US2442572A - Timing device - Google Patents

Description

June l, i948. r. H. sHEEHAN TIMING DEVICE Filed Feb. 15, 1947 2 Sheets-Sheet 1 ffl- 5.1;

INVENTOR. Thomas h. Shea/1an A TroR/VE y;

June l, 1948. T. H. sHEr-:HAN

TIMING DEVICE 2 Sheets-Sheet 2 Filed Feb. l5, 1947 IN VEN TOR. Tha/72a: h. 5/766790/7 ATTO/PNEXS' Patented June l, 1948 STATES PATENT OFFICE TIMIN G DEVICE Thomas H. Sheehan, Detroit, Mich.

Application February 15, 1947, Serial No. 728,753

9 Claims.

1 This invention relates to a timing device and more particularly to a mechanical device of this type adapted for timed actuation of control mechanisms.

Among the objects of this invention is the provision of a mechanical timing device for producing a snap movement after the elapse of a desired time interval and which effects instantaneous re sponse of a control mechanism.

Another object or my invention is to provide a mechanical timing device which can be accurately adjusted for different time intervals and'which is adapted for use with a great variety of both mechanical as Well as electrical control systems.

In the drawings:

Fig. 1 is a side view partly in section of a door stop mechanism embodying one application of my invention.

Fig. 2 is an end view of the structure shown in Fig. 1.

Fig. 3 is a tcp view of the locking means provided at the upper end of the door stop.

Fig. 4 is an end view of the iiuid reservoir showing the manner in which it is mounted on its support bracket.

Fig. 5 is a view taken along the line 5 5 of Fig. 1.

Fig. 6 is a view taken along line E-G of Fig. 4.

Referring to the drawings, and particularly to Fig 1, I have shown my timing device employed as an automatic door closer in which a bolt ill is mounted for vertical movement on a door plate i i which may be secured adjacent the lower edge of a door. The bolt is provided with a stopper l2 at the lower end arranged to engage a sta tionary pin di in a door surface to hold the door in a xed position and is urged upwardly by a compression spring i3 acting between ange I9 at the bottom of plate l! and washer 42 which is retained on the bolt, A spring detent i4 mounted on plate li is arranged to engage with a shouldered portion i5 on bolt lo and thereby lock the bolt in its lowered position against the tension of springl i3.

To effect tripping of the spring detent after A small detent 22 projecting outwardly from arm inder.

23 of yoke 2| and into a largeropening 24 in bracket I8 limits the pivotal movement of the yoke as is best shown in Fig. 6. The rear end of cylinder I i5 is provided with a stop plate 25 which is adapted to abut against and rotate yoke 2i as the cylinder pivots downwardly. When the cylinder pivots upwardly its upper surface contacts the yoke and pivots it in the other direction, At the lower end of arm 23 directly below pin I1 there is secured one end of a tension spring 25) the other end of which is secured to an arm 26 which extends outwardly from the upper end of bracket i8. A screw and nut arrangement 2'! permits adjustment of the tension in the spring. When the -cylinder is in the raised position, as indicated by broken line 28, it will be observed that the axis of the spring 2Q is to the left of pivot pin l1 and the yoke 2| is retained in its uppermost position, When the cylinder is in the position indicated by lines 29, spring 2B lies to the right of pin I1 and stop 25 has moved yoke 2| to the other side of center position where it is snapped rapidly downwardly by spring 22.

The movement of the cylinder is coordinated with the release of spring detent lll by an engaging lug 30 which is secured to the detent and adapted to receive a sharp blow from a pin projecting laterally from the rear end of the cyl- Lug 30 is arrange-d to be struck by Apin 35 and retract detent i4 from shoulder i5 as cylinder It is moving downwardly at its greatest velocity.

Within the cylinder there is provided a ball member 43 arranged to travel through the liquid from one end of the cylinder to the other. The ball member must be heavy enough to produce sufcient leverage as it approaches the outer end of the cylinder to overcome the tension of spring 2Q as well as the resilience of detent ifi and its frictional engagement with shoulder i5 on bolt iii.

At a suitable position on ybolt lil there is provided a stop member 3! which extends through the bolt perpendicular'to plate il. As the bolt moves-upwardly, under the force of spring ifi, the outer end of stop 3! abuts against the underside of cylinder i6 and carries it upwardly to its starting positionZ. The' inner' end of stop 3l extends into a guide 32 formed in plate i i and prevents the bolt from turning. A pivotal catch 33 at the upper end of plate i! is arranged to be moved into engagement with the top of bolt lil when it is desired to maintain the stopper i2 in the pin engaging position although detent M may have been released by the action of the cylinder. i i

lowered position. At the same time cylinder I6,

by reason of its own Weight and the weight of the liquid within it, rotates downwardly about; pivot I1 until' stop plate 25' abuts against yoke` 2 I, that is, the position indicated by full lines in Fig. 1.

