July 21, ,546,372

Transcription

1 July 21, ,46,372 S. M. FARCHILD APPARATUS FOR AERIAL PHOTOGRAPHY Filed March 1, Sheets-Sheet l NS S. a INVENTOR S. 7. Cu1-red-u1 AttoRNEY.j

2 July 21, ,46,372 S. M. FARCHILD w APPARATUS FOR AERIAL PHOTOGRAPHY Filed March l, Sheets-Sheet 2 7u 6. INVEN TOR N- e-7. A2-r la ATTORNEYS

3 Patented July 21, 192. UNITED STATES 1,46,372 PATENT OFFICE. SHERMAN M. FAIRCHILD, OF NEw YoRK, N. Y. APPARATUS FOR AERIAL PHOTOGRAPHY, Application fled March 1, Serial No. 822,037, To all whom it may concern: Be it known that I, SHERMAN M. FAIR complication of these devices might be un CHILD, a citizen of the United States of desirable, and for these cases it is advanta America, residing at New York city, in the geous to provide means for indicating the county of New York and State of New relative orientation of the camera E. the 60 York, have invented certain new and useful gyroscope, and to manually control the po Improvements in Apparatus for. Aerial Pho tography, of which the following is a full, indication. sition of the camera in accordance with this clear, and exact description. It is, of course, well known that a spirit 0. In aerial photography it is often neces level or similar device is subject-to large er 6 sary or at least desirable to have the camera rors due to the varying and erratic accelera stabilized so that its axis will keep a con tions of an airplane. -.. stant position with reference to the object to My present invention relates to the prob be photographed. For example, in taking lem of having the camera axis vertical or in the successive production ETE o of the ground for some other known relation to the object to a mosaic map or print the be photographed, but in its preferred form 70 camera axis should, in most cases, be as the gyroscope does not actually maintain. nearly as possible vertical, or normal to the the camera in position. On the contrary, earth, when the exposures are made. It has the gyro is employed as an indicating de been proposed to employ a gyroscope for the vice, and means are provided for erecting' 7 purpose, connected Egy to the camera so the gyro so that its axis is stabilized in the as to take advantage of the tendency of the vertical position or will be returned to the gyroscope to maintain its axis in constant vertical if caused to depart therefrom. The 2 parallelism to its successive positions in camera is universally mounted and is con space as the airplane advances. In general, nected with the gyroscope in such manner 80 however, this method is not suitable, for the that it may be adjusted relatively to the lat reason that if the gyro axis is initially verti ter by the operator, who, by reference to the cal to the ground and if it is maintained par indicator, can shift the camera to position 30 allel to this initial position, it will, after a its axis whenever necessary or desirable. short time, no longer be vertical but will make an appreciably oblique angle to the tographing The invention the also indicator includes to record means the for diver pho normal because of the rotation of the earth and the travel of the airplane. Assumin desired gence, if position. any, of the camera axis from the that the gyro axis was initially vertical ES A simple embodiment of the invention is that it accurately maintains its parallelism, in illustrated which in the accompanying drawings, the angular divergence between the axis and the true vertical at another point in the path Fig. 1 is a side view, partly in section on of the plane depends, theoretically, upon the line 1-1 of Fig angular separation of the two points, meas Fig. 2 is a plan view with part of the top ured on a great circle of the terrestrial of the gyroscope casing broken away. 9 sphere or spheroid, and the angle of rotation Fig. 3 is a detail plan view of the trans of the earth during the time elapsed in the rent indicator Flat with travel of the airplane; and it will readily be roken away to s art of the same seen that a few miles of travel suffice to make disk below. ow the indicator button or this divergence appreciable. Fig. 4 is a detail sectional view of the in 100 Even if means are employed for correct dicator, showing conventionally a camera ing the gyroscope for these errors, to stabi for Egg the same to record the lize a camera within any degree of precision position of the axis of the main camera. would require an excessively large gyro Fig. is a diagram illustrating a system scope, which might even then be subject to of electrical control which may be used when 0 errors due to unbalance of the camera due a recording camera is employed. to shift of the film or other causes. While In the apparatus illustrated the camera devices for causing the camera to maintain 10 is fixed in one end of a rectangular frame its position relative to the gyroscope with 11, the other end of which carries the gyro out applying serious disturbing forces to the scope casing or housing 12. The support 110 gyroscope are possible, in some cases the ing frame mentioned is universally mounted so as to be capable of pivotal adjustment in

