U.S. patent number 3,750,318 [Application Number 05/196,533] was granted by the patent office on 1973-08-07 for riflescope mount.
This patent grant is currently assigned to Outdoor Sports Industries, Inc.. Invention is credited to Donald J. Burris.
United States Patent |
3,750,318 |
Burris |
August 7, 1973 |
RIFLESCOPE MOUNT
Abstract
A ring-type dovetail mount for attaching a riflescope to the
barrel or receiver of a rifle that includes a base, a split ring
that sits atop the base and a clamp subassembly that detachably
fastens the two together in assembled relation is disclosed. The
base has parallel undercut grooves alongside thereof that produce a
dovetail-shaped rail topped by a longitudinally extending recoil
rib having a transverse notch therethrough. The split ring is
longitudinally grooved to fit down over the recoil rib. The clamp
subassembly includes a screw, the shank of which does not rotate
but extends across the groove in the split ring and seats within
the notch in the recoil rib. The head of this screw defines the
fixed shoe of a clamp that engages the undercut groove on one side
of the dovetail rail while a movable shoe is drawn against the
other by a nut.
Inventors: |
Burris; Donald J. (Aurora,
CO) |
Assignee: |
Outdoor Sports Industries, Inc.
(Denver, CO)
|
Family
ID: |
22725789 |
Appl.
No.: |
05/196,533 |
Filed: |
November 8, 1971 |
Current U.S.
Class: |
42/127 |
Current CPC
Class: |
F41G
11/003 (20130101) |
Current International
Class: |
F41G
1/00 (20060101); F41G 1/387 (20060101); F41c
027/00 (); F41g 001/38 () |
Field of
Search: |
;42/1S ;33/245,250 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"Redfield 1971 Scopes-Mounts-Sights," 1971 Catalog 2 page insert
received May 17, 1971..
|
Primary Examiner: Borchelt; Benjamin A.
Assistant Examiner: Jordan; C. T.
Claims
What is claimed is:
1. The riflescope mount which comprises: a base with its underside
adapted for attachment to a rifle, said base having its top surface
bordered on both sides by undercut grooves cooperating therewith to
define a dovetail rail, and said base having an upstanding rib atop
thereof extending longitudinally intermediate its side margins,
said rib including a transverse notch intermediate its ends; a
split ring sized to encircle the barrel of a riflescope in
supporting relation thereto and with a foot depending from its
lower arch, the undersurface of said foot being shaped to mate with
the top surface of the base and permit relative transverse slidable
movement therebetween when thus assembled, said foot having a
downwardly opening groove extending longitudinally intermediate the
sides thereof sized to loosely receive the rib, and said foot
including a transverse passage intersecting the downwardly opening
groove therein positionable in transverse alignment with the notch
in the rib upon relative longitudinal movement between the ring and
base in assembled relation; and, a clamp subassembly operative to
detachably fasten the ring atop the base, said subassembly
including a bolt with a head on one end of its shank and a nut
threaded on the other end thereof mountable within the passage in
the foot, said bolt cooperating with the notch in the rib when
seated therein to lock the ring and base together against relative
longitudinal movement, and a pair of shoes mounted on the shank of
the bolt between the nut and head thereof for relative transverse
movement, the lower margins of said shoes defining jaws adapted to
engage the dovetail rail within the undercut grooves and draw the
foot down snug atop the base upon actuation of the nut in a
direction to close the gap therebetween, and at least one of said
shoes including a jaw along the upper edge thereof adapted upon
actuation of the nut in the aforesaid direction to engage the
adjacent side of the foot and push same sideways until the adjacent
face of the downwardly opening groove engages the opposed face of
the rib.
2. The riflescope mount as set forth in claim 1 in which: the width
of the foot is less than the width of the rail.
3. The riflescope mount as set forth in claim 1 in which: the jaws
along the bottom of the shoes lie spaced above the bottom of the
grooves when the foot is seated atop the base.
4. The riflescope mount as set forth in claim 1 in which: the shoe
remote from the nut is non-rotatably fastened to the shank of the
bolt.
