US2938968A - Arrangement for a contact switch - Google Patents

Description

May 31, 1960 A. sALzER ARRANGEMENT FOR A CONTACT SWITCH 6 Sheets-Sheet 1 Filed Dec. 4, 1956 k m n S w E m n mm? Ag u May 31, 1960 A. sALzER ARRANGEMENT FOR A CONTACT SWITCH 6 Sheets-Sheet 2 Filed Dec. 4, 1956 Inverrgar:

May 31, 1960 A. SALZER ARRANGEMENT FOR A CONTACT SWITCH 6 Sheets-Sheet 3 Filed Dec. 4. 1956 WII ALBERT $41.25

INVENTOR ATTORNEY May 31, 1960 A. sALzER ARRANGEMENT FOR A CONTACT SWITCH 6 Sheets-Sheet 4 Filed Dec. 4, 1956 HIHHII flLBERT 541 ZEIQ INVENTOR ATTOR NEY May 31, 1960 A. SA'LZER ARRANGEMENT FOR A CONTACT SWITCH 6 Sheets-Sheet 5 Filed Dec. 4, 1956 4105a? SmzE/e by a/ENT R ATTORNEY May 31, 1960 A. sALzER 2,938,968

ARRANGEMENT FOR A CONTACT SWITCH Filed Dec. 4, 1956 6 Sheets-Sheet 6 Int anion United States Patent ARRANGEMENT FOR A CONTACT SWITCH Albert Salzer, Geisweid, Germany, assignor to Friedrich Uhde G.m.b.H., Dortmund, Germany Filed Dec. 4, 1956, Ser. No. 626,218

Claims priority, application Germany Dec. 17, 1955 2 Claims. (Cl. 200-18) The invention relates to an arrangement for a contact switch composed of a plurality of partial switches, particularly for controlling contacts having large contact surfaces for high current intensities, for example 20 to 130,000 or more amperes, in electrolytic cells to be shortcircuited. It is well-known that direct-current of low voltage but very high current intensity flows through electrolytic cells, which are usually connected in series .in relatively large numbers.

and these necessitate considerable closing forces if a .low loss switching process is to be obtained.

Contact switches of this kind, which are composedof a' plurality of partial switches, have been disclosed.

The hitherto known constructions of such contact switches have the disadvantage however that all the partial switches forming the contact switch haveto "be operated independently of one another but at the same time, whereby it is necessary, for example when an electrolytic cell containing four electrolyte elements is to be short-circuited, to operate a separate partial switch for each of the electrolyte elements, an operator beingrequired for each of these and the operators having to operate the individual partial switches on command.

Since relatively great closing forces are required for controlling such contact switches, it has not hitherto been possible to bring a plurality of partial switches of a contact switch into force-closed switching connection with one another in such manner that all the partial switches to be operated can be operated from one point.

The present invention provides an arrangement which enables a plurality of partial switches forming a contact switch to be controlled from one point, and in which the aforesaid disadvantages are avoided primarily by providing a control linkage between the partial switches and the driving device actuating'the contact switch, said linkage being connected to each of the partial switches through at least one coupling which produces synchronous operation of the partial switches even when the axes of the partial switches are considerably out of alignment relative to one another and even when longitudinal movements of. the structural parts of. the switches occur during operation in the direction of said axes, for exampleas a result of thermal expansion.

In' further development of the principle of the in- "ice allowing movements of said shaft portions in the direction of said axes.