At this time ball 40 is adjacent the pivoted end4 of the cylinder and its effective weight onjlever age is insufficient to overcome the tension of spring on yoke 2|. end of the cylinder is disposed ata lower levelthan the pivot end, ball 2T begins to travelslowly through the liquid toward the lower end;

the ball travels toward the outer end of the cylinder andv away fromv pivotA` I l, its leverage increases and after the. elapse ofea desired.-` time interval. the ball reaches.: a point .where its effective: weight or leverage plus the weight :of the cylinder and the liquidoverbalances spring 2li and causes yokeI 2| to be. snapped. over centerinffadownward direction.. This movement of the yoke. releases the cylinder. and permits ity to.- fall very rapidly to theposition indicatedvby line 23: inf Fig. 1. In fallingx the. cylinder accumulates considerable momentum. and causes pin to strike lug 3U a heavy` blow to discngage. detent I4 from shoulder |15 and' effect an instantaneous release of bolt IU. The. bolt then-moves upwardly under the influence. of spring I3, and stop member 3| carries' the cylinder back to its raisedposition 28; In -so Adoing` the. cylinder strikes yoke 2| and snaps it back over center to the starting position and the mechanism. is= ready for another kcycle of. operation..

It wil-l thus be observed. that the timing 'device of. my i-nvention is of simple construction' and yet operates. very effectively. Latitude' in the dura:- tion-ot the time intervalmay be obtained im severalways, that is, adjustment of the tension'in spring 20, the. amountand viscosity ofthe' liquid in the cylinder and the diametral differencefor clearance between theV ball and the inside: diameter of theV tube. Ihave found thatV lubricating cil serves satisfactorily asl a'liquid within cylinder I 6 where large ambient temperature changes are not encountered. In applications which have a large ambient temperature range, kerosene hasv been format-more satisfactory and it is also possible to make arm 26 a bimetal thermal element in order to change` tension on spring 20 and thereby compensate for liquid viscosity changes in cylinder Ii relation toY ambient temperature changes. 'Ihey improved snap action resulting from employing an over-center springV asdescribed adapts the device forl usein many diierent applications, especially in conjunction with electrical switches and circuit breakers where instantaneous release is necessary if .arcingbetween the contacts is'to be'avoided.

Iclaim:

1. A timing device comprising a support, a reservoir containingv a body of liquid and pivotally supported on said support, over-center resilient means acting between said reservoir and said support, said resilient means adapted to oppose downward pivotal movement of said reservoir in one: over-center position and accelerate said movement in the other over-center position, and gravity influenced means located in said body of However, sincef'tlie" freer liquid within said reservoir and arranged to travel away from the axis of pivoting of said reservoir and thereby overcome the tendency for said resilient means to oppose downward pivoting movement of said reservoir whereby said overcenter resilient means passes over to the other side of center position and abruptly accelerates said downward pivoting movement of said reservoir.

2. timing device comprising a support, a reservoir containing a body of liquid and pivotally supported on said support, over-center resilient means acting between said reservoir and said support, said resilient means adapted to oppose downward pivotal movement of said reservoir in onev overecenter position and accelerate said movement in. the other over-center position, means for adjusting the force exerted by said resilient means on said reservoir to increase or diminish its influence on the downward pivoting movement of the reservoir, and gravity influenced means located in said body of liquid within saidreservoir and arranged to travel away from the axis of pivoting of said reservoir and thereby overcome the tendency for said resi-lient means'to opposedownward pivoting movement ofsaidreservoir whereby said over-center resilientr means passes over to the other side of center position and abruptly accelerates said downward'pivoting movement of said reservoir,

3. Atiming device comprising a support, a reservoir containing a body of fluid and pi-Votally supported on said support, releasable stop means arranged to limit the. downward movement of said reservoir, over-center resilient means operati'vely connected to said stop means and to said support,l said resilient means adapted to oppose downward pivotal movement of said reservoir in uncover-center position and accelerate said movement in the other over-center position, and gravity' influenced means within said cylinder adapted to travel' away from the axis of pivoting of said reservoirand thereby overbalance said stop means. whereby said resilient means passes to the other side of center position and assistsA said gravity influenced means in abruptly accelerating the downward pivotal movement of said cylinder.