5. The riflescope mount as set forth in claim 1 in which: the sides
of the downwardly opening groove lie in substantially parallel
planes normal to the axis of the bolt shank; and, in which the
opposed face of the rib is planar and adapted to mate in
face-to-face parallel relation with either face of the downwardly
opening groove when assembled in juxtaposed position thereto.
6. The riflescope mount as set forth in claim 1 in which: the shoe
remote from the nut is fastened to the shank and shaped so as to
remain in spaced relation to the foot when the adjacent shoe has
pushed the latter against the rib.
7. The riflescope mount as set forth in claim 1 in which: the
height of the rib is less than the depth of the downwardly opening
groove so as to leave a gap therebetween in assembled relation.
8. The riflescope mount as set forth in claim 1 in which: the shoe
remote from the nut is mounted on the shank for limited tiltable
movement sufficient for the upper marginal edge thereof to engage
the near side of the foot and push the latter sideways until the
adjacent face of the downwardly opening groove contacts the opposed
face of the rib.
9. The riflescope mount as set forth in claim 1 in which: the
downwardly opening groove is offset toward one side of the
foot.
10. The riflescope mount as set forth in claim 1 in which: the
downwardly opening groove is offset toward the side of the foot
nearest where the side of the rib engages same.
11. The riflescope mount as set forth in claim 1 in which: the
upper marginal edge of the shoe adjacent the nut carries the jaw
and the remote shoe of the pair includes only a lower jaw.
12. The riflescope mount as set forth in claim 1 in which: the
upper marginal edge of the shoe remote from the nut defines an
upper jaw.
13. The riflescope mount as set forth in claim 1 in which: the
upper marginal edges of both shoes define jaws adapted to contact
the foot on opposite sides thereof, and the shoe remote from the
nut is tiltable from side to side on the shank.
Description
An accurate riflescope with precision optics and a rugged
mechanical system that will withstand both recoil from a heavy
powder load and the occasional abuse of hunting in rough country is
expensive, so much so, in fact, that few hunters are able to afford
one for each different rifle they may own. They prefer, therefore,
to be able to remove and remount their scope on any one of several
rifles with a minimum of time and effort while remaining confident
that it will go back in place in precisely the same adjusted
position it occupied originally. Unless this can be done, the mount
must be considered a more or less permanent one because it becomes
completely impractical to "sight-in" the rifle all over again every
time the scope's position is disturbed. Some shooters may even wish
to remove the scope from their rifle and substitute some type of
so-called "iron" sight for target shooting provided, once again, it
can be done in such a way that the scope is returned to the rifle
in exactly the same position. Needless to say, this is no simple
problem to solve because, not only does one have to design a mount
that will return the scope to a precise position vertically and
transversely while at the same time securing it against relative
longitudinal movement, but this feat must be duplicated for both
the front and rear mounts.
It has now been found in accordance with the teaching of the
instant invention that these and other desirable objectives can be
achieved by the novel, though unobvious, expedient of fastening a
split ring to a dovetail rail with a clamp that has the fixed and
movable shoes thereof so related to one another and to the base
both structurally and dimensionally that these elements always
return to the same precise pre-existing relationship. In the
preferred form of the invention, the so-called "fixed shoe" defines
a head of the clamp subassembly screw that does not move at all
relative thereto; whereas, in an alternative embodiment, this same
shoe can tilt slightly with respect to the screw shank while
remaining fixed against relative rotation. Both embodiments "return
to zero" but in somewhat different ways. In one, the axial pressure
of the nut against the movable shoe pushes the grooved lug on the
bottom of the split ring against the near face of the recoil rib
leaving the gap at the remote face thereof. Conversely, the
alternative embodiment functions in the opposite manner by pulling
the screw shank toward the movable shoe causing the fixed shoe to
tilt and press the grooved ring lug up snug against the remote face
of the recoil rib.
Both embodiments can be relied upon to accurately reposition the
scope in precisely its former location and with no adjustments of
any type being required. Loosening and retightening of one nut on
each of the front and rear mounts does the complete job. Once in
place, the scope is securely fastened to the rifle barrel and can
readily withstand the shocks to which it is subjected by reason of
the recoil from a heavy powder load.
