Chain connecting pin

A chain connecting pin basically includes a pin body, a connecting portion and an inserting portion. The pin body has a first axial end face and a second axial end face, the second axial end face having a recessed surface with respect to an outermost edge of the second axial end face. The connecting portion is attached to the recessed surface of the second axial end face of the pin body. The inserting portion is attached to the connecting portion.

BACKGROUND

1. Field of the Invention

This invention generally relates to a chain connecting pin. More specifically, the present invention relates to a chain connecting pin that interconnects link plates together.

2. Background Information

Most bicycles have a drive train that uses a chain to transmit the pedaling action from the rider to the rear wheel. Bicycle chains have a plurality of inner links and a plurality of outer links that are interconnected in an alternating manner by a plurality of connecting pins. Typically, each of the inner links includes a pair of parallel inner link plates having pin holes at opposite ends. Likewise, each of the outer links includes a pair of parallel outer link plates having pin holes at opposite ends. These inner and outer link plates are overlapped at their ends so as to align the respective corresponding pin holes with each other. Then, a connecting pin is forcibly inserted into the common pin holes defined by the overlapped inner and outer link plates. In order to form a single continuous chain, a pair of the outer link plates and a pair of the inner links are connected together by a releasable connecting link, which is often called a master chain link.

SUMMARY

Generally, the present disclosure is directed to various features of a chain connecting pin. In one feature, a chain connecting pin is provided which permits easier pin connecting operation while also results in a pin that reliably does not protrude outward from a pin body after the pin connecting operation is completed.

In view of the state of the known technology, a chain connecting pin is provided that basically comprises a pin body, a connecting portion and an inserting portion. The pin body has a first axial end face and a second axial end face, the second axial end face having a recessed surface with respect to an outermost edge of the second axial end face. The connecting portion is attached to the recessed surface of the second axial end face of the pin body. The inserting portion is attached to the connecting portion.

Other objects, features, aspects and advantages of the disclosed chain connecting pin will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the chain connecting pin.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring initially toFIGS. 1 to 3, a portion of a bicycle drive chain10is illustrated in accordance with a first embodiment. As used herein to describe the parts of the bicycle drive chain10, the following directional terms “inside”, “outside”, “inner”, “outer”, “above”, “below”, “width”, and “longitudinal” as well as any other similar directional terms refer to those directions relative to the bicycle drive chain10in an installed position on a bicycle that is upright on a horizontal surface. The bicycle drive chain10basically includes a plurality of outer link plates12, a plurality of inner link plates14and a plurality of connecting pins16and a plurality of rollers18. The outer link plates12, the inner link plates14, the connecting pins16and the rollers18are metal parts that are well known in the bicycle chain field. The rollers18are disposed on the chain connecting pins16to rotate on the chain connecting pins16. Since the outer link plates12, the inner link plates14, the chain connecting pins16, the rollers18are well known structures, they will not be discussed and/or illustrated in detail herein, except as needed to explain the construction of the bicycle drive chain10. Of course, it will be apparent to those skilled in the art from this disclosure that these parts can vary as needed and/or desired.

In order to form a single continuous chain loop, an end pair of the outer link plates12and an end pair of the inner links14are connected together by a chain connecting pin16A as best seen inFIG. 3. The chain connecting pin16A is a solid pin, which is installed in a different manner than the chain connecting pins16, as discussed below. Similar to chain connecting pins16, one of the rollers18is also disposed around the chain connecting pin16A. The chain connecting pins16are illustrated as hollow cylinders with a tapered portion at each end so that the chain connecting pins16can be easily deformed at each end. However, the connecting pins16could be solid pins if needed and/or desired.

As seen inFIG. 3, each of the outer link plates12has a pair of pin openings12afor receiving the chain connecting pins16or16A. Similarly, each of the inner link plates14has a pair of pin openings14afor each receiving one of the chain connecting pins16or16A, The inner link plates14have integrated (swaged) bushings forming the pin openings14a. Of course, separate bushings can be used if needed and/or desired. Basically, inner end faces of the outer link plates12are overlapped on outer end faces of the inner link plates14with respective ones of the pin openings12aand14abeing aligned. Then, first, the chain connecting pins are inserted through the pin openings12aand14aso as to connect the inner link plates14and the outer link plates12with each other to form an elongated chain of a prescribed length. Finally, the chain connecting pin16A is then used to interconnect the end pair of the outer link plates12and the end pair of the inner links14together to form a continuous loop. Thus, each opposed pair of the outer link plates12connected together by two of the chain connecting pins16, or one of the chain connecting pins16and the chain connecting pin16A, to form an outer link. Likewise, each opposed pair of the inner link plates14connected together by two of the chain connecting pins16, or one of the chain connecting pins16and the chain connecting pin16A, to form an inner link. The inner link plates14are interconnected in an alternating manner with the outer link plates12by the chain connecting pins16and16A in a conventional manner. Thus, the outer link plates12are arranged outside of the inner link plates14with respect to a center longitudinal plane of the bicycle drive chain10.

