US909158A - Block-signal system. - Google Patents

Description

P. B. CDREY. BLOCK SIGNAL SYSTEM. APPLICATION FILED MAR.30, 190a Patented Jgn.12,1909.

I I 1 I T FRED B. CURE/Y. BY Q2 amasm. f

UNITED sTArEs PATENT OFF/ICE.

FRED B. COREY, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

BLOCK-SIGNAL SYSTEM.

Specification of Letters Patent.

Patented Jan. 12, 1909.

Application filed March 30, 1908. Serial No. 42%,036.

that is, systems in which the signal arms are arran ed to'assume three distinct positions to indicate danger caution and clear, respectively. In such a system it is customary to,employ contacts on each signal to control the movement of the signal next in the rear from caution to clear position. This control is ordinarily performed through ,a line relay, sometimes termed a three position relay, placed at the signal in the rear. It has furthermore been customary to construct three position signals with a stationary lock magnet, or some similar device, so that the signal maybe stopped in caution position, When it is moved from clear position by a train backing into the block in advance and thereby putting the signal for the a block in advance from caution to danger pbsition. With some signal mechanyisms, however, as for instance such a signal 'mechanism as is described i Patent #868,648 issued October 22nd, 19o /,1t is not possible, conveniently, to provide means. for stopping the signal in an mtermediate position when moving from clear toward danger; It therefore becomes necessary when the signal is to move from clear to caution, to allow it to move first to danger position momentarily and then to return to caution. In a signal operating in 40 this manner, however, it has not heretofore been practicable any longer to control the signal in the rear from contacts on the signal shaft, since if a train should back into one block putting the si al at danger, it

would throw the signa for the block next in the rear, from clear to caution, but in making this movement the signal for thc block 111 the rear, having to move momentarily t0 dan er position, would throw the next signal be ind it from clear position momentarily to dan er, and this action I might be repeated for t e entire length of the road. For this reason, when signals of the type described in my former patent have been operated as three position signals,- it

has been customary to control the movement of each signal from caution to clear and vice versa, not by contacts on the shaft of the si nal in advance, but by contacts on the trac relay for the block in advance. This, however, is objectionable, because, if a block is clear but thesignal mechanism out of order, the signal for that block might stand at danger with the signal next in the rear at clear. That is, each signal no longer under all conditions accurately indicates the condition of the signal in advance and the failure of a signal mechanism may result in forcing each train approaching it to "make an emergency stop in order to avoid running past it. .1

By means of my invention 1 am enabled to control each signal by contacts on the signal mechanism itself of the block next in ad- .vance and yetto avoidj throwing a series of signals to dangers behind a train when it backs into a blocks I accomplish this by pro- 'viding means fo'r r'endering the contacts on the signal shaft inoperative to control the signal next in the reanwhen the first mentioned signal goes momentarily to danger inmoving from "clear to. caution. More specifical y stated, I providemeans for shortcircuiting the contacts when the driving motor of the, signal is in operation.

My inventionwill'best be understood by reference to the;drawing which shows diagrammatically ai signal! system arranged in accordance with iny invention.

. In the drawing, A, A and A represent the rails of three successive blocks supplied With current from track batteries B, B and B The block A is shown occupied by a train and the direction of traffic is indicated by an arrow.

(1,"(1 and C re resent track relays for three blocks, the re ay O being denergized, and the other two being energized since their blocks are clear.

D, D and D represent the signals for the block's. These are three position signals, the signal D being shown atdanger posi tion, the signal D at caution and the signal D at clear; The signal mechanisms are shown dia rammatically; their construction may be i( entical with that described in my former patent No. 868,648 above re-. ferred to. r

E represents the driving motor for the signal D. This motor is provided with a with an auxiliary series winding G represents the line or three position relay which controls the movement of the signal from caution" to'clear.

H represents the switch contacts which move with the signal arm. These contacts would, in practice, be placed on the signal shaft, and would be constructed substantially as shown in my prior patent, but for the sake of clearness in illustration 1 have shown the contacts developed on a plain surface. There are nine stationary contacts h to 71. and. movable contacts as shown.

T represents the battery, or the source of current for supplyin the signal mechanism.

J represents a re ay connected in series with the motor and arranged to short-circuit the pair of contacts h and k The operation of the system is as follows: As long the car or train remains in block A, the signals will remain in the position shown. Wlien the train passes out block A, track relay C is energized and closes the circuit from the left hand terminal of the battery through relay J, series clutch magnet Winding f, motor field 6, motor armature E, contacts 7r, h and h and armature of track relay C, to right'hand terminal of battery I. The circuit of the shunt winding]? of the clutch or slot magnet is closed through contacts h it and k and the contact of track relay C. Both motor and slot magnet are consequently energized and the motor begins to drive the signal from danger-position. When the caution iosition is reached the circuit connections become the same as are shown for signal D The circuit of the motor is open at contact in so that the signal arm comes to rest, the circuit of the shunt winding of the slot magnet bcing kept closed. While signal D has thus been moving from danger to caution position, signal D has been moving from caution to clear position, because since the circuit of the motor E is closed, re-,

lay J in series with it is energized, thereby.

