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Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 CPYRGHT General Mills, Inc. Q 1ECHANICAL DIVISION rpp THE MECHANICAL ARM A remotely controlled manipulator for performing a handling job in nuclear labora- tories, in powder plants, and in other activities where exposure of an operator is undesirable. This general purpose manipulator is power driven electrically. Unit provides for shoulder, elbow, wrist, and hand motions. Hand and special tools replacement remotely interchangeable. Crane bridge carriage and vertical telescop- ing column available for extensive space coverage if desired. Variations of unit specified obtainable for specific applications. Typical specifications, accessories, and special features indicated on reverse side of this sheet. Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 CPYRGHT TYPICAL SPECIFICAT ONS* (Specifica ?ions below based o Model C) ARM MEMBER SHOULDER ROTATION - SHOULDER SWING - - ELBOW SWING - - - WRIST ROTATION - - HAND CLOSING; - - - HAND FORCE - - - WRIST TORQUE - - - ARM SWING TORQUES - SHOULDER ROTATION TORQUE VERTICAL LIFT (With all members of arm vertical) - - CONTROL POWER SOURCE - CONTROL WEIGHT - ACCESSORIES AND SPECIAL FEATURES - 21/2 R FM Max. Speed, 1400? range 2/3 R FM Max. Speed, 1.80? range 2/3 R M Max. Speed, 110 range 6 R M Max. Speed, Continuous range 15 I r. P.M. Max. Speed, 5-inch range 1501 s. 30 Ft. Lbs. 120 F . Lbs. 40F.Lbs. 110 lolt 60 Cycle Single Phstse 1KW Normal Max. 200 L s. 135 L s. (without crane or column) Determined by environmental conditions Teles ping columns for vertical motion, bridge carriages, under-water operation featu s, grip and load indicators, cable reel take-up units for crane bridge applica- tions, use of special materials, special power source requirements,' and load re- quirements are all items which can be sup- plied and/or adapted to special installa- tions. *Custom manipulators of all sizes and capacity can be esigned and constructed to meet specific application requirements. Specifications of other models obt inable upon request. For further information Write to ... EQUIPMENT SALES DEPARTMENT Approved Fqr Release 1999/09/10 : CIA-RDP83?00423R0012000700 GP 'A .,oo~fA A'i Approved For Release 1221/09/10 : CIA-RDP83-00423R001200070002-9 CPYRGHT General Mills, Inc. 1. QVIECHANICAL DIVISION THE MECHANICAL ARM A remotely controlled manipulator for performing a handling job in nuclear labora- tories, in powder plants, and in other activities where exposure of an operator is undesirable. This general purpose manipulator is power driven electrically. Unit provides for shoulder, elbow, wrist, and hand motions. Hand and special tools replacement remotely interchangeable. Crane bridge carriage and vertical telescop- ing column available for extensive space coverage if desired. Variations of unit specified obtainable for specific applications. Typical specifications, accessories, and special features indicated on reverse side of this sheet. Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 CPYR9Troved For Release 1999/09/10: CIA-RDP83?00423R001200070002-9 TYPICAL SPECIFICATIONS* (Specificat!ons below based on Model C) RM MEMBER A SHOULDER ROTATION - - - - - - 2'/s RP Max. Speed, 1400? irange SHOULDER SWING - - - - - - - - 2/3 RP Max. Speed, 180 range ELBOW SWING "- - - - - - - - 2/3 RP Max. Speed, 110*! range WRIST ROTATION - - - - - - 6 R Max. Speed, Continuous range HAND CLOSING! - - - - - - - - - 15 In P.M. Max. Speed, 5-inch range! HAND FORCE - - - - - - - r - 150 L s. WRIST TORQUE - - - - - - - - - 30 Ft Lbs. ARM SWING TORQUES - - - - - - 120 F Lbs. SHOULDER ROTATION TORQUE - - VERTICAL LIFT (with all members - 40 Ft Lbs. of arm vertical) - - - - - - - 750 L s. CONTROL POWER SOURCE - - - - 110 V~ It 60 Cycle Single Phase -KW II Normal Max. CONTROL WEIGHT - - - - - - - 200 L s. ARM WEIGHT - - - - - - - 135 L s. (without crane or column) MATERIALS - - - - - - - - Deter ined by environmental conditions ACCESSORIES AND SPECIAL FEATURES - - Telescoping columns for vertical motion, bridge carriages, under-water operation featur s, grip and load indicators, cable reel t ke-up units for crane bridge applica- tions, use of special materials, special powe source requirements,! and load re- quire ents are all items which can be sup- plied nd/or adapted to special installa- tions. *Custom manipulators of all sizes and capacity can be signed and constructed to meet specific application requirements. Specifications of other models obt inable upon request. For further information Write to ... EQUIPMENT SALES DEPARTMENT ZOp3f yfyv `$ rjljc~?~ PHONE R 8811 Approved For Release 1999/09/10 : CIA-RDP83kOO423ROO12OOO7OOO2Mkk 53-8-4proved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 CPYRGHT PLEASE NOTE: Reprint of paper to be delivered at the Con- ference of the Instrument Society of America September 21 - 25, 1953, Morrison Hotel, Chi- cago, Illinois. CPYRGHT This paper or any part thereof must not be reproduced in any form without the written per- mission of the Instrument Society of America, 1319 Allegheny Avenue, Pittsburgh 33, Penn- sylvania. Price to members, 25c; to non-members, 50c. A REMOTE CONTROLLED MECHANICAL ARM By E. R. VAN KREVELEN, Project Engineer General Mills Mechanical Division Engineering Research and Development Department Minneapolis, Minnesota ABSTRACT: This paper describes an electrically powered mechanical arm and a unique remote control system. This equipment has been developed to fill a need in certain industries, such as Atomic Energy, Munitions and Chemical, for a manipu- lator with the versatility and flexibility of a human arm to be used in areas unsafe for per- sonnel. The design considerations, features, and applications of the equipment are presented. A REMOTE CONTROLLED MECHANICAL ARM INTRODUCTION The advent of atomic energy and increased expansion in the fields of high explosives and chemistry has brought about increased de- mands for the safeguarding of operating per- sonnel. The handling of radioactive materials with their penetrating and harmful radiations requires remotely controlled manipulators. Op- erations in this field are many and varied, and impose difficult requirements for versatility and dependability. Such requirements preclude the design of special devices of limited use in favor of more universal units having a variety of functions. A good compromise in remote handling equipment is the Model E Mechanical Arm de- scribed in this paper. This manipulator is a gen- eral purpose, heavy duty instrument capable of many independent and precisely controlled motions. Since the human arm is one of the most versatile handling devices known, the Model E Mechanical Arm has been designed to incorporate many of its features. Added to these features are tireless operation and the ability to assume any working position for in- definite lengths of time. A wide range of sensi- tivity permits the handling of fragile glassware or heavy equipment weighing up to 750 pounds. The use of electric drive motors and control circuits places no limitation on the dis- tance between the operator and the Arm. Fig. 1.