US3562595A - Plug-in solid-state timer module for convertible reed relay - Google Patents

Abstract

A molded cover and case are secured together to retain a printed timing circuit board therein and the assembly is inserted into the housing of a reed relay in the space normally provided for several reed switch modules and a connector module. A second board containing several resistors is housed in an external portion of the case. An auxiliary instantaneous pole unit is optionally provided and has plug-in connections to the printed circuit board, and all wiring terminals are of the pressure plate type.

Description

United States Patent Inventors William C. Swanson;

David R. Stewart, Milwaukee, Wis. App]. No. 821,682 Filed May 5, 1969 Patented Feb. 9, 1971 Assignee CutterJ-lammer, Inc.

Milwaukee, Wis. a corporation of Delaware PLUG-1N SOLID-STATE TIMER MODULE FOR CONVERTIBLE REED RELAY 4 Claims, 6 Drawing Figs.

U.S.Cl 317/113, 317/112335/59 Int. Cl 1101b 47/18; H02b l /04 FieldofSearch 317/113,

[56] 1 References Cited UNITED STATES PATENTS 3,215,800 11/1965 Hurer 335/202X 3,254,177 5/1966 Gottsacker 335/60 3,407,312 10/1968 Pearse 317/142X Primary Examiner-Laramie E. Askin Assistant Examiner-Gerald P. Tolin Altorney- Hugh R. Rather ABSTRACT: A molded cover and case are secured together to retain a printed timing circuit board therein and the assembly is inserted into the housing of a reed relay in the space normally provided for several reed switch modules and a connector module. A second board containing several resistors is housed in an external portion of the case. An auxiliary instantaneous pole unit is optionally provided and has plug-in connections to the printed circuit board, and all wiring terminals are of the pressure plate type.

'IPATENTIEDFEBI 5H9?! SHEET 1 OF 2 j $562,595

Jul anions PLUG-IN SOLID-STATE TIMER MODULE FOR CONVERTIBLE REED RELAY CROSS-REFERENCE TO RELATEDAPPLICATION BACKGROUND OF THEINVENTION This invention relates to timersfor electrical relays and particularly to a solid-state timer module for a reed relay. Specifically the invention relates to a novel modular-packaging concept for the solid-state timer to permit easy attachment thereof to the reed relay.

The prior art solid-state timing devices for industrial control use have lacked the versatility and flexibility required of other industrial control devices. A typical timing device is panel mounted, approximately the size of a companion relay, has one or two output terminals which are fixed to eithernormally open or normally closed functions, is packaged in a relatively expensive potted housing and is electrically connected to the relay to be controlled by external wiring.

The timing device of this invention comprises a timer module having a relatively inexpensive, separable, two-piece housing which traps a printed eircuitboard inside ,uponits assembly. The timer module connects directly to aconvertible reed relay of the aforementioned type by-pluggingthe timer into an opening in the relay normally occupied by several modular .poles of the relay thereby-requiring no additional panel area for the mounting of the timer. The electrical-connections between the timer and relay are of .the plug-in type and serve to connect the relay coil to the outputoftheatiming circuit. Additionally, the relay has four remaining poles which are availableas timed contacts and may bereadily converted to either normally open or normally closed as desiredJTl'he timermay be provided with an optional pole-for aninstantaneous contact operation if desired,.and provisions are available to readily connect a'rerriote potentiometer into-thecontrol of the timing cireuittoprovideadjustment from a remote point.

SUMMARY OF THE INVENTION It is therefor a primary object of this invention -to provide a solid-state timer module for a convertible reed relay which is packaged in a housing. designed to permit electrical and mechanical plug-in connection to the relay.

It is a further object of this invention .to-provide a-solid-state timer of the above-mentioned type which may be readily altered to provide adjustment thereof .by a remote pointeontrol device and may be provided with an auxiliary contact pole that is operated independently of the timingcircuit.

