Title of Invention

" SCOOTER BODY FRAME"

Abstract

The present invention relates to a scooter body frame. The down frame is substantially as wide as a scooter itself, and has a cross section in the shape of an inverted square U. The rear frame is as wide as the down frame at a position where they are joined, and becomes wider toward its rear end. The foot rest is in the shape of a frame having an open bottom. In order to couple the down frame and the rear frame firmly, the down frame and the foot rest are ribbed near where the foregoing frames are joined. In this structure, the frame body between the head pipe and the foot rest are longitudinally so rigid that an external force applied to the body frame may be transmitted to a rider when the scooter is running over steps o a road or on a rough road. There is provided a scooter body frame which comprises a head pipe, a rearward sloping portion extending rearward and downward from the head pipe, curved portions connecting with a rear end of the rearward sloping portion, and foot rest portions extending rearward from the curved portions.

Full Text

[ Detailed Description of the Invention] [Field of the Invention] The present invention relates to a body frame)of a scooter, and more particularly \ ' to a body frame comprising a head pipe, a rearward sloping portion extending downward from the head pipe, curved portions connecting with the rearward sloping portion, and a foot rest extending rearward from the curved portions. In the prior art, a scooter body frame usually comprises a head pipe and a down frame which are integrally cast-molded as one unit, and a foot rest which is cast-molded as a part of a rear frame .and is coupled to a rear end of the down frame, as disclosed in Japanese Patent Lid-Open Publication No. Hei 3-186,492. [Problems to be solved by the Invention ] In the foregoing prior art, the down frame is substantially as wide as a scooter itself, and has a cross section in the shape of an inverted square U. The rear frame is as wide as the down frame at a position where they arc joined, and becomes wider toward its rear end. The foot rest is in the shape of a frame having an open bottom. In order to couple the down frame and the rear frame firmly, the down frame and the foot rest are ribbed near where the foregoing frames are joined. In this structure, the frame body between the head pipe and the foot rest are longitudinally so rigid that an external force applied to the body frame may be transmitted to a rider when the scooter is running over steps on a road or on a rough road, s This means that the scooter cannot offer good ride quality. If a height of the ribs is simply reduced in order to overcome this problem, other characteristics such as torsional rigidity (stress) of the body frame might be adversely affected. The present invention is conceived in order to overcome the foregoing problems, and is intended to provide a body frame of a scooter which can easily absorb external force and assure good ride quality. J0005I (Means to solve the Problems] According to claim I /there is provided a scooter body frame which comprises a head pipe, a rearward sloping portion extending rearward and downward from the head pipe, curved portions connecting with a rear end of the rearward sloping portion, and foot rest portions extending rearward from the curved portions Jin this s«y>t?r body frame, the head pipe, the rearward sloping portion constituted by one frame element, the curved portions constituted by a plurality of frame elements, and the foot rest portions constituted by a plurality of frame elements are integrally formed as one member, and the frame elements have a cross section in the shape of the letter U . In this configuration, the rearward sloping portion, curved portions and foot rest have a cross section in the shape of the letter U. When external force is applied to a running scooter, the members constituting the body frame are flexed along side edges at their open tops, thereby absorbing the external force. This is effective in minimizing direct application of the external force to the rider, and improving the ride quality. |0007| in accordance with claim 2. longitudinal rigidity of the curved portions is set lower than longitudinal rigidity of the rearward sloping portion and the foot rest portions. The curved portions mainly absorb the external force, which minimizes the chance of a steering handle being adversely affected by the external force. The foot rest