Information
-
Patent Grant
-
6360734
-
Patent Number
6,360,734
-
Date Filed
Tuesday, June 6, 200024 years ago
-
Date Issued
Tuesday, March 26, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Reising, Ethington, Barnes, Kisselle, Learman & McCulloch, P.C.
-
CPC
-
US Classifications
Field of Search
US
- 124 231
- 124 241
- 124 256
- 124 86
- 124 88
-
International Classifications
-
Abstract
A connector for adjustably mounting a limb of a compound archery bow to a riser of the bow has a connector, a first washer with a sliding surface and a guide surface complementary to and received against the sliding surface and permitting the first washer to pivot in substantially any direction relative to the connector. In assembly, a threaded shank of the connector is received in a threaded blind bore in the riser and a head of the connector traps the first washer against the limb. The connector may be loosened or backed out of the riser to permit adjustment of the orientation of the limb relative to t he riser to thereby adjust the draw weight of the bow. As the orientation of the limb is changed, the orientation of the first washer relative to the connector is likewise changed without changing the orientation of the connector to limit the bending or lateral forces applied to the connector and prevent it from being sheared or otherwise failing. Preferably, an insert which defines the guide surface is disposed within a recessed sliding surface of the washer between the washer and the head of the connector and is complementarily shaped to the recess to permit angular or pivotal movement of the first washer relative to the connector in substantially any direction.
Description
FIELD OF THE INVENTION
This invention relates generally to archery bows and more particularly to compound archery bows and a system for mounting limbs to a riser of the bow.
BACKGROUND OF THE INVENTION
Compound archery bows having a handle or riser portion with a pair of limbs extending from opposed sides or ends of the riser are well known. Typically to connect the limbs to the riser, a bolt or connector extends through the limb and into the riser.
After assembly of the bow, with the limbs under tension, it may be desirable to change the draw weight or force required to pull a draw string of the bow to its fully drawn position. To do this, the bow may be disassembled and a bow string of a different length provided to change the initial flex of the bow limbs, or the cap screw connecting the limbs to the riser may be loosened or backed out slightly to change the orientation of the limb relative to the riser and thereby change the initial loading of the limb. Notably, significant shearing forces are exerted on the bolt as the orientation of the limb relative to the riser is changed which greatly limits the degree to which the connector may be backed out or adjusted without shearing or breaking the connector. Therefore, the draw weight of a bow with only a connector extending through the limb and into the riser can only be adjusted a very minimal amount, if at all, after assembly of the bow.
In some bows, a separate steel, cylindrical pin is provided in the riser for each limb and threadedly receives the end of the connector extending through its associated limb and into the riser. The pins can pivot or rotate relative to the riser only in a single plane generally transverse to the axis of the pin to permit some relative pivotal movement of the connectors relative to the riser. This limits the shearing forces on the connectors within a limited range when they are backed out to adjust the draw weight of the bow. With the addition of the pins, the draw weight of the bow may be adjusted over a somewhat wider although still very limited range after assembly of the bow as compared to a compound bow without any pins.
The pins are generally cylindrical, formed of steel for high strength and are received in complementary bores in the riser and may each weigh up to one ounce or more which undesirably adds to the weight of the bow. Notably, the pins and the bores in the riser which receive them must be very accurately located in the riser to achieve their intended purpose. This increases the time and cost to manufacture and assemble the bow. Still further, the total range of adjustment of the draw weight of the bow is still limited even with the pins wherein the relative movement between the connectors and the limbs occurs at the end of the connectors within the riser and pin. Undesirably, each connector is received in a threaded blind bore in its pin which reduces the number of threads of the connector that are received in and retained by the riser. Accordingly, the extent to which the connector can be backed out to change the bow draw weight without stripping the connector or the threads in the bore of the pin, is limited.
