US1413927A - Fuse setter controller for antiaircraft guns - Google Patents

Description

aaes ao B. V. MORSE.

FUSE SETTER CONTROLLER FOR ANTIMRCRAFT GUNS.

APPLICATION HLED SEPT.13,1917.

2 bHtEl'SSHEET1 Patented Apr. 25, 1922.

R. V. MORSE.

FUSE SETTER CONTROLLER FOR ANTIAIRCRAFT GUNS.

APPLICATION FILED SEW-Z13. 1917- 1,4 1 3,927. Pate ted Apr. 25, 1922.

2 SHhETS-SHEET 2.

N a k BAA/6E INVENTOR UNITED STATES PATENT OFFICE.

ROBERT V. MORSE, OF ITHACA, NEW YORK, ASSIGNOR TO MORSE INSTRUMENT COMPANY, INC., OF ITHACA, NEW YORK, A CORPORATION OF NEW YORK.

FUSE SETTER CONTROLLER FOR ANTIAIR-CRAFT GUNS.

Specification of Letters Patent.

Patented Apr. 25, 1922.

Application filed September 13, 1917. Serial No. 191,266.

To all whom it may concern:

Be it known that 1, ROBERT V. MORSE, a citizen of the United States, residing at Ithaca, in the county of Tompkins and State of New York, have invented a new and useful Fuse-Setter Controller for Antiaircraft Guns, of which the following, taken with the accompanying drawings, is a specification.

This invention relates to artillery stationed on the ground and employed against aircraft, and has to do particularly with the operation of the fuse setter by which the time of flight to the moment of burst of the shell is determined. WVith the rapidly changing range and angle of projection which generally obtain with a flying target, the proper time or flight for the projectile is a rapidly varying quantity, and hence for accurate fire an automatic device controlling the fuse setter is as essential as an automatic sight controller.

The object of this invention is to provide a mechanism which will continuously and automatically compute the time of flight of a projectile to a given altitude, for any angle of projectiom-this mechanism to be connected to any suitable form of fuse setter to continuously give it the proper setting. Another object of this invention is to eliminate the error due to the time lag between the moment when the fuse is set by the fuse setter and the moment when the projectile is discharged from the gun,so as to make the fuse setting correct at the instant the projectile leaves the gun. Another object is to provide the gunner with data by which to allow the proper lead to his sight to compensate for the movement of the target during the flight of the projectile. Other obj cuts will appear as the description proceeds; in general the objects are to increase the accuracy of fire of anti-aircraft artillery, The automatic fuse setter should of course be used in conjunction with some form of automatic sight setter in order to make the anti-air craft gun an accurate instrument.

In the drawings forming part of this specification. Fig. 1 illustrates a simple form of automatic range computer; Fig. 2 is a side View of the indicator of Fig. 1; Fig. 3 shows a more refined form of automatic fuse setter controller; Fig. 4 is a side view partly in section showing the indicator and loading time lag compensator for the controller of Fig. 3; Fig. 5 shows a modified form of flexi ble altitude bar; Fig. 6 shows the apparatus of Figs. 3 and 4 as mounted on an anti-aircraft gun; Fig. 7 shows how fuse settings vary with range, for a constant altitude, and illustrates the fact that fuse settings and range do not increase in direct and simple proportion; Fig. 8 illustrates one method of estimating altitude of target.

l/Ve will first take up the automatic range computer, and then consider the somewhat similar automatic. fuse setter. Referring to Fig. 1, the altitude bar 1 can be raised and lowered by means of the screws 2, 2, which are connected by any suitable gearing as (g) so as to operate simultaneously and equally,thus maintaining the altitude bar 1 horizontal wherever it may be moved. The range rod 3 has pivoted to its upper end a sliding block 4. which slides along the under side of the altitude bar 1. The range rod 3 is either rigidly or mechanically connected with the sight bars of the sighting apparatus so as to remain parallel thereto. An inspection of Fig. 1 will show that if the range rod 3 is parallel to the line of sight, that is, has an inclination equal to the angle of position of the target, and the altitude bar 1 has an elevation corresponding on some scale to the flying altitude of the target, the distance measured along the range rod 3 from the sliding block 4 to the central indicator gear 5 on the shaft 5 will represent to scale the range of the target. If the range rod 3 is provided with rack teeth, the amount of rotation of the indicator gear 5 will be proportional to the range. Any suitable form of uniformly graduated dial or indicator drum can be attached to the gear 5 and the range read directly. For example, an indicator drum is shown in Fig. 2 in which the scale is wrapped spirally around a drum 6 which is rotated by the indicator gear 5, (operated by the rack on the range rod 3 of Fig. 1), the drum 6 being fed along by a nut 7 on a screw thread 1 8. The range is, expressed in figures read opposite the pointer 9.

