TW201529397A - Foldable two-wheeled vehicle - Google Patents

Abstract

A foldable two-wheeled vehicle of this invention includes a frame, a seat, a front wheel and a rear wheel. The frame includes a front support, a vertical tube and a rear support. The front support includes a first section and a second section. The bottom of the second section is pivotally attached to the bottom of the first section. The front support has a virtual pivot shaft between the first section and the second section in order that the first section and the second section are able to bend against each other in a pivotal manner. The second section of the front support also has a seat tube. The vertical tube is pivotally attached to the first section. A front fork extends from the vertical tube. The rear support is connected to the second section of the front support. The seat is installed on the seat tube. The front wheel is pivotally attached to the front fork while the rear wheel is pivotally attached to the rear support. Due to a simple folding structure, the two-wheeled vehicle can be folded quickly.

Description

Folding two-wheeler

The invention mainly discloses a folding two-wheeled vehicle, in particular to a folding two-wheeled vehicle with simple structure.

Please refer to the patent of the "Folding Bicycle Two-Segment Quick Release Structure" of the Chinese Patent No. M464387, which discloses a bicycle folding method. The folding method of the general folding bicycle is to divide the upper tube of the frame into two sections. And the upper tube can be folded in the horizontal direction, so that after folding the bicycle, the front wheel and the rear wheel are arranged side by side in the axial direction to reduce the volume of the bicycle, thereby achieving the effect of convenient carrying and storage.

However, the bicycle adopting the above folding method can reduce the length of the bicycle, but increases the width of the bicycle. When the user is towing the bicycle, it is very easy to rub the other pedestrians, and when the bicycle is carried by the mass transit, the bicycle is used. It also occupies the width of the aisle very much, and the handlebar that is dragged by the user after the bicycle is folded is not located in the middle of the bicycle, which tends to cause the bicycle to be unevenly stressed and shifts during the movement.

In view of the above-described deficiencies in the conventional structure, the inventors have devised to design a folding two-wheeled vehicle which overcomes all of the disadvantages of the above-described conventional structure.

The main purpose of the folding two-wheeled vehicle of the present invention is to provide a two-wheeled vehicle including a frame, a seat cushion, a front wheel and a rear wheel. The frame includes a front bracket, a vertical tube and a rear bracket. The front bracket includes There is a first section and a second section, the bottom side of the second section is pivoted on the bottom side of the first section, and the front bracket has a virtual pivot axis between the first section and the second section, so that the front bracket is The first section and the second section are pivotally bent relative to each other between the deployed position and the folded position, and the front end of the first bracket away from the second section is further provided with a front tube, and the second section of the front bracket is further provided with a seat The tube is pivotally disposed in the front tube of the front bracket. The bottom end of the vertical tube extends with a front fork. The top end of the vertical tube is provided with two handles, and the rear bracket is connected to the second end of the front bracket away from the first end. The seat cushion is pivoted at one end of the seat tube away from the second section of the front bracket, the front wheel is pivoted on the front fork, the front wheel has a virtual rotating shaft, the virtual rotating shaft of the front wheel is parallel to the virtual pivot axis of the front bracket, and the rear wheel is pivoted to the rear bracket The rear wheel has a virtual turn Virtual rear shaft parallel to the front bracket virtual pivot axis, due to the simple structure of the motorcycle of the folding, so that the motorcycle can be very quickly folded.

Other objects, advantages and novel features of the invention will become apparent from the description and appended claims.

The technology, the means and the functions of the present invention are described in detail with reference to the accompanying drawings.

Please refer to FIG. 1 and FIG. 2 , which are a perspective view and a side view of the folding two-wheeled vehicle of the present invention. The motorcycle 10 of the present invention includes a frame 20, a seat cushion 30, a front wheel 40 and a rear wheel 50;

The frame 20 includes a front bracket 21, a vertical tube 22 and a rear bracket 23. The front bracket 21 includes a first section 211 and a second section 212. The first section 211 is adjacent to the second section 212. One side is formed with a first abutting surface 213 (shown in FIG. 4), and a second abutting surface 214 is formed on a side of the second segment 212 adjacent to the first segment 211 (as shown in FIG. 4). The second abutting surface 213 can selectively abut the first abutting surface 213 . The second section 212 is pivotally disposed on the bottom side of the first section 211 in the direction of the plumb direction, so that the front bracket 21 has a virtual relationship between the first section 211 and the second section 212. a pivoting shaft 215, the virtual pivoting shaft 215 of the front bracket 21 extends in a horizontal direction, so that the first section 211 and the second section 212 of the front bracket 21 can be pivotally bent relative to each other between the deployed position and the folded position. When the front bracket 21 is in the deployed position, the second abutting surface 214 abuts against the first abutting surface 213 .

