US2696553A - Electric switch - Google Patents

Description

Dec. 7, 1954 A. BROWN ErAL ELECTRIC SWITCH 6 Sheets-Sheet l Filed Jan. 8, 1949 fl T TOF'NEY Dec. 7, 1954 A. BROWN ETAL 2,696,553

` ELECTRIC SWITCH Filed Jan. 8, 1949 6 sheets-sheet 2 @WMV /QL Dec. 7, 1954 A, BROWN ETAL 2,695,553

ELECTRIC SWITCH Filed Jan. 8, 1949 e sheets-sheet s ATTORNEY' De- 7, 1954 A. BROWN ETAL 2,696,553

ELECTRIC SWITCH Filed Jan. 8, 1949 6 Sheets-Sheet 4 TTOZP/VEY Dec. 7, 1954 A, BROWN ErAL ELECTRIC SWITCH 6 Sheets-Sheet 5 Filed Jan. 8, 1949 U WkOQ.

l Y WKDQQ Dec. 7, 1954 A. BROWN rs1-AL 2,696,553

ELECTRIC SWITCH Filed Jan. 8, 1949 6 Sheets-Sheet 6 v Q Q Q QJ Lk O fn 2' N F/G/Oa. F/G/Oc. 42 42 g LD' l l INVENTORS A TTOFNEY United States Patent C ELECTRIC SWITCH yAndrew Brown and Denis Alexander Tomlin, London,

Application January 8, 1949, Serial No. 69,882

Claimsvpriority, application Great Britain January 22, 1948 1 Claim. (Cl. 246-434) The invention is concerned with electrical switches.

The main feature of the invention is an electric switch comprising a number of contact sets and means for selecting and operating any one or any combination of the contact sets, wherein selection of a contact set or sets to be operated is carried out without disturbance of any contact set.

One possible application of this type of switch is for use in railway signal and/or points control systems of the kind using multi-position motor-driven rotary control switches for controlling the selection and setting up of any one of a number of diierent routes outgoing from a particular position as described in the U. S. Patent 2,241,906 which was vissued on May 13, 1'941. Such systems require less apparatus than alternative relay systems and each switch can accommodate manycontacts and can be used for a number of routes equal tothe number of positions to which it can be set.-v This has been done by having a rotor, carrying a number of cams, being arranged to stop 1n a number of different angular positions. These different positions are allocated to -ditcrent routes, and the cams are cut to give the desiredcontact arrangement in each position. The routes which conflict with one another are allocated to positions on the same switch and interlocking between them isV automatic, since the. rotor can be in only one position' at ay time. However, conflict between routes on different switches cannot usually be avoided. Previous. switches of the kind described have had certain disadvantages. In passing from the home or normal position of the rotor to say position 5, positions 1-4 must be passedl through. These positions may have been: allocated to routes which conllict with routes already setup on other switches. Prod vision. has therefore had to be made so that when the first switch passes through these conicting route positions it does not break down the routesf set upl on the other switches. A-t ther same time itl has had to be arranged that if, by some fault, the first switch should stop in any of these conflicting route positions, noy dangerous condition will arise. Further disadvantageshave been, (1) that a switch could stop by fault between two route positions, (2) the rotor assembly has had to belv specially made for every particular switch, and (3,) that a change in a circuit or interlocking required the removal of the switch rotor and alteration in the'. cutting of the cams.

A switch, according to the present invention, while achieving. the economy of spaceY and contacts. of the motor-driven. multi-position switches', has none'- of: the above disadvantages when used in. railway' signalling systems. g

The invention will be particularly described in relationk to two embodiments thereof shown in theaccompanying drawings, in which:

Fig. 1 showsV an elevation, part sectionedf, ofva switch according to the first embodiment;

Fig. 2 shows a diagrammatic elevation of the switchy shown. in Fig. 1 from a viewpoint' at ,right angles t'o thatused for Fig. 1;

Fig. 3 shows schematicallyv circuits for the driving andpositioning camsA of the switchshown; inthe previous two figures; l

E ig.. 4v is: a diagrammatic elevation' of a switchv according to. the. second embo'dimentlof thel invention;

Fig.. 51? illustrates diagrammatieally the methodn adoptedE 2,6 6,553 ice 9 Patented Dec. 7, 1954 2 in this second embodiment for ensuring the engagement of one of the Code bars with the contact sets, whilst` Fig. 6 shows in some detail, part of the operating method outlined in Fig. 5, this view being of a limited nature, only three selecting bars and one cfode bar being included;

Fig. 7 is a section on the line X--X of Fig. 6;

Fig. 8 shows in schematic form the circuit arrangements for the switch forming the subject of Figs'.` 4-7,

Fig. 9 shows a diagrammatic elevation of a modified switch of the same general kind as shown in Fig. 4, Whilst Figs. 10A to 10D show dilierent positions which may be taken up by a latch forming an important 'part of this modified switch.

