US2817703A - Electric selective apparatus - Google Patents

Description

v Dec. 24, 1957 I. NAXON ELECTRIC SELECTIVE APPARATUS 2 Sheets-Sheet 1 Filed Dec. 15, 1952 INVENTOR: Y [rdzrzg ZZa'xarz ATTORNEYL Dec. 24, 1957 1. NAXON ELECTRIC SELECTIVE APPARATUS 2 Sheets-Sheet 2 Filed Dec. 15, 1952 INVE OR: frying gczxovz ATTO R NEYS United States Patent ELECTRIC SELECTIVE APPARATUS Irving Naxon, Chicago, Ill.

Application December 15, 1952, Serial No. 326,084

7 Claims. (Cl. 17817.5)

My invention relates to electric selective apparatus and in the illustrated form to the impulse-receiving and character-forming apparatus of traveling display or message signs, and constitutes an improvement upon the means covered in Patent No. 2,006,999, dated July 2, 1935.

In the aforesaid patent, the making of the electrical contacts to produce the illuminated characters involved a series of metallic ball-s carried by an endless-belt type of conveyor over track units connected electrically to the lamps forming the sign characters, while accessory apparatus served to return balls from one end of the conveyor to the ball-depositing end thereof. Both of the facilities just described involved a large number of parts, rendering the apparatus expensive to produce. Moreover, the balls were electrically active in the lamp circuits which was objectionable from maintenance and other practical reasons. It is therefore one object of the present invention to devise a moving element for the traveling balls in the form of a parallel series of simple screws whose rotation causes their threads to impart longitudinal traveling movement to the balls, and further to key the balls electroconductively out of the circuits.

A further object is to effect a ball-selecting apparatus which operates by imparting a magnetic action directly to the balls, and with extreme accuracy.

Another object is to provide a screw conveyor apparatus for a ball-storage mechanism.

An additional object is to employ a single feed screw for one ball circuit as well as for a pair of the same.

A still further object is to provide a ball-selecting apparatus which in the light of the large number of contacts required in certain applications-such as in traveling message signswill be exceedingly compact while permitting of ready access for the electric lamp wire connections to the electric contact elements.

With the above objects in view, a better understanding of the invention may be had by reference to the accompany drawings, in which- Fig. l is a side elevation of the improved apparatus;

Fig. 2 is a top plan view;

Fig. 3 is an enlarged detail of a section of Fig. 1;

Fig. 4 is an enlarged section taken on the line 44 of Fig. 2 and illustrating the selective ball-depositing arrangement;

Fig. 5 is an enlarged section on the line 5-5 of Fig. 1;

Fig. 6 is a section on the line 66 of Fig. 2 looking downwardly and showing the arrangement for returning the balls into the conduits; and

Fig. 7 is a circuit diagram.

Referring specifically to the drawings, 1 denotes a framework which supports a pair of end plates 2 and 3. These journal a series of laterally-arranged screws 10. Each of these carries a gear 11 intermeshed with idler gears 12 journaled to rotate on frame studs 12a, so that all the screws are joined for unidirectional rotation. One of the idler gears is extended with a pulley 12b, which is driven from a motor 6 by a belt 7.

' Adjacent the end of each screw 10, which is proximate 2,817,703 Patented Dec. 24, 1957 to end plate 3, is erected a pair of magnetic units, each designed to operate and control a ball circuit. Primarily, each circuit involves a conduit section 14 rising from a position adjacent to one end of the screw, a section 17 curving from the upper end of the section 14 toward the other end of the screw, an inclined continuation 16 from the curved section 17, and a vertical section 18 descending from the inclined section 16 to terminate with a section 19 curved to a point adjacent to the other end of the corresponding screw. The conduit is partially filled with a succession of ferromagnetic balls which may be considered as deposited in the end of the screw adjacent plate 3 and, traveling to the left as the screws rotate, returned into the conduit circuit by the end of the screw adjacent plate 2.

The vertical section 18 of each conduit forms the tubular core of an electro-magnet 12; and the latter has a yoke 13 at the top which projects laterally as a support for a companion electro-magnet 12a which has a solid core 102 (Fig. 4).