-Model E Mechanical Arm and Control - Console. Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 CPYRGHTproved For Release 1999/09/10 : CIA-RDP83 00423R001200070002-9 The Mechanical Arm with its associated crane is positioned by eight basic: motions. These motions are non-interacting and are all controlled by two pistol grip type control han- dles on a single control console. The left hand controls the crane bridge, cross carriage and hoist while the right hand controls the shoulder rotation, shoulder joint, elbow joint, wrist rota- tion and grip member. Each motion has a con- trol range of six speeds in each direction. The control handle mechanism is designed in such a way that movements of the operators arm, as he grasps each handle, corresponds to simi- lar movements of the Mechanical Arm. The con- trol handle motions and the resulting arm and crane motions are tabulated in Figure 2. may be assembled or repaired remotely. "Feel" has been purposely omitted from the hand in favor of visual indication of the direct measure- ment of gripping force ;and wrist torque. These m ters have high and low sensitivity ranges, so th it the operator can: control applied forces raging from a few ounces to several hundred unds. An audible system for force indication h Js also been developed. Audio tone pulses e anate from a loud speaker in the console. A force increases the pulse rate increases pro- rtionately making it unnecessary for the op- erator to take his eyes away from the work. This system is used in conjunction with the me- ters so that either audio or visual indication may be selected at the, throw of a switch. CRANE DESIGN ARM CONTROLLING CONTROL ' ACTION HANDLE HANDLE ROTATION CONTROL HANDLE LDRM MOTION CRANE BRIDGE LEFT LEFT B RIGHT SWING +r CROSS CARRIAGE LEFT IN B OUT TRANSLATIONAL , VERTICAL HOIST LEFT UP 8 DOWN SWING / y GRIP RIGHT SQUEEZE HANDLE WRIST RIGHT LEFT a RIGHT N ROTATION HANDLE ROTATIO ELBOW UP B DOWN l JOINT RIGHT SWING SHOULDER JOINT RIGHT IN a OUT TRANSLATIONAL I l/ m SHOULDER ROTATION RIGHT LEFT B RIGHT SWING Fig. 2.-Table of Control Actions arid Corres- ponding Arm Movements. Two types of remotely interchangeable grip members or hands permit a variety of objects to be handled. One hand is a pair of spring loaded parallel jaws and is used for general purpose work. The other hand has a hook and anvil arrangement for heavy lifting and for the handling of round objects. Many special tools as well as screw drivers and socket wrenches may be grasped by these hands so that motors, gear reducers and other mechanical equipment he crane mount is made in two units. One unit is a movable crane bridge which complete- ly pans the work area..A cross carriage or trol- le rides the crane bridge and provides transla- tional freedom at right angles to the bridge tr vel. The Mechanical Arm proper is suspend- ed below the carriage: by a telescoping tube ho st. Fig[ 3.-Cross Carriage Assembly showing Ver- cal Hoists and Transverse Drive Motors. Approved For Release 1999/09/10 : CIA-RDP83.00423R001200070002-9 CPYRGH I pproved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 Fig. 7.-Schematic Diagram of Crane Bridge Control. This is typical of all of the Motor Control Circuits. One of the eight motor control circuits is shown schematically in Figure 7. Each motor has a bank of seven relays associated with it. The two relays K, and K2 reverse the polarity of the DC voltage from the rectifier which in turn reverses motor rotation. The other five re- lays K3 through K, are for tap switching. It can be readily seen that these relays are in a fail- safe circuit. If a relay should fail to close, only the voltage tap picked up by that relay will be lost. The rest of the circuit will remain undis- turbed. If a relay should freeze in the closed position, this voltage will automatically excite the motor when the reversing relay closes. The highest speed relay closed at any time always takes precedence, so any combination of relays may be closed without danger of short circuits or other detrimental effects. The relays are energized by rotary switches of special design. These switches are mounted on the control mechanism and are actuated by movement of the control handle. The relays op- erate from 24 volts AC which is supplied by a separate transformer. Each relay coil is shunted with a capacitor to reduce transients across the switch contacts when the circuit is opened on an AC peak. All other voltage supplies are taken from the main power transformer. There are three sec- Fig. 8.-Basic Five Motion Control Mechanism showing Rotary Switch Construction. ondary windings on this transformer. The first winding is rated at 260 volts and is tapped at 16, 24, 32, 48, 64, 82, 128, 156, 200, and 260 volts. These taps are wired in multiple to eight rows of 10 jacks located on the relay mounting panel. Immediately below each row of jacks is a row of 6 cords and plugs. These cords termi- nate at the normally open contacts of the speed relays. With this arrangement any combination of six speeds may be independently set up for each motor. The motor field rectifier is excited by the second winding which is also rated at 260 volts. The third winding supplies 18 volts to the wrist torque and grip force indicator re- sistance bridges. All AC voltages are about 20 per cent higher than the desired DC voltage. These higher voltages are necessary to offset the IR drop in the selenium rectifiers. Figure 9 is a simplified diagram of one of the force measuring bridges. DC excitation is supplied to the bridge by a full wave selenium rectifier. The resistance element is in the fore- arm gearbox and is connected in potentiome- ter fashion making it possible to sense both an opening and a closing grip force. This also doubles the system sensitivity since the bridge has two active arms. The potentiometer