US1137474A - Selective signaling apparatus. - Google Patents

Description

E. R. GILL.

SELECTIVE SIGNALING APPARATUS.

APPLICATION FILED 0cT.21.1910.

Patented Apr. 27, 1915.

4 SHEETS-SHEET I.

Figi Fig; 2

WITNESSES: I EM 2 4 ATTORNEYS E. R. GILL.

SELECTIVE SIGNALING APPARATUS.

APPLICATION FILED OCT- 21,1910.

Patented Apr. 27, 1915.

4 SHEETS-SHEET 2.

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WITNESSES:

ATTORNEYS Patented Apr. 27, 1915.

4 SHEETS-SHEET 3.

WITNESSES:

.E. R. GILL. SELECTIVE SIGNALING APPARATUS. APPLICATION -HLEI-D OCT. 2l. 19l0.

Patente dApI'. 27, 1915.

4 SHEETS-SHEET 4.

\ w/mmsm I ww , anwm n GILL,1OF-YO1 \TKERS, NEW YonK, .assrenon, BY :umsnn assrem/rnnrs, 'ro

HALL swrrcn & SIGNAL COMPANY, ,A conronA'r-Ion or MAINE.

s LnorIv-E srenamne Arr-rents.

Specification of Letters Patent.

Patented 'Apr.j2 *7,' 1915.

Application filed October- 21, 1910.v .Ser ial No. 588,359.

To all 'gvkom it may concern:

Bet knownth'at I, EDWIN R. GILL, re-

. siding at Ynkers,;in the county of W'estchester and State of New York, have in will cause a selector-to operate at .a different vented certainnew and usefullmprovements "inSelective Signaling Apparatus, of which the following is a specification.

. This invention relates to what are known as high. speed. selectors 'for. telephones,

.telegraphs, and the like, Such selectors have .heretofore'been contrived, wherebya number of signals at different points may beselectively operated by electrical impulses over a single wire without interferenceamong themselves, the several selectors being controlled as by an automatic sender, where in ,a .n'iovable contact is'impell'ed forward rapidly step-by-step', the mechanism. being-so arranged that pauses may be produced after anyone step forward, so that each pause 51 andonly onestation. By pausing after the appropriate forward step, the operator is able to cause the operation of the selector at whichever station he pleases, thus to call that station without disturbing any other 7 upon the line. The selectorslused in connection with such selective signaling are known as high speed selectors, and an example, and upon which the present inven tion is an improvement, is shown in my eo- .pending application Serial No. l51,662, filed September 1th, 1908, patented-October 3, 1911, No. 1,004,566. In the-use of such selectors, there is one selector for each .station to be called, and any one or succession may be caused to operate, as the operator makes a pause after one or a succession of attuating impulses. The difficulty has been that the selectors could not be returned to normal, save by stepping them up through their appointed movement. Accordingly, if

the first selector, for instance, of a series were operated, in order to bring all the instruments to normal, the actuating impulses would have to be continued until all,

even the. very last, of the selectors had com- "pletedtheir appointed phase and been e0 factp returned to the normal condition necessary'to proper operation.

The present invention, therefore, contemplates a change in the construction of selectors of the kind referred to whereby upon a break in the'line, such as 1S caused when plications of principles, all as will be hereinafter fully setiforth; and the scope of protection contemplated will be indicated in the claims. i r

1 In'the accompanying drawings, which are to be taken as a part of this application, and inwhich I show a merely preferred form of embodiment of the invention; Figure 1 is a sectional View of a selector embodying my invention, showing certain of the parts in elevation; Figs. 2 and 3 are perspective views of details; Fig. 431's an .end elevation of the selector with the casing removed; Fig. 5 is a top' plan view ofthe same,-partly broken away; Fig. 6 is a side elevation,

looking at one side ofthe selector; Fig. 7

is a similar view looking at the other side of the selector; and Fig. 8 is a perspective of one of the timing devices.-

. Referring to the numerals on thedraw mgs, 1 ndicates a caslng, mclosmg a'frame work 2 that supports a horizontal shaft 4,

upon which is carried a ratchet wheel 5 that is normally impelled in the direction of the arrow in Fig. by the spiral spring 6' and which may be termed a control wheel for the mechanism. An electro-magnet 7 acts through armature 8, bowed spring 9 and connecting rod 10 to operate an impelling the magnet permits the lever 11 to move.

downward on its pivot' 17, the impelling pawl 12 will engage the ratchet wheel 5, and move the same one tooth forward. hen the electro-magnet' 7 is deenergized, the spring 9 causes the lever 11,.and with it the pawl 12, to rise. When this, motion takes place a retaining pawl 18 on a pivoted arm .19, acts on the teeth of the ratchet 5 to prevent return to normal under the influence of spring 6 (see Figs. '5 and 6).

