US1641643A - Quick-acting mechanism for time relays - Google Patents

Description

Sept. 6,1927.

. W. H. PETEfiSEN v QUICK ACTING MECHANISM FOR TIME ELAYS Filed Jan. 11, 1923 nvvsflrowr ATTY.

Patented Sept. 6, 1927.

UNITED STATES.

,PATENT OFFICEQ WILHELM 'HENNING PETERSEN, or LUDVIKA, swnmsiv, ASSIGNOR T ALLMANNA SVENSKA ELEKTRISKA AKTrnBoLAenT, ,oravasrnaas, swnnnn, A CORPORATION OF SWEDEN.

QUICK-ACTING MECHANISM FOR TIME RELAYS.

Application filed January 11, 1923. Serial No. 611,990.

Relays for releasing purposes which are destined to act only after the operating value of current has been sustained for a certain period of time,said time being either independent of the-current or variable inversely thereto, are either of the type which \are quick-acting in itself, but provided with a retarding device based for instance upon fluid friction or clock-work movement, or of 0 the type where the primary operative member normally moves at aslow speed. The latter is especially the case in the induction type of relays, where a motor armature or Ferraris disc moves at a' speed varying with the current, in general substantially proportioned thereto. 1

In such relays, it has been found advisable to provide a special quick-acting mechanism at the end of the path of saidoperative 2 member to actuate a pair of contacts or other releasing device, and the chief object of my present invention is to provide such ,a device.

lVhile the said quick-acting device may be of different design, ithas been found preferably to construct it to perform its quick-acting movement under magnetic action. Especially when the primary operative member of the relay is moved under magnetic action, as for instance in induc- .tion type relays, a simple and elfective solution of the quick-action problem may be had by providing a magnetic shunt to a magnet acting upon said primary member.

A form of the invention, based upon the last-mentioned principle, is illustrated in the accompanying drawing, Where Figure 1 shows a relay in a front view with certain parts broken away, which are non-essential to the invention. Figure 2shows the principle parts of the quick-acting mechanism in an end view. c i 1 Referring to drawing, 1 is an induction disc rotatingunder the influence of an electromagnet having a core 2, a main coil 3, and two short circuit'coils'l embracingportion of its poles for creating an auxiliary field phase. The induction disc is journa-lled in a frame 5, which is capable of being dis-' placed in the manner described in my pending application No. 472,848, for bringing the worm 6 on the shaft of said disc into engagementwith the toothed segmenti, as soon as the current traversing the coil 3 exceeds a certain value. When this is done, the disc (which is supposed to be continuously rotating) imparts its motion to the toothed segment which is then lifted. At

the end of its upward motion, the segment is intended to perform a releasing action, lfor instance by bringing a pair of contact pieces .8, 9 into contact with each other. Since the motion of the segment, however, is comparatively slow, and the motion of, the releasing device, as the contacts, preferably should be quick, there is interposed between these devices a quick-acting mechanism. In the form'shown, this mechanism consists of a piece 10, insulated from the contact piece 8 by means of a washer 11 secured to the latter, said piece 10 being mounted on a magnet armature 12. Said armature is pivotally mounted in an iron yoke 13 by means of pin 1 1. The two magnetic pieces 12 and 13 form part of a magnetic path shunting the air gap of the'electromagnet core 2, said shunt path comprising'also a longitudinal piece 15 and a cross piece 16. In the form shown, the yoke 13 is solid, while the piece 15 is partly solid, partly laminated, and the piece 16 entirely laminated. propriate form in practice. 17 is a piece of non-magnetic metal serving to brace the upper end of the piece 15 with the yoke 13.

The armature 12 extends to both sides of its pivoting point and is separated from the main core 2 of the electromagnet-by approximately equal air'gaps at both ends. However, it is normally prevented from moving in more than one direction by an adjustable stop screw 18. When a projection 19 on the segment 7 strikes the piece 10 and raises the corresponding end of the armature 12, thus increasing one air gap and reducing the other, the force of attraction in the latter will soon overcome that of the former, which normally is supposed to be a little predominant, and cause a sudden attraction of the corresponding end of the armature, the other end of which then strikes the movable contact piece 8 and brings it into contact with the fixed piece so that the relay will perform its releasing action.

