US1381514A - Electromagnetic step-by-step mechanism - Google Patents

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C. P; SOPER AND J. A. HALL. ELECTROMAGNETIC STEP-BY-STEP MECHANlSMi APPLICATION FILED SEPT. 29. 1919.

1,381,514, Patented June 14,1921.

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UNITED (STATES PATENT OFFICE.

CHARLES P. SOPEIh OF MAPLEWOOD. NEW JERSEY, AND JOHN A HALL, OF BAY SIDE,

NEW YORK, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N.' Y., A CORPORATION OF NEW YORK. I

ELECTROMAGNETIC STEP-BY-STEP MECHANISM.

'Toallwhomitmayconcem:

Be it known that we. CHARLES P. Sornn and J OHN A. HAiIL, citizc hs of the United States, residing at Maplewo'od, in, the county of Essex andStat ecof New Jersey, and at Bayside, Lon Island,- in'the county of Queens andtate of New York, respectively, have inventedcertain new and useful Improvements in Electromagnetic Stepby-Step Mechanisms, of which thefollowmg is a full, clear, concise; and "exact de- T isinvention relates Step-by;step mechanisms and moreiparticu larly to means for electrically controlling I the operation of such. mechanisms.

1 The object ofthe invent'ion is to provide an improved step-by-step mechanism in which the full step both forward and backward is insured, not by any mechanical adjustment of springs, but rather by the movement of the. member to be moved;

Heretofore in such arrangements the movement of the actuating member has been:

c'ontrolle'dfiby mechanictihmeans which although adjusted to correspondfwith the movement ofthe member to be .moved, nevertheless did not cooperate with it. According tothe above object the. present invention contemplates an. arrangement, wherein no special adjustment is necessary since the movement of the; actuating member is con- 'trolled by the ,movement of the actuated member. 1 I

.More specifically this invention .-comprises a magnet caly actuated pawl adapted to step a'ratchet member forward. and a holding pawl adapted to, prevent backward movement of said ratchet member. Each of these pawls controls contacts in the energizing circuit of the. electromagnet, said contacts being so arranged that on the forward movement of the ratchet. member the circuit arrangement is maintained undisturbed until the holding pawl drops into a succeeding tooth at the end of a step. Thereupon the condition of the circuit is changed and this changed condition '18 maintained until the" stepping pawl drops into a succeeding tooth at which time the mechanism 'is ready to repeat this cycle of operations. Any desired means for closing the electrical circuit to initiate stepping and opening it to arrest stepping may be provided. The

to electromagnetic Specification of Letters Patent. Patented'June 14, 1921. Application filed September 29, 1919. SerialNo; 327,123.v

mechanism may be employed to rotate a shaft, to advance a toothed bar, or wherever a step-by-ste'p-movement is desired;

In the drawings Figure 1 is a view in elevation of the invention applied-to a mechanism in which an electromagnet inattracting its armature actuatesa'a pawl to stepa ratchet wheel, and in retractinglits armature moves the pawl into'enga'gement with a succeeding toothqn'eparatory to the next step. Fig; 2 is a view'in elevation of the invention applied to "a mechanism in" which an electromagnet iii-attracting its armature moves a pawlbackward to engage'a tooth of a'ratchet wheel, and in retractingits armature aotuates the pawl to step the ratchet wheel forward. I I

Both Figs. land 2 show the mechanisms in normal position with theelectromagnets deenergized. The circuits for the electromagnets are indicated diagrammatically. Fig. 3 shows a portion ofthe mechanism illustrated in Fig.2 at the moment just. before the armature is completely attracted anew tooth. v

Referring more particularly to Fig. 1, an

and as the stepping pawl is vabout toengage electromagnet 1"is secured to a yoke 2 upon.

which is pivotally supported an armature 3; at the point 4. Contact springs 5-, 6;? and 8 are mounted upon a -bent'overportion 9 ofthe yoke 2, being insulated therefrom I and from each other in any desired manner.

A spring 10 retracts the armature 3 when the magnet 1 is deenergized, the retracting movement being arrested by a stop 11 fined to the frame (not shown). A stepping pawl is pivotallymounted at the end 12 of armature 3. The pawl 13 is held in engagement with the teeth of a ratchet wheel 14 by'the pressure of spring 8 on a button 18 of insulating material rigidly fixed to pawl 13'. The ratchet wheel is rigidly mounted on a shaft 15 which may be rotatably supported in any desired manner. Backward movemnt of wheel 1.4 is prevented by the end 17 I of s ring 5 which acts as a holdingpawl.

en the switch 16 is closed, a circuit is completed to energize magnet 1, which circuit may be traced from grounded battery, switch 16, through, the winding of magnet 1, springs 8 and 7 to ground. Magnet 1 in attracting its armature actuates pawl 13 to step ratchet wheel 14 forward, that is n springs 7 and 10- 6. thus completing a substitute energizing circuit for magnet 1 which may be traced through springs 5 and 6 in parallel with the circuits previously traced through 8. Just after the closure of springs 5 and 6, the button 18 carried by pawl 13 encounters a bent portion 19 of spring 8, thus forcing springs 7 and 8 apart. The button 18 is it will hold springs 7 and 8 apart throughout the a'ema-inder of "the forward step of pawl 13. The ma netthus remains energized until the bolt ing end 17 of spring 5 passes over the edge of the tooth upon which it has been riding and drops into engagement with the next tooth. Tn dropping into engagement with the next tooth. spring 5 opens the circuit for magnet 1 at the contact between springs 5 and 6. and magnet 1 dccnergizes, its armature3 being under the tension of spring until it cucounters stop 11. uring the retraction of armature 3, springs and 8 are held apart by theengagement of button 18 with spring 8 until pawl 13, in dropping into engagement with the next tooth, again closes the contact between springs 7 and 8, whereupon the cycle of operations described is repeated. Thus stepping continues as long as switch 16 remains closed.

