CA1090761A - Swivel hook - Google Patents

Abstract

SWIVEL HOOK

ABSTRACT OF THE DISCLOSURE

A swivel hook has a hook member with a frustoconical projec-tion terminating in a cylindrical extension of diameter less than the smaller diameter end of the frustoconical portion. The mount-ing member for the swivel hook is a U-shaped mounting element having a mounting screw permanently affixed to the center of the U, and a bridge element extending between the ends of the U-shaped element, said bridge element having a frustoconical hole into which the frustoconical projection is fitted. The elements of the swivel hook are adapted to be cast of a metal or molded of a plastic, in such a manner that the bearing surfaces of one of the elements forms a part of the die for the bearing surface of the other element. During the casting or molding process, the cylindrical extension is beyond the frustoconical hole, and the elements are moved relative to each other following casting or molding to move the cylindrical extension into alignment with the frustoconical hole.

Description

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 not always feasible to transmit sufficient forces to the swivel hook to effect ~s rotation. For example, if the swivel hook is employed to suspend an article by means of a cord, it is desirable that rota-tion 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 minimi-zing costs in their production, and have hence not been particularly desirable for use in locations where ornamental aspects are necessary.
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.

1~90761 In the past, however, the pivotable joints of such articles have not had sufficient freedome 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, whereby the pivotable joints are freely movable.
Briefly stated, in accordance with the invention, an article is provided having first and second elements which are assembled to form a pivotable joint therebetween. The first element has a frusto~
conical hole extending therethrough, and the second article, which may be the hook of a swivel hook, has a frustoconical projection 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 arrangement 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 ~etween the elements 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 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;

'109~7~;1 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 ~riew 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 10907~1 of the hook. In use, the swivel hook of Fig. 1 may be mounted with the yoke 20, extending over any suitable mounting member, wh~reby 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 example, 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. Pate~t 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 1.0907~1 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 aoart 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 No. 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, lS 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. l.
Figs. 2-4 more clearly illustrate the swivel hook of Fig. l in accordance with the ~vention. 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-`` -across. The bridge 24 m~y have a yenerally flat uL,per and lower s uxface 25 and 26 respectively, preferably at least in the vicinity of a tapered h~le 27 extendin~ through the bridge between the sur-faces 25 and 26. The hole 27, which Eorms a frustoconical bearing surface, has its lower diameter end directed to~ard the U-shap~d member 23. As an example, the angle of taper of the hole 27 may 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 (~ 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-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 ~ong as its maximum transverse dimension is less than the lower diameter e~ld of the hole 27.
Fig. 5 illustrates, in simplified form, a casting technique for forming the swivel hook o~ Figs. 1-4. This drawing illustrates one die me~ber 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 ~amak No. 3 zinc alloy is injected into the dies at the aperture 41 to flow around a core rod 42 in conventional lO90t761 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.

-9a-1090~61 The die may be provided with a removable insert 43 for forming the U-shaped member of the yoke, for example, wlth a central hole for mounting. In this case, the pin 3~ 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 frustoconical 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 10~'~761 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.

10S~07'61 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 \
10907~1 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.
Referring 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 1()9()7~;1 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, i.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 Sl, 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, 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 of 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 ', ~,:

:10~7~i1 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 cross 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 also 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 Eigs. 13 - 15 also has a ~O~C~7~

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 by 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 no-t 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 ' `' 10~0761 therein. Thus, the method and a~pardt-ls 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.

Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A swivel hook comprising a U-shaped mounting element, a bridge element extending between the ends of the U-shaped element and pivotable therein, a mounting screw affixed in said U-shaped element at the center thereof and extending away from the pivotal axis between said U-shaped element and said bridge element, the axis of said screw being normal to and intersecting said pivotal axis, and a hook portion pivoted to the center of said bridge element, the hook portion being rotatably movable with respect to the bridge element, whereby said hook member may be moved about both said aforementioned axes, the ends of said U-shaped element being wing-shaped to enable manual rotation of said U-shaped element and hence said screw.

2. A swivel hook as claimed in Claim 1 wherein said hook portion is further axially movable with respect to the bridge element over a distance which is small compared to the thickness of the bridge element.