Kick scooter combination frame structure

A kick scooter combination frame structure is constructed to include a handlebar and front fork assembly holding a front wheel, a head frame, the head frame having a vertical tube coupled to the handlebar and front fork assembly and two parallel lugs extended from the periphery of the vertical tube, and a footplate pivoted to the head frame and supported on a rear wheel, the footplate having a front opening, which receives the lugs of the head frame, and two longitudinal mounting rails perpendicularly raised from a bottom side wall thereof and reinforced with reinforcing ribs, the mounting rails each having a plurality of mounting holes respectively fastened to respective mounting holes on the lugs of the head frame by screw bolts.

BACKGROUND OF THE INVENTION 
 The present invention relates to kick scooters, and more particularly to a 
 combination frame structure for a kick scooter. 
 FIG. 1 shows a kick scooter according to the prior art. The frame structure
 of this structure of kick scooter is generally comprised of a handlebar 
 and front fork assembly A, a footplate C, an oblique bar B and a rear 
 wheel holder frame D. The handlebar and front fork assembly A is supported
 on a front wheel. The oblique bar B has a front end welded to a head tube 
 at the handlebar and front fork assembly A, and a rear end welded to the 
 footplate C. The footplate C has a rear end welded to the rear wheel 
 holder frame D. This kick scooter frame structure has drawbacks. Because 
 the head tube at the handlebar and front fork assembly A, the oblique bar 
 B, the footplate C and the rear wheel holder frame D are respectively 
 fastened together by welding, the fabrication procedure of the kick 
 scooter is complicated, and the welding procedure greatly increases the 
 manufacturing cost of the kick scooter. During welding, waste gas is 
 produced to pollute the air, and produced sparks, bright light and heat 
 may cause damage to the worker's eyes or body. After welding, the welding 
 areas E must be washed with diluted sulfuric acid and clean water, and 
 then polished after washing. Further, the welding areas E wear quickly 
 with the use of the kick scooter, and tend to be forced to break when the 
 kick scooter moves over an uneven road surface or encounters impact. 
 SUMMARY OF THE INVENTION 
 The present invention provides a combination frame structure for a kick 
 scooter, which eliminates the aforesaid drawbacks. It is one object of the
 present invention to provide a combination frame structure for a kick 
 scooter, which is easy and inexpensive to manufacture. It is another 
 object of the present invention to provide a combination frame structure 
 for a kick scooter, which eliminates a welding process. It is still 
 another object of the present invention to provide a combination frame 
 structure for a kick scooter, which is strong and durable in use. 
 According to one aspect of the present invention, the kick scooter 
 combination frame structure comprises a handlebar and front fork assembly 
 holding a front wheel, a head frame, the head frame having a vertical tube
 coupled to the handlebar and front fork assembly and two parallel lugs 
 extended from the periphery of the vertical tube, and a footplate pivoted 
 to the head frame and supported on a rear wheel, the footplate having a 
 front opening, which receives the lugs of the head frame, and two 
 longitudinal mounting rails perpendicularly raised from a bottom side wall
 thereof, the mounting rails each having a plurality of mounting holes 
 respectively fastened to respective mounting holes on the lugs of the head
 frame by screw bolts. According to another aspect of the present 
 invention, two reinforcing ribs are respectively fastened to the mounting 
 rails and the lugs of the head frame to reinforce the structural strength 
 of the combination frame structure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
 Referring to FIGS. from 2 through 4, a kick scooter combination frame 
 structure 1 is shown comprised of a handlebar and front fork assembly 11 
 holding a front wheel 14, a head frame 12 pivoted to the handlebar and 
 front fork assembly 11, and a footplate 13 having a front side coupled to 
 the head frame 12 and a rear side mounted with a rear wheel 15. 
 Referring to FIGS. 5 and 6 and from FIGS. 2 through 4 again, the head frame
 12 and the footplate 13 are respectively made of metal in integrity. The 
 head frame 12 comprises a tube 121 vertically disposed at its front side 
 and coupled to the handlebar and front fork assembly 11, and two parallel 
 lugs 122 backwardly extended from the periphery of the tube 121. The lugs 
 122 each have a plurality of mounting holes 123. The footplate 13 is made 
 of metal with its front side curved forwardly upwards, comprising a front 
 opening 131 at the front side thereof, and two longitudinal mounting rails
 132 perpendicularly raised from the bottom side wall thereof and extended 
 from the front side to the rear side and disposed at two opposite lateral 
 sides of the front opening 131. The mounting rails 132 each have a 
 plurality of mounting holes 133 corresponding to the mounting holes 123 on
 the lugs 122 of the head frame 12. The lugs 122 of the head frame 12 are 
 inserted into the front opening 131, and screw bolts 124 are respectively 
 fastened to the mounting holes 133 on the mounting rails 132 and the 
 mounting holes 123 on the lugs 122 to fixedly secure the footplate 13 to 
 the head frame 12. 
 Referring to FIGS. from 2 through 6 again, during the assembly process, the
 tube 121 of the head frame 12 is sleeved onto the handlebar and front fork
 assembly 11 and supported on the front fork of the handlebar and front 
 fork assembly 11, and then the two parallel lugs 12 are inserted into the 
 front opening 131 of the footplate 13 and respectively attached to the 
 mounting rails 132, and then screw bolts 124 arc respectively fastened to 
 the mounting holes 133 on the mounting rails 132 and the mounting holes 
 123 on the lugs 122 to fixedly secure the footplate 13 to the head frame 
 12. 
 Referring to FIGS. 2, 3 and 5 again two reinforcing ribs 134 are 
 respectively fastened to the mounting rails 132 and the lugs 122 of the 
 head frame 12 to reinforce the structural strength of the combination 
 frame structure 1.