SUMMARY OF THE INVENTION
A connector for adjustably mounting a limb of a compound archery bow to a riser of the bow has a connector, a first washer with a sliding surface and a guide surface complementary to and received adjacent to the sliding surface of the first washer and permitting the first washer to pivot in substantially any direction relative to the connector. In assembly, a threaded shank of the connector is received in a threaded blind bore in the riser and a head of the connector traps the first washer between the connector and the limb. The connector may be loosened or backed out of the riser to permit adjustment of the orientation of the limb relative to the riser to reduce the degree to which the limb is initially flexed and thereby adjust the draw weight of the bow. As the orientation of the limb is changed, the orientation of the first washer relative to the connector is likewise changed without changing the axial orientation of the connector or bending it which limits the shearing forces applied to L the connector and prevents it from being sheared or otherwise failing. Preferably, an insert which defines the guide surface is disposed within a generally concave recess of the washer between the washer and the head of the connector and is complementarily shaped to the recess to permit angular or pivotal movement of the first washer relative to the connector in substantially any direction.
The first washer preferably has a flat face adjacent to and preferably fully engaged by or flush against the limb of the bow in assembly. As the connector is displaced relative to the riser such that the orientation or position of the limb relative to the riser is changed, the flat face of the washer is maintained flush against the limb and the washer pivots with the limb relative to the connector to avoid placing undue stress on the connector. With this arrangement, the draw weight of the bow may be changed over a wide range without breaking or putting undue stress on the connector. If desired, a flat, annular second washer may be disposed between the limb and the washer. The second washer may be formed of a generally resilient or ductile material to reduce vibrations of the bow in use, and prevent damage to the limbs from the first washer. Alternatively, the head of the connector may defame the guide surface and may be shaped complementary to the sliding surface of the first washer to permit the first washer to pivot relative to the head of the cap screw without any insert between them.
Objects, features and advantages of this invention include providing a compound bow with a connector assembly for mounting the limbs of the bow to the riser which facilitates adjustment of the draw weight of the bow, permits the draw weight of the bow to be adjusted over a wide range after assembly of the bow, reduces the overall weight of the bow, prevents undue stress from being applied to a connector attaching the limb to the riser, provides improved engagement of the connector with the riser to more securely mount the limbs to the risers, eliminates pivoting of the connector relative to the riser, is of relatively simple design and economical manufacture and assembly and has a long, useful life in service.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of this invention will be apparent from the following detailed description of the preferred embodiments and best mode, appended claims and accompanying drawings in which:
FIG. 1
is a side view of a compound bow having a pair of limbs each mounted to a riser by a connector assembly according to the present invention;
FIG. 2
in an exploded assembly view of the connector assembly for mounting a limb to the riser of the bow;
FIG. 3
is an enlarged fragmentary sectional view taken generally along line
3
—
3
of
FIG. 1
;
FIG. 4
is an enlarged fragmentary sectional view taken generally along line
4
—
4
of
FIG. 1
;
FIG. 5
is an enlarged fragmentary sectional view of an alternate embodiment of a connector assembly; and
FIG. 6
is an enlarged fragmentary sectional view of another alternate embodiment of a connector assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring in more detail to the drawings,
FIG. 1
illustrates a compound archery bow
10
having a handle or riser
12
with a pair of limbs
14
,
16
extending from opposed ends of the riser
12
each attached thereto at one end by a connector assembly
20
(
FIGS. 2 and 3
) having a connector such as a cap screw
22
and a pivotable washer
24
which permits adjustment of the orientation of the limbs
14
,
16
relative to the riser
12
after assembly of the bow
10
to adjust the initial loading of the limbs or, in other words, the degree to which they are initially flexed. A cam
26
and wheel
28
, or a pair of cams without a wheel, may be fixed to the free ends of the limbs
14
,
16
in a known manner with one or more strings or cables
30
extending between the cams or wheels and the free ends of the limbs. A drawstring portion
32
of a string or cable is drawn away from the riser
12
to flex the free ends of the limbs
14
,
16
inwardly towards each other, to store energy within the limbs
14
,
16
which is released upon release of the drawstring portion
32
, to shoot an arrow releasably coupled to the drawstring.
