US2750586A - Random binary pattern generator - Google Patents

Description

June 12, 1956 H. L. DANIELS RANDOM BINARY PATTERN GENERATOR Filed Jan. 19, 1954 llill INVENTOR. How/1R0 L DAN/as H T TORA/E) States 2,750,586 RANDOM BINARY PATTERN GENERATOR Application January 19, 1954, Serial No. 405,055

12 Claims. (Cl. 340--357) This invention is directed to a random binary pattern generator for use in coding equipment and more particularly the invention is directed to a random binary pattern generator for providing a completely unpredictable electrical pattern at each operational cycle.

The random binary pattern generator described herein can be used in the equipment of patent application Serial No. 405,270, filed January 20, 1954, by Walter L. Anderson, Howard L. Daniels and Robert R. Reisinger for Time Delay Scramble Equipment.

In codingequipment which employs the time delay scramble principle it is extremely important to constantly vary the scrambling scheme whereby an input voice signal is. divided into short consecutive voice segments and scrambled into an unintelligible sound signal. Time dclay scrambling equipment generally includes a plurality of cross-wired wheels of the character described in Serial No. 405,056, filed January 19,, 1 954, for Variable Cross Wired Wheels. These cross-wired wheels are arranged for rotation so as to change the scrambling sequence for the divided segments of the inputvoice signal. The rotation of the cross-wired wheels usedin such equipment can be accomplished manually. However any change of the position of the cross-wired wheels in the sending equipment has to be accompanied by a corresponding change of the position of the corresponding' cross-wired wheels in the receiving equipment. This information has to be transmitted along with the scrambled voice signal. There are major disadvantages in the manual method of varying. the position of the cross-wired wheels. Primarily manual operation limits the number of changes. Information on the change has to be transmitted prior to the. change. Limited security results.

This invention provides a device which is adapted for use in coding equipment to provide. an unpredictable output electrical pattern for each operational cycle of the device and adapted to control the positioning of crosswired-wheels in both sending and receiving equipment. Essentially the generator comprises a series ofi on-off (binary) switches all of which are simultaneously controlled by electromagnetic means in combination with a continuously rotatable setting device driven by a motor. The output electric pattern: from this device is completely unpredictable in view of the factthat it depends upon several nonconstant parameters. These parameters com prise, in part, the amount of dust in the surrounding atmosphere, the amount of available lubrication on each of thebearings forming part of' this invention, the sizes of the balls-in each of the ball bearings, and ambient temperature.

An object of this invention is to provide a random binary-pattern generator which produces anunpredictable output electrical pattern.

A. further object is to provide a random binary pattern generator which requires a minimum of care since atent I 17. The legs its purpose is to provide a nonconstant unpredictable output.

A further object is to provide a random binary pattern generator which utilizes the variable surrounding natural conditions to provide an unpredictable output binary elec trical' pattern.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a front side elevation of a preferred embodiment of this invention,

Fig. 2 is a plan view from the top of Fig. 1 with parts broken'away, and

Fig. 3 is an enlarged detail view of one cam and ball bearing assembly used in this invention.

The device shown in Figs. 1 and 2 comprises" a fiat supporting base member 11. Secured centrally of the base 11 and extending transversely thereof is a shaft supporting structure 12. The shaft supporting structure 12 is in the form of a U-shaped member having two upstanding legs 13 and 14, secured to the base 11 through a plurality of vibration inhibiting members such as rubber pads 15 for preventing the transfer of vibrational forces to the switch parts subsequently described. The upstanding legs Band 14 are provided with axially aligned bores, not shown, adjacent the upper ends thereof and each bore communicates with a horizontally extending open slot' 13 and 14 are suitably drilled and tapped to'recei-ve bolts 19 extending across the slots 17 inthe legs 13 and 14. The bolts 19 serve to secure bearings, not shown, in the bores through the two legs 13 and 14 of the support member 12.

