line between resistances 26 and 27 at 47.

Assuming that the tsystemhas been designed or adjusted to initiate an alarm with a change of oscillator energy sufiicient to charge into or discharge from series capacitor 1 8, two or more micro-amperes; the indicator of relay 29, wire 45, one or the other of contacts 42 or 43, indicator 23 of Wesson relay 19, wire 48, Day-Night switch 49, wire 50 and wire 7 to the side of battery'i9. The closing of this circuit energizes relay 29 andmoves its blade 28 to open position shown at 28a in dot-dash lines, thus opening the control circuit forthealarm means 14. When the control circuit for the alarm means 14 is thus opened'it is de-energized, de-energizing relay- 35. H' which drops blade 36 to position 36a closing the alarm circuit and ringing be1l33.

'When thealarm has been triggered in this manner by l operation of Wesson indicator 23, the system may be'v 7 line 7 for determining power flow at varioustimes during the operation of the system.

In installing the alarm system, its sensitivity may be adjusted to the desired amount by adjusting a variable resistor 53 connected with capacitor 54 and to the ground and also to the signal means circuit at 55. This sensivity adjustment may also be accomplished by installing a resistor 53 of selected value. l

' The system, requires no otherradjnstme'nt for installation, setup and operation. It is self-correcting as far as all internal temperature or transistor characteristics or voltage shifts are concerned. One outstanding advantage of the system is that only one transistor 10is required or used. This minimizes component failure and the amountof circuitry required.

' fAs indicated, the sensitivity may be adjusted on installationand such adjustment may be made so that actual contact with the protected object 1 is required to trigger .the alarm; or movements of an intruder at a distance of say one to two feet with respect to the protected object 1, or the single wires and 12, may trigger thealarm. The entire system maybe housed in asingle compact unit located at any desired place and connected by a sin- 13. Any foreign object or body contacting the protected object 1 or single wires '2 or 12, or moving within'the zone of one or two feet of any of these elements, depending upon the adjusted sensitivity of the system, will cause a change in the established electromagnetic iield. This" change is reflected by current flow in the monitor means circuit resulting in a positive or negative swing of indicator 23 to contact veither contact 42 or 43 which actuates the circuit of alarm means 14 to operate the alarm. In accordance with the invention, the defea ditficulty heretofore encountered with prior art devices is avoided in that the connection 1 2 between the signal means and monitor means is protected and not subject to de teat. Heretofore, in prior alarm systems, defeat measures could be applied to the two-wire connection previously required or used between the signal means and the monitor means.

Thus, the improved device protects all major components of the system, that is, the protected device 1, the single wire 2 connected with the signal means 4,

the signal means itself, and the singlewire 12 connected 7 to the monitor means.

gle wire 2' with theprotected object. Alternatively, the

monitoring means and alarm means may be remotely installed with respect to the signal means and protected object with a single wire I2 connection between the signal means and the monitor means; i Alternatively, the alarm system may be monitored remotely by utilizing an RF amplifier at the monitor means tuned to the same frequency as the RF energy supplied by the signalmeans circuit to single wires 2 and 12. I

The improved capacity alarm device may be used in conjunction with any existing alarm systems, such as local,

central station and police alarms. Thus, the device 'instead of operating the bell 33 may be connected into such existing alarm systems.

the protected'objects, in the alternative, may be connected with sensitive screens placed under rugs or floors or in walls or ceilings or over doors or windows to serve as anintrusion detection device with such screens or other sensing elements either visible or completely concealed.

