Swivel snap hook connector assembly having increased holding power when under load

A snap hook and complementary buckle member having a connector assembly for connecting the snap hook to the buckle and having increased holding power when under a load including a buckle member having a male connector member to be attached to the snap hook having an elongate stem with first and second opposite ends and a shoulder formed on the first end of the stem having a predetermined shape and exterior dimensions, a snap hook including a female receptor member for receiving the shoulder therein having a tapered channel extending therethrough with a first tapered end, a second opposite flared end and a side wall therebetween forming the channel, the interior dimensions of the first tapered end being smaller, and the interior dimensions of the second flared end being larger, than the exterior dimensions of the shoulder, and at least one slot formed through the side wall of the channel having a first end open to the tapered end and extending along the side wall toward the flared end to terminate in a second closed end of the slot where the slot enables outward resilient expansion of the tapered end for insertion of the shoulder therethrough and where the tapered end closes behind the shoulder about the stem and upon a tensile load between the male and female members the tapered end further collapses against and provides increased holding of the stem behind the shoulder.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to connector assemblies, and more 
particularly to a connector assembly for a snap hook and complementary 
buckle member where the connector assembly readily rotatably attaches the 
snap hook to the buckle member and provides an increased holding or 
gripping force between the snap hook and the buckle when tension is 
provided therebetween. 
2. Description of the Related Art 
Snap hooks typically are utilized with a free end of a cord, strap or the 
like to quickly and securely connect the free end of the cord to another 
cord or article. Such snap hooks include a base having a hook and a 
complementary resilient blade connected to the base where the blade 
extends from the base to engage the distal end of the hook and close off 
the area defined by the hook. Manipulation of the blade with respect to 
the hook enables the hook to capture another member therein and provide 
the desired connection therewith. In order to secure the base of the snap 
hook to a free end of the cord which is to be connected to another 
article, the base can include a connector or buckle member formed with or 
attached thereto. 
During use, the cord typically twists which in turn exerts an undesirable 
twisting force on the buckle and the snap hook. In order to prevent such 
twisting forces, a rotatable or swivel-type connection can be provided 
between the base of the snap hook and the buckle member. 
An example of such a swivel connection is illustrated in U.S. Pat. No. 
4,868,954 which discloses a swivel joint assembly which includes a 
connector, an elongate support rotatably mounted on the connector and a 
hook rotatably mounted to the elongate support. The hook includes a head 
composed of four locking members angularly and equally spaced and 
separated by two slots forming a cross-shape, each locking member having a 
neck and a retaining member formed on its distal end. To rotatably attach 
the hook head to the elongate support, the retaining members are forced 
through an aperture in the elongate support while the locking members 
initially are flexed inward. After the retaining members clear the far 
side of the aperture, the retaining members flex outward and become seated 
behind the aperture. This type of connection, however, is subject to 
failure upon tension placed between the hook and the elongate member which 
will flex the locking and retaining members inward and pull the retaining 
members back through the aperture. 
It therefore would be desirable to provide a connector assembly for use 
with a snap hook and complementary buckle member which readily rotatably 
mounts the snap hook to the buckle and provides an increased holding or 
gripping force between the snap hook and the buckle when tension is 
provided therebetween. 
SUMMARY OF THE INVENTION 
The invention provides a snap hook and complementary buckle member device 
having a connector assembly for connecting the snap hook to the buckle 
member and having increased holding power when under a load. The device 
includes a buckle member having a male connector member with an elongate 
stem having first and second opposite ends and a shoulder formed on the 
first end of the stem where the shoulder has a predetermined shape and 
exterior dimensions. A snap hook having a female receptor member is 
provided for receiving the shoulder of the first end of the male connector 
member therein where the female receptor member includes a tapered channel 
extending therethrough. The channel includes a first tapered end, a second 
opposite flared end and a side wall interconnecting the first and second 
ends and forming the channel where the interior dimensions of the tapered 
end of the channel are smaller, and the interior dimensions of the flared 
end are larger, than the exterior dimensions of the shoulder of the stem 
of the male connector member. The channel further includes at least one 
slot formed through a portion of the side wall of the channel where a 
first end of the slot is open to the first tapered end of the channel and 
the slot extends along the side wall a predetermined distance toward the 
second flared end of the channel and terminates in a second closed end of 
the slot where the slot enables outward resilient expansion of the first 
tapered end of the channel for insertion of the shoulder therethrough from 
the inside of the female receptor member and the first tapered end 
resiliently closes about the stem behind the shoulder after insertion and, 
upon placing a tensile load between the male connector member and the 
female receptor member, the first tapered end further collapses against 
the stem and provides increased holding of the stem behind the shoulder. 
Additionally, the male connector member can be formed to rotate or swivel 
with respect to the female receptor member, if desired.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIG. 1, the swivel snap hook assembly of the invention is 
designated generally by the reference numeral 10. The assembly 10 includes 
only two discrete parts: a snap hook member 14, illustrated separately in 
FIG. 2, and a buckle connector member 16, illustrated separately in FIG. 