The general operating arrangements of the switches according to three embodiments of the invention will now b e described. In the tir'st, the motor-driven rotor of prior art switches as shown for instance in U. S. Patent No. 2,260,292 is retained, but instead of cams, it has a rotor, around which are attached a number of code bars extending parallel to the axis of the' rotor and spaced around the periphery thereof, each having a distinctive cut in the free end thereof. The code bars are so placed that in each of the route positions one of the bars can engage with a predetermined number of contact sets in accordance with the distinctive cut in the ends of the code bars. A prime mover and cams are associated with the rotor to drive it into and prove its position. This having been proved, a solenoid, motor-driven cam or other' eleci trically operated mechanism causes relative movement between the rotor and the contact sets.- Acco'rding toV how the code bar is cut, a predetermined selection of these contact sets is operated. Therefore, any4 desired contact' set or combination of contact sets may be operated in each of the route positions,

The code bars are made easily detachable so that eachcan be removed and its cutting altered without interfering with the use of the switch in the remainder of its route positions. Since the solenoid or other mechanism is not operated untill the rotor .is in the exact position desired, passing through other route positions hasl no effect on the contacts, and can be ignored from an inter; locking point of view.

In the second form of the switch, no rotor is used and the code bars are in parallel slides. They are individually selected by electromagnets, and lifted to operate the contacts by solenoids, motor-driven cams, or other means'. This second arrangement has the advantage of being quicker operating than the first switch utilizingthe rotor.-

In Figs. 1 and 2 aswitch of the rotor type is shownV with its rotor 1 mounted on a shaft 1A together with 7 double-sided cams 2- 8l along with one part 9A of a magnetic clutch indicated generally at 9'. The shaft l-A is rotatably mounted in twobearings 10, said bearings being carried on pivoted arms 11 joined together toform the armature cooperating with ay magnet 1-2'-, In Fig. 2 the rotor is shown as' having sixpcode bars 13, one of them being immediately' beneath the insulating studs 14I of the Contact sets 1'5. When the magnet 12in energized, the rotor is raised and the-uppermost code bar 1'3 is brought into `engagement" with the" insulated studs of certain of the contact sets. Where the code bar has` been cut away the insulated studi 14 is not contacted and contacts 15 remain unoperated, but where the code bar' has been left the contacts are operated. This is clearly shown in` Fig'. l.

If it is desired to operate the route allocated to position A of the rotor, the circuit' is ma'de over the contacts` of the route switchl and other appropriatey switches- (not shown) to prove that no' coniiicting route has been' set up and from thereto thevwipersof cams 3l and 6 simultaneously. The cams 2. 8f consist of suitably cut discs' 2e', 2f 8e, 8f of copper or bronze rivetted to'insulatedy discs 2b 8b, r'espectively'as-shown inx Fig. l. Thecam surfaces'e and f therefore form one unit 6 in` electrical contact with eachother. AA contact is made between the three camy units 6- and 6a, 7- andv 7a, 8i and 8a, by means* of' metallic rin'gsl1'6 between them; Separate wipers 2c', 2d, 3c, 311,746, 4d, 5e, 6c, 6d, 7c,7d, are provided for' corresponding cams. Anladditionallwiper 17 istil-evicted to complete the circuit to relay ZR. If the cani 6 is in the position shown in Fig. 3, which position corresponds to route A, it will be seen that a circuit is made for relay ZR via battery, winding of relay ZR, wiper 17, metallic ring 16, contact surface of cam 16, wiper 6c, lead A, route allocation selector switch (not shown), positive battery. Relay ZR having operated, the clutch coil 9 is energized over positive battery zr1 front coil 9, to negative battery (Fig. 3). When the clutch is energised it attracts to it a clutch armature plate 18, which is held by a spring spider 19 connected to part 9a on the rotor shaft. The main shaft is driven by an electric motor (not shown), and drives the magnet coil portion 9b of the clutch through gears 21. The main drive motor may be either continuously running or started by the operation of a contact (not shown) controlled by the ZR relay. When the clutch armature plate 18 is attracted by the energised rotating magnet coil, friction between surfaces is suicient to drive the rotor. This continues until position A is reached, when the circuit for relay ZR is broken by the insulating segment on cam 6 as shown in Fig. 3. The cam 2 is used to continue the drive after relay ZR is released, until the rotor is accurately positioned. When the clutch coil 9b is deenergised the armature 18 is released, and the drive to the rotor is broken, so that the rotor stops in position A. With the rotor in this position a circuit is made for relay ZCR over cam 3, as shown in Fig. 3, and the relay is operated via negative battery, winding of relays zcr, wiper 17a, negative battery, contact surface of cam 3, wiper 3c, lead A, route selecting switch (not shown), positive battery. Cams 3/5 are assembled similarly to the cams 6/ 8. When relay ZCR is operated a circuit is provided for the contact operating magnet 12 via: positive battery, contact zcrl; winding of magnet 12, negative battery, causing the magnet 12 to attract its armature, and in so doing to lift the whole rotor 1. When the rotor is lifted the code bar 13 is engaged with the insulated studs 14 of the contact sets, thus operating a particular combination of the sets. All the contact sets shown are make contacts, but break or changeover contacts can be used when required.