The front bracket 21 is further provided with a locking buckle 216, which is selectively connected to the top side of the first section 211 in the plumb direction and the top side of the second section 212 in the plumb direction. The front bracket 21 is maintained in the deployed position. The front end of the first section 211 of the front bracket 21 away from the second section 212 is further provided with a front tube 217, and the front bracket 21 is formed by a distance L from the front tube 217 to the virtual pivot shaft 215.

The standpipe 22 is pivotally disposed in the front tube 217 of the front bracket 21, and the standpipe 22 has a front fork 221 extending along the bottom end of the plumb direction. The standpipe 22 is pivotally disposed at the top end of the plumb direction. The handle 222, the two handles 222 can be pivoted relative to the standpipe 22 between the deployed position and the folded position, wherein the two handles 222 are in the horizontal position when the two handles 222 are in the deployed position Extending in a direction away from the standpipe 22.

The rear bracket 23 is connected to an end of the second section 212 of the front bracket 21 away from the first section 211. The rear bracket 23 includes a rear fork 231, a shock absorber 232, a first support rod 233 and a second. a support rod 234, one end of the rear fork 231 is disposed in the second section 212 of the front bracket 21, one end of the shock absorber 232 is pivotally disposed between the two ends of the rear fork 231, and one end of the first support rod 233 is pivoted An end of the second support rod 234 is pivoted away from the end 231 of the shock absorber 232 away from the rear fork and the other end is pivotally disposed away from the first support rod 233. One end of the rear fork 231.

The rear bracket 23 is further connected with a mud baffle 235 at the connection between the shock absorber 232 and the second support rod 234. When the virtual pivot shaft 215 of the front bracket 21 is axially viewed, the mud baffle 235 is along the The virtual extension line connecting the two ends of the rear end 231 extends away from the rear fork 231, and a guide wheel 236 is respectively disposed on two sides of the mud baffle 235 away from one end of the rear fork 231.

The frame 20 is further pivotally disposed on the second section 212 of the front bracket 21 with a seat tube 24 that is pivotable relative to the front bracket 21 between a deployed position and a folded position, the seat tube 24 being When the position is deployed, the seat tube 24 extends away from the front bracket 21. The frame 20 is further provided with two pedal members 25, and the two pedal members 25 are respectively pivoted on two sides of the front bracket 21, and the two pedal members 25 can be in the deployed position. The folding position is pivoted relative to the front bracket 21, and the two pedal members 25 extend in a direction away from the seat tube 24 when the two pedal members 25 are in the deployed position.

The seat cushion 30 is pivotally disposed at an end of the seat tube 24 away from the second section 212 of the front bracket 21 .

The front wheel 40 is pivotally disposed on the front fork 221 such that the front wheel 40 has a virtual rotating shaft 41. The virtual rotating shaft 41 of the front wheel 40 is parallel to the virtual pivot axis 215 of the front bracket 21, and the front wheel 40 has a wheel radius R. The front section length L of the front bracket 21 is smaller than the wheel radius R of the front wheel 40.

The rear wheel 50 is pivotally disposed on the first support rod 233 and the second support rod 234 of the rear bracket 23 such that the rear wheel 50 has a virtual rotating shaft 51, and the virtual rotating shaft 51 of the rear wheel 50 is parallel to the front bracket 21 Virtual pivot axis 215.

Please refer to FIG. 3 to FIG. 8 , which are the folding operation diagram of the folding two-wheeled vehicle, the stereoscopic appearance after folding, and the state of the towing use state. The two-wheeled vehicle 10 can be used for riding by a rider, and the rider can sit on the seat cushion 30 when riding, step on the two pedal members 25, and hold the two hands on the Two handles 222 that can advance the two-wheeled vehicle 10 in an electrically driven manner.

