US3604137A

US3604137A - Sighting system for a firearm-carried grenade launcher

Info

Publication number: US3604137A
Application number: US834117A
Authority: US
Inventors: Stanley D Silsby
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1969-06-17
Filing date: 1969-06-17
Publication date: 1971-09-14
Anticipated expiration: 1988-09-14

Abstract

A sighting system for a grenade launcher carried by a shouldersupported firearm includes a front sight mounted on the launcher for elevational adjustment by means of a track disposed at a predetermined angle relative to the vertical axis thereof to compensate for grenade drift as the front sight is moved along the track for range adjustment. The rear sight is adjustable for windage correction and is pivotally mounted on the firearm so as to be swung thereagainst, out of the way, when not in use.

Description

United States Patent [72] Inventor Stanley D. Silsby Granby, Mass. [21] Appl. No, 834,117 [22] Filed June 17, 11969 [45] Patented Sept. 14, 1971 [73] Assignee The United States of America as represented by the Secretary of the Army [54] SIGHTING SYSTEM FOR A FIREARM-CARRIED GRENADE LAUNCHER 5 Claims, 11 Drawing Figs.

[52] US. Cl 42/1 S,

' 33/47 [51] lnt.Cl F4lc [50] Field of Search 42/1 F, 1 S; 33/47, 48, 53

[56] References Cited UNITED STATES PATENTS 1,340,453 5/1920 Lera 42/1 F 2,068,821 1/1937 Savani 42/1 1- 2,335,881 12/1943 Persinger... 33/47 3,165,836 1/1965 Magardo... 33/47 3,435,549 4/1969 Kermode.... 42/1 F Primary Examiner-Benjamin A. Borchelt Assistant Examiner-C. T. Jordan AnomeysHarry M. Saragovitz, Edward J. Kelly, Herbert Berl and Albert E. Arnold, Jr.

ABSTRACT: A sighting system for a grenade launcher carried by a shoulder-supported firearm includes a front 'sight" mounted on the launcher for elevational adjustment by means of a track disposed at a predetermined angle relative to the vertical axis thereof to compensate for grenade drift as the front sight is moved along the track for range adjustment. The rear sight is adjustable for windage correction and is pivotally mounted on the firearm so as to be swung thereagainst, out of the way, when not in use.

PATENTED SEPI 41971 SHfEI 1 [IF 2 INVENTOR Elunlgy I! 5 flag ATTORNEYS PATENTEU SEP] 4 |97| SHEET 2 OF 2 SIGHTING SYSTEM FOR A FIREARM-CARRIED GRENADE LAUNCHER The invention described herein may be manufactured, used, and licensed by or for the US. Government for governmental purposes without the payment to me of any royalty thereon.

BACKGROUND OF THE INVENTION This invention pertains to sighting devices for firearms and provides for grenade launchers carried by shoulder-supported firearms, a separate sighting system that includes a front sight mounted on the grenade launcher and adapted for elevational adjustment and automatic compensation for lateral drift of the grenade in flight, and a rear sight pivotally mounted on the basic firearm so that it can be swung out of the way when not in use and which is adjustable for windage correction.

Included in the arsenal of modern firearms are shouldersupported firearms which carry an auxiliary firearm for launching grenades to thereby increase the firepower available to the troops. These grenade launchers discharge the grenade at a low velocity and high trajectory and therefore the sight system for the launcher must be entirely different from that of the basic firearm. Considerable difficulty has been encountered in providing for these launchers a suitable sighting system which can be used comfortably by the shooter. Because of the necessary elevation required of the firearm to lob the grenade to distant targets, and because of the proximity of the rear sights to the eye of the shooter with conventional sighting systems, considerable and awkward adjustment of the head of the shooter is required for the full-range adjustments and sometimes the firearm cannot even be supported on the shoulder when sighting at a long-range target.

SUMMARY OF THE INVENTION It is a principal object of this invention to provide for shoulder-supported firearms having an auxiliary grenade launcher mounted thereon a separate sighting system for the launcher designed so that the firearm can be elevated for the different range adjustments of the launcher from the shoulder of the shooter, and with a minimum of a change required in the head position of the shooter, when sighting on the target.

it is another object of this invention to provide such a sighting system in which the rear sight is adjustable for windage correction and the front sight is adjustable for elevation and is also adapted to automatically compensate for lateral drift of the grenade caused by the induced spin therein, at the different range adjustments.