It is important to note that it is not the actual range at ,the instant the fuse is set that is desired in anti-aircraft fire, but the value which the range will. have to the point indicated by the cross-hairs fat the instant of discharge. To obtain this, the man reading the range scale should watch its movement under the pointer, and endeavor to allow for the interval of time from the moment the shell leaves the fuse setter until it is discharged from the gun. If this time inter val with his gun crew is normally five seconds he should watch the progress of the indicator and endeavor to judge what reading will come under the pointer in five seconds,that is, what reading will be under the pointer when the gun is fired. This is not a difficult matter, as the movement of the range indicator scale is fairly steady, and the speed )of a well drilled gun crew a fairly constant quantity. To facilitate the estimate, two pointers may be provided, one fixed and one movable,-as will be described in connection with Fig. 4 for example. The distance between the pointers then corresponds to the time required by the gun crew in loading and firing.

The automatic fuse setter controller which we will now take up is of the mechanical type and is based on a principle similar to the range computer above described. Referring now to Fig. 3, the altitude bar 1 is horizontally supported on the elevating screws 2, 2 connected by a suitable gearing (g) by which the bar 1 may be raised and lowered to correspond to the flying altitude of the target. The trajectory bar 3 is provided with a sliding block 4 which slides along the lower side of the altitude bar 1. The block f is also slidably connected to the rod 5", which is connected with the gun mechanism so as to remain parallel to the line of sight or line of position of the target, so that the rod 5 will have an angular motion equal to that of the line of sight. For example, in Fig. 3, the rod 5 is shown at-' tached to the sight bar s,which sight is of course kept trained on the target by the gunner operating the gun controls in the usual manner. The trajectory bar 3 may be curved toward its lower end, and is provided with teeth which engage with the teeth of the pinion 6. The pinion 6 is mounted on the shaft 7 which also carries the planetary gearing 8. This gearing 8, as shown in longitudinal cross-section in Fig. 4,consists of the inner gear 9 keyed to the shaft 7"; the planetary gears 10, carried on the spider 11 which is keyed to the shaft 12; and

the outer gear or housing 13, provided with internal teeth and mounted on the bearings 20 freely rotatable on the shaft 7 The housing 13 is rotated by means of the handle 14. This housing 13 is also provided with the gear teeth 21, which rotate the casing 22 through the intermediate gears 23. The casing 22 is also free to rotate on the shaft 7 and is provided with a pointer 15 which plays over a scale 16 keyed to the shaft 7 This scale 16 also is provided with a fixed pointer 17. The gearing 21, 22, 23 is so proportioned as to make the movement of the pointer 15 correspond to the lead of the shaft 12 over the shaft 7 This lead is given by operating the handle 14, which turns the shaft 12 relative to the shaft 7 The shaft 12 is mechanically connected to any suitable form of fuse setter 27 of the ordinary type, such for example as is shown in the patent to Scanferla, No. 1,246,331, Nov. 13, 1917. In Fig. 4: for example the range worm 26 of the fuse setter 27 is shown directly mounted on the shaft 12. The range worm 26 through a worm wheel rotates the range ring 28. The setting of this range ring 28 determines the setting of the fuse when a projectile is inserted and turned until a fixed stop on the projectile encounters a fixed stop in the fuse setter. It will be noted that the range ring 28 is not uniformly graduated. This is due to the fact that the range or distance is not uniformly proportional to the time of flight, that is, time of fuse burning. For example, a fuse must burn more than twice as long for a range of 2000 yds. than for a range of 1000 yds.- Thus, if one rotation of the worm 26 would set the fuse setter for a target at 1000 yds., more than two rotations of the worm 26 would be necessary for a target at 2000 yds. In order to give this increasing rate of rotation per unit range, the trajectory bar 3 is given an increasing curvature toward its end, so that as the bar 3 is withdrawn radially at a uniform rate for example it will cause the gear 6 and shafts 7 and 12 to rotate at an increasing rate. In general, the curvature of the bar 3 is proportioned so that if the fuse setter were graduated for range, the reading at the fuse setter will at all times correspond to the range graphically represented by the distance from the sliding block 4 to the central gear, as described in connection with Fig. 1.

