J NOV- 5, 1946. J_ c, TROTTER 2,410,614 GUN MOUNT Filed June 28, 1944 L46 . W 3A IN VEN TOR. JOHN C. TROTTER BY when Patented Nov. 5, 1946 l.~~=umrsn stares Parent OFFECE GUN MOUNT ‘ John C. TrottenB‘urlington, Vt,, assignor to Bell ' 1 Aircraft Corporation ‘ Application June 28, 1944; Serial No. 542,499 3 Claims. (Cl. 89—-37.5) 2 , adapted to be accurately adjusted with improved This-invention relates to gun mounts, and more particularly to ?xed-aim type mountings for facility without the use of wrenches or other tools aerial machine guns and cannon or the like. orthelike. Another object of the invention is Such gun mount devices customarily embody a pair of gun connection units extending from the airplane fuselageor wing or other frame struc tureupon which the gun is to be mounted; said to: provide a device of the character aforesaid which is adapted to: bemanuallymanipulated by gunserVice personnel with improved ease and facility to provide micrometer-?ne vadjustments of the mounted gun aim. Another object of the connection units being relatively spaced in the direction. of the longitudinal extent of the gun invention is to provide a gun mount. device hav and generally referred to asi-the front trunnion 10 ing the features hereinabove ‘recited and which is self-locking atv all positions of adjustment and. rear-trurmion, respectively.’ The front trun thereof and requires no accessory locking means. nion-‘unit is customarily provided in ‘the form of ther objects and advantages .of the invention aiswivel connection device whereby the gun- may be rocked thereon about transverse axes for regu latingv the aim of the gun relative to the support will app?ar I in the (specification hereinafter. 15 ing 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 20 purposes. > . 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. ‘_ 1 For example, manufacturing tolerances which aregnecessary in connection with large airplane A gun mountdevice of. the invention i'SillllS". trated 'infthe. drawing-in connection with the productionprograms and varying tactical require mounting-eta machine gun or cannon as indi ments calling for different rates of plural gun ?re 25 cated at H] upon a frameelem'entvindicated 12. convergences require that for such purposes must It will .be understood that the frame member I2 embody. aim adjustment means for the guns rela may beanyportion. of a framing structure, such as interiorly of the fuselage or wing of'an air tive to the airplane fuselage or wing structures, as explained hereinabove. Prior art' arrange plane, and it will also beunderstood that the gun ments' for. providing the adjustability features. re lil~~will be preferably arranged to be carriedat ferred to hereinabove usually employ paired screw thread ‘connection devices having transverse axes forconnecting the ‘gun and support frame ele ments, whereby screw adjustments thereof obtain corresponding lateral and vertical adjustments of vthe 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 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 locked inmounted position. 'Such adjustments axes for adjusting the gun aim‘ in azimuth and of the screw threadconnection devices are, how 40 elevation relativeito the frame l2. Although the present invention may be applied either- to the eifenaccoinbli'shed through use of wrenches or other tools thereon as in l5atent No. 2,076,256, for front or the rear gun mount connection, it is example, and it is usually extremely difficult to shown in the. drawing herein to relate only to the design the gun mount and airplane frame struc rear gun mount connection; and in the interests tures so as to inake adequate provision for room of‘simplification of the specification onlyv the rear sufficient-to allow quick and effective handling gun mount'connection form of the inventionis of wrenches or. the like in the regions of the screw described in detail hereinafter. devices referred to. Also, under such conditions Thus, as illustrated, the gun mount of thein it is extremely dii?cult to effect relatively minute vention may comprise a mounting sleeve It which and‘aocurateadjustments.of the screw devices. 