Prior to installation of the chain connecting pin16A to the outer and inner link plates12and14, the chain connecting pin16A includes a pin body20, an inserting portion22and a connecting portion24. The connecting portion24is positioned between the pin body20and the inserting portion22. Thus, the connecting portion24interconnects the pin body20and the inserting portion22.

In one preferred embodiment illustrated inFIG. 6, the pin body20, the inserting portion22and the connecting portion24are formed integrally with one another. Preferably, the chain connecting pin16A is preferably formed as a one-piece, unitary member from a hard, rigid material such as a metallic material that is known to be used for manufacturing bicycle chains. For example, the chain connecting pin16A can be made of nickel chrome molybdenum steel. Preferably, the chain connecting pin16A is subjected to a surface hardening treatment to improve abrasion resistance.

The pin body20is actually used for the connection between the outer link plates12and the inner link plates14as the pin body20is forcibly inserted through the pin openings12aof a pair of the outer link plates12and a pair of the pin openings14aof the inner link plates14. The inserting portion22is used for initially guiding the chain connecting pin16A through the pair of the outer link plates12and the pair of the pin openings14aof the inner link plates14during the assembly process of manufacturing the bicycle drive chain10.

As explained below, the connecting portion24is configured to shear from the pin body20and remain attached to the inserting portion22after the pin body20is installed between a pair of adjacent links of the bicycle drive chain10. Preferably, the pin body20, the inserting portion22and the connecting portion24are formed integrally with one another. The connecting portion24preferably has a smaller maximum diameter than the pin body20and the inserting portion22.

The pin body20has a first axial end face31and a second axial end face32. The pin body20has a length slightly greater than a lateral distance between the outer link plates12when the drive chain10is assembled. The first axial end face31of the pin body20includes a recess33. Preferably, the recess33of the first axial end face31of the pin body20is conically shaped. The recess33can be used for receiving a tool that is used for installing the pin body20into a pair of adjacent links. The second axial end face32has a recessed surface34with respect to an outermost edge35of the second axial end face32. As seen inFIGS. 7 and 8, the recessed surface34preferably includes a tapering part34athat tapers closer toward the first axial end face31as the tapering part34aextends in a direction from the outermost edge35of the second axial end face32toward a center axis of the pin body20. While in the illustrated embodiment, the entire recessed surface34is formed by the tapering part34a, the recessed surface34could have a non-tapering part if needed and/or desired.

In the illustrated embodiment, the pin body20further includes a center cylindrical part40, a first flange41and a second flange42. The center cylindrical part40of the pin body20has a maximum outer diameter that is greater than a maximum outer diameter or width of the inserting portion22. The center cylindrical part40is preferably formed with two cylindrical sections40aand40b. The cylindrical section40amay have a slightly larger diameter than the cylindrical section40b. Both of the cylindrical sections40aand40bmay have a maximum outer diameter that is greater than a maximum outer diameter or width of the inserting portion22. The cylindrical section40ahas a diameter slightly larger than that of the pin opening12a. The axial length of the cylindrical section40ais preferably about equal to the thickness of the outer link plate12.

The first flange41is disposed adjacent the first axial end face31, while the second flange42is disposed adjacent the second axial end face32. Thus, the first and second flanges41and42are disposed at opposite longitudinal ends of the center cylindrical part40for preventing the pin body20from inadvertently slipping out of the pin openings12a. The second flange42includes a partial spherical surface42athat extends in a radially outward direction from the outermost edge35of the second axial end face32. The partial spherical surface42aaids in the insertion of the pin body20into the pin opening12aand14a.

The connecting portion24will be discussed in more detail. The connecting portion24can be formed by annually cutting an intermediate peripheral section of the chain connecting pin16A between the second flange42of the pin body20and the inserting portion22. Thus, the connecting portion24has a reduced diameter relative to the pin body20, and the inserting portion22so that the portion3can be easily detached from the pin body20by applying shearing force to the inserting portion22. Moreover, the connecting portion24has an axial length that is preferably slightly shorter than the thickness of the outer link plate12so as to facilitate the insertion of the inserting portion22into the pin opening12a.

