The opinion of the court was delivered by: BYERS
These causes, consolidated for trial, present conventional issues of infringement and validity of five patents, three of which deal with mechanism to control the successive purging, washing and drying of sugar in centrifugal machines in sugar refineries and factories; the remaining two cover, respectively, a syrup separator, and a water cooled brake. These devices promote the successful accomplishment of the tasks of the contrifugal machines.
Purging is the first step in the sequence in which the so-called green syrup (containing about 95% pure sugar) is "centrifuged" or separated from the sugar grains and collected for subsequent treatment in the bottom of the jacket which encases the perforate basket into which the partially treated sugar -- then known as massecuite or magma -- had been placed; when that step has been accomplished, a period of centrifugal washing ensues as the result of introducing water into the whirling mass; when the washing has proceeded sufficiently (which is a critical and fairly precise requirement in the process), the water supply is cut off, and a drying period follows, upon the completion of which the centrifugal is stopped and the sugar is removed either manually or through an open bottom in the basket. This is the complete cycle of operation so far as the centrifugals are concerned.
Because it has been outlined tersely for brevity's sake, there is nothing casual or fortuitous about any of the steps. Each has its carefully calculated duration, based upon many factors to which allusion cannot serve any present purpose.
The plaintiff's patents were granted to Roberts, and were successfully embodied in commercial structures which found a ready market from about 1926 until the filing of these suits. In other words, plaintiff's commercial success is not questioned. Commencing in 1936 the defendant inaugurated its own efforts to compete with the plaintiff, and the pending and other litigations were instituted to determine whether its unpatented (except as to its water-cooled brake) structures infringe; and, if they do, whether the Roberts patents are valid.
The successive steps in centrifugal operation, which have been stated, were formerly controlled manually and in turn, by the operators of the machines. This involved eccentricities of performance and frequent repetition of one or more of the operations, whereby production costs were enhanced, and the entire process was unnecessarily costly. Preliminary grading of the massecuite -- which varied widely in constituency -- to induce uniformity in treatment is said not to have been practicable prior to the introduction of mechanical control of the operation of the centrifugal machines, but has since been introduced; the accomplishments fairly to be attributed to the plaintiff's patents have been in the public interest, in that production costs have been lowered through savings in labor and material wastage; also the operation of the centrifugals has been speeded up from around 850 R.P.M. to double that, and more.
The Roberts Patents in Suit.
It will be convenient to consider these in the order of their importance and in three parts:
I. The control patents -- cause No. 1544.
II. The separator patent -- cause No. 1636.
III. The brake cooling patent -- cause No. 1544.
I. Roberts No. 1,758,901 -- Application filed December 8, 1925 -- "Means for Automatically Controlling Centrifugal Machines". Granted May 13, 1930.
The structure described is an intricate assembly of mechanical devices which together constitute an operable control of the centrifugal, best understood by consulting plaintiff's Exhibit 59.
A handwheel for manual operation, which turns a shaft 9 to which it is affixed.
Two separated gears on that shaft engage two other levers, 4 and 11, which have independent functions.
Lever 4 controls a clutch which in turn engages the pulley and thus the shaft which turns the centrifugal. As will be seen later, the application of the power which operates the centrifugal cannot coincide with the application of the brake. Those actions are mutually antagonistic and that relationship is maintained by the control mechanism.
Lever 11 performs two functions: (a) it releases through rod 50 the brake 55 which holds the centrifugal at frest, and (b) it causes the timer control to be engaged through rod 15, engaging bell crank 16, and associated element 17, so that the ensuing period of operation of the centrifugal can be established.
Clockwise rotation of the handwheel 8 therefore is responsible for the foregoing. A repetition, however, would not be possible with the mechanism thus far described. The brake must be reset, and the clutch must be disengaged, and a new cycle inaugarated. To accomplish this, the shaft 9 is equipped with a powerful coil spring 6 which is wound up by the rotation of the handwheel. The energy thus created opposes the action of lever 11 in releasing the brake 55 and in establishing the engagement of the timer control through 16 and 17.
That opposing energy is held in check by an ingenious latching device which engages the top of lever 11, whereby bell crank 13 is brought into play.
