US1738467A

US1738467A - Frictionless clock contact

Info

Publication number: US1738467A
Application number: US314465A
Authority: US
Inventors: Henry E Warren
Original assignee: WARREN TELECHRON CO
Current assignee: WARREN TELECHRON CO
Priority date: 1928-10-23
Filing date: 1928-10-23
Publication date: 1929-12-03
Anticipated expiration: 1946-12-03

Description

1929- H. E. WARREN I 1,738,467

FRICTIONLESS CLOCK CONTACT 1 Filed Oct. 25. 1928 Inventor:

Henry E. War-Pew y Hi5 AbZoPney Pat'ehted Dec. 3, 1929 II/JL/NITED "STATES PATENT OFFICE HENRY E. WARREN, OF ASHLANI), MASSACHUSETTS, ASSIGNOB TO WARREN TELE- CHRON COMPANY, OF ASHLAND, MASSACHUSETTS, A CORPORATION OF MAINE rnIo'rIonLnss oLocx CONTACT Application filed 0ctober 23, 1928. Serial No. 314,465.

My invention relates to an electric contact making and breaking device suitable for obtaining timed electric impulses from a clock without imposing any additional load on the clock mechanism such as might stop it or inv terfere with its time keeping function. In many clock systems master clocks are employed to send out electric impulses at timed intervals. Analogous functions are perlight, this work is liable to interfere with the correct running of the clock movement. Light switch contacts are objectionable because of the small amount of current that can be handled without destructive burning.

The purpose of my invention is to provide anexceptionally heavy contact pressure in a clockoperated device without imposing any appreciable load on the clock movement whereby accurately timed currentimpulses of considerable magnitude may be produced.

In carrying my invention into effect in the preferred form I provide a metallic pointer driven directly by the clockwork and permit said pointer to pass between spaced metallic rollers the adjacent surfaces of which are driven in the same direction and at the same or approximately the same speed as the pointer in such manner that the pointer is momentarily and periodically firmly clasped between the rollers to establish a contact therethrough without interfering with the normal movement of the pointer.

The features of my invention which are believed to be novel and patentab'le will be pointed out in the claims appended hereto. For a better understanding of my invention reference is made in the following description to the accompanying drawing, Fig. 1 of which shows a preferred invention as applied to an electrically wound 'clock, 2 represents the relation of the contacting surfaces of the apparatus of Fig. 1 when contact is made and Fig. 3 represents a modification of the contact device.

In the drawing, Fig. 1, I have represented embodiment of the wind the main spring of the clock.

the essential features of my invention as applied to a clock or watch movement the main spring of which is arranged to be wound by an electric motor which also serves to rotate the contacting rollers. Many of the details of the clock mechanism itself are not shown since in general they willbe similar to those employed in any standard clock or watch movement. The clock winding motor is represented at the right of the case 10 which may be assumed to contain the usual type of spring drivenclock or watch mechanism and the contact device is represented at the'left. In the commercial form it will be understoodthat all parts of the device would preferably be assembled in a more compact form and be contained in the same casing.

The clock spring winding mechanism will be first described. 11 represents an electric motor. It may be of the direct or alternating current type and'should-run at a substantially constant speed. It will be constantly con nected to a suitable source of supplyand will be in operation continuously except when the power supply fails. Its shaft 12 is connected through

reduction gears

13, 14; and 15 to a gear wheel 16. Wheel 16 is, free to rotate on shaft 17 extending from the interior to the exterior of casing 10. Shaft 17 is the main clock sp ring winding shaft and is arranged to be rotated by motor 11 to keep the main spring (not shown) wound up. Secured to shaft 17 is a collar 18 into which is fastened one end of a spiral spring 19. The other end of'this spring is straightened out and extends into the path of movement of a roller 20 on the gear wheel 16. As wheel 16 is driven in the direction indicated by the arrow thereon roller 20 will move against the free endv of spring 19 and if the main clock spring is not fully wound up torque will be transmitted through spring 19, collar 18.and shaft 17 to stantially fully wound the torque transmitted will be suflicient to permit roller 20 to pass over the free end of the spring and no more winding will take place until the main' spring tension has been reduced to a point where the roller 20 will again rotate shaft 17 through the lVhen subcured on the second hand shaft of the clock movement, and 22 the second hand secured to bushing 21 by a flexible connection. In this case the second hand is apiece of thin spring wire one end of which is wound in a spiral about 21 and secured thereto. As the second hand moves in a clockwise direction its outer end asses between. the. peripheries of two metallic wheels or

rollers

23 and 24 driven from motor 11 through shaft 12, and

gears

24, 25, 26, 27, 28, 29. The wheels and 24 are arranged to be driven so that theiradjacent peripheral surfaces move in the samedirection and at the same or approximately the same speed as that portion of the second hand 22 which passes between them.

