Note: Descriptions are shown in the official language in which they were submitted.
105~076U
This invention relates to articles having relatively pivotable
components, and is particularly directed to such articles whereby
the pivotable joint between the elements is completely free.
As will be apparent in the following paragraphs, the invention
is directed especially toward swivel hooks. The pivotable joints in
swivel hook articles are preferably completely free since, unlike
pivotable joints in some other articles such as hinges, it is nGt
always feasible to transmit sufficient forces to the swivel hook to
effect its rotation. For example, if the swivel hook is employed to
suspend an article by means of a cord, it is desirable that rotation
of the article to alter its position will also affect the rotation
of the hook elements. It is consequently desirable to make articles
of this type as freely pivotable as possible.
In the past various forms of swivel hooks have been provided.
In general, such hooks have been purely utilitarian in appearance due
to the method required to form them and the necessity of minimizing
costs in their production, and have hence not been particularly
desirable for use in locations where ornamental aspects are necessa~y.
The present invention is thus directed to the provision of a
swivel hook that can economically be fabricated, and which may
readily be provided with a pleasing ornamental appearance.
In the past it has been common to employ such techniques as
die casting or plastic molding in the formation of articles that
have pivotable joints, and that have ornamental appearances.
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In the past, however, the pivotable joints of such articles have
not had sufficient freedom to enable their use in swivel hooks,
or other products requiring extremely free joints.
The invention is thus further directed to the provision of
a pivotable joint, adaptable to be formed by casting or molding
techniques, whereb~ the pivotable joints are freely movable.
Briefly stated, in accordance with the invention, an article
is provided having fist and second elements which are assembled to
form a pivotable joint therebetween. The first element has a
frustoconical hole extending therethrough, and the second article,
which may be the hook of a swivel hook, has a frustoconical projec-
tion adapted to mate the frustoconical aperture of the first element.
An extension is provided on the projection of the second element, at
the lesser diameter end of the frustoconical portion thereof, the
extension having a maximum transverse dimension that is smaller than
the smaller diameter end of the frustoconical hole. This arrange-
ment enables the projection to be moved relative to the frustoconical
hole, so that the extension extends into alignment with the end of
the frustoconical hole, thereby ensuring adequate spacing of the
frustoconical bearing surfaces that free movement between the ele-
ment~ is attained.
Further, in accordance with the invention, in the production
of an article having first and second relatively pivotable elements,
the first element is first formed with a frustoconical bearing
surface, and then the second element is cast or molded with the
bearing surface of the first element forming a portion of the die
~090760
for the bearing surface of the second element. The element
whose bearing surface constitutes a projection is formed with an
extension, preferably cylindrical, having a maximum transverse
dimension less than the lesser diameter end of the frustoconical
bearing surface. The extension also has an axial length substan-
tially less than the axial length of the frustoconical bearing
surfaces. Following the formation of the elements, the elements
are moved relative to one another, whereby the extension is moved
into alignment with the end of the frustoconical aperture in the
other element, so that the pivotable joint between the two elements
is completely freed.
In order that the invention will be more clearly understood,
it will now be described in greater detail, with reference to the
following figures, wherein:
FIGURE 1 is a perspective view of a swivel hook in accordance
with one embodiment of the invention;
Fig. 2 is a plan view of the hook of Fig. 1, prior to relative
movement of the two elements to free the pivotable joint;
Fig. 3 is an enlarged deta~ view of a portion of the hook of
Figs. 1 and 2;
Fig. 4 is an enlarg~ detail view of another portion of the hook
of Fig. l;
Fig. 5 is a simplified illustration of a method ~ forming the
hook of Fig. l;
Fig. 6 is a simplified illustration of the finished form of
the hook of Fig. l;
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Fig. 7 is a perspective view of a swivel hook in accordance
with a second embodiment of the invention;
Fig. 8 is a perspective view of the mounting plate of the
swivel hook of Fig. 7;
Fig. 9 is a perspective ~iew of the lower portion of the
swivel hook of Fig. 7;
Fig. 10 is a perspective view of a third embodiment of a swivel
hook in accordance with the invention, mounted on a horizontal
surface;
Fig. 11 is a perspective view of the hook of Fig. 10 mounted
on a vertical surface;
Fig. 12 is a plan view of the swivel hook of Fig. 10 and 11;
Fig. 13 is a perspective view of a swivel hook in accordance
with a fourth embodiment of the invention, mounted on a horizontal
surface;
Fig. 14 is a perspective view of the swivel hook of Fig. 13
mounted on a vertical surface; and
Fig. 15 is a plan view of the swivel hook of Figs. 13 and 14.
