US2389451A - Mechanical movement - Google Patents

Description

1945- J.' J. MOYNIHAN ,389, 51

" MECHANICAL MOVEMENT 2 Sheets-Sheet 1 Filed April 1, 1942 INVENTOR. JOHN J.MOYNIHAN ATTORNEYS adjusting knob or Patented Nov. 20, 1945 UNITED STATES OFFICE MECHANICAL MOVEMENT John J. Moynihan, Rochester, N. Y., assignor of one-half to Joseph B. Brennan, Cleveland,

Ohio

16 Claims.

This invention relates as indicated to a mechanical movement and is designed for the purpose of providing a means whereby a plurality of movable members may be maintained in what I term for convenience an offset synchronous relation. For example, the one movable element is maintained either in leading or lagging relation with respect to the other, with the amount of such lead or lag proportional to the rate of movement of one of said members. This device is believed novel per se. However, for convenience in the illustration and description of the same, the embodiment thus selected is designed as a component of the coordinating apparatus forming the subject matter of my co-pending application Serial No. 429,897, filed February '7, 1942. In that application an apparatus is disclosed whereby the manipulation of a proto-target may be utilized as the means for not only locating a target, such as an airplane in flight, but to also maintain sighted on such airplane a projection apparatus such as a gun.

It will be apparent that when the gun or other projection apparatus is thus caused to be trained upon the target and follow the target in its flight the time interval for the passage of sound from the target to the detecting apparatus by which the target is located and the time interval of flight of the projectile from the gun to the target must be taken into account in aiming the gun or other projection device relatively to the target so that the projectile and target will both arrive at the same point at the same time.

In the apparatus of my said co-pending application there is provided a proto-target which is connected to stations representative of the stations of the detecting and projecting devices by means of extensible rods. changes in the azimuth and elevation of which are indicated by the rotation of shafts with which are connected the beat frequency oscillators which form a part of the means whereby the actual counterpart of the particular station in the detecting device is controlled with respect to its azimuth and elevation. Thus in my said copending application the shaft or shafts which by their rotation are indicative of a change in the azimuth or elevation of the target and the shaft or shafts which by their rotation are indicative of a change in the azimuth or elevation of one of the projection devices, such as the gun, comprise a plurality of movable elements which are desirably maintained in offset synchronous movemen so that the trajectory of the gun always leads the apparent position of the target rate of moverelated ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims, the annexed drawings and the following description setting forth in detail certain means and one mode of carrying out the invention, such disclosed means and mode illustrating, however, but one of various ways in which the principle of the invention may be used.

In said annexed drawings:

Fig. 1 is a longitudinal section through a mechanical device for advancing the line of sight of the gun by an amount proportional to the rate of change of elevation of the target;

Fig. 2 is a longitudinal section through a modified mechanical device for correcting the line of sight for the rate of change of elevation as in Fig. 1 and also for the acceleration of the target whether linear or angular;

Fig. 3 is a longitudinal section through the escapement shown in Figs. 1 and 2 to a larger scale than in thosefigures;

Fig. 4 is a transverse section through Fig. 3 taken on a plane substantially indicated by the line 4-4; and

Fig. 5 is an elevation of the linkage for controlling the rate of escape of the escapement of Figs. 3 and 4.

Fig. 6 is a fragmentary detail showing how the control cord of the escapement is connected to the proto-target,

Referring now more specifically to the drawings and more especially to Fig. 1, the device here illustrated, is shown in association with a beat frequency oscillator generally indicated at l, the adjustment of which may be efiected by rotation of a knob 2. It is desired that the output frequency of the beat frequency oscillator I be a function of the position of shaft 3 and also of the rate of change of position of shaft 3 with respect to time, such a shaft being for example in the alt-azimuth target follower above referred to, and being turned in spotting an airplane. Expressed mathematically, if on is the angular displacement of shaft 3 and 19 is the angular displacement of knob 2 of the beat freshaft 3. It will be quency oscillator I, it is desired that the following equation hold:

1 (To be read: beta equals alpha plus the derivative of alpha with respect to time.)