For reasons explained hereinafter, the

arm 19 is carried on a shaft 20, rotatable in opposite side pieces of the frame, and movable upon the long journals shown in Fig.

,4, whereby the pawl 18 may be disengaged 1 driving parts should besubstantially as follows: lVhen the wheel is at-normal, and-before any call is begun, any rapid impulses should produce only a back and forth mo-' tion through the space of one tooth. .When a a call is to be begun, a pause during an impulse (the magnet 7 being energized)should prepare the wheel for action, and thereafter every impulse, whether including apause or not, should cause the wheel. tomove forward one step without backward movement, until the, phase of movement of the wheel has been completed. Fig. 2 shows the normal position of the wheel 5 and lever 19. In this position the lev or 19 is supported in an elevated position with the pawl 18 out of engagement with the wheel, a catch 21 on the lever 19 being held over a hook 22 which is fixed to a rock-shaft 23 (see Fig.1). This relation between the catch 21 and the heel: 22 is permitted because a tail-piece 24 of the hook bears on a flattened part 25 of the hub 26, fixed to the shaft 4: (Figs. 1 and The movement of the wheel 5 the distance of one tooth removes the member 37 from the end of the lever 19 and permits the part '21 to engage the'hook 22 but does not cause sufiicient movement of the hook 22 to libcrate the lever 19 and drop the pawl 18 upon the wheel 5, and therefore any number ofquick movements of the impelling'p'awl 12 merely produces quick back and forth movement of the wheel 5. I In order'to' cause thewheel 5 to progress through its whole intended course, means are provided whereby a pause of sufiicient duration, occurring while the pawl 12 is depressed, causes the pawl '18 to be dropped upon the Wheel into position to hold the same during upward movement of the impelling pawl 12. For

- this purpose I prefer to em loy the follow- 5 track 32' by the arm 34:, bnjl the' love ing meanszUpon a shaft 2 which is suitably journaledin the frame 2 (Fig. 5) is fixed a lever .28 (Figs. 7 and 8) to the outer extremity of which is'pivoted 'a frame work 29 carrying an inertia wheel 30, the hub 31 whereof rests upon 'an inclined track 32 and is adapted. to slide or roll thereon. This wheel is held' near the. upper end of the an inclined-tooth 36 (Figs. 1 and 2) of t ia va pivoted stud 32 and Whose upper endie fixed within a movable; stud 32", the latter extending through a vertical slot formed the frame 2 and being provided onthe opposite face of the side of the frame with a set screw. This permits the adjustmentof the track 32 for thepurpose ofregulating the rate of movement of the wheel 32 (Fig. 7 If the impelling pawl 12 be die I pressed'long enough, the wheel 30-will roll down far enough to permit the frame work 29 to contact a lever 35, fixed to the revoluble shaft 23, (Figs. 1 and 7) to which the heal r 22 is fixed: Thisaction pushes the hook 22 away from under, the catch 21, thus releae ing the pawl 18, and permitting itto f upon the wheel'5. After this, as the wht progresses step-by-step under the influence of the impelling pawl 12, the catch} 21 does not at any time rise high enough. to rest upon the hook which moreover is held out of engaging position by the engagement of the rounded portion of hub 26 with the hook extension 24. It follows therefore that whether the forward impulses foilow each other quickly or with intermediate pauses, thewheel 5 will move forward until wheel 5 comes in Contact with the pawl The function of this inclined tooth 36 is cause the lever 19 and its pawl 18 to move laterally so as to release thewheel The spring 6 (see. Fig. 4) at once. returns the wheel to normah'at the end of which return movement an inclined pin 37 Figs. 1 and 2) on the wheel 5 acting upon the inclined. forward face of lever 19 raises the catch 1 above the hook 22,-this being possible' cause the hookextension 2 1 is now resting against the flat face of hub 26, and the hook may therefore swing beneath catch 21. The inclined pin 37 on the wheel also causesreturn longitudinal movement of the shaft20,

whereby the'pawl 18 is brought back into' the plane of the wheel 5. It will'thus be seen that by beginning, with a long impulse followed by either long or-short impala-ice,

.the wheel 5 may be progressed any prede termined number of teeth.

