A one-piece resilient sight movable for windage adjustment along the axis of a screw mounted on a firearm wherein the sight has spaced bearing abutment portions on opposite diametrical sides of the screw and is stressed when assembled to urge the bearing abutment portions into engagement with the firearm for taking up manufacturing variations and tolerances and positively retaining the sight by the resiliency of its own material in a selected adjusted position.
Application Number:
05/233482
Publication Date:
07/23/1974
Assignee:
Colt Industries Operating Corp. (Hartford, CT)
International Classes:
F41G1/10; F41G1/26; F41G1/00; F41G1/26; F41G1/10
Field of Search:
33/252,244,241,242,257,258
Primary Examiner:
Martin Jr., William D.
Assistant Examiner:
Stephan, Steven L.
Attorney, Agent or Firm:
Prutzman, Hayes, Kalb & Chilton
Claims:
I claim
1. A firearm sight assembly comprising an adjustment screw attachable to a firearm, a sight having a one-piece body of resilient material, the sight body including an apertured intermediate portion, an elongated sight member and a "U" shaped yoke, the sight member and the yoke being integrally connected to the apertured intermediate portion of the one-piece sight body, the sight member providing a bearing abutment portion engageable with the firearm, the "U" shaped yoke having a bearing abutment portion of reduced cross section relative to said first bearing abutment portion and said yoke bearing abutment portion extending in generally parallel relation to the sight member and said adjustment screw, with the yoke bearing abutment portion and the sight member on opposite sides of said apertured intermediate portion, the apertured intermediate portion of the sight body being threaded at least in part for engagement with the adjustment screw for selective adjustment of the position of the sight axially along the length of the adjustment screw, the yoke bearing abutment portion being subject to being resiliently deformed under stress and so dimensioned and configured that upon being assembled to the firearm, the adjustment screw cooperates with the firearm and stresses the sight sufficiently to deform said yoke bearing abutment portion at its reduced cross section and urges the spaced bearing abutment portions into pressing engagement with the firearm on opposite diametrical sides of the adjustment screw.
2. The firearm sight assembly of claim 1 wherein the material of the sight is nylon resin.
3. The firearm sight assembly of claim 1 wherein the sight member has a planar base defining its bearing abutment portion with the base providing surface bearing engagement with the firearm of enlarged area relative to that provided by the yoke bearing abutment portion, the sight member being relatively unaffected by the stress of assembly while the bearing yoke is flexed to take up manufacturing variations and tolerances while additionally positively retaining the sight in selected adjusted position on the adjustment screw.
4. The firearm sight assembly of claim 1 wherein the material of the sight has an elastic limit greater than the maximum unit stress applied to the assembled sight.
5. The firearm sight assembly of claim 1 wherein the yoke has parallel spaced arms connecting the yoke bearing abutment portion to the apertured intermediate portion of the sight body, and wherein the apertured intermediate portion of the sight includes a pair of screw receiving lugs connecting the sight member to the arms of the yoke.
6. The firearm sight assembly of claim 5 wherein upon securing the sight and the adjustment screw to the firearm, the yoke bearing abutment portion is flexurally stressed to take up manufacturing variations and tolerances while maintaining the sight member in a selected adjusted position on the firearm and in a relatively unstressed condition.
7. A firearm sight assembly comprising an adjustment screw attachable to a firearm, a sight having a one-piece body of resilient material, the sight including an apertured intermediate portion, an elongated sight member and a "U" shaped yoke, the sight member being in generally parallel relation to the adjustment screw, the sight member and the yoke being spaced apart and engageable with the firearm on opposite sides of the apertured intermediate portion of the sight, the apertured intermediate portion of the sight being threaded at least in part for engagement with the adjustment screw for selective adjustment of the position of the sight axially along the length of the adjustment screw, the "U" shaped yoke having parallel spaced arms with a crossbar interconnecting the arms, the yoke crossbar disposed in generally parallel relation to the sight member, the apertured intermediate portion of the sight including a pair of screw receiving lugs connecting the sight member to the arms of the yoke, the crossbar of the yoke having a bottom surface with a central arcuate projection formed on the bottom surface and defining a bearing abutment portion on one side of the adjustment screw, the sight member having a planar base defining a second bearing abutment portion on an opposite side of the adjustment screw, the first bearing abutment portion providing a bearing surface engageable with the firearm of substantially reduced area relative to the surface area of the planar base engageable with the firearm, the sight being dimensioned and configured such that upon its being assembled to the firearm, the adjustment screw stresses the sight and urges its spaced bearing abutment portions into engagement with the firearm.