According to another feature of the invention, it is proposed that the couplings for the individual shaftportions forming the switch shaft be formed by flanges provided at the ends of said shaft portions or in forceclosed driving connection with the latter, and by spring bodies which are in each case mounted in a plurality between the flanges of adjacent shaft portions and which are combined to form a flexible coupling or connecting member. In this case it is advantageous according to the invention to make the coupling flanges long in relation to their width, the flanges of adjoining shaft portions being held so as to be in each case turned through 90 relative to one another in their longitudinal direction on opposite sides of a flexible connecting member forming an annular body, in such manner that amultiple-cardanic connection of the individual shaftportions to one another is effected, whereby if any of the individual partial switch axes are not in line with one another the shaft portions can perform a deflection movement relative to one another without thereby obstruct- .ing synchronous operation of the partial switches.-

Another further development according to the invention comprises bringing the individual shaft portions or their coupling flanges into force-closed connection with the flexible connecting or coupling members by screws or similar detachable connecting elements, each of the individual shaft portions forming the switch shaft being in force-closed driving connection through tongues and grooves so as to be movable in its axial direction with at least one of the coupling flanges provided at each of its ends. The individual shaft portions are at the same time capable of performing longitudinal movements, occurring during operation for example as a result of thermal expansion, relatively to said coupling flanges without obstructing the synchronous operation of the partial switches. a

According to another feature of-the invention it is proposed to bring the adjoining shaft portions of the switch shaft, insulated from one another, into operative connection with the corresponding coupling or connecting members, laminated bodies of insulating material, for example of hard paper, being held in each case between the coupling flanges and the flexible coupling or connecting members of the couplings and between the screws-or the like connecting the coupling flanges to the flexible coupling members.

Furthermore, according to the invention it is advantageous to form each of the flexiblecoupling or connecting members from leaf springs in the form of circular rings, of which a plurality are superimposed and combined to form a spring packet, which is capable of taking bending stresses about axes extending in'or parallel to the plane of the ring or spring packet.

A furflier development according to the invention moreover consists in that the switch shaft comprising a plurality of shaft portions connected together by conplings is brought into operative connection with the movable switch contact banks of the individual partial switch forming a contact switch, through toggle lever transv missions in each case and that the driving device for the switch shaft operating the partial switches of the contact switch is a hand lever, the switch'shaft being in operative connection with means which can assist or bring to an end the operating movement of the switch shaft initiated by the driving device. i

For the structural construction of the present invention, it is proposed that the means supporting the switch shaft movement should be springs which can act at least on the ends of the switch shaft through lever arms in operative connection with the latter, said springs being capable of imparting a torque to the switch shaft.

Finally, according to the present invention it is proposed that the switching path of the movable switch contact banks of each partial switch forming the one contact switch and/or of the individual switch contacts of each of the switch contact banks be adjustable and displaceable relative to the fixed contact bars associated with them and to the toggle lever transmissions operating the partial switches, and also to the switch shaft in driving connection with said transmissions.

The invention will now be described in greater detail with reference to the drawing illustrating the same by way of example and in which:

Figure 1 is a diagrammatical illustration of a control arrangement constructed according to the invention, for contact switches comprising a plurality of partial switches.

Figure 2 also diagrammatically illustrates in side elevation the control arrangement according to the invention in operative connection with a contact switch.

Figure 3 shows the arrangement of the control arrangement shown in Figure 2, but in an intermediate working position.

Figures 4 and 5 show the coupling used in the control device according to Figures 1 to 3, for the individual shaft portions on a larger scale.

Figure 6 shows the contact switch illustrated in Figures 2 and 3, on an enlarged scale and is a view on the line 66 of Figure 7.

Figure 7 is a sectional view on the line 7-7 of Figure 6.

Figure 8 is a view looking in the direction of the arrow 5 of Figure 6; and

Figure 9 is a modification of the hand lever in comparison with that used in Figure 1.

In Figure 1 of the drawing is illustrated a contact switch A, which is used for example as a bridging switch in electrolytic cells. The contact switch A is split up into a plurality of partial switches according to the number of electrolyte elements provided in the electrolytic cell in question, namely four partial switches A A A and A in the exemplified embodiment illustrated, and said partial switches are provided at relatively great distances from one another according to the intensity of the current fed to the electrolytic cell. Thus in the case of a current intensity of 50,000 amperes the partial switches A toA of a contact switch A are provided at distances of about three metres from one another.