These and other objects and advantages ,of the invention will become more apparent in the followingspecification and claims when read in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of the timer module of this invention inserted into a reed relay housing;

FIG. 2 is a side elevational view of the right-hand side of the timer module and reed relay housing of FIG. 1;

FIG. 3 is a front view of the reed relay housing with the timer module removed therefrom;

FIG. 4 is a top plan view of the timer module;

FIG. 5 is a longitudinal sectional view of the timer module taken generally along the line 5-5 in FIG. 4; and

FIG. 6 is an electrical diagram of one preferred solid-state timing circuit used in the timing module of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT,

With reference to the drawings, the timer module is shown in conjunction with the convertible reed relay of the aforementioned copending application. While reference may be had thereto for a complete description of 'the relay, a brief description thereof follows to facilitate the understanding of the invention of this application.

The relay 2 comprises a hollow insulating enclosing case 4 riveted to .a metal base plate 6 for securing the relay to a mounting panel. An electromagnet comprising a core 8, coil '10 and core pole extensions 1'2 and 14 is positioned within the insulating case 4 as shown in FIG. 2.

Insulating case 4 has upper and lower openings 40 and 412, respectively, which extend across the front of the case and rearwardly along the respective upper and lower sides thereof. A central web :40 extends across the front of the case 4 between the opposite vertical-sides thereof, separating the upper and lower openings 40 and 4b. Each of the openings 4a and (4b are divided into four pockets and each pocket may receive a pole-unit module which is to be inserted into the opening, or pocket, from the front of the case.

As seen in FIG. 3, the lower opening 4b contains the maximum of four pole 'unit modules. Each of these modules containa sealed reed switch member fixedly mounted therein and are therefor termed switch pole units. When inserted into the openings of case 4, thesuperstructures of the switch pole units serve to position thereed switch members in a definite operationalrelationship to the magnetic gas gap between core pole extensions 12 and 14 as depicted by the dotted line showing in FIG. 2. Energization of the coil 10 of the electromagnet establishesamagnetic flux across the gap between core pole extensions 12 and 14 and through the reed contacts of the reed switch members "to operate the latter. Although not specifically shown in the drawings, the reedcontacts of the switch members are connected internally of each module to the respective wiring terminals shown on the exterior of each of the pole unit modules in FIGS. 1 and 3 which therefor serve asfour sets of timed output terminals for the assembled timer and relay device. 7

The web 4c is provided along its edges with recessed .keyways formed adjacentthezpockets. The various pole unit modules are'provided with key extensions which fit within corresponding ones of thekeyways when the respective unit is inserted into the pocket. In FIGS. 1 and 3, the right-hand pair of switch pole units 16 inserted in the lower opening 4b are of the normally open type while the left-hand pair of switch pole units I8 are of the normally closed type and therefore have a different key and keywaycombination.

As seen specifically in FIG. 3, the upper opening 40 of case 4 has three pockets suitably provided with recessed keyways adjacent thereto in web 4c to receive three switch pole units of either the :normally open or normally closed type. The extreme right-hand, or forth pocket, in opening 44 is provided with a dovetail keyway adjacent thereto and a projecting nib 20 formed within the case. A'foot portion of coil 10 ex tends into the extreme right-hand pocket of opening 4a at the back end of the case 4. Foot portion 10a carries a pair of upstanding blade connectors 22 which extend toward to front of the case.

In an ordinary application .of the relay, a plug-in coil pole unit would be inserted into the right-hand pocket vof opening 40. Such coil pole unit would have a superstructure physically similar to the switch pole units, but would be provided with plug-in female connector clips which would connect to the blades 22 to supply current to the coil 10 when an electrical supply source is connected to wiring terminals on the exterior of the coil pole unit. Where alternating current is supplied to the coil pole, the latter also houses a full wave rectifier bridge to provide direct current to the relay coil.

The solid-state timer module 24 is designed to be easily attached to the reed relay device, take no additional panel space and generally offer the same convenience and versatility features for installation required dynamic industrial control devices. As will be apparent in the following description, the timer module 24 offers solid-state timing circuitry in a housing which plugs into the relay in the space normally occupied by three switch pole units and a coil pole unit. The timer provides an optional instantaneous operating pole, pressure plate wiring terminals and other variations generally accorded only the prior art pneumatic timing devices used in conjunction with dynamic relays.

