BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of this invention will become apparent in the following detailed description of the preferred embodiments of this invention, with reference to the accompanying drawings, in which:
FIG. 1 is a fragmentary sectional view of a conventional chain;
FIG. 2 is a schematic front view of a first conventional assembly of a link plate and a link pin, which is disclosed in Taiwanese Patent Publication No. 171756;
FIG. 3 is a schematic front view of a second conventional assembly of a link plate and a link pin, which is disclosed in Taiwanese Patent Publication No. 205326;
FIG. 4 is a fragmentary perspective view of a chain including the first preferred embodiment of a link plate according to this invention, illustrating connections among the link plate and other elements;
FIG. 5 is a fragmentary sectional view of two chain link units and a connecting unit of the chain shown in FIG. 4;
FIG. 6 is a perspective view of the first preferred embodiment;
FIG. 7 is a front view of the first preferred embodiment;
FIG. 8 is a fragmentary, partly exploded sectional view of the chain shown in FIG. 4, illustrating connections among the preferred embodiment and two link pins;
FIG. 9 is a fragmentary sectional view of the chain shown in FIG. 4, illustrating how a retaining end portion of one of the link pins is moved within a first hole portion of a retaining hole in the link plate to thereby project outwardly from a sliding surface portion;
FIG. 10 is a front view of the first preferred embodiment, illustrating how the link pin is located within a first hole portion of the retaining hole;
FIG. 11 is a front view of the first preferred embodiment, illustrating how the link pin is moved into a second hole portion of the retaining hole;
FIG. 12 is a perspective view of the second preferred embodiment of a link plate according to this invention;
FIG. 13 is a front view of the second preferred embodiment;
FIG. 14 is a perspective view of the third preferred embodiment of a link plate according to this invention; and
FIG. 15 is a front view of the third preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before the present invention is described in greater detail in connection with the preferred embodiments, it should be noted that similar elements and structures are designated by like reference numerals throughout the entire disclosure.
Referring to FIGS. 4 and 5, the first preferred embodiment of a link plate 1 according to this invention is one element of a chain. The chain includes a connecting unit 2 and a plurality of chain link units 3. The connecting unit 2 includes two link plates 1 and a pair of first and second link pins 4, 4′ for interconnecting an adjacent pair of the chain link units 3. Each of the chain link units 3 includes two parallel inner chain plates 31. Each of the first and second link pins 4, 4, has an anchoring end portion 41, a retaining end portion 42 opposite to the anchoring end portion 41 and having a diameter (ψ1) smaller than the diameter (ψ2) of the anchoring end portion 41, and a neck portion 43 connected to the retaining end portion 42 so as to define a shoulder 44 therebetween.
Referring to FIGS. 5, 6, 7, and 8, the link plate 1 includes an inner side surface 12 adjacent to the corresponding inner chain plate 31, an outer side surface 13 opposite to the inner side surface 12, a through hole 14 extending from the inner side surface 12 to the outer side surface 13 and allowing the anchoring end portion 41 of the first link pin 4 to be riveted therein, and an inner surrounding surface 15 extending from the inner side surface 12 to the outer side surface 13 to define a retaining hole 18. The retaining hole 18 is spaced apart from the through hole 14, and is used to allow for extension of the retaining end portion 42 of the second link pin 4′ therethrough.
The link plate 1 is gourd-shaped, and has two opposite annular end portions 131, and a contracted middle portion having two opposite sides 132.
The inner surrounding surface 15 has a mounting portion 151 disposed about a first central point (A), and a positioning portion 152 disposed about a second central point (B). The positioning portion 152 has two positioning ends 153 connected respectively to two ends of the mounting portion 151 and spaced apart from each other by a distance (d1) smaller than the diameter (ψ1) of the retaining end portion 42. As such, the retaining hole 18 has a first hole portion 181 defined by the mounting portion 151, and a second hole portion 182 defined by the positioning portion 152.
The link plate 1 further includes a flange 16 extending from the positioning portion 152 of the inner surrounding surface 15 toward the second central point (B), and two bridging notches 17 formed between the inner surrounding surface 15 and the outer side surface 13 and between the mounting portion 151 and the positioning portion 152 of the inner surrounding surface 15. The flange 16 is adjacent to the inner side surface 12 and distal from the outer side surface 13, and has an extension face 161 coplanar with the inner side surface 12, and an abutment face 162 parallel to the extension face 161. The shoulder 44 of the corresponding one of the first and second link pins 4, 4′ abuts against the abutment face 162.