As shown in more detail in
FIGS. 2-4
, each limb
14
,
16
is received in a complementary and generally rectangular pocket
34
formed in a block
36
attached to or integral with the riser
12
with aligned bores
38
,
40
through the limb and the pocket, respectively, to receive the cap screw
22
therethrough. As shown in
FIG. 4
, the block
36
may have blind bores
42
open to the pocket with a dowel
44
having an enlarged dome shaped head
46
received in each blind bore
42
. A pivot plate
48
disposed between each limb
14
,
16
and its associated dowels
44
, defines a fulcrum or support about which the limbs
14
,
16
are flexed.
Each limb
14
,
16
may be a single, unitary body, may comprise two limb pieces completely separate from each other and retained by the same connector assembly or may be a split limb, as shown in
FIG. 2
, with a pair of substantially separate limb pieces
50
,
52
integral with the other at one end
54
. In any form, each limb
14
,
16
may be retained by one connector assembly
20
as described hereinafter. The aligned bores
38
,
40
through each limb and its associated pocket
34
lead to a threaded blind bore
56
in the riser
12
, which threadably receives the cap screw
22
of the connector assembly
20
.
In more detail, the connector assembly
20
has a connector such as a cap screw
22
, a first washer
24
with a sliding surface embodied as a concave recess
60
permitting pivotal movement of the first washer
24
relative to the cap screw
22
and preferably a second washer
62
disposed between the first washer
24
and the limb
14
,
16
of the bow
10
. Also preferably, an insert
66
is disposed between a head
68
of the cap screw
22
and the first washer
24
to facilitate pivotal movement of the first washer
24
relative to the cap screw
22
.
The cap screw
22
has a threaded shank
70
and the enlarged head
68
at one end of the shank with a generally frustoconical or tapered sidewall
72
extending from the shank
70
. The tapered sidewall
72
is complementary in shape to an inner surface of the insert
66
provided between the cap screw
22
and the first washer
24
. A socket
74
in the head
68
is adapted to receive a tool to turn or drive the cap screw
22
.
The insert
66
is annular with a through bore
76
and is generally frustum shaped with an inner tapered, generally concave or conical surface
78
complementary in shape to the tapered conical surface
72
of the cap screw
22
and an outer surface
80
generally complementary in shape to the recess
60
of the first washer
24
defining a preferably semi-spherical guide surface about which the first washer
24
pivots. The insert
66
is preferably light weight to reduce the overall weight of the bow
10
and may be formed of substantially any material including polymers such as thermoplastics and thermosets, ceramics, metals or other materials, and may be coated with a material such as polytetrafluoroethylene or a non-solid lubricant to reduce sliding friction between adjacent components and the insert
66
. Preferably, the insert
66
is formed of brass, or Delrin AF.
The first washer
24
is annular with a through bore
82
and has the concave recess
60
open to one face
84
and leading to the through bore
82
. The recess
60
is preferably arcuate and complementary to a generally semi-spherical surface. The sidewall is circumferentially continuous to permit pivoting of the first washer
24
relative to the cap screw
22
in substantially any direction. A bottom face
86
of the first washer
24
is planar and is disposed on a flat upper face
88
of its limb
14
,
16
or on a flat upper face
90
of the second washer
62
disposed between it and the limb
14
,
16
, if desired. The first washer
24
may be formed of substantially any metal such as steel or aluminum, various plastics, ceramics and/or may be coated with polytetraflouraetheylene, grease or some other material to reduce friction between it and the insert
66
or cap screw
22
, if no insert
66
is used.
The second washer
62
is annular and has opposed flat faces
90
,
92
with a through bore
94
aligned in assembly with the bores of the insert
66
, first washer
24
and riser
12
to receive the cap screw
22
. The upper flat face
90
is seated against the lower flat face
86
of the first washer
24
and the lower flat face
92
of the second washer
62
is seated on the flat upper face
88
of the limb
14
,
16
. The second washer
62
may be formed of substantially any material and is preferably light weight to avoid adding any significant weight to the bow. Additionally, the second washer
62
may be formed of a resilient, elastomeric synthetic rubber or other ductile material to dampen vibrations in the bow
10
.