The operation is as follows :The altitude bar 1 is set in accordance with the altitude as announced by the officer controlling the fire of the batteries. The altitude may be determined by any well known method, such as triangulation, or by trial shots for example, such as illustrated in Fig. 8. Then as the gun 35 swings, following the target, the

rod 5", keeping parallel with the line of sight of the gun, slides the block 4 along the altitude bar 1, thus moving the trajectory bar 3 whose gear teeth rotate the pinion 6' on the shaft 7 By curving the bar 3', like an irregular gear, more gear teeth are made to move over the teeth of the pinion 6, so that for a given motion of the slide 4 the pinion will be given an amount of rotation greater than the amount it would receive if a straight rack bar, such as in Fig. 1, were used. The function of an irregular mechanical element, such as this irregular gear, is to transform motion of one type into motion of another type. In this instance we desire,- in place of a motion which would be according to range if the bar 3' were straight,to substitute a motion according to that desired at the fuse setter mechanism 27. It will be evident from an inspection of Fig. 7' that some form of irregular mechanical element, such as the curved gear 3, must be introduced at some point in the mechanism, since the fuse settings do not increase in direct and uniform proportion to the range. Fig. 7 shows the fuse settings increasing more rapidly than the range; accordingly, the bar 3 must be curved sufficiently to provide enough additional teeth as it is extended to impart the required additional motion to the pinion 6 and the fuse setter 27. The actual shape of the bar 3' will depend to some extent on the nature of the mechanical elements through which it is connected to the fuse setter 27, and various arrangements of the connecting mechanical elements can of course be used. Owing to the curvature of the bar 3, the rotation of the pinion 6' and shaft 7' is proportional to the time of flight of the shell, instead of proportional to the range as in Fig. 1. The apparatus of both Fig. 1 and Fig. 3 are based on the same fundamental principle, namely, that if the pivot of the sliding block 4 is elevated by an amount proportional to the altitude of the target, and the angle between the altitude bar 1 and the range rod 3, (or corresponding rod 5 of Fig. 3), is equal to the angle of position of the target, then the extension of the rod 3 is proportional to the range,or with the curved rod 3 the extension is proportional to the corresponding fuse setting. Strictly speaking, it is the distance from the center of the pivot of the block 4 to the center of the shaft 5, (Fig. 1) or shaft 7, (Fig. 3), that is proportional to the range. The size of the gear 5, (Fig. 1) or gear 6, (Fig. 3), relative to the toothed bar 3 or 3, is greatly exaggerated in the drawing for the sake of clearness; yet even when that gear is made small relative to the toothed bar, a slight variation in the range reading or fuse setting with a given extension of the rod 3 or 3 would occur as the angle of position varied. This slight variation may be prevented by letting the apparatus illustrated in Fig. 2 or Fig. 4 swing through the same angle that the rod 3 or rod 5 does. so as to eliminate relative angular motion between the rod and the recording apparatus. The variation will also be greatfor the same altitude.

inausmaa 1y reduced by mounting the recording apparatus of Fig. 2 or Fig. 4 to swing with the gun, so that their angular motion corresponds to that of the line of projection, which swings in somewhat the same manner as the line of sight. But though these slight variations may be eliminated or minimized as described, it is not generally desirable to do so, since these variations may be utilized by the designer to offset slight variations which generally occur in the ballistic factors, and thus give an even greater precision to the apparatus. For example, the time of flight to a certain range is substantially the same for all angles of fire in the ranges used in anti-aircraft work, (owing to the decreased density of the air for higher angles almost exactly offsetting the increased component of gravity); yet it is not always exactly so, and the slight variation when it exists can sometimes be neutralized by the variation due to the gear 5 or 6' having an appreciable diameter, which occurs when the recorder of Fig. 2 or fuse setter of Fig. 4 does not participate in the angular motion of sight or gun. Another means by which a slight compensating variation may be introduced is by pivoting the altitude bar 1 at its ends as shown in Fig. 5, so as to introduce slight variations in its elevation, either by springing it by converging screws or by having the pitch of one screw 2 slightly different from that of the other screw 2, so that they would elevate at slightly different rates. Of course we are here dealing with the correction of only minor errors, as the general apparatus will give closely approximate results.