One pair of split rings remains fastened to the riflescope barrel
at all times, a set of ring bases is permanently mounted on each
rifle on which the scope is to be used, and a single pair of clamp
subassemblies provides the detachable connection therebetween. In
fact, the clamp subassemblies can be used to fasten the rings
directly to the grooved receivers found on certain .22 caliber
rifles.
Accordingly, it is, therefore, the principal object of the present
invention to provide a novel and improved riflescope mount.
A second objective of the invention herein disclosed and claimed is
the provision of a unit of the type aforementioned that is
virtually insensitive to recoil even when used on large caliber
rifles with heavy powder loads.
Another object is to provide a scope mount that is readily
adaptable for use on the various sizes, types and shapes of rifle
barrels.
Still another objective of the within-described invention is the
provision of a scope-mounting bracket which, once the barrel has
been tapped and the bases mounted, no longer requires the services
of a skilled gunsmith to mount and demount the scope.
An additional object is to provide an improved riflescope mounting
assembly that requires no tools so that the scope can be removed
and remounted in the field following the initial installation.
Further objects of the invention defined herein are to provide a
riflescope mount that is simple, lightweight, rugged, compact,
versatile, uncomplicated, easy to use, simple to manufacture and
even decorative in appearance.
Other objects will be in part apparent and in part pointed out
specifically hereinafter in connection with the description of the
drawings that follows, and in which:
FIG. 1 is a rear elevation showing the split ring in position to
seat atop the base and the clamp subassembly in released
position;
FIG. 2 is a rear elevation similar to FIG. 1 except that the ring
is shown releasably clamped in place atop the base and portions of
the ring and clamp subassembly have been broken away and shown in
section;
FIG. 3 is a side elevation of the unit, with the nut removed and
the shank of the screw in the clamp subassembly shown in
section;
FIG. 4 is a section taken along line 4--4 of FIG. 2;
FIG. 5 is a fragmentary rear elevation similar to FIG. 1 except
showing the elements in fully assembled relation;
FIG. 6 is a fragmentary rear elevation similar to FIG. 5 showing a
modified form of the mount with the shoes in position ready to seat
within the undercut grooves alongside the dovetail rail;
FIG. 7 is a fragmentary rear elevation of the modification of FIG.
6 but showing the clamp subassembly thereof in tightened
position;
FIG. 8 is a fragmentary detail, portions of which have been shown
in section, revealing the tiltable connection of the fixed shoe on
the upset head of the pin; and,
FIG. 9 is an elevational view of the pin and shoe of FIG. 8.
Referring next to the drawings for a detailed description of the
present invention and, initially, to FIGS. 1-5, inclusive, for this
purpose, reference numeral 10 has been chosen to designate the
riflescope mount in its entirety while numerals 12, 14 and 16 have
been selected to similarly denominate the ring, clamp subassembly
and base thereof. Ring 12 is of the split-ring type having upper
and lower arches 18 and 20 with integral outturned bosses 22 at the
extremities thereof which mate in face-to-face relation and are
connected together by a screw fastener 24. Ring arches 18 and 20
together with the aforementioned fasteners cooperate to define a
clamp adapted to releasably fasten around the barrel of a
riflescope (not shown).
The lower arch 20 of the ring includes an integrally formed foot 26
which projects downwardly from a position intermediate its ends.
This foot parallels the axis of the ring in spaced relation to the
latter and it has essentially vertical sidewalls 28 and 30 that are
located on opposite sides of a longitudinally extending groove 32
that opens downwardly as shown. As illustrated, groove 32 is offset
slightly toward the righthand sidewall 30 when the ring is received
from the rear as in FIGS. 1, 2 and 5.
Groove 32 is shown as having a generally rectangular cross section
with the right and left faces 34 and 36, respectively, thereof
parallel to one another and normal to the transversely extending
axis of the thumbscrew 38 which intersects the latter. These groove
faces are also essentially perpendicular and they lie in planes
paralleling the axis of the ring which in turn, of course,
supposedly parallels the axis of the rifle bore. The bottom surface
40 of the foot is preferably planar and horizontal.