In use, as the bow
10
is assembled, a limb
14
,
16
is disposed in a pocket
34
of one of the blocks
36
on the riser
12
such that the bore
38
through the limb
14
,
16
(or gap between two separate limb portions) aligns with the bore
40
through the pocket
34
and the blind bore
56
in the riser
12
. The cap screw
22
is inserted through the insert
66
, first washer
24
, second washer
62
, the bore
38
of the limb
14
,
16
, the bore
40
of the pocket
34
and is threaded into the blind bore
56
in the riser
12
. The cap screw
22
is initially fully tightened to firmly trap the end
54
of the limb
14
,
16
between the second washer
62
and the pocket
34
.
After the other limb
14
,
16
is assembled in the same manner, the riser
12
with attached limbs
14
,
16
may be placed into a bow press to flex the limbs to facilitate attaching and routing the string or strings
30
of the bow
10
to the cams, wheels or limbs in a conventional manner and as appropriate for the particular bow
10
being assembled. When removed from the bow press, the limbs
14
,
16
may extend slightly but preferably remain under tension even at the fully at rest position of the bow
10
as shown in
FIG. 1
to define a first orientation of the end of the limb
14
,
16
relative to the block
36
, the dowels
44
therein and the pivot plate
48
and an initial preloading or flex of the limbs.
With each cap screw
22
fully tightened, the bow
10
is set for its maximum draw weight for the particular string length and configuration as assembled. To adjust t the draw weight of the bow
10
, the cap screws
22
may be backed out from their fully tightened position to change the orientation of the ends
54
of the limbs
14
,
16
relative to the block
36
and riser
12
and thereby reduce the degree to which the limbs are flexed and hence, reduce the stress on the limbs. Desirably, as the orientation of the ends
54
of the limbs
14
,
16
changes, each second was her
62
remains flush against its limb
14
,
16
and each first washer
24
remains flush against its second washer
62
so that the orientation of the second washer
62
and first washer
24
change relative to their corresponding cap screw
22
while the cap screws
22
remain axially aligned with their blind bores
56
to limit the side, lateral, non-axial forces or shearing forces applied to the cap screws
22
. In this manner, each cap screw
22
may be backed out to a relatively large extent thereby changing the orientation of the limb
14
,
16
relative to the block
36
and permitting the draw weight of the bow
10
to be changed over a considerable range. Notably, in one exemplary embodiment, the draw weight of the bow
10
can be changed by about 20 to 30 pounds without compromising the integrity of the cap screw itself or the integrity of the connection between the cap screw
22
and the riser
12
. Therefore, the archer has a tremendous ability to significantly vary the draw weight of a single bow without disassembly or other servicing of the bow. This same advantage permits manufacture of fewer bows with different draw weights as any one bow can readily have its draw weight changed over a wide range.
As shown in
FIG. 3
, the shank
70
o f the cap screw
22
is closely received in the bore
76
of the insert
66
. With this construction, the first washer
24
pivots or swivels relative to the insert
66
which remains substantially aligned with the cap screw
22
. It may also be possible to provide a larger bore
76
through the insert
66
providing a gap between the shank
70
of the cap screw
22
and the insert
66
so that the insert pivots at least slightly relative to the cap screw
22
along with the pivotal movement of the first washer
24
. In either embodiment, the cap screw
22
remains substantially stationary and does not bend or pivot relative to the blind bore
56
of the riser
12
in which it is received to prevent excessive stress on the cap screw
22
which may cause it to fail or break in use.
As shown in
FIG. 5
, an alternate embodiment connector assembly
20
′ is constructed in substantially the same manner as the connector assembly
20
except no insert
66
is provided. Instead, the cap screw head
68
′ has an integral guide surface
100
disposed in and complementary in shape to the sliding surface, shown as recess
60
in the first washer
24
to permit the first washer
24
to pivot relative to the cap screw
22
′. The connector assembly
20
′ functions in the same manner as the connector assembly
20
and hence, will not be described further.