3. Preferably, both the snap hook member 14 and the buckle connector 
member 16 each are integrally formed in one-piece from plastic and are 
designed for cooperative engagement with each other as will be explained 
hereinafter. 
As FIGS. 1 and 2 illustrate, the snap hook member 14 typically is utilized 
to quickly connect to an additional buckle member 17 having an eyelet 17a 
therethrough. The snap hook 14 includes a hook portion 18, a blade portion 
20 and a base portion 22. The hook portion 18 includes a first proximal 
end 24, which is integrally formed with a first side 26 of the base 
portion 22, and a second distal end 28, positioned remote from the base 
portion 22. The hook portion 18 defines an interior area 30 for capturing 
another member therein, such as the buckle member 17. 
The blade portion 20 includes a first proximal end 32, which is integrally 
formed with a second side 34 of the base portion 22 opposite the first 
side 26, and a second distal end 36, positioned remote from the base 
portion 22 proximate the second distal end 28 of the hook 18. FIG. 2 
illustrates three typical positions of the distal end 36 of the blade 20 
with respect to the distal end 28 of the hook 18, two of those positions 
being illustrated in dotted outline and designated by reference letters A 
and B. The typical operating position of the distal end 36 of the blade 20 
is illustrated in solid lines where it is resiliently engaged with an 
interior surface 38 of the distal end 28 of the hook 18. 
In order to provide the resilient engagement, the blade 20 preferably is 
molded with the distal end 36 in the initial or at-rest position 
illustrated in dotted outline designated by the reference letter A. After 
molding and before connection of the snap hook member 14 to another 
object, the distal end 28 is flexed into its position against the inside 
surface 38 of the distal end 28 of the hook 18. 
Briefly, in operation, to attach the buckle member 17 to the snap hook 
member 14, the blade 20 is flexed inward within the interior 30 defined by 
the hook 18 to the position illustrated in dotted outline designated by 
the reference letter B. Thereafter, the eyelet 17a of the buckle member 17 
is inserted over the distal end 28 of the hook 18 and the blade 20 is 
released so that the distal end 36 of the blade 20 springs back to its 
position against the inside surface 38 to capture the buckle member 17 
within the interior 30. To remove the buckle member 17, this procedure 
substantially is reversed. 
As FIGS. 2 illustrates, the base portion 22 of the snap hook member 14 
includes a tapered channel 42, illustrated in dotted outline, extending 
therethrough from a first interior tapered end 44 to a second exterior 
flared end 46. The channel 42 generally has the shape of a truncated cone 
which is defined by an interior wall 48 and is designed to accept a 
portion of the buckle connector member 16 therein. It is to be understood, 
however, that the channel 42 can be shaped other than an annular cone, 
such as rectangular or other shape (not illustrated), so long as it 
substantially is tapered and provides the cooperative engagement with the 
buckle connector member 16 as described herein. 
As FIGS. 2 and 3 illustrate, the interior wall 48 preferably includes two 
slots 50 formed on opposite sides therethrough, the lengths of the slots 
50 extending along the interior wall 48 a predetermined distance from a 
first open end 52 to a second closed end 54 of the slots 50. The slots 50 
allow for resilient outward expansion and inward contraction of the first 
tapered end 44 of the channel 42 where the second closed end 54 provides a 
point or axis of rotation as described below. It is to be understood, 
however, that the number and shape of the slots 50 can vary so long as the 
assembly 10 operates as described herein. 
The buckle connector member 16 includes a strap or web connector portion 
60, to which a strap or web (not illustrated) is threaded about, and a 
male connector portion 62, which is received within the channel 42 of the 
base 22 of the snap hook member 14. The strap connector portion 60 
substantially is rectangular in shape with an aperture 61 therethrough 
which is defined by first and second opposite elongate legs 64 and 66 
which are interconnected at their ends by first and second opposite end 
portions 68 and 70, respectively. 
The first elongate leg 64 is designed to accept a strap threaded thereabout 
and includes an interior surface 72 having a plurality of strap gripping 
teeth 74 spaced along its length. To provide added strength to the first 
leg 64 and gripping engagement with a strap, especially during tension of 
the assembly 10, the first elongate leg 64 is slightly bowed inward along 
its length toward the aperture of the strap connector portion 60. 
The second elongate leg 66 is formed opposite the first leg 64 and includes 
a first exterior surface 76 where the male connector member 62 integrally 
is formed along the first exterior surface 76 proximate its midpoint. To 
provide added strength to the second leg 66, especially during tension of 
the assembly 10, the second leg 66 also can be slightly bowed outward 
along its length away from the aperture 61 of the strap connector portion 
60. 
The male connector portion 62 includes a tapered stem 78 having a first 
tapered distal end 80 and a second flared proximal end 82. The first 
distal end 80 includes a shoulder 84 formed thereabout for cooperative 
engagement with the channel 42 of the snap hook member 14. To assist in 
insertion of the shoulder 84 within the channel 42, a width or side 
surface 86 of the shoulder 84 can be tapered toward the distal end 80. To 
assist in seating of the first tapered end 44 of the channel 42 of the 
snap hook 14 behind the shoulder 84 and about the stem 78, a portion 88 of 
the stem 78 proximate the shoulder 84 can be linear rather than tapered. 