The means by which this is accomplished iscontained in the following description The shaft 3 is keyed by means of a key 4 to bevel gear 5 so that the angular displacements of gear 5 correspond to those of shaft 3. The shaft 3 also drives a collar 6 having a dog 1, shown in more detail in Fig. 5, attached thereto. Dog I is coupled to gear 8, which is loosely fitted to shaft 3, by means of a spring 9 and pillar plate In so that the rotation of shaft 3 tends to rotate gear 8 in the same direction. Gear 8 and pillar plate H), however, are prevented from rotating by an escapement mechanism comprising a fixed internal gear ll stationary with respect to the frame of the entire machine, an idler pinion I2 meshing with internal gear H, a pinion l3 engaging idler mam staked to a shaft M, Shaft 14 also carries an escapement wheel l5 staked thereto. An anchor I6 is provided for unlocking escape wheel l5 at ,a rate determined by the rate of oscilla-.

tion of; the balance wheel IT. The rate of escape of the-entire escapement is adjustable by means of the setting lever I8 which regulates the tenthe relative displacement of shaft 3 with respect to gear 8 through the linkage shown in Fig. 5 and including a collar and dog 20 fastened to shaft 3, a link 2| connecting dog 20 to doubletree 22 and a link 23 from double-tree to settinglever I 8. Double-tree 22 is provided with joints 24 and 25 and the action of the linkage so far described is to modify the location of the x setting lever l8, and consequentl the rate of escape of the entire escapement, as a function of the displacement of shaft 3 with respect to gear 8. Assuming for a moment that the point 25 is I fixed, the position of the setting lever I8 is seen and the angular. difference in displacement of the two members is small, As shaft 3 rotates more rapidl gear 8 lags behind shaft 3 to a greater extent, but because of the linkage controlling the rate of escape an equilibrium point is reached where for any given rate of angular displacement of. shaft 3 a position of the escape setting lever is attained which permits gear 8 to follow the displacements of shaft 3 isochronously but at an angular relationship thereto dependent on the magnitude of the angular velocity of observed that the pillar plate In is rigidly secured to the gear 8 by means of a plurality of pillars 18a. and that this assembl is freely rotatable on the reduced extension 3a of the shaft 3. I The gear I2 is supported on a spin- -dle l2a which, at opposite ends, is journalled in the plate I!) andgear 8 respectively, Similar spindles are provided for the remaining elements -of the escapement train, However, since such construction is conventional, it is believed unthe collar 6 by having a reduced extension of r the former extended into a radial opening in the collar. One end of. the spring 9 is connected to the end of the arm I, and the other end of the spring is connected to the plate In by means of the stub shaft 9a. It will thus be observed that the only driving connection between the shaft 3a and the plate I0 is through the spring 9. As the shaft 3a is rotated at different speeds, respectivel different amounts of energy will be transmitted by such shaft through the spring 9 to the plate I 0, and accordingly the spring 9 will be deformed by different amounts for each different rate of rotation of the shaft 3.

As a concrete illustration, assume that shaft 3 is rotating at the rate of 1 R. P. M., gear 8 must also be made to rotate at the rate of l R. P, M. This can be accomplished b ,allowing the escapement to release gear 8 sufficiently rapidly to follow the angular displacements of shaft 3. The position for which such escapement rate is possible may be, as an illustration, at a point Where gear 8 lags shaft 3 by, say, 15. Now let the rate of rotation of shaft 3 be increased to 2 R. P, M. A setting of the escapement can be found where gear 8 will also rotate at 2 R. P. M., but this setting is only possible if gear 8 lags behind shaft 3 by, say, 30. 'We have, therefore, a mechanism in which a member, here gear 8, may be caused to lag another member, here shaft 3, by an amount proportional to the rate of rotation of the second member. Expressed mathematically, the displacement of gear 8 related to that of shaft 3 is equal to 2 (To be read: "gamma equals alpha minus the derivatlVP of alpha with respect to time) (The value of (la E may be modified by a coefficient in dependent on the particular design of the mechanism.)

It will be noted that this expression is identical with the previous expression for the desired rate of rotation of the dial 2 of beat frequency oscillator I except that the second term is reversed in sign. In other words, we have here a member 8 lagging behind shaft 3 by the same amount by which it is desired that knob 2 lead shaft 3. The remainder of the mechanical device shown in Fig. l is a mechanism whereby the lag of member 8 may be translated into a lead of the same amount, The mechanism comprises a planetary spider 26 free to rotate on shaft 3 and a cluster gear composed of two bevel gears 21 and 28 arranged to rotate freely in unison about stud 29 of spider 25. Gear 21' engages verted to a lag of stud 29, behind the corresponding position with reference to gear 5, of half the magnitude. Gear 28 is made sufficiently larger in diameter than gear 21 so that ,a mechanical disadvantage is introduced with reference to its operation on gear 30, the net effect of which is to cause the point on the periphery (To be read: theta equals alpha ,plus the derivative of alpha with respect to time) The gear 3| rotating in unison with gear 30 and a pinion 32 mounted on the shaft of the knob 2 of the beat frequency oscillator 'l are provided to transfer the movements of gear 30 to the setting of the beat frequency oscillator.