\Vhere the slope of the altitude bar is varied in order to introduce compensating corrections, the method of procedure is briefly to try out the mechanism at various angular positions and with various altitude settings, checking the resulting reading at the fuse setter 27 against the known desired fuse set ting for that angle and altitude, as obtained from approved range tables or firing sheets. lVhen it is found that in a certain region the settings given by the mechanism are for example below those desired, the elevating mechanism is redesigned so that the altitude bar. will be a corresponding amount aboveat those points, so that the error may be compensated.

Continuing the discussion of the operation, we have seen that the gear 6 is rotated by an amount to correspond to the time of flight of the projectile to the designated altitude, along the trajectory indicated by the gun. But by the time that a shell having a fuse set according to that determination has actually been discharged from the gun, the gun will usually have swung to a new position, giving a slightly different time of flight What we wish to do is to set the fuse of a projectile at the value which will be indicated at the instant the gun is discharged. To do this, we interpose the mechanism shown in Fig. 4, by which we can give the fuse setter a lead corresponding to the interval of time required to get the shell from the fuse setter to the gun and discharge it. The dial 16 carries numbers indicating the correct setting of the fuse for the existing position of the gun,this dial being controlled by the gear 6 operated from the trajectory bar 3 of Fig. 3,-the dial therefore rotating slowly as the length of the trajectory changes. The proper setting for every position of the gun is indicated by the fixed pointer 17. If the fuse setter 27 were driven directly by the shaft 7 on which the dial 16 is mounted, it would give a setting correct for the existing range at every present instant; but if a shell Whose fuse was then set by the fuse setter were then withdrawn from the fuse setter and inserted in the gun, its fuse setting would probably not be correct by the time the gun was fired. lVhat we desire to do is to give the fuse such a setting that, at the instant when the gun is fired, the setting we have given the shell then discharged can be the same as the correct existing setting for that instant then read under the fixed pointer; that is, we set the fuse according to the number which will be under the fixed pointer when the gun is fired. As the dial 16 is turning, we must select some number which is approaching the fixed pointer 17, and which we judge from the speed of the dial will come under the fixed pointer by the time the gun crew has the shell in the gun and fired. In order that this loading lead may be closely estimated,-

we employ in general two indicators which play over the scale; both indicators move relative to the scale at the same rate, actuated by the apparatus, but the distance between the indicators can be altered by hand. The first indicator, which we may call the primary indicator, such for example as the indicator 17, gives a reading which depends entirely on the operation of the automatic apparatus described, and which corresponds to the existing correct value of the range or time of flight at each instant,that is, what should be the fuse setting of a shell discharged from the gun at that instant. The secondary indicator, as for example the indicator 15, gives a reading which, while responding mechanically to the automatic apparatus as did the reading of the primary indicator 17, leads or lags behind the pri-- mary reading by an amount controlled by the operator. The actual setting of the fuse setter 27 corresponds to the reading of the secondary indicator; the actual setting of the fuse when in the gun at the instant of discharge should correspond to the reading at the primary indicator. One means of giving this lead for example is shown in Fig. 4, in which the principles of planetary gearing are utilized to give one shaft a lead over the other. By moving the handle 14 the planetary casing 13 is rotated on the shaft 7, and the internal teeth of this casing 13, operating on the planetary gears 10, give the shaft 12 more or less lead over the shaft 7 The shaft 12 being connected to the fuse setter 27, the actual fuse setting at the instant it is made is indicated by the pointer 15,-the distance between the pointers 15 and 17 corresponding to the lead which has thus been given. The movable pointer 15 is geared so as to permit the lead to be read directly on the same scale 16 as is used for the pointer 17; or gearing may be used to control the indicator scale, and then the pointer 15 can be fixed to the casing 13 if desired.