A control arrangement by which synchronous operar tion of all the partial switches A A A and A forming the contact switch Acan be effected is shown in Figures 1 to 3 0f the drawing.

Said control arrangement comprises a control linkage I -1 and 3 to 8, which comprises a switch shaft 1, which is formed by a control shaft or a shaft portion 3 in each case for each of the partial switches A to A and by a plurality of connecting shafts or connecting shaft portions 4 holding said control shaft portions 3 of the individual partial switches A to A in driving connection with one another; and a plurality of lever transmissions 6, 7, which bring the switch shaft 1 into operative connection with the individual partial switches A to A and a driving device 8 which transmits is control movement to the switch shaft 1.

As will be seen from Figure l, the individual control shaft portions 3 are in each case held in two bearings 2 disposed on each of the partial switches A to A while each of the connecting shaft portions 4 of the switch shaft 1 is provided between two control shaft portions 3 mounted at a distance from one another in the axial direction in the bearings 2 of the individual partial switches A to A The connecting shaft portions 4 are at the same time in force-closed rotary driving connection at each of their shaft ends through a cardanic coupling 5 with the shaft ends of the control shaft portions 3. The individual couplings 5 are at the same time arranged in such manner that they transmit with the greatest accuracy a rotary or partial rotary movement of the switch shaft 1 over its entire length to all the shaft portions 3, 4, but at the same time allow deviations in the alignment of the individual axes of the shaft portions 3, 4 of the switch shaft 1 and movements of the shaft portions 3, 4 in the direction of said axes. By the cardanic coupling of the individual control shaft portions to one another, with the interpositioning of the connecting shaft portions 4, it is achieved that the control of the individual partial switches A to A can be effected without great expenditure of force and synchronously in spite of the relatively high closing forceswhich are required for each individual partial switch-and even when the individual control shaft portions 3 do not lie in one line. Since the connecting shaft portions 4 of the control shaft 1 are held between the control shaft portions 3 of the latter only by the cardan couplings 5 and are not in special bearings, said connecting shaft portions 4 can be adapted to all deviations of the individual control shaft portions 3 from alignment as occur in practice.

As will be seen particularly from Figures 2 and 3 of the drawing, lever arms 6 are provided on the switch shaft 1 or on its control shaft portions 3 in each case in the region of the partial switches A to A of the contact switch A and are in force-closed driving connection with said shaft 1 or control shaft portions 3. One end of a lever arm 7 is articulated to the free ends of each of said lever arms 6, the other end of said lever arm 7 being pivotally connected to the movable banks a of switch contacts of each of the partial switches A to A All the lever arms 6 and 7 in driving connection with the switch shaft 1 form toggle lever transmissions 6/7 which, on a rotary or partially rotary movement of the switch shaft from left to right, impart to the switch contact banks a associated with said transmissions in Figures 2 and 3 of the drawing, a rocking movement away from the banks of contact bars b associated with them, and on the reverse rotary or partially rotary movement of the switch shaft 1 a rocking motion towards the banks b of contact bars.

Figure 2 of the drawing shows the contact switch A and the position of the control arrangement associated with it when the contacts a and b are closed, in side elevation, while Figure 3 shows the same contact switch A with the contacts a and b open and the corresponding position of the control arrangement associated with said contact switch.

In Figures 1 to 3 of the drawing the driving device provided for the control linkage 1 and 3 to 8 is a hand lever 8 which is in force-closed driving connection with the switch shaft 1 at a suitable place, for example at the head end of the electrolytic cell.

Since, in controlling a contact switch A for high current intensities, for example 20,000 to 30,000 or more amperes, the formation of a continuous are between the switch contacts A and the contact bars b must be avoided as far as possible, a high closing and/ or opening speed of the individual partial switches A to A is necessary.