It is a further object of this invention to provide such a sighting system wherein the rear sight is mounted on the basic, shoulder-supported firearm for pivotal displacement against the firearm when not in use and the front sight is mounted on the auxiliary grenade launcher.

It is a still further object of this invention to provide such a sighting system which is simple and rugged in construction so as to be adaptable for rough usage and which adds a minimum amount of bulk to the firearms.

Further objects and advantages of the invention will be apparent from the following specification and the accompanying drawings which are for the purpose of illustration only.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of a shoulder-supported firearm with a grenade launcher mounted thereon;

FIG. 2 is an enlarged, fragmentary view of the firearm where the sighting system of this invention is mounted thereto;

FIG. 3 is a view taken along line 3-3 of FIG. 2;

FIG. 4 is a view similar to FIG. 3 but showing the rear sight pressed in to release it so it can be swung to the folded position;

FIG. 5 is a view taken along line 5-5 of FIG. 2;

FIG. 6 is a view taken along line 6-6 of FIG. 2;

FIG. 7 is a view taken along 7-7 of FIG. 6;

FIG. 8 is a view taken along line 88 of FIG. 2;

FIG. 9 is a schematic view showing, exaggerated, the relationship between the sight line and bore axis of the launcher in the horizontal plane with the drift of the grenade being compensated for at the 75-yard adjustment;

FIG. 9a is a view similar to FIG. 9 but shows the relationship between the sight line and bore axis when the sighting system is adjusted for the 250-yard range; and

FIG. 9b is a view similar to FIGS. 9 and 9a but shows the relationship between the sight line and bore axis when the sighting system is adjusted for the 375-yard range.

DESCRIPTION OF A PREFERRED EMBODIMENT Shown in the figures is a rifle 12 with a grenade launcher 14 mounted underneath barrel 16 thereof. Launcher 14 includes a housing 18 having a T-slot 22 formed in the left side so as to slant upwardly and outwardly at a predetermined angle relative to the vertical axis of the launcher, for a purpose to be explained hereinafter. T-slot 22 slidingly mounts a metering bar 24 which is slidable therein for bore-sighting adjustment and is secured in the adjusted position by screw 26. Extending along the length of metering bar 24 is a T-shaped channel 28 which opens outwardly along the left side thereof and slidingly mounted in such channel is a front sight 30 of blade type. The upward and downward movement of front sight 30 in channel 28 is limited by roll pins 32 which extend through channel 28, as shown in FIG. 2.

Provided along the rear face of metering bar 24 so as to be seen by the shooter, as shown in FIG. 8, is a scale 33 which has been calibrated in increments of 25 yards of range adjustment extending from 75 to 375 yards. A reference line 34 on the rear face of front sight 30 is alignable with the calibrations of scale 33 to correctly index the front sight at the desired range setting. Front sight 30 is releasably held in the selected position through the cooperation of a spring-pressed ball 36 in the front sight with spherical indents 38 formed in inner surface 44 of channel 28, as shown in FIG. 2. Because of the angle of T-slot 22 relative to the vertical axis of launcher l4, metering bar 24 is similarly inclined and this angle is determined by the predetermined lateral drift of the grenade at the different range calibrations on scale 33.

Rifle 12 is provided with a handle 42 located along the top thereof rearwardly of launcher 14, which handle includes an opening 45 for receiving the fingers ofa hand for carrying the firearms. Opening 45 is terminated at the rear end by a planar wall 46 which is normal to the longitudinal axis of rifle 12. Extending forwardly from wall 46 is a lug 48 which is hexagonal in cross section as shown in FIG. 4 and which pivotally supports rear sight 50. Such rear sight 50 includes a collar 52 which receives lug 48 so as to permit radial displacement rela' tive thereto, and a shaft 54 that extends radially therefrom. Shaft 54 is bored axially at 56 into collar 52 and installed in such bore is a plunger 58 and a spring 60 for biasing the plunger against lug 48. The outer end of bore 56 is threaded at 62 to threadingly mount an aperture 64 having an eyepiece 66 with a rod 68 extending therefrom. Rod 68 includes a threaded portion 70 that engages threaded section of bore 56, and a calibrated section 72 disposed between the threaded section and eyepiece 66. Installation of aperture 64 in bore 56 tensions spring 60 to bias plunger 58 against side 76 of lug 48, which is formed normal to the axis of rear sight 50 when located in its extended operative position, as shown in FIG. 3. Lug 48 is also provided with two sides 78 which are disposed opposite side 76 and symmetrical thereto and such sides contact mating sides 80 formed in collar 52, as shown in FIGS. 3 and 4, when rear sight 50 is in its extended operative position, to releasably hold the rear sight therein. To swing rear sight 50 down to its folded inoperative position, aperture 64 is pressed inwardly against the bias of spring 60 as shown in FIG. 4 for disengaging sides 78 on lug 48 from sides 80 in ring 52, to where the rear sight is free for pivotal displacement. When rear sight 50 is in its inoperative position, as shown in phantom in FIG. 3, it is held therein by the spring-pressed contact of plunger 58 with side 82 of lug 48. Rear sight 50 is pivoted to its operative position by reversing the above steps and when in the operative position it is positioned for operational cooperation with front sight 30, as shown in FIG. 8.