If it is assumed for the moment that the balls are moved upwardly in each conduit section 14, it follows that they tend by gravity to cross through the inclined section 16 and descend in the return section 18. The selection of the balls for character-forming purposes occurs where they travel from the curved conduit section 19 toward the end of the screw proximate to plate 3. The entrance of the balls into a terminal screw thread would cause themon the rotation of the screw in the proper direction-to :be moved along the screw to the opposite end thereof. The rotation of the screw is such as to move balls stored therein from the right toward the left according to Figs. 1 and 2.

In the aforesaid patent that weight against the lowermost ball varied with the quantity of balls in the hopper 17. The accurate selection of the balls in the improved embodiment requires that the lowermost balls be relieved of the variable head or the cumulative weight of balls in the inclined conduit section 16, and this function is performed, as noted in Fig. 3, by virtue of the wide angle betwen the conduit sections 16 and 18-these being fastened by braces 8so that balls rolling down the incline exert almost horizontal, rather than a downward, pressure against the wall portion 18a of the conduit section 18.

The selection of the balls for signal purposes by the electro- magnets 12 and 12a is effected by placing the same in an electro-magnetic circuit which is normally closed; and the periodical breaking of this circuit is relied upon to restore the gravitational downfeed of the balls. Thus, while the ball about to be selected is designed to be influenced with a powerful tendency to locate itself in the conveyor by the constant cumulative weight of the balls in conduit section 18, such tendency is countered directly with magnetism, whereby to normally prevent the ball from feeding into the conveyor. in this manner, only a brief interruption of the magnetism restraining the ball will permit it to enter the conveyor system. This operation requires no moving parts apart from the ball itself, making high speed selection possible, since the only inertia necessarily overcome during this operation is that of the ball itself. Whereas in other signaling systems where the end result is mechanical and a line relay receiving the impulses is called upon to interpret the message into a mechanism of any character, in the sense just considered the ball being released constitutes directly the equivalent of the very armature of the line relay because the incoming impulses act magnetically and directly upon the balls without relying on a conventional armature for any mechanical interpretation.

The present apparatus employs a vertical column of balls in a conduit whose bottom 19 is curved, so that the discharging end thereof+-supported by a rail opens on the receiving end of the feed screw, as shown in Fig. 4. It is noted that the solid core 102 extends with a bottom tip 103 directly over the path of the balls in the curved con duit section 19. It is now apparent, when the balls in the conduit sections are free of influence, that the weight of the entire vertical column of balls exerts a force against the bottom ball under the pole tip 103, communicating strong pressure to push such ball into a U- shaped thread 21 of the feed s'crew. Normally counteracting this pressure is the magnetic influence due to the additive magnetic force of the coils 12 and 12a. The circuitous path of the magnetism commencing from the bottom ball referred to combines the pole tip 103, the solid core 102, the magnetic yoke .13, the ferrous lower section 19 and all the balls within the magnetic influence of the magnets12 and 12a. It should be noted that the thin wall of the conduit section 19, though of considerably less magnetic capacity than the solid core 102, nevertheless becomes a substantial magnetic companion core when filled with steel balls by virtue of the added iron in the latter.

With particular reference to Fig. 4, and assuming for the present that a continuous flow of balls is received into the'conduit 18 and that the balls pour out into the feed screw in a steady flow, the instant the magnetic circuit just described is energized the flow of balls is retarded very abruptly by a dual magnetic influence. A part of this is the magnetic influence in conduit section 19 which causes the column of balls to freeze, since they become a solenoid core inside the coil 12. However, this freezing or solenoid actionin itself would not be too accurate and upon reenergization might permit an extra ball or two to flow out, were it not for the more accurate and forceful indexing action of the tip 103 of the core 102, this being the other part of the dual magnetic influence. Since the entire magnetic circuit must pass through this tip and the ball under it which has registered accurately with the tip, the ball under the tip is frozen accurately to the same. The tip being smaller than the ball diameter therefore arrests all chosen balls in exactly the same spot every time. The normal condition of the system is that all the ball columns are stopped magnetically by steady currents through the coils when there is no transmission of signals. These are actuated by selective interruption of these steady currents, each interruption releasing one or more balls dependent upon the duration of the interruption with respect to the speed of rotation of the screws. It is obvious from this analogy that for the mere release of a single ball the current-interruption need be very brief indeed, and that the length of the interruption will determine the number of balls released successively during a given current-break.

