Title of Invention

"HANDLE LOCKING DEVICE FOR A TWO-WHEELED MOTOR VEHICLE"

Abstract

A handle locking device for a two-wheeled motor vehicle wherein a lock bar provided in a retractably protrudable manner in a cylinder lock is brought into engagement with a lock hole formed in a steering shaft which is rotatably fitted in a head pipe, to inhibit the rotation of the steering shaft, characterized in that a mounting bracket fixed to the head pipe to support the cylinder lock is integrally provided with a guide member which is separate from the cylinder lock and which guides the lock bar slidably, the outer periphery of a front end portion of the guide member being engaged with the inner periphery of a support hole formed in the head pipe.

Full Text

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a handle locking device for a two-wheeled motor vehicle wherein a lock bar provided in a retractably protrudable manner in a cylinder lock is brought into engagement with a lock hole formed in a steering shaft which is rotatably fitted in a head pipe, to inhibit the rotation of the steering shaft. [Prior Art] Such a handle locking device for a two-wheeled motor vehicle is well known from, for example, Japanese Patent Laid Open No.224878/91. In this known locking device, the front end of a guide member projecting integrally from a cylinder lock is brought into engagement with a support hole formed in a head pipe, and the front end of a lock bar which is slidably fitted in the interior of the said guide member is brought into engagement with a lock hole formed in a steering shaft which is rotatably supported in the head pipe. According to this structure, a load transferred from the steering shaft to the lock bar is received by the head pipe, thus making it possible to enhance the durability of the cylinder lock. [Problem to be Solved by the Invention] In the above conventional handle locking device, since the cylinder lock having the guide member integrally is fixd to the head pipe through a mounting bracket, the positional accuracy between the guide member and the lock hole formed in the steering shaft may be deteriorated, depending on in what state the cylinder lock is mounted. If the diameter of the lock hole formed in the steering shaft is set larger than that of the lock bar to compensate for the deterioration of the said positional accuracy, there is formed a clearance between the lock bar and the lock hole, resulting in that not only it becomes difficult to surely lock the handle but also the cylinder lock may become less durable against the load transmitted from the steering shaft. The present invention has been accomplished in view of the above-mentioned circumstances and it is an object of the invention to minimize the clearance between the lock bar of the cylinder lock and the lock hole formed in the steering shaft. [Means for Solving the Problem] According to the invention defined in claim 1, in order to achieve the above-mentioned object, in a handle locking device for a two-wheeled motor vehicle wherein a lock bar provided in a retractably protrudable manner in a cylinder lock is brought into engagement with a lock hole formed in a steering shaft which is rotatably fitted in a head pipe, to inhibit the rotation of the steering shaft, there is provided an improvement characterized in that a mounting bracket fixed to the head pipe to support the cylinder lock is integrally provided with a guide member which is separate from the cylinder lock and which guides the lock bar slidably, the outer periphery of a front end portion of the guide member being engaged with the inner periphery of a support hole formed in the head pipe. According to the invention defined in claim 2, in combination with the invention defined in claim 1, the outer periphery of a front end portion of the guide member is engaged with and welded to the inner periphery of the support hole formed in the head pipe. Accordingly, the present invention relates to a handle locking device for a two-wheeled motor vehicle wherein a lock bar provided in a retractably protrudable manner in a cylinder lock is brought into engagement with a lock hole formed in a steering shaft which is rotatably fitted in a head pipe, to inhibit the rotation of the steering shaft, the improvement characterized in that a mounting bracket fixed to the head pipe to support the cylinder lock is integrally provided with a guide (member which is separate from the cylinder lock and which guides the lock bar slidably, the outer periphery of a front end portion of the guide member being engaged with the inner periphery of a support hole formed in the head pipe. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Fig. 1 is a side view of the whole of a scooter type two-wheeled motor vehicle; Fig. 2 is an enlarged view of a principal portion shown in Fig. 1; Fig. 3 is a view as seen in the direction of arrow 3 in Fig. 2; Fig. 4 is a view as seen in the direction,of arrow 4 in Fig. 3; Fig. 5 is a sectional view taken on line 5-5 in Fig. 4; and Fig. 6 is an exploded view of a handle locking device, corresponding to Fig. 5. [Embodiment of the Invention] An embodiment of the present invention will be described hereinunder with reference to the accompanying drawings. Figs.l to 6 illustrate an embodiment of the present invention, of which Fig.l is a side view of the whole of a scooter type two-wheeled motor vehicle, Fig.2 is an enlarged view of a principal portion shown in Fig.l, Fig.3 is a view as seen in the direction of arrow 3 in Fig.2, Fig.4 is a view as seen in the direction of arrow 4 in Fig.3, Fig.5 is a sectional view taken on line 5-5 in Fig.4, and Fig.6 is an exploded view of a handle locking device, corresponding to Fig.5. As shown in Fig.l, a frame F formed by welding steel pipes and which constitutes a skeletal structure of a scooter type two-wheeled motor vehicle V comprises a head pipe l, a down tube 3 connected to the head pipe 1 through gussets 2 ,2 and extending backward and downward of the vehicle body, and right and left main fames 4,4 branched right and left from a position near the lower end of the down tube 3 and extending backward and upward of the vehicle body, the main frames 4,4 being curved in U shape and coupled together at their rear ends. The front portions of the right and left main frames 4 and the lower end of the down tube 3 are connected with each other through a pair of reinforcing pipes 5,5. Middle portions and rear portions in the longitudinal direction of the right and left main frames 4,4 are respectively connected together using first and second cross members 6,7 extending in the transverse direction of the vehicle body. A body B formed of a synthetic resin and supported by the frame F comprises a leg shielding front member 8 which covers the front side of the head pipe 1, a leg shielding rear member 9 connected to the rear side of the leg shielding front member 8 to cover the rear side of the head pipe 1, a step floor 10 adjacent to the lower end of the leg shielding rear member 9, an under cover 11 adjacent to the lower end of the leg shielding lower member 8 to cover the underside of the step floor 10, a rear cover 12 which covers the rear portion of the vehicle body, and right and left side covers 13,13 extending from the right and left front portions of the rear cover 12 up to the rear ends of the step floor 10 and under cover 11. A front wheel Wf, whose upper portion is covered with a front fender 15, is journaled at the lower end of a front fork 14 which is supported rotatably by the head pipe 1. An upper-end opening defined by both leg shielding front and rear members 8,9 is covered with an upper panel 16, and a handle post 17 extends upward from the upper panel 16. To the upper surface of the handle post 17 is connected a transversely central portion of a bar handle 18. A headlight 19 and a speedometer 20 are supported by the handle post 17. Further, on the right side face of the head pipe 1 is supported a handle locking device 21 having an ignition switch integrally. A rear wheel Wr is journaled at the rear end of a power unit P, while the front end of the power unit P is supported vertically swingably by the first cross member 6. The power unit P and the second cross member 7 are connected with each other through a rear cushion 22. On the upper surface of the rear cover 12 is mounted a seat 23 for a rider to sit thereon. As shown in Figs.2 and 3, a steering shaft 31 which supports the front fork 14 (see Fig.l) at the lower end thereof is inserted into the head pipe 1 and is supported rotatably and axially movably. The handle post 17, which is fixed to the steering shaft 31 projecting upward from the upper end of the head pipe 1, comprises a connection pipe 40 fitted on the outer periphery of the upper end of the steering shaft 31 and clamped with a bolt 38 and a nut 39, a plate-like bar handle mounting member 41 welded to the upper end of the connection pipe 40, a pair of right and left block-like under holders 43,43 fixed to the upper surface of the bar handle mounting memer 41 