That is an angular member, held in position by a pin at the apex of the angle composed of the two arms. The lower arm contains a fixed roller 13c which falls into a notch at the upper end of lever 11 (which is prolonged laterally), when that moves in response to the lower end of lever 11 (which is pinioned by post 12 as shown). The clockwise rotation of staft 9, transmitted through gear 11b to the cogs of the lower segment of lever 11, causes counterclockwise action there and the reverse at the upper aspect or top prolongation of 11, whereby the roller 13c slips into and remains held in notch 11c.
Thus the energy of spring 6 is latched until 13c disengages 11c.
That action results when the short arm of 13 is pulled laterally by the action of rod 15 in obedience to a downward pull thereon, through 16, of rod 40, which is caused by force applied at its lower angular end delivered by arm 23 of the timer mechanism.
When 13c is released from 11c, the torsion energy of spring 6 is freed and causes shaft 9 to rotate counter-clockwise, and the levers 11 and 4 to move clockwise, whereby clutch 3 is disengaged and brake rod 15 moves so as to put the brake on.
The timer mechanism, which brought this result about, consists of two elements, connected to rod 15, through lever arm 16 to which rod 40 is attached as shown. These elements are shaft 20 which terminates inwardly in clutch member 18, and a worm gear which forms part of a revolving member which also terminates in the second half of the clutch (no number). When the two elements of the clutch are engaged through the lateral movement of the lower segment of lever 17, the timer mechanism is ready to function.
It is caused to operate by power supplied from the spindle (shaft) which actuates the centrifugal itself, through friction disc 31 which engages that spindle. The rotation of 31 delivers power to shaft 20 (through the clutch 18) to enable it to turn two discs affixed to it, each containing a radial projection or arm, which respectively strike and thus actuate two other elements.
The shaft 20 rotates slowly so that the arc described by arm 23 (which is less than 360 degrees) is completed in an adjustable changeable, and predetermined interval of, for exampe, 120 seconds.
The length of the interval is established by the position of the arm 23 which is adjustable according to the insertion of a pin through the arm, into holes in the disc radially disposed, as shown in the said exhibit. Thus the length of the arc to be traversed by the arm 23, from its starting position until it strikes the lower end of 41, is subject to predetermination. It measures the duration of the entire cycle from the application of power to spin the centrifugal, to the concomitant release thereof and application of the brake.
It will become important to recall that the energy which enables this device to function has its source not in the control mechanism itself, but in the agency which supplies power to operate the centrifugal.
Before leaving this subject, it is required to understand that there is of necessity a counter force which tends to oppose shaft 20 in its initial rotation and which comes into play to return it, and disc 22, and therefore arm 23, to their positions at the inception of the rotation of shaft 20. That force is supplied by coil spring 21, which rotates shaft 20 (and attendant elements) back to their initial positions, which spring is released and permitted to function immediately when 41 is tripped by 23. That is accomplished because 23 is set with reference to stop pin 22a which strikes rest 20b as 23 completes its arc, and thus spring 21 functions to reset the timer.
The second disc, also shown as 22, is another timer, which functions to open and shut off the water which is sprayed into the walled-up sugar, when the purging operation has been accomplished. Arm 24 projects from this disc as shown, and as the latter rotates with shaft 20 it strikes an attachment which starts the water to spray, and that independent mechanism continues for a predetermined interval until, by its own internal organization, that water is shut off. So much of the entire assembly is an embodiment of an earlier Roberts patent and is not involved in this litigation. Obviously this timer disc and the arm 24 begin and cease operation within the interval established by the partial revolution of the arm 23. The power to operate the washing mechansim is derived from the same disc 31 which has been described; the resetting of this disc and attendant arm is accomplished as has been described above.
The important aspect of this particular mechanism is that it is regulated as to the turning on and off of the water with reference to the cycle established by the first or governing timing control, so that the washing begins at a predetermined point which corresponds with the completion of purging, and continues for a predetermined interval, and is then stopped so as to permit of a predetermined period of drying which must elapse before the cycle is ended. That subordinate control of the washing period is essential to the successful operation of the entire control mechanism.