As shown in
FIG. 6
, another alternate embodiment connector assembly
150
has a cap screw
152
with a shank
154
and a head
156
. The head
156
has a generally concave guide surface
158
which is complementary to a generally convex sliding surface
160
of a first washer
162
disposed between the limb
14
and head
156
. A through bore
164
of the first washer
162
is oversized relative to the shank
154
to permit the first washer
162
to pivot relative to the cap screw
152
as the draw weight of the bow is changed as described herein. A second washer
166
may be disposed between the first washer
162
and limb
14
as in the other embodiments.
In any form, the orientation of each limb
14
,
16
and its corresponding second washer
62
,
166
and first washer
24
,
162
can be changed relative to the cap screw
22
,
152
and the riser
12
to permit the draw weight of the bow
10
to be changed or varied over a wide range without significantly affecting the integrity of the connection of the limb
14
,
16
to the riser
12
by the cap screw
22
,
152
. Desirably, the guide surface
80
,
100
or
158
and sliding surface
60
,
160
of the connector assembly
20
,
20
′,
150
can have substantially any size, shape or orientation which permits the limb, first washer and second washer, if any, to pivot relative to the cap screw
22
,
152
which remains essentially stationary and unbent in the blind bore of the riser. Thus, it will be appreciated by those skilled in the art that shapes other than the concave and convex sliding and guide surfaces may be utilized.
Notably, in prior bows having a cap screw extending into the riser and into a pivot block received in a bore formed in the riser, the cap screw engaged the riser itself over only a limited number of threads limiting the strength of the connection between them and providing a significant constraint to the adjustment of the draw weight of the bow. In this embodiment, the blind bore
56
is preferably fully threaded and even when the cap screw
22
,
152
is significantly backed off from its fully tightened position to reduce the draw weight of the bow
10
, the cap screw
22
,
152
has a sufficient number of threads received in the blind bore
56
of the riser
12
to maintain a strong connection between the cap screw
22
,
152
and riser
12
. Further, as mentioned above, the integrity of the connection between the cap screw
22
,
152
and the riser
12
is maintained according to the present invention by pivoting the washers
24
,
162
and
62
,
166
relative to the cap screws
22
,
152
rather than pivoting the cap screws
22
,
152
relative to the riser
12
as is done with a cylindrical pin arrangement. If desired, a connector assembly
20
,
20
′,
150
of similar construction can be used to mount other items to the bow such as, for example, bow
10
accessories such as sights, quivers, overdraws, rests or stabilizers.
Claims
- 1. A connector assembly for an archery bow, comprising:a connector having a shank and a head fixed to one end of the shank; a first washer having a generally semi-spherical sliding surface on one face and a through bore to receive the shank of the connector in assembly, with the first washer disposed between the head of the connector and an object being connected to the bow in assembly; and a generally semi-spherical guide surface on the head of the connector received adjacent to and complementary in shape to the sliding surface of the first washer to permit the first washer to pivot relative to the connector as the orientation of the object connected to the bow is changed.
- 2. The assembly of claim 1 wherein the guide surface is integral with the head of the connector.
- 3. The assembly of claim 1 which also comprises a second washer having opposed planar faces disposed between the first washer and the object connected to the bow.
- 4. The assembly of claim 3 wherein the second washer is formed of a polymeric material.
- 5. The assembly of claim 1 wherein the sliding surface is concave.
- 6. A connector assembly for an archery bow, comprising:a connector having a shank and a head at one end of the shank; a first washer having a sliding surface on one face and a through bore to receive the shank of the connector in assembly, with the first washer disposed between the head of the connector and an object being connected to the bow in assembly; and an insert disposed between the head of the connector and the first washer and defining a guide surface received adjacent to and complementary in shape to the sliding surface of the first washer to permit the first washer to pivot relative to the connector as the orientation of the object connected to the bow is changed.
- 7. The assembly of claim 6 wherein the insert is annular and generally frustum shaped with an inner face having a generally concave, circumferentially continuous sidewall to closely receive an adjacent portion of the head of the connector and an outer surface to be closely slidably received adjacent to the sliding surface of the first washer.
- 8. The assembly of claim 6 wherein the insert is formed of a polymeric material.
- 9. The assembly of claim 6 wherein the insert is coated to reduce friction between it and the first washer.