There is secured uponthe shaft 18 a plurality of equally spaced ball bearings 20; all the ball bearings have identical commercial-dimensions. The inner race 21 of each of the ball bearings 20 is conventionally secured upon the shaft 18. Inthe embodiment'shown, ten ball bearings are mounted on the shaft 18. This is not to be construed as a limitation on the number of ball bearings that can be. used in this invention since the device operates equally well Whether a bigger or smaller number of ball: bearings are used. Secured to the outer race of. each. of the ball bearings is a cam 23 which cam is retained in place on the outer race by an insulating sleeve member 24. There is no slippage between either the cam 23 and the insulating sleeve 24 or the insulating sleeve 24' and the outer race of ballbearings 20. Each of. the cams 23is divided into a plurality of sectors such asquadrants. The periphery of the oppositely disposed quadrants have equal radii for balance; adjacent quadrants. are separated by aradial projection 26. The shaft 18 supporting the plurality of ball bearings 20 is retained inplace in the legs 13 and 14- of a support 12. The shaft 18 is free to rotate in the legs 13 and 14 of the support 12. Shaft 18 supports a; pulley 27 at one of its ends; The shaft 18 is adapted to be continuously driven by a motor 28' through the medium of a loose slipping belt 29 passing over the pulley 27 of the shaft 18. The

belt 29 is designedly selected'to be of such dimension and such frictional characteristics as to not transmit a constant torque from the driving motor 28 to the shaft 18. As a result of using a slipping belt the R. P. M.

and the angular velocity ofthe shaft 18 bears no fixed relationship to the R. P. M. and the angular velocity of the driving motor. Since no two ball bearings are exfreed to rotate the influence of forces transferred frictionally from the shaft 18 to each of the outer races, any slight differences in the amounts of lubrication within bearings 20 or differences in the amounts of dust within bearings 20 or variations in the sizes of the balls of the bearing 20 cause different amounts of force to be transferred to each of the outer races. Therefore with continuous rotation of the shaft 18 and with each outer race of the ball bearings freed to rotate, the relative angular positions of each of the outer races is completely unpredictable at any instant after the earns 23 are freed.

Mounted adjacent each side of the fiat base member 11 is an electromagnet 31. Each electromagnet is supported within a frame 33. The frame 33 of each electromagnet 31 is fixedly mounted upon the base 11 by means of bolts 34. Each of the electromagnets 31 is provided with an armature assembly 36. Each armature assembly 36 has an armature plate 37 and a pair of downwardly projecting arms 38. One of each of the pairs of downwardly projecting arms 38 is arranged in cooperative relationship with a stop 39. The other arm 38, not shown, of each pair of downwardly projecting arms is engaged with one end of a tension spring 41. The other ends of the tension springs 41 are secured to any convenient portion of the support 12. The spring 41 retains the downwardly projecting arm 38 seen on the drawing in abutting relationship with the stop 39. Therefore the armature plates 37 are normally in the position shown on the drawing.

Secured to each of the armature plates 37 is a flat rectangular support member 43. Each flat rectangular support member 43 supports a plurality of conventional binary leaf spring switch units 44. Each switch unit can assume an open circuit position and a closed circuit position and is therefore described as binary switches.

The spring leaf switches 44 comprise in each case a pair of spring leaves 45 and 46, the spring leaf 45 being disposed directly above the spring leaf 46. Each pair of leaf springs 45 and 46 are insulatably supported relative to one another. The contacts 47 and 48 on the ends of the spring leaves 45 and 46, respectively, are normally in spaced relationship with respect to one another.