When the cycle has been completed, arm 23 trips hook 41 on rod 40, which causes rod 50 to move to the right, which disengages 13c from 11c, which unlatches torsion spring 6, which causes shaft 9 to rotate counter-clockwise, which disengages clutch 3 and applies the brakes through rod 15.
The resetting of the timer mechanism consists in the disengagement of clutch member 18 from its counterpart and the resetting through the action of coil spring 21. The disengagement of 18 is completed because the roller 13c is prevented from falling back into 11c because coil spring 6 exerts its power so as to move the upper segment of lever 11 to the right.
The evidence for the plaintiff is undisputed that the coordination of the various mechanical elements, which together constitute the structure described in this first of the Roberts patents, accomplishes effective control of the centrifugal machine. Thus the operator, having by experiment or trained observation decided upon the appropriate intervals for the several steps in the treatment of a given batch or "strike" of massecuite, makes the proper adjustment of arms 23 and 24 on the timer discs, and loads the centrifugal by turning wheel 8 clockwise, first at low speed to secure the uniform walling up in the basket of the strike, then turning 8 further to high speed, and, having done this, moves to another machine for the same purpose. In his absence, the purging, washing and drying proceed without manual participation by him, and at the end of the cycle he returns, and either he puts the centrifugal into slow speed to remove the sugar as it adheres to the sides of the basket in a partially dried state, or it has fallen of its own weight through an open-bottom basket if that type is employed.Then the operation is repeated.
One skilled operator runs three machines in this way, instead of having to confine his efforts to one centrifugal as was required in the days of hand control. The more scientific handling of the strikes, which was thus rendered possible, reduced the necessity for reprocessing incompletely or improperly handled massecutie, and the unnecessary melting of pure sugar, and reduced evaporating and pan boiling.
In other words, the patented device proved to be an important contribution to the industry in which it was employed.
II. Roberts No. 1,719,132 -- Application filed November 5, 1926 -- "Centrifugal Apparatus". Granted July 2, 1929.
Notwithstanding its earlier allowance, this patent follows the first in its proper place in this recital, since the description asserts that the patent covers an improvement on or modification of the first patent already discussed.
It is not disputed that the mechanism here portrayed is not basically different from patent No. 1,758,901, and consequently it will be unnecessary to describe it at length. It is for a centrifugal control mechanism, best shown in plaintiff's Exhibit 60, in which the power to turn the centrifugal is supplied by a two-speed motor.
The control is started by moving lever 1, which can establish an operating circuit in the motor through the functioning of switch arm 28, actuated by rod 22 connected with 1 at 20; that rod also effects the operation of brake shaft 24, through brake lever 23.
Again power and brake are engaged alternately.Switch arm 28 is moved to low speed connection (28a, and 28c), then to high speed (28c and 28b), as the result of the manual control of lever 1; in the showing of Exhibit 60, the brake is set, and switch arm 28 is not in a position to establish the contacts which would open either the low speed or high speed circuits of the motor.
The upper end of lever 1 engages shaft 2, which is impelled to rotate clockwise while torsion spring 9 can deliver its energy, and that holds lever 1 and therefore switch arm 28 in the off position, and brake arm 24 and the brake shoes g in engagement.
To counteract that effect, lever 1 is moved manually to the right, and switch arm 28 approaches the electrical contract stations; it can stop at neutral, and then move successively to the low speed (for loading the centrifugal) and then to high speed. The latter movement of lever 1 causes the latch or dog 12 to swing in back of the lever 1, through the action of coil spring 14 actuating shaft 13 (and arm 15 and attendant arms 16 and 17 later referred to) so as to hold it securely against the energy of coil spring 9.
This is the equivalent of the latching position of 13c when it engages 11c in the first patent.
The timing devices T1, T2, and T3, as shown, rotate on shaft 43 which receives its energy from the rotation of disc 30 through contact with the actuating spindle of the centrifugal. This also is in accord with the first patent. Once the spindle has started in the power-on position of the motor, the timer mechanism starts to function: T1 designates disc 45 having a peripheral finger 45d which is fixed in any desired position by 45c, thereby establishing the arc to be described from the starting position to its engagement with 60b on bar 60 which causes the wash water to start by opening valve WWV, after which 45d continues on its way.