When rear sight 50 is in its extended operative position, the sighting system 84 of this invention is used for aiming launcher 14 at target 86 by moving front sight 30 along meter bar 24 to where reference line 34 is in alignment with the calibration on scale 33 which corresponds to the estimated distance of the target. As front sight 30 is moved up meter bar 24, to decrease the target range adjustment by decreasing the angle of sight line xx relative to bore axis y-y of launcher 14, it is also moved outwardly according to the angle of the bar relative to the vertical axis of launcher 14 to compensate for the predetermined lateral drift of the projectile at the selected range setting, as shown in FIGS. 9, 9a and 9b. Moreover, it is obvious that by having the rear sight fixed to rifle 12 for elevational sighting and having the front sight adjustable, the adjustment of sighting system 84 for elevation requires less adjustment of the eye of the shooter to the various range settings than when the front sight is fixed and the rear sight is adjustable as in conventional sight systems.

lwish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. A sighting system for a firearm comprising a shouldersupported rifle and a launcher for grenades mounted thereon including a front sight, a channeled metering bar mounting said front sight on said launcher for sliding elevational adjustments, a rear sight including an aperture, means for mounting said rear sight for windage adjustment, and a lug on said rifle cooperating with said rear sight for releasably securing said rear sight in an extended operative position and a folded inoperative position.

2. The sighting system as defined in claim 1 wherein said metering bar is provided with a scale calibrated according to increments of range distances and said front sight is provided with an index line alignable with said calibrations. and including a T-slot formed in said firearm for slidingly mounting said metering bar for bore sight adjustment and to incline said metering bar relative to the vertical axis of the firearm so as to position said front sight for automatically compensating said front sight for lateral drift of the grenades at the different range calibrations on said metering bar.

3. The sighting system as defined in claim 2 wherein said metering bar is provided with a channel ofT-configuration for slidingly mounting said front sight, and including a springpressed ball in said front sight, and spherical indents in said channel cooperating with said ball for releasably securing said front sight at the different calibrations on said metering bar.

4. The sighting system as defined in claim 2 wherein said front sight is mounted on said launcher and said rear sight is mounted on said rifle.

5. The sighting system as defined in claim 2 wherein said lug is longitudinally disposed on the rifle and is of hexagonal configuration in cross section, and including a collar portion of said rear sight encircling said lug to provide pivotal support for said rear sight and permit radial movement thereof respective to said lug, a spring-biased plunger pressed against said lug, a one side of said lug arranged for contact by said plunger when said rear sight is in the extended operative position, a pair of sides of said lug disposed opposite said one side so as to be pressed against a mating pair of surfaces in said collar by the bias of said plunger to releasably hold said rear sight in the extended operative position and so as to be free of said pair of surfaces when said rear sight is pressed inwardly against the bias of said plunger to release said rear sight for pivotal displacement to a folded inoperative position, and a fourth side on said lug contactable by said plunger when said rear sight is in the inoperative position to releasably hold the sight therein.

Claims

2. The sighting system as defined in claim 1 wherein said metering bar is provided with a scale calibrated according to increments of range distances and said front sight is provided with an index line alignable with said calibrations, and including a T-slot formed in said firearm for slidingly mounting said metering bar for bore sight adjustment and to incline said metering bar relative to the vertical axis of the firearm so as to position said front sight for automatically compensating said front sight for lateral drift of the grenades at the different range calibrations on saId metering bar.

3. The sighting system as defined in claim 2 wherein said metering bar is provided with a channel of T-configuration for slidingly mounting said front sight, and including a spring-pressed ball in said front sight, and spherical indents in said channel cooperating with said ball for releasably securing said front sight at the different calibrations on said metering bar.