50 is externally threaded to extend substantially 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' 'I‘runnion, forexample, vertically and in screw thread mounted relation upon an internally threaded ferrule 16 carried by the framegstructure I2. The upper. end of the sleeve I4 is rotatably heldagainst a collar andwhich-isjof rugged and compact formand its 18 by. means of a bolt 20, passing throughthe 2,410,614 3 4 sleeve I4 and provided with a head portion 22 I4 and is freely rotatable thereon and main-e tained. against accidental displacement subse 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 quent to assembly of the device by means of a spring washer 48. The ring 46 carries an up standing shaft 50 which mounts in freely rotat able relation a dual gear 52 having gear elements in coaxial relation with each other and fastened threaded stub end portion 26 may be separately together 'for unison rotation.» The lower one of fabricated and inserted within a suitably bored the gear elements is of a slightly larger diam portion of the bolt 20 and keyed thereto by means eter than the upper gear element thereof. The of a pin 28; and subsequent to ?nal assembly of lower gear element meshes with a ring gear por the sleeve and collar and bolt elements the nut tion 55 of the sleeve l4, and the upper gear ele 24 may be locked upon the stub 26 by means of ment meshes with a ring gear portion 56 of the a cotter pin 29. " collar l8. Since the collar I8 is non-rotatably A socket member 30 is arranged to embrace the upper end of the bolt head 22, to be rotat 15 attached through the socket member 30 to the trunnion bolt 34 whenever the connector device able thereon,_ and the socket member 30 is formed 45 is in gun mounting condition, any manual ro with an integral extending eye portion 3|; the tation of the casing 44by gun servicing personnel bore of the eye portion 3I being horizontally di will cause the gear unit 52 to be rotated upon rected transversely of the longitudinal axis of the shaft 55 while being simultaneouslylcarried the gun to be mounted. The eye portion 3| is by the ring 48 to rotate with .a planetary motion internally threaded to receive a trunnion unit in- ‘ about the vertical sleeve I 4. Such rotation of eluding a bolt 34 which slip-?ts through paired the gear unit about the shaft 53 causes the lugs 35—35 extending downwardly from the gun toothed portion 55 of the sleeve L4 to be simul-_ I!) and formed integral therewith to mount the latter upon the upper end of the gun mount sleeve 25 taneously driven to rotate the sleeve about its vertical axis, but the speed of rotation of the I4. A key 36 is ?tted upon the bolt 34 between sleeve I4 will be at greatly reduced rate com the positions of the lugs 35-35 of the gun to key pared to the speed of manual rotation of the a sleeve 38 of externally threaded form to the casing 44 because of the slight difference in di bolt 34 subsequent to screwthreaded insertion of the sleeve 38 within the eye portion 3|. Thus, 30 ameters of the upper and lower elements of the gear unit 52. Thus, it will be appreciated that it will be understood that the displacements in the speed of rotation of the mounting sleeve I4 vertical directions of the post sleeve [4 relative relative to the speed of manual rotation of the to the mounting frame. I2 will either raise or casing 44 will be governed by the difference be-v lower the elevation of the trunnion bolt 34, and tween the diameters of the elements of the gear thus effect elevational adjustments of the gun unit 52, and that this may be regulated to provide aim relative to the frame I2. any desired degree of rotational speed reduction. The socket member 30 is arranged to be de A pair of spring detents 60—60 are preferably tachably connected to the bolt head 22 for quick mounted to extend in cantilever fashion from gun dismounting and remounting purposes and to be held against axial movement therewith, 40 the base ring 46 to bear at their free ends against the gear unit 52 to impose thereagainst rotation when in gun mounting condition by any suitable restraining in?uences, whereby to retard the means. This may be accomplished through use power supply unit against accidental rotation. of a retaining ring 40 which encircles the socket Thus, it will be understoodthat because of the member and controls an interconnection device speed reduction ratio which is provided by the thereon. This feature of the mechanism is not gear unit the casing 44 is adapted to be easily a part of the present invention, however, as such quick-disconnect devices are presently well known rotated manually by only one hand of the oper ator even though nearby portions of the gun in the gun mount art, and may employ for exam ple operative elements of the type shown and and gun mount and frame support elements pro vide only restricted room for insertion of the op described in detail in Patent No. 1,939,699. The erator’s hand into actuating position, and that collar I8 is held against rotation relative to the socket member 35 by means of a number of de thereby the need for applying wrenches or other tent lugs 32 carried by the collar and engaging tools or the like to the control device is elimi notches 33 formed in the lower edge of the socket nated. Also, it