The two-wheeled vehicle 10 can be folded in a non-use state to reduce the volume and is convenient to carry. After the two-wheeled vehicle 10 is folded, when the front bracket 21 is in the folding position, the first abutting surface 213 and the second abutting surface 214 are mutually The front wheel 40 is separated between the two pedal members 25, and the virtual pivot shaft 215 of the front bracket 21 is axially viewed. The virtual pivot shaft 215 of the front bracket 21 and the virtual shaft 41 of the front wheel 40 are separated. The virtual rotating shaft 51 of the rear wheel 50 is not on the same straight line, and the two-wheeled vehicle 10 further has a virtual plane P, and the virtual rotating shaft 41 of the front wheel 40 and the virtual rotating shaft 51 of the rear wheel 50 are both on the virtual plane P. The virtual pivot axis 215 of the front bracket 21 is located on a side of the virtual plane P that is adjacent to the second section 212 of the front bracket 21.

When the two handles 222 are in the folded position, the two handles 222 and the standpipe 22 are arranged side by side, and when the two pedal members 25 are in the folded position, the two pedals are The piece 25 and the second section 212 of the front bracket 21 are juxtaposed to each other, and the two pedal members 25 extend away from the rear bracket 23. When the seat tube 24 is in the folded position, the seat tube 24 and the second section 212 of the front bracket 21 are juxtaposed to each other, and the seat tube 24 extends away from the rear bracket 23.

The two-wheeled vehicle 10 is straight in a folded shape, and the user can hold the handle 90 by hand to tow the two-wheeled vehicle 10, making the two-wheeled vehicle 10 easy to carry, and since the two-wheeled vehicle 10 has the two guide wheels 236, When the rider is towed the two-wheeled vehicle 10, the two guide wheels 236 can form a two-point contact against the ground to prevent the two-wheeled vehicle 10 from falling over, thereby effectively saving the rider's strength. Moreover, since the folding structure of the two-wheeled vehicle 10 is simple, the two-wheeled vehicle 10 can be folded very quickly.

Referring to FIG. 9 to FIG. 12 , a perspective view, a side view, a front bracket folding operation diagram and a towing use state diagram of the second embodiment of the folding two-wheeled vehicle according to the present invention are shown. The main difference between the second embodiment of the present invention and the first embodiment is that the two-wheeled vehicle 10a includes two rear wheels 50a, and the two rear wheels 50a are respectively pivotally disposed on the rear fork 231a away from the front bracket 21a. One end of the rear bracket 23a is further connected with a supporting leg 237a. When the virtual pivoting shaft 215a of the front bracket 21a is axially viewed, the supporting leg 237a extends away from the front bracket 21a, and the second The rest of the structure of the embodiment is the same as that of the first embodiment, and will not be described again here.

After the two-wheeled vehicle 10a is folded, two points of contact can be formed by the two rear wheels 50a against the ground for the user to drag, avoiding the dumping of the two-wheeled vehicle 10, and effectively saving the rider's strength. Further, since the support leg 237a can be supported on the ground, the two rear wheels 50a can be erected by the two rear wheels 50a.

Referring to FIG. 13 to FIG. 15 , a perspective view, a side view and a front stand folding operation diagram of a third embodiment of the folding two-wheeled vehicle of the present invention are shown. The main difference between the third embodiment of the present invention and the first embodiment is that the two-wheeled vehicle 10b further includes a transmission assembly 60b coupled to the bottom side of the front bracket 21b, and the transmission assembly 60b includes a first a connecting rod 61b, a second connecting rod 62b, a third connecting rod 63b and a driving shaft 64b. One end of the first connecting rod 61b is pivotally disposed on the virtual pivot shaft 215b of the front bracket 21b, and the second connecting rod 62b The first link 63b is pivotally disposed at an end of the second link 62b away from the front bracket 21b, and the drive shaft 64b is simultaneously connected to the first The link 61b is away from one end of the front bracket 21b and an end of the third link 63b away from the front bracket 21b.

The transmission assembly 60b further includes two cranks 65b, a transmission wheel 66b and a transmission belt 67b. The two cranks 65b are respectively connected to the two ends of the transmission shaft 64b. The transmission wheel 66b is sleeved on the transmission shaft 64b. In addition, the transmission wheel 66b is located between the two cranks 65b, and the transmission belt 67b is sleeved outside the transmission wheel 66b. The rest of the structure of the third embodiment is the same as that of the first embodiment. No longer.