Although an adequately high closing and/or opening speed of the partial switches A to A is obtained with the hand lever control arrangement according to the invention, steps are taken to increase the speeds of closing and/ or opening of the contact switch A still further.

To this end, lever arms 9 are provided at the ends of the switch shaft 1 and should extend at least in the same direction as the hand lever 8 but preferably, seen in Figure 1 from the front and in Figure 2 from the right, extend inclined rearwardly and upwardly away from the axis of the switch shaft 1. Helical tension springs 10 act in each case on said lever arms 9, and when the hand lever is in its top dead centre position (with the contact leaf spring packet 50 through screws e. connection of the coupling flanges 5a, 5b to the flexible s'witeh'A closed) try to impartto the switch shaft 1 "a torque to the left (Figure 2), whereby there is imparted to the switch contact banks a of the individual partial switches A to A a pressure force which is directed onto the contact bar banks b of said partial switches A to A. If the hand lever 8 is moved to the right out of its top position (Figure :2) until the top dead centre of the lever 9 has been overcome, the helical springs 10 impart a torque to the right to the switch shaft 1 through the levers 9, whereby the switch shaft 1, without the hand lever 8 having to be further operated, performs a partial rotation to the right at high speed, so that the contact switch a thus opens automatically.

The couplings 5 which hold the control shaft portions 3 in force-closure with the connecting shaft portions 4 consist in each case, as shown in the exemplified embodiment in Figures 4 and 5, of two coupling flanges 5a, 5b

and a spring packet 50 of leaf springs 5d of circular annular shape held between said coupling flanges 5a, 5b.

The shape of the latter is long in relation to their width and said coupling flanges 5a, 5b are turned through 90 'in their longitudinal direction relative to one another on opposite sides of a packet of leaf springs 5c in each case and are in force-closed connection with the corresponding The crosswise coupling or connecting member 5f gives a coupling element which transmits rotary movements with the greatest accuracy to the shafts 3, 4 coupled together, but which at the same time allows deviations from alignment of the individual coupled axes of the shaft portions 3, 4.

The coupling flanges 5a, 5b are held at the ends of the shaft portions 3 4 in such manner that at the one shaft tions 3, or 4, and is connected by force-closure to the shaft portions 3 or 4 through grooves 5' and tongues 5". The longitudinal movability of the shaft portions 3 or 4 relative to the coupling flanges 5a enables longitudinal movements of the individual shaft'portions 3 or 4 relative to their coupling flanges as occur during operation of the switch for example as a result of thermal expansion, to be performed without the switch shaft 1 thereby being bent and synchronous control of the contact switch A prevented.

In order to prevent there being any connection via the switch shaft 1 through which current could flow between the contact banks a of the individual partial switches 'A to A laminated bodies 11, 12, 1 3 of insulating material, for example hard-paper, are provided at the surfaces of contact between the coupling flanges 5a, 5b and the spring packet 50 and at the surfaces of contact between the screws 5e connect-ing the coupling flanges 5a, 5b to the spring packet 50, and prevent current from passing from one of the shaft portions 3 through a shaft portion 4 to another shaft portion 3.

While the control shaft portions 3 of the switch shaft 1' are advantageously of solid construction, the connecting shaft portions 4 are of tubular or hollow construction.

In order to be able to adapt the switch contact banks a of the individual partial switches A to A of the contact switch A or all of their individual contacts to the predetermined switching path, the switch contact banks a and also the individual switch contacts of said switch contact banks are adjustable, 'by way of special adjustment devices 14 and 15, with respect to the associated toggle lever transmissions 6, 7, the switch shaft 1 and the individual contact bars b of each of the partial switches A to A While the switch contact banks a are displaced as a unit by the adjustment device 14, the individual switch contacts of the switch contact banks a can 6 be adjusted by the adjustment device 15. The adjustment device 15 of each switch contact of the switch contact banks a comprises four screw bolts 15 which have at their front ends a square extension over which a hand lever can be placed, by means of which said screw bolts 15 are adjustable independently of one another. The adjustability of the individual switch contacts renders it possible to adapt the contact plane of the latter exactly to the contact plane of the contact bars associated with them, so that the available contact surface of the contact switch A is completely utilised.