wiper is mechanically linked to a non-linear spring which deflects with grip reaction force. The non- linear characteristic provides increased sensi- tivity for small gripping forces. The meter has Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 Approved For Release 1999/09/10 : CIA-RDP83 00423R001200070002-9 CPYRGHT shoulder joint and elbow joint and their respec- tive gear trains are enclosed in the upper hous- ing. The wrist rotation and grip motors are ex- ternally mounted on either side of he elbow. These two motors are coupled by flexible shafts to the forearm gearbox. The leads to all motors pass through a slip; ring assembly inside the main housing. A multiconductor coiled cable, enclosed by the telescoping tubes, terminates in a brush assembly fixed to the wall of the main housing. A pancake slip ring is mounted above the internal gear trains allowing the whole mechanism from the. shoulder down to continu- ously rotate within the housing. A speed range from a few degrees per minute to 8 RPM is pro- vided for this shoulder rotation motion. The upper arm has a vertical swing of 180 degrees about the shoulder joint at a maximum speed of 2/3 RPM and a torque of 75 foot pounds. The forearm has 200 degrees of vertical swing at approximately the same speed and torque. A pantograph chain drive between tFe forearm and upper arm keeps the forearm in the some angular position in space as the upper arm is swung forward and! back. This feature is par- ticularly valuable 'When open containers of liquid are to be handled without spilling. The wrist may LLe rotated continuously in either direction at a maximum speed of 6 RPM and will exert torques up to 30 foot pounds. The hand will open or close at a maximum rate of 15 inches per minute with a maximum force of 150 pounds for the parallel jaws and 600 pounds for the hook and anvil. CONTROL SYSTEM All crane and arm motors, with the exception of the grip, are shunt wound and separately excited. The shunt motor was expressly selected because of its very wide speed range and con- stant torque characteristics. The use of shunt motors permits dynamic braking and allows changes in position of only a few thousandths of an inch at a time for all motions including the crane. A split field, series wound motor was selected for the grip because of its variable torque characteristics. Fit. 6.-Control Console showing Tilted Control Handle Construction for Ease of Operation. Early models of the Mechanical Arm utilized th ratrons and magnetic amplifiers for motor co trot. These controls provided a continuously a justable speed range but sacrificed low cost, re iability and valuable space. Field use of these early arms showed, that at most, a six speed control was ample for even the most exacting work. With the six speed requirement d finitely established, ci simple Ward Leonard control system was designed. The basic element of the present control sys- te is a power transformer with a tapped sec- o dory which provides a stiff source of variable voltage. Relays, actuated by the control han- dl s, select desired voltages from the trans- former and feed them to selenium rectifier bridges which in turn excite the motor arma- tures. Approved For Release 1999/09/10 : CIA-RDP83 00423 R001200070002-9 Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 CPYRGHT The crane bridge assembly is supported on two stainless steel tubes 33/8 inches in diameter. This tubing size allows a maximum span of 15 feet with minimum deflection under full load- ing. A '/a horsepower, 220 volt DC motor is vertically mounted at one end of the bridge. A drive shaft through one of the tubes is geared to the motor. Pinion gears on either end of the shaft engage racks on the bridge tracks. Maxi- mum bridge speed is 15 feet per minute. The carriage is driven by a 1/6 horsepower, 220 volt DC, gear head motor. A pinion gear on the gear head output shaft engages a single rack traveling the length of one of the bridge tubes. The hoist is powered by a'/s horsepower, 220 volt DC motor. A drum which is geared to the motor shaft drives the hoisting cable which travels down the inside of the telescoping tubes. An electrically released brake, integral with the motor, will hold the hoist in any position. A vertical travel of 87 inches can be provided by only three telescoping tubes. Additional tubes may be added for increased vertical travel. Over-travel in all motions of the crane is limited by cam operated micro-switches. The up and down hoist limit switches are actuated by a traveling nut riding on a threaded member directly coupled to the cable supply drum. The carriage and bridge have roller actuated switches that are tripped by stationary cams. Further protection is received from four spring loaded switches mounted below the four cor- ners of the cross carriage. These switches are ensitive to a slight amount of carriage tilt and interrupt the appropriate motion should the rm or telescoping tube strike a fixed object. When the Mechanical Arm is to be exposed to corrosive atmospheres, all exposed metal arts are either painted with Amercoat or are abricated of stainless steel. By totally enclosing he electric motors and using polyethylene in- ulated wire, maximum protection is afforded he electrical system. ARM DESIGN Fig. 4.-Mechanical Arm with Parallel Jaw Grip. The arm is powered by five 1/50 horsepow- Fig. 5.-Mechanical Arm with Hook and Anvil r, 115 volt DC motors. The shoulder rotation, Grip. Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 Approved For Release 1999/09/10 : CIA-RDP83?00423R001200070002-9 CPYRGHT Fig. 9.-Schematic Diagram of Typical Circuit for Measurement of Grip Force. a zero center scale, and range changing is ac- complished by varying the shunt resistance across the meter terminals. Each motor circuit is fused separately and all fuses are located in the right hand leci compart- ment of the control console. The output terminal strips are also located in this section. The central compartment contains the transformers, crane rectifiers and relays; The arm motor rectifiers are housed in the left leg. Front, rear, top and side panels are removable for service and maintenance. Fig 10.