US1488448A - Motor stop or release for electric switches - Google Patents

Description

March as 1924. 1,48 ,443

S. 5. WHEELER MOTOR STOP 0R RELEASE FOR -ELECTRIC SWITCHES Filed Nov. 5 1920 Fig. 1.

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- m S chuyler SX/Vheder, By Attorney Patented Mar. 25, 1924.

PATENT OFFICE.

UNITED STATES SCHUYLER S. WHEELER, BERNARDSVILLE, NEW JERSEY, ASSIGNOR TO CROCKER- WHEELER COMPANY, OF AMPERE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

MOTOR STOP OR RELEASE FOR ELECTRIC SWITCHES.

Application filed November 5, 1920. Serial No. 422,093.

To all whom it may concern Be it known that I, SCHUYLER S. Wrmnu ER, a citizen of the United States, residing at Bernardsville, county of Somerset, and State of New Jersey, have invented certain new and useful Improvements in Motor Stops or Releases for Electric Switches, of which the following is a specification.

Anobject of the invention is to provide a heavy or powerful locking device controlled by a small magnet which, in requiring to be maintained constantly by the line, draws only a small amount of current, and generates only a small amount of heat.

This being one of the objects of the present invention, other objects of which will appear herein, the invention consists of certain features of construction and combinations of parts to be hereinafter described,

and then claimed with reference to the ac compa-nying drawings, illustrating one embodiment of the invention, in which- Fig. 1 is a plan view of the apparatus, partly broken away, and showing the switch locked;

Fig. 2 is a front elevation thereof, showing the switch locked;

Fig. 3 is a sectional view on the line IIL-III, Fig. 4:, showing parts related directly with the. switch; and

. Fig. 4 is a sectional front elevation of parts of the apparatus, showing the posi tion which they assume when the switch is opened.

7 Referring to the drawings, a main-spring 10, like a clock-spring, surrounds and .is

also

fastened to a. shaft 11, which is provided with a handle 12. A bracket or frame 13 is supported upon a slate or other suitable slab 141, and the other end of the spring is secured to said bracket. A member 15 is fastened to the shaft 11 and carries atone end a hammer 16, and the other end is extended as a tail 16 acting as a resetting part. 7

Hammer 16 constitutes the keeper or armature for the magnet 17, which is in a shunt-circuit 17 a connected across the motor line For alternating current, the keeper 16 and the magnet 17 are laminated. Knifeswitches 18, 19, 20 are connected by a bar 21, which is adapted to be locked in circuit-closing position by means of a lat-ch 22 pivoted at 23 to a bracket 24, which is mounted on the slab 14. The operative end of the latch is provided with an anti-friction roller 25, which engages with the bar 21 to lock the knife-switches closed. After the switch is closed the latch 22 will be brought into engagement with the switch-bar 21, and the switch will be kept closed by the presence of the roller 25 in the path of the switch-bar. The knife-switches are provided with means, such as shown, or equivalentmeans, having a tendency to open them, such means as shown consisting of a suitable pressure spring 26, which is mounted upon the slab 14. Means having a tendency to delicately vhold the latch in either the looking or free position, are fully shown in Fig. 3, and consist of two pins 27, 27, carrying rollers 28 and located in a recess 29 of the latch, in which recess enter a pair of flat springs 30, 31, fixed to the bracket 24:. The free ends of said springs, where they enter said recess 29, are provided with smallhumps or projections 32, 33 adapted to bear upon said rollers 28. When the latch is in looking position, in engagement with. the switch-bar 21. the pins 27,27, will be located to oneside of the humps or projections 32, 33, the latter. bearing upon the said pins and the springs 30, 31, being thus freed of tension. When the latch is moved to open position, the springs 30, 31 will first be pressed outwardly and then freed, thus setting the latch to the position shown in Fig. and the pins 27, 27. will be at the opposite sides of the humps 32, 33. Limit pins or stops 34, 35, restrict the degree of moven'ient of the latch.

The apparatus describedis enclosed in a. box 36, with the exception of the operative end of the latch and the handle 12. which is used to latch the switch. To set the parts for locking the knife- switches 18, 19, 20 against their contacts, the operator closes the switches and latches them in closed position by rotating the crank-handle 12 until the tail or re-sett-ing means 16 of the hammer 16 raises the latch. The hammer is then held by the energized magnet 17. It at any time the current in the magnet fails, the hammer 16 will be released and will revolve violently about the shaft- 11, due to actuation by the main-spring 10, and will strike the latch 22, knocking it to the release position, thus releasing the knife-switches under the actuation of the retractor spring 26.

