Motor vehicles – Special wheel base – Having only two wheels
Reexamination Certificate
1999-09-10
2001-07-03
Dickson, Paul N. (Department: 3618)
Motor vehicles
Special wheel base
Having only two wheels
C280S284000, C280S288000
Reexamination Certificate
active
06253868
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the structure of a pivot portion of a rear swing arm of a motorcycle.
2. Description of the Background Art
A pivot structure of a rear swing arm of a motorcycle is known in which a pair of left and right pivot plates made of iron are used. Front ends of a rear swing arm are placed between the left and right pivot plates, and coupled by a pivot bolt. An adjusting collar is installed at a bolt through hole of one of the pivot plates (refer to JP-A-62-60491U).
The above-described pivot structure is a structure fastened together by an axial force produced by a bolt-and-nut coupling. The adjusting collar is present and therefore, deformation of the left and right pivot plates can be reduced. However, when the pivot plates are arranged on inner sides of the rear swing arms, such a fastening structure cannot be adopted. Therefore, there is desired an adjusting mechanism which may be used even in an arrangement where vehicle body frame members such as pivot plates are arranged on inner sides of rear swing arms.
Further, in the case of a backbone type vehicle frame, when it is of a type in which rear swing arms are interposed between a pair of left end right pivot plates, other parts of a carburetor and the like are difficult to lay out without interfering with the vehicle body frame and therefore, integral formation of a center frame is also desired.
Further, in view of promoting frame rigidity, it would be desirable to also connect a crankcase of an engine at the pivot portion along a single axis. The present invention resolves such problems.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a structure of a pivot portion of a rear swing arm. A single piece of a center frame constituting a backbone type vehicle body frame is arranged in an up and down direction on a rear side of an engine. Attaching portions installed on left and right sides of a front end portion of a rear swing arm are coupled to pivot plates installed at a lower portion of the center frame by a pivot shaft. The pivot plates are provided with sidewalls on left and right sides. The left and right sidewalls are arranged between the left and right attaching portions of the rear swing arm. The attaching portions of a crankcase are placed between the left and right sidewalls. An adjusting collar is placed between the crankcase and one of the left and right sidewalls. These elements are coupled together by a pivot shaft.
The adjusting collar has a screw portion and a nut coupled thereto. The adjusting collar can be withdrawn from and inserted through a window hole formed at a rear face wall of the center frame. A pivot lock portion of the collar having the screw portion projected from the window hole and engaged with a side of the center frame is brought into contact with the side of the center frame.
The adjusting collar is interposed between either of the left and right sidewalls and the attaching portion of the crankcase. Accordingly, a distance between the left and right sidewalls can be made constant. Therefore, even when the pivot plates are fastened up by a bolt and a nut, tolerances of the coupled portions are adjusted between the attaching portion of the rear swing arm on the outer side and the sidewall, and deformation of the sidewalls can be reduced. The occurrence of residual stresses can be reduced. Accordingly, even when the pivot plates are made of an aluminum alloy, sufficient fastening is made feasible.
Further, a distance between the left and right sidewalls can be made constant by the crankcase and the adjusting collar, and the structure can withstand axial force by utilizing the rigidity of the crankcase. By coupling the crankcase to the center frame along with the rear swing arms in a single axis, the frame rigidity is promoted.
The adjusting collar can be withdrawn from and inserted through the window hole provided at the rear face wall of the pivot plates and therefore, the adjusting collar can be mounted even after an engine is placed between the left and right sidewalls. Therefore, in an assembling operation, there is no restriction caused by the mounting procedure of the adjusting collar. The operational efficiency is excellent and attachment and detachment of the engine is facilitated. The adjusting collar includes an engaging portion for pivot locking, and thereby the adjusting operation of the adjusting collar is facilitated.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
REFERENCES:
patent: 4540062 (1985-09-01), Kashiwai
patent: 5007497 (1991-04-01), Trema
patent: 5487443 (1996-01-01), Thurm
patent: 5960902 (1999-10-01), Mancini et al.
patent: 6098736 (2000-08-01), Smith
patent: 62-60491 U (1987-04-01), None
Horii Yoshiyuki
Matsuno Toshio
Muto Kenji
Birch & Stewart Kolasch & Birch, LLP
Dickson Paul N.
Honda Giken Kogyo Kabushiki Kaisha
Lerner Avraham H.
LandOfFree
Structure of pivot portion of rear swing arm does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Structure of pivot portion of rear swing arm, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structure of pivot portion of rear swing arm will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2466775