Description:
This invention generally relates to firearm sights and particularly concerns a sight assembly which provides windage adjustment.
A primary object of this invention is to provide a new and improved sight assembly which is quick and easy to manufacture and assemble at low cost and is particularly suited to take up manufacturing variations and tolerances upon being assembled in an operative position on a firearm.
Another object of this invention is to provide such a sight assembly which is quick and easy to adjust and which positively maintains a sight member in selected adjusted position relative to the firearm.
Other objects will be in part obvious and in part pointed out in more detail hereinafter.
A better understanding of the objects, advantages, features, properties and relationships of the invention will be obtained from the following detailed description and accompanying drawing which sets forth an illustrative embodiment and is indicative of the way in which the principle of this invention is employed.
In the drawing:
FIG. 1 is a front view of a sight assembly incorporating this invention; and
FIG. 2 is a side view of the sight assembly taken generally along line 2--2 of FIG. 1.
Referring to the drawing in detail, a preferred embodiment of a rear sight assembly 10 incorporating this invention is adapted to be mounted on a suitable support such as a barrel of a pistol, e.g., or the frame or housing illustrated at 12 which will be understood to be the housing of a fire control group of a machine pistol. The housing 12 has a pair of upstanding, parallel ears 14, 16 which are spaced apart on opposite lateral sides of the housing 12 for supporting a sight adjustment member such as the screw 18 for providing windage adjustment. The screw 18 extends laterally across the housing 12 in perpendicular relation to the line of sight along the firearm barrel.
In the specifically illustrated embodiment, the ears 14, 16 are suitably apertured to support opposite ends of the adjustment screw 18 for rotary movement in either angular direction. The adjustment screw 18 has a shank and an enlarged head 20 shown slotted for quick and easy adjustment by means of a suitable tool. The head 20 is connected to the shank of the adjustment screw 18 by a concentric collar 22 which extends through a conforming opening 24 in the ear 14. The other ear 16 illustrated as having an opening 26 of a relatively smaller size than opening 24 but formed in coaxial alignment therewith to receive an unthreaded terminal portion 28 of the screw shank. The screw shank is shown having a threaded portion 30 which extends a substantial distance along its length from the collar 22 and the diameter of the unthreaded terminal portion 28 is shown as being approximately equal to the root diameter of the threaded portion 30 of the screw 18. To maintain the adjustment screw 18 in assembled relation to the housing 12, a retaining ring 32 is preferably mounted in a groove 34 circumferentially extending about the collar 22 with the ring 32 being in a slightly compressed condition between the ear 14 and a shoulder 36 formed by the groove 34 in the collar 22.
To provide a sight assembly 10 having a compact rugged construction quick and easy to manufacture and assemble at low cost and which positively retains its sight member in a selected adjusted position against unintended movement relative to the firearm while also serving to take up or absorb manufacturing variations and tolerances, a one-piece sight 40 is provided with a body of a suitable tough and resilient, form sustaining material which serves as a combination sight member and bearing yoke in accordance with this invention. More specifically, the sight 40 incorporates a laterally extending, generally rectilinear sight member 42 having a sight notch 44 and which has an integral pair of lugs 46 and 48 for receiving the shank of the adjustment screw 18. As viewed in FIG. 1, the left hand lug 46 is preferably internally threaded for engaging the threaded portion 30 of the screw shank. The other lug 48 is provided with an opening 50 which will be understood to have a smoothly contoured bore for receiving the unthreaded terminal portion 28 of the screw 18 for relative movement. Extending forwardly from the lugs 46, 48 is a generally "U" shaped yoke having relatively short parallel arms such as the one shown at 52 in FIG. 2 and an interconnecting crossbar 54 which, when mounted in operative position on the adjustment screw 18, extends in generally parallel relation to the sight member 42 on the opposite side of the screw 18 and laterally across the line of sight along the firearm barrel.