Timer module 24 includes an insulating housing comprising a molded case 26 and a molded cover 28 secured together by screws 30 which take into threaded openings in the case 26 (FIGS. 4 and While only one pair of screws 30 are shown at the left-hand end of the timer as viewed in FIGS. 4 and 5, a second pair of screws are provided at the right-hand, or outer end of the timer housing. A printed circuit board 32 is trapped within the cover 28 by the case 26 when the housing is assembled. Similarly, the shaft of a potentiometer extends through mating semicircular openings formed in the front surfaces of the case 26 and cover 28 to be trapped in position when the two housing portions are secured together by screws 30. While not specifically shown, the potentiometer case and timer hous ing may be assumed to be suitably keyed or provided with cooperating abutting portions to prevent rotational movement of the potentiometer case within the housing of timer 24.

The potentiometer shaft further extends through an opening in an insulating trim panel 34 and has a skirted knob 36 permanently secured to its outer end. Trim panel 34 has an index mark and the skirt of knob 36 is suitably provided with indicia to facilitate adjustment of the potentiometer. A knurled screw 38 is threaded into a tapped hole in the front of the timer housing adjacent the potentiometer knob 36. The underside of screw 38 is formed at a parallel angle to that of the skirt on knob 36 and a resilient washer 40 to is disposed about the screw shank to overlie the skirt on knob 36. Potentiometer knob 36 may be rigidly fixed at any setting by threading screw 38 inwardly to compress the washer 40 down tightly upon the skirt of the knob 36.

Molded case 26 has a hollow, rectangular boxlike portion 26a which is open on the side facing cover 28. Boxlike portion 26a extends along the upper exterior surface of relay housing 4 as seen in the drawings. A second printed circuit board 42 is secured within portion 260 against a boss therein and one recessed edge of the portion 261: by a screw 44. Board 42 carries the majority of the resistors utilized in the timing circuit, particularly those which produce high amounts of heat. The external positioning of portion 26a and board 42 provides for better heat dissipation from the resistors and keeps the heatproducing members away from the interior of the relay. While not shown in the drawings, wire connections are provided internally of the timer housing to connect the two printed circuit boards together.

Printed circuit board 32 has a pair of fingers 32a (FIG. 4) which extend rearwardly through an opening between the case 26 and cover 28. Each finger 32a rigidly carries a female connector clip 46 positioned for engagement with a respective blade terminal 22 of coil 10. As seen in FIG. 10, case 26 is provided with an insulating barrier which extends rearwardly between the connector clips 46 to prevent against short circuit between the connectors in operation of the device.

Insulating case 26 is provided with six wiring terminals 48, 50, 52, 54, 56 and 58, all of the pressure plate type. The terminals are arranged in two rows and are angled for easy frontal access in accordance with present industrial control device design requirements. Each terminal is riveted to the inside of the case and has an angled portion which extends through an opening in the wall. The angled portion carries the terminal screw and pressure plate thereon.

The timer module 24 is also provided with an auxiliary instantaneous operating pole unit if desired, and the same is shown in the drawings. The pole unit includes a molded insulating case 60 which attached to the case 26 by a screw 62 FIGS. 4 and 5). The exterior configuration of case 60 is very similar to that of the case 26 in the area of the terminals and provides the timer with an appearance of continuity across the top surface. The case 60 is provided with a pair of terminal members. and 66 which are identical to the terminals 48- 58 of the timer 24. A reed rclay unit 68 is inserted within the case 60, positioned therein by ledges formed on the inner sides of the case. An interference fit between the case 60 and relay unit 68 serves to retain the relay unit within the case. The relay unit 68 is provided with wires which are soldered to the respective terminals 64 and 66 to connect the contacts of the unit to the external terminals. The coil terminals of the relay unit 68 are of the female plug-in connector type and are contained within the ends of the unit. As seen in FIG. 5, when the optional pole unit is mounted to the timer, the relay unit 68 operably receives plug-in connector pins 70 of printed circuit board 32.

