SHAFT-MOUNTED SNAP LOCK ASSEMBLY AND TOOL

Abstract: A snap lock assembly which may by mounted on a shaft without passing over an end of the shaft. The assembly (10, 101) comprises two segments which are sized and shaped to encircle the shaft and which snap lock with each other. The shaft may be a rod, a bolt, or the like and; the assembly may be a nut, a washer, or the like. Various adaptors (80, 92, 96) are disclosed for adapting the assembly to threadless shafts (90). Also a tool (50) for disengaging the snap lock assembly is disclosed.

Description: SHAFT-MOUNTED SNAP LOCK ASSEMBLY AND TOOL Related Patent The instant invention relates to the subject matter of United States patent No. 4,274,323 entitled "Shaft- Mounted Assembly " of common inventorship herewith. Field of the Invention This invention relates to a snap lock assembly which is to be mounted on a shaft and a tool for applying the assembly. It may, for instance, relate to a nut for a threaded member such as a rod, a bolt, a sleeve, or the like. More particularly, this invention relates to an assembly which mav be quickly applied to or released from a shaft and which may be placed in position on the shaft regardless of the accessibility of the ends of the shaft or the presence of intervening assemblies on the shaft. Background of the Invention The purpose of this invention is to provide a snap lock assembly which can be quickly mounted on a shaft without passing over an end of the shaft and a tool for applying said assembly. In conventional nut and bolt assemblies, the nut is passed over the free end of the bolt and threaded into position to secure a member between the head of the bolt and the nut. This, of course, requires access to the free end of the bolt, and it may also require the expenditure, of a substantial amount of time to thread the nut into position. OMPI In the past others have sought ways to exDedite the assembly of nuts onto threaded members. In the assembly disclosed in United States Patent No. 1,406,804, issued February 14, 1922, to .S. Alexander and entitled "Quick Releasable Nut and Bolt," an internally threaded nut is split into two segments which may be placed in mating relationship with external threads on a bolt at any point intermediate the length of the bolt. The nut segments are held in position by means of a unitary retaining member which has wedge-shaped surfaces which engage and interact with wedge surfaces on the nut segments so that, when the bolt is tightened, the retaining member is forced into surrounding engagement with the nut segment to maintain the nut in place. In that device, however, the mating member is unitary and must be slid over the free end of the bolt. Therefore, the assembly is not usable with a threaded member when there is no accessible free end. A significant advance was realized in the art by the disclosure of the above-identified United States Patent No. 4,274,323. In this connection several embodiments are disclosed of an assembly which may be facilely mounted about a shaft without requiring access to the ends of the shaft. Most of the embodiments disclosed in Patent No. 4,274,323, however, comprise four components. Accordingly, such shaft-mounted assemblies may be somewhat complicated to manufacture and assemble for certain purposes. Further, although some embodiments are composed of only two segments, such assemblies are not positively retained in an assembled condition, which can be a disadvantage in some applica¬ tions. The difficulties suggested in the preceding with regard to prior shaft-mounted assemblies are not inten- ded to be exhaustive, but rather are among many which may tend to limit the effectiveness and satisfaction with prior units. Other noteworthy problems may also exist; however, those presented above should be sufficient to demonstrate that prior lateral shaft- mounted assemblies will admit to worthwhile improvement. Obiects of the Invention It is, therefore the general objective of the invention to provide an assembly which will obviate or minimize difficulties of the type previously described. It is a specific object of this invention to provide a novel shaft-mounted assembly which consists of only two components. It is another object of this invention to provide a novel shaft-mounted assembly in which the components are positively retained in an assembled condition. It is a further object of the invention to provide a novel shaft-mounted assembly composed of two identical components which may be laterally interlocked about a threaded shaft or the like. It is yet a further object of the invention to provide a novel tool for assembling and disassembling components of the instant invention. Summary of the Invention This invention provides an assembly which may be radially mounted about a shaft without passing