US2410614A - Gun mount - Google Patents

Description

J NOV- 5, 1946. J c, TROTTER 2,410,614-

GUN MOUNT Filed June 28, 1944 IN V EN TOR. JOHN C. TROTTER Patented Nov. 5, 1946 when .--=umrsn stares Parent OFFECE GUN MOUNT John C. TrottenBurlington, Vt,, assignor to Bell 1 Aircraft Corporation Application June 28, 1944; Serial No. 542,499

3 Claims.

Thi -invention relates to gun mounts, and more particularly to fixed-aim type mountings for aerial machine guns and cannon or the like. Such gun mount devices customarily embody a pair of gun connection units extending from the airplane fuselageor wing or other frame structureupon which the gun is to be mounted; said connection units being relatively spaced in the direction of the longitudinal extent of the gun and generally referred to as -the front trunnion and rear-trurmion, respectively. The front trunnionunit is customarily provided in the form of a swivel connection device whereby the gunmay be rocked thereon about transverse axes for regulatingv the aim of the gun relative to the supporting frame. The rear trunnion unit customarily comprises a laterally and vertically adjustable linkage between the mounting-frame and the gun, whereby to providefor pivoting of the gun upon the front ..mount device for aim adjustment purposes.

1 For example, manufacturing tolerances which are necessary in connection with large airplane productionprograms and varying tactical requirements calling for different rates of plural gun fire convergences require that for such purposes must embody. aim adjustment means for the guns relative to the airplane fuselage or wing structures, as explained hereinabove. Prior art' arrangements' for. providing the adjustability features referred to hereinabove usually employ paired screw thread connection devices having transverse axes forconnecting the gun and support frame elements, whereby screw adjustments thereof obtain corresponding lateral and vertical adjustments of the rear end portion of the gun relative. to the supporting frame, whereby the gun aim is shifted about the front trunnion, while keeping the gun locked inmounted position. 'Such adjustments of the screw threadconnection devices are, howeifenaccoinbli'shed through use of wrenches or other tools thereon as in l atent No. 2,076,256, for example, and it is usually extremely difficult to design the gun mount and airplane frame structures so as to inake adequate provision for room sufficient-to allow quick and effective handling of wrenches or the like in the regions of the screw devices referred to. Also, under such conditions it is extremely diificult to effect relatively minute andaocurateadjustments of the screw devices.

Itis a primary object of the present invention to provide an improved aim-adjustable gun mount device. .as an improvement over the Standard Armyv Type A GunRear' 'Irunnion, forexample, andwhich-is of rugged and compact formand adapted to be accurately adjusted with improved facility without the use of wrenches or other tools orthelike. Another object of the invention is to: provide a device of the character aforesaid which is adapted to bemanuallymanipulated by gunserVice personnel with improved ease and facility to provide micrometer-fine adjustments of the mounted gun aim. Another object of the invention is to provide a gun mount. device having the features hereinabove recited and which is self-locking atv all positions of adjustment thereof and requires no accessory locking means.

ther objects and advantages .of the invention will appfiar I in the (specification hereinafter.

In the drawing": I I

Fig. 1 is an elevation of a gun mount'device of the invention, with portionsshown'in section; and

Fig. 215 a section taken along line II-II of Fig. 1.

Fig. ,3 is airagmenta'ry sectional view. of the device taken along line IIL-III of Fig. 2.

A gun mountdevice of. the invention i'SillllS". trated 'infthe. drawing-in connection with the mounting-eta machine gun or cannon as indicated at H] upon a frameelem'ent indicated 12. It will .be understood that the frame member I2 may beanyportion. of a framing structure, such as interiorly of the fuselage or wing of'an airplane, and it will also beunderstood that the gun lil--will be preferably arranged to be carriedat positions spaced longitudinally of the gun-by means of a pair of mount connectiondevices, whereby to rigidlymount the gun It upon the frame l2. At the relatively forward position the connection device may comprise any suitable form of swivelable mount; that is, a connection device permittingthe. gun tobe rotated thereon about substantially transverse horizontal and vertical axes for adjusting the gun aim in azimuth and elevation relative to the frame l2. Although the present invention may be applied eitherto the front or the rear gun mount connection, it is shown in the. drawing herein to relate only to the rear gun mount connection; and in the interests of simplification of the specification only the rear gun mount connection form of the inventionis described in detail hereinafter.