'An illustrative object of the entire device is to cause the closing of a normallybpened circuit, and this end is attained as follows:

A spring contact'arm 38 is secured to an} insulating block 39(Fig. 1) that is adjust- .ably fixed to the roclrshaft 27, whose movements, as will be understood, are governed by those of the wheel 30. This spring tel urinal is connected by a fine flexible cancels The'contact 46 is adjustably held onshaft' 4, and by this adjustment any given instrw' 'ment may'be arranged for operation by any desired proper combination of impulses within its scope. As the wheel 5 is revolved,

the contact arm 46 will be brought directly beneath the spring contact 38, and contact between the two members will be efiected,

if at this point a pause is made after the impulse, so that the inertia wheel 30 will have an opportunity to roll down its track 32 and cause the shaft 27 of the spring contact to rock; contact, of course, continuing only so long as pawl 12 remains depressed.

Referring to Figs. ,1, 3, 4, and 5, the numeral 47 indicates an inertia device to prevent undesirable rebound of wheel 5. This takes the form of a weight, friction-ally attached to shaft 4, extending across the same and pressed against it by wire 48, so as to produce the proper amount of friction.

The construction and operation of the device thus far described are similar to those of the device described in my copending ap plication already referred to, but aside from minor differences between that invention and the present one, it is to be noted. that I have provided another timing element, whose function is to return the wheel 5 to normal automaticallyin a case where the wheel has not been progressed. sufliciently to bring its inclined tooth 36 into action, upon the happening of a break in the line ofpre determined extent. To this end I have provided upon the opposite side of the frame from that occupied by the inertia wheel 30,

Y a second inertia wheel 49, (Figs. 4, 5 and 6) which controls means for returning the wheel 5 to normal as stated, This timing element comprises an arm 50, fixed to a shaft 51 held at the side of the machine frame,

and to the outer end of which is pivoted a frame work 52, carrying a hub 54 and wheel 49, similar to those already described upon the opposite. side of themachine. The hub 54 runs upon a track 56 the inclination of which to the horizontal is opposite to that of the track 32." lhe wheel 49 is adapted to be slid up its track by means of an arm 57 which is secured to the forward end of the lever11, so that upon each downward movement of the impelling pawl 12, the inertia wheel 49 is slid up its track. When the impelling pawl 12 riseszupon deenergization of the magnet 7, the inertia wheel 49. will beg'in to roll slowly down its track,'and if this movement isallowed to continue for a sulfici nt. time, the ratchet wheel -5 will be re-" leased from any engagement which it may have with the pawl 18, in :the following manner: I 1

Referring to Figs. 1 and 5 a piece 58 is loosely mounted upon two pins 59 and 30, secured in the machine'frame, so that it may have considerable lateral movement, this movement being preferably limited. by collars and 71 on the pins between which I it plays. The said piece 58. has a finger- 61 which is in line withthe arm 19;, when the pawl 18 of the latter'is restingupon the wheel 5. Said piece 58also hasa part 62, which extends betwee member '65 and one side of the frame work When upon depression of the pawl 12, the wheel is i moved up its track, part 62 of piece 58; is engagedby the member 65 of the frame work 52, and the piece 58 is moved on its bearings in such a way as to draw the finger 61 away from the arm;1.9. When there is a break in the line for a certaintime, that is to say, when, after the pawl 12 has been allowed to rise andthere is no succeeding downward movement of the pawl 12 for 'a certain period, the inertia wheel 49 will be free to roll down its track, andas it does so the part '62 of piece 58' is engaged by the frame Work 52, which causes the finger 61 to move toward and engage the arm 19'if the pawl 18 is in engagement with the wheel '5, moving the shaft 20 laterally on its long journals and thereby disengaging the pawl 18 from the wheel, which thereupon is re turned to normal by its spring 6.

The operation of my selectors, whereby a circuit is closed at a selected station exclu :sively is as follows: Supposing the group of stations upon a single line to be twenty-- four, then one of my instruments is placed at each station, and the contact arms 4601i thedifierent. shafts 4 are separately adjust:

rot

edto twenty-four difierent positions. In;

strument number one will be arranged so that movement of the -wheel 5 by one tooth beyond thestarting position will bring its contact'arm 46 directly'under the tip of its contact arm 38. Instrument number two will be arranged to reach this position after two forward impulses of the Wheel; and so on with the other twenty-two insuccession.