closing a circuit from the left hand terminal of battery I through the armature of relay ,J, through the upper line wire to line relay G back through the lower line wire and through armature of track. relay 0 to right hand terminal of battery I. Line relay G is conseuently energized and closes the circuit from t e left hand terminal of battery I through relay J slot magnet f series field e, armature E contacts h h armature of relay G, and armature of relay C to the right hand terminal of battery I Signal D is therefore driven from caution to clear. osition. When clear position is reache the circuit connections become the same as those shown in signal D The motor is 'disconnected from the battery at contact 7L3 butis short-circuited through contacts 71 and h,

and therefore, because of its shunt field, acts relay G is not deenergize. when the signal D reaches caution position and the circuit of motor E 18 opened because before this time the circuit of line relay Gr has been closed by the contacts ]i and k of switch H.

So far as the movement of the signalsfrom danger to caution and to clear is concerned, the relay J performs no useful function except to cause the signal D to start its movement from caution to clear simultaneously with the movement of the signal D from danger, to caution. It is upon the reverse movement of the signals that the operation of the relay J becomes of im ortance.

Suppose t at the train, after leaving" block A backs into this block again, thereby returning signal D to danger position; this opens the circuit of line relay G andallows signal 1), which had been cleared, to start back again toward danger position. Since the signal'mechanism is not constructed so as to catch the signal arm at "caution position, its movement must be continued until danger position is reached; the

motor then immediately returning the arm to caution position. If it were not for the relay the signal 1) would be thrown momentai'ily to danger by the movement of si nal D to dan er and similaril the h n I signal in the rear of D and all the remaining signals on the road might be thrown' to- Relay J}, however, prevents daiigei. this from occurring, for, before contacts h and /i have been opened by their movable contacts, the circuit of motor E and conse' quentlv relay J 'lias been closed at contacts h it and k The relay J is therefore energized and pulls up its armature to short-circuit contacts 7t and-7i before their circuit is v opened at their movable contacts.

Thus

the contacts h 70 of switch H are rendered inoperative to vopen the circuit of line relay G when signal 1) goes only momentarily to danger and motor E is in operation to drive it back to caution.

I do not desire to limit myself to the particular construction and arrangementgof 130' 1 at-ion.

- electric motor for moving said arm, contacts signal next in the rear arranged to open said parts shown in the drawing, hut aim in the appended claims to cover all modifications I which are within the scope of my invention. i What I claim as new and desire to secure l by Letters Patentof the United States, is, l 1. In a signal system, a signal arm adapti ed to assume three distinct positions, a motor for moving said arm, contacts controlled 1 by the movement olsaid arm controlling, the a signal next in the rear, and means for renderi ing said contacts inoperative to control the i signal in the rear when said motor is in operl l l 2. In a signal system, a signal arm adapted to assume threedistinct positions, a motor for moving said arm, contacts controlled by the movement of said arm controlling the signal next in the rear, and means for shortcircuiting' said contacts when said motor is in operation.

3. In a signal system, a sigma]. arm adapted to assume three distinct positions, an electric motor for m'ovirnr said arm, contacts cgmtrolled hr the movement of said arm l controlling the signal next in the'rcaryand 'a relay in circuit with said motor-adapted when energized to render said contacjs inoperative to control the signal in. the rear.

4. Ina signal system, a signal arm adaptedto assume three distinct positions, an

controlled by the movement of said arm controlling the signal next in the rear, and a relay. in circuit with. said motor adapted when energized to short-circuit said contacts] 5. In a signal system, a signal arm adapt ed to assume three distinct positions to indicate danger, caution, and clear, a motor for moving said arm, .a line relay controlling said arm in its clear position, contacts in circuit with'the line relay of the circuit when said arm is at danger and to close it when said arm is at caution or caution or clear clear when said arm moves clear,- and means for rendering said contacts inoperative to open said. circuit when said motor is in operation.

6. In a signal system, a signal arm adapted to assume three distinct positions to ind cate danger, caution am clear, an electric motor for moving said arm, a line relay controlling said arm in its clear position, contacts in circuit with the line relay of the signal next in the rear arranged to open said circuit whensaid arm" is at danger and to close it when said arm is at and a relay in circuit with said motor arranged when energized to short-circuit said contacts.

7. In a signal system, a signalarm adapted to assume three distinct positions to md1 eate danger, ,cautioni'and clear, contacts controlledhy the movement of said arm and controlling the signal next in the rear to cause it to-move from caution to clear when said arm moves From danqer" to" caution, and'means for preventing said contacts from affecting the signal in the rear when said arm goes momentarily todangerin moving from clear to caution. 8; In a slgnalsystem, a signal arm adapted to assume three distinct positions to lndlcate danger, caution and "clear", contacts controlled by the move'mentot said arm andcontrolhng the signal next in the rear to cause it to move from caution to ger to caution, and means cuitlng' said contacts when said arm goes I P a momentarily to danger in movlng irom clear to caution.

In witness whereof, Ihave hereunto set my

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