A very important trigger-action is effected by my novel arrangement since in high speed signaling it is desirable to make the actual electrical signal (in this case interruption of current) as brief as possible as compared with the time allotted for receiving such signal. It will be'noted, where there is already a previously released ball 100a ahead of the registering one in the outlet of the curved conduit section 19, that there is a gap between these two balls while the foremost one is bottomed in the screw thread which is U-shaped to correspond to the ball curvature, and the depth of which screw thread accommodates one-half of the ball. The other half of the ball is guided in a horizontal, U-shaped channel 20a in the non-ferrous rails 20 and along the entire length of the latter. Now, when a given thread groove 21"approaches the ball depositing opening, a brief current interruption releasing a ball from the grip of the pole tip, even ifthe thread is otf and only permits the ball to drop partially therein, will yield the ball from its magnetic grip. This will occur even if the magnetism is resumed before the ball drops fully into the thread since the system will obviously not work backwards because the magnetism is not great enough to lift the column away from the screw, and particularly because of the freezing action of the electromagnet 12. Thus, if for example it takes a fraction of a second for a full thread to pass the outlet, the current interruption need only be for a fraction of that time, since a resumption of current while the thread-seated ball is still opposite the outlet will not cause the ball to recede into the outlet. The turning of the screw will shear the seated ballawayfrom any overlapping magnetic influence.

On the theory that each ball is delivered to a receiving thread of .the screw in precise synchronism with each current interruption directed to the magnetic ball environment, it follows that balls may be fed into the screw threads in a predetermined number and sequence according to the occurrence of elements in a character series. In a traveling message sign, such as is illustrated in the abovementioned patent, the elements may be one of the horizontal lamp rows forming part of each illuminated letter or character. In the present illustration there are shown seven rails 20, each one adapted to carry a series of lampactuating contacts 22, each series being employed for each horizontal row of lamps.

As the balls travel from the selection end of the screw 10 towardthe remote end thereof, the occurrence of the balls is transferred to electrical contact means designed to individually energize the lamps in the rows referred to. Thus, reference to Fig. 5 shows a bank of the contact means as a series of points 22 and spring blades 22a supporting the same, for flashing the lamps. The blades extend along the back of the channel rail 20 and normally-bear against the outer ends of a series of rivetshaped plungers 23 slidable transversely in the channel rail to the extent of locating the inner ends of the plungers in the traveling path of the balls 100. Thus, in traveling, each ballcloses the blades and contacts 22 in consecutive series. Consequently, lamps in the sign panel referred to are energized in character-formation and traveling sequence according to the number and sequence of theballs delivered into the screws 10. Fig. 4 shows that the balls are fed to both sides of a given screw; and Fig. 2 shows the apparatus to contain four screws. A later form of the traveling character sign illustrated in the above-mentioned patent employs only seven horizontal rows of character forming elements instead of the eight shown in the patent, so that both sides of three screws and only one side of the fourth are used for accommodating the seven ball series employed for the control of the related element rows.

When the balls traveling along a given screw reach the remote end portion thereof, they approach the side entrance 14a of the upward conduit section 14. The last screw thread tapers off as indicated in Fig. 610- ward a conical collar 24 which adjoins the entrance 14a referred to. Thus, the ball in the last thread groove is gradually crowded by the end of the latter to seat into the side entrance 14a by the conical collar. Now the ball .next behind is crowded in the same manner against the foremost one for which the only escape is the entrance 14a. The foremost ball is therefore forced into the entrance; and similar action by the succeeding balls urges the advancing ones to rise in the conduit section 14, so that each screw procures the positive overhead and return travel of the balls in this manner.

As the balls rising in the conduit sections 14 may retain a degree .of residual magnetism, suitable demagnetizing units 25 are disposed around such conduit section to remove any tendency in the balls to cling to each other .or assume a progress-deterring friction in the .walls of the conduit. The units 25 are all series-connected and placed across an A. C. source, not shown.

One of the screws carries for rotation therewith a cam 26 designed to send an impulse for each revolution of the screws, the latter being synchronized together through the medium of the gears and idlers 11 and 12 so as to rotate not only in unison but to cause their respective thread grooves to be timed, each for simultaneous registration, with the respective discharge-openings of the conduits 19. In this respect, since three of the screws are centered between a pair of such ball-releasing devices, it should be noted that, as judged from Fig. 2, the rearmost of the ball-releasing devices are staggered to the left with respect to the companion devices, by one-half thread. This offset permits two balls to be dropped into the diametrically opposite sides of the same thread-turn, simultaneously.