The new capacity alarm device may be connected with the protected object at all times. When it is desired to render the alarm device inoperative, say during the daytime, the Day-Night switch 49 is moved to fDay po-' sition so as to enable use of the protected object such as a safe 1 without triggering the "alarm. The switch 49 may be moved to Night position at the end of the day to render the alarm device operative. Prior to such adjustment, if desired, the bell or other alarm signal may be tested by actuating the bell test button 25 in the manner'described. I

When the alarm system is set for protective use by moving switch 49 to Night position, the electromagnetic energy balance is reached'in a few moments as the fieldis saturated around the protected object 1, around the single wire 2 leading from the protected object 1 to the signal means 4, and around the single wire 12 connected between the signal means 4-v and monitor means One of the fundamental aspects of the invention is the protection of the line 12. between the signal means 4 and the monitor means 13 coupled with the construction of this line with onesingle wire. I

A turther important aspect of the invention is the simplification of the system by utilizing only one transistor in the signalmeans.

A further important advantage of the new system is the ability to adjust the capacity balance to ground on installing the device by the selection of the desired resistance value for resistor '53 so as to impart the desired sensitivity to the device without necessarily insulating the protected object from the floor or surrounding metal objects. In addition, since the improved device is not aifected by temper-ateure changes, etc. it is completely foolproof in operation under all conditions.

Accordingly, the new capacity alarm system of the present invention is greatly improved over prior systems, is completely transistorized with controllable sensitivity; has reliability, protects more of the system circuitry with a more simplified and less costly construction than prior devices, and achieves many advantages not present or achieved in or by prior known systems or devices.

As indicated, the entire system may be housed as a single compact unit, such as in a metal cabinet '56 (FIG. 2) having a cover or door 57 and locked with a lock 58. When the components of the system illustrated in FIG. 1 are housed in a cabinet 56, the lock 58 may be opened with an authorized key by authorized personnel for inspection and testing of the components without triggering the alarm. In such case, the authorized key must have an insulated handle such as a plastic or wood handle.

In accordance with .an established practice for controlling and handling alarm devices, it may be required that the alarm device should be tested at selected intervals, such as once a day, for determining whether the power supply batteries are functioning or whether the alarm means is operating. Such' requirements may be satisfied if the opening of the cabinet door 57, even for authorized operation with an authorized-key, triggers the alarm when the device is set for protective operation.

Thus, upon opening the cab'met door 57 the alarm is triggered indicating proper functioning of the. device.

The tailure to give an alarm, upon opening the door,

indicates malfunctioning of the device, such as a 'low battery.

In order, to achieve the additional control just..de-

scribed, the system may be provided with an automatica-l- 7 whenthe door is closed and released'by the door to move to its other position when the door is opened.

Switch 59 may be connected to the signal means cirouit of FIG. 1 by connecting a branch line 60 to signal means circuit line 7 adjacent the side of main power supply battery 9; byconnecting a branch line 61; to signal means circuit point 55; and by introducing a resistance 62 between point 55 and the H- side of battery 9'.

Branch line 60 is connected to one pole 63 of control switch 59, while branch line 61 is connected to the other pole 64 f control switch 591. A high value capacitor 65 is connected-between switch pole 63 and one end of switch blade 66, at 67; and a low value capacitor 68 is connected between pole 64 and the end of blade 66 at 67. Thus, when switch blade 66' contacts pole 63 the I high value capacitor 65 is shunted outand when blade 66 contactspole 64 the low value capacitor68 is shunted out. I t I i I When the control switch 59 is added as a control device for the alarm system, its operation is as follows:

. With the cabinet door 57 in the closed position ,of-

FIG. 2 switch 59 is held with blade 66 incontact with pole 63 shunting ut heavy capacitor 65. .When the door 57 is opened as illustrated in FIG. 3, switchj59 is I released permitting blade 66 to swing to the dotted po sition shown in FIG. 4'in contact with pole 64 thus almain circuit'mom entarily unbalancing the main circuit and triggering the alarm; In order tocut oif the alarm," it is then necessary to operate reset member 51. (FIG. 1) to .heavy capacitor 65 which is shunted rout of the circuit.

However, nothing happens to disturb the balance of the main signal means circuit as the low value'rcapacitor 68 compensates the system atthis time.