over an end of the shaft. The assembly comprises two segments which are sized and ' shaped to encircle the shaft and which snap interlock with one another. In a preferred embodiment, each segment is identical, including inter¬ nal threading and may be manufactured as interchangeable parts. The invention further comprises a tool to facilely lock and unlock the snap action seσments radiallv about a shaft using pushing actions of opposing parts for both operations . Brief Description of the Drawings Figure 1 is a perspective view of first embodi¬ ment of the ' invention in an assembled condition; Figure 2 is a perspective view of the first embodi¬ ment of the invention in an assembled condition, showing the opposite side from Figure 1; Figure 3 is an exploded perspective view of the two components . of the first embodiment of the invention in an unassembled condition; Figure 4 is a plan view of the components of the first embodiment of the invention being assembled, showing the components in a posture ready to be snapped into an assembled condition; Figure 5 is a plan view of the first embodiment of the invention in an assembled condition; Figure 6 is a plan view of a special tool in accordance with the invention, which is used to assemble and disassemble the first embodiment of the invention, showing the first embodiment ' being assembled; Figure 7 is a fragmentary plan view of the special tool showing the first embodiment being disassembled; Figure 8 is a fragmentary side view of portions of the special tool and the first embodiment of the inven¬ tion illustrating how disassembly of the first embodi¬ ment is accomplished; Figure 9 is a plan view showing a two-part adapter such that the first embodiment of the invention can be used with a shaft which is not threaded; Figure 10 is a view along section line 10-10 in Figure 9; Figure 11 is a view similar to Figure 10 but showing a smooth shaft received in the two-part adapter and the first embodiment of the invention mounted over the two-part adaptor assembly; - '" Figure 12 is a view similar to Figure 10 of a second embodiment of the two-part adaptor assemblv; OMPI Figure 13 is a view similar to Figure 10 of a third embodiment of the two-part adaptor assembly suitable for use with a wire rope or the like; Figure 14 is a plan view of a second embodiment of the invention disclosing two components in an unassem¬ bled condition; • Fiσure 15 is a side view in the direction of line 15-15 in Figure 14; Figure 16 is a side view in the direction of line 16-16 in Figure 14; Figure 17 is a side view in the direction of line 17-17 in Figure 14; Figure 18 is a side view in the direction of line 18-18 in Figure 14; Fiσure 19 is an exploded perspective view of the second embodiment of the invention showing the- two components in an unassembled condition; Figure 20 is a side view of an optional retaining rod previously shown in Figure 1; Fiσure 21 is a view along line 21-21 in Figure 20; Figure 22 is a view along line 22-22 in Figure 20; and Figure 23 is a view along line 23-23 in Figure 20. Detailed Description of Presently Preferred Embodiments of the Invention A snap lock assembly 10 is shown in Figures 1-5 which essentially comprises two segments, 12 and 14. (A third component, a retaining rod 16, to be described later, is optional.) A particular advantage of the invention is that the segments 12 and 14 mav be (and preferably are) identical, which facilitates both manufacture and assembly. Threads 18 extend about the inner profile of the segments 12 and 14 and may be formed before use or they may be formed in place, as bv turning the assembly 10 on a threading tool. OMPI The segments 12 and 14 are sized and shaped to encircle a threaded shaft (not shown) . The assemble 10 may, for instance, serve as a nut, and in that case the circumferential surface of the assemble 10 is preferable polygonal in shape (as shown) to facilitate turning of the assembly 10 on the shaft. In any event, the segments 12 and 14 are designed to radially snap interlock with each other in an assem¬ bled condition. In this regard, each segment 12 and 14 includes a body portion 22 which defines part of an inner bore 20 and two circumferentially spaced and mutually facing projections or tongues 24 and 26 which axially extend preferrably one-half of the length of the body 22. Each projection 24 and 26 has teeth 28, which are preferably ratchet shaped, on an inwardly locking face, and each portion 22 has corresponding teeth 30 on an outwardly looking face. The ratchet shaped teeth 28 and 30 are sized, shaped, and positioned to be mutually opposing and interengage by a snap fit relatively easily, but cannot be pulled apart without a special tool, to be described below, thereby mutually interlock¬ ing the segments. Further in the above connection, the