Rotation of the cam 26 causes the opening and closing of a pair of contacts 27 and this causes a direct current impulse, starting from a source of energy marked to pass through the contacts 27 through a line 28, through a tape-stepping magnet coil 29 and thence to ground; the earth forming the return-circuit to the source of direct-current potential since the negative side of the latter (not shown) is also grounded at its source.

The outline 30 represents the ball-releasing and storing mechanism heretofore described and which may here- .forated with characters such as described in my c0- pending application, Serial No. 752,124. Said tape is provided with feed-holes and is adapted to be fed through the transmitter by means of a conventional tape feedwheel 32 having sprocket teeth 33. The feed-wheel also carries for rotation therewith a ratchet wheel 34 having ratchet teeth equal in number to the sprocket teeth and the arrangement is such that a single downward pull by a pawl 35, caused by the magnetic pull of the coil 29 on the core 36, causes the tape to advance one step forward. An armature lever 37 serves to connect the magnet core with the pawl with springs 38 and 39, respectively, serving to restore the armature core and pawl to normal positions.

From the above description, it will be apparent that each time a cam-impulse is transmitted from the controller to the transmitter over the line 28, the message tape will be advanced one feed-hole forward, thus assuring that the transmitter and controller remain in step at all times. In order to selectively release balls in the controller system, it is necessary, as heretofore explained, to interrupt the current in the coils 12-12a, and such interruption is occasioned by brief interruptions 0f the direct-current flowing from the positive side of the current source, through a conductor 40 common to the entire group of coil-sets 1212zz, through the corresponding seven signaling lines stretched between the controller and the transmitter, through seven sets of normally-closed contact points 41 (only one of which is illustrated) and thence to ground which, of course, again comprises the return circuit for the source of direct current originating at the transmitter. The negative side of the direct-current source is not shown, but can be the grounded negative pull of a battery or a direct-current generator, the positive side of which being connected to the positive terminal indicated. As in printing-telegraph-transmitters, the paper tape 42 is fed to the left and passes under a bridge 43 comprising a fiat plate containing a lateral row of holes corresponding to a full lateral row of holes in the tape, the latter combina-tion of holes incidentally representing the letter 1. Means for seeking out the holes in the tape is provided in a set of seven rocker arms 44, carried side by side on a common pivot 45, and each arm of which carries a hole-seeking finger 4-6. These fingers are disposed with their upper ends normally immediately below the tape and are of such a size as to pass through the holes in the tape and freely through the holes in the bridge 43, this upward motion of each lever 44 being occasioned by light springs, not shown. The upper contacts of the seven pairs of points 41 are carried by a lateral row of contact tongues 41a, insulated from one another, while all of the lower contact points 41 are connected together, by the grounding of all the lovers 44.

In transmitting messages, the motor 6 rotates continuously, thereby sending timed impulses over the line 28 in order to step the tape forward. In so doing, and when the armature 29 first becomes energized, it causes an inverted U-shaped bail 50 having its free ends fastened to the lever 37 to pull all the tape fingers 46 downwardly and away from the tape; at the end of this stroke, or at least at the point when the tape fingers are clear of the tape, the feed pawl advances the tape one step to the left and a detent wheel (not shown) may be provided to yieldably retain the ratchet wheel in this position. At this point all of the contact sets 41 are closed and none of the balls are released into the conveyor mechanism, but as soon as the current becomes interrupted in line 28, the spring 38 causes an upward movement of the armature system including bail 56, thus permitting the springs which normally yieldably lift the contact fingers upwardly towards the tape to contact the latter; obviously, such fingers as the holes in the tape are permitted to pass through the tape, and this action momentarily interrupts the current by the opening of the corresponding contact points 41. The yieldable force or springs employed to lift the contact fingers and levers 44 upwardly are sutliciently heavy to open the contact points 41 when a corresponding finger falls through the tape and into the holes in the bridge 43, yet said springs are not so strong as to cause the fingers to perforate the tape in conjunction with the bridge holes.