In the specifically illustrated embodiment the body of the sight 40 is preferably formed of a suitable plastic such as a nylon resin. Nylon resins have been found to satisfactorily maintain their flexibility and resiliency over a wide range of temperatures and additionally exhibit a desirable mechanical toughness which increases with age. The resiliency of such material ensures deformation of the sight body under load and return to its original dimension and shape when the load is removed. Moreover, such material is neither affected by lubricating oils and greases nor by most chemicals and is particularly adapted to be quickly and easily molded with little or no finishing required.
To mount the sight assembly 10 in operative position on the firearm, the sight 40 is positioned between the ears 14, 16 of the housing 12 while the unthreaded terminal portion 28 of the adjustment screw 18 is inserted through the opening 24 in the ears 14 and passed through the apertured lugs 46 and 48 to threadably engage portion 30 of the shank with the threaded bore of lug 46 and fit the unthreaded terminal portion 28 within the opening 26 in the ear 16. Once the adjustment screw 18 is mounted for rotation in operative assembly to the housing 12 and the sight 40, the retaining ring 32 can be assembled to the collar 22 to secure the components in position.
To take up or absorb any manufacturing variations or tolerances and to positively retain the sight member 42 in a selected adjusted position, the sight 40 is dimensioned and configured such that upon its being assembled, the adjustment screw 18 cooperates with the firearm to stress the sight 40 and urge bearing abutment portions of the sight 40 into engagement with the firearm on opposite diametrical sides of the adjustment screw 18. A forward bearing abutment portion of the sight 40 is formed by a depending arcuate projection 60 provided on a centrally located bottom surface of the crossbar 54 which in the preferred embodiment has a cross-section of reduced size relative to the sight member 42 whereby the unit stress imposed on the bearing yoke is substantially greater than that imposed on the sight member 42. Accordingly, upon assembling the sight 40 on the adjustment screw 18 and fitting its unthreaded shank portion 28 into the opening 26 of the ear 16, the intermediate portion of the sight 40 is deflected to introduce a flexural stress to the yoke crossbar 54 which flexes under an elastic strain by the concentrated load acting on the crossbar projection 60 which is a relatively small area in relation to the planar bearing surface 62 afforded by the base of the sight member 42. The sight 40 is designed and configured to ensure that the flexural stress thus introduced is well within the elastic limit of the material of the sight to minimize any possibility of potential rupture or applying a permanent set to the material, while additionally limiting the deformation principally to the bearing yoke wherein its crossbar 54 tends to become bowed with its upper portion in tensile stress and its lower portion being in compressive stress (relative to its relaxed condition depicted by broken lines at 64 in FIG. 1).
By virtue of the above described construction, the sight assembly 10 of this invention will be seen to effectively accommodate manufacturing variations and tolerances, and the projection 60 centrally formed on the bottom of the crossbar 54 of the yoke will ensure that the planar base of the sight member 42 is urged into bearing engagement with the firearm while at the same time providing a concentrated or localized bearing engagement with the firearm in forwardly spaced relation to the sight member 42 on the opposite side of the adjustment screw 18. This construction provides a particularly stable but simplified sight assembly 10 wherein the resiliency of the material of the sight 40 inherently secures the sight in any of its selected adjusted positions against unintended displacement due to the high frictional engagement between the crossbar 54 of the bearing yoke and the firearm.
As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.