The operator having given the pointer 15 what he judges is the proper lead, watches to see whena shell is taken from the fuse setter. He then drops his eye, catches the number opposite the pointer 15, and follows its progress toward the pointer 17 until he hears the discharge of the gun. If he has estimated correctly, the number he has been watching will at the instant of discharge be under the pointer 17. If it was beyond the pointer 17, he will give more lead; if it had not reached the pointer 17 he will reduce the lead. As the gun crew operates regularly and continuously, the interval of time becomes a fairly constant quantity, and with a little practice the operator can accurately set the pointer 15. When this is accomplished, we have the fuse correctly set for the position of the gun at the instant of discharge. The gunner has the gun pointed at an imaginary point ahead of the target, to which he judges the target will have travelled by the time the shell reaches there. That is, the gunner has given the gain a lead to compensate for the time of flight of the projectile; in this he is aided by cross-hairs in his sight calibrated in angular units, which he can set according to the known angular speed of the target and the known time of flight of the projectile as called off by the man reading the dial 16. The lead given by the mechanism of Fig. 4 compensates for the time lag in loading the gun. Thus with the automatic fuse setter, (combined with a suitable automatic sight elevation controller), the gunner can depend on the shell bursting on the cross-hairs at the proper altitude,and hence, with a substantially accurate instrument to work with can pasilly correct an error in his own estimated In anti-aircraft fire, the gunner must aim a considerable distance ahead of the swiftly moving target. This lead covers a time interval which can be divided into two parts, namely, (1) the loading lead, which covers the time from the primary observations of the target to the discharge of the gun set according to those observations, (2), the gunners lead, which covers the time of flight of the projectile. In prior apparatus the data upon which the fuse was set was obtained by apparatus not mechanically connected to the fuse setter, was transmitted with some time lag to the fuse setter, the fuse then set, and the shell passed to the gun, involving in all a loading lead of about ten seconds. If the time of flight was six seconds for example, the gunner was compelled to aim at the location it was estimated the aircraft would have sixteen seconds in the future. With the high speeds of aircraft, such a prediction is difficult to make accurately. In the foregoing specification I have described apparatus which (1) mechanically rotates the worm of the fuse setter at a rate corresponding to the existing angular velocity of the target, and (2) which permits the operator to simultaneously introduce a correction which compensates for the substantially constant lag or lead of about two seconds covering the time required to get the shell from the fuse setter into the gun and discharge it. The loading lead, so far as the gunner is concerned, is thus reduced to zero, and the gun need only be aimed sufficiently far ahead to cover the time of flight of the projectile. In the example given above, instead of a prediction covering sixteen seconds, the prediction would be merely for six seconds later, and thechance of an accurate prediction very greatly increased.

It will be understood that the apparatus described will operate equally well in any position; and that elements such as the bars 3 and 5" which have been described as parallel to the line of sight will operate equally well if they maintain any fixed angle to the line of sight, provided that the rest of the apparatus with which they graphically interact is also shifted to-a corresponding angle. For example, it will often be found convenient to invert the entire apparatus, so that the altitude bar 1 will be elevated downward.

In the claims the term computer bar refers to an element having the function of the range rod 3 or trajectory bar 3',that is, an element which graphically. approxi mates the primary determination desired. The general term contact member is used in place of sliding block, since any member the locus of whose pivot corresponds to the altitude of fire desiredmay be used, regardless of whether the member slides, rolls, or is constrained by whatever means to follow the desired path.

It will be understood that the devices described in the foregoing are not limited to the precise form and construction there set t b are p b e of various adaptations and variations as will be evident to those skilled in the, art, without departing from the scope of the invention as indicated by the following claims.

1. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of an altitude bar, a contact member guided by said bar, a computer bar connected to the contact member, an in dicator shaft, gearing connecting the computer bar with the indicator shaft, and. means for moving the contact member.

2. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of an altitude bar, means for adjusting the elevation of the altitude bar, a contact member guided by said bar, a computer bar connected to the contact member, an indicator shaft, gearin connecting the computer bar with the indlcator shaft, and means for moving the contact member.

3. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of an altitude bar, means for adjusting the elevation of the altitude bar, a contact member guided by said bar, a computer bar connected to the contact member, an indicator shaft, gearing connecting the computer bar with the indicator shaft, an indicator controlled by the rotation of the indicator shaft to indicate the time of flight, and means for moving the contact member.

4. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of an altitude bar, means for adjusting the elevation of the altitude bar, a contact member guided by said bar, a computer bar having some curvature connected to the contact member, an indicator shaft, gearing connecting the computer bar with the indicator shaft, and means for moving the contact member.

5. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of an altitude bar, means for adjusting the elevation of the altitude bar, a contact member guided by said bar, a computer bar having some curvature connected to the contact member, an indicator shaft, gearing connecting the computer bar with the indicator shaft, an indicator controlled by the rotation of the indicator shaft to indicate the time of flight, and means for moving the contact member.

6. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of an altitude bar, means for changing the shape and elevation of the altitude bar, a contact member guided by saidbar, a computer bar connected to the contact member, an indicator shaft, gearing connecting the computer bar with the indicator shaft, and means for moving the contact member,

7. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of means for determining the time of flight of the projectile, a shaft operated by said determining means, a second shaft whereby the setting of the fuse setter is determined, and means for giving the second shaft a lead over the first shaft corresponding to the interval of time between the fuse setting and the discharge of the gun.

8. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of an altitude bar, means for adjusting the elevation of the altitude bar, a contact member guided by said altitude bar, a computer bar connected to the contact member, an indicator shaft, gearing connecting the computer bar with the indicator shaft, an indicator device connected to said shaft, a fixed pointer, a second shaft, means for varying the angular relation between the first mentioned shaft and said second shaft, a movable pointer whose distance from the fixed pointer is .a measure of the angular lead between the first mentioned shaft and the second shaft, and means for moving the contact member on the altitude bar.

9. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of an altitude bar, means for adjusting the elevation of the altitude bar, a contact member guided by said altitude bar, a computer bar having some curvature connected to the contact member, an indicator shaft, gearing connecting the computer bar with the indicator shaft, an indicator device connected to said shaft, a fixed pointer, a second shaft, means for varying the angular relation between the first mentioned shaft and said second shaft, a movable pointer whose distance from the fixed pointer is a measure of the angular lead between the first mentioned shaft and said second shaft, and means for moving the contact member on the altitude bar.

10. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of an altitude bar, means for changing the shape and elevation of the altitude bar, a contact member guided by said altitude bar, a computer bar connected to the contact member, .an indicator shaft, gearing connecting the computer bar with the indicator shaft, an indicator device connected to said shaft, a fixed pointer, a second shaft means for varying the angular relation between the first mentioned shaft and said second shaft, a movable pointer whose distance from the fixed pointer is a measure of the angular lead between the first mentioned shaft and said second shaft, and means for moving the contact member on the altitude bar,

11. In anti-aircraft artillery, a gun conwhich continuously shows the actual setting at the fuse setter, and means for obtaining:

a difference between the two indicators corresponding to the change in the reading of; the first indicator occurring in the interval from the time when a shell is withdrawn from the fuse setter to the time when :the shell is fired from the gun. i v

13. In a mechanism for determining the fuse setting for anti-aircraft artillery, thecombination of an indicator which continuously shows the setting corresponding to the existing point of aim, a second indicator which continuously shows the actual setting at the fuse setter, said second indicator being mechanically cionnected t0 the first men tioned indicator, and means for obtaining a difference between the two indicators corresponding to the change in the reading of the first indicator occurring in the interval-from the time when a shell is withdrawn from the fuse setter to the time when the shell is fire from the gun.

14. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of an altitude bar, means for adj usting the elevation of the altitude bar, said adjusting means being arranged so that the angular relation between it and the altitude bar may vary for different settings of the altitude bar, a contact member guided by said bar, a computer bar connected to the contact member, an indicator shaft, gearing connecting the computer bar with the indicator shaft, and means for moving the 0011-. tact member. r

15. In a mechanism for determining the fuse setting for anti-aircraft artillery, the

combination of an altitude bar, a screw for 1 adjusting the elevation of the altitude bar,

a contact member guided by said bargacomputer bar connected to the contact mBm-y her, an indicator shaft, gearing connecting the computer bar with the indicator shaft, and means for moving the contact member.

16. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of a contact member, a computer bar pivotally connected to the contact member, means for moving the contact member to corres 0nd to the movements of the target, a sha t, and gearing connecting the computer bar and the shaft.

tri

hiertsmae 17. In a mechanism for determining the fuse setting for anti-aircraft artillery, the combination of means for observing the target, a fuse setter, and automatic means mechanically connected to both the observing means and the fuse setter for setting the fuse setter simultaneously with the operation of the observing means, whereby the time interval of the gunners lead is reduced to that of the time of flight of the projectile. 10 In Witness whereof I have hereunto set my hand this 7th day of September, 1917.

ROBERT V. MORSE. Witnesses:

ELMER H. MAUZER, T. S. BARR.

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