US793063A - Electrical instrument. - Google Patents

Description

No. 798,063. PATENTED JUNE 27, 1905. J. J. GHEGAN.

ELECTRICAL INSTRUMENT.

APPLICATION FILED JAN. 27, 1904.

Patented June 27, 1905.

PATENT OFFICE.

JOHN J. GHEGAN, OF NEWARK, NEIV JERSEY.

ELECTRICAL INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 793,063, dated June 27, 1905.

Application filed January 27, 1904. Serial No. 190,782.

1'0 all whom it may concern.-

Be it known that I, JOHN J. GHEGAN, a citizen of the United States, and a resident of Newark, Essex county, State of New Jersey, have invented an Electrical Instrument, of which the following is a specification.

This invention relates to electrical instruments, and has for its object to construct a device, such as a telegraph-relay, that will adjust itself to varying strengths of battery-current and will also respond to comparatively slight changes in the resistance of its circuit.

On telegraph-lines of considerable length, even when battery strength is constant, great difliculty is found in keeping the relays properly adjusted, particularly in damp or wet weather, when leaks or escapes of the current occur from imperfect insulation. My invention overcomes this difficulty even when the leaks or escapes amount to over fifty per cent. of the line-current.

Another advantage gained by my invention is that when the key simply adds a given resistance to the circuit instead of opening it, as is generally done, the leaving of the keyswitch open, accidentally or otherwise, does not necessarily leave the line open or unavailable, even for the oflice where such opening occurs, as on the working of any key all relays immediately adjust themselves to the changed condition.

The principle upon which my invention is based is very simple and can be utilized in various ways, so that while I have shown but one adaptation I do not limit myself to the construction or arrangement shown.

My invention consists, broadly, of a movable armature, the extent or amplitude of its motion being governed by the strength of a battery-current and adapted under slight variations of current strength to move correspondingly.

The accompanying drawing represents diagrammatically an arrangement of telegraphic instruments illustrating one adaptation of my invention.

In this arrangement the relay comprises a magnet 1, preferably of the solenoid type, with a sliding core 2. Satisfactory results may be obtained with the pivoted disk form of solenoid, such as used in voltmeters; but it is not even essential to use a solenoid, as other arrangements have proved available to obtain amovable armature the extent of motion of which is governed by the strength of the battery-current. As shown, the core-tube 3 of the magnet 1 is extended beyond one end of the coils of the magnet, and each end of this tube is closed or capped except for openings through which the extensions 4 and 5 of core 2 pass to guide the core in its motions. Compression-springs 6 and 7, bearing between the outer closed ends of tube 3, and stops 8 and 9, secured to the rod extensions 4.- and 5, all respectively as shown, tend to maintain the core 2 in its normal position when no current is passing through the coils. This core and its extensions constitute the movable armature to which I have referred. In order to cause the movements of the arma ture to operate a local sounder, I provide a movable contact or follower that will be automatically adjusted for operation by slight movements of the armature in any position of the latter given it by changes in the strength of current in the coils 1. There are various ways of obtaining such a contact; but in the drawing I have shown a preferred construction. A dash-pot 10, containing glycerin or any other suitable fluid, (or it may be an air dashpot,) is provided with a piston 11 and rod 12, preferably of lighter specific gravity than the fluid in the dash-pot. The rod 12 has an insulated stop 13 and a contact-stop 14, between which stops the contact-point 15 of the core-armature is arranged to play.

When a current is passing through the coils of magnetl, the core 2 is drawn down, causing the contact-point 15 to press upon contact-stop 14: and force the piston 11 farther down into the dash-pot, the extent of downward motion corresponding to the strength of the current acting upon core 2. If the current in coils 1 materially decreases or is cut off, the core 2 rises and its contact-point 15, pressing against the insulated stop 13, forces the piston 11, and consequently the contact-stop 14, upward. The piston 11 and rod 12 being of lighter specific gravity than the fluid in the dash-pot 10 will gradually rise up until contact-stop 14 reaches contact-point 15 of the armature, so

I that the instrument is in readiness at all times for operation by the usual means of signaling. The dash-pot arrangement acts to retard the movements of thefollower-contact, and consequently to cushion the longer or extreme motions of the armature, thus preventing jerking of the armature and its movable contact due to sudden material changes in the current strength in coils 1. The coils of magnet 1 are connected up in the main line of the telegraphic system, as with an ordinary relay.