Wheels

23 and 24 are not in contact with each other but are spaced apart a small distance corresponding to about the thickness of the pointer 22 such that when the pointer 22 moves between them the pointer will bridge the gap and the rollers will squeeze the pointer to a greater or lesser extent depending on the adjustment. This condition is represented in Fig. 2 where the parts are numbered as in Fig. 1.

The desired spacing of

rollers

23 and 24 may be accomplished by arranging their shafts 30 and 31

incadjustable frames

32 and 33 which in turn are secured to

shafts

34 and 35 respectively. The last mentioned shafts are pivoted in a supporting frame 36 and are provided with adjusting

arms

37 and 38. Arm 38 and the exact position of wheel 24 are adjusted by means of the adjusting screws 39 between which the outer end of arm 38 extends and wheel 23 is spaced away from wheel 24 by an adjusting screw 40 on which the outer end of arm 37 rests. The small amount of adjustment necessary is not sufficient to interfere with the gear mesh between

gears

28 and 29 or between

gears

26 and 27. The rollers are suitably insulated from each other in the supporting structure.

Gears

28 and 29 may be made of some non-conducting material and frame 32 is then suitably insulated from 36 such that

frames

32 and 33 are electrically insulated from each other in the device except at the moment when the metallic pointer 22 passes between and is grasped by wheels 23. and 24. At this moment, once per minute in the arrangement described, a positive electric contact capable of making and breaking considerable current without damage is made between

wheels

23 and 24 without imposing any load on the clock movement through the second hand. It will be evident that a heavy contact pressure is ossible without imposing any load on the-c ock.

If the motion of the second hand is pulsatiiig, as it is in many clock and watch movements, there will be an exceedingly slight alteration in the normal actual motion at the outer end of the second hand. However, at the moment when the second hand is grasped between the

roller wheels

23 and 24 it must move at its average rate and can not pulsate. This is taken care of where necessary by the flexible connection between the second hand and its drivingshaft as previously described. The average eifect of such pulsations on the clock movement will be zero and the rate gf the clock movement is not influenced there- In some cases I may omit the gear driving connection between the rollers 23 and 24' so that one of them becomes an idler roller. By proper adjustment the idler roller will then be driven from the other roller through the pointer as it comes between them without imposing any load on the clock. Where only a small amount of current is to be handled I may even omit one roller entirely and arrange the contacting device and circuit as represented in Fig. 3 where 22 is the second hand pointer, 21' its shaft of conducting material, and 23 a driven roller having a peripheral movement equal to that of the end of the pointer 22 which momentarily makes point contact with the roller in one position. The resilient connection between the pointer and its shaft permits good contacting pressure between the end of the pointer and roller 23.

In case of an interruption in the power supply to motor 11, the

wheels

23 and 24 will obviously stop rotating and under this condition, unless the wheels are separated to allow pointer 22 to pass freely between them, this will stop the clock. Ordinarily the clock will run until its springis completely unwound so that occasional interruptions in the power supply of short duration will not interfere with its operation. To take care of such conditions I prefer to employ a novoltage release relay represented at 42. The armature 43 of this relay is secured to a shaft 44. On the opposite end of this shaft is an arm 45 extending beneath the adjusting lever 37. Relay 42 is connected to the same source' as motor 11 so that when power is on and the motor is operating the relay is energized and attracts its armature 43. Under this condition, arm 45 does not interfere with the adjusted position of arm 37 which then rests, due to gravity, against stop screw 40 to correctly position wheel 23. When the power fails, and motor 11 stops, armature 43' will 11 will then start. Belay 42 will operate andnormal operation of the contact device will be resumed. I

v I have indicated a secondary clock circuit at 46 which is controlled by the clock contact device of my invention. Due'to the unusually large amount of current that may be successfully controlled, an unusually large number of secondary .impulse clocks such as indicated at 47 may be connected to the system without danger of failure due to feeble currentimpulses. Moreover, a high grade accurate watch or clock movement may be employed as a master clock without having the contactor interfere with its accuracy.

WVhile I have described the contact as being made every minute the rate may obviously be made anything desired and the same master clock may have additional contact devices of the same character for producing impulses at different rates.