The end of the armature'12 which thus is intended to be attractive to the core may be provided with a shading coil 20 .to prevent its vibrations-when attracted. On the This has proved to be an apmature around its centre andicausing the core tojattract both ends thereoit .18 that a mechanical action from outside is always necessary for inltiating the movement of attraction. If the armature 1s acted upon only or predominantly by the same pole, which is intended to eventually attract it, and normally kept away "trom' that pole only by mechanical' means, the result of a-heavy overload will be that it is attracted without such iiiitiating mechanical action. and thus in case of such an overload the relay will act instantancously,- independently of the time setting. .In some cases this may be desirable, and it is easily accomplished even in the case of a balanced armatureby an appropriate use oi the stop screw 1'8. It. by means of this screw the corresponding end of the armature is approached to the main core so that the attraction on this end will be normally a little in excess of that on the otherwhich excess may then be balanced; by the overweight-of the other endor even if this attraction is normally less, but will be in excess at a certain overload on account of the variable reluctance of the different portions of the magnetic path, the action ot the relay in case of sucl'ran overload wi-ll be instantaneous. The stop-screw 18 thus will have two different positionsi'or two different kinds of action of the relay. For being safely held in these different poons, it may be provided with a l-Inurled head 21 engaged by a spring pi-eceQQand also slits orother marks on its top to clearly show the position set.

I claim as my invention 1. In 'tinie relays, anelectromagnet havinglaminated iron core. a metallic member capable of being moved in an gap of said corebyin-duction from said electromagnet, an operative member connected to said induction member by speedreduclng gear, a movable magnetic core portion shunting said gap and a member con nected to said movable core portion and lying the path of said operative member.

'2. In time relays, an electromagnet. an operative member capable of being moved at slowspeed under the action of: said electromagnet, a movable coreflportion of the said elcctromagnet ffo'rm'ing two magnetical- 1y parallelled air gaps, and .mec'lianically associated Withsaid operative member so as to move quickly when actuated thereby.

In time relays, an electromagnet, an operative member capable oi being moved at slow speed under the action of said electromagnet,. a movable c-ore portion of .said electromagnet forming two .magnetically parallelled air gaps and mechanically associated. with said operative member and adjusting means for the said movable core portion for. reducing one of said air gaps and increasing the other.

t. In time relays, an elcctromagn-et havinglaminated iron core, a metallic member ca pable of being moved in an air gap of said core,.by induction from-said clectromagnet. inoperative member connected to said indu-ction member, an iron core portion magnetically shunting said air gap, an armature pivotally mounted in said core portion and separated from the fixed iron core by air gap at both ends, and a member connected to said armature and lying in the path of said operative member.

5. 111 time relays, an electromagnet, an operative .m-ember moving througha path at a low speed under the influence of the current of said electromagnenan armature pivoted atits centre and attracted at both ends by portion of said electromagnet; having the same polarity, a projectiono't' said armature lying inthe pathof said operative member. and. a movable contact lying in the path of said armature.

6. In time relays, an electromagnet having three magnetically parallel air gaps. one of said airj gaps being of constant width and embracing an induction disc, while the two others are limited by afpivoted portion ol the core so as to be mutually variable, an adjust ing device for regulating the initial position of said pivoted portion. and a movable contact actuated by said. pivoted portion.

7. 111 time relays, an electromagnet having a laminated main iron core withan air 7' ap. u I a b I an induction disc lllOVZIblBlll] said air gap, a speed reducing gear connecting said disc to an operative member. an additional core portion. of the electromagnet bridging said air gap, and havingtwo lateral arms, an armature pivoted in said additional core portion and adapted to be attracted by either arm thereof, ,a projection of said armature lying in the path of said operativemember, and a movable-contact arm lying in: the I ath of said armature.

Iii-testimony whereof -I have signed my nameto t his speci'fication. V VILH' ELM HENNING PETERSE N.

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