assembly 10 is assembled by placing the two segments.12 and 14 against each other as shown in Figure 4, then imposing diametri¬ cally opposite forces on the segments 12 and 14 as indicated by the arrows 32 and 34. These forces cause the projection 24 and 26 to deflect slightly outwardly and the teeth 28 to ride up over the teeth 30 in ratchet fashion until the two segments are held in tightly interlocked fashion, as shown in Figures 1, 2, and 5. The amount of force required to effect the necessary outward deflection obviously depends greatly on the dimensions of the projections 24 and 26, the axial length of the assemble, the size and shape of the teeth 28 and 30, and the material from which the segments 12 and 14 are fabricated. However, only very slight angular distortion is required, and in practice it has OMPI been found entirely practical to manually assemble elements 12 and 14 fabricated from steel usinσ a special tool shown in Figure 6-8 and described hereinafter, or in some cases, even hand pressure. To facilitate outward flexure of the segments 12 and 14 during assembly and disassembly, an inwardly opening relief 36 is preferably provided between each body 22 and each of the projections or tongues 24 and 26. However, a planar axial surface 38 is preferably provided on each body 22 adjacent each relief 36 and radially inwardly of the adjacent tongue 24 or 26 in position to abut against a corresponding planar axial surface 38 on a corresponding body portion 22 when the segments 12 and 14 are in an assembled condition. Preferably, the body portions 22 and the projec¬ tions 24 and 26 of each member all have coplanar outer radial surfaces so that, as shown in Figures 1 and 2, the snap lock assembly 10 has a planar, continuous end surface on both axial sides. Each projection 24 and 26 preferably is manufac¬ tured with an axially extending opening 40 (preferably in the form of a through bore) for use in disassembly. The functioning of this opening will be explained hereinafter in connection with the description of a special tool shown in Figures 6-8. One or more of the axially extending openings 42 may be provided in the segments 12 and 14 in position to be axially aligned with a corresponding opening 42 in the other segment 12 or 14. (The openings 42 are preferably communicating with and forming a part of the reliefs 36 in order to provide an optional or additional flexibility or relief, but that is not essential.) The openings 42 are sized and shaped to receive retaining rods 16, which may be press fit into the openings 42. In practice it has been found that the rods 16 are not required in most situations. In anv event, if the rods 16 are used, the rods 16 may be easily tapped through the openings 42 prior to disassembly of the segments. Finally, in the foregoing description the bore 20 is fashioned with threads 18. The threads intimatelv engage corresponding threads on a shaft and prevent relative ' axial travel of one of the segments with respect to the other. In a preferred embodiment the threads, body, and projections of each segment are identical and thus interchangeable and facilely manufac¬ tured in bulk lots and sold as a set. The Special Tool A special tool 50, shown in Figure 6-8, is used to assemble and disassemble the shaft-mounted assembly shown in Figure 1-5. The tool 50 consists of two major arms 52 and 54 pivoted together at 56 and two pairs of minor arms 58 and 60. Each pair of minor arms 58 and 60 is pivotably mounted on a stub shaft 62 which is rotatablv received in a corresponding bore 64 in a working .portion of the major arms 52 and 54. Each minor arm 58 or 56 carries a pin 66 ' which is sized, shaped, and positioned to be received within openings 40 in a snap assembly segment 12 or 14. In order to assemble the snap unit 10, the segments 12 and 14 are operably grasped between the working portions of the major arms 52 and 54 and forced to¬ gether, as previously explained with reference to Figure 4. In this mode, the minor arms 58 and 60 are held in inoperative position by recesses 68 in the major arms 52 and 54. The recesses 68 function as detent means, releasably holding the minor arms 58 and 60 out of the way. A notch 70 is preferably provided in the working surfaces of the major arms 52 and 54, sized, shaped, and positioned to receive and position the segments 1? and 14 correctly for assembly. The minor arms 58 and 60 and the stub shaft 62 are preferably provided as an assembly, and that assembly is preferably movable axially relative to the major arms 52 and 54, as indicated by the arrows 72 in Figure 8. However, only one minor arm need be able to move axiallv; the other may be fixed. If the bottom one (with the tool held horizontally to place an assembly on a vertical threaded rod) is fixed, it will not fall out or away in