All of the instruments will be arranged in a well known manner, so that their magnets 7 are all energized simultaneously by any.

make and break upon the common line wire.

Supposing now that station number 6 is to be. exclusively actuated. The instruments being all in the normal position (through the operation of the. timing element 49) the operator will first hold circuit through all the magnets 7 closed long enough to permit the timing element 30 to release catches 21'.

from hooks 22, so that pawls 18 may engage the first teeth on wheels 5-. Six impulses will now be produced, of which the first five ters Patent,.is:

may be long or short, but the last must be long enough to give the contact arm 38 time to descend. lhese six impulses will have brought the contact arm 46 at instrument number six directly under the contact arm 38, while the contact arms 46 in all the other instruments will have moved either too far or not far enough. Consequently, although the contact arms 38 in all -the grouped instruments will descend simultaneously during the last pause, only that at station six will descend upon its corresponding contact arm &6. Aslocal circuit willthus be controlled at station number six only.

j -Any or all of the. selectors on a line may thus be actuated in rapid succession. It is only'necessary to produce, say twenty-four energizations of all the magnets in succes- I sion, pausing at the proper intervals corre:

spondmg to the stations wanted, whereby local signals may be produced in such stations as are selected, in rapid succession, and

dill

without disturbing others. Obviously, to it is necessary that. all instruments should start from normal; Without the second timing elelnent which I have provided, supposing that station'one only had been called, the other twenty-three, instruments would be held stepped up to thc'extent or one tooth, and to bring them to normal, they would all have to complete their phase of movement. That the invention, which as a matter of lanis, twentyvthree moredmpulses would have to be produced. With my restoring device the instrumentsof a group are-all automatioally returned to normal when the sending 'of impulses ceases for a given length of time. As many clnnges could be made in the above construe ion and many apparently widely different embodiments of this inven-' tion' could be made without departing from the Scope thereof, it is intended that all mat- ,ter contained in the above description orv shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense. Y It is lalso to be understood that the language used in the following claims is intended to cover all of the generic and spe- "cific features of the invention herein described and all statements of the scope of guage, might be said to falltherebetween.

Having thus described .my invention, what I claim as new 'and desire to secure by Let- 1.111 a' device of the kind described, a c m-m1- Wheel adapted to be moved in a stepby-stop rotation, means tending to retain said control wheel in a normalposition, means actuated by a series of impulses' and enga ing, said cont1 'olwheel to impart a vstepiy-step' rotation thereto against the action of said, retainingmea'ns, and a timeela,

merit whose; function. is. to, render said rah-f mamas tuating means inoperative for rotating said control wheel until a long impulse has been said control wheel maybe restored to normal position by said first mentioned means after any degree of rotation.

2. In a device of the kind described, a

control member adapted to be stepped through a phase of movement, means for stepping said control member, means opposing the stepping of said control mem ber, means cooperating to free said control member from the action of said stepping means after said control member has been rotated through its full phase of movement, and a'time element cooperating to free said control member and permit its return to normal position under the influence of said opposing means after the completion of any movement of said control member in the event of the failure of said first mentioned freeing means to operate.

3. Ina device of the kind described, a toothed control member adapted to be stopped by one long and a series of short impulses, means tending to return-said'control member to normal position, a pawl adapted. to engage the teeth of said control member to preventzsuch return movement, a time controlled mechanism adapted to bring the control'member and the pawl into operative relation, and a second time controlled mechanism adaptedto throw said pawl out of operative relation with said control member, said last mentioned time controlled mechanism being normally inoperative against said pawl.

4. In a device of the kind described, a toothed control member adapted to a be stopped by one long and a series of short impulses, meansjtending to return said control member to normal position, a pawl adapted to engage the teeth of said control member to prevent such return movement, means whose operation is determined by said long impulse for bringing the pawl and the control member into operative relation, and means whose operation is allected by a determined length of -pause between impulses for throwing'the pawl and the control member to normal position, a pawl adapted to engage the teeth of said control member to prevent" such return movement,

a time element whose operation is determined by said. long impulse for bringing about operative relation between the control member and the pawl, and means whose operation all determined length "as throwing the pause betw pawl and the ative relation. I I

6. In a device the kind described, a

toothed control member adapted to the impulses for successively stepping said anember adapted for bring ng about operative relation between the control member and the pawl, and a time element whose operation is determined by a pause of a greater length then the pauses between said stepping impulses for throwing the pawl and control member out of operative relation.

