US3428924A

US3428924A - Solenoid operated impulse relay

Info

Publication number: US3428924A
Application number: US636778A
Authority: US
Inventors: Wilhelm W Brockway
Original assignee: WILHELM W BROCKWAY
Current assignee: WILHELM W BROCKWAY
Priority date: 1967-05-08
Filing date: 1967-05-08
Publication date: 1969-02-18
Anticipated expiration: 1986-02-18

Description

Feb. 18, 1969 w. w. BROCKWAY SOLENOID OPERATED IMPULSE RELAY Filed May a, 1967 INVEN'TOR. V/LHE L M \J.

.BEOCK WAY fl z g AT TOPNE Y United States Patent Ofice 3,428,924 SOLENOID OPERATED IMPULSE RELAY Wilhelm W. Brockway, 16188 Meadowcrest Road, Sherman Oaks, Calif. 91403 Filed May 8, 1967, Ser. No. 636,778 US. Cl. 335-196 Int. Cl. H01h 1/28 Claims ABSTRACT OF THE DISCLOSURE A double-pole relay wherein a spring blade, carrying laterally-spaced dual contacts on its free end, is actuated by a star wheel which in turn is rotated in steps by successive strokes of a solenoid armature. For purposes of assembly and compact design, the spring blade is aligned with one of the contacts and the other contact is offset laterally from the axis of the blade.

Background of invention A relay of the general type contemplated by this invention and outlined, above, is disclosed in my prior Patent No. 2,547,999. The present invention is an improvement on that patent.

Summary of invention This invention provides an improved arrangement of fixed and movable spring contacts wherein a pair of spaced contacts are bridged by a shorting bar comprising two contact fingers on a free end of a spring blade, the contact fingers being of a configuration and positioning such as to equalize the contact pressures of the two contact fingers against their respective fixed contacts, and to attain simultaneous make and break of both contact fingers with reference to their respective fixed contacts.

city of the relay and to avoid any impairment of the spring blade of the movable contact that might result from pass ing current through such spring blade. To this end, a shortening bar, adapted to bridge between two fixed contacts, formed transversely on the end of the spring blade, carries the current directly between the fixed contacts without the current passing lengthwise through the blade.

Description These and other objects will become apparent in the ensuing description and appended drawings, wherein:

FIG. 1. is a fragmentary sectional view of an electric outlet box with the relay of my invention, shown partially in section, installed therein;

FIG. 2 is a sectional view thereof on line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view of the switch unit taken on line 3-3 of FIG. 1;

FIG. 4 is a sectional view of the switch unit, on line 4-4 of FIG. 1;

FIG. 5 is a detail cross-sectional view of the switch unit, on line 5-5 of FIG. 4;

FIG. 6 is a detail cross-sectional view of the switch unit, on line 6-6 of FIG. 4;

FIG. 7 is a detail cross-sectional view of the switch unit, on line 7-7 of FIG. 4;

3,428,924 Patented Feb. 18, 1969 FIG. 8 is a detail fragmentary sectional view of the star-wheel actuator cam and cooperating cam-follower.

FIG. 9 is a detail view of the lock spring;

FIG. 10 is a detail view of the holding pawl; and

FIG. 11 is a detail view of the driving pawl.

Referring now to the drawing in detail, I have shown therein, as an example of one form in which the invention may be embodied, a relay mechanism comprising in general, a solenoid unit A and a switch unit B in an assembly which is mounted in an electric outlet box '0. Solenoid unit A comprises a cylindrical coil housing 10, a coil 11 and an axially slidable armature 12. It is mounted in a knockout aperture of box C which is lined with a rubber grommet 13, and is secured by a lock spring 14 having 0pposed jaws gripping the opposide sides of coil housing 10.

The switch unit B comprises a rectangular case 15 of H-section, including a median bridging wall 16 having a window 17 (FIG. 3) and a box frame 18 extending from both faces of wall 16 to define chambers 19 and 20 (FIG. 2) on respective sides thereof. In chamber 19 a star cam wheel 21 (FIG. 2) is rotatably mounted upon a stud 22 (FIG. 3) fixed in frame 18, and has ratchet teeth in its end faces, engaged by opposed embracing driving ratchet 23 (FIG. 11) and holding pawl 27 (FIG. 10). Driving ratchet 23 has a lever tail pivoted at 24 to the end of armature 12 (FIG. 2) whereby star wheel 21 is steprotated by oscillating movements of ratchet 23 transmitted from armature 12 as solenoid A is consecutively pulsed. A coil spring 28, encircling stud 22, is engaged at respective ends with driving ratchet 23 and an adjacent side wall of case frame 18, and is torsionally preloaded for return of ratchet 23 and armature 12 to normal positions shown in FIG. 2 after each pulsing of solenoid A. A back cover 25 is clasped onto case 15, to cover chamber,19, the armature 12 projecting through an aperture therein. Switch case 15 has a front cover 29 closing this switch chamber 20.

Chamber 20 encloses the switch contacts, comprising a pair of fixed but yieldable spring leaves 30 and 31 (FIG. 4) mounted on an integral bridge bar 32 traversing case 15 and carrying respective contacts 33 and 34 (FIG. 6); and a movable spring blade 35 which is disposed directly below contact leaf 30 in registering relation thereto, one end of blade 35 being anchored at 36 (e.g. by riveting) to web 16 at one side of window 17. The intermediate portion f0 blade 35 extends across window 17 and is engaged by star wheel 21 which extends into the window. The other end of blade 35 is formed integrally with a transverse shorting bar comprising

respective fingers

37 and 38 projecting in opposite directions from a neck 39 which joins them to blade 35.