-View of Control Console showing Ac- cessibility of Components for Maintenance. Approved For Release 1999/09/10 : CIA-RDP83?00423R001200070002-9 A8012 Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 General Mills, Inc. a ECHANICAL DIVISION LWO CPYRGHT THE GENERAL MILLS RYAN FLIGHT RECORDER Model A SOME IMPORTANT FEATURES AND ADVANTAGES ? Records air speed, altitude, vertical acceleration, time and heading (optional). ? Continuous 300-hour recording. ? Operation for 10 minutes following power source failure. ? Recorded data will not be destroyed by 1/2 hour exposure to 2000?F open fire. ? No electronic circuitry - maximum reliability, minimum maintenance. ? Self-contained - no remote pickups; connections to standard equip- ment only. ? Direct recording - no magnetic playback, photographic reproduction, or other process required. ? Weighs 16 pounds with fireproof case; 12 pounds with non-fireproof case. ? Repeatability - no sensitivity or zero shifts. CPYRGHT Approved For Release 1999/09/10: CIA-RDP83 00423RO01200070002-9 SPECIFICATION FOR THE GENERAL MILLS RYAN FLIGHT RECORDER RANGE OF FUNCTIONS MEASURED* ACCURACY OF RECORDING - - Indicated air-speed: 0 to 500 miles per hr. Altitude (standard pressure conditions): 1000 feet to + 40,000 feet. erticat acceleration: -- 3G to + 12G`s. ime: 1 minute, 15 minute, 30 minute and 0 minute marks. eading (optional): 0-360?. 2% of full scale altitude pressure and indicated air speed, -?= 0.2G on vertical cceleration, and ? 3?: on heading. Vertical accelerometer flat to two cycles er second for optimum measurement of ust and shock characteristics. alibration charts provided with recorder. OPERATING AMBIENT TEMPERATURES - 430?C to + 50?C. METHOD OF RECORDING - - - - - - tyli embossing on aluminum foill 21/4 inches ide and 1 mil thick. SPEED OF RECORDING CHART - - - - - - 1/2 to 5'/2 inches per hour (constant rota- ional speed on take-up spool). Time marks oordinate trace events., LENGTH OF RECORDING - - - - - - - ontinuous, 300 hours; maximum. METHOD OF DRIVE - - - - - - - - - 8-volt motor with power spring to escape- ent mechanism which controls speed of hart take-up drive. PRESSURE SOURCE - - - - - - - - - - perates from standard pitot-static tube nstalled on aircraft. 1/4 inch flared tubing :onnection for pitot tube, 3/s inch flared tubing connection for static pressure. POWER SOURCE - - - - - - - - - - 22 to 32 volts D.C. No change in chart speed results from voltage variation. Approved For Release 1999/09/10 : CIA-RDP83.00423R001200070002-9 C P ~ MRT For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 THE GENERAL MILLS RYAN FLIGHT RECORDER A record of a flight with various maneuvers. Test record of flight at a series of altitudes for different indicated ai'r-speeds. 2.0 G LETTERS "A" SHOW RELATIVE A INSTANTANEOUS POSITIONS For further information Write to ... MECHANICAL DIVISION CP,M1w For Release 1999/09/10: CIA-RDP83.00423R001200070002-9 TIME OF OPERATION WITHOUT POWER Approximately 10 mint. (except heading). 16.5 lbs. total with fireproof case; 12 lbs. with non-fireproof case. EXTERNAL DIMENSIONS - - - - - - - - INSTRUMENT MATERIALS - RESISTANCE TO FIRE** RESISTANCE TO SHOCK - RESISTANCE TO SEA WATER AND HUMIDITY - METHOD OF ANALYSIS OF RECORD INSTALLATION*** - * Heading funciJion optional; availability subject to type ** Fireproof case optional. With fireproof case inclluding supports, ap- proximately 13'/s inches x 16 inches x 15 inches high. With non-fireproof ease, approximately 111/2 inches x 14 inches x 13 inches. Frame, aluminum; spherical fireproofing case is double walled; outside wall zinc plated mild steel; inside wall aluminum; insulation between we Hs Perlite. Record is preserved under 2000?F tempera- ture for one-half hour': resulting from open fire when fireproof case is used. Designed such that record will not be dam- aged under 100G acceleration or shock. Record will withstand; 36 hours immersion in sea water. Instrument designed to with- stand salt spray and normal humidity tests. Use of transparent overlay for rapid scan- ning: For precision analysis, tool maker's microscope or photographic enlargement. Recommended for installation in tail of air- craft to further increase resistance to fire. Mounting lugs at essentially C.G. of in- strument provided. of compass instruments installed on aircraft. *** All functions self-contained. No remote pickups require compass instruments already installed in the aircraft). that acceleration response of commercial aircraft to g any part of the aircraft as it is at the C.G. (except for connection to existing pitot-static and is believed sufficient evidence exists to conclude usts and landing shock is essentially the same in Approved For Release 1999/09/10 : CIA-RDP83?00423R001200070002-9 CPYRGHT PreprAppFgl1 do FtprbReL d19WQ%i t~C4ArR12P , A4&380 1200070002-9 Instrument Society of America, September 21-25, 1953, Hotel Morrison, Chicago, Ill. Discussion sent to the ISA will be considered if received by October 1, 1953. This paper or any part thereof must not be reproduced In any form without the written permission of the Instrument Society of America, 1319 Allegheny Avenue, Pittsburgh 33, Pa. Price to members 25 cents, to non-members 50 cents. Please Note: Statements and opinions advanced in this paper are to be under- stood as individual expressions of the author(s) and not those of the Society. The V.G.A. Flight Recorder CPYRGHT Abstract. The V.G.A. Flight Recorder is a permanently installed instrument for con- tinuously recording, on aluminum foil, the indicated air speed, static pressure-altitude, compass heading, and vertical acceleration of aircraft for long operating periods. The instrument records information sufficient for determining the three dimensional flight path of the aircraft. Abnormal atmos- pheric disturbances, aircraft operational variations, and other flight conditions are recorded. The instrument, mounted in the tail of the aircraft, is light in weight, small in size, predominantly mechanical, extremely rugged, fire resistant, designed for mini- mum maintenance, and will operate for a period of time without electrical power. IN 1948, the Civil Aeronautics Admin- istration outlined suggested specifi- cations for a flight recorder which was proposed for installation in all com- mercial aircraft. The purpose of the recorder at that time was to aid the government in accumulating data which could be employed in arriving at recom- mended operating procedures designed to reduce air mishaps. A survey revealed that there was a need for development of a recorder which would require a minimum of at- tention with maximum reliability, pro- vide for long recording, and offer re- sistance to destruction by fire, water and shock. Since that time, a number f recorders have been developed. One r more of the following disadvantages