A switch constructed according to the second embodiment of the invention, the parallel slide-bar type is the subject of Figs. 4-8, Fig. 4 showing an assembly of selecting and code bars. Resting along the top of the code bars 13 are the contact levers 22, which operate the contact sets 15. The lifting arms 23 are raised by cams or eccentrics (as at 24) and are pivotted so that their motion is parallel to that of the contact levers 22. The

code bars 13 and the selecting bars 25 are assembled together with separating guides 26 in a box (see Fig. 7), so that the selecting bars 25 can be moved longitudinally in a direction normal to the plane of the paper and vertically and the code bars 13 vertically only. The lifting of a selecting bar raises its associated code bar. The sets of code and selecting bars are separated by the thin sheet-metal guides 26 which are anchored so that they only have a small amount of side-play.

When a selecting bar has been operated, that is, moved longitudinally, its engaging detents 27 become positioned above the lifting arms 23 (Fig. 5), so that the raising of the lifting arms raises the selecting bar and its associated code bar. The selecting bars which are not operated have their clearing detents 28 above the lifting arm, so that the raising of the arm does not aect them.

Since the lifting arms 23 Vand the contact levers 22 are parallel, the latter are lifted by the same amount, no matter which pair of selecting and code bars acts as the link between them.

Fig. 6 shows in greater detail the method of operating the selecting bars. The selecting bars each have cut away from them a number of similar notches 29. The notches except for one different one of each bar, are equally spaced. This different notch in each case is displaced to the right, and no bar has the notch in the same position displaced. A switch to handle l2 routes will therefore require 12, 12-notch selecting bars, and 12 code bars. Cams 30 are engaged with the notches so that when a cam is turned through 90 all the notches in that position are brought into line as shown at the central notch in the figure. This brings all except one of the selecting bars into the unoperated position. The selecting bar that has a displaced notch in that position is however moved to the left as is indicated by dotted lines, so that its engaging detents 27 are above the lifting arms 23.

Each selecting cam is operated by its own electro magnet 31, 32, 33 through cooperating armatures 31a 33a to which are coupled linkage levers 31b 33b, respectively.

The stop arm 34 prevents any selecting bar from being lifted unless it is in the operated position; a bar in the operated position allows the stop arm to drop into a cooperating slot 35 adjacent one end of selecting bar 25, which slot is provided for the purpose.

Electrical contact cams are provided on the same shaft as the lifting cams or eccentrics but are not shown in the drawing. These cams are similar to those described for the rst embodiment. Some are used to drive and position the lifting cams, while others are used to isolate the selecting magnets when the lifting cams are operated. In Fig. 8 only there are indicated the contacts which are required to close when the selecting cams are operated.

If it is desired to operate route A (see Fig. 8) a circuit is provided from the route key via the contacts of other interlocking switches to cam C of the interlocking switch, and by a contact made in the normal position to the selecting magnet SMA. This operates the associated selecting bar via the selecting cam, and locks the remainder of the bars in the unoperated position, in the manner as has already been described and shown in Figs. 6 and 7. The contact of the selecting cam smal front extends the circuit already provided for cam D, to cam G, which, in the normal position, connects to the clutch coil Z, which is energised over an obvious circuit.

This clutch, which may be similar to that described for the first embodiment, drives the lifting and selecting cams. Immediately the cams leave the normal or unoperated position, the circuit for the selecting magnet is broken at cam D, and to the clutch coil Z by the contact smal and cam G. The clutch remains energised however, over cam H which .is cut to be disconnected in both the normal and reverse positions, and connected in inter mediate positions. Therefore the drive is continued until the reverse position is reached, when the circuit for the clutch is broken, and the cams stop, the selecting bar cam having been turned through The lifting arms having been raised, the contact sets required for route A are operated. One of these contacts, acl (which is only operated in that route position) extends the original circuit from cam D (now in the reverse position), to relay ZCR, which operates and proves that the switch is in the desired route position.