'5. In a device of. the kind described, a toothed control. member adapted to be stepped, means tending to return said control member to normal position, a pawl adapted to engage the teeth of said control member to prevent such return movement, a time element whose operation is determined by an impulse of longer duration thanthe impulses "for successively stepping said mem ber adapted for bringing about operative relation between the control member and the pawl, means whose operation is determined by step rotation, means tending to retain 1 said control wheel in a normal position, means actuated by a series of impulses and engaging said control wheel to impart astep by step rotation thereto the action of said retaining means; and a time element whose function it is to render said actuating means inoperative for rotating said control wheel, except alter a long impulse has first been impressed upon the line; all in combinationwith a second time controlled means whose function it is to release said control wheel, whereby it may be restored to normal position by first mentionedmeans whenill the line of suliiclent adapted to retain said her against such. return ti-oi member out of oper effecting operative relation betweensaid circuit closing "member and said retaining means only after predetermined length of time; and a second time controlled member adapted to move said retaining means out of operative relation wi .iid circuit closing member. V

- 10. In a device of the kind described, a toothed wheel adapted to be stepped and having a hub provided with a flattened portion, means tending'to return said wheel to normal position, a pawl adapted to engage the teeth of said wheel to resist suoh return movement movable toward said wheel along two planes, and means engaging the flattened portion of said hub whereby to retain said pawl. against movement along one of said planes.

11. In a device'of the kind described, a toothed member adapted to he stepped, means opposing the stepping of said memher, a pawl adapted to engage the teeth of said member andprevent operation of said opposing means, and a hook adapted to support said pawl out of engagement with the teeth of said member, a time element for throwing the pawl out of engagement with the hook and into engagement with the teeth, and a time element for throwing the pawl out of engagement with the teeth.

12. In a device of the kind described, a toothed wheel adapted to be stepped, means opposing said stepping movement, a pawl movable toward and from the wheel in two planes, a hook adapted to hold the pawl away from the wheel in one of its planes of movement, an oscillatory member adapted to engage the pawl and move it in its other plane of movement, and a time element for actuating said oscillatory member. 13. in a device of the 'kind described, a toothed wheel adapted to be stepped and having a hub provided with a flattened portion, means opposing the stepping of said Wheel, a pawl movable toward and from the wheel in two planes of movement, a hook adapted to hold the pawl away from the wheel in one of its planes of movement, an extension on sa d hook resting upon the flattened portion of said hub, an oscillatory member adapted to-engage the pawl and move it away from the wheel in a parallel plane obmovement, and a movable" element adapted to ride into engagement with said oscillatory member and swing the latter.

14. in a device of the kind described, a toothed wheel adapted to be stepped and having a hub provided with a flattened portion, means 1' riding to return said wheel to normal posi on, a pawl adapted to engage the teeth of said wheel to resist such return movement movable toward said wheel ilong two planes, means engagingthe flattened portion oi said hub whereby to retain said against movement along one of said planes, and said hub beingadapted to holdsaid last mentioned means out of retaining relation with said pawl while the wheel is .being stepped.

15. In a device of the kind described, a toothed wheel adapted to be stepped and having a hub provided with a flattened portion, means tending to return said wheel .to normal position, a pawl adapted to engage the teeth of said wheel to resist such return movement movable toward said wheel along two planes, and a pivotally mounted hook having, a part engaging the flattened portionof said hub whereby to retain said pawl against movement along one of said planes.

16. In a device of the kind described, a toothed wheel adapted to be stepped and having a hub provided with a flattened portion, means tending to return said wheel to normal position, a pawl adapted to engage the teeth of said wheel to resist such return movement, and means normally engaging the flattened portion of .said hub whereby to retain said pawl out of cooperative relation with said wheel' 17. In a device of the kind described, a toothed wheel adapted to he stepped and having a hub provided with a flattened portion, means tending to return said wheel to normal position, a pawl adapted to engage the teeth of'said wheel to resist such return movement, means normally engaging the flattened portion of said hub 'whereby to retain said pawl out of cooperative relation with saidwheehand said hub being adapted to hold said last mentioned means out of retaining relation with said pawl while the wheel is being stepped.