4. A timing device comprising a support,- a reservoir containing' a body of iluid and' pivotally supported on said support, pivotal stop means arranged to retain said reservoir in a position inclined downwardly from the axis of pivoting, overcenter resilient means operatively connected to said' stop means and to said support, said resilient means adaptedl to oppose downward pivotal movement of saidv reservoir in one over-center position and accelerate said movement in the other over-center position, and gravityinfluenced means with said reservoir adapted to travel away from the axis of pivoting of said reservoir and overbal'ance the restraining force exerted by said over-center resilient means on said stop means whereby said over-center resilient means shifts to the other side of center position and produces a downward snap movement of said reservoir.

5L A device for producing timed actuation of a 'control mechanism comprising a, pivotallysupported reservoir containing iluid, pivotal stop means adapted to limit the downward pivotal movement of said reservoir, over-center resilient means connected to said stop means and arranged to oppose downward pivotal movement of the cylinder in one over-center position and accelerate said movement in the other over-center position, control means arranged to' beactuated by the pivotal movement oi said reservoir, and gravity influenced means within said reservoir adapted to travel away from the axis of pivoting of said reservoir and thereby overbalance said stop means whereby said resilient means passes to the other side of center position and produces a downward snap movement of the reservoir which is transferred to said control means as an abrupt actuation thereof.

6. A device for producing timed actuation of a control mechanism comprising a cylindrical reservoir containing liquid and pivotally supported adjacent one end thereof, a rolling member within said reservoir arranged to travel from the supported toward the free end thereof under the influence of gravity, mechanism control means arranged to be actuated by the pivotal movement of said reservoir, a releasable stop member arranged to limit the pivotal movement of said reservoir, and over-center resilient means operatively -connected with said stop member, said overcenter means arranged to oppose the gravitational influence of said rolling member until the eirective leverage of said rolling member and the weight of said reservoir and liquid overbalance the restraining influence of said stop means whereby said downward pivotal movement is abruptly accelerated and said mechanism control means is abruptly actuated.

'7. A timing device comprising a support, a reservoir containing a body of liquid and pivotally supported on said support, gravity influenced means within said reservoir arranged to travel through said liquid toward and away from the axis of pivoting of said reservoir, over-center resilient means operatively connected between said reservoir and said support which opposes downward pivotal movement of the reservoir in one over-center position and accelerates said movement in the 'other over-center position, means for holding said reservoir in an uncooked position inclined upwardly to said axis of pivoting to permit said gravity influenced means to travel toward said axis of pivoting, and releasable latch means for permitting said reservoir to pivot downwardly when cocked to a position inclined downwardly from said pivotal axis whereby said gravity iniluence means travels to a point away from said pivotal aXis where its effective leverage together with the Weight of said body of liquid and said reservoir overbalance said resilient means and cause said resilient means to pass over to the other side of center position and thereby snap said reservoir downwardly to a position below said cocked position.

8. A timing device comprising a support, a reservoir containing a body of liquid and pivotally supported on said support, gravity influenced means within said reservoir arranged to travel through said liquid toward and away from the axis of pivoting of said reservoir, over-center resilient means operatively connected between said reservoir and said support which opposes downward pivotal movement of the reservoir in one over-center position and accelerates said movement in the other over-center position, means for holding said reservoir in an uncooked position inclined upwardly to said axis of pivoting to permit said gravity iniluenced means to travel toward said axis of pivoting, and releasable latch means for permitting said reservoir to pivot downwardly when cocked to a position inclined downwardly from said pivotal axis whereby said gravity iniluence means travels to a point away from said pivotal axis where its effective leverage together with the weight of said body of liquid and said reservoir overbalance said resilient means and cause said resilient means to pass over to the other side of center position and thereby snap said reservoir downwardly to a position below said cocked position, and means for automatically returning said reservoir to the said uncooked position after it has been snapped downwardly by said over-center resilient means.

9. A timing device comprising a support, a reservoir containing liquid and pivotally supported on said support, mechanism control means arranged to be actuated by said reservoir as it pivots to its most downwardly position, a pivotal stop member of restricted movement, overcenter resilient means acting between said support and said stop member and tending to hold said reservoir in a position downwardly inclined to the pivotal axis thereof, and gravity influenced means within said reservoir adapted to travel away from its axis of pivoting and thereby overcome the tendency for said resilient means to hold said reservoir in said downwardly inclined position whereby said over-center means passes to the other side of center position and allows said reservoir to freely pivot downwardly under the influence of said gravity iniluenced means thereby gathering momentum and abruptly actuating said controlmechanism as it reaches its most downwardly position.

THOMAS H. SHEEHAN.

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