In operation, when the electromagnets 31 are energized the armatures 37 are urged downwardly against the bias of springs 41. As is more clearly shown in Fig. 2 each of the switches 44 are associated with a single one of the earns 23. Therefore, when the electromagnets 31 are energized the armatures 37 and switches 44 are urged downwardly and into operative position in which position the switches may be open or closed. The end 51 of each of the spring leaves 46 engages its associated cam 23. Though the shaft 18 continues to rotate the ends 51 of each of the spring leaves 46 engage the radial projections 26 and restrain the cams from rotating. If end 51 of a leaf spring 46, which is the actuator portion of the switch comes into engagement with a peripheral surface of a cam of smaller radius the contacts 47 and 48 remain in spaced relationship. However if end 51 of a leaf spring 46 comes into engagement with a peripheral surface of a cam 23 of bigger radius the contacts 47 and 48 are forced into engagement. As a result some of the switches 44 are closed while some of the other switches 44 remain open. Since the outer races of the ball bearings assume unpredictable angular positions at any one instant the particular switches that will remain open and those that will close do not follow any predetermined schedule. For so long as the electromagnets 31 remain energized the switch pattern set up when said energization of the electromagnets 31 took place remains in effect and the outer races of all the ball bearings remain stationary. When the electromagnets 31 are again deenergized and the armature assemblies 36 are pivoted under the bias of the springs 41 to inoperative position, the outer races are freed for rotation.

At that time the outer races of all the ball bearings again begin to rotate in a random manner as previously described and the generator may again be used to set up another completely random binary pattern. The switch units 44 are adapted to control separate relays for controlling the setting of cross-wired wheels in coding equipment.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. A random binary pattern generator comprising a support; control means including an actuatable portion and two conditions of operation; said control means being biased to one of its two conditions of operation; means attached to said support and attached to said control means for positioning said control means in either one of two positions relative to said support, second means, antifriction means supporting said second means on said support and adjacent said control means, said second means being adapted to be positioned in any one of a plurality of positions relative to said support adjacent said control means whereby in any one of the positions of said second means and for one of the positions of said control means, the clearance between said control means and said second means is one of two distances, third means mechanically coupled to said antifriction means for moving said second means randomly to any of its positions whereby said control means is actuated out of its biased condition to its second condition only when said second means is in a position corresponding to reduced clearance and said control means is moved by the said means attached thereto to its other position wherein it engages and is actuated by said second means.

2. A random binary generator comprising support means; a shaft mounted for rotation in said support means; antifriction means including relatively rotatable inner and outer elements, the inner element of said antifriction means being fixed to said shaft; a balanced peripherial cam secured to the outer element of said antifriction means, the peripheral surface of said cam being divided into at least four arcuate, concentric peripheral surface portions separated by narrow radial projections, the arcuate peripheral surface portions being separated by narrow radial projections, the arcuate peripheral surface portions of said cam each being formed at one of two radii; a switch having an open circuit condition and a closed .circuit condition and normally biased to one of its two conditions, said switch being provided with an actuatable portion for changing the condition of said switch from its normally biased condition to its other condition; means supporting said switch on said support means and adapted to position said switch in one of two positions relative to said support means and biased to normally position said switch at one of its positions, said means supporting said switch adapted to be selectively stimulated to overcome its bias for positioning said switch in the other position; whereby when said switch is in one of its positions its actuatable portion is spaced from said cam, and when said switch is in the other of its two positions, its actuatable portion engages one of the arcuate peripheral surface portions of said cam and prevents said cam from rotating by engaging one of the narrow radial projections of said cam, and whereby if the arcuate peripheral surface portion engaged by the actuatable portion of said switch is of the smaller radius said switch remains in its normally biased condition but if its actuatable portion engages an arcuate peripheral surface portion of larger radius said switch is actuated to its other condition.

3. A random binary generator comprising; a base; a bracket secured on said base; a shaft mounted for rotation eg'rsmese in said bracket; a'ballbearingmounted on saidshaffi'the inner race ofsaid ball bearing being-fixed to said shaft; 'a balancedperipherial cam secured to the outer race of 'said ball bearing, theperipheral surface of said cam 'beingldiv-ide'dintoan even number of atleast'four arcuate, concentric, peripheral surfacessep'arated by narrow radial projections, thearcuate peripheral surfaces of said cam each beingformed atone of'two radii'gia switch havingan open circuit condition and a closed circuit condition and normally" biasedfor. one of these conditions, said switch beingprovided with an actuatable portion for changing the condition of the switch from its normally. biased condition to its other condition; means supporting said switch on said base and adapted to'positi'on said switch in one of two positions and biased to normally position said switch at a first position, said means adapted to be selecti'velystimulated to overcome its bias for positioning said switch in. its second position; whereby when said switch is in the one of its two positions, its actuatable portion is spaced from said cam, and when said switch is'inthe otherof its two positions, its actuatable portion engages one of the arcuate peripheral surfaces of said cam and prevents. said cam. from rotating by. abutting one of its narrow radial projections, and whereby if the arcuate peripheral surface engaged by said switch is of the: smaller-radius it remains. in its normally biased condition but if: it' engages. an. arcuate peripheral surface of larger radius: it is. actuatedto its other condition;-