Referring now to the drawings, and more in particular to Fig.
1, therein is illustrated a swivel hook in accordance with one
embodiment of the invention. The swivel hook is comprised of two
unitary components, i.e., a yoke 20 and a hook 21 pivotally mounted
to the yoke. The elements of the hook may be formed, for ~xample,
of a die casting metal or a molded plastic material. By forming
the swivel hook of such materials, it is possible to provide the
elements with ornamental designs, thereby to enhance the appearance
,, 10907~;o
of the hook. In use, the swivel hook of Fig. 1 may be mounted with
the yoke 20, extending over any suitable mounting member, whereby
the hook 21 may be swiveled to any desired angular position for sus-
pending an article. If desired, the yoke 20 may be provided with
an aperture (not shown) extending vertically through its upper por-
tion, for mounting of the hook by other means. As an exa~ple, if
it is desired to hang the hook on a cord, the cord may be passed
through such an aperture and knotted at its lower portion to suspend
the yoke as desired.
In the provision of a hook such as illustrated in Fig. 1, it
is necessary that the hook portion 21 be freely rotatable with respect
to the yoke 20. conventional die casting and plastic molding
techniques are not readily adaptable to the provision of free pivotal
movement, unless the bearing surfaces of the elements are undesirably
loose or if complicated and time consuming steps are taken in the
formation of the hook.
As will be apparent in the following paragraphs, the present
invention is particularly directed to the provision of a hook, as
well as other articles, having freely swivelable joincs, wherein
the second element to be formed is molded or cast with the bearings
surfaces of the first formed element serving as a die for the
bearing surfaces of the second formed element. Such techniques are
disclosed, for example, in U.S. Pateht 2,819,494, Morin.
When the pivotal joints are formed by such techniques, these
joints will initially be quite stiff due, for example, to imper-
fections in the first cast bearing surface. Several techniques are
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~-- 109076V
known for loosening such pivot joints. For example, as disclosed
in U.S. Patent No. 3,742,555, the bearing surfaces may be formed
with frustoconical shapes, and one of the articles may be staked
or deformed in such a manner that the bearing surfaces are moved
apart to free the joint. Such a technique is of course not adapt-
able in the formation of all types of articles. In another technique,
as disclosed in U.S. Patent ~o. 3,891,172 assigned to the assignee
of the present app~ication, when an article having only a single
joint is provided, the internal frustoconical bearing surface may
be made axially longer than the frustoconical surface of the outer
bearing member, whereby the joint may be freed by axial movement of
the inner member.
While each of the above two techniques for providing free
pivoting movement is satisfactory for some purposes, such as hinges,
wherein a certain degree of force can be expected to rotate the
joint in use, the techniques are not adaptable to provide the free
pivotal movement necessary in a swivel hook of the type illustrated
in Fig. 1.
Figs. 2-4 more clearly illustrate the swivel hook of Fig. 1 in
accordance with the nvention. Thus, Fig. 2 is a plan view of the
assembled hook after the die casting or molding of the yoke 20 and
hook 21, Figs. 3 and 4 are enlarged plan views of the yoke 20 and
hook 21 respectively.
As shown in Figs. 2 and 3, the yoke is comprised of a u-shaped
member 23, forming the upper portion of the swivel hook, the ends
of the yoke portion 23 being joined by a bridge 24 extending there-
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across. The bridge 24 m~y have a generally flat upper and lowers urface 25 and 26 respectively, preferably at least in the vicinity
of a tapered hole 27 extendin~ through the bridge between the sur-
faces 25 and 26. The hole 27, which forms a frustoconical bearing
surface, has its lower diameter end directed to~ard the U-shaped
member 23. As an example, the angle of taper of the hole 27 ~y
be about 5, although it will be understood that this is not a
limiting feature of the present invention.
As illustrated in Figs. 2 and 4, the hook 21 is provided with
an upwardly extending frustoconical projection 30 having the same
taper and substantially the same axial length as the hole 27 in the
yoke. A cylindrical portion 31 is provided coaxially extending
from the upper smaller diameter end of the projection 30. The
cylindrical portion 31 has a diameter less than the diameter of the
smaller end of the projection 30. As an example, the cylindrical
portion may have a diameter of 0.225 inches, with the smaller dia-
meter end of the projection 30 having a diameter of 0.235 inches.