The connecting portion24is preferably attached to the recessed surface34of the second axial end face32of the pin body20by a frangible connection50. The frangible connection50constitutes a shear line between the pin body20and the connecting portion24where the connecting portion24will shear off of the pin body20when the inserting portion22is broken off. The connecting portion24is preferably frustoconically shaped so that the frangible connection50is located below a plane forming the second axial end face32. In other words, the connecting portion24has a small diameter end51and a large diameter end52. The small diameter end51is attached to the recessed surface34of the pin body20at the frangible connection50. The large diameter end51is attached to the inserting portion22. The connecting portion24has a reduced diameter relative to the pin body20and the inserting portion22. The connecting portion24has an axial length that is preferably equal to or less than one millimeter.

Now the inserting portion22will be discussed in more detail. As mentioned above, the inserting portion22is attached to the connecting portion24(i.e., integrally formed in the illustrated embodiment). The inserting portion22preferably includes a cylindrical part60and a narrowing tip part61. The cylindrical part60extends axially between the connecting portion24and the narrowing tip part61. The narrowing tip part61narrows as the narrowing tip part61extends in a direction away from the connecting portion24toward a center axis A of the pin body20.

Referring toFIGS. 9 to 11, a chain connecting operation using the chain connecting pin16A having the above-described construction will now be more particularly described. Usually, in the chain connecting operation, a pin installation tool70is used for installing the chain connecting pin16A into the pin openings12aand14aof the outer and inner link plates12and14. As seen inFIG. 11, the pin installation and removal tool70has a cradle72for holding the drive chain during installation of the chain connecting pin16A. The pin installation and removal tool70further has a driving pin74that is movably mounted to the cradle72for axial movement. Typically, the driving pin74has threaded portion that is threaded into a threaded bore of the cradle72such that rotation of the driving pin74causes the driving pin74to move axially. Preferably, the driving pin74has a handle76at one end for rotating the driving pin72relative to the cradle72. Pin installation and removal tool such as the one illustrated are well known, and thus, the pin installation and removal tool70will not be discussed and/or illustrated in detail herein.

First, for connecting free ends of a disconnected chain, the inner end faces of the outer link plates12are overlapped on the outer end faces of the inner link plates14, with the pin openings12aand14abeing aligned with each other In this condition, the inserting portion22is inserted through a first pair of the pin openings12aand14aand then through a second pair of the pin openings12aand14aas seen inFIG. 9. This can be done using by hand or by using the driving pin74depending on the maximum diameter of the inserting portion22relative to the diameters of the pin openings12aand14a, In any event, the first axial end face31of the pin body20is pushed so that the inserting portion22is disposed in the pin openings12aand14aas seen inFIG. 9. Next, as seen inFIGS. 9 and 10, the driving pin74is used to insert the pin body20into the pin openings12aand14aso that the first and second flanges41and42engage the outer end faces of the outer link plates12.

As seen inFIG. 10, once the pin body20is disposed in the pin openings12aand14a, the inserting portion22substantially entirely projects out of the outer link plate12. Then, this projecting inserting portion22is fitted into a receiving hole78of the pin installation and removal tool70, and the pin installation and removal tool70is wrenched relative to the drive chain10. As a result, the connecting portion24is sheared way from the pin body20at the frangible connection50. Because the connecting portion24is attached to the recessed surface34of the pin body20, the remaining connecting portion does not protrude outward from a pin body after the chain connecting operation is completed so as to prevent undesirable contacts of the remaining connecting portion with other components, such as a sprocket, a derailleur, and so on. Finally, if needed, the drive chain10can be reinstalled into the pin installation and removal tool70to deform the second flange42for more securely fixing the chain connecting pin16A.

In the foregoing embodiment, the inserting portion22is formed with the cylindrical part60and the narrowing tip part61. Instead, this inserting portion22can have a different configuration. For instance, it is conceivable to form the entire inserting portion22with a tapered shape. Also, the length of this inserting portion22is not limited to the one described in the foregoing embodiment.

The foregoing embodiment has been described by way of the bicycle drive chain. However, it is to be understood that the connecting pin and the connecting method of the present invention can be used in many other applications for connecting various elements having through holes.

In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. Also it will be understood that although the terms first and second may be used herein to describe various components these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, for example, a first component discussed above could be termed a second component and vice-a-versa without departing from the teachings of the present invention. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. Finally, terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed.

While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.