use. The top pair of arms can slide axially. The axial mobility of the minor arms 58 and 60 permits them to be moved' into the position shown in Figure 8, in which position the assembly 10 is located between the working portions of the major arms 52 and 54, after which the stub shafts 62 are inserted into the corresponding bores 64 in the major arms 52 and 54 and the pins 66 are inserted into the corresponding openings 40 in the tongues 24 and 26. When so inserted, inward motion of the working portions of the major arms 52 and 54 causes the minor arms 58 and 60 in each pair to pivot apart. Outward pivotal movement of the minor arms 58 and 60 in turn causes the projections or tongues 24 and 26 to flex outwardly, releasing the engagement of the teeth 28 with the teeth 30. Concomitantly, inward movement of the jaws 52 and 54 produces relative outward pushing action between segments 12 and 14 as indicated by directional arrows in Figure 7. Once the teeth 28 clear teeth 30, the segments 12 and 14 pop out of engagement, and the assembly 10 is disassembled. It should be particularly noted that the normal (closing) movement of the jaws of the tool, in addition to closing the snapnut by pushing action, separates and pushes the segments of the assembly apart. Illustrative Uses of the First Embodiment Figures 9-11 illustrate use of the assembly 10 in association with a smooth shaft. In this connection, Figures 9 and 10 show a two-part bearinσ sleeve 80 consisting of threaded segments 82 and 84. The segments 82 and 84 have internal splines 86 which are rectangular ιn cross-section and which, as shown in Figure 11, are received in corresponding rectangular slots 88 in a smooth shaft 90. Thus, the segments 82 and 84 may be placed in position around the shaft 90 and then held in position with the assembly 10. The segments 82 and 84 are shown with end flanges. Alternatively a pair of snap assemblies 10 may be used and turned into each other to form a locked unit without use of flanges. Figure 12 illustrates a second, two-part adapter sleeve 92 which is similar to the sleeve 80 except that internal prongs or points 94 are fashioned to be triang¬ ular in cross-section rather than rectangular and serve to wedge themselves into a smooth shaft and eliminate any necessity for prior grooving of the smooth exterior of a shaft. Note that the tips lie along a sloped line so that, as the snapnut assembly 10 is screwed onto the end of the sleeve, it gradually forces the points, one by one, to penetrate the shaft material so as to axially secure the adaptor with respect to the smooth shaft. Figure 13 illustrates another two-part adapter ,clamp 96 which is similar to the adapter sleeves 80 and 92 except that the inner bore 98 is shaped to receive and clamp a coiled rope or wire cable. The Second Embodiment A second preferred embodiment of the invention is disclosed m Figure 14-19. In this connection, self- interlocking, snap action assembly 100 is shown which essentially comprises two segments, 102 and 104. The segments 102 and 104 are preferably identical,- which facilitates both manufacture and assembly. The assem¬ blies are sized and shaped to encircle a shaft (not shown) . The snap action assembly 100 may, for instance, serve as a washer, and in that case the circumferential surface of the assembly is preferably cylindrical in shape (as shown) . OMPI The segments 102 and 104 are designed to interlock with each other in their assembled condition. In this regard, each segment 102 and 104 comprises a body 106 which defines part of a bore 108 for the reception of a shaft, two axially spaced projections or tongues 110 and 112 which project from the body 106 in a first angular sense (i.e., either clockwise or counterclockwise, depending on which side of the segment is observed, and a third, axially intermediate tongue 114 which projects from the body 106 in the opposite, angular sense (i.e., either counterclockwise or clockwise) . The third projection or tongue 114 is sized and shaped to be received between and to axially interface with the axially spaced tongues 110 and 112 on the other one of the segments 102 and 104, and the six projections or tongues (three on each segment) together define, in cooperation with the body portions, a cylindrical bore 108. When this member is used as a washer it will be appreciated that the bore 108 will be sized somewhat larger than the shaft intended to receive the washer. Alternatively, if- the snap action unit depicted in Figures 14-19 is used as a tightfitting washer, wheel, gear, pully, etc., the bore 108 will be. selected to securely surround and grip an associated shaft. Axially inwardly projecting teeth 116 are provided on each of the axially spaced tongues 110 and 112, and axially outwardly projecting teeth 118 are provided on each axial