The following is a more detailed description of these adjusting means:

The control shaft sections 3 of the switch shaft 1 are rotatably mounted on both sides of the component switches A to A in a socket 40 which is secured through a screw-and-nut connection 20 to a fixed holder 21. Due to the screw-and-nut connection 20, the contacts b are secured at predetermined positions in relation to the holder 21. Angle pieces 24 are fixed to the holder 21 beneath the contacts b on opposite sides of each com ponent switch A to A by means of screws and nuts 23, each of these angle members pivotally supporting a single-armed lever 26 by means of a pin 25. The free end of each of the levers 26 is engaged with one of the elbow levers 7, by a pivot pin 41, which can be rocked by means of the levers 6 fixed on the control shaft sections 3 when the control shaft is rotated. Arranged on the free end of each lever 26 is a screw bolt 14 which extends at right-angles to the length of the lever and which carries several nuts 28. A U-section member 29 is so arranged between these nuts 28 that it connects the two levers 26 of each component switch A to A in the region of the pivot 41 of the elbow lever 7.

In order that contact switches for high current intensities all contact surfaces of all component switches A to A can be brought absolutely simultaneously and mi formly over their entire surface into and out of the contact position, so as to avoid overloading of individual contact surfaces, it is proposed according to the invention that each one of the movable contact surfaces a of a component switch A to A should be connected through a spring how 30 to the U-section member 29 connecting the two levers 26 of one component switch. Each of the spring bows 30 is fixed by means of a screw 36 to the U-section member 29, while four setting screws 15 are arranged symmetrically around the screw 36. The ends of the screws 15 project through member 29 into contact with bow 30 so as to determine the spacing between member 29 and the adjacent leg of the bow 30. All movable contact surfaces a of a component switch A to A* can be jointly aligned relatively to the fixed contact surfaces b by the U-section member 29 being displaced by means of the nuts 28 on the screw bolt 27. Bythis means, it is possible substantially to establish the contact pressure of the contact surfaces in the closed position at all places of the component switch. The accurate alignment of each one of the movable contact surfaces va relatively to the fixed contact surfaces b, so that all contact surfaces of the component switches A to A forming the contact switch come into and out of the contact position simultaneously and uniformly over their entire surfaces, is achieved by the fact that each movable contact a is adjusted through its spring bow 30 by means of the setting screws 15. Thereby, each movable contact a can be brought independently of the others into such a position that it can be adapted to the prescribed switching movement relatively to its associated fixed contact B, even with deviations in alignment between the individual component switches A to A and also with inaccurate alignment of the fixed cont-acts b of any component switch. When the contact switch A is actuated,

all switch contacts of the component switches A to A are simultaneously brought either into the contact-making or contact-breaking positions, whereby overloading of separate switch contacts because of too heavy passage of current is effectively avoided.

Secured between the spring bows and the movable contacts a by means of the screws 31 are the current supply lines 32, which consist of a yieldable metal which can participate as often as required in the movements of the level 26 without becoming broken. Fixed to the end of the spring bow E30 by means of a screW-and-nut connection 33 is an arcing contact 34 which is bent to substantially Z-shape and also consists of resilient material of good conductivity. A supporting component 35 which supports the arcing contact 34 after a specific spring travel and lifts from the contact b in question is also held by the screw-and-nut connection 33.

Figure 9 of the drawing shows a hand lever control device for the switch shaft 1 or control linkage 1 and 3 to 8, which differs from the hand lever control device shown in Figure 1 essentially in that the hand lever 8 is disposed not at the head end of the electrolytic cell, but at one of its long sides. this hand lever 8 is in this case transmitted through a bevel gear 16 to the switch shaft 1, which extends at an acute angle or at right angles to the rocking axis of the hand lever 8. Such a hand lever arrangement is advantageously used when there is no room at the head end of the electrolytic cell to fit or provide the hand lever control device.