can be made as rigid as possible so as to prevent extensive vibrations thereof. Further, the head pipe, rearward sloping portion, curved portions and foot rest portions are formed as an integral member, so that they can be balanced with respect to their rigidity. |0008| As defined in claim 3, the rigidity of the rearward sloping portion and the foot rest portions is increased by providing ribs on at least a part of the frame elements. These ribs are effective in relatively increasing the rigidity of the rearward sloping portion and the foot rest portions but relatively reducing the rigidity of the rounded portions. !0009| In accordance with claim 4, the ribs are formed along a flat surface which is substantially parallel to the axis of the head pipe. The body frame between the head pipe and the foot rest can be formed as an integral ribbed frame which can be removed from a mold in the axial direction of the head pipe. |OOIO| As defined in claim 5, the rearward sloping portion and the foot rest portion have a cross sectional depth larger than that of the curved portions in order to make the rearward sloping portion and the foot rest portions more rigid than the curved portions. Therefore, the ribbed rearward sloping portion and foot rest portions have relatively high rigidity while the curved portions have relatively low rigidity. (001 11 Accordingly, the present invention provides a scooter body frame comprising a head pipe, a rearward sloping portion extending rearward and downwaard from the head pipe, curved portions connecting with a rear end of the rearward sloping portion, and foot rest portions extending rearward from the curved portions, wherein the head pipe, the rearward sloping portion constituted by one frame element, the curved portions constituted by a plurality of frame elements and the foot rest portions constituted by a plurality of frame elements are integrally formed as one member, and the frame elements have a cross section in the shape of the letter U. (Brief Description of the Drawings; Fig. 1 is a perspective view of the scooter body frame. Fig. 2 is a side view of the body frame. Fig. 3 is a enlarged side view of the front frame with the head pipe arranged upright. Fig. 4 is a front view of the front frame observed in the direction of arrow 4 in Fig. 3. . Fig. 5 is a cross section taken along line 5-5 in Fig. 4. Fig. 6 is a cross section taken along line 6-6 in Fig. 4. Fig. 7 is a cross section taken along line 7-7 in Fig. 4. (Description of Embodiment) The present invention will be described with reference to an embodiment shown on the accompanying drawings. |0012) Fig. 1 to Fig. 7 show the embodiment of the invention. Fig. 1 is a perspective view of a body frame of a scooter. Fig. 2 is a side view of the body frame. Fig. 3 is an enlarged side view of a front frame with a head pipe maintained vertical. Fig. 4 is a view observed in the direction of arrow 4 in Fig. 3. Fig. 5 is a cross sectional view taken along line 5-5 in Fig. 4. Fig. 6 is a cross sectionaJ view taken along line 6-6 in Fig. 4. Fig. 7. is a cross sectional view taken along line 7-7 in Fig. 4. IOOI3I - Referring to Figs. 1 and 2, a body frame F of the scooter comprises a front frame 11 and a rear frame 12 which are coupled. | OOI4| The front frame 11 comprises a head pipe 13, a rearward sloping portion 14, curved portions IS connecting with a rear end of the rearward sloping portion 14, fool rest portions 16 extending re*rwardiy from the curved portions 15. and a cross member 17 which is integrally formed as a pan of the foot rest portions 16. The foregoing members are made of light metal such as aluminum alloy, and are cast-molded as an integral member. |00I5| The rear frame 12 comprises a main frame section 12a substantially in the shape of the letter U and having an open front, a front reinforcement 12b and a rear reinforcement 12c extending across the main frame section 12a atthe front and rear parts thereof, and is made of light metal such as aluminum alloy as an integral member. |0016| Both front ends of the main frame section 12a are coupled to both rear ends of the front frame 11 using a plurality of bolts 18 and a plurality of nuts 19. In this state, the rear frame 12 slopes upward to the rear of the scooter. 