When it is desired to break down the route, the original circuit is broken, and relay ZCR is released. This will effect the route signals being changed to red, but will not release the route contact selection. When it is considered safe to break down this selection the release circuit for route A is made, which over a02 front energises the ZNR relay. Over znr2 front the clutch coil is energised over the reverse contact of cam G. The cams are thereafter driven until they are in the normal position, when the circuit for relay ZNR is broken, and the clutch is de-energised.

Where a route requires a larger number of contact sets than are normally available on one switch, there may be attached to it one or more extension units. These units will have code bars, Contact levers, and contact sets similar to the main switch, but the code bars will be lifted by means of push rods 35 interposed over the code bars of the main switch as shown in Fig. 6. The extension units will therefore be mounted in layers above the main switch.

In order to guard against the possible false contact due to failure or breakage of studs on the contact springs, contact sets required to be normally closed are mounted below the contact lever, or equivalent contact spring, and held there by the initial tension on the contact lever. In this case, the breakage of any operating stud has the effect of opening rather than closing the contact.

In the rst embodiment, as well as in the second, a motor-driven cam can be used to lift the code bar assembly (e. g. the rotor). This motor may be an individual drive motor or, common motor driving a cam through clutches as pointed out previously in connection with the description of Fig. l. Other variations possible include the use of self-latching armatures with specialrelease arrangements.

In a third embodiment, it is proposed to incorporate in a standard arrangement two sets of contacts, one operated as beforev when the liftingarms 23 are raised whilst the other set requires for its operation that the arms 23 shall be lowered. This scheme is shown generally in Fig. 9 and it will be seen that an cectromagnet 37 is included in place of the eccentric lifting device 24 indicated in Fig. 4. There are shown the usual code bars 13, selecting bars 25 and contact levers 22, but the latter is arranged not only to actuate an upper contact set 15, but also a lower set 38. The lifting arms 23 co-operate, at the end away from the electromagnet 37, with a latch 39 which has a stepped slot. An end elevation of this latch is shown in Fig. 10A, wherein the slot 40 can be clearly seen, whilst Figs. 10B, 10C and 10D will help in an understanding of the operation of this device.

As before the arms 23 ou being lifted operate the make-contact sets 15 so arranging the setting up of the required route, The normal relative positions of the arm 23 and the latch 39 are shown in Fig. 10A, it being understood that the latch is pivotted about the spindle 41. The arm 23 on being raised knocks against the surface 42 of the slot 40 so that as seen in Fig. 10B, the latch is displaced clockwise about its pivot 41. When the control switch of the route is released, the signals are arranged to go to danger immediately the upper contact set 15 is broken, but the arrangement is designed to ensure that no further route involving the contacts which have just been operated can be set up on any switch until a well-known back-lock has freed them for further service.

This desired result is achieved as follows: The magnet 37 releases the arms 23 but the fall is checked by the step 43 in the latch slot 40. This condition is shown in Fig. 10C. When the setting up of further routes is permissible the back-lock controls the quick operation of electromagnet 44. This attracts an armature extension 45 of the latch and as will be seen from Fig. 10D,

the latch 39 is rotated counter-clockwise and the arm 23 is released from the step 43 and drops down in normal position so that the contacts 38 are remade. The magnet 44 soon afterwards releases and the latch 39 returns to its normal vertical position shown in Fig. 10A. The

circuit arrangements are such that elements of the route which has been broken down may now be used in the setting up of the routes.

While the principles of the invention have been described above in connection with specific embodiments, and particular modifications thereof, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of the invention.

What is claimed is:

An electric switch comprising a plurality of code bars operable to engage through contact levers with a rst plurality of contact sets, any bars being operable to effect the operation of one or more of the said contact sets, a plurality of selecting bars one for each of the said code bars, means which engage notches in the said selecting bars operable to effect movement in a first plane of any one selecting bar at a time and a pivotted lever operable to be displaced after said movement has taken place so as to engage with the said particular selecting bar, displacing the latter and its associated code bar in a second plane thus operating the appropriate contact set or sets via their contact levers.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,873,729 Wheelock Aug. 23, 1932 1,969,978 Hanel Aug. 14, 1934 2,116,731 Noll May 10, 1938 2,241,906 Grths et al May 13, 1941 2,248,704 Griffiths et al July 8, 1941 2,260,292 Brown et al. Oct. 28, 1941 2,323,824 Maschmeyer July 6, 1943 2,361,246 Stibitz Oct. 24, 1944 2,364,446 Hubbard Dec. 5, 1944 2,480,945 Marmony Sept. 6, 1949

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