When the user rides the two-wheeled vehicle 10b, the two cranks 65b can be stepped on to drive the transmission shaft 64b to rotate. After the transmission shaft 64b drives the transmission wheel 66b to rotate, the transmission wheel 66b drives the transmission belt 67b. The rear wheel 50b rotates. The transmission assembly 60b is selectively movable between a deployed position and a folded position. When the transmission assembly 60b is in the deployed position, the second link 62b and the third link 63b extend in the same direction, so that the transmission shaft 64b away from the front bracket 21b, when the transmission assembly 60b is moved from the deployed position to the folding position, the second link 62b and the third link 63b pivot relative to each other, the first link 61b is opposite to the front bracket 21b When the transmission assembly 60b is in the folded position, the transmission shaft 64b is close to the front bracket 21b, and the folding manner of the two-wheeled vehicle 10b can be applied to a plurality of different types of vehicles by the above structure.

As far as the above is concerned, it can be concluded that the present invention has the following advantages:

1. The folding two-wheeled vehicle of the present invention, wherein the two-wheeled vehicle comprises a frame, a seat cushion, a front wheel and a rear wheel, the frame comprises a front bracket, a vertical tube and a rear bracket, and the front bracket includes a first a section and a second section, the bottom side of the second section is pivoted on the bottom side of the first section, and the front bracket has a virtual pivot axis between the first section and the second section, so that the first section of the front bracket The second segment can be pivotally bent relative to each other between the deployed position and the folded position, and the front end of the first bracket away from the second section is further provided with a front tube, and the second section of the front bracket is further provided with a seat tube. The tube is pivotally disposed in the front tube of the front bracket, the bottom end of the vertical tube extends with a front fork, the top end of the vertical tube is provided with two handles, and the rear bracket is connected to the second end of the front bracket away from the first end, the seat cushion The front wheel is pivoted on the front fork, the front wheel is pivoted on the front fork, the front wheel has a virtual rotating shaft, the virtual rotating shaft of the front wheel is parallel to the virtual pivot axis of the front bracket, and the rear wheel is pivotally disposed on the rear bracket and the rear wheel. Has a virtual shaft and a virtual turn of the rear wheel Parallel to the front bracket virtual pivot axis, due to the simple structure of the motorcycle of the folding, so that the motorcycle can be very quickly folded.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, so that the numerical value is changed or the equivalent element is replaced, or the equivalent of the scope of the patent application of the present invention. Changes and modifications are still within the scope of the invention patent.

10‧‧‧Two-wheeler
20‧‧‧ frame
21‧‧‧ front bracket
211‧‧‧ first paragraph
212‧‧‧second paragraph
213‧‧‧First abutment
214‧‧‧Second abutment
215‧‧‧Virtual pivot axis
216‧‧‧Locking buckle
217‧‧‧Before the tube
22‧‧‧ erector
221‧‧‧ Front fork
222‧‧‧Handle
23‧‧‧ rear bracket
231‧‧‧ rear fork
232‧‧‧Shock absorber
233‧‧‧First support rod
234‧‧‧second support rod
235‧‧‧ mud baffle
236‧‧‧guide wheel
24‧‧‧ seat tube
25‧‧‧ pedals
30‧‧‧Cushion
40‧‧‧front wheel
41‧‧‧Virtual shaft
50‧‧‧ Rear wheel
51‧‧‧Virtual shaft
10a‧‧‧Two-wheeler
21a‧‧‧ front bracket
215a‧‧‧Virtual pivot axis
23a‧‧‧After bracket
231a‧‧‧ rear fork
237a‧‧‧Support feet
50a‧‧‧ Rear wheel
10b‧‧‧Two-wheeler
21b‧‧‧ front bracket
215b‧‧‧Virtual pivot axis
50b‧‧‧ Rear wheel
60b‧‧‧Transmission components
61b‧‧‧first link
62b‧‧‧second link
63b‧‧‧third link
64b‧‧‧ drive shaft
65b‧‧‧ crank
66b‧‧‧Drive wheel
67b‧‧‧ drive belt
90‧‧‧Hands
L‧‧‧Leng length
R‧‧‧ wheel radius
P‧‧‧ virtual plane