T2 designates rotating disc 47, similarly equipped, and its finger 47d in time trips lever 62, which causes the wash water to stop.
As to this phase of the operation, the only difference in the two patents is that the timing of the wash water action is governed by the timing divice of the control mechanism, instead of by means contained within the wash water mechanism.
T3 designates rotating disc 46, having a similar finger 46d which eventually encounters the end of lever 19, causing a downward pull on rod 18, which, through the functioning of 17b, 17a, 16 and 15, unlatches 12 by causing it to move out of the path of lever 1, and thus the initial power of torsion spring 9 is released to enable it to return 1 to the power-off position of switch arm 28 and the brake-on position of brake shaft 24, so that the centrifugal now comes to rest.
It is unnecessary to discuss the timer mechansim in detail as the functioning of the timer clutch 41, and the reset spring 43b which is being wound up as time shaft 43 revolves, will be understood from comparison with the similar elements in the first patent.
The predetermination of the duration of each period, i.e., purging, washing and drying, is accomplished by the adjustment of the respective positions on the three discs of the fingers 45d, 47d and 46d, by pins 45c, 47c and 46c, by the operator of the control.
Thus far it appears that the essential characteristics of the first patent have been carried forward and embodied in the second, with a certain element of flexibility added in connection with the disengagement of the timer mechanism, arising from the nature of the knock off arm 19 construction, as explained at line 123, etc., of page 7 of the specifications.
The improvements are that lever 1, corresponding to handwheel 8 in the first patent, can be set in neutral, low or high speed, the brake being on prior to the first of these. When the timer mechanism releases latch or dog 12, lever 1 moves directly to brake-on, power-off position. Also the timers are mounted as a unit, and the sprayer control is one element of that unit, as has been indicated.
III. Roberts No. 1,861,978 -- Application filed April 23, 1929 -- "Automatic Control for Centrifugal Machines". Granted June 7, 1932.
The teaching of this patent is of an improvement upon the second one in this group, and again the basic features of the first have been retained, but expressed in slightly different form. The important change is that the brake is released by one device, and the power and timing mechanism caused to function by another.
Exhibit 61 depicts the association of elements in convenient aspect, and reveals the control at rest, with brake set, as at the completion of a cycle.
Lever 15 at its upper end fits over but is not firmly held on hub 5 carrying brakearm 6, which in turn actuates brake-arm 7, attached to brake lever 8 in the now familiar brake construction.
Hub 5 is secured to shaft 1 which is caused to rotate counter-clockwise by torsion spring 3, so as to expend its energy in causing hub 5 to rotate with the shaft and thus to actuate brake-arm 6 and attendant elements to establish the brake-on condition. Release is effected by the operator's application of the hand-grip 16 on lever 15 so as to engage the top of that lever into hub 5 by the setting of a pin at 5a. Then, if 15 is pushed back, the brake is unset, and the torsion spring 3 is wound up. At the limit of that backward thrust, shaft 1 is locked in its then position, because hook latch 20 engages a pin 17a on adjacent collar 17 which is also firmly held on shaft 1.
Thus the torsion spring 3 is latched, and the brake is off, and brake lever 15 can fall into vertical position. This is the equivalent of what takes place in the first patent when 13c falls into 11c.
By a separate element starting handle 23, which can function only if pin 17c on disc 17 is out of its way (which cannot happen in the brake-on position) and to the extent permitted by the position of the pin 17a also on the disc 17, is then ready to be moved into neutral, low, and then high speed engagement with the contacts of the 2-speed motor, at its upper aspect as shown.
The importance of the governing of the range of movement of starting lever 23, by the pins 17c and 17a on disc 17, is that thereby the alternating periods of brake-on, and high speed off, and vice versa, are maintained.
When lever 23 moves into low speed position, the motor starts; into high speed, the timer T3 starts, and thereby the length of the cycle is determined.