Thus, as illustrated, the gun mount of theinvention may comprise a mounting sleeve It which is externally threaded to extend substantially vertically and in screw thread mounted relation upon an internally threaded ferrule 16 carried by the frame structure I2. The upper end of the sleeve I4 is rotatably heldagainst a collar 18 by. means of a bolt 20 passing throughthe sleeve I4 and provided with a head portion 22 which rests against the collar I8 so as to pull downwardly thereon in reaction to the clamping forces of a nut 24 which is screwed upon a stub end portion 25 of the bolt 20 at the lower end thereof. For convenience of manufacture the threaded stub end portion 26 may be separately fabricated and inserted within a suitably bored portion of the bolt 20 and keyed thereto by means of a pin 28; and subsequent to final assembly of the sleeve and collar and bolt elements the nut 24 may be locked upon the stub 26 by means of a cotter pin 29.

A socket member 30 is arranged to embrace the upper end of the bolt head 22, to be rotatable thereon, and the socket member 30 is formed with an integral extending eye portion 3|; the bore of the eye portion 3I being horizontally directed transversely of the longitudinal axis of the gun to be mounted. The eye portion 3| is internally threaded to receive a trunnion unit ineluding a bolt 34 which slip-fits through paired lugs 3535 extending downwardly from the gun I!) and formed integral therewith to mount the latter upon the upper end of the gun mount sleeve I4. A key 36 is fitted upon the bolt 34 between the positions of the lugs 35-35 of the gun to key a sleeve 38 of externally threaded form to the bolt 34 subsequent to screwthreaded insertion of the sleeve 38 within the eye portion 3|. Thus, it will be understood that the displacements in vertical directions of the post sleeve [4 relative to the mounting frame. I2 will either raise or lower the elevation of the trunnion bolt 34, and thus effect elevational adjustments of the gun aim relative to the frame I2.

The socket member 30 is arranged to be detachably connected to the bolt head 22 for quick gun dismounting and remounting purposes and to be held against axial movement therewith, when in gun mounting condition by any suitable means. This may be accomplished through use of a retaining ring 40 which encircles the socket member and controls an interconnection device thereon. This feature of the mechanism is not a part of the present invention, however, as such quick-disconnect devices are presently well known in the gun mount art, and may employ for example operative elements of the type shown and described in detail in Patent No. 1,939,699. The collar I8 is held against rotation relative to the socket member 35 by means of a number of detent lugs 32 carried by the collar and engaging notches 33 formed in the lower edge of the socket member.

To eifect gun aim adjusting vertical displacements of the sleeve l4 relative to the frame l2 it is of course onlynecessary to cause the sleeve to rotate relative to the frame, whereby the screw thread devices thereof will cause the sleeve to correspondingly rise or lower. Whereas to apply manual rotating forces directly to the sleeve I4 would require the use of a wrench or the like and would inevitably result in relatively coarse adjustments of the sleeve I4, the present invention employs a novel power supply mechanism which is adapted to be manually actuated to translate manual movements thereof into mi- (lnometer-fine rotational movements of the sleeve For example, as shown in the drawing, the power supply mechanism may conveniently comprise a casing 44 keyed to a base ring 46 (as by screws 41 shown in Fig. 2) which encircles a shouldered portion of the upper end of the sleeve I4 and is freely rotatable thereon and main-e tained. against accidental displacement subsequent to assembly of the device by means of a spring washer 48. The ring 46 carries an upstanding shaft 50 which mounts in freely rotatable relation a dual gear 52 having gear elements in coaxial relation with each other and fastened together 'for unison rotation. The lower one of the gear elements is of a slightly larger diameter than the upper gear element thereof. The lower gear element meshes with a ring gear portion 55 of the sleeve l4, and the upper gear element meshes with a ring gear portion 56 of the collar l8. Since the collar I8 is non-rotatably attached through the socket member 30 to the trunnion bolt 34 whenever the connector device 45 is in gun mounting condition, any manual rotation of the casing 44by gun servicing personnel will cause the gear unit 52 to be rotated upon the shaft 55 while being simultaneously carried by the ring 48 to rotate with .a planetary motion about the vertical sleeve I 4. Such rotation of the gear unit about the shaft 53 causes the toothed portion 55 of the sleeve L4 to be simultaneously driven to rotate the sleeve about its vertical axis, but the speed of rotation of the sleeve I4 will be at greatly reduced rate compared to the speed of manual rotation of the casing 44 because of the slight difference in diameters of the upper and lower elements of the gear unit 52. Thus, it will be appreciated that the speed of rotation of the mounting sleeve I4 relative to the speed of manual rotation of the casing 44 will be governed by the difference be-v tween the diameters of the elements of the gear unit 52, and that this may be regulated to provide any desired degree of rotational speed reduction. A pair of spring detents 6060 are preferably mounted to extend in cantilever fashion from the base ring 46 to bear at their free ends against the gear unit 52 to impose thereagainst rotationrestraining influences, whereby to retard the power supply unit against accidental rotation.