Fingers

37 and 38 carry respective contacts for engagement with the

contacts

33 and 34.

Fingers

37 and 38 are of equal resiliency and project substantially equal lengths from their junction with neck 39, which is located midway between the sides of case 115. Thus they engage their contacts against the

mating contacts

33, 34 with equal yielding action and the make and break is evenly balanced with respect to both

contacts

33 and 34.

Referring now to FIG! 8, star wheel 21 has a plurality of cam teeth 41 each having an inclined forward face 42 and a substantially radial back face 43. Switch blade 35 has a cam-follower projection 45 with an inclined forward side 46 and a substantially vertical back side 47.

Between teeth 41, star wheel 21 has respective circumferential dwell shoulders 44 of approximately the same circumferential width as the teeth 41 at their bases. The stroke of driving ratchet 23 is such as to rotate the star wheel half the distance between teeth 41 each time the solenoid is pulsed. The holding pawl 27 and spring 28 cooperate to hold the star wheel cam in each new the cam in the position shown in FIG. 8, with the nose of projection 45 resting on the nose of a cam finger 41, and intervening pulses will leave the cam 21 in the posi tion shown in phantom in FIG. 8 (and in full lines in FIG. 2) in which the nose of projection 45 rests in the corner defined between shoulder 44 and the inclined face of the next tooth 41 following a tooth off of which the projection 45 has previously dropped. The arrangement provides for spring-urged snap-fall of the projection 45 from the tip of a tooth 41 as soon as the back 43 of the tooth has cleared the back side 47 of projection 45, free of any retardation by the back 43 of the tooth. Thus there is maximum rapidity of opening of the contact gap, which minimizes arcing.

Arcing (both on break and make) is further minimized by the balanced loading of the

fixed contact elements

30, 31 against the

bridge contacts

33, 34, and the correspondingly balanced separation which results in both pair of contacts separating simultaneously. Since contact gap is duplicated at both sides of the switch contact assembly, and since both gaps are always equalized, the gap dimension is always double that of a single gap and velocity of contact breaking and inhibition of arcing is at least doubled.

I claim:

:1. In a double-pole stepping relay, in combination:

a solenoid including a coil housing, means to mount the same in a knock-out aperture in an electric outlet box, and an axially slidable armature;

a switch case of elongated rectangular box form attached to an end of said coil housing and having a median bridging wall dividing the interior thereof into an actuator chamber and a contact chamber on respective sides of said wall, said wall having a window intermediate its ends;

a star wheel having circumferentially-spaced cam teeth, rotatably mounted in said actuator chamber, and ratchet means coupled to the end of said armature and cooperable with an end of said star wheel for rotation thereof in steps of half the distance between consecutive cam teeth;

a pair of fixed contact elements mounted in said contact chamber and laterally-spaced positions adjacent respective side walls of said case;

a movable contact element including a spring blade 'mounted in said contact chamber alongside one of said side walls in opposed, registering relation to one of said fixed contact elements, with one end of said blade secured to said median wall adjacent one end of said case and an intermediate portion of said blade extending across said window and having a follower engaged by said star wheel for deflectio toward said fixed contacts;

a shorting bar extending traversely on the other end of said movable element;

a neck joining said shorting bar to the free end of said spring blade in an integral one-piece structure of spring sheet metal, said neck extending transversely from said free end and having an integral junction with said shorting bar midway between the sides of said case;

said shorting bar comprising a pair of fingers extending transversely in opposite directions from said junction and having substantially balanced flexibility, and

respective contacts on said fingers, positioned for registering circuit-closing engagement with said fixed contact elements upon engagement of said follower on the nose of cam tooth on a step of actuation of solenoid, said spring blade being loaded to withdraw said contacts from said fixed contact elements upon a succeeding step of actuation of said solenoid in which said follower drops into a space between consecutive cam teeth.

2. A relay as defined in claim 1, wherein said fixed contact elements comprise respective leaf springs each secured to said case at a respective side thereof and each having a projecting flexible portion and a contact at the end thereof in registering relation to the contacts of said bridge.

3. A relay as defined in claim 2, wherein said case includes a transversely extending bridge bar on which said leaf springs are mounted, said bridge bar being spaced from said median wall.

4. A relay as defined in claim 1, wherein said neck extends diagonally from said blade to said junction.

5. A relay as defined in claim 1, each of said cam teeth having an inclined forward side and a substantially radial back side and having circumferential, dwell shoulders between said teeth;

said spring blade including a cam follower projection having an inclined forward side for camming engagement and a substantially radial back side whereby said projection may drop from the tip of a cam tooth to an adjacent dwell shoulder without riding against said back side of the tooth thereby increasing break velocity and minimizing arcing.

References Cited UNITED STATES PATENTS 2,532,624 12/1950 Kircher 335-196 2,547,999 4/ 195-1 Brockway 335---l 2,600,247 6/ 1952 Huetten 200-1661 2,788,419 4/1957 Young ZOO-166.1

BERNARD A. GILHEANY, Primary Examiner.

-H. BROOME, Assistant Examiner.