It is still within the scope of the present invention that if the control linkage 1 and 3 to 8 used is not the switch shaft 1 rotatable or partially rotatable about its longitudinal axis, but a control linkage movable in its longitudinal direction and which can also comprise a plurality of individual linkages, which are connected by couplings in such manner that their control movement is transmitted with the greatest accuracy to the partial switches of the contact switch while all the other additionally occurring movements of the control linkage are taken by said couplings.

I claim:

1. In an electrical switch apparatus having a series of switches operated simultaneously by a common operating member, the provision of an operating shaft member for operating each switch, toggle devices at least one for each switch and operatively connecting each switch with its operating shaft member, an intermediate shaft member between each pair of adjacent operating shaft members, a coupling between each pair of adjacent ends of an operating shaft member and an intermediate shaft member respectively, a lever on at least one of aid shaft operating members, and a spring acting on said lever to impart a torque to the shaft operating members in at least one direction past the dead centre position of the common operating member, each switch comprising at least two movable switch contacts, a corresponding number of fixed contacts, a pivotedly mounted device connected with one of said toggle devices, a mounting member on which said movable switch contacts are mounted, means for carrying said mounting member on the pivotally mounted device and for adjusting said mounting member and movable contacts as a unit on the pivotally mounted de- The control movement of vice towards and away from the fixed contacts, and means for adjusting the movable contacts independently of each other on the mounting member towards and away from the fixed contacts, said pivotally movable device being movable by the toggle device for moving the movable contacts towards and away from the fixed contacts.

2. In an electrical switch apparatus having a series of switces operated simultaneously by a common operating member, the provision of an operating shaft member for operating each switch, toggle devices at least one for each switch and operatively connecting each switch with its operating shaft member, an intermediate shaft member between each pair of adjacent operating shaft members, a coupling between each pair of adjacent ends of an operating shaft member and an intermediate shaft member respectively, each coupling comprising two flanges connected together with a spring plate device between them, means connecting one flange of each said couplings slidably and non-rotatably to the first of said adjacent ends, and means connecting the other flange non-rotatably to the second of said ends, said flanges of each coupling being fixed to the spring plate device at positions offset radially of the shaft member said positions of each flange being spaced apart a greater distance than the thickness of the coupling; the said positions of one flange being olfset angularly with respect to said positions of the other flange, a lever on at least one of said shaft operating members, and a spring acting on said lever to impart a torque to the shaft operating members in at least one direction past the dead centre position of the common operating member, each switch comprising at least two movable switch contacts, a corresponding number of fixed contacts, a pivotedly mounted device connected with one of said toggle devices, a mounting member on which said movable switch contacts are mounted, means for carrying said mounting member on the pivotally mounted device and for adjusting said mounting member and movable contacts as a unit on the pivotally mounted device towards and away from the fixed contacts, and means for adjusting the movable contacts independently of each other on the mounting member towards and away from the fixed contacts, said pivotally movable device being movable by the toggle device for moving the movable contacts towards and away from the fixed contacts.

References Cited in the file of this patent UNITED STATES PATENTS 925,731 Thomson June 22, 1909 1,246,445 Ludeman Nov. 13, 1917 1,298,556 Persson "Mar. 25, 1919 1,322,087 Bogert Nov. 18, 1919 1,483,715 Burns Feb. 12, 1924 1,825,159 Pinkham Sept. 29, 1931 2,354,991 Gussow et al Aug. 1, 1944 2,748,209 Florschutz May 29, 1956 FOREIGN PATENTS 933,063 France Dec. 17, 1947 308,398 Great Britain Mar. 28, 1929

Images