Base 16 has the underside 42 thereof cut to provide a concavity
with a radius matching that of the rifle barrel or receiver upon
which it is to be mounted. The top surface 44 is planar and
essentially horizontal except for upstanding recoil rib 46 that
rises vertically between its side margins and extends
longitudinally down the middle thereof. This recoil rib 46 is
interrupted intermediate its front and rear ends by a transverse
notch 48 (FIG. 4) adapted to receive the shank 50 of the screw 38.
With the shank 50 of the screw seated as shown in FIG. 4 within the
notch 48 in the recoil rib 46, almost no relative longitudinal
movement between the ring 12 and base 16 can take place when the
rifle recoils.
The right and left sides 52 and 54, respectively, of rib 46 are
perpendicular, parallel to one another and parallel to the mating
faces 34 and 36 of the groove 32. The top surface 56 of the rib is
planar, horizontal and at right angles to its sides.
Now, before proceeding further, it would be good to explore in some
detail the critical relationships between the mating ring foot and
base surfaces just described as well as those which are not
critical. Note in FIG. 5 that the depth and width of groove 32 is
greater than the height and width of the rib 46 that enters the
latter. Thus, when these parts occupy the assembled relation shown
most clearly in FIG. 5, the top surface 56 of the rib does not seat
in the bottom of the groove nor does the left face 36 of the latter
contact the opposed surface 54 of the rib. What this means, of
course, is that from a functional standpoint rib surface 54 needn't
necessarily be vertical, planar or even parallel to the opposite
face 52 so long as it remains out of contact with the opposed
groove face 36. On the other hand, as a practical matter the shape
shown is by far the easiest to machine and no useful purpose would
be served by making it any other configuration. This same thing is
true of the other non-mating surfaces, namely, the top of the rib
56 and the bottom of the groove 32 together with the outside
surfaces of the foot.
The critical mating surfaces, therefore, are the righthand faces 34
and 52 of the groove and rib, respectively, and the bottom 40 of
the ring foot which rests atop the upwardly facing surface 44 of
the base. It is important that opposed faces 34 and 52 are parallel
to one another as this provides substantial area contact. Opposed
planar surfaces are the easiest to machine and little would be
gained by having non-planar parallel mating surfaces especially
when relative longitudinal movement is prevented by the notch and
pin interlock. Running these plane parallel surfaces in parallel
relation to the ring axis and the latter, in turn, in parallel
relation to the rifle bore axis is, obviously, of considerable
practical importance from an alignment standpoint. Finally, these
plane, parallel longitudinally extending surfaces 34 and 52
preferably lie in normal relation to the axis of the shank 50 of
thumbscrew 38 so that when the latter is tightened to fasten the
ring to the base there will be no force component produced which
would tend to slip one of these surfaces up or down along the
other.
The next set of critical mating surfaces are the upwardly facing
platform 44 defined atop the base 16 and the bottom surface 40 of
the ring foot. These surfaces should be parallel to one another
and, preferably, parallel to the axis of the set screw. These
surfaces could, of course, be other than horizontal but to tilt
them would serve no useful purpose, would be expensive and might
conceivably even result in some vertical displacement of the ring
axis should the clamp subassembly fail to bring mating vertical
surfaces 34 and 52 into face-to-face contacting relation with one
another.
While on the subject of critical versus non-critical surfaces,
attention is directed to FIGS. 6 and 7 where a comparison thereof
with FIG. 5 will reveal that surfaces 36 and 54 become the mating
ones instead of 34 and 52 as was the case with the embodiment just
described. In other words, ring 12 in the alternative embodiment of
FIGS. 6 and 7 moves to the right relative to the base and rib atop
thereof rather than the left. The reason for this is that the fixed
shoe 58 of the principal form of the mount illustrated in FIGS. 1-5
is fastened against relative tiltable movement with respect to the
screw shank 50; whereas, in the alternative embodiment of FIGS.