The above description has assumed that the only correction required in the output frequency of the beat frequency oscillator I is that due to the rate of change of the displacement of shaft '3 with respect to time, A further correction is necessary, however, in order to adapt the device to the gun-pointing mechanism of my co-pendapplication Serial No. 429,897, filed February 7.. 1942. The necessity for this other correction is apparent from the following considerations. Assume that an audible sight is taken on four aircraft flying at four different elevations above the reference point. Assume, for simplicity of computation, that the aircraft are flying at altitudes of 800, 1600, 2400 and 3200 .feet respectively and "that the speeds of each of the craft are 100 miles per hour, 200 miles per hour, 300 miles per hour and 400 miles per hour, respectively. As-

iect to movement when the proto-target is moved in spotting an airplane. This rod is slidably mounted in an alt-azimuth mechanism, the detail :of such "mounting being unnecessary to the understanding of the present invention, it being sufficient to note that as the pinto-target 33 is moved in sight with an airplane, the rod :34 is moved longitudinally in extension or retraction and can also rotationally move the axis of the support in which it is slidabl mounted. In fixed relation on rod 34 and at a point near the ball :and socket joint in the proto-target 33 an anchorage 3-5 is provided for a flexible, substantially inextensible cord 36 which is conducted parallel to rod 34 to the axis of shaft 3 and by means of pulleys, not shown, is directed along the axis of tshaft 3, said shaft being hollow to provide for this construction. The cord 36 is led out from shaft '3 at the escapement end of the shaft and means of pulleys 31 and 38 is directed to point 2 5 on double-tree 22 where it is anchored. Thus the extension or retraction movement of the target follower 33 and rod '34 operates the cord 36 and changes the adjustable escapement lever l8.

In operation, the extension of member 34 due to the motion of the proto-target at varying altitudes will cause the extension andcontraction of cord '36 with deference to the center of rotation the altitude of the some further that at the time the sight is taken the aircraft are apparently at the same elevation, 4'5 with the horizon. Under these circumstances the apparent increment in elevation with respect to time will be constant. and in the present case will approximate 14 per second. Since we are dealing with a detector which uses sound as the detection energy, the elapsed time from the origin of the sound "to its detection at the ground will be '1 second, 2 seconds, '3 seconds and 4 seconds, respectively, for the example given above, if we assume that the velocity of sound'is equal to 1100 feet per second. This means that although all four planes are apparently at an angular elevation of a more correct statement would be t at the highest altitude plane had the same apparent elevation four seconds ago which the lowest altitude plane had one second ago, and the position of the highest altitude plane at the presout t me if it has continued on its course is ahead of the apparent position by four seconds travel. Since the highest altitude plane is assumed to be travelling at 400 miles an hour, one seconds travel is equal to 584 feet and four seconds travel is equal to 2336 feet. The lowest altitude plane assumed to be travelling at 100 miles per hour will have travelled one second or 146 feet in the same time. It is apparent, therefore, that a shell intended to hit the higher target must be advanced over the apparent angular elevation of the target by a considerable amount more than one intended to hit the lowest target. Expressed in another way, for constant apparent rate of change of elevation, the distance by which the target must be led in order to secure a hit will vary as the square of the altitude of the target. A correction for this factor must therefore be introduced into the mechanism,

Referring to Fig. 6, 33 is a proto-target corresponding to Ag in my co-pending application Serial No. 429,897. 34 is the rod from the protogun-mount to the proto-target, and which is subof shaft 3 and will likewise result in the motion of point 25 in such manner as to change the setting of the setting lever [B and correct the rate of the escapement to compensate for changes in target. The above corrective device will operate satisfactorily where the target is moving :at constant velocit either in a straight line or with constant angular motion above the gun mount as a center. These conditions, however, are not likel to be fulfilled "in actual warfare since it is in the interest of the target to accelerate his path either linearly or angularly so as to render gun fire less effective. A corrective feature will now be described by which linear and angular accelerations of the target ,can be taken into account in the aiming of the gun. Referring to Fig. 2, a mechanism somewhat similar to Fig. 1 is shown, The right hand side of the mechanism is in all respects similar to Fig. i and corresponding parts have been given corresponding identification numerals. The gear 30, however, instead of operating directly to control the setting of the beat frequency oscillator "-l is coupled to a bevel gear 33, the motion of which represents one component of the motion of planetary gear 40. Another component 'of the motion :of gear Ml must be functional of the acceleration of shaft 23. Expressed mathematically, we require an element '41, the rate of rotation of which, A, is equal to (For A: owl- 5 4 (To be read delta equals alpha plus the second deriv ati-ve "of alpha with respect to timel') This is accomplished :as follows:

A collar "42 is keyed on shaft 3 which is coupled'by means of a stiff spring 43 to a heavy flywheel or inertia member 44 having mounted thereon a bevel gear 15 :arranged to rotate in unisonw i'th the motion of flywheel 1H Flywheel "M and gear 15 are free to rotate on shaft 3, subject to the constraintimposed by the stiff spring "43. A bevel gear 46 is provided keyed as at H to shaft 3 so that the motion of gear '46 is identical with the motion of shaft 3. Now when shaft 3 is rotating at constant velocity (which maybe zero). flywheel 44 will also rotate at constant velocity, being coupled to shaft 3 by means of a stiff spring 43. Howeven'when shaft 3 is accelerating or decelerating, flywheel 44 will tend to maintain its condition of constant velocity so (To be read "small delta equals alpha minus the second derivative of alpha with respect to time) As in the analysis of the mechanism of Fig. 1,

we have a member 45 having a motion with respect to shaft 3 similar to that desired for member 4| except that the second term is reversed in sign, 'A construction analogous to the construction of Fig, 1 is utilized. A spider 41a corresponds to spider 2B of Fig. 1, gears 48 and 49 correspond to gears 21 and 28 of Fig. 1, and stud 50 corresponds to stud 29 of Fig; 1. Gear 49 meshes with gear which is directly coupled to gear 4|, The unit comprising gears 4| and 5| is free to rotate on shaft 3, We have,

therefore, I

twoelements, gears 39 and 4|, the motion of the former being proportional to the displacement of the shaft 3 plus the velocity of displacement, and the motion of the latter being proportional to the displacement of the shaft 3 plus the acceleration of the displacement, Gears 39 and 4| engage differential pinions 52 mounted on studs 53 in gear so that the motion of gear 40 is equal to the sum of the displacements of gears 39 and 4| Gear 40 drives pinion 54 which in turn drives flexible shaft 55 which turns knob 2 of the frequency oscillator The entire mechanism is suitably housed in a casing 56. From the foregoing description it will'be observed that I have provided a mechanical movement whereby the two movable elements, Nos. 3 and 32 forexample, are maintained in offset synchronous relation with the degree of such offset proportional to the rate of movement of one of "said elements, such as element 3, for example.

By the term offset synchronous relation" as used in the specification and in the claims, is meant that relationship whereby the movement of one element with respect to the other is in either leading or lagging relationship with the degree of lead or lag proportiona1 to the rate of movement of one of the elements. It will be observed that when the rate of movement of the element upon which the degree of lag is dependent is uniform, then the two elements will move at the same rate although in leading or lagging relationship, or, stated in another way, in out-ofphase'synchronism, From the foregoing it will be observed that when the rate of movement of the element upon which the degree of lead or lag depends decreases, the amount of such lead or lag, or offset, will likewise decrease until at the moment the elements come to rest they will be in true synchronism, that is, there will be no offset or phase displacement between them.

From the foregoing it will be observed that the amount of lead or lag or offset or phase displacement between the elements is proportional by a 1 given 'factor to the rate of movement of one of tion of a first movable membena second movsaid members. It will be observed that I have provided two means or modes for varying the value of said factor, such variation being either independent or concurrent. Thus, for example, the influence exerted by the cable 36 is one means by which the value of this factor may be varied, and accordingly the amount of offset or out-ofphase relation varied. Furthermore, the flywheel 44 and its associated mechanism providesanother means of and mode for varying the value of said factor, and in this connection it will be observed that this means for varying the value of said factor is proportional to or dependent I upon the rate of change or acceleration (negative Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the means and the steps herein disclosed, provided those stated by any of the following claims or their equivalent be employed.

I therefore particularly point out and dis tinctly claim as my invention:

1. In a mechanical movement, the combination of afirst. movable member, a, second movable member, and mechanism connecting therebetween including gearing and a regulatable escapement controlling the gearing for maintaining said members in offset-synchronous relation with the degree of such offset proportional to the rate of movement of one of said members.

- 2. In a mechanical movement, the combination of a first movable member, a second movable member, and mechanism connecting therebetween including differential gearing and a regulatableescapement controlling said gearing for maintaining said second member in offset-synchronous relationto said first member with the degree ofsuch offset proportional to the rate of movement of said first member,

3. In a mechanical movement, the combination of a first rotatable member, a second rotatable member, and means therebetween including differential gearing, a dog having a spring'connection to one element of the said'gearing, and, an escapement having a connection to the said element and havingv a gear connection with ,a fixed gear element for maintaining said second member in offset-synchronous relation to said first member with the degree of such offset proportional to the rate of movement of said first member.