as been found to prevail: weight was oo great; occupied considerable space; recording time was low; no resistance o water, fire and shock was nil; elec- ronic circuitry generally increased aintenance, made reliability uncertain, nd offered questionable repeatability haracteristics. Initial, operating, and naintenance costs were high. Recognizing the limitations of elec- ronic type recorders, Professor James Ryan of the University of Minnesota, eveloped a recorder which would pre- lude these difficulties and disadvan- ages. The principles developed by him [ages. since been embodied in the General ills Ryan Flight Recorder. ?L Manager of Market Development, Me- chanical Division, General Mills, Inc., Min- neapolis 13, Minn. *2 Technical Specialist, Engineering Re- search and Development Department, Uni- versity- of Minnesota. This recorder is unique in that it is small; light in weight; preserves the record under conditions of high tem- perature, shock, and exposure to water; is self-contained; and provides for long recording. Elimination of electronics on all functions, with the possible exception of one, provides a high degree of reli- ability, low maintenance, and repeat- ability. Operation for a short time following a power failure is another advantageous feature. Fig, 1. Upper Half of Housing Being Re- moved DESCRIPTION The Flight Recorder shown in Fig. 1 measures vertical acceleration, indicated air speed, standard pressure-altitude, and time. Direction recording, with the requirement of remote sensing, is avail- able as an optional feature. These func- tions, and the direction element, are mounted in a spherical case, 111/2-in. x 14-in. x 13-in. high, including the exter- nal instrument supports. An insulated fireproof case, also available, slightly increased the external dimensions to 131/2-in. x 16-in. x 15-in. high. Fireproof Case The fireproof case, made in two hemi- spheres as illustrated in Fig. 1, consists of an outer stainless steel shell and an inner aluminum shell. Between these shells is a one-inch layer of granulated Perlite, an excellent temperature in- sulator. At the separation diameter of each half of the case, a solid retainer is made from Marinite, also a high tem- perature fire resistant material. The fireproof case prevented destruction of the record when the instrument was exposed to a 2,000 F. flame for a period of 30 minutes. General Assembly of Recording Mechanisms Fig. 2 illustrates an exploded view of the recorder elements. Fig. 3 shows the recorder with the upper and lower housings removed. A portion of the instrument is mounted on the upper side of a support plate and the remainder on the lower side. The upper assembly contains the recording mechanism and the air speed sensing component; the lower assembly contains the altimeter sensing unit, the electric chart drive motor, and the accelerometer element. Pipelines leading to the pres- sure sensing components are connected at the side of the case. An electrical receptacle for connection to the 28-volt motor on the chart drive mechanism and the conductors for the direction function are at the same location. The total weight of the instrument is 16.5 lbs in the fireproof housing and 12 lbs. with a non-fireproof case. The instrument assembly without a case weighs 8 lbs. Air Speed and Altimeter Elements The air speed element is a pressure diaphragm having static and dynamic chambers. The air speed unit provides a total displacement at the chart of about s/.%-in. for an indicated speed of 500 miles per hour at sea level. The altimeter unit is an aneroid bellows and provides, at the chart, approximately two inches of displacement for altitude indications up to 40,000 feet. In each of these elements, the diaphragms act upon simple lever mechanisms providing a magnification of approximately five at the recording styli. Vertical Accelerometer The accelerometer element consists of a block of metal supported by cantilever springs. It is so designed that the move- ment of the weight and, therefore the stylus, is in a straight line. The accel- erometer measures between the limits of minus 3G and plus 12G for a total dis- placement of about two inches on the recording chart. The natural frequency of the accelerometer is approximately Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 CPYRGHT Apprnvpd 430 cycles per minute. It is, by design, damped for flat response pp to approxi- mately two cycles per second. This value was selected after careful consideration of the nature of aircraft movement due to air disturbances and landing shocks. Therefore, in order to maintain this natural frequency in the most active range, a secondary spring is introduced in the assembly which increases the over-all spring rate when shock loads are between 4.5 and 12G. The styli of all the elements are slightly displaced in the direction of chart movement to preve t interference. with successively larger m ica ions ea An additional stylus p ovides a base fifteen minutes, 30 minutes and 60 min- line for all the primary unctions. The utes of time. These markings correlate styli emboss impressions o a line width all recorded events with time. of approximately 0.001 nches, as the cha: t passes over a back ng plate. Record Analysis Recording Medium and rive The recording medium is full-hard aluminum foil, 21/4-in. wide and 0.001-in. thick. The recorder will accommodate a chart strip up to 100 feet in length. This length of record pro ides recording for approximately 300 h rs flight time. The recording strip is r Iled on a spool which is driven at the rate of one turn TIME MARK Fig. S. Recorder Witj.iout Housing per hour by means of a small 28-volt d-c motor operating at revolutions per hoar. At this drive seed, the chart mcvement varies from .5 to 5.5-in. per hour, depending upon he diameter of the roll, or an averag of 41/2-in. per hoar. The speed of the c art drive motor is governed by a clock ork mechanism. A spring drive betwee the motor and the escapement mechan sm permits the chart drive to run a proximately 10 minutes after the pow r to the chart drive motor is turned o , or if the power in the aircraft fails. Time-Marker A cam-operated styl s, activated by a gear, indicates 1-minu a time intervals For a quick analysis of the record to provide a general indication of the mag- nitude of recorded data, a transparent template, which shows the calibration of each function, is placed over the record for reading at any instant of time. The template, illustrated in Fig. 4, is