100171 /• A front fork 22 having a steering handle 21 at its top is attached to the head pipe 13 of the front frame 11, and pivotally supports a front wheel WF at its bottom, thereby enabling the front fork 22 to be steered. Near the front reinforcement 12b, a link 23 is coupled to the main frame section 12a of the rear frame 12 via a support 24 so that the rear frame 12 can swing up and down in a limited range. A power unit 25 comprising an engine and a transmission is suspended from the rear frame 12 via the link 23. A rear wheel WR is pivotally supported behind the power unit 25. A bracket 26 integral with the rear reinforcement I2c is coupled to an upper end of a rear cushion 27 disposed between the power unit 25 and the rear frame 12. |OOJ,«| Referring to Figs. 3 and 4, the rearward sloping portion 14 of the front frame 11 is constituted by a frame element 14, connecting with the rear end of the head pipe 13 at the center of the body frame F and extending rearward and downward. The frame element 14, has an open top and a cross section in the shape of the letter U or V. |OOI9| As shown in Figs. 5 and 6, the curved portions 15 comprise first to third frame elements 15,. 15,, 15,. The first frame element 15, curves downward and rearward. extends leftward from the width wise center of the body frame F. and joins with one lower end of the frame element 14,. Similarly, the second frame element 1S2 curves downward and rearward, extends rightward from the widthwise center of the body frame F. and joins with the other lower end of the frame element 14. The third frame element IS, curves downward at the widthwise center of the body frame F. and joins with the frame element 14, . The frame elements 15, •— I53 have a cross section in the shape of the letter U or V . 100201 Referring further to Fig. 7, the foot rest portions 16 comprise the first to third frame elements 16, . 16, , 16,. and extend along the length of the body frame F. The first frame element 16, joins with the rear end of the first frame element 15, of the curved portion 15 while the second frame element 16 joins with the second frame element 152 of the curved portion 1 5. The third frame element 163 extends across the body frame F, and joins with front ends of the first and second frame elements 16, , 162 . The frame elements have a cross section in the shape of the letter U or V. The cross member section 17 comprises rear extensions 17, and 172 joining with the rear ends of the first and second frame elements 16, and 162 of the foot rest portions 16, and a linking member 173. The rear extensions 17, and 172 have bosses 28 and 29 at their front and rear ends for connection with the rear frame 12. The cross member section 17 is in the shape of a box having an open top. Returning back to Fig. 2, the linking member 173 has a bracket 30 for mounting a stand, not shown. With the foregoing front frame 1 1 , the frame elements 14 , , 15, ~ 153, and 16, ~163 and the rearward extending members 17, and 172 have the cross sections in the shape of the letter U. In order to facilitate cast-molding of the front 1 1 made of aluminum alloy, the upward portions of the members 14 , , 15, ~ 153, 16, ~163 and 17, and 172 are slightly sloped so that they are gradually spaced apart toward their tops. 100231 Further, in the front frame 1 1 . upward and downward rigidity of the curved portion 15 is designed to be lower than that of the rearward sloping portion 14 and the foot rest 16. In order to accomplish this, the frame element 14, of the rearward sloping portion 14 is formed with ribs 31, 32 and 33, and the frame elements 16, and 162 are formed with ribs 34, 35 and 36. Specifically, the rib 31 is open at its front end, i.e. is in the shape of an inverted letter V, and is present in front of the frame element 14, , the rib 32 is substantially in the shape of a letter X. and is formed rearward from the middle portion of the frame element 14,, and the rib 33 extends to the left and right and is present at the rear end of the frame element 14,. Further, a pair of ribs 34 and 35 are formed on each of the first and second frame elements 16, and 162 of the foot rest 16 at the positions corresponding to the opposite ends of the third frame element I63 . and extend on extensions along the length of the third frame element 165 . Still further, a rib 36 is formed in the middle of the frame elements 16, and 16, . and extend along the width of the body frame F. Bosses 28 and 29 are formed at the front and rear ends of the rearward extending members 17, and 17} of the cross member 17, and function as ribs. Therefore, the upward and downward rigidity of the cross member 17 is designed to be higher than that of the curved portion IS. |0024| The