with bolts 42,42, and an upper holder 44 clamped to the upper surfaces of the under holders 43,43 with bolts 32 used two each on the right and left sides. A central mounting portion 181 is held between the under holders 43,43 and the upper holder 44, whereby the bar handle 18 is fixed. The headlight 19 is supported by the bar handle mounting member 41 of the handle post 17 through a stay 33, and the speedometer 20 is supported by the upper holder 44 through a mounting bracket 34 (see Fig.2). Now, the structure of the handle locking device 21 will be described below with reference to Figs.3 to 6. A mounting bracket 51 formed by bending a steel plate in H shape in section is fixed to the right side face of the head pipe 1 by welding as indicated at W1 ,W1. Two nuts 52,52 are fixed to the back (the side opposed to the head pipe 1) of a flat mounting portion 511 of the mounting bracket 51 by welding as indicated at W2 ,W2. A support hole 11 is formed in the head pipe 1 on the side opposed to the mounting bracket 51. One end of a cylindrical guide member 53 provided internally with a guide bore 531 is fitted in the support hole 11 and welded at W3 , while the opposite end of the guide member 53 is welded at W4 to the back of the mounting portion 511 of the mounting bracket 51. In this way the mounting bracket 51 provided with the guide member 53 integrally is fixed to the head pipe 1. A cylinder lock 54 is of a well-known structure having incorporated therein an ignition switch which is operated by an ignition key K. When the ignition key K is turned to a handle lock position, a lock bar 57 projects from a boss portion 56 which is formed projectingly on the side face of a cylinder body 55. The boss portion 56 of the cylinder lock 54 is brought into abutment with one side of a mounting plate 58 and is fixed in this state to the mounting plate 58 with two flush bolts 59,59. At this time, the lock bar 57 projecting from the cylinder body 55 passes through a guide hole 581 formed in the mounting plate 58. Through the mounting plate 58 with the cylinder lock 54 thus fixed thereto using two flush bolts 59,59 there extend two breaking bolts 60,60, which are screwed into the two nuts 52,52 fixed to the mounting bracket 51. In this way the mounting plate 58 is fixed to the mounting bracket 51. At this time, heads 601 ,601 (see Fig.6) of the breaking bolts 60,60 are broken down by a clamping torque. As a result, the cylinder lock 54 can no longer be separated from the mounting bracket 51 because the heads of the flush bolts 59, 59 are covered with the mounting portion 511 of the mounting bracket. In such an inseparably fixed state of the cylinder lock 54 to the mounting bracket 51, the lock bar 57 is inserted into a guide hole 512 formed in the mounting bracket 51 and the guide bore 531 of the guide member 53, with its front end in a protruded state thereof being engaged with a lock hole 311 formed in the steering shaft 31 (see Fig.5). Next, the operation of this embodiment having the above construction will be described below. When the handle locking device 21 is not in operation, the lock bar 57 of the cylinder lock 54 is in its retracted position indicated with a chain line in Fig.5, with its front end being spaced away from the lock hole 311 of the steering shaft 31. In this state, by operating the bar handle 18, the steering shaft 31 can be turned freely to steer the front wheel Wf. For operation of the handle locking device 21, if the cylinder lock 54 is operated with the ignition key K to protrude the lock bar 57, the lock bar 57 protrudes to its solid-line position in Fig.5 while being guided by the guide bore 531 of the guide member 53 and its front end comes into engagement with the lock hole 311 of the steering shaft 31. Even if an attempt is made to operate the bar handle 18 in this state, it is impossible to steer the front wheel Wf because the rotation of the steering shaft 31 is inhibited by the lock bar 57. When an operation load on the bar handle 18 tries to turn the steering handle 31 in the direction of arrow a in Fig.5 for example, the lock bar 57 with its front end engaged with the lock hole 311 of the steering shaft 31 is pressed in the direction of arrow b, but since the front end of the guide member 53 fitted on the outer periphery of the lock lever 57 is fitted in the inner periphery of the support hole l1 of the head pipe 1 and is welded at W3 , the torque in the arrow a direction of the steering shaft 31 is transmitted to and borne by the head pipe 1 having a high