In the drawing is represented a key 16, adapted to add a given resistance 17 to the circuit when opened. The key-switch 18 is shown as left open. The coils of the soundermagnet 19 are connected to the movable armature through wire'2O and to contact-stop 14 through wire 21, in which is shown alocal battery 22. The key is shown as inserted in line-wire 23, running to the magnet 1, the

other end of the coils of magnet 1 passing to the line-wire 24.

The operation of the device is as follows: Assuming the normal current strength to be on the line, when a key is operated, either to open the circuit or to insert an additional resistance in the line, core2 will rise in response to the variation in current strength in coils 1. This will break the contact at 14 15 and open the local circuit through sounder-magnet 19. Upon the closing of the key core 2 is drawn down again and contact is made at 14 15 and the local circuit through sounder-magnet 19 again closed. Core 2 will respond to very slight changes in current strength to make and break at 14 15, and although'the piston 11, rod 12, and contact-stop 14 tend to rise when released by contact-point 15 this rising motion takes place very slowly and does not interfere with the operation described. Assuming that a key-switch 18 has been left open by mistake, all the core-armatures along the line will remain in the position corresponding to the reduced current strength of the main line and the movable contacts 14 will follow contacts 15, as described, so that when another key is operated the further reduction in the main-line current will act upon cores 2 to draw them farther up and break contact at 14 15. If the key-switch is then closed, the added strength of current will force core 2, contacts 14 and 15, and piston 11 all down again to their original positions. It will be quite evident that leakages will act upon the movable core-armatures in the same manner as leaving key-switches open and putting in resistances will and that the relay will not cease to act unless the main-line current becomes so Weak as not to affect the core 2.

I claim as my invention- 1. The combination of an electric circuit, an armature adapted to shift its position according to the strength of current in said circuit,. and means for cushioning the movements of with a second electrical circuit and a movable 7 contact automatically adjustable to the varying positions of said armature, said contact and said armature being electrically connected to this second circuit and adapted to make and break it when the armature is vibrated.

2. The combination of an electrical circuit, an armature adapted to shift its position according to the strength of current in said circuit, and means for cushioning the movements of the armature when thus changing its position to prevent recoil -or jerking, said armature adapted to be vibrated in its various positions by signal impulses sent through the circuit, with a second electrical circuit and a movable contact adapted to be adjusted by motion of said armature to a constant relative operative position with the armature, said contact and said armature being electrically connected to this second circuit and adapted to makeand break it when the armature is vibrated.

3. In a telegraphic system, a main line, a key for sending signals over the main line, a local circuit, a solenoid connected up in the main line and provided with an armature adapted to shift its position according to the strength of current passing through the solenoid and means for cushioning themovements of the armature when thus changing its position, said armature adapted tobe vibrated by the operation of said key while in various positions, and a movable contact'automatically adjustable to the varying positions of said armature, said contact and said armature being electrically connected tosaid local circuit, and adapted to make and break it when said armature is vibrated.

4. The combination with an electric circuit, of a movable armature the extent of motion of which is governed by the strength of current in said circuit, and a dash-pot provided with a piston and piston-rod, a contact carried by said piston-rod, said piston, rod and contact adapted to be moved by said armature to adjust the said contact to the varying positions of said armature.

5. An electrical instrument comprising a tube, coils of wire surrounding a portion of said tube, a core movable within said tube and provided with extensions, and caps on the ends of said tube, said caps havingopenings through which said extensions pass to guide and center said core in said tube.

In testimony whereofI have signed my name to this specification in the presence of two subscribing witnesses.

JOHN J. GHEGAN. Witnesses: MABELLE F. LAKE, EDITH J. GRIsWoLD.

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