6-9, fixed shoe 58M is mounted non-rotatably on shank 50 of
thumbscrew 38M but is free to tilt relative thereto. The
differences in the clamping action between the two clamp
subassemblies 14 and 14M will be described in greater detail
presently, it being sufficient to note for now that the ring moves
to the left in the first and to the right in the second thus
switching the critical and non-critical mating surfaces of the rib
and grooves. As far as the horizontal mating surfaces are
concerned, they remain the same in both embodiments.
Before leaving the subject of these critical vertical mating
surfaces on the groove and rib, cognizance should also be taken of
the fact that both of the illustrated embodiments are shown
assembled as righthand mounts where the movable shoe 60 and nut 62
are to the right of the shooter as he raises the rifle into firing
position. The base 16 can, of course, be turned end-for-end and not
effect this relation, provided both vertical faces 52 and 54 of its
rib will mate interchangeably with the opposed critical surface of
the groove. On some rifles, the base may mount more satisfactorily
one way than the other. This fact coupled with the fact that the
ring may need to be rotated 180.degree. to place the nut 62 on the
lefthand side for lefthanded shooters makes it advisable that
vertical surfaces 34 and 36 of the groove mate interchangeably with
vertical surfaces 52 and 54 of the rib even though the relationship
between one of the two opposed pairs thereof is critical in any
given mounting situation.
Summarizing the foregoing, all faces vertical surfaces 34, 36, 52
and 54 are preferably parallel to one another, normal to the axis
of the clamp bolt shank 50, and parallel to the axis of the ring.
Any other configuration, while easily made operable in accordance
with the teaching of the instant invention, is generally more
expensive and difficult to machine as well as being less
versatile.
Referring once again to FIGS. 1-5, the base will be seen to project
well beyond one face of the ring so as to provide an extension 64
through which the mounting screws (not shown) can pass that fasten
the base down atop the rifle barrel or receiver. Countersunk
passages 66 are provided for this purpose arranged as shown in FIG.
4 one in front of the other. Alongside the rib in the area occupied
by the ring and clamp subassembly are a pair of undercut grooves 68
cooperating with one another to define a dovetail rail 70. This
rail cooperates in a manner which will be explained in detail
presently with the clamp subassembly 14 to hold the ring down
securely atop the base. The upwardly and outwardly inclined faces
72 of these undercut grooves mate with the interior oppositely
inclined surfaces 74 along the lower edges of the shoes 58 and 60.
Surfaces 72 thus comprise the only critical undercut groove
surfaces and they are preferably both planar and respectively
parallel to the ring axis although oppositely inclined relative to
each other.
The clamp subassembly 14 remains to be described and it is most
clearly revealed in FIGS. 1, 2 and 5 to which detailed reference
will now be made. At one end of the shank 50 is a threaded section
76 onto which is screwed the nut 62. In the particular form shown,
the threaded end is upset slightly as shown at 78 once the nut is
in place so as to prevent its being removed and lost. Merely
loosening it produces sufficient slack to allow the shoes 58 and 60
to be spread apart and thus disengaged from the dovetail rail
70.
The opposite end of the shank is also upset to produce a head 80
(FIG. 2) which, in the particular embodiment illustrated in FIGS.
1-5 is fastened to the fixed shoe 58 so that neither relative
rotational or relative tiltable movement can occur. In other words,
from a functional standpoint, the fixed shoe could be formed as an
integral part of the shank.
The fixed shoe 58 comprises a small, generally rectangular plate
having the lower margin thereof bent inward slightly to define
inclined surface 74 that parallels and mates with the opposed
inclined groove surface 72 thus locking it therebeneath.
The movable shoe 60 is also rectangular and has its lower margin
similarly bent to produce an inside surface 74 that mates with the
oppositely inclined undercut groove surface 72. In the case of the
movable shoe, however, its upper margin is also turned inwardly to
produce a cleat 82 that will engage the opposed exterior face of
the ring foot and move the latter to the left until the righthand
vertical groove surface 34 comes to rest against the mating surface
52 of the rib. An examination of FIG. 2 will reveal that the
movable shoe 60 is loosely mounted on the shank 50 so that it is
free to tilt relative to the latter.