In the mechanism shown in Fig. 2, a magnet 20.is secured to a frame member 21, on which is pivotally mounted at 22 an armature 23. Armature 23 is normally held in retracted position against a stop 24 hyspring 25. A lever 26 rigidly mounted on armature 23 pivotally supports at 27 a cranbshapcd stepping pawl 28. Contact springs 29, 30, 31 and 32 are secured to frame piece 21 by a screw 37 and are insulated therefrom and from each other. Pawl 28 is held in engagement with the teeth of a ratchet wheel 34 by the pressure of spring 29 on the arm 33. and the pressure of the teeth on the nose of pawl 28 causes arm to close the contact between springs 29 and 30 at all times except that just after pawl 28 has ridden over the edge of a tooth and has dropped into engagement with the next tooth. The ratchet wheel 34 is rigidly secured to a shaft which is rotatably mounted in any desired manner. Spring 31 acts as a holding pawl, and is positioned so as to make con tact with spring 32 only in the position which it occupies just after spring 31 has ridden over the edge of .a tooth. In other positions the pressure of the tooth moving under spring 31 forces it away from spring 32 so as to break their contact.

,en switch 36 is closed, a circuit is com- 5 is forced by the into engagement with spring ,by the tooth over which it is facts between springs 29 and 30.

so positioned that retracted mechanism, a

pleted from grounded battery, switch 36, through contact springs 29, 30, 31 and 32, in series, throuwb the windingof magnet 20 to ground. It agnct 20 is energized in this circuit and attracts its armature 23. Throughout the attractive step of armature 23 the nose of the pawl 28 is forced upward passing, thereby'holding arm 33 againstspring 29 to maintain the closed condition of the conahS this step, in contact. Fig.

wheel34 is not in motion during springs 31 and 32 remain 3 shows the position of the pawls and contact springsnear the end of the attractive step of armature 23. Thus the energizing circuit for magnet 20 is maintained until the pawl 28- in dropping into engagement with the next tooth allows spring 29 to give a clockwise rotation to the pawl 28,'thereby opening the contact between springs 29 and 30. he energizing circuit being thus broken, magnet 20 dlienergizes and its armature 23 is retracted by spring 25. Durin this retractive movement pawl 28 is moved "to the right by lever 26 to step in a clockwise direction. Spring 31 in riding over the tooth with which. it is in engagement, opens the contact between springs 31 and 32, so that the energizing circuit of magnet 20 is maintained open atthis point until spring 31 drops into engagement with the nexttooth.' At this time pawl 28 has completed its forward step and closed the contact between springs 29 and 30 so that .100 the circuit is again completed for energiz; ing magnet 20, and this cycle of operations continues as long as switch 36 is closed.

Thus it will be seen that in both the types ot mechanism illustrated in Fig. 1, and in Fig. 2, the magnet circuit ischanged to cause a forward step of the ratchet wheel when the stepping pawl passes over the edge of one tooth to drop into engagement with a new tooth, and that this conditionof the circuit ismaintained through the forward step until the holding pawl passes over the edge of one tooth and drops into engagement with a succeeding tooth. In each case the droppin of the holding pawl into enga ement wit the succeeding tooth changes t e condition of the circuit to cause backward movement of the stepping pawl preparatory to the next s ep.

What is claimed is:

1. In an electromagnetic step-by-step ratchet member, means for stepplng said ratchet member forward, an electromagnetic means ztor operating said stepping means, mechanical means actuated when said electromagnetic means is rendered inoperative to restore said stepping means to normal position, means for holding said ratchet member after ithas been stepped forward, means actuated by said stepping means in dropping into engagement with a ratchet tooth to actuate saidelectromagneticoperating means, and means actuated by said holding means in dropping into engagement with a ratchet tooth to render inoperative said electromagnetic means,

2. In an electromagnetic stepping device, a ratchet member, a pawl tostep said ratchet member, a pawl to hold said ratchet member after it has been stepped, a magnet to operate said stepping pawl, a spring to restore said stepping pawl, an energizing circuit for said magnet, means actuated by said stepping pawl when it. drops into engagement with a ratchet tooth tocomplete said energizing circuit, and means operated by said holding pawl when it drops into engagement w1th a ratchettoothto break said energizing circuit to allow said spring to move saidvstepping pawl into engagement with afresh tooth.

3. In an electromagnetic stepping device, a ratchet member, a pawl to step said ratchet member, a pawl to hold said ratchet member after it has been stopped, a magnet to operate said stepping pawl, a spring to restore said stepping pawl, an energizing circuit 'for said magnet, a contact member actuated by said stepping pawl when it drops into engagement with a ratchet tooth to complete said energizing circuit, and a second contact member operated by said holding pawl when it drops into engagement with a ratchet tooth to break said energizing circuit to allow said spring to move said stepping pawl into engagement with a fresh tooth. T

In witness whereof, we hereunto subscribe our names this 23rd day of September, A. D.

CHARLES P. SOPER. JOHN A. HALL.

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