US1621835A - Electrical contact device for follow-up systems - Google Patents

Description

.. a. w Y 1 2 March 22, T9127. A. P. DAVIS 6 1 835 ELECTRICAL CONTACT DEVICE FOR FOLLOW-UP SYSTEMS Filed Jan. 9, 1925 INVENTOR M ,/4%-M ATTORNEY operated fo Patented Mar. 22, 1927.

PATENT OFFICE.

ARTHUR P. DAVIS, 01 BROOKLYN, NEW YORK.

ELECTRICAL CONTACT DEVICE FOR FOLLOW-UP SYSTEMS.

Application filed January 9, 1923. Serial No. 611,680.

This invention relates in general to followup systems and particular y to electrically llow-up systems in which the controlling element is a direction indicator such as a ma netic or gyroscopic compass. The principaIobject of the invention is to provide such an apparatus having a contact device includin an electrical contact switch or a similar evice actuated by means which will not impart mechanical vibration to the device.

"Heretofore the follow-up member of a roscopic direction indicating apparatus as been operated by an electric motor, the apparatus being arranged so that the controlling member operated the motor switch by means of a spring connection. In this system, the spring is mounted on the gyro frame, and carries a contact point at the free end thereof adapted to engage a contact on the follow-up member. Hence, when the gyro frame rotates with respect to the follow-up member, the motor circuit is closed by virtue of the spring contact engaging the contact on the follow-up member. The motor then operates until the follow-up member again assumes its normal position with respect to the gyro frame and the contact switch opens. During the normal use of gyro apparatus, the gyro frame is subjected to severe mechanical vibration due to the high speed of rotation of the gyroscope. In a follow-up system, such as that described in the preceding paragraph, this vibration is transmitted to the contact device on the follow-up member by means of the spring or equivalent connecting member carried by the gyro frame. This makes it necessary to have high contact pressure between the moving element of the switch and the switch contacts, and even with this high pressure it is not possible to secure contact good enou h to insure steady and re- '..able operation 0 the motor; Furthermore, the reaction on the gyro frame, of the moving elements of the switch produces undesirable results which cannot be readily avoided when high contact pressures are used between the actlve surfaces of the contact switch.

In orderto obviate the disadvantages of the contact devices commonly employed with follow-up systems, I have devised an improved system of such a character that the mechanical vibration experienced by the switch contacts carried b the follow-up member. In general, the improved switch mechanism comprises an actuating elementearned by the gyro frame and adapted to operate a switch associated with the followup member. I prefer to use magnetic means carried by the gyro frame and arranged so that it may operate the switch supported by the follow-up member. This member may carry two contacts and a movable element pivoted between these contacts, the movable element being arranged so that it may be swung to one contact or the other by the magnet1c means associated with the gyro frame. lVhen the movable element is turned so that it engages one of the contacts on the follow-up member, the follow-u member rotates in one direction; and w en the movable member engages the other con tact, the follow-up member rotates in the opposite direction. In either case, the followup member continues to rotate until it assumes its normal position with respect to the gyro frame.

Even though the contact pressure of the improved switch device is very slight, yet the reaction of this slight pressure may be great enough to produce a detrimental effect on the operation of the roscope. This small force of reaction limits the freedom of movement of the gyro frame and in order to eliminate this imperfection, I have devised a means for neutralizing this force. One means which may be employed for this purpose consists of one or more electromagnets arranged so that they exert a force on the magnetic switch-actuatin member carried by the gyro frame, the force being of the proper magnitude and direction to neutralize the force of reaction.

This invention may be best understood by referring to the following detailed description which is to be considered in conjunction with the accompanying drawing. The fi ure of this drawing is a plan view of a fol owup system provided with one embodiment of the improved contact device.

The drawing shows a direction findin element comprising a gyroscope 1 mounted to rotate on a horizontal shaft 2 supported by the usual frame 3. A follow-up member 4 encircles the gyro frame and is adapted to be rotated by means of a suitable motor 5. The follow-up member is progyro frame cannot be transmitted to the vided with gearteeth 6 engaged by the pin- 1 ion 7 carried by the shaft of the motor 5. e member 4 is supported by a mercury float bearing indicated at 8.

The follow-up member 4 carries two contacts 9 and 10 rigidly mounted thereon. A movable switch member 11 is pivoted between the contacts 9 and 10, the arrangement being such that the movable member may engage either of the contacts 9 and 10. These contacts are each connected to a source of electrical energy indicated at 12. The movable switch member 11 is connected to the motor 5 which, in turn, is connected to the source of electric energy 12. The gyro frame 3 carries a magnet 13 which is shown in the form of an ordinary bar magnet, one end of which is supported by the gyro frame, the other end projecting outward into close proximity to the movable switch member 11 which is attracted by the magnet.

In the neutral or rest portion of the follow-up system, the bar magnet 13 and the movable element 11 are in direct alignment' as shown in the drawing. When relative movement takes place between the gyro frame 3 and the follow-up member 4, the magnet 13 is displaced with the gyro frame, and causes the movable switch element 11 to rotate in one direction or the other depending upon the direction of the movement of the gyro frame with respect to the follow-up member If the gyro frame moves with respect to the follow-up member in the direction indicated by the arrow a, the movable switch element 11 is turned until it engages contact 9. Current then flows in the motor circuit, the circuit being as follows: source of electrical energy 12, movable element 11, contact 9, motor 5, and source of energy 12. The motor 5 then operates to rotate the follow-up member 4 in the direction of the arrow a until it has reached its normal rest position with respect to the gyro frame 3, at which time the switch is opened by magnet 13. If the gyro frame rotates in the direction indicated by the arrow 6, the motor circuit is closed through the contact 10 and the motor operates in the reverse direction to cause the followup member 4 to rotate in the direction of the arrow b until the follow-up member again registers properly with gyro frame.