18. In a device of the kind described, a toothed wheel adapted to be stepped and having a hub provided with a flattened portion, means tending to return said wheel to normal position, a pawl adapted to engage the teeth of said wheel to resist such return movement, and inovable toward said wheel along two planes, and two time controlled means operating independently of each other one for influencing the movements of said pawl in each of its planes of movement, one ofsaid time controlled means depending for its effectiveness upon the position of the flattened portion oi said hub.

19, In a device of the kind described, a toothed wheel adapted to be stepped and having a hub provided with a flattened portion, means tending to return said wheel to normal position, a pawl adapted to engage the teeth of said wheel toresist such return movement movable toward said wheel along two planes, and means engaging the flattened portion of said hub whereby to retain said pawl against movement along one of said planes, and independent means adapted to move the pawl toward the wheel along its other plane of movement. J

20. In a device of the kind described, a toothed wheel adapted to be stepped and having a hub provided with a flattened portion, means tending to return said wheel to normal position, a pawl adapted to engage the teeth of said wheel to resist such return movement movable toward said wheel along two planes, and means engag ing the flattened portion of said hub whereby to retain said pawl. against movement along one of said planes, and independent means adapted to engage the awl to move it away from the wheel along i s other plane of movement.

21. In a device'of the kind described, a toothed wheel adapted to he stepped and having a hub provided with. a flattened por tion, means tending to return said wheel to normal position, a pawl adapted to engage the teeth of said wheel to resist such return movement movable toward said wheel along two planes, and means engaging the flattened portion of said hub whereby to'retain said pawl against movement along one of said planes, means adapted to move the pawl toward the wheelalong its other plane'of movement, and independent means operating to move the pawl away from the wheel from the wheel along its other plane of movement.

23. In a device of the kind described, a toothed wheel adapted to be stepped and having a hub provided with a flattened portion, means tending to return said wheel to normal position, a pawl adapted to engage the teeth of said wheel to resist such return movement movable toward said wheel along two planes, means engaging the flattened portion of said hub whereby to retain said pawl against movement along one of said planes, means adapted to move the pawl toward the wheel along its other plane of movement, and time controlled means operating to move the pawl away from the wheel along its last mentioned plane of movement, 24. In a device of the class described, control wheel adapted to be rotated in a step by step movement, means tending to retain said control wheel in .a normal position, means for stepping said control wheel against the action of said retaining. mean a pawl adapted to prevent operation of said mergers retaining means, a retaining member adaptr ftaining relation with the pawl after the wheel has been rotated a notable distance.

25 In a device ofthe class described,a control wheel adapted to be rotated in a step by step movement, means tending to retain said control wheel in a normal position, means for. stepping said control wheel against the action of said'restraining means, a pawl'adapted to prevent operation of said retaining means, a retaining member adapted to normally hold said pawl out of engaging relation with said wheel, time controlled means for removing said retaining member out of retaining relation with the pawl, and

be'rotated into a predetermined position, a,

means movable with said wheel adapted to engage said retaining member to hold it out of retaining relation with the pawl after said time controlled means has performed its function and the wheel has been rotated a notable distance. I

26. In a device of the class described, a rotatably mounted contact point adapted to be rotated. into a predetermined position, a

second contact point adapted to be moved into engagement with said first contact point, and independently operating time controlled mechanisms, one governing the movements of each of said contact points.

27. In a device of the class described, a rotatably mounted contact point adapted to second contact point adapted to be moved into engagement with said first contact point, a plurality of independently operatmg time controlled mechanismsfor governing the movements of said first contact point, and one of said time controlled mech member adapted to be stepped through a phase of movement by a series of impulses, means normally opposing the rotation of said member, means for retaining said member against the action of said opposing means, automatically operating means for releasingsaid member from the action or" said retaining means when the member has been stepped through its phase of movement, and a second means automatically operative for releasing said member before the latter has finished its normal phase of movement.

29. In a device of the kind described, a member adapted to be stepped through a phase of movement by a series of impulses, means opposing the steppingof said member, means whose operation is determined by an impulse of predetermined length adapted to render said opposing means inoperative, means on said member for automatically restoring said opposing means to opmeans to operative condition when the member has not been stepped. through. its full phase of movement.

In testimony whereof I aflix my signature in the presence of two witnesses.

EDWIN R. GILL.

Witnesses:

A. S. Momosnnno, M. A. BUSCHER.

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