4. In a mechanical movement, the combinaable member, and means connected therebetween including an escapement wheel and a balance Wheel with balance wheel spring an a setting levenregulating the tension of the, spring for variably maintaining said members in offset-synchronous relation with the degree of such offset proportional, by a given factor, to the rate of movement of one of said members. 1

5. In a mechanical movement, the combination of a first rotatable member, a second rotatable member, means actuated by said first member including differential gear mechanism and another differential gear mechanism operatedthereby. formaintaining said members in offset-synchronous relation with the degree of such offset proportional, by a given factor, to the rate of movement of one of said members and means for varying the value of said factor.

6. In a mechanical movement, the combination of a first rotatable member, a second rotatable member, means connected therebetween including an inertia member and differential gear mechanism and a regulatable escapement controlling the differential gear mechanism for variably maintaining said second rotatable member in offset-synchronous relation to said first member with the degree of such offset proportional, by a given factor, to the rate of movement of said first member.

7. Ina mechanical movement, the combination of a first movable member, a second movable member, and connecting means therebetween including differential gearing and an escapement connected to one element of said gearing, said escapement having a balance wheel and a balance spring and a variable setting lever for the control of the balance wheel.

8. In a mechanical movement, the combination of a first rotatable member, a second rotatable member, means therebetween including a regulatable escapement for maintaining said second member in offset-synchronous relation to said first member with the degree of such offset proportional by a given factor to the rate of rotation of said first member and means functionally responsive to a change in the rate of movement of said first member for varying the value of said factor.

9. In a mechanical movement, the combination of a first member, a second member, a resilient driving connection between said members, an adjustable escapement controlling the rate of movement of one of said members, and means functionally responsive to variations of movement of one of said members including deflections of said resilient connection for adjusting said escapement,

10. In a mechanical movement, the combination of a driving member, a driven member, a resilient driving connection between said members, an adjustable escapement controlling the rate of movement of said driven member, and means including differential mechanism functionally responsive to variations of movement of one of said members including deflections of said resilient connection for adjusting said escapement,

11. In a mechanical movement, the combination of a driving member, a driven member, a resilient driving connection between said members, an adjustable escapement controlling the rate of movement of said driven member, means functionally responsive to variations of movement of one of said members including deflections of said resilient connection for adjusting said escapement, and additional means for adjusting said escapement.

12. In a mechanical movement, the combination of a rotatable shaft member, a second rotatable member and means maintaining said members in offset-synchronous relation wit the degree of such offset proportional to the rate of movement of said first member, said means including an adjustable escapement, a fixed ring gear, a pinion meshing therewith, differential gear mechanism having one element with which said pinion is carried and another element fixed to said shaft and a differential pinion between said elements, and a connection driven by said differential pinion for actuating the aforesaid second rotatable member.

13. In a mechanical movement, the combination of a rotatable shaft member, a second rotatable member and means maintaining said members in offset-synchronous relation with the degree of such offset proportional to the rate of movement of said first member, said means including a relatively constant speed member and a resilient connection to said shaft, an adjustable escapement -a fixed ring gear, a pinion gree of such offset proportional to the rate of movement of said first member, said means including an inertia flywheel free on said shaft, a resilient connection between said flywheel and said shaft, an adjustable escapement, a fixed ring gear, a pinion meshing therewith, differential gear mechanism having one element with which said pinion is carried and another element fixed to said shaft and a differential pinion be-' tween said elements, a second differential gear mechanism having one element moving with said flywheel and another element fixed to said shaft and a differential pinion between said elements, and a third differential gear mechanism operated by both said differential pinions for actuating the aforesaid second rotatable member.

15. In a mechanical movement the combination of a first rotatable member, a second rotatable member, and connecting means therebetween including differential gearing and an escapement wheel carried with one element of said differential gearing, said escapement wheel having a balancewheel and balance spring and a variable setting lever for control of the balance wheel, said setting lever having a connection to one of said rotatable members, a pinion driven by said escapement wheel, and a ring gear with which said pinion meshes for reaction.

16. In a mechanical movement, the combination of a first movable member, a second movable member, and connecting means including differential gearing and an escapement wheel carried with one element of said differential gearing, said escapement wheel having a balance wheel and a balance spring and a variable setting lever for control of the balance wheel, said setting lever having a connection to one of said rotatable members, a pinion driven by said escapement wheel, a fixed ring gear in mesh with said pinion, and other differential gearing hav- JOHN J. MOYNIHAN.

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