The bridging notches 17 are located respectively to two sides of a longitudinal line (L1) extending through the first and second central points (A, B). Each of the bridging notches 17 is defined by a bridging surface portion 171 and a sliding surface portion 172. The bridging surface portions 171 extend from the outer side surface 13 toward the inner side surface 12, and face each other so as to define a passage permitting movement of the retaining end portion 42 of the corresponding one of the first and second link pin 4′ between the mounting portion 151 and the positioning portion 152 of the inner surrounding surface 15 therethrough. That is, a minimum distance between the bridging surface portions 171 is greater than the diameter (ψ1) of the retaining end portion 42. In this embodiment, each of the bridging surface portions 171 is curved, and has a first end 173 connected to the mounting portion 151, and a second end 174 connected to the positioning portion 152. The sliding surface portions 172 are parallel to the inner and outer side surfaces 12, 13, and are disposed on a plane located between the outer side surface 13 and the flange 16. The first ends 173 are spaced apart from a transverse line (L2) extending through the positioning ends 153 of the positioning portion 152 by a distance (d2) greater than the distance (d3) between the transverse line (L2) and a line (L3) extending through the first central point (A) and perpendicular to the longitudinal line (L1).
With particular reference to FIG. 8, during assembly of the connecting unit 2, the anchoring end portions 41 of the first and second link pins 4, 4′ are first riveted respectively within the through holes 14 in the link plates 1. The first and second link pins 4, 4′ are passed respectively through the chain link units 3 (see FIG. 5) and into the first hole portions 181 of the retaining holes 18 in the link plates 1 such that the retaining end portions 42 just project respectively and outwardly from the sliding surface portions 172, as shown in FIG. 9 (i.e., the flanges 16 are aligned respectively with the neck portions 43 of the first and second link pins 4, 4′). Subsequently, with additional reference to FIGS. 10 and 11, the retaining end portions 42 are moved respectively from the first hole portions 181 into the second hole portions 182 via the passage defined by the bridging surfaces 171, and then toward the flanges 16, respectively. As a consequence, an outer end surface 421 of each of the retaining portions 42 of the first and second link pins 4, 4′ is aligned with the outer side surface 13 of the corresponding link plate 1, as shown in FIG. 5. In this state, since the distance (d1) between the positioning ends 153 of each of the link plates 1 is smaller than the diameter (ψ1) of the corresponding retaining end portion 42, movement of the retaining end portions 42 from the second hole portions 182 into the first hole portions 181 in a direction parallel to the outer side surfaces 13 can be prevented. That is, the first and second link pins 4, 4′ can be retained respectively and effectively on the link plates 1.
Due to the presence of the bridging notches 17, the first and second link pins 4, 4′ can be shortened so as to reduce the space formed between each adjacent pair of the inner chain plate 31 and the link plate 1 and, thus, the noise generated during use of the chain, as compared to that occurring in Taiwanese Patent Publication NO. 171756.
With particular reference to FIGS. 5 and 7, there may be cause for concern that such design of the inner surrounding surface 15 may result in a reduction in the distance (d4) between the mounting portion 151 and the sides 132 of the link plate 1, in which case, the link plate 1 could break at areas between the mounting portion 151 and the sides 132 of the link plate 1. To solve this possible breakage problem, the distance (d5) between the sides 132 may be increased. This, however, would affect adversely the engagement of the chain with a bicycle sprocket (not shown). In this embodiment, therefore, since the diameter (ψ1) of the retaining end portion 42 is smaller than the diameter (ψ2) of the anchoring end portion 41, the size of the inner surrounding surface 15 can be reduced so as to increase the distance (d4) between the mounting portion 151 and the sides 132 of the link plate 1.
FIGS. 12 and 13 show modified bridging surface portions 171 that are flat, parallel to each other, and perpendicular to the inner and outer side surfaces 12, 13. The distance between the modified bridging surface portions 171 is greater than the diameter (ψ1) of the retaining end portion 42.
FIGS. 14 and 15 show modified bridging notches 17 that are defined merely by inclined bridging surface portions 171. In this embodiment, the sliding surface portions 172 are omitted.
With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated by the appended claims.
Patent Application
20070249448
