US2993964A - Spring switch currents of high strength - Google Patents

Description

July 25, 1961 H. HENKEL ETAL 2,993,964

SPRING SWITCH CURRENTS OF HIGH STRENGTH Filed Feb. 17, 1959 2 Sheets-Sheet 1 INVENTORS Heinr'LchHmZ/fld Albert Szlzer" BY/gwwziwzg ATTORNEYS July 25, 1961 H. HENKEL ET AL SPRING SWITCH CURRENTS OF HIGH STRENGTH 2 Sheets-Sheet 2 Filed Feb. 1'7, 1959 ATTORNEYS United States Patent Filed Feb. 17, 1959, Ser. No. 793,869 Claims priority, application Germany Feb. '18, 1958 Claims. (Cl. 200-33) The present invention relates to a switch for currents of high strength in which springs are used for opening the switch. The switches are particularly useful for operating electrolytic cells.

Switches are now known which operate by means of :1V sweeping arrangement, vin which a spring is first put under tension and subsequently released. The proper switching process is brought about with the release of the spring. Attempts have been made to increase the tension of the spring byadditional joints or curved pieces on the side of the switch where the sweeping action occurs in order to enable a rapid manual switching of currents of higher strength. The rapidity of the switching operation is important since the opening are readily burns the contacts so that'the switch would form an electric resistance in the following closed state, depending on the degree of burning. In spite of the aid of joints and curved pieces it has hitherto only been possible to connect currents of lower strength with manual switches.

The present invention provides a device which enables currents of about 100,000 amperes, as are used in electrolytic units, to be switched in an unobjectionable manner. Two springs of spring groups are provided of which each spring or group acts eccentrically upon separate shafts. One shaft is;a drivenl shaft for operating the contacts and the other shaft acts to place a spring under tension through use of a control lever. Both shafts are connected with one another by a claw clutch and betweenthe claws of the clutch a free space is provided which approximately corresponds to the switching or sweeping movement.

It is possible, of course, to turn the driving shaft not only by hand but also by means of an electric motor via a cog-wheel transmission so that the range of the current intensity to be switched can, be further extended.

The-driven shaft between, the clutch and the point of action of the spring may be subdivided into two individual shafts which are connected with one another by a quadruple joint. The quadruple joint advantageously brings about an opposing rotation of the two individual shafts connected therewith. The levers of the quadruple joint attached to the shafts are arranged in such a manner that the rate of the rotary motion of the two shafts is different when the switch is operating.

According to a further feature of the invention, a spring or spring group acts by means of a stirrup upon a point in eccentric position to the shaft of a gear wheel which is fixed by means of a rest. The rest is detachable with a magnet.

In a further variant of the invention, the shaft has the form of a stirrup or a Z and on the deflected part a stirrup for the spring is arranged in turnable manner. This latter form is a simpler form of execution of the device according to the invention. The application thereof is, however, somewhat restricted since said. variant only permits manual switching of currents of lower strength due to the required forces. The advantage of said variant resides in the lower expenditure. Said variant may be further improved by a gear arranged between the control lever and the claw clutch which enlarges the rotary movement of the control lever. This gear may also be used in any other form of execution of the device according to the invention.

The accompanying drawings diagrammatically show the device of the invention.

FIGURE 1 is aschematic view of the entire switch gear installation,

FIGURE 2 shows the installation in another switching position,

FIGURE 3 represents another embodiment of the device according to the invention,

FIGURE 4 is a side view of the embodiment shown in FIGURE 3,

FIGURE 5 is a detail of the above embodiment.

FIGURES 6a and 6b illustrate two different switching positions of the claw clutch.

In FIGURE 1, a shaft 1 is turned by a hand lever 2 with the aid of a jack 3 and a gear wheel 4. Hand lever 2 pivots loosely on shaft 1 while gear wheel 4 is firmly connected with said shaft. Jack 3 comes into close contact with gear wheel 4 by the pressure of spring 5 and it is designed so that it drives gear wheel 4 in the one direction of rotation while it can slide over the teeth in the other direction of rotation. Since the gear wheel is only partially provided with teeth, shaft 1 can also turn in an opposite direction in a reversed switching operation. Laterally and eccentrically to the center of gear wheel 4, a stirrup 6 acts on the gear wheel, a spring or spring group 7 being fixed to the other end of said stirrup.

By turning the gear wheel in the one direction mentioned above said spring 7 is put under tension and in the other direction it is released. Gear wheel 4 and thus spring 7 is held by rest 8 which engages in the gear wheel by the force of a spring 10. Since rest 8 is pivotable round an axis it can be loosened manually or with the aid of a magnet 9. Magnet 9 is fed as occasion demands by an electric line via a switch 12.

At the one end of shaft 1 there is mounted a claw clutch 13 consisting in the present variant of a circular segment 13a attached of shaft 1 and of a claw 13b extending into the opening of the segment with a certain free space. Claw 13b is fixed to a second shaft 11. It is likewise possible, of course, to exchange the clawfor the segment so that the claw is connected with shaft 1 and the segment with shaft 11. From shaft 11 a rotary motion is transmitted by way of quadruple joint 14 to a driven shaft 15 operating contacts 16. Quadruple joint 14 consists of a 3 interconnected levers which are arranged so that the direction-of rotation of the rotary motion is inversed.