Again there is a timer clutch having two members, 38 and 39, and the former is moved from spring-held open position, laterally into engagement with the former, as the result of the turning of shaft 22, to which lever 23 is attached, through the actuation of members 34, 35, 36 and 37. The reset of this timer occurs when the spring shown to the right of the clutch member 38 is allowed to function on the completion of the cycle.
Clutch member 39 takes its movement not from association with the centrifugal spindle, but from another exterior source of power, shaft 90, the further history of which is not presently important.
T1 and T2 respectively turn on and off the flow of wash water at valve WWV as in the second patent, and they function within the period established by T3, the major timer element. Again the several periods of purging, washing and drying are adjustable, and predeterminable.
At the end of the cycle, a peripheral finger, on disc T3 which is turning counter-clockwise, engages lever 61 controlling lever 62, connected with rod 63 which turns latch 20, which releases finger 17a, whereby torsion spring 3 is unlatched and turns shaft 1 clockwise, and two things happen: (a) pin 17c in disc 17 moves forward and actuates lever 23 so as to open the switch and thus break the circuit to the high speed winding of the motor, and (b) the brake mechanism which has been described is actuated into the brake-on position through the functioning of hub 5, arm 6, rod 7, etc.
Thus the basic teachings of the first patent, and the improvements of the second are embodied in this disclosure, with the additional feature of the separately disposed elements, the one to release and reset the brake and the torsion spring which actuates it, and the other to engage the power in successive steps, those devices being interconnected so as to preserve at all hazards the alternating operation of the braking and driving phases of the control mechanism.
The evidence is barren of any indication that these inventions of Roberts came to him in a vision, or were imparated to him by any clairvoyant process. Nevertheless it is probably still the duty of the District Court to endeavor to deal with the issues of validity and infringement according to established principles.
Roberts had been engaged in the business of making and selling machinery for use in the manufacture of refined sugar during his entire career. He was schooled almost exclusively in the problems of that industry, and his understanding and insight were the products of experience based upon first-hand observation. He sensed the need for mechanical control of the centrifugal machines if their true possibilities were to be realized, and if hit or miss methods of operation were to be superseded; with that understanding he pondered and studied in the fall of 1923 and, having conceived of an assembly of known mechanical devices which as he believed could be coordinated so as to be operable as a unit, in which purging, washing and drying could be controlled in successive periods which could be predetermined, he made a sketch of his own, and submitted it to Jenkins, the then Chief Engineer of Federal Sugar Refining Co., Yonkers, New York.
The date is agreed to have been December 11, 1923, which is found to be the date of disclosure.
Plaintiff's Exhibit 10 is the sketch which Roberts made and then exhibited to Jenkins and discussed with him and others employed by the Federal Company. What was later to become coil spring 6, in the first patent, was substituted for the showing of a wheel and a weight to which Jenkins objected; and thereafter a draftsman prepared a technically better sketch, which is Exhibit 11. The substitution of the coil spring came after that sketch was examined and discussed by the same group.
Roberts' concept was embodied in an experimental machine which was built by him with assistance from the mechancial department of the Federal Company, some members of which were placed under Roberts' supervision by Jenkins for that purpose. This unusual procedure is explained in Jenkins' testimony as having been authorized because he realized from his conversations with Roberts and from his study of the two sketches, that the concept thus revealed, it embodied in operable mechanism, would greatly improve and cheapen the sugar-making process as then practised in the Federal plant.
Exhibit 10 did not depict the control in its final form, but it did sufficiently portray Roberts' concept, to enable Jenkins to see it for what it was, and to advise Roberts to cause his own crude drawing to be reproduced by one capable of illustrating the concept in the pictorial language of mechanical draftsmanship.
The reduction to practise did not occur until the lapse of a year or more, and it is safe to say that the first machine was not completed and in running order until 1925. It was operated experimentally for some weeks, and then sent out to Roberts' factory, where it remained until the trial, at which it was produced and offered as Exhibit 17.
In 1926 the Federal Company ordered and installed eighteen of the control machines, which embodied the original concept of Roberts as revealed in the first patent in suit, filed December 8, 1925.