4. A random binary generator as described in claim 2 further including means coupled to said shaft for rotating said shaft at a continually variable angular velocity.

5. A random binary generator as described in claim 2 further including a pulley secured to one end of said shaft; a motor; a pulley secured to said motor; a belt engaging both said pulleys, said belt being sufliciently loose so that there is continuing change in the relationship between the angular velocity of said shaft and that of said motor.

6. A random binary pattern generator comprising; a base; a bracket secured on said base; a shaft mounted for rotation in said bracket; a plurality of substantially identical ball bearings mounted on said shaft in axially spaced relationship; the inner race of each of said ball bearings being fixed to said shaft; a corresponding plurality of balanced peripheral cams, each being secured to the outer race of a corresponding one of said ball bearings, the peripheral surface of each of said cams being divided into an even number of at least four arcuate, concentric, peripheral surface portions separated by narrow radial projections, the arcuate peripheral surface portions of said cams each being formed at one of two radii; a corresponding plurality of switches, each switch having an open circuit condition and normally biased for one of the two conditions, each switch being provided with an actuatable portion for changing the condition of the switch from the normally biased condition to the other condition; means supporting said switches on said base, said means adapted to position said switches in one of two positions and biased to normally position said switches at one of the two positions, said means adapted to be selectively stimulated to overcome its bias for positioning said switches in the second position; whereby when said switches are in the one of the two positions, their actuatable portions are spaced from said cams, and when said switches are in the other of their two positions, their actuatable portions each engage one of the arcuate peripheral surface portions and one of the narrow radial projections of the corresponding one of said cams and prevent same from rotating and whereby whenever the arcuate peripheral surface portion engaged by the actuatable portion of a switch is of the smaller radius, the corresponding switch remains in its normally biased condition but wherever an arcuate peripheral surface portion engaged by an actuatable portion of a switch is of the larger radius,- the corresponding switch is actuated; to its other condition;

7., A randornt binary pattern generator as described in. claim. 6 further, including means. coupled. to said shaft for rotating said" shaft" at a. continually variable angular velocity.

8. A random binary pattern generator as described in claim 6 further including a pulley secured to one end of said shaft; a motor; a pulley'secured to said motor; a beltengagingboth saidpulleys, saidbelt being sufficiently loose sothat there is continuing; change in the relation ship between the angular velocity of saidishaft. and that of said motor.

9'. A random: binary' pattern generator as recitedin claim 6 wherein said means supporting said switches on said base includes an electromagnetsecuredionsaidibase. andhaving an armature, a' core and stop; said switches being secured tosaid armature; spring means secured to. said base and' tosaid armature for biasing saidarmature against the stop; whereby when said electromagnet. is energized; its armatureis'moved against the bias of said spring means intoengagementwith' its core;