surface of the third intermediate tongue 114. The teeth 116 on each segment are sized, shaped, and positioned to engage the teeth 118 on a corresponding segment, thereby interlocking the segments 102 and 104. Each tongue 110, and 112 ends in a planar abutment surface 120. Preferably (and as shown) the planar abutment surfaces 120 and 122 lie in planes which are not parallel to the axis of the bore 108. To assemble the assembly 100, the two segments 102 and 104 are snapped together as indicated by the arrows 124 in Figure 14. Diametrically opposite forces on the segments 102 and 104 cause the tongues 110, 112, and 114 to flex outwardly, permitting the teeth 116 and 118 to ride over one another in ratchet fashion until the two segments are held in tightly interlocked engagement. The amount of force required to effect the necessary flexure of the segments 102 and 104 depends on the size and shape of the tongues 110, 112, and 114; the size, number, depth, angle, and shape of the teeth 116 and 118; the material from which the segments 102 and 104 are fabricated; and the axial length of the assembly. However, only very slight angular distortion is normally require , and in practice it has been found entirely practical to manually assemble units fabricated form steel. Such assembly can be accomplished using the special tool 50 shown in Figure 8. Retaining Pod One embodiment of the previously .discussed retain¬ ing rod 16 is shown in more detail in Figure 20 through 23. As depicted therein, the rod 16 is basically cylindrical in shape, but is chamfered at 126 and 128. Additionally, a- V-shaped axial slot 130 is formed in one end surface, and ' a second V-shaped axial slot 132 is formed in the other end surface perpendicularly oriented with respect to the slot 130. The two axial slots are deep enough to intersect each other, providing consider¬ able radial flexibility during assembly and disassembly- -that is, as the rods 16 are forced into or out of the openings 42. Although the above discloses one embodiment of pin 16, other forms of the pin are envisioned such as a pin having two or more sets of slots or slits in each end. Moreover, the pin 16 may be a cylinder with one or more axially extending, wedge shaped sections. Still further, the pin 16 may assume the shape of a cylindri¬ cal sinusoidal wire spring.

Claims: CLAIMS 1. A snap lock assembly operable to be mounted about a shaft without passing over an end of the shaft, said assembly comprising two segments which are sized and shaped to encircle the shaft and which interlock with each other, each of said two segments comprising: a body portion which defines part of a bore for the reception of the shaft, two circumferentially spaced projections which axially extend from and partially along the axial length of said body portion and which have teeth on a radially inner face thereof, and corresponding teeth formed on radially outer faces of said body portion and being sized, shaped, and positioned to engage said teeth on said projections of the other of said segments, thereby interlocking said segments. A snap lock assembly as defined in claim 1 wherein: an inwardly opening relief is provided between said body portion and e ' ach of said projections to facilitate outward flexure of said projections dur¬ ing assembly. A snap lock assembly as defined in claim 1 wherein: said portion of said body of each of said segments which interfaces with the shaft is threaded. O PI 4. A snap lock assembly as defined in claim 3 and further comprising: an adaptor means for a non-threaded shaft comprising, a cylindrical member axially divided into a first and second opposing halves and being threaded on an exterior surface thereof to match the threads on the interior of said segments and means internal to said cylindrical member for operably engaging a generally cylindrical shaft. 5. A snap lock assembly as defined in claim 4 wherein said means internal to said cylindrical member comprises: at least one transverse spline for engaging a recess in the shaft. 6. A snap lock assembly as defined in claim 4 wherein said means internal to said cylindrical member comprises: a plurality of axially spaced transversely extend¬ ing teeth which increase in depth from one " end of said cylindrical member to the other for grippingly engaging an external surface of the shaft. 7. A snap lock assembly as defined in claim 4 wherein said means internal to said cylindrical member comprises: a braided surface operable to securely engage an external surface of a braided rope. 8. A snap lock assembly as defined in claim 1, 3 or 4 wherein: said two segments are identical. 9. A snap lock assembly as defined in claim 1 wherein: said body portions have flat planar axial extending surfaces which abut each other in assembled condi¬ tion and said projections are located radially outwardly of said planar axial surfaces. 