The tamper switch 59, operating as just described tri :gers the alarm at all times when the dooris opened and when the system is set for protective. operation. As an alternative, it maybe desired to ma-intain capacity pro' tection for the components of the alarm device at all times,.'even though not set for protective operation, so

as to permitthe protected safe 1 to be used during author ized daytime intervals without triggering the alarm, but so that opening of. the cabinet door 57 at any time triggers the alarm. This may be accomplished after the cabinet door 57 is opened, by moving Day-Night switch 49 to Day position. 'I hispermits line 2 runningtoprotected safe 1 to be disconnected at 3 and a dummy load connected to the system at point 3. Undersuoh alternative ment ofrelay indicator '23, even though energizedandf it which otherwise would result-in the indicator Z S contact I lowing discharged heavy capacitor- 65. to charge from the arrangement the protectedobject 1 maybe used for au-' thorized purposes, without triggering the alarm, and yet the remaining components of the capacity alarm device are protected against tampering by the reclosure of switch 49 after disconnecting single line 2 from the system, and

the subsequent closing of dOOl 5.7.

r "As an alternative to the use of the Day-Night switch 49 1 of FIG. 1, amanually ope-rated reset actuating cam means rnay be provided for indicator 23 of relay 19 asshown in FIGS. 5, 6 and 7.

' A typioal commercial Wesson relay 19 with its magnetic contacts 42 and 43 and indicator 23 has a reset member 51 which actuates movablefin'ger positioning members 69 and 70.

x The normal position of finger members 69 and 70 is shown in FIG. 7 permitting the indicator 23 to swing in either direction and, contact either of the magnetic conoperated to actuate the fingers 69 and 70* to/centrally positacts'42 or 43 When the reset member 51 is normally tion indicator 23 as shown to a centralposition while thesystem'balances' In accordance with this aspect of the invent-ion, a manual reset control earn 71 is provided, rotatable ,on axis 72, and operated by a finger hole or knob 73. The cam 7 1, preferably is formed of an insulating material such as a plastic. The cam 71 preferably is shaped cylindrif cally at 74 throughout a portion otits periphery andhas two cam lobes 75 connected by surfaces 76 With ,the'cyl1ndrical portion 74. The two lobes 75 are connected with each other by a raised curved surface portion -77, wh ch is spaced a greater radialdistance from the cam center I 72 than the cylindrical surface 74.

When the cam 71 is in the position I is inoperative to engage reset member 51. This may be termed the cam Night position with the relay indicator '23 unobstructed in movement so that indicator 23 may. respond to current changes in the monitor means circui I Whenthe :cam 71 is-rnoved to the position of FIGrS', "cam surface 77 engages reset member 51 holding it sufiiciently, depressed to locate positioning arms '69 and 70 I at intermediate positions which block full swinging moveing either of contacts 42 or 43.

' Thus the cam positionjof FIG, 5 may be termed a Day positionfor. team 71 since it holds relay indicator 23 from actuating the alarm circuit, even though indicator 23 is energized by current flow in-tlr'e monitor means. I a I Cam means 71 has a third or; intermediate position as shown in FIG. 6 where one orthe other of lobes 75 [fully I depresses reset mernber 5-1 to centrally position relay in. i f

dieator .2 3 whenever the cam 71 is moved from Day to Night position or vice versa. .whencontrol cam,71 118 used, as described, for Day-Night and reset operationspthe Day-Night switch 49 rnaybe omittedfrom thetsysten'r shown in MG. -1. Thus, the Day-Night positions of cam 71 correspond to Day-Night positions of switch 49.,

Accordingly, the new. capacity alarm system of the present invention provides further protective, means in that it mayinclude devices for triggering thealarni at any time when the cabinet which houses one or more of the II system components is open; and in that the entire 5315- term can be protected against tampering atall times, even. during those periods when the protected object :1 may be Y disconnected.