ribs 31 to 36 are formed on the plane which extends substantially along the axis of the head pipe 13, and the bosses 28 and 29 are formed such that they have axes extending substantially along the axis of the head pipe 13. |0025| A longitudinal and cross sectional length L, of the rearward extending portion 14 (shown in Fig. 5) and a longitudinal and cross sectional length L, of the foot rest 16 (shown in Fig. 7) are designed to be larger than a longitudinal and cross sectional length L, of the curved portion 15 (shown in Fig. 6). Thus, the upward and downward rigidity of the curved portion 15 is made lower than that of the foot rest 16 by determining the longitudinal lengths L, , Lj and L, as described above. |0026| The frame elements 14 , , 15, ~ 153, and 16, ~163 and the rearward extending members 17, and !72 are in the shape of grooves which are open at their tops, so that the front frame 11 have drainage holes 37 • • • formed in bottoms of compartments defined by the frame elements 14 , , 15, ~~ 153, and 16, ~~163 and the rearward extending members 17, and 172 in order to discharge rain or the like gathering thereon. |0027| In operation, when the scooter is passing over a step on a road or running on a bumpy road, the following forces act on the frame 11 as an external force: force pushing the head pipe 13 obliquely rearward and downward from the front wheel WF via the front fork 22 as shown by arrow C in Fig. I; force pushing the front frame 11 obliquely forward and upward from the rear wheel WR via the rear cushion 27 and the rear frame 27 as shown by arrow B in Fig. I; and force pushing the front frame 11 around the upport 24 via the seat because of the rider's weight as shown by arrow C in Fig. I. If the front frame 11 has large upward and downward rigidity, the foregoing external force is easily transmitted to the rider, which means poor riding quality. The frame elements 14 , . 15, — 15,. and 16, ~~16j constituting the rearward sloping portion 14, curved portions 15 and foot rest portions 16 have the cross section in the shape of a letter U, and are flexed such that the upright side edges of these frame elements vary the areas of their open tops. Further, the upright side edges of these frame elements arc sloped toward their tops, and are flexed to enlarge the open areas thereof, thereby absorbing and minimizing the external force applied to the body frame. This is effective in improving the riding quality. |0028| In the front frame II, the curved portions 15 have upward and downward rigidity which is lower than those of the rearward sloping portion 14, foot rest portions 16 and cross member 17. Therefore, the frame elements 15, ~ 15, of the curved portions are relatively extensively flexed at their upright side edges as shown by dotted lines in Fig. 6, thereby permitting mainly the curved portions 15 to absorb the external force. This can minimize the displacement of the steering handle 21 when the external force is applied because of longitudinal deformation of the front frame 11, and make die foot rest portions 16 rigid enough to prevent the front rest portions 16 from vibrating extensively. Further, the head pipe 13, rearward sloping portion 14, curved portions 15. foot rest portions 16 and cross member 17 are cast-molded as one unit, so that it is easy to balance the rigidity of the members between the head pipe 13 and the cross member 17. |0029| In order to make the upward and downward rigidity of the foregoing members different, the frame element 14 , of the rearward sloping portion 14 in front of the curved portions is formed with the three ribs 31 to 33,. The first and second frame elements 16, ~I62 of the foot rest portions 16 behind the curved portions 15 are provided with the three ribs 34 to 36. The rigidity of the rearward sloping portion 14 and foot rest portions 16 are relatively increased by the ribs 31 to 36 compared with that of the curved portions 15. The heights L, and Lj of the rearward sloping poition 14 and foot rest portions 16 are larger than the height L, of the curved portions 15, which can easily make a structure for relatively reducing the rigidity of the curved portions 15. |0030| The ribs 31 to 36 and the bosses 28 --and 29--at the cross member 17 are formed on the plane substantially parallel to the axis of the head pipe 13. Therefore, the ribbed front frame 11 between the head pipe 13 and the cross member 17 can be easily cast molded using a mold structure which can be opened in the direction along the axis of the head pipe 13. 