10. A snap lock assembly as defined in claim 1 wherein: said body portions have planar outer radial surfaces which are coplaner with and an extension, of the planar outer radial surface of the associ¬ ated body. 11. A snap lock assembly as defined in claim 1 wherein: each projection contains an axially extending opening for use in disassembly. 12. A snap lock assembly as defined in claim 1 wherein: the circumferential surface of said snap lock assembly is polygonal in configuration. OMPI _ 13. A snap lock assembly as defined in claim 1 wherein: ^ each of said segments contains at least one axially extending opening in position to communicate with a corresponding axially extending opening in the other segment and further comprising, at least one retaining member sized and shaped to be fit into- said at least one opening. 14. A snap lock assembly as defined in claim 13 wherein: said retaining member is cylindrical in shape; at least a first axial slot is formed in one end surface; and at least a second axial slot is formed in the other surface. 15. A snap lock assembly as defined in claim 14 wherein: said axial slots are mutually perpendicular and axially deep enought to intersect each other. 16. A snap lock assembly as defined in claim 14 wherein: said axial slots are V-shaped. 17. A snap lock assembly as defined in claim 14 wherein: said rod is chamfered at least at one end. OMPI 18. A tool for assembling and disassembling a snap lock assembly as defined in claim 1, said tool comprising: two major arms pivotally connected in a posture intermediate the ends thereof and defining working jaws at one end and handles at the other, each of said major arms having pivotally mounted on the working jaws a pair of minor arms each of which is operable to engage said snap lock assembly, whereby, when said major arms are forced together, the ends of said minor arms which engage said snap lock assembly are forced apart, disengaging said segments from one another. 19. A tool as defined in claim 18 wherein: each pair of minor arms is- pivoted about' a common axis on the associated one of said pair of major arms. 20. A tool as defined in claim 18 wherein: at least one of said minor arms is movable along its pivot axis.' 21. A tool as defined in claim 18 and further comprising: detent means on the jaws of said major arms for releasably holding said minor arms in an inopera¬ tive position. OMPI IPO 22. A tool as defined in claim 18 wherein: each of said major arms has a notch on the surface of said working jaws thereof sized, shaped, and positioned to receive and position said segments during assembly. 23. A tool as defined in claim 18 wherein: each of said minor arms has an axially projecting extension at the end thereof remote from the associated major arms and being sized, shaped, and positioned to be operably received in a correspond¬ ing opening in said snap lock assembly. 24. A snap lock assembly operable to be.mounted on a shaft without passing over an end of the shaft,, said assembly comprising two segments which are sized and shaped to encircle- the shaft and which interlock with each other, each of said two segments comprising: a body portion which defines part of a bore for the reception of the shaft, two axially spaced projections which extend from said body in a first circumferential sense and which define a further part of the bore, and a third projection which extends from said body in an opposite circumferential sense, which is sized and shaped to be recieved and to axially interface with axially spaced projections on the other .of said two segments and which define the remainder of the bore. 25. A snap lock assembly as defined in claim 24 and 'further comprising: axially inwardly projecting teeth on each of said axially spaced projections; and axially outwardly projecting teeth on each axial surface of said third projection and being sized, shaped, and positioned to engage the teeth on said axially spaced projections of the other of said segments thereby interlocking said segments. 26. A snap lock assembly as defined in claim 24 wherein: each of said projections terminates in a planar abutment surface which interfaces with a planar abutment surface at the beginning of a correspond¬ ing projection on the other segment. 27. A snap lock assembly as defined in claim 26 wherein: said planar abutment surfaces lie in planes which are not parallel to the axis of the bore. 28. A snap lock assembly as defined ' ' in claim 24 wherein: the circumferential surface of said assembly is cylindrical.

Inventors: RESNICOW HERBERT E, RESNICOW, HERBERT, E.
Applicants: AMERICAN SNAPNUT ASSOCIATES
Application year: 1984
Main classification: F16B17
IPC codes: B25B7, B25B27, F16B21, F16B37, F16C35, F16D1, F16G11