marked in miles per hour, the alti- tude in feet, the acceleration in G's, and the direction in degrees. The template and foil may be magnified by means of a film reader for continuous scanning. For a more accurate analysis, the record may be' analyzed under a toolmaker's microscope or other magnifying device; or it may be photographed with edge lighting and enlarged to any size de- sired. Operating Conditions The instrument is highly resistant to extreme humidity effects, and will with- stand the vibration and impact condi- tions experienced by normal aircraft operation. The recorder is so designed that the record will not be damaged under a 10OG acceleration. The record will not be destroyed when exposed to a 2,000 F temperature, re- sulting from an open fire, for a period of up to 30 minutes and will be pre- served for over 36 hours when immersed in sea water. Operating ambient temperatures are in the range between minus 30 C and plus 50 C. Approved For Release 1999/09/10 : CIA-RDP8300423R001200070002-9 53-9-1 CPYRGHT The dr a eo vary from 22 to 32 volts d-c without affecting the operation of the chart Accuracy The accuracy of recording is com- mensurate with the pilot's instrument indications, since standard aircraft sens- ing elements are employed. Simplicity of design, ruggedness, reliability and repeatability of results led to an instru- ment with the following performance tolerances: 1. Pressure-altitude at standard con- ditions: Plus or minus 2 per cent of full scale and plus or minus 200 feet at low altitudes. 2. Vertical acceleration: Plus or minus 0.2G over the full range. 3. Air speed: Plus or minus 3 per cent of full scale and plus or minus 6 miles per hour at low speeds. 4. Direction: Plus or minus 3?. Figs. 5, 6 and 7 illustrate typical cali- bration curves for acceleration, air speed, and altitude, respectively. Fig. 8 is an altitude correction chart taking into consideration the existing baromet- ric pressure at the time of recording. As an instrument to provide data for Fig. 5. Typical Calibration Curve for Verti- cal Accelerometer 00 a 2.00 1 a00 00 30 0O 200 10000 SEA L.E VEL E INDI~ FUNCTIONS INCLUDE COM PR E SSIBILI \1 loo 010 .30 AO .7o .9 t 1.10 INCHES DISPLACEMENT FROM REFERENCE 0 Fig. 6. Typical Calibration Curve for Air Speed Element 1 r to altitude in feet. .6 .B 40 Fig. 7. Typical Calibration sure-Altitude (Standard Curve for Pres- Atmosphere) 29-0 29.5 30.0 30.5 31.0 Fig. S. Altitude Correction Curve 00- 00 00 00 'U N - ff 00 00 - 5 0 0 2 0 3 0 0 5 o, ALTITUDE IN THOUSANDS OF FEET Fig. 9. Conversion Curve, Pressure in Milli- bars to Altitude In Feet analyzing air mishaps, it is desirable to have a repeatable record based on standard atmospheric conditions which may be later corrected to the existing barometric pressure for the area at the time corresponding to the recorded event. Such information is available from meteorological records throughout the country. Fig. 9 is a chart converting pressure Figs. 10 and 11 are typical flight rec- ords illustrating recorded impressions for various aircraft maneuvers. INSTALLATION For most applications, recommenda- tion is made that the recorder be in- stalled in the tail of the aircraft to aid in its recovery in the event of an acci- dent. There is sufficient evidence to indicate that the movement of most air- craft responding to gusts or landing shock is essentially the same in the nose and the tail as it is at the center of gravity. Installation in the tail, there- fore is quite feasible and desirable. there are no special remote pickups required; all connections being made directly to existing aircraft signals in parallel with instrumentation in the cockpit of the aircraft. The air speed and altimeter elements are connected to the aircraft pitot-static lines. Similarly, appropriate signals from the fluxgate/gyrosyn instruments in the cockpit are received by the re- corder for use in the servo unit of the direction element. In the event such navigation instruments are not avail- able or do not lend themselves to con- nection in this way, a separate signal- producing compass may be employed. APPLICATION CONSIDERATIONS It is believed that a recorder of the design described should have wide ap- plication by commercial airlines, execu- tive aircraft operators, the transport service of the military, fighter and bomber wings, and aeronautical re- search and development activities. The Airlines and Executive Aircraft Use Some uses, mentioned below, have been suggested as a means of increasing efficiency and reducing operating and maintenance costs. There are very likely many more uses of benefit to the airlines not mentioned here. 1. Minimize inspection time required through a knowledge of gust, landing shock, and other overstressing loads. An inspection procedure could be estab- lished such that the degree of inspection is a function of the degree of accelera- tion measurement which the aircraft has experienced. For instance, a small recorded shock may suggest limited in- spection, a larger record of acceleration would mean slightly more inspection; and a large record of shock may mean complete inspection. The problem of how much inspection need no longer be left to guesswork. 2. Minimize consumption of fuel by statistical determination of optimum altitude, air speed, and take-off condi- tions, for specific aircraft and various payloads. 3. Comparison of performance of like and different aircraft to aid in evalu- ating future fleet purchases. 53-9-1 Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 CPYRGHT 4. Statistical determination of elapsed time of flight between established points; assisting in the preparation of time tables and providing statistical information for establishing engine checkup and overhaul periods. 5. Statistical determination of the practicability of following flight plans in altitude and direction for given fore- casted weather and traffic conditions. 6. Based on the statistical determina- tions of best flight conditions for maxi- mum efficiency, pilots can! be advised as to how best to fly the airgraft to obtain flight efficiency and to reduce wear and tear on equipment. 7. Determination of the degree of flight roughness experienced for re- ported atmospheric conditions; provid- ing data for determining' the limiting passenger comfort conditions and the limiting conditions for precluding over- stressing the aircraft. 8. Determination of fatigue condi- tions through a knowledge of frequency and intensity of stress conditions, per- mitting studies on the life expectancy of aircraft. The executive aircraft! owner gains the same kind of benefit: from the use of such a recorder. Development and Design; Use The use of a recorder #vhich will re- produce true acceleration! phenomena is vital in aircraft structural design. The concept of a true recording at low fre- quency conditions is very important, since the majority of overstressing con- ditions resulting from air disturbances and landing shocks are believed to occur at frequencies below two cycles per second. The V.G.A. Flight ;Recorder, of course, is not a laboratory instrument; but it is a simple and rugged instru- ment for field use and will yield results, the validity of which, within the error tolerances specified, is certain because of the direct linkage recording mecha- nism. Its direct recording feature is desir- able in flight test work where immediate analysis is necessary to permit continu- ation of the next phase of the test pro- gram. The Military Use The Armed Services can rightfully claim to be the largest operating airline in the world. While the, military can gain through reduction of operating and maintenance costs of this' vast fleet, the matter of safety in this particular oper- ation is an aspect where! an immediate gain can be realized. Analysis of air accidents is extremely vital not only to the saving of lives, but also in minimiz- ing the number of aircraft losses. To emphasize the unusual need for reducing air accidents in the military, one has only to review :statistics pre- sented recently by the past president of the Aero Medical Association, Major General Harry G. Armstrong, in a talk expressing the need for "An Aero Medi- cal Center for the Unified States Air Fig. 10. Typical Flight Becc'rd of Hard Turns, Drives, Pull-outs, and a Stall, Showing the Variation n Normal Acceledr'ation, Altitude Air Speed, and Time During Maneuvers for a Fig. 11. Test Record of Flight at a Series of Altitudes or Different Indicated Air Speeds "During the first two y months of World War States Air Force lost while, it lost approxi ately 11,000 through flying accidents in the United Air Force, within the co of this country, suffere aircraft accidents resultin of 15,613 crew members; billion or more dollars destroyed aircraft, and airplanes' represents oft test for the effort and in the training of the fabrication of the airpl These figures are p in studying flight recor "'Crash-Worthiness of Air Injury Prevention", by E J. J. Ryan, The Journal o Approved For Release 1999/09/10: CIA-RDP83 55,821 major in the death major injury era; the total the damaged part of the me consumed ews, and the raft and Crash J. Baldes and Aviation Medi- promotion of safety; that is, in reduc- tion of aircraft losses, in training of pilots, etc. There is another area of benefit to be derived by the military service from the use of recorders. Installation of flight records aboard combat aircraft may provide statistical data relating to the manes in which pilots fly aircraft under combat conditions. This data would seem important to operational re- search units of the military to aid in determining statistically, if possible, how the Ace pilot differs from other pilots in terms of methods of handling combat aircraft. In sumimary, instrumentation, as in the V.G.A. Recorder, has application in the promotion of safety, in research and development, and in reducing aircraft operating and maintenance costs. It is hoped that the acceptance of recorders will be as wide as possible so that every aircraft will carry a permanent record of the unusual conditions which it has encountered. 00423R001200070002-9 CPYRG,(,T,roved For Release 1999/09/10: CIA-RDP83-00423 R001200070002-9 PLEASE NOTE Reprint of paper to be delivered at the National Instrument Conference and Exhibit of The Instrument Society of America, Septem- ber 8 - 12, 1952, Public Auditorium, Cleveland, Ohio. CPYRGHT This paper or any part thereof must not b reproduced in any form without the writte permission of the Instrument Society of Amer ica, 1319 Allegheny Avenue, Pittsburgh 33, Pennsylvania. Price to members, 25c; to non-members, 50c A NEW TYPE OF PACKAGE HYGROMETER By KENNETH C. COON* INTRODUCTION The predominant factors affecting the pres- ervation state of materials in storage are the existing temperature and moisture conditions. In determining the pertinent moisture condition for non-hygroscopic materials, it is obvious that a relative humidity measurement is sufficient. For moisture determination of hygroscopic ma- terials in equilibrium with the surrounding at- mosphere either absolute moisture content or relative humidity may be measured. A number of instrument types, such as the sling psychro- mater, hair hygrometer, dew point indicator, and electric hygrometer are and have been available for determining relative humidity in physically large enclosures. The Package Hy- grometer was primarily developed as an in- strument to be used in determining moisture conditions existing within small low-cost pack- ages or enclosures where conventional instru- mentation techniques are impractical. Two types of Package Hygrometer, differing pri- marily in the type of sensing system, have been developed and tested. A description of each type and its relative merits will be presented and discussed. GENERAL DESCRIPTION Though not limited to use in small spaces, the Package Hygrometer's greatest usefulness is expected to be in the field of packaged per- ishables. A small, dual passage probe is used to pierce the container or package and project into the enclosed air space. A continuously flowing air sample is withdrawn from the pack- age by a small centrifugal blower. The air sam- ple passes from the probe passage into the *-Associate Engineer, General Mills, Inc., Engineering Research and Development Department. , ing and is returned to the package through a second probe passage. The sensing elements are mounted in the measuring chamber. The determination of relative humidity in- volves the measurement of two variables: tem- perature, and quantity of water vapor present per unit volume. The package hygrometer util- izes a thermistor for obtaining the temperature measurement, while commercially available Dunmore type humidity sensing elements are used for obtaining the humidity measurement. Each Dunmore type element consists of a bifilar coil wound on a polystyrene form. The form provides a base for a lithium chloride coating, which serves as a variable resistance conductor between the two halves of the bifilar winding. The resistance of the conductive lithium chloride coating is a function of the quantity of water vapor present in the surrounding air, and de- creases as the quantity of water vapor per unit volume increases. The sensing elements are mounted in the probe unit as shown in Figure 1. The power supply and indicating equipment are included in a separate, portable case. The indicating equipment is used to measure the Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 CPYRC~PAroved For Release 1999/09/10: CIA-RDP83.00423R001200070002-9 conductance of the humidity sensing elements, and, by proper switch positioning, of the ther- mistor. A current magnitude in microamperes, when referred to the proper calibration curve, is a measure of the humidity or temperature. The indicating equipment may be operated from the AC line, or from self-contained storage batteries. For battery operation a 24-volt vibra- tor supply is incorporated. The meter, sockets, and all controls are mounted on the instrument panel. The indicating equipment and probe unit are illustrated in Figure 2. MULTIPLE HUMIDITY ELEMENT SENSING SYSTEM Since each humidity sensing element is sen- sitive over only a narrow range of relative hu- midities, a total of eight elements are necessary to cover the entire humidity range. The eight elements are paralleled through a suitable re- sistance network, so that only a single conduct- ance measurement is necessary. Operating procedure for the instrument is straightforward. The cables are connected to their respective sockets and the instrument armed up and standardized. The package hose humidity is to be measured is pierced with the. probe. The blower motor is'then ener- g zed and allowed to run until the humidity meter indication stabilizes. If the measured relative humidity is only moderately different ( 0% - 30%) from the relative humidity of the a r trapped within the enclosed probe passages fr m previous measurements, stabilization will h ve occurred within two and one-half minutes. T e temperature is obtained by switching the indicating circuit to temperature and referring the microammeter scale reading to the ther- mistor calibration curve. After the measure= ments have been completed and the probe withdrawn from the package, the small hole must be carefully sealed to maintain the pack- a e integrity. The stabilized humidity reading is referred to the humidity calibration curve for the particular temperature. Interpolation be- tween humidity element temperature curves may be necessary. The relative humidity in percent is obtained directly from the humidity el ment calibration curves. The thermistor and h midity calibration curves are illustrated in Fi ures 3 and 4. Approved For Release 1999/09/10: CIA-RDP83 CPYRToved For Release 1999/09/10: CIA-RDP83-00423 R001200070002-9 With careful operation, the accuracy of the instrument is plus or minus 3% relative humid- ity. It has been calibrated for use over the tem- perature range of 40 - 100 degrees F. How- ever, increased error will be introduced if the package free air space is less than 500 cc. SINGLE HUMIDITY ELEMENT SENSING SYSTEM A probe unit using a single Dunmore type element was designed and tested. The humidity element which was selected is sensitive to low relative humidities only. An electric heater was introduced in the air inlet passage to the meas- uring chamber. When relative humidities above the normal range of the single humidity ele- ment are encountered, the heater is energized, which raises the air stream temperature. Since the absolute quantity of water vapor contained in the air stream is constant, raising the temper- ature effectively decreases the relative humid- ity. The air stream temperature is gradually increased until the relative humidity lies within he sensitivity range of the single humidity ele- ment. This type of construction reduced the volume f air passages enclosed within the probe unit, enabling accurate measurements to be made in .enclosures as small as 250 cc. However, the humidity elements are temperature sensitive as well as humidity sensitive; and the humidity elements introduced excessive thermal lag into the system. Also, a high humidity measure- ment could not be immediately followed by a low humidity measurement, since sufficient heat remained in the probe unit to reduce the relative humidity below the sensitivity range of the single humidity element. The unit was satisfactory as a laboratory instrument, but was limited to semi-continuous use. CALIBRATION To calibrate both instruments it was neces- sary to provide a wide range of constant rela- tive humidities. The relative humidities above enclosed saturated salt solutions were accepted as standard. Published data is available *, ** on the equilibrium relative humidities over var- ious salt solutions. The use of supersaturated solutions must be avoided, and extreme care exercised to maintain constant temperature. The Package Hygrometer was calibrated direct- ly using the salt solutions as absolute standard. MAINTENANCE Routine maintenance should include no more than storage battery servicing. The sensing ele- ments should maintain their calibration for at least one year. However, excessive dust has a detrimental effect on the elements; generally slowing the response time and/or shifting the calibration slightly. To maintain extreme ac- curacy, the unit should be re-calibrated period- ically. . SUMMARY The Package Hygrometer is a portable instru- ment, primarily useful in determining moisture donditions existing within low cost cartons or packages. The multiple sensing element type is recommended for ease of operation and maxi- mum reliability. The accuracy of 3% relative humidity is maintained without difficulty. The instrument is calibrated for a wide range of temperature and relative humidity, covering most commonly encountered storage conditions. The instrument is a useful aid in packaging de- velopment and research. *-American Paper and Pulp Assoc., Report No. 40 (1945). **-International Critical Tables, Vol. 1, pp. 67, Mc. Graw-Hill, (1926). Acknowledgement: The support of Wright Air Development Center, United States Air Force, in sponsoring this project is gratefully acknowledged. Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9 25X1A2g Inquiries for Info. on Flight Recorders, Mechanical Arms, Package Hygrometer and Plastic Balloons. Approved For Release 1999/09/10 : CIA-RDP83-00423R001200070002-9