rigidity. Thus, a large bending load is prevented from acting on the base end of the lock bar 57 which is supported by the cylinder body 55, and hence the durability of the cylinder lock 54 is improved. Further, since the guide member 53 for guiding the lock bar 57 is integral with the mounting bracket 51, a proper positional relation between the guide bore 531 and the lock hole 311 of the steering shaft 31 is established upon fixing of the mounting bracket 51 to the head pipe 1. The said positional relation is not influenced by the state of mounting of the cylinder lock 54 relative to the mounting bracket 51. Consequently, not only it is possible to minimize the clearance between the lock bar 57 which is guided by the guide bore 531 and the lock hole 311 of the steering shaft 31 and attain a positive lock of the bar handle, but also it is possible to further enhance the durability of the cylinder lock 54 against the load transmitted from the bar handle 18 to the steering shaft 31. Although an embodiment of the present invention has been described in detail hereinabove, various design modifications may be made within the scope not departing from the gist of the invention. [Effects of the Invention] As set forth above, according to the invention defined in claim 1, a mounting bracket fixed to the head pipe to support the cylinder lock is integrally provided with a guide member which is separate from the cylinder lock and which guides the lock bar slidably, and the outer periphery of the front end portion of the guide member is brought into engagement with the inner periphery of a support hole formed in the head pipe. Therefore, not only it becomes possible for the head pipe to bear the load transmitted from the steering shaft to the lock bar and thereby enhance the durability of the cylinder lock, but also it is possible to a proper positional accuracy between the guide member and the lock hole formed in the steering shaft upon fixing of the mounting bracket to the head pipe and thereby minimize the clearance between the lock bar which is guided by the guide member and the lock hole formed in the steering shaft. As a result, a positive lock of the bar handle can be effected and the cylinder lock can be rendered more durable against the load transmitted to the steering shaft. Further, according to the invention defined in claim 2, since the outer periphery of the front end portion of the guide member is engaged with and welded to the inner periphery of the support hole formed in the head pipe, it is possible to further improve the positional accuracty between the guide member and the support hole formed in the steering shaft and thereby further enhance the durability of the cylinder lock. [Explanation of Reference Numerals] 1 ... head pipe l1 ...support hole 31 ...steering shaft 311 ...lock hole 51 ...mounting bracket 53 ...guide member 54 ...cylinder lock 57 ...lock bar W3 ...welding claim: 1. A handle locking device for a two-wheeled motor vehicle wherein a lock bar (57) provided in a retractably protrudable manner in a cylinder lock (54) is brought into engagement with a lock hole (31i) formed in a steering shaft (31) which is rotatably fitted in a head pipe (1), to inhibit the rotation of the steering shaft (31), characterized in that a mounting bracket (51) fixed to the head pipe (1) to support the cylinder lock (54) is integrally provided with a guide member (53) which is separate from the cylinder lock (54) and which guides the lock bar (57) slidably, the outer periphery of a front end portion of the guide member (53) being engaged with the inner periphery of a support hole (ll) formed in the head pipe (1). 2. A handle locking device for a two-wheeled motor vehicle as claimed in claim 1, wherein the outer periphery of a front end portion of the guide member (53) is engaged and with welded (W3) to the inner periphery of the support hole (li) formed in the head pipe (1). 3. A handle locking device for a two-wheeled motor vehicle substantially as herein described with reference to the accompanying drawings.

Documents:

1214-del-1997-abstract.pdf

1214-del-1997-claims.pdf

1214-del-1997-correspondence-others.pdf

1214-del-1997-correspondence-po.pdf

1214-del-1997-description (complete).pdf

1214-del-1997-drawings.pdf

1214-del-1997-form-1.pdf

1214-del-1997-form-13.pdf

1214-del-1997-form-19.pdf

1214-del-1997-form-2.pdf

1214-del-1997-form-3.pdf

1214-del-1997-form-4.pdf

1214-del-1997-form-6.pdf

1214-del-1997-gpa.pdf

1214-del-1997-petition-137.pdf

1214-del-1997-petition-138.pdf