The assembled timer module 24 is inserted into the opening 4a of reed relay housing 4. Timer cover 28 is provided with to two projecting keys 72 and 74, the latter of which is rectangular, and will therefor only fit within the dovetail keyway adjacent the right-hand pocket to insure that the timer module is not inserted into opening 4b. Screws 76 are provided to hold the timer in place in the relay housing and a cover plate 78 is secured over the central web 4c to cover the keys and keyways. When the timer module is inserted as described, the connector clips 46 on printed circuit board 32 engage blades 22 of coil 10 to connect the coil to the timing circuit.

With reference to the circuit diagram of FIG. 6, the assembled relay and timer are connected to an AC source by wiring supply lines to the terminals 48 and 50 of the timer. Suitable internal wire leads connect these terminals to a full wave rectifier bridge 80 on printed circuit board 32.

The timing circuit is connected across a pair of lines leading from the output terminals of rectifier bridge 80. However, by suitable wire connections, terminals 52 and 54 are interposed in the positive polarity line to break the circuit and place it under the control of a remote switch 82 externally wired to the terminals 52 and 54 of the timer-24.

The timinginterval of the circuit is varied by the setting of the potentiometer POT mounted in the front wall of timer 24 and operated by knob 36 as earlier described. The slider terminal of potentiometer POT is connected to the remainder of the timing circuit through terminals 56 and 58 and a jumper strap 84 connected therebetween. If it is desired to control the timing interval from some point remote from the panel on which the relay and timer are mounted, the jumper strap 84 may be removed and a remote potentiometer may be externally wired to the terminals 56 and 58.

The timing circuit itself is of a well-known type and the following description thereof will be brief, only certain essential elements being mentioned. When the AC supply source is connected to the timer, a positive voltage is applied to the base of an NPN transistor T1 to render that transistor conducting and in turn short out, or discharge a timing capacitor C1. When switch 82 is closed to begin the timing period, positive voltage is applied to the base of a second NPN transistor T2 to render it conducting and thereby short out the base current to transistor T1 to turn oh the latter. Immediately capacitor C 1 begins to charge up at a rate determined by the values of itself and the resistance setting of potentiometer POT. The

voltage across capacitor C1 is applied to the base of a unijunction transistor UJT and it gradually builds up until, at the end of the desired time interval, it reaches a value sufficient to cause unijunction transistor UJT to fire. The latter causes a gate signal to be applied to a silicon controlled rectifier SCR which turns the latter on to connect the reed relay coil I0 to the circuit, thereby actuating the reed switch pole units 16 and 18. The coil 10 remains energized until the switch 82 is opened, at which time voltage is removed from the base of transistor T2 and reapplied to the base of transistor T1 to discharge the timing capacitor C1. It should be noted that when the optional pole unit is added to the timer, the reed relay unit therein is energized immediately upon closure of switch 82 to complete a circuit to terminals 64 and 66 and the external device connected thereto.

Thus there is disclosed herein a modular timer assembly which is readily connected to an industrial type reed relay,

such timer combining the advantages of solid-state circuitry and devices with the flexibility of prior art industrial control devices of the dynamic type. While a single preferred embodiment is disclosed, the timer module is susceptible of various modifications without departing from the scope of the appended claims.

We claim:

1. The combination with a convertible reed relay having an electromagnet mounted within an insulating housing, a pair of frontal openings in said housing on opposite sides of said electromagnet for each receiving a plurality of modular sealed reed switch pole units therein alongside said electromagnet, a plurality of said modular sealed reed switch pole units inserted in only one of said frontal openings to extend alongside said electromagnet in operational relationship therewith and having wiring terminal means on an exposed end of each of said modular switch pole units for connecting the reed switch contacts to respective load circuits, and plug-in electrical connector means on said electromagnet for connecting the latter to a supply source, said plug-in means being positioned within said insulating housing and in alignment with the other of said frontal openings; of a timer inserted into the said other of said frontal openings and comprising; and insulating case, a plurality or wiring terminals secured to said case, plug-in electrical connector means extending outwardly of said case and engaging with said plug-in means on said electromagnet, a solidstate timing circuit housed within said case, means connecting the input portion of said timing circuit to a pair of said wiring tenninals for externally connecting said timer to a supply source, and means connecting the output portion of said timing circuit to said plug-in electrical connector means to providc time-controlled response of said electromagnet to operate a said plurality of modular sealed reed switch pole units.