'10. A randonr binary pattern generator comprising; a base having a planar supporting surface; a generally U-shaped bracket; rubber pads supporting said bracket on the planar supporting; surface of said' base with the ends ofthe' legsof said bracket projecting. perpendicularly' away" from said base; said pads being; adapted to inhibit transfer of vibrational energy from said bracket tosa-id base; a bearing secured in each of the legs of said generally U-shaped bracket, said bearings defining a common axis parallel to the planar surface of said base; a shaft mounted for rotation in said bearings; a plurality of substantially identical ball bearings mounted on said shaft in axially spaced relationship; the inner race of each of said ball bearings being fixed to said shaft; a corresponding plurality of identical balanced peripheral cams, each cam being secured to the outer race of a corresponding one of said ball bearings, each cam being formed with four arcuate, concentric, equiangular, peripheral surfaces separated by narrow radial projections, the radii of opposed peripheral surfaces of each cam being equal but different from the radii of the adjacent peripheral surfaces; at corresponding plurality of normally-open binary leaf spring switches, the free end of one leaf spring of each of said switches being extended and bent to project away at an angle; a pair of electromagnets secured on said base, each electromagnet including an armature pivotable about an axis parallel to the axis of said shaft, a core, and a stop; spring means secured to said base and to each armature for biasing each armature against its respective stop, each of the armatures being adapted to be pivoted against the bias of said spring means out of engagement with the respective stop and into engagement with the respective core, each of said switches being secured to one of said armatures and disposed for cooperation with a respective one of said cams whereby when said electromagnets are not energized, each of said switches are open and said cams are adapted to rotate relative to said shaft at unequal and variable angular velocities, and when said electromagnets are energized said armatures are caused to pivot against the bias of said spring means and into engagement with the respective cores whereby the bent projecting end of the one leaf spring of each of said switches engages a peripheral surface and a radial projection of the corresponding cam for preventing it from moving relative to said base and whereby each switch whose one leaf spring engages a cam periphery of the larger radius is closed and all other switches remain open.

11. A random binary pattern generator as recited in claim 10 further including means coupled to said shaft for rotating said shaft at a continually variable angular velocity.

12. A random binary pattern generator comprising; a

base having a planar supporting surface; a generally U-shaped bracket; rubber pads supporting said bracket on the planar supporting surface of said base with the legs of said bracket projecting perpendicularly away from said base, said pads being adapted to inhibit transfer of vibrational energy from said bracket to said base; a bearing secured in each of the legs of said generally U-shaped bracket, said bearings defining a common axis parallel to the planar surface of said base; a shaft mounted for rotation in said bearings; a pulley secured to one end of said shaft; a motor; a pulley secured to said motor; a belt engaging both said pulleys, said belt being sufficiently loose so that there is continuing change in. the relationship between the angular velocity of said shaft and that of said motor; a plurality of substantially identical ball bearings mounted on said shaft in axially spaced relationship; the inner race of each of said ball bearings being fixed to said shaft; a corresponding plurality of identical balanced peripheral cams, each cam being secured to the outer race of a corresponding one of said ball bearings, each cam being formed with four arcuate, concentric, equiangular, peripheral surfaces separated by narrow radial projections, the radii of opposed peripheral surfaces of each cam being equal but different from the radii of adjacent peripheral surfaces; a corresponding plurality of normally-open binary leaf spring switches, the free end of one leaf spring of each of said switches being extended and bent to project away at an angle; a pair of electromagnets secured on said base, each electromagnet including an armature pivotable about an axis parallel to the axis'of said shaft, a core, and a stop; spring means secured to said base and to each armature for biasing each armature against its respective stop, each of the armatures being adapted to be pivoted against the bias of said spring means out of engagement with the respective stop and into engagement with the respective core, each of said switches being secured to one of said armatures and disposed for cooperation with a respective one of said cams whereby when said electromagnets are not energized, each of said switches are open and said cams are rotating relative to said shaft under the influence of said driving motor at unequal and variable angular velocities, and when said electromagnets are energized said armatures are caused to pivot against the bias of said spring means and into engagement with the respective cores whereby the bent projecting end of the one leaf spring of each of said switches engages the corresponding cam causing it to cease moving relative to said base by engaging one of its radial projections and whereby each switch whose one leaf spring engages a peripheral surface of the larger radius is closed and all other switches remain open, whereby there is generated a random binary pattern.

References Cited in the file of this patent UNITED STATES PATENTS 2,302,769 Haselton, et al Nov. 24, 1942 2,406,024 McCann Aug. 20, 1946 2,406,031 Parker Aug. 20, 1946

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