In addition, the axial length of the cylindrical portion 31 is
substantially less than the axial length of the frustoconical portion
30. For example, in one embodiment of the invention the cylindrical
portion 31 has an axial length of 0.43 inches, with the frustoconical
projection 30 having an axial length of 0.210 inches and equal to
axial
the/length of the hole 27 in the yoke.
An enlarged portion 32 is provided on the upper end of the
cylindrical portion 31, the enlarged portion 32 having outer dimen-
sions greater than the diameter of the smaller end of the frusto-
105~07~0
conical portion 30. In addition, it is preferred that the under-
surface 33 of the enlarged portion 32 facing the hook 21 be fla,
for engagement with the upper surface 25 of the bridge of the yoke.
Further, the portion 3~ of the hook 21 adjacent the projection 30
preferably has a transverse dimension at least as great as the
larger diameter end of the hole 27.
While in the above example the portion 31 was described as
being cylindrical, it will be apparent that a round cross section
of this portion is not necessary, as long as its cross sectional
area is sufficiently large to withstand the load expected to be
placed on the hook, and as long as its maximum transverse dimension
is less than the lower diameter end of the hole 27.
Fig. 5 illustrates, in simplified form, a casting technique
for forming the swivel hook of Figs. 1-4. This drawing illustrates
one die member of a set of movable dies, the die member 35 having
a first cavity 36 shaped to form the yoke member,and a second
cavity 37 in the form of the yoke adjoined to a cavity 38 shaped to
form the hook in the relative positions illustrated in Fig. 2.
An aperture is provided in the die, into which a tapered pin 39
extends through the portion of the cavity 27 corresponding to the
frustoconical hole in the yoke. The die member is also provided
with cavity 40 to form the gates.
In a first casting sequence, a yoke member has been previously
die cast and fitted in the cavity 37. Then, a suitable die casting
material, such as zamak No. 3 zinc alloy is injected into the dies
at the aperture 41 to flow around a core rod 42 in conventional
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manner, and thence by way of the cavities 40 to the cavities 36
and 38. Thus, a yoke is formed in the cavity 36, and a hook is
formed in the cavity 38 pivotally attached to the yoke previously
set in the cavity 37. The pin 39 is then axially withdrawn, the
dies opened, and the core rod 42 axially displaced downwardly to
set the yoke formed in the cavity 36 into the cavity 37. Then,
upon closing of the dies and reinserting the pin 39, the procedure
is repeated. The gates formed on the components are removed by
conventional practice.
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1090'7~iO
.
The die may be provided with a removable insert 43 for
forming the U-shaped member of the yoke, for example, with a
central hole for mounting. In this case, the pin 39 may be
provided with an axial extension extending through the U-
shaped portion, so that this hole may also be formed in the
yoke during the die casting process.
The cavity 36, cooperating with the pin 39, is shaped to
form the yoke as above described with reference to Fig. 2, so
that a frustoconical aperture extends between the opposed
surfaces of the bridge of the yoke. The cavity 38 is shaped
to form the hook portion of the hook, with the frustoconical
hole in the yoke inserted in the cavity 37 thus forming the
die for the frustoconical projection of the hook. The die
portion 38 has a cylindrical cavity 44 corresponding to the
cylindrical portion on the projection of the hook, and an
enlarged cavity 45 for forming the enlarged end on the cylin-
drical portion. It is to be noted that, in the arrangement
illustrated in Fig. 5, as in the illustration of Fig. 2, the
cylindrical portion is exposed, i.e., it is axially displaced
from the f-rus*~conical surface of the yoke member. In this
position, after the completed hook has been removed from the
die, the pivotal joint will not be free. Accordingly, as
illustrated in Fig. 6, the elements 20 and 21 of the hook are
relatively moved, so that the cylindrical portion on the frusto-
conical projection extends into the frustoconical aperture of
the yoke. In other words, referring to Fig. 2, the hook 21 is
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moved relative to the yoke 20 in the direction extending
between the surfaces 25 and 26 of the yoke~ By this means,
the frustoconical bearing surfaces of the two elements are
slightly separated, to provide very free pivotal movement
therebetween, the freedom of movement being satisfactory for
a swivel hook.