It should be stated that the evidence is persuasive to this court, that the period which elapsed, between the disclosure and the filing of the application, did not admit of uninterrupted attention on the part of Roberts to his invention, by reason of a period of illness, and the change in his business connections from the American Tool and Machinery Company to the plaintiff in this action, which is the corporation organized by him to enable him to prosecute his various endeavors.
There was a continuity of development of the inventive concept which he had disclosed in December of 1923 to Jenkins and others, as has been stated, which was entirely consistent with his own belief in the efficacy of his invention once it could be rendered mechanically responsive thereto.
It will be convenient to examine the claims in suit in connection with specific issues touching infringement.
It now becomes necessary to consider whatever the evidence discloses at to the extent to which Roberts sought to occupy precincts which had already been preempted, and as to which he was merely a trespasser.
The defendant leans heavily upon the following patents to demonstrate that Roberts claimed occupancy in a domain that had already been so widely appropriated that there was little or no area available to him:
Andrews and Neuman No. 1,615,433 -- Application filed December 27, 1922 -- "Centrifugal Extractor-Operating Plant". Granted January 25, 1927.
This is pertinent on the issue of priority of invention, since the application antedated Roberts'. See Alexander Milburn Co. v. Davis-Bournonville Co., 270 U.S. 390, 46 S. Ct. 324, 70 L. Ed. 651.
The question then is whether Andrews and Neuman invented what Roberts did, at an earlier date.Just what they did invent is complicated by the showing that on June 1, 1925, they withdrew their specifications and claims and substituted new ones, and whether these merely revised what had already been announced, or embodied a different invention, is the subject of conflicting views. The discussion of this patent will proceed with that caution.
It must be understood that the apparent concern of the patentees was to provide means whereby the electrical power that ran the centrifugals might be conserved. Economy of power was the important consideration.
Since the cycle of operation is of brief duration (for example, 90 to 120 seconds) it will be apparent that starting at low speed, advancing to high and then coming back to low speed or stopping altogether make demands upon the power source which it was desirable to ameliorate. Also that such a result might not be an impressive accomplishment in itself, but if associated with such a conduct of the successive purging, washing and drying periods as would enable the centrifugals to do their work properly, the combined effect would be desirable. So much can be read into the recitals in this patent, although not in such simple language. The concept then was of something more comprehensive than an agency of control, although that was an incident of the "Centrifugal Extractor-Operating Plant".
The defendant's testimony is that the power-saving and control features were not required to be interrelated, but could have been separately presented and operated; the fact is, however, that they were; that control was not claimed as part of the invention will appear from a consideration of the claims of the patent. If those are presently comprehended, they assert nothing about the control element of the patented structure, except as it may be incidentally disclosed in the operation of some of the circuits comprehended in the structure.
The structure is an assembly of familiar electrical elements and embodies: (Exhibit P)
(a) A drum containing many strips or segments which serve as switches to open a series of circuits having various functions in the processes involved in the treatment of massecuite. That drum rotates to cause fingers held in constant relation thereto to engage those strips on the drum for the varying periods during which the circuits function. When the strips are rotated beyond the fingers, the circuits are closed. When all circuits have thus served their several purposes, the drum reverses to its starting position, because one or more other circuits, then closed, function to that end. In some instances, the circuits are completed by other means in addition to the engagement of both fingers with one strip or segment of the drum, but that is not destructive of the foregoing statement.
(b) A drum control member, also a smaller drum, which rotates in the same way and as a monitor to govern the larger drum, in response to a hand controller which actuates the electric power to run this element.
There are two movements of this small drum also, forward and reverse, and circuits are established through its rotation, as in the case of the larger drum control, which in turn cause the latter to function.
1. To fix the duration of the cycle.
2. To start the wash water.
3. To stop the wash water.
The braking or slowing down (stopping is debatable) of the centrifugals results from regenerative action in the motor which starts in obedience to the timing out of timer 1 (timer of cycle), which is followed by the reverse action of the pilot and the larger drum.
The acceleration of the power supply to the centrifugals is accomplished by two agencies: The increase in voltage applied to the D.C. motor by balancer set generators, and the increase in resistance applied to the magnetic field, i.e., the stationary part of the motor; the increase in the latter resistance decreases the strength of the magnetic field which in turn causes the motor itself to run faster.