In the foregoing description, certain terms; have been used for brevity, clearness' and understanding, but no unnecessary limitations are to be implied therefrom beyond thefrequirements of the prior ;art; ibec ause such words are used fior descriptive purposes herein and n'ot for the purpose oflimitation and are intended to be,

broadly construed. I I

,=Moreover, the invention'is not limited to the exact circnitry arrangement illustratedbecause the particular ar-,

rangement may be varied to provide other structural em- 7 7 bodiments without departing from the scope of the present invention. I I

-Having now described the features, discoveries and principles of the invention, the construction, operation and use of the improved capacity alarm system, and the advantageous, new and useful results obtained thereby;

the new and useful systems, devices, apparatus, constructions, parts, elements, combinations and arrangements, and mechanical equivalents obviousto those skilled in the art, are set forth-in the appended claims. V

I claim: Y

,1. In an electronic alarm circuit, a relay for actuating the alarm circuit, reset means for the relay, and a rotatable manually operable means engageable with the reset means movable to'norrnal, reset and intermediate 7 positions; said normal campositionper-mitting disengagement of the reset means fromthe relay, said reset cam position moving the reset 'means t-o engage and reset the in FIG. 6, fingers 69'and 70 r are in the position there illustrated confinhigindicator 23 I shown in FIG. 7, it-

. 9 relay, and said intermediate cam position actuating the reset means to engage and hold the relay against actuation of the relay upon energizing the relay.

2. A capacity alarm system for a protected object including signal means forming a source of RF energy, monitor means, alarm means actuated by the monitor means, a first singlewire connecting the signal means and protected object, a second single wire connecting the signal means and monitor means, and the signal means establishing a field of RF energy around the protected object and said first and second single wires, whereby entry of an intruder into said field causes current flow in the monitor means which actuates the alarm means, the alarm means including a normally de-energized alarm circuit, a relayin the monitor means actuated by current flow in the monitor means to energize the alarm circuit, reset means for the relay, and a rotatable manually operable cam engageable with the reset means and movable to normal, reset and intermediate positions, said normal cam position permitting disengagement of the reset means from the relay, said reset cam position moving the reset means to engage and reset the relay, and said intermediate cam position actuating the reset means to engage and hold the relay against actuation of the relay upon current flow in the monitor means.

3. A capacity alarm system for a protected object including a power supply, signal means forming a source of RF energy, monitor means, alarmmeans actuated by the monitor means, a first single wire connecting the signal means and protected object, a second single wire connecting the signal means and monitor means, and the signal means establishing a field of RF energy around the protected object and said first and second single wires, whereby entry of an intruder into said field causes current flow in the monitor means which actuates the alarm means, a cabinet housing the signal, monitor and alarm means, a door upon the cabinet, means for disengaging the first single wire connecting the signal means and protected object, and means for actuating the alarm means upon opening the door, said last named means comprising a capacitor and a resistor connected in series across the power supply, and a switch normally shunting the capacitor When the door is closed, said switch being released when the door is opened so as to insert the capacitor into series with the resistor and allowing the discharged capacitor to charge so as to momentarily change the system voltage, the change in voltage affecting the signal means which in turn affects the monitor means and actuates the alarm means whereby the system is protected at all times against tampering whether or not the system is set for security protection of the protected object.

References Cited in the file of this patent I UNITED STATES PATENTS 1,290,644

Claims (1)

1. IN AN ELECTRONIC ALARM CIRCUIT, A RELAY FOR ACTUATING THE ALARM CIRCUIT, RESET MEANS FOR THE RELAY, AND A ROTATABLE MANUALLY OPERABLE CAM MEANS ENGAGEABLE WITH THE RESET MEANS MOVABLE TO NORMAL, RESET AND INTERMEDIATE POSITIONS; SAID NORMAL CAM POSITION PERMITTING DISENGAGEMENT OF THE RESET MEANS FROM THE RELAY, SAID RESET CAM POSITION MOVING THE RESET MEANS TO ENGAGE AND RESET THE RELAY, AND SAID INTERMEDIATE CAM POSITION ACTUATING THE RESET MEANS TO ENGAGE AND HOLD THE RELAY AGAINST ACTUATION OF THE RELAY UPON ENERGIZING THE RELAY.

Images