2. The combination according to claim 1 together with manually adjustable control means for varying the timing interval of said timer, said control means being carried by said case and having an operator portion thereof extending exteriorly of said case, means connecting the output portion of said control means to said timing circuit through an electrical series connection to a second pair of said plurality of wiring terminals, and means for externally joining said second pair of wiring terminals to complete the connection of said control means to said timing circuit.

3. The combination according to claim 2 wherein said insu' lating case includes a removable cover normally attached to said case and said timing circuit is formed upon at least one insulating board, and wherein said board and said manually adjustable control means are firmly secured within said timer case by cooperating portions formed on said case and cover to respectively trap said board and said control means therebetween upon attachment of said cover to said case.

4. The combination according to claim 2 together with an auxiliary pole unit module attached to said timer case, electromagnetic switching means carried by said auxiliary pole unit module, plug-in connector means electrically connecting the input of said electromagnetic switching means across the input of said timing circuit, and wiring terminals carried by said auxiliary pole unit module electrically connected to the output of said electromagnetic switching means.

@33 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,562,595 D t d February 9, 1971 Ui1]iam (I Swanson and David R Stewart It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 26: "gas" should be omitted Column 2, line 72: "required dynamic industrial" should rez -required in dynamic industrial- Column 3, line 551: "FIG. 10" should be --FIG. 4--

Column 3, line 70: "which attached to the case" should read --which attaches to the case--" Column 4, line 36: "by the setting" should read --by changi the setting-- Claim 1, Column 5, line 22: "of a timer inserted" should re --of a timer module inserted-- Claim 1, Column 5, line 23: "and insulating case" should re --an insulating case-- Claim 1, Column 5, line 24: "or wiring terminals" should re --of wiring terminals-- Signed and sealed this 29th day of June 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents

Claims (4)

1. The combination with a convertible reed relay having an electromagnet mounted within an insulating housing, a pair of frontal openings in said housing on opposite sides of said electromagnet for each receiving a plurality of modular sealed reed switch pole units therein alongside said electromagnet, a plurality of said modular sealed reed switch pole units inserted in only one of said frontal openings to extend alongside said electromagnet in operational relationship therewith and having wiring terminal means on an exposed end of each of said modular switch pole units for connecting the reed switch contacts to respective load circuits, and plug-in electrical connector means on said electromagnet for connecting the latter to a supply source, said plug-in means being positioned within said insulating housing and in alignment with the other of said frontal openings; of a timer inserted into the said other of said frontal openings and comprising; and insulating case, a plurality or wiring terminals secured to said case, plug-in electrical connector means extending outwardly of said case and engaging with said plug-in means on said electromagnet, a solid-state timing circuit housed within said case, means connecting the input portion of said timing circuit to a pair of said wiring terminals for externally connecting said timer to a supply source, and means connecting the output portion of said timing circuit to said plug-in electrical connector means to provide time-controlled response of said electromagnet to operate a said plurality of modular sealed reed switch pole units.

2. The combination according to claim 1 together with manually adjustable control means for varying the timIng interval of said timer, said control means being carried by said case and having an operator portion thereof extending exteriorly of said case, means connecting the output portion of said control means to said timing circuit through an electrical series connection to a second pair of said plurality of wiring terminals, and means for externally joining said second pair of wiring terminals to complete the connection of said control means to said timing circuit.

3. The combination according to claim 2 wherein said insulating case includes a removable cover normally attached to said case and said timing circuit is formed upon at least one insulating board, and wherein said board and said manually adjustable control means are firmly secured within said timer case by cooperating portions formed on said case and cover to respectively trap said board and said control means therebetween upon attachment of said cover to said case.

4. The combination according to claim 2 together with an auxiliary pole unit module attached to said timer case, electromagnetic switching means carried by said auxiliary pole unit module, plug-in connector means electrically connecting the input of said electromagnetic switching means across the input of said timing circuit, and wiring terminals carried by said auxiliary pole unit module electrically connected to the output of said electromagnetic switching means.

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