In setting up the controller, the normal requirement of steel balls in each conduit-screw circuit is such that the two vertical columns 14 and 18 in each circuit are filled with balls, in addition to which the inclined tube 16 of the corresponding circuit contains sufiicient balls to correspond to the number of thread-turn in the screw. Thus, in signalling, the vertical columns always remain filled while the number of balls cushioned in the inclined tube varies as the ball-requirement in the corresponding screw and guide channel 20a vary. When the side of a screw allotted to a ball circuit becomes full of balls, the corresponding inclined tube 16 becomes practically empty and vice versa.

The contact-spring assembly for the points 27 may be mounted on an insulating disc (not shown) through which the camshaft freely revolves and this disc, including the contact assembly, may be adjustably rotated by hand about the camshaft in order to orient the timing of the cam-pulses to enable an adjustment to be made, permitting the balls to b released into the screw-threads to the most desirable timing. In lieu of the above, the cam 26 may be set-screwed to its shaft and orientation may be effected by adjusting the relation between the cam and its shaft, although with this manner of phasing the machine may have to be stopped for each adjustment.

I claim:

1. Electric selective apparatus comprising a columnar series of free magnetizable elements, a ferro-magnetic circuit including a plurality of elements in said series of elements, means effective upon the magnetization of said circuit for magnetically arresting said plurality of elements and operable upon the selective demagnetization of said circuit for selectively releasing said elements in response to signals electro-magnetically affecting said circuit.

2. An electric selective apparatus comprising a plurality of magnetizable free elements, a conveyor adapted to receive and store said elements in response to and in accordance with signaling impulses, said conveyor adapted at one end thereof to receive the elements as selected, convey them in signal formation, and eject them from the other end of the conveyor into a conduit system, the latteradapted to return said ejected elements to the receiving endof-theconveyor,-a column forming the return portion ofsaid conduit and leading to the first-mentioned end of the conveyor, and an electromagnet surrounding said column and normally eifective on such elements as are re ceived therein to arrest their motion, said signaling impulses operating to deenergize said electromagnet according to incidents in said formation.

3. The structure of claim 2, said elements comprising steel balls, and a plurality of those in said column operating as an armature for said electromagnet.

4. An electric selective mechanism comprising a conveyor system, a plurality of balls designed to be conveyed therein, and electro-magnetic means effective in one part to influence a series of the balls directly and ferromagnetically and in another part to similarly influence a single ball, the influencing actions comprising the release of the affected balls from said electro-magnetic means in response to signals and into said conveyor system, a conduit for said balls communicating with said conveyor system and having one portion as a column and another portion as an outlet into said conveyor system, said one part being an electromagnet surrounding said column, and said other part being a second electromagnet with a core directed to said single ball.

5. An electric selective mechanism comprising a conveyor system, a plurality of balls designed to be conveyed therein, and electro-magnetic means etiective in one part to influence a series of the balls directly and term-magnetically and in another part to similarly influence a single ball, the influencing actions comprising the release of the affected balls from said electro-magnetic means in response to signals and into said conveyor system, a conduit for said balls communicating with said conveyor system and having one portion as a column and another portion as an outlet into said conveyor system, said one Q 0 part being an electromagnet surrounding said column, and said other part being a second electromagnet with a core directed to said single ball,.and such core having a tip along the path taken by said ball for fixing the position of the latter by the influence of the second electromagnet when such ball is to be released as stated.

6. An electric selective apparatus comprising a screw conveyor, and means for selectively depositing in response to electric signals a series of free elements into the thread turns of said conveyor, said means comprising a solenoid electro-magnet having a core, and said series of tree elements comprising said core.

7. An electric selective apparatus comprising an electro-magnetic Winding having a movable solenoid core therein, said core comprising a series of free magnetizable elements normally restrained from motion through said winding by an electric current passing through the latter, means normally tending to move said series of elements as a group through and against the magnetic action of said winding, and means for selectively interrupting the current passing through said winding to release said elements individually in accordance with predetermined signals.

References Cited in the file of this patent UNITED STATES PATENTS 767,599 Sedgwick et al Aug. 16, 1904 1,563,906 Kleinschmidt Dec. 1, 1925 2,006,999 Nachumsohn July 2, 1935 2,254,289 Aamodt Sept. 2, 1941. 2,254,814 Angel et a1 Sept. 2, 1941 2,275,436 Holcomb Mar. 10, 1942 2,292,489 StibitZ Aug. 11, 1942 2,343,297 Holcomb Mar. 7, 1944 2,406,028 Myers Aug. 20, 1946

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