The hammer 16 may be designed to strike the latch with any desired force, whether it be one pound, ten pounds, or a ton, and yet will be held by the magnet 17 by a current of any desired degree of fcebleness, such as 1-100 ampere. This is for the reason that when the hammerhead is against the magnet 17, it is in such a position that its weight is counterbalancing the mainspring 10, while at the moment it strikes the latch 22 its weight is adding to the force of said spring. If the spring has a force say, of one pound, and the hammer head weighs fifteen ounces, it will strike with a weight of one pound and fifteen ounces, plus a hammer-blow, depending upon the length of the arc of travel, as designed, but it will require to hold it in the other position against the magnet only one ounce. The blow of the hammer against the latch is augmented by the momentum acquired by the hammer in swinging. The force of the blow is made larger by lengthenin the hammer-arm.

The principle or the apparatus 1s to make the operator, when locking the switch, store up the desired energy, whatever it ma} be, by turning the hammer crankhandle 12, while the power required by the magnet 17 to hold the hammer remains very small or negligible. In cases of very heavy blow employing a heavy hammer, a weight and rope wound on a drum, like in a large clock, is better than a spring. Also, to use a long spring on the hammer so that it pulls nearly as hard at the moment of striking, and to latch the switch with a latch which is indifferent to the weight ot the switch.

The operator is compelled to bring the hammer up to be held by the magnet, and, incidentally, to wind up the main spring by reason of limiting him to the use of the tail or resetting means 16 of the hammer as the only means he has of setting the latch 22 to hold the switch.

The mechanism described may be used to lock or unlock a valve or other control device instead of a switch.

Obviously, the present invention is susceptible ot' modification, as pars may be omitted. parts added, and parts altered, without changing the scope of the invention as defined in the claims.

hat I claim as new is:

1. In electrical apparatus of the class described, a holding magnet of limited power, means for energizing it, a switch. a latch therefor, setting means for said latch, tripping means, comprising a hammer, subject to the holding power of the cncrgized magnet, when said setting means has operated on said latch to lock the switch, and, when said magnet is dc-energized to release said hammer, permitting the hammer to strike and trip said latch and allow the switch to open, said setting means constituting a tail-extension of said hammer, means for pivotally supporting said hammer and its setting means, and means for subjecting said hammer and setting means to tension when said setting means has locked the switch.

2. In apparatus of the class described, the combination, with an openable and closablc control device having means tending to throw it open, of a balanced latch for said device, having a position such that, when holding said device closed, aforesaid means has no tendency to move the latch, a power-operated hammer adapted to release said latch from said device, and means of slight force for restraining said hammer.

3.111 apparatus of the class described, a latch, having a. securing and a releasing position, a power-operated hammer, and releasing means in addition to the weight of the hammer for restraining the action of the hammer upon said latch.

a. In apparatus of the class described, the combination, with an openable and closable control device having means tending to throw it open, of a latch for holding the device closed by overcoming the tend cncy of said means, spring means having a tendency to urge said latch into its holding posit-ion or its releasing position, and to delicately restrain the latch from moving to either of said positions, a power device, latch-disengaging means operable by the power device, and means independent of the latch for setting said latch to holding position.

5. In apparatus of the class described, the combination, with an openable and closable control device having means tending to throw it open, of a latch for holding the device closed by overcoming the tendency of said means, and having two rollers thereon, and duplex spring means on which said rollers may bear, and having a tendency to restrain said latch from its holding position or its releasing position.

6. In apparatus of the class described, the combination, with an openable and closable control device having means tendin to throw it open, of a balanced latch for said device, having a position such that, when holding said device closed, aforesaid mcans has no tendency to move the latch, a power-o rated hammer adapted to position, a s ring-operated hammer, and release said late from said device, means means in ad ition to the weight of the of slight force for restraining said hamhammer for overcoming the action of said 1 mer, and means for setting the latch to spring restraining the action of the hammer B holding position. upon the latch.

7. In apparatus of the class described, a latch, having a securing and a releasing SCHUYLER S. WHEELER.

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