As above discussed, in one prior technique for loosening
a pivotal joint, the frustoconical projection on the one
element was formed to be longer than the frustoconical hole
in the other element, whereby the joint could be freed by axial
movement of the projection with respect to the aperture. It
has been found, however, that this technique does not provide
a completely free pivotal movement between the two elements.
Thus, if a slight inaccuracy occurs in the dies, with respect
to the alignment of the extension of the frustoconical pro-
jection and the frustoconical aperture serving to form the die
for the remainder of the frustoconical projection, freeing of
the joint by relative movement of the elements will result in
a slight degree of binding, and hence a completely free
swiveling joint will not result. In the arrangement of the
present invention, it has been found that a mismatch of up
0.005 inches between the axis of the cylindrical projection
and the axis of the frustoconical aperture will not interfere
with the production of a completely free joint.
10~07~;0
In another embodiment of the invention, as illustrated in
~igs. 7 - 9, a swivel hook is provided especially adapted to be
mounted on a ceiling, without the showing of support means such
as screws or the like~ This arrangement is comprised of a
plate 50 adapted to be affixed to the ceiling, and a swivel
hook 51 releasably affixed to the plate 50.
Referring to Fig, 8, the plate 50 may be circular in
shape and has an upper flat surface 52 adapted to be fitted
against a ceiling. A central hole 53 extends through the plate,
so that the plate may be mounted to the ceiling by means of a
conventional fastener such as a screw. The plate is further
provided with a guide in the form of a pair of generally
parallel downwardly extending projections 54 on opposite sides
of a flat surface 55 parallel to the surface 52. The facing
surfaces of the projections 54 are bevelled, so that the
surfaces are further apart at the surface 55 than at the lower
extremity of the projections, in order to form a guide. For
example, the incline of the surfaces 56 may be at 30 with
respect to the perpendicular to the plate 50. In addition,
the surfaces 56 do not extend exactly parallel, and are thus
! closer together at one end than the other. Thus, when a mating
piece is inserted in the guide formed by the projections 54
in the surface 55, it will be locked in place at a desired
position. In addition, an aperture 57 is provided extending
into the surface 55. This aperture 57 may, if desired, extend
1090760
completely through the plate 50, in order to simplify the
manufacture of the article. As will be noted in the figure,
the mounting hole 53 extends through the surface 55.
Referrlng to Fig, 9, the swivel hook is formed of a
hook portion 60 and a mounting yoke 61. The mounting yoke
61 has a lower bridge 62 with a tapered hole extending there-
through. The hook 60 has an upwardly extending projection
63 formed in the same manner as above disclosed with
reference to Figs. 1 - 6, and hence a swivel joint is
provided between the yoke member 61 and the hook 60 in the
same manner as abvoe described. The upper portion of the
yoke 61 is formed to mate in the guide of the plate 50.
Thus, the yoke has an upper generally flat surface 64
bounded on two opposite sides by bevelled surfaces 65 shaped
to match the configuration of the flat surface 55 and surfaces
56 of the plate 50. In addition, a projection 66 is pro-
vided on the flat surface 64, the projection 66 being
positioned to be aligned with the aperture 57 when the
hook element 51 is mounted to the plate 50.
In use, the plate 50 is secured to a ceiling, for
example by means of a screw, and then the hook member is
affixed to the plate member by sliding the upper portion
of the yoke 61 into the mating lower portion of the plate
50 until the projection 66 engages the aperture 57. The
engagement of the projection 66 in the aperture 57 serves to
10907~;0
lock the hook 51 in place~ In addition, the non-parallel
alignment of the edges of the projections 54, and the
corresponding non-parallel alignment of the surfaces 65
of the hook 51 serve to lock the hook 51 to the plage 50.
Thus, the hook is inhibited from movement with respect to
the plage 50 by two means, l.e., the mating guide means
and upper portion of the yoke 61, and the projection 66
and aperture 57.
The swivel hook illustrated in Figs, 7 - 9 is
particularly adaptable to the hanging of articles such as
planter pots from a ceiling, although it will be apparent
that it may also be employed in other applications. The
plate 50 may be cast of a die casting metal or molded of
a plastic material, as may be the hook portion 51, as
above discussed, and hence the swivel hook in accordance
with Figs. 7 - 9 may be shaped to have any desired ornamental
configuration, whereby it may be advantageously employed in
locations where purely utilitarian hooks would be inappro-
priate.