Deceleration is the reverse of that process, namely, the field resistance is cut out and the strength of the magnetic field is thus restored; this causes the motor to transmit current to the main lines, i.e., to regenerate, which means that the motor then becomes a generator and slows down; also the balancer set generators are cut out, which steps down the voltage to the D.C. motor. Thus is induced what Andrews described as follows: "We had a short period of dynamic braking through which the motor was practically short circuited on itself."
The braking therefore is accomplished by control of the electric energy which it is the office of the motor to supply to operate the entrifugals, i.e., by causing that energy in effect to serve two successive and contrary purposes.
As has been said, the timer of cycle, timer 1, measures the duration of the interval which starts with the movement of the hand controller switch into high speed and ends with the slowing down to the slow speed at which the sugar is plowed out, and the basket is ready for reloading at that same speed. The circuits established by contact of the fingers on 7 and 8 of the large drum start and reset the timer in succession.
After the high speed connection has been made, and at an interval which depends upon the position of the fingers which engage strip 10, the wash water solenoid valve is turned on while that circuit is closed, and the wash water is applied. When that circuit is opened by the completion of the contact, the wash water valve is closed.
Then the reverse rotation of the pilot drum and the control drum occurs as the result of the opening of the circuit which was closed so long as the fingers were in contact with strip or segment 6.
The wiring diagram whereby these various circuits can be traced is so complex that even the inventors, who were on the stand, were unable to identify the original diagram as that actually followed in the installation of these structures in the National Sugar Refinery; nor were they entirely convincing as to whether anything amounting to substantial changes had been made in respect thereto either then or later.
It is beyond question that about May 5, 1923, two machines generally corresponding to the structure of the Andrews and Neuman patent were erected and operated in that refinery; and that in all twentyeight such machines were thereafter installed and have continuously operated since that time. Whether this has ever been a public use in the practical sense, certainly as to the years 1923-1926, inclusive, is so doubtful that if the issue turned on that question it would require careful consideration.
As has been said, a control of sugar centrifugals was necessarily comprehended in the Andrews and Neuman disclosure, for uniformity of operation and product were stated to be among the contemplated incidents of the operation of their powersaving combination of electrical devices.
Since Andrews and Neuman do not discuss the duration of the drying period, or even refer to that as a necessary step in the cycle, it is left to inference entirely whether there was a predetermination of the washing period with reference to this third step in the cycle. The timing out of their wash period preceded the timing out of the time of cycle timer (Y in figure 1) so there was an interval in which drying could take place, which probably they understood since they were engineers in the employ of the National Sugar Company, but they also failed to mention it in their specifications or claims.
Roberts Nos. 1,758,901; 7,719,132; and 1,861,978 are now held to have been patentable over Andrews and Neuman No. 1,615,433, giving to the latter, for the sake of argument only, all that was asserted in the amended specifucations and claims, in that:
(a) The control is adaptable to a centrifugal which is driven by mechanical energy through a pulley or other suitable connection, as well as to an electrically driven centrifugal, whether D.C. or A.C.
(b) The control of the drying period is provided for as an identifiable stage in the cycle.
(c) The timers are reset not by the energy which started them, but from sources exterior thereto.
(d) The timers can be altered as to the duration of their respective actions by visible, accessible, and easily disposed adjustments.
In the Andrews and Neuman structure this adjustment can be made only by altering the length of the appropriate segments, or by substituting one for another -- a feasible but cumbersome and dilatory process, requiring the stoppage of the control drum while the necessary changes are made manually.
(e) The control is not so integrated with the centrifugal but that it can be assembled therewith without fundamental reorganization of the centrifugal plant as a whole; this is a striking advance over Andrews and Neuman.
(f) There is no combination disclosed by Andrews and Neuman which includes a brake, self-setting or otherwise, and the centrifugal as operated never comes to rest; this may not be necessary according to refinery practise, but thereby a distinguishing feature is revealed in the Roberts patents as contrasted with Andrews and Neuman.
(g) The last-named do not teach alternate braking and power engagement, although the circuits function so that, as power declines, the regenerative so-called braking is actuated, which means that the effective energy ...