In accordance with the provisions of the patent statutes I have described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown and described is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric contact device comprising a pail-of rollers having spaced apart adjacent peripheral surfaces of conducting material, a clock driven pointermountedfor rotation about an axis such that its free end passes between the adjacentcperipheral surfaces of said rollers, the spacing of said rollers being such as to grasp the pointer as it moves between them, and means for driving sa1d rollers so that the adjacent peripheralsurfaces move in the same direction and at approximately the same speed as that of the contacting portion of the pointer, said contacting portion being made of conducting material whereby an electric contact is established between said rollers when the pointermoves between them.

2. A contact device comprising. a pair of rollers having adjacent spaced apart surfaces of conducting material, a clock driven conducting member arranged to be moved between and to bridge the space between the ad acent surfaces of saidrollers and means for driving said rollers so that'the peripheral portions which are bridged by the clock driven conductor move in the same direc- 1,

tion and at approximately the same speed as that of the conductor. a

3. A contact making clock comprising aj clock movement, a conductor driven thereby,

a second conductor, said conductors being mounted for rotation on axes such that 1n one rotative position of the clock driven conductor, said conductors touch each other to establish an electric circuit between them, and means for moving the second mentioned conductor at the same speed and in the same direction as the clock .driv'en conductor at the contacting surfaces thereof whereby an electric contact is established without imposing load on the clock movement.

4. A contact device comprising a conductor arm mounted for rotation about an axis, a timing device for moving said conductor about said axis, a roller having a peripheral surface of conducting material positioned adjacent to a point 1n the path of movement of the outer end of said conductor arm whereby electrical contact is made between said arm and the peripheral portion of said roller once for each complete rotation of said arm, and an electric motor for driving said roller such that the peripheral surface 7 thereof, with which contact is made by said arm, moves in the same direction and at apapproximately the same speed as the clock driven arm at the point of contact.

5. An intermittent contact device comprising' a clock driven pointer havin an outer end portion of conducting materlal, a pair of rollers having adjacent peripheral portions of conducting material so positioned and spaced that the pointer moves between and establishes an electric circuit between the adjacent peripheral portions of said rollers, means for driving said rollers so that the contacting surfaces move at approximately the same speed and in the same direction when the circuit is made, and means for adjusting the spacing between said rollers.

6. An intermittent contact device -com prising a clock driven'pointer of conducting material, a roller having a peripheral surface of conducting material normally positioned adjacent to a point in the path of movement of the outer end of said pointer whereby an electrical contact is made between them during each revolution of said pointer, an electric motorfor driving said roller such that it moves at approximately the same speed and in the same direction as the pointer at the points of contact, a source said inotor for moving the roller out of contacting position with said pointer. 7. A contact device for clocks comprism a clock driven pointer having an outer'en portion of conducting material, a pair of heral' surfaces rollers' being v my hand this 19th day of October, 1928.

rollers having adjacent peri of conductin material, sai normally positioned and spaced such that the conducting portion of the pointer bridges the gap'b'etween saidrollers at one point 1n its movement, an electric motor for driving said rollers such that the peripheral surfaces which make contact with the pointer move at approximately the same speed and in the same direction as the contacting part of the pointer when contact is made, a source of supplyfor said motor, and means responsive to a failure of said source for separating said rollers to vthe extent necessary to allow the ointer to pass between then; without makmg contact.

8. A contactmaking clock, comprising a clock movement, a ointer of conducting material driven there y, a roller having a surface of conducting material positioned adjacent to a point in the path of movement of the outer end of the pointer whereby an electric contact is established between them once during each revolution of the pointer, means for drlvmg said roller at a uniform rate such that at the point of contact between the pointer and roller the contacting surfaces move in the same direction and at approximately the samejspeed,-and a resilient driving connection between said ointer and clock movement to compensat or pulsating clock movements.

9. A contact making clock comprising a spring driven clock movement, a pointer having an outer end comprised of conducting material driven by said clock movement, a

conducting surface normally ositioned adjacent to a point in the path 0 movement of the pointer such that an electric contact is i made between the conducting portion of said pointer and said conducting surface during each revolution of the pointer, an electric motor for winding the spring of the clock and for moving said conducting surface at a speed and in a direction such that no load is imposed upon the clock movement by reason of the contact made between such conducting surface and pointer, a source of supply for said motor, and means responsive to a failure of the source of supply for moving said conducting surface to a position where it will not be touched by the pointer. x

10. A contact making. clock comprising a spring driven clock movement, apointer having a conducting portion driven by said clock movement, moving conducting surfaces adapted to grasp the conducting portion of said pointer, and establish an electric circuit therethrough at a definite point in its path of its pointer being grasped by such con- HENRY E. WARREN.