To assemble the buckle member 16 to the snap hook member 14, the male 
connector member 62 of the buckle member 16 is inserted into the channel 
42 of the snap hook member 14 from the second exterior flared end 46 of 
the channel 42. As FIG. 5 illustrates, continued insertion of the male 
connector member 62 provides contact of the shoulder 84 with the interior 
wall 48 of the channel 42 at a predetermined position C. As FIG. 6 
illustrates, further insertion of the male connector member 62 causes 
resilient outward expansion of the first tapered end 44 of the channel 42. 
Expansion of the first tapered end 44 substantially is provided by the 
slots 50 which flex outward and effectively provide rotation of the first 
and second sides 26 and 34 of the base portion 22 about the second closed 
ends 54 of the slots 50. Upon continued insertion of the male connector 
member 62, the slots 50 flex further outward until the shoulder 84 clears 
the first tapered end 44 of the channel 42 and the first tapered end 44 
snaps back to its original at-rest position illustrated in FIG. 1 where it 
is collapsed about the liner portion 88 of the stem 78 beneath the 
shoulder 84. 
In this position, the male connector member 62 is retained within the 
channel 42 and the tapered portion of the stem 78, which substantially 
complements the taper of the channel 42, can rotate within the channel 42 
to provide the desired swivel or rotational connection between the snap 
hook member 14 and the buckle connector member 16. 
FIG. 7 illustrates increased gripping or holding of the buckle member 16 
within the snap hook member 14. Specifically, upon tension between the 
buckle member 16 and the snap hook member 14, illustrated by oppositely 
pointing arrows D and E, the tapered end 44 of the channel 42 further 
collapses, due to inward flexing of the slots 50 as illustrated, and grips 
the linear portion 88 of the stem 78 beneath the shoulder 84, the gripping 
increasing with increased tension. This type of tension typically is 
provided during use of such swivel hook assemblies and significantly 
expands the use of the assembly 10 of the invention into applications 
requiring increased tension. 
Preferably, as FIG. 2 illustrates, the channel 42 is tapered at an angle of 
approximately twenty degrees ( .+-.one degree) with respect to a central 
longitudinal axis 90 of the channel 42. Furthermore, as FIG. 5 
illustrates, the outside dimension or diameter of the shoulder 84 is 
selected to be less than the inside dimension or diameter of the channel 
42 at a position F which substantially corresponds to the position of the 
closed end 54 of the slot 50 in the interior wall 48 of the channel 42. 
Additionally, to provide the desired flexing without failure or breakage 
of the snap hook member 14, it has been determined that the length of each 
slot 50 between the first open end 52 and the second closed end 54 should 
be approximately sixty percent (.+-.10 percent) of the total length of the 
channel 42. These dimensions have been determined to be critical for the 
proper operation of the assembly 10 when formed with the preferred plastic 
material. 
The assembly 10 of the embodiment of FIGS. 1-7 is capable of performing 
under tensile load conditions greater than that of previous assemblies. 
Under extreme tensile load conditions, however, the assembly 10 can fail 
either by breakage of the plastic material or by sever distortion as FIG. 
8 generally illustrates. Typically, as the tensile load is increased, the 
blade portion 20 snaps outside the confines of the hook portion 18. Upon 
further tensile load, the slots 50 expand and the edges of the open ends 
52 of each slot 50 on the side of the slots 50 proximate the first side 26 
of the base portion 22 move or walk along the shoulder 84 of the male 
connector portion 62. When the edge of each slot 50 clears the shoulder 
84, the male connector portion 62 disengages from the channel 42 of the 
snap hook member 14. 
FIG. 9 illustrates another embodiment of the assembly of the invention 
which provides increased holding power during such extreme tensile load 
conditions where similar elements have been identified with the same 
reference numerals. In this embodiment, the snap hook member 14a is 
modified so that the open end 52 of each slot 50 includes a rib 90 which 
is integrally formed with the first tapered end 44 of the base portion 22 
on the first side 26 of the base portion 22. The ribs 90 extend into the 
interior of each slot 50 a predetermined distance and substantially 
perpendicular to the length of each slot 50. 
The further the ribs 90 extend across the slots 50 the more holding power 
provided. If desired, the ribs 90 can extend all the way across the slots 
50 to engage the other sides of the slots 50 if desired. Preferably, the 
ribs 90 extend slightly past the longitudinal central axis of each slot 
50, but can vary. 
During increased tensile load between the snap hook member 14a and the 
buckle connector member 16, the blade portion 20 snaps outside the 
confines of the hook portion 18 and the slots 50 expand as in the 
embodiment of FIGS. 1-7. In the embodiment of FIG. 9, however, the edge of 
each slot 50 is extended by the ribs 90 which delays the clearing of the 
shoulder 84 to provide the desired increased holding. 
Modifications and variations of the present invention are possible in light 
of the above teachings. It therefore is to be understood that within the 
scope of the appended claims, the invention may be practiced otherwise 
than as specifically described.