- 10. A connector assembly for an archery bow, comprising:a connector having a shank and a head at one end of the shank; a first washer having a generally semi-spherical sliding surface on one face and a through bore to receive the shank of the connector in assembly, with the first washer disposed between the head of the connector and an object being connected to the bow in assembly; a generally semi-spherical guide surface received adjacent to and complementary in shape to the sliding surface of the first washer to permit the first washer to pivot relative to the connector as the orientation of the object connected to the bow is changed; and a second washer having opposed planar faces disposed between the first washer and the object connected to the bow with one face flush against the first washer and the other face generally flush against the object connected to the bow.
- 11. A connector assembly for an archery bow, comprising:a connector having a shank and a head fixed to one end of the shank; a first washer having a convex sliding surface on one face and a through bore to receive the shank of the connector in assembly, with the first washer disposed between the head of the connector and an object being connected to the bow in assembly; and a guide surface on the head of the connector received adjacent to and complementary in shape to the sliding surface of the first washer to permit the first washer to pivot relative to the connector as the orientation of the object connected to the bow is changed.
- 12. An assembly for connecting a limb to a riser of an archery bow, comprising:a connector having a head at one end and a threaded shank integral with the head and adapted to be received in a threaded blind bore in a riser of an archery bow; a first washer having a semi-spherical sliding surface and a through bore to receive the shank of the connector in assembly, with the first washer disposed between the head of the connector and a limb being connected to the bow in assembly; and a semi-spherical guide surface received adjacent to and complementary in shape to the sliding surface of the first washer to permit the first washer to pivot relative to the connector as the orientation of the limb connected to the bow is changed.
- 13. The assembly of claim 12 wherein the guide surface is integral with the head of the connector.
- 14. The assembly of claim 12 which also comprises a second washer disposed between the first washer and the limb connected to the bow and formed of a material suitable to dampen vibrations at the second washer.
- 15. An assembly for connecting a limb to a riser of an archery bow, comprising:a connector having a head at one end and a threaded shank adapted to be received in a threaded blind bore in a riser of an archery bow; a first washer having a sliding surface and a through bore to receive the shank of the connector in assembly, with the first washer disposed between the head of the connector and a limb being connected to the bow in assembly; and an insert disposed between the head of the connector and the first washer and defining a guide surface received adjacent to and complementary in shape to the sliding surface of the first washer to permit the first washer to pivot relative to the connector as the orientation of the limb connected to the bow is changed.
- 16. The assembly of claim 15 herein the insert is coated to reduce friction between it and the first washer.
- 17. The assembly of claim 15 wherein the sliding surface and guide surface are semi-spherical.
- 18. A compound archery bow, comprising:a riser having a pair of ends, and a threaded blind bore adjacent to each end; a pair of limbs each extending from a separate end of the riser; and a pair of connector assemblies each releasably and adjustably connecting a separate limb to the riser and each having a connector with a threaded shank received at least in part in an associated blind bore in the riser and an enlarged head fixed to one end of the shank, a first washer disposed between the connector head and the limb with a semi-spherical sliding surface, and a semi-spherical guide surface on the connector head received against and complementary in shape to the sliding surface of the first washer to permit the first washer to pivot relative to the connector when the orientation of its associated limb relative to the riser is changed by moving the connector relative to the riser.
- 19. The bow of claim 18 wherein the guide surface is integral with the head of the connector.
- 20. An archery bow, comprising:a riser having a pair of ends, and a threaded blind bore adjacent to each end; a pair of limbs each extending from a separate end of the riser; a pair of connector assemblies each releasably and adjustably connecting a separate limb to the riser and each having a connector with a threaded shank received at least in part in an associated blind bore in the riser and an enlarged head at one end of the shank, a first washer disposed between the connector head and the limb with a semi-spherical sliding surface, and a semi-spherical guide surface received against and complementary in shape to the sliding surface of the first washer to permit the first washer to pivot relative to the connector when the orientation of its associated limb relative to the riser is changed by moving the connector relative to the riser; and an insert disposed between the head of the connector and the first washer and defining the guide surface.
US Referenced Citations (8)