Fig. 1 is a perspective view showing the first embodiment of the folding two-wheeled vehicle of the present invention. Fig. 2 is a side elevational view showing the first embodiment of the folding two-wheeled vehicle of the present invention. Fig. 3 is a view showing the operation of folding the handle of the first embodiment of the folding two-wheeled vehicle of the present invention. Fig. 4 is a view showing the folding operation of the bracket before the first embodiment of the folding two-wheeled vehicle of the present invention. Fig. 5 is a view showing the folding operation of the bracket before the first embodiment of the folding two-wheeled vehicle of the present invention. Fig. 6 is a view showing the folding operation of the pedal member and the seat tube of the first embodiment of the folding two-wheeled vehicle of the present invention. Fig. 7 is a perspective view showing the folding of the first embodiment of the folding two-wheeled vehicle of the present invention. Fig. 8 is a view showing the state of use of the first embodiment of the folding two-wheeled vehicle of the present invention. Figure 9 is a perspective view showing a second embodiment of the folding two-wheeled vehicle of the present invention. Figure 10 is a side elevational view of a second embodiment of a folding two-wheeled vehicle of the present invention. Figure 11 is a front view showing the folding operation of the second embodiment of the folding two-wheeled vehicle of the present invention. Figure 12 is a diagram showing the state of use of the second embodiment of the folding two-wheeled vehicle of the present invention. Figure 13 is a perspective view showing the third embodiment of the folding two-wheeled vehicle of the present invention. Figure 14 is a side elevational view of a third embodiment of a folding two-wheeled vehicle of the present invention. Fig. 15 is a view showing the folding operation of the bracket before the third embodiment of the folding two-wheeled vehicle of the present invention.

10‧‧‧Two-wheeler

20‧‧‧ frame

21‧‧‧ front bracket

211‧‧‧ first paragraph

212‧‧‧second paragraph

215‧‧‧Virtual pivot axis

216‧‧‧Locking buckle

217‧‧‧Before

22‧‧‧ erector

221‧‧‧ Front fork

222‧‧‧Handle

23‧‧‧ rear bracket

231‧‧‧ rear fork

232‧‧‧Shock absorber

233‧‧‧First support rod

234‧‧‧second support rod

235‧‧‧ mud baffle

236‧‧‧guide wheel

24‧‧‧ seat tube

25‧‧‧ pedals

30‧‧‧Cushion

40‧‧‧front wheel

41‧‧‧Virtual shaft

50‧‧‧ Rear wheel

51‧‧‧Virtual shaft

Claims (12)