100311 Although the present invention has been described in detail with reference to the preferred embodiment, it is not to be taken by way of limitation. Various changes or modifications are conceivable without departing from the scope of the claims. |0032| In the foregoing embodiment, the front frame 11 includes the cross member as its integral pan. The present invention is also applicable to a front frame which includes members from the head pipe 13 and the foot rest portions 16. Further, the present invention is also applicable to a front frame which includes the members from the head pipe and the foot rest portions, and is made of eject-molded plastics. |0033| lEffects of the Invention) In accordance with the invention defined in claim 1, the side edges of the frame elements are flexed in such a manner that they vary their open areas in response to the external forces applied thereto. This is effective in minimizing the external force applied to the rider, and improving the riding quality. 10034] According to claim 2, the external force is mainly absorbed by the curved portions, which is effective in minimizing .the displacement of the steering handle. Further, it is possible to improve the rigidity so as to prevent extensive vibrations of the foot rest portions. Still further, it is possible to easily balance the rigidity of the members between the head pipe and the foot rest portions. |0035| As defined in claim 3 and 5, it is easily possible to make the rigidity of the rearward sloping portion and the foot rest portions relatively high compared with that of the curved portions. |0036| According to claim 4, the ribbed frame including the head pipe and the foot rest portions can be easily cast-molded as one unit using a mold which can be opened in the __dite.ction. along the axis of the head pipe. (Description of Reference Numerals! 13 ... head pipe 14 ... rearward sloping portion 14,. 15, ~~ I53. and 16, ~ 163 ... frame elements 15 ... curved portions 31 — 36... ribs F ... body frame WE CLAIM: 1. A scooter body frame comprising a head pipe (13), a rearward sloping portion (14) extending rearward and downward from the head pipe (13), curved portions (15) connecting with a rear end of the rearward sloping portion (14), and foot rest portions (16) extending rearward from the C..\^o^rovi_-ZJicL' (/v\, tk-£\t curved portions (15), wherein the head pipe (13), the rearward sloping portion (14) constituted by one frame element (14i), the curved portions (15) constituted by a plurality of frame elements (15i, 15a) and the foot rest portions (16) constituted by a plurality of frame elements (16i, 162, 16s] are integrally formed as one member, and the frame elements (14i, 15i, ISz, 15s, 16i, 16a, 163) have a cross section in the shape of the letter U, wherein the rearward sloping portion (14), the curved portions (15) and the foot rest portions (16), each having U-shaped cross section, are opened upwardly. 2. The scooter body frame as claimed in claim 1, wherein longitudinal rigidity of the curved portions (15) is set smaller than longitudinal rigidity of the rearward sloping portion (14) and the foot rest portions (16). 3. The scooter body frame as claimed in claim 2 wherein the rigidity of the rearward sloping portion (14) and the foot rest portions (16) is increased by providing ribs (31, 32, 33; 34, 35, 36) on at least a part of the frame elements (14i; 16i ~ 16a). 4. The scooter body frame as claimed in claim 3, wherein the ribs (31 ~ 36) are formed on a flat surface which is substantially parallel to the axis of the head pipe (13). 5. The scooter body frame as claimed in claim 2, wherein the rearward sloping portion (14) and the foot rest portions (16) have a cross sectional depth larger than that of the curved portions (15) in order that the rearward sloping portion (14) and the foot rest portions (16) are more rigid than the curved portions (15). 6. A scooter body frame substantially as herein described with reference to the accompanying drawings.

Documents:

19-del-1998-abstract.pdf

19-del-1998-claims.pdf

19-del-1998-correspondence-others.pdf

19-del-1998-correspondence-po.pdf

19-del-1998-description (complete).pdf

19-del-1998-drawings.pdf

19-del-1998-form-1.pdf

19-del-1998-form-13.pdf

19-del-1998-form-19.pdf

19-del-1998-form-2.pdf

19-del-1998-form-3.pdf

19-del-1998-form-4.pdf

19-del-1998-form-6.pdf

19-del-1998-gpa.pdf

19-del-1998-petition-137.pdf

19-del-1998-petition-138.pdf