As thus constructed, shoes 58 and 60 come together with a vise-like
action upon actuation of the nut 62 to push the movable one to the
left in the direction of the fixed one. When this occurs, movable
shoe 60 strikes the righthand vertical face 30 of the foot 26 and
pushes it to the left closing the gap between opposed surfaces 34
and 52 of the groove and rib respectively. The movable shoe 60 is
free to rock on the shank 50 of the clamp screw to the degree
necessary to force the ring foot snug against the rib. Note also in
this connection that the ledge 44 atop the base is wider than the
underside 40 of the foot that rests atop thereof thus leaving a gap
between the fixed shoe 58 and the lefthand vertical face 28 of the
foot at all times. If this were not the case, the foot might
otherwise strike the fixed shoe before the gap at the right side of
the rib closed with the result that the assembly would not
necessarily have returned to the same position. As it is, on the
other hand, the precise transverse relationship of the elements 12,
14 and 16 is reproduced each time they are assembled and clamped
together.
Next, note that when the inside inclined faces 74 of the shoes
engage the mating inclined surfaces 72 of the undercut grooves, the
ring foot will be drawn down until its undersurface 40 rests firmly
atop the upturned surface 44 of the base. To insure that this takes
place, the depth of the undercut grooves 68 is chosen such relative
to the height of the shoes that the latter will not contact the
bottom of the former when the ring foot seats atop the base.
Provision is thus made for returning the elements 12, 14 and 16 of
the assembly 10 to their precise pre-existing vertical relationship
each time they are reassembled.
The manner in which the relative longitudinal positions of the
elements is reproduced and maintained has already been described in
detail, namely, the locking of the screw shank 50 within the
transverse notch 48 in the rib; therefore, the only other
relationship that remains to be explored is the axial orientation
of the ring relative to the rifle barrel bore axis through the base
16 which remains permanently fastened to the latter. Actually, this
is rather simply accomplished by restoring the alignment between
the groove and rib that has already been set forth in considerable
detail.
Next, with reference once again to FIGS. 6-9, inclusive, the
modified version 10M of the riflescope mount will be set forth in
detail. The ring 12 and base 16 remain exactly the same and all the
changes are embodied in the clamp subassembly 14M. Even in the
latter subassembly, several of the elements are unchanged such as,
for example, movable shoe 60, nut 62 and the shank 50 of modified
thumbscrew 38M. Aside from the slightly different functional
interrelationship to be set forth in detail presently, the main
changes lie in fixed shoe 58M and the thumbscrew 38M, in particular
the head 82M of the latter. In the particular form revealed in FIG.
9, the head 82M will be seen to have a rectangular configuration
and fit loosely into a similarly shaped socket 84 in the fixed
shoe. The rectangularly shaped head and socket therefor cooperate
with one another to prevent relative rotational movement
therebetween.
The bottom 86 of the socket is shown having a cylindrically concave
shape while the opposed undersurface 88 of the head 82M is
similarly curved to mate therewith and define a connection capable
of limited relative tiltable movement about a horizontal axis. The
hole 90 in the shoe through which the thumbscrew shank 50 passes is
oversize to accommodate the aforementioned relative motion.
The above-described tiltable connection of the fixed shoe on the
head of the thumbscrew is intended as being merely representative
of one type that can be used while preventing relative rotational
movement from taking place and, of course, there are many other
configurations well known in the art by means of which this
selfsame functional relationship can be achieved. The critical
factors are that the shank not be free to rotate relative to the
fixed shoe so that the nut 62 can be tightened and, secondly, that
the fixed shoe be free to tilt from side-to-side about a horizontal
axis.
Finally, with reference to FIGS. 6 and 7, it will be seen that the
unit functions somewhat differently than that of the previously
described embodiment. In this one as the nut 62 is tightened, the
fixed shoe tilts to the right using the base as its fulcrum and
engages the left vertical face 28 of the ring foot. As the nut is
tightened further, fixed shoe 58M pushes the ring to the right
until the lefthand face 36 of the groove engages the corresponding
opposed face 54 of the rib. The shoes cooperate as before to draw
the ring foot snugly down atop the base and keep it properly
oriented fore and aft.
* * * * *