A folding two-wheeled vehicle includes: a frame including a front bracket, a vertical tube and a rear bracket, the front bracket including a first section and a second section, the second section The bottom side is pivotally disposed on a bottom side of the first section, and the front bracket has a virtual pivot axis between the first section and the second section, so that the first section and the second section of the front bracket can be deployed The position and the folding position are pivotally bent relative to each other, and the front end of the first bracket away from the second section is further provided with a front tube, and the front bracket forms a front section from the distance of the front tube to the virtual pivot shaft The second section of the front bracket is further provided with a seat tube pivotally disposed in the front tube of the front bracket, the bottom end of the vertical tube extending with a front fork, and the top end of the vertical tube is provided with two a front bracket connected to an end of the second section of the front bracket away from the first section; a seat cushion pivotally disposed at an end of the seat tube away from the second section of the front bracket; a front wheel, the front wheel hub Located on the front fork, the front wheel has a virtual shaft and a wheel half The front section of the front bracket has a length smaller than a wheel radius of the front wheel; a rear wheel pivotally disposed on the rear bracket, the rear wheel has a virtual rotating shaft; and the front bracket is in a folded position by the front bracket The virtual pivot axis is axially viewed. The virtual pivot axis of the front bracket, the virtual rotating shaft of the front wheel, and the virtual rotating shaft of the rear wheel are not in the same line. The two-wheeled vehicle also has a virtual plane, and the virtual rotating shaft of the front wheel and the rear wheel The virtual axis is on the virtual plane, and the virtual pivot axis of the front bracket is located on a side of the virtual plane that is adjacent to the second section of the front bracket. The folding two-wheeled vehicle of claim 1, wherein the virtual rotating shaft of the front wheel is parallel to the virtual pivot axis of the front bracket, and the virtual rotating shaft of the rear wheel is parallel to the virtual pivot axis of the front bracket. The folding two-wheeled vehicle according to claim 1 or 2, wherein a side of the first section adjacent to the second section is formed with a first abutting surface, and a side of the second section adjacent to the first section is formed with a a second abutting surface, the second abutting surface abuts against the first abutting surface when the front bracket is in the deployed position, the first abutting surface and the second abutting when the front bracket is in the folded position Separated from each other. The folding two-wheeled vehicle of claim 3, wherein the front bracket is further provided with a locking buckle, and the locking buckle is selectively connected to the top side of the first section in the direction of the plumb and the second section The top side of the plumb direction maintains the front bracket in the deployed position. The folding two-wheeled vehicle of claim 3, wherein the two handles are pivotable relative to the standpipe between a deployed position and a folded position, the two handles being in the deployed position, the two The handles extend in a horizontal direction away from the standpipe, and the two handles and the standpipe are juxtaposed to each other when the two handles are in the folded position. The folding two-wheeled vehicle according to claim 3, wherein the rear bracket comprises a rear fork, a shock absorber, a first support rod and a second support rod, and one end of the rear fork is disposed on the front bracket second And one end of the first support rod is pivotally disposed at an end of the rear fork away from the front bracket, and one end of the second support rod is pivoted at one end of the second support rod The shock absorber is disposed away from one end of the rear fork and the other end is pivotally disposed at an end of the first support rod away from the rear fork. The rear wheel is pivotally disposed on the first support rod and the second support rod of the rear bracket. The folding two-wheeled vehicle of claim 6, wherein the rear bracket is further connected with a mud baffle at the connection between the shock absorber and the second support rod, when the virtual pivot axis of the front bracket is axially observed. The mud baffle extends along a virtual extension line connecting the two ends of the shock absorber away from the rear fork. The folding two-wheeled vehicle according to claim 7, wherein the mud baffle is respectively disposed with a guide wheel on both sides of one end of the rear fork. The folding two-wheeled vehicle of claim 3, wherein the seat tube is pivotally disposed on the second section of the frame of the front bracket, the seat tube being pivotable relative to the front bracket between the deployed position and the folded position, When the seat tube is in the deployed position, the seat tube extends away from the front bracket. When the seat tube is in the folded position, the seat tube and the second portion of the front bracket are side by side with each other, and the seat tube is away from the The rear bracket extends in the direction. The folding two-wheeled vehicle according to claim 3, wherein the frame is further provided with two pedal members, and the two pedal members are respectively pivoted on two sides of the front bracket, and the two pedals are respectively The piece is pivotable relative to the front bracket between a deployed position and a folded position, the two pedal members extending away from the seat tube when the two pedal members are in the deployed position, When the two pedal members are in the folding position, the two pedal members and the second segment of the front bracket are arranged side by side, and the two pedal members extend away from the rear bracket, When the front bracket is in the folded position, the front wheel is located between the two pedal members. The folding two-wheeled vehicle according to claim 3, wherein the rear bracket includes a rear fork, one end of the rear fork is disposed in the second section of the front bracket, and the two-wheeled vehicle has two rear wheels in total, and the two rear wheels The wheel is respectively disposed at an end of the rear fork away from the front bracket, and the rear bracket is further connected with a supporting leg. When the virtual pivot axis of the front bracket is axially viewed, the supporting leg is away from the front bracket. The direction extends. The folding two-wheeled vehicle of claim 3, wherein the two-wheeled vehicle further includes a transmission assembly coupled to a bottom side of the front bracket, the transmission assembly including a first link and a second link, a third link and a drive shaft, one end of the first link is pivotally disposed on a virtual pivot axis of the front bracket, and the second link is pivoted at a position of the front bracket away from the virtual pivot axis, the first The three-link is pivotally disposed at an end of the second link away from the front bracket, and the transmission shaft is simultaneously connected to an end of the first link away from the front bracket and an end of the third link away from the front bracket, the transmission The assembly further includes two cranks, a transmission wheel and a transmission belt, wherein the two cranks are respectively connected to two ends of the transmission shaft, the transmission wheel is sleeved outside the transmission shaft, and the transmission wheel is located at the Between the two cranks, the transmission belt is sleeved outside the transmission wheel, and the transmission assembly is selectively moved between a deployed position and a folded position. When the transmission assembly is in the deployed position, the second link and the third The connecting rod extends in the same direction When the transmission shaft is moved away from the front bracket, the second link and the third link pivot relative to each other when the transmission assembly is moved from the deployed position to the folded position, and the first link pivots relative to the front bracket When the transmission assembly is in the folded position, the transmission shaft is adjacent to the front bracket.