A still further embodiment of a swivel hook in accordance
with the invention is illustrated in Figs. 10 - 12. This
swivel hook is formed of a hook member 70 formed in the same
manner as the hook illustrated in Figs. 1 - 6. In addition,
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the swivel hook of Figs. 10 - 12 has a yoke member 71 with
a central frustoconical hole 72 forming the bearing surface
for the projection of the hook 70. The ends of the yoke
71 are separately pivotally mounted to the ends o~ a yoke
member 73, and a central aperture 74 is provided in the
yoke 73 for mounting of the swivel hook. The pivotal
interconnection between the yokes 71 and 73 may also be
formed by a casting technique, in which case one of these
members, for example the yoke 73 may be provided with frusto-
conical projections 75 which are fitted into mating frusto-
conical apertures in the yoke member 71.
The swivel hook of Figs. 10 - 12 provides several
advantages. Thus, as described above, the hook may be
mounted by means of a screw extending through the hole 74
in yoke 73. For the purposes of mounting, the yoke 71 may
pivoted out of alignment with the center of the yoke 73, so
that the mounting screw may be inserted without difficulty,
in the mounting hole 74. In addition, the swivel hook of
Figs. 10 ~ 12 is adapted to be mounted on the ceiling as
illustrated in Fig. 10, or on a vertical surface as illus-
trated in Fig. 11, since a universal coupling arrangement
is provided in this article.
The swivel hook of Figs. 10 - 12 may be formed by
casting of a die casting metal, or by molding of a suitable
plastic. As an example, the swivel hook may be formed in a
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two-step process by first forming the hook 70 and the yoke
73, and then forming the center yoke 71, employing the bear-
ing surfaces of the hook 70 and yoke 73 as the corresponding
mating bearing surfaces of the yoke 71. Alternatively, the
center yoke 71 may be die cast or molded first, followed by
the simultaneous die casting or molding of the yoke 73 and
hook 70, whereby the bearing surfaces of the yoke 71 form
the dies for the corresponding bearing surfaces of the yoke
73 and hook 70.
In a still further embodiment of a swivel hook in
accordance with the invention, as illustrated in Figs. 13 -
15, a yoke member 80 is provided with a mounting screw 81
affixed to the central portion therein. A bridging member
82 is pivotally mounted between the ends of the yoke 80.
The bridging member 82 may, for example, have a circular
cro~s section, and is provided with projections 83 which
extend into the ends of the yoke 80 to form the pivotal
connection therebetween. The swivel hook of Figs. 13 - 15
aIso comprises a hook element 85 formed in the same manner
as the hook element of the embodiment of the invention
illustrated in Figs. 1 - 6. The bridge member 82 is provided
with a central frustoconical hole to provide the bearing
surface for the frustoconical projection on the hook 85.
The hook illustrated in Figs. 13 - 15 also has a
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universal movement, so that it may advantageously be mounted
on a ceiling, as illustrated in Fig. 13, or on a wall as
illustrated in Fig. 14.
The swivel hook of Figs. 13 - 15 may be formed b~ a
die casting or molding technique similar to that employed
in the fabrication of the swivel hook of Figs. 10 - 12.
For example, the bridging member 82 may first be cast or
molded, followed by the simultaneous casting or molding of
the yoke 80 and hook 85, employing the bearing surfaces of
the bridge member 82 as the bearing portions of the die for
the casting of the yoke 80 and hook 85. Alternatively, of
course, the hook 85 and the yoke 80 may be first simul-
taneously cast, followed by the casting of the bridge member
82 as above discussed. The screw 81 may also be die cast
as a unitary part of the yoke 80, or it may be comprised of
a screw of harder material around which the yoke 80 is cast.
The yoke 80 as is apparent in Figs. 13 - 15, has a
"wing" shape, functionally similar to a wing nut, so that
the user may apply torque to the yoke 80 with his fingers.
This facilitates the installation of the hook, since addi-
tional tools, such as screwdrivers, are not required to
screw the screw 81 into a surface.
While the invention has been described and disclosed
with reference to a limited number of embodiments, it will
be apparent that modifications and variations may be made
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:1090760
therein. Thus, the method and apparatus in accordance with
broad aspects of the invention may be employed for other
articles, such as eyes or threaded bolts, as well as many
other types of articles. In addition, the hanging arrange-
ments, such as for example, the arrangement of Figs. 7 - 9,
may be employed for other hanging devices such as quarter
turn fasteners, etc.
It is therefore intended in the following claims to
cover each such variation and modification as falls within
the true spirit and scope of the invention.
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