Thus, it will be understoodthat because of the speed reduction ratio which is provided by the gear unit the casing 44 is adapted to be easily rotated manually by only one hand of the operator even though nearby portions of the gun and gun mount and frame support elements provide only restricted room for insertion of the operators hand into actuating position, and that thereby the need for applying wrenches or other tools or the like to the control device is eliminated. Also, it will be appreciated that due to the rotational speed reduction feature of the control unit extremely fine adjustments of the gun mount sleeve [4 relative to the frame I2 can be effected without difficulty by the operator.

As illustrated generally at 65, Fig. 1, an azimuth adjustment control device will Preferably be employed in conjunction with the trunnion bolt 34 and the gun lugs 35-35; and the adjustment control device may comprise aunit which is substantially identical to the control unit enclosed within the casing 44. That is, the control unit 65 may comprisea manually rotatable casing 66 which is dualeared internally thereof to both the trunnion bolt 34 and a sleeve.

about the axis of the trunnion bolt 34 will cause the gear unit internally of the control device 65 to react against the fixed gun lug andto cause;

the trunnion bolt 34 to rotate within the gun lugs 35--35 at a greatly reduced speed relative to the speed of rotation of the casing 66. Such rotation of the trunnion bolt 34 will drive the threaded sleeve 38 to rotate within the eye portion 3| of the gun mount post device, whereby a corresponding screw threading displacement of the gun l0 laterally of the mounting sleeve M will occur to provide a micrometer-fine adjustment of the gun aim in azimuth about the vertical axis of rotation of the front gun mount device.

It will be appreciated that the gun aim adjustment mechanisms of the invention are freely reversible in the sense that they are readily rotated in either direction by the operator to procure corresponding reverse-direction adjustments of the gun aim; but that under all conditions of adjustment the mechanisms are inoperable to permit changes in the gun aim in response to forces from any source except when applied to the control casings 44-66 of the mechanisms. It will also be understood that although only one form of the invention has been shown and described in detail it will be apparent to those skilled in the art that the invention is not so limited but that various changes may be made therein without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. A gun support comprising in combination, bolt means formed to be connected to a gun for support thereof, a sleeve rotatably mounted upon said bolt means and formed with external screw threads for screw threaded engagement upon a positionally fixed frame, means for retaining said bolt means and said sleeve against axial displacements relative to each other, a ring rotatably mounted upon said sleeve, differentially sized gear means carried upon said sleeve and said bolt means respectively, and a pair of differentially sized pinions rigidly interconnected and carried by said ring in positionally fixed relation thereon, said pinions meshing with the bolt means and sleeve gear means respectively.

2. A gun support comprising in combination, bolt means formed at one end to be connected to a gun for support thereof, a sleeve rotatably mounted upon said bolt means and formed with external screw threads for screw threaded engagement upon a positionally fixed frame, means for retaining said bolt means and said sleeve against axial displacements relative to each other, a ring rotatably mounted upon said sleeve in axially non-displaceable relation thereon, difi'erentially sized gear means carried upon said sleeve and said bolt means respectively, and a pair of differentially sized pinions rigidly interconnected and carried by said ring in positionally fixed relation thereon, said pinions meshing with the bolt means and sleeve gear means respectively.

3. A gun support comprising in combination, a bolt formed to be connected to a gun for sup port thereof, a sleeve rotatably mounted upon said bolt and formed with external screw threads for screw threaded engagement upon a positionally fixed frame, a collar mounted upon said bolt and fixed against relative rotation with the gun, means for retaining said bolt and said sleeve against axial displacements relative to each other, a ring rotatably mounted upon said sleeve, gear means formed upon said sleeve, relatively larger gear means formed upon said collar, and a pair of axially aligned pinions rigidly interconnected and carried by said ring in positionally fixed relation thereon, said pinions meshing with the collar and sleeve gear means respectively, whereby said ring may be manually rotated relative to said collar to procure rotation of said sleeve at reduced speed.

JOHN C. TRO-ITER.

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