will be appreciated that due to member. the rotational speed reduction feature of the con trol unit extremely ?ne adjustments of the gun To eifect gun aim adjusting vertical displace mount sleeve [4 relative to the frame I2 can be ments of the sleeve l4 relative to the frame l2 effected without difficulty by the operator. to rotate relative to the frame, whereby the screw As illustrated generally at 65, Fig. 1, an azi thread devices thereof will cause the sleeve to (if) muth adjustment control device will Preferably correspondingly rise or lower. Whereas to apply be employed in conjunction with the trunnion manual rotating forces directly to the sleeve I4 bolt 34 and the gun lugs 35-35; and the ad it is of course onlynecessary to cause the sleeve would require the use of a wrench or the like and would inevitably result in relatively coarse adjustments of the sleeve I4, the present inven tion employs a novel power supply mechanism which is adapted to be manually actuated to translate manual movements thereof into mi (ln‘ometer-?ne rotational movements of the sleeve For example, as shown in the drawing, the power supply mechanism may conveniently com prise 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 justment control device 65 may comprise a‘unit which is substantially identical to the control unit enclosed within the casing 44. That is, the control unit 65 may comprisea manually rotat able casing 66 which is dual-geared internally thereof to both the trunnion bolt 34 and a sleeve. 68 carried by a locknut ‘H! which is in turn'keyed to one of the gun lugs 35. Thus, it will be un derstood that manual rotation of the casing“ 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 2,410,614 5 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 por tion 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-?ne adjust ment of the gun aim in azimuth about the verti cal axis of rotation of the front gun mount de vice. It will be appreciated that the gun aim adjust ment mechanisms of the invention are ‘freely re versible in the sense that they are readily rotated 6 sized pinions rigidly interconnected and carried by said ring in positionally ?xed 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 en 10 gagement upon a positionally ?xed 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, di?'er in either direction by the operator to procure 15 entially sized gear means carried upon said sleeve corresponding reverse-direction adjustments of and said bolt means respectively, and a pair of the gun aim; but that under all conditions of differentially sized pinions rigidly interconnected adjustment the mechanisms are inoperable to and carried by said ring in positionally ?xed rela permit changes in the gun aim in response to tion thereon, said pinions meshing with the bolt forces from any source except when applied to 20 means and sleeve gear means respectively. the control casings 44-66 of the mechanisms. 3. A gun support comprising in combination, It will also be understood that although only one a bolt formed to be connected to a gun for sup— form of the invention‘ has been shown and de port thereof, a sleeve rotatably mounted upon scribed in detail it will be apparent to those said bolt and formed with external screw threads skilled in the art that the invention is not so 25 for screw threaded engagement upon a position limited but that various changes may be made ally ?xed frame, a collar mounted upon said bolt therein without departing from the spirit of the and ?xed against relative rotation with the gun, invention or the scope of the appended claims. means for retaining said bolt and said sleeve I claim: against axial displacements relative to each other, 1. A gun support comprising in combination, 30 a ring rotatably mounted upon said sleeve, gear bolt means formed to be connected to a gun for means formed upon said sleeve, relatively larger support thereof, a sleeve rotatably mounted upon gear means formed upon said collar, and a pair said bolt means and formed with external screw of axially aligned pinions rigidly interconnected threads for screw threaded engagement upon a and carried by said ring‘ in positionally ?xed rela positionally ?xed frame, means for retaining said 35 tion thereon, said pinions meshing with the collar bolt means and said sleeve against axial dis and sleeve gear means respectively, whereby said placements relative to each other, a ring rotatably mounted upon said sleeve, differentially sized gear ring may be manually rotated relative to said collar to procure rotation of said sleeve at reduced means carried upon said sleeve and said bolt speed. means respectively, and a pair of differentially 40 JOHN C. TRO-‘I‘TER.