In order that driven shaft 13 can operate the contacts under spring pull it is repeatedly bent so as to form stirrups. A spring 17 acts on the first stirrup and to the second stirrup there is attached a bar 18 closing or opening contact 16. At this end the shaft is represented in a manner to show that several contacts can be operated with the switching device. Contact 16 bridges across an apparatus representing in the instant case an electrolytic cell.

In FIGURE 1 apparatus 19 is switched off. Spring 17 is under tension while spring 7 is released. Claw 13b is in its upper resting position, as separately shown in FIGURE 6a. When contact 16 shall be opened spring 7 must be put under tension. This can be achieved readily with hand lever =2 via gear wheel 4. Thus seg ment 13a is deviated and entrains claw 13b with one edge shortly before the one resting position, lifts said claw over its dead-center position and leaves with the other edge enough blank space for the rotation of shafts 11 and 15. The rotary motion of segment 13a is thus somewhat greater than the free space between the claws. The levers of quadruple joint 14 are arranged in a manner such that a small motion of shaft 11 results in a large motion of shaft 15, the field of traverse of the latter thus being enlarged. By this means the stirrup of shaft 15 on which there acts spring 17 is rapidly'shifted and spring 17 opens with its force contact 16. The switching operation being terminated, the switching device occupies-the position represented in FIGURE 2 and the claw clutch has the position shown in FIGURE 6b.

' In order to obtain again the opposite switching position rest 8 is detached from gear wheel 4, whereupon spring 7 is released. Thus segment 13a lifts claw 13b and puts spring 17 under tension since spring 7 has a considerably higher tension than spring 17. By that rotary motion contact 16 is simultaneously closed bridging across cell 19.

The device according to the invention can likewise be designed in different manner. Segment 13a can be replaced by two claw pieces which leave blank about the same angle space as segment 13a. For the switching operation only the edges of segment 13a are necessary. The angle space of claw 13b can also be enlarged at the expense of the angle space of claw 13a. In any case a definite blank space must remain between the claws of the clutch ends.

A further embodiment of the device according to the invention is represented in FIGURES 3, 4 and 5. Spring 7 is replaced by a torsion spring 20 which is put under tension by means of angular axis 21 and rests in casing 22. Gear wheel 4 is replaced by a Z-shaped distortion of shaft 1. The distortion is arranged, however, in a manner such that stirrup 6 is lifted over the dead center when the spring is put under tension and rests against a stop plate 2.3. In order to facilitate the rotary motion, shaft 1 is subdivided and gear wheels 24 and 25 cause step-down gearing. The quadruple joint in the driving shaft after clutch '13 is dispensed with. This embodiment saves much space, particularly as regards the space required for the springs. Since the hand lever cannot be put under tension in stages as shown, for example in the device of FIGURE 1, and the lever must be shifted in one stage, said embodiment is no longer suitable for switching currents of equally high strength. It may serve, however, for connecting currents of somewhat lower strength with considerable reduced technical expenditure.

We claim:

1. A switch operating mechanism comprising a pair of cooperating first and second gear wheels, a torsion spring device operatively connected to the first gear wheel by a lever arrangement and urging said gear wheel to rotate in one direction about its axis, said lever arrangement consisting of a crank pin connected with said torsion spring and joined by a bar with the crank shaft of said gear wheel, actuating means operatively connected with said crank shaft of the gear wheel for moving it in the opposite direction thereby tensioning the torsion spring, a crank switch shaft, switch means eccentrically connected with said shaft and operated by the rotation of said shaft, connecting means between said shaft and the second gear wheel consisting of a 10st motion coupling, resilient means eccentrically acting on said switch shaft and tensioned by the lost motion coupling as the coupling moves up to its dead-center position, said resilient means being weaker than the torsion spring so that on release of the torsion spring it rotates the gear wheels and the switch shaft to close the switch means against the action of the resilient means, said resilient means being eifective after the lost motion coupling is moved by the second gear wheel beyond its dead-center position to actuate the switch shaft and open the switch means during lost motion movement of the coupling.

2. A mechanism as claimed in claim 1, wherein said actuating means comprises a hand lever fixed on the crank shaft of said first gear wheel so that reciprocation of the lever advances the gear in corresponding directions and simultaneously effects the tension and release of said torsion spring.

3. A mechanism as claimed in claim 1, wherein the gear wheels between said actuating means and the lost motion coupling consists of two cooperating gears of difierent diameter to effect an increase of the driving rotary motion.

4. A mechanism as claimed in claim 1, wherein the bar of said lever arrangement connecting the crank pin of the torsion spring with the crank shaft of the first gear wheel is blocked by a limit stop when, by tensioning the torsion spring, the said crank shaft moves up to its dead position.

5. A mechanism as claimed in claim 1, wherein said lost motion coupling comprises a pair of dogs, the first of which is carried by the second gear wheel and the second of which is connected with the switch shaft, at which the lost motion between the dogs approximately is corresponding to the switching movement of the switch shaft.

References Cited in the file of this patent UNITED STATES PATENTS 2,290,198 More July 21, 1942 2,401,801 Seese June 11, 1946 2,851,560 Billeter Sept. 9, 1958 2,680,164 Lennox June 1,

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