The bar magnet 13 is preferably pivoted on the gyro frame as indicated at 14. This arangement permits the bar magnet 13 to swing on its pivot to remain in alignment with the movable switch element 11 until this element engages one of the segments 9 and 10. WVith this arrangement, the gyro.

frame is not subjected to any sudden force of reaction during the operation of moving the switch member 11, and flexible action is provided. After the contact 11 engages contact 9 or contact 10, the bar magnet 13 may be pulled away from the switch element mamas 11 by the continued rotation of the gyro frame. This continued movement of the bar magnet 13 introduces a force of reaction tending to retard the movement of the gyro frame. This force need not be great, however, for I preferably employ a bar magnet of relatively low strength.

In order to avoid the relatively small force of reaction referred to in the preceding paragraph, I may employ magnetic means capable of neutralizing this force of reaction. This magnetic means is arranged in such a manner that it exerts a force on the bar magnet 13 of such a magnitude and in such a direction that it neutralizes the force of reaction on the bar magnet 13, this force of reaction being exerted by the movable switch element 11 on the follow-up member. This magnetic means may be in the form of one or more electromagnets. Two such electromagnets are indicated in the drawing at 16 and 17, the electromagnet 16 being in circuit with contact 10, and electromagnet 17 is in circuit with the contact 9. The electrical circuits are arranged in such a manner that when the motor circuit is closed through the contact 9, current flows through the coil of clectromagnet 17 and this electromagnet exerts a force on bar magnet 13 in the direction to oppose the force of reaction on this bar magnet. In like manner, electromagnet 16 is arranged to exert an opposite force on the bar magnet 13 when the motor circuit is closed through contact 10. The electromagnets 16 and 17 are of such a character that the force exerted by them substantially neutralizes the force of reaction on the gyro frame and this frame is therefore free to rotate about its vertical axis unrestrained by any force transmitted thereto by the switch elements carried by the follow-up member. In other words, the forcev necessary to operate the switch member 11 is supplied by the electromagnets 16 and 17 instead of by the bar magnet 13, this bar magnet serving merely to direct or control the operation of the switch member 11 so as to cause the follow'up member to rotate in one direction or the other depending upon the direction of rotation of the gyro frame 3.

From the above description it is apparent that the improved contact device comprises means associated with a controlling member for actuating a switch on a controlled member, the arrangement being such that the switch is operated positively by the controlling member in such a manner that mechanical vibrations may not be transmitted from the controlling to the controlled member. Furthermore, this invention provides means for neutralizing all the undesirable effects now produced on the controlling member of a follow-up system, by the follow-up memher.

1,ea1,sas

It is tobe understood that the size, pro portion and arrangement of the various parts of this invention may be varied with out departing from the spirit of the invention which is not confined to the particular embodiments shown and described, but is intended to include such modifications thereof as fall within the scope of the appended claims.

I claim:

1. In a system of the type described, the combination of a controlling element, a con-- trolled element, an electrical contact device carried by said controlled element, means formoving said controlled element, responsive to the action of said contact device, and ma netic means associated with said control ing element for actuating said contact device, said means bein incapable of transmitting mechanical vi rations from said controlling element to said contact device.

2. In a system of the type described, the combination of a direction finding element, a power-driven follow-up element means whereby said direction finding element controls said follow element, said means com-- prising a reversing contact device supported y said follow-up element, and magnetic means associated with said direction finding element for actuating said contact device, said means being incapable of transmitting mechanical vibrations to said contact device.

3. In a system of the type described, the combination of a controlling element, a controlled element, an electrical contact device carried by said controlled element, means as sociated with said controlling element for exerting a force on said contact device to actuate the same, and means for neutralizing the reaction on said controlling element, of said actuating means.

4. In a system of the type described, the combination of a controlling element, a controlled element, an electrical contact device associated with said controlled element, magnetic means associated with said controlling element for exerting a force on said contact device, said means being incapable of transmitting mechanical vibrations to said contact device, and means for neutralizing the reaction on said controlling element, of said force exerting means.

5. In a system of the type described, the combination of a controlling element, a controlled element, an electrical contact device associated with said controlled element, means associated with said controlling element for exerting a force on said contact device to actuate the same, and magnetic means for neutralizing the reaction on said controlling element of said force exerting means.

6. The combination of a direction finding element, a power driven follow up element associated with said direction finding element, a reversing contact device supported by said follow up element, magnetic means associated with said direction finding element for exerting a force on said contact device to actuate the same, and magnetic means controlled by said contact device, adapted to neutralize the reaction on said direction finding element, of said force exerting means.

7. In a system of the type described, the combination of a direction finding element, a follow-up element associated with said direction finding element, electrically controlled driving means for said follow-up element, an electrical contact and a movable switch element carried by said'follow-up ele ment and connected to said driving means, and magnetic meansassociated with said direction finding element and adapted to aciu ate said movable switch element. whereby the follow-up element is caused to follow the movements of the direction finding element.

In testimony whereof I affix my signature.

ARTHUR P. DAVIS.

CERTIFICATE OF CORRECTION.

Patent No. l, 621,

above numbered patent requiring corre 'word "portion" read "position"; trolled by" read "first mentioned magnetic" these corrections therein that the same ma Granted March 22, 1927, to

ARTHUR P. DAVIS.

It is hereby certified that error appears in the printed specification of the P "in circuit with" the Patent Office.

Signed and sealed this 5th day of April.

ction as follows: Page 3, line 71, claim 6, for the words "consnd lines 73 and 74, for "force exerting" read and that the said Letters y conform to the record of the case in 2, line 21, for the Patent should be read with M. J. Moore,

Actfne Commissioner of Patents.

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