4 all directions. As indicative of such a For the purpose of recording the relative mounting I have shown a ball-and-socket positions of the axes of the camera and gy joint, the ball 13 being on top of a pedestal roscope, the gyro housing 12 may be 14 and the socket 1 on a bar 16 extending equipped with a camera, 32, Fig. 4, in posi across the frame 11. It will be understood tion to photograph the indicator, and sup that the pedestal can be mounted on any ported in any convenient way, as for ex suitable part of an airplane or other flying ample by a hood 33, which may have an craft. For convenient grasp in adjusting opening 34 in one side to permit visual ob the frame it is provided with handle 17. servation of the indicator. The latter can The optical axis of the camera is perpendic be suitably illuminated by a hooded electric ular to the plane of the frame 11. lamp 3. Preferably the two exposures (by The gyroscope, which may be of the the main camera 10 and the auxiliary or re erected' type described in U. S. patent cording camera 32) are made at precisely of J. and J. G. Gray No. 1,308,783, issued the same instant, and accordingly both July 8, 1919, is represented somewhat dia cameras may be of the electrically-controlled 8 grammatically at 18. As shown, it is pivot type, in which the shutters are tripped si ally mounted in a gimbal ring 19, which is multaneously by devices under the control itself pivotally mounted (on pivots in the of, say, the same electric circuit. This mode same plane but at right angles to the gyro of operation is indicated in Fig., in which scope pivots) in a fork mounted on a ro the electrically actuated or controlled shut tatable hollow spindle 21 in the lower part ters of the main and auxiliary cameras, of the housing 12. The spindle is coaxial represented diagrammatically at 10 and 32 with the gyroscope rotor. The gyroscope is respectively, are in parallel in a normally driven electrically by current supplied open circuit which may be closed at will by through a cable 22 which extends into the means of a spring key 38 to release the shut spindle 21 where its conductors are con ters simultaneously. If successive exposures nected to slip rings 23 upon which the at regularly recurring intervals are to be brushes 24 are held in any convenient man made, the circuit may be closed and opened ner, not shown. It will be understood that periodically by timing mechanism, of any the spinning element or rotor of the gyro suitable kind, represented diagrammatical scope is inside of the casing or chamber 18. ly at 39. This mechanism may be bridged In order to maintain the axis of the gyro across the key 38 through a switch 40. The scope vertical, or causing it to return auto circuit is controlled by the key when the matically to the vertical position after de switch is open and by the automatic timing parting therefrom, the spindle 21 is ro mechanism when the switch is closed, as tated continuously in the direction of rota will be readily understood. tion of the spinning element. say in the di It will be observed that the camera and rection of the arrow in Fig. 2. For this the indicator dial 30 are in fixed relation to purpose the spindle is equipped with a each other, since both are fixed to the uni worm gear 2 meshing with a worm 26 driv versally pivoted frame or carrier 11. On en by an electric motor 27, Fig. 2. A gyro the other hand, the gyroscope, 18, is uni scope so operated is said to be stabilized or versally mounted SEFE to the indi erected'. cator dial and camera, and hence does not Extending upwardly from the gyroscope affect the position of the latter parts but 4 casing 18 and in line with the axis of the serves to provide, through the agency of the rotor is a pointer 28, terminating in a button pointer 28, a line of reference which is al or disk 29 in a position below and close to a ways Substantially vertical with respect to transparent window 30 arranged in a plane the earth. - perpendicular to the camera axis and bear It is to be understood that the invention 0 ing a series of concentric indicating circles is not limited to the construction herein 31, Fig. 3, so located that when the axis of specifically illustrated and described but the camera, which is fixed with respect to may be embodied in other forms without de the supporting frame i? and gyroscope parture from its spirit. housing 12, is parallel to the axis of the claim:- gyroscope, the circles will be concentric 1. In apparatus for aerial photography, with the indicator button 29. In using the apparatus the operator notes dial in fixed relation to each other, a gyro by reference to the indicator in the top of scope having a pointer in fixed relation to the gyroscope housing whether or not the its axis and cooperating with the indicator 60 camera axis is parallel to the gyroscope dial, means for erecting the gyroscope, and axis. If not, he can correct the position of pivotal supporting means for the camera the camera before the exposure by tilting and dial whereby they may be shifted with the frame 11 in the proper direction, bring respect to said pointer. ing the indicator circles to the position at 2. In combination, a gyroscope, erecting 6 which they are concentric with the disk 29. means therefor, a camera, means for indi ,46,372 8 :

5 10 1,46,872 and gyroscope, and means for angular ad justment of the camera relative to the gyro Scope. 3. In apparatus for aerial photography, dial fixed in relation to each other, a gyro scope having a pointer in fixed relation to its axis and cooperating with the indicator dial, means for erecting the gyroscope, piv otal supporting means for the camera and dial whereby they may be shifted with re spect to said pointer, and means for record ing the relative positions of said indicator and dial when making an exposure with the Cae. 4. In apparatus for aerial photography, dial in fixed relation to each other, a gyro scope having a pointer in fixed relation to its axis and cooperating with the indicator dial, means for erecting the gyroscope, piv otal supporting means for the camera and dial whereby they may be shifted with re spect to said pointer, and means for photo graphically recording the relative positions of said indicator and dial when making an exposure, with the camera.. In combination, a gyroscope, erecting means therefor, a camera, means for indi and gyroscope, means for angular adjust ment of the camera relative to the gyroscope, and means for recording the relative orienta tion of the camera and gyroscope when mak ing an exposure with the camera. 6. In combination, a gyroscope, erecting means therefor, a camera, means for indi 40 and gyroscope, means for an lar adjust ment of the camera relative to the gyroscope, and means for photographically recordin the relative orientation of the camera an... gyroscope when making an exposure with the camera. 7. ln combination, a universally mounted frame, a camera and a dial rigidly mounted on the frame, a gyroscope and erector there for universally mounted on the frame, and relative orientation of the gyroscope and the camera. 8. In combination, a universally mounted frame and a camera and a dial rigidly at tached to the frame, a gyroscope and erector therefor universally mounted on the frame, relative orientation of the gyroscope and the camera, and means for recording the rela tive Rii, of the pointer and dial. 9. In combination, a universally mounted frame, and a camera and a dial rigidly at tached to the frame, a gyroscope s erector therefor universally mounted on the frame, relative orientation of the gyroscope and the camera, and means for recordin E. relative positions of the pointer and dial at the time of making an exposure with the camera. 10. In combination, a universally mount ed frame, and a camera and a dial, and uni versally mounted thereon a gyroscope and erector therefor universally mounted on the frame, a pointer mounted on the gyroscope and cooperating with the dial, for indicatin the relative orientation of the gyroscope an the camera, and photographic means for re cording the relative positions of the pointer and dial at the time of